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v5.14.15
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3   SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
   4   file Documentation/scsi/st.rst for more information.
   5
   6   History:
   7   Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
   8   Contribution and ideas from several people including (in alphabetical
   9   order) Klaus Ehrenfried, Eugene Exarevsky, Eric Lee Green, Wolfgang Denk,
  10   Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
  11   Michael Schaefer, J"org Weule, and Eric Youngdale.
  12
  13   Copyright 1992 - 2016 Kai Makisara
  14   email Kai.Makisara@kolumbus.fi
  15
  16   Some small formal changes - aeb, 950809
  17
  18   Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
  19 */
  20
  21static const char *verstr = "20160209";
  22
  23#include <linux/module.h>
  24
  25#include <linux/compat.h>
  26#include <linux/fs.h>
  27#include <linux/kernel.h>
  28#include <linux/sched/signal.h>
  29#include <linux/mm.h>
  30#include <linux/init.h>
  31#include <linux/string.h>
  32#include <linux/slab.h>
  33#include <linux/errno.h>
  34#include <linux/mtio.h>
  35#include <linux/cdrom.h>
  36#include <linux/ioctl.h>
  37#include <linux/fcntl.h>
  38#include <linux/spinlock.h>
  39#include <linux/blkdev.h>
  40#include <linux/moduleparam.h>
  41#include <linux/cdev.h>
  42#include <linux/idr.h>
  43#include <linux/delay.h>
  44#include <linux/mutex.h>
  45
  46#include <linux/uaccess.h>
  47#include <asm/dma.h>
  48#include <asm/unaligned.h>
  49
  50#include <scsi/scsi.h>
  51#include <scsi/scsi_dbg.h>
  52#include <scsi/scsi_device.h>
  53#include <scsi/scsi_driver.h>
  54#include <scsi/scsi_eh.h>
  55#include <scsi/scsi_host.h>
  56#include <scsi/scsi_ioctl.h>
  57#include <scsi/sg.h>
  58
  59
  60/* The driver prints some debugging information on the console if DEBUG
  61   is defined and non-zero. */
  62#define DEBUG 1
  63#define NO_DEBUG 0
  64
  65#define ST_DEB_MSG  KERN_NOTICE
  66#if DEBUG
  67/* The message level for the debug messages is currently set to KERN_NOTICE
  68   so that people can easily see the messages. Later when the debugging messages
  69   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
  70#define DEB(a) a
  71#define DEBC(a) if (debugging) { a ; }
  72#else
  73#define DEB(a)
  74#define DEBC(a)
  75#endif
  76
  77#define ST_KILOBYTE 1024
  78
  79#include "st_options.h"
  80#include "st.h"
  81
  82static int buffer_kbs;
  83static int max_sg_segs;
  84static int try_direct_io = TRY_DIRECT_IO;
  85static int try_rdio = 1;
  86static int try_wdio = 1;
  87static int debug_flag;
  88
  89static struct class st_sysfs_class;
  90static const struct attribute_group *st_dev_groups[];
  91static const struct attribute_group *st_drv_groups[];
  92
  93MODULE_AUTHOR("Kai Makisara");
  94MODULE_DESCRIPTION("SCSI tape (st) driver");
  95MODULE_LICENSE("GPL");
  96MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  97MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  98
  99/* Set 'perm' (4th argument) to 0 to disable module_param's definition
 100 * of sysfs parameters (which module_param doesn't yet support).
 101 * Sysfs parameters defined explicitly later.
 102 */
 103module_param_named(buffer_kbs, buffer_kbs, int, 0);
 104MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
 105module_param_named(max_sg_segs, max_sg_segs, int, 0);
 106MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 107module_param_named(try_direct_io, try_direct_io, int, 0);
 108MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 109module_param_named(debug_flag, debug_flag, int, 0);
 110MODULE_PARM_DESC(debug_flag, "Enable DEBUG, same as setting debugging=1");
 111
 112
 113/* Extra parameters for testing */
 114module_param_named(try_rdio, try_rdio, int, 0);
 115MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 116module_param_named(try_wdio, try_wdio, int, 0);
 117MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 118
 119#ifndef MODULE
 120static int write_threshold_kbs;  /* retained for compatibility */
 121static struct st_dev_parm {
 122	char *name;
 123	int *val;
 124} parms[] __initdata = {
 125	{
 126		"buffer_kbs", &buffer_kbs
 127	},
 128	{       /* Retained for compatibility with 2.4 */
 129		"write_threshold_kbs", &write_threshold_kbs
 130	},
 131	{
 132		"max_sg_segs", NULL
 133	},
 134	{
 135		"try_direct_io", &try_direct_io
 136	},
 137	{
 138		"debug_flag", &debug_flag
 139	}
 140};
 141#endif
 142
 143/* Restrict the number of modes so that names for all are assigned */
 144#if ST_NBR_MODES > 16
 145#error "Maximum number of modes is 16"
 146#endif
 147/* Bit reversed order to get same names for same minors with all
 148   mode counts */
 149static const char *st_formats[] = {
 150	"",  "r", "k", "s", "l", "t", "o", "u",
 151	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 152
 153/* The default definitions have been moved to st_options.h */
 154
 155#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 156
 157/* The buffer size should fit into the 24 bits for length in the
 158   6-byte SCSI read and write commands. */
 159#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 160#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 161#endif
 162
 163static int debugging = DEBUG;
 164
 165#define MAX_RETRIES 0
 166#define MAX_WRITE_RETRIES 0
 167#define MAX_READY_RETRIES 0
 168#define NO_TAPE  NOT_READY
 169
 170#define ST_TIMEOUT (900 * HZ)
 171#define ST_LONG_TIMEOUT (14000 * HZ)
 172
 173/* Remove mode bits and auto-rewind bit (7) */
 174#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 175	(iminor(x) & ((1 << ST_MODE_SHIFT)-1)))
 176#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 177
 178/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 179#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 180  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 181
 182/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 183   24 bits) */
 184#define SET_DENS_AND_BLK 0x10001
 185
 186static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 187static int st_max_sg_segs = ST_MAX_SG;
 188
 189static int modes_defined;
 190
 191static int enlarge_buffer(struct st_buffer *, int);
 192static void clear_buffer(struct st_buffer *);
 193static void normalize_buffer(struct st_buffer *);
 194static int append_to_buffer(const char __user *, struct st_buffer *, int);
 195static int from_buffer(struct st_buffer *, char __user *, int);
 196static void move_buffer_data(struct st_buffer *, int);
 197
 198static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 199			      unsigned long, size_t, int);
 200static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 201
 202static int st_probe(struct device *);
 203static int st_remove(struct device *);
 204
 205static struct scsi_driver st_template = {
 206	.gendrv = {
 207		.name		= "st",
 208		.owner		= THIS_MODULE,
 209		.probe		= st_probe,
 210		.remove		= st_remove,
 211		.groups		= st_drv_groups,
 212	},
 213};
 214
 215static int st_compression(struct scsi_tape *, int);
 216
 217static int find_partition(struct scsi_tape *);
 218static int switch_partition(struct scsi_tape *);
 219
 220static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 221
 222static void scsi_tape_release(struct kref *);
 223
 224#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 225
 226static DEFINE_MUTEX(st_ref_mutex);
 227static DEFINE_SPINLOCK(st_index_lock);
 228static DEFINE_SPINLOCK(st_use_lock);
 229static DEFINE_IDR(st_index_idr);
 230
 231
 232
 233#ifndef SIGS_FROM_OSST
 234#define SIGS_FROM_OSST \
 235	{"OnStream", "SC-", "", "osst"}, \
 236	{"OnStream", "DI-", "", "osst"}, \
 237	{"OnStream", "DP-", "", "osst"}, \
 238	{"OnStream", "USB", "", "osst"}, \
 239	{"OnStream", "FW-", "", "osst"}
 240#endif
 241
 242static struct scsi_tape *scsi_tape_get(int dev)
 243{
 244	struct scsi_tape *STp = NULL;
 245
 246	mutex_lock(&st_ref_mutex);
 247	spin_lock(&st_index_lock);
 248
 249	STp = idr_find(&st_index_idr, dev);
 250	if (!STp) goto out;
 251
 252	kref_get(&STp->kref);
 253
 254	if (!STp->device)
 255		goto out_put;
 256
 257	if (scsi_device_get(STp->device))
 258		goto out_put;
 259
 260	goto out;
 261
 262out_put:
 263	kref_put(&STp->kref, scsi_tape_release);
 264	STp = NULL;
 265out:
 266	spin_unlock(&st_index_lock);
 267	mutex_unlock(&st_ref_mutex);
 268	return STp;
 269}
 270
 271static void scsi_tape_put(struct scsi_tape *STp)
 272{
 273	struct scsi_device *sdev = STp->device;
 274
 275	mutex_lock(&st_ref_mutex);
 276	kref_put(&STp->kref, scsi_tape_release);
 277	scsi_device_put(sdev);
 278	mutex_unlock(&st_ref_mutex);
 279}
 280
 281struct st_reject_data {
 282	char *vendor;
 283	char *model;
 284	char *rev;
 285	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 286};
 287
 288static struct st_reject_data reject_list[] = {
 289	/* {"XXX", "Yy-", "", NULL},  example */
 290	SIGS_FROM_OSST,
 291	{NULL, }};
 292
 293/* If the device signature is on the list of incompatible drives, the
 294   function returns a pointer to the name of the correct driver (if known) */
 295static char * st_incompatible(struct scsi_device* SDp)
 296{
 297	struct st_reject_data *rp;
 298
 299	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 300		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 301		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 302		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 303			if (rp->driver_hint)
 304				return rp->driver_hint;
 305			else
 306				return "unknown";
 307		}
 308	return NULL;
 309}
 310
 311
 312static inline char *tape_name(struct scsi_tape *tape)
 313{
 314	return tape->disk->disk_name;
 315}
 316
 317#define st_printk(prefix, t, fmt, a...) \
 318	sdev_prefix_printk(prefix, (t)->device, tape_name(t), fmt, ##a)
 319#ifdef DEBUG
 320#define DEBC_printk(t, fmt, a...) \
 321	if (debugging) { st_printk(ST_DEB_MSG, t, fmt, ##a ); }
 322#else
 323#define DEBC_printk(t, fmt, a...)
 324#endif
 325
 326static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 327{
 328	const u8 *ucp;
 329	const u8 *sense = SRpnt->sense;
 330
 331	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 332				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 333	s->flags = 0;
 334
 335	if (s->have_sense) {
 336		s->deferred = 0;
 337		s->remainder_valid =
 338			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 339		switch (sense[0] & 0x7f) {
 340		case 0x71:
 341			s->deferred = 1;
 342			fallthrough;
 343		case 0x70:
 344			s->fixed_format = 1;
 345			s->flags = sense[2] & 0xe0;
 346			break;
 347		case 0x73:
 348			s->deferred = 1;
 349			fallthrough;
 350		case 0x72:
 351			s->fixed_format = 0;
 352			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 353			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 354			break;
 355		}
 356	}
 357}
 358
 359
 360/* Convert the result to success code */
 361static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 362{
 363	int result = SRpnt->result;
 364	u8 scode;
 365	DEB(const char *stp;)
 366	char *name = tape_name(STp);
 367	struct st_cmdstatus *cmdstatp;
 368
 369	if (!result)
 370		return 0;
 371
 372	cmdstatp = &STp->buffer->cmdstat;
 373	st_analyze_sense(SRpnt, cmdstatp);
 374
 375	if (cmdstatp->have_sense)
 376		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 377	else
 378		scode = 0;
 379
 380	DEB(
 381	if (debugging) {
 382		st_printk(ST_DEB_MSG, STp,
 383			    "Error: %x, cmd: %x %x %x %x %x %x\n", result,
 384			    SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 385			    SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 386		if (cmdstatp->have_sense)
 387			__scsi_print_sense(STp->device, name,
 388					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 389	} ) /* end DEB */
 390	if (!debugging) { /* Abnormal conditions for tape */
 391		if (!cmdstatp->have_sense)
 392			st_printk(KERN_WARNING, STp,
 393			       "Error %x (driver bt 0, host bt 0x%x).\n",
 394			       result, host_byte(result));
 395		else if (cmdstatp->have_sense &&
 396			 scode != NO_SENSE &&
 397			 scode != RECOVERED_ERROR &&
 398			 /* scode != UNIT_ATTENTION && */
 399			 scode != BLANK_CHECK &&
 400			 scode != VOLUME_OVERFLOW &&
 401			 SRpnt->cmd[0] != MODE_SENSE &&
 402			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 403
 404			__scsi_print_sense(STp->device, name,
 405					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 406		}
 407	}
 408
 409	if (cmdstatp->fixed_format &&
 410	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 411		if (STp->cln_sense_value)
 412			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 413					       STp->cln_sense_mask) == STp->cln_sense_value);
 414		else
 415			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 416					       STp->cln_sense_mask) != 0);
 417	}
 418	if (cmdstatp->have_sense &&
 419	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 420		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 421
 422	STp->pos_unknown |= STp->device->was_reset;
 423
 424	if (cmdstatp->have_sense &&
 425	    scode == RECOVERED_ERROR
 426#if ST_RECOVERED_WRITE_FATAL
 427	    && SRpnt->cmd[0] != WRITE_6
 428	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 429#endif
 430	    ) {
 431		STp->recover_count++;
 432		STp->recover_reg++;
 433
 434		DEB(
 435		if (debugging) {
 436			if (SRpnt->cmd[0] == READ_6)
 437				stp = "read";
 438			else if (SRpnt->cmd[0] == WRITE_6)
 439				stp = "write";
 440			else
 441				stp = "ioctl";
 442			st_printk(ST_DEB_MSG, STp,
 443				  "Recovered %s error (%d).\n",
 444				  stp, STp->recover_count);
 445		} ) /* end DEB */
 446
 447		if (cmdstatp->flags == 0)
 448			return 0;
 449	}
 450	return (-EIO);
 451}
 452
 453static struct st_request *st_allocate_request(struct scsi_tape *stp)
 454{
 455	struct st_request *streq;
 456
 457	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 458	if (streq)
 459		streq->stp = stp;
 460	else {
 461		st_printk(KERN_ERR, stp,
 462			  "Can't get SCSI request.\n");
 463		if (signal_pending(current))
 464			stp->buffer->syscall_result = -EINTR;
 465		else
 466			stp->buffer->syscall_result = -EBUSY;
 467	}
 468
 469	return streq;
 470}
 471
 472static void st_release_request(struct st_request *streq)
 473{
 474	kfree(streq);
 475}
 476
 477static void st_do_stats(struct scsi_tape *STp, struct request *req)
 478{
 479	ktime_t now;
 480
 481	now = ktime_get();
 482	if (scsi_req(req)->cmd[0] == WRITE_6) {
 483		now = ktime_sub(now, STp->stats->write_time);
 484		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 485		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 486		atomic64_inc(&STp->stats->write_cnt);
 487		if (scsi_req(req)->result) {
 488			atomic64_add(atomic_read(&STp->stats->last_write_size)
 489				- STp->buffer->cmdstat.residual,
 490				&STp->stats->write_byte_cnt);
 491			if (STp->buffer->cmdstat.residual > 0)
 492				atomic64_inc(&STp->stats->resid_cnt);
 493		} else
 494			atomic64_add(atomic_read(&STp->stats->last_write_size),
 495				&STp->stats->write_byte_cnt);
 496	} else if (scsi_req(req)->cmd[0] == READ_6) {
 497		now = ktime_sub(now, STp->stats->read_time);
 498		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 499		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 500		atomic64_inc(&STp->stats->read_cnt);
 501		if (scsi_req(req)->result) {
 502			atomic64_add(atomic_read(&STp->stats->last_read_size)
 503				- STp->buffer->cmdstat.residual,
 504				&STp->stats->read_byte_cnt);
 505			if (STp->buffer->cmdstat.residual > 0)
 506				atomic64_inc(&STp->stats->resid_cnt);
 507		} else
 508			atomic64_add(atomic_read(&STp->stats->last_read_size),
 509				&STp->stats->read_byte_cnt);
 510	} else {
 511		now = ktime_sub(now, STp->stats->other_time);
 512		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 513		atomic64_inc(&STp->stats->other_cnt);
 514	}
 515	atomic64_dec(&STp->stats->in_flight);
 516}
 517
 518static void st_scsi_execute_end(struct request *req, blk_status_t status)
 519{
 520	struct st_request *SRpnt = req->end_io_data;
 521	struct scsi_request *rq = scsi_req(req);
 522	struct scsi_tape *STp = SRpnt->stp;
 523	struct bio *tmp;
 524
 525	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 526	STp->buffer->cmdstat.residual = rq->resid_len;
 527
 528	st_do_stats(STp, req);
 529
 530	tmp = SRpnt->bio;
 531	if (rq->sense_len)
 532		memcpy(SRpnt->sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
 533	if (SRpnt->waiting)
 534		complete(SRpnt->waiting);
 535
 536	blk_rq_unmap_user(tmp);
 537	blk_put_request(req);
 538}
 539
 540static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 541			   int data_direction, void *buffer, unsigned bufflen,
 542			   int timeout, int retries)
 543{
 544	struct request *req;
 545	struct scsi_request *rq;
 546	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 547	int err = 0;
 548	struct scsi_tape *STp = SRpnt->stp;
 549
 550	req = blk_get_request(SRpnt->stp->device->request_queue,
 551			data_direction == DMA_TO_DEVICE ?
 552			REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 553	if (IS_ERR(req))
 554		return PTR_ERR(req);
 555	rq = scsi_req(req);
 556	req->rq_flags |= RQF_QUIET;
 557
 558	mdata->null_mapped = 1;
 559
 560	if (bufflen) {
 561		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 562				      GFP_KERNEL);
 563		if (err) {
 564			blk_put_request(req);
 565			return err;
 566		}
 567	}
 568
 569	atomic64_inc(&STp->stats->in_flight);
 570	if (cmd[0] == WRITE_6) {
 571		atomic_set(&STp->stats->last_write_size, bufflen);
 572		STp->stats->write_time = ktime_get();
 573	} else if (cmd[0] == READ_6) {
 574		atomic_set(&STp->stats->last_read_size, bufflen);
 575		STp->stats->read_time = ktime_get();
 576	} else {
 577		STp->stats->other_time = ktime_get();
 578	}
 579
 580	SRpnt->bio = req->bio;
 581	rq->cmd_len = COMMAND_SIZE(cmd[0]);
 582	memset(rq->cmd, 0, BLK_MAX_CDB);
 583	memcpy(rq->cmd, cmd, rq->cmd_len);
 584	req->timeout = timeout;
 585	rq->retries = retries;
 586	req->end_io_data = SRpnt;
 587
 588	blk_execute_rq_nowait(NULL, req, 1, st_scsi_execute_end);
 589	return 0;
 590}
 591
 592/* Do the scsi command. Waits until command performed if do_wait is true.
 593   Otherwise write_behind_check() is used to check that the command
 594   has finished. */
 595static struct st_request *
 596st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 597	   int bytes, int direction, int timeout, int retries, int do_wait)
 598{
 599	struct completion *waiting;
 600	struct rq_map_data *mdata = &STp->buffer->map_data;
 601	int ret;
 602
 603	/* if async, make sure there's no command outstanding */
 604	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 605		st_printk(KERN_ERR, STp,
 606			  "Async command already active.\n");
 607		if (signal_pending(current))
 608			(STp->buffer)->syscall_result = (-EINTR);
 609		else
 610			(STp->buffer)->syscall_result = (-EBUSY);
 611		return NULL;
 612	}
 613
 614	if (!SRpnt) {
 615		SRpnt = st_allocate_request(STp);
 616		if (!SRpnt)
 617			return NULL;
 618	}
 619
 620	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 621	   which IO is outstanding. It's nulled out when the IO completes. */
 622	if (!do_wait)
 623		(STp->buffer)->last_SRpnt = SRpnt;
 624
 625	waiting = &STp->wait;
 626	init_completion(waiting);
 627	SRpnt->waiting = waiting;
 628
 629	if (STp->buffer->do_dio) {
 630		mdata->page_order = 0;
 631		mdata->nr_entries = STp->buffer->sg_segs;
 632		mdata->pages = STp->buffer->mapped_pages;
 633	} else {
 634		mdata->page_order = STp->buffer->reserved_page_order;
 635		mdata->nr_entries =
 636			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 637		mdata->pages = STp->buffer->reserved_pages;
 638		mdata->offset = 0;
 639	}
 640
 641	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 642	STp->buffer->cmdstat.have_sense = 0;
 643	STp->buffer->syscall_result = 0;
 644
 645	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 646			      retries);
 647	if (ret) {
 648		/* could not allocate the buffer or request was too large */
 649		(STp->buffer)->syscall_result = (-EBUSY);
 650		(STp->buffer)->last_SRpnt = NULL;
 651	} else if (do_wait) {
 652		wait_for_completion(waiting);
 653		SRpnt->waiting = NULL;
 654		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 655	}
 656
 657	return SRpnt;
 658}
 659
 660
 661/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 662   write has been correct but EOM early warning reached, -EIO if write ended in
 663   error or zero if write successful. Asynchronous writes are used only in
 664   variable block mode. */
 665static int write_behind_check(struct scsi_tape * STp)
 666{
 667	int retval = 0;
 668	struct st_buffer *STbuffer;
 669	struct st_partstat *STps;
 670	struct st_cmdstatus *cmdstatp;
 671	struct st_request *SRpnt;
 672
 673	STbuffer = STp->buffer;
 674	if (!STbuffer->writing)
 675		return 0;
 676
 677	DEB(
 678	if (STp->write_pending)
 679		STp->nbr_waits++;
 680	else
 681		STp->nbr_finished++;
 682	) /* end DEB */
 683
 684	wait_for_completion(&(STp->wait));
 685	SRpnt = STbuffer->last_SRpnt;
 686	STbuffer->last_SRpnt = NULL;
 687	SRpnt->waiting = NULL;
 688
 689	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 690	st_release_request(SRpnt);
 691
 692	STbuffer->buffer_bytes -= STbuffer->writing;
 693	STps = &(STp->ps[STp->partition]);
 694	if (STps->drv_block >= 0) {
 695		if (STp->block_size == 0)
 696			STps->drv_block++;
 697		else
 698			STps->drv_block += STbuffer->writing / STp->block_size;
 699	}
 700
 701	cmdstatp = &STbuffer->cmdstat;
 702	if (STbuffer->syscall_result) {
 703		retval = -EIO;
 704		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 705		    (cmdstatp->flags & SENSE_EOM) &&
 706		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 707		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 708			/* EOM at write-behind, has all data been written? */
 709			if (!cmdstatp->remainder_valid ||
 710			    cmdstatp->uremainder64 == 0)
 711				retval = -ENOSPC;
 712		}
 713		if (retval == -EIO)
 714			STps->drv_block = -1;
 715	}
 716	STbuffer->writing = 0;
 717
 718	DEB(if (debugging && retval)
 719		    st_printk(ST_DEB_MSG, STp,
 720				"Async write error %x, return value %d.\n",
 721				STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 722
 723	return retval;
 724}
 725
 726
 727/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 728   it messes up the block number). */
 729static int cross_eof(struct scsi_tape * STp, int forward)
 730{
 731	struct st_request *SRpnt;
 732	unsigned char cmd[MAX_COMMAND_SIZE];
 733
 734	cmd[0] = SPACE;
 735	cmd[1] = 0x01;		/* Space FileMarks */
 736	if (forward) {
 737		cmd[2] = cmd[3] = 0;
 738		cmd[4] = 1;
 739	} else
 740		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 741	cmd[5] = 0;
 742
 743	DEBC_printk(STp, "Stepping over filemark %s.\n",
 744		    forward ? "forward" : "backward");
 745
 746	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 747			   STp->device->request_queue->rq_timeout,
 748			   MAX_RETRIES, 1);
 749	if (!SRpnt)
 750		return (STp->buffer)->syscall_result;
 751
 752	st_release_request(SRpnt);
 753	SRpnt = NULL;
 754
 755	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 756		st_printk(KERN_ERR, STp,
 757			  "Stepping over filemark %s failed.\n",
 758			  forward ? "forward" : "backward");
 759
 760	return (STp->buffer)->syscall_result;
 761}
 762
 763
 764/* Flush the write buffer (never need to write if variable blocksize). */
 765static int st_flush_write_buffer(struct scsi_tape * STp)
 766{
 767	int transfer, blks;
 768	int result;
 769	unsigned char cmd[MAX_COMMAND_SIZE];
 770	struct st_request *SRpnt;
 771	struct st_partstat *STps;
 772
 773	result = write_behind_check(STp);
 774	if (result)
 775		return result;
 776
 777	result = 0;
 778	if (STp->dirty == 1) {
 779
 780		transfer = STp->buffer->buffer_bytes;
 781		DEBC_printk(STp, "Flushing %d bytes.\n", transfer);
 782
 783		memset(cmd, 0, MAX_COMMAND_SIZE);
 784		cmd[0] = WRITE_6;
 785		cmd[1] = 1;
 786		blks = transfer / STp->block_size;
 787		cmd[2] = blks >> 16;
 788		cmd[3] = blks >> 8;
 789		cmd[4] = blks;
 790
 791		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 792				   STp->device->request_queue->rq_timeout,
 793				   MAX_WRITE_RETRIES, 1);
 794		if (!SRpnt)
 795			return (STp->buffer)->syscall_result;
 796
 797		STps = &(STp->ps[STp->partition]);
 798		if ((STp->buffer)->syscall_result != 0) {
 799			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 800
 801			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 802			    (cmdstatp->flags & SENSE_EOM) &&
 803			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 804			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 805			    (!cmdstatp->remainder_valid ||
 806			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 807				STp->dirty = 0;
 808				(STp->buffer)->buffer_bytes = 0;
 809				if (STps->drv_block >= 0)
 810					STps->drv_block += blks;
 811				result = (-ENOSPC);
 812			} else {
 813				st_printk(KERN_ERR, STp, "Error on flush.\n");
 814				STps->drv_block = (-1);
 815				result = (-EIO);
 816			}
 817		} else {
 818			if (STps->drv_block >= 0)
 819				STps->drv_block += blks;
 820			STp->dirty = 0;
 821			(STp->buffer)->buffer_bytes = 0;
 822		}
 823		st_release_request(SRpnt);
 824		SRpnt = NULL;
 825	}
 826	return result;
 827}
 828
 829
 830/* Flush the tape buffer. The tape will be positioned correctly unless
 831   seek_next is true. */
 832static int flush_buffer(struct scsi_tape *STp, int seek_next)
 833{
 834	int backspace, result;
 835	struct st_partstat *STps;
 836
 837	/*
 838	 * If there was a bus reset, block further access
 839	 * to this device.
 840	 */
 841	if (STp->pos_unknown)
 842		return (-EIO);
 843
 844	if (STp->ready != ST_READY)
 845		return 0;
 846	STps = &(STp->ps[STp->partition]);
 847	if (STps->rw == ST_WRITING)	/* Writing */
 848		return st_flush_write_buffer(STp);
 849
 850	if (STp->block_size == 0)
 851		return 0;
 852
 853	backspace = ((STp->buffer)->buffer_bytes +
 854		     (STp->buffer)->read_pointer) / STp->block_size -
 855	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 856	    STp->block_size;
 857	(STp->buffer)->buffer_bytes = 0;
 858	(STp->buffer)->read_pointer = 0;
 859	result = 0;
 860	if (!seek_next) {
 861		if (STps->eof == ST_FM_HIT) {
 862			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 863			if (!result)
 864				STps->eof = ST_NOEOF;
 865			else {
 866				if (STps->drv_file >= 0)
 867					STps->drv_file++;
 868				STps->drv_block = 0;
 869			}
 870		}
 871		if (!result && backspace > 0)
 872			result = st_int_ioctl(STp, MTBSR, backspace);
 873	} else if (STps->eof == ST_FM_HIT) {
 874		if (STps->drv_file >= 0)
 875			STps->drv_file++;
 876		STps->drv_block = 0;
 877		STps->eof = ST_NOEOF;
 878	}
 879	return result;
 880
 881}
 882
 883/* Set the mode parameters */
 884static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 885{
 886	int set_it = 0;
 887	unsigned long arg;
 888
 889	if (!STp->density_changed &&
 890	    STm->default_density >= 0 &&
 891	    STm->default_density != STp->density) {
 892		arg = STm->default_density;
 893		set_it = 1;
 894	} else
 895		arg = STp->density;
 896	arg <<= MT_ST_DENSITY_SHIFT;
 897	if (!STp->blksize_changed &&
 898	    STm->default_blksize >= 0 &&
 899	    STm->default_blksize != STp->block_size) {
 900		arg |= STm->default_blksize;
 901		set_it = 1;
 902	} else
 903		arg |= STp->block_size;
 904	if (set_it &&
 905	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 906		st_printk(KERN_WARNING, STp,
 907			  "Can't set default block size to %d bytes "
 908			  "and density %x.\n",
 909			  STm->default_blksize, STm->default_density);
 910		if (modes_defined)
 911			return (-EINVAL);
 912	}
 913	return 0;
 914}
 915
 916
 917/* Lock or unlock the drive door. Don't use when st_request allocated. */
 918static int do_door_lock(struct scsi_tape * STp, int do_lock)
 919{
 920	int retval;
 921
 922	DEBC_printk(STp, "%socking drive door.\n", do_lock ? "L" : "Unl");
 923
 924	retval = scsi_set_medium_removal(STp->device,
 925			do_lock ? SCSI_REMOVAL_PREVENT : SCSI_REMOVAL_ALLOW);
 926	if (!retval)
 927		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 928	else
 929		STp->door_locked = ST_LOCK_FAILS;
 930	return retval;
 931}
 932
 933
 934/* Set the internal state after reset */
 935static void reset_state(struct scsi_tape *STp)
 936{
 937	int i;
 938	struct st_partstat *STps;
 939
 940	STp->pos_unknown = 0;
 941	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 942		STps = &(STp->ps[i]);
 943		STps->rw = ST_IDLE;
 944		STps->eof = ST_NOEOF;
 945		STps->at_sm = 0;
 946		STps->last_block_valid = 0;
 947		STps->drv_block = -1;
 948		STps->drv_file = -1;
 949	}
 950	if (STp->can_partitions) {
 951		STp->partition = find_partition(STp);
 952		if (STp->partition < 0)
 953			STp->partition = 0;
 954		STp->new_partition = STp->partition;
 955	}
 956}
 957
 958/* Test if the drive is ready. Returns either one of the codes below or a negative system
 959   error code. */
 960#define CHKRES_READY       0
 961#define CHKRES_NEW_SESSION 1
 962#define CHKRES_NOT_READY   2
 963#define CHKRES_NO_TAPE     3
 964
 965#define MAX_ATTENTIONS    10
 966
 967static int test_ready(struct scsi_tape *STp, int do_wait)
 968{
 969	int attentions, waits, max_wait, scode;
 970	int retval = CHKRES_READY, new_session = 0;
 971	unsigned char cmd[MAX_COMMAND_SIZE];
 972	struct st_request *SRpnt = NULL;
 973	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 974
 975	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 976
 977	for (attentions=waits=0; ; ) {
 978		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 979		cmd[0] = TEST_UNIT_READY;
 980		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 981				   STp->long_timeout, MAX_READY_RETRIES, 1);
 982
 983		if (!SRpnt) {
 984			retval = (STp->buffer)->syscall_result;
 985			break;
 986		}
 987
 988		if (cmdstatp->have_sense) {
 989
 990			scode = cmdstatp->sense_hdr.sense_key;
 991
 992			if (scode == UNIT_ATTENTION) { /* New media? */
 993				new_session = 1;
 994				if (attentions < MAX_ATTENTIONS) {
 995					attentions++;
 996					continue;
 997				}
 998				else {
 999					retval = (-EIO);
1000					break;
1001				}
1002			}
1003
1004			if (scode == NOT_READY) {
1005				if (waits < max_wait) {
1006					if (msleep_interruptible(1000)) {
1007						retval = (-EINTR);
1008						break;
1009					}
1010					waits++;
1011					continue;
1012				}
1013				else {
1014					if ((STp->device)->scsi_level >= SCSI_2 &&
1015					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
1016						retval = CHKRES_NO_TAPE;
1017					else
1018						retval = CHKRES_NOT_READY;
1019					break;
1020				}
1021			}
1022		}
1023
1024		retval = (STp->buffer)->syscall_result;
1025		if (!retval)
1026			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
1027		break;
1028	}
1029
1030	if (SRpnt != NULL)
1031		st_release_request(SRpnt);
1032	return retval;
1033}
1034
1035
1036/* See if the drive is ready and gather information about the tape. Return values:
1037   < 0   negative error code from errno.h
1038   0     drive ready
1039   1     drive not ready (possibly no tape)
1040*/
1041static int check_tape(struct scsi_tape *STp, struct file *filp)
1042{
1043	int i, retval, new_session = 0, do_wait;
1044	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
1045	unsigned short st_flags = filp->f_flags;
1046	struct st_request *SRpnt = NULL;
1047	struct st_modedef *STm;
1048	struct st_partstat *STps;
1049	struct inode *inode = file_inode(filp);
1050	int mode = TAPE_MODE(inode);
1051
1052	STp->ready = ST_READY;
1053
1054	if (mode != STp->current_mode) {
1055		DEBC_printk(STp, "Mode change from %d to %d.\n",
1056			    STp->current_mode, mode);
1057		new_session = 1;
1058		STp->current_mode = mode;
1059	}
1060	STm = &(STp->modes[STp->current_mode]);
1061
1062	saved_cleaning = STp->cleaning_req;
1063	STp->cleaning_req = 0;
1064
1065	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1066	retval = test_ready(STp, do_wait);
1067
1068	if (retval < 0)
1069	    goto err_out;
1070
1071	if (retval == CHKRES_NEW_SESSION) {
1072		STp->pos_unknown = 0;
1073		STp->partition = STp->new_partition = 0;
1074		if (STp->can_partitions)
1075			STp->nbr_partitions = 1; /* This guess will be updated later
1076                                                    if necessary */
1077		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1078			STps = &(STp->ps[i]);
1079			STps->rw = ST_IDLE;
1080			STps->eof = ST_NOEOF;
1081			STps->at_sm = 0;
1082			STps->last_block_valid = 0;
1083			STps->drv_block = 0;
1084			STps->drv_file = 0;
1085		}
1086		new_session = 1;
1087	}
1088	else {
1089		STp->cleaning_req |= saved_cleaning;
1090
1091		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1092			if (retval == CHKRES_NO_TAPE)
1093				STp->ready = ST_NO_TAPE;
1094			else
1095				STp->ready = ST_NOT_READY;
1096
1097			STp->density = 0;	/* Clear the erroneous "residue" */
1098			STp->write_prot = 0;
1099			STp->block_size = 0;
1100			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1101			STp->partition = STp->new_partition = 0;
1102			STp->door_locked = ST_UNLOCKED;
1103			return CHKRES_NOT_READY;
1104		}
1105	}
1106
1107	if (STp->omit_blklims)
1108		STp->min_block = STp->max_block = (-1);
1109	else {
1110		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1111		cmd[0] = READ_BLOCK_LIMITS;
1112
1113		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1114				   STp->device->request_queue->rq_timeout,
1115				   MAX_READY_RETRIES, 1);
1116		if (!SRpnt) {
1117			retval = (STp->buffer)->syscall_result;
1118			goto err_out;
1119		}
1120
1121		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1122			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1123			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1124			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1125			    (STp->buffer)->b_data[5];
1126			if ( DEB( debugging || ) !STp->inited)
1127				st_printk(KERN_INFO, STp,
1128					  "Block limits %d - %d bytes.\n",
1129					  STp->min_block, STp->max_block);
1130		} else {
1131			STp->min_block = STp->max_block = (-1);
1132			DEBC_printk(STp, "Can't read block limits.\n");
1133		}
1134	}
1135
1136	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1137	cmd[0] = MODE_SENSE;
1138	cmd[4] = 12;
1139
1140	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1141			   STp->device->request_queue->rq_timeout,
1142			   MAX_READY_RETRIES, 1);
1143	if (!SRpnt) {
1144		retval = (STp->buffer)->syscall_result;
1145		goto err_out;
1146	}
1147
1148	if ((STp->buffer)->syscall_result != 0) {
1149		DEBC_printk(STp, "No Mode Sense.\n");
1150		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1151		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1152		STp->drv_write_prot = 0;
1153	} else {
1154		DEBC_printk(STp,"Mode sense. Length %d, "
1155			    "medium %x, WBS %x, BLL %d\n",
1156			    (STp->buffer)->b_data[0],
1157			    (STp->buffer)->b_data[1],
1158			    (STp->buffer)->b_data[2],
1159			    (STp->buffer)->b_data[3]);
1160
1161		if ((STp->buffer)->b_data[3] >= 8) {
1162			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1163			STp->density = (STp->buffer)->b_data[4];
1164			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1165			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1166			DEBC_printk(STp, "Density %x, tape length: %x, "
1167				    "drv buffer: %d\n",
1168				    STp->density,
1169				    (STp->buffer)->b_data[5] * 65536 +
1170				    (STp->buffer)->b_data[6] * 256 +
1171				    (STp->buffer)->b_data[7],
1172				    STp->drv_buffer);
1173		}
1174		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1175		if (!STp->drv_buffer && STp->immediate_filemark) {
1176			st_printk(KERN_WARNING, STp,
1177				  "non-buffered tape: disabling "
1178				  "writing immediate filemarks\n");
1179			STp->immediate_filemark = 0;
1180		}
1181	}
1182	st_release_request(SRpnt);
1183	SRpnt = NULL;
1184	STp->inited = 1;
1185
1186	if (STp->block_size > 0)
1187		(STp->buffer)->buffer_blocks =
1188			(STp->buffer)->buffer_size / STp->block_size;
1189	else
1190		(STp->buffer)->buffer_blocks = 1;
1191	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1192
1193	DEBC_printk(STp, "Block size: %d, buffer size: %d (%d blocks).\n",
1194		    STp->block_size, (STp->buffer)->buffer_size,
1195		    (STp->buffer)->buffer_blocks);
1196
1197	if (STp->drv_write_prot) {
1198		STp->write_prot = 1;
1199
1200		DEBC_printk(STp, "Write protected\n");
1201
1202		if (do_wait &&
1203		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1204		     (st_flags & O_ACCMODE) == O_RDWR)) {
1205			retval = (-EROFS);
1206			goto err_out;
1207		}
1208	}
1209
1210	if (STp->can_partitions && STp->nbr_partitions < 1) {
1211		/* This code is reached when the device is opened for the first time
1212		   after the driver has been initialized with tape in the drive and the
1213		   partition support has been enabled. */
1214		DEBC_printk(STp, "Updating partition number in status.\n");
1215		if ((STp->partition = find_partition(STp)) < 0) {
1216			retval = STp->partition;
1217			goto err_out;
1218		}
1219		STp->new_partition = STp->partition;
1220		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1221	}
1222
1223	if (new_session) {	/* Change the drive parameters for the new mode */
1224		STp->density_changed = STp->blksize_changed = 0;
1225		STp->compression_changed = 0;
1226		if (!(STm->defaults_for_writes) &&
1227		    (retval = set_mode_densblk(STp, STm)) < 0)
1228		    goto err_out;
1229
1230		if (STp->default_drvbuffer != 0xff) {
1231			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1232				st_printk(KERN_WARNING, STp,
1233					  "Can't set default drive "
1234					  "buffering to %d.\n",
1235					  STp->default_drvbuffer);
1236		}
1237	}
1238
1239	return CHKRES_READY;
1240
1241 err_out:
1242	return retval;
1243}
1244
1245
1246/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1247   module count. */
1248static int st_open(struct inode *inode, struct file *filp)
1249{
1250	int i, retval = (-EIO);
1251	int resumed = 0;
1252	struct scsi_tape *STp;
1253	struct st_partstat *STps;
1254	int dev = TAPE_NR(inode);
1255
1256	/*
1257	 * We really want to do nonseekable_open(inode, filp); here, but some
1258	 * versions of tar incorrectly call lseek on tapes and bail out if that
1259	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1260	 */
1261	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1262
1263	if (!(STp = scsi_tape_get(dev))) {
1264		return -ENXIO;
1265	}
1266
1267	filp->private_data = STp;
1268
1269	spin_lock(&st_use_lock);
1270	if (STp->in_use) {
1271		spin_unlock(&st_use_lock);
1272		DEBC_printk(STp, "Device already in use.\n");
1273		scsi_tape_put(STp);
 
1274		return (-EBUSY);
1275	}
1276
1277	STp->in_use = 1;
1278	spin_unlock(&st_use_lock);
1279	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1280
1281	if (scsi_autopm_get_device(STp->device) < 0) {
1282		retval = -EIO;
1283		goto err_out;
1284	}
1285	resumed = 1;
1286	if (!scsi_block_when_processing_errors(STp->device)) {
1287		retval = (-ENXIO);
1288		goto err_out;
1289	}
1290
1291	/* See that we have at least a one page buffer available */
1292	if (!enlarge_buffer(STp->buffer, PAGE_SIZE)) {
1293		st_printk(KERN_WARNING, STp,
1294			  "Can't allocate one page tape buffer.\n");
1295		retval = (-EOVERFLOW);
1296		goto err_out;
1297	}
1298
1299	(STp->buffer)->cleared = 0;
1300	(STp->buffer)->writing = 0;
1301	(STp->buffer)->syscall_result = 0;
1302
1303	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1304
1305	STp->dirty = 0;
1306	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1307		STps = &(STp->ps[i]);
1308		STps->rw = ST_IDLE;
1309	}
1310	STp->try_dio_now = STp->try_dio;
1311	STp->recover_count = 0;
1312	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1313	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1314
1315	retval = check_tape(STp, filp);
1316	if (retval < 0)
1317		goto err_out;
1318	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1319	    retval != CHKRES_READY) {
1320		if (STp->ready == NO_TAPE)
1321			retval = (-ENOMEDIUM);
1322		else
1323			retval = (-EIO);
1324		goto err_out;
1325	}
1326	return 0;
1327
1328 err_out:
1329	normalize_buffer(STp->buffer);
1330	spin_lock(&st_use_lock);
1331	STp->in_use = 0;
1332	spin_unlock(&st_use_lock);
1333	if (resumed)
1334		scsi_autopm_put_device(STp->device);
1335	scsi_tape_put(STp);
1336	return retval;
1337
1338}
1339
1340
1341/* Flush the tape buffer before close */
1342static int st_flush(struct file *filp, fl_owner_t id)
1343{
1344	int result = 0, result2;
1345	unsigned char cmd[MAX_COMMAND_SIZE];
1346	struct st_request *SRpnt;
1347	struct scsi_tape *STp = filp->private_data;
1348	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1349	struct st_partstat *STps = &(STp->ps[STp->partition]);
1350
1351	if (file_count(filp) > 1)
1352		return 0;
1353
1354	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1355		result = st_flush_write_buffer(STp);
1356		if (result != 0 && result != (-ENOSPC))
1357			goto out;
1358	}
1359
1360	if (STp->can_partitions &&
1361	    (result2 = switch_partition(STp)) < 0) {
1362		DEBC_printk(STp, "switch_partition at close failed.\n");
1363		if (result == 0)
1364			result = result2;
1365		goto out;
1366	}
1367
1368	DEBC( if (STp->nbr_requests)
1369		st_printk(KERN_DEBUG, STp,
1370			  "Number of r/w requests %d, dio used in %d, "
1371			  "pages %d.\n", STp->nbr_requests, STp->nbr_dio,
1372			  STp->nbr_pages));
1373
1374	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1375		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1376
1377#if DEBUG
1378		DEBC_printk(STp, "Async write waits %d, finished %d.\n",
1379			    STp->nbr_waits, STp->nbr_finished);
1380#endif
1381		memset(cmd, 0, MAX_COMMAND_SIZE);
1382		cmd[0] = WRITE_FILEMARKS;
1383		if (STp->immediate_filemark)
1384			cmd[1] = 1;
1385		cmd[4] = 1 + STp->two_fm;
1386
1387		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1388				   STp->device->request_queue->rq_timeout,
1389				   MAX_WRITE_RETRIES, 1);
1390		if (!SRpnt) {
1391			result = (STp->buffer)->syscall_result;
1392			goto out;
1393		}
1394
1395		if (STp->buffer->syscall_result == 0 ||
1396		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1397		     (cmdstatp->flags & SENSE_EOM) &&
1398		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1399		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1400		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1401			/* Write successful at EOM */
1402			st_release_request(SRpnt);
1403			SRpnt = NULL;
1404			if (STps->drv_file >= 0)
1405				STps->drv_file++;
1406			STps->drv_block = 0;
1407			if (STp->two_fm)
1408				cross_eof(STp, 0);
1409			STps->eof = ST_FM;
1410		}
1411		else { /* Write error */
1412			st_release_request(SRpnt);
1413			SRpnt = NULL;
1414			st_printk(KERN_ERR, STp,
1415				  "Error on write filemark.\n");
1416			if (result == 0)
1417				result = (-EIO);
1418		}
1419
1420		DEBC_printk(STp, "Buffer flushed, %d EOF(s) written\n", cmd[4]);
1421	} else if (!STp->rew_at_close) {
1422		STps = &(STp->ps[STp->partition]);
1423		if (!STm->sysv || STps->rw != ST_READING) {
1424			if (STp->can_bsr)
1425				result = flush_buffer(STp, 0);
1426			else if (STps->eof == ST_FM_HIT) {
1427				result = cross_eof(STp, 0);
1428				if (result) {
1429					if (STps->drv_file >= 0)
1430						STps->drv_file++;
1431					STps->drv_block = 0;
1432					STps->eof = ST_FM;
1433				} else
1434					STps->eof = ST_NOEOF;
1435			}
1436		} else if ((STps->eof == ST_NOEOF &&
1437			    !(result = cross_eof(STp, 1))) ||
1438			   STps->eof == ST_FM_HIT) {
1439			if (STps->drv_file >= 0)
1440				STps->drv_file++;
1441			STps->drv_block = 0;
1442			STps->eof = ST_FM;
1443		}
1444	}
1445
1446      out:
1447	if (STp->rew_at_close) {
1448		result2 = st_int_ioctl(STp, MTREW, 1);
1449		if (result == 0)
1450			result = result2;
1451	}
1452	return result;
1453}
1454
1455
1456/* Close the device and release it. BKL is not needed: this is the only thread
1457   accessing this tape. */
1458static int st_release(struct inode *inode, struct file *filp)
1459{
 
1460	struct scsi_tape *STp = filp->private_data;
1461
1462	if (STp->door_locked == ST_LOCKED_AUTO)
1463		do_door_lock(STp, 0);
1464
1465	normalize_buffer(STp->buffer);
1466	spin_lock(&st_use_lock);
1467	STp->in_use = 0;
1468	spin_unlock(&st_use_lock);
1469	scsi_autopm_put_device(STp->device);
1470	scsi_tape_put(STp);
1471
1472	return 0;
1473}
1474
1475/* The checks common to both reading and writing */
1476static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1477{
1478	ssize_t retval = 0;
1479
1480	/*
1481	 * If we are in the middle of error recovery, don't let anyone
1482	 * else try and use this device.  Also, if error recovery fails, it
1483	 * may try and take the device offline, in which case all further
1484	 * access to the device is prohibited.
1485	 */
1486	if (!scsi_block_when_processing_errors(STp->device)) {
1487		retval = (-ENXIO);
1488		goto out;
1489	}
1490
1491	if (STp->ready != ST_READY) {
1492		if (STp->ready == ST_NO_TAPE)
1493			retval = (-ENOMEDIUM);
1494		else
1495			retval = (-EIO);
1496		goto out;
1497	}
1498
1499	if (! STp->modes[STp->current_mode].defined) {
1500		retval = (-ENXIO);
1501		goto out;
1502	}
1503
1504
1505	/*
1506	 * If there was a bus reset, block further access
1507	 * to this device.
1508	 */
1509	if (STp->pos_unknown) {
1510		retval = (-EIO);
1511		goto out;
1512	}
1513
1514	if (count == 0)
1515		goto out;
1516
1517	DEB(
1518	if (!STp->in_use) {
1519		st_printk(ST_DEB_MSG, STp,
1520			  "Incorrect device.\n");
1521		retval = (-EIO);
1522		goto out;
1523	} ) /* end DEB */
1524
1525	if (STp->can_partitions &&
1526	    (retval = switch_partition(STp)) < 0)
1527		goto out;
1528
1529	if (STp->block_size == 0 && STp->max_block > 0 &&
1530	    (count < STp->min_block || count > STp->max_block)) {
1531		retval = (-EINVAL);
1532		goto out;
1533	}
1534
1535	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1536	    !do_door_lock(STp, 1))
1537		STp->door_locked = ST_LOCKED_AUTO;
1538
1539 out:
1540	return retval;
1541}
1542
1543
1544static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1545			   size_t count, int is_read)
1546{
1547	int i, bufsize, retval = 0;
1548	struct st_buffer *STbp = STp->buffer;
1549
1550	if (is_read)
1551		i = STp->try_dio_now && try_rdio;
1552	else
1553		i = STp->try_dio_now && try_wdio;
1554
1555	if (i && ((unsigned long)buf & queue_dma_alignment(
1556					STp->device->request_queue)) == 0) {
1557		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1558				       count, (is_read ? READ : WRITE));
1559		if (i > 0) {
1560			STbp->do_dio = i;
1561			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1562		}
1563		else
1564			STbp->do_dio = 0;  /* fall back to buffering with any error */
1565		STbp->sg_segs = STbp->do_dio;
1566		DEB(
1567		     if (STbp->do_dio) {
1568			STp->nbr_dio++;
1569			STp->nbr_pages += STbp->do_dio;
1570		     }
1571		)
1572	} else
1573		STbp->do_dio = 0;
1574	DEB( STp->nbr_requests++; )
1575
1576	if (!STbp->do_dio) {
1577		if (STp->block_size)
1578			bufsize = STp->block_size > st_fixed_buffer_size ?
1579				STp->block_size : st_fixed_buffer_size;
1580		else {
1581			bufsize = count;
1582			/* Make sure that data from previous user is not leaked even if
1583			   HBA does not return correct residual */
1584			if (is_read && STp->sili && !STbp->cleared)
1585				clear_buffer(STbp);
1586		}
1587
1588		if (bufsize > STbp->buffer_size &&
1589		    !enlarge_buffer(STbp, bufsize)) {
1590			st_printk(KERN_WARNING, STp,
1591				  "Can't allocate %d byte tape buffer.\n",
1592				  bufsize);
1593			retval = (-EOVERFLOW);
1594			goto out;
1595		}
1596		if (STp->block_size)
1597			STbp->buffer_blocks = bufsize / STp->block_size;
1598	}
1599
1600 out:
1601	return retval;
1602}
1603
1604
1605/* Can be called more than once after each setup_buffer() */
1606static void release_buffering(struct scsi_tape *STp, int is_read)
1607{
1608	struct st_buffer *STbp;
1609
1610	STbp = STp->buffer;
1611	if (STbp->do_dio) {
1612		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1613		STbp->do_dio = 0;
1614		STbp->sg_segs = 0;
1615	}
1616}
1617
1618
1619/* Write command */
1620static ssize_t
1621st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1622{
1623	ssize_t total;
1624	ssize_t i, do_count, blks, transfer;
1625	ssize_t retval;
1626	int undone, retry_eot = 0, scode;
1627	int async_write;
1628	unsigned char cmd[MAX_COMMAND_SIZE];
1629	const char __user *b_point;
1630	struct st_request *SRpnt = NULL;
1631	struct scsi_tape *STp = filp->private_data;
1632	struct st_modedef *STm;
1633	struct st_partstat *STps;
1634	struct st_buffer *STbp;
1635
1636	if (mutex_lock_interruptible(&STp->lock))
1637		return -ERESTARTSYS;
1638
1639	retval = rw_checks(STp, filp, count);
1640	if (retval || count == 0)
1641		goto out;
1642
1643	/* Write must be integral number of blocks */
1644	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1645		st_printk(KERN_WARNING, STp,
1646			  "Write not multiple of tape block size.\n");
1647		retval = (-EINVAL);
1648		goto out;
1649	}
1650
1651	STm = &(STp->modes[STp->current_mode]);
1652	STps = &(STp->ps[STp->partition]);
1653
1654	if (STp->write_prot) {
1655		retval = (-EACCES);
1656		goto out;
1657	}
1658
1659
1660	if (STps->rw == ST_READING) {
1661		retval = flush_buffer(STp, 0);
1662		if (retval)
1663			goto out;
1664		STps->rw = ST_WRITING;
1665	} else if (STps->rw != ST_WRITING &&
1666		   STps->drv_file == 0 && STps->drv_block == 0) {
1667		if ((retval = set_mode_densblk(STp, STm)) < 0)
1668			goto out;
1669		if (STm->default_compression != ST_DONT_TOUCH &&
1670		    !(STp->compression_changed)) {
1671			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1672				st_printk(KERN_WARNING, STp,
1673					  "Can't set default compression.\n");
1674				if (modes_defined) {
1675					retval = (-EINVAL);
1676					goto out;
1677				}
1678			}
1679		}
1680	}
1681
1682	STbp = STp->buffer;
1683	i = write_behind_check(STp);
1684	if (i) {
1685		if (i == -ENOSPC)
1686			STps->eof = ST_EOM_OK;
1687		else
1688			STps->eof = ST_EOM_ERROR;
1689	}
1690
1691	if (STps->eof == ST_EOM_OK) {
1692		STps->eof = ST_EOD_1;  /* allow next write */
1693		retval = (-ENOSPC);
1694		goto out;
1695	}
1696	else if (STps->eof == ST_EOM_ERROR) {
1697		retval = (-EIO);
1698		goto out;
1699	}
1700
1701	/* Check the buffer readability in cases where copy_user might catch
1702	   the problems after some tape movement. */
1703	if (STp->block_size != 0 &&
1704	    !STbp->do_dio &&
1705	    (copy_from_user(&i, buf, 1) != 0 ||
1706	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1707		retval = (-EFAULT);
1708		goto out;
1709	}
1710
1711	retval = setup_buffering(STp, buf, count, 0);
1712	if (retval)
1713		goto out;
1714
1715	total = count;
1716
1717	memset(cmd, 0, MAX_COMMAND_SIZE);
1718	cmd[0] = WRITE_6;
1719	cmd[1] = (STp->block_size != 0);
1720
1721	STps->rw = ST_WRITING;
1722
1723	b_point = buf;
1724	while (count > 0 && !retry_eot) {
1725
1726		if (STbp->do_dio) {
1727			do_count = count;
1728		}
1729		else {
1730			if (STp->block_size == 0)
1731				do_count = count;
1732			else {
1733				do_count = STbp->buffer_blocks * STp->block_size -
1734					STbp->buffer_bytes;
1735				if (do_count > count)
1736					do_count = count;
1737			}
1738
1739			i = append_to_buffer(b_point, STbp, do_count);
1740			if (i) {
1741				retval = i;
1742				goto out;
1743			}
1744		}
1745		count -= do_count;
1746		b_point += do_count;
1747
1748		async_write = STp->block_size == 0 && !STbp->do_dio &&
1749			STm->do_async_writes && STps->eof < ST_EOM_OK;
1750
1751		if (STp->block_size != 0 && STm->do_buffer_writes &&
1752		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1753		    STbp->buffer_bytes < STbp->buffer_size) {
1754			STp->dirty = 1;
1755			/* Don't write a buffer that is not full enough. */
1756			if (!async_write && count == 0)
1757				break;
1758		}
1759
1760	retry_write:
1761		if (STp->block_size == 0)
1762			blks = transfer = do_count;
1763		else {
1764			if (!STbp->do_dio)
1765				blks = STbp->buffer_bytes;
1766			else
1767				blks = do_count;
1768			blks /= STp->block_size;
1769			transfer = blks * STp->block_size;
1770		}
1771		cmd[2] = blks >> 16;
1772		cmd[3] = blks >> 8;
1773		cmd[4] = blks;
1774
1775		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1776				   STp->device->request_queue->rq_timeout,
1777				   MAX_WRITE_RETRIES, !async_write);
1778		if (!SRpnt) {
1779			retval = STbp->syscall_result;
1780			goto out;
1781		}
1782		if (async_write && !STbp->syscall_result) {
1783			STbp->writing = transfer;
1784			STp->dirty = !(STbp->writing ==
1785				       STbp->buffer_bytes);
1786			SRpnt = NULL;  /* Prevent releasing this request! */
1787			DEB( STp->write_pending = 1; )
1788			break;
1789		}
1790
1791		if (STbp->syscall_result != 0) {
1792			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1793
1794			DEBC_printk(STp, "Error on write:\n");
1795			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1796				scode = cmdstatp->sense_hdr.sense_key;
1797				if (cmdstatp->remainder_valid)
1798					undone = (int)cmdstatp->uremainder64;
1799				else if (STp->block_size == 0 &&
1800					 scode == VOLUME_OVERFLOW)
1801					undone = transfer;
1802				else
1803					undone = 0;
1804				if (STp->block_size != 0)
1805					undone *= STp->block_size;
1806				if (undone <= do_count) {
1807					/* Only data from this write is not written */
1808					count += undone;
1809					b_point -= undone;
1810					do_count -= undone;
1811					if (STp->block_size)
1812						blks = (transfer - undone) / STp->block_size;
1813					STps->eof = ST_EOM_OK;
1814					/* Continue in fixed block mode if all written
1815					   in this request but still something left to write
1816					   (retval left to zero)
1817					*/
1818					if (STp->block_size == 0 ||
1819					    undone > 0 || count == 0)
1820						retval = (-ENOSPC); /* EOM within current request */
1821					DEBC_printk(STp, "EOM with %d "
1822						    "bytes unwritten.\n",
1823						    (int)count);
1824				} else {
1825					/* EOT within data buffered earlier (possible only
1826					   in fixed block mode without direct i/o) */
1827					if (!retry_eot && !cmdstatp->deferred &&
1828					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1829						move_buffer_data(STp->buffer, transfer - undone);
1830						retry_eot = 1;
1831						if (STps->drv_block >= 0) {
1832							STps->drv_block += (transfer - undone) /
1833								STp->block_size;
1834						}
1835						STps->eof = ST_EOM_OK;
1836						DEBC_printk(STp, "Retry "
1837							    "write of %d "
1838							    "bytes at EOM.\n",
1839							    STp->buffer->buffer_bytes);
1840						goto retry_write;
1841					}
1842					else {
1843						/* Either error within data buffered by driver or
1844						   failed retry */
1845						count -= do_count;
1846						blks = do_count = 0;
1847						STps->eof = ST_EOM_ERROR;
1848						STps->drv_block = (-1); /* Too cautious? */
1849						retval = (-EIO);	/* EOM for old data */
1850						DEBC_printk(STp, "EOM with "
1851							    "lost data.\n");
1852					}
1853				}
1854			} else {
1855				count += do_count;
1856				STps->drv_block = (-1);		/* Too cautious? */
1857				retval = STbp->syscall_result;
1858			}
1859
1860		}
1861
1862		if (STps->drv_block >= 0) {
1863			if (STp->block_size == 0)
1864				STps->drv_block += (do_count > 0);
1865			else
1866				STps->drv_block += blks;
1867		}
1868
1869		STbp->buffer_bytes = 0;
1870		STp->dirty = 0;
1871
1872		if (retval || retry_eot) {
1873			if (count < total)
1874				retval = total - count;
1875			goto out;
1876		}
1877	}
1878
1879	if (STps->eof == ST_EOD_1)
1880		STps->eof = ST_EOM_OK;
1881	else if (STps->eof != ST_EOM_OK)
1882		STps->eof = ST_NOEOF;
1883	retval = total - count;
1884
1885 out:
1886	if (SRpnt != NULL)
1887		st_release_request(SRpnt);
1888	release_buffering(STp, 0);
1889	mutex_unlock(&STp->lock);
1890
1891	return retval;
1892}
1893
1894/* Read data from the tape. Returns zero in the normal case, one if the
1895   eof status has changed, and the negative error code in case of a
1896   fatal error. Otherwise updates the buffer and the eof state.
1897
1898   Does release user buffer mapping if it is set.
1899*/
1900static long read_tape(struct scsi_tape *STp, long count,
1901		      struct st_request ** aSRpnt)
1902{
1903	int transfer, blks, bytes;
1904	unsigned char cmd[MAX_COMMAND_SIZE];
1905	struct st_request *SRpnt;
1906	struct st_modedef *STm;
1907	struct st_partstat *STps;
1908	struct st_buffer *STbp;
1909	int retval = 0;
1910
1911	if (count == 0)
1912		return 0;
1913
1914	STm = &(STp->modes[STp->current_mode]);
1915	STps = &(STp->ps[STp->partition]);
1916	if (STps->eof == ST_FM_HIT)
1917		return 1;
1918	STbp = STp->buffer;
1919
1920	if (STp->block_size == 0)
1921		blks = bytes = count;
1922	else {
1923		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1924			blks = (STp->buffer)->buffer_blocks;
1925			bytes = blks * STp->block_size;
1926		} else {
1927			bytes = count;
1928			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1929				bytes = (STp->buffer)->buffer_size;
1930			blks = bytes / STp->block_size;
1931			bytes = blks * STp->block_size;
1932		}
1933	}
1934
1935	memset(cmd, 0, MAX_COMMAND_SIZE);
1936	cmd[0] = READ_6;
1937	cmd[1] = (STp->block_size != 0);
1938	if (!cmd[1] && STp->sili)
1939		cmd[1] |= 2;
1940	cmd[2] = blks >> 16;
1941	cmd[3] = blks >> 8;
1942	cmd[4] = blks;
1943
1944	SRpnt = *aSRpnt;
1945	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1946			   STp->device->request_queue->rq_timeout,
1947			   MAX_RETRIES, 1);
1948	release_buffering(STp, 1);
1949	*aSRpnt = SRpnt;
1950	if (!SRpnt)
1951		return STbp->syscall_result;
1952
1953	STbp->read_pointer = 0;
1954	STps->at_sm = 0;
1955
1956	/* Something to check */
1957	if (STbp->syscall_result) {
1958		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1959
1960		retval = 1;
1961		DEBC_printk(STp,
1962			    "Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1963			    SRpnt->sense[0], SRpnt->sense[1],
1964			    SRpnt->sense[2], SRpnt->sense[3],
1965			    SRpnt->sense[4], SRpnt->sense[5],
1966			    SRpnt->sense[6], SRpnt->sense[7]);
1967		if (cmdstatp->have_sense) {
1968
1969			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1970				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1971
1972			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1973				/* Compute the residual count */
1974				if (cmdstatp->remainder_valid)
1975					transfer = (int)cmdstatp->uremainder64;
1976				else
1977					transfer = 0;
1978				if (cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR) {
1979					if (STp->block_size == 0)
1980						transfer = bytes;
1981					/* Some drives set ILI with MEDIUM ERROR */
1982					cmdstatp->flags &= ~SENSE_ILI;
1983				}
1984
1985				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1986					if (STp->block_size == 0 &&
1987					    transfer < 0) {
1988						st_printk(KERN_NOTICE, STp,
1989							  "Failed to read %d "
1990							  "byte block with %d "
1991							  "byte transfer.\n",
1992							  bytes - transfer,
1993							  bytes);
1994						if (STps->drv_block >= 0)
1995							STps->drv_block += 1;
1996						STbp->buffer_bytes = 0;
1997						return (-ENOMEM);
1998					} else if (STp->block_size == 0) {
1999						STbp->buffer_bytes = bytes - transfer;
2000					} else {
2001						st_release_request(SRpnt);
2002						SRpnt = *aSRpnt = NULL;
2003						if (transfer == blks) {	/* We did not get anything, error */
2004							st_printk(KERN_NOTICE, STp,
2005								  "Incorrect "
2006								  "block size.\n");
2007							if (STps->drv_block >= 0)
2008								STps->drv_block += blks - transfer + 1;
2009							st_int_ioctl(STp, MTBSR, 1);
2010							return (-EIO);
2011						}
2012						/* We have some data, deliver it */
2013						STbp->buffer_bytes = (blks - transfer) *
2014						    STp->block_size;
2015						DEBC_printk(STp, "ILI but "
2016							    "enough data "
2017							    "received %ld "
2018							    "%d.\n", count,
2019							    STbp->buffer_bytes);
2020						if (STps->drv_block >= 0)
2021							STps->drv_block += 1;
2022						if (st_int_ioctl(STp, MTBSR, 1))
2023							return (-EIO);
2024					}
2025				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
2026					if (STps->eof != ST_FM_HIT)
2027						STps->eof = ST_FM_HIT;
2028					else
2029						STps->eof = ST_EOD_2;
2030					if (STp->block_size == 0)
2031						STbp->buffer_bytes = 0;
2032					else
2033						STbp->buffer_bytes =
2034						    bytes - transfer * STp->block_size;
2035					DEBC_printk(STp, "EOF detected (%d "
2036						    "bytes read).\n",
2037						    STbp->buffer_bytes);
2038				} else if (cmdstatp->flags & SENSE_EOM) {
2039					if (STps->eof == ST_FM)
2040						STps->eof = ST_EOD_1;
2041					else
2042						STps->eof = ST_EOM_OK;
2043					if (STp->block_size == 0)
2044						STbp->buffer_bytes = bytes - transfer;
2045					else
2046						STbp->buffer_bytes =
2047						    bytes - transfer * STp->block_size;
2048
2049					DEBC_printk(STp, "EOM detected (%d "
2050						    "bytes read).\n",
2051						    STbp->buffer_bytes);
2052				}
2053			}
2054			/* end of EOF, EOM, ILI test */
2055			else {	/* nonzero sense key */
2056				DEBC_printk(STp, "Tape error while reading.\n");
2057				STps->drv_block = (-1);
2058				if (STps->eof == ST_FM &&
2059				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
2060					DEBC_printk(STp, "Zero returned for "
2061						    "first BLANK CHECK "
2062						    "after EOF.\n");
2063					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
2064				} else	/* Some other extended sense code */
2065					retval = (-EIO);
2066			}
2067
2068			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
2069				STbp->buffer_bytes = 0;
2070		}
2071		/* End of extended sense test */
2072		else {		/* Non-extended sense */
2073			retval = STbp->syscall_result;
2074		}
2075
2076	}
2077	/* End of error handling */
2078	else {			/* Read successful */
2079		STbp->buffer_bytes = bytes;
2080		if (STp->sili) /* In fixed block mode residual is always zero here */
2081			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
2082	}
2083
2084	if (STps->drv_block >= 0) {
2085		if (STp->block_size == 0)
2086			STps->drv_block++;
2087		else
2088			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2089	}
2090	return retval;
2091}
2092
2093
2094/* Read command */
2095static ssize_t
2096st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2097{
2098	ssize_t total;
2099	ssize_t retval = 0;
2100	ssize_t i, transfer;
2101	int special, do_dio = 0;
2102	struct st_request *SRpnt = NULL;
2103	struct scsi_tape *STp = filp->private_data;
2104	struct st_modedef *STm;
2105	struct st_partstat *STps;
2106	struct st_buffer *STbp = STp->buffer;
2107
2108	if (mutex_lock_interruptible(&STp->lock))
2109		return -ERESTARTSYS;
2110
2111	retval = rw_checks(STp, filp, count);
2112	if (retval || count == 0)
2113		goto out;
2114
2115	STm = &(STp->modes[STp->current_mode]);
2116	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2117		if (!STm->do_read_ahead) {
2118			retval = (-EINVAL);	/* Read must be integral number of blocks */
2119			goto out;
2120		}
2121		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2122	}
2123
2124	STps = &(STp->ps[STp->partition]);
2125	if (STps->rw == ST_WRITING) {
2126		retval = flush_buffer(STp, 0);
2127		if (retval)
2128			goto out;
2129		STps->rw = ST_READING;
2130	}
2131	DEB(
2132	if (debugging && STps->eof != ST_NOEOF)
2133		st_printk(ST_DEB_MSG, STp,
2134			  "EOF/EOM flag up (%d). Bytes %d\n",
2135			  STps->eof, STbp->buffer_bytes);
2136	) /* end DEB */
2137
2138	retval = setup_buffering(STp, buf, count, 1);
2139	if (retval)
2140		goto out;
2141	do_dio = STbp->do_dio;
2142
2143	if (STbp->buffer_bytes == 0 &&
2144	    STps->eof >= ST_EOD_1) {
2145		if (STps->eof < ST_EOD) {
2146			STps->eof += 1;
2147			retval = 0;
2148			goto out;
2149		}
2150		retval = (-EIO);	/* EOM or Blank Check */
2151		goto out;
2152	}
2153
2154	if (do_dio) {
2155		/* Check the buffer writability before any tape movement. Don't alter
2156		   buffer data. */
2157		if (copy_from_user(&i, buf, 1) != 0 ||
2158		    copy_to_user(buf, &i, 1) != 0 ||
2159		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2160		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2161			retval = (-EFAULT);
2162			goto out;
2163		}
2164	}
2165
2166	STps->rw = ST_READING;
2167
2168
2169	/* Loop until enough data in buffer or a special condition found */
2170	for (total = 0, special = 0; total < count && !special;) {
2171
2172		/* Get new data if the buffer is empty */
2173		if (STbp->buffer_bytes == 0) {
2174			special = read_tape(STp, count - total, &SRpnt);
2175			if (special < 0) {	/* No need to continue read */
2176				retval = special;
2177				goto out;
2178			}
2179		}
2180
2181		/* Move the data from driver buffer to user buffer */
2182		if (STbp->buffer_bytes > 0) {
2183			DEB(
2184			if (debugging && STps->eof != ST_NOEOF)
2185				st_printk(ST_DEB_MSG, STp,
2186					  "EOF up (%d). Left %d, needed %d.\n",
2187					  STps->eof, STbp->buffer_bytes,
2188					  (int)(count - total));
2189			) /* end DEB */
2190			transfer = STbp->buffer_bytes < count - total ?
2191			    STbp->buffer_bytes : count - total;
2192			if (!do_dio) {
2193				i = from_buffer(STbp, buf, transfer);
2194				if (i) {
2195					retval = i;
2196					goto out;
2197				}
2198			}
2199			buf += transfer;
2200			total += transfer;
2201		}
2202
2203		if (STp->block_size == 0)
2204			break;	/* Read only one variable length block */
2205
2206	}			/* for (total = 0, special = 0;
2207                                   total < count && !special; ) */
2208
2209	/* Change the eof state if no data from tape or buffer */
2210	if (total == 0) {
2211		if (STps->eof == ST_FM_HIT) {
2212			STps->eof = ST_FM;
2213			STps->drv_block = 0;
2214			if (STps->drv_file >= 0)
2215				STps->drv_file++;
2216		} else if (STps->eof == ST_EOD_1) {
2217			STps->eof = ST_EOD_2;
2218			STps->drv_block = 0;
2219			if (STps->drv_file >= 0)
2220				STps->drv_file++;
2221		} else if (STps->eof == ST_EOD_2)
2222			STps->eof = ST_EOD;
2223	} else if (STps->eof == ST_FM)
2224		STps->eof = ST_NOEOF;
2225	retval = total;
2226
2227 out:
2228	if (SRpnt != NULL) {
2229		st_release_request(SRpnt);
2230		SRpnt = NULL;
2231	}
2232	if (do_dio) {
2233		release_buffering(STp, 1);
2234		STbp->buffer_bytes = 0;
2235	}
2236	mutex_unlock(&STp->lock);
2237
2238	return retval;
2239}
2240
2241
2242
2243DEB(
2244/* Set the driver options */
2245static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm)
2246{
2247	if (debugging) {
2248		st_printk(KERN_INFO, STp,
2249			  "Mode %d options: buffer writes: %d, "
2250			  "async writes: %d, read ahead: %d\n",
2251			  STp->current_mode, STm->do_buffer_writes,
2252			  STm->do_async_writes, STm->do_read_ahead);
2253		st_printk(KERN_INFO, STp,
2254			  "    can bsr: %d, two FMs: %d, "
2255			  "fast mteom: %d, auto lock: %d,\n",
2256			  STp->can_bsr, STp->two_fm, STp->fast_mteom,
2257			  STp->do_auto_lock);
2258		st_printk(KERN_INFO, STp,
2259			  "    defs for wr: %d, no block limits: %d, "
2260			  "partitions: %d, s2 log: %d\n",
2261			  STm->defaults_for_writes, STp->omit_blklims,
2262			  STp->can_partitions, STp->scsi2_logical);
2263		st_printk(KERN_INFO, STp,
2264			  "    sysv: %d nowait: %d sili: %d "
2265			  "nowait_filemark: %d\n",
2266			  STm->sysv, STp->immediate, STp->sili,
2267			  STp->immediate_filemark);
2268		st_printk(KERN_INFO, STp, "    debugging: %d\n", debugging);
2269	}
2270}
2271	)
2272
2273
2274static int st_set_options(struct scsi_tape *STp, long options)
2275{
2276	int value;
2277	long code;
2278	struct st_modedef *STm;
2279	struct cdev *cd0, *cd1;
2280	struct device *d0, *d1;
2281
2282	STm = &(STp->modes[STp->current_mode]);
2283	if (!STm->defined) {
2284		cd0 = STm->cdevs[0];
2285		cd1 = STm->cdevs[1];
2286		d0  = STm->devs[0];
2287		d1  = STm->devs[1];
2288		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2289		STm->cdevs[0] = cd0;
2290		STm->cdevs[1] = cd1;
2291		STm->devs[0]  = d0;
2292		STm->devs[1]  = d1;
2293		modes_defined = 1;
2294		DEBC_printk(STp, "Initialized mode %d definition from mode 0\n",
2295			    STp->current_mode);
2296	}
2297
2298	code = options & MT_ST_OPTIONS;
2299	if (code == MT_ST_BOOLEANS) {
2300		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2301		STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2302		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2303		STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2304		STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2305		STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2306		STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2307		STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2308		STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2309		if ((STp->device)->scsi_level >= SCSI_2)
2310			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2311		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2312		STp->immediate = (options & MT_ST_NOWAIT) != 0;
2313		STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
2314		STm->sysv = (options & MT_ST_SYSV) != 0;
2315		STp->sili = (options & MT_ST_SILI) != 0;
2316		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2317		     st_log_options(STp, STm); )
2318	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2319		value = (code == MT_ST_SETBOOLEANS);
2320		if ((options & MT_ST_BUFFER_WRITES) != 0)
2321			STm->do_buffer_writes = value;
2322		if ((options & MT_ST_ASYNC_WRITES) != 0)
2323			STm->do_async_writes = value;
2324		if ((options & MT_ST_DEF_WRITES) != 0)
2325			STm->defaults_for_writes = value;
2326		if ((options & MT_ST_READ_AHEAD) != 0)
2327			STm->do_read_ahead = value;
2328		if ((options & MT_ST_TWO_FM) != 0)
2329			STp->two_fm = value;
2330		if ((options & MT_ST_FAST_MTEOM) != 0)
2331			STp->fast_mteom = value;
2332		if ((options & MT_ST_AUTO_LOCK) != 0)
2333			STp->do_auto_lock = value;
2334		if ((options & MT_ST_CAN_BSR) != 0)
2335			STp->can_bsr = value;
2336		if ((options & MT_ST_NO_BLKLIMS) != 0)
2337			STp->omit_blklims = value;
2338		if ((STp->device)->scsi_level >= SCSI_2 &&
2339		    (options & MT_ST_CAN_PARTITIONS) != 0)
2340			STp->can_partitions = value;
2341		if ((options & MT_ST_SCSI2LOGICAL) != 0)
2342			STp->scsi2_logical = value;
2343		if ((options & MT_ST_NOWAIT) != 0)
2344			STp->immediate = value;
2345		if ((options & MT_ST_NOWAIT_EOF) != 0)
2346			STp->immediate_filemark = value;
2347		if ((options & MT_ST_SYSV) != 0)
2348			STm->sysv = value;
2349		if ((options & MT_ST_SILI) != 0)
2350			STp->sili = value;
2351		DEB(
2352		if ((options & MT_ST_DEBUGGING) != 0)
2353			debugging = value;
2354			st_log_options(STp, STm); )
2355	} else if (code == MT_ST_WRITE_THRESHOLD) {
2356		/* Retained for compatibility */
2357	} else if (code == MT_ST_DEF_BLKSIZE) {
2358		value = (options & ~MT_ST_OPTIONS);
2359		if (value == ~MT_ST_OPTIONS) {
2360			STm->default_blksize = (-1);
2361			DEBC_printk(STp, "Default block size disabled.\n");
2362		} else {
2363			STm->default_blksize = value;
2364			DEBC_printk(STp,"Default block size set to "
2365				    "%d bytes.\n", STm->default_blksize);
2366			if (STp->ready == ST_READY) {
2367				STp->blksize_changed = 0;
2368				set_mode_densblk(STp, STm);
2369			}
2370		}
2371	} else if (code == MT_ST_TIMEOUTS) {
2372		value = (options & ~MT_ST_OPTIONS);
2373		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2374			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2375			DEBC_printk(STp, "Long timeout set to %d seconds.\n",
2376				    (value & ~MT_ST_SET_LONG_TIMEOUT));
2377		} else {
2378			blk_queue_rq_timeout(STp->device->request_queue,
2379					     value * HZ);
2380			DEBC_printk(STp, "Normal timeout set to %d seconds.\n",
2381				    value);
2382		}
2383	} else if (code == MT_ST_SET_CLN) {
2384		value = (options & ~MT_ST_OPTIONS) & 0xff;
2385		if (value != 0 &&
2386			(value < EXTENDED_SENSE_START ||
2387				value >= SCSI_SENSE_BUFFERSIZE))
2388			return (-EINVAL);
2389		STp->cln_mode = value;
2390		STp->cln_sense_mask = (options >> 8) & 0xff;
2391		STp->cln_sense_value = (options >> 16) & 0xff;
2392		st_printk(KERN_INFO, STp,
2393			  "Cleaning request mode %d, mask %02x, value %02x\n",
2394			  value, STp->cln_sense_mask, STp->cln_sense_value);
2395	} else if (code == MT_ST_DEF_OPTIONS) {
2396		code = (options & ~MT_ST_CLEAR_DEFAULT);
2397		value = (options & MT_ST_CLEAR_DEFAULT);
2398		if (code == MT_ST_DEF_DENSITY) {
2399			if (value == MT_ST_CLEAR_DEFAULT) {
2400				STm->default_density = (-1);
2401				DEBC_printk(STp,
2402					    "Density default disabled.\n");
2403			} else {
2404				STm->default_density = value & 0xff;
2405				DEBC_printk(STp, "Density default set to %x\n",
2406					    STm->default_density);
2407				if (STp->ready == ST_READY) {
2408					STp->density_changed = 0;
2409					set_mode_densblk(STp, STm);
2410				}
2411			}
2412		} else if (code == MT_ST_DEF_DRVBUFFER) {
2413			if (value == MT_ST_CLEAR_DEFAULT) {
2414				STp->default_drvbuffer = 0xff;
2415				DEBC_printk(STp,
2416					    "Drive buffer default disabled.\n");
2417			} else {
2418				STp->default_drvbuffer = value & 7;
2419				DEBC_printk(STp,
2420					    "Drive buffer default set to %x\n",
2421					    STp->default_drvbuffer);
2422				if (STp->ready == ST_READY)
2423					st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2424			}
2425		} else if (code == MT_ST_DEF_COMPRESSION) {
2426			if (value == MT_ST_CLEAR_DEFAULT) {
2427				STm->default_compression = ST_DONT_TOUCH;
2428				DEBC_printk(STp,
2429					    "Compression default disabled.\n");
2430			} else {
2431				if ((value & 0xff00) != 0) {
2432					STp->c_algo = (value & 0xff00) >> 8;
2433					DEBC_printk(STp, "Compression "
2434						    "algorithm set to 0x%x.\n",
2435						    STp->c_algo);
2436				}
2437				if ((value & 0xff) != 0xff) {
2438					STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2439					DEBC_printk(STp, "Compression default "
2440						    "set to %x\n",
2441						    (value & 1));
2442					if (STp->ready == ST_READY) {
2443						STp->compression_changed = 0;
2444						st_compression(STp, (STm->default_compression == ST_YES));
2445					}
2446				}
2447			}
2448		}
2449	} else
2450		return (-EIO);
2451
2452	return 0;
2453}
2454
2455#define MODE_HEADER_LENGTH  4
2456
2457/* Mode header and page byte offsets */
2458#define MH_OFF_DATA_LENGTH     0
2459#define MH_OFF_MEDIUM_TYPE     1
2460#define MH_OFF_DEV_SPECIFIC    2
2461#define MH_OFF_BDESCS_LENGTH   3
2462#define MP_OFF_PAGE_NBR        0
2463#define MP_OFF_PAGE_LENGTH     1
2464
2465/* Mode header and page bit masks */
2466#define MH_BIT_WP              0x80
2467#define MP_MSK_PAGE_NBR        0x3f
2468
2469/* Don't return block descriptors */
2470#define MODE_SENSE_OMIT_BDESCS 0x08
2471
2472#define MODE_SELECT_PAGE_FORMAT 0x10
2473
2474/* Read a mode page into the tape buffer. The block descriptors are included
2475   if incl_block_descs is true. The page control is ored to the page number
2476   parameter, if necessary. */
2477static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2478{
2479	unsigned char cmd[MAX_COMMAND_SIZE];
2480	struct st_request *SRpnt;
2481
2482	memset(cmd, 0, MAX_COMMAND_SIZE);
2483	cmd[0] = MODE_SENSE;
2484	if (omit_block_descs)
2485		cmd[1] = MODE_SENSE_OMIT_BDESCS;
2486	cmd[2] = page;
2487	cmd[4] = 255;
2488
2489	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2490			   STp->device->request_queue->rq_timeout, 0, 1);
2491	if (SRpnt == NULL)
2492		return (STp->buffer)->syscall_result;
2493
2494	st_release_request(SRpnt);
2495
2496	return STp->buffer->syscall_result;
2497}
2498
2499
2500/* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2501   in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2502static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2503{
2504	int pgo;
2505	unsigned char cmd[MAX_COMMAND_SIZE];
2506	struct st_request *SRpnt;
2507	int timeout;
2508
2509	memset(cmd, 0, MAX_COMMAND_SIZE);
2510	cmd[0] = MODE_SELECT;
2511	cmd[1] = MODE_SELECT_PAGE_FORMAT;
2512	pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2513	cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2514
2515	/* Clear reserved fields */
2516	(STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2517	(STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2518	(STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2519	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2520
2521	timeout = slow ?
2522		STp->long_timeout : STp->device->request_queue->rq_timeout;
2523	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2524			   timeout, 0, 1);
2525	if (SRpnt == NULL)
2526		return (STp->buffer)->syscall_result;
2527
2528	st_release_request(SRpnt);
2529
2530	return STp->buffer->syscall_result;
2531}
2532
2533
2534#define COMPRESSION_PAGE        0x0f
2535#define COMPRESSION_PAGE_LENGTH 16
2536
2537#define CP_OFF_DCE_DCC          2
2538#define CP_OFF_C_ALGO           7
2539
2540#define DCE_MASK  0x80
2541#define DCC_MASK  0x40
2542#define RED_MASK  0x60
2543
2544
2545/* Control the compression with mode page 15. Algorithm not changed if zero.
2546
2547   The block descriptors are read and written because Sony SDT-7000 does not
2548   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2549   Including block descriptors should not cause any harm to other drives. */
2550
2551static int st_compression(struct scsi_tape * STp, int state)
2552{
2553	int retval;
2554	int mpoffs;  /* Offset to mode page start */
2555	unsigned char *b_data = (STp->buffer)->b_data;
2556
2557	if (STp->ready != ST_READY)
2558		return (-EIO);
2559
2560	/* Read the current page contents */
2561	retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2562	if (retval) {
2563		DEBC_printk(STp, "Compression mode page not supported.\n");
2564		return (-EIO);
2565	}
2566
2567	mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2568	DEBC_printk(STp, "Compression state is %d.\n",
2569		    (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0));
2570
2571	/* Check if compression can be changed */
2572	if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2573		DEBC_printk(STp, "Compression not supported.\n");
2574		return (-EIO);
2575	}
2576
2577	/* Do the change */
2578	if (state) {
2579		b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2580		if (STp->c_algo != 0)
2581			b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2582	}
2583	else {
2584		b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2585		if (STp->c_algo != 0)
2586			b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2587	}
2588
2589	retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2590	if (retval) {
2591		DEBC_printk(STp, "Compression change failed.\n");
2592		return (-EIO);
2593	}
2594	DEBC_printk(STp, "Compression state changed to %d.\n", state);
2595
2596	STp->compression_changed = 1;
2597	return 0;
2598}
2599
2600
2601/* Process the load and unload commands (does unload if the load code is zero) */
2602static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2603{
2604	int retval = (-EIO), timeout;
2605	unsigned char cmd[MAX_COMMAND_SIZE];
2606	struct st_partstat *STps;
2607	struct st_request *SRpnt;
2608
2609	if (STp->ready != ST_READY && !load_code) {
2610		if (STp->ready == ST_NO_TAPE)
2611			return (-ENOMEDIUM);
2612		else
2613			return (-EIO);
2614	}
2615
2616	memset(cmd, 0, MAX_COMMAND_SIZE);
2617	cmd[0] = START_STOP;
2618	if (load_code)
2619		cmd[4] |= 1;
2620	/*
2621	 * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2622	 */
2623	if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2624	    && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2625		DEBC_printk(STp, " Enhanced %sload slot %2d.\n",
2626			    (cmd[4]) ? "" : "un",
2627			    load_code - MT_ST_HPLOADER_OFFSET);
2628		cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2629	}
2630	if (STp->immediate) {
2631		cmd[1] = 1;	/* Don't wait for completion */
2632		timeout = STp->device->request_queue->rq_timeout;
2633	}
2634	else
2635		timeout = STp->long_timeout;
2636
2637	DEBC(
2638		if (!load_code)
2639			st_printk(ST_DEB_MSG, STp, "Unloading tape.\n");
2640		else
2641			st_printk(ST_DEB_MSG, STp, "Loading tape.\n");
2642		);
2643
2644	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2645			   timeout, MAX_RETRIES, 1);
2646	if (!SRpnt)
2647		return (STp->buffer)->syscall_result;
2648
2649	retval = (STp->buffer)->syscall_result;
2650	st_release_request(SRpnt);
2651
2652	if (!retval) {	/* SCSI command successful */
2653
2654		if (!load_code) {
2655			STp->rew_at_close = 0;
2656			STp->ready = ST_NO_TAPE;
2657		}
2658		else {
2659			STp->rew_at_close = STp->autorew_dev;
2660			retval = check_tape(STp, filp);
2661			if (retval > 0)
2662				retval = 0;
2663		}
2664	}
2665	else {
2666		STps = &(STp->ps[STp->partition]);
2667		STps->drv_file = STps->drv_block = (-1);
2668	}
2669
2670	return retval;
2671}
2672
2673#if DEBUG
2674#define ST_DEB_FORWARD  0
2675#define ST_DEB_BACKWARD 1
2676static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd)
2677{
2678	s32 sc;
2679
2680	if (!debugging)
2681		return;
2682
2683	sc = sign_extend32(get_unaligned_be24(&cmd[2]), 23);
 
2684	if (direction)
2685		sc = -sc;
2686	st_printk(ST_DEB_MSG, STp, "Spacing tape %s over %d %s.\n",
2687		  direction ? "backward" : "forward", sc, units);
2688}
2689#else
2690#define ST_DEB_FORWARD  0
2691#define ST_DEB_BACKWARD 1
2692static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd) {}
2693#endif
2694
2695
2696/* Internal ioctl function */
2697static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2698{
2699	int timeout;
2700	long ltmp;
2701	int ioctl_result;
2702	int chg_eof = 1;
2703	unsigned char cmd[MAX_COMMAND_SIZE];
2704	struct st_request *SRpnt;
2705	struct st_partstat *STps;
2706	int fileno, blkno, at_sm, undone;
2707	int datalen = 0, direction = DMA_NONE;
2708
2709	WARN_ON(STp->buffer->do_dio != 0);
2710	if (STp->ready != ST_READY) {
2711		if (STp->ready == ST_NO_TAPE)
2712			return (-ENOMEDIUM);
2713		else
2714			return (-EIO);
2715	}
2716	timeout = STp->long_timeout;
2717	STps = &(STp->ps[STp->partition]);
2718	fileno = STps->drv_file;
2719	blkno = STps->drv_block;
2720	at_sm = STps->at_sm;
2721
2722	memset(cmd, 0, MAX_COMMAND_SIZE);
2723	switch (cmd_in) {
2724	case MTFSFM:
2725		chg_eof = 0;	/* Changed from the FSF after this */
2726		fallthrough;
2727	case MTFSF:
2728		cmd[0] = SPACE;
2729		cmd[1] = 0x01;	/* Space FileMarks */
2730		cmd[2] = (arg >> 16);
2731		cmd[3] = (arg >> 8);
2732		cmd[4] = arg;
2733		deb_space_print(STp, ST_DEB_FORWARD, "filemarks", cmd);
2734		if (fileno >= 0)
2735			fileno += arg;
2736		blkno = 0;
2737		at_sm &= (arg == 0);
2738		break;
2739	case MTBSFM:
2740		chg_eof = 0;	/* Changed from the FSF after this */
2741		fallthrough;
2742	case MTBSF:
2743		cmd[0] = SPACE;
2744		cmd[1] = 0x01;	/* Space FileMarks */
2745		ltmp = (-arg);
2746		cmd[2] = (ltmp >> 16);
2747		cmd[3] = (ltmp >> 8);
2748		cmd[4] = ltmp;
2749		deb_space_print(STp, ST_DEB_BACKWARD, "filemarks", cmd);
2750		if (fileno >= 0)
2751			fileno -= arg;
2752		blkno = (-1);	/* We can't know the block number */
2753		at_sm &= (arg == 0);
2754		break;
2755	case MTFSR:
2756		cmd[0] = SPACE;
2757		cmd[1] = 0x00;	/* Space Blocks */
2758		cmd[2] = (arg >> 16);
2759		cmd[3] = (arg >> 8);
2760		cmd[4] = arg;
2761		deb_space_print(STp, ST_DEB_FORWARD, "blocks", cmd);
2762		if (blkno >= 0)
2763			blkno += arg;
2764		at_sm &= (arg == 0);
2765		break;
2766	case MTBSR:
2767		cmd[0] = SPACE;
2768		cmd[1] = 0x00;	/* Space Blocks */
2769		ltmp = (-arg);
2770		cmd[2] = (ltmp >> 16);
2771		cmd[3] = (ltmp >> 8);
2772		cmd[4] = ltmp;
2773		deb_space_print(STp, ST_DEB_BACKWARD, "blocks", cmd);
2774		if (blkno >= 0)
2775			blkno -= arg;
2776		at_sm &= (arg == 0);
2777		break;
2778	case MTFSS:
2779		cmd[0] = SPACE;
2780		cmd[1] = 0x04;	/* Space Setmarks */
2781		cmd[2] = (arg >> 16);
2782		cmd[3] = (arg >> 8);
2783		cmd[4] = arg;
2784		deb_space_print(STp, ST_DEB_FORWARD, "setmarks", cmd);
2785		if (arg != 0) {
2786			blkno = fileno = (-1);
2787			at_sm = 1;
2788		}
2789		break;
2790	case MTBSS:
2791		cmd[0] = SPACE;
2792		cmd[1] = 0x04;	/* Space Setmarks */
2793		ltmp = (-arg);
2794		cmd[2] = (ltmp >> 16);
2795		cmd[3] = (ltmp >> 8);
2796		cmd[4] = ltmp;
2797		deb_space_print(STp, ST_DEB_BACKWARD, "setmarks", cmd);
2798		if (arg != 0) {
2799			blkno = fileno = (-1);
2800			at_sm = 1;
2801		}
2802		break;
2803	case MTWEOF:
2804	case MTWEOFI:
2805	case MTWSM:
2806		if (STp->write_prot)
2807			return (-EACCES);
2808		cmd[0] = WRITE_FILEMARKS;
2809		if (cmd_in == MTWSM)
2810			cmd[1] = 2;
2811		if (cmd_in == MTWEOFI ||
2812		    (cmd_in == MTWEOF && STp->immediate_filemark))
2813			cmd[1] |= 1;
2814		cmd[2] = (arg >> 16);
2815		cmd[3] = (arg >> 8);
2816		cmd[4] = arg;
2817		timeout = STp->device->request_queue->rq_timeout;
2818		DEBC(
2819			if (cmd_in != MTWSM)
2820				st_printk(ST_DEB_MSG, STp,
2821					  "Writing %d filemarks.\n",
2822					  cmd[2] * 65536 +
2823					  cmd[3] * 256 +
2824					  cmd[4]);
2825			else
2826				st_printk(ST_DEB_MSG, STp,
2827					  "Writing %d setmarks.\n",
2828					  cmd[2] * 65536 +
2829					  cmd[3] * 256 +
2830					  cmd[4]);
2831		)
2832		if (fileno >= 0)
2833			fileno += arg;
2834		blkno = 0;
2835		at_sm = (cmd_in == MTWSM);
2836		break;
2837	case MTREW:
2838		cmd[0] = REZERO_UNIT;
2839		if (STp->immediate) {
2840			cmd[1] = 1;	/* Don't wait for completion */
2841			timeout = STp->device->request_queue->rq_timeout;
2842		}
2843		DEBC_printk(STp, "Rewinding tape.\n");
2844		fileno = blkno = at_sm = 0;
2845		break;
2846	case MTNOP:
2847		DEBC_printk(STp, "No op on tape.\n");
2848		return 0;	/* Should do something ? */
 
2849	case MTRETEN:
2850		cmd[0] = START_STOP;
2851		if (STp->immediate) {
2852			cmd[1] = 1;	/* Don't wait for completion */
2853			timeout = STp->device->request_queue->rq_timeout;
2854		}
2855		cmd[4] = 3;
2856		DEBC_printk(STp, "Retensioning tape.\n");
2857		fileno = blkno = at_sm = 0;
2858		break;
2859	case MTEOM:
2860		if (!STp->fast_mteom) {
2861			/* space to the end of tape */
2862			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2863			fileno = STps->drv_file;
2864			if (STps->eof >= ST_EOD_1)
2865				return 0;
2866			/* The next lines would hide the number of spaced FileMarks
2867			   That's why I inserted the previous lines. I had no luck
2868			   with detecting EOM with FSF, so we go now to EOM.
2869			   Joerg Weule */
2870		} else
2871			fileno = (-1);
2872		cmd[0] = SPACE;
2873		cmd[1] = 3;
2874		DEBC_printk(STp, "Spacing to end of recorded medium.\n");
2875		blkno = -1;
2876		at_sm = 0;
2877		break;
2878	case MTERASE:
2879		if (STp->write_prot)
2880			return (-EACCES);
2881		cmd[0] = ERASE;
2882		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
2883		if (STp->immediate) {
2884			cmd[1] |= 2;	/* Don't wait for completion */
2885			timeout = STp->device->request_queue->rq_timeout;
2886		}
2887		else
2888			timeout = STp->long_timeout * 8;
2889
2890		DEBC_printk(STp, "Erasing tape.\n");
2891		fileno = blkno = at_sm = 0;
2892		break;
2893	case MTSETBLK:		/* Set block length */
2894	case MTSETDENSITY:	/* Set tape density */
2895	case MTSETDRVBUFFER:	/* Set drive buffering */
2896	case SET_DENS_AND_BLK:	/* Set density and block size */
2897		chg_eof = 0;
2898		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2899			return (-EIO);	/* Not allowed if data in buffer */
2900		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2901		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2902		    STp->max_block > 0 &&
2903		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2904		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2905			st_printk(KERN_WARNING, STp, "Illegal block size.\n");
2906			return (-EINVAL);
2907		}
2908		cmd[0] = MODE_SELECT;
2909		if ((STp->use_pf & USE_PF))
2910			cmd[1] = MODE_SELECT_PAGE_FORMAT;
2911		cmd[4] = datalen = 12;
2912		direction = DMA_TO_DEVICE;
2913
2914		memset((STp->buffer)->b_data, 0, 12);
2915		if (cmd_in == MTSETDRVBUFFER)
2916			(STp->buffer)->b_data[2] = (arg & 7) << 4;
2917		else
2918			(STp->buffer)->b_data[2] =
2919			    STp->drv_buffer << 4;
2920		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
2921		if (cmd_in == MTSETDENSITY) {
2922			(STp->buffer)->b_data[4] = arg;
2923			STp->density_changed = 1;	/* At least we tried ;-) */
2924		} else if (cmd_in == SET_DENS_AND_BLK)
2925			(STp->buffer)->b_data[4] = arg >> 24;
2926		else
2927			(STp->buffer)->b_data[4] = STp->density;
2928		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2929			ltmp = arg & MT_ST_BLKSIZE_MASK;
2930			if (cmd_in == MTSETBLK)
2931				STp->blksize_changed = 1; /* At least we tried ;-) */
2932		} else
2933			ltmp = STp->block_size;
2934		(STp->buffer)->b_data[9] = (ltmp >> 16);
2935		(STp->buffer)->b_data[10] = (ltmp >> 8);
2936		(STp->buffer)->b_data[11] = ltmp;
2937		timeout = STp->device->request_queue->rq_timeout;
2938		DEBC(
2939			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2940				st_printk(ST_DEB_MSG, STp,
2941					  "Setting block size to %d bytes.\n",
2942					  (STp->buffer)->b_data[9] * 65536 +
2943					  (STp->buffer)->b_data[10] * 256 +
2944					  (STp->buffer)->b_data[11]);
2945			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2946				st_printk(ST_DEB_MSG, STp,
2947					  "Setting density code to %x.\n",
2948					  (STp->buffer)->b_data[4]);
2949			if (cmd_in == MTSETDRVBUFFER)
2950				st_printk(ST_DEB_MSG, STp,
2951					  "Setting drive buffer code to %d.\n",
2952					  ((STp->buffer)->b_data[2] >> 4) & 7);
2953		)
2954		break;
2955	default:
2956		return (-ENOSYS);
2957	}
2958
2959	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2960			   timeout, MAX_RETRIES, 1);
2961	if (!SRpnt)
2962		return (STp->buffer)->syscall_result;
2963
2964	ioctl_result = (STp->buffer)->syscall_result;
2965
2966	if (!ioctl_result) {	/* SCSI command successful */
2967		st_release_request(SRpnt);
2968		SRpnt = NULL;
2969		STps->drv_block = blkno;
2970		STps->drv_file = fileno;
2971		STps->at_sm = at_sm;
2972
2973		if (cmd_in == MTBSFM)
2974			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2975		else if (cmd_in == MTFSFM)
2976			ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2977
2978		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2979			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2980			if (STp->block_size != 0) {
2981				(STp->buffer)->buffer_blocks =
2982				    (STp->buffer)->buffer_size / STp->block_size;
2983			}
2984			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2985			if (cmd_in == SET_DENS_AND_BLK)
2986				STp->density = arg >> MT_ST_DENSITY_SHIFT;
2987		} else if (cmd_in == MTSETDRVBUFFER)
2988			STp->drv_buffer = (arg & 7);
2989		else if (cmd_in == MTSETDENSITY)
2990			STp->density = arg;
2991
2992		if (cmd_in == MTEOM)
2993			STps->eof = ST_EOD;
2994		else if (cmd_in == MTFSF)
2995			STps->eof = ST_FM;
2996		else if (chg_eof)
2997			STps->eof = ST_NOEOF;
2998
2999		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
3000			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
3001	} else { /* SCSI command was not completely successful. Don't return
3002                    from this block without releasing the SCSI command block! */
3003		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
3004
3005		if (cmdstatp->flags & SENSE_EOM) {
3006			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
3007			    cmd_in != MTBSR && cmd_in != MTBSS)
3008				STps->eof = ST_EOM_OK;
3009			STps->drv_block = 0;
3010		}
3011
3012		if (cmdstatp->remainder_valid)
3013			undone = (int)cmdstatp->uremainder64;
3014		else
3015			undone = 0;
3016
3017		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
3018		    cmdstatp->have_sense &&
3019		    (cmdstatp->flags & SENSE_EOM)) {
3020			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
3021			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
3022				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
3023				STps->eof = ST_NOEOF;
3024			} else {  /* Writing EOF(s) failed */
3025				if (fileno >= 0)
3026					fileno -= undone;
3027				if (undone < arg)
3028					STps->eof = ST_NOEOF;
3029			}
3030			STps->drv_file = fileno;
3031		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
3032			if (fileno >= 0)
3033				STps->drv_file = fileno - undone;
3034			else
3035				STps->drv_file = fileno;
3036			STps->drv_block = -1;
3037			STps->eof = ST_NOEOF;
3038		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
3039			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3040				undone = (-undone);
3041			if (STps->drv_file >= 0)
3042				STps->drv_file = fileno + undone;
3043			STps->drv_block = 0;
3044			STps->eof = ST_NOEOF;
3045		} else if (cmd_in == MTFSR) {
3046			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3047				if (STps->drv_file >= 0)
3048					STps->drv_file++;
3049				STps->drv_block = 0;
3050				STps->eof = ST_FM;
3051			} else {
3052				if (blkno >= undone)
3053					STps->drv_block = blkno - undone;
3054				else
3055					STps->drv_block = (-1);
3056				STps->eof = ST_NOEOF;
3057			}
3058		} else if (cmd_in == MTBSR) {
3059			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3060				STps->drv_file--;
3061				STps->drv_block = (-1);
3062			} else {
3063				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3064					undone = (-undone);
3065				if (STps->drv_block >= 0)
3066					STps->drv_block = blkno + undone;
3067			}
3068			STps->eof = ST_NOEOF;
3069		} else if (cmd_in == MTEOM) {
3070			STps->drv_file = (-1);
3071			STps->drv_block = (-1);
3072			STps->eof = ST_EOD;
3073		} else if (cmd_in == MTSETBLK ||
3074			   cmd_in == MTSETDENSITY ||
3075			   cmd_in == MTSETDRVBUFFER ||
3076			   cmd_in == SET_DENS_AND_BLK) {
3077			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
3078			    !(STp->use_pf & PF_TESTED)) {
3079				/* Try the other possible state of Page Format if not
3080				   already tried */
3081				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
3082				st_release_request(SRpnt);
3083				SRpnt = NULL;
3084				return st_int_ioctl(STp, cmd_in, arg);
3085			}
3086		} else if (chg_eof)
3087			STps->eof = ST_NOEOF;
3088
3089		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
3090			STps->eof = ST_EOD;
3091
3092		st_release_request(SRpnt);
3093		SRpnt = NULL;
3094	}
3095
3096	return ioctl_result;
3097}
3098
3099
3100/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
3101   structure. */
3102
3103static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
3104			int logical)
3105{
3106	int result;
3107	unsigned char scmd[MAX_COMMAND_SIZE];
3108	struct st_request *SRpnt;
3109
3110	if (STp->ready != ST_READY)
3111		return (-EIO);
3112
3113	memset(scmd, 0, MAX_COMMAND_SIZE);
3114	if ((STp->device)->scsi_level < SCSI_2) {
3115		scmd[0] = QFA_REQUEST_BLOCK;
3116		scmd[4] = 3;
3117	} else {
3118		scmd[0] = READ_POSITION;
3119		if (!logical && !STp->scsi2_logical)
3120			scmd[1] = 1;
3121	}
3122	SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3123			   STp->device->request_queue->rq_timeout,
3124			   MAX_READY_RETRIES, 1);
3125	if (!SRpnt)
3126		return (STp->buffer)->syscall_result;
3127
3128	if ((STp->buffer)->syscall_result != 0 ||
3129	    (STp->device->scsi_level >= SCSI_2 &&
3130	     ((STp->buffer)->b_data[0] & 4) != 0)) {
3131		*block = *partition = 0;
3132		DEBC_printk(STp, " Can't read tape position.\n");
3133		result = (-EIO);
3134	} else {
3135		result = 0;
3136		if ((STp->device)->scsi_level < SCSI_2) {
3137			*block = ((STp->buffer)->b_data[0] << 16)
3138			    + ((STp->buffer)->b_data[1] << 8)
3139			    + (STp->buffer)->b_data[2];
3140			*partition = 0;
3141		} else {
3142			*block = ((STp->buffer)->b_data[4] << 24)
3143			    + ((STp->buffer)->b_data[5] << 16)
3144			    + ((STp->buffer)->b_data[6] << 8)
3145			    + (STp->buffer)->b_data[7];
3146			*partition = (STp->buffer)->b_data[1];
3147			if (((STp->buffer)->b_data[0] & 0x80) &&
3148			    (STp->buffer)->b_data[1] == 0)	/* BOP of partition 0 */
3149				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3150		}
3151		DEBC_printk(STp, "Got tape pos. blk %d part %d.\n",
3152			    *block, *partition);
3153	}
3154	st_release_request(SRpnt);
3155	SRpnt = NULL;
3156
3157	return result;
3158}
3159
3160
3161/* Set the tape block and partition. Negative partition means that only the
3162   block should be set in vendor specific way. */
3163static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3164			int logical)
3165{
3166	struct st_partstat *STps;
3167	int result, p;
3168	unsigned int blk;
3169	int timeout;
3170	unsigned char scmd[MAX_COMMAND_SIZE];
3171	struct st_request *SRpnt;
3172
3173	if (STp->ready != ST_READY)
3174		return (-EIO);
3175	timeout = STp->long_timeout;
3176	STps = &(STp->ps[STp->partition]);
3177
3178	DEBC_printk(STp, "Setting block to %d and partition to %d.\n",
3179		    block, partition);
3180	DEB(if (partition < 0)
3181		return (-EIO); )
3182
3183	/* Update the location at the partition we are leaving */
3184	if ((!STp->can_partitions && partition != 0) ||
3185	    partition >= ST_NBR_PARTITIONS)
3186		return (-EINVAL);
3187	if (partition != STp->partition) {
3188		if (get_location(STp, &blk, &p, 1))
3189			STps->last_block_valid = 0;
3190		else {
3191			STps->last_block_valid = 1;
3192			STps->last_block_visited = blk;
3193			DEBC_printk(STp, "Visited block %d for "
3194				    "partition %d saved.\n",
3195				    blk, STp->partition);
3196		}
3197	}
3198
3199	memset(scmd, 0, MAX_COMMAND_SIZE);
3200	if ((STp->device)->scsi_level < SCSI_2) {
3201		scmd[0] = QFA_SEEK_BLOCK;
3202		scmd[2] = (block >> 16);
3203		scmd[3] = (block >> 8);
3204		scmd[4] = block;
3205		scmd[5] = 0;
3206	} else {
3207		scmd[0] = SEEK_10;
3208		scmd[3] = (block >> 24);
3209		scmd[4] = (block >> 16);
3210		scmd[5] = (block >> 8);
3211		scmd[6] = block;
3212		if (!logical && !STp->scsi2_logical)
3213			scmd[1] = 4;
3214		if (STp->partition != partition) {
3215			scmd[1] |= 2;
3216			scmd[8] = partition;
3217			DEBC_printk(STp, "Trying to change partition "
3218				    "from %d to %d\n", STp->partition,
3219				    partition);
3220		}
3221	}
3222	if (STp->immediate) {
3223		scmd[1] |= 1;		/* Don't wait for completion */
3224		timeout = STp->device->request_queue->rq_timeout;
3225	}
3226
3227	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3228			   timeout, MAX_READY_RETRIES, 1);
3229	if (!SRpnt)
3230		return (STp->buffer)->syscall_result;
3231
3232	STps->drv_block = STps->drv_file = (-1);
3233	STps->eof = ST_NOEOF;
3234	if ((STp->buffer)->syscall_result != 0) {
3235		result = (-EIO);
3236		if (STp->can_partitions &&
3237		    (STp->device)->scsi_level >= SCSI_2 &&
3238		    (p = find_partition(STp)) >= 0)
3239			STp->partition = p;
3240	} else {
3241		if (STp->can_partitions) {
3242			STp->partition = partition;
3243			STps = &(STp->ps[partition]);
3244			if (!STps->last_block_valid ||
3245			    STps->last_block_visited != block) {
3246				STps->at_sm = 0;
3247				STps->rw = ST_IDLE;
3248			}
3249		} else
3250			STps->at_sm = 0;
3251		if (block == 0)
3252			STps->drv_block = STps->drv_file = 0;
3253		result = 0;
3254	}
3255
3256	st_release_request(SRpnt);
3257	SRpnt = NULL;
3258
3259	return result;
3260}
3261
3262
3263/* Find the current partition number for the drive status. Called from open and
3264   returns either partition number of negative error code. */
3265static int find_partition(struct scsi_tape *STp)
3266{
3267	int i, partition;
3268	unsigned int block;
3269
3270	if ((i = get_location(STp, &block, &partition, 1)) < 0)
3271		return i;
3272	if (partition >= ST_NBR_PARTITIONS)
3273		return (-EIO);
3274	return partition;
3275}
3276
3277
3278/* Change the partition if necessary */
3279static int switch_partition(struct scsi_tape *STp)
3280{
3281	struct st_partstat *STps;
3282
3283	if (STp->partition == STp->new_partition)
3284		return 0;
3285	STps = &(STp->ps[STp->new_partition]);
3286	if (!STps->last_block_valid)
3287		STps->last_block_visited = 0;
3288	return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3289}
3290
3291/* Functions for reading and writing the medium partition mode page. */
3292
3293#define PART_PAGE   0x11
3294#define PART_PAGE_FIXED_LENGTH 8
3295
3296#define PP_OFF_MAX_ADD_PARTS   2
3297#define PP_OFF_NBR_ADD_PARTS   3
3298#define PP_OFF_FLAGS           4
3299#define PP_OFF_PART_UNITS      6
3300#define PP_OFF_RESERVED        7
3301
3302#define PP_BIT_IDP             0x20
3303#define PP_BIT_FDP             0x80
3304#define PP_MSK_PSUM_MB         0x10
3305#define PP_MSK_PSUM_UNITS      0x18
3306#define PP_MSK_POFM            0x04
3307
3308/* Get the number of partitions on the tape. As a side effect reads the
3309   mode page into the tape buffer. */
3310static int nbr_partitions(struct scsi_tape *STp)
3311{
3312	int result;
3313
3314	if (STp->ready != ST_READY)
3315		return (-EIO);
3316
3317	result = read_mode_page(STp, PART_PAGE, 1);
3318
3319	if (result) {
3320		DEBC_printk(STp, "Can't read medium partition page.\n");
3321		result = (-EIO);
3322	} else {
3323		result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3324					      PP_OFF_NBR_ADD_PARTS] + 1;
3325		DEBC_printk(STp, "Number of partitions %d.\n", result);
3326	}
3327
3328	return result;
3329}
3330
3331
3332static int format_medium(struct scsi_tape *STp, int format)
3333{
3334	int result = 0;
3335	int timeout = STp->long_timeout;
3336	unsigned char scmd[MAX_COMMAND_SIZE];
3337	struct st_request *SRpnt;
3338
3339	memset(scmd, 0, MAX_COMMAND_SIZE);
3340	scmd[0] = FORMAT_UNIT;
3341	scmd[2] = format;
3342	if (STp->immediate) {
3343		scmd[1] |= 1;		/* Don't wait for completion */
3344		timeout = STp->device->request_queue->rq_timeout;
3345	}
3346	DEBC_printk(STp, "Sending FORMAT MEDIUM\n");
3347	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3348			   timeout, MAX_RETRIES, 1);
3349	if (!SRpnt)
3350		result = STp->buffer->syscall_result;
3351	return result;
3352}
3353
3354
3355/* Partition the tape into two partitions if size > 0 or one partition if
3356   size == 0.
3357
3358   The block descriptors are read and written because Sony SDT-7000 does not
3359   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3360
3361   My HP C1533A drive returns only one partition size field. This is used to
3362   set the size of partition 1. There is no size field for the default partition.
3363   Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3364   used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3365   The following algorithm is used to accommodate both drives: if the number of
3366   partition size fields is greater than the maximum number of additional partitions
3367   in the mode page, the second field is used. Otherwise the first field is used.
3368
3369   For Seagate DDS drives the page length must be 8 when no partitions is defined
3370   and 10 when 1 partition is defined (information from Eric Lee Green). This is
3371   is acceptable also to some other old drives and enforced if the first partition
3372   size field is used for the first additional partition size.
3373
3374   For drives that advertize SCSI-3 or newer, use the SSC-3 methods.
3375 */
3376static int partition_tape(struct scsi_tape *STp, int size)
3377{
3378	int result;
3379	int target_partition;
3380	bool scsi3 = STp->device->scsi_level >= SCSI_3, needs_format = false;
3381	int pgo, psd_cnt, psdo;
3382	int psum = PP_MSK_PSUM_MB, units = 0;
3383	unsigned char *bp;
3384
3385	result = read_mode_page(STp, PART_PAGE, 0);
3386	if (result) {
3387		DEBC_printk(STp, "Can't read partition mode page.\n");
3388		return result;
3389	}
3390	target_partition = 1;
3391	if (size < 0) {
3392		target_partition = 0;
3393		size = -size;
3394	}
3395
3396	/* The mode page is in the buffer. Let's modify it and write it. */
3397	bp = (STp->buffer)->b_data;
3398	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3399	DEBC_printk(STp, "Partition page length is %d bytes.\n",
3400		    bp[pgo + MP_OFF_PAGE_LENGTH] + 2);
3401
3402	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
3403
3404	if (scsi3) {
3405		needs_format = (bp[pgo + PP_OFF_FLAGS] & PP_MSK_POFM) != 0;
3406		if (needs_format && size == 0) {
3407			/* No need to write the mode page when clearing
3408			 *  partitioning
3409			 */
3410			DEBC_printk(STp, "Formatting tape with one partition.\n");
3411			result = format_medium(STp, 0);
3412			goto out;
3413		}
3414		if (needs_format)  /* Leave the old value for HP DATs claiming SCSI_3 */
3415			psd_cnt = 2;
3416		if ((bp[pgo + PP_OFF_FLAGS] & PP_MSK_PSUM_UNITS) == PP_MSK_PSUM_UNITS) {
3417			/* Use units scaling for large partitions if the device
3418			 * suggests it and no precision lost. Required for IBM
3419			 * TS1140/50 drives that don't support MB units.
3420			 */
3421			if (size >= 1000 && (size % 1000) == 0) {
3422				size /= 1000;
3423				psum = PP_MSK_PSUM_UNITS;
3424				units = 9; /* GB */
3425			}
3426		}
3427		/* Try it anyway if too large to specify in MB */
3428		if (psum == PP_MSK_PSUM_MB && size >= 65534) {
3429			size /= 1000;
3430			psum = PP_MSK_PSUM_UNITS;
3431			units = 9;  /* GB */
3432		}
3433	}
3434
3435	if (size >= 65535 ||  /* Does not fit into two bytes */
3436	    (target_partition == 0 && psd_cnt < 2)) {
3437		result = -EINVAL;
3438		goto out;
3439	}
3440
3441	psdo = pgo + PART_PAGE_FIXED_LENGTH;
3442	/* The second condition is for HP DDS which use only one partition size
3443	 * descriptor
3444	 */
3445	if (target_partition > 0 &&
3446	    (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS] ||
3447	     bp[pgo + PP_OFF_MAX_ADD_PARTS] != 1)) {
3448		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest to partition 0 */
3449		psdo += 2;
3450	}
3451	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3452
3453	DEBC_printk(STp, "psd_cnt %d, max.parts %d, nbr_parts %d\n",
3454		    psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3455		    bp[pgo + PP_OFF_NBR_ADD_PARTS]);
3456
3457	if (size == 0) {
3458		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3459		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3460		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3461		DEBC_printk(STp, "Formatting tape with one partition.\n");
3462	} else {
3463		bp[psdo] = (size >> 8) & 0xff;
3464		bp[psdo + 1] = size & 0xff;
3465		if (target_partition == 0)
3466			bp[psdo + 2] = bp[psdo + 3] = 0xff;
3467		bp[pgo + 3] = 1;
3468		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3469		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3470		DEBC_printk(STp,
3471			    "Formatting tape with two partitions (%i = %d MB).\n",
3472			    target_partition, units > 0 ? size * 1000 : size);
3473	}
3474	bp[pgo + PP_OFF_PART_UNITS] = 0;
3475	bp[pgo + PP_OFF_RESERVED] = 0;
3476	if (size != 1 || units != 0) {
3477		bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | psum |
3478			(bp[pgo + PP_OFF_FLAGS] & 0x07);
3479		bp[pgo + PP_OFF_PART_UNITS] = units;
3480	} else
3481		bp[pgo + PP_OFF_FLAGS] = PP_BIT_FDP |
3482			(bp[pgo + PP_OFF_FLAGS] & 0x1f);
3483	bp[pgo + MP_OFF_PAGE_LENGTH] = 6 + psd_cnt * 2;
3484
3485	result = write_mode_page(STp, PART_PAGE, 1);
3486
3487	if (!result && needs_format)
3488		result = format_medium(STp, 1);
3489
3490	if (result) {
3491		st_printk(KERN_INFO, STp, "Partitioning of tape failed.\n");
3492		result = (-EIO);
3493	}
3494
3495out:
3496	return result;
3497}
3498
3499
3500
3501/* The ioctl command */
3502static long st_ioctl_common(struct file *file, unsigned int cmd_in, void __user *p)
3503{
3504	int i, cmd_nr, cmd_type, bt;
3505	int retval = 0;
3506	unsigned int blk;
3507	struct scsi_tape *STp = file->private_data;
3508	struct st_modedef *STm;
3509	struct st_partstat *STps;
 
3510
3511	if (mutex_lock_interruptible(&STp->lock))
3512		return -ERESTARTSYS;
3513
3514	DEB(
3515	if (debugging && !STp->in_use) {
3516		st_printk(ST_DEB_MSG, STp, "Incorrect device.\n");
3517		retval = (-EIO);
3518		goto out;
3519	} ) /* end DEB */
3520
3521	STm = &(STp->modes[STp->current_mode]);
3522	STps = &(STp->ps[STp->partition]);
3523
3524	/*
3525	 * If we are in the middle of error recovery, don't let anyone
3526	 * else try and use this device.  Also, if error recovery fails, it
3527	 * may try and take the device offline, in which case all further
3528	 * access to the device is prohibited.
3529	 */
3530	retval = scsi_ioctl_block_when_processing_errors(STp->device, cmd_in,
3531			file->f_flags & O_NDELAY);
3532	if (retval)
3533		goto out;
3534
3535	cmd_type = _IOC_TYPE(cmd_in);
3536	cmd_nr = _IOC_NR(cmd_in);
3537
3538	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3539		struct mtop mtc;
3540
3541		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3542			retval = (-EINVAL);
3543			goto out;
3544		}
3545
3546		i = copy_from_user(&mtc, p, sizeof(struct mtop));
3547		if (i) {
3548			retval = (-EFAULT);
3549			goto out;
3550		}
3551
3552		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3553			st_printk(KERN_WARNING, STp,
3554				  "MTSETDRVBUFFER only allowed for root.\n");
3555			retval = (-EPERM);
3556			goto out;
3557		}
3558		if (!STm->defined &&
3559		    (mtc.mt_op != MTSETDRVBUFFER &&
3560		     (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3561			retval = (-ENXIO);
3562			goto out;
3563		}
3564
3565		if (!STp->pos_unknown) {
3566
3567			if (STps->eof == ST_FM_HIT) {
3568				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3569                                    mtc.mt_op == MTEOM) {
3570					mtc.mt_count -= 1;
3571					if (STps->drv_file >= 0)
3572						STps->drv_file += 1;
3573				} else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3574					mtc.mt_count += 1;
3575					if (STps->drv_file >= 0)
3576						STps->drv_file += 1;
3577				}
3578			}
3579
3580			if (mtc.mt_op == MTSEEK) {
3581				/* Old position must be restored if partition will be
3582                                   changed */
3583				i = !STp->can_partitions ||
3584				    (STp->new_partition != STp->partition);
3585			} else {
3586				i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3587				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3588				    mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3589				    mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3590				    mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3591				    mtc.mt_op == MTCOMPRESSION;
3592			}
3593			i = flush_buffer(STp, i);
3594			if (i < 0) {
3595				retval = i;
3596				goto out;
3597			}
3598			if (STps->rw == ST_WRITING &&
3599			    (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3600			     mtc.mt_op == MTSEEK ||
3601			     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3602				i = st_int_ioctl(STp, MTWEOF, 1);
3603				if (i < 0) {
3604					retval = i;
3605					goto out;
3606				}
3607				if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3608					mtc.mt_count++;
3609				STps->rw = ST_IDLE;
3610			     }
3611
3612		} else {
3613			/*
3614			 * If there was a bus reset, block further access
3615			 * to this device.  If the user wants to rewind the tape,
3616			 * then reset the flag and allow access again.
3617			 */
3618			if (mtc.mt_op != MTREW &&
3619			    mtc.mt_op != MTOFFL &&
3620			    mtc.mt_op != MTRETEN &&
3621			    mtc.mt_op != MTERASE &&
3622			    mtc.mt_op != MTSEEK &&
3623			    mtc.mt_op != MTEOM) {
3624				retval = (-EIO);
3625				goto out;
3626			}
3627			reset_state(STp);
3628			/* remove this when the midlevel properly clears was_reset */
3629			STp->device->was_reset = 0;
3630		}
3631
3632		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3633		    mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3634		    mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3635			STps->rw = ST_IDLE;	/* Prevent automatic WEOF and fsf */
3636
3637		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3638			do_door_lock(STp, 0);	/* Ignore result! */
3639
3640		if (mtc.mt_op == MTSETDRVBUFFER &&
3641		    (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3642			retval = st_set_options(STp, mtc.mt_count);
3643			goto out;
3644		}
3645
3646		if (mtc.mt_op == MTSETPART) {
3647			if (!STp->can_partitions ||
3648			    mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3649				retval = (-EINVAL);
3650				goto out;
3651			}
3652			if (mtc.mt_count >= STp->nbr_partitions &&
3653			    (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3654				retval = (-EIO);
3655				goto out;
3656			}
3657			if (mtc.mt_count >= STp->nbr_partitions) {
3658				retval = (-EINVAL);
3659				goto out;
3660			}
3661			STp->new_partition = mtc.mt_count;
3662			retval = 0;
3663			goto out;
3664		}
3665
3666		if (mtc.mt_op == MTMKPART) {
3667			if (!STp->can_partitions) {
3668				retval = (-EINVAL);
3669				goto out;
3670			}
3671			i = do_load_unload(STp, file, 1);
3672			if (i < 0) {
3673				retval = i;
3674				goto out;
3675			}
3676			i = partition_tape(STp, mtc.mt_count);
3677			if (i < 0) {
3678				retval = i;
3679				goto out;
3680			}
3681			for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3682				STp->ps[i].rw = ST_IDLE;
3683				STp->ps[i].at_sm = 0;
3684				STp->ps[i].last_block_valid = 0;
3685			}
3686			STp->partition = STp->new_partition = 0;
3687			STp->nbr_partitions = mtc.mt_count != 0 ? 2 : 1;
3688			STps->drv_block = STps->drv_file = 0;
3689			retval = 0;
3690			goto out;
3691		}
3692
3693		if (mtc.mt_op == MTSEEK) {
3694			i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3695			if (!STp->can_partitions)
3696				STp->ps[0].rw = ST_IDLE;
3697			retval = i;
3698			goto out;
3699		}
3700
3701		if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3702			retval = do_load_unload(STp, file, 0);
3703			goto out;
3704		}
3705
3706		if (mtc.mt_op == MTLOAD) {
3707			retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3708			goto out;
3709		}
3710
3711		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3712			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3713			goto out;
3714		}
3715
3716		if (STp->can_partitions && STp->ready == ST_READY &&
3717		    (i = switch_partition(STp)) < 0) {
3718			retval = i;
3719			goto out;
3720		}
3721
3722		if (mtc.mt_op == MTCOMPRESSION)
3723			retval = st_compression(STp, (mtc.mt_count & 1));
3724		else
3725			retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3726		goto out;
3727	}
3728	if (!STm->defined) {
3729		retval = (-ENXIO);
3730		goto out;
3731	}
3732
3733	if ((i = flush_buffer(STp, 0)) < 0) {
3734		retval = i;
3735		goto out;
3736	}
3737	if (STp->can_partitions &&
3738	    (i = switch_partition(STp)) < 0) {
3739		retval = i;
3740		goto out;
3741	}
3742
3743	if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
3744		struct mtget mt_status;
3745
3746		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3747			 retval = (-EINVAL);
3748			 goto out;
3749		}
3750
3751		mt_status.mt_type = STp->tape_type;
3752		mt_status.mt_dsreg =
3753		    ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3754		    ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3755		mt_status.mt_blkno = STps->drv_block;
3756		mt_status.mt_fileno = STps->drv_file;
3757		if (STp->block_size != 0) {
3758			if (STps->rw == ST_WRITING)
3759				mt_status.mt_blkno +=
3760				    (STp->buffer)->buffer_bytes / STp->block_size;
3761			else if (STps->rw == ST_READING)
3762				mt_status.mt_blkno -=
3763                                        ((STp->buffer)->buffer_bytes +
3764                                         STp->block_size - 1) / STp->block_size;
3765		}
3766
3767		mt_status.mt_gstat = 0;
3768		if (STp->drv_write_prot)
3769			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3770		if (mt_status.mt_blkno == 0) {
3771			if (mt_status.mt_fileno == 0)
3772				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3773			else
3774				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3775		}
3776		mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3777		mt_status.mt_resid = STp->partition;
3778		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3779			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3780		else if (STps->eof >= ST_EOM_OK)
3781			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3782		if (STp->density == 1)
3783			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3784		else if (STp->density == 2)
3785			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3786		else if (STp->density == 3)
3787			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3788		if (STp->ready == ST_READY)
3789			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3790		if (STp->ready == ST_NO_TAPE)
3791			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3792		if (STps->at_sm)
3793			mt_status.mt_gstat |= GMT_SM(0xffffffff);
3794		if (STm->do_async_writes ||
3795                    (STm->do_buffer_writes && STp->block_size != 0) ||
3796		    STp->drv_buffer != 0)
3797			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3798		if (STp->cleaning_req)
3799			mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3800
3801		retval = put_user_mtget(p, &mt_status);
3802		if (retval)
 
3803			goto out;
 
3804
3805		STp->recover_reg = 0;		/* Clear after read */
 
3806		goto out;
3807	}			/* End of MTIOCGET */
3808	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3809		struct mtpos mt_pos;
3810		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3811			 retval = (-EINVAL);
3812			 goto out;
3813		}
3814		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3815			retval = i;
3816			goto out;
3817		}
3818		mt_pos.mt_blkno = blk;
3819		retval = put_user_mtpos(p, &mt_pos);
 
 
3820		goto out;
3821	}
3822	mutex_unlock(&STp->lock);
3823	switch (cmd_in) {
3824		case SCSI_IOCTL_STOP_UNIT:
3825			/* unload */
3826			retval = scsi_ioctl(STp->device, cmd_in, p);
3827			if (!retval) {
3828				STp->rew_at_close = 0;
3829				STp->ready = ST_NO_TAPE;
3830			}
3831			return retval;
3832
3833		case SCSI_IOCTL_GET_IDLUN:
3834		case SCSI_IOCTL_GET_BUS_NUMBER:
3835			break;
3836
3837		default:
3838			if ((cmd_in == SG_IO ||
3839			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3840			     cmd_in == CDROM_SEND_PACKET) &&
3841			    !capable(CAP_SYS_RAWIO))
3842				i = -EPERM;
3843			else
3844				i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3845						   file->f_mode, cmd_in, p);
3846			if (i != -ENOTTY)
3847				return i;
3848			break;
3849	}
3850	return -ENOTTY;
 
 
 
 
 
3851
3852 out:
3853	mutex_unlock(&STp->lock);
3854	return retval;
3855}
3856
3857static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3858{
3859	void __user *p = (void __user *)arg;
3860	struct scsi_tape *STp = file->private_data;
3861	int ret;
3862
3863	ret = st_ioctl_common(file, cmd_in, p);
3864	if (ret != -ENOTTY)
3865		return ret;
3866
3867	return scsi_ioctl(STp->device, cmd_in, p);
3868}
3869
3870#ifdef CONFIG_COMPAT
3871static long st_compat_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3872{
3873	void __user *p = compat_ptr(arg);
3874	struct scsi_tape *STp = file->private_data;
3875	int ret;
3876
3877	/* argument conversion is handled using put_user_mtpos/put_user_mtget */
3878	switch (cmd_in) {
3879	case MTIOCPOS32:
3880		return st_ioctl_common(file, MTIOCPOS, p);
3881	case MTIOCGET32:
3882		return st_ioctl_common(file, MTIOCGET, p);
3883	}
3884
3885	ret = st_ioctl_common(file, cmd_in, p);
3886	if (ret != -ENOTTY)
3887		return ret;
3888
3889	return scsi_compat_ioctl(STp->device, cmd_in, p);
 
3890}
3891#endif
3892
3893
3894
3895/* Try to allocate a new tape buffer. Calling function must not hold
3896   dev_arr_lock. */
3897static struct st_buffer *new_tape_buffer(int max_sg)
3898{
3899	struct st_buffer *tb;
3900
3901	tb = kzalloc(sizeof(struct st_buffer), GFP_KERNEL);
3902	if (!tb) {
3903		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3904		return NULL;
3905	}
3906	tb->frp_segs = 0;
3907	tb->use_sg = max_sg;
 
3908	tb->buffer_size = 0;
3909
3910	tb->reserved_pages = kcalloc(max_sg, sizeof(struct page *),
3911				     GFP_KERNEL);
3912	if (!tb->reserved_pages) {
3913		kfree(tb);
3914		return NULL;
3915	}
3916
3917	return tb;
3918}
3919
3920
3921/* Try to allocate enough space in the tape buffer */
3922#define ST_MAX_ORDER 6
3923
3924static int enlarge_buffer(struct st_buffer * STbuffer, int new_size)
3925{
3926	int segs, max_segs, b_size, order, got;
3927	gfp_t priority;
3928
3929	if (new_size <= STbuffer->buffer_size)
3930		return 1;
3931
3932	if (STbuffer->buffer_size <= PAGE_SIZE)
3933		normalize_buffer(STbuffer);  /* Avoid extra segment */
3934
3935	max_segs = STbuffer->use_sg;
3936
3937	priority = GFP_KERNEL | __GFP_NOWARN;
 
 
3938
3939	if (STbuffer->cleared)
3940		priority |= __GFP_ZERO;
3941
3942	if (STbuffer->frp_segs) {
3943		order = STbuffer->reserved_page_order;
3944		b_size = PAGE_SIZE << order;
3945	} else {
3946		for (b_size = PAGE_SIZE, order = 0;
3947		     order < ST_MAX_ORDER &&
3948			     max_segs * (PAGE_SIZE << order) < new_size;
3949		     order++, b_size *= 2)
3950			;  /* empty */
3951		STbuffer->reserved_page_order = order;
3952	}
3953	if (max_segs * (PAGE_SIZE << order) < new_size) {
3954		if (order == ST_MAX_ORDER)
3955			return 0;
3956		normalize_buffer(STbuffer);
3957		return enlarge_buffer(STbuffer, new_size);
3958	}
3959
3960	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3961	     segs < max_segs && got < new_size;) {
3962		struct page *page;
3963
3964		page = alloc_pages(priority, order);
3965		if (!page) {
3966			DEB(STbuffer->buffer_size = got);
3967			normalize_buffer(STbuffer);
3968			return 0;
3969		}
3970
3971		STbuffer->frp_segs += 1;
3972		got += b_size;
3973		STbuffer->buffer_size = got;
3974		STbuffer->reserved_pages[segs] = page;
3975		segs++;
3976	}
3977	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3978
3979	return 1;
3980}
3981
3982
3983/* Make sure that no data from previous user is in the internal buffer */
3984static void clear_buffer(struct st_buffer * st_bp)
3985{
3986	int i;
3987
3988	for (i=0; i < st_bp->frp_segs; i++)
3989		memset(page_address(st_bp->reserved_pages[i]), 0,
3990		       PAGE_SIZE << st_bp->reserved_page_order);
3991	st_bp->cleared = 1;
3992}
3993
3994
3995/* Release the extra buffer */
3996static void normalize_buffer(struct st_buffer * STbuffer)
3997{
3998	int i, order = STbuffer->reserved_page_order;
3999
4000	for (i = 0; i < STbuffer->frp_segs; i++) {
4001		__free_pages(STbuffer->reserved_pages[i], order);
4002		STbuffer->buffer_size -= (PAGE_SIZE << order);
4003	}
4004	STbuffer->frp_segs = 0;
4005	STbuffer->sg_segs = 0;
4006	STbuffer->reserved_page_order = 0;
4007	STbuffer->map_data.offset = 0;
4008}
4009
4010
4011/* Move data from the user buffer to the tape buffer. Returns zero (success) or
4012   negative error code. */
4013static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
4014{
4015	int i, cnt, res, offset;
4016	int length = PAGE_SIZE << st_bp->reserved_page_order;
4017
4018	for (i = 0, offset = st_bp->buffer_bytes;
4019	     i < st_bp->frp_segs && offset >= length; i++)
4020		offset -= length;
4021	if (i == st_bp->frp_segs) {	/* Should never happen */
4022		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
4023		return (-EIO);
4024	}
4025	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4026		struct page *page = st_bp->reserved_pages[i];
4027		cnt = length - offset < do_count ? length - offset : do_count;
4028		res = copy_from_user(page_address(page) + offset, ubp, cnt);
4029		if (res)
4030			return (-EFAULT);
4031		do_count -= cnt;
4032		st_bp->buffer_bytes += cnt;
4033		ubp += cnt;
4034		offset = 0;
4035	}
4036	if (do_count) /* Should never happen */
4037		return (-EIO);
4038
4039	return 0;
4040}
4041
4042
4043/* Move data from the tape buffer to the user buffer. Returns zero (success) or
4044   negative error code. */
4045static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
4046{
4047	int i, cnt, res, offset;
4048	int length = PAGE_SIZE << st_bp->reserved_page_order;
4049
4050	for (i = 0, offset = st_bp->read_pointer;
4051	     i < st_bp->frp_segs && offset >= length; i++)
4052		offset -= length;
4053	if (i == st_bp->frp_segs) {	/* Should never happen */
4054		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
4055		return (-EIO);
4056	}
4057	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4058		struct page *page = st_bp->reserved_pages[i];
4059		cnt = length - offset < do_count ? length - offset : do_count;
4060		res = copy_to_user(ubp, page_address(page) + offset, cnt);
4061		if (res)
4062			return (-EFAULT);
4063		do_count -= cnt;
4064		st_bp->buffer_bytes -= cnt;
4065		st_bp->read_pointer += cnt;
4066		ubp += cnt;
4067		offset = 0;
4068	}
4069	if (do_count) /* Should never happen */
4070		return (-EIO);
4071
4072	return 0;
4073}
4074
4075
4076/* Move data towards start of buffer */
4077static void move_buffer_data(struct st_buffer * st_bp, int offset)
4078{
4079	int src_seg, dst_seg, src_offset = 0, dst_offset;
4080	int count, total;
4081	int length = PAGE_SIZE << st_bp->reserved_page_order;
4082
4083	if (offset == 0)
4084		return;
4085
4086	total=st_bp->buffer_bytes - offset;
4087	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
4088		src_offset = offset;
4089		if (src_offset < length)
4090			break;
4091		offset -= length;
4092	}
4093
4094	st_bp->buffer_bytes = st_bp->read_pointer = total;
4095	for (dst_seg=dst_offset=0; total > 0; ) {
4096		struct page *dpage = st_bp->reserved_pages[dst_seg];
4097		struct page *spage = st_bp->reserved_pages[src_seg];
4098
4099		count = min(length - dst_offset, length - src_offset);
4100		memmove(page_address(dpage) + dst_offset,
4101			page_address(spage) + src_offset, count);
4102		src_offset += count;
4103		if (src_offset >= length) {
4104			src_seg++;
4105			src_offset = 0;
4106		}
4107		dst_offset += count;
4108		if (dst_offset >= length) {
4109			dst_seg++;
4110			dst_offset = 0;
4111		}
4112		total -= count;
4113	}
4114}
4115
4116/* Validate the options from command line or module parameters */
4117static void validate_options(void)
4118{
4119	if (buffer_kbs > 0)
4120		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
4121	if (max_sg_segs >= ST_FIRST_SG)
4122		st_max_sg_segs = max_sg_segs;
4123}
4124
4125#ifndef MODULE
4126/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
4127 */
4128static int __init st_setup(char *str)
4129{
4130	int i, len, ints[5];
4131	char *stp;
4132
4133	stp = get_options(str, ARRAY_SIZE(ints), ints);
4134
4135	if (ints[0] > 0) {
4136		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
4137			if (parms[i].val)
4138				*parms[i].val = ints[i + 1];
4139	} else {
4140		while (stp != NULL) {
4141			for (i = 0; i < ARRAY_SIZE(parms); i++) {
4142				len = strlen(parms[i].name);
4143				if (!strncmp(stp, parms[i].name, len) &&
4144				    (*(stp + len) == ':' || *(stp + len) == '=')) {
4145					if (parms[i].val)
4146						*parms[i].val =
4147							simple_strtoul(stp + len + 1, NULL, 0);
4148					else
4149						printk(KERN_WARNING "st: Obsolete parameter %s\n",
4150						       parms[i].name);
4151					break;
4152				}
4153			}
4154			if (i >= ARRAY_SIZE(parms))
4155				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
4156					stp);
4157			stp = strchr(stp, ',');
4158			if (stp)
4159				stp++;
4160		}
4161	}
4162
4163	validate_options();
4164
4165	return 1;
4166}
4167
4168__setup("st=", st_setup);
4169
4170#endif
4171
4172static const struct file_operations st_fops =
4173{
4174	.owner =	THIS_MODULE,
4175	.read =		st_read,
4176	.write =	st_write,
4177	.unlocked_ioctl = st_ioctl,
4178#ifdef CONFIG_COMPAT
4179	.compat_ioctl = st_compat_ioctl,
4180#endif
4181	.open =		st_open,
4182	.flush =	st_flush,
4183	.release =	st_release,
4184	.llseek =	noop_llseek,
4185};
4186
4187static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
4188{
4189	int i, error;
4190	dev_t cdev_devno;
4191	struct cdev *cdev;
4192	struct device *dev;
4193	struct st_modedef *STm = &(tape->modes[mode]);
4194	char name[10];
4195	int dev_num = tape->index;
4196
4197	cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
4198
4199	cdev = cdev_alloc();
4200	if (!cdev) {
4201		pr_err("st%d: out of memory. Device not attached.\n", dev_num);
4202		error = -ENOMEM;
4203		goto out;
4204	}
4205	cdev->owner = THIS_MODULE;
4206	cdev->ops = &st_fops;
4207	STm->cdevs[rew] = cdev;
4208
4209	error = cdev_add(cdev, cdev_devno, 1);
4210	if (error) {
4211		pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
4212		       rew ? "non" : "auto", mode);
4213		pr_err("st%d: Device not attached.\n", dev_num);
4214		goto out_free;
4215	}
4216
4217	i = mode << (4 - ST_NBR_MODE_BITS);
4218	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4219		 tape->disk->disk_name, st_formats[i]);
4220
4221	dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
4222			    cdev_devno, &tape->modes[mode], "%s", name);
4223	if (IS_ERR(dev)) {
4224		pr_err("st%d: device_create failed\n", dev_num);
4225		error = PTR_ERR(dev);
4226		goto out_free;
4227	}
4228
4229	STm->devs[rew] = dev;
4230
4231	return 0;
4232out_free:
4233	cdev_del(STm->cdevs[rew]);
4234out:
4235	STm->cdevs[rew] = NULL;
4236	STm->devs[rew] = NULL;
4237	return error;
4238}
4239
4240static int create_cdevs(struct scsi_tape *tape)
4241{
4242	int mode, error;
4243	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4244		error = create_one_cdev(tape, mode, 0);
4245		if (error)
4246			return error;
4247		error = create_one_cdev(tape, mode, 1);
4248		if (error)
4249			return error;
4250	}
4251
4252	return sysfs_create_link(&tape->device->sdev_gendev.kobj,
4253				 &tape->modes[0].devs[0]->kobj, "tape");
4254}
4255
4256static void remove_cdevs(struct scsi_tape *tape)
4257{
4258	int mode, rew;
4259	sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
4260	for (mode = 0; mode < ST_NBR_MODES; mode++) {
4261		struct st_modedef *STm = &(tape->modes[mode]);
4262		for (rew = 0; rew < 2; rew++) {
4263			if (STm->cdevs[rew])
4264				cdev_del(STm->cdevs[rew]);
4265			if (STm->devs[rew])
4266				device_unregister(STm->devs[rew]);
4267		}
4268	}
4269}
4270
4271static int st_probe(struct device *dev)
4272{
4273	struct scsi_device *SDp = to_scsi_device(dev);
4274	struct gendisk *disk = NULL;
4275	struct scsi_tape *tpnt = NULL;
4276	struct st_modedef *STm;
4277	struct st_partstat *STps;
4278	struct st_buffer *buffer;
4279	int i, error;
4280	char *stp;
4281
4282	if (SDp->type != TYPE_TAPE)
4283		return -ENODEV;
4284	if ((stp = st_incompatible(SDp))) {
4285		sdev_printk(KERN_INFO, SDp,
4286			    "OnStream tapes are no longer supported;\n");
4287		sdev_printk(KERN_INFO, SDp,
4288			    "please mail to linux-scsi@vger.kernel.org.\n");
4289		return -ENODEV;
4290	}
4291
4292	scsi_autopm_get_device(SDp);
4293	i = queue_max_segments(SDp->request_queue);
4294	if (st_max_sg_segs < i)
4295		i = st_max_sg_segs;
4296	buffer = new_tape_buffer(i);
4297	if (buffer == NULL) {
4298		sdev_printk(KERN_ERR, SDp,
4299			    "st: Can't allocate new tape buffer. "
4300			    "Device not attached.\n");
4301		goto out;
4302	}
4303
4304	disk = alloc_disk(1);
4305	if (!disk) {
4306		sdev_printk(KERN_ERR, SDp,
4307			    "st: out of memory. Device not attached.\n");
4308		goto out_buffer_free;
4309	}
4310
4311	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_KERNEL);
4312	if (tpnt == NULL) {
4313		sdev_printk(KERN_ERR, SDp,
4314			    "st: Can't allocate device descriptor.\n");
4315		goto out_put_disk;
4316	}
4317	kref_init(&tpnt->kref);
4318	tpnt->disk = disk;
4319	disk->private_data = &tpnt->driver;
4320	/* SCSI tape doesn't register this gendisk via add_disk().  Manually
4321	 * take queue reference that release_disk() expects. */
4322	if (!blk_get_queue(SDp->request_queue))
4323		goto out_put_disk;
4324	disk->queue = SDp->request_queue;
4325	tpnt->driver = &st_template;
4326
4327	tpnt->device = SDp;
4328	if (SDp->scsi_level <= 2)
4329		tpnt->tape_type = MT_ISSCSI1;
4330	else
4331		tpnt->tape_type = MT_ISSCSI2;
4332
4333	tpnt->buffer = buffer;
4334	tpnt->buffer->last_SRpnt = NULL;
4335
4336	tpnt->inited = 0;
4337	tpnt->dirty = 0;
4338	tpnt->in_use = 0;
4339	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
 
4340	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4341	tpnt->density = 0;
4342	tpnt->do_auto_lock = ST_AUTO_LOCK;
4343	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4344	tpnt->can_partitions = 0;
4345	tpnt->two_fm = ST_TWO_FM;
4346	tpnt->fast_mteom = ST_FAST_MTEOM;
4347	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4348	tpnt->sili = ST_SILI;
4349	tpnt->immediate = ST_NOWAIT;
4350	tpnt->immediate_filemark = 0;
4351	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4352	tpnt->partition = 0;
4353	tpnt->new_partition = 0;
4354	tpnt->nbr_partitions = 0;
4355	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4356	tpnt->long_timeout = ST_LONG_TIMEOUT;
4357	tpnt->try_dio = try_direct_io;
4358
4359	for (i = 0; i < ST_NBR_MODES; i++) {
4360		STm = &(tpnt->modes[i]);
4361		STm->defined = 0;
4362		STm->sysv = ST_SYSV;
4363		STm->defaults_for_writes = 0;
4364		STm->do_async_writes = ST_ASYNC_WRITES;
4365		STm->do_buffer_writes = ST_BUFFER_WRITES;
4366		STm->do_read_ahead = ST_READ_AHEAD;
4367		STm->default_compression = ST_DONT_TOUCH;
4368		STm->default_blksize = (-1);	/* No forced size */
4369		STm->default_density = (-1);	/* No forced density */
4370		STm->tape = tpnt;
4371	}
4372
4373	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4374		STps = &(tpnt->ps[i]);
4375		STps->rw = ST_IDLE;
4376		STps->eof = ST_NOEOF;
4377		STps->at_sm = 0;
4378		STps->last_block_valid = 0;
4379		STps->drv_block = (-1);
4380		STps->drv_file = (-1);
4381	}
4382
4383	tpnt->current_mode = 0;
4384	tpnt->modes[0].defined = 1;
4385
4386	tpnt->density_changed = tpnt->compression_changed =
4387	    tpnt->blksize_changed = 0;
4388	mutex_init(&tpnt->lock);
4389
4390	idr_preload(GFP_KERNEL);
4391	spin_lock(&st_index_lock);
4392	error = idr_alloc(&st_index_idr, tpnt, 0, ST_MAX_TAPES + 1, GFP_NOWAIT);
4393	spin_unlock(&st_index_lock);
4394	idr_preload_end();
4395	if (error < 0) {
4396		pr_warn("st: idr allocation failed: %d\n", error);
4397		goto out_put_queue;
4398	}
4399	tpnt->index = error;
4400	sprintf(disk->disk_name, "st%d", tpnt->index);
4401	tpnt->stats = kzalloc(sizeof(struct scsi_tape_stats), GFP_KERNEL);
4402	if (tpnt->stats == NULL) {
4403		sdev_printk(KERN_ERR, SDp,
4404			    "st: Can't allocate statistics.\n");
4405		goto out_idr_remove;
4406	}
4407
4408	dev_set_drvdata(dev, tpnt);
4409
4410
4411	error = create_cdevs(tpnt);
4412	if (error)
4413		goto out_remove_devs;
4414	scsi_autopm_put_device(SDp);
4415
4416	sdev_printk(KERN_NOTICE, SDp,
4417		    "Attached scsi tape %s\n", tape_name(tpnt));
4418	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4419		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4420		    queue_dma_alignment(SDp->request_queue) + 1);
4421
4422	return 0;
4423
4424out_remove_devs:
4425	remove_cdevs(tpnt);
4426	kfree(tpnt->stats);
4427out_idr_remove:
4428	spin_lock(&st_index_lock);
4429	idr_remove(&st_index_idr, tpnt->index);
4430	spin_unlock(&st_index_lock);
4431out_put_queue:
4432	blk_put_queue(disk->queue);
4433out_put_disk:
4434	put_disk(disk);
4435	kfree(tpnt);
4436out_buffer_free:
4437	kfree(buffer);
4438out:
4439	scsi_autopm_put_device(SDp);
4440	return -ENODEV;
4441};
4442
4443
4444static int st_remove(struct device *dev)
4445{
4446	struct scsi_tape *tpnt = dev_get_drvdata(dev);
4447	int index = tpnt->index;
4448
4449	scsi_autopm_get_device(to_scsi_device(dev));
4450	remove_cdevs(tpnt);
4451
4452	mutex_lock(&st_ref_mutex);
4453	kref_put(&tpnt->kref, scsi_tape_release);
4454	mutex_unlock(&st_ref_mutex);
4455	spin_lock(&st_index_lock);
4456	idr_remove(&st_index_idr, index);
4457	spin_unlock(&st_index_lock);
4458	return 0;
4459}
4460
4461/**
4462 *      scsi_tape_release - Called to free the Scsi_Tape structure
4463 *      @kref: pointer to embedded kref
4464 *
4465 *      st_ref_mutex must be held entering this routine.  Because it is
4466 *      called on last put, you should always use the scsi_tape_get()
4467 *      scsi_tape_put() helpers which manipulate the semaphore directly
4468 *      and never do a direct kref_put().
4469 **/
4470static void scsi_tape_release(struct kref *kref)
4471{
4472	struct scsi_tape *tpnt = to_scsi_tape(kref);
4473	struct gendisk *disk = tpnt->disk;
4474
4475	tpnt->device = NULL;
4476
4477	if (tpnt->buffer) {
4478		normalize_buffer(tpnt->buffer);
4479		kfree(tpnt->buffer->reserved_pages);
4480		kfree(tpnt->buffer);
4481	}
4482
4483	disk->private_data = NULL;
4484	put_disk(disk);
4485	kfree(tpnt->stats);
4486	kfree(tpnt);
4487	return;
4488}
4489
4490static struct class st_sysfs_class = {
4491	.name = "scsi_tape",
4492	.dev_groups = st_dev_groups,
4493};
4494
4495static int __init init_st(void)
4496{
4497	int err;
4498
4499	validate_options();
4500
4501	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4502		verstr, st_fixed_buffer_size, st_max_sg_segs);
4503
4504	debugging = (debug_flag > 0) ? debug_flag : NO_DEBUG;
4505	if (debugging) {
4506		printk(KERN_INFO "st: Debugging enabled debug_flag = %d\n",
4507			debugging);
4508	}
4509
4510	err = class_register(&st_sysfs_class);
4511	if (err) {
4512		pr_err("Unable register sysfs class for SCSI tapes\n");
4513		return err;
4514	}
4515
4516	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4517				     ST_MAX_TAPE_ENTRIES, "st");
4518	if (err) {
4519		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4520		       SCSI_TAPE_MAJOR);
4521		goto err_class;
4522	}
4523
4524	err = scsi_register_driver(&st_template.gendrv);
4525	if (err)
4526		goto err_chrdev;
4527
4528	return 0;
4529
4530err_chrdev:
4531	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4532				 ST_MAX_TAPE_ENTRIES);
4533err_class:
4534	class_unregister(&st_sysfs_class);
4535	return err;
4536}
4537
4538static void __exit exit_st(void)
4539{
4540	scsi_unregister_driver(&st_template.gendrv);
4541	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4542				 ST_MAX_TAPE_ENTRIES);
4543	class_unregister(&st_sysfs_class);
4544	idr_destroy(&st_index_idr);
4545	printk(KERN_INFO "st: Unloaded.\n");
4546}
4547
4548module_init(init_st);
4549module_exit(exit_st);
4550
4551
4552/* The sysfs driver interface. Read-only at the moment */
4553static ssize_t try_direct_io_show(struct device_driver *ddp, char *buf)
4554{
4555	return scnprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4556}
4557static DRIVER_ATTR_RO(try_direct_io);
4558
4559static ssize_t fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4560{
4561	return scnprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4562}
4563static DRIVER_ATTR_RO(fixed_buffer_size);
4564
4565static ssize_t max_sg_segs_show(struct device_driver *ddp, char *buf)
4566{
4567	return scnprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4568}
4569static DRIVER_ATTR_RO(max_sg_segs);
4570
4571static ssize_t version_show(struct device_driver *ddd, char *buf)
4572{
4573	return scnprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4574}
4575static DRIVER_ATTR_RO(version);
4576
4577#if DEBUG
4578static ssize_t debug_flag_store(struct device_driver *ddp,
4579	const char *buf, size_t count)
4580{
4581/* We only care what the first byte of the data is the rest is unused.
4582 * if it's a '1' we turn on debug and if it's a '0' we disable it. All
4583 * other values have -EINVAL returned if they are passed in.
4584 */
4585	if (count > 0) {
4586		if (buf[0] == '0') {
4587			debugging = NO_DEBUG;
4588			return count;
4589		} else if (buf[0] == '1') {
4590			debugging = 1;
4591			return count;
4592		}
4593	}
4594	return -EINVAL;
4595}
4596
4597static ssize_t debug_flag_show(struct device_driver *ddp, char *buf)
4598{
4599	return scnprintf(buf, PAGE_SIZE, "%d\n", debugging);
4600}
4601static DRIVER_ATTR_RW(debug_flag);
4602#endif
4603
4604static struct attribute *st_drv_attrs[] = {
4605	&driver_attr_try_direct_io.attr,
4606	&driver_attr_fixed_buffer_size.attr,
4607	&driver_attr_max_sg_segs.attr,
4608	&driver_attr_version.attr,
4609#if DEBUG
4610	&driver_attr_debug_flag.attr,
4611#endif
4612	NULL,
4613};
4614ATTRIBUTE_GROUPS(st_drv);
4615
4616/* The sysfs simple class interface */
4617static ssize_t
4618defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4619{
4620	struct st_modedef *STm = dev_get_drvdata(dev);
4621	ssize_t l = 0;
4622
4623	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4624	return l;
4625}
4626static DEVICE_ATTR_RO(defined);
4627
4628static ssize_t
4629default_blksize_show(struct device *dev, struct device_attribute *attr,
4630		     char *buf)
4631{
4632	struct st_modedef *STm = dev_get_drvdata(dev);
4633	ssize_t l = 0;
4634
4635	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4636	return l;
4637}
4638static DEVICE_ATTR_RO(default_blksize);
4639
4640static ssize_t
4641default_density_show(struct device *dev, struct device_attribute *attr,
4642		     char *buf)
4643{
4644	struct st_modedef *STm = dev_get_drvdata(dev);
4645	ssize_t l = 0;
4646	char *fmt;
4647
4648	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4649	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4650	return l;
4651}
4652static DEVICE_ATTR_RO(default_density);
4653
4654static ssize_t
4655default_compression_show(struct device *dev, struct device_attribute *attr,
4656			 char *buf)
4657{
4658	struct st_modedef *STm = dev_get_drvdata(dev);
4659	ssize_t l = 0;
4660
4661	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4662	return l;
4663}
4664static DEVICE_ATTR_RO(default_compression);
4665
4666static ssize_t
4667options_show(struct device *dev, struct device_attribute *attr, char *buf)
4668{
4669	struct st_modedef *STm = dev_get_drvdata(dev);
4670	struct scsi_tape *STp = STm->tape;
4671	int options;
4672	ssize_t l = 0;
4673
4674	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4675	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4676	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4677	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4678	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4679	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4680	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4681	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4682	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4683	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4684	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4685	options |= STm->sysv ? MT_ST_SYSV : 0;
4686	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4687	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4688	options |= STp->sili ? MT_ST_SILI : 0;
4689
4690	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4691	return l;
4692}
4693static DEVICE_ATTR_RO(options);
4694
4695/* Support for tape stats */
4696
4697/**
4698 * read_cnt_show - return read count - count of reads made from tape drive
4699 * @dev: struct device
4700 * @attr: attribute structure
4701 * @buf: buffer to return formatted data in
4702 */
4703static ssize_t read_cnt_show(struct device *dev,
4704	struct device_attribute *attr, char *buf)
4705{
4706	struct st_modedef *STm = dev_get_drvdata(dev);
4707
4708	return sprintf(buf, "%lld",
4709		       (long long)atomic64_read(&STm->tape->stats->read_cnt));
4710}
4711static DEVICE_ATTR_RO(read_cnt);
4712
4713/**
4714 * read_byte_cnt_show - return read byte count - tape drives
4715 * may use blocks less than 512 bytes this gives the raw byte count of
4716 * of data read from the tape drive.
4717 * @dev: struct device
4718 * @attr: attribute structure
4719 * @buf: buffer to return formatted data in
4720 */
4721static ssize_t read_byte_cnt_show(struct device *dev,
4722	struct device_attribute *attr, char *buf)
4723{
4724	struct st_modedef *STm = dev_get_drvdata(dev);
4725
4726	return sprintf(buf, "%lld",
4727		       (long long)atomic64_read(&STm->tape->stats->read_byte_cnt));
4728}
4729static DEVICE_ATTR_RO(read_byte_cnt);
4730
4731/**
4732 * read_ns_show - return read ns - overall time spent waiting on reads in ns.
4733 * @dev: struct device
4734 * @attr: attribute structure
4735 * @buf: buffer to return formatted data in
4736 */
4737static ssize_t read_ns_show(struct device *dev,
4738	struct device_attribute *attr, char *buf)
4739{
4740	struct st_modedef *STm = dev_get_drvdata(dev);
4741
4742	return sprintf(buf, "%lld",
4743		       (long long)atomic64_read(&STm->tape->stats->tot_read_time));
4744}
4745static DEVICE_ATTR_RO(read_ns);
4746
4747/**
4748 * write_cnt_show - write count - number of user calls
4749 * to write(2) that have written data to tape.
4750 * @dev: struct device
4751 * @attr: attribute structure
4752 * @buf: buffer to return formatted data in
4753 */
4754static ssize_t write_cnt_show(struct device *dev,
4755	struct device_attribute *attr, char *buf)
4756{
4757	struct st_modedef *STm = dev_get_drvdata(dev);
4758
4759	return sprintf(buf, "%lld",
4760		       (long long)atomic64_read(&STm->tape->stats->write_cnt));
4761}
4762static DEVICE_ATTR_RO(write_cnt);
4763
4764/**
4765 * write_byte_cnt_show - write byte count - raw count of
4766 * bytes written to tape.
4767 * @dev: struct device
4768 * @attr: attribute structure
4769 * @buf: buffer to return formatted data in
4770 */
4771static ssize_t write_byte_cnt_show(struct device *dev,
4772	struct device_attribute *attr, char *buf)
4773{
4774	struct st_modedef *STm = dev_get_drvdata(dev);
4775
4776	return sprintf(buf, "%lld",
4777		       (long long)atomic64_read(&STm->tape->stats->write_byte_cnt));
4778}
4779static DEVICE_ATTR_RO(write_byte_cnt);
4780
4781/**
4782 * write_ns_show - write ns - number of nanoseconds waiting on write
4783 * requests to complete.
4784 * @dev: struct device
4785 * @attr: attribute structure
4786 * @buf: buffer to return formatted data in
4787 */
4788static ssize_t write_ns_show(struct device *dev,
4789	struct device_attribute *attr, char *buf)
4790{
4791	struct st_modedef *STm = dev_get_drvdata(dev);
4792
4793	return sprintf(buf, "%lld",
4794		       (long long)atomic64_read(&STm->tape->stats->tot_write_time));
4795}
4796static DEVICE_ATTR_RO(write_ns);
4797
4798/**
4799 * in_flight_show - number of I/Os currently in flight -
4800 * in most cases this will be either 0 or 1. It may be higher if someone
4801 * has also issued other SCSI commands such as via an ioctl.
4802 * @dev: struct device
4803 * @attr: attribute structure
4804 * @buf: buffer to return formatted data in
4805 */
4806static ssize_t in_flight_show(struct device *dev,
4807	struct device_attribute *attr, char *buf)
4808{
4809	struct st_modedef *STm = dev_get_drvdata(dev);
4810
4811	return sprintf(buf, "%lld",
4812		       (long long)atomic64_read(&STm->tape->stats->in_flight));
4813}
4814static DEVICE_ATTR_RO(in_flight);
4815
4816/**
4817 * io_ns_show - io wait ns - this is the number of ns spent
4818 * waiting on all I/O to complete. This includes tape movement commands
4819 * such as rewinding, seeking to end of file or tape, it also includes
4820 * read and write. To determine the time spent on tape movement
4821 * subtract the read and write ns from this value.
4822 * @dev: struct device
4823 * @attr: attribute structure
4824 * @buf: buffer to return formatted data in
4825 */
4826static ssize_t io_ns_show(struct device *dev,
4827	struct device_attribute *attr, char *buf)
4828{
4829	struct st_modedef *STm = dev_get_drvdata(dev);
4830
4831	return sprintf(buf, "%lld",
4832		       (long long)atomic64_read(&STm->tape->stats->tot_io_time));
4833}
4834static DEVICE_ATTR_RO(io_ns);
4835
4836/**
4837 * other_cnt_show - other io count - this is the number of
4838 * I/O requests other than read and write requests.
4839 * Typically these are tape movement requests but will include driver
4840 * tape movement. This includes only requests issued by the st driver.
4841 * @dev: struct device
4842 * @attr: attribute structure
4843 * @buf: buffer to return formatted data in
4844 */
4845static ssize_t other_cnt_show(struct device *dev,
4846	struct device_attribute *attr, char *buf)
4847{
4848	struct st_modedef *STm = dev_get_drvdata(dev);
4849
4850	return sprintf(buf, "%lld",
4851		       (long long)atomic64_read(&STm->tape->stats->other_cnt));
4852}
4853static DEVICE_ATTR_RO(other_cnt);
4854
4855/**
4856 * resid_cnt_show - A count of the number of times we get a residual
4857 * count - this should indicate someone issuing reads larger than the
4858 * block size on tape.
4859 * @dev: struct device
4860 * @attr: attribute structure
4861 * @buf: buffer to return formatted data in
4862 */
4863static ssize_t resid_cnt_show(struct device *dev,
4864	struct device_attribute *attr, char *buf)
4865{
4866	struct st_modedef *STm = dev_get_drvdata(dev);
4867
4868	return sprintf(buf, "%lld",
4869		       (long long)atomic64_read(&STm->tape->stats->resid_cnt));
4870}
4871static DEVICE_ATTR_RO(resid_cnt);
4872
4873static struct attribute *st_dev_attrs[] = {
4874	&dev_attr_defined.attr,
4875	&dev_attr_default_blksize.attr,
4876	&dev_attr_default_density.attr,
4877	&dev_attr_default_compression.attr,
4878	&dev_attr_options.attr,
4879	NULL,
4880};
4881
4882static struct attribute *st_stats_attrs[] = {
4883	&dev_attr_read_cnt.attr,
4884	&dev_attr_read_byte_cnt.attr,
4885	&dev_attr_read_ns.attr,
4886	&dev_attr_write_cnt.attr,
4887	&dev_attr_write_byte_cnt.attr,
4888	&dev_attr_write_ns.attr,
4889	&dev_attr_in_flight.attr,
4890	&dev_attr_io_ns.attr,
4891	&dev_attr_other_cnt.attr,
4892	&dev_attr_resid_cnt.attr,
4893	NULL,
4894};
4895
4896static struct attribute_group stats_group = {
4897	.name = "stats",
4898	.attrs = st_stats_attrs,
4899};
4900
4901static struct attribute_group st_group = {
4902	.attrs = st_dev_attrs,
4903};
4904
4905static const struct attribute_group *st_dev_groups[] = {
4906	&st_group,
4907	&stats_group,
4908	NULL,
4909};
4910
4911/* The following functions may be useful for a larger audience. */
4912static int sgl_map_user_pages(struct st_buffer *STbp,
4913			      const unsigned int max_pages, unsigned long uaddr,
4914			      size_t count, int rw)
4915{
4916	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4917	unsigned long start = uaddr >> PAGE_SHIFT;
4918	const int nr_pages = end - start;
4919	int res, i;
4920	struct page **pages;
4921	struct rq_map_data *mdata = &STbp->map_data;
4922
4923	/* User attempted Overflow! */
4924	if ((uaddr + count) < uaddr)
4925		return -EINVAL;
4926
4927	/* Too big */
4928        if (nr_pages > max_pages)
4929		return -ENOMEM;
4930
4931	/* Hmm? */
4932	if (count == 0)
4933		return 0;
4934
4935	pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
4936	if (pages == NULL)
4937		return -ENOMEM;
4938
4939        /* Try to fault in all of the necessary pages */
4940        /* rw==READ means read from drive, write into memory area */
4941	res = pin_user_pages_fast(uaddr, nr_pages, rw == READ ? FOLL_WRITE : 0,
4942				  pages);
4943
4944	/* Errors and no page mapped should return here */
4945	if (res < nr_pages)
4946		goto out_unmap;
4947
4948        for (i=0; i < nr_pages; i++) {
4949                /* FIXME: flush superflous for rw==READ,
4950                 * probably wrong function for rw==WRITE
4951                 */
4952		flush_dcache_page(pages[i]);
4953        }
4954
4955	mdata->offset = uaddr & ~PAGE_MASK;
4956	STbp->mapped_pages = pages;
4957
4958	return nr_pages;
4959 out_unmap:
4960	if (res > 0) {
4961		unpin_user_pages(pages, res);
 
4962		res = 0;
4963	}
4964	kfree(pages);
4965	return res;
4966}
4967
4968
4969/* And unmap them... */
4970static int sgl_unmap_user_pages(struct st_buffer *STbp,
4971				const unsigned int nr_pages, int dirtied)
4972{
4973	/* FIXME: cache flush missing for rw==READ */
4974	unpin_user_pages_dirty_lock(STbp->mapped_pages, nr_pages, dirtied);
4975
 
 
 
 
 
 
 
 
 
 
4976	kfree(STbp->mapped_pages);
4977	STbp->mapped_pages = NULL;
4978
4979	return 0;
4980}
v5.4
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3   SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
   4   file Documentation/scsi/st.txt for more information.
   5
   6   History:
   7   Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
   8   Contribution and ideas from several people including (in alphabetical
   9   order) Klaus Ehrenfried, Eugene Exarevsky, Eric Lee Green, Wolfgang Denk,
  10   Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
  11   Michael Schaefer, J"org Weule, and Eric Youngdale.
  12
  13   Copyright 1992 - 2016 Kai Makisara
  14   email Kai.Makisara@kolumbus.fi
  15
  16   Some small formal changes - aeb, 950809
  17
  18   Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
  19 */
  20
  21static const char *verstr = "20160209";
  22
  23#include <linux/module.h>
  24
 
  25#include <linux/fs.h>
  26#include <linux/kernel.h>
  27#include <linux/sched/signal.h>
  28#include <linux/mm.h>
  29#include <linux/init.h>
  30#include <linux/string.h>
  31#include <linux/slab.h>
  32#include <linux/errno.h>
  33#include <linux/mtio.h>
  34#include <linux/cdrom.h>
  35#include <linux/ioctl.h>
  36#include <linux/fcntl.h>
  37#include <linux/spinlock.h>
  38#include <linux/blkdev.h>
  39#include <linux/moduleparam.h>
  40#include <linux/cdev.h>
  41#include <linux/idr.h>
  42#include <linux/delay.h>
  43#include <linux/mutex.h>
  44
  45#include <linux/uaccess.h>
  46#include <asm/dma.h>
 
  47
  48#include <scsi/scsi.h>
  49#include <scsi/scsi_dbg.h>
  50#include <scsi/scsi_device.h>
  51#include <scsi/scsi_driver.h>
  52#include <scsi/scsi_eh.h>
  53#include <scsi/scsi_host.h>
  54#include <scsi/scsi_ioctl.h>
  55#include <scsi/sg.h>
  56
  57
  58/* The driver prints some debugging information on the console if DEBUG
  59   is defined and non-zero. */
  60#define DEBUG 1
  61#define NO_DEBUG 0
  62
  63#define ST_DEB_MSG  KERN_NOTICE
  64#if DEBUG
  65/* The message level for the debug messages is currently set to KERN_NOTICE
  66   so that people can easily see the messages. Later when the debugging messages
  67   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
  68#define DEB(a) a
  69#define DEBC(a) if (debugging) { a ; }
  70#else
  71#define DEB(a)
  72#define DEBC(a)
  73#endif
  74
  75#define ST_KILOBYTE 1024
  76
  77#include "st_options.h"
  78#include "st.h"
  79
  80static int buffer_kbs;
  81static int max_sg_segs;
  82static int try_direct_io = TRY_DIRECT_IO;
  83static int try_rdio = 1;
  84static int try_wdio = 1;
  85static int debug_flag;
  86
  87static struct class st_sysfs_class;
  88static const struct attribute_group *st_dev_groups[];
  89static const struct attribute_group *st_drv_groups[];
  90
  91MODULE_AUTHOR("Kai Makisara");
  92MODULE_DESCRIPTION("SCSI tape (st) driver");
  93MODULE_LICENSE("GPL");
  94MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  95MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  96
  97/* Set 'perm' (4th argument) to 0 to disable module_param's definition
  98 * of sysfs parameters (which module_param doesn't yet support).
  99 * Sysfs parameters defined explicitly later.
 100 */
 101module_param_named(buffer_kbs, buffer_kbs, int, 0);
 102MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
 103module_param_named(max_sg_segs, max_sg_segs, int, 0);
 104MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 105module_param_named(try_direct_io, try_direct_io, int, 0);
 106MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 107module_param_named(debug_flag, debug_flag, int, 0);
 108MODULE_PARM_DESC(debug_flag, "Enable DEBUG, same as setting debugging=1");
 109
 110
 111/* Extra parameters for testing */
 112module_param_named(try_rdio, try_rdio, int, 0);
 113MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 114module_param_named(try_wdio, try_wdio, int, 0);
 115MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 116
 117#ifndef MODULE
 118static int write_threshold_kbs;  /* retained for compatibility */
 119static struct st_dev_parm {
 120	char *name;
 121	int *val;
 122} parms[] __initdata = {
 123	{
 124		"buffer_kbs", &buffer_kbs
 125	},
 126	{       /* Retained for compatibility with 2.4 */
 127		"write_threshold_kbs", &write_threshold_kbs
 128	},
 129	{
 130		"max_sg_segs", NULL
 131	},
 132	{
 133		"try_direct_io", &try_direct_io
 134	},
 135	{
 136		"debug_flag", &debug_flag
 137	}
 138};
 139#endif
 140
 141/* Restrict the number of modes so that names for all are assigned */
 142#if ST_NBR_MODES > 16
 143#error "Maximum number of modes is 16"
 144#endif
 145/* Bit reversed order to get same names for same minors with all
 146   mode counts */
 147static const char *st_formats[] = {
 148	"",  "r", "k", "s", "l", "t", "o", "u",
 149	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 150
 151/* The default definitions have been moved to st_options.h */
 152
 153#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 154
 155/* The buffer size should fit into the 24 bits for length in the
 156   6-byte SCSI read and write commands. */
 157#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 158#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 159#endif
 160
 161static int debugging = DEBUG;
 162
 163#define MAX_RETRIES 0
 164#define MAX_WRITE_RETRIES 0
 165#define MAX_READY_RETRIES 0
 166#define NO_TAPE  NOT_READY
 167
 168#define ST_TIMEOUT (900 * HZ)
 169#define ST_LONG_TIMEOUT (14000 * HZ)
 170
 171/* Remove mode bits and auto-rewind bit (7) */
 172#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 173	(iminor(x) & ((1 << ST_MODE_SHIFT)-1)))
 174#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 175
 176/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 177#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 178  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 179
 180/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 181   24 bits) */
 182#define SET_DENS_AND_BLK 0x10001
 183
 184static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 185static int st_max_sg_segs = ST_MAX_SG;
 186
 187static int modes_defined;
 188
 189static int enlarge_buffer(struct st_buffer *, int, int);
 190static void clear_buffer(struct st_buffer *);
 191static void normalize_buffer(struct st_buffer *);
 192static int append_to_buffer(const char __user *, struct st_buffer *, int);
 193static int from_buffer(struct st_buffer *, char __user *, int);
 194static void move_buffer_data(struct st_buffer *, int);
 195
 196static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 197			      unsigned long, size_t, int);
 198static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 199
 200static int st_probe(struct device *);
 201static int st_remove(struct device *);
 202
 203static struct scsi_driver st_template = {
 204	.gendrv = {
 205		.name		= "st",
 206		.owner		= THIS_MODULE,
 207		.probe		= st_probe,
 208		.remove		= st_remove,
 209		.groups		= st_drv_groups,
 210	},
 211};
 212
 213static int st_compression(struct scsi_tape *, int);
 214
 215static int find_partition(struct scsi_tape *);
 216static int switch_partition(struct scsi_tape *);
 217
 218static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 219
 220static void scsi_tape_release(struct kref *);
 221
 222#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 223
 224static DEFINE_MUTEX(st_ref_mutex);
 225static DEFINE_SPINLOCK(st_index_lock);
 226static DEFINE_SPINLOCK(st_use_lock);
 227static DEFINE_IDR(st_index_idr);
 228
 229
 230
 231#ifndef SIGS_FROM_OSST
 232#define SIGS_FROM_OSST \
 233	{"OnStream", "SC-", "", "osst"}, \
 234	{"OnStream", "DI-", "", "osst"}, \
 235	{"OnStream", "DP-", "", "osst"}, \
 236	{"OnStream", "USB", "", "osst"}, \
 237	{"OnStream", "FW-", "", "osst"}
 238#endif
 239
 240static struct scsi_tape *scsi_tape_get(int dev)
 241{
 242	struct scsi_tape *STp = NULL;
 243
 244	mutex_lock(&st_ref_mutex);
 245	spin_lock(&st_index_lock);
 246
 247	STp = idr_find(&st_index_idr, dev);
 248	if (!STp) goto out;
 249
 250	kref_get(&STp->kref);
 251
 252	if (!STp->device)
 253		goto out_put;
 254
 255	if (scsi_device_get(STp->device))
 256		goto out_put;
 257
 258	goto out;
 259
 260out_put:
 261	kref_put(&STp->kref, scsi_tape_release);
 262	STp = NULL;
 263out:
 264	spin_unlock(&st_index_lock);
 265	mutex_unlock(&st_ref_mutex);
 266	return STp;
 267}
 268
 269static void scsi_tape_put(struct scsi_tape *STp)
 270{
 271	struct scsi_device *sdev = STp->device;
 272
 273	mutex_lock(&st_ref_mutex);
 274	kref_put(&STp->kref, scsi_tape_release);
 275	scsi_device_put(sdev);
 276	mutex_unlock(&st_ref_mutex);
 277}
 278
 279struct st_reject_data {
 280	char *vendor;
 281	char *model;
 282	char *rev;
 283	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 284};
 285
 286static struct st_reject_data reject_list[] = {
 287	/* {"XXX", "Yy-", "", NULL},  example */
 288	SIGS_FROM_OSST,
 289	{NULL, }};
 290
 291/* If the device signature is on the list of incompatible drives, the
 292   function returns a pointer to the name of the correct driver (if known) */
 293static char * st_incompatible(struct scsi_device* SDp)
 294{
 295	struct st_reject_data *rp;
 296
 297	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 298		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 299		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 300		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 301			if (rp->driver_hint)
 302				return rp->driver_hint;
 303			else
 304				return "unknown";
 305		}
 306	return NULL;
 307}
 308
 309
 310static inline char *tape_name(struct scsi_tape *tape)
 311{
 312	return tape->disk->disk_name;
 313}
 314
 315#define st_printk(prefix, t, fmt, a...) \
 316	sdev_prefix_printk(prefix, (t)->device, tape_name(t), fmt, ##a)
 317#ifdef DEBUG
 318#define DEBC_printk(t, fmt, a...) \
 319	if (debugging) { st_printk(ST_DEB_MSG, t, fmt, ##a ); }
 320#else
 321#define DEBC_printk(t, fmt, a...)
 322#endif
 323
 324static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 325{
 326	const u8 *ucp;
 327	const u8 *sense = SRpnt->sense;
 328
 329	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 330				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 331	s->flags = 0;
 332
 333	if (s->have_sense) {
 334		s->deferred = 0;
 335		s->remainder_valid =
 336			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 337		switch (sense[0] & 0x7f) {
 338		case 0x71:
 339			s->deferred = 1;
 340			/* fall through */
 341		case 0x70:
 342			s->fixed_format = 1;
 343			s->flags = sense[2] & 0xe0;
 344			break;
 345		case 0x73:
 346			s->deferred = 1;
 347			/* fall through */
 348		case 0x72:
 349			s->fixed_format = 0;
 350			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 351			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 352			break;
 353		}
 354	}
 355}
 356
 357
 358/* Convert the result to success code */
 359static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 360{
 361	int result = SRpnt->result;
 362	u8 scode;
 363	DEB(const char *stp;)
 364	char *name = tape_name(STp);
 365	struct st_cmdstatus *cmdstatp;
 366
 367	if (!result)
 368		return 0;
 369
 370	cmdstatp = &STp->buffer->cmdstat;
 371	st_analyze_sense(SRpnt, cmdstatp);
 372
 373	if (cmdstatp->have_sense)
 374		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 375	else
 376		scode = 0;
 377
 378	DEB(
 379	if (debugging) {
 380		st_printk(ST_DEB_MSG, STp,
 381			    "Error: %x, cmd: %x %x %x %x %x %x\n", result,
 382			    SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 383			    SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 384		if (cmdstatp->have_sense)
 385			__scsi_print_sense(STp->device, name,
 386					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 387	} ) /* end DEB */
 388	if (!debugging) { /* Abnormal conditions for tape */
 389		if (!cmdstatp->have_sense)
 390			st_printk(KERN_WARNING, STp,
 391			       "Error %x (driver bt 0x%x, host bt 0x%x).\n",
 392			       result, driver_byte(result), host_byte(result));
 393		else if (cmdstatp->have_sense &&
 394			 scode != NO_SENSE &&
 395			 scode != RECOVERED_ERROR &&
 396			 /* scode != UNIT_ATTENTION && */
 397			 scode != BLANK_CHECK &&
 398			 scode != VOLUME_OVERFLOW &&
 399			 SRpnt->cmd[0] != MODE_SENSE &&
 400			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 401
 402			__scsi_print_sense(STp->device, name,
 403					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 404		}
 405	}
 406
 407	if (cmdstatp->fixed_format &&
 408	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 409		if (STp->cln_sense_value)
 410			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 411					       STp->cln_sense_mask) == STp->cln_sense_value);
 412		else
 413			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 414					       STp->cln_sense_mask) != 0);
 415	}
 416	if (cmdstatp->have_sense &&
 417	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 418		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 419
 420	STp->pos_unknown |= STp->device->was_reset;
 421
 422	if (cmdstatp->have_sense &&
 423	    scode == RECOVERED_ERROR
 424#if ST_RECOVERED_WRITE_FATAL
 425	    && SRpnt->cmd[0] != WRITE_6
 426	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 427#endif
 428	    ) {
 429		STp->recover_count++;
 430		STp->recover_reg++;
 431
 432		DEB(
 433		if (debugging) {
 434			if (SRpnt->cmd[0] == READ_6)
 435				stp = "read";
 436			else if (SRpnt->cmd[0] == WRITE_6)
 437				stp = "write";
 438			else
 439				stp = "ioctl";
 440			st_printk(ST_DEB_MSG, STp,
 441				  "Recovered %s error (%d).\n",
 442				  stp, STp->recover_count);
 443		} ) /* end DEB */
 444
 445		if (cmdstatp->flags == 0)
 446			return 0;
 447	}
 448	return (-EIO);
 449}
 450
 451static struct st_request *st_allocate_request(struct scsi_tape *stp)
 452{
 453	struct st_request *streq;
 454
 455	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 456	if (streq)
 457		streq->stp = stp;
 458	else {
 459		st_printk(KERN_ERR, stp,
 460			  "Can't get SCSI request.\n");
 461		if (signal_pending(current))
 462			stp->buffer->syscall_result = -EINTR;
 463		else
 464			stp->buffer->syscall_result = -EBUSY;
 465	}
 466
 467	return streq;
 468}
 469
 470static void st_release_request(struct st_request *streq)
 471{
 472	kfree(streq);
 473}
 474
 475static void st_do_stats(struct scsi_tape *STp, struct request *req)
 476{
 477	ktime_t now;
 478
 479	now = ktime_get();
 480	if (scsi_req(req)->cmd[0] == WRITE_6) {
 481		now = ktime_sub(now, STp->stats->write_time);
 482		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 483		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 484		atomic64_inc(&STp->stats->write_cnt);
 485		if (scsi_req(req)->result) {
 486			atomic64_add(atomic_read(&STp->stats->last_write_size)
 487				- STp->buffer->cmdstat.residual,
 488				&STp->stats->write_byte_cnt);
 489			if (STp->buffer->cmdstat.residual > 0)
 490				atomic64_inc(&STp->stats->resid_cnt);
 491		} else
 492			atomic64_add(atomic_read(&STp->stats->last_write_size),
 493				&STp->stats->write_byte_cnt);
 494	} else if (scsi_req(req)->cmd[0] == READ_6) {
 495		now = ktime_sub(now, STp->stats->read_time);
 496		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 497		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 498		atomic64_inc(&STp->stats->read_cnt);
 499		if (scsi_req(req)->result) {
 500			atomic64_add(atomic_read(&STp->stats->last_read_size)
 501				- STp->buffer->cmdstat.residual,
 502				&STp->stats->read_byte_cnt);
 503			if (STp->buffer->cmdstat.residual > 0)
 504				atomic64_inc(&STp->stats->resid_cnt);
 505		} else
 506			atomic64_add(atomic_read(&STp->stats->last_read_size),
 507				&STp->stats->read_byte_cnt);
 508	} else {
 509		now = ktime_sub(now, STp->stats->other_time);
 510		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 511		atomic64_inc(&STp->stats->other_cnt);
 512	}
 513	atomic64_dec(&STp->stats->in_flight);
 514}
 515
 516static void st_scsi_execute_end(struct request *req, blk_status_t status)
 517{
 518	struct st_request *SRpnt = req->end_io_data;
 519	struct scsi_request *rq = scsi_req(req);
 520	struct scsi_tape *STp = SRpnt->stp;
 521	struct bio *tmp;
 522
 523	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 524	STp->buffer->cmdstat.residual = rq->resid_len;
 525
 526	st_do_stats(STp, req);
 527
 528	tmp = SRpnt->bio;
 529	if (rq->sense_len)
 530		memcpy(SRpnt->sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
 531	if (SRpnt->waiting)
 532		complete(SRpnt->waiting);
 533
 534	blk_rq_unmap_user(tmp);
 535	blk_put_request(req);
 536}
 537
 538static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 539			   int data_direction, void *buffer, unsigned bufflen,
 540			   int timeout, int retries)
 541{
 542	struct request *req;
 543	struct scsi_request *rq;
 544	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 545	int err = 0;
 546	struct scsi_tape *STp = SRpnt->stp;
 547
 548	req = blk_get_request(SRpnt->stp->device->request_queue,
 549			data_direction == DMA_TO_DEVICE ?
 550			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 551	if (IS_ERR(req))
 552		return DRIVER_ERROR << 24;
 553	rq = scsi_req(req);
 554	req->rq_flags |= RQF_QUIET;
 555
 556	mdata->null_mapped = 1;
 557
 558	if (bufflen) {
 559		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 560				      GFP_KERNEL);
 561		if (err) {
 562			blk_put_request(req);
 563			return DRIVER_ERROR << 24;
 564		}
 565	}
 566
 567	atomic64_inc(&STp->stats->in_flight);
 568	if (cmd[0] == WRITE_6) {
 569		atomic_set(&STp->stats->last_write_size, bufflen);
 570		STp->stats->write_time = ktime_get();
 571	} else if (cmd[0] == READ_6) {
 572		atomic_set(&STp->stats->last_read_size, bufflen);
 573		STp->stats->read_time = ktime_get();
 574	} else {
 575		STp->stats->other_time = ktime_get();
 576	}
 577
 578	SRpnt->bio = req->bio;
 579	rq->cmd_len = COMMAND_SIZE(cmd[0]);
 580	memset(rq->cmd, 0, BLK_MAX_CDB);
 581	memcpy(rq->cmd, cmd, rq->cmd_len);
 582	req->timeout = timeout;
 583	rq->retries = retries;
 584	req->end_io_data = SRpnt;
 585
 586	blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
 587	return 0;
 588}
 589
 590/* Do the scsi command. Waits until command performed if do_wait is true.
 591   Otherwise write_behind_check() is used to check that the command
 592   has finished. */
 593static struct st_request *
 594st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 595	   int bytes, int direction, int timeout, int retries, int do_wait)
 596{
 597	struct completion *waiting;
 598	struct rq_map_data *mdata = &STp->buffer->map_data;
 599	int ret;
 600
 601	/* if async, make sure there's no command outstanding */
 602	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 603		st_printk(KERN_ERR, STp,
 604			  "Async command already active.\n");
 605		if (signal_pending(current))
 606			(STp->buffer)->syscall_result = (-EINTR);
 607		else
 608			(STp->buffer)->syscall_result = (-EBUSY);
 609		return NULL;
 610	}
 611
 612	if (!SRpnt) {
 613		SRpnt = st_allocate_request(STp);
 614		if (!SRpnt)
 615			return NULL;
 616	}
 617
 618	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 619	   which IO is outstanding. It's nulled out when the IO completes. */
 620	if (!do_wait)
 621		(STp->buffer)->last_SRpnt = SRpnt;
 622
 623	waiting = &STp->wait;
 624	init_completion(waiting);
 625	SRpnt->waiting = waiting;
 626
 627	if (STp->buffer->do_dio) {
 628		mdata->page_order = 0;
 629		mdata->nr_entries = STp->buffer->sg_segs;
 630		mdata->pages = STp->buffer->mapped_pages;
 631	} else {
 632		mdata->page_order = STp->buffer->reserved_page_order;
 633		mdata->nr_entries =
 634			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 635		mdata->pages = STp->buffer->reserved_pages;
 636		mdata->offset = 0;
 637	}
 638
 639	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 640	STp->buffer->cmdstat.have_sense = 0;
 641	STp->buffer->syscall_result = 0;
 642
 643	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 644			      retries);
 645	if (ret) {
 646		/* could not allocate the buffer or request was too large */
 647		(STp->buffer)->syscall_result = (-EBUSY);
 648		(STp->buffer)->last_SRpnt = NULL;
 649	} else if (do_wait) {
 650		wait_for_completion(waiting);
 651		SRpnt->waiting = NULL;
 652		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 653	}
 654
 655	return SRpnt;
 656}
 657
 658
 659/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 660   write has been correct but EOM early warning reached, -EIO if write ended in
 661   error or zero if write successful. Asynchronous writes are used only in
 662   variable block mode. */
 663static int write_behind_check(struct scsi_tape * STp)
 664{
 665	int retval = 0;
 666	struct st_buffer *STbuffer;
 667	struct st_partstat *STps;
 668	struct st_cmdstatus *cmdstatp;
 669	struct st_request *SRpnt;
 670
 671	STbuffer = STp->buffer;
 672	if (!STbuffer->writing)
 673		return 0;
 674
 675	DEB(
 676	if (STp->write_pending)
 677		STp->nbr_waits++;
 678	else
 679		STp->nbr_finished++;
 680	) /* end DEB */
 681
 682	wait_for_completion(&(STp->wait));
 683	SRpnt = STbuffer->last_SRpnt;
 684	STbuffer->last_SRpnt = NULL;
 685	SRpnt->waiting = NULL;
 686
 687	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 688	st_release_request(SRpnt);
 689
 690	STbuffer->buffer_bytes -= STbuffer->writing;
 691	STps = &(STp->ps[STp->partition]);
 692	if (STps->drv_block >= 0) {
 693		if (STp->block_size == 0)
 694			STps->drv_block++;
 695		else
 696			STps->drv_block += STbuffer->writing / STp->block_size;
 697	}
 698
 699	cmdstatp = &STbuffer->cmdstat;
 700	if (STbuffer->syscall_result) {
 701		retval = -EIO;
 702		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 703		    (cmdstatp->flags & SENSE_EOM) &&
 704		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 705		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 706			/* EOM at write-behind, has all data been written? */
 707			if (!cmdstatp->remainder_valid ||
 708			    cmdstatp->uremainder64 == 0)
 709				retval = -ENOSPC;
 710		}
 711		if (retval == -EIO)
 712			STps->drv_block = -1;
 713	}
 714	STbuffer->writing = 0;
 715
 716	DEB(if (debugging && retval)
 717		    st_printk(ST_DEB_MSG, STp,
 718				"Async write error %x, return value %d.\n",
 719				STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 720
 721	return retval;
 722}
 723
 724
 725/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 726   it messes up the block number). */
 727static int cross_eof(struct scsi_tape * STp, int forward)
 728{
 729	struct st_request *SRpnt;
 730	unsigned char cmd[MAX_COMMAND_SIZE];
 731
 732	cmd[0] = SPACE;
 733	cmd[1] = 0x01;		/* Space FileMarks */
 734	if (forward) {
 735		cmd[2] = cmd[3] = 0;
 736		cmd[4] = 1;
 737	} else
 738		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 739	cmd[5] = 0;
 740
 741	DEBC_printk(STp, "Stepping over filemark %s.\n",
 742		    forward ? "forward" : "backward");
 743
 744	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 745			   STp->device->request_queue->rq_timeout,
 746			   MAX_RETRIES, 1);
 747	if (!SRpnt)
 748		return (STp->buffer)->syscall_result;
 749
 750	st_release_request(SRpnt);
 751	SRpnt = NULL;
 752
 753	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 754		st_printk(KERN_ERR, STp,
 755			  "Stepping over filemark %s failed.\n",
 756			  forward ? "forward" : "backward");
 757
 758	return (STp->buffer)->syscall_result;
 759}
 760
 761
 762/* Flush the write buffer (never need to write if variable blocksize). */
 763static int st_flush_write_buffer(struct scsi_tape * STp)
 764{
 765	int transfer, blks;
 766	int result;
 767	unsigned char cmd[MAX_COMMAND_SIZE];
 768	struct st_request *SRpnt;
 769	struct st_partstat *STps;
 770
 771	result = write_behind_check(STp);
 772	if (result)
 773		return result;
 774
 775	result = 0;
 776	if (STp->dirty == 1) {
 777
 778		transfer = STp->buffer->buffer_bytes;
 779		DEBC_printk(STp, "Flushing %d bytes.\n", transfer);
 780
 781		memset(cmd, 0, MAX_COMMAND_SIZE);
 782		cmd[0] = WRITE_6;
 783		cmd[1] = 1;
 784		blks = transfer / STp->block_size;
 785		cmd[2] = blks >> 16;
 786		cmd[3] = blks >> 8;
 787		cmd[4] = blks;
 788
 789		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 790				   STp->device->request_queue->rq_timeout,
 791				   MAX_WRITE_RETRIES, 1);
 792		if (!SRpnt)
 793			return (STp->buffer)->syscall_result;
 794
 795		STps = &(STp->ps[STp->partition]);
 796		if ((STp->buffer)->syscall_result != 0) {
 797			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 798
 799			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 800			    (cmdstatp->flags & SENSE_EOM) &&
 801			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 802			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 803			    (!cmdstatp->remainder_valid ||
 804			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 805				STp->dirty = 0;
 806				(STp->buffer)->buffer_bytes = 0;
 807				if (STps->drv_block >= 0)
 808					STps->drv_block += blks;
 809				result = (-ENOSPC);
 810			} else {
 811				st_printk(KERN_ERR, STp, "Error on flush.\n");
 812				STps->drv_block = (-1);
 813				result = (-EIO);
 814			}
 815		} else {
 816			if (STps->drv_block >= 0)
 817				STps->drv_block += blks;
 818			STp->dirty = 0;
 819			(STp->buffer)->buffer_bytes = 0;
 820		}
 821		st_release_request(SRpnt);
 822		SRpnt = NULL;
 823	}
 824	return result;
 825}
 826
 827
 828/* Flush the tape buffer. The tape will be positioned correctly unless
 829   seek_next is true. */
 830static int flush_buffer(struct scsi_tape *STp, int seek_next)
 831{
 832	int backspace, result;
 833	struct st_partstat *STps;
 834
 835	/*
 836	 * If there was a bus reset, block further access
 837	 * to this device.
 838	 */
 839	if (STp->pos_unknown)
 840		return (-EIO);
 841
 842	if (STp->ready != ST_READY)
 843		return 0;
 844	STps = &(STp->ps[STp->partition]);
 845	if (STps->rw == ST_WRITING)	/* Writing */
 846		return st_flush_write_buffer(STp);
 847
 848	if (STp->block_size == 0)
 849		return 0;
 850
 851	backspace = ((STp->buffer)->buffer_bytes +
 852		     (STp->buffer)->read_pointer) / STp->block_size -
 853	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 854	    STp->block_size;
 855	(STp->buffer)->buffer_bytes = 0;
 856	(STp->buffer)->read_pointer = 0;
 857	result = 0;
 858	if (!seek_next) {
 859		if (STps->eof == ST_FM_HIT) {
 860			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 861			if (!result)
 862				STps->eof = ST_NOEOF;
 863			else {
 864				if (STps->drv_file >= 0)
 865					STps->drv_file++;
 866				STps->drv_block = 0;
 867			}
 868		}
 869		if (!result && backspace > 0)
 870			result = st_int_ioctl(STp, MTBSR, backspace);
 871	} else if (STps->eof == ST_FM_HIT) {
 872		if (STps->drv_file >= 0)
 873			STps->drv_file++;
 874		STps->drv_block = 0;
 875		STps->eof = ST_NOEOF;
 876	}
 877	return result;
 878
 879}
 880
 881/* Set the mode parameters */
 882static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 883{
 884	int set_it = 0;
 885	unsigned long arg;
 886
 887	if (!STp->density_changed &&
 888	    STm->default_density >= 0 &&
 889	    STm->default_density != STp->density) {
 890		arg = STm->default_density;
 891		set_it = 1;
 892	} else
 893		arg = STp->density;
 894	arg <<= MT_ST_DENSITY_SHIFT;
 895	if (!STp->blksize_changed &&
 896	    STm->default_blksize >= 0 &&
 897	    STm->default_blksize != STp->block_size) {
 898		arg |= STm->default_blksize;
 899		set_it = 1;
 900	} else
 901		arg |= STp->block_size;
 902	if (set_it &&
 903	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 904		st_printk(KERN_WARNING, STp,
 905			  "Can't set default block size to %d bytes "
 906			  "and density %x.\n",
 907			  STm->default_blksize, STm->default_density);
 908		if (modes_defined)
 909			return (-EINVAL);
 910	}
 911	return 0;
 912}
 913
 914
 915/* Lock or unlock the drive door. Don't use when st_request allocated. */
 916static int do_door_lock(struct scsi_tape * STp, int do_lock)
 917{
 918	int retval;
 919
 920	DEBC_printk(STp, "%socking drive door.\n", do_lock ? "L" : "Unl");
 921
 922	retval = scsi_set_medium_removal(STp->device,
 923			do_lock ? SCSI_REMOVAL_PREVENT : SCSI_REMOVAL_ALLOW);
 924	if (!retval)
 925		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 926	else
 927		STp->door_locked = ST_LOCK_FAILS;
 928	return retval;
 929}
 930
 931
 932/* Set the internal state after reset */
 933static void reset_state(struct scsi_tape *STp)
 934{
 935	int i;
 936	struct st_partstat *STps;
 937
 938	STp->pos_unknown = 0;
 939	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 940		STps = &(STp->ps[i]);
 941		STps->rw = ST_IDLE;
 942		STps->eof = ST_NOEOF;
 943		STps->at_sm = 0;
 944		STps->last_block_valid = 0;
 945		STps->drv_block = -1;
 946		STps->drv_file = -1;
 947	}
 948	if (STp->can_partitions) {
 949		STp->partition = find_partition(STp);
 950		if (STp->partition < 0)
 951			STp->partition = 0;
 952		STp->new_partition = STp->partition;
 953	}
 954}
 955
 956/* Test if the drive is ready. Returns either one of the codes below or a negative system
 957   error code. */
 958#define CHKRES_READY       0
 959#define CHKRES_NEW_SESSION 1
 960#define CHKRES_NOT_READY   2
 961#define CHKRES_NO_TAPE     3
 962
 963#define MAX_ATTENTIONS    10
 964
 965static int test_ready(struct scsi_tape *STp, int do_wait)
 966{
 967	int attentions, waits, max_wait, scode;
 968	int retval = CHKRES_READY, new_session = 0;
 969	unsigned char cmd[MAX_COMMAND_SIZE];
 970	struct st_request *SRpnt = NULL;
 971	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 972
 973	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 974
 975	for (attentions=waits=0; ; ) {
 976		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 977		cmd[0] = TEST_UNIT_READY;
 978		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 979				   STp->long_timeout, MAX_READY_RETRIES, 1);
 980
 981		if (!SRpnt) {
 982			retval = (STp->buffer)->syscall_result;
 983			break;
 984		}
 985
 986		if (cmdstatp->have_sense) {
 987
 988			scode = cmdstatp->sense_hdr.sense_key;
 989
 990			if (scode == UNIT_ATTENTION) { /* New media? */
 991				new_session = 1;
 992				if (attentions < MAX_ATTENTIONS) {
 993					attentions++;
 994					continue;
 995				}
 996				else {
 997					retval = (-EIO);
 998					break;
 999				}
1000			}
1001
1002			if (scode == NOT_READY) {
1003				if (waits < max_wait) {
1004					if (msleep_interruptible(1000)) {
1005						retval = (-EINTR);
1006						break;
1007					}
1008					waits++;
1009					continue;
1010				}
1011				else {
1012					if ((STp->device)->scsi_level >= SCSI_2 &&
1013					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
1014						retval = CHKRES_NO_TAPE;
1015					else
1016						retval = CHKRES_NOT_READY;
1017					break;
1018				}
1019			}
1020		}
1021
1022		retval = (STp->buffer)->syscall_result;
1023		if (!retval)
1024			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
1025		break;
1026	}
1027
1028	if (SRpnt != NULL)
1029		st_release_request(SRpnt);
1030	return retval;
1031}
1032
1033
1034/* See if the drive is ready and gather information about the tape. Return values:
1035   < 0   negative error code from errno.h
1036   0     drive ready
1037   1     drive not ready (possibly no tape)
1038*/
1039static int check_tape(struct scsi_tape *STp, struct file *filp)
1040{
1041	int i, retval, new_session = 0, do_wait;
1042	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
1043	unsigned short st_flags = filp->f_flags;
1044	struct st_request *SRpnt = NULL;
1045	struct st_modedef *STm;
1046	struct st_partstat *STps;
1047	struct inode *inode = file_inode(filp);
1048	int mode = TAPE_MODE(inode);
1049
1050	STp->ready = ST_READY;
1051
1052	if (mode != STp->current_mode) {
1053		DEBC_printk(STp, "Mode change from %d to %d.\n",
1054			    STp->current_mode, mode);
1055		new_session = 1;
1056		STp->current_mode = mode;
1057	}
1058	STm = &(STp->modes[STp->current_mode]);
1059
1060	saved_cleaning = STp->cleaning_req;
1061	STp->cleaning_req = 0;
1062
1063	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1064	retval = test_ready(STp, do_wait);
1065
1066	if (retval < 0)
1067	    goto err_out;
1068
1069	if (retval == CHKRES_NEW_SESSION) {
1070		STp->pos_unknown = 0;
1071		STp->partition = STp->new_partition = 0;
1072		if (STp->can_partitions)
1073			STp->nbr_partitions = 1; /* This guess will be updated later
1074                                                    if necessary */
1075		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1076			STps = &(STp->ps[i]);
1077			STps->rw = ST_IDLE;
1078			STps->eof = ST_NOEOF;
1079			STps->at_sm = 0;
1080			STps->last_block_valid = 0;
1081			STps->drv_block = 0;
1082			STps->drv_file = 0;
1083		}
1084		new_session = 1;
1085	}
1086	else {
1087		STp->cleaning_req |= saved_cleaning;
1088
1089		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1090			if (retval == CHKRES_NO_TAPE)
1091				STp->ready = ST_NO_TAPE;
1092			else
1093				STp->ready = ST_NOT_READY;
1094
1095			STp->density = 0;	/* Clear the erroneous "residue" */
1096			STp->write_prot = 0;
1097			STp->block_size = 0;
1098			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1099			STp->partition = STp->new_partition = 0;
1100			STp->door_locked = ST_UNLOCKED;
1101			return CHKRES_NOT_READY;
1102		}
1103	}
1104
1105	if (STp->omit_blklims)
1106		STp->min_block = STp->max_block = (-1);
1107	else {
1108		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1109		cmd[0] = READ_BLOCK_LIMITS;
1110
1111		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1112				   STp->device->request_queue->rq_timeout,
1113				   MAX_READY_RETRIES, 1);
1114		if (!SRpnt) {
1115			retval = (STp->buffer)->syscall_result;
1116			goto err_out;
1117		}
1118
1119		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1120			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1121			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1122			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1123			    (STp->buffer)->b_data[5];
1124			if ( DEB( debugging || ) !STp->inited)
1125				st_printk(KERN_INFO, STp,
1126					  "Block limits %d - %d bytes.\n",
1127					  STp->min_block, STp->max_block);
1128		} else {
1129			STp->min_block = STp->max_block = (-1);
1130			DEBC_printk(STp, "Can't read block limits.\n");
1131		}
1132	}
1133
1134	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1135	cmd[0] = MODE_SENSE;
1136	cmd[4] = 12;
1137
1138	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1139			   STp->device->request_queue->rq_timeout,
1140			   MAX_READY_RETRIES, 1);
1141	if (!SRpnt) {
1142		retval = (STp->buffer)->syscall_result;
1143		goto err_out;
1144	}
1145
1146	if ((STp->buffer)->syscall_result != 0) {
1147		DEBC_printk(STp, "No Mode Sense.\n");
1148		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1149		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1150		STp->drv_write_prot = 0;
1151	} else {
1152		DEBC_printk(STp,"Mode sense. Length %d, "
1153			    "medium %x, WBS %x, BLL %d\n",
1154			    (STp->buffer)->b_data[0],
1155			    (STp->buffer)->b_data[1],
1156			    (STp->buffer)->b_data[2],
1157			    (STp->buffer)->b_data[3]);
1158
1159		if ((STp->buffer)->b_data[3] >= 8) {
1160			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1161			STp->density = (STp->buffer)->b_data[4];
1162			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1163			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1164			DEBC_printk(STp, "Density %x, tape length: %x, "
1165				    "drv buffer: %d\n",
1166				    STp->density,
1167				    (STp->buffer)->b_data[5] * 65536 +
1168				    (STp->buffer)->b_data[6] * 256 +
1169				    (STp->buffer)->b_data[7],
1170				    STp->drv_buffer);
1171		}
1172		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1173		if (!STp->drv_buffer && STp->immediate_filemark) {
1174			st_printk(KERN_WARNING, STp,
1175				  "non-buffered tape: disabling "
1176				  "writing immediate filemarks\n");
1177			STp->immediate_filemark = 0;
1178		}
1179	}
1180	st_release_request(SRpnt);
1181	SRpnt = NULL;
1182	STp->inited = 1;
1183
1184	if (STp->block_size > 0)
1185		(STp->buffer)->buffer_blocks =
1186			(STp->buffer)->buffer_size / STp->block_size;
1187	else
1188		(STp->buffer)->buffer_blocks = 1;
1189	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1190
1191	DEBC_printk(STp, "Block size: %d, buffer size: %d (%d blocks).\n",
1192		    STp->block_size, (STp->buffer)->buffer_size,
1193		    (STp->buffer)->buffer_blocks);
1194
1195	if (STp->drv_write_prot) {
1196		STp->write_prot = 1;
1197
1198		DEBC_printk(STp, "Write protected\n");
1199
1200		if (do_wait &&
1201		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1202		     (st_flags & O_ACCMODE) == O_RDWR)) {
1203			retval = (-EROFS);
1204			goto err_out;
1205		}
1206	}
1207
1208	if (STp->can_partitions && STp->nbr_partitions < 1) {
1209		/* This code is reached when the device is opened for the first time
1210		   after the driver has been initialized with tape in the drive and the
1211		   partition support has been enabled. */
1212		DEBC_printk(STp, "Updating partition number in status.\n");
1213		if ((STp->partition = find_partition(STp)) < 0) {
1214			retval = STp->partition;
1215			goto err_out;
1216		}
1217		STp->new_partition = STp->partition;
1218		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1219	}
1220
1221	if (new_session) {	/* Change the drive parameters for the new mode */
1222		STp->density_changed = STp->blksize_changed = 0;
1223		STp->compression_changed = 0;
1224		if (!(STm->defaults_for_writes) &&
1225		    (retval = set_mode_densblk(STp, STm)) < 0)
1226		    goto err_out;
1227
1228		if (STp->default_drvbuffer != 0xff) {
1229			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1230				st_printk(KERN_WARNING, STp,
1231					  "Can't set default drive "
1232					  "buffering to %d.\n",
1233					  STp->default_drvbuffer);
1234		}
1235	}
1236
1237	return CHKRES_READY;
1238
1239 err_out:
1240	return retval;
1241}
1242
1243
1244/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1245   module count. */
1246static int st_open(struct inode *inode, struct file *filp)
1247{
1248	int i, retval = (-EIO);
1249	int resumed = 0;
1250	struct scsi_tape *STp;
1251	struct st_partstat *STps;
1252	int dev = TAPE_NR(inode);
1253
1254	/*
1255	 * We really want to do nonseekable_open(inode, filp); here, but some
1256	 * versions of tar incorrectly call lseek on tapes and bail out if that
1257	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1258	 */
1259	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1260
1261	if (!(STp = scsi_tape_get(dev))) {
1262		return -ENXIO;
1263	}
1264
1265	filp->private_data = STp;
1266
1267	spin_lock(&st_use_lock);
1268	if (STp->in_use) {
1269		spin_unlock(&st_use_lock);
 
1270		scsi_tape_put(STp);
1271		DEBC_printk(STp, "Device already in use.\n");
1272		return (-EBUSY);
1273	}
1274
1275	STp->in_use = 1;
1276	spin_unlock(&st_use_lock);
1277	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1278
1279	if (scsi_autopm_get_device(STp->device) < 0) {
1280		retval = -EIO;
1281		goto err_out;
1282	}
1283	resumed = 1;
1284	if (!scsi_block_when_processing_errors(STp->device)) {
1285		retval = (-ENXIO);
1286		goto err_out;
1287	}
1288
1289	/* See that we have at least a one page buffer available */
1290	if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1291		st_printk(KERN_WARNING, STp,
1292			  "Can't allocate one page tape buffer.\n");
1293		retval = (-EOVERFLOW);
1294		goto err_out;
1295	}
1296
1297	(STp->buffer)->cleared = 0;
1298	(STp->buffer)->writing = 0;
1299	(STp->buffer)->syscall_result = 0;
1300
1301	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1302
1303	STp->dirty = 0;
1304	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1305		STps = &(STp->ps[i]);
1306		STps->rw = ST_IDLE;
1307	}
1308	STp->try_dio_now = STp->try_dio;
1309	STp->recover_count = 0;
1310	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1311	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1312
1313	retval = check_tape(STp, filp);
1314	if (retval < 0)
1315		goto err_out;
1316	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1317	    retval != CHKRES_READY) {
1318		if (STp->ready == NO_TAPE)
1319			retval = (-ENOMEDIUM);
1320		else
1321			retval = (-EIO);
1322		goto err_out;
1323	}
1324	return 0;
1325
1326 err_out:
1327	normalize_buffer(STp->buffer);
1328	spin_lock(&st_use_lock);
1329	STp->in_use = 0;
1330	spin_unlock(&st_use_lock);
1331	if (resumed)
1332		scsi_autopm_put_device(STp->device);
1333	scsi_tape_put(STp);
1334	return retval;
1335
1336}
1337
1338
1339/* Flush the tape buffer before close */
1340static int st_flush(struct file *filp, fl_owner_t id)
1341{
1342	int result = 0, result2;
1343	unsigned char cmd[MAX_COMMAND_SIZE];
1344	struct st_request *SRpnt;
1345	struct scsi_tape *STp = filp->private_data;
1346	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1347	struct st_partstat *STps = &(STp->ps[STp->partition]);
1348
1349	if (file_count(filp) > 1)
1350		return 0;
1351
1352	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1353		result = st_flush_write_buffer(STp);
1354		if (result != 0 && result != (-ENOSPC))
1355			goto out;
1356	}
1357
1358	if (STp->can_partitions &&
1359	    (result2 = switch_partition(STp)) < 0) {
1360		DEBC_printk(STp, "switch_partition at close failed.\n");
1361		if (result == 0)
1362			result = result2;
1363		goto out;
1364	}
1365
1366	DEBC( if (STp->nbr_requests)
1367		st_printk(KERN_DEBUG, STp,
1368			  "Number of r/w requests %d, dio used in %d, "
1369			  "pages %d.\n", STp->nbr_requests, STp->nbr_dio,
1370			  STp->nbr_pages));
1371
1372	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1373		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1374
1375#if DEBUG
1376		DEBC_printk(STp, "Async write waits %d, finished %d.\n",
1377			    STp->nbr_waits, STp->nbr_finished);
1378#endif
1379		memset(cmd, 0, MAX_COMMAND_SIZE);
1380		cmd[0] = WRITE_FILEMARKS;
1381		if (STp->immediate_filemark)
1382			cmd[1] = 1;
1383		cmd[4] = 1 + STp->two_fm;
1384
1385		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1386				   STp->device->request_queue->rq_timeout,
1387				   MAX_WRITE_RETRIES, 1);
1388		if (!SRpnt) {
1389			result = (STp->buffer)->syscall_result;
1390			goto out;
1391		}
1392
1393		if (STp->buffer->syscall_result == 0 ||
1394		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1395		     (cmdstatp->flags & SENSE_EOM) &&
1396		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1397		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1398		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1399			/* Write successful at EOM */
1400			st_release_request(SRpnt);
1401			SRpnt = NULL;
1402			if (STps->drv_file >= 0)
1403				STps->drv_file++;
1404			STps->drv_block = 0;
1405			if (STp->two_fm)
1406				cross_eof(STp, 0);
1407			STps->eof = ST_FM;
1408		}
1409		else { /* Write error */
1410			st_release_request(SRpnt);
1411			SRpnt = NULL;
1412			st_printk(KERN_ERR, STp,
1413				  "Error on write filemark.\n");
1414			if (result == 0)
1415				result = (-EIO);
1416		}
1417
1418		DEBC_printk(STp, "Buffer flushed, %d EOF(s) written\n", cmd[4]);
1419	} else if (!STp->rew_at_close) {
1420		STps = &(STp->ps[STp->partition]);
1421		if (!STm->sysv || STps->rw != ST_READING) {
1422			if (STp->can_bsr)
1423				result = flush_buffer(STp, 0);
1424			else if (STps->eof == ST_FM_HIT) {
1425				result = cross_eof(STp, 0);
1426				if (result) {
1427					if (STps->drv_file >= 0)
1428						STps->drv_file++;
1429					STps->drv_block = 0;
1430					STps->eof = ST_FM;
1431				} else
1432					STps->eof = ST_NOEOF;
1433			}
1434		} else if ((STps->eof == ST_NOEOF &&
1435			    !(result = cross_eof(STp, 1))) ||
1436			   STps->eof == ST_FM_HIT) {
1437			if (STps->drv_file >= 0)
1438				STps->drv_file++;
1439			STps->drv_block = 0;
1440			STps->eof = ST_FM;
1441		}
1442	}
1443
1444      out:
1445	if (STp->rew_at_close) {
1446		result2 = st_int_ioctl(STp, MTREW, 1);
1447		if (result == 0)
1448			result = result2;
1449	}
1450	return result;
1451}
1452
1453
1454/* Close the device and release it. BKL is not needed: this is the only thread
1455   accessing this tape. */
1456static int st_release(struct inode *inode, struct file *filp)
1457{
1458	int result = 0;
1459	struct scsi_tape *STp = filp->private_data;
1460
1461	if (STp->door_locked == ST_LOCKED_AUTO)
1462		do_door_lock(STp, 0);
1463
1464	normalize_buffer(STp->buffer);
1465	spin_lock(&st_use_lock);
1466	STp->in_use = 0;
1467	spin_unlock(&st_use_lock);
1468	scsi_autopm_put_device(STp->device);
1469	scsi_tape_put(STp);
1470
1471	return result;
1472}
1473
1474/* The checks common to both reading and writing */
1475static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1476{
1477	ssize_t retval = 0;
1478
1479	/*
1480	 * If we are in the middle of error recovery, don't let anyone
1481	 * else try and use this device.  Also, if error recovery fails, it
1482	 * may try and take the device offline, in which case all further
1483	 * access to the device is prohibited.
1484	 */
1485	if (!scsi_block_when_processing_errors(STp->device)) {
1486		retval = (-ENXIO);
1487		goto out;
1488	}
1489
1490	if (STp->ready != ST_READY) {
1491		if (STp->ready == ST_NO_TAPE)
1492			retval = (-ENOMEDIUM);
1493		else
1494			retval = (-EIO);
1495		goto out;
1496	}
1497
1498	if (! STp->modes[STp->current_mode].defined) {
1499		retval = (-ENXIO);
1500		goto out;
1501	}
1502
1503
1504	/*
1505	 * If there was a bus reset, block further access
1506	 * to this device.
1507	 */
1508	if (STp->pos_unknown) {
1509		retval = (-EIO);
1510		goto out;
1511	}
1512
1513	if (count == 0)
1514		goto out;
1515
1516	DEB(
1517	if (!STp->in_use) {
1518		st_printk(ST_DEB_MSG, STp,
1519			  "Incorrect device.\n");
1520		retval = (-EIO);
1521		goto out;
1522	} ) /* end DEB */
1523
1524	if (STp->can_partitions &&
1525	    (retval = switch_partition(STp)) < 0)
1526		goto out;
1527
1528	if (STp->block_size == 0 && STp->max_block > 0 &&
1529	    (count < STp->min_block || count > STp->max_block)) {
1530		retval = (-EINVAL);
1531		goto out;
1532	}
1533
1534	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1535	    !do_door_lock(STp, 1))
1536		STp->door_locked = ST_LOCKED_AUTO;
1537
1538 out:
1539	return retval;
1540}
1541
1542
1543static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1544			   size_t count, int is_read)
1545{
1546	int i, bufsize, retval = 0;
1547	struct st_buffer *STbp = STp->buffer;
1548
1549	if (is_read)
1550		i = STp->try_dio_now && try_rdio;
1551	else
1552		i = STp->try_dio_now && try_wdio;
1553
1554	if (i && ((unsigned long)buf & queue_dma_alignment(
1555					STp->device->request_queue)) == 0) {
1556		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1557				       count, (is_read ? READ : WRITE));
1558		if (i > 0) {
1559			STbp->do_dio = i;
1560			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1561		}
1562		else
1563			STbp->do_dio = 0;  /* fall back to buffering with any error */
1564		STbp->sg_segs = STbp->do_dio;
1565		DEB(
1566		     if (STbp->do_dio) {
1567			STp->nbr_dio++;
1568			STp->nbr_pages += STbp->do_dio;
1569		     }
1570		)
1571	} else
1572		STbp->do_dio = 0;
1573	DEB( STp->nbr_requests++; )
1574
1575	if (!STbp->do_dio) {
1576		if (STp->block_size)
1577			bufsize = STp->block_size > st_fixed_buffer_size ?
1578				STp->block_size : st_fixed_buffer_size;
1579		else {
1580			bufsize = count;
1581			/* Make sure that data from previous user is not leaked even if
1582			   HBA does not return correct residual */
1583			if (is_read && STp->sili && !STbp->cleared)
1584				clear_buffer(STbp);
1585		}
1586
1587		if (bufsize > STbp->buffer_size &&
1588		    !enlarge_buffer(STbp, bufsize, STp->restr_dma)) {
1589			st_printk(KERN_WARNING, STp,
1590				  "Can't allocate %d byte tape buffer.\n",
1591				  bufsize);
1592			retval = (-EOVERFLOW);
1593			goto out;
1594		}
1595		if (STp->block_size)
1596			STbp->buffer_blocks = bufsize / STp->block_size;
1597	}
1598
1599 out:
1600	return retval;
1601}
1602
1603
1604/* Can be called more than once after each setup_buffer() */
1605static void release_buffering(struct scsi_tape *STp, int is_read)
1606{
1607	struct st_buffer *STbp;
1608
1609	STbp = STp->buffer;
1610	if (STbp->do_dio) {
1611		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1612		STbp->do_dio = 0;
1613		STbp->sg_segs = 0;
1614	}
1615}
1616
1617
1618/* Write command */
1619static ssize_t
1620st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1621{
1622	ssize_t total;
1623	ssize_t i, do_count, blks, transfer;
1624	ssize_t retval;
1625	int undone, retry_eot = 0, scode;
1626	int async_write;
1627	unsigned char cmd[MAX_COMMAND_SIZE];
1628	const char __user *b_point;
1629	struct st_request *SRpnt = NULL;
1630	struct scsi_tape *STp = filp->private_data;
1631	struct st_modedef *STm;
1632	struct st_partstat *STps;
1633	struct st_buffer *STbp;
1634
1635	if (mutex_lock_interruptible(&STp->lock))
1636		return -ERESTARTSYS;
1637
1638	retval = rw_checks(STp, filp, count);
1639	if (retval || count == 0)
1640		goto out;
1641
1642	/* Write must be integral number of blocks */
1643	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1644		st_printk(KERN_WARNING, STp,
1645			  "Write not multiple of tape block size.\n");
1646		retval = (-EINVAL);
1647		goto out;
1648	}
1649
1650	STm = &(STp->modes[STp->current_mode]);
1651	STps = &(STp->ps[STp->partition]);
1652
1653	if (STp->write_prot) {
1654		retval = (-EACCES);
1655		goto out;
1656	}
1657
1658
1659	if (STps->rw == ST_READING) {
1660		retval = flush_buffer(STp, 0);
1661		if (retval)
1662			goto out;
1663		STps->rw = ST_WRITING;
1664	} else if (STps->rw != ST_WRITING &&
1665		   STps->drv_file == 0 && STps->drv_block == 0) {
1666		if ((retval = set_mode_densblk(STp, STm)) < 0)
1667			goto out;
1668		if (STm->default_compression != ST_DONT_TOUCH &&
1669		    !(STp->compression_changed)) {
1670			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1671				st_printk(KERN_WARNING, STp,
1672					  "Can't set default compression.\n");
1673				if (modes_defined) {
1674					retval = (-EINVAL);
1675					goto out;
1676				}
1677			}
1678		}
1679	}
1680
1681	STbp = STp->buffer;
1682	i = write_behind_check(STp);
1683	if (i) {
1684		if (i == -ENOSPC)
1685			STps->eof = ST_EOM_OK;
1686		else
1687			STps->eof = ST_EOM_ERROR;
1688	}
1689
1690	if (STps->eof == ST_EOM_OK) {
1691		STps->eof = ST_EOD_1;  /* allow next write */
1692		retval = (-ENOSPC);
1693		goto out;
1694	}
1695	else if (STps->eof == ST_EOM_ERROR) {
1696		retval = (-EIO);
1697		goto out;
1698	}
1699
1700	/* Check the buffer readability in cases where copy_user might catch
1701	   the problems after some tape movement. */
1702	if (STp->block_size != 0 &&
1703	    !STbp->do_dio &&
1704	    (copy_from_user(&i, buf, 1) != 0 ||
1705	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1706		retval = (-EFAULT);
1707		goto out;
1708	}
1709
1710	retval = setup_buffering(STp, buf, count, 0);
1711	if (retval)
1712		goto out;
1713
1714	total = count;
1715
1716	memset(cmd, 0, MAX_COMMAND_SIZE);
1717	cmd[0] = WRITE_6;
1718	cmd[1] = (STp->block_size != 0);
1719
1720	STps->rw = ST_WRITING;
1721
1722	b_point = buf;
1723	while (count > 0 && !retry_eot) {
1724
1725		if (STbp->do_dio) {
1726			do_count = count;
1727		}
1728		else {
1729			if (STp->block_size == 0)
1730				do_count = count;
1731			else {
1732				do_count = STbp->buffer_blocks * STp->block_size -
1733					STbp->buffer_bytes;
1734				if (do_count > count)
1735					do_count = count;
1736			}
1737
1738			i = append_to_buffer(b_point, STbp, do_count);
1739			if (i) {
1740				retval = i;
1741				goto out;
1742			}
1743		}
1744		count -= do_count;
1745		b_point += do_count;
1746
1747		async_write = STp->block_size == 0 && !STbp->do_dio &&
1748			STm->do_async_writes && STps->eof < ST_EOM_OK;
1749
1750		if (STp->block_size != 0 && STm->do_buffer_writes &&
1751		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1752		    STbp->buffer_bytes < STbp->buffer_size) {
1753			STp->dirty = 1;
1754			/* Don't write a buffer that is not full enough. */
1755			if (!async_write && count == 0)
1756				break;
1757		}
1758
1759	retry_write:
1760		if (STp->block_size == 0)
1761			blks = transfer = do_count;
1762		else {
1763			if (!STbp->do_dio)
1764				blks = STbp->buffer_bytes;
1765			else
1766				blks = do_count;
1767			blks /= STp->block_size;
1768			transfer = blks * STp->block_size;
1769		}
1770		cmd[2] = blks >> 16;
1771		cmd[3] = blks >> 8;
1772		cmd[4] = blks;
1773
1774		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1775				   STp->device->request_queue->rq_timeout,
1776				   MAX_WRITE_RETRIES, !async_write);
1777		if (!SRpnt) {
1778			retval = STbp->syscall_result;
1779			goto out;
1780		}
1781		if (async_write && !STbp->syscall_result) {
1782			STbp->writing = transfer;
1783			STp->dirty = !(STbp->writing ==
1784				       STbp->buffer_bytes);
1785			SRpnt = NULL;  /* Prevent releasing this request! */
1786			DEB( STp->write_pending = 1; )
1787			break;
1788		}
1789
1790		if (STbp->syscall_result != 0) {
1791			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1792
1793			DEBC_printk(STp, "Error on write:\n");
1794			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1795				scode = cmdstatp->sense_hdr.sense_key;
1796				if (cmdstatp->remainder_valid)
1797					undone = (int)cmdstatp->uremainder64;
1798				else if (STp->block_size == 0 &&
1799					 scode == VOLUME_OVERFLOW)
1800					undone = transfer;
1801				else
1802					undone = 0;
1803				if (STp->block_size != 0)
1804					undone *= STp->block_size;
1805				if (undone <= do_count) {
1806					/* Only data from this write is not written */
1807					count += undone;
1808					b_point -= undone;
1809					do_count -= undone;
1810					if (STp->block_size)
1811						blks = (transfer - undone) / STp->block_size;
1812					STps->eof = ST_EOM_OK;
1813					/* Continue in fixed block mode if all written
1814					   in this request but still something left to write
1815					   (retval left to zero)
1816					*/
1817					if (STp->block_size == 0 ||
1818					    undone > 0 || count == 0)
1819						retval = (-ENOSPC); /* EOM within current request */
1820					DEBC_printk(STp, "EOM with %d "
1821						    "bytes unwritten.\n",
1822						    (int)count);
1823				} else {
1824					/* EOT within data buffered earlier (possible only
1825					   in fixed block mode without direct i/o) */
1826					if (!retry_eot && !cmdstatp->deferred &&
1827					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1828						move_buffer_data(STp->buffer, transfer - undone);
1829						retry_eot = 1;
1830						if (STps->drv_block >= 0) {
1831							STps->drv_block += (transfer - undone) /
1832								STp->block_size;
1833						}
1834						STps->eof = ST_EOM_OK;
1835						DEBC_printk(STp, "Retry "
1836							    "write of %d "
1837							    "bytes at EOM.\n",
1838							    STp->buffer->buffer_bytes);
1839						goto retry_write;
1840					}
1841					else {
1842						/* Either error within data buffered by driver or
1843						   failed retry */
1844						count -= do_count;
1845						blks = do_count = 0;
1846						STps->eof = ST_EOM_ERROR;
1847						STps->drv_block = (-1); /* Too cautious? */
1848						retval = (-EIO);	/* EOM for old data */
1849						DEBC_printk(STp, "EOM with "
1850							    "lost data.\n");
1851					}
1852				}
1853			} else {
1854				count += do_count;
1855				STps->drv_block = (-1);		/* Too cautious? */
1856				retval = STbp->syscall_result;
1857			}
1858
1859		}
1860
1861		if (STps->drv_block >= 0) {
1862			if (STp->block_size == 0)
1863				STps->drv_block += (do_count > 0);
1864			else
1865				STps->drv_block += blks;
1866		}
1867
1868		STbp->buffer_bytes = 0;
1869		STp->dirty = 0;
1870
1871		if (retval || retry_eot) {
1872			if (count < total)
1873				retval = total - count;
1874			goto out;
1875		}
1876	}
1877
1878	if (STps->eof == ST_EOD_1)
1879		STps->eof = ST_EOM_OK;
1880	else if (STps->eof != ST_EOM_OK)
1881		STps->eof = ST_NOEOF;
1882	retval = total - count;
1883
1884 out:
1885	if (SRpnt != NULL)
1886		st_release_request(SRpnt);
1887	release_buffering(STp, 0);
1888	mutex_unlock(&STp->lock);
1889
1890	return retval;
1891}
1892
1893/* Read data from the tape. Returns zero in the normal case, one if the
1894   eof status has changed, and the negative error code in case of a
1895   fatal error. Otherwise updates the buffer and the eof state.
1896
1897   Does release user buffer mapping if it is set.
1898*/
1899static long read_tape(struct scsi_tape *STp, long count,
1900		      struct st_request ** aSRpnt)
1901{
1902	int transfer, blks, bytes;
1903	unsigned char cmd[MAX_COMMAND_SIZE];
1904	struct st_request *SRpnt;
1905	struct st_modedef *STm;
1906	struct st_partstat *STps;
1907	struct st_buffer *STbp;
1908	int retval = 0;
1909
1910	if (count == 0)
1911		return 0;
1912
1913	STm = &(STp->modes[STp->current_mode]);
1914	STps = &(STp->ps[STp->partition]);
1915	if (STps->eof == ST_FM_HIT)
1916		return 1;
1917	STbp = STp->buffer;
1918
1919	if (STp->block_size == 0)
1920		blks = bytes = count;
1921	else {
1922		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1923			blks = (STp->buffer)->buffer_blocks;
1924			bytes = blks * STp->block_size;
1925		} else {
1926			bytes = count;
1927			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1928				bytes = (STp->buffer)->buffer_size;
1929			blks = bytes / STp->block_size;
1930			bytes = blks * STp->block_size;
1931		}
1932	}
1933
1934	memset(cmd, 0, MAX_COMMAND_SIZE);
1935	cmd[0] = READ_6;
1936	cmd[1] = (STp->block_size != 0);
1937	if (!cmd[1] && STp->sili)
1938		cmd[1] |= 2;
1939	cmd[2] = blks >> 16;
1940	cmd[3] = blks >> 8;
1941	cmd[4] = blks;
1942
1943	SRpnt = *aSRpnt;
1944	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1945			   STp->device->request_queue->rq_timeout,
1946			   MAX_RETRIES, 1);
1947	release_buffering(STp, 1);
1948	*aSRpnt = SRpnt;
1949	if (!SRpnt)
1950		return STbp->syscall_result;
1951
1952	STbp->read_pointer = 0;
1953	STps->at_sm = 0;
1954
1955	/* Something to check */
1956	if (STbp->syscall_result) {
1957		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1958
1959		retval = 1;
1960		DEBC_printk(STp,
1961			    "Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1962			    SRpnt->sense[0], SRpnt->sense[1],
1963			    SRpnt->sense[2], SRpnt->sense[3],
1964			    SRpnt->sense[4], SRpnt->sense[5],
1965			    SRpnt->sense[6], SRpnt->sense[7]);
1966		if (cmdstatp->have_sense) {
1967
1968			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1969				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1970
1971			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1972				/* Compute the residual count */
1973				if (cmdstatp->remainder_valid)
1974					transfer = (int)cmdstatp->uremainder64;
1975				else
1976					transfer = 0;
1977				if (cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR) {
1978					if (STp->block_size == 0)
1979						transfer = bytes;
1980					/* Some drives set ILI with MEDIUM ERROR */
1981					cmdstatp->flags &= ~SENSE_ILI;
1982				}
1983
1984				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1985					if (STp->block_size == 0 &&
1986					    transfer < 0) {
1987						st_printk(KERN_NOTICE, STp,
1988							  "Failed to read %d "
1989							  "byte block with %d "
1990							  "byte transfer.\n",
1991							  bytes - transfer,
1992							  bytes);
1993						if (STps->drv_block >= 0)
1994							STps->drv_block += 1;
1995						STbp->buffer_bytes = 0;
1996						return (-ENOMEM);
1997					} else if (STp->block_size == 0) {
1998						STbp->buffer_bytes = bytes - transfer;
1999					} else {
2000						st_release_request(SRpnt);
2001						SRpnt = *aSRpnt = NULL;
2002						if (transfer == blks) {	/* We did not get anything, error */
2003							st_printk(KERN_NOTICE, STp,
2004								  "Incorrect "
2005								  "block size.\n");
2006							if (STps->drv_block >= 0)
2007								STps->drv_block += blks - transfer + 1;
2008							st_int_ioctl(STp, MTBSR, 1);
2009							return (-EIO);
2010						}
2011						/* We have some data, deliver it */
2012						STbp->buffer_bytes = (blks - transfer) *
2013						    STp->block_size;
2014						DEBC_printk(STp, "ILI but "
2015							    "enough data "
2016							    "received %ld "
2017							    "%d.\n", count,
2018							    STbp->buffer_bytes);
2019						if (STps->drv_block >= 0)
2020							STps->drv_block += 1;
2021						if (st_int_ioctl(STp, MTBSR, 1))
2022							return (-EIO);
2023					}
2024				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
2025					if (STps->eof != ST_FM_HIT)
2026						STps->eof = ST_FM_HIT;
2027					else
2028						STps->eof = ST_EOD_2;
2029					if (STp->block_size == 0)
2030						STbp->buffer_bytes = 0;
2031					else
2032						STbp->buffer_bytes =
2033						    bytes - transfer * STp->block_size;
2034					DEBC_printk(STp, "EOF detected (%d "
2035						    "bytes read).\n",
2036						    STbp->buffer_bytes);
2037				} else if (cmdstatp->flags & SENSE_EOM) {
2038					if (STps->eof == ST_FM)
2039						STps->eof = ST_EOD_1;
2040					else
2041						STps->eof = ST_EOM_OK;
2042					if (STp->block_size == 0)
2043						STbp->buffer_bytes = bytes - transfer;
2044					else
2045						STbp->buffer_bytes =
2046						    bytes - transfer * STp->block_size;
2047
2048					DEBC_printk(STp, "EOM detected (%d "
2049						    "bytes read).\n",
2050						    STbp->buffer_bytes);
2051				}
2052			}
2053			/* end of EOF, EOM, ILI test */
2054			else {	/* nonzero sense key */
2055				DEBC_printk(STp, "Tape error while reading.\n");
2056				STps->drv_block = (-1);
2057				if (STps->eof == ST_FM &&
2058				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
2059					DEBC_printk(STp, "Zero returned for "
2060						    "first BLANK CHECK "
2061						    "after EOF.\n");
2062					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
2063				} else	/* Some other extended sense code */
2064					retval = (-EIO);
2065			}
2066
2067			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
2068				STbp->buffer_bytes = 0;
2069		}
2070		/* End of extended sense test */
2071		else {		/* Non-extended sense */
2072			retval = STbp->syscall_result;
2073		}
2074
2075	}
2076	/* End of error handling */
2077	else {			/* Read successful */
2078		STbp->buffer_bytes = bytes;
2079		if (STp->sili) /* In fixed block mode residual is always zero here */
2080			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
2081	}
2082
2083	if (STps->drv_block >= 0) {
2084		if (STp->block_size == 0)
2085			STps->drv_block++;
2086		else
2087			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2088	}
2089	return retval;
2090}
2091
2092
2093/* Read command */
2094static ssize_t
2095st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2096{
2097	ssize_t total;
2098	ssize_t retval = 0;
2099	ssize_t i, transfer;
2100	int special, do_dio = 0;
2101	struct st_request *SRpnt = NULL;
2102	struct scsi_tape *STp = filp->private_data;
2103	struct st_modedef *STm;
2104	struct st_partstat *STps;
2105	struct st_buffer *STbp = STp->buffer;
2106
2107	if (mutex_lock_interruptible(&STp->lock))
2108		return -ERESTARTSYS;
2109
2110	retval = rw_checks(STp, filp, count);
2111	if (retval || count == 0)
2112		goto out;
2113
2114	STm = &(STp->modes[STp->current_mode]);
2115	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2116		if (!STm->do_read_ahead) {
2117			retval = (-EINVAL);	/* Read must be integral number of blocks */
2118			goto out;
2119		}
2120		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2121	}
2122
2123	STps = &(STp->ps[STp->partition]);
2124	if (STps->rw == ST_WRITING) {
2125		retval = flush_buffer(STp, 0);
2126		if (retval)
2127			goto out;
2128		STps->rw = ST_READING;
2129	}
2130	DEB(
2131	if (debugging && STps->eof != ST_NOEOF)
2132		st_printk(ST_DEB_MSG, STp,
2133			  "EOF/EOM flag up (%d). Bytes %d\n",
2134			  STps->eof, STbp->buffer_bytes);
2135	) /* end DEB */
2136
2137	retval = setup_buffering(STp, buf, count, 1);
2138	if (retval)
2139		goto out;
2140	do_dio = STbp->do_dio;
2141
2142	if (STbp->buffer_bytes == 0 &&
2143	    STps->eof >= ST_EOD_1) {
2144		if (STps->eof < ST_EOD) {
2145			STps->eof += 1;
2146			retval = 0;
2147			goto out;
2148		}
2149		retval = (-EIO);	/* EOM or Blank Check */
2150		goto out;
2151	}
2152
2153	if (do_dio) {
2154		/* Check the buffer writability before any tape movement. Don't alter
2155		   buffer data. */
2156		if (copy_from_user(&i, buf, 1) != 0 ||
2157		    copy_to_user(buf, &i, 1) != 0 ||
2158		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2159		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2160			retval = (-EFAULT);
2161			goto out;
2162		}
2163	}
2164
2165	STps->rw = ST_READING;
2166
2167
2168	/* Loop until enough data in buffer or a special condition found */
2169	for (total = 0, special = 0; total < count && !special;) {
2170
2171		/* Get new data if the buffer is empty */
2172		if (STbp->buffer_bytes == 0) {
2173			special = read_tape(STp, count - total, &SRpnt);
2174			if (special < 0) {	/* No need to continue read */
2175				retval = special;
2176				goto out;
2177			}
2178		}
2179
2180		/* Move the data from driver buffer to user buffer */
2181		if (STbp->buffer_bytes > 0) {
2182			DEB(
2183			if (debugging && STps->eof != ST_NOEOF)
2184				st_printk(ST_DEB_MSG, STp,
2185					  "EOF up (%d). Left %d, needed %d.\n",
2186					  STps->eof, STbp->buffer_bytes,
2187					  (int)(count - total));
2188			) /* end DEB */
2189			transfer = STbp->buffer_bytes < count - total ?
2190			    STbp->buffer_bytes : count - total;
2191			if (!do_dio) {
2192				i = from_buffer(STbp, buf, transfer);
2193				if (i) {
2194					retval = i;
2195					goto out;
2196				}
2197			}
2198			buf += transfer;
2199			total += transfer;
2200		}
2201
2202		if (STp->block_size == 0)
2203			break;	/* Read only one variable length block */
2204
2205	}			/* for (total = 0, special = 0;
2206                                   total < count && !special; ) */
2207
2208	/* Change the eof state if no data from tape or buffer */
2209	if (total == 0) {
2210		if (STps->eof == ST_FM_HIT) {
2211			STps->eof = ST_FM;
2212			STps->drv_block = 0;
2213			if (STps->drv_file >= 0)
2214				STps->drv_file++;
2215		} else if (STps->eof == ST_EOD_1) {
2216			STps->eof = ST_EOD_2;
2217			STps->drv_block = 0;
2218			if (STps->drv_file >= 0)
2219				STps->drv_file++;
2220		} else if (STps->eof == ST_EOD_2)
2221			STps->eof = ST_EOD;
2222	} else if (STps->eof == ST_FM)
2223		STps->eof = ST_NOEOF;
2224	retval = total;
2225
2226 out:
2227	if (SRpnt != NULL) {
2228		st_release_request(SRpnt);
2229		SRpnt = NULL;
2230	}
2231	if (do_dio) {
2232		release_buffering(STp, 1);
2233		STbp->buffer_bytes = 0;
2234	}
2235	mutex_unlock(&STp->lock);
2236
2237	return retval;
2238}
2239
2240
2241
2242DEB(
2243/* Set the driver options */
2244static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm)
2245{
2246	if (debugging) {
2247		st_printk(KERN_INFO, STp,
2248			  "Mode %d options: buffer writes: %d, "
2249			  "async writes: %d, read ahead: %d\n",
2250			  STp->current_mode, STm->do_buffer_writes,
2251			  STm->do_async_writes, STm->do_read_ahead);
2252		st_printk(KERN_INFO, STp,
2253			  "    can bsr: %d, two FMs: %d, "
2254			  "fast mteom: %d, auto lock: %d,\n",
2255			  STp->can_bsr, STp->two_fm, STp->fast_mteom,
2256			  STp->do_auto_lock);
2257		st_printk(KERN_INFO, STp,
2258			  "    defs for wr: %d, no block limits: %d, "
2259			  "partitions: %d, s2 log: %d\n",
2260			  STm->defaults_for_writes, STp->omit_blklims,
2261			  STp->can_partitions, STp->scsi2_logical);
2262		st_printk(KERN_INFO, STp,
2263			  "    sysv: %d nowait: %d sili: %d "
2264			  "nowait_filemark: %d\n",
2265			  STm->sysv, STp->immediate, STp->sili,
2266			  STp->immediate_filemark);
2267		st_printk(KERN_INFO, STp, "    debugging: %d\n", debugging);
2268	}
2269}
2270	)
2271
2272
2273static int st_set_options(struct scsi_tape *STp, long options)
2274{
2275	int value;
2276	long code;
2277	struct st_modedef *STm;
2278	struct cdev *cd0, *cd1;
2279	struct device *d0, *d1;
2280
2281	STm = &(STp->modes[STp->current_mode]);
2282	if (!STm->defined) {
2283		cd0 = STm->cdevs[0];
2284		cd1 = STm->cdevs[1];
2285		d0  = STm->devs[0];
2286		d1  = STm->devs[1];
2287		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2288		STm->cdevs[0] = cd0;
2289		STm->cdevs[1] = cd1;
2290		STm->devs[0]  = d0;
2291		STm->devs[1]  = d1;
2292		modes_defined = 1;
2293		DEBC_printk(STp, "Initialized mode %d definition from mode 0\n",
2294			    STp->current_mode);
2295	}
2296
2297	code = options & MT_ST_OPTIONS;
2298	if (code == MT_ST_BOOLEANS) {
2299		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2300		STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2301		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2302		STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2303		STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2304		STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2305		STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2306		STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2307		STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2308		if ((STp->device)->scsi_level >= SCSI_2)
2309			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2310		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2311		STp->immediate = (options & MT_ST_NOWAIT) != 0;
2312		STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
2313		STm->sysv = (options & MT_ST_SYSV) != 0;
2314		STp->sili = (options & MT_ST_SILI) != 0;
2315		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2316		     st_log_options(STp, STm); )
2317	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2318		value = (code == MT_ST_SETBOOLEANS);
2319		if ((options & MT_ST_BUFFER_WRITES) != 0)
2320			STm->do_buffer_writes = value;
2321		if ((options & MT_ST_ASYNC_WRITES) != 0)
2322			STm->do_async_writes = value;
2323		if ((options & MT_ST_DEF_WRITES) != 0)
2324			STm->defaults_for_writes = value;
2325		if ((options & MT_ST_READ_AHEAD) != 0)
2326			STm->do_read_ahead = value;
2327		if ((options & MT_ST_TWO_FM) != 0)
2328			STp->two_fm = value;
2329		if ((options & MT_ST_FAST_MTEOM) != 0)
2330			STp->fast_mteom = value;
2331		if ((options & MT_ST_AUTO_LOCK) != 0)
2332			STp->do_auto_lock = value;
2333		if ((options & MT_ST_CAN_BSR) != 0)
2334			STp->can_bsr = value;
2335		if ((options & MT_ST_NO_BLKLIMS) != 0)
2336			STp->omit_blklims = value;
2337		if ((STp->device)->scsi_level >= SCSI_2 &&
2338		    (options & MT_ST_CAN_PARTITIONS) != 0)
2339			STp->can_partitions = value;
2340		if ((options & MT_ST_SCSI2LOGICAL) != 0)
2341			STp->scsi2_logical = value;
2342		if ((options & MT_ST_NOWAIT) != 0)
2343			STp->immediate = value;
2344		if ((options & MT_ST_NOWAIT_EOF) != 0)
2345			STp->immediate_filemark = value;
2346		if ((options & MT_ST_SYSV) != 0)
2347			STm->sysv = value;
2348		if ((options & MT_ST_SILI) != 0)
2349			STp->sili = value;
2350		DEB(
2351		if ((options & MT_ST_DEBUGGING) != 0)
2352			debugging = value;
2353			st_log_options(STp, STm); )
2354	} else if (code == MT_ST_WRITE_THRESHOLD) {
2355		/* Retained for compatibility */
2356	} else if (code == MT_ST_DEF_BLKSIZE) {
2357		value = (options & ~MT_ST_OPTIONS);
2358		if (value == ~MT_ST_OPTIONS) {
2359			STm->default_blksize = (-1);
2360			DEBC_printk(STp, "Default block size disabled.\n");
2361		} else {
2362			STm->default_blksize = value;
2363			DEBC_printk(STp,"Default block size set to "
2364				    "%d bytes.\n", STm->default_blksize);
2365			if (STp->ready == ST_READY) {
2366				STp->blksize_changed = 0;
2367				set_mode_densblk(STp, STm);
2368			}
2369		}
2370	} else if (code == MT_ST_TIMEOUTS) {
2371		value = (options & ~MT_ST_OPTIONS);
2372		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2373			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2374			DEBC_printk(STp, "Long timeout set to %d seconds.\n",
2375				    (value & ~MT_ST_SET_LONG_TIMEOUT));
2376		} else {
2377			blk_queue_rq_timeout(STp->device->request_queue,
2378					     value * HZ);
2379			DEBC_printk(STp, "Normal timeout set to %d seconds.\n",
2380				    value);
2381		}
2382	} else if (code == MT_ST_SET_CLN) {
2383		value = (options & ~MT_ST_OPTIONS) & 0xff;
2384		if (value != 0 &&
2385			(value < EXTENDED_SENSE_START ||
2386				value >= SCSI_SENSE_BUFFERSIZE))
2387			return (-EINVAL);
2388		STp->cln_mode = value;
2389		STp->cln_sense_mask = (options >> 8) & 0xff;
2390		STp->cln_sense_value = (options >> 16) & 0xff;
2391		st_printk(KERN_INFO, STp,
2392			  "Cleaning request mode %d, mask %02x, value %02x\n",
2393			  value, STp->cln_sense_mask, STp->cln_sense_value);
2394	} else if (code == MT_ST_DEF_OPTIONS) {
2395		code = (options & ~MT_ST_CLEAR_DEFAULT);
2396		value = (options & MT_ST_CLEAR_DEFAULT);
2397		if (code == MT_ST_DEF_DENSITY) {
2398			if (value == MT_ST_CLEAR_DEFAULT) {
2399				STm->default_density = (-1);
2400				DEBC_printk(STp,
2401					    "Density default disabled.\n");
2402			} else {
2403				STm->default_density = value & 0xff;
2404				DEBC_printk(STp, "Density default set to %x\n",
2405					    STm->default_density);
2406				if (STp->ready == ST_READY) {
2407					STp->density_changed = 0;
2408					set_mode_densblk(STp, STm);
2409				}
2410			}
2411		} else if (code == MT_ST_DEF_DRVBUFFER) {
2412			if (value == MT_ST_CLEAR_DEFAULT) {
2413				STp->default_drvbuffer = 0xff;
2414				DEBC_printk(STp,
2415					    "Drive buffer default disabled.\n");
2416			} else {
2417				STp->default_drvbuffer = value & 7;
2418				DEBC_printk(STp,
2419					    "Drive buffer default set to %x\n",
2420					    STp->default_drvbuffer);
2421				if (STp->ready == ST_READY)
2422					st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2423			}
2424		} else if (code == MT_ST_DEF_COMPRESSION) {
2425			if (value == MT_ST_CLEAR_DEFAULT) {
2426				STm->default_compression = ST_DONT_TOUCH;
2427				DEBC_printk(STp,
2428					    "Compression default disabled.\n");
2429			} else {
2430				if ((value & 0xff00) != 0) {
2431					STp->c_algo = (value & 0xff00) >> 8;
2432					DEBC_printk(STp, "Compression "
2433						    "algorithm set to 0x%x.\n",
2434						    STp->c_algo);
2435				}
2436				if ((value & 0xff) != 0xff) {
2437					STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2438					DEBC_printk(STp, "Compression default "
2439						    "set to %x\n",
2440						    (value & 1));
2441					if (STp->ready == ST_READY) {
2442						STp->compression_changed = 0;
2443						st_compression(STp, (STm->default_compression == ST_YES));
2444					}
2445				}
2446			}
2447		}
2448	} else
2449		return (-EIO);
2450
2451	return 0;
2452}
2453
2454#define MODE_HEADER_LENGTH  4
2455
2456/* Mode header and page byte offsets */
2457#define MH_OFF_DATA_LENGTH     0
2458#define MH_OFF_MEDIUM_TYPE     1
2459#define MH_OFF_DEV_SPECIFIC    2
2460#define MH_OFF_BDESCS_LENGTH   3
2461#define MP_OFF_PAGE_NBR        0
2462#define MP_OFF_PAGE_LENGTH     1
2463
2464/* Mode header and page bit masks */
2465#define MH_BIT_WP              0x80
2466#define MP_MSK_PAGE_NBR        0x3f
2467
2468/* Don't return block descriptors */
2469#define MODE_SENSE_OMIT_BDESCS 0x08
2470
2471#define MODE_SELECT_PAGE_FORMAT 0x10
2472
2473/* Read a mode page into the tape buffer. The block descriptors are included
2474   if incl_block_descs is true. The page control is ored to the page number
2475   parameter, if necessary. */
2476static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2477{
2478	unsigned char cmd[MAX_COMMAND_SIZE];
2479	struct st_request *SRpnt;
2480
2481	memset(cmd, 0, MAX_COMMAND_SIZE);
2482	cmd[0] = MODE_SENSE;
2483	if (omit_block_descs)
2484		cmd[1] = MODE_SENSE_OMIT_BDESCS;
2485	cmd[2] = page;
2486	cmd[4] = 255;
2487
2488	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2489			   STp->device->request_queue->rq_timeout, 0, 1);
2490	if (SRpnt == NULL)
2491		return (STp->buffer)->syscall_result;
2492
2493	st_release_request(SRpnt);
2494
2495	return STp->buffer->syscall_result;
2496}
2497
2498
2499/* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2500   in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2501static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2502{
2503	int pgo;
2504	unsigned char cmd[MAX_COMMAND_SIZE];
2505	struct st_request *SRpnt;
2506	int timeout;
2507
2508	memset(cmd, 0, MAX_COMMAND_SIZE);
2509	cmd[0] = MODE_SELECT;
2510	cmd[1] = MODE_SELECT_PAGE_FORMAT;
2511	pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2512	cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2513
2514	/* Clear reserved fields */
2515	(STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2516	(STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2517	(STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2518	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2519
2520	timeout = slow ?
2521		STp->long_timeout : STp->device->request_queue->rq_timeout;
2522	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2523			   timeout, 0, 1);
2524	if (SRpnt == NULL)
2525		return (STp->buffer)->syscall_result;
2526
2527	st_release_request(SRpnt);
2528
2529	return STp->buffer->syscall_result;
2530}
2531
2532
2533#define COMPRESSION_PAGE        0x0f
2534#define COMPRESSION_PAGE_LENGTH 16
2535
2536#define CP_OFF_DCE_DCC          2
2537#define CP_OFF_C_ALGO           7
2538
2539#define DCE_MASK  0x80
2540#define DCC_MASK  0x40
2541#define RED_MASK  0x60
2542
2543
2544/* Control the compression with mode page 15. Algorithm not changed if zero.
2545
2546   The block descriptors are read and written because Sony SDT-7000 does not
2547   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2548   Including block descriptors should not cause any harm to other drives. */
2549
2550static int st_compression(struct scsi_tape * STp, int state)
2551{
2552	int retval;
2553	int mpoffs;  /* Offset to mode page start */
2554	unsigned char *b_data = (STp->buffer)->b_data;
2555
2556	if (STp->ready != ST_READY)
2557		return (-EIO);
2558
2559	/* Read the current page contents */
2560	retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2561	if (retval) {
2562		DEBC_printk(STp, "Compression mode page not supported.\n");
2563		return (-EIO);
2564	}
2565
2566	mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2567	DEBC_printk(STp, "Compression state is %d.\n",
2568		    (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0));
2569
2570	/* Check if compression can be changed */
2571	if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2572		DEBC_printk(STp, "Compression not supported.\n");
2573		return (-EIO);
2574	}
2575
2576	/* Do the change */
2577	if (state) {
2578		b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2579		if (STp->c_algo != 0)
2580			b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2581	}
2582	else {
2583		b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2584		if (STp->c_algo != 0)
2585			b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2586	}
2587
2588	retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2589	if (retval) {
2590		DEBC_printk(STp, "Compression change failed.\n");
2591		return (-EIO);
2592	}
2593	DEBC_printk(STp, "Compression state changed to %d.\n", state);
2594
2595	STp->compression_changed = 1;
2596	return 0;
2597}
2598
2599
2600/* Process the load and unload commands (does unload if the load code is zero) */
2601static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2602{
2603	int retval = (-EIO), timeout;
2604	unsigned char cmd[MAX_COMMAND_SIZE];
2605	struct st_partstat *STps;
2606	struct st_request *SRpnt;
2607
2608	if (STp->ready != ST_READY && !load_code) {
2609		if (STp->ready == ST_NO_TAPE)
2610			return (-ENOMEDIUM);
2611		else
2612			return (-EIO);
2613	}
2614
2615	memset(cmd, 0, MAX_COMMAND_SIZE);
2616	cmd[0] = START_STOP;
2617	if (load_code)
2618		cmd[4] |= 1;
2619	/*
2620	 * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2621	 */
2622	if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2623	    && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2624		DEBC_printk(STp, " Enhanced %sload slot %2d.\n",
2625			    (cmd[4]) ? "" : "un",
2626			    load_code - MT_ST_HPLOADER_OFFSET);
2627		cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2628	}
2629	if (STp->immediate) {
2630		cmd[1] = 1;	/* Don't wait for completion */
2631		timeout = STp->device->request_queue->rq_timeout;
2632	}
2633	else
2634		timeout = STp->long_timeout;
2635
2636	DEBC(
2637		if (!load_code)
2638			st_printk(ST_DEB_MSG, STp, "Unloading tape.\n");
2639		else
2640			st_printk(ST_DEB_MSG, STp, "Loading tape.\n");
2641		);
2642
2643	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2644			   timeout, MAX_RETRIES, 1);
2645	if (!SRpnt)
2646		return (STp->buffer)->syscall_result;
2647
2648	retval = (STp->buffer)->syscall_result;
2649	st_release_request(SRpnt);
2650
2651	if (!retval) {	/* SCSI command successful */
2652
2653		if (!load_code) {
2654			STp->rew_at_close = 0;
2655			STp->ready = ST_NO_TAPE;
2656		}
2657		else {
2658			STp->rew_at_close = STp->autorew_dev;
2659			retval = check_tape(STp, filp);
2660			if (retval > 0)
2661				retval = 0;
2662		}
2663	}
2664	else {
2665		STps = &(STp->ps[STp->partition]);
2666		STps->drv_file = STps->drv_block = (-1);
2667	}
2668
2669	return retval;
2670}
2671
2672#if DEBUG
2673#define ST_DEB_FORWARD  0
2674#define ST_DEB_BACKWARD 1
2675static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd)
2676{
2677	s32 sc;
2678
2679	if (!debugging)
2680		return;
2681
2682	sc = cmd[2] & 0x80 ? 0xff000000 : 0;
2683	sc |= (cmd[2] << 16) | (cmd[3] << 8) | cmd[4];
2684	if (direction)
2685		sc = -sc;
2686	st_printk(ST_DEB_MSG, STp, "Spacing tape %s over %d %s.\n",
2687		  direction ? "backward" : "forward", sc, units);
2688}
2689#else
2690#define ST_DEB_FORWARD  0
2691#define ST_DEB_BACKWARD 1
2692static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd) {}
2693#endif
2694
2695
2696/* Internal ioctl function */
2697static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2698{
2699	int timeout;
2700	long ltmp;
2701	int ioctl_result;
2702	int chg_eof = 1;
2703	unsigned char cmd[MAX_COMMAND_SIZE];
2704	struct st_request *SRpnt;
2705	struct st_partstat *STps;
2706	int fileno, blkno, at_sm, undone;
2707	int datalen = 0, direction = DMA_NONE;
2708
2709	WARN_ON(STp->buffer->do_dio != 0);
2710	if (STp->ready != ST_READY) {
2711		if (STp->ready == ST_NO_TAPE)
2712			return (-ENOMEDIUM);
2713		else
2714			return (-EIO);
2715	}
2716	timeout = STp->long_timeout;
2717	STps = &(STp->ps[STp->partition]);
2718	fileno = STps->drv_file;
2719	blkno = STps->drv_block;
2720	at_sm = STps->at_sm;
2721
2722	memset(cmd, 0, MAX_COMMAND_SIZE);
2723	switch (cmd_in) {
2724	case MTFSFM:
2725		chg_eof = 0;	/* Changed from the FSF after this */
2726		/* fall through */
2727	case MTFSF:
2728		cmd[0] = SPACE;
2729		cmd[1] = 0x01;	/* Space FileMarks */
2730		cmd[2] = (arg >> 16);
2731		cmd[3] = (arg >> 8);
2732		cmd[4] = arg;
2733		deb_space_print(STp, ST_DEB_FORWARD, "filemarks", cmd);
2734		if (fileno >= 0)
2735			fileno += arg;
2736		blkno = 0;
2737		at_sm &= (arg == 0);
2738		break;
2739	case MTBSFM:
2740		chg_eof = 0;	/* Changed from the FSF after this */
2741		/* fall through */
2742	case MTBSF:
2743		cmd[0] = SPACE;
2744		cmd[1] = 0x01;	/* Space FileMarks */
2745		ltmp = (-arg);
2746		cmd[2] = (ltmp >> 16);
2747		cmd[3] = (ltmp >> 8);
2748		cmd[4] = ltmp;
2749		deb_space_print(STp, ST_DEB_BACKWARD, "filemarks", cmd);
2750		if (fileno >= 0)
2751			fileno -= arg;
2752		blkno = (-1);	/* We can't know the block number */
2753		at_sm &= (arg == 0);
2754		break;
2755	case MTFSR:
2756		cmd[0] = SPACE;
2757		cmd[1] = 0x00;	/* Space Blocks */
2758		cmd[2] = (arg >> 16);
2759		cmd[3] = (arg >> 8);
2760		cmd[4] = arg;
2761		deb_space_print(STp, ST_DEB_FORWARD, "blocks", cmd);
2762		if (blkno >= 0)
2763			blkno += arg;
2764		at_sm &= (arg == 0);
2765		break;
2766	case MTBSR:
2767		cmd[0] = SPACE;
2768		cmd[1] = 0x00;	/* Space Blocks */
2769		ltmp = (-arg);
2770		cmd[2] = (ltmp >> 16);
2771		cmd[3] = (ltmp >> 8);
2772		cmd[4] = ltmp;
2773		deb_space_print(STp, ST_DEB_BACKWARD, "blocks", cmd);
2774		if (blkno >= 0)
2775			blkno -= arg;
2776		at_sm &= (arg == 0);
2777		break;
2778	case MTFSS:
2779		cmd[0] = SPACE;
2780		cmd[1] = 0x04;	/* Space Setmarks */
2781		cmd[2] = (arg >> 16);
2782		cmd[3] = (arg >> 8);
2783		cmd[4] = arg;
2784		deb_space_print(STp, ST_DEB_FORWARD, "setmarks", cmd);
2785		if (arg != 0) {
2786			blkno = fileno = (-1);
2787			at_sm = 1;
2788		}
2789		break;
2790	case MTBSS:
2791		cmd[0] = SPACE;
2792		cmd[1] = 0x04;	/* Space Setmarks */
2793		ltmp = (-arg);
2794		cmd[2] = (ltmp >> 16);
2795		cmd[3] = (ltmp >> 8);
2796		cmd[4] = ltmp;
2797		deb_space_print(STp, ST_DEB_BACKWARD, "setmarks", cmd);
2798		if (arg != 0) {
2799			blkno = fileno = (-1);
2800			at_sm = 1;
2801		}
2802		break;
2803	case MTWEOF:
2804	case MTWEOFI:
2805	case MTWSM:
2806		if (STp->write_prot)
2807			return (-EACCES);
2808		cmd[0] = WRITE_FILEMARKS;
2809		if (cmd_in == MTWSM)
2810			cmd[1] = 2;
2811		if (cmd_in == MTWEOFI ||
2812		    (cmd_in == MTWEOF && STp->immediate_filemark))
2813			cmd[1] |= 1;
2814		cmd[2] = (arg >> 16);
2815		cmd[3] = (arg >> 8);
2816		cmd[4] = arg;
2817		timeout = STp->device->request_queue->rq_timeout;
2818		DEBC(
2819			if (cmd_in != MTWSM)
2820				st_printk(ST_DEB_MSG, STp,
2821					  "Writing %d filemarks.\n",
2822					  cmd[2] * 65536 +
2823					  cmd[3] * 256 +
2824					  cmd[4]);
2825			else
2826				st_printk(ST_DEB_MSG, STp,
2827					  "Writing %d setmarks.\n",
2828					  cmd[2] * 65536 +
2829					  cmd[3] * 256 +
2830					  cmd[4]);
2831		)
2832		if (fileno >= 0)
2833			fileno += arg;
2834		blkno = 0;
2835		at_sm = (cmd_in == MTWSM);
2836		break;
2837	case MTREW:
2838		cmd[0] = REZERO_UNIT;
2839		if (STp->immediate) {
2840			cmd[1] = 1;	/* Don't wait for completion */
2841			timeout = STp->device->request_queue->rq_timeout;
2842		}
2843		DEBC_printk(STp, "Rewinding tape.\n");
2844		fileno = blkno = at_sm = 0;
2845		break;
2846	case MTNOP:
2847		DEBC_printk(STp, "No op on tape.\n");
2848		return 0;	/* Should do something ? */
2849		break;
2850	case MTRETEN:
2851		cmd[0] = START_STOP;
2852		if (STp->immediate) {
2853			cmd[1] = 1;	/* Don't wait for completion */
2854			timeout = STp->device->request_queue->rq_timeout;
2855		}
2856		cmd[4] = 3;
2857		DEBC_printk(STp, "Retensioning tape.\n");
2858		fileno = blkno = at_sm = 0;
2859		break;
2860	case MTEOM:
2861		if (!STp->fast_mteom) {
2862			/* space to the end of tape */
2863			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2864			fileno = STps->drv_file;
2865			if (STps->eof >= ST_EOD_1)
2866				return 0;
2867			/* The next lines would hide the number of spaced FileMarks
2868			   That's why I inserted the previous lines. I had no luck
2869			   with detecting EOM with FSF, so we go now to EOM.
2870			   Joerg Weule */
2871		} else
2872			fileno = (-1);
2873		cmd[0] = SPACE;
2874		cmd[1] = 3;
2875		DEBC_printk(STp, "Spacing to end of recorded medium.\n");
2876		blkno = -1;
2877		at_sm = 0;
2878		break;
2879	case MTERASE:
2880		if (STp->write_prot)
2881			return (-EACCES);
2882		cmd[0] = ERASE;
2883		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
2884		if (STp->immediate) {
2885			cmd[1] |= 2;	/* Don't wait for completion */
2886			timeout = STp->device->request_queue->rq_timeout;
2887		}
2888		else
2889			timeout = STp->long_timeout * 8;
2890
2891		DEBC_printk(STp, "Erasing tape.\n");
2892		fileno = blkno = at_sm = 0;
2893		break;
2894	case MTSETBLK:		/* Set block length */
2895	case MTSETDENSITY:	/* Set tape density */
2896	case MTSETDRVBUFFER:	/* Set drive buffering */
2897	case SET_DENS_AND_BLK:	/* Set density and block size */
2898		chg_eof = 0;
2899		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2900			return (-EIO);	/* Not allowed if data in buffer */
2901		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2902		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2903		    STp->max_block > 0 &&
2904		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2905		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2906			st_printk(KERN_WARNING, STp, "Illegal block size.\n");
2907			return (-EINVAL);
2908		}
2909		cmd[0] = MODE_SELECT;
2910		if ((STp->use_pf & USE_PF))
2911			cmd[1] = MODE_SELECT_PAGE_FORMAT;
2912		cmd[4] = datalen = 12;
2913		direction = DMA_TO_DEVICE;
2914
2915		memset((STp->buffer)->b_data, 0, 12);
2916		if (cmd_in == MTSETDRVBUFFER)
2917			(STp->buffer)->b_data[2] = (arg & 7) << 4;
2918		else
2919			(STp->buffer)->b_data[2] =
2920			    STp->drv_buffer << 4;
2921		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
2922		if (cmd_in == MTSETDENSITY) {
2923			(STp->buffer)->b_data[4] = arg;
2924			STp->density_changed = 1;	/* At least we tried ;-) */
2925		} else if (cmd_in == SET_DENS_AND_BLK)
2926			(STp->buffer)->b_data[4] = arg >> 24;
2927		else
2928			(STp->buffer)->b_data[4] = STp->density;
2929		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2930			ltmp = arg & MT_ST_BLKSIZE_MASK;
2931			if (cmd_in == MTSETBLK)
2932				STp->blksize_changed = 1; /* At least we tried ;-) */
2933		} else
2934			ltmp = STp->block_size;
2935		(STp->buffer)->b_data[9] = (ltmp >> 16);
2936		(STp->buffer)->b_data[10] = (ltmp >> 8);
2937		(STp->buffer)->b_data[11] = ltmp;
2938		timeout = STp->device->request_queue->rq_timeout;
2939		DEBC(
2940			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2941				st_printk(ST_DEB_MSG, STp,
2942					  "Setting block size to %d bytes.\n",
2943					  (STp->buffer)->b_data[9] * 65536 +
2944					  (STp->buffer)->b_data[10] * 256 +
2945					  (STp->buffer)->b_data[11]);
2946			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2947				st_printk(ST_DEB_MSG, STp,
2948					  "Setting density code to %x.\n",
2949					  (STp->buffer)->b_data[4]);
2950			if (cmd_in == MTSETDRVBUFFER)
2951				st_printk(ST_DEB_MSG, STp,
2952					  "Setting drive buffer code to %d.\n",
2953					  ((STp->buffer)->b_data[2] >> 4) & 7);
2954		)
2955		break;
2956	default:
2957		return (-ENOSYS);
2958	}
2959
2960	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2961			   timeout, MAX_RETRIES, 1);
2962	if (!SRpnt)
2963		return (STp->buffer)->syscall_result;
2964
2965	ioctl_result = (STp->buffer)->syscall_result;
2966
2967	if (!ioctl_result) {	/* SCSI command successful */
2968		st_release_request(SRpnt);
2969		SRpnt = NULL;
2970		STps->drv_block = blkno;
2971		STps->drv_file = fileno;
2972		STps->at_sm = at_sm;
2973
2974		if (cmd_in == MTBSFM)
2975			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2976		else if (cmd_in == MTFSFM)
2977			ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2978
2979		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2980			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2981			if (STp->block_size != 0) {
2982				(STp->buffer)->buffer_blocks =
2983				    (STp->buffer)->buffer_size / STp->block_size;
2984			}
2985			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2986			if (cmd_in == SET_DENS_AND_BLK)
2987				STp->density = arg >> MT_ST_DENSITY_SHIFT;
2988		} else if (cmd_in == MTSETDRVBUFFER)
2989			STp->drv_buffer = (arg & 7);
2990		else if (cmd_in == MTSETDENSITY)
2991			STp->density = arg;
2992
2993		if (cmd_in == MTEOM)
2994			STps->eof = ST_EOD;
2995		else if (cmd_in == MTFSF)
2996			STps->eof = ST_FM;
2997		else if (chg_eof)
2998			STps->eof = ST_NOEOF;
2999
3000		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
3001			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
3002	} else { /* SCSI command was not completely successful. Don't return
3003                    from this block without releasing the SCSI command block! */
3004		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
3005
3006		if (cmdstatp->flags & SENSE_EOM) {
3007			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
3008			    cmd_in != MTBSR && cmd_in != MTBSS)
3009				STps->eof = ST_EOM_OK;
3010			STps->drv_block = 0;
3011		}
3012
3013		if (cmdstatp->remainder_valid)
3014			undone = (int)cmdstatp->uremainder64;
3015		else
3016			undone = 0;
3017
3018		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
3019		    cmdstatp->have_sense &&
3020		    (cmdstatp->flags & SENSE_EOM)) {
3021			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
3022			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
3023				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
3024				STps->eof = ST_NOEOF;
3025			} else {  /* Writing EOF(s) failed */
3026				if (fileno >= 0)
3027					fileno -= undone;
3028				if (undone < arg)
3029					STps->eof = ST_NOEOF;
3030			}
3031			STps->drv_file = fileno;
3032		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
3033			if (fileno >= 0)
3034				STps->drv_file = fileno - undone;
3035			else
3036				STps->drv_file = fileno;
3037			STps->drv_block = -1;
3038			STps->eof = ST_NOEOF;
3039		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
3040			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3041				undone = (-undone);
3042			if (STps->drv_file >= 0)
3043				STps->drv_file = fileno + undone;
3044			STps->drv_block = 0;
3045			STps->eof = ST_NOEOF;
3046		} else if (cmd_in == MTFSR) {
3047			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3048				if (STps->drv_file >= 0)
3049					STps->drv_file++;
3050				STps->drv_block = 0;
3051				STps->eof = ST_FM;
3052			} else {
3053				if (blkno >= undone)
3054					STps->drv_block = blkno - undone;
3055				else
3056					STps->drv_block = (-1);
3057				STps->eof = ST_NOEOF;
3058			}
3059		} else if (cmd_in == MTBSR) {
3060			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3061				STps->drv_file--;
3062				STps->drv_block = (-1);
3063			} else {
3064				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3065					undone = (-undone);
3066				if (STps->drv_block >= 0)
3067					STps->drv_block = blkno + undone;
3068			}
3069			STps->eof = ST_NOEOF;
3070		} else if (cmd_in == MTEOM) {
3071			STps->drv_file = (-1);
3072			STps->drv_block = (-1);
3073			STps->eof = ST_EOD;
3074		} else if (cmd_in == MTSETBLK ||
3075			   cmd_in == MTSETDENSITY ||
3076			   cmd_in == MTSETDRVBUFFER ||
3077			   cmd_in == SET_DENS_AND_BLK) {
3078			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
3079			    !(STp->use_pf & PF_TESTED)) {
3080				/* Try the other possible state of Page Format if not
3081				   already tried */
3082				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
3083				st_release_request(SRpnt);
3084				SRpnt = NULL;
3085				return st_int_ioctl(STp, cmd_in, arg);
3086			}
3087		} else if (chg_eof)
3088			STps->eof = ST_NOEOF;
3089
3090		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
3091			STps->eof = ST_EOD;
3092
3093		st_release_request(SRpnt);
3094		SRpnt = NULL;
3095	}
3096
3097	return ioctl_result;
3098}
3099
3100
3101/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
3102   structure. */
3103
3104static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
3105			int logical)
3106{
3107	int result;
3108	unsigned char scmd[MAX_COMMAND_SIZE];
3109	struct st_request *SRpnt;
3110
3111	if (STp->ready != ST_READY)
3112		return (-EIO);
3113
3114	memset(scmd, 0, MAX_COMMAND_SIZE);
3115	if ((STp->device)->scsi_level < SCSI_2) {
3116		scmd[0] = QFA_REQUEST_BLOCK;
3117		scmd[4] = 3;
3118	} else {
3119		scmd[0] = READ_POSITION;
3120		if (!logical && !STp->scsi2_logical)
3121			scmd[1] = 1;
3122	}
3123	SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3124			   STp->device->request_queue->rq_timeout,
3125			   MAX_READY_RETRIES, 1);
3126	if (!SRpnt)
3127		return (STp->buffer)->syscall_result;
3128
3129	if ((STp->buffer)->syscall_result != 0 ||
3130	    (STp->device->scsi_level >= SCSI_2 &&
3131	     ((STp->buffer)->b_data[0] & 4) != 0)) {
3132		*block = *partition = 0;
3133		DEBC_printk(STp, " Can't read tape position.\n");
3134		result = (-EIO);
3135	} else {
3136		result = 0;
3137		if ((STp->device)->scsi_level < SCSI_2) {
3138			*block = ((STp->buffer)->b_data[0] << 16)
3139			    + ((STp->buffer)->b_data[1] << 8)
3140			    + (STp->buffer)->b_data[2];
3141			*partition = 0;
3142		} else {
3143			*block = ((STp->buffer)->b_data[4] << 24)
3144			    + ((STp->buffer)->b_data[5] << 16)
3145			    + ((STp->buffer)->b_data[6] << 8)
3146			    + (STp->buffer)->b_data[7];
3147			*partition = (STp->buffer)->b_data[1];
3148			if (((STp->buffer)->b_data[0] & 0x80) &&
3149			    (STp->buffer)->b_data[1] == 0)	/* BOP of partition 0 */
3150				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3151		}
3152		DEBC_printk(STp, "Got tape pos. blk %d part %d.\n",
3153			    *block, *partition);
3154	}
3155	st_release_request(SRpnt);
3156	SRpnt = NULL;
3157
3158	return result;
3159}
3160
3161
3162/* Set the tape block and partition. Negative partition means that only the
3163   block should be set in vendor specific way. */
3164static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3165			int logical)
3166{
3167	struct st_partstat *STps;
3168	int result, p;
3169	unsigned int blk;
3170	int timeout;
3171	unsigned char scmd[MAX_COMMAND_SIZE];
3172	struct st_request *SRpnt;
3173
3174	if (STp->ready != ST_READY)
3175		return (-EIO);
3176	timeout = STp->long_timeout;
3177	STps = &(STp->ps[STp->partition]);
3178
3179	DEBC_printk(STp, "Setting block to %d and partition to %d.\n",
3180		    block, partition);
3181	DEB(if (partition < 0)
3182		return (-EIO); )
3183
3184	/* Update the location at the partition we are leaving */
3185	if ((!STp->can_partitions && partition != 0) ||
3186	    partition >= ST_NBR_PARTITIONS)
3187		return (-EINVAL);
3188	if (partition != STp->partition) {
3189		if (get_location(STp, &blk, &p, 1))
3190			STps->last_block_valid = 0;
3191		else {
3192			STps->last_block_valid = 1;
3193			STps->last_block_visited = blk;
3194			DEBC_printk(STp, "Visited block %d for "
3195				    "partition %d saved.\n",
3196				    blk, STp->partition);
3197		}
3198	}
3199
3200	memset(scmd, 0, MAX_COMMAND_SIZE);
3201	if ((STp->device)->scsi_level < SCSI_2) {
3202		scmd[0] = QFA_SEEK_BLOCK;
3203		scmd[2] = (block >> 16);
3204		scmd[3] = (block >> 8);
3205		scmd[4] = block;
3206		scmd[5] = 0;
3207	} else {
3208		scmd[0] = SEEK_10;
3209		scmd[3] = (block >> 24);
3210		scmd[4] = (block >> 16);
3211		scmd[5] = (block >> 8);
3212		scmd[6] = block;
3213		if (!logical && !STp->scsi2_logical)
3214			scmd[1] = 4;
3215		if (STp->partition != partition) {
3216			scmd[1] |= 2;
3217			scmd[8] = partition;
3218			DEBC_printk(STp, "Trying to change partition "
3219				    "from %d to %d\n", STp->partition,
3220				    partition);
3221		}
3222	}
3223	if (STp->immediate) {
3224		scmd[1] |= 1;		/* Don't wait for completion */
3225		timeout = STp->device->request_queue->rq_timeout;
3226	}
3227
3228	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3229			   timeout, MAX_READY_RETRIES, 1);
3230	if (!SRpnt)
3231		return (STp->buffer)->syscall_result;
3232
3233	STps->drv_block = STps->drv_file = (-1);
3234	STps->eof = ST_NOEOF;
3235	if ((STp->buffer)->syscall_result != 0) {
3236		result = (-EIO);
3237		if (STp->can_partitions &&
3238		    (STp->device)->scsi_level >= SCSI_2 &&
3239		    (p = find_partition(STp)) >= 0)
3240			STp->partition = p;
3241	} else {
3242		if (STp->can_partitions) {
3243			STp->partition = partition;
3244			STps = &(STp->ps[partition]);
3245			if (!STps->last_block_valid ||
3246			    STps->last_block_visited != block) {
3247				STps->at_sm = 0;
3248				STps->rw = ST_IDLE;
3249			}
3250		} else
3251			STps->at_sm = 0;
3252		if (block == 0)
3253			STps->drv_block = STps->drv_file = 0;
3254		result = 0;
3255	}
3256
3257	st_release_request(SRpnt);
3258	SRpnt = NULL;
3259
3260	return result;
3261}
3262
3263
3264/* Find the current partition number for the drive status. Called from open and
3265   returns either partition number of negative error code. */
3266static int find_partition(struct scsi_tape *STp)
3267{
3268	int i, partition;
3269	unsigned int block;
3270
3271	if ((i = get_location(STp, &block, &partition, 1)) < 0)
3272		return i;
3273	if (partition >= ST_NBR_PARTITIONS)
3274		return (-EIO);
3275	return partition;
3276}
3277
3278
3279/* Change the partition if necessary */
3280static int switch_partition(struct scsi_tape *STp)
3281{
3282	struct st_partstat *STps;
3283
3284	if (STp->partition == STp->new_partition)
3285		return 0;
3286	STps = &(STp->ps[STp->new_partition]);
3287	if (!STps->last_block_valid)
3288		STps->last_block_visited = 0;
3289	return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3290}
3291
3292/* Functions for reading and writing the medium partition mode page. */
3293
3294#define PART_PAGE   0x11
3295#define PART_PAGE_FIXED_LENGTH 8
3296
3297#define PP_OFF_MAX_ADD_PARTS   2
3298#define PP_OFF_NBR_ADD_PARTS   3
3299#define PP_OFF_FLAGS           4
3300#define PP_OFF_PART_UNITS      6
3301#define PP_OFF_RESERVED        7
3302
3303#define PP_BIT_IDP             0x20
3304#define PP_BIT_FDP             0x80
3305#define PP_MSK_PSUM_MB         0x10
3306#define PP_MSK_PSUM_UNITS      0x18
3307#define PP_MSK_POFM            0x04
3308
3309/* Get the number of partitions on the tape. As a side effect reads the
3310   mode page into the tape buffer. */
3311static int nbr_partitions(struct scsi_tape *STp)
3312{
3313	int result;
3314
3315	if (STp->ready != ST_READY)
3316		return (-EIO);
3317
3318	result = read_mode_page(STp, PART_PAGE, 1);
3319
3320	if (result) {
3321		DEBC_printk(STp, "Can't read medium partition page.\n");
3322		result = (-EIO);
3323	} else {
3324		result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3325					      PP_OFF_NBR_ADD_PARTS] + 1;
3326		DEBC_printk(STp, "Number of partitions %d.\n", result);
3327	}
3328
3329	return result;
3330}
3331
3332
3333static int format_medium(struct scsi_tape *STp, int format)
3334{
3335	int result = 0;
3336	int timeout = STp->long_timeout;
3337	unsigned char scmd[MAX_COMMAND_SIZE];
3338	struct st_request *SRpnt;
3339
3340	memset(scmd, 0, MAX_COMMAND_SIZE);
3341	scmd[0] = FORMAT_UNIT;
3342	scmd[2] = format;
3343	if (STp->immediate) {
3344		scmd[1] |= 1;		/* Don't wait for completion */
3345		timeout = STp->device->request_queue->rq_timeout;
3346	}
3347	DEBC_printk(STp, "Sending FORMAT MEDIUM\n");
3348	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3349			   timeout, MAX_RETRIES, 1);
3350	if (!SRpnt)
3351		result = STp->buffer->syscall_result;
3352	return result;
3353}
3354
3355
3356/* Partition the tape into two partitions if size > 0 or one partition if
3357   size == 0.
3358
3359   The block descriptors are read and written because Sony SDT-7000 does not
3360   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3361
3362   My HP C1533A drive returns only one partition size field. This is used to
3363   set the size of partition 1. There is no size field for the default partition.
3364   Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3365   used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3366   The following algorithm is used to accommodate both drives: if the number of
3367   partition size fields is greater than the maximum number of additional partitions
3368   in the mode page, the second field is used. Otherwise the first field is used.
3369
3370   For Seagate DDS drives the page length must be 8 when no partitions is defined
3371   and 10 when 1 partition is defined (information from Eric Lee Green). This is
3372   is acceptable also to some other old drives and enforced if the first partition
3373   size field is used for the first additional partition size.
3374
3375   For drives that advertize SCSI-3 or newer, use the SSC-3 methods.
3376 */
3377static int partition_tape(struct scsi_tape *STp, int size)
3378{
3379	int result;
3380	int target_partition;
3381	bool scsi3 = STp->device->scsi_level >= SCSI_3, needs_format = false;
3382	int pgo, psd_cnt, psdo;
3383	int psum = PP_MSK_PSUM_MB, units = 0;
3384	unsigned char *bp;
3385
3386	result = read_mode_page(STp, PART_PAGE, 0);
3387	if (result) {
3388		DEBC_printk(STp, "Can't read partition mode page.\n");
3389		return result;
3390	}
3391	target_partition = 1;
3392	if (size < 0) {
3393		target_partition = 0;
3394		size = -size;
3395	}
3396
3397	/* The mode page is in the buffer. Let's modify it and write it. */
3398	bp = (STp->buffer)->b_data;
3399	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3400	DEBC_printk(STp, "Partition page length is %d bytes.\n",
3401		    bp[pgo + MP_OFF_PAGE_LENGTH] + 2);
3402
3403	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
3404
3405	if (scsi3) {
3406		needs_format = (bp[pgo + PP_OFF_FLAGS] & PP_MSK_POFM) != 0;
3407		if (needs_format && size == 0) {
3408			/* No need to write the mode page when clearing
3409			 *  partitioning
3410			 */
3411			DEBC_printk(STp, "Formatting tape with one partition.\n");
3412			result = format_medium(STp, 0);
3413			goto out;
3414		}
3415		if (needs_format)  /* Leave the old value for HP DATs claiming SCSI_3 */
3416			psd_cnt = 2;
3417		if ((bp[pgo + PP_OFF_FLAGS] & PP_MSK_PSUM_UNITS) == PP_MSK_PSUM_UNITS) {
3418			/* Use units scaling for large partitions if the device
3419			 * suggests it and no precision lost. Required for IBM
3420			 * TS1140/50 drives that don't support MB units.
3421			 */
3422			if (size >= 1000 && (size % 1000) == 0) {
3423				size /= 1000;
3424				psum = PP_MSK_PSUM_UNITS;
3425				units = 9; /* GB */
3426			}
3427		}
3428		/* Try it anyway if too large to specify in MB */
3429		if (psum == PP_MSK_PSUM_MB && size >= 65534) {
3430			size /= 1000;
3431			psum = PP_MSK_PSUM_UNITS;
3432			units = 9;  /* GB */
3433		}
3434	}
3435
3436	if (size >= 65535 ||  /* Does not fit into two bytes */
3437	    (target_partition == 0 && psd_cnt < 2)) {
3438		result = -EINVAL;
3439		goto out;
3440	}
3441
3442	psdo = pgo + PART_PAGE_FIXED_LENGTH;
3443	/* The second condition is for HP DDS which use only one partition size
3444	 * descriptor
3445	 */
3446	if (target_partition > 0 &&
3447	    (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS] ||
3448	     bp[pgo + PP_OFF_MAX_ADD_PARTS] != 1)) {
3449		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest to partition 0 */
3450		psdo += 2;
3451	}
3452	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3453
3454	DEBC_printk(STp, "psd_cnt %d, max.parts %d, nbr_parts %d\n",
3455		    psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3456		    bp[pgo + PP_OFF_NBR_ADD_PARTS]);
3457
3458	if (size == 0) {
3459		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3460		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3461		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3462		DEBC_printk(STp, "Formatting tape with one partition.\n");
3463	} else {
3464		bp[psdo] = (size >> 8) & 0xff;
3465		bp[psdo + 1] = size & 0xff;
3466		if (target_partition == 0)
3467			bp[psdo + 2] = bp[psdo + 3] = 0xff;
3468		bp[pgo + 3] = 1;
3469		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3470		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3471		DEBC_printk(STp,
3472			    "Formatting tape with two partitions (%i = %d MB).\n",
3473			    target_partition, units > 0 ? size * 1000 : size);
3474	}
3475	bp[pgo + PP_OFF_PART_UNITS] = 0;
3476	bp[pgo + PP_OFF_RESERVED] = 0;
3477	if (size != 1 || units != 0) {
3478		bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | psum |
3479			(bp[pgo + PP_OFF_FLAGS] & 0x07);
3480		bp[pgo + PP_OFF_PART_UNITS] = units;
3481	} else
3482		bp[pgo + PP_OFF_FLAGS] = PP_BIT_FDP |
3483			(bp[pgo + PP_OFF_FLAGS] & 0x1f);
3484	bp[pgo + MP_OFF_PAGE_LENGTH] = 6 + psd_cnt * 2;
3485
3486	result = write_mode_page(STp, PART_PAGE, 1);
3487
3488	if (!result && needs_format)
3489		result = format_medium(STp, 1);
3490
3491	if (result) {
3492		st_printk(KERN_INFO, STp, "Partitioning of tape failed.\n");
3493		result = (-EIO);
3494	}
3495
3496out:
3497	return result;
3498}
3499
3500
3501
3502/* The ioctl command */
3503static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3504{
3505	int i, cmd_nr, cmd_type, bt;
3506	int retval = 0;
3507	unsigned int blk;
3508	struct scsi_tape *STp = file->private_data;
3509	struct st_modedef *STm;
3510	struct st_partstat *STps;
3511	void __user *p = (void __user *)arg;
3512
3513	if (mutex_lock_interruptible(&STp->lock))
3514		return -ERESTARTSYS;
3515
3516	DEB(
3517	if (debugging && !STp->in_use) {
3518		st_printk(ST_DEB_MSG, STp, "Incorrect device.\n");
3519		retval = (-EIO);
3520		goto out;
3521	} ) /* end DEB */
3522
3523	STm = &(STp->modes[STp->current_mode]);
3524	STps = &(STp->ps[STp->partition]);
3525
3526	/*
3527	 * If we are in the middle of error recovery, don't let anyone
3528	 * else try and use this device.  Also, if error recovery fails, it
3529	 * may try and take the device offline, in which case all further
3530	 * access to the device is prohibited.
3531	 */
3532	retval = scsi_ioctl_block_when_processing_errors(STp->device, cmd_in,
3533			file->f_flags & O_NDELAY);
3534	if (retval)
3535		goto out;
3536
3537	cmd_type = _IOC_TYPE(cmd_in);
3538	cmd_nr = _IOC_NR(cmd_in);
3539
3540	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3541		struct mtop mtc;
3542
3543		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3544			retval = (-EINVAL);
3545			goto out;
3546		}
3547
3548		i = copy_from_user(&mtc, p, sizeof(struct mtop));
3549		if (i) {
3550			retval = (-EFAULT);
3551			goto out;
3552		}
3553
3554		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3555			st_printk(KERN_WARNING, STp,
3556				  "MTSETDRVBUFFER only allowed for root.\n");
3557			retval = (-EPERM);
3558			goto out;
3559		}
3560		if (!STm->defined &&
3561		    (mtc.mt_op != MTSETDRVBUFFER &&
3562		     (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3563			retval = (-ENXIO);
3564			goto out;
3565		}
3566
3567		if (!STp->pos_unknown) {
3568
3569			if (STps->eof == ST_FM_HIT) {
3570				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3571                                    mtc.mt_op == MTEOM) {
3572					mtc.mt_count -= 1;
3573					if (STps->drv_file >= 0)
3574						STps->drv_file += 1;
3575				} else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3576					mtc.mt_count += 1;
3577					if (STps->drv_file >= 0)
3578						STps->drv_file += 1;
3579				}
3580			}
3581
3582			if (mtc.mt_op == MTSEEK) {
3583				/* Old position must be restored if partition will be
3584                                   changed */
3585				i = !STp->can_partitions ||
3586				    (STp->new_partition != STp->partition);
3587			} else {
3588				i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3589				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3590				    mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3591				    mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3592				    mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3593				    mtc.mt_op == MTCOMPRESSION;
3594			}
3595			i = flush_buffer(STp, i);
3596			if (i < 0) {
3597				retval = i;
3598				goto out;
3599			}
3600			if (STps->rw == ST_WRITING &&
3601			    (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3602			     mtc.mt_op == MTSEEK ||
3603			     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3604				i = st_int_ioctl(STp, MTWEOF, 1);
3605				if (i < 0) {
3606					retval = i;
3607					goto out;
3608				}
3609				if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3610					mtc.mt_count++;
3611				STps->rw = ST_IDLE;
3612			     }
3613
3614		} else {
3615			/*
3616			 * If there was a bus reset, block further access
3617			 * to this device.  If the user wants to rewind the tape,
3618			 * then reset the flag and allow access again.
3619			 */
3620			if (mtc.mt_op != MTREW &&
3621			    mtc.mt_op != MTOFFL &&
3622			    mtc.mt_op != MTRETEN &&
3623			    mtc.mt_op != MTERASE &&
3624			    mtc.mt_op != MTSEEK &&
3625			    mtc.mt_op != MTEOM) {
3626				retval = (-EIO);
3627				goto out;
3628			}
3629			reset_state(STp);
3630			/* remove this when the midlevel properly clears was_reset */
3631			STp->device->was_reset = 0;
3632		}
3633
3634		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3635		    mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3636		    mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3637			STps->rw = ST_IDLE;	/* Prevent automatic WEOF and fsf */
3638
3639		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3640			do_door_lock(STp, 0);	/* Ignore result! */
3641
3642		if (mtc.mt_op == MTSETDRVBUFFER &&
3643		    (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3644			retval = st_set_options(STp, mtc.mt_count);
3645			goto out;
3646		}
3647
3648		if (mtc.mt_op == MTSETPART) {
3649			if (!STp->can_partitions ||
3650			    mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3651				retval = (-EINVAL);
3652				goto out;
3653			}
3654			if (mtc.mt_count >= STp->nbr_partitions &&
3655			    (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3656				retval = (-EIO);
3657				goto out;
3658			}
3659			if (mtc.mt_count >= STp->nbr_partitions) {
3660				retval = (-EINVAL);
3661				goto out;
3662			}
3663			STp->new_partition = mtc.mt_count;
3664			retval = 0;
3665			goto out;
3666		}
3667
3668		if (mtc.mt_op == MTMKPART) {
3669			if (!STp->can_partitions) {
3670				retval = (-EINVAL);
3671				goto out;
3672			}
3673			i = do_load_unload(STp, file, 1);
3674			if (i < 0) {
3675				retval = i;
3676				goto out;
3677			}
3678			i = partition_tape(STp, mtc.mt_count);
3679			if (i < 0) {
3680				retval = i;
3681				goto out;
3682			}
3683			for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3684				STp->ps[i].rw = ST_IDLE;
3685				STp->ps[i].at_sm = 0;
3686				STp->ps[i].last_block_valid = 0;
3687			}
3688			STp->partition = STp->new_partition = 0;
3689			STp->nbr_partitions = mtc.mt_count != 0 ? 2 : 1;
3690			STps->drv_block = STps->drv_file = 0;
3691			retval = 0;
3692			goto out;
3693		}
3694
3695		if (mtc.mt_op == MTSEEK) {
3696			i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3697			if (!STp->can_partitions)
3698				STp->ps[0].rw = ST_IDLE;
3699			retval = i;
3700			goto out;
3701		}
3702
3703		if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3704			retval = do_load_unload(STp, file, 0);
3705			goto out;
3706		}
3707
3708		if (mtc.mt_op == MTLOAD) {
3709			retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3710			goto out;
3711		}
3712
3713		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3714			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3715			goto out;
3716		}
3717
3718		if (STp->can_partitions && STp->ready == ST_READY &&
3719		    (i = switch_partition(STp)) < 0) {
3720			retval = i;
3721			goto out;
3722		}
3723
3724		if (mtc.mt_op == MTCOMPRESSION)
3725			retval = st_compression(STp, (mtc.mt_count & 1));
3726		else
3727			retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3728		goto out;
3729	}
3730	if (!STm->defined) {
3731		retval = (-ENXIO);
3732		goto out;
3733	}
3734
3735	if ((i = flush_buffer(STp, 0)) < 0) {
3736		retval = i;
3737		goto out;
3738	}
3739	if (STp->can_partitions &&
3740	    (i = switch_partition(STp)) < 0) {
3741		retval = i;
3742		goto out;
3743	}
3744
3745	if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
3746		struct mtget mt_status;
3747
3748		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3749			 retval = (-EINVAL);
3750			 goto out;
3751		}
3752
3753		mt_status.mt_type = STp->tape_type;
3754		mt_status.mt_dsreg =
3755		    ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3756		    ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3757		mt_status.mt_blkno = STps->drv_block;
3758		mt_status.mt_fileno = STps->drv_file;
3759		if (STp->block_size != 0) {
3760			if (STps->rw == ST_WRITING)
3761				mt_status.mt_blkno +=
3762				    (STp->buffer)->buffer_bytes / STp->block_size;
3763			else if (STps->rw == ST_READING)
3764				mt_status.mt_blkno -=
3765                                        ((STp->buffer)->buffer_bytes +
3766                                         STp->block_size - 1) / STp->block_size;
3767		}
3768
3769		mt_status.mt_gstat = 0;
3770		if (STp->drv_write_prot)
3771			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3772		if (mt_status.mt_blkno == 0) {
3773			if (mt_status.mt_fileno == 0)
3774				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3775			else
3776				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3777		}
3778		mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3779		mt_status.mt_resid = STp->partition;
3780		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3781			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3782		else if (STps->eof >= ST_EOM_OK)
3783			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3784		if (STp->density == 1)
3785			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3786		else if (STp->density == 2)
3787			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3788		else if (STp->density == 3)
3789			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3790		if (STp->ready == ST_READY)
3791			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3792		if (STp->ready == ST_NO_TAPE)
3793			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3794		if (STps->at_sm)
3795			mt_status.mt_gstat |= GMT_SM(0xffffffff);
3796		if (STm->do_async_writes ||
3797                    (STm->do_buffer_writes && STp->block_size != 0) ||
3798		    STp->drv_buffer != 0)
3799			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3800		if (STp->cleaning_req)
3801			mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3802
3803		i = copy_to_user(p, &mt_status, sizeof(struct mtget));
3804		if (i) {
3805			retval = (-EFAULT);
3806			goto out;
3807		}
3808
3809		STp->recover_reg = 0;		/* Clear after read */
3810		retval = 0;
3811		goto out;
3812	}			/* End of MTIOCGET */
3813	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3814		struct mtpos mt_pos;
3815		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3816			 retval = (-EINVAL);
3817			 goto out;
3818		}
3819		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3820			retval = i;
3821			goto out;
3822		}
3823		mt_pos.mt_blkno = blk;
3824		i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
3825		if (i)
3826			retval = (-EFAULT);
3827		goto out;
3828	}
3829	mutex_unlock(&STp->lock);
3830	switch (cmd_in) {
 
 
 
 
 
 
 
 
 
3831		case SCSI_IOCTL_GET_IDLUN:
3832		case SCSI_IOCTL_GET_BUS_NUMBER:
3833			break;
 
3834		default:
3835			if ((cmd_in == SG_IO ||
3836			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3837			     cmd_in == CDROM_SEND_PACKET) &&
3838			    !capable(CAP_SYS_RAWIO))
3839				i = -EPERM;
3840			else
3841				i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3842						   file->f_mode, cmd_in, p);
3843			if (i != -ENOTTY)
3844				return i;
3845			break;
3846	}
3847	retval = scsi_ioctl(STp->device, cmd_in, p);
3848	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
3849		STp->rew_at_close = 0;
3850		STp->ready = ST_NO_TAPE;
3851	}
3852	return retval;
3853
3854 out:
3855	mutex_unlock(&STp->lock);
3856	return retval;
3857}
3858
 
 
 
 
 
 
 
 
 
 
 
 
 
3859#ifdef CONFIG_COMPAT
3860static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3861{
 
3862	struct scsi_tape *STp = file->private_data;
3863	struct scsi_device *sdev = STp->device;
3864	int ret = -ENOIOCTLCMD;
3865	if (sdev->host->hostt->compat_ioctl) { 
 
 
 
 
 
 
3866
3867		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
 
 
3868
3869	}
3870	return ret;
3871}
3872#endif
3873
3874
3875
3876/* Try to allocate a new tape buffer. Calling function must not hold
3877   dev_arr_lock. */
3878static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
3879{
3880	struct st_buffer *tb;
3881
3882	tb = kzalloc(sizeof(struct st_buffer), GFP_KERNEL);
3883	if (!tb) {
3884		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3885		return NULL;
3886	}
3887	tb->frp_segs = 0;
3888	tb->use_sg = max_sg;
3889	tb->dma = need_dma;
3890	tb->buffer_size = 0;
3891
3892	tb->reserved_pages = kcalloc(max_sg, sizeof(struct page *),
3893				     GFP_KERNEL);
3894	if (!tb->reserved_pages) {
3895		kfree(tb);
3896		return NULL;
3897	}
3898
3899	return tb;
3900}
3901
3902
3903/* Try to allocate enough space in the tape buffer */
3904#define ST_MAX_ORDER 6
3905
3906static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
3907{
3908	int segs, max_segs, b_size, order, got;
3909	gfp_t priority;
3910
3911	if (new_size <= STbuffer->buffer_size)
3912		return 1;
3913
3914	if (STbuffer->buffer_size <= PAGE_SIZE)
3915		normalize_buffer(STbuffer);  /* Avoid extra segment */
3916
3917	max_segs = STbuffer->use_sg;
3918
3919	priority = GFP_KERNEL | __GFP_NOWARN;
3920	if (need_dma)
3921		priority |= GFP_DMA;
3922
3923	if (STbuffer->cleared)
3924		priority |= __GFP_ZERO;
3925
3926	if (STbuffer->frp_segs) {
3927		order = STbuffer->reserved_page_order;
3928		b_size = PAGE_SIZE << order;
3929	} else {
3930		for (b_size = PAGE_SIZE, order = 0;
3931		     order < ST_MAX_ORDER &&
3932			     max_segs * (PAGE_SIZE << order) < new_size;
3933		     order++, b_size *= 2)
3934			;  /* empty */
3935		STbuffer->reserved_page_order = order;
3936	}
3937	if (max_segs * (PAGE_SIZE << order) < new_size) {
3938		if (order == ST_MAX_ORDER)
3939			return 0;
3940		normalize_buffer(STbuffer);
3941		return enlarge_buffer(STbuffer, new_size, need_dma);
3942	}
3943
3944	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3945	     segs < max_segs && got < new_size;) {
3946		struct page *page;
3947
3948		page = alloc_pages(priority, order);
3949		if (!page) {
3950			DEB(STbuffer->buffer_size = got);
3951			normalize_buffer(STbuffer);
3952			return 0;
3953		}
3954
3955		STbuffer->frp_segs += 1;
3956		got += b_size;
3957		STbuffer->buffer_size = got;
3958		STbuffer->reserved_pages[segs] = page;
3959		segs++;
3960	}
3961	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3962
3963	return 1;
3964}
3965
3966
3967/* Make sure that no data from previous user is in the internal buffer */
3968static void clear_buffer(struct st_buffer * st_bp)
3969{
3970	int i;
3971
3972	for (i=0; i < st_bp->frp_segs; i++)
3973		memset(page_address(st_bp->reserved_pages[i]), 0,
3974		       PAGE_SIZE << st_bp->reserved_page_order);
3975	st_bp->cleared = 1;
3976}
3977
3978
3979/* Release the extra buffer */
3980static void normalize_buffer(struct st_buffer * STbuffer)
3981{
3982	int i, order = STbuffer->reserved_page_order;
3983
3984	for (i = 0; i < STbuffer->frp_segs; i++) {
3985		__free_pages(STbuffer->reserved_pages[i], order);
3986		STbuffer->buffer_size -= (PAGE_SIZE << order);
3987	}
3988	STbuffer->frp_segs = 0;
3989	STbuffer->sg_segs = 0;
3990	STbuffer->reserved_page_order = 0;
3991	STbuffer->map_data.offset = 0;
3992}
3993
3994
3995/* Move data from the user buffer to the tape buffer. Returns zero (success) or
3996   negative error code. */
3997static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3998{
3999	int i, cnt, res, offset;
4000	int length = PAGE_SIZE << st_bp->reserved_page_order;
4001
4002	for (i = 0, offset = st_bp->buffer_bytes;
4003	     i < st_bp->frp_segs && offset >= length; i++)
4004		offset -= length;
4005	if (i == st_bp->frp_segs) {	/* Should never happen */
4006		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
4007		return (-EIO);
4008	}
4009	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4010		struct page *page = st_bp->reserved_pages[i];
4011		cnt = length - offset < do_count ? length - offset : do_count;
4012		res = copy_from_user(page_address(page) + offset, ubp, cnt);
4013		if (res)
4014			return (-EFAULT);
4015		do_count -= cnt;
4016		st_bp->buffer_bytes += cnt;
4017		ubp += cnt;
4018		offset = 0;
4019	}
4020	if (do_count) /* Should never happen */
4021		return (-EIO);
4022
4023	return 0;
4024}
4025
4026
4027/* Move data from the tape buffer to the user buffer. Returns zero (success) or
4028   negative error code. */
4029static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
4030{
4031	int i, cnt, res, offset;
4032	int length = PAGE_SIZE << st_bp->reserved_page_order;
4033
4034	for (i = 0, offset = st_bp->read_pointer;
4035	     i < st_bp->frp_segs && offset >= length; i++)
4036		offset -= length;
4037	if (i == st_bp->frp_segs) {	/* Should never happen */
4038		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
4039		return (-EIO);
4040	}
4041	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4042		struct page *page = st_bp->reserved_pages[i];
4043		cnt = length - offset < do_count ? length - offset : do_count;
4044		res = copy_to_user(ubp, page_address(page) + offset, cnt);
4045		if (res)
4046			return (-EFAULT);
4047		do_count -= cnt;
4048		st_bp->buffer_bytes -= cnt;
4049		st_bp->read_pointer += cnt;
4050		ubp += cnt;
4051		offset = 0;
4052	}
4053	if (do_count) /* Should never happen */
4054		return (-EIO);
4055
4056	return 0;
4057}
4058
4059
4060/* Move data towards start of buffer */
4061static void move_buffer_data(struct st_buffer * st_bp, int offset)
4062{
4063	int src_seg, dst_seg, src_offset = 0, dst_offset;
4064	int count, total;
4065	int length = PAGE_SIZE << st_bp->reserved_page_order;
4066
4067	if (offset == 0)
4068		return;
4069
4070	total=st_bp->buffer_bytes - offset;
4071	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
4072		src_offset = offset;
4073		if (src_offset < length)
4074			break;
4075		offset -= length;
4076	}
4077
4078	st_bp->buffer_bytes = st_bp->read_pointer = total;
4079	for (dst_seg=dst_offset=0; total > 0; ) {
4080		struct page *dpage = st_bp->reserved_pages[dst_seg];
4081		struct page *spage = st_bp->reserved_pages[src_seg];
4082
4083		count = min(length - dst_offset, length - src_offset);
4084		memmove(page_address(dpage) + dst_offset,
4085			page_address(spage) + src_offset, count);
4086		src_offset += count;
4087		if (src_offset >= length) {
4088			src_seg++;
4089			src_offset = 0;
4090		}
4091		dst_offset += count;
4092		if (dst_offset >= length) {
4093			dst_seg++;
4094			dst_offset = 0;
4095		}
4096		total -= count;
4097	}
4098}
4099
4100/* Validate the options from command line or module parameters */
4101static void validate_options(void)
4102{
4103	if (buffer_kbs > 0)
4104		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
4105	if (max_sg_segs >= ST_FIRST_SG)
4106		st_max_sg_segs = max_sg_segs;
4107}
4108
4109#ifndef MODULE
4110/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
4111 */
4112static int __init st_setup(char *str)
4113{
4114	int i, len, ints[5];
4115	char *stp;
4116
4117	stp = get_options(str, ARRAY_SIZE(ints), ints);
4118
4119	if (ints[0] > 0) {
4120		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
4121			if (parms[i].val)
4122				*parms[i].val = ints[i + 1];
4123	} else {
4124		while (stp != NULL) {
4125			for (i = 0; i < ARRAY_SIZE(parms); i++) {
4126				len = strlen(parms[i].name);
4127				if (!strncmp(stp, parms[i].name, len) &&
4128				    (*(stp + len) == ':' || *(stp + len) == '=')) {
4129					if (parms[i].val)
4130						*parms[i].val =
4131							simple_strtoul(stp + len + 1, NULL, 0);
4132					else
4133						printk(KERN_WARNING "st: Obsolete parameter %s\n",
4134						       parms[i].name);
4135					break;
4136				}
4137			}
4138			if (i >= ARRAY_SIZE(parms))
4139				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
4140					stp);
4141			stp = strchr(stp, ',');
4142			if (stp)
4143				stp++;
4144		}
4145	}
4146
4147	validate_options();
4148
4149	return 1;
4150}
4151
4152__setup("st=", st_setup);
4153
4154#endif
4155
4156static const struct file_operations st_fops =
4157{
4158	.owner =	THIS_MODULE,
4159	.read =		st_read,
4160	.write =	st_write,
4161	.unlocked_ioctl = st_ioctl,
4162#ifdef CONFIG_COMPAT
4163	.compat_ioctl = st_compat_ioctl,
4164#endif
4165	.open =		st_open,
4166	.flush =	st_flush,
4167	.release =	st_release,
4168	.llseek =	noop_llseek,
4169};
4170
4171static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
4172{
4173	int i, error;
4174	dev_t cdev_devno;
4175	struct cdev *cdev;
4176	struct device *dev;
4177	struct st_modedef *STm = &(tape->modes[mode]);
4178	char name[10];
4179	int dev_num = tape->index;
4180
4181	cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
4182
4183	cdev = cdev_alloc();
4184	if (!cdev) {
4185		pr_err("st%d: out of memory. Device not attached.\n", dev_num);
4186		error = -ENOMEM;
4187		goto out;
4188	}
4189	cdev->owner = THIS_MODULE;
4190	cdev->ops = &st_fops;
4191	STm->cdevs[rew] = cdev;
4192
4193	error = cdev_add(cdev, cdev_devno, 1);
4194	if (error) {
4195		pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
4196		       rew ? "non" : "auto", mode);
4197		pr_err("st%d: Device not attached.\n", dev_num);
4198		goto out_free;
4199	}
4200
4201	i = mode << (4 - ST_NBR_MODE_BITS);
4202	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4203		 tape->disk->disk_name, st_formats[i]);
4204
4205	dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
4206			    cdev_devno, &tape->modes[mode], "%s", name);
4207	if (IS_ERR(dev)) {
4208		pr_err("st%d: device_create failed\n", dev_num);
4209		error = PTR_ERR(dev);
4210		goto out_free;
4211	}
4212
4213	STm->devs[rew] = dev;
4214
4215	return 0;
4216out_free:
4217	cdev_del(STm->cdevs[rew]);
4218out:
4219	STm->cdevs[rew] = NULL;
4220	STm->devs[rew] = NULL;
4221	return error;
4222}
4223
4224static int create_cdevs(struct scsi_tape *tape)
4225{
4226	int mode, error;
4227	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4228		error = create_one_cdev(tape, mode, 0);
4229		if (error)
4230			return error;
4231		error = create_one_cdev(tape, mode, 1);
4232		if (error)
4233			return error;
4234	}
4235
4236	return sysfs_create_link(&tape->device->sdev_gendev.kobj,
4237				 &tape->modes[0].devs[0]->kobj, "tape");
4238}
4239
4240static void remove_cdevs(struct scsi_tape *tape)
4241{
4242	int mode, rew;
4243	sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
4244	for (mode = 0; mode < ST_NBR_MODES; mode++) {
4245		struct st_modedef *STm = &(tape->modes[mode]);
4246		for (rew = 0; rew < 2; rew++) {
4247			if (STm->cdevs[rew])
4248				cdev_del(STm->cdevs[rew]);
4249			if (STm->devs[rew])
4250				device_unregister(STm->devs[rew]);
4251		}
4252	}
4253}
4254
4255static int st_probe(struct device *dev)
4256{
4257	struct scsi_device *SDp = to_scsi_device(dev);
4258	struct gendisk *disk = NULL;
4259	struct scsi_tape *tpnt = NULL;
4260	struct st_modedef *STm;
4261	struct st_partstat *STps;
4262	struct st_buffer *buffer;
4263	int i, error;
4264	char *stp;
4265
4266	if (SDp->type != TYPE_TAPE)
4267		return -ENODEV;
4268	if ((stp = st_incompatible(SDp))) {
4269		sdev_printk(KERN_INFO, SDp,
4270			    "OnStream tapes are no longer supported;\n");
4271		sdev_printk(KERN_INFO, SDp,
4272			    "please mail to linux-scsi@vger.kernel.org.\n");
4273		return -ENODEV;
4274	}
4275
4276	scsi_autopm_get_device(SDp);
4277	i = queue_max_segments(SDp->request_queue);
4278	if (st_max_sg_segs < i)
4279		i = st_max_sg_segs;
4280	buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
4281	if (buffer == NULL) {
4282		sdev_printk(KERN_ERR, SDp,
4283			    "st: Can't allocate new tape buffer. "
4284			    "Device not attached.\n");
4285		goto out;
4286	}
4287
4288	disk = alloc_disk(1);
4289	if (!disk) {
4290		sdev_printk(KERN_ERR, SDp,
4291			    "st: out of memory. Device not attached.\n");
4292		goto out_buffer_free;
4293	}
4294
4295	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_KERNEL);
4296	if (tpnt == NULL) {
4297		sdev_printk(KERN_ERR, SDp,
4298			    "st: Can't allocate device descriptor.\n");
4299		goto out_put_disk;
4300	}
4301	kref_init(&tpnt->kref);
4302	tpnt->disk = disk;
4303	disk->private_data = &tpnt->driver;
4304	/* SCSI tape doesn't register this gendisk via add_disk().  Manually
4305	 * take queue reference that release_disk() expects. */
4306	if (!blk_get_queue(SDp->request_queue))
4307		goto out_put_disk;
4308	disk->queue = SDp->request_queue;
4309	tpnt->driver = &st_template;
4310
4311	tpnt->device = SDp;
4312	if (SDp->scsi_level <= 2)
4313		tpnt->tape_type = MT_ISSCSI1;
4314	else
4315		tpnt->tape_type = MT_ISSCSI2;
4316
4317	tpnt->buffer = buffer;
4318	tpnt->buffer->last_SRpnt = NULL;
4319
4320	tpnt->inited = 0;
4321	tpnt->dirty = 0;
4322	tpnt->in_use = 0;
4323	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
4324	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4325	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4326	tpnt->density = 0;
4327	tpnt->do_auto_lock = ST_AUTO_LOCK;
4328	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4329	tpnt->can_partitions = 0;
4330	tpnt->two_fm = ST_TWO_FM;
4331	tpnt->fast_mteom = ST_FAST_MTEOM;
4332	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4333	tpnt->sili = ST_SILI;
4334	tpnt->immediate = ST_NOWAIT;
4335	tpnt->immediate_filemark = 0;
4336	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4337	tpnt->partition = 0;
4338	tpnt->new_partition = 0;
4339	tpnt->nbr_partitions = 0;
4340	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4341	tpnt->long_timeout = ST_LONG_TIMEOUT;
4342	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
4343
4344	for (i = 0; i < ST_NBR_MODES; i++) {
4345		STm = &(tpnt->modes[i]);
4346		STm->defined = 0;
4347		STm->sysv = ST_SYSV;
4348		STm->defaults_for_writes = 0;
4349		STm->do_async_writes = ST_ASYNC_WRITES;
4350		STm->do_buffer_writes = ST_BUFFER_WRITES;
4351		STm->do_read_ahead = ST_READ_AHEAD;
4352		STm->default_compression = ST_DONT_TOUCH;
4353		STm->default_blksize = (-1);	/* No forced size */
4354		STm->default_density = (-1);	/* No forced density */
4355		STm->tape = tpnt;
4356	}
4357
4358	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4359		STps = &(tpnt->ps[i]);
4360		STps->rw = ST_IDLE;
4361		STps->eof = ST_NOEOF;
4362		STps->at_sm = 0;
4363		STps->last_block_valid = 0;
4364		STps->drv_block = (-1);
4365		STps->drv_file = (-1);
4366	}
4367
4368	tpnt->current_mode = 0;
4369	tpnt->modes[0].defined = 1;
4370
4371	tpnt->density_changed = tpnt->compression_changed =
4372	    tpnt->blksize_changed = 0;
4373	mutex_init(&tpnt->lock);
4374
4375	idr_preload(GFP_KERNEL);
4376	spin_lock(&st_index_lock);
4377	error = idr_alloc(&st_index_idr, tpnt, 0, ST_MAX_TAPES + 1, GFP_NOWAIT);
4378	spin_unlock(&st_index_lock);
4379	idr_preload_end();
4380	if (error < 0) {
4381		pr_warn("st: idr allocation failed: %d\n", error);
4382		goto out_put_queue;
4383	}
4384	tpnt->index = error;
4385	sprintf(disk->disk_name, "st%d", tpnt->index);
4386	tpnt->stats = kzalloc(sizeof(struct scsi_tape_stats), GFP_KERNEL);
4387	if (tpnt->stats == NULL) {
4388		sdev_printk(KERN_ERR, SDp,
4389			    "st: Can't allocate statistics.\n");
4390		goto out_idr_remove;
4391	}
4392
4393	dev_set_drvdata(dev, tpnt);
4394
4395
4396	error = create_cdevs(tpnt);
4397	if (error)
4398		goto out_remove_devs;
4399	scsi_autopm_put_device(SDp);
4400
4401	sdev_printk(KERN_NOTICE, SDp,
4402		    "Attached scsi tape %s\n", tape_name(tpnt));
4403	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4404		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4405		    queue_dma_alignment(SDp->request_queue) + 1);
4406
4407	return 0;
4408
4409out_remove_devs:
4410	remove_cdevs(tpnt);
4411	kfree(tpnt->stats);
4412out_idr_remove:
4413	spin_lock(&st_index_lock);
4414	idr_remove(&st_index_idr, tpnt->index);
4415	spin_unlock(&st_index_lock);
4416out_put_queue:
4417	blk_put_queue(disk->queue);
4418out_put_disk:
4419	put_disk(disk);
4420	kfree(tpnt);
4421out_buffer_free:
4422	kfree(buffer);
4423out:
4424	scsi_autopm_put_device(SDp);
4425	return -ENODEV;
4426};
4427
4428
4429static int st_remove(struct device *dev)
4430{
4431	struct scsi_tape *tpnt = dev_get_drvdata(dev);
4432	int index = tpnt->index;
4433
4434	scsi_autopm_get_device(to_scsi_device(dev));
4435	remove_cdevs(tpnt);
4436
4437	mutex_lock(&st_ref_mutex);
4438	kref_put(&tpnt->kref, scsi_tape_release);
4439	mutex_unlock(&st_ref_mutex);
4440	spin_lock(&st_index_lock);
4441	idr_remove(&st_index_idr, index);
4442	spin_unlock(&st_index_lock);
4443	return 0;
4444}
4445
4446/**
4447 *      scsi_tape_release - Called to free the Scsi_Tape structure
4448 *      @kref: pointer to embedded kref
4449 *
4450 *      st_ref_mutex must be held entering this routine.  Because it is
4451 *      called on last put, you should always use the scsi_tape_get()
4452 *      scsi_tape_put() helpers which manipulate the semaphore directly
4453 *      and never do a direct kref_put().
4454 **/
4455static void scsi_tape_release(struct kref *kref)
4456{
4457	struct scsi_tape *tpnt = to_scsi_tape(kref);
4458	struct gendisk *disk = tpnt->disk;
4459
4460	tpnt->device = NULL;
4461
4462	if (tpnt->buffer) {
4463		normalize_buffer(tpnt->buffer);
4464		kfree(tpnt->buffer->reserved_pages);
4465		kfree(tpnt->buffer);
4466	}
4467
4468	disk->private_data = NULL;
4469	put_disk(disk);
4470	kfree(tpnt->stats);
4471	kfree(tpnt);
4472	return;
4473}
4474
4475static struct class st_sysfs_class = {
4476	.name = "scsi_tape",
4477	.dev_groups = st_dev_groups,
4478};
4479
4480static int __init init_st(void)
4481{
4482	int err;
4483
4484	validate_options();
4485
4486	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4487		verstr, st_fixed_buffer_size, st_max_sg_segs);
4488
4489	debugging = (debug_flag > 0) ? debug_flag : NO_DEBUG;
4490	if (debugging) {
4491		printk(KERN_INFO "st: Debugging enabled debug_flag = %d\n",
4492			debugging);
4493	}
4494
4495	err = class_register(&st_sysfs_class);
4496	if (err) {
4497		pr_err("Unable register sysfs class for SCSI tapes\n");
4498		return err;
4499	}
4500
4501	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4502				     ST_MAX_TAPE_ENTRIES, "st");
4503	if (err) {
4504		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4505		       SCSI_TAPE_MAJOR);
4506		goto err_class;
4507	}
4508
4509	err = scsi_register_driver(&st_template.gendrv);
4510	if (err)
4511		goto err_chrdev;
4512
4513	return 0;
4514
4515err_chrdev:
4516	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4517				 ST_MAX_TAPE_ENTRIES);
4518err_class:
4519	class_unregister(&st_sysfs_class);
4520	return err;
4521}
4522
4523static void __exit exit_st(void)
4524{
4525	scsi_unregister_driver(&st_template.gendrv);
4526	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4527				 ST_MAX_TAPE_ENTRIES);
4528	class_unregister(&st_sysfs_class);
4529	idr_destroy(&st_index_idr);
4530	printk(KERN_INFO "st: Unloaded.\n");
4531}
4532
4533module_init(init_st);
4534module_exit(exit_st);
4535
4536
4537/* The sysfs driver interface. Read-only at the moment */
4538static ssize_t try_direct_io_show(struct device_driver *ddp, char *buf)
4539{
4540	return scnprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4541}
4542static DRIVER_ATTR_RO(try_direct_io);
4543
4544static ssize_t fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4545{
4546	return scnprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4547}
4548static DRIVER_ATTR_RO(fixed_buffer_size);
4549
4550static ssize_t max_sg_segs_show(struct device_driver *ddp, char *buf)
4551{
4552	return scnprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4553}
4554static DRIVER_ATTR_RO(max_sg_segs);
4555
4556static ssize_t version_show(struct device_driver *ddd, char *buf)
4557{
4558	return scnprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4559}
4560static DRIVER_ATTR_RO(version);
4561
4562#if DEBUG
4563static ssize_t debug_flag_store(struct device_driver *ddp,
4564	const char *buf, size_t count)
4565{
4566/* We only care what the first byte of the data is the rest is unused.
4567 * if it's a '1' we turn on debug and if it's a '0' we disable it. All
4568 * other values have -EINVAL returned if they are passed in.
4569 */
4570	if (count > 0) {
4571		if (buf[0] == '0') {
4572			debugging = NO_DEBUG;
4573			return count;
4574		} else if (buf[0] == '1') {
4575			debugging = 1;
4576			return count;
4577		}
4578	}
4579	return -EINVAL;
4580}
4581
4582static ssize_t debug_flag_show(struct device_driver *ddp, char *buf)
4583{
4584	return scnprintf(buf, PAGE_SIZE, "%d\n", debugging);
4585}
4586static DRIVER_ATTR_RW(debug_flag);
4587#endif
4588
4589static struct attribute *st_drv_attrs[] = {
4590	&driver_attr_try_direct_io.attr,
4591	&driver_attr_fixed_buffer_size.attr,
4592	&driver_attr_max_sg_segs.attr,
4593	&driver_attr_version.attr,
4594#if DEBUG
4595	&driver_attr_debug_flag.attr,
4596#endif
4597	NULL,
4598};
4599ATTRIBUTE_GROUPS(st_drv);
4600
4601/* The sysfs simple class interface */
4602static ssize_t
4603defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4604{
4605	struct st_modedef *STm = dev_get_drvdata(dev);
4606	ssize_t l = 0;
4607
4608	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4609	return l;
4610}
4611static DEVICE_ATTR_RO(defined);
4612
4613static ssize_t
4614default_blksize_show(struct device *dev, struct device_attribute *attr,
4615		     char *buf)
4616{
4617	struct st_modedef *STm = dev_get_drvdata(dev);
4618	ssize_t l = 0;
4619
4620	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4621	return l;
4622}
4623static DEVICE_ATTR_RO(default_blksize);
4624
4625static ssize_t
4626default_density_show(struct device *dev, struct device_attribute *attr,
4627		     char *buf)
4628{
4629	struct st_modedef *STm = dev_get_drvdata(dev);
4630	ssize_t l = 0;
4631	char *fmt;
4632
4633	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4634	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4635	return l;
4636}
4637static DEVICE_ATTR_RO(default_density);
4638
4639static ssize_t
4640default_compression_show(struct device *dev, struct device_attribute *attr,
4641			 char *buf)
4642{
4643	struct st_modedef *STm = dev_get_drvdata(dev);
4644	ssize_t l = 0;
4645
4646	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4647	return l;
4648}
4649static DEVICE_ATTR_RO(default_compression);
4650
4651static ssize_t
4652options_show(struct device *dev, struct device_attribute *attr, char *buf)
4653{
4654	struct st_modedef *STm = dev_get_drvdata(dev);
4655	struct scsi_tape *STp = STm->tape;
4656	int options;
4657	ssize_t l = 0;
4658
4659	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4660	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4661	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4662	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4663	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4664	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4665	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4666	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4667	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4668	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4669	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4670	options |= STm->sysv ? MT_ST_SYSV : 0;
4671	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4672	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4673	options |= STp->sili ? MT_ST_SILI : 0;
4674
4675	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4676	return l;
4677}
4678static DEVICE_ATTR_RO(options);
4679
4680/* Support for tape stats */
4681
4682/**
4683 * read_cnt_show - return read count - count of reads made from tape drive
4684 * @dev: struct device
4685 * @attr: attribute structure
4686 * @buf: buffer to return formatted data in
4687 */
4688static ssize_t read_cnt_show(struct device *dev,
4689	struct device_attribute *attr, char *buf)
4690{
4691	struct st_modedef *STm = dev_get_drvdata(dev);
4692
4693	return sprintf(buf, "%lld",
4694		       (long long)atomic64_read(&STm->tape->stats->read_cnt));
4695}
4696static DEVICE_ATTR_RO(read_cnt);
4697
4698/**
4699 * read_byte_cnt_show - return read byte count - tape drives
4700 * may use blocks less than 512 bytes this gives the raw byte count of
4701 * of data read from the tape drive.
4702 * @dev: struct device
4703 * @attr: attribute structure
4704 * @buf: buffer to return formatted data in
4705 */
4706static ssize_t read_byte_cnt_show(struct device *dev,
4707	struct device_attribute *attr, char *buf)
4708{
4709	struct st_modedef *STm = dev_get_drvdata(dev);
4710
4711	return sprintf(buf, "%lld",
4712		       (long long)atomic64_read(&STm->tape->stats->read_byte_cnt));
4713}
4714static DEVICE_ATTR_RO(read_byte_cnt);
4715
4716/**
4717 * read_ns_show - return read ns - overall time spent waiting on reads in ns.
4718 * @dev: struct device
4719 * @attr: attribute structure
4720 * @buf: buffer to return formatted data in
4721 */
4722static ssize_t read_ns_show(struct device *dev,
4723	struct device_attribute *attr, char *buf)
4724{
4725	struct st_modedef *STm = dev_get_drvdata(dev);
4726
4727	return sprintf(buf, "%lld",
4728		       (long long)atomic64_read(&STm->tape->stats->tot_read_time));
4729}
4730static DEVICE_ATTR_RO(read_ns);
4731
4732/**
4733 * write_cnt_show - write count - number of user calls
4734 * to write(2) that have written data to tape.
4735 * @dev: struct device
4736 * @attr: attribute structure
4737 * @buf: buffer to return formatted data in
4738 */
4739static ssize_t write_cnt_show(struct device *dev,
4740	struct device_attribute *attr, char *buf)
4741{
4742	struct st_modedef *STm = dev_get_drvdata(dev);
4743
4744	return sprintf(buf, "%lld",
4745		       (long long)atomic64_read(&STm->tape->stats->write_cnt));
4746}
4747static DEVICE_ATTR_RO(write_cnt);
4748
4749/**
4750 * write_byte_cnt_show - write byte count - raw count of
4751 * bytes written to tape.
4752 * @dev: struct device
4753 * @attr: attribute structure
4754 * @buf: buffer to return formatted data in
4755 */
4756static ssize_t write_byte_cnt_show(struct device *dev,
4757	struct device_attribute *attr, char *buf)
4758{
4759	struct st_modedef *STm = dev_get_drvdata(dev);
4760
4761	return sprintf(buf, "%lld",
4762		       (long long)atomic64_read(&STm->tape->stats->write_byte_cnt));
4763}
4764static DEVICE_ATTR_RO(write_byte_cnt);
4765
4766/**
4767 * write_ns_show - write ns - number of nanoseconds waiting on write
4768 * requests to complete.
4769 * @dev: struct device
4770 * @attr: attribute structure
4771 * @buf: buffer to return formatted data in
4772 */
4773static ssize_t write_ns_show(struct device *dev,
4774	struct device_attribute *attr, char *buf)
4775{
4776	struct st_modedef *STm = dev_get_drvdata(dev);
4777
4778	return sprintf(buf, "%lld",
4779		       (long long)atomic64_read(&STm->tape->stats->tot_write_time));
4780}
4781static DEVICE_ATTR_RO(write_ns);
4782
4783/**
4784 * in_flight_show - number of I/Os currently in flight -
4785 * in most cases this will be either 0 or 1. It may be higher if someone
4786 * has also issued other SCSI commands such as via an ioctl.
4787 * @dev: struct device
4788 * @attr: attribute structure
4789 * @buf: buffer to return formatted data in
4790 */
4791static ssize_t in_flight_show(struct device *dev,
4792	struct device_attribute *attr, char *buf)
4793{
4794	struct st_modedef *STm = dev_get_drvdata(dev);
4795
4796	return sprintf(buf, "%lld",
4797		       (long long)atomic64_read(&STm->tape->stats->in_flight));
4798}
4799static DEVICE_ATTR_RO(in_flight);
4800
4801/**
4802 * io_ns_show - io wait ns - this is the number of ns spent
4803 * waiting on all I/O to complete. This includes tape movement commands
4804 * such as rewinding, seeking to end of file or tape, it also includes
4805 * read and write. To determine the time spent on tape movement
4806 * subtract the read and write ns from this value.
4807 * @dev: struct device
4808 * @attr: attribute structure
4809 * @buf: buffer to return formatted data in
4810 */
4811static ssize_t io_ns_show(struct device *dev,
4812	struct device_attribute *attr, char *buf)
4813{
4814	struct st_modedef *STm = dev_get_drvdata(dev);
4815
4816	return sprintf(buf, "%lld",
4817		       (long long)atomic64_read(&STm->tape->stats->tot_io_time));
4818}
4819static DEVICE_ATTR_RO(io_ns);
4820
4821/**
4822 * other_cnt_show - other io count - this is the number of
4823 * I/O requests other than read and write requests.
4824 * Typically these are tape movement requests but will include driver
4825 * tape movement. This includes only requests issued by the st driver.
4826 * @dev: struct device
4827 * @attr: attribute structure
4828 * @buf: buffer to return formatted data in
4829 */
4830static ssize_t other_cnt_show(struct device *dev,
4831	struct device_attribute *attr, char *buf)
4832{
4833	struct st_modedef *STm = dev_get_drvdata(dev);
4834
4835	return sprintf(buf, "%lld",
4836		       (long long)atomic64_read(&STm->tape->stats->other_cnt));
4837}
4838static DEVICE_ATTR_RO(other_cnt);
4839
4840/**
4841 * resid_cnt_show - A count of the number of times we get a residual
4842 * count - this should indicate someone issuing reads larger than the
4843 * block size on tape.
4844 * @dev: struct device
4845 * @attr: attribute structure
4846 * @buf: buffer to return formatted data in
4847 */
4848static ssize_t resid_cnt_show(struct device *dev,
4849	struct device_attribute *attr, char *buf)
4850{
4851	struct st_modedef *STm = dev_get_drvdata(dev);
4852
4853	return sprintf(buf, "%lld",
4854		       (long long)atomic64_read(&STm->tape->stats->resid_cnt));
4855}
4856static DEVICE_ATTR_RO(resid_cnt);
4857
4858static struct attribute *st_dev_attrs[] = {
4859	&dev_attr_defined.attr,
4860	&dev_attr_default_blksize.attr,
4861	&dev_attr_default_density.attr,
4862	&dev_attr_default_compression.attr,
4863	&dev_attr_options.attr,
4864	NULL,
4865};
4866
4867static struct attribute *st_stats_attrs[] = {
4868	&dev_attr_read_cnt.attr,
4869	&dev_attr_read_byte_cnt.attr,
4870	&dev_attr_read_ns.attr,
4871	&dev_attr_write_cnt.attr,
4872	&dev_attr_write_byte_cnt.attr,
4873	&dev_attr_write_ns.attr,
4874	&dev_attr_in_flight.attr,
4875	&dev_attr_io_ns.attr,
4876	&dev_attr_other_cnt.attr,
4877	&dev_attr_resid_cnt.attr,
4878	NULL,
4879};
4880
4881static struct attribute_group stats_group = {
4882	.name = "stats",
4883	.attrs = st_stats_attrs,
4884};
4885
4886static struct attribute_group st_group = {
4887	.attrs = st_dev_attrs,
4888};
4889
4890static const struct attribute_group *st_dev_groups[] = {
4891	&st_group,
4892	&stats_group,
4893	NULL,
4894};
4895
4896/* The following functions may be useful for a larger audience. */
4897static int sgl_map_user_pages(struct st_buffer *STbp,
4898			      const unsigned int max_pages, unsigned long uaddr,
4899			      size_t count, int rw)
4900{
4901	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4902	unsigned long start = uaddr >> PAGE_SHIFT;
4903	const int nr_pages = end - start;
4904	int res, i, j;
4905	struct page **pages;
4906	struct rq_map_data *mdata = &STbp->map_data;
4907
4908	/* User attempted Overflow! */
4909	if ((uaddr + count) < uaddr)
4910		return -EINVAL;
4911
4912	/* Too big */
4913        if (nr_pages > max_pages)
4914		return -ENOMEM;
4915
4916	/* Hmm? */
4917	if (count == 0)
4918		return 0;
4919
4920	pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
4921	if (pages == NULL)
4922		return -ENOMEM;
4923
4924        /* Try to fault in all of the necessary pages */
4925        /* rw==READ means read from drive, write into memory area */
4926	res = get_user_pages_fast(uaddr, nr_pages, rw == READ ? FOLL_WRITE : 0,
4927				  pages);
4928
4929	/* Errors and no page mapped should return here */
4930	if (res < nr_pages)
4931		goto out_unmap;
4932
4933        for (i=0; i < nr_pages; i++) {
4934                /* FIXME: flush superflous for rw==READ,
4935                 * probably wrong function for rw==WRITE
4936                 */
4937		flush_dcache_page(pages[i]);
4938        }
4939
4940	mdata->offset = uaddr & ~PAGE_MASK;
4941	STbp->mapped_pages = pages;
4942
4943	return nr_pages;
4944 out_unmap:
4945	if (res > 0) {
4946		for (j=0; j < res; j++)
4947			put_page(pages[j]);
4948		res = 0;
4949	}
4950	kfree(pages);
4951	return res;
4952}
4953
4954
4955/* And unmap them... */
4956static int sgl_unmap_user_pages(struct st_buffer *STbp,
4957				const unsigned int nr_pages, int dirtied)
4958{
4959	int i;
 
4960
4961	for (i=0; i < nr_pages; i++) {
4962		struct page *page = STbp->mapped_pages[i];
4963
4964		if (dirtied)
4965			SetPageDirty(page);
4966		/* FIXME: cache flush missing for rw==READ
4967		 * FIXME: call the correct reference counting function
4968		 */
4969		put_page(page);
4970	}
4971	kfree(STbp->mapped_pages);
4972	STbp->mapped_pages = NULL;
4973
4974	return 0;
4975}