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v6.8
   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/major.h>
  36#include <linux/cdrom.h>
  37#include <linux/ioctl.h>
  38#include <linux/fcntl.h>
  39#include <linux/spinlock.h>
  40#include <linux/blkdev.h>
  41#include <linux/moduleparam.h>
  42#include <linux/cdev.h>
  43#include <linux/idr.h>
  44#include <linux/delay.h>
  45#include <linux/mutex.h>
  46
  47#include <linux/uaccess.h>
  48#include <asm/dma.h>
  49#include <asm/unaligned.h>
  50
  51#include <scsi/scsi.h>
  52#include <scsi/scsi_dbg.h>
  53#include <scsi/scsi_device.h>
  54#include <scsi/scsi_driver.h>
  55#include <scsi/scsi_eh.h>
  56#include <scsi/scsi_host.h>
  57#include <scsi/scsi_ioctl.h>
  58#include <scsi/sg.h>
  59
  60
  61/* The driver prints some debugging information on the console if DEBUG
  62   is defined and non-zero. */
  63#define DEBUG 1
  64#define NO_DEBUG 0
  65
  66#define ST_DEB_MSG  KERN_NOTICE
  67#if DEBUG
  68/* The message level for the debug messages is currently set to KERN_NOTICE
  69   so that people can easily see the messages. Later when the debugging messages
  70   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
  71#define DEB(a) a
  72#define DEBC(a) if (debugging) { a ; }
  73#else
  74#define DEB(a)
  75#define DEBC(a)
  76#endif
  77
  78#define ST_KILOBYTE 1024
  79
  80#include "st_options.h"
  81#include "st.h"
  82
  83static int buffer_kbs;
  84static int max_sg_segs;
  85static int try_direct_io = TRY_DIRECT_IO;
  86static int try_rdio = 1;
  87static int try_wdio = 1;
  88static int debug_flag;
  89
  90static struct class st_sysfs_class;
  91static const struct attribute_group *st_dev_groups[];
  92static const struct attribute_group *st_drv_groups[];
  93
  94MODULE_AUTHOR("Kai Makisara");
  95MODULE_DESCRIPTION("SCSI tape (st) driver");
  96MODULE_LICENSE("GPL");
  97MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  98MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  99
 100/* Set 'perm' (4th argument) to 0 to disable module_param's definition
 101 * of sysfs parameters (which module_param doesn't yet support).
 102 * Sysfs parameters defined explicitly later.
 103 */
 104module_param_named(buffer_kbs, buffer_kbs, int, 0);
 105MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
 106module_param_named(max_sg_segs, max_sg_segs, int, 0);
 107MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 108module_param_named(try_direct_io, try_direct_io, int, 0);
 109MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 110module_param_named(debug_flag, debug_flag, int, 0);
 111MODULE_PARM_DESC(debug_flag, "Enable DEBUG, same as setting debugging=1");
 112
 113
 114/* Extra parameters for testing */
 115module_param_named(try_rdio, try_rdio, int, 0);
 116MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 117module_param_named(try_wdio, try_wdio, int, 0);
 118MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 119
 120#ifndef MODULE
 121static int write_threshold_kbs;  /* retained for compatibility */
 122static struct st_dev_parm {
 123	char *name;
 124	int *val;
 125} parms[] __initdata = {
 126	{
 127		"buffer_kbs", &buffer_kbs
 128	},
 129	{       /* Retained for compatibility with 2.4 */
 130		"write_threshold_kbs", &write_threshold_kbs
 131	},
 132	{
 133		"max_sg_segs", NULL
 134	},
 135	{
 136		"try_direct_io", &try_direct_io
 137	},
 138	{
 139		"debug_flag", &debug_flag
 140	}
 141};
 142#endif
 143
 144/* Restrict the number of modes so that names for all are assigned */
 145#if ST_NBR_MODES > 16
 146#error "Maximum number of modes is 16"
 147#endif
 148/* Bit reversed order to get same names for same minors with all
 149   mode counts */
 150static const char *st_formats[] = {
 151	"",  "r", "k", "s", "l", "t", "o", "u",
 152	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 153
 154/* The default definitions have been moved to st_options.h */
 155
 156#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 157
 158/* The buffer size should fit into the 24 bits for length in the
 159   6-byte SCSI read and write commands. */
 160#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 161#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 162#endif
 163
 164static int debugging = DEBUG;
 165
 166#define MAX_RETRIES 0
 167#define MAX_WRITE_RETRIES 0
 168#define MAX_READY_RETRIES 0
 169#define NO_TAPE  NOT_READY
 170
 171#define ST_TIMEOUT (900 * HZ)
 172#define ST_LONG_TIMEOUT (14000 * HZ)
 173
 174/* Remove mode bits and auto-rewind bit (7) */
 175#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 176	(iminor(x) & ((1 << ST_MODE_SHIFT)-1)))
 177#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 178
 179/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 180#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 181  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 182
 183/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 184   24 bits) */
 185#define SET_DENS_AND_BLK 0x10001
 186
 187static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 188static int st_max_sg_segs = ST_MAX_SG;
 189
 190static int modes_defined;
 191
 192static int enlarge_buffer(struct st_buffer *, int);
 193static void clear_buffer(struct st_buffer *);
 194static void normalize_buffer(struct st_buffer *);
 195static int append_to_buffer(const char __user *, struct st_buffer *, int);
 196static int from_buffer(struct st_buffer *, char __user *, int);
 197static void move_buffer_data(struct st_buffer *, int);
 198
 199static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 200			      unsigned long, size_t, int);
 201static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 202
 203static int st_probe(struct device *);
 204static int st_remove(struct device *);
 205
 206static struct scsi_driver st_template = {
 207	.gendrv = {
 208		.name		= "st",
 209		.owner		= THIS_MODULE,
 210		.probe		= st_probe,
 211		.remove		= st_remove,
 212		.groups		= st_drv_groups,
 213	},
 214};
 215
 216static int st_compression(struct scsi_tape *, int);
 217
 218static int find_partition(struct scsi_tape *);
 219static int switch_partition(struct scsi_tape *);
 220
 221static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 222
 223static void scsi_tape_release(struct kref *);
 224
 225#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 226
 227static DEFINE_MUTEX(st_ref_mutex);
 228static DEFINE_SPINLOCK(st_index_lock);
 229static DEFINE_SPINLOCK(st_use_lock);
 230static DEFINE_IDR(st_index_idr);
 231
 232
 233
 
 234#ifndef SIGS_FROM_OSST
 235#define SIGS_FROM_OSST \
 236	{"OnStream", "SC-", "", "osst"}, \
 237	{"OnStream", "DI-", "", "osst"}, \
 238	{"OnStream", "DP-", "", "osst"}, \
 239	{"OnStream", "USB", "", "osst"}, \
 240	{"OnStream", "FW-", "", "osst"}
 241#endif
 242
 243static struct scsi_tape *scsi_tape_get(int dev)
 244{
 245	struct scsi_tape *STp = NULL;
 246
 247	mutex_lock(&st_ref_mutex);
 248	spin_lock(&st_index_lock);
 249
 250	STp = idr_find(&st_index_idr, dev);
 251	if (!STp) goto out;
 252
 253	kref_get(&STp->kref);
 254
 255	if (!STp->device)
 256		goto out_put;
 257
 258	if (scsi_device_get(STp->device))
 259		goto out_put;
 260
 261	goto out;
 262
 263out_put:
 264	kref_put(&STp->kref, scsi_tape_release);
 265	STp = NULL;
 266out:
 267	spin_unlock(&st_index_lock);
 268	mutex_unlock(&st_ref_mutex);
 269	return STp;
 270}
 271
 272static void scsi_tape_put(struct scsi_tape *STp)
 273{
 274	struct scsi_device *sdev = STp->device;
 275
 276	mutex_lock(&st_ref_mutex);
 277	kref_put(&STp->kref, scsi_tape_release);
 278	scsi_device_put(sdev);
 279	mutex_unlock(&st_ref_mutex);
 280}
 281
 282struct st_reject_data {
 283	char *vendor;
 284	char *model;
 285	char *rev;
 286	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 287};
 288
 289static struct st_reject_data reject_list[] = {
 290	/* {"XXX", "Yy-", "", NULL},  example */
 291	SIGS_FROM_OSST,
 292	{NULL, }};
 293
 294/* If the device signature is on the list of incompatible drives, the
 295   function returns a pointer to the name of the correct driver (if known) */
 296static char * st_incompatible(struct scsi_device* SDp)
 297{
 298	struct st_reject_data *rp;
 299
 300	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 301		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 302		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 303		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 304			if (rp->driver_hint)
 305				return rp->driver_hint;
 306			else
 307				return "unknown";
 308		}
 309	return NULL;
 310}
 311
 312
 
 
 
 
 
 313#define st_printk(prefix, t, fmt, a...) \
 314	sdev_prefix_printk(prefix, (t)->device, (t)->name, fmt, ##a)
 315#ifdef DEBUG
 316#define DEBC_printk(t, fmt, a...) \
 317	if (debugging) { st_printk(ST_DEB_MSG, t, fmt, ##a ); }
 318#else
 319#define DEBC_printk(t, fmt, a...)
 320#endif
 321
 322static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 323{
 324	const u8 *ucp;
 325	const u8 *sense = SRpnt->sense;
 326
 327	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 328				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 329	s->flags = 0;
 330
 331	if (s->have_sense) {
 332		s->deferred = 0;
 333		s->remainder_valid =
 334			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 335		switch (sense[0] & 0x7f) {
 336		case 0x71:
 337			s->deferred = 1;
 338			fallthrough;
 339		case 0x70:
 340			s->fixed_format = 1;
 341			s->flags = sense[2] & 0xe0;
 342			break;
 343		case 0x73:
 344			s->deferred = 1;
 345			fallthrough;
 346		case 0x72:
 347			s->fixed_format = 0;
 348			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 349			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 350			break;
 351		}
 352	}
 353}
 354
 355
 356/* Convert the result to success code */
 357static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 358{
 359	int result = SRpnt->result;
 360	u8 scode;
 361	DEB(const char *stp;)
 362	char *name = STp->name;
 363	struct st_cmdstatus *cmdstatp;
 364
 365	if (!result)
 366		return 0;
 367
 368	cmdstatp = &STp->buffer->cmdstat;
 369	st_analyze_sense(SRpnt, cmdstatp);
 370
 371	if (cmdstatp->have_sense)
 372		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 373	else
 374		scode = 0;
 375
 376	DEB(
 377	if (debugging) {
 378		st_printk(ST_DEB_MSG, STp,
 379			    "Error: %x, cmd: %x %x %x %x %x %x\n", result,
 380			    SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 381			    SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 382		if (cmdstatp->have_sense)
 383			__scsi_print_sense(STp->device, name,
 384					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 385	} ) /* end DEB */
 386	if (!debugging) { /* Abnormal conditions for tape */
 387		if (!cmdstatp->have_sense)
 388			st_printk(KERN_WARNING, STp,
 389			       "Error %x (driver bt 0, host bt 0x%x).\n",
 390			       result, host_byte(result));
 391		else if (cmdstatp->have_sense &&
 392			 scode != NO_SENSE &&
 393			 scode != RECOVERED_ERROR &&
 394			 /* scode != UNIT_ATTENTION && */
 395			 scode != BLANK_CHECK &&
 396			 scode != VOLUME_OVERFLOW &&
 397			 SRpnt->cmd[0] != MODE_SENSE &&
 398			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 399
 400			__scsi_print_sense(STp->device, name,
 401					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 402		}
 403	}
 404
 405	if (cmdstatp->fixed_format &&
 406	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 407		if (STp->cln_sense_value)
 408			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 409					       STp->cln_sense_mask) == STp->cln_sense_value);
 410		else
 411			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 412					       STp->cln_sense_mask) != 0);
 413	}
 414	if (cmdstatp->have_sense &&
 415	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 416		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 417	if (cmdstatp->have_sense && scode == UNIT_ATTENTION && cmdstatp->sense_hdr.asc == 0x29)
 418		STp->pos_unknown = 1; /* ASC => power on / reset */
 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	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
 478	ktime_t now;
 479
 480	now = ktime_get();
 481	if (scmd->cmnd[0] == WRITE_6) {
 482		now = ktime_sub(now, STp->stats->write_time);
 483		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 484		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 485		atomic64_inc(&STp->stats->write_cnt);
 486		if (scmd->result) {
 487			atomic64_add(atomic_read(&STp->stats->last_write_size)
 488				- STp->buffer->cmdstat.residual,
 489				&STp->stats->write_byte_cnt);
 490			if (STp->buffer->cmdstat.residual > 0)
 491				atomic64_inc(&STp->stats->resid_cnt);
 492		} else
 493			atomic64_add(atomic_read(&STp->stats->last_write_size),
 494				&STp->stats->write_byte_cnt);
 495	} else if (scmd->cmnd[0] == READ_6) {
 496		now = ktime_sub(now, STp->stats->read_time);
 497		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 498		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 499		atomic64_inc(&STp->stats->read_cnt);
 500		if (scmd->result) {
 501			atomic64_add(atomic_read(&STp->stats->last_read_size)
 502				- STp->buffer->cmdstat.residual,
 503				&STp->stats->read_byte_cnt);
 504			if (STp->buffer->cmdstat.residual > 0)
 505				atomic64_inc(&STp->stats->resid_cnt);
 506		} else
 507			atomic64_add(atomic_read(&STp->stats->last_read_size),
 508				&STp->stats->read_byte_cnt);
 509	} else {
 510		now = ktime_sub(now, STp->stats->other_time);
 511		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 512		atomic64_inc(&STp->stats->other_cnt);
 513	}
 514	atomic64_dec(&STp->stats->in_flight);
 515}
 516
 517static enum rq_end_io_ret st_scsi_execute_end(struct request *req,
 518					      blk_status_t status)
 519{
 520	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
 521	struct st_request *SRpnt = req->end_io_data;
 
 522	struct scsi_tape *STp = SRpnt->stp;
 523	struct bio *tmp;
 524
 525	STp->buffer->cmdstat.midlevel_result = SRpnt->result = scmd->result;
 526	STp->buffer->cmdstat.residual = scmd->resid_len;
 527
 528	st_do_stats(STp, req);
 529
 530	tmp = SRpnt->bio;
 531	if (scmd->sense_len)
 532		memcpy(SRpnt->sense, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
 533	if (SRpnt->waiting)
 534		complete(SRpnt->waiting);
 535
 536	blk_rq_unmap_user(tmp);
 537	blk_mq_free_request(req);
 538	return RQ_END_IO_NONE;
 539}
 540
 541static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 542			   int data_direction, void *buffer, unsigned bufflen,
 543			   int timeout, int retries)
 544{
 545	struct request *req;
 
 546	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 547	int err = 0;
 548	struct scsi_tape *STp = SRpnt->stp;
 549	struct scsi_cmnd *scmd;
 550
 551	req = scsi_alloc_request(SRpnt->stp->device->request_queue,
 552			data_direction == DMA_TO_DEVICE ?
 553			REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 554	if (IS_ERR(req))
 555		return PTR_ERR(req);
 556	scmd = blk_mq_rq_to_pdu(req);
 557	req->rq_flags |= RQF_QUIET;
 558
 559	mdata->null_mapped = 1;
 560
 561	if (bufflen) {
 562		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 563				      GFP_KERNEL);
 564		if (err) {
 565			blk_mq_free_request(req);
 566			return err;
 567		}
 568	}
 569
 570	atomic64_inc(&STp->stats->in_flight);
 571	if (cmd[0] == WRITE_6) {
 572		atomic_set(&STp->stats->last_write_size, bufflen);
 573		STp->stats->write_time = ktime_get();
 574	} else if (cmd[0] == READ_6) {
 575		atomic_set(&STp->stats->last_read_size, bufflen);
 576		STp->stats->read_time = ktime_get();
 577	} else {
 578		STp->stats->other_time = ktime_get();
 579	}
 580
 581	SRpnt->bio = req->bio;
 582	scmd->cmd_len = COMMAND_SIZE(cmd[0]);
 583	memcpy(scmd->cmnd, cmd, scmd->cmd_len);
 
 584	req->timeout = timeout;
 585	scmd->allowed = retries;
 586	req->end_io = st_scsi_execute_end;
 587	req->end_io_data = SRpnt;
 588
 589	blk_execute_rq_nowait(req, true);
 590	return 0;
 591}
 592
 593/* Do the scsi command. Waits until command performed if do_wait is true.
 594   Otherwise write_behind_check() is used to check that the command
 595   has finished. */
 596static struct st_request *
 597st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 598	   int bytes, int direction, int timeout, int retries, int do_wait)
 599{
 600	struct completion *waiting;
 601	struct rq_map_data *mdata = &STp->buffer->map_data;
 602	int ret;
 603
 604	/* if async, make sure there's no command outstanding */
 605	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 606		st_printk(KERN_ERR, STp,
 607			  "Async command already active.\n");
 608		if (signal_pending(current))
 609			(STp->buffer)->syscall_result = (-EINTR);
 610		else
 611			(STp->buffer)->syscall_result = (-EBUSY);
 612		return NULL;
 613	}
 614
 615	if (!SRpnt) {
 616		SRpnt = st_allocate_request(STp);
 617		if (!SRpnt)
 618			return NULL;
 619	}
 620
 621	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 622	   which IO is outstanding. It's nulled out when the IO completes. */
 623	if (!do_wait)
 624		(STp->buffer)->last_SRpnt = SRpnt;
 625
 626	waiting = &STp->wait;
 627	init_completion(waiting);
 628	SRpnt->waiting = waiting;
 629
 630	if (STp->buffer->do_dio) {
 631		mdata->page_order = 0;
 632		mdata->nr_entries = STp->buffer->sg_segs;
 633		mdata->pages = STp->buffer->mapped_pages;
 634	} else {
 635		mdata->page_order = STp->buffer->reserved_page_order;
 636		mdata->nr_entries =
 637			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 638		mdata->pages = STp->buffer->reserved_pages;
 639		mdata->offset = 0;
 640	}
 641
 642	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 643	STp->buffer->cmdstat.have_sense = 0;
 644	STp->buffer->syscall_result = 0;
 645
 646	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 647			      retries);
 648	if (ret) {
 649		/* could not allocate the buffer or request was too large */
 650		(STp->buffer)->syscall_result = (-EBUSY);
 651		(STp->buffer)->last_SRpnt = NULL;
 652	} else if (do_wait) {
 653		wait_for_completion(waiting);
 654		SRpnt->waiting = NULL;
 655		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 656	}
 657
 658	return SRpnt;
 659}
 660
 661
 662/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 663   write has been correct but EOM early warning reached, -EIO if write ended in
 664   error or zero if write successful. Asynchronous writes are used only in
 665   variable block mode. */
 666static int write_behind_check(struct scsi_tape * STp)
 667{
 668	int retval = 0;
 669	struct st_buffer *STbuffer;
 670	struct st_partstat *STps;
 671	struct st_cmdstatus *cmdstatp;
 672	struct st_request *SRpnt;
 673
 674	STbuffer = STp->buffer;
 675	if (!STbuffer->writing)
 676		return 0;
 677
 678	DEB(
 679	if (STp->write_pending)
 680		STp->nbr_waits++;
 681	else
 682		STp->nbr_finished++;
 683	) /* end DEB */
 684
 685	wait_for_completion(&(STp->wait));
 686	SRpnt = STbuffer->last_SRpnt;
 687	STbuffer->last_SRpnt = NULL;
 688	SRpnt->waiting = NULL;
 689
 690	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 691	st_release_request(SRpnt);
 692
 693	STbuffer->buffer_bytes -= STbuffer->writing;
 694	STps = &(STp->ps[STp->partition]);
 695	if (STps->drv_block >= 0) {
 696		if (STp->block_size == 0)
 697			STps->drv_block++;
 698		else
 699			STps->drv_block += STbuffer->writing / STp->block_size;
 700	}
 701
 702	cmdstatp = &STbuffer->cmdstat;
 703	if (STbuffer->syscall_result) {
 704		retval = -EIO;
 705		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 706		    (cmdstatp->flags & SENSE_EOM) &&
 707		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 708		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 709			/* EOM at write-behind, has all data been written? */
 710			if (!cmdstatp->remainder_valid ||
 711			    cmdstatp->uremainder64 == 0)
 712				retval = -ENOSPC;
 713		}
 714		if (retval == -EIO)
 715			STps->drv_block = -1;
 716	}
 717	STbuffer->writing = 0;
 718
 719	DEB(if (debugging && retval)
 720		    st_printk(ST_DEB_MSG, STp,
 721				"Async write error %x, return value %d.\n",
 722				STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 723
 724	return retval;
 725}
 726
 727
 728/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 729   it messes up the block number). */
 730static int cross_eof(struct scsi_tape * STp, int forward)
 731{
 732	struct st_request *SRpnt;
 733	unsigned char cmd[MAX_COMMAND_SIZE];
 734
 735	cmd[0] = SPACE;
 736	cmd[1] = 0x01;		/* Space FileMarks */
 737	if (forward) {
 738		cmd[2] = cmd[3] = 0;
 739		cmd[4] = 1;
 740	} else
 741		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 742	cmd[5] = 0;
 743
 744	DEBC_printk(STp, "Stepping over filemark %s.\n",
 745		    forward ? "forward" : "backward");
 746
 747	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 748			   STp->device->request_queue->rq_timeout,
 749			   MAX_RETRIES, 1);
 750	if (!SRpnt)
 751		return (STp->buffer)->syscall_result;
 752
 753	st_release_request(SRpnt);
 754	SRpnt = NULL;
 755
 756	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 757		st_printk(KERN_ERR, STp,
 758			  "Stepping over filemark %s failed.\n",
 759			  forward ? "forward" : "backward");
 760
 761	return (STp->buffer)->syscall_result;
 762}
 763
 764
 765/* Flush the write buffer (never need to write if variable blocksize). */
 766static int st_flush_write_buffer(struct scsi_tape * STp)
 767{
 768	int transfer, blks;
 769	int result;
 770	unsigned char cmd[MAX_COMMAND_SIZE];
 771	struct st_request *SRpnt;
 772	struct st_partstat *STps;
 773
 774	result = write_behind_check(STp);
 775	if (result)
 776		return result;
 777
 778	result = 0;
 779	if (STp->dirty == 1) {
 780
 781		transfer = STp->buffer->buffer_bytes;
 782		DEBC_printk(STp, "Flushing %d bytes.\n", transfer);
 783
 784		memset(cmd, 0, MAX_COMMAND_SIZE);
 785		cmd[0] = WRITE_6;
 786		cmd[1] = 1;
 787		blks = transfer / STp->block_size;
 788		cmd[2] = blks >> 16;
 789		cmd[3] = blks >> 8;
 790		cmd[4] = blks;
 791
 792		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 793				   STp->device->request_queue->rq_timeout,
 794				   MAX_WRITE_RETRIES, 1);
 795		if (!SRpnt)
 796			return (STp->buffer)->syscall_result;
 797
 798		STps = &(STp->ps[STp->partition]);
 799		if ((STp->buffer)->syscall_result != 0) {
 800			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 801
 802			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 803			    (cmdstatp->flags & SENSE_EOM) &&
 804			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 805			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 806			    (!cmdstatp->remainder_valid ||
 807			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 808				STp->dirty = 0;
 809				(STp->buffer)->buffer_bytes = 0;
 810				if (STps->drv_block >= 0)
 811					STps->drv_block += blks;
 812				result = (-ENOSPC);
 813			} else {
 814				st_printk(KERN_ERR, STp, "Error on flush.\n");
 815				STps->drv_block = (-1);
 816				result = (-EIO);
 817			}
 818		} else {
 819			if (STps->drv_block >= 0)
 820				STps->drv_block += blks;
 821			STp->dirty = 0;
 822			(STp->buffer)->buffer_bytes = 0;
 823		}
 824		st_release_request(SRpnt);
 825		SRpnt = NULL;
 826	}
 827	return result;
 828}
 829
 830
 831/* Flush the tape buffer. The tape will be positioned correctly unless
 832   seek_next is true. */
 833static int flush_buffer(struct scsi_tape *STp, int seek_next)
 834{
 835	int backspace, result;
 
 836	struct st_partstat *STps;
 837
 
 
 838	/*
 839	 * If there was a bus reset, block further access
 840	 * to this device.
 841	 */
 842	if (STp->pos_unknown)
 843		return (-EIO);
 844
 845	if (STp->ready != ST_READY)
 846		return 0;
 847	STps = &(STp->ps[STp->partition]);
 848	if (STps->rw == ST_WRITING)	/* Writing */
 849		return st_flush_write_buffer(STp);
 850
 851	if (STp->block_size == 0)
 852		return 0;
 853
 854	backspace = ((STp->buffer)->buffer_bytes +
 855		     (STp->buffer)->read_pointer) / STp->block_size -
 856	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 857	    STp->block_size;
 858	(STp->buffer)->buffer_bytes = 0;
 859	(STp->buffer)->read_pointer = 0;
 860	result = 0;
 861	if (!seek_next) {
 862		if (STps->eof == ST_FM_HIT) {
 863			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 864			if (!result)
 865				STps->eof = ST_NOEOF;
 866			else {
 867				if (STps->drv_file >= 0)
 868					STps->drv_file++;
 869				STps->drv_block = 0;
 870			}
 871		}
 872		if (!result && backspace > 0)
 873			result = st_int_ioctl(STp, MTBSR, backspace);
 874	} else if (STps->eof == ST_FM_HIT) {
 875		if (STps->drv_file >= 0)
 876			STps->drv_file++;
 877		STps->drv_block = 0;
 878		STps->eof = ST_NOEOF;
 879	}
 880	return result;
 881
 882}
 883
 884/* Set the mode parameters */
 885static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 886{
 887	int set_it = 0;
 888	unsigned long arg;
 889
 890	if (!STp->density_changed &&
 891	    STm->default_density >= 0 &&
 892	    STm->default_density != STp->density) {
 893		arg = STm->default_density;
 894		set_it = 1;
 895	} else
 896		arg = STp->density;
 897	arg <<= MT_ST_DENSITY_SHIFT;
 898	if (!STp->blksize_changed &&
 899	    STm->default_blksize >= 0 &&
 900	    STm->default_blksize != STp->block_size) {
 901		arg |= STm->default_blksize;
 902		set_it = 1;
 903	} else
 904		arg |= STp->block_size;
 905	if (set_it &&
 906	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 907		st_printk(KERN_WARNING, STp,
 908			  "Can't set default block size to %d bytes "
 909			  "and density %x.\n",
 910			  STm->default_blksize, STm->default_density);
 911		if (modes_defined)
 912			return (-EINVAL);
 913	}
 914	return 0;
 915}
 916
 917
 918/* Lock or unlock the drive door. Don't use when st_request allocated. */
 919static int do_door_lock(struct scsi_tape * STp, int do_lock)
 920{
 921	int retval;
 922
 923	DEBC_printk(STp, "%socking drive door.\n", do_lock ? "L" : "Unl");
 924
 925	retval = scsi_set_medium_removal(STp->device,
 926			do_lock ? SCSI_REMOVAL_PREVENT : SCSI_REMOVAL_ALLOW);
 927	if (!retval)
 928		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 929	else
 930		STp->door_locked = ST_LOCK_FAILS;
 931	return retval;
 932}
 933
 934
 935/* Set the internal state after reset */
 936static void reset_state(struct scsi_tape *STp)
 937{
 938	int i;
 939	struct st_partstat *STps;
 940
 941	STp->pos_unknown = 0;
 942	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 943		STps = &(STp->ps[i]);
 944		STps->rw = ST_IDLE;
 945		STps->eof = ST_NOEOF;
 946		STps->at_sm = 0;
 947		STps->last_block_valid = 0;
 948		STps->drv_block = -1;
 949		STps->drv_file = -1;
 950	}
 951	if (STp->can_partitions) {
 952		STp->partition = find_partition(STp);
 953		if (STp->partition < 0)
 954			STp->partition = 0;
 955		STp->new_partition = STp->partition;
 956	}
 957}
 958
 959/* Test if the drive is ready. Returns either one of the codes below or a negative system
 960   error code. */
 961#define CHKRES_READY       0
 962#define CHKRES_NEW_SESSION 1
 963#define CHKRES_NOT_READY   2
 964#define CHKRES_NO_TAPE     3
 965
 966#define MAX_ATTENTIONS    10
 967
 968static int test_ready(struct scsi_tape *STp, int do_wait)
 969{
 970	int attentions, waits, max_wait, scode;
 971	int retval = CHKRES_READY, new_session = 0;
 972	unsigned char cmd[MAX_COMMAND_SIZE];
 973	struct st_request *SRpnt = NULL;
 974	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 975
 976	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 977
 978	for (attentions=waits=0; ; ) {
 979		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 980		cmd[0] = TEST_UNIT_READY;
 981		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 982				   STp->long_timeout, MAX_READY_RETRIES, 1);
 983
 984		if (!SRpnt) {
 985			retval = (STp->buffer)->syscall_result;
 986			break;
 987		}
 988
 989		if (cmdstatp->have_sense) {
 990
 991			scode = cmdstatp->sense_hdr.sense_key;
 992
 993			if (scode == UNIT_ATTENTION) { /* New media? */
 994				new_session = 1;
 995				if (attentions < MAX_ATTENTIONS) {
 996					attentions++;
 997					continue;
 998				}
 999				else {
1000					retval = (-EIO);
1001					break;
1002				}
1003			}
1004
1005			if (scode == NOT_READY) {
1006				if (waits < max_wait) {
1007					if (msleep_interruptible(1000)) {
1008						retval = (-EINTR);
1009						break;
1010					}
1011					waits++;
1012					continue;
1013				}
1014				else {
1015					if ((STp->device)->scsi_level >= SCSI_2 &&
1016					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
1017						retval = CHKRES_NO_TAPE;
1018					else
1019						retval = CHKRES_NOT_READY;
1020					break;
1021				}
1022			}
1023		}
1024
1025		retval = (STp->buffer)->syscall_result;
1026		if (!retval)
1027			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
1028		break;
1029	}
1030
1031	if (SRpnt != NULL)
1032		st_release_request(SRpnt);
1033	return retval;
1034}
1035
1036
1037/* See if the drive is ready and gather information about the tape. Return values:
1038   < 0   negative error code from errno.h
1039   0     drive ready
1040   1     drive not ready (possibly no tape)
1041*/
1042static int check_tape(struct scsi_tape *STp, struct file *filp)
1043{
1044	int i, retval, new_session = 0, do_wait;
1045	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
1046	unsigned short st_flags = filp->f_flags;
1047	struct st_request *SRpnt = NULL;
1048	struct st_modedef *STm;
1049	struct st_partstat *STps;
1050	struct inode *inode = file_inode(filp);
1051	int mode = TAPE_MODE(inode);
1052
1053	STp->ready = ST_READY;
1054
1055	if (mode != STp->current_mode) {
1056		DEBC_printk(STp, "Mode change from %d to %d.\n",
1057			    STp->current_mode, mode);
1058		new_session = 1;
1059		STp->current_mode = mode;
1060	}
1061	STm = &(STp->modes[STp->current_mode]);
1062
1063	saved_cleaning = STp->cleaning_req;
1064	STp->cleaning_req = 0;
1065
1066	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1067	retval = test_ready(STp, do_wait);
1068
1069	if (retval < 0)
1070	    goto err_out;
1071
1072	if (retval == CHKRES_NEW_SESSION) {
1073		STp->pos_unknown = 0;
1074		STp->partition = STp->new_partition = 0;
1075		if (STp->can_partitions)
1076			STp->nbr_partitions = 1; /* This guess will be updated later
1077                                                    if necessary */
1078		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1079			STps = &(STp->ps[i]);
1080			STps->rw = ST_IDLE;
1081			STps->eof = ST_NOEOF;
1082			STps->at_sm = 0;
1083			STps->last_block_valid = 0;
1084			STps->drv_block = 0;
1085			STps->drv_file = 0;
1086		}
1087		new_session = 1;
1088	}
1089	else {
1090		STp->cleaning_req |= saved_cleaning;
1091
1092		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1093			if (retval == CHKRES_NO_TAPE)
1094				STp->ready = ST_NO_TAPE;
1095			else
1096				STp->ready = ST_NOT_READY;
1097
1098			STp->density = 0;	/* Clear the erroneous "residue" */
1099			STp->write_prot = 0;
1100			STp->block_size = 0;
1101			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1102			STp->partition = STp->new_partition = 0;
1103			STp->door_locked = ST_UNLOCKED;
1104			return CHKRES_NOT_READY;
1105		}
1106	}
1107
1108	if (STp->omit_blklims)
1109		STp->min_block = STp->max_block = (-1);
1110	else {
1111		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1112		cmd[0] = READ_BLOCK_LIMITS;
1113
1114		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1115				   STp->device->request_queue->rq_timeout,
1116				   MAX_READY_RETRIES, 1);
1117		if (!SRpnt) {
1118			retval = (STp->buffer)->syscall_result;
1119			goto err_out;
1120		}
1121
1122		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1123			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1124			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1125			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1126			    (STp->buffer)->b_data[5];
1127			if ( DEB( debugging || ) !STp->inited)
1128				st_printk(KERN_INFO, STp,
1129					  "Block limits %d - %d bytes.\n",
1130					  STp->min_block, STp->max_block);
1131		} else {
1132			STp->min_block = STp->max_block = (-1);
1133			DEBC_printk(STp, "Can't read block limits.\n");
1134		}
1135	}
1136
1137	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1138	cmd[0] = MODE_SENSE;
1139	cmd[4] = 12;
1140
1141	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1142			   STp->device->request_queue->rq_timeout,
1143			   MAX_READY_RETRIES, 1);
1144	if (!SRpnt) {
1145		retval = (STp->buffer)->syscall_result;
1146		goto err_out;
1147	}
1148
1149	if ((STp->buffer)->syscall_result != 0) {
1150		DEBC_printk(STp, "No Mode Sense.\n");
1151		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1152		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1153		STp->drv_write_prot = 0;
1154	} else {
1155		DEBC_printk(STp,"Mode sense. Length %d, "
1156			    "medium %x, WBS %x, BLL %d\n",
1157			    (STp->buffer)->b_data[0],
1158			    (STp->buffer)->b_data[1],
1159			    (STp->buffer)->b_data[2],
1160			    (STp->buffer)->b_data[3]);
1161
1162		if ((STp->buffer)->b_data[3] >= 8) {
1163			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1164			STp->density = (STp->buffer)->b_data[4];
1165			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1166			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1167			DEBC_printk(STp, "Density %x, tape length: %x, "
1168				    "drv buffer: %d\n",
1169				    STp->density,
1170				    (STp->buffer)->b_data[5] * 65536 +
1171				    (STp->buffer)->b_data[6] * 256 +
1172				    (STp->buffer)->b_data[7],
1173				    STp->drv_buffer);
1174		}
1175		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1176		if (!STp->drv_buffer && STp->immediate_filemark) {
1177			st_printk(KERN_WARNING, STp,
1178				  "non-buffered tape: disabling "
1179				  "writing immediate filemarks\n");
1180			STp->immediate_filemark = 0;
1181		}
1182	}
1183	st_release_request(SRpnt);
1184	SRpnt = NULL;
1185	STp->inited = 1;
1186
1187	if (STp->block_size > 0)
1188		(STp->buffer)->buffer_blocks =
1189			(STp->buffer)->buffer_size / STp->block_size;
1190	else
1191		(STp->buffer)->buffer_blocks = 1;
1192	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1193
1194	DEBC_printk(STp, "Block size: %d, buffer size: %d (%d blocks).\n",
1195		    STp->block_size, (STp->buffer)->buffer_size,
1196		    (STp->buffer)->buffer_blocks);
1197
1198	if (STp->drv_write_prot) {
1199		STp->write_prot = 1;
1200
1201		DEBC_printk(STp, "Write protected\n");
1202
1203		if (do_wait &&
1204		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1205		     (st_flags & O_ACCMODE) == O_RDWR)) {
1206			retval = (-EROFS);
1207			goto err_out;
1208		}
1209	}
1210
1211	if (STp->can_partitions && STp->nbr_partitions < 1) {
1212		/* This code is reached when the device is opened for the first time
1213		   after the driver has been initialized with tape in the drive and the
1214		   partition support has been enabled. */
1215		DEBC_printk(STp, "Updating partition number in status.\n");
1216		if ((STp->partition = find_partition(STp)) < 0) {
1217			retval = STp->partition;
1218			goto err_out;
1219		}
1220		STp->new_partition = STp->partition;
1221		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1222	}
1223
1224	if (new_session) {	/* Change the drive parameters for the new mode */
1225		STp->density_changed = STp->blksize_changed = 0;
1226		STp->compression_changed = 0;
1227		if (!(STm->defaults_for_writes) &&
1228		    (retval = set_mode_densblk(STp, STm)) < 0)
1229		    goto err_out;
1230
1231		if (STp->default_drvbuffer != 0xff) {
1232			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1233				st_printk(KERN_WARNING, STp,
1234					  "Can't set default drive "
1235					  "buffering to %d.\n",
1236					  STp->default_drvbuffer);
1237		}
1238	}
1239
1240	return CHKRES_READY;
1241
1242 err_out:
1243	return retval;
1244}
1245
1246
1247/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1248   module count. */
1249static int st_open(struct inode *inode, struct file *filp)
1250{
1251	int i, retval = (-EIO);
1252	int resumed = 0;
1253	struct scsi_tape *STp;
1254	struct st_partstat *STps;
1255	int dev = TAPE_NR(inode);
1256
1257	/*
1258	 * We really want to do nonseekable_open(inode, filp); here, but some
1259	 * versions of tar incorrectly call lseek on tapes and bail out if that
1260	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1261	 */
1262	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1263
1264	if (!(STp = scsi_tape_get(dev))) {
1265		return -ENXIO;
1266	}
1267
1268	filp->private_data = STp;
1269
1270	spin_lock(&st_use_lock);
1271	if (STp->in_use) {
1272		spin_unlock(&st_use_lock);
1273		DEBC_printk(STp, "Device already in use.\n");
1274		scsi_tape_put(STp);
 
1275		return (-EBUSY);
1276	}
1277
1278	STp->in_use = 1;
1279	spin_unlock(&st_use_lock);
1280	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1281
1282	if (scsi_autopm_get_device(STp->device) < 0) {
1283		retval = -EIO;
1284		goto err_out;
1285	}
1286	resumed = 1;
1287	if (!scsi_block_when_processing_errors(STp->device)) {
1288		retval = (-ENXIO);
1289		goto err_out;
1290	}
1291
1292	/* See that we have at least a one page buffer available */
1293	if (!enlarge_buffer(STp->buffer, PAGE_SIZE)) {
1294		st_printk(KERN_WARNING, STp,
1295			  "Can't allocate one page tape buffer.\n");
1296		retval = (-EOVERFLOW);
1297		goto err_out;
1298	}
1299
1300	(STp->buffer)->cleared = 0;
1301	(STp->buffer)->writing = 0;
1302	(STp->buffer)->syscall_result = 0;
1303
1304	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1305
1306	STp->dirty = 0;
1307	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1308		STps = &(STp->ps[i]);
1309		STps->rw = ST_IDLE;
1310	}
1311	STp->try_dio_now = STp->try_dio;
1312	STp->recover_count = 0;
1313	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1314	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1315
1316	retval = check_tape(STp, filp);
1317	if (retval < 0)
1318		goto err_out;
1319	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1320	    retval != CHKRES_READY) {
1321		if (STp->ready == NO_TAPE)
1322			retval = (-ENOMEDIUM);
1323		else
1324			retval = (-EIO);
1325		goto err_out;
1326	}
1327	return 0;
1328
1329 err_out:
1330	normalize_buffer(STp->buffer);
1331	spin_lock(&st_use_lock);
1332	STp->in_use = 0;
1333	spin_unlock(&st_use_lock);
1334	if (resumed)
1335		scsi_autopm_put_device(STp->device);
1336	scsi_tape_put(STp);
1337	return retval;
1338
1339}
1340
1341
1342/* Flush the tape buffer before close */
1343static int st_flush(struct file *filp, fl_owner_t id)
1344{
1345	int result = 0, result2;
1346	unsigned char cmd[MAX_COMMAND_SIZE];
1347	struct st_request *SRpnt;
1348	struct scsi_tape *STp = filp->private_data;
1349	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1350	struct st_partstat *STps = &(STp->ps[STp->partition]);
1351
1352	if (file_count(filp) > 1)
1353		return 0;
1354
1355	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1356		result = st_flush_write_buffer(STp);
1357		if (result != 0 && result != (-ENOSPC))
1358			goto out;
1359	}
1360
1361	if (STp->can_partitions &&
1362	    (result2 = switch_partition(STp)) < 0) {
1363		DEBC_printk(STp, "switch_partition at close failed.\n");
1364		if (result == 0)
1365			result = result2;
1366		goto out;
1367	}
1368
1369	DEBC( if (STp->nbr_requests)
1370		st_printk(KERN_DEBUG, STp,
1371			  "Number of r/w requests %d, dio used in %d, "
1372			  "pages %d.\n", STp->nbr_requests, STp->nbr_dio,
1373			  STp->nbr_pages));
1374
1375	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1376		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1377
1378#if DEBUG
1379		DEBC_printk(STp, "Async write waits %d, finished %d.\n",
1380			    STp->nbr_waits, STp->nbr_finished);
1381#endif
1382		memset(cmd, 0, MAX_COMMAND_SIZE);
1383		cmd[0] = WRITE_FILEMARKS;
1384		if (STp->immediate_filemark)
1385			cmd[1] = 1;
1386		cmd[4] = 1 + STp->two_fm;
1387
1388		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1389				   STp->device->request_queue->rq_timeout,
1390				   MAX_WRITE_RETRIES, 1);
1391		if (!SRpnt) {
1392			result = (STp->buffer)->syscall_result;
1393			goto out;
1394		}
1395
1396		if (STp->buffer->syscall_result == 0 ||
1397		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1398		     (cmdstatp->flags & SENSE_EOM) &&
1399		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1400		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1401		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1402			/* Write successful at EOM */
1403			st_release_request(SRpnt);
1404			SRpnt = NULL;
1405			if (STps->drv_file >= 0)
1406				STps->drv_file++;
1407			STps->drv_block = 0;
1408			if (STp->two_fm)
1409				cross_eof(STp, 0);
1410			STps->eof = ST_FM;
1411		}
1412		else { /* Write error */
1413			st_release_request(SRpnt);
1414			SRpnt = NULL;
1415			st_printk(KERN_ERR, STp,
1416				  "Error on write filemark.\n");
1417			if (result == 0)
1418				result = (-EIO);
1419		}
1420
1421		DEBC_printk(STp, "Buffer flushed, %d EOF(s) written\n", cmd[4]);
1422	} else if (!STp->rew_at_close) {
1423		STps = &(STp->ps[STp->partition]);
1424		if (!STm->sysv || STps->rw != ST_READING) {
1425			if (STp->can_bsr)
1426				result = flush_buffer(STp, 0);
1427			else if (STps->eof == ST_FM_HIT) {
1428				result = cross_eof(STp, 0);
1429				if (result) {
1430					if (STps->drv_file >= 0)
1431						STps->drv_file++;
1432					STps->drv_block = 0;
1433					STps->eof = ST_FM;
1434				} else
1435					STps->eof = ST_NOEOF;
1436			}
1437		} else if ((STps->eof == ST_NOEOF &&
1438			    !(result = cross_eof(STp, 1))) ||
1439			   STps->eof == ST_FM_HIT) {
1440			if (STps->drv_file >= 0)
1441				STps->drv_file++;
1442			STps->drv_block = 0;
1443			STps->eof = ST_FM;
1444		}
1445	}
1446
1447      out:
1448	if (STp->rew_at_close) {
1449		result2 = st_int_ioctl(STp, MTREW, 1);
1450		if (result == 0)
1451			result = result2;
1452	}
1453	return result;
1454}
1455
1456
1457/* Close the device and release it. BKL is not needed: this is the only thread
1458   accessing this tape. */
1459static int st_release(struct inode *inode, struct file *filp)
1460{
 
1461	struct scsi_tape *STp = filp->private_data;
1462
1463	if (STp->door_locked == ST_LOCKED_AUTO)
1464		do_door_lock(STp, 0);
1465
1466	normalize_buffer(STp->buffer);
1467	spin_lock(&st_use_lock);
1468	STp->in_use = 0;
1469	spin_unlock(&st_use_lock);
1470	scsi_autopm_put_device(STp->device);
1471	scsi_tape_put(STp);
1472
1473	return 0;
1474}
1475
1476/* The checks common to both reading and writing */
1477static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1478{
1479	ssize_t retval = 0;
1480
1481	/*
1482	 * If we are in the middle of error recovery, don't let anyone
1483	 * else try and use this device.  Also, if error recovery fails, it
1484	 * may try and take the device offline, in which case all further
1485	 * access to the device is prohibited.
1486	 */
1487	if (!scsi_block_when_processing_errors(STp->device)) {
1488		retval = (-ENXIO);
1489		goto out;
1490	}
1491
1492	if (STp->ready != ST_READY) {
1493		if (STp->ready == ST_NO_TAPE)
1494			retval = (-ENOMEDIUM);
1495		else
1496			retval = (-EIO);
1497		goto out;
1498	}
1499
1500	if (! STp->modes[STp->current_mode].defined) {
1501		retval = (-ENXIO);
1502		goto out;
1503	}
1504
1505
1506	/*
1507	 * If there was a bus reset, block further access
1508	 * to this device.
1509	 */
1510	if (STp->pos_unknown) {
1511		retval = (-EIO);
1512		goto out;
1513	}
1514
1515	if (count == 0)
1516		goto out;
1517
1518	DEB(
1519	if (!STp->in_use) {
1520		st_printk(ST_DEB_MSG, STp,
1521			  "Incorrect device.\n");
1522		retval = (-EIO);
1523		goto out;
1524	} ) /* end DEB */
1525
1526	if (STp->can_partitions &&
1527	    (retval = switch_partition(STp)) < 0)
1528		goto out;
1529
1530	if (STp->block_size == 0 && STp->max_block > 0 &&
1531	    (count < STp->min_block || count > STp->max_block)) {
1532		retval = (-EINVAL);
1533		goto out;
1534	}
1535
1536	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1537	    !do_door_lock(STp, 1))
1538		STp->door_locked = ST_LOCKED_AUTO;
1539
1540 out:
1541	return retval;
1542}
1543
1544
1545static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1546			   size_t count, int is_read)
1547{
1548	int i, bufsize, retval = 0;
1549	struct st_buffer *STbp = STp->buffer;
1550
1551	if (is_read)
1552		i = STp->try_dio_now && try_rdio;
1553	else
1554		i = STp->try_dio_now && try_wdio;
1555
1556	if (i && ((unsigned long)buf & queue_dma_alignment(
1557					STp->device->request_queue)) == 0) {
1558		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1559				       count, (is_read ? READ : WRITE));
1560		if (i > 0) {
1561			STbp->do_dio = i;
1562			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1563		}
1564		else
1565			STbp->do_dio = 0;  /* fall back to buffering with any error */
1566		STbp->sg_segs = STbp->do_dio;
1567		DEB(
1568		     if (STbp->do_dio) {
1569			STp->nbr_dio++;
1570			STp->nbr_pages += STbp->do_dio;
1571		     }
1572		)
1573	} else
1574		STbp->do_dio = 0;
1575	DEB( STp->nbr_requests++; )
1576
1577	if (!STbp->do_dio) {
1578		if (STp->block_size)
1579			bufsize = STp->block_size > st_fixed_buffer_size ?
1580				STp->block_size : st_fixed_buffer_size;
1581		else {
1582			bufsize = count;
1583			/* Make sure that data from previous user is not leaked even if
1584			   HBA does not return correct residual */
1585			if (is_read && STp->sili && !STbp->cleared)
1586				clear_buffer(STbp);
1587		}
1588
1589		if (bufsize > STbp->buffer_size &&
1590		    !enlarge_buffer(STbp, bufsize)) {
1591			st_printk(KERN_WARNING, STp,
1592				  "Can't allocate %d byte tape buffer.\n",
1593				  bufsize);
1594			retval = (-EOVERFLOW);
1595			goto out;
1596		}
1597		if (STp->block_size)
1598			STbp->buffer_blocks = bufsize / STp->block_size;
1599	}
1600
1601 out:
1602	return retval;
1603}
1604
1605
1606/* Can be called more than once after each setup_buffer() */
1607static void release_buffering(struct scsi_tape *STp, int is_read)
1608{
1609	struct st_buffer *STbp;
1610
1611	STbp = STp->buffer;
1612	if (STbp->do_dio) {
1613		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1614		STbp->do_dio = 0;
1615		STbp->sg_segs = 0;
1616	}
1617}
1618
1619
1620/* Write command */
1621static ssize_t
1622st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1623{
1624	ssize_t total;
1625	ssize_t i, do_count, blks, transfer;
1626	ssize_t retval;
1627	int undone, retry_eot = 0, scode;
1628	int async_write;
1629	unsigned char cmd[MAX_COMMAND_SIZE];
1630	const char __user *b_point;
1631	struct st_request *SRpnt = NULL;
1632	struct scsi_tape *STp = filp->private_data;
1633	struct st_modedef *STm;
1634	struct st_partstat *STps;
1635	struct st_buffer *STbp;
1636
1637	if (mutex_lock_interruptible(&STp->lock))
1638		return -ERESTARTSYS;
1639
1640	retval = rw_checks(STp, filp, count);
1641	if (retval || count == 0)
1642		goto out;
1643
1644	/* Write must be integral number of blocks */
1645	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1646		st_printk(KERN_WARNING, STp,
1647			  "Write not multiple of tape block size.\n");
1648		retval = (-EINVAL);
1649		goto out;
1650	}
1651
1652	STm = &(STp->modes[STp->current_mode]);
1653	STps = &(STp->ps[STp->partition]);
1654
1655	if (STp->write_prot) {
1656		retval = (-EACCES);
1657		goto out;
1658	}
1659
1660
1661	if (STps->rw == ST_READING) {
1662		retval = flush_buffer(STp, 0);
1663		if (retval)
1664			goto out;
1665		STps->rw = ST_WRITING;
1666	} else if (STps->rw != ST_WRITING &&
1667		   STps->drv_file == 0 && STps->drv_block == 0) {
1668		if ((retval = set_mode_densblk(STp, STm)) < 0)
1669			goto out;
1670		if (STm->default_compression != ST_DONT_TOUCH &&
1671		    !(STp->compression_changed)) {
1672			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1673				st_printk(KERN_WARNING, STp,
1674					  "Can't set default compression.\n");
1675				if (modes_defined) {
1676					retval = (-EINVAL);
1677					goto out;
1678				}
1679			}
1680		}
1681	}
1682
1683	STbp = STp->buffer;
1684	i = write_behind_check(STp);
1685	if (i) {
1686		if (i == -ENOSPC)
1687			STps->eof = ST_EOM_OK;
1688		else
1689			STps->eof = ST_EOM_ERROR;
1690	}
1691
1692	if (STps->eof == ST_EOM_OK) {
1693		STps->eof = ST_EOD_1;  /* allow next write */
1694		retval = (-ENOSPC);
1695		goto out;
1696	}
1697	else if (STps->eof == ST_EOM_ERROR) {
1698		retval = (-EIO);
1699		goto out;
1700	}
1701
1702	/* Check the buffer readability in cases where copy_user might catch
1703	   the problems after some tape movement. */
1704	if (STp->block_size != 0 &&
1705	    !STbp->do_dio &&
1706	    (copy_from_user(&i, buf, 1) != 0 ||
1707	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1708		retval = (-EFAULT);
1709		goto out;
1710	}
1711
1712	retval = setup_buffering(STp, buf, count, 0);
1713	if (retval)
1714		goto out;
1715
1716	total = count;
1717
1718	memset(cmd, 0, MAX_COMMAND_SIZE);
1719	cmd[0] = WRITE_6;
1720	cmd[1] = (STp->block_size != 0);
1721
1722	STps->rw = ST_WRITING;
1723
1724	b_point = buf;
1725	while (count > 0 && !retry_eot) {
1726
1727		if (STbp->do_dio) {
1728			do_count = count;
1729		}
1730		else {
1731			if (STp->block_size == 0)
1732				do_count = count;
1733			else {
1734				do_count = STbp->buffer_blocks * STp->block_size -
1735					STbp->buffer_bytes;
1736				if (do_count > count)
1737					do_count = count;
1738			}
1739
1740			i = append_to_buffer(b_point, STbp, do_count);
1741			if (i) {
1742				retval = i;
1743				goto out;
1744			}
1745		}
1746		count -= do_count;
1747		b_point += do_count;
1748
1749		async_write = STp->block_size == 0 && !STbp->do_dio &&
1750			STm->do_async_writes && STps->eof < ST_EOM_OK;
1751
1752		if (STp->block_size != 0 && STm->do_buffer_writes &&
1753		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1754		    STbp->buffer_bytes < STbp->buffer_size) {
1755			STp->dirty = 1;
1756			/* Don't write a buffer that is not full enough. */
1757			if (!async_write && count == 0)
1758				break;
1759		}
1760
1761	retry_write:
1762		if (STp->block_size == 0)
1763			blks = transfer = do_count;
1764		else {
1765			if (!STbp->do_dio)
1766				blks = STbp->buffer_bytes;
1767			else
1768				blks = do_count;
1769			blks /= STp->block_size;
1770			transfer = blks * STp->block_size;
1771		}
1772		cmd[2] = blks >> 16;
1773		cmd[3] = blks >> 8;
1774		cmd[4] = blks;
1775
1776		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1777				   STp->device->request_queue->rq_timeout,
1778				   MAX_WRITE_RETRIES, !async_write);
1779		if (!SRpnt) {
1780			retval = STbp->syscall_result;
1781			goto out;
1782		}
1783		if (async_write && !STbp->syscall_result) {
1784			STbp->writing = transfer;
1785			STp->dirty = !(STbp->writing ==
1786				       STbp->buffer_bytes);
1787			SRpnt = NULL;  /* Prevent releasing this request! */
1788			DEB( STp->write_pending = 1; )
1789			break;
1790		}
1791
1792		if (STbp->syscall_result != 0) {
1793			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1794
1795			DEBC_printk(STp, "Error on write:\n");
1796			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1797				scode = cmdstatp->sense_hdr.sense_key;
1798				if (cmdstatp->remainder_valid)
1799					undone = (int)cmdstatp->uremainder64;
1800				else if (STp->block_size == 0 &&
1801					 scode == VOLUME_OVERFLOW)
1802					undone = transfer;
1803				else
1804					undone = 0;
1805				if (STp->block_size != 0)
1806					undone *= STp->block_size;
1807				if (undone <= do_count) {
1808					/* Only data from this write is not written */
1809					count += undone;
1810					b_point -= undone;
1811					do_count -= undone;
1812					if (STp->block_size)
1813						blks = (transfer - undone) / STp->block_size;
1814					STps->eof = ST_EOM_OK;
1815					/* Continue in fixed block mode if all written
1816					   in this request but still something left to write
1817					   (retval left to zero)
1818					*/
1819					if (STp->block_size == 0 ||
1820					    undone > 0 || count == 0)
1821						retval = (-ENOSPC); /* EOM within current request */
1822					DEBC_printk(STp, "EOM with %d "
1823						    "bytes unwritten.\n",
1824						    (int)count);
1825				} else {
1826					/* EOT within data buffered earlier (possible only
1827					   in fixed block mode without direct i/o) */
1828					if (!retry_eot && !cmdstatp->deferred &&
1829					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1830						move_buffer_data(STp->buffer, transfer - undone);
1831						retry_eot = 1;
1832						if (STps->drv_block >= 0) {
1833							STps->drv_block += (transfer - undone) /
1834								STp->block_size;
1835						}
1836						STps->eof = ST_EOM_OK;
1837						DEBC_printk(STp, "Retry "
1838							    "write of %d "
1839							    "bytes at EOM.\n",
1840							    STp->buffer->buffer_bytes);
1841						goto retry_write;
1842					}
1843					else {
1844						/* Either error within data buffered by driver or
1845						   failed retry */
1846						count -= do_count;
1847						blks = do_count = 0;
1848						STps->eof = ST_EOM_ERROR;
1849						STps->drv_block = (-1); /* Too cautious? */
1850						retval = (-EIO);	/* EOM for old data */
1851						DEBC_printk(STp, "EOM with "
1852							    "lost data.\n");
1853					}
1854				}
1855			} else {
1856				count += do_count;
1857				STps->drv_block = (-1);		/* Too cautious? */
1858				retval = STbp->syscall_result;
1859			}
1860
1861		}
1862
1863		if (STps->drv_block >= 0) {
1864			if (STp->block_size == 0)
1865				STps->drv_block += (do_count > 0);
1866			else
1867				STps->drv_block += blks;
1868		}
1869
1870		STbp->buffer_bytes = 0;
1871		STp->dirty = 0;
1872
1873		if (retval || retry_eot) {
1874			if (count < total)
1875				retval = total - count;
1876			goto out;
1877		}
1878	}
1879
1880	if (STps->eof == ST_EOD_1)
1881		STps->eof = ST_EOM_OK;
1882	else if (STps->eof != ST_EOM_OK)
1883		STps->eof = ST_NOEOF;
1884	retval = total - count;
1885
1886 out:
1887	if (SRpnt != NULL)
1888		st_release_request(SRpnt);
1889	release_buffering(STp, 0);
1890	mutex_unlock(&STp->lock);
1891
1892	return retval;
1893}
1894
1895/* Read data from the tape. Returns zero in the normal case, one if the
1896   eof status has changed, and the negative error code in case of a
1897   fatal error. Otherwise updates the buffer and the eof state.
1898
1899   Does release user buffer mapping if it is set.
1900*/
1901static long read_tape(struct scsi_tape *STp, long count,
1902		      struct st_request ** aSRpnt)
1903{
1904	int transfer, blks, bytes;
1905	unsigned char cmd[MAX_COMMAND_SIZE];
1906	struct st_request *SRpnt;
1907	struct st_modedef *STm;
1908	struct st_partstat *STps;
1909	struct st_buffer *STbp;
1910	int retval = 0;
1911
1912	if (count == 0)
1913		return 0;
1914
1915	STm = &(STp->modes[STp->current_mode]);
1916	STps = &(STp->ps[STp->partition]);
1917	if (STps->eof == ST_FM_HIT)
1918		return 1;
1919	STbp = STp->buffer;
1920
1921	if (STp->block_size == 0)
1922		blks = bytes = count;
1923	else {
1924		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1925			blks = (STp->buffer)->buffer_blocks;
1926			bytes = blks * STp->block_size;
1927		} else {
1928			bytes = count;
1929			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1930				bytes = (STp->buffer)->buffer_size;
1931			blks = bytes / STp->block_size;
1932			bytes = blks * STp->block_size;
1933		}
1934	}
1935
1936	memset(cmd, 0, MAX_COMMAND_SIZE);
1937	cmd[0] = READ_6;
1938	cmd[1] = (STp->block_size != 0);
1939	if (!cmd[1] && STp->sili)
1940		cmd[1] |= 2;
1941	cmd[2] = blks >> 16;
1942	cmd[3] = blks >> 8;
1943	cmd[4] = blks;
1944
1945	SRpnt = *aSRpnt;
1946	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1947			   STp->device->request_queue->rq_timeout,
1948			   MAX_RETRIES, 1);
1949	release_buffering(STp, 1);
1950	*aSRpnt = SRpnt;
1951	if (!SRpnt)
1952		return STbp->syscall_result;
1953
1954	STbp->read_pointer = 0;
1955	STps->at_sm = 0;
1956
1957	/* Something to check */
1958	if (STbp->syscall_result) {
1959		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1960
1961		retval = 1;
1962		DEBC_printk(STp,
1963			    "Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1964			    SRpnt->sense[0], SRpnt->sense[1],
1965			    SRpnt->sense[2], SRpnt->sense[3],
1966			    SRpnt->sense[4], SRpnt->sense[5],
1967			    SRpnt->sense[6], SRpnt->sense[7]);
1968		if (cmdstatp->have_sense) {
1969
1970			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1971				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1972
1973			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1974				/* Compute the residual count */
1975				if (cmdstatp->remainder_valid)
1976					transfer = (int)cmdstatp->uremainder64;
1977				else
1978					transfer = 0;
1979				if (cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR) {
1980					if (STp->block_size == 0)
1981						transfer = bytes;
1982					/* Some drives set ILI with MEDIUM ERROR */
1983					cmdstatp->flags &= ~SENSE_ILI;
1984				}
1985
1986				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1987					if (STp->block_size == 0 &&
1988					    transfer < 0) {
1989						st_printk(KERN_NOTICE, STp,
1990							  "Failed to read %d "
1991							  "byte block with %d "
1992							  "byte transfer.\n",
1993							  bytes - transfer,
1994							  bytes);
1995						if (STps->drv_block >= 0)
1996							STps->drv_block += 1;
1997						STbp->buffer_bytes = 0;
1998						return (-ENOMEM);
1999					} else if (STp->block_size == 0) {
2000						STbp->buffer_bytes = bytes - transfer;
2001					} else {
2002						st_release_request(SRpnt);
2003						SRpnt = *aSRpnt = NULL;
2004						if (transfer == blks) {	/* We did not get anything, error */
2005							st_printk(KERN_NOTICE, STp,
2006								  "Incorrect "
2007								  "block size.\n");
2008							if (STps->drv_block >= 0)
2009								STps->drv_block += blks - transfer + 1;
2010							st_int_ioctl(STp, MTBSR, 1);
2011							return (-EIO);
2012						}
2013						/* We have some data, deliver it */
2014						STbp->buffer_bytes = (blks - transfer) *
2015						    STp->block_size;
2016						DEBC_printk(STp, "ILI but "
2017							    "enough data "
2018							    "received %ld "
2019							    "%d.\n", count,
2020							    STbp->buffer_bytes);
2021						if (STps->drv_block >= 0)
2022							STps->drv_block += 1;
2023						if (st_int_ioctl(STp, MTBSR, 1))
2024							return (-EIO);
2025					}
2026				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
2027					if (STps->eof != ST_FM_HIT)
2028						STps->eof = ST_FM_HIT;
2029					else
2030						STps->eof = ST_EOD_2;
2031					if (STp->block_size == 0)
2032						STbp->buffer_bytes = 0;
2033					else
2034						STbp->buffer_bytes =
2035						    bytes - transfer * STp->block_size;
2036					DEBC_printk(STp, "EOF detected (%d "
2037						    "bytes read).\n",
2038						    STbp->buffer_bytes);
2039				} else if (cmdstatp->flags & SENSE_EOM) {
2040					if (STps->eof == ST_FM)
2041						STps->eof = ST_EOD_1;
2042					else
2043						STps->eof = ST_EOM_OK;
2044					if (STp->block_size == 0)
2045						STbp->buffer_bytes = bytes - transfer;
2046					else
2047						STbp->buffer_bytes =
2048						    bytes - transfer * STp->block_size;
2049
2050					DEBC_printk(STp, "EOM detected (%d "
2051						    "bytes read).\n",
2052						    STbp->buffer_bytes);
2053				}
2054			}
2055			/* end of EOF, EOM, ILI test */
2056			else {	/* nonzero sense key */
2057				DEBC_printk(STp, "Tape error while reading.\n");
2058				STps->drv_block = (-1);
2059				if (STps->eof == ST_FM &&
2060				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
2061					DEBC_printk(STp, "Zero returned for "
2062						    "first BLANK CHECK "
2063						    "after EOF.\n");
2064					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
2065				} else	/* Some other extended sense code */
2066					retval = (-EIO);
2067			}
2068
2069			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
2070				STbp->buffer_bytes = 0;
2071		}
2072		/* End of extended sense test */
2073		else {		/* Non-extended sense */
2074			retval = STbp->syscall_result;
2075		}
2076
2077	}
2078	/* End of error handling */
2079	else {			/* Read successful */
2080		STbp->buffer_bytes = bytes;
2081		if (STp->sili) /* In fixed block mode residual is always zero here */
2082			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
2083	}
2084
2085	if (STps->drv_block >= 0) {
2086		if (STp->block_size == 0)
2087			STps->drv_block++;
2088		else
2089			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2090	}
2091	return retval;
2092}
2093
2094
2095/* Read command */
2096static ssize_t
2097st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2098{
2099	ssize_t total;
2100	ssize_t retval = 0;
2101	ssize_t i, transfer;
2102	int special, do_dio = 0;
2103	struct st_request *SRpnt = NULL;
2104	struct scsi_tape *STp = filp->private_data;
2105	struct st_modedef *STm;
2106	struct st_partstat *STps;
2107	struct st_buffer *STbp = STp->buffer;
2108
2109	if (mutex_lock_interruptible(&STp->lock))
2110		return -ERESTARTSYS;
2111
2112	retval = rw_checks(STp, filp, count);
2113	if (retval || count == 0)
2114		goto out;
2115
2116	STm = &(STp->modes[STp->current_mode]);
2117	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2118		if (!STm->do_read_ahead) {
2119			retval = (-EINVAL);	/* Read must be integral number of blocks */
2120			goto out;
2121		}
2122		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2123	}
2124
2125	STps = &(STp->ps[STp->partition]);
2126	if (STps->rw == ST_WRITING) {
2127		retval = flush_buffer(STp, 0);
2128		if (retval)
2129			goto out;
2130		STps->rw = ST_READING;
2131	}
2132	DEB(
2133	if (debugging && STps->eof != ST_NOEOF)
2134		st_printk(ST_DEB_MSG, STp,
2135			  "EOF/EOM flag up (%d). Bytes %d\n",
2136			  STps->eof, STbp->buffer_bytes);
2137	) /* end DEB */
2138
2139	retval = setup_buffering(STp, buf, count, 1);
2140	if (retval)
2141		goto out;
2142	do_dio = STbp->do_dio;
2143
2144	if (STbp->buffer_bytes == 0 &&
2145	    STps->eof >= ST_EOD_1) {
2146		if (STps->eof < ST_EOD) {
2147			STps->eof += 1;
2148			retval = 0;
2149			goto out;
2150		}
2151		retval = (-EIO);	/* EOM or Blank Check */
2152		goto out;
2153	}
2154
2155	if (do_dio) {
2156		/* Check the buffer writability before any tape movement. Don't alter
2157		   buffer data. */
2158		if (copy_from_user(&i, buf, 1) != 0 ||
2159		    copy_to_user(buf, &i, 1) != 0 ||
2160		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2161		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2162			retval = (-EFAULT);
2163			goto out;
2164		}
2165	}
2166
2167	STps->rw = ST_READING;
2168
2169
2170	/* Loop until enough data in buffer or a special condition found */
2171	for (total = 0, special = 0; total < count && !special;) {
2172
2173		/* Get new data if the buffer is empty */
2174		if (STbp->buffer_bytes == 0) {
2175			special = read_tape(STp, count - total, &SRpnt);
2176			if (special < 0) {	/* No need to continue read */
2177				retval = special;
2178				goto out;
2179			}
2180		}
2181
2182		/* Move the data from driver buffer to user buffer */
2183		if (STbp->buffer_bytes > 0) {
2184			DEB(
2185			if (debugging && STps->eof != ST_NOEOF)
2186				st_printk(ST_DEB_MSG, STp,
2187					  "EOF up (%d). Left %d, needed %d.\n",
2188					  STps->eof, STbp->buffer_bytes,
2189					  (int)(count - total));
2190			) /* end DEB */
2191			transfer = STbp->buffer_bytes < count - total ?
2192			    STbp->buffer_bytes : count - total;
2193			if (!do_dio) {
2194				i = from_buffer(STbp, buf, transfer);
2195				if (i) {
2196					retval = i;
2197					goto out;
2198				}
2199			}
2200			buf += transfer;
2201			total += transfer;
2202		}
2203
2204		if (STp->block_size == 0)
2205			break;	/* Read only one variable length block */
2206
2207	}			/* for (total = 0, special = 0;
2208                                   total < count && !special; ) */
2209
2210	/* Change the eof state if no data from tape or buffer */
2211	if (total == 0) {
2212		if (STps->eof == ST_FM_HIT) {
2213			STps->eof = ST_FM;
2214			STps->drv_block = 0;
2215			if (STps->drv_file >= 0)
2216				STps->drv_file++;
2217		} else if (STps->eof == ST_EOD_1) {
2218			STps->eof = ST_EOD_2;
2219			STps->drv_block = 0;
2220			if (STps->drv_file >= 0)
2221				STps->drv_file++;
2222		} else if (STps->eof == ST_EOD_2)
2223			STps->eof = ST_EOD;
2224	} else if (STps->eof == ST_FM)
2225		STps->eof = ST_NOEOF;
2226	retval = total;
2227
2228 out:
2229	if (SRpnt != NULL) {
2230		st_release_request(SRpnt);
2231		SRpnt = NULL;
2232	}
2233	if (do_dio) {
2234		release_buffering(STp, 1);
2235		STbp->buffer_bytes = 0;
2236	}
2237	mutex_unlock(&STp->lock);
2238
2239	return retval;
2240}
2241
2242
2243
2244DEB(
2245/* Set the driver options */
2246static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm)
2247{
2248	if (debugging) {
2249		st_printk(KERN_INFO, STp,
2250			  "Mode %d options: buffer writes: %d, "
2251			  "async writes: %d, read ahead: %d\n",
2252			  STp->current_mode, STm->do_buffer_writes,
2253			  STm->do_async_writes, STm->do_read_ahead);
2254		st_printk(KERN_INFO, STp,
2255			  "    can bsr: %d, two FMs: %d, "
2256			  "fast mteom: %d, auto lock: %d,\n",
2257			  STp->can_bsr, STp->two_fm, STp->fast_mteom,
2258			  STp->do_auto_lock);
2259		st_printk(KERN_INFO, STp,
2260			  "    defs for wr: %d, no block limits: %d, "
2261			  "partitions: %d, s2 log: %d\n",
2262			  STm->defaults_for_writes, STp->omit_blklims,
2263			  STp->can_partitions, STp->scsi2_logical);
2264		st_printk(KERN_INFO, STp,
2265			  "    sysv: %d nowait: %d sili: %d "
2266			  "nowait_filemark: %d\n",
2267			  STm->sysv, STp->immediate, STp->sili,
2268			  STp->immediate_filemark);
2269		st_printk(KERN_INFO, STp, "    debugging: %d\n", debugging);
2270	}
2271}
2272	)
2273
2274
2275static int st_set_options(struct scsi_tape *STp, long options)
2276{
2277	int value;
2278	long code;
2279	struct st_modedef *STm;
2280	struct cdev *cd0, *cd1;
2281	struct device *d0, *d1;
2282
2283	STm = &(STp->modes[STp->current_mode]);
2284	if (!STm->defined) {
2285		cd0 = STm->cdevs[0];
2286		cd1 = STm->cdevs[1];
2287		d0  = STm->devs[0];
2288		d1  = STm->devs[1];
2289		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2290		STm->cdevs[0] = cd0;
2291		STm->cdevs[1] = cd1;
2292		STm->devs[0]  = d0;
2293		STm->devs[1]  = d1;
2294		modes_defined = 1;
2295		DEBC_printk(STp, "Initialized mode %d definition from mode 0\n",
2296			    STp->current_mode);
2297	}
2298
2299	code = options & MT_ST_OPTIONS;
2300	if (code == MT_ST_BOOLEANS) {
2301		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2302		STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2303		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2304		STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2305		STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2306		STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2307		STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2308		STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2309		STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2310		if ((STp->device)->scsi_level >= SCSI_2)
2311			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2312		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2313		STp->immediate = (options & MT_ST_NOWAIT) != 0;
2314		STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
2315		STm->sysv = (options & MT_ST_SYSV) != 0;
2316		STp->sili = (options & MT_ST_SILI) != 0;
2317		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2318		     st_log_options(STp, STm); )
2319	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2320		value = (code == MT_ST_SETBOOLEANS);
2321		if ((options & MT_ST_BUFFER_WRITES) != 0)
2322			STm->do_buffer_writes = value;
2323		if ((options & MT_ST_ASYNC_WRITES) != 0)
2324			STm->do_async_writes = value;
2325		if ((options & MT_ST_DEF_WRITES) != 0)
2326			STm->defaults_for_writes = value;
2327		if ((options & MT_ST_READ_AHEAD) != 0)
2328			STm->do_read_ahead = value;
2329		if ((options & MT_ST_TWO_FM) != 0)
2330			STp->two_fm = value;
2331		if ((options & MT_ST_FAST_MTEOM) != 0)
2332			STp->fast_mteom = value;
2333		if ((options & MT_ST_AUTO_LOCK) != 0)
2334			STp->do_auto_lock = value;
2335		if ((options & MT_ST_CAN_BSR) != 0)
2336			STp->can_bsr = value;
2337		if ((options & MT_ST_NO_BLKLIMS) != 0)
2338			STp->omit_blklims = value;
2339		if ((STp->device)->scsi_level >= SCSI_2 &&
2340		    (options & MT_ST_CAN_PARTITIONS) != 0)
2341			STp->can_partitions = value;
2342		if ((options & MT_ST_SCSI2LOGICAL) != 0)
2343			STp->scsi2_logical = value;
2344		if ((options & MT_ST_NOWAIT) != 0)
2345			STp->immediate = value;
2346		if ((options & MT_ST_NOWAIT_EOF) != 0)
2347			STp->immediate_filemark = value;
2348		if ((options & MT_ST_SYSV) != 0)
2349			STm->sysv = value;
2350		if ((options & MT_ST_SILI) != 0)
2351			STp->sili = value;
2352		DEB(
2353		if ((options & MT_ST_DEBUGGING) != 0)
2354			debugging = value;
2355			st_log_options(STp, STm); )
2356	} else if (code == MT_ST_WRITE_THRESHOLD) {
2357		/* Retained for compatibility */
2358	} else if (code == MT_ST_DEF_BLKSIZE) {
2359		value = (options & ~MT_ST_OPTIONS);
2360		if (value == ~MT_ST_OPTIONS) {
2361			STm->default_blksize = (-1);
2362			DEBC_printk(STp, "Default block size disabled.\n");
2363		} else {
2364			STm->default_blksize = value;
2365			DEBC_printk(STp,"Default block size set to "
2366				    "%d bytes.\n", STm->default_blksize);
2367			if (STp->ready == ST_READY) {
2368				STp->blksize_changed = 0;
2369				set_mode_densblk(STp, STm);
2370			}
2371		}
2372	} else if (code == MT_ST_TIMEOUTS) {
2373		value = (options & ~MT_ST_OPTIONS);
2374		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2375			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2376			DEBC_printk(STp, "Long timeout set to %d seconds.\n",
2377				    (value & ~MT_ST_SET_LONG_TIMEOUT));
2378		} else {
2379			blk_queue_rq_timeout(STp->device->request_queue,
2380					     value * HZ);
2381			DEBC_printk(STp, "Normal timeout set to %d seconds.\n",
2382				    value);
2383		}
2384	} else if (code == MT_ST_SET_CLN) {
2385		value = (options & ~MT_ST_OPTIONS) & 0xff;
2386		if (value != 0 &&
2387			(value < EXTENDED_SENSE_START ||
2388				value >= SCSI_SENSE_BUFFERSIZE))
2389			return (-EINVAL);
2390		STp->cln_mode = value;
2391		STp->cln_sense_mask = (options >> 8) & 0xff;
2392		STp->cln_sense_value = (options >> 16) & 0xff;
2393		st_printk(KERN_INFO, STp,
2394			  "Cleaning request mode %d, mask %02x, value %02x\n",
2395			  value, STp->cln_sense_mask, STp->cln_sense_value);
2396	} else if (code == MT_ST_DEF_OPTIONS) {
2397		code = (options & ~MT_ST_CLEAR_DEFAULT);
2398		value = (options & MT_ST_CLEAR_DEFAULT);
2399		if (code == MT_ST_DEF_DENSITY) {
2400			if (value == MT_ST_CLEAR_DEFAULT) {
2401				STm->default_density = (-1);
2402				DEBC_printk(STp,
2403					    "Density default disabled.\n");
2404			} else {
2405				STm->default_density = value & 0xff;
2406				DEBC_printk(STp, "Density default set to %x\n",
2407					    STm->default_density);
2408				if (STp->ready == ST_READY) {
2409					STp->density_changed = 0;
2410					set_mode_densblk(STp, STm);
2411				}
2412			}
2413		} else if (code == MT_ST_DEF_DRVBUFFER) {
2414			if (value == MT_ST_CLEAR_DEFAULT) {
2415				STp->default_drvbuffer = 0xff;
2416				DEBC_printk(STp,
2417					    "Drive buffer default disabled.\n");
2418			} else {
2419				STp->default_drvbuffer = value & 7;
2420				DEBC_printk(STp,
2421					    "Drive buffer default set to %x\n",
2422					    STp->default_drvbuffer);
2423				if (STp->ready == ST_READY)
2424					st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2425			}
2426		} else if (code == MT_ST_DEF_COMPRESSION) {
2427			if (value == MT_ST_CLEAR_DEFAULT) {
2428				STm->default_compression = ST_DONT_TOUCH;
2429				DEBC_printk(STp,
2430					    "Compression default disabled.\n");
2431			} else {
2432				if ((value & 0xff00) != 0) {
2433					STp->c_algo = (value & 0xff00) >> 8;
2434					DEBC_printk(STp, "Compression "
2435						    "algorithm set to 0x%x.\n",
2436						    STp->c_algo);
2437				}
2438				if ((value & 0xff) != 0xff) {
2439					STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2440					DEBC_printk(STp, "Compression default "
2441						    "set to %x\n",
2442						    (value & 1));
2443					if (STp->ready == ST_READY) {
2444						STp->compression_changed = 0;
2445						st_compression(STp, (STm->default_compression == ST_YES));
2446					}
2447				}
2448			}
2449		}
2450	} else
2451		return (-EIO);
2452
2453	return 0;
2454}
2455
2456#define MODE_HEADER_LENGTH  4
2457
2458/* Mode header and page byte offsets */
2459#define MH_OFF_DATA_LENGTH     0
2460#define MH_OFF_MEDIUM_TYPE     1
2461#define MH_OFF_DEV_SPECIFIC    2
2462#define MH_OFF_BDESCS_LENGTH   3
2463#define MP_OFF_PAGE_NBR        0
2464#define MP_OFF_PAGE_LENGTH     1
2465
2466/* Mode header and page bit masks */
2467#define MH_BIT_WP              0x80
2468#define MP_MSK_PAGE_NBR        0x3f
2469
2470/* Don't return block descriptors */
2471#define MODE_SENSE_OMIT_BDESCS 0x08
2472
2473#define MODE_SELECT_PAGE_FORMAT 0x10
2474
2475/* Read a mode page into the tape buffer. The block descriptors are included
2476   if incl_block_descs is true. The page control is ored to the page number
2477   parameter, if necessary. */
2478static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2479{
2480	unsigned char cmd[MAX_COMMAND_SIZE];
2481	struct st_request *SRpnt;
2482
2483	memset(cmd, 0, MAX_COMMAND_SIZE);
2484	cmd[0] = MODE_SENSE;
2485	if (omit_block_descs)
2486		cmd[1] = MODE_SENSE_OMIT_BDESCS;
2487	cmd[2] = page;
2488	cmd[4] = 255;
2489
2490	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2491			   STp->device->request_queue->rq_timeout, 0, 1);
2492	if (SRpnt == NULL)
2493		return (STp->buffer)->syscall_result;
2494
2495	st_release_request(SRpnt);
2496
2497	return STp->buffer->syscall_result;
2498}
2499
2500
2501/* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2502   in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2503static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2504{
2505	int pgo;
2506	unsigned char cmd[MAX_COMMAND_SIZE];
2507	struct st_request *SRpnt;
2508	int timeout;
2509
2510	memset(cmd, 0, MAX_COMMAND_SIZE);
2511	cmd[0] = MODE_SELECT;
2512	cmd[1] = MODE_SELECT_PAGE_FORMAT;
2513	pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2514	cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2515
2516	/* Clear reserved fields */
2517	(STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2518	(STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2519	(STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2520	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2521
2522	timeout = slow ?
2523		STp->long_timeout : STp->device->request_queue->rq_timeout;
2524	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2525			   timeout, 0, 1);
2526	if (SRpnt == NULL)
2527		return (STp->buffer)->syscall_result;
2528
2529	st_release_request(SRpnt);
2530
2531	return STp->buffer->syscall_result;
2532}
2533
2534
2535#define COMPRESSION_PAGE        0x0f
2536#define COMPRESSION_PAGE_LENGTH 16
2537
2538#define CP_OFF_DCE_DCC          2
2539#define CP_OFF_C_ALGO           7
2540
2541#define DCE_MASK  0x80
2542#define DCC_MASK  0x40
2543#define RED_MASK  0x60
2544
2545
2546/* Control the compression with mode page 15. Algorithm not changed if zero.
2547
2548   The block descriptors are read and written because Sony SDT-7000 does not
2549   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2550   Including block descriptors should not cause any harm to other drives. */
2551
2552static int st_compression(struct scsi_tape * STp, int state)
2553{
2554	int retval;
2555	int mpoffs;  /* Offset to mode page start */
2556	unsigned char *b_data = (STp->buffer)->b_data;
2557
2558	if (STp->ready != ST_READY)
2559		return (-EIO);
2560
2561	/* Read the current page contents */
2562	retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2563	if (retval) {
2564		DEBC_printk(STp, "Compression mode page not supported.\n");
2565		return (-EIO);
2566	}
2567
2568	mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2569	DEBC_printk(STp, "Compression state is %d.\n",
2570		    (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0));
2571
2572	/* Check if compression can be changed */
2573	if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2574		DEBC_printk(STp, "Compression not supported.\n");
2575		return (-EIO);
2576	}
2577
2578	/* Do the change */
2579	if (state) {
2580		b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2581		if (STp->c_algo != 0)
2582			b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2583	}
2584	else {
2585		b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2586		if (STp->c_algo != 0)
2587			b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2588	}
2589
2590	retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2591	if (retval) {
2592		DEBC_printk(STp, "Compression change failed.\n");
2593		return (-EIO);
2594	}
2595	DEBC_printk(STp, "Compression state changed to %d.\n", state);
2596
2597	STp->compression_changed = 1;
2598	return 0;
2599}
2600
2601
2602/* Process the load and unload commands (does unload if the load code is zero) */
2603static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2604{
2605	int retval = (-EIO), timeout;
2606	unsigned char cmd[MAX_COMMAND_SIZE];
2607	struct st_partstat *STps;
2608	struct st_request *SRpnt;
2609
2610	if (STp->ready != ST_READY && !load_code) {
2611		if (STp->ready == ST_NO_TAPE)
2612			return (-ENOMEDIUM);
2613		else
2614			return (-EIO);
2615	}
2616
2617	memset(cmd, 0, MAX_COMMAND_SIZE);
2618	cmd[0] = START_STOP;
2619	if (load_code)
2620		cmd[4] |= 1;
2621	/*
2622	 * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2623	 */
2624	if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2625	    && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2626		DEBC_printk(STp, " Enhanced %sload slot %2d.\n",
2627			    (cmd[4]) ? "" : "un",
2628			    load_code - MT_ST_HPLOADER_OFFSET);
2629		cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2630	}
2631	if (STp->immediate) {
2632		cmd[1] = 1;	/* Don't wait for completion */
2633		timeout = STp->device->request_queue->rq_timeout;
2634	}
2635	else
2636		timeout = STp->long_timeout;
2637
2638	DEBC(
2639		if (!load_code)
2640			st_printk(ST_DEB_MSG, STp, "Unloading tape.\n");
2641		else
2642			st_printk(ST_DEB_MSG, STp, "Loading tape.\n");
2643		);
2644
2645	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2646			   timeout, MAX_RETRIES, 1);
2647	if (!SRpnt)
2648		return (STp->buffer)->syscall_result;
2649
2650	retval = (STp->buffer)->syscall_result;
2651	st_release_request(SRpnt);
2652
2653	if (!retval) {	/* SCSI command successful */
2654
2655		if (!load_code) {
2656			STp->rew_at_close = 0;
2657			STp->ready = ST_NO_TAPE;
2658		}
2659		else {
2660			STp->rew_at_close = STp->autorew_dev;
2661			retval = check_tape(STp, filp);
2662			if (retval > 0)
2663				retval = 0;
2664		}
2665	}
2666	else {
2667		STps = &(STp->ps[STp->partition]);
2668		STps->drv_file = STps->drv_block = (-1);
2669	}
2670
2671	return retval;
2672}
2673
2674#if DEBUG
2675#define ST_DEB_FORWARD  0
2676#define ST_DEB_BACKWARD 1
2677static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd)
2678{
2679	s32 sc;
2680
2681	if (!debugging)
2682		return;
2683
2684	sc = sign_extend32(get_unaligned_be24(&cmd[2]), 23);
 
2685	if (direction)
2686		sc = -sc;
2687	st_printk(ST_DEB_MSG, STp, "Spacing tape %s over %d %s.\n",
2688		  direction ? "backward" : "forward", sc, units);
2689}
2690#else
2691#define ST_DEB_FORWARD  0
2692#define ST_DEB_BACKWARD 1
2693static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd) {}
2694#endif
2695
2696
2697/* Internal ioctl function */
2698static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2699{
2700	int timeout;
2701	long ltmp;
2702	int ioctl_result;
2703	int chg_eof = 1;
2704	unsigned char cmd[MAX_COMMAND_SIZE];
2705	struct st_request *SRpnt;
2706	struct st_partstat *STps;
2707	int fileno, blkno, at_sm, undone;
2708	int datalen = 0, direction = DMA_NONE;
2709
2710	WARN_ON(STp->buffer->do_dio != 0);
2711	if (STp->ready != ST_READY) {
2712		if (STp->ready == ST_NO_TAPE)
2713			return (-ENOMEDIUM);
2714		else
2715			return (-EIO);
2716	}
2717	timeout = STp->long_timeout;
2718	STps = &(STp->ps[STp->partition]);
2719	fileno = STps->drv_file;
2720	blkno = STps->drv_block;
2721	at_sm = STps->at_sm;
2722
2723	memset(cmd, 0, MAX_COMMAND_SIZE);
2724	switch (cmd_in) {
2725	case MTFSFM:
2726		chg_eof = 0;	/* Changed from the FSF after this */
2727		fallthrough;
2728	case MTFSF:
2729		cmd[0] = SPACE;
2730		cmd[1] = 0x01;	/* Space FileMarks */
2731		cmd[2] = (arg >> 16);
2732		cmd[3] = (arg >> 8);
2733		cmd[4] = arg;
2734		deb_space_print(STp, ST_DEB_FORWARD, "filemarks", cmd);
2735		if (fileno >= 0)
2736			fileno += arg;
2737		blkno = 0;
2738		at_sm &= (arg == 0);
2739		break;
2740	case MTBSFM:
2741		chg_eof = 0;	/* Changed from the FSF after this */
2742		fallthrough;
2743	case MTBSF:
2744		cmd[0] = SPACE;
2745		cmd[1] = 0x01;	/* Space FileMarks */
2746		ltmp = (-arg);
2747		cmd[2] = (ltmp >> 16);
2748		cmd[3] = (ltmp >> 8);
2749		cmd[4] = ltmp;
2750		deb_space_print(STp, ST_DEB_BACKWARD, "filemarks", cmd);
2751		if (fileno >= 0)
2752			fileno -= arg;
2753		blkno = (-1);	/* We can't know the block number */
2754		at_sm &= (arg == 0);
2755		break;
2756	case MTFSR:
2757		cmd[0] = SPACE;
2758		cmd[1] = 0x00;	/* Space Blocks */
2759		cmd[2] = (arg >> 16);
2760		cmd[3] = (arg >> 8);
2761		cmd[4] = arg;
2762		deb_space_print(STp, ST_DEB_FORWARD, "blocks", cmd);
2763		if (blkno >= 0)
2764			blkno += arg;
2765		at_sm &= (arg == 0);
2766		break;
2767	case MTBSR:
2768		cmd[0] = SPACE;
2769		cmd[1] = 0x00;	/* Space Blocks */
2770		ltmp = (-arg);
2771		cmd[2] = (ltmp >> 16);
2772		cmd[3] = (ltmp >> 8);
2773		cmd[4] = ltmp;
2774		deb_space_print(STp, ST_DEB_BACKWARD, "blocks", cmd);
2775		if (blkno >= 0)
2776			blkno -= arg;
2777		at_sm &= (arg == 0);
2778		break;
2779	case MTFSS:
2780		cmd[0] = SPACE;
2781		cmd[1] = 0x04;	/* Space Setmarks */
2782		cmd[2] = (arg >> 16);
2783		cmd[3] = (arg >> 8);
2784		cmd[4] = arg;
2785		deb_space_print(STp, ST_DEB_FORWARD, "setmarks", cmd);
2786		if (arg != 0) {
2787			blkno = fileno = (-1);
2788			at_sm = 1;
2789		}
2790		break;
2791	case MTBSS:
2792		cmd[0] = SPACE;
2793		cmd[1] = 0x04;	/* Space Setmarks */
2794		ltmp = (-arg);
2795		cmd[2] = (ltmp >> 16);
2796		cmd[3] = (ltmp >> 8);
2797		cmd[4] = ltmp;
2798		deb_space_print(STp, ST_DEB_BACKWARD, "setmarks", cmd);
2799		if (arg != 0) {
2800			blkno = fileno = (-1);
2801			at_sm = 1;
2802		}
2803		break;
2804	case MTWEOF:
2805	case MTWEOFI:
2806	case MTWSM:
2807		if (STp->write_prot)
2808			return (-EACCES);
2809		cmd[0] = WRITE_FILEMARKS;
2810		if (cmd_in == MTWSM)
2811			cmd[1] = 2;
2812		if (cmd_in == MTWEOFI ||
2813		    (cmd_in == MTWEOF && STp->immediate_filemark))
2814			cmd[1] |= 1;
2815		cmd[2] = (arg >> 16);
2816		cmd[3] = (arg >> 8);
2817		cmd[4] = arg;
2818		timeout = STp->device->request_queue->rq_timeout;
2819		DEBC(
2820			if (cmd_in != MTWSM)
2821				st_printk(ST_DEB_MSG, STp,
2822					  "Writing %d filemarks.\n",
2823					  cmd[2] * 65536 +
2824					  cmd[3] * 256 +
2825					  cmd[4]);
2826			else
2827				st_printk(ST_DEB_MSG, STp,
2828					  "Writing %d setmarks.\n",
2829					  cmd[2] * 65536 +
2830					  cmd[3] * 256 +
2831					  cmd[4]);
2832		)
2833		if (fileno >= 0)
2834			fileno += arg;
2835		blkno = 0;
2836		at_sm = (cmd_in == MTWSM);
2837		break;
2838	case MTREW:
2839		cmd[0] = REZERO_UNIT;
2840		if (STp->immediate) {
2841			cmd[1] = 1;	/* Don't wait for completion */
2842			timeout = STp->device->request_queue->rq_timeout;
2843		}
2844		DEBC_printk(STp, "Rewinding tape.\n");
2845		fileno = blkno = at_sm = 0;
2846		break;
2847	case MTNOP:
2848		DEBC_printk(STp, "No op on tape.\n");
2849		return 0;	/* Should do something ? */
 
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	void __user *p = (void __user *)arg;
3506	int i, cmd_nr, cmd_type, bt;
3507	int retval = 0;
3508	unsigned int blk;
3509	struct scsi_tape *STp = file->private_data;
3510	struct st_modedef *STm;
3511	struct st_partstat *STps;
 
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		retval = put_user_mtget(p, &mt_status);
3804		if (retval)
 
3805			goto out;
 
3806
3807		STp->recover_reg = 0;		/* Clear after read */
 
3808		goto out;
3809	}			/* End of MTIOCGET */
3810	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3811		struct mtpos mt_pos;
3812		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3813			 retval = (-EINVAL);
3814			 goto out;
3815		}
3816		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3817			retval = i;
3818			goto out;
3819		}
3820		mt_pos.mt_blkno = blk;
3821		retval = put_user_mtpos(p, &mt_pos);
 
 
3822		goto out;
3823	}
3824	mutex_unlock(&STp->lock);
3825
3826	switch (cmd_in) {
3827	case SG_IO:
3828	case SCSI_IOCTL_SEND_COMMAND:
3829	case CDROM_SEND_PACKET:
3830		if (!capable(CAP_SYS_RAWIO))
3831			return -EPERM;
3832		break;
3833	default:
3834		break;
 
 
 
 
 
 
 
3835	}
3836
3837	retval = scsi_ioctl(STp->device, file->f_mode & FMODE_WRITE, cmd_in, p);
3838	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) {
3839		/* unload */
3840		STp->rew_at_close = 0;
3841		STp->ready = ST_NO_TAPE;
3842	}
3843	return retval;
3844
3845 out:
3846	mutex_unlock(&STp->lock);
3847	return retval;
3848}
3849
3850#ifdef CONFIG_COMPAT
3851static long st_compat_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3852{
3853	/* argument conversion is handled using put_user_mtpos/put_user_mtget */
3854	switch (cmd_in) {
3855	case MTIOCPOS32:
3856		cmd_in = MTIOCPOS;
3857		break;
3858	case MTIOCGET32:
3859		cmd_in = MTIOCGET;
3860		break;
3861	}
3862
3863	return st_ioctl(file, cmd_in, arg);
 
3864}
3865#endif
3866
3867
3868
3869/* Try to allocate a new tape buffer. Calling function must not hold
3870   dev_arr_lock. */
3871static struct st_buffer *new_tape_buffer(int max_sg)
3872{
3873	struct st_buffer *tb;
3874
3875	tb = kzalloc(sizeof(struct st_buffer), GFP_KERNEL);
3876	if (!tb) {
3877		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3878		return NULL;
3879	}
3880	tb->frp_segs = 0;
3881	tb->use_sg = max_sg;
 
3882	tb->buffer_size = 0;
3883
3884	tb->reserved_pages = kcalloc(max_sg, sizeof(struct page *),
3885				     GFP_KERNEL);
3886	if (!tb->reserved_pages) {
3887		kfree(tb);
3888		return NULL;
3889	}
3890
3891	return tb;
3892}
3893
3894
3895/* Try to allocate enough space in the tape buffer */
3896#define ST_MAX_ORDER 6
3897
3898static int enlarge_buffer(struct st_buffer * STbuffer, int new_size)
3899{
3900	int segs, max_segs, b_size, order, got;
3901	gfp_t priority;
3902
3903	if (new_size <= STbuffer->buffer_size)
3904		return 1;
3905
3906	if (STbuffer->buffer_size <= PAGE_SIZE)
3907		normalize_buffer(STbuffer);  /* Avoid extra segment */
3908
3909	max_segs = STbuffer->use_sg;
3910
3911	priority = GFP_KERNEL | __GFP_NOWARN;
 
 
3912
3913	if (STbuffer->cleared)
3914		priority |= __GFP_ZERO;
3915
3916	if (STbuffer->frp_segs) {
3917		order = STbuffer->reserved_page_order;
3918		b_size = PAGE_SIZE << order;
3919	} else {
3920		for (b_size = PAGE_SIZE, order = 0;
3921		     order < ST_MAX_ORDER &&
3922			     max_segs * (PAGE_SIZE << order) < new_size;
3923		     order++, b_size *= 2)
3924			;  /* empty */
3925		STbuffer->reserved_page_order = order;
3926	}
3927	if (max_segs * (PAGE_SIZE << order) < new_size) {
3928		if (order == ST_MAX_ORDER)
3929			return 0;
3930		normalize_buffer(STbuffer);
3931		return enlarge_buffer(STbuffer, new_size);
3932	}
3933
3934	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3935	     segs < max_segs && got < new_size;) {
3936		struct page *page;
3937
3938		page = alloc_pages(priority, order);
3939		if (!page) {
3940			DEB(STbuffer->buffer_size = got);
3941			normalize_buffer(STbuffer);
3942			return 0;
3943		}
3944
3945		STbuffer->frp_segs += 1;
3946		got += b_size;
3947		STbuffer->buffer_size = got;
3948		STbuffer->reserved_pages[segs] = page;
3949		segs++;
3950	}
3951	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3952
3953	return 1;
3954}
3955
3956
3957/* Make sure that no data from previous user is in the internal buffer */
3958static void clear_buffer(struct st_buffer * st_bp)
3959{
3960	int i;
3961
3962	for (i=0; i < st_bp->frp_segs; i++)
3963		memset(page_address(st_bp->reserved_pages[i]), 0,
3964		       PAGE_SIZE << st_bp->reserved_page_order);
3965	st_bp->cleared = 1;
3966}
3967
3968
3969/* Release the extra buffer */
3970static void normalize_buffer(struct st_buffer * STbuffer)
3971{
3972	int i, order = STbuffer->reserved_page_order;
3973
3974	for (i = 0; i < STbuffer->frp_segs; i++) {
3975		__free_pages(STbuffer->reserved_pages[i], order);
3976		STbuffer->buffer_size -= (PAGE_SIZE << order);
3977	}
3978	STbuffer->frp_segs = 0;
3979	STbuffer->sg_segs = 0;
3980	STbuffer->reserved_page_order = 0;
3981	STbuffer->map_data.offset = 0;
3982}
3983
3984
3985/* Move data from the user buffer to the tape buffer. Returns zero (success) or
3986   negative error code. */
3987static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3988{
3989	int i, cnt, res, offset;
3990	int length = PAGE_SIZE << st_bp->reserved_page_order;
3991
3992	for (i = 0, offset = st_bp->buffer_bytes;
3993	     i < st_bp->frp_segs && offset >= length; i++)
3994		offset -= length;
3995	if (i == st_bp->frp_segs) {	/* Should never happen */
3996		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
3997		return (-EIO);
3998	}
3999	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4000		struct page *page = st_bp->reserved_pages[i];
4001		cnt = length - offset < do_count ? length - offset : do_count;
4002		res = copy_from_user(page_address(page) + offset, ubp, cnt);
4003		if (res)
4004			return (-EFAULT);
4005		do_count -= cnt;
4006		st_bp->buffer_bytes += cnt;
4007		ubp += cnt;
4008		offset = 0;
4009	}
4010	if (do_count) /* Should never happen */
4011		return (-EIO);
4012
4013	return 0;
4014}
4015
4016
4017/* Move data from the tape buffer to the user buffer. Returns zero (success) or
4018   negative error code. */
4019static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
4020{
4021	int i, cnt, res, offset;
4022	int length = PAGE_SIZE << st_bp->reserved_page_order;
4023
4024	for (i = 0, offset = st_bp->read_pointer;
4025	     i < st_bp->frp_segs && offset >= length; i++)
4026		offset -= length;
4027	if (i == st_bp->frp_segs) {	/* Should never happen */
4028		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
4029		return (-EIO);
4030	}
4031	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4032		struct page *page = st_bp->reserved_pages[i];
4033		cnt = length - offset < do_count ? length - offset : do_count;
4034		res = copy_to_user(ubp, page_address(page) + offset, cnt);
4035		if (res)
4036			return (-EFAULT);
4037		do_count -= cnt;
4038		st_bp->buffer_bytes -= cnt;
4039		st_bp->read_pointer += cnt;
4040		ubp += cnt;
4041		offset = 0;
4042	}
4043	if (do_count) /* Should never happen */
4044		return (-EIO);
4045
4046	return 0;
4047}
4048
4049
4050/* Move data towards start of buffer */
4051static void move_buffer_data(struct st_buffer * st_bp, int offset)
4052{
4053	int src_seg, dst_seg, src_offset = 0, dst_offset;
4054	int count, total;
4055	int length = PAGE_SIZE << st_bp->reserved_page_order;
4056
4057	if (offset == 0)
4058		return;
4059
4060	total=st_bp->buffer_bytes - offset;
4061	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
4062		src_offset = offset;
4063		if (src_offset < length)
4064			break;
4065		offset -= length;
4066	}
4067
4068	st_bp->buffer_bytes = st_bp->read_pointer = total;
4069	for (dst_seg=dst_offset=0; total > 0; ) {
4070		struct page *dpage = st_bp->reserved_pages[dst_seg];
4071		struct page *spage = st_bp->reserved_pages[src_seg];
4072
4073		count = min(length - dst_offset, length - src_offset);
4074		memmove(page_address(dpage) + dst_offset,
4075			page_address(spage) + src_offset, count);
4076		src_offset += count;
4077		if (src_offset >= length) {
4078			src_seg++;
4079			src_offset = 0;
4080		}
4081		dst_offset += count;
4082		if (dst_offset >= length) {
4083			dst_seg++;
4084			dst_offset = 0;
4085		}
4086		total -= count;
4087	}
4088}
4089
4090/* Validate the options from command line or module parameters */
4091static void validate_options(void)
4092{
4093	if (buffer_kbs > 0)
4094		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
4095	if (max_sg_segs >= ST_FIRST_SG)
4096		st_max_sg_segs = max_sg_segs;
4097}
4098
4099#ifndef MODULE
4100/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
4101 */
4102static int __init st_setup(char *str)
4103{
4104	int i, len, ints[5];
4105	char *stp;
4106
4107	stp = get_options(str, ARRAY_SIZE(ints), ints);
4108
4109	if (ints[0] > 0) {
4110		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
4111			if (parms[i].val)
4112				*parms[i].val = ints[i + 1];
4113	} else {
4114		while (stp != NULL) {
4115			for (i = 0; i < ARRAY_SIZE(parms); i++) {
4116				len = strlen(parms[i].name);
4117				if (!strncmp(stp, parms[i].name, len) &&
4118				    (*(stp + len) == ':' || *(stp + len) == '=')) {
4119					if (parms[i].val)
4120						*parms[i].val =
4121							simple_strtoul(stp + len + 1, NULL, 0);
4122					else
4123						printk(KERN_WARNING "st: Obsolete parameter %s\n",
4124						       parms[i].name);
4125					break;
4126				}
4127			}
4128			if (i >= ARRAY_SIZE(parms))
4129				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
4130					stp);
4131			stp = strchr(stp, ',');
4132			if (stp)
4133				stp++;
4134		}
4135	}
4136
4137	validate_options();
4138
4139	return 1;
4140}
4141
4142__setup("st=", st_setup);
4143
4144#endif
4145
4146static const struct file_operations st_fops =
4147{
4148	.owner =	THIS_MODULE,
4149	.read =		st_read,
4150	.write =	st_write,
4151	.unlocked_ioctl = st_ioctl,
4152#ifdef CONFIG_COMPAT
4153	.compat_ioctl = st_compat_ioctl,
4154#endif
4155	.open =		st_open,
4156	.flush =	st_flush,
4157	.release =	st_release,
4158	.llseek =	noop_llseek,
4159};
4160
4161static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
4162{
4163	int i, error;
4164	dev_t cdev_devno;
4165	struct cdev *cdev;
4166	struct device *dev;
4167	struct st_modedef *STm = &(tape->modes[mode]);
4168	char name[10];
4169	int dev_num = tape->index;
4170
4171	cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
4172
4173	cdev = cdev_alloc();
4174	if (!cdev) {
4175		pr_err("st%d: out of memory. Device not attached.\n", dev_num);
4176		error = -ENOMEM;
4177		goto out;
4178	}
4179	cdev->owner = THIS_MODULE;
4180	cdev->ops = &st_fops;
4181	STm->cdevs[rew] = cdev;
4182
4183	error = cdev_add(cdev, cdev_devno, 1);
4184	if (error) {
4185		pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
4186		       rew ? "non" : "auto", mode);
4187		pr_err("st%d: Device not attached.\n", dev_num);
4188		goto out_free;
4189	}
4190
4191	i = mode << (4 - ST_NBR_MODE_BITS);
4192	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4193		 tape->name, st_formats[i]);
4194
4195	dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
4196			    cdev_devno, &tape->modes[mode], "%s", name);
4197	if (IS_ERR(dev)) {
4198		pr_err("st%d: device_create failed\n", dev_num);
4199		error = PTR_ERR(dev);
4200		goto out_free;
4201	}
4202
4203	STm->devs[rew] = dev;
4204
4205	return 0;
4206out_free:
4207	cdev_del(STm->cdevs[rew]);
4208out:
4209	STm->cdevs[rew] = NULL;
4210	STm->devs[rew] = NULL;
4211	return error;
4212}
4213
4214static int create_cdevs(struct scsi_tape *tape)
4215{
4216	int mode, error;
4217	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4218		error = create_one_cdev(tape, mode, 0);
4219		if (error)
4220			return error;
4221		error = create_one_cdev(tape, mode, 1);
4222		if (error)
4223			return error;
4224	}
4225
4226	return sysfs_create_link(&tape->device->sdev_gendev.kobj,
4227				 &tape->modes[0].devs[0]->kobj, "tape");
4228}
4229
4230static void remove_cdevs(struct scsi_tape *tape)
4231{
4232	int mode, rew;
4233	sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
4234	for (mode = 0; mode < ST_NBR_MODES; mode++) {
4235		struct st_modedef *STm = &(tape->modes[mode]);
4236		for (rew = 0; rew < 2; rew++) {
4237			if (STm->cdevs[rew])
4238				cdev_del(STm->cdevs[rew]);
4239			if (STm->devs[rew])
4240				device_unregister(STm->devs[rew]);
4241		}
4242	}
4243}
4244
4245static int st_probe(struct device *dev)
4246{
4247	struct scsi_device *SDp = to_scsi_device(dev);
 
4248	struct scsi_tape *tpnt = NULL;
4249	struct st_modedef *STm;
4250	struct st_partstat *STps;
4251	struct st_buffer *buffer;
4252	int i, error;
 
4253
4254	if (SDp->type != TYPE_TAPE)
4255		return -ENODEV;
4256	if (st_incompatible(SDp)) {
4257		sdev_printk(KERN_INFO, SDp,
4258			    "OnStream tapes are no longer supported;\n");
4259		sdev_printk(KERN_INFO, SDp,
4260			    "please mail to linux-scsi@vger.kernel.org.\n");
4261		return -ENODEV;
4262	}
4263
4264	scsi_autopm_get_device(SDp);
4265	i = queue_max_segments(SDp->request_queue);
4266	if (st_max_sg_segs < i)
4267		i = st_max_sg_segs;
4268	buffer = new_tape_buffer(i);
4269	if (buffer == NULL) {
4270		sdev_printk(KERN_ERR, SDp,
4271			    "st: Can't allocate new tape buffer. "
4272			    "Device not attached.\n");
4273		goto out;
4274	}
4275
4276	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_KERNEL);
 
 
 
 
 
 
 
4277	if (tpnt == NULL) {
4278		sdev_printk(KERN_ERR, SDp,
4279			    "st: Can't allocate device descriptor.\n");
4280		goto out_buffer_free;
4281	}
4282	kref_init(&tpnt->kref);
 
 
 
 
 
 
 
 
4283
4284	tpnt->device = SDp;
4285	if (SDp->scsi_level <= 2)
4286		tpnt->tape_type = MT_ISSCSI1;
4287	else
4288		tpnt->tape_type = MT_ISSCSI2;
4289
4290	tpnt->buffer = buffer;
4291	tpnt->buffer->last_SRpnt = NULL;
4292
4293	tpnt->inited = 0;
4294	tpnt->dirty = 0;
4295	tpnt->in_use = 0;
4296	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
 
4297	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4298	tpnt->density = 0;
4299	tpnt->do_auto_lock = ST_AUTO_LOCK;
4300	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4301	tpnt->can_partitions = 0;
4302	tpnt->two_fm = ST_TWO_FM;
4303	tpnt->fast_mteom = ST_FAST_MTEOM;
4304	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4305	tpnt->sili = ST_SILI;
4306	tpnt->immediate = ST_NOWAIT;
4307	tpnt->immediate_filemark = 0;
4308	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4309	tpnt->partition = 0;
4310	tpnt->new_partition = 0;
4311	tpnt->nbr_partitions = 0;
4312	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4313	tpnt->long_timeout = ST_LONG_TIMEOUT;
4314	tpnt->try_dio = try_direct_io;
4315
4316	for (i = 0; i < ST_NBR_MODES; i++) {
4317		STm = &(tpnt->modes[i]);
4318		STm->defined = 0;
4319		STm->sysv = ST_SYSV;
4320		STm->defaults_for_writes = 0;
4321		STm->do_async_writes = ST_ASYNC_WRITES;
4322		STm->do_buffer_writes = ST_BUFFER_WRITES;
4323		STm->do_read_ahead = ST_READ_AHEAD;
4324		STm->default_compression = ST_DONT_TOUCH;
4325		STm->default_blksize = (-1);	/* No forced size */
4326		STm->default_density = (-1);	/* No forced density */
4327		STm->tape = tpnt;
4328	}
4329
4330	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4331		STps = &(tpnt->ps[i]);
4332		STps->rw = ST_IDLE;
4333		STps->eof = ST_NOEOF;
4334		STps->at_sm = 0;
4335		STps->last_block_valid = 0;
4336		STps->drv_block = (-1);
4337		STps->drv_file = (-1);
4338	}
4339
4340	tpnt->current_mode = 0;
4341	tpnt->modes[0].defined = 1;
4342
4343	tpnt->density_changed = tpnt->compression_changed =
4344	    tpnt->blksize_changed = 0;
4345	mutex_init(&tpnt->lock);
4346
4347	idr_preload(GFP_KERNEL);
4348	spin_lock(&st_index_lock);
4349	error = idr_alloc(&st_index_idr, tpnt, 0, ST_MAX_TAPES + 1, GFP_NOWAIT);
4350	spin_unlock(&st_index_lock);
4351	idr_preload_end();
4352	if (error < 0) {
4353		pr_warn("st: idr allocation failed: %d\n", error);
4354		goto out_free_tape;
4355	}
4356	tpnt->index = error;
4357	sprintf(tpnt->name, "st%d", tpnt->index);
4358	tpnt->stats = kzalloc(sizeof(struct scsi_tape_stats), GFP_KERNEL);
4359	if (tpnt->stats == NULL) {
4360		sdev_printk(KERN_ERR, SDp,
4361			    "st: Can't allocate statistics.\n");
4362		goto out_idr_remove;
4363	}
4364
4365	dev_set_drvdata(dev, tpnt);
4366
4367
4368	error = create_cdevs(tpnt);
4369	if (error)
4370		goto out_remove_devs;
4371	scsi_autopm_put_device(SDp);
4372
4373	sdev_printk(KERN_NOTICE, SDp,
4374		    "Attached scsi tape %s\n", tpnt->name);
4375	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4376		    tpnt->name, tpnt->try_dio ? "yes" : "no",
4377		    queue_dma_alignment(SDp->request_queue) + 1);
4378
4379	return 0;
4380
4381out_remove_devs:
4382	remove_cdevs(tpnt);
4383	kfree(tpnt->stats);
4384out_idr_remove:
4385	spin_lock(&st_index_lock);
4386	idr_remove(&st_index_idr, tpnt->index);
4387	spin_unlock(&st_index_lock);
4388out_free_tape:
 
 
 
4389	kfree(tpnt);
4390out_buffer_free:
4391	kfree(buffer);
4392out:
4393	scsi_autopm_put_device(SDp);
4394	return -ENODEV;
4395};
4396
4397
4398static int st_remove(struct device *dev)
4399{
4400	struct scsi_tape *tpnt = dev_get_drvdata(dev);
4401	int index = tpnt->index;
4402
4403	scsi_autopm_get_device(to_scsi_device(dev));
4404	remove_cdevs(tpnt);
4405
4406	mutex_lock(&st_ref_mutex);
4407	kref_put(&tpnt->kref, scsi_tape_release);
4408	mutex_unlock(&st_ref_mutex);
4409	spin_lock(&st_index_lock);
4410	idr_remove(&st_index_idr, index);
4411	spin_unlock(&st_index_lock);
4412	return 0;
4413}
4414
4415/**
4416 *      scsi_tape_release - Called to free the Scsi_Tape structure
4417 *      @kref: pointer to embedded kref
4418 *
4419 *      st_ref_mutex must be held entering this routine.  Because it is
4420 *      called on last put, you should always use the scsi_tape_get()
4421 *      scsi_tape_put() helpers which manipulate the semaphore directly
4422 *      and never do a direct kref_put().
4423 **/
4424static void scsi_tape_release(struct kref *kref)
4425{
4426	struct scsi_tape *tpnt = to_scsi_tape(kref);
 
4427
4428	tpnt->device = NULL;
4429
4430	if (tpnt->buffer) {
4431		normalize_buffer(tpnt->buffer);
4432		kfree(tpnt->buffer->reserved_pages);
4433		kfree(tpnt->buffer);
4434	}
4435
 
 
4436	kfree(tpnt->stats);
4437	kfree(tpnt);
4438	return;
4439}
4440
4441static struct class st_sysfs_class = {
4442	.name = "scsi_tape",
4443	.dev_groups = st_dev_groups,
4444};
4445
4446static int __init init_st(void)
4447{
4448	int err;
4449
4450	validate_options();
4451
4452	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4453		verstr, st_fixed_buffer_size, st_max_sg_segs);
4454
4455	debugging = (debug_flag > 0) ? debug_flag : NO_DEBUG;
4456	if (debugging) {
4457		printk(KERN_INFO "st: Debugging enabled debug_flag = %d\n",
4458			debugging);
4459	}
4460
4461	err = class_register(&st_sysfs_class);
4462	if (err) {
4463		pr_err("Unable register sysfs class for SCSI tapes\n");
4464		return err;
4465	}
4466
4467	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4468				     ST_MAX_TAPE_ENTRIES, "st");
4469	if (err) {
4470		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4471		       SCSI_TAPE_MAJOR);
4472		goto err_class;
4473	}
4474
4475	err = scsi_register_driver(&st_template.gendrv);
4476	if (err)
4477		goto err_chrdev;
4478
4479	return 0;
4480
4481err_chrdev:
4482	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4483				 ST_MAX_TAPE_ENTRIES);
4484err_class:
4485	class_unregister(&st_sysfs_class);
4486	return err;
4487}
4488
4489static void __exit exit_st(void)
4490{
4491	scsi_unregister_driver(&st_template.gendrv);
4492	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4493				 ST_MAX_TAPE_ENTRIES);
4494	class_unregister(&st_sysfs_class);
4495	idr_destroy(&st_index_idr);
4496	printk(KERN_INFO "st: Unloaded.\n");
4497}
4498
4499module_init(init_st);
4500module_exit(exit_st);
4501
4502
4503/* The sysfs driver interface. Read-only at the moment */
4504static ssize_t try_direct_io_show(struct device_driver *ddp, char *buf)
4505{
4506	return scnprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4507}
4508static DRIVER_ATTR_RO(try_direct_io);
4509
4510static ssize_t fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4511{
4512	return scnprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4513}
4514static DRIVER_ATTR_RO(fixed_buffer_size);
4515
4516static ssize_t max_sg_segs_show(struct device_driver *ddp, char *buf)
4517{
4518	return scnprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4519}
4520static DRIVER_ATTR_RO(max_sg_segs);
4521
4522static ssize_t version_show(struct device_driver *ddd, char *buf)
4523{
4524	return scnprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4525}
4526static DRIVER_ATTR_RO(version);
4527
4528#if DEBUG
4529static ssize_t debug_flag_store(struct device_driver *ddp,
4530	const char *buf, size_t count)
4531{
4532/* We only care what the first byte of the data is the rest is unused.
4533 * if it's a '1' we turn on debug and if it's a '0' we disable it. All
4534 * other values have -EINVAL returned if they are passed in.
4535 */
4536	if (count > 0) {
4537		if (buf[0] == '0') {
4538			debugging = NO_DEBUG;
4539			return count;
4540		} else if (buf[0] == '1') {
4541			debugging = 1;
4542			return count;
4543		}
4544	}
4545	return -EINVAL;
4546}
4547
4548static ssize_t debug_flag_show(struct device_driver *ddp, char *buf)
4549{
4550	return scnprintf(buf, PAGE_SIZE, "%d\n", debugging);
4551}
4552static DRIVER_ATTR_RW(debug_flag);
4553#endif
4554
4555static struct attribute *st_drv_attrs[] = {
4556	&driver_attr_try_direct_io.attr,
4557	&driver_attr_fixed_buffer_size.attr,
4558	&driver_attr_max_sg_segs.attr,
4559	&driver_attr_version.attr,
4560#if DEBUG
4561	&driver_attr_debug_flag.attr,
4562#endif
4563	NULL,
4564};
4565ATTRIBUTE_GROUPS(st_drv);
4566
4567/* The sysfs simple class interface */
4568static ssize_t
4569defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4570{
4571	struct st_modedef *STm = dev_get_drvdata(dev);
4572	ssize_t l = 0;
4573
4574	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4575	return l;
4576}
4577static DEVICE_ATTR_RO(defined);
4578
4579static ssize_t
4580default_blksize_show(struct device *dev, struct device_attribute *attr,
4581		     char *buf)
4582{
4583	struct st_modedef *STm = dev_get_drvdata(dev);
4584	ssize_t l = 0;
4585
4586	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4587	return l;
4588}
4589static DEVICE_ATTR_RO(default_blksize);
4590
4591static ssize_t
4592default_density_show(struct device *dev, struct device_attribute *attr,
4593		     char *buf)
4594{
4595	struct st_modedef *STm = dev_get_drvdata(dev);
4596	ssize_t l = 0;
4597	char *fmt;
4598
4599	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4600	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4601	return l;
4602}
4603static DEVICE_ATTR_RO(default_density);
4604
4605static ssize_t
4606default_compression_show(struct device *dev, struct device_attribute *attr,
4607			 char *buf)
4608{
4609	struct st_modedef *STm = dev_get_drvdata(dev);
4610	ssize_t l = 0;
4611
4612	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4613	return l;
4614}
4615static DEVICE_ATTR_RO(default_compression);
4616
4617static ssize_t
4618options_show(struct device *dev, struct device_attribute *attr, char *buf)
4619{
4620	struct st_modedef *STm = dev_get_drvdata(dev);
4621	struct scsi_tape *STp = STm->tape;
4622	int options;
4623	ssize_t l = 0;
4624
4625	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4626	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4627	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4628	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4629	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4630	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4631	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4632	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4633	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4634	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4635	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4636	options |= STm->sysv ? MT_ST_SYSV : 0;
4637	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4638	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4639	options |= STp->sili ? MT_ST_SILI : 0;
4640
4641	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4642	return l;
4643}
4644static DEVICE_ATTR_RO(options);
4645
4646/* Support for tape stats */
4647
4648/**
4649 * read_cnt_show - return read count - count of reads made from tape drive
4650 * @dev: struct device
4651 * @attr: attribute structure
4652 * @buf: buffer to return formatted data in
4653 */
4654static ssize_t read_cnt_show(struct device *dev,
4655	struct device_attribute *attr, char *buf)
4656{
4657	struct st_modedef *STm = dev_get_drvdata(dev);
4658
4659	return sprintf(buf, "%lld",
4660		       (long long)atomic64_read(&STm->tape->stats->read_cnt));
4661}
4662static DEVICE_ATTR_RO(read_cnt);
4663
4664/**
4665 * read_byte_cnt_show - return read byte count - tape drives
4666 * may use blocks less than 512 bytes this gives the raw byte count of
4667 * of data read from the tape drive.
4668 * @dev: struct device
4669 * @attr: attribute structure
4670 * @buf: buffer to return formatted data in
4671 */
4672static ssize_t read_byte_cnt_show(struct device *dev,
4673	struct device_attribute *attr, char *buf)
4674{
4675	struct st_modedef *STm = dev_get_drvdata(dev);
4676
4677	return sprintf(buf, "%lld",
4678		       (long long)atomic64_read(&STm->tape->stats->read_byte_cnt));
4679}
4680static DEVICE_ATTR_RO(read_byte_cnt);
4681
4682/**
4683 * read_ns_show - return read ns - overall time spent waiting on reads in ns.
4684 * @dev: struct device
4685 * @attr: attribute structure
4686 * @buf: buffer to return formatted data in
4687 */
4688static ssize_t read_ns_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->tot_read_time));
4695}
4696static DEVICE_ATTR_RO(read_ns);
4697
4698/**
4699 * write_cnt_show - write count - number of user calls
4700 * to write(2) that have written data to tape.
4701 * @dev: struct device
4702 * @attr: attribute structure
4703 * @buf: buffer to return formatted data in
4704 */
4705static ssize_t write_cnt_show(struct device *dev,
4706	struct device_attribute *attr, char *buf)
4707{
4708	struct st_modedef *STm = dev_get_drvdata(dev);
4709
4710	return sprintf(buf, "%lld",
4711		       (long long)atomic64_read(&STm->tape->stats->write_cnt));
4712}
4713static DEVICE_ATTR_RO(write_cnt);
4714
4715/**
4716 * write_byte_cnt_show - write byte count - raw count of
4717 * bytes written to tape.
4718 * @dev: struct device
4719 * @attr: attribute structure
4720 * @buf: buffer to return formatted data in
4721 */
4722static ssize_t write_byte_cnt_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->write_byte_cnt));
4729}
4730static DEVICE_ATTR_RO(write_byte_cnt);
4731
4732/**
4733 * write_ns_show - write ns - number of nanoseconds waiting on write
4734 * requests to complete.
4735 * @dev: struct device
4736 * @attr: attribute structure
4737 * @buf: buffer to return formatted data in
4738 */
4739static ssize_t write_ns_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->tot_write_time));
4746}
4747static DEVICE_ATTR_RO(write_ns);
4748
4749/**
4750 * in_flight_show - number of I/Os currently in flight -
4751 * in most cases this will be either 0 or 1. It may be higher if someone
4752 * has also issued other SCSI commands such as via an ioctl.
4753 * @dev: struct device
4754 * @attr: attribute structure
4755 * @buf: buffer to return formatted data in
4756 */
4757static ssize_t in_flight_show(struct device *dev,
4758	struct device_attribute *attr, char *buf)
4759{
4760	struct st_modedef *STm = dev_get_drvdata(dev);
4761
4762	return sprintf(buf, "%lld",
4763		       (long long)atomic64_read(&STm->tape->stats->in_flight));
4764}
4765static DEVICE_ATTR_RO(in_flight);
4766
4767/**
4768 * io_ns_show - io wait ns - this is the number of ns spent
4769 * waiting on all I/O to complete. This includes tape movement commands
4770 * such as rewinding, seeking to end of file or tape, it also includes
4771 * read and write. To determine the time spent on tape movement
4772 * subtract the read and write ns from this value.
4773 * @dev: struct device
4774 * @attr: attribute structure
4775 * @buf: buffer to return formatted data in
4776 */
4777static ssize_t io_ns_show(struct device *dev,
4778	struct device_attribute *attr, char *buf)
4779{
4780	struct st_modedef *STm = dev_get_drvdata(dev);
4781
4782	return sprintf(buf, "%lld",
4783		       (long long)atomic64_read(&STm->tape->stats->tot_io_time));
4784}
4785static DEVICE_ATTR_RO(io_ns);
4786
4787/**
4788 * other_cnt_show - other io count - this is the number of
4789 * I/O requests other than read and write requests.
4790 * Typically these are tape movement requests but will include driver
4791 * tape movement. This includes only requests issued by the st driver.
4792 * @dev: struct device
4793 * @attr: attribute structure
4794 * @buf: buffer to return formatted data in
4795 */
4796static ssize_t other_cnt_show(struct device *dev,
4797	struct device_attribute *attr, char *buf)
4798{
4799	struct st_modedef *STm = dev_get_drvdata(dev);
4800
4801	return sprintf(buf, "%lld",
4802		       (long long)atomic64_read(&STm->tape->stats->other_cnt));
4803}
4804static DEVICE_ATTR_RO(other_cnt);
4805
4806/**
4807 * resid_cnt_show - A count of the number of times we get a residual
4808 * count - this should indicate someone issuing reads larger than the
4809 * block size on tape.
4810 * @dev: struct device
4811 * @attr: attribute structure
4812 * @buf: buffer to return formatted data in
4813 */
4814static ssize_t resid_cnt_show(struct device *dev,
4815	struct device_attribute *attr, char *buf)
4816{
4817	struct st_modedef *STm = dev_get_drvdata(dev);
4818
4819	return sprintf(buf, "%lld",
4820		       (long long)atomic64_read(&STm->tape->stats->resid_cnt));
4821}
4822static DEVICE_ATTR_RO(resid_cnt);
4823
4824static struct attribute *st_dev_attrs[] = {
4825	&dev_attr_defined.attr,
4826	&dev_attr_default_blksize.attr,
4827	&dev_attr_default_density.attr,
4828	&dev_attr_default_compression.attr,
4829	&dev_attr_options.attr,
4830	NULL,
4831};
4832
4833static struct attribute *st_stats_attrs[] = {
4834	&dev_attr_read_cnt.attr,
4835	&dev_attr_read_byte_cnt.attr,
4836	&dev_attr_read_ns.attr,
4837	&dev_attr_write_cnt.attr,
4838	&dev_attr_write_byte_cnt.attr,
4839	&dev_attr_write_ns.attr,
4840	&dev_attr_in_flight.attr,
4841	&dev_attr_io_ns.attr,
4842	&dev_attr_other_cnt.attr,
4843	&dev_attr_resid_cnt.attr,
4844	NULL,
4845};
4846
4847static struct attribute_group stats_group = {
4848	.name = "stats",
4849	.attrs = st_stats_attrs,
4850};
4851
4852static struct attribute_group st_group = {
4853	.attrs = st_dev_attrs,
4854};
4855
4856static const struct attribute_group *st_dev_groups[] = {
4857	&st_group,
4858	&stats_group,
4859	NULL,
4860};
4861
4862/* The following functions may be useful for a larger audience. */
4863static int sgl_map_user_pages(struct st_buffer *STbp,
4864			      const unsigned int max_pages, unsigned long uaddr,
4865			      size_t count, int rw)
4866{
4867	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4868	unsigned long start = uaddr >> PAGE_SHIFT;
4869	const int nr_pages = end - start;
4870	int res, i;
4871	struct page **pages;
4872	struct rq_map_data *mdata = &STbp->map_data;
4873
4874	/* User attempted Overflow! */
4875	if ((uaddr + count) < uaddr)
4876		return -EINVAL;
4877
4878	/* Too big */
4879        if (nr_pages > max_pages)
4880		return -ENOMEM;
4881
4882	/* Hmm? */
4883	if (count == 0)
4884		return 0;
4885
4886	pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
4887	if (pages == NULL)
4888		return -ENOMEM;
4889
4890        /* Try to fault in all of the necessary pages */
4891        /* rw==READ means read from drive, write into memory area */
4892	res = pin_user_pages_fast(uaddr, nr_pages, rw == READ ? FOLL_WRITE : 0,
4893				  pages);
4894
4895	/* Errors and no page mapped should return here */
4896	if (res < nr_pages)
4897		goto out_unmap;
4898
4899        for (i=0; i < nr_pages; i++) {
4900                /* FIXME: flush superflous for rw==READ,
4901                 * probably wrong function for rw==WRITE
4902                 */
4903		flush_dcache_page(pages[i]);
4904        }
4905
4906	mdata->offset = uaddr & ~PAGE_MASK;
4907	STbp->mapped_pages = pages;
4908
4909	return nr_pages;
4910 out_unmap:
4911	if (res > 0) {
4912		unpin_user_pages(pages, res);
 
4913		res = 0;
4914	}
4915	kfree(pages);
4916	return res;
4917}
4918
4919
4920/* And unmap them... */
4921static int sgl_unmap_user_pages(struct st_buffer *STbp,
4922				const unsigned int nr_pages, int dirtied)
4923{
4924	/* FIXME: cache flush missing for rw==READ */
4925	unpin_user_pages_dirty_lock(STbp->mapped_pages, nr_pages, dirtied);
4926
 
 
 
 
 
 
 
 
 
 
4927	kfree(STbp->mapped_pages);
4928	STbp->mapped_pages = NULL;
4929
4930	return 0;
4931}
v4.17
 
   1/*
   2   SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
   3   file Documentation/scsi/st.txt for more information.
   4
   5   History:
   6   Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
   7   Contribution and ideas from several people including (in alphabetical
   8   order) Klaus Ehrenfried, Eugene Exarevsky, Eric Lee Green, Wolfgang Denk,
   9   Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
  10   Michael Schaefer, J"org Weule, and Eric Youngdale.
  11
  12   Copyright 1992 - 2016 Kai Makisara
  13   email Kai.Makisara@kolumbus.fi
  14
  15   Some small formal changes - aeb, 950809
  16
  17   Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
  18 */
  19
  20static const char *verstr = "20160209";
  21
  22#include <linux/module.h>
  23
 
  24#include <linux/fs.h>
  25#include <linux/kernel.h>
  26#include <linux/sched/signal.h>
  27#include <linux/mm.h>
  28#include <linux/init.h>
  29#include <linux/string.h>
  30#include <linux/slab.h>
  31#include <linux/errno.h>
  32#include <linux/mtio.h>
 
  33#include <linux/cdrom.h>
  34#include <linux/ioctl.h>
  35#include <linux/fcntl.h>
  36#include <linux/spinlock.h>
  37#include <linux/blkdev.h>
  38#include <linux/moduleparam.h>
  39#include <linux/cdev.h>
  40#include <linux/idr.h>
  41#include <linux/delay.h>
  42#include <linux/mutex.h>
  43
  44#include <linux/uaccess.h>
  45#include <asm/dma.h>
 
  46
  47#include <scsi/scsi.h>
  48#include <scsi/scsi_dbg.h>
  49#include <scsi/scsi_device.h>
  50#include <scsi/scsi_driver.h>
  51#include <scsi/scsi_eh.h>
  52#include <scsi/scsi_host.h>
  53#include <scsi/scsi_ioctl.h>
  54#include <scsi/sg.h>
  55
  56
  57/* The driver prints some debugging information on the console if DEBUG
  58   is defined and non-zero. */
  59#define DEBUG 1
  60#define NO_DEBUG 0
  61
  62#define ST_DEB_MSG  KERN_NOTICE
  63#if DEBUG
  64/* The message level for the debug messages is currently set to KERN_NOTICE
  65   so that people can easily see the messages. Later when the debugging messages
  66   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
  67#define DEB(a) a
  68#define DEBC(a) if (debugging) { a ; }
  69#else
  70#define DEB(a)
  71#define DEBC(a)
  72#endif
  73
  74#define ST_KILOBYTE 1024
  75
  76#include "st_options.h"
  77#include "st.h"
  78
  79static int buffer_kbs;
  80static int max_sg_segs;
  81static int try_direct_io = TRY_DIRECT_IO;
  82static int try_rdio = 1;
  83static int try_wdio = 1;
  84static int debug_flag;
  85
  86static struct class st_sysfs_class;
  87static const struct attribute_group *st_dev_groups[];
  88static const struct attribute_group *st_drv_groups[];
  89
  90MODULE_AUTHOR("Kai Makisara");
  91MODULE_DESCRIPTION("SCSI tape (st) driver");
  92MODULE_LICENSE("GPL");
  93MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  94MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  95
  96/* Set 'perm' (4th argument) to 0 to disable module_param's definition
  97 * of sysfs parameters (which module_param doesn't yet support).
  98 * Sysfs parameters defined explicitly later.
  99 */
 100module_param_named(buffer_kbs, buffer_kbs, int, 0);
 101MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
 102module_param_named(max_sg_segs, max_sg_segs, int, 0);
 103MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 104module_param_named(try_direct_io, try_direct_io, int, 0);
 105MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 106module_param_named(debug_flag, debug_flag, int, 0);
 107MODULE_PARM_DESC(debug_flag, "Enable DEBUG, same as setting debugging=1");
 108
 109
 110/* Extra parameters for testing */
 111module_param_named(try_rdio, try_rdio, int, 0);
 112MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 113module_param_named(try_wdio, try_wdio, int, 0);
 114MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 115
 116#ifndef MODULE
 117static int write_threshold_kbs;  /* retained for compatibility */
 118static struct st_dev_parm {
 119	char *name;
 120	int *val;
 121} parms[] __initdata = {
 122	{
 123		"buffer_kbs", &buffer_kbs
 124	},
 125	{       /* Retained for compatibility with 2.4 */
 126		"write_threshold_kbs", &write_threshold_kbs
 127	},
 128	{
 129		"max_sg_segs", NULL
 130	},
 131	{
 132		"try_direct_io", &try_direct_io
 133	},
 134	{
 135		"debug_flag", &debug_flag
 136	}
 137};
 138#endif
 139
 140/* Restrict the number of modes so that names for all are assigned */
 141#if ST_NBR_MODES > 16
 142#error "Maximum number of modes is 16"
 143#endif
 144/* Bit reversed order to get same names for same minors with all
 145   mode counts */
 146static const char *st_formats[] = {
 147	"",  "r", "k", "s", "l", "t", "o", "u",
 148	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 149
 150/* The default definitions have been moved to st_options.h */
 151
 152#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 153
 154/* The buffer size should fit into the 24 bits for length in the
 155   6-byte SCSI read and write commands. */
 156#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 157#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 158#endif
 159
 160static int debugging = DEBUG;
 161
 162#define MAX_RETRIES 0
 163#define MAX_WRITE_RETRIES 0
 164#define MAX_READY_RETRIES 0
 165#define NO_TAPE  NOT_READY
 166
 167#define ST_TIMEOUT (900 * HZ)
 168#define ST_LONG_TIMEOUT (14000 * HZ)
 169
 170/* Remove mode bits and auto-rewind bit (7) */
 171#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 172    (iminor(x) & ~(-1 << ST_MODE_SHIFT)) )
 173#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 174
 175/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 176#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 177  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 178
 179/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 180   24 bits) */
 181#define SET_DENS_AND_BLK 0x10001
 182
 183static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 184static int st_max_sg_segs = ST_MAX_SG;
 185
 186static int modes_defined;
 187
 188static int enlarge_buffer(struct st_buffer *, int, int);
 189static void clear_buffer(struct st_buffer *);
 190static void normalize_buffer(struct st_buffer *);
 191static int append_to_buffer(const char __user *, struct st_buffer *, int);
 192static int from_buffer(struct st_buffer *, char __user *, int);
 193static void move_buffer_data(struct st_buffer *, int);
 194
 195static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 196			      unsigned long, size_t, int);
 197static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 198
 199static int st_probe(struct device *);
 200static int st_remove(struct device *);
 201
 202static struct scsi_driver st_template = {
 203	.gendrv = {
 204		.name		= "st",
 205		.owner		= THIS_MODULE,
 206		.probe		= st_probe,
 207		.remove		= st_remove,
 208		.groups		= st_drv_groups,
 209	},
 210};
 211
 212static int st_compression(struct scsi_tape *, int);
 213
 214static int find_partition(struct scsi_tape *);
 215static int switch_partition(struct scsi_tape *);
 216
 217static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 218
 219static void scsi_tape_release(struct kref *);
 220
 221#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 222
 223static DEFINE_MUTEX(st_ref_mutex);
 224static DEFINE_SPINLOCK(st_index_lock);
 225static DEFINE_SPINLOCK(st_use_lock);
 226static DEFINE_IDR(st_index_idr);
 227
 228
 229
 230#include "osst_detect.h"
 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		case 0x70:
 341			s->fixed_format = 1;
 342			s->flags = sense[2] & 0xe0;
 343			break;
 344		case 0x73:
 345			s->deferred = 1;
 
 346		case 0x72:
 347			s->fixed_format = 0;
 348			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 349			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 350			break;
 351		}
 352	}
 353}
 354
 355
 356/* Convert the result to success code */
 357static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 358{
 359	int result = SRpnt->result;
 360	u8 scode;
 361	DEB(const char *stp;)
 362	char *name = tape_name(STp);
 363	struct st_cmdstatus *cmdstatp;
 364
 365	if (!result)
 366		return 0;
 367
 368	cmdstatp = &STp->buffer->cmdstat;
 369	st_analyze_sense(SRpnt, cmdstatp);
 370
 371	if (cmdstatp->have_sense)
 372		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 373	else
 374		scode = 0;
 375
 376	DEB(
 377	if (debugging) {
 378		st_printk(ST_DEB_MSG, STp,
 379			    "Error: %x, cmd: %x %x %x %x %x %x\n", result,
 380			    SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 381			    SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 382		if (cmdstatp->have_sense)
 383			__scsi_print_sense(STp->device, name,
 384					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 385	} ) /* end DEB */
 386	if (!debugging) { /* Abnormal conditions for tape */
 387		if (!cmdstatp->have_sense)
 388			st_printk(KERN_WARNING, STp,
 389			       "Error %x (driver bt 0x%x, host bt 0x%x).\n",
 390			       result, driver_byte(result), host_byte(result));
 391		else if (cmdstatp->have_sense &&
 392			 scode != NO_SENSE &&
 393			 scode != RECOVERED_ERROR &&
 394			 /* scode != UNIT_ATTENTION && */
 395			 scode != BLANK_CHECK &&
 396			 scode != VOLUME_OVERFLOW &&
 397			 SRpnt->cmd[0] != MODE_SENSE &&
 398			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 399
 400			__scsi_print_sense(STp->device, name,
 401					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 402		}
 403	}
 404
 405	if (cmdstatp->fixed_format &&
 406	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 407		if (STp->cln_sense_value)
 408			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 409					       STp->cln_sense_mask) == STp->cln_sense_value);
 410		else
 411			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 412					       STp->cln_sense_mask) != 0);
 413	}
 414	if (cmdstatp->have_sense &&
 415	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 416		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 
 
 417
 418	STp->pos_unknown |= STp->device->was_reset;
 419
 420	if (cmdstatp->have_sense &&
 421	    scode == RECOVERED_ERROR
 422#if ST_RECOVERED_WRITE_FATAL
 423	    && SRpnt->cmd[0] != WRITE_6
 424	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 425#endif
 426	    ) {
 427		STp->recover_count++;
 428		STp->recover_reg++;
 429
 430		DEB(
 431		if (debugging) {
 432			if (SRpnt->cmd[0] == READ_6)
 433				stp = "read";
 434			else if (SRpnt->cmd[0] == WRITE_6)
 435				stp = "write";
 436			else
 437				stp = "ioctl";
 438			st_printk(ST_DEB_MSG, STp,
 439				  "Recovered %s error (%d).\n",
 440				  stp, STp->recover_count);
 441		} ) /* end DEB */
 442
 443		if (cmdstatp->flags == 0)
 444			return 0;
 445	}
 446	return (-EIO);
 447}
 448
 449static struct st_request *st_allocate_request(struct scsi_tape *stp)
 450{
 451	struct st_request *streq;
 452
 453	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 454	if (streq)
 455		streq->stp = stp;
 456	else {
 457		st_printk(KERN_ERR, stp,
 458			  "Can't get SCSI request.\n");
 459		if (signal_pending(current))
 460			stp->buffer->syscall_result = -EINTR;
 461		else
 462			stp->buffer->syscall_result = -EBUSY;
 463	}
 464
 465	return streq;
 466}
 467
 468static void st_release_request(struct st_request *streq)
 469{
 470	kfree(streq);
 471}
 472
 473static void st_do_stats(struct scsi_tape *STp, struct request *req)
 474{
 
 475	ktime_t now;
 476
 477	now = ktime_get();
 478	if (scsi_req(req)->cmd[0] == WRITE_6) {
 479		now = ktime_sub(now, STp->stats->write_time);
 480		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 481		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 482		atomic64_inc(&STp->stats->write_cnt);
 483		if (scsi_req(req)->result) {
 484			atomic64_add(atomic_read(&STp->stats->last_write_size)
 485				- STp->buffer->cmdstat.residual,
 486				&STp->stats->write_byte_cnt);
 487			if (STp->buffer->cmdstat.residual > 0)
 488				atomic64_inc(&STp->stats->resid_cnt);
 489		} else
 490			atomic64_add(atomic_read(&STp->stats->last_write_size),
 491				&STp->stats->write_byte_cnt);
 492	} else if (scsi_req(req)->cmd[0] == READ_6) {
 493		now = ktime_sub(now, STp->stats->read_time);
 494		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 495		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 496		atomic64_inc(&STp->stats->read_cnt);
 497		if (scsi_req(req)->result) {
 498			atomic64_add(atomic_read(&STp->stats->last_read_size)
 499				- STp->buffer->cmdstat.residual,
 500				&STp->stats->read_byte_cnt);
 501			if (STp->buffer->cmdstat.residual > 0)
 502				atomic64_inc(&STp->stats->resid_cnt);
 503		} else
 504			atomic64_add(atomic_read(&STp->stats->last_read_size),
 505				&STp->stats->read_byte_cnt);
 506	} else {
 507		now = ktime_sub(now, STp->stats->other_time);
 508		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 509		atomic64_inc(&STp->stats->other_cnt);
 510	}
 511	atomic64_dec(&STp->stats->in_flight);
 512}
 513
 514static void st_scsi_execute_end(struct request *req, blk_status_t status)
 
 515{
 
 516	struct st_request *SRpnt = req->end_io_data;
 517	struct scsi_request *rq = scsi_req(req);
 518	struct scsi_tape *STp = SRpnt->stp;
 519	struct bio *tmp;
 520
 521	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 522	STp->buffer->cmdstat.residual = rq->resid_len;
 523
 524	st_do_stats(STp, req);
 525
 526	tmp = SRpnt->bio;
 527	if (rq->sense_len)
 528		memcpy(SRpnt->sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
 529	if (SRpnt->waiting)
 530		complete(SRpnt->waiting);
 531
 532	blk_rq_unmap_user(tmp);
 533	__blk_put_request(req->q, req);
 
 534}
 535
 536static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 537			   int data_direction, void *buffer, unsigned bufflen,
 538			   int timeout, int retries)
 539{
 540	struct request *req;
 541	struct scsi_request *rq;
 542	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 543	int err = 0;
 544	struct scsi_tape *STp = SRpnt->stp;
 
 545
 546	req = blk_get_request(SRpnt->stp->device->request_queue,
 547			data_direction == DMA_TO_DEVICE ?
 548			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
 549	if (IS_ERR(req))
 550		return DRIVER_ERROR << 24;
 551	rq = scsi_req(req);
 552	req->rq_flags |= RQF_QUIET;
 553
 554	mdata->null_mapped = 1;
 555
 556	if (bufflen) {
 557		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 558				      GFP_KERNEL);
 559		if (err) {
 560			blk_put_request(req);
 561			return DRIVER_ERROR << 24;
 562		}
 563	}
 564
 565	atomic64_inc(&STp->stats->in_flight);
 566	if (cmd[0] == WRITE_6) {
 567		atomic_set(&STp->stats->last_write_size, bufflen);
 568		STp->stats->write_time = ktime_get();
 569	} else if (cmd[0] == READ_6) {
 570		atomic_set(&STp->stats->last_read_size, bufflen);
 571		STp->stats->read_time = ktime_get();
 572	} else {
 573		STp->stats->other_time = ktime_get();
 574	}
 575
 576	SRpnt->bio = req->bio;
 577	rq->cmd_len = COMMAND_SIZE(cmd[0]);
 578	memset(rq->cmd, 0, BLK_MAX_CDB);
 579	memcpy(rq->cmd, cmd, rq->cmd_len);
 580	req->timeout = timeout;
 581	rq->retries = retries;
 
 582	req->end_io_data = SRpnt;
 583
 584	blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
 585	return 0;
 586}
 587
 588/* Do the scsi command. Waits until command performed if do_wait is true.
 589   Otherwise write_behind_check() is used to check that the command
 590   has finished. */
 591static struct st_request *
 592st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 593	   int bytes, int direction, int timeout, int retries, int do_wait)
 594{
 595	struct completion *waiting;
 596	struct rq_map_data *mdata = &STp->buffer->map_data;
 597	int ret;
 598
 599	/* if async, make sure there's no command outstanding */
 600	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 601		st_printk(KERN_ERR, STp,
 602			  "Async command already active.\n");
 603		if (signal_pending(current))
 604			(STp->buffer)->syscall_result = (-EINTR);
 605		else
 606			(STp->buffer)->syscall_result = (-EBUSY);
 607		return NULL;
 608	}
 609
 610	if (!SRpnt) {
 611		SRpnt = st_allocate_request(STp);
 612		if (!SRpnt)
 613			return NULL;
 614	}
 615
 616	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 617	   which IO is outstanding. It's nulled out when the IO completes. */
 618	if (!do_wait)
 619		(STp->buffer)->last_SRpnt = SRpnt;
 620
 621	waiting = &STp->wait;
 622	init_completion(waiting);
 623	SRpnt->waiting = waiting;
 624
 625	if (STp->buffer->do_dio) {
 626		mdata->page_order = 0;
 627		mdata->nr_entries = STp->buffer->sg_segs;
 628		mdata->pages = STp->buffer->mapped_pages;
 629	} else {
 630		mdata->page_order = STp->buffer->reserved_page_order;
 631		mdata->nr_entries =
 632			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 633		mdata->pages = STp->buffer->reserved_pages;
 634		mdata->offset = 0;
 635	}
 636
 637	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 638	STp->buffer->cmdstat.have_sense = 0;
 639	STp->buffer->syscall_result = 0;
 640
 641	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 642			      retries);
 643	if (ret) {
 644		/* could not allocate the buffer or request was too large */
 645		(STp->buffer)->syscall_result = (-EBUSY);
 646		(STp->buffer)->last_SRpnt = NULL;
 647	} else if (do_wait) {
 648		wait_for_completion(waiting);
 649		SRpnt->waiting = NULL;
 650		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 651	}
 652
 653	return SRpnt;
 654}
 655
 656
 657/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 658   write has been correct but EOM early warning reached, -EIO if write ended in
 659   error or zero if write successful. Asynchronous writes are used only in
 660   variable block mode. */
 661static int write_behind_check(struct scsi_tape * STp)
 662{
 663	int retval = 0;
 664	struct st_buffer *STbuffer;
 665	struct st_partstat *STps;
 666	struct st_cmdstatus *cmdstatp;
 667	struct st_request *SRpnt;
 668
 669	STbuffer = STp->buffer;
 670	if (!STbuffer->writing)
 671		return 0;
 672
 673	DEB(
 674	if (STp->write_pending)
 675		STp->nbr_waits++;
 676	else
 677		STp->nbr_finished++;
 678	) /* end DEB */
 679
 680	wait_for_completion(&(STp->wait));
 681	SRpnt = STbuffer->last_SRpnt;
 682	STbuffer->last_SRpnt = NULL;
 683	SRpnt->waiting = NULL;
 684
 685	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 686	st_release_request(SRpnt);
 687
 688	STbuffer->buffer_bytes -= STbuffer->writing;
 689	STps = &(STp->ps[STp->partition]);
 690	if (STps->drv_block >= 0) {
 691		if (STp->block_size == 0)
 692			STps->drv_block++;
 693		else
 694			STps->drv_block += STbuffer->writing / STp->block_size;
 695	}
 696
 697	cmdstatp = &STbuffer->cmdstat;
 698	if (STbuffer->syscall_result) {
 699		retval = -EIO;
 700		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 701		    (cmdstatp->flags & SENSE_EOM) &&
 702		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 703		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 704			/* EOM at write-behind, has all data been written? */
 705			if (!cmdstatp->remainder_valid ||
 706			    cmdstatp->uremainder64 == 0)
 707				retval = -ENOSPC;
 708		}
 709		if (retval == -EIO)
 710			STps->drv_block = -1;
 711	}
 712	STbuffer->writing = 0;
 713
 714	DEB(if (debugging && retval)
 715		    st_printk(ST_DEB_MSG, STp,
 716				"Async write error %x, return value %d.\n",
 717				STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 718
 719	return retval;
 720}
 721
 722
 723/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 724   it messes up the block number). */
 725static int cross_eof(struct scsi_tape * STp, int forward)
 726{
 727	struct st_request *SRpnt;
 728	unsigned char cmd[MAX_COMMAND_SIZE];
 729
 730	cmd[0] = SPACE;
 731	cmd[1] = 0x01;		/* Space FileMarks */
 732	if (forward) {
 733		cmd[2] = cmd[3] = 0;
 734		cmd[4] = 1;
 735	} else
 736		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 737	cmd[5] = 0;
 738
 739	DEBC_printk(STp, "Stepping over filemark %s.\n",
 740		    forward ? "forward" : "backward");
 741
 742	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 743			   STp->device->request_queue->rq_timeout,
 744			   MAX_RETRIES, 1);
 745	if (!SRpnt)
 746		return (STp->buffer)->syscall_result;
 747
 748	st_release_request(SRpnt);
 749	SRpnt = NULL;
 750
 751	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 752		st_printk(KERN_ERR, STp,
 753			  "Stepping over filemark %s failed.\n",
 754			  forward ? "forward" : "backward");
 755
 756	return (STp->buffer)->syscall_result;
 757}
 758
 759
 760/* Flush the write buffer (never need to write if variable blocksize). */
 761static int st_flush_write_buffer(struct scsi_tape * STp)
 762{
 763	int transfer, blks;
 764	int result;
 765	unsigned char cmd[MAX_COMMAND_SIZE];
 766	struct st_request *SRpnt;
 767	struct st_partstat *STps;
 768
 769	result = write_behind_check(STp);
 770	if (result)
 771		return result;
 772
 773	result = 0;
 774	if (STp->dirty == 1) {
 775
 776		transfer = STp->buffer->buffer_bytes;
 777		DEBC_printk(STp, "Flushing %d bytes.\n", transfer);
 778
 779		memset(cmd, 0, MAX_COMMAND_SIZE);
 780		cmd[0] = WRITE_6;
 781		cmd[1] = 1;
 782		blks = transfer / STp->block_size;
 783		cmd[2] = blks >> 16;
 784		cmd[3] = blks >> 8;
 785		cmd[4] = blks;
 786
 787		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 788				   STp->device->request_queue->rq_timeout,
 789				   MAX_WRITE_RETRIES, 1);
 790		if (!SRpnt)
 791			return (STp->buffer)->syscall_result;
 792
 793		STps = &(STp->ps[STp->partition]);
 794		if ((STp->buffer)->syscall_result != 0) {
 795			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 796
 797			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 798			    (cmdstatp->flags & SENSE_EOM) &&
 799			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 800			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 801			    (!cmdstatp->remainder_valid ||
 802			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 803				STp->dirty = 0;
 804				(STp->buffer)->buffer_bytes = 0;
 805				if (STps->drv_block >= 0)
 806					STps->drv_block += blks;
 807				result = (-ENOSPC);
 808			} else {
 809				st_printk(KERN_ERR, STp, "Error on flush.\n");
 810				STps->drv_block = (-1);
 811				result = (-EIO);
 812			}
 813		} else {
 814			if (STps->drv_block >= 0)
 815				STps->drv_block += blks;
 816			STp->dirty = 0;
 817			(STp->buffer)->buffer_bytes = 0;
 818		}
 819		st_release_request(SRpnt);
 820		SRpnt = NULL;
 821	}
 822	return result;
 823}
 824
 825
 826/* Flush the tape buffer. The tape will be positioned correctly unless
 827   seek_next is true. */
 828static int flush_buffer(struct scsi_tape *STp, int seek_next)
 829{
 830	int backspace, result;
 831	struct st_buffer *STbuffer;
 832	struct st_partstat *STps;
 833
 834	STbuffer = STp->buffer;
 835
 836	/*
 837	 * If there was a bus reset, block further access
 838	 * to this device.
 839	 */
 840	if (STp->pos_unknown)
 841		return (-EIO);
 842
 843	if (STp->ready != ST_READY)
 844		return 0;
 845	STps = &(STp->ps[STp->partition]);
 846	if (STps->rw == ST_WRITING)	/* Writing */
 847		return st_flush_write_buffer(STp);
 848
 849	if (STp->block_size == 0)
 850		return 0;
 851
 852	backspace = ((STp->buffer)->buffer_bytes +
 853		     (STp->buffer)->read_pointer) / STp->block_size -
 854	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 855	    STp->block_size;
 856	(STp->buffer)->buffer_bytes = 0;
 857	(STp->buffer)->read_pointer = 0;
 858	result = 0;
 859	if (!seek_next) {
 860		if (STps->eof == ST_FM_HIT) {
 861			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 862			if (!result)
 863				STps->eof = ST_NOEOF;
 864			else {
 865				if (STps->drv_file >= 0)
 866					STps->drv_file++;
 867				STps->drv_block = 0;
 868			}
 869		}
 870		if (!result && backspace > 0)
 871			result = st_int_ioctl(STp, MTBSR, backspace);
 872	} else if (STps->eof == ST_FM_HIT) {
 873		if (STps->drv_file >= 0)
 874			STps->drv_file++;
 875		STps->drv_block = 0;
 876		STps->eof = ST_NOEOF;
 877	}
 878	return result;
 879
 880}
 881
 882/* Set the mode parameters */
 883static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 884{
 885	int set_it = 0;
 886	unsigned long arg;
 887
 888	if (!STp->density_changed &&
 889	    STm->default_density >= 0 &&
 890	    STm->default_density != STp->density) {
 891		arg = STm->default_density;
 892		set_it = 1;
 893	} else
 894		arg = STp->density;
 895	arg <<= MT_ST_DENSITY_SHIFT;
 896	if (!STp->blksize_changed &&
 897	    STm->default_blksize >= 0 &&
 898	    STm->default_blksize != STp->block_size) {
 899		arg |= STm->default_blksize;
 900		set_it = 1;
 901	} else
 902		arg |= STp->block_size;
 903	if (set_it &&
 904	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 905		st_printk(KERN_WARNING, STp,
 906			  "Can't set default block size to %d bytes "
 907			  "and density %x.\n",
 908			  STm->default_blksize, STm->default_density);
 909		if (modes_defined)
 910			return (-EINVAL);
 911	}
 912	return 0;
 913}
 914
 915
 916/* Lock or unlock the drive door. Don't use when st_request allocated. */
 917static int do_door_lock(struct scsi_tape * STp, int do_lock)
 918{
 919	int retval;
 920
 921	DEBC_printk(STp, "%socking drive door.\n", do_lock ? "L" : "Unl");
 922
 923	retval = scsi_set_medium_removal(STp->device,
 924			do_lock ? SCSI_REMOVAL_PREVENT : SCSI_REMOVAL_ALLOW);
 925	if (!retval)
 926		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 927	else
 928		STp->door_locked = ST_LOCK_FAILS;
 929	return retval;
 930}
 931
 932
 933/* Set the internal state after reset */
 934static void reset_state(struct scsi_tape *STp)
 935{
 936	int i;
 937	struct st_partstat *STps;
 938
 939	STp->pos_unknown = 0;
 940	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 941		STps = &(STp->ps[i]);
 942		STps->rw = ST_IDLE;
 943		STps->eof = ST_NOEOF;
 944		STps->at_sm = 0;
 945		STps->last_block_valid = 0;
 946		STps->drv_block = -1;
 947		STps->drv_file = -1;
 948	}
 949	if (STp->can_partitions) {
 950		STp->partition = find_partition(STp);
 951		if (STp->partition < 0)
 952			STp->partition = 0;
 953		STp->new_partition = STp->partition;
 954	}
 955}
 956
 957/* Test if the drive is ready. Returns either one of the codes below or a negative system
 958   error code. */
 959#define CHKRES_READY       0
 960#define CHKRES_NEW_SESSION 1
 961#define CHKRES_NOT_READY   2
 962#define CHKRES_NO_TAPE     3
 963
 964#define MAX_ATTENTIONS    10
 965
 966static int test_ready(struct scsi_tape *STp, int do_wait)
 967{
 968	int attentions, waits, max_wait, scode;
 969	int retval = CHKRES_READY, new_session = 0;
 970	unsigned char cmd[MAX_COMMAND_SIZE];
 971	struct st_request *SRpnt = NULL;
 972	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 973
 974	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 975
 976	for (attentions=waits=0; ; ) {
 977		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 978		cmd[0] = TEST_UNIT_READY;
 979		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 980				   STp->long_timeout, MAX_READY_RETRIES, 1);
 981
 982		if (!SRpnt) {
 983			retval = (STp->buffer)->syscall_result;
 984			break;
 985		}
 986
 987		if (cmdstatp->have_sense) {
 988
 989			scode = cmdstatp->sense_hdr.sense_key;
 990
 991			if (scode == UNIT_ATTENTION) { /* New media? */
 992				new_session = 1;
 993				if (attentions < MAX_ATTENTIONS) {
 994					attentions++;
 995					continue;
 996				}
 997				else {
 998					retval = (-EIO);
 999					break;
1000				}
1001			}
1002
1003			if (scode == NOT_READY) {
1004				if (waits < max_wait) {
1005					if (msleep_interruptible(1000)) {
1006						retval = (-EINTR);
1007						break;
1008					}
1009					waits++;
1010					continue;
1011				}
1012				else {
1013					if ((STp->device)->scsi_level >= SCSI_2 &&
1014					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
1015						retval = CHKRES_NO_TAPE;
1016					else
1017						retval = CHKRES_NOT_READY;
1018					break;
1019				}
1020			}
1021		}
1022
1023		retval = (STp->buffer)->syscall_result;
1024		if (!retval)
1025			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
1026		break;
1027	}
1028
1029	if (SRpnt != NULL)
1030		st_release_request(SRpnt);
1031	return retval;
1032}
1033
1034
1035/* See if the drive is ready and gather information about the tape. Return values:
1036   < 0   negative error code from errno.h
1037   0     drive ready
1038   1     drive not ready (possibly no tape)
1039*/
1040static int check_tape(struct scsi_tape *STp, struct file *filp)
1041{
1042	int i, retval, new_session = 0, do_wait;
1043	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
1044	unsigned short st_flags = filp->f_flags;
1045	struct st_request *SRpnt = NULL;
1046	struct st_modedef *STm;
1047	struct st_partstat *STps;
1048	struct inode *inode = file_inode(filp);
1049	int mode = TAPE_MODE(inode);
1050
1051	STp->ready = ST_READY;
1052
1053	if (mode != STp->current_mode) {
1054		DEBC_printk(STp, "Mode change from %d to %d.\n",
1055			    STp->current_mode, mode);
1056		new_session = 1;
1057		STp->current_mode = mode;
1058	}
1059	STm = &(STp->modes[STp->current_mode]);
1060
1061	saved_cleaning = STp->cleaning_req;
1062	STp->cleaning_req = 0;
1063
1064	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1065	retval = test_ready(STp, do_wait);
1066
1067	if (retval < 0)
1068	    goto err_out;
1069
1070	if (retval == CHKRES_NEW_SESSION) {
1071		STp->pos_unknown = 0;
1072		STp->partition = STp->new_partition = 0;
1073		if (STp->can_partitions)
1074			STp->nbr_partitions = 1; /* This guess will be updated later
1075                                                    if necessary */
1076		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1077			STps = &(STp->ps[i]);
1078			STps->rw = ST_IDLE;
1079			STps->eof = ST_NOEOF;
1080			STps->at_sm = 0;
1081			STps->last_block_valid = 0;
1082			STps->drv_block = 0;
1083			STps->drv_file = 0;
1084		}
1085		new_session = 1;
1086	}
1087	else {
1088		STp->cleaning_req |= saved_cleaning;
1089
1090		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1091			if (retval == CHKRES_NO_TAPE)
1092				STp->ready = ST_NO_TAPE;
1093			else
1094				STp->ready = ST_NOT_READY;
1095
1096			STp->density = 0;	/* Clear the erroneous "residue" */
1097			STp->write_prot = 0;
1098			STp->block_size = 0;
1099			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1100			STp->partition = STp->new_partition = 0;
1101			STp->door_locked = ST_UNLOCKED;
1102			return CHKRES_NOT_READY;
1103		}
1104	}
1105
1106	if (STp->omit_blklims)
1107		STp->min_block = STp->max_block = (-1);
1108	else {
1109		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1110		cmd[0] = READ_BLOCK_LIMITS;
1111
1112		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1113				   STp->device->request_queue->rq_timeout,
1114				   MAX_READY_RETRIES, 1);
1115		if (!SRpnt) {
1116			retval = (STp->buffer)->syscall_result;
1117			goto err_out;
1118		}
1119
1120		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1121			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1122			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1123			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1124			    (STp->buffer)->b_data[5];
1125			if ( DEB( debugging || ) !STp->inited)
1126				st_printk(KERN_INFO, STp,
1127					  "Block limits %d - %d bytes.\n",
1128					  STp->min_block, STp->max_block);
1129		} else {
1130			STp->min_block = STp->max_block = (-1);
1131			DEBC_printk(STp, "Can't read block limits.\n");
1132		}
1133	}
1134
1135	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1136	cmd[0] = MODE_SENSE;
1137	cmd[4] = 12;
1138
1139	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1140			   STp->device->request_queue->rq_timeout,
1141			   MAX_READY_RETRIES, 1);
1142	if (!SRpnt) {
1143		retval = (STp->buffer)->syscall_result;
1144		goto err_out;
1145	}
1146
1147	if ((STp->buffer)->syscall_result != 0) {
1148		DEBC_printk(STp, "No Mode Sense.\n");
1149		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1150		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1151		STp->drv_write_prot = 0;
1152	} else {
1153		DEBC_printk(STp,"Mode sense. Length %d, "
1154			    "medium %x, WBS %x, BLL %d\n",
1155			    (STp->buffer)->b_data[0],
1156			    (STp->buffer)->b_data[1],
1157			    (STp->buffer)->b_data[2],
1158			    (STp->buffer)->b_data[3]);
1159
1160		if ((STp->buffer)->b_data[3] >= 8) {
1161			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1162			STp->density = (STp->buffer)->b_data[4];
1163			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1164			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1165			DEBC_printk(STp, "Density %x, tape length: %x, "
1166				    "drv buffer: %d\n",
1167				    STp->density,
1168				    (STp->buffer)->b_data[5] * 65536 +
1169				    (STp->buffer)->b_data[6] * 256 +
1170				    (STp->buffer)->b_data[7],
1171				    STp->drv_buffer);
1172		}
1173		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1174		if (!STp->drv_buffer && STp->immediate_filemark) {
1175			st_printk(KERN_WARNING, STp,
1176				  "non-buffered tape: disabling "
1177				  "writing immediate filemarks\n");
1178			STp->immediate_filemark = 0;
1179		}
1180	}
1181	st_release_request(SRpnt);
1182	SRpnt = NULL;
1183	STp->inited = 1;
1184
1185	if (STp->block_size > 0)
1186		(STp->buffer)->buffer_blocks =
1187			(STp->buffer)->buffer_size / STp->block_size;
1188	else
1189		(STp->buffer)->buffer_blocks = 1;
1190	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1191
1192	DEBC_printk(STp, "Block size: %d, buffer size: %d (%d blocks).\n",
1193		    STp->block_size, (STp->buffer)->buffer_size,
1194		    (STp->buffer)->buffer_blocks);
1195
1196	if (STp->drv_write_prot) {
1197		STp->write_prot = 1;
1198
1199		DEBC_printk(STp, "Write protected\n");
1200
1201		if (do_wait &&
1202		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1203		     (st_flags & O_ACCMODE) == O_RDWR)) {
1204			retval = (-EROFS);
1205			goto err_out;
1206		}
1207	}
1208
1209	if (STp->can_partitions && STp->nbr_partitions < 1) {
1210		/* This code is reached when the device is opened for the first time
1211		   after the driver has been initialized with tape in the drive and the
1212		   partition support has been enabled. */
1213		DEBC_printk(STp, "Updating partition number in status.\n");
1214		if ((STp->partition = find_partition(STp)) < 0) {
1215			retval = STp->partition;
1216			goto err_out;
1217		}
1218		STp->new_partition = STp->partition;
1219		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1220	}
1221
1222	if (new_session) {	/* Change the drive parameters for the new mode */
1223		STp->density_changed = STp->blksize_changed = 0;
1224		STp->compression_changed = 0;
1225		if (!(STm->defaults_for_writes) &&
1226		    (retval = set_mode_densblk(STp, STm)) < 0)
1227		    goto err_out;
1228
1229		if (STp->default_drvbuffer != 0xff) {
1230			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1231				st_printk(KERN_WARNING, STp,
1232					  "Can't set default drive "
1233					  "buffering to %d.\n",
1234					  STp->default_drvbuffer);
1235		}
1236	}
1237
1238	return CHKRES_READY;
1239
1240 err_out:
1241	return retval;
1242}
1243
1244
1245/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1246   module count. */
1247static int st_open(struct inode *inode, struct file *filp)
1248{
1249	int i, retval = (-EIO);
1250	int resumed = 0;
1251	struct scsi_tape *STp;
1252	struct st_partstat *STps;
1253	int dev = TAPE_NR(inode);
1254
1255	/*
1256	 * We really want to do nonseekable_open(inode, filp); here, but some
1257	 * versions of tar incorrectly call lseek on tapes and bail out if that
1258	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1259	 */
1260	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1261
1262	if (!(STp = scsi_tape_get(dev))) {
1263		return -ENXIO;
1264	}
1265
1266	filp->private_data = STp;
1267
1268	spin_lock(&st_use_lock);
1269	if (STp->in_use) {
1270		spin_unlock(&st_use_lock);
 
1271		scsi_tape_put(STp);
1272		DEBC_printk(STp, "Device already in use.\n");
1273		return (-EBUSY);
1274	}
1275
1276	STp->in_use = 1;
1277	spin_unlock(&st_use_lock);
1278	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1279
1280	if (scsi_autopm_get_device(STp->device) < 0) {
1281		retval = -EIO;
1282		goto err_out;
1283	}
1284	resumed = 1;
1285	if (!scsi_block_when_processing_errors(STp->device)) {
1286		retval = (-ENXIO);
1287		goto err_out;
1288	}
1289
1290	/* See that we have at least a one page buffer available */
1291	if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1292		st_printk(KERN_WARNING, STp,
1293			  "Can't allocate one page tape buffer.\n");
1294		retval = (-EOVERFLOW);
1295		goto err_out;
1296	}
1297
1298	(STp->buffer)->cleared = 0;
1299	(STp->buffer)->writing = 0;
1300	(STp->buffer)->syscall_result = 0;
1301
1302	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1303
1304	STp->dirty = 0;
1305	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1306		STps = &(STp->ps[i]);
1307		STps->rw = ST_IDLE;
1308	}
1309	STp->try_dio_now = STp->try_dio;
1310	STp->recover_count = 0;
1311	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1312	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1313
1314	retval = check_tape(STp, filp);
1315	if (retval < 0)
1316		goto err_out;
1317	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1318	    retval != CHKRES_READY) {
1319		if (STp->ready == NO_TAPE)
1320			retval = (-ENOMEDIUM);
1321		else
1322			retval = (-EIO);
1323		goto err_out;
1324	}
1325	return 0;
1326
1327 err_out:
1328	normalize_buffer(STp->buffer);
1329	spin_lock(&st_use_lock);
1330	STp->in_use = 0;
1331	spin_unlock(&st_use_lock);
1332	if (resumed)
1333		scsi_autopm_put_device(STp->device);
1334	scsi_tape_put(STp);
1335	return retval;
1336
1337}
1338
1339
1340/* Flush the tape buffer before close */
1341static int st_flush(struct file *filp, fl_owner_t id)
1342{
1343	int result = 0, result2;
1344	unsigned char cmd[MAX_COMMAND_SIZE];
1345	struct st_request *SRpnt;
1346	struct scsi_tape *STp = filp->private_data;
1347	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1348	struct st_partstat *STps = &(STp->ps[STp->partition]);
1349
1350	if (file_count(filp) > 1)
1351		return 0;
1352
1353	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1354		result = st_flush_write_buffer(STp);
1355		if (result != 0 && result != (-ENOSPC))
1356			goto out;
1357	}
1358
1359	if (STp->can_partitions &&
1360	    (result2 = switch_partition(STp)) < 0) {
1361		DEBC_printk(STp, "switch_partition at close failed.\n");
1362		if (result == 0)
1363			result = result2;
1364		goto out;
1365	}
1366
1367	DEBC( if (STp->nbr_requests)
1368		st_printk(KERN_DEBUG, STp,
1369			  "Number of r/w requests %d, dio used in %d, "
1370			  "pages %d.\n", STp->nbr_requests, STp->nbr_dio,
1371			  STp->nbr_pages));
1372
1373	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1374		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1375
1376#if DEBUG
1377		DEBC_printk(STp, "Async write waits %d, finished %d.\n",
1378			    STp->nbr_waits, STp->nbr_finished);
1379#endif
1380		memset(cmd, 0, MAX_COMMAND_SIZE);
1381		cmd[0] = WRITE_FILEMARKS;
1382		if (STp->immediate_filemark)
1383			cmd[1] = 1;
1384		cmd[4] = 1 + STp->two_fm;
1385
1386		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1387				   STp->device->request_queue->rq_timeout,
1388				   MAX_WRITE_RETRIES, 1);
1389		if (!SRpnt) {
1390			result = (STp->buffer)->syscall_result;
1391			goto out;
1392		}
1393
1394		if (STp->buffer->syscall_result == 0 ||
1395		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1396		     (cmdstatp->flags & SENSE_EOM) &&
1397		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1398		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1399		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1400			/* Write successful at EOM */
1401			st_release_request(SRpnt);
1402			SRpnt = NULL;
1403			if (STps->drv_file >= 0)
1404				STps->drv_file++;
1405			STps->drv_block = 0;
1406			if (STp->two_fm)
1407				cross_eof(STp, 0);
1408			STps->eof = ST_FM;
1409		}
1410		else { /* Write error */
1411			st_release_request(SRpnt);
1412			SRpnt = NULL;
1413			st_printk(KERN_ERR, STp,
1414				  "Error on write filemark.\n");
1415			if (result == 0)
1416				result = (-EIO);
1417		}
1418
1419		DEBC_printk(STp, "Buffer flushed, %d EOF(s) written\n", cmd[4]);
1420	} else if (!STp->rew_at_close) {
1421		STps = &(STp->ps[STp->partition]);
1422		if (!STm->sysv || STps->rw != ST_READING) {
1423			if (STp->can_bsr)
1424				result = flush_buffer(STp, 0);
1425			else if (STps->eof == ST_FM_HIT) {
1426				result = cross_eof(STp, 0);
1427				if (result) {
1428					if (STps->drv_file >= 0)
1429						STps->drv_file++;
1430					STps->drv_block = 0;
1431					STps->eof = ST_FM;
1432				} else
1433					STps->eof = ST_NOEOF;
1434			}
1435		} else if ((STps->eof == ST_NOEOF &&
1436			    !(result = cross_eof(STp, 1))) ||
1437			   STps->eof == ST_FM_HIT) {
1438			if (STps->drv_file >= 0)
1439				STps->drv_file++;
1440			STps->drv_block = 0;
1441			STps->eof = ST_FM;
1442		}
1443	}
1444
1445      out:
1446	if (STp->rew_at_close) {
1447		result2 = st_int_ioctl(STp, MTREW, 1);
1448		if (result == 0)
1449			result = result2;
1450	}
1451	return result;
1452}
1453
1454
1455/* Close the device and release it. BKL is not needed: this is the only thread
1456   accessing this tape. */
1457static int st_release(struct inode *inode, struct file *filp)
1458{
1459	int result = 0;
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 result;
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, STp->restr_dma)) {
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 = cmd[2] & 0x80 ? 0xff000000 : 0;
2684	sc |= (cmd[2] << 16) | (cmd[3] << 8) | cmd[4];
2685	if (direction)
2686		sc = -sc;
2687	st_printk(ST_DEB_MSG, STp, "Spacing tape %s over %d %s.\n",
2688		  direction ? "backward" : "forward", sc, units);
2689}
2690#else
2691#define ST_DEB_FORWARD  0
2692#define ST_DEB_BACKWARD 1
2693static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd) {}
2694#endif
2695
2696
2697/* Internal ioctl function */
2698static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2699{
2700	int timeout;
2701	long ltmp;
2702	int ioctl_result;
2703	int chg_eof = 1;
2704	unsigned char cmd[MAX_COMMAND_SIZE];
2705	struct st_request *SRpnt;
2706	struct st_partstat *STps;
2707	int fileno, blkno, at_sm, undone;
2708	int datalen = 0, direction = DMA_NONE;
2709
2710	WARN_ON(STp->buffer->do_dio != 0);
2711	if (STp->ready != ST_READY) {
2712		if (STp->ready == ST_NO_TAPE)
2713			return (-ENOMEDIUM);
2714		else
2715			return (-EIO);
2716	}
2717	timeout = STp->long_timeout;
2718	STps = &(STp->ps[STp->partition]);
2719	fileno = STps->drv_file;
2720	blkno = STps->drv_block;
2721	at_sm = STps->at_sm;
2722
2723	memset(cmd, 0, MAX_COMMAND_SIZE);
2724	switch (cmd_in) {
2725	case MTFSFM:
2726		chg_eof = 0;	/* Changed from the FSF after this */
 
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	case MTBSF:
2742		cmd[0] = SPACE;
2743		cmd[1] = 0x01;	/* Space FileMarks */
2744		ltmp = (-arg);
2745		cmd[2] = (ltmp >> 16);
2746		cmd[3] = (ltmp >> 8);
2747		cmd[4] = ltmp;
2748		deb_space_print(STp, ST_DEB_BACKWARD, "filemarks", cmd);
2749		if (fileno >= 0)
2750			fileno -= arg;
2751		blkno = (-1);	/* We can't know the block number */
2752		at_sm &= (arg == 0);
2753		break;
2754	case MTFSR:
2755		cmd[0] = SPACE;
2756		cmd[1] = 0x00;	/* Space Blocks */
2757		cmd[2] = (arg >> 16);
2758		cmd[3] = (arg >> 8);
2759		cmd[4] = arg;
2760		deb_space_print(STp, ST_DEB_FORWARD, "blocks", cmd);
2761		if (blkno >= 0)
2762			blkno += arg;
2763		at_sm &= (arg == 0);
2764		break;
2765	case MTBSR:
2766		cmd[0] = SPACE;
2767		cmd[1] = 0x00;	/* Space Blocks */
2768		ltmp = (-arg);
2769		cmd[2] = (ltmp >> 16);
2770		cmd[3] = (ltmp >> 8);
2771		cmd[4] = ltmp;
2772		deb_space_print(STp, ST_DEB_BACKWARD, "blocks", cmd);
2773		if (blkno >= 0)
2774			blkno -= arg;
2775		at_sm &= (arg == 0);
2776		break;
2777	case MTFSS:
2778		cmd[0] = SPACE;
2779		cmd[1] = 0x04;	/* Space Setmarks */
2780		cmd[2] = (arg >> 16);
2781		cmd[3] = (arg >> 8);
2782		cmd[4] = arg;
2783		deb_space_print(STp, ST_DEB_FORWARD, "setmarks", cmd);
2784		if (arg != 0) {
2785			blkno = fileno = (-1);
2786			at_sm = 1;
2787		}
2788		break;
2789	case MTBSS:
2790		cmd[0] = SPACE;
2791		cmd[1] = 0x04;	/* Space Setmarks */
2792		ltmp = (-arg);
2793		cmd[2] = (ltmp >> 16);
2794		cmd[3] = (ltmp >> 8);
2795		cmd[4] = ltmp;
2796		deb_space_print(STp, ST_DEB_BACKWARD, "setmarks", cmd);
2797		if (arg != 0) {
2798			blkno = fileno = (-1);
2799			at_sm = 1;
2800		}
2801		break;
2802	case MTWEOF:
2803	case MTWEOFI:
2804	case MTWSM:
2805		if (STp->write_prot)
2806			return (-EACCES);
2807		cmd[0] = WRITE_FILEMARKS;
2808		if (cmd_in == MTWSM)
2809			cmd[1] = 2;
2810		if (cmd_in == MTWEOFI ||
2811		    (cmd_in == MTWEOF && STp->immediate_filemark))
2812			cmd[1] |= 1;
2813		cmd[2] = (arg >> 16);
2814		cmd[3] = (arg >> 8);
2815		cmd[4] = arg;
2816		timeout = STp->device->request_queue->rq_timeout;
2817		DEBC(
2818			if (cmd_in != MTWSM)
2819				st_printk(ST_DEB_MSG, STp,
2820					  "Writing %d filemarks.\n",
2821					  cmd[2] * 65536 +
2822					  cmd[3] * 256 +
2823					  cmd[4]);
2824			else
2825				st_printk(ST_DEB_MSG, STp,
2826					  "Writing %d setmarks.\n",
2827					  cmd[2] * 65536 +
2828					  cmd[3] * 256 +
2829					  cmd[4]);
2830		)
2831		if (fileno >= 0)
2832			fileno += arg;
2833		blkno = 0;
2834		at_sm = (cmd_in == MTWSM);
2835		break;
2836	case MTREW:
2837		cmd[0] = REZERO_UNIT;
2838		if (STp->immediate) {
2839			cmd[1] = 1;	/* Don't wait for completion */
2840			timeout = STp->device->request_queue->rq_timeout;
2841		}
2842		DEBC_printk(STp, "Rewinding tape.\n");
2843		fileno = blkno = at_sm = 0;
2844		break;
2845	case MTNOP:
2846		DEBC_printk(STp, "No op on tape.\n");
2847		return 0;	/* Should do something ? */
2848		break;
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(struct file *file, unsigned int cmd_in, unsigned long arg)
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	void __user *p = (void __user *)arg;
3511
3512	if (mutex_lock_interruptible(&STp->lock))
3513		return -ERESTARTSYS;
3514
3515	DEB(
3516	if (debugging && !STp->in_use) {
3517		st_printk(ST_DEB_MSG, STp, "Incorrect device.\n");
3518		retval = (-EIO);
3519		goto out;
3520	} ) /* end DEB */
3521
3522	STm = &(STp->modes[STp->current_mode]);
3523	STps = &(STp->ps[STp->partition]);
3524
3525	/*
3526	 * If we are in the middle of error recovery, don't let anyone
3527	 * else try and use this device.  Also, if error recovery fails, it
3528	 * may try and take the device offline, in which case all further
3529	 * access to the device is prohibited.
3530	 */
3531	retval = scsi_ioctl_block_when_processing_errors(STp->device, cmd_in,
3532			file->f_flags & O_NDELAY);
3533	if (retval)
3534		goto out;
3535
3536	cmd_type = _IOC_TYPE(cmd_in);
3537	cmd_nr = _IOC_NR(cmd_in);
3538
3539	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3540		struct mtop mtc;
3541
3542		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3543			retval = (-EINVAL);
3544			goto out;
3545		}
3546
3547		i = copy_from_user(&mtc, p, sizeof(struct mtop));
3548		if (i) {
3549			retval = (-EFAULT);
3550			goto out;
3551		}
3552
3553		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3554			st_printk(KERN_WARNING, STp,
3555				  "MTSETDRVBUFFER only allowed for root.\n");
3556			retval = (-EPERM);
3557			goto out;
3558		}
3559		if (!STm->defined &&
3560		    (mtc.mt_op != MTSETDRVBUFFER &&
3561		     (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3562			retval = (-ENXIO);
3563			goto out;
3564		}
3565
3566		if (!STp->pos_unknown) {
3567
3568			if (STps->eof == ST_FM_HIT) {
3569				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3570                                    mtc.mt_op == MTEOM) {
3571					mtc.mt_count -= 1;
3572					if (STps->drv_file >= 0)
3573						STps->drv_file += 1;
3574				} else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3575					mtc.mt_count += 1;
3576					if (STps->drv_file >= 0)
3577						STps->drv_file += 1;
3578				}
3579			}
3580
3581			if (mtc.mt_op == MTSEEK) {
3582				/* Old position must be restored if partition will be
3583                                   changed */
3584				i = !STp->can_partitions ||
3585				    (STp->new_partition != STp->partition);
3586			} else {
3587				i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3588				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3589				    mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3590				    mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3591				    mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3592				    mtc.mt_op == MTCOMPRESSION;
3593			}
3594			i = flush_buffer(STp, i);
3595			if (i < 0) {
3596				retval = i;
3597				goto out;
3598			}
3599			if (STps->rw == ST_WRITING &&
3600			    (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3601			     mtc.mt_op == MTSEEK ||
3602			     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3603				i = st_int_ioctl(STp, MTWEOF, 1);
3604				if (i < 0) {
3605					retval = i;
3606					goto out;
3607				}
3608				if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3609					mtc.mt_count++;
3610				STps->rw = ST_IDLE;
3611			     }
3612
3613		} else {
3614			/*
3615			 * If there was a bus reset, block further access
3616			 * to this device.  If the user wants to rewind the tape,
3617			 * then reset the flag and allow access again.
3618			 */
3619			if (mtc.mt_op != MTREW &&
3620			    mtc.mt_op != MTOFFL &&
3621			    mtc.mt_op != MTRETEN &&
3622			    mtc.mt_op != MTERASE &&
3623			    mtc.mt_op != MTSEEK &&
3624			    mtc.mt_op != MTEOM) {
3625				retval = (-EIO);
3626				goto out;
3627			}
3628			reset_state(STp);
3629			/* remove this when the midlevel properly clears was_reset */
3630			STp->device->was_reset = 0;
3631		}
3632
3633		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3634		    mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3635		    mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3636			STps->rw = ST_IDLE;	/* Prevent automatic WEOF and fsf */
3637
3638		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3639			do_door_lock(STp, 0);	/* Ignore result! */
3640
3641		if (mtc.mt_op == MTSETDRVBUFFER &&
3642		    (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3643			retval = st_set_options(STp, mtc.mt_count);
3644			goto out;
3645		}
3646
3647		if (mtc.mt_op == MTSETPART) {
3648			if (!STp->can_partitions ||
3649			    mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3650				retval = (-EINVAL);
3651				goto out;
3652			}
3653			if (mtc.mt_count >= STp->nbr_partitions &&
3654			    (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3655				retval = (-EIO);
3656				goto out;
3657			}
3658			if (mtc.mt_count >= STp->nbr_partitions) {
3659				retval = (-EINVAL);
3660				goto out;
3661			}
3662			STp->new_partition = mtc.mt_count;
3663			retval = 0;
3664			goto out;
3665		}
3666
3667		if (mtc.mt_op == MTMKPART) {
3668			if (!STp->can_partitions) {
3669				retval = (-EINVAL);
3670				goto out;
3671			}
3672			i = do_load_unload(STp, file, 1);
3673			if (i < 0) {
3674				retval = i;
3675				goto out;
3676			}
3677			i = partition_tape(STp, mtc.mt_count);
3678			if (i < 0) {
3679				retval = i;
3680				goto out;
3681			}
3682			for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3683				STp->ps[i].rw = ST_IDLE;
3684				STp->ps[i].at_sm = 0;
3685				STp->ps[i].last_block_valid = 0;
3686			}
3687			STp->partition = STp->new_partition = 0;
3688			STp->nbr_partitions = mtc.mt_count != 0 ? 2 : 1;
3689			STps->drv_block = STps->drv_file = 0;
3690			retval = 0;
3691			goto out;
3692		}
3693
3694		if (mtc.mt_op == MTSEEK) {
3695			i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3696			if (!STp->can_partitions)
3697				STp->ps[0].rw = ST_IDLE;
3698			retval = i;
3699			goto out;
3700		}
3701
3702		if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3703			retval = do_load_unload(STp, file, 0);
3704			goto out;
3705		}
3706
3707		if (mtc.mt_op == MTLOAD) {
3708			retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3709			goto out;
3710		}
3711
3712		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3713			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3714			goto out;
3715		}
3716
3717		if (STp->can_partitions && STp->ready == ST_READY &&
3718		    (i = switch_partition(STp)) < 0) {
3719			retval = i;
3720			goto out;
3721		}
3722
3723		if (mtc.mt_op == MTCOMPRESSION)
3724			retval = st_compression(STp, (mtc.mt_count & 1));
3725		else
3726			retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3727		goto out;
3728	}
3729	if (!STm->defined) {
3730		retval = (-ENXIO);
3731		goto out;
3732	}
3733
3734	if ((i = flush_buffer(STp, 0)) < 0) {
3735		retval = i;
3736		goto out;
3737	}
3738	if (STp->can_partitions &&
3739	    (i = switch_partition(STp)) < 0) {
3740		retval = i;
3741		goto out;
3742	}
3743
3744	if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
3745		struct mtget mt_status;
3746
3747		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3748			 retval = (-EINVAL);
3749			 goto out;
3750		}
3751
3752		mt_status.mt_type = STp->tape_type;
3753		mt_status.mt_dsreg =
3754		    ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3755		    ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3756		mt_status.mt_blkno = STps->drv_block;
3757		mt_status.mt_fileno = STps->drv_file;
3758		if (STp->block_size != 0) {
3759			if (STps->rw == ST_WRITING)
3760				mt_status.mt_blkno +=
3761				    (STp->buffer)->buffer_bytes / STp->block_size;
3762			else if (STps->rw == ST_READING)
3763				mt_status.mt_blkno -=
3764                                        ((STp->buffer)->buffer_bytes +
3765                                         STp->block_size - 1) / STp->block_size;
3766		}
3767
3768		mt_status.mt_gstat = 0;
3769		if (STp->drv_write_prot)
3770			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3771		if (mt_status.mt_blkno == 0) {
3772			if (mt_status.mt_fileno == 0)
3773				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3774			else
3775				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3776		}
3777		mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3778		mt_status.mt_resid = STp->partition;
3779		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3780			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3781		else if (STps->eof >= ST_EOM_OK)
3782			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3783		if (STp->density == 1)
3784			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3785		else if (STp->density == 2)
3786			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3787		else if (STp->density == 3)
3788			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3789		if (STp->ready == ST_READY)
3790			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3791		if (STp->ready == ST_NO_TAPE)
3792			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3793		if (STps->at_sm)
3794			mt_status.mt_gstat |= GMT_SM(0xffffffff);
3795		if (STm->do_async_writes ||
3796                    (STm->do_buffer_writes && STp->block_size != 0) ||
3797		    STp->drv_buffer != 0)
3798			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3799		if (STp->cleaning_req)
3800			mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3801
3802		i = copy_to_user(p, &mt_status, sizeof(struct mtget));
3803		if (i) {
3804			retval = (-EFAULT);
3805			goto out;
3806		}
3807
3808		STp->recover_reg = 0;		/* Clear after read */
3809		retval = 0;
3810		goto out;
3811	}			/* End of MTIOCGET */
3812	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3813		struct mtpos mt_pos;
3814		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3815			 retval = (-EINVAL);
3816			 goto out;
3817		}
3818		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3819			retval = i;
3820			goto out;
3821		}
3822		mt_pos.mt_blkno = blk;
3823		i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
3824		if (i)
3825			retval = (-EFAULT);
3826		goto out;
3827	}
3828	mutex_unlock(&STp->lock);
 
3829	switch (cmd_in) {
3830		case SCSI_IOCTL_GET_IDLUN:
3831		case SCSI_IOCTL_GET_BUS_NUMBER:
3832			break;
3833		default:
3834			if ((cmd_in == SG_IO ||
3835			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3836			     cmd_in == CDROM_SEND_PACKET) &&
3837			    !capable(CAP_SYS_RAWIO))
3838				i = -EPERM;
3839			else
3840				i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3841						   file->f_mode, cmd_in, p);
3842			if (i != -ENOTTY)
3843				return i;
3844			break;
3845	}
3846	retval = scsi_ioctl(STp->device, cmd_in, p);
3847	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
 
 
3848		STp->rew_at_close = 0;
3849		STp->ready = ST_NO_TAPE;
3850	}
3851	return retval;
3852
3853 out:
3854	mutex_unlock(&STp->lock);
3855	return retval;
3856}
3857
3858#ifdef CONFIG_COMPAT
3859static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3860{
3861	struct scsi_tape *STp = file->private_data;
3862	struct scsi_device *sdev = STp->device;
3863	int ret = -ENOIOCTLCMD;
3864	if (sdev->host->hostt->compat_ioctl) { 
3865
3866		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
 
 
 
3867
3868	}
3869	return ret;
3870}
3871#endif
3872
3873
3874
3875/* Try to allocate a new tape buffer. Calling function must not hold
3876   dev_arr_lock. */
3877static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
3878{
3879	struct st_buffer *tb;
3880
3881	tb = kzalloc(sizeof(struct st_buffer), GFP_ATOMIC);
3882	if (!tb) {
3883		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3884		return NULL;
3885	}
3886	tb->frp_segs = 0;
3887	tb->use_sg = max_sg;
3888	tb->dma = need_dma;
3889	tb->buffer_size = 0;
3890
3891	tb->reserved_pages = kzalloc(max_sg * sizeof(struct page *),
3892				     GFP_ATOMIC);
3893	if (!tb->reserved_pages) {
3894		kfree(tb);
3895		return NULL;
3896	}
3897
3898	return tb;
3899}
3900
3901
3902/* Try to allocate enough space in the tape buffer */
3903#define ST_MAX_ORDER 6
3904
3905static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
3906{
3907	int segs, max_segs, b_size, order, got;
3908	gfp_t priority;
3909
3910	if (new_size <= STbuffer->buffer_size)
3911		return 1;
3912
3913	if (STbuffer->buffer_size <= PAGE_SIZE)
3914		normalize_buffer(STbuffer);  /* Avoid extra segment */
3915
3916	max_segs = STbuffer->use_sg;
3917
3918	priority = GFP_KERNEL | __GFP_NOWARN;
3919	if (need_dma)
3920		priority |= GFP_DMA;
3921
3922	if (STbuffer->cleared)
3923		priority |= __GFP_ZERO;
3924
3925	if (STbuffer->frp_segs) {
3926		order = STbuffer->reserved_page_order;
3927		b_size = PAGE_SIZE << order;
3928	} else {
3929		for (b_size = PAGE_SIZE, order = 0;
3930		     order < ST_MAX_ORDER &&
3931			     max_segs * (PAGE_SIZE << order) < new_size;
3932		     order++, b_size *= 2)
3933			;  /* empty */
3934		STbuffer->reserved_page_order = order;
3935	}
3936	if (max_segs * (PAGE_SIZE << order) < new_size) {
3937		if (order == ST_MAX_ORDER)
3938			return 0;
3939		normalize_buffer(STbuffer);
3940		return enlarge_buffer(STbuffer, new_size, need_dma);
3941	}
3942
3943	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3944	     segs < max_segs && got < new_size;) {
3945		struct page *page;
3946
3947		page = alloc_pages(priority, order);
3948		if (!page) {
3949			DEB(STbuffer->buffer_size = got);
3950			normalize_buffer(STbuffer);
3951			return 0;
3952		}
3953
3954		STbuffer->frp_segs += 1;
3955		got += b_size;
3956		STbuffer->buffer_size = got;
3957		STbuffer->reserved_pages[segs] = page;
3958		segs++;
3959	}
3960	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3961
3962	return 1;
3963}
3964
3965
3966/* Make sure that no data from previous user is in the internal buffer */
3967static void clear_buffer(struct st_buffer * st_bp)
3968{
3969	int i;
3970
3971	for (i=0; i < st_bp->frp_segs; i++)
3972		memset(page_address(st_bp->reserved_pages[i]), 0,
3973		       PAGE_SIZE << st_bp->reserved_page_order);
3974	st_bp->cleared = 1;
3975}
3976
3977
3978/* Release the extra buffer */
3979static void normalize_buffer(struct st_buffer * STbuffer)
3980{
3981	int i, order = STbuffer->reserved_page_order;
3982
3983	for (i = 0; i < STbuffer->frp_segs; i++) {
3984		__free_pages(STbuffer->reserved_pages[i], order);
3985		STbuffer->buffer_size -= (PAGE_SIZE << order);
3986	}
3987	STbuffer->frp_segs = 0;
3988	STbuffer->sg_segs = 0;
3989	STbuffer->reserved_page_order = 0;
3990	STbuffer->map_data.offset = 0;
3991}
3992
3993
3994/* Move data from the user buffer to the tape buffer. Returns zero (success) or
3995   negative error code. */
3996static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3997{
3998	int i, cnt, res, offset;
3999	int length = PAGE_SIZE << st_bp->reserved_page_order;
4000
4001	for (i = 0, offset = st_bp->buffer_bytes;
4002	     i < st_bp->frp_segs && offset >= length; i++)
4003		offset -= length;
4004	if (i == st_bp->frp_segs) {	/* Should never happen */
4005		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
4006		return (-EIO);
4007	}
4008	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4009		struct page *page = st_bp->reserved_pages[i];
4010		cnt = length - offset < do_count ? length - offset : do_count;
4011		res = copy_from_user(page_address(page) + offset, ubp, cnt);
4012		if (res)
4013			return (-EFAULT);
4014		do_count -= cnt;
4015		st_bp->buffer_bytes += cnt;
4016		ubp += cnt;
4017		offset = 0;
4018	}
4019	if (do_count) /* Should never happen */
4020		return (-EIO);
4021
4022	return 0;
4023}
4024
4025
4026/* Move data from the tape buffer to the user buffer. Returns zero (success) or
4027   negative error code. */
4028static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
4029{
4030	int i, cnt, res, offset;
4031	int length = PAGE_SIZE << st_bp->reserved_page_order;
4032
4033	for (i = 0, offset = st_bp->read_pointer;
4034	     i < st_bp->frp_segs && offset >= length; i++)
4035		offset -= length;
4036	if (i == st_bp->frp_segs) {	/* Should never happen */
4037		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
4038		return (-EIO);
4039	}
4040	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4041		struct page *page = st_bp->reserved_pages[i];
4042		cnt = length - offset < do_count ? length - offset : do_count;
4043		res = copy_to_user(ubp, page_address(page) + offset, cnt);
4044		if (res)
4045			return (-EFAULT);
4046		do_count -= cnt;
4047		st_bp->buffer_bytes -= cnt;
4048		st_bp->read_pointer += cnt;
4049		ubp += cnt;
4050		offset = 0;
4051	}
4052	if (do_count) /* Should never happen */
4053		return (-EIO);
4054
4055	return 0;
4056}
4057
4058
4059/* Move data towards start of buffer */
4060static void move_buffer_data(struct st_buffer * st_bp, int offset)
4061{
4062	int src_seg, dst_seg, src_offset = 0, dst_offset;
4063	int count, total;
4064	int length = PAGE_SIZE << st_bp->reserved_page_order;
4065
4066	if (offset == 0)
4067		return;
4068
4069	total=st_bp->buffer_bytes - offset;
4070	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
4071		src_offset = offset;
4072		if (src_offset < length)
4073			break;
4074		offset -= length;
4075	}
4076
4077	st_bp->buffer_bytes = st_bp->read_pointer = total;
4078	for (dst_seg=dst_offset=0; total > 0; ) {
4079		struct page *dpage = st_bp->reserved_pages[dst_seg];
4080		struct page *spage = st_bp->reserved_pages[src_seg];
4081
4082		count = min(length - dst_offset, length - src_offset);
4083		memmove(page_address(dpage) + dst_offset,
4084			page_address(spage) + src_offset, count);
4085		src_offset += count;
4086		if (src_offset >= length) {
4087			src_seg++;
4088			src_offset = 0;
4089		}
4090		dst_offset += count;
4091		if (dst_offset >= length) {
4092			dst_seg++;
4093			dst_offset = 0;
4094		}
4095		total -= count;
4096	}
4097}
4098
4099/* Validate the options from command line or module parameters */
4100static void validate_options(void)
4101{
4102	if (buffer_kbs > 0)
4103		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
4104	if (max_sg_segs >= ST_FIRST_SG)
4105		st_max_sg_segs = max_sg_segs;
4106}
4107
4108#ifndef MODULE
4109/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
4110 */
4111static int __init st_setup(char *str)
4112{
4113	int i, len, ints[5];
4114	char *stp;
4115
4116	stp = get_options(str, ARRAY_SIZE(ints), ints);
4117
4118	if (ints[0] > 0) {
4119		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
4120			if (parms[i].val)
4121				*parms[i].val = ints[i + 1];
4122	} else {
4123		while (stp != NULL) {
4124			for (i = 0; i < ARRAY_SIZE(parms); i++) {
4125				len = strlen(parms[i].name);
4126				if (!strncmp(stp, parms[i].name, len) &&
4127				    (*(stp + len) == ':' || *(stp + len) == '=')) {
4128					if (parms[i].val)
4129						*parms[i].val =
4130							simple_strtoul(stp + len + 1, NULL, 0);
4131					else
4132						printk(KERN_WARNING "st: Obsolete parameter %s\n",
4133						       parms[i].name);
4134					break;
4135				}
4136			}
4137			if (i >= ARRAY_SIZE(parms))
4138				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
4139					stp);
4140			stp = strchr(stp, ',');
4141			if (stp)
4142				stp++;
4143		}
4144	}
4145
4146	validate_options();
4147
4148	return 1;
4149}
4150
4151__setup("st=", st_setup);
4152
4153#endif
4154
4155static const struct file_operations st_fops =
4156{
4157	.owner =	THIS_MODULE,
4158	.read =		st_read,
4159	.write =	st_write,
4160	.unlocked_ioctl = st_ioctl,
4161#ifdef CONFIG_COMPAT
4162	.compat_ioctl = st_compat_ioctl,
4163#endif
4164	.open =		st_open,
4165	.flush =	st_flush,
4166	.release =	st_release,
4167	.llseek =	noop_llseek,
4168};
4169
4170static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
4171{
4172	int i, error;
4173	dev_t cdev_devno;
4174	struct cdev *cdev;
4175	struct device *dev;
4176	struct st_modedef *STm = &(tape->modes[mode]);
4177	char name[10];
4178	int dev_num = tape->index;
4179
4180	cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
4181
4182	cdev = cdev_alloc();
4183	if (!cdev) {
4184		pr_err("st%d: out of memory. Device not attached.\n", dev_num);
4185		error = -ENOMEM;
4186		goto out;
4187	}
4188	cdev->owner = THIS_MODULE;
4189	cdev->ops = &st_fops;
4190	STm->cdevs[rew] = cdev;
4191
4192	error = cdev_add(cdev, cdev_devno, 1);
4193	if (error) {
4194		pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
4195		       rew ? "non" : "auto", mode);
4196		pr_err("st%d: Device not attached.\n", dev_num);
4197		goto out_free;
4198	}
4199
4200	i = mode << (4 - ST_NBR_MODE_BITS);
4201	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4202		 tape->disk->disk_name, st_formats[i]);
4203
4204	dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
4205			    cdev_devno, &tape->modes[mode], "%s", name);
4206	if (IS_ERR(dev)) {
4207		pr_err("st%d: device_create failed\n", dev_num);
4208		error = PTR_ERR(dev);
4209		goto out_free;
4210	}
4211
4212	STm->devs[rew] = dev;
4213
4214	return 0;
4215out_free:
4216	cdev_del(STm->cdevs[rew]);
4217out:
4218	STm->cdevs[rew] = NULL;
4219	STm->devs[rew] = NULL;
4220	return error;
4221}
4222
4223static int create_cdevs(struct scsi_tape *tape)
4224{
4225	int mode, error;
4226	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4227		error = create_one_cdev(tape, mode, 0);
4228		if (error)
4229			return error;
4230		error = create_one_cdev(tape, mode, 1);
4231		if (error)
4232			return error;
4233	}
4234
4235	return sysfs_create_link(&tape->device->sdev_gendev.kobj,
4236				 &tape->modes[0].devs[0]->kobj, "tape");
4237}
4238
4239static void remove_cdevs(struct scsi_tape *tape)
4240{
4241	int mode, rew;
4242	sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
4243	for (mode = 0; mode < ST_NBR_MODES; mode++) {
4244		struct st_modedef *STm = &(tape->modes[mode]);
4245		for (rew = 0; rew < 2; rew++) {
4246			if (STm->cdevs[rew])
4247				cdev_del(STm->cdevs[rew]);
4248			if (STm->devs[rew])
4249				device_unregister(STm->devs[rew]);
4250		}
4251	}
4252}
4253
4254static int st_probe(struct device *dev)
4255{
4256	struct scsi_device *SDp = to_scsi_device(dev);
4257	struct gendisk *disk = NULL;
4258	struct scsi_tape *tpnt = NULL;
4259	struct st_modedef *STm;
4260	struct st_partstat *STps;
4261	struct st_buffer *buffer;
4262	int i, error;
4263	char *stp;
4264
4265	if (SDp->type != TYPE_TAPE)
4266		return -ENODEV;
4267	if ((stp = st_incompatible(SDp))) {
4268		sdev_printk(KERN_INFO, SDp, "Found incompatible tape\n");
 
4269		sdev_printk(KERN_INFO, SDp,
4270			    "st: The suggested driver is %s.\n", stp);
4271		return -ENODEV;
4272	}
4273
4274	scsi_autopm_get_device(SDp);
4275	i = queue_max_segments(SDp->request_queue);
4276	if (st_max_sg_segs < i)
4277		i = st_max_sg_segs;
4278	buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
4279	if (buffer == NULL) {
4280		sdev_printk(KERN_ERR, SDp,
4281			    "st: Can't allocate new tape buffer. "
4282			    "Device not attached.\n");
4283		goto out;
4284	}
4285
4286	disk = alloc_disk(1);
4287	if (!disk) {
4288		sdev_printk(KERN_ERR, SDp,
4289			    "st: out of memory. Device not attached.\n");
4290		goto out_buffer_free;
4291	}
4292
4293	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
4294	if (tpnt == NULL) {
4295		sdev_printk(KERN_ERR, SDp,
4296			    "st: Can't allocate device descriptor.\n");
4297		goto out_put_disk;
4298	}
4299	kref_init(&tpnt->kref);
4300	tpnt->disk = disk;
4301	disk->private_data = &tpnt->driver;
4302	/* SCSI tape doesn't register this gendisk via add_disk().  Manually
4303	 * take queue reference that release_disk() expects. */
4304	if (!blk_get_queue(SDp->request_queue))
4305		goto out_put_disk;
4306	disk->queue = SDp->request_queue;
4307	tpnt->driver = &st_template;
4308
4309	tpnt->device = SDp;
4310	if (SDp->scsi_level <= 2)
4311		tpnt->tape_type = MT_ISSCSI1;
4312	else
4313		tpnt->tape_type = MT_ISSCSI2;
4314
4315	tpnt->buffer = buffer;
4316	tpnt->buffer->last_SRpnt = NULL;
4317
4318	tpnt->inited = 0;
4319	tpnt->dirty = 0;
4320	tpnt->in_use = 0;
4321	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
4322	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4323	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4324	tpnt->density = 0;
4325	tpnt->do_auto_lock = ST_AUTO_LOCK;
4326	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4327	tpnt->can_partitions = 0;
4328	tpnt->two_fm = ST_TWO_FM;
4329	tpnt->fast_mteom = ST_FAST_MTEOM;
4330	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4331	tpnt->sili = ST_SILI;
4332	tpnt->immediate = ST_NOWAIT;
4333	tpnt->immediate_filemark = 0;
4334	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4335	tpnt->partition = 0;
4336	tpnt->new_partition = 0;
4337	tpnt->nbr_partitions = 0;
4338	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4339	tpnt->long_timeout = ST_LONG_TIMEOUT;
4340	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
4341
4342	for (i = 0; i < ST_NBR_MODES; i++) {
4343		STm = &(tpnt->modes[i]);
4344		STm->defined = 0;
4345		STm->sysv = ST_SYSV;
4346		STm->defaults_for_writes = 0;
4347		STm->do_async_writes = ST_ASYNC_WRITES;
4348		STm->do_buffer_writes = ST_BUFFER_WRITES;
4349		STm->do_read_ahead = ST_READ_AHEAD;
4350		STm->default_compression = ST_DONT_TOUCH;
4351		STm->default_blksize = (-1);	/* No forced size */
4352		STm->default_density = (-1);	/* No forced density */
4353		STm->tape = tpnt;
4354	}
4355
4356	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4357		STps = &(tpnt->ps[i]);
4358		STps->rw = ST_IDLE;
4359		STps->eof = ST_NOEOF;
4360		STps->at_sm = 0;
4361		STps->last_block_valid = 0;
4362		STps->drv_block = (-1);
4363		STps->drv_file = (-1);
4364	}
4365
4366	tpnt->current_mode = 0;
4367	tpnt->modes[0].defined = 1;
4368
4369	tpnt->density_changed = tpnt->compression_changed =
4370	    tpnt->blksize_changed = 0;
4371	mutex_init(&tpnt->lock);
4372
4373	idr_preload(GFP_KERNEL);
4374	spin_lock(&st_index_lock);
4375	error = idr_alloc(&st_index_idr, tpnt, 0, ST_MAX_TAPES + 1, GFP_NOWAIT);
4376	spin_unlock(&st_index_lock);
4377	idr_preload_end();
4378	if (error < 0) {
4379		pr_warn("st: idr allocation failed: %d\n", error);
4380		goto out_put_queue;
4381	}
4382	tpnt->index = error;
4383	sprintf(disk->disk_name, "st%d", tpnt->index);
4384	tpnt->stats = kzalloc(sizeof(struct scsi_tape_stats), GFP_KERNEL);
4385	if (tpnt->stats == NULL) {
4386		sdev_printk(KERN_ERR, SDp,
4387			    "st: Can't allocate statistics.\n");
4388		goto out_idr_remove;
4389	}
4390
4391	dev_set_drvdata(dev, tpnt);
4392
4393
4394	error = create_cdevs(tpnt);
4395	if (error)
4396		goto out_remove_devs;
4397	scsi_autopm_put_device(SDp);
4398
4399	sdev_printk(KERN_NOTICE, SDp,
4400		    "Attached scsi tape %s\n", tape_name(tpnt));
4401	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4402		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4403		    queue_dma_alignment(SDp->request_queue) + 1);
4404
4405	return 0;
4406
4407out_remove_devs:
4408	remove_cdevs(tpnt);
4409	kfree(tpnt->stats);
4410out_idr_remove:
4411	spin_lock(&st_index_lock);
4412	idr_remove(&st_index_idr, tpnt->index);
4413	spin_unlock(&st_index_lock);
4414out_put_queue:
4415	blk_put_queue(disk->queue);
4416out_put_disk:
4417	put_disk(disk);
4418	kfree(tpnt);
4419out_buffer_free:
4420	kfree(buffer);
4421out:
4422	scsi_autopm_put_device(SDp);
4423	return -ENODEV;
4424};
4425
4426
4427static int st_remove(struct device *dev)
4428{
4429	struct scsi_tape *tpnt = dev_get_drvdata(dev);
4430	int index = tpnt->index;
4431
4432	scsi_autopm_get_device(to_scsi_device(dev));
4433	remove_cdevs(tpnt);
4434
4435	mutex_lock(&st_ref_mutex);
4436	kref_put(&tpnt->kref, scsi_tape_release);
4437	mutex_unlock(&st_ref_mutex);
4438	spin_lock(&st_index_lock);
4439	idr_remove(&st_index_idr, index);
4440	spin_unlock(&st_index_lock);
4441	return 0;
4442}
4443
4444/**
4445 *      scsi_tape_release - Called to free the Scsi_Tape structure
4446 *      @kref: pointer to embedded kref
4447 *
4448 *      st_ref_mutex must be held entering this routine.  Because it is
4449 *      called on last put, you should always use the scsi_tape_get()
4450 *      scsi_tape_put() helpers which manipulate the semaphore directly
4451 *      and never do a direct kref_put().
4452 **/
4453static void scsi_tape_release(struct kref *kref)
4454{
4455	struct scsi_tape *tpnt = to_scsi_tape(kref);
4456	struct gendisk *disk = tpnt->disk;
4457
4458	tpnt->device = NULL;
4459
4460	if (tpnt->buffer) {
4461		normalize_buffer(tpnt->buffer);
4462		kfree(tpnt->buffer->reserved_pages);
4463		kfree(tpnt->buffer);
4464	}
4465
4466	disk->private_data = NULL;
4467	put_disk(disk);
4468	kfree(tpnt->stats);
4469	kfree(tpnt);
4470	return;
4471}
4472
4473static struct class st_sysfs_class = {
4474	.name = "scsi_tape",
4475	.dev_groups = st_dev_groups,
4476};
4477
4478static int __init init_st(void)
4479{
4480	int err;
4481
4482	validate_options();
4483
4484	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4485		verstr, st_fixed_buffer_size, st_max_sg_segs);
4486
4487	debugging = (debug_flag > 0) ? debug_flag : NO_DEBUG;
4488	if (debugging) {
4489		printk(KERN_INFO "st: Debugging enabled debug_flag = %d\n",
4490			debugging);
4491	}
4492
4493	err = class_register(&st_sysfs_class);
4494	if (err) {
4495		pr_err("Unable register sysfs class for SCSI tapes\n");
4496		return err;
4497	}
4498
4499	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4500				     ST_MAX_TAPE_ENTRIES, "st");
4501	if (err) {
4502		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4503		       SCSI_TAPE_MAJOR);
4504		goto err_class;
4505	}
4506
4507	err = scsi_register_driver(&st_template.gendrv);
4508	if (err)
4509		goto err_chrdev;
4510
4511	return 0;
4512
4513err_chrdev:
4514	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4515				 ST_MAX_TAPE_ENTRIES);
4516err_class:
4517	class_unregister(&st_sysfs_class);
4518	return err;
4519}
4520
4521static void __exit exit_st(void)
4522{
4523	scsi_unregister_driver(&st_template.gendrv);
4524	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4525				 ST_MAX_TAPE_ENTRIES);
4526	class_unregister(&st_sysfs_class);
4527	idr_destroy(&st_index_idr);
4528	printk(KERN_INFO "st: Unloaded.\n");
4529}
4530
4531module_init(init_st);
4532module_exit(exit_st);
4533
4534
4535/* The sysfs driver interface. Read-only at the moment */
4536static ssize_t try_direct_io_show(struct device_driver *ddp, char *buf)
4537{
4538	return scnprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4539}
4540static DRIVER_ATTR_RO(try_direct_io);
4541
4542static ssize_t fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4543{
4544	return scnprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4545}
4546static DRIVER_ATTR_RO(fixed_buffer_size);
4547
4548static ssize_t max_sg_segs_show(struct device_driver *ddp, char *buf)
4549{
4550	return scnprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4551}
4552static DRIVER_ATTR_RO(max_sg_segs);
4553
4554static ssize_t version_show(struct device_driver *ddd, char *buf)
4555{
4556	return scnprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4557}
4558static DRIVER_ATTR_RO(version);
4559
4560#if DEBUG
4561static ssize_t debug_flag_store(struct device_driver *ddp,
4562	const char *buf, size_t count)
4563{
4564/* We only care what the first byte of the data is the rest is unused.
4565 * if it's a '1' we turn on debug and if it's a '0' we disable it. All
4566 * other values have -EINVAL returned if they are passed in.
4567 */
4568	if (count > 0) {
4569		if (buf[0] == '0') {
4570			debugging = NO_DEBUG;
4571			return count;
4572		} else if (buf[0] == '1') {
4573			debugging = 1;
4574			return count;
4575		}
4576	}
4577	return -EINVAL;
4578}
4579
4580static ssize_t debug_flag_show(struct device_driver *ddp, char *buf)
4581{
4582	return scnprintf(buf, PAGE_SIZE, "%d\n", debugging);
4583}
4584static DRIVER_ATTR_RW(debug_flag);
4585#endif
4586
4587static struct attribute *st_drv_attrs[] = {
4588	&driver_attr_try_direct_io.attr,
4589	&driver_attr_fixed_buffer_size.attr,
4590	&driver_attr_max_sg_segs.attr,
4591	&driver_attr_version.attr,
4592#if DEBUG
4593	&driver_attr_debug_flag.attr,
4594#endif
4595	NULL,
4596};
4597ATTRIBUTE_GROUPS(st_drv);
4598
4599/* The sysfs simple class interface */
4600static ssize_t
4601defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4602{
4603	struct st_modedef *STm = dev_get_drvdata(dev);
4604	ssize_t l = 0;
4605
4606	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4607	return l;
4608}
4609static DEVICE_ATTR_RO(defined);
4610
4611static ssize_t
4612default_blksize_show(struct device *dev, struct device_attribute *attr,
4613		     char *buf)
4614{
4615	struct st_modedef *STm = dev_get_drvdata(dev);
4616	ssize_t l = 0;
4617
4618	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4619	return l;
4620}
4621static DEVICE_ATTR_RO(default_blksize);
4622
4623static ssize_t
4624default_density_show(struct device *dev, struct device_attribute *attr,
4625		     char *buf)
4626{
4627	struct st_modedef *STm = dev_get_drvdata(dev);
4628	ssize_t l = 0;
4629	char *fmt;
4630
4631	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4632	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4633	return l;
4634}
4635static DEVICE_ATTR_RO(default_density);
4636
4637static ssize_t
4638default_compression_show(struct device *dev, struct device_attribute *attr,
4639			 char *buf)
4640{
4641	struct st_modedef *STm = dev_get_drvdata(dev);
4642	ssize_t l = 0;
4643
4644	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4645	return l;
4646}
4647static DEVICE_ATTR_RO(default_compression);
4648
4649static ssize_t
4650options_show(struct device *dev, struct device_attribute *attr, char *buf)
4651{
4652	struct st_modedef *STm = dev_get_drvdata(dev);
4653	struct scsi_tape *STp = STm->tape;
4654	int options;
4655	ssize_t l = 0;
4656
4657	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4658	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4659	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4660	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4661	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4662	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4663	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4664	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4665	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4666	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4667	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4668	options |= STm->sysv ? MT_ST_SYSV : 0;
4669	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4670	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4671	options |= STp->sili ? MT_ST_SILI : 0;
4672
4673	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4674	return l;
4675}
4676static DEVICE_ATTR_RO(options);
4677
4678/* Support for tape stats */
4679
4680/**
4681 * read_cnt_show - return read count - count of reads made from tape drive
4682 * @dev: struct device
4683 * @attr: attribute structure
4684 * @buf: buffer to return formatted data in
4685 */
4686static ssize_t read_cnt_show(struct device *dev,
4687	struct device_attribute *attr, char *buf)
4688{
4689	struct st_modedef *STm = dev_get_drvdata(dev);
4690
4691	return sprintf(buf, "%lld",
4692		       (long long)atomic64_read(&STm->tape->stats->read_cnt));
4693}
4694static DEVICE_ATTR_RO(read_cnt);
4695
4696/**
4697 * read_byte_cnt_show - return read byte count - tape drives
4698 * may use blocks less than 512 bytes this gives the raw byte count of
4699 * of data read from the tape drive.
4700 * @dev: struct device
4701 * @attr: attribute structure
4702 * @buf: buffer to return formatted data in
4703 */
4704static ssize_t read_byte_cnt_show(struct device *dev,
4705	struct device_attribute *attr, char *buf)
4706{
4707	struct st_modedef *STm = dev_get_drvdata(dev);
4708
4709	return sprintf(buf, "%lld",
4710		       (long long)atomic64_read(&STm->tape->stats->read_byte_cnt));
4711}
4712static DEVICE_ATTR_RO(read_byte_cnt);
4713
4714/**
4715 * read_ns_show - return read ns - overall time spent waiting on reads in ns.
4716 * @dev: struct device
4717 * @attr: attribute structure
4718 * @buf: buffer to return formatted data in
4719 */
4720static ssize_t read_ns_show(struct device *dev,
4721	struct device_attribute *attr, char *buf)
4722{
4723	struct st_modedef *STm = dev_get_drvdata(dev);
4724
4725	return sprintf(buf, "%lld",
4726		       (long long)atomic64_read(&STm->tape->stats->tot_read_time));
4727}
4728static DEVICE_ATTR_RO(read_ns);
4729
4730/**
4731 * write_cnt_show - write count - number of user calls
4732 * to write(2) that have written data to tape.
4733 * @dev: struct device
4734 * @attr: attribute structure
4735 * @buf: buffer to return formatted data in
4736 */
4737static ssize_t write_cnt_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->write_cnt));
4744}
4745static DEVICE_ATTR_RO(write_cnt);
4746
4747/**
4748 * write_byte_cnt_show - write byte count - raw count of
4749 * bytes written to tape.
4750 * @dev: struct device
4751 * @attr: attribute structure
4752 * @buf: buffer to return formatted data in
4753 */
4754static ssize_t write_byte_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_byte_cnt));
4761}
4762static DEVICE_ATTR_RO(write_byte_cnt);
4763
4764/**
4765 * write_ns_show - write ns - number of nanoseconds waiting on write
4766 * requests to complete.
4767 * @dev: struct device
4768 * @attr: attribute structure
4769 * @buf: buffer to return formatted data in
4770 */
4771static ssize_t write_ns_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->tot_write_time));
4778}
4779static DEVICE_ATTR_RO(write_ns);
4780
4781/**
4782 * in_flight_show - number of I/Os currently in flight -
4783 * in most cases this will be either 0 or 1. It may be higher if someone
4784 * has also issued other SCSI commands such as via an ioctl.
4785 * @dev: struct device
4786 * @attr: attribute structure
4787 * @buf: buffer to return formatted data in
4788 */
4789static ssize_t in_flight_show(struct device *dev,
4790	struct device_attribute *attr, char *buf)
4791{
4792	struct st_modedef *STm = dev_get_drvdata(dev);
4793
4794	return sprintf(buf, "%lld",
4795		       (long long)atomic64_read(&STm->tape->stats->in_flight));
4796}
4797static DEVICE_ATTR_RO(in_flight);
4798
4799/**
4800 * io_ns_show - io wait ns - this is the number of ns spent
4801 * waiting on all I/O to complete. This includes tape movement commands
4802 * such as rewinding, seeking to end of file or tape, it also includes
4803 * read and write. To determine the time spent on tape movement
4804 * subtract the read and write ns from this value.
4805 * @dev: struct device
4806 * @attr: attribute structure
4807 * @buf: buffer to return formatted data in
4808 */
4809static ssize_t io_ns_show(struct device *dev,
4810	struct device_attribute *attr, char *buf)
4811{
4812	struct st_modedef *STm = dev_get_drvdata(dev);
4813
4814	return sprintf(buf, "%lld",
4815		       (long long)atomic64_read(&STm->tape->stats->tot_io_time));
4816}
4817static DEVICE_ATTR_RO(io_ns);
4818
4819/**
4820 * other_cnt_show - other io count - this is the number of
4821 * I/O requests other than read and write requests.
4822 * Typically these are tape movement requests but will include driver
4823 * tape movement. This includes only requests issued by the st driver.
4824 * @dev: struct device
4825 * @attr: attribute structure
4826 * @buf: buffer to return formatted data in
4827 */
4828static ssize_t other_cnt_show(struct device *dev,
4829	struct device_attribute *attr, char *buf)
4830{
4831	struct st_modedef *STm = dev_get_drvdata(dev);
4832
4833	return sprintf(buf, "%lld",
4834		       (long long)atomic64_read(&STm->tape->stats->other_cnt));
4835}
4836static DEVICE_ATTR_RO(other_cnt);
4837
4838/**
4839 * resid_cnt_show - A count of the number of times we get a residual
4840 * count - this should indicate someone issuing reads larger than the
4841 * block size on tape.
4842 * @dev: struct device
4843 * @attr: attribute structure
4844 * @buf: buffer to return formatted data in
4845 */
4846static ssize_t resid_cnt_show(struct device *dev,
4847	struct device_attribute *attr, char *buf)
4848{
4849	struct st_modedef *STm = dev_get_drvdata(dev);
4850
4851	return sprintf(buf, "%lld",
4852		       (long long)atomic64_read(&STm->tape->stats->resid_cnt));
4853}
4854static DEVICE_ATTR_RO(resid_cnt);
4855
4856static struct attribute *st_dev_attrs[] = {
4857	&dev_attr_defined.attr,
4858	&dev_attr_default_blksize.attr,
4859	&dev_attr_default_density.attr,
4860	&dev_attr_default_compression.attr,
4861	&dev_attr_options.attr,
4862	NULL,
4863};
4864
4865static struct attribute *st_stats_attrs[] = {
4866	&dev_attr_read_cnt.attr,
4867	&dev_attr_read_byte_cnt.attr,
4868	&dev_attr_read_ns.attr,
4869	&dev_attr_write_cnt.attr,
4870	&dev_attr_write_byte_cnt.attr,
4871	&dev_attr_write_ns.attr,
4872	&dev_attr_in_flight.attr,
4873	&dev_attr_io_ns.attr,
4874	&dev_attr_other_cnt.attr,
4875	&dev_attr_resid_cnt.attr,
4876	NULL,
4877};
4878
4879static struct attribute_group stats_group = {
4880	.name = "stats",
4881	.attrs = st_stats_attrs,
4882};
4883
4884static struct attribute_group st_group = {
4885	.attrs = st_dev_attrs,
4886};
4887
4888static const struct attribute_group *st_dev_groups[] = {
4889	&st_group,
4890	&stats_group,
4891	NULL,
4892};
4893
4894/* The following functions may be useful for a larger audience. */
4895static int sgl_map_user_pages(struct st_buffer *STbp,
4896			      const unsigned int max_pages, unsigned long uaddr,
4897			      size_t count, int rw)
4898{
4899	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4900	unsigned long start = uaddr >> PAGE_SHIFT;
4901	const int nr_pages = end - start;
4902	int res, i, j;
4903	struct page **pages;
4904	struct rq_map_data *mdata = &STbp->map_data;
4905
4906	/* User attempted Overflow! */
4907	if ((uaddr + count) < uaddr)
4908		return -EINVAL;
4909
4910	/* Too big */
4911        if (nr_pages > max_pages)
4912		return -ENOMEM;
4913
4914	/* Hmm? */
4915	if (count == 0)
4916		return 0;
4917
4918	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_KERNEL)) == NULL)
 
4919		return -ENOMEM;
4920
4921        /* Try to fault in all of the necessary pages */
4922        /* rw==READ means read from drive, write into memory area */
4923	res = get_user_pages_fast(uaddr, nr_pages, rw == READ, pages);
 
4924
4925	/* Errors and no page mapped should return here */
4926	if (res < nr_pages)
4927		goto out_unmap;
4928
4929        for (i=0; i < nr_pages; i++) {
4930                /* FIXME: flush superflous for rw==READ,
4931                 * probably wrong function for rw==WRITE
4932                 */
4933		flush_dcache_page(pages[i]);
4934        }
4935
4936	mdata->offset = uaddr & ~PAGE_MASK;
4937	STbp->mapped_pages = pages;
4938
4939	return nr_pages;
4940 out_unmap:
4941	if (res > 0) {
4942		for (j=0; j < res; j++)
4943			put_page(pages[j]);
4944		res = 0;
4945	}
4946	kfree(pages);
4947	return res;
4948}
4949
4950
4951/* And unmap them... */
4952static int sgl_unmap_user_pages(struct st_buffer *STbp,
4953				const unsigned int nr_pages, int dirtied)
4954{
4955	int i;
 
4956
4957	for (i=0; i < nr_pages; i++) {
4958		struct page *page = STbp->mapped_pages[i];
4959
4960		if (dirtied)
4961			SetPageDirty(page);
4962		/* FIXME: cache flush missing for rw==READ
4963		 * FIXME: call the correct reference counting function
4964		 */
4965		put_page(page);
4966	}
4967	kfree(STbp->mapped_pages);
4968	STbp->mapped_pages = NULL;
4969
4970	return 0;
4971}