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v6.13.7
   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 <linux/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 const 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		.probe		= st_probe,
 210		.remove		= st_remove,
 211		.groups		= st_drv_groups,
 212	},
 213};
 214
 215static int st_compression(struct scsi_tape *, int);
 216
 217static int find_partition(struct scsi_tape *);
 218static int switch_partition(struct scsi_tape *);
 219
 220static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 221
 222static void scsi_tape_release(struct kref *);
 223
 224#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 225
 226static DEFINE_MUTEX(st_ref_mutex);
 227static DEFINE_SPINLOCK(st_index_lock);
 228static DEFINE_SPINLOCK(st_use_lock);
 229static DEFINE_IDR(st_index_idr);
 230
 231
 232
 233#ifndef SIGS_FROM_OSST
 234#define SIGS_FROM_OSST \
 235	{"OnStream", "SC-", "", "osst"}, \
 236	{"OnStream", "DI-", "", "osst"}, \
 237	{"OnStream", "DP-", "", "osst"}, \
 238	{"OnStream", "USB", "", "osst"}, \
 239	{"OnStream", "FW-", "", "osst"}
 240#endif
 241
 242static struct scsi_tape *scsi_tape_get(int dev)
 243{
 244	struct scsi_tape *STp = NULL;
 245
 246	mutex_lock(&st_ref_mutex);
 247	spin_lock(&st_index_lock);
 248
 249	STp = idr_find(&st_index_idr, dev);
 250	if (!STp) goto out;
 251
 252	kref_get(&STp->kref);
 253
 254	if (!STp->device)
 255		goto out_put;
 256
 257	if (scsi_device_get(STp->device))
 258		goto out_put;
 259
 260	goto out;
 261
 262out_put:
 263	kref_put(&STp->kref, scsi_tape_release);
 264	STp = NULL;
 265out:
 266	spin_unlock(&st_index_lock);
 267	mutex_unlock(&st_ref_mutex);
 268	return STp;
 269}
 270
 271static void scsi_tape_put(struct scsi_tape *STp)
 272{
 273	struct scsi_device *sdev = STp->device;
 274
 275	mutex_lock(&st_ref_mutex);
 276	kref_put(&STp->kref, scsi_tape_release);
 277	scsi_device_put(sdev);
 278	mutex_unlock(&st_ref_mutex);
 279}
 280
 281struct st_reject_data {
 282	char *vendor;
 283	char *model;
 284	char *rev;
 285	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 286};
 287
 288static struct st_reject_data reject_list[] = {
 289	/* {"XXX", "Yy-", "", NULL},  example */
 290	SIGS_FROM_OSST,
 291	{NULL, }};
 292
 293/* If the device signature is on the list of incompatible drives, the
 294   function returns a pointer to the name of the correct driver (if known) */
 295static char * st_incompatible(struct scsi_device* SDp)
 296{
 297	struct st_reject_data *rp;
 298
 299	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 300		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 301		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 302		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 303			if (rp->driver_hint)
 304				return rp->driver_hint;
 305			else
 306				return "unknown";
 307		}
 308	return NULL;
 309}
 310
 311
 
 
 
 
 
 312#define st_printk(prefix, t, fmt, a...) \
 313	sdev_prefix_printk(prefix, (t)->device, (t)->name, fmt, ##a)
 314#ifdef DEBUG
 315#define DEBC_printk(t, fmt, a...) \
 316	if (debugging) { st_printk(ST_DEB_MSG, t, fmt, ##a ); }
 317#else
 318#define DEBC_printk(t, fmt, a...)
 319#endif
 320
 321static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 322{
 323	const u8 *ucp;
 324	const u8 *sense = SRpnt->sense;
 325
 326	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 327				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 328	s->flags = 0;
 329
 330	if (s->have_sense) {
 331		s->deferred = 0;
 332		s->remainder_valid =
 333			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 334		switch (sense[0] & 0x7f) {
 335		case 0x71:
 336			s->deferred = 1;
 337			fallthrough;
 338		case 0x70:
 339			s->fixed_format = 1;
 340			s->flags = sense[2] & 0xe0;
 341			break;
 342		case 0x73:
 343			s->deferred = 1;
 344			fallthrough;
 345		case 0x72:
 346			s->fixed_format = 0;
 347			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 348			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 349			break;
 350		}
 351	}
 352}
 353
 354
 355/* Convert the result to success code */
 356static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 357{
 358	int result = SRpnt->result;
 359	u8 scode;
 360	DEB(const char *stp;)
 361	char *name = STp->name;
 362	struct st_cmdstatus *cmdstatp;
 363
 364	if (!result)
 365		return 0;
 366
 367	cmdstatp = &STp->buffer->cmdstat;
 368	st_analyze_sense(SRpnt, cmdstatp);
 369
 370	if (cmdstatp->have_sense)
 371		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 372	else
 373		scode = 0;
 374
 375	DEB(
 376	if (debugging) {
 377		st_printk(ST_DEB_MSG, STp,
 378			    "Error: %x, cmd: %x %x %x %x %x %x\n", result,
 379			    SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 380			    SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 381		if (cmdstatp->have_sense)
 382			__scsi_print_sense(STp->device, name,
 383					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 384	} ) /* end DEB */
 385	if (!debugging) { /* Abnormal conditions for tape */
 386		if (!cmdstatp->have_sense)
 387			st_printk(KERN_WARNING, STp,
 388			       "Error %x (driver bt 0, host bt 0x%x).\n",
 389			       result, host_byte(result));
 390		else if (cmdstatp->have_sense &&
 391			 scode != NO_SENSE &&
 392			 scode != RECOVERED_ERROR &&
 393			 /* scode != UNIT_ATTENTION && */
 394			 scode != BLANK_CHECK &&
 395			 scode != VOLUME_OVERFLOW &&
 396			 SRpnt->cmd[0] != MODE_SENSE &&
 397			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 398
 399			__scsi_print_sense(STp->device, name,
 400					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 401		}
 402	}
 403
 404	if (cmdstatp->fixed_format &&
 405	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 406		if (STp->cln_sense_value)
 407			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 408					       STp->cln_sense_mask) == STp->cln_sense_value);
 409		else
 410			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 411					       STp->cln_sense_mask) != 0);
 412	}
 413	if (cmdstatp->have_sense &&
 414	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 415		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 416	if (cmdstatp->have_sense && scode == UNIT_ATTENTION && cmdstatp->sense_hdr.asc == 0x29)
 417		STp->pos_unknown = 1; /* ASC => power on / reset */
 418
 419	STp->pos_unknown |= STp->device->was_reset;
 420
 421	if (cmdstatp->have_sense &&
 422	    scode == RECOVERED_ERROR
 423#if ST_RECOVERED_WRITE_FATAL
 424	    && SRpnt->cmd[0] != WRITE_6
 425	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 426#endif
 427	    ) {
 428		STp->recover_count++;
 429		STp->recover_reg++;
 430
 431		DEB(
 432		if (debugging) {
 433			if (SRpnt->cmd[0] == READ_6)
 434				stp = "read";
 435			else if (SRpnt->cmd[0] == WRITE_6)
 436				stp = "write";
 437			else
 438				stp = "ioctl";
 439			st_printk(ST_DEB_MSG, STp,
 440				  "Recovered %s error (%d).\n",
 441				  stp, STp->recover_count);
 442		} ) /* end DEB */
 443
 444		if (cmdstatp->flags == 0)
 445			return 0;
 446	}
 447	return (-EIO);
 448}
 449
 450static struct st_request *st_allocate_request(struct scsi_tape *stp)
 451{
 452	struct st_request *streq;
 453
 454	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 455	if (streq)
 456		streq->stp = stp;
 457	else {
 458		st_printk(KERN_ERR, stp,
 459			  "Can't get SCSI request.\n");
 460		if (signal_pending(current))
 461			stp->buffer->syscall_result = -EINTR;
 462		else
 463			stp->buffer->syscall_result = -EBUSY;
 464	}
 465
 466	return streq;
 467}
 468
 469static void st_release_request(struct st_request *streq)
 470{
 471	kfree(streq);
 472}
 473
 474static void st_do_stats(struct scsi_tape *STp, struct request *req)
 475{
 476	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
 477	ktime_t now;
 478
 479	now = ktime_get();
 480	if (scmd->cmnd[0] == WRITE_6) {
 481		now = ktime_sub(now, STp->stats->write_time);
 482		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 483		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 484		atomic64_inc(&STp->stats->write_cnt);
 485		if (scmd->result) {
 486			atomic64_add(atomic_read(&STp->stats->last_write_size)
 487				- STp->buffer->cmdstat.residual,
 488				&STp->stats->write_byte_cnt);
 489			if (STp->buffer->cmdstat.residual > 0)
 490				atomic64_inc(&STp->stats->resid_cnt);
 491		} else
 492			atomic64_add(atomic_read(&STp->stats->last_write_size),
 493				&STp->stats->write_byte_cnt);
 494	} else if (scmd->cmnd[0] == READ_6) {
 495		now = ktime_sub(now, STp->stats->read_time);
 496		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 497		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 498		atomic64_inc(&STp->stats->read_cnt);
 499		if (scmd->result) {
 500			atomic64_add(atomic_read(&STp->stats->last_read_size)
 501				- STp->buffer->cmdstat.residual,
 502				&STp->stats->read_byte_cnt);
 503			if (STp->buffer->cmdstat.residual > 0)
 504				atomic64_inc(&STp->stats->resid_cnt);
 505		} else
 506			atomic64_add(atomic_read(&STp->stats->last_read_size),
 507				&STp->stats->read_byte_cnt);
 508	} else {
 509		now = ktime_sub(now, STp->stats->other_time);
 510		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 511		atomic64_inc(&STp->stats->other_cnt);
 512	}
 513	atomic64_dec(&STp->stats->in_flight);
 514}
 515
 516static enum rq_end_io_ret st_scsi_execute_end(struct request *req,
 517					      blk_status_t status)
 518{
 519	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
 520	struct st_request *SRpnt = req->end_io_data;
 
 521	struct scsi_tape *STp = SRpnt->stp;
 522	struct bio *tmp;
 523
 524	STp->buffer->cmdstat.midlevel_result = SRpnt->result = scmd->result;
 525	STp->buffer->cmdstat.residual = scmd->resid_len;
 526
 527	st_do_stats(STp, req);
 528
 529	tmp = SRpnt->bio;
 530	if (scmd->sense_len)
 531		memcpy(SRpnt->sense, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
 532	if (SRpnt->waiting)
 533		complete(SRpnt->waiting);
 534
 535	blk_rq_unmap_user(tmp);
 536	blk_mq_free_request(req);
 537	return RQ_END_IO_NONE;
 538}
 539
 540static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 541			   int data_direction, void *buffer, unsigned bufflen,
 542			   int timeout, int retries)
 543{
 544	struct request *req;
 
 545	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 546	int err = 0;
 547	struct scsi_tape *STp = SRpnt->stp;
 548	struct scsi_cmnd *scmd;
 549
 550	req = scsi_alloc_request(SRpnt->stp->device->request_queue,
 551			data_direction == DMA_TO_DEVICE ?
 552			REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 553	if (IS_ERR(req))
 554		return PTR_ERR(req);
 555	scmd = blk_mq_rq_to_pdu(req);
 556	req->rq_flags |= RQF_QUIET;
 557
 558	mdata->null_mapped = 1;
 559
 560	if (bufflen) {
 561		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 562				      GFP_KERNEL);
 563		if (err) {
 564			blk_mq_free_request(req);
 565			return err;
 566		}
 567	}
 568
 569	atomic64_inc(&STp->stats->in_flight);
 570	if (cmd[0] == WRITE_6) {
 571		atomic_set(&STp->stats->last_write_size, bufflen);
 572		STp->stats->write_time = ktime_get();
 573	} else if (cmd[0] == READ_6) {
 574		atomic_set(&STp->stats->last_read_size, bufflen);
 575		STp->stats->read_time = ktime_get();
 576	} else {
 577		STp->stats->other_time = ktime_get();
 578	}
 579
 580	SRpnt->bio = req->bio;
 581	scmd->cmd_len = COMMAND_SIZE(cmd[0]);
 582	memcpy(scmd->cmnd, cmd, scmd->cmd_len);
 
 583	req->timeout = timeout;
 584	scmd->allowed = retries;
 585	req->end_io = st_scsi_execute_end;
 586	req->end_io_data = SRpnt;
 587
 588	blk_execute_rq_nowait(req, true);
 589	return 0;
 590}
 591
 592/* Do the scsi command. Waits until command performed if do_wait is true.
 593   Otherwise write_behind_check() is used to check that the command
 594   has finished. */
 595static struct st_request *
 596st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 597	   int bytes, int direction, int timeout, int retries, int do_wait)
 598{
 599	struct completion *waiting;
 600	struct rq_map_data *mdata = &STp->buffer->map_data;
 601	int ret;
 602
 603	/* if async, make sure there's no command outstanding */
 604	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 605		st_printk(KERN_ERR, STp,
 606			  "Async command already active.\n");
 607		if (signal_pending(current))
 608			(STp->buffer)->syscall_result = (-EINTR);
 609		else
 610			(STp->buffer)->syscall_result = (-EBUSY);
 611		return NULL;
 612	}
 613
 614	if (!SRpnt) {
 615		SRpnt = st_allocate_request(STp);
 616		if (!SRpnt)
 617			return NULL;
 618	}
 619
 620	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 621	   which IO is outstanding. It's nulled out when the IO completes. */
 622	if (!do_wait)
 623		(STp->buffer)->last_SRpnt = SRpnt;
 624
 625	waiting = &STp->wait;
 626	init_completion(waiting);
 627	SRpnt->waiting = waiting;
 628
 629	if (STp->buffer->do_dio) {
 630		mdata->page_order = 0;
 631		mdata->nr_entries = STp->buffer->sg_segs;
 632		mdata->pages = STp->buffer->mapped_pages;
 633	} else {
 634		mdata->page_order = STp->buffer->reserved_page_order;
 635		mdata->nr_entries =
 636			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 637		mdata->pages = STp->buffer->reserved_pages;
 638		mdata->offset = 0;
 639	}
 640
 641	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 642	STp->buffer->cmdstat.have_sense = 0;
 643	STp->buffer->syscall_result = 0;
 644
 645	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 646			      retries);
 647	if (ret) {
 648		/* could not allocate the buffer or request was too large */
 649		(STp->buffer)->syscall_result = (-EBUSY);
 650		(STp->buffer)->last_SRpnt = NULL;
 651	} else if (do_wait) {
 652		wait_for_completion(waiting);
 653		SRpnt->waiting = NULL;
 654		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 655	}
 656
 657	return SRpnt;
 658}
 659
 660
 661/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 662   write has been correct but EOM early warning reached, -EIO if write ended in
 663   error or zero if write successful. Asynchronous writes are used only in
 664   variable block mode. */
 665static int write_behind_check(struct scsi_tape * STp)
 666{
 667	int retval = 0;
 668	struct st_buffer *STbuffer;
 669	struct st_partstat *STps;
 670	struct st_cmdstatus *cmdstatp;
 671	struct st_request *SRpnt;
 672
 673	STbuffer = STp->buffer;
 674	if (!STbuffer->writing)
 675		return 0;
 676
 677	DEB(
 678	if (STp->write_pending)
 679		STp->nbr_waits++;
 680	else
 681		STp->nbr_finished++;
 682	) /* end DEB */
 683
 684	wait_for_completion(&(STp->wait));
 685	SRpnt = STbuffer->last_SRpnt;
 686	STbuffer->last_SRpnt = NULL;
 687	SRpnt->waiting = NULL;
 688
 689	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 690	st_release_request(SRpnt);
 691
 692	STbuffer->buffer_bytes -= STbuffer->writing;
 693	STps = &(STp->ps[STp->partition]);
 694	if (STps->drv_block >= 0) {
 695		if (STp->block_size == 0)
 696			STps->drv_block++;
 697		else
 698			STps->drv_block += STbuffer->writing / STp->block_size;
 699	}
 700
 701	cmdstatp = &STbuffer->cmdstat;
 702	if (STbuffer->syscall_result) {
 703		retval = -EIO;
 704		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 705		    (cmdstatp->flags & SENSE_EOM) &&
 706		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 707		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 708			/* EOM at write-behind, has all data been written? */
 709			if (!cmdstatp->remainder_valid ||
 710			    cmdstatp->uremainder64 == 0)
 711				retval = -ENOSPC;
 712		}
 713		if (retval == -EIO)
 714			STps->drv_block = -1;
 715	}
 716	STbuffer->writing = 0;
 717
 718	DEB(if (debugging && retval)
 719		    st_printk(ST_DEB_MSG, STp,
 720				"Async write error %x, return value %d.\n",
 721				STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 722
 723	return retval;
 724}
 725
 726
 727/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 728   it messes up the block number). */
 729static int cross_eof(struct scsi_tape * STp, int forward)
 730{
 731	struct st_request *SRpnt;
 732	unsigned char cmd[MAX_COMMAND_SIZE];
 733
 734	cmd[0] = SPACE;
 735	cmd[1] = 0x01;		/* Space FileMarks */
 736	if (forward) {
 737		cmd[2] = cmd[3] = 0;
 738		cmd[4] = 1;
 739	} else
 740		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 741	cmd[5] = 0;
 742
 743	DEBC_printk(STp, "Stepping over filemark %s.\n",
 744		    forward ? "forward" : "backward");
 745
 746	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 747			   STp->device->request_queue->rq_timeout,
 748			   MAX_RETRIES, 1);
 749	if (!SRpnt)
 750		return (STp->buffer)->syscall_result;
 751
 752	st_release_request(SRpnt);
 753	SRpnt = NULL;
 754
 755	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 756		st_printk(KERN_ERR, STp,
 757			  "Stepping over filemark %s failed.\n",
 758			  forward ? "forward" : "backward");
 759
 760	return (STp->buffer)->syscall_result;
 761}
 762
 763
 764/* Flush the write buffer (never need to write if variable blocksize). */
 765static int st_flush_write_buffer(struct scsi_tape * STp)
 766{
 767	int transfer, blks;
 768	int result;
 769	unsigned char cmd[MAX_COMMAND_SIZE];
 770	struct st_request *SRpnt;
 771	struct st_partstat *STps;
 772
 773	result = write_behind_check(STp);
 774	if (result)
 775		return result;
 776
 777	result = 0;
 778	if (STp->dirty == 1) {
 779
 780		transfer = STp->buffer->buffer_bytes;
 781		DEBC_printk(STp, "Flushing %d bytes.\n", transfer);
 782
 783		memset(cmd, 0, MAX_COMMAND_SIZE);
 784		cmd[0] = WRITE_6;
 785		cmd[1] = 1;
 786		blks = transfer / STp->block_size;
 787		cmd[2] = blks >> 16;
 788		cmd[3] = blks >> 8;
 789		cmd[4] = blks;
 790
 791		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 792				   STp->device->request_queue->rq_timeout,
 793				   MAX_WRITE_RETRIES, 1);
 794		if (!SRpnt)
 795			return (STp->buffer)->syscall_result;
 796
 797		STps = &(STp->ps[STp->partition]);
 798		if ((STp->buffer)->syscall_result != 0) {
 799			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 800
 801			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 802			    (cmdstatp->flags & SENSE_EOM) &&
 803			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 804			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 805			    (!cmdstatp->remainder_valid ||
 806			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 807				STp->dirty = 0;
 808				(STp->buffer)->buffer_bytes = 0;
 809				if (STps->drv_block >= 0)
 810					STps->drv_block += blks;
 811				result = (-ENOSPC);
 812			} else {
 813				st_printk(KERN_ERR, STp, "Error on flush.\n");
 814				STps->drv_block = (-1);
 815				result = (-EIO);
 816			}
 817		} else {
 818			if (STps->drv_block >= 0)
 819				STps->drv_block += blks;
 820			STp->dirty = 0;
 821			(STp->buffer)->buffer_bytes = 0;
 822		}
 823		st_release_request(SRpnt);
 824		SRpnt = NULL;
 825	}
 826	return result;
 827}
 828
 829
 830/* Flush the tape buffer. The tape will be positioned correctly unless
 831   seek_next is true. */
 832static int flush_buffer(struct scsi_tape *STp, int seek_next)
 833{
 834	int backspace, result;
 835	struct st_partstat *STps;
 836
 837	if (STp->ready != ST_READY)
 838		return 0;
 839
 840	/*
 841	 * If there was a bus reset, block further access
 842	 * to this device.
 843	 */
 844	if (STp->pos_unknown)
 845		return (-EIO);
 846
 
 
 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				if (cmdstatp->sense_hdr.asc == 0x28) { /* New media */
 995					new_session = 1;
 996					DEBC_printk(STp, "New tape session.");
 997				}
 998				if (attentions < MAX_ATTENTIONS) {
 999					attentions++;
1000					continue;
1001				}
1002				else {
1003					retval = (-EIO);
1004					break;
1005				}
1006			}
1007
1008			if (scode == NOT_READY) {
1009				if (waits < max_wait) {
1010					if (msleep_interruptible(1000)) {
1011						retval = (-EINTR);
1012						break;
1013					}
1014					waits++;
1015					continue;
1016				}
1017				else {
1018					if ((STp->device)->scsi_level >= SCSI_2 &&
1019					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
1020						retval = CHKRES_NO_TAPE;
1021					else
1022						retval = CHKRES_NOT_READY;
1023					break;
1024				}
1025			}
1026		}
1027
1028		retval = (STp->buffer)->syscall_result;
1029		if (!retval)
1030			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
1031		break;
1032	}
1033	if (STp->first_tur) {
1034		/* Don't set pos_unknown right after device recognition */
1035		STp->pos_unknown = 0;
1036		STp->first_tur = 0;
1037	}
1038
1039	if (SRpnt != NULL)
1040		st_release_request(SRpnt);
1041	return retval;
1042}
1043
1044
1045/* See if the drive is ready and gather information about the tape. Return values:
1046   < 0   negative error code from errno.h
1047   0     drive ready
1048   1     drive not ready (possibly no tape)
1049*/
1050static int check_tape(struct scsi_tape *STp, struct file *filp)
1051{
1052	int i, retval, new_session = 0, do_wait;
1053	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
1054	unsigned short st_flags = filp->f_flags;
1055	struct st_request *SRpnt = NULL;
1056	struct st_modedef *STm;
1057	struct st_partstat *STps;
1058	struct inode *inode = file_inode(filp);
1059	int mode = TAPE_MODE(inode);
1060
1061	STp->ready = ST_READY;
1062
1063	if (mode != STp->current_mode) {
1064		DEBC_printk(STp, "Mode change from %d to %d.\n",
1065			    STp->current_mode, mode);
1066		new_session = 1;
1067		STp->current_mode = mode;
1068	}
1069	STm = &(STp->modes[STp->current_mode]);
1070
1071	saved_cleaning = STp->cleaning_req;
1072	STp->cleaning_req = 0;
1073
1074	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1075	retval = test_ready(STp, do_wait);
1076
1077	if (retval < 0)
1078	    goto err_out;
1079
1080	if (retval == CHKRES_NEW_SESSION) {
1081		STp->pos_unknown = 0;
1082		STp->partition = STp->new_partition = 0;
1083		if (STp->can_partitions)
1084			STp->nbr_partitions = 1; /* This guess will be updated later
1085                                                    if necessary */
1086		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1087			STps = &(STp->ps[i]);
1088			STps->rw = ST_IDLE;
1089			STps->eof = ST_NOEOF;
1090			STps->at_sm = 0;
1091			STps->last_block_valid = 0;
1092			STps->drv_block = 0;
1093			STps->drv_file = 0;
1094		}
1095		new_session = 1;
1096	}
1097	else {
1098		STp->cleaning_req |= saved_cleaning;
1099
1100		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1101			if (retval == CHKRES_NO_TAPE)
1102				STp->ready = ST_NO_TAPE;
1103			else
1104				STp->ready = ST_NOT_READY;
1105
1106			STp->density = 0;	/* Clear the erroneous "residue" */
1107			STp->write_prot = 0;
1108			STp->block_size = 0;
1109			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1110			STp->partition = STp->new_partition = 0;
1111			STp->door_locked = ST_UNLOCKED;
1112			return CHKRES_NOT_READY;
1113		}
1114	}
1115
1116	if (STp->omit_blklims)
1117		STp->min_block = STp->max_block = (-1);
1118	else {
1119		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1120		cmd[0] = READ_BLOCK_LIMITS;
1121
1122		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1123				   STp->device->request_queue->rq_timeout,
1124				   MAX_READY_RETRIES, 1);
1125		if (!SRpnt) {
1126			retval = (STp->buffer)->syscall_result;
1127			goto err_out;
1128		}
1129
1130		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1131			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1132			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1133			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1134			    (STp->buffer)->b_data[5];
1135			if ( DEB( debugging || ) !STp->inited)
1136				st_printk(KERN_INFO, STp,
1137					  "Block limits %d - %d bytes.\n",
1138					  STp->min_block, STp->max_block);
1139		} else {
1140			STp->min_block = STp->max_block = (-1);
1141			DEBC_printk(STp, "Can't read block limits.\n");
1142		}
1143	}
1144
1145	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1146	cmd[0] = MODE_SENSE;
1147	cmd[4] = 12;
1148
1149	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1150			   STp->device->request_queue->rq_timeout,
1151			   MAX_READY_RETRIES, 1);
1152	if (!SRpnt) {
1153		retval = (STp->buffer)->syscall_result;
1154		goto err_out;
1155	}
1156
1157	if ((STp->buffer)->syscall_result != 0) {
1158		DEBC_printk(STp, "No Mode Sense.\n");
1159		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1160		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1161		STp->drv_write_prot = 0;
1162	} else {
1163		DEBC_printk(STp,"Mode sense. Length %d, "
1164			    "medium %x, WBS %x, BLL %d\n",
1165			    (STp->buffer)->b_data[0],
1166			    (STp->buffer)->b_data[1],
1167			    (STp->buffer)->b_data[2],
1168			    (STp->buffer)->b_data[3]);
1169
1170		if ((STp->buffer)->b_data[3] >= 8) {
1171			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1172			STp->density = (STp->buffer)->b_data[4];
1173			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1174			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1175			DEBC_printk(STp, "Density %x, tape length: %x, "
1176				    "drv buffer: %d\n",
1177				    STp->density,
1178				    (STp->buffer)->b_data[5] * 65536 +
1179				    (STp->buffer)->b_data[6] * 256 +
1180				    (STp->buffer)->b_data[7],
1181				    STp->drv_buffer);
1182		}
1183		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1184		if (!STp->drv_buffer && STp->immediate_filemark) {
1185			st_printk(KERN_WARNING, STp,
1186				  "non-buffered tape: disabling "
1187				  "writing immediate filemarks\n");
1188			STp->immediate_filemark = 0;
1189		}
1190	}
1191	st_release_request(SRpnt);
1192	SRpnt = NULL;
1193	STp->inited = 1;
1194
1195	if (STp->block_size > 0)
1196		(STp->buffer)->buffer_blocks =
1197			(STp->buffer)->buffer_size / STp->block_size;
1198	else
1199		(STp->buffer)->buffer_blocks = 1;
1200	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1201
1202	DEBC_printk(STp, "Block size: %d, buffer size: %d (%d blocks).\n",
1203		    STp->block_size, (STp->buffer)->buffer_size,
1204		    (STp->buffer)->buffer_blocks);
1205
1206	if (STp->drv_write_prot) {
1207		STp->write_prot = 1;
1208
1209		DEBC_printk(STp, "Write protected\n");
1210
1211		if (do_wait &&
1212		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1213		     (st_flags & O_ACCMODE) == O_RDWR)) {
1214			retval = (-EROFS);
1215			goto err_out;
1216		}
1217	}
1218
1219	if (STp->can_partitions && STp->nbr_partitions < 1) {
1220		/* This code is reached when the device is opened for the first time
1221		   after the driver has been initialized with tape in the drive and the
1222		   partition support has been enabled. */
1223		DEBC_printk(STp, "Updating partition number in status.\n");
1224		if ((STp->partition = find_partition(STp)) < 0) {
1225			retval = STp->partition;
1226			goto err_out;
1227		}
1228		STp->new_partition = STp->partition;
1229		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1230	}
1231
1232	if (new_session) {	/* Change the drive parameters for the new mode */
1233		STp->density_changed = STp->blksize_changed = 0;
1234		STp->compression_changed = 0;
1235		if (!(STm->defaults_for_writes) &&
1236		    (retval = set_mode_densblk(STp, STm)) < 0)
1237		    goto err_out;
1238
1239		if (STp->default_drvbuffer != 0xff) {
1240			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1241				st_printk(KERN_WARNING, STp,
1242					  "Can't set default drive "
1243					  "buffering to %d.\n",
1244					  STp->default_drvbuffer);
1245		}
1246	}
1247
1248	return CHKRES_READY;
1249
1250 err_out:
1251	return retval;
1252}
1253
1254
1255/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1256   module count. */
1257static int st_open(struct inode *inode, struct file *filp)
1258{
1259	int i, retval = (-EIO);
1260	int resumed = 0;
1261	struct scsi_tape *STp;
1262	struct st_partstat *STps;
1263	int dev = TAPE_NR(inode);
1264
1265	/*
1266	 * We really want to do nonseekable_open(inode, filp); here, but some
1267	 * versions of tar incorrectly call lseek on tapes and bail out if that
1268	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1269	 */
1270	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1271
1272	if (!(STp = scsi_tape_get(dev))) {
1273		return -ENXIO;
1274	}
1275
1276	filp->private_data = STp;
1277
1278	spin_lock(&st_use_lock);
1279	if (STp->in_use) {
1280		spin_unlock(&st_use_lock);
1281		DEBC_printk(STp, "Device already in use.\n");
1282		scsi_tape_put(STp);
 
1283		return (-EBUSY);
1284	}
1285
1286	STp->in_use = 1;
1287	spin_unlock(&st_use_lock);
1288	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1289
1290	if (scsi_autopm_get_device(STp->device) < 0) {
1291		retval = -EIO;
1292		goto err_out;
1293	}
1294	resumed = 1;
1295	if (!scsi_block_when_processing_errors(STp->device)) {
1296		retval = (-ENXIO);
1297		goto err_out;
1298	}
1299
1300	/* See that we have at least a one page buffer available */
1301	if (!enlarge_buffer(STp->buffer, PAGE_SIZE)) {
1302		st_printk(KERN_WARNING, STp,
1303			  "Can't allocate one page tape buffer.\n");
1304		retval = (-EOVERFLOW);
1305		goto err_out;
1306	}
1307
1308	(STp->buffer)->cleared = 0;
1309	(STp->buffer)->writing = 0;
1310	(STp->buffer)->syscall_result = 0;
1311
1312	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1313
1314	STp->dirty = 0;
1315	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1316		STps = &(STp->ps[i]);
1317		STps->rw = ST_IDLE;
1318	}
1319	STp->try_dio_now = STp->try_dio;
1320	STp->recover_count = 0;
1321	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1322	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1323
1324	retval = check_tape(STp, filp);
1325	if (retval < 0)
1326		goto err_out;
1327	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1328	    retval != CHKRES_READY) {
1329		if (STp->ready == NO_TAPE)
1330			retval = (-ENOMEDIUM);
1331		else
1332			retval = (-EIO);
1333		goto err_out;
1334	}
1335	return 0;
1336
1337 err_out:
1338	normalize_buffer(STp->buffer);
1339	spin_lock(&st_use_lock);
1340	STp->in_use = 0;
1341	spin_unlock(&st_use_lock);
1342	if (resumed)
1343		scsi_autopm_put_device(STp->device);
1344	scsi_tape_put(STp);
1345	return retval;
1346
1347}
1348
1349
1350/* Flush the tape buffer before close */
1351static int st_flush(struct file *filp, fl_owner_t id)
1352{
1353	int result = 0, result2;
1354	unsigned char cmd[MAX_COMMAND_SIZE];
1355	struct st_request *SRpnt;
1356	struct scsi_tape *STp = filp->private_data;
1357	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1358	struct st_partstat *STps = &(STp->ps[STp->partition]);
1359
1360	if (file_count(filp) > 1)
1361		return 0;
1362
1363	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1364		result = st_flush_write_buffer(STp);
1365		if (result != 0 && result != (-ENOSPC))
1366			goto out;
1367	}
1368
1369	if (STp->can_partitions &&
1370	    (result2 = switch_partition(STp)) < 0) {
1371		DEBC_printk(STp, "switch_partition at close failed.\n");
1372		if (result == 0)
1373			result = result2;
1374		goto out;
1375	}
1376
1377	DEBC( if (STp->nbr_requests)
1378		st_printk(KERN_DEBUG, STp,
1379			  "Number of r/w requests %d, dio used in %d, "
1380			  "pages %d.\n", STp->nbr_requests, STp->nbr_dio,
1381			  STp->nbr_pages));
1382
1383	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1384		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1385
1386#if DEBUG
1387		DEBC_printk(STp, "Async write waits %d, finished %d.\n",
1388			    STp->nbr_waits, STp->nbr_finished);
1389#endif
1390		memset(cmd, 0, MAX_COMMAND_SIZE);
1391		cmd[0] = WRITE_FILEMARKS;
1392		if (STp->immediate_filemark)
1393			cmd[1] = 1;
1394		cmd[4] = 1 + STp->two_fm;
1395
1396		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1397				   STp->device->request_queue->rq_timeout,
1398				   MAX_WRITE_RETRIES, 1);
1399		if (!SRpnt) {
1400			result = (STp->buffer)->syscall_result;
1401			goto out;
1402		}
1403
1404		if (STp->buffer->syscall_result == 0 ||
1405		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1406		     (cmdstatp->flags & SENSE_EOM) &&
1407		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1408		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1409		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1410			/* Write successful at EOM */
1411			st_release_request(SRpnt);
1412			SRpnt = NULL;
1413			if (STps->drv_file >= 0)
1414				STps->drv_file++;
1415			STps->drv_block = 0;
1416			if (STp->two_fm)
1417				cross_eof(STp, 0);
1418			STps->eof = ST_FM;
1419		}
1420		else { /* Write error */
1421			st_release_request(SRpnt);
1422			SRpnt = NULL;
1423			st_printk(KERN_ERR, STp,
1424				  "Error on write filemark.\n");
1425			if (result == 0)
1426				result = (-EIO);
1427		}
1428
1429		DEBC_printk(STp, "Buffer flushed, %d EOF(s) written\n", cmd[4]);
1430	} else if (!STp->rew_at_close) {
1431		STps = &(STp->ps[STp->partition]);
1432		if (!STm->sysv || STps->rw != ST_READING) {
1433			if (STp->can_bsr)
1434				result = flush_buffer(STp, 0);
1435			else if (STps->eof == ST_FM_HIT) {
1436				result = cross_eof(STp, 0);
1437				if (result) {
1438					if (STps->drv_file >= 0)
1439						STps->drv_file++;
1440					STps->drv_block = 0;
1441					STps->eof = ST_FM;
1442				} else
1443					STps->eof = ST_NOEOF;
1444			}
1445		} else if ((STps->eof == ST_NOEOF &&
1446			    !(result = cross_eof(STp, 1))) ||
1447			   STps->eof == ST_FM_HIT) {
1448			if (STps->drv_file >= 0)
1449				STps->drv_file++;
1450			STps->drv_block = 0;
1451			STps->eof = ST_FM;
1452		}
1453	}
1454
1455      out:
1456	if (STp->rew_at_close) {
1457		result2 = st_int_ioctl(STp, MTREW, 1);
1458		if (result == 0)
1459			result = result2;
1460	}
1461	return result;
1462}
1463
1464
1465/* Close the device and release it. BKL is not needed: this is the only thread
1466   accessing this tape. */
1467static int st_release(struct inode *inode, struct file *filp)
1468{
1469	struct scsi_tape *STp = filp->private_data;
1470
1471	if (STp->door_locked == ST_LOCKED_AUTO)
1472		do_door_lock(STp, 0);
1473
1474	normalize_buffer(STp->buffer);
1475	spin_lock(&st_use_lock);
1476	STp->in_use = 0;
1477	spin_unlock(&st_use_lock);
1478	scsi_autopm_put_device(STp->device);
1479	scsi_tape_put(STp);
1480
1481	return 0;
1482}
1483
1484/* The checks common to both reading and writing */
1485static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1486{
1487	ssize_t retval = 0;
1488
1489	/*
1490	 * If we are in the middle of error recovery, don't let anyone
1491	 * else try and use this device.  Also, if error recovery fails, it
1492	 * may try and take the device offline, in which case all further
1493	 * access to the device is prohibited.
1494	 */
1495	if (!scsi_block_when_processing_errors(STp->device)) {
1496		retval = (-ENXIO);
1497		goto out;
1498	}
1499
1500	if (STp->ready != ST_READY) {
1501		if (STp->ready == ST_NO_TAPE)
1502			retval = (-ENOMEDIUM);
1503		else
1504			retval = (-EIO);
1505		goto out;
1506	}
1507
1508	if (! STp->modes[STp->current_mode].defined) {
1509		retval = (-ENXIO);
1510		goto out;
1511	}
1512
1513
1514	/*
1515	 * If there was a bus reset, block further access
1516	 * to this device.
1517	 */
1518	if (STp->pos_unknown) {
1519		retval = (-EIO);
1520		goto out;
1521	}
1522
1523	if (count == 0)
1524		goto out;
1525
1526	DEB(
1527	if (!STp->in_use) {
1528		st_printk(ST_DEB_MSG, STp,
1529			  "Incorrect device.\n");
1530		retval = (-EIO);
1531		goto out;
1532	} ) /* end DEB */
1533
1534	if (STp->can_partitions &&
1535	    (retval = switch_partition(STp)) < 0)
1536		goto out;
1537
1538	if (STp->block_size == 0 && STp->max_block > 0 &&
1539	    (count < STp->min_block || count > STp->max_block)) {
1540		retval = (-EINVAL);
1541		goto out;
1542	}
1543
1544	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1545	    !do_door_lock(STp, 1))
1546		STp->door_locked = ST_LOCKED_AUTO;
1547
1548 out:
1549	return retval;
1550}
1551
1552
1553static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1554			   size_t count, int is_read)
1555{
1556	int i, bufsize, retval = 0;
1557	struct st_buffer *STbp = STp->buffer;
1558
1559	if (is_read)
1560		i = STp->try_dio_now && try_rdio;
1561	else
1562		i = STp->try_dio_now && try_wdio;
1563
1564	if (i && ((unsigned long)buf & queue_dma_alignment(
1565					STp->device->request_queue)) == 0) {
1566		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1567				       count, (is_read ? READ : WRITE));
1568		if (i > 0) {
1569			STbp->do_dio = i;
1570			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1571		}
1572		else
1573			STbp->do_dio = 0;  /* fall back to buffering with any error */
1574		STbp->sg_segs = STbp->do_dio;
1575		DEB(
1576		     if (STbp->do_dio) {
1577			STp->nbr_dio++;
1578			STp->nbr_pages += STbp->do_dio;
1579		     }
1580		)
1581	} else
1582		STbp->do_dio = 0;
1583	DEB( STp->nbr_requests++; )
1584
1585	if (!STbp->do_dio) {
1586		if (STp->block_size)
1587			bufsize = STp->block_size > st_fixed_buffer_size ?
1588				STp->block_size : st_fixed_buffer_size;
1589		else {
1590			bufsize = count;
1591			/* Make sure that data from previous user is not leaked even if
1592			   HBA does not return correct residual */
1593			if (is_read && STp->sili && !STbp->cleared)
1594				clear_buffer(STbp);
1595		}
1596
1597		if (bufsize > STbp->buffer_size &&
1598		    !enlarge_buffer(STbp, bufsize)) {
1599			st_printk(KERN_WARNING, STp,
1600				  "Can't allocate %d byte tape buffer.\n",
1601				  bufsize);
1602			retval = (-EOVERFLOW);
1603			goto out;
1604		}
1605		if (STp->block_size)
1606			STbp->buffer_blocks = bufsize / STp->block_size;
1607	}
1608
1609 out:
1610	return retval;
1611}
1612
1613
1614/* Can be called more than once after each setup_buffer() */
1615static void release_buffering(struct scsi_tape *STp, int is_read)
1616{
1617	struct st_buffer *STbp;
1618
1619	STbp = STp->buffer;
1620	if (STbp->do_dio) {
1621		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1622		STbp->do_dio = 0;
1623		STbp->sg_segs = 0;
1624	}
1625}
1626
1627
1628/* Write command */
1629static ssize_t
1630st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1631{
1632	ssize_t total;
1633	ssize_t i, do_count, blks, transfer;
1634	ssize_t retval;
1635	int undone, retry_eot = 0, scode;
1636	int async_write;
1637	unsigned char cmd[MAX_COMMAND_SIZE];
1638	const char __user *b_point;
1639	struct st_request *SRpnt = NULL;
1640	struct scsi_tape *STp = filp->private_data;
1641	struct st_modedef *STm;
1642	struct st_partstat *STps;
1643	struct st_buffer *STbp;
1644
1645	if (mutex_lock_interruptible(&STp->lock))
1646		return -ERESTARTSYS;
1647
1648	retval = rw_checks(STp, filp, count);
1649	if (retval || count == 0)
1650		goto out;
1651
1652	/* Write must be integral number of blocks */
1653	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1654		st_printk(KERN_WARNING, STp,
1655			  "Write not multiple of tape block size.\n");
1656		retval = (-EINVAL);
1657		goto out;
1658	}
1659
1660	STm = &(STp->modes[STp->current_mode]);
1661	STps = &(STp->ps[STp->partition]);
1662
1663	if (STp->write_prot) {
1664		retval = (-EACCES);
1665		goto out;
1666	}
1667
1668
1669	if (STps->rw == ST_READING) {
1670		retval = flush_buffer(STp, 0);
1671		if (retval)
1672			goto out;
1673		STps->rw = ST_WRITING;
1674	} else if (STps->rw != ST_WRITING &&
1675		   STps->drv_file == 0 && STps->drv_block == 0) {
1676		if ((retval = set_mode_densblk(STp, STm)) < 0)
1677			goto out;
1678		if (STm->default_compression != ST_DONT_TOUCH &&
1679		    !(STp->compression_changed)) {
1680			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1681				st_printk(KERN_WARNING, STp,
1682					  "Can't set default compression.\n");
1683				if (modes_defined) {
1684					retval = (-EINVAL);
1685					goto out;
1686				}
1687			}
1688		}
1689	}
1690
1691	STbp = STp->buffer;
1692	i = write_behind_check(STp);
1693	if (i) {
1694		if (i == -ENOSPC)
1695			STps->eof = ST_EOM_OK;
1696		else
1697			STps->eof = ST_EOM_ERROR;
1698	}
1699
1700	if (STps->eof == ST_EOM_OK) {
1701		STps->eof = ST_EOD_1;  /* allow next write */
1702		retval = (-ENOSPC);
1703		goto out;
1704	}
1705	else if (STps->eof == ST_EOM_ERROR) {
1706		retval = (-EIO);
1707		goto out;
1708	}
1709
1710	/* Check the buffer readability in cases where copy_user might catch
1711	   the problems after some tape movement. */
1712	if (STp->block_size != 0 &&
1713	    !STbp->do_dio &&
1714	    (copy_from_user(&i, buf, 1) != 0 ||
1715	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1716		retval = (-EFAULT);
1717		goto out;
1718	}
1719
1720	retval = setup_buffering(STp, buf, count, 0);
1721	if (retval)
1722		goto out;
1723
1724	total = count;
1725
1726	memset(cmd, 0, MAX_COMMAND_SIZE);
1727	cmd[0] = WRITE_6;
1728	cmd[1] = (STp->block_size != 0);
1729
1730	STps->rw = ST_WRITING;
1731
1732	b_point = buf;
1733	while (count > 0 && !retry_eot) {
1734
1735		if (STbp->do_dio) {
1736			do_count = count;
1737		}
1738		else {
1739			if (STp->block_size == 0)
1740				do_count = count;
1741			else {
1742				do_count = STbp->buffer_blocks * STp->block_size -
1743					STbp->buffer_bytes;
1744				if (do_count > count)
1745					do_count = count;
1746			}
1747
1748			i = append_to_buffer(b_point, STbp, do_count);
1749			if (i) {
1750				retval = i;
1751				goto out;
1752			}
1753		}
1754		count -= do_count;
1755		b_point += do_count;
1756
1757		async_write = STp->block_size == 0 && !STbp->do_dio &&
1758			STm->do_async_writes && STps->eof < ST_EOM_OK;
1759
1760		if (STp->block_size != 0 && STm->do_buffer_writes &&
1761		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1762		    STbp->buffer_bytes < STbp->buffer_size) {
1763			STp->dirty = 1;
1764			/* Don't write a buffer that is not full enough. */
1765			if (!async_write && count == 0)
1766				break;
1767		}
1768
1769	retry_write:
1770		if (STp->block_size == 0)
1771			blks = transfer = do_count;
1772		else {
1773			if (!STbp->do_dio)
1774				blks = STbp->buffer_bytes;
1775			else
1776				blks = do_count;
1777			blks /= STp->block_size;
1778			transfer = blks * STp->block_size;
1779		}
1780		cmd[2] = blks >> 16;
1781		cmd[3] = blks >> 8;
1782		cmd[4] = blks;
1783
1784		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1785				   STp->device->request_queue->rq_timeout,
1786				   MAX_WRITE_RETRIES, !async_write);
1787		if (!SRpnt) {
1788			retval = STbp->syscall_result;
1789			goto out;
1790		}
1791		if (async_write && !STbp->syscall_result) {
1792			STbp->writing = transfer;
1793			STp->dirty = !(STbp->writing ==
1794				       STbp->buffer_bytes);
1795			SRpnt = NULL;  /* Prevent releasing this request! */
1796			DEB( STp->write_pending = 1; )
1797			break;
1798		}
1799
1800		if (STbp->syscall_result != 0) {
1801			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1802
1803			DEBC_printk(STp, "Error on write:\n");
1804			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1805				scode = cmdstatp->sense_hdr.sense_key;
1806				if (cmdstatp->remainder_valid)
1807					undone = (int)cmdstatp->uremainder64;
1808				else if (STp->block_size == 0 &&
1809					 scode == VOLUME_OVERFLOW)
1810					undone = transfer;
1811				else
1812					undone = 0;
1813				if (STp->block_size != 0)
1814					undone *= STp->block_size;
1815				if (undone <= do_count) {
1816					/* Only data from this write is not written */
1817					count += undone;
1818					b_point -= undone;
1819					do_count -= undone;
1820					if (STp->block_size)
1821						blks = (transfer - undone) / STp->block_size;
1822					STps->eof = ST_EOM_OK;
1823					/* Continue in fixed block mode if all written
1824					   in this request but still something left to write
1825					   (retval left to zero)
1826					*/
1827					if (STp->block_size == 0 ||
1828					    undone > 0 || count == 0)
1829						retval = (-ENOSPC); /* EOM within current request */
1830					DEBC_printk(STp, "EOM with %d "
1831						    "bytes unwritten.\n",
1832						    (int)count);
1833				} else {
1834					/* EOT within data buffered earlier (possible only
1835					   in fixed block mode without direct i/o) */
1836					if (!retry_eot && !cmdstatp->deferred &&
1837					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1838						move_buffer_data(STp->buffer, transfer - undone);
1839						retry_eot = 1;
1840						if (STps->drv_block >= 0) {
1841							STps->drv_block += (transfer - undone) /
1842								STp->block_size;
1843						}
1844						STps->eof = ST_EOM_OK;
1845						DEBC_printk(STp, "Retry "
1846							    "write of %d "
1847							    "bytes at EOM.\n",
1848							    STp->buffer->buffer_bytes);
1849						goto retry_write;
1850					}
1851					else {
1852						/* Either error within data buffered by driver or
1853						   failed retry */
1854						count -= do_count;
1855						blks = do_count = 0;
1856						STps->eof = ST_EOM_ERROR;
1857						STps->drv_block = (-1); /* Too cautious? */
1858						retval = (-EIO);	/* EOM for old data */
1859						DEBC_printk(STp, "EOM with "
1860							    "lost data.\n");
1861					}
1862				}
1863			} else {
1864				count += do_count;
1865				STps->drv_block = (-1);		/* Too cautious? */
1866				retval = STbp->syscall_result;
1867			}
1868
1869		}
1870
1871		if (STps->drv_block >= 0) {
1872			if (STp->block_size == 0)
1873				STps->drv_block += (do_count > 0);
1874			else
1875				STps->drv_block += blks;
1876		}
1877
1878		STbp->buffer_bytes = 0;
1879		STp->dirty = 0;
1880
1881		if (retval || retry_eot) {
1882			if (count < total)
1883				retval = total - count;
1884			goto out;
1885		}
1886	}
1887
1888	if (STps->eof == ST_EOD_1)
1889		STps->eof = ST_EOM_OK;
1890	else if (STps->eof != ST_EOM_OK)
1891		STps->eof = ST_NOEOF;
1892	retval = total - count;
1893
1894 out:
1895	if (SRpnt != NULL)
1896		st_release_request(SRpnt);
1897	release_buffering(STp, 0);
1898	mutex_unlock(&STp->lock);
1899
1900	return retval;
1901}
1902
1903/* Read data from the tape. Returns zero in the normal case, one if the
1904   eof status has changed, and the negative error code in case of a
1905   fatal error. Otherwise updates the buffer and the eof state.
1906
1907   Does release user buffer mapping if it is set.
1908*/
1909static long read_tape(struct scsi_tape *STp, long count,
1910		      struct st_request ** aSRpnt)
1911{
1912	int transfer, blks, bytes;
1913	unsigned char cmd[MAX_COMMAND_SIZE];
1914	struct st_request *SRpnt;
1915	struct st_modedef *STm;
1916	struct st_partstat *STps;
1917	struct st_buffer *STbp;
1918	int retval = 0;
1919
1920	if (count == 0)
1921		return 0;
1922
1923	STm = &(STp->modes[STp->current_mode]);
1924	STps = &(STp->ps[STp->partition]);
1925	if (STps->eof == ST_FM_HIT)
1926		return 1;
1927	STbp = STp->buffer;
1928
1929	if (STp->block_size == 0)
1930		blks = bytes = count;
1931	else {
1932		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1933			blks = (STp->buffer)->buffer_blocks;
1934			bytes = blks * STp->block_size;
1935		} else {
1936			bytes = count;
1937			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1938				bytes = (STp->buffer)->buffer_size;
1939			blks = bytes / STp->block_size;
1940			bytes = blks * STp->block_size;
1941		}
1942	}
1943
1944	memset(cmd, 0, MAX_COMMAND_SIZE);
1945	cmd[0] = READ_6;
1946	cmd[1] = (STp->block_size != 0);
1947	if (!cmd[1] && STp->sili)
1948		cmd[1] |= 2;
1949	cmd[2] = blks >> 16;
1950	cmd[3] = blks >> 8;
1951	cmd[4] = blks;
1952
1953	SRpnt = *aSRpnt;
1954	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1955			   STp->device->request_queue->rq_timeout,
1956			   MAX_RETRIES, 1);
1957	release_buffering(STp, 1);
1958	*aSRpnt = SRpnt;
1959	if (!SRpnt)
1960		return STbp->syscall_result;
1961
1962	STbp->read_pointer = 0;
1963	STps->at_sm = 0;
1964
1965	/* Something to check */
1966	if (STbp->syscall_result) {
1967		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1968
1969		retval = 1;
1970		DEBC_printk(STp,
1971			    "Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1972			    SRpnt->sense[0], SRpnt->sense[1],
1973			    SRpnt->sense[2], SRpnt->sense[3],
1974			    SRpnt->sense[4], SRpnt->sense[5],
1975			    SRpnt->sense[6], SRpnt->sense[7]);
1976		if (cmdstatp->have_sense) {
1977
1978			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1979				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1980
1981			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1982				/* Compute the residual count */
1983				if (cmdstatp->remainder_valid)
1984					transfer = (int)cmdstatp->uremainder64;
1985				else
1986					transfer = 0;
1987				if (cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR) {
1988					if (STp->block_size == 0)
1989						transfer = bytes;
1990					/* Some drives set ILI with MEDIUM ERROR */
1991					cmdstatp->flags &= ~SENSE_ILI;
1992				}
1993
1994				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1995					if (STp->block_size == 0 &&
1996					    transfer < 0) {
1997						st_printk(KERN_NOTICE, STp,
1998							  "Failed to read %d "
1999							  "byte block with %d "
2000							  "byte transfer.\n",
2001							  bytes - transfer,
2002							  bytes);
2003						if (STps->drv_block >= 0)
2004							STps->drv_block += 1;
2005						STbp->buffer_bytes = 0;
2006						return (-ENOMEM);
2007					} else if (STp->block_size == 0) {
2008						STbp->buffer_bytes = bytes - transfer;
2009					} else {
2010						st_release_request(SRpnt);
2011						SRpnt = *aSRpnt = NULL;
2012						if (transfer == blks) {	/* We did not get anything, error */
2013							st_printk(KERN_NOTICE, STp,
2014								  "Incorrect "
2015								  "block size.\n");
2016							if (STps->drv_block >= 0)
2017								STps->drv_block += blks - transfer + 1;
2018							st_int_ioctl(STp, MTBSR, 1);
2019							return (-EIO);
2020						}
2021						/* We have some data, deliver it */
2022						STbp->buffer_bytes = (blks - transfer) *
2023						    STp->block_size;
2024						DEBC_printk(STp, "ILI but "
2025							    "enough data "
2026							    "received %ld "
2027							    "%d.\n", count,
2028							    STbp->buffer_bytes);
2029						if (STps->drv_block >= 0)
2030							STps->drv_block += 1;
2031						if (st_int_ioctl(STp, MTBSR, 1))
2032							return (-EIO);
2033					}
2034				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
2035					if (STps->eof != ST_FM_HIT)
2036						STps->eof = ST_FM_HIT;
2037					else
2038						STps->eof = ST_EOD_2;
2039					if (STp->block_size == 0)
2040						STbp->buffer_bytes = 0;
2041					else
2042						STbp->buffer_bytes =
2043						    bytes - transfer * STp->block_size;
2044					DEBC_printk(STp, "EOF detected (%d "
2045						    "bytes read).\n",
2046						    STbp->buffer_bytes);
2047				} else if (cmdstatp->flags & SENSE_EOM) {
2048					if (STps->eof == ST_FM)
2049						STps->eof = ST_EOD_1;
2050					else
2051						STps->eof = ST_EOM_OK;
2052					if (STp->block_size == 0)
2053						STbp->buffer_bytes = bytes - transfer;
2054					else
2055						STbp->buffer_bytes =
2056						    bytes - transfer * STp->block_size;
2057
2058					DEBC_printk(STp, "EOM detected (%d "
2059						    "bytes read).\n",
2060						    STbp->buffer_bytes);
2061				}
2062			}
2063			/* end of EOF, EOM, ILI test */
2064			else {	/* nonzero sense key */
2065				DEBC_printk(STp, "Tape error while reading.\n");
2066				STps->drv_block = (-1);
2067				if (STps->eof == ST_FM &&
2068				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
2069					DEBC_printk(STp, "Zero returned for "
2070						    "first BLANK CHECK "
2071						    "after EOF.\n");
2072					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
2073				} else	/* Some other extended sense code */
2074					retval = (-EIO);
2075			}
2076
2077			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
2078				STbp->buffer_bytes = 0;
2079		}
2080		/* End of extended sense test */
2081		else {		/* Non-extended sense */
2082			retval = STbp->syscall_result;
2083		}
2084
2085	}
2086	/* End of error handling */
2087	else {			/* Read successful */
2088		STbp->buffer_bytes = bytes;
2089		if (STp->sili) /* In fixed block mode residual is always zero here */
2090			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
2091	}
2092
2093	if (STps->drv_block >= 0) {
2094		if (STp->block_size == 0)
2095			STps->drv_block++;
2096		else
2097			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2098	}
2099	return retval;
2100}
2101
2102
2103/* Read command */
2104static ssize_t
2105st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2106{
2107	ssize_t total;
2108	ssize_t retval = 0;
2109	ssize_t i, transfer;
2110	int special, do_dio = 0;
2111	struct st_request *SRpnt = NULL;
2112	struct scsi_tape *STp = filp->private_data;
2113	struct st_modedef *STm;
2114	struct st_partstat *STps;
2115	struct st_buffer *STbp = STp->buffer;
2116
2117	if (mutex_lock_interruptible(&STp->lock))
2118		return -ERESTARTSYS;
2119
2120	retval = rw_checks(STp, filp, count);
2121	if (retval || count == 0)
2122		goto out;
2123
2124	STm = &(STp->modes[STp->current_mode]);
2125	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2126		if (!STm->do_read_ahead) {
2127			retval = (-EINVAL);	/* Read must be integral number of blocks */
2128			goto out;
2129		}
2130		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2131	}
2132
2133	STps = &(STp->ps[STp->partition]);
2134	if (STps->rw == ST_WRITING) {
2135		retval = flush_buffer(STp, 0);
2136		if (retval)
2137			goto out;
2138		STps->rw = ST_READING;
2139	}
2140	DEB(
2141	if (debugging && STps->eof != ST_NOEOF)
2142		st_printk(ST_DEB_MSG, STp,
2143			  "EOF/EOM flag up (%d). Bytes %d\n",
2144			  STps->eof, STbp->buffer_bytes);
2145	) /* end DEB */
2146
2147	retval = setup_buffering(STp, buf, count, 1);
2148	if (retval)
2149		goto out;
2150	do_dio = STbp->do_dio;
2151
2152	if (STbp->buffer_bytes == 0 &&
2153	    STps->eof >= ST_EOD_1) {
2154		if (STps->eof < ST_EOD) {
2155			STps->eof += 1;
2156			retval = 0;
2157			goto out;
2158		}
2159		retval = (-EIO);	/* EOM or Blank Check */
2160		goto out;
2161	}
2162
2163	if (do_dio) {
2164		/* Check the buffer writability before any tape movement. Don't alter
2165		   buffer data. */
2166		if (copy_from_user(&i, buf, 1) != 0 ||
2167		    copy_to_user(buf, &i, 1) != 0 ||
2168		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2169		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2170			retval = (-EFAULT);
2171			goto out;
2172		}
2173	}
2174
2175	STps->rw = ST_READING;
2176
2177
2178	/* Loop until enough data in buffer or a special condition found */
2179	for (total = 0, special = 0; total < count && !special;) {
2180
2181		/* Get new data if the buffer is empty */
2182		if (STbp->buffer_bytes == 0) {
2183			special = read_tape(STp, count - total, &SRpnt);
2184			if (special < 0) {	/* No need to continue read */
2185				retval = special;
2186				goto out;
2187			}
2188		}
2189
2190		/* Move the data from driver buffer to user buffer */
2191		if (STbp->buffer_bytes > 0) {
2192			DEB(
2193			if (debugging && STps->eof != ST_NOEOF)
2194				st_printk(ST_DEB_MSG, STp,
2195					  "EOF up (%d). Left %d, needed %d.\n",
2196					  STps->eof, STbp->buffer_bytes,
2197					  (int)(count - total));
2198			) /* end DEB */
2199			transfer = STbp->buffer_bytes < count - total ?
2200			    STbp->buffer_bytes : count - total;
2201			if (!do_dio) {
2202				i = from_buffer(STbp, buf, transfer);
2203				if (i) {
2204					retval = i;
2205					goto out;
2206				}
2207			}
2208			buf += transfer;
2209			total += transfer;
2210		}
2211
2212		if (STp->block_size == 0)
2213			break;	/* Read only one variable length block */
2214
2215	}			/* for (total = 0, special = 0;
2216                                   total < count && !special; ) */
2217
2218	/* Change the eof state if no data from tape or buffer */
2219	if (total == 0) {
2220		if (STps->eof == ST_FM_HIT) {
2221			STps->eof = ST_FM;
2222			STps->drv_block = 0;
2223			if (STps->drv_file >= 0)
2224				STps->drv_file++;
2225		} else if (STps->eof == ST_EOD_1) {
2226			STps->eof = ST_EOD_2;
2227			STps->drv_block = 0;
2228			if (STps->drv_file >= 0)
2229				STps->drv_file++;
2230		} else if (STps->eof == ST_EOD_2)
2231			STps->eof = ST_EOD;
2232	} else if (STps->eof == ST_FM)
2233		STps->eof = ST_NOEOF;
2234	retval = total;
2235
2236 out:
2237	if (SRpnt != NULL) {
2238		st_release_request(SRpnt);
2239		SRpnt = NULL;
2240	}
2241	if (do_dio) {
2242		release_buffering(STp, 1);
2243		STbp->buffer_bytes = 0;
2244	}
2245	mutex_unlock(&STp->lock);
2246
2247	return retval;
2248}
2249
2250
2251
2252DEB(
2253/* Set the driver options */
2254static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm)
2255{
2256	if (debugging) {
2257		st_printk(KERN_INFO, STp,
2258			  "Mode %d options: buffer writes: %d, "
2259			  "async writes: %d, read ahead: %d\n",
2260			  STp->current_mode, STm->do_buffer_writes,
2261			  STm->do_async_writes, STm->do_read_ahead);
2262		st_printk(KERN_INFO, STp,
2263			  "    can bsr: %d, two FMs: %d, "
2264			  "fast mteom: %d, auto lock: %d,\n",
2265			  STp->can_bsr, STp->two_fm, STp->fast_mteom,
2266			  STp->do_auto_lock);
2267		st_printk(KERN_INFO, STp,
2268			  "    defs for wr: %d, no block limits: %d, "
2269			  "partitions: %d, s2 log: %d\n",
2270			  STm->defaults_for_writes, STp->omit_blklims,
2271			  STp->can_partitions, STp->scsi2_logical);
2272		st_printk(KERN_INFO, STp,
2273			  "    sysv: %d nowait: %d sili: %d "
2274			  "nowait_filemark: %d\n",
2275			  STm->sysv, STp->immediate, STp->sili,
2276			  STp->immediate_filemark);
2277		st_printk(KERN_INFO, STp, "    debugging: %d\n", debugging);
2278	}
2279}
2280	)
2281
2282
2283static int st_set_options(struct scsi_tape *STp, long options)
2284{
2285	int value;
2286	long code;
2287	struct st_modedef *STm;
2288	struct cdev *cd0, *cd1;
2289	struct device *d0, *d1;
2290
2291	STm = &(STp->modes[STp->current_mode]);
2292	if (!STm->defined) {
2293		cd0 = STm->cdevs[0];
2294		cd1 = STm->cdevs[1];
2295		d0  = STm->devs[0];
2296		d1  = STm->devs[1];
2297		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2298		STm->cdevs[0] = cd0;
2299		STm->cdevs[1] = cd1;
2300		STm->devs[0]  = d0;
2301		STm->devs[1]  = d1;
2302		modes_defined = 1;
2303		DEBC_printk(STp, "Initialized mode %d definition from mode 0\n",
2304			    STp->current_mode);
2305	}
2306
2307	code = options & MT_ST_OPTIONS;
2308	if (code == MT_ST_BOOLEANS) {
2309		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2310		STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2311		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2312		STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2313		STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2314		STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2315		STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2316		STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2317		STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2318		if ((STp->device)->scsi_level >= SCSI_2)
2319			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2320		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2321		STp->immediate = (options & MT_ST_NOWAIT) != 0;
2322		STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
2323		STm->sysv = (options & MT_ST_SYSV) != 0;
2324		STp->sili = (options & MT_ST_SILI) != 0;
2325		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2326		     st_log_options(STp, STm); )
2327	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2328		value = (code == MT_ST_SETBOOLEANS);
2329		if ((options & MT_ST_BUFFER_WRITES) != 0)
2330			STm->do_buffer_writes = value;
2331		if ((options & MT_ST_ASYNC_WRITES) != 0)
2332			STm->do_async_writes = value;
2333		if ((options & MT_ST_DEF_WRITES) != 0)
2334			STm->defaults_for_writes = value;
2335		if ((options & MT_ST_READ_AHEAD) != 0)
2336			STm->do_read_ahead = value;
2337		if ((options & MT_ST_TWO_FM) != 0)
2338			STp->two_fm = value;
2339		if ((options & MT_ST_FAST_MTEOM) != 0)
2340			STp->fast_mteom = value;
2341		if ((options & MT_ST_AUTO_LOCK) != 0)
2342			STp->do_auto_lock = value;
2343		if ((options & MT_ST_CAN_BSR) != 0)
2344			STp->can_bsr = value;
2345		if ((options & MT_ST_NO_BLKLIMS) != 0)
2346			STp->omit_blklims = value;
2347		if ((STp->device)->scsi_level >= SCSI_2 &&
2348		    (options & MT_ST_CAN_PARTITIONS) != 0)
2349			STp->can_partitions = value;
2350		if ((options & MT_ST_SCSI2LOGICAL) != 0)
2351			STp->scsi2_logical = value;
2352		if ((options & MT_ST_NOWAIT) != 0)
2353			STp->immediate = value;
2354		if ((options & MT_ST_NOWAIT_EOF) != 0)
2355			STp->immediate_filemark = value;
2356		if ((options & MT_ST_SYSV) != 0)
2357			STm->sysv = value;
2358		if ((options & MT_ST_SILI) != 0)
2359			STp->sili = value;
2360		DEB(
2361		if ((options & MT_ST_DEBUGGING) != 0)
2362			debugging = value;
2363			st_log_options(STp, STm); )
2364	} else if (code == MT_ST_WRITE_THRESHOLD) {
2365		/* Retained for compatibility */
2366	} else if (code == MT_ST_DEF_BLKSIZE) {
2367		value = (options & ~MT_ST_OPTIONS);
2368		if (value == ~MT_ST_OPTIONS) {
2369			STm->default_blksize = (-1);
2370			DEBC_printk(STp, "Default block size disabled.\n");
2371		} else {
2372			STm->default_blksize = value;
2373			DEBC_printk(STp,"Default block size set to "
2374				    "%d bytes.\n", STm->default_blksize);
2375			if (STp->ready == ST_READY) {
2376				STp->blksize_changed = 0;
2377				set_mode_densblk(STp, STm);
2378			}
2379		}
2380	} else if (code == MT_ST_TIMEOUTS) {
2381		value = (options & ~MT_ST_OPTIONS);
2382		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2383			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2384			DEBC_printk(STp, "Long timeout set to %d seconds.\n",
2385				    (value & ~MT_ST_SET_LONG_TIMEOUT));
2386		} else {
2387			blk_queue_rq_timeout(STp->device->request_queue,
2388					     value * HZ);
2389			DEBC_printk(STp, "Normal timeout set to %d seconds.\n",
2390				    value);
2391		}
2392	} else if (code == MT_ST_SET_CLN) {
2393		value = (options & ~MT_ST_OPTIONS) & 0xff;
2394		if (value != 0 &&
2395			(value < EXTENDED_SENSE_START ||
2396				value >= SCSI_SENSE_BUFFERSIZE))
2397			return (-EINVAL);
2398		STp->cln_mode = value;
2399		STp->cln_sense_mask = (options >> 8) & 0xff;
2400		STp->cln_sense_value = (options >> 16) & 0xff;
2401		st_printk(KERN_INFO, STp,
2402			  "Cleaning request mode %d, mask %02x, value %02x\n",
2403			  value, STp->cln_sense_mask, STp->cln_sense_value);
2404	} else if (code == MT_ST_DEF_OPTIONS) {
2405		code = (options & ~MT_ST_CLEAR_DEFAULT);
2406		value = (options & MT_ST_CLEAR_DEFAULT);
2407		if (code == MT_ST_DEF_DENSITY) {
2408			if (value == MT_ST_CLEAR_DEFAULT) {
2409				STm->default_density = (-1);
2410				DEBC_printk(STp,
2411					    "Density default disabled.\n");
2412			} else {
2413				STm->default_density = value & 0xff;
2414				DEBC_printk(STp, "Density default set to %x\n",
2415					    STm->default_density);
2416				if (STp->ready == ST_READY) {
2417					STp->density_changed = 0;
2418					set_mode_densblk(STp, STm);
2419				}
2420			}
2421		} else if (code == MT_ST_DEF_DRVBUFFER) {
2422			if (value == MT_ST_CLEAR_DEFAULT) {
2423				STp->default_drvbuffer = 0xff;
2424				DEBC_printk(STp,
2425					    "Drive buffer default disabled.\n");
2426			} else {
2427				STp->default_drvbuffer = value & 7;
2428				DEBC_printk(STp,
2429					    "Drive buffer default set to %x\n",
2430					    STp->default_drvbuffer);
2431				if (STp->ready == ST_READY)
2432					st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2433			}
2434		} else if (code == MT_ST_DEF_COMPRESSION) {
2435			if (value == MT_ST_CLEAR_DEFAULT) {
2436				STm->default_compression = ST_DONT_TOUCH;
2437				DEBC_printk(STp,
2438					    "Compression default disabled.\n");
2439			} else {
2440				if ((value & 0xff00) != 0) {
2441					STp->c_algo = (value & 0xff00) >> 8;
2442					DEBC_printk(STp, "Compression "
2443						    "algorithm set to 0x%x.\n",
2444						    STp->c_algo);
2445				}
2446				if ((value & 0xff) != 0xff) {
2447					STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2448					DEBC_printk(STp, "Compression default "
2449						    "set to %x\n",
2450						    (value & 1));
2451					if (STp->ready == ST_READY) {
2452						STp->compression_changed = 0;
2453						st_compression(STp, (STm->default_compression == ST_YES));
2454					}
2455				}
2456			}
2457		}
2458	} else
2459		return (-EIO);
2460
2461	return 0;
2462}
2463
2464#define MODE_HEADER_LENGTH  4
2465
2466/* Mode header and page byte offsets */
2467#define MH_OFF_DATA_LENGTH     0
2468#define MH_OFF_MEDIUM_TYPE     1
2469#define MH_OFF_DEV_SPECIFIC    2
2470#define MH_OFF_BDESCS_LENGTH   3
2471#define MP_OFF_PAGE_NBR        0
2472#define MP_OFF_PAGE_LENGTH     1
2473
2474/* Mode header and page bit masks */
2475#define MH_BIT_WP              0x80
2476#define MP_MSK_PAGE_NBR        0x3f
2477
2478/* Don't return block descriptors */
2479#define MODE_SENSE_OMIT_BDESCS 0x08
2480
2481#define MODE_SELECT_PAGE_FORMAT 0x10
2482
2483/* Read a mode page into the tape buffer. The block descriptors are included
2484   if incl_block_descs is true. The page control is ored to the page number
2485   parameter, if necessary. */
2486static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2487{
2488	unsigned char cmd[MAX_COMMAND_SIZE];
2489	struct st_request *SRpnt;
2490
2491	memset(cmd, 0, MAX_COMMAND_SIZE);
2492	cmd[0] = MODE_SENSE;
2493	if (omit_block_descs)
2494		cmd[1] = MODE_SENSE_OMIT_BDESCS;
2495	cmd[2] = page;
2496	cmd[4] = 255;
2497
2498	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2499			   STp->device->request_queue->rq_timeout, 0, 1);
2500	if (SRpnt == NULL)
2501		return (STp->buffer)->syscall_result;
2502
2503	st_release_request(SRpnt);
2504
2505	return STp->buffer->syscall_result;
2506}
2507
2508
2509/* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2510   in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2511static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2512{
2513	int pgo;
2514	unsigned char cmd[MAX_COMMAND_SIZE];
2515	struct st_request *SRpnt;
2516	int timeout;
2517
2518	memset(cmd, 0, MAX_COMMAND_SIZE);
2519	cmd[0] = MODE_SELECT;
2520	cmd[1] = MODE_SELECT_PAGE_FORMAT;
2521	pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2522	cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2523
2524	/* Clear reserved fields */
2525	(STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2526	(STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2527	(STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2528	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2529
2530	timeout = slow ?
2531		STp->long_timeout : STp->device->request_queue->rq_timeout;
2532	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2533			   timeout, 0, 1);
2534	if (SRpnt == NULL)
2535		return (STp->buffer)->syscall_result;
2536
2537	st_release_request(SRpnt);
2538
2539	return STp->buffer->syscall_result;
2540}
2541
2542
2543#define COMPRESSION_PAGE        0x0f
2544#define COMPRESSION_PAGE_LENGTH 16
2545
2546#define CP_OFF_DCE_DCC          2
2547#define CP_OFF_C_ALGO           7
2548
2549#define DCE_MASK  0x80
2550#define DCC_MASK  0x40
2551#define RED_MASK  0x60
2552
2553
2554/* Control the compression with mode page 15. Algorithm not changed if zero.
2555
2556   The block descriptors are read and written because Sony SDT-7000 does not
2557   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2558   Including block descriptors should not cause any harm to other drives. */
2559
2560static int st_compression(struct scsi_tape * STp, int state)
2561{
2562	int retval;
2563	int mpoffs;  /* Offset to mode page start */
2564	unsigned char *b_data = (STp->buffer)->b_data;
2565
2566	if (STp->ready != ST_READY)
2567		return (-EIO);
2568
2569	/* Read the current page contents */
2570	retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2571	if (retval) {
2572		DEBC_printk(STp, "Compression mode page not supported.\n");
2573		return (-EIO);
2574	}
2575
2576	mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2577	DEBC_printk(STp, "Compression state is %d.\n",
2578		    (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0));
2579
2580	/* Check if compression can be changed */
2581	if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2582		DEBC_printk(STp, "Compression not supported.\n");
2583		return (-EIO);
2584	}
2585
2586	/* Do the change */
2587	if (state) {
2588		b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2589		if (STp->c_algo != 0)
2590			b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2591	}
2592	else {
2593		b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2594		if (STp->c_algo != 0)
2595			b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2596	}
2597
2598	retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2599	if (retval) {
2600		DEBC_printk(STp, "Compression change failed.\n");
2601		return (-EIO);
2602	}
2603	DEBC_printk(STp, "Compression state changed to %d.\n", state);
2604
2605	STp->compression_changed = 1;
2606	return 0;
2607}
2608
2609
2610/* Process the load and unload commands (does unload if the load code is zero) */
2611static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2612{
2613	int retval = (-EIO), timeout;
2614	unsigned char cmd[MAX_COMMAND_SIZE];
2615	struct st_partstat *STps;
2616	struct st_request *SRpnt;
2617
2618	if (STp->ready != ST_READY && !load_code) {
2619		if (STp->ready == ST_NO_TAPE)
2620			return (-ENOMEDIUM);
2621		else
2622			return (-EIO);
2623	}
2624
2625	memset(cmd, 0, MAX_COMMAND_SIZE);
2626	cmd[0] = START_STOP;
2627	if (load_code)
2628		cmd[4] |= 1;
2629	/*
2630	 * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2631	 */
2632	if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2633	    && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2634		DEBC_printk(STp, " Enhanced %sload slot %2d.\n",
2635			    (cmd[4]) ? "" : "un",
2636			    load_code - MT_ST_HPLOADER_OFFSET);
2637		cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2638	}
2639	if (STp->immediate) {
2640		cmd[1] = 1;	/* Don't wait for completion */
2641		timeout = STp->device->request_queue->rq_timeout;
2642	}
2643	else
2644		timeout = STp->long_timeout;
2645
2646	DEBC(
2647		if (!load_code)
2648			st_printk(ST_DEB_MSG, STp, "Unloading tape.\n");
2649		else
2650			st_printk(ST_DEB_MSG, STp, "Loading tape.\n");
2651		);
2652
2653	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2654			   timeout, MAX_RETRIES, 1);
2655	if (!SRpnt)
2656		return (STp->buffer)->syscall_result;
2657
2658	retval = (STp->buffer)->syscall_result;
2659	st_release_request(SRpnt);
2660
2661	if (!retval) {	/* SCSI command successful */
2662
2663		if (!load_code) {
2664			STp->rew_at_close = 0;
2665			STp->ready = ST_NO_TAPE;
2666		}
2667		else {
2668			STp->rew_at_close = STp->autorew_dev;
2669			retval = check_tape(STp, filp);
2670			if (retval > 0)
2671				retval = 0;
2672		}
2673	}
2674	else {
2675		STps = &(STp->ps[STp->partition]);
2676		STps->drv_file = STps->drv_block = (-1);
2677	}
2678
2679	return retval;
2680}
2681
2682#if DEBUG
2683#define ST_DEB_FORWARD  0
2684#define ST_DEB_BACKWARD 1
2685static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd)
2686{
2687	s32 sc;
2688
2689	if (!debugging)
2690		return;
2691
2692	sc = sign_extend32(get_unaligned_be24(&cmd[2]), 23);
2693	if (direction)
2694		sc = -sc;
2695	st_printk(ST_DEB_MSG, STp, "Spacing tape %s over %d %s.\n",
2696		  direction ? "backward" : "forward", sc, units);
2697}
2698#else
2699#define ST_DEB_FORWARD  0
2700#define ST_DEB_BACKWARD 1
2701static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd) {}
2702#endif
2703
2704
2705/* Internal ioctl function */
2706static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2707{
2708	int timeout;
2709	long ltmp;
2710	int ioctl_result;
2711	int chg_eof = 1;
2712	unsigned char cmd[MAX_COMMAND_SIZE];
2713	struct st_request *SRpnt;
2714	struct st_partstat *STps;
2715	int fileno, blkno, at_sm, undone;
2716	int datalen = 0, direction = DMA_NONE;
2717
2718	WARN_ON(STp->buffer->do_dio != 0);
2719	if (STp->ready != ST_READY) {
2720		if (STp->ready == ST_NO_TAPE)
2721			return (-ENOMEDIUM);
2722		else
2723			return (-EIO);
2724	}
2725	timeout = STp->long_timeout;
2726	STps = &(STp->ps[STp->partition]);
2727	fileno = STps->drv_file;
2728	blkno = STps->drv_block;
2729	at_sm = STps->at_sm;
2730
2731	memset(cmd, 0, MAX_COMMAND_SIZE);
2732	switch (cmd_in) {
2733	case MTFSFM:
2734		chg_eof = 0;	/* Changed from the FSF after this */
2735		fallthrough;
2736	case MTFSF:
2737		cmd[0] = SPACE;
2738		cmd[1] = 0x01;	/* Space FileMarks */
2739		cmd[2] = (arg >> 16);
2740		cmd[3] = (arg >> 8);
2741		cmd[4] = arg;
2742		deb_space_print(STp, ST_DEB_FORWARD, "filemarks", cmd);
2743		if (fileno >= 0)
2744			fileno += arg;
2745		blkno = 0;
2746		at_sm &= (arg == 0);
2747		break;
2748	case MTBSFM:
2749		chg_eof = 0;	/* Changed from the FSF after this */
2750		fallthrough;
2751	case MTBSF:
2752		cmd[0] = SPACE;
2753		cmd[1] = 0x01;	/* Space FileMarks */
2754		ltmp = (-arg);
2755		cmd[2] = (ltmp >> 16);
2756		cmd[3] = (ltmp >> 8);
2757		cmd[4] = ltmp;
2758		deb_space_print(STp, ST_DEB_BACKWARD, "filemarks", cmd);
2759		if (fileno >= 0)
2760			fileno -= arg;
2761		blkno = (-1);	/* We can't know the block number */
2762		at_sm &= (arg == 0);
2763		break;
2764	case MTFSR:
2765		cmd[0] = SPACE;
2766		cmd[1] = 0x00;	/* Space Blocks */
2767		cmd[2] = (arg >> 16);
2768		cmd[3] = (arg >> 8);
2769		cmd[4] = arg;
2770		deb_space_print(STp, ST_DEB_FORWARD, "blocks", cmd);
2771		if (blkno >= 0)
2772			blkno += arg;
2773		at_sm &= (arg == 0);
2774		break;
2775	case MTBSR:
2776		cmd[0] = SPACE;
2777		cmd[1] = 0x00;	/* Space Blocks */
2778		ltmp = (-arg);
2779		cmd[2] = (ltmp >> 16);
2780		cmd[3] = (ltmp >> 8);
2781		cmd[4] = ltmp;
2782		deb_space_print(STp, ST_DEB_BACKWARD, "blocks", cmd);
2783		if (blkno >= 0)
2784			blkno -= arg;
2785		at_sm &= (arg == 0);
2786		break;
2787	case MTFSS:
2788		cmd[0] = SPACE;
2789		cmd[1] = 0x04;	/* Space Setmarks */
2790		cmd[2] = (arg >> 16);
2791		cmd[3] = (arg >> 8);
2792		cmd[4] = arg;
2793		deb_space_print(STp, ST_DEB_FORWARD, "setmarks", cmd);
2794		if (arg != 0) {
2795			blkno = fileno = (-1);
2796			at_sm = 1;
2797		}
2798		break;
2799	case MTBSS:
2800		cmd[0] = SPACE;
2801		cmd[1] = 0x04;	/* Space Setmarks */
2802		ltmp = (-arg);
2803		cmd[2] = (ltmp >> 16);
2804		cmd[3] = (ltmp >> 8);
2805		cmd[4] = ltmp;
2806		deb_space_print(STp, ST_DEB_BACKWARD, "setmarks", cmd);
2807		if (arg != 0) {
2808			blkno = fileno = (-1);
2809			at_sm = 1;
2810		}
2811		break;
2812	case MTWEOF:
2813	case MTWEOFI:
2814	case MTWSM:
2815		if (STp->write_prot)
2816			return (-EACCES);
2817		cmd[0] = WRITE_FILEMARKS;
2818		if (cmd_in == MTWSM)
2819			cmd[1] = 2;
2820		if (cmd_in == MTWEOFI ||
2821		    (cmd_in == MTWEOF && STp->immediate_filemark))
2822			cmd[1] |= 1;
2823		cmd[2] = (arg >> 16);
2824		cmd[3] = (arg >> 8);
2825		cmd[4] = arg;
2826		timeout = STp->device->request_queue->rq_timeout;
2827		DEBC(
2828			if (cmd_in != MTWSM)
2829				st_printk(ST_DEB_MSG, STp,
2830					  "Writing %d filemarks.\n",
2831					  cmd[2] * 65536 +
2832					  cmd[3] * 256 +
2833					  cmd[4]);
2834			else
2835				st_printk(ST_DEB_MSG, STp,
2836					  "Writing %d setmarks.\n",
2837					  cmd[2] * 65536 +
2838					  cmd[3] * 256 +
2839					  cmd[4]);
2840		)
2841		if (fileno >= 0)
2842			fileno += arg;
2843		blkno = 0;
2844		at_sm = (cmd_in == MTWSM);
2845		break;
2846	case MTREW:
2847		cmd[0] = REZERO_UNIT;
2848		if (STp->immediate) {
2849			cmd[1] = 1;	/* Don't wait for completion */
2850			timeout = STp->device->request_queue->rq_timeout;
2851		}
2852		DEBC_printk(STp, "Rewinding tape.\n");
2853		fileno = blkno = at_sm = 0;
2854		break;
2855	case MTNOP:
2856		DEBC_printk(STp, "No op on tape.\n");
2857		return 0;	/* Should do something ? */
 
2858	case MTRETEN:
2859		cmd[0] = START_STOP;
2860		if (STp->immediate) {
2861			cmd[1] = 1;	/* Don't wait for completion */
2862			timeout = STp->device->request_queue->rq_timeout;
2863		}
2864		cmd[4] = 3;
2865		DEBC_printk(STp, "Retensioning tape.\n");
2866		fileno = blkno = at_sm = 0;
2867		break;
2868	case MTEOM:
2869		if (!STp->fast_mteom) {
2870			/* space to the end of tape */
2871			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2872			fileno = STps->drv_file;
2873			if (STps->eof >= ST_EOD_1)
2874				return 0;
2875			/* The next lines would hide the number of spaced FileMarks
2876			   That's why I inserted the previous lines. I had no luck
2877			   with detecting EOM with FSF, so we go now to EOM.
2878			   Joerg Weule */
2879		} else
2880			fileno = (-1);
2881		cmd[0] = SPACE;
2882		cmd[1] = 3;
2883		DEBC_printk(STp, "Spacing to end of recorded medium.\n");
2884		blkno = -1;
2885		at_sm = 0;
2886		break;
2887	case MTERASE:
2888		if (STp->write_prot)
2889			return (-EACCES);
2890		cmd[0] = ERASE;
2891		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
2892		if (STp->immediate) {
2893			cmd[1] |= 2;	/* Don't wait for completion */
2894			timeout = STp->device->request_queue->rq_timeout;
2895		}
2896		else
2897			timeout = STp->long_timeout * 8;
2898
2899		DEBC_printk(STp, "Erasing tape.\n");
2900		fileno = blkno = at_sm = 0;
2901		break;
2902	case MTSETBLK:		/* Set block length */
2903	case MTSETDENSITY:	/* Set tape density */
2904	case MTSETDRVBUFFER:	/* Set drive buffering */
2905	case SET_DENS_AND_BLK:	/* Set density and block size */
2906		chg_eof = 0;
2907		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2908			return (-EIO);	/* Not allowed if data in buffer */
2909		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2910		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2911		    STp->max_block > 0 &&
2912		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2913		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2914			st_printk(KERN_WARNING, STp, "Illegal block size.\n");
2915			return (-EINVAL);
2916		}
2917		cmd[0] = MODE_SELECT;
2918		if ((STp->use_pf & USE_PF))
2919			cmd[1] = MODE_SELECT_PAGE_FORMAT;
2920		cmd[4] = datalen = 12;
2921		direction = DMA_TO_DEVICE;
2922
2923		memset((STp->buffer)->b_data, 0, 12);
2924		if (cmd_in == MTSETDRVBUFFER)
2925			(STp->buffer)->b_data[2] = (arg & 7) << 4;
2926		else
2927			(STp->buffer)->b_data[2] =
2928			    STp->drv_buffer << 4;
2929		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
2930		if (cmd_in == MTSETDENSITY) {
2931			(STp->buffer)->b_data[4] = arg;
2932			STp->density_changed = 1;	/* At least we tried ;-) */
2933		} else if (cmd_in == SET_DENS_AND_BLK)
2934			(STp->buffer)->b_data[4] = arg >> 24;
2935		else
2936			(STp->buffer)->b_data[4] = STp->density;
2937		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2938			ltmp = arg & MT_ST_BLKSIZE_MASK;
2939			if (cmd_in == MTSETBLK)
2940				STp->blksize_changed = 1; /* At least we tried ;-) */
2941		} else
2942			ltmp = STp->block_size;
2943		(STp->buffer)->b_data[9] = (ltmp >> 16);
2944		(STp->buffer)->b_data[10] = (ltmp >> 8);
2945		(STp->buffer)->b_data[11] = ltmp;
2946		timeout = STp->device->request_queue->rq_timeout;
2947		DEBC(
2948			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2949				st_printk(ST_DEB_MSG, STp,
2950					  "Setting block size to %d bytes.\n",
2951					  (STp->buffer)->b_data[9] * 65536 +
2952					  (STp->buffer)->b_data[10] * 256 +
2953					  (STp->buffer)->b_data[11]);
2954			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2955				st_printk(ST_DEB_MSG, STp,
2956					  "Setting density code to %x.\n",
2957					  (STp->buffer)->b_data[4]);
2958			if (cmd_in == MTSETDRVBUFFER)
2959				st_printk(ST_DEB_MSG, STp,
2960					  "Setting drive buffer code to %d.\n",
2961					  ((STp->buffer)->b_data[2] >> 4) & 7);
2962		)
2963		break;
2964	default:
2965		return (-ENOSYS);
2966	}
2967
2968	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2969			   timeout, MAX_RETRIES, 1);
2970	if (!SRpnt)
2971		return (STp->buffer)->syscall_result;
2972
2973	ioctl_result = (STp->buffer)->syscall_result;
2974
2975	if (!ioctl_result) {	/* SCSI command successful */
2976		st_release_request(SRpnt);
2977		SRpnt = NULL;
2978		STps->drv_block = blkno;
2979		STps->drv_file = fileno;
2980		STps->at_sm = at_sm;
2981
2982		if (cmd_in == MTBSFM)
2983			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2984		else if (cmd_in == MTFSFM)
2985			ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2986
2987		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2988			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2989			if (STp->block_size != 0) {
2990				(STp->buffer)->buffer_blocks =
2991				    (STp->buffer)->buffer_size / STp->block_size;
2992			}
2993			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2994			if (cmd_in == SET_DENS_AND_BLK)
2995				STp->density = arg >> MT_ST_DENSITY_SHIFT;
2996		} else if (cmd_in == MTSETDRVBUFFER)
2997			STp->drv_buffer = (arg & 7);
2998		else if (cmd_in == MTSETDENSITY)
2999			STp->density = arg;
3000
3001		if (cmd_in == MTEOM)
3002			STps->eof = ST_EOD;
3003		else if (cmd_in == MTFSF)
3004			STps->eof = ST_FM;
3005		else if (chg_eof)
3006			STps->eof = ST_NOEOF;
3007
3008		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
3009			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
3010	} else { /* SCSI command was not completely successful. Don't return
3011                    from this block without releasing the SCSI command block! */
3012		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
3013
3014		if (cmdstatp->flags & SENSE_EOM) {
3015			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
3016			    cmd_in != MTBSR && cmd_in != MTBSS)
3017				STps->eof = ST_EOM_OK;
3018			STps->drv_block = 0;
3019		}
3020
3021		if (cmdstatp->remainder_valid)
3022			undone = (int)cmdstatp->uremainder64;
3023		else
3024			undone = 0;
3025
3026		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
3027		    cmdstatp->have_sense &&
3028		    (cmdstatp->flags & SENSE_EOM)) {
3029			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
3030			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
3031				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
3032				STps->eof = ST_NOEOF;
3033			} else {  /* Writing EOF(s) failed */
3034				if (fileno >= 0)
3035					fileno -= undone;
3036				if (undone < arg)
3037					STps->eof = ST_NOEOF;
3038			}
3039			STps->drv_file = fileno;
3040		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
3041			if (fileno >= 0)
3042				STps->drv_file = fileno - undone;
3043			else
3044				STps->drv_file = fileno;
3045			STps->drv_block = -1;
3046			STps->eof = ST_NOEOF;
3047		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
3048			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3049				undone = (-undone);
3050			if (STps->drv_file >= 0)
3051				STps->drv_file = fileno + undone;
3052			STps->drv_block = 0;
3053			STps->eof = ST_NOEOF;
3054		} else if (cmd_in == MTFSR) {
3055			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3056				if (STps->drv_file >= 0)
3057					STps->drv_file++;
3058				STps->drv_block = 0;
3059				STps->eof = ST_FM;
3060			} else {
3061				if (blkno >= undone)
3062					STps->drv_block = blkno - undone;
3063				else
3064					STps->drv_block = (-1);
3065				STps->eof = ST_NOEOF;
3066			}
3067		} else if (cmd_in == MTBSR) {
3068			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3069				STps->drv_file--;
3070				STps->drv_block = (-1);
3071			} else {
3072				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3073					undone = (-undone);
3074				if (STps->drv_block >= 0)
3075					STps->drv_block = blkno + undone;
3076			}
3077			STps->eof = ST_NOEOF;
3078		} else if (cmd_in == MTEOM) {
3079			STps->drv_file = (-1);
3080			STps->drv_block = (-1);
3081			STps->eof = ST_EOD;
3082		} else if (cmd_in == MTSETBLK ||
3083			   cmd_in == MTSETDENSITY ||
3084			   cmd_in == MTSETDRVBUFFER ||
3085			   cmd_in == SET_DENS_AND_BLK) {
3086			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
3087			    !(STp->use_pf & PF_TESTED)) {
3088				/* Try the other possible state of Page Format if not
3089				   already tried */
3090				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
3091				st_release_request(SRpnt);
3092				SRpnt = NULL;
3093				return st_int_ioctl(STp, cmd_in, arg);
3094			}
3095		} else if (chg_eof)
3096			STps->eof = ST_NOEOF;
3097
3098		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
3099			STps->eof = ST_EOD;
3100
3101		st_release_request(SRpnt);
3102		SRpnt = NULL;
3103	}
3104
3105	return ioctl_result;
3106}
3107
3108
3109/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
3110   structure. */
3111
3112static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
3113			int logical)
3114{
3115	int result;
3116	unsigned char scmd[MAX_COMMAND_SIZE];
3117	struct st_request *SRpnt;
3118
3119	if (STp->ready != ST_READY)
3120		return (-EIO);
3121
3122	memset(scmd, 0, MAX_COMMAND_SIZE);
3123	if ((STp->device)->scsi_level < SCSI_2) {
3124		scmd[0] = QFA_REQUEST_BLOCK;
3125		scmd[4] = 3;
3126	} else {
3127		scmd[0] = READ_POSITION;
3128		if (!logical && !STp->scsi2_logical)
3129			scmd[1] = 1;
3130	}
3131	SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3132			   STp->device->request_queue->rq_timeout,
3133			   MAX_READY_RETRIES, 1);
3134	if (!SRpnt)
3135		return (STp->buffer)->syscall_result;
3136
3137	if ((STp->buffer)->syscall_result != 0 ||
3138	    (STp->device->scsi_level >= SCSI_2 &&
3139	     ((STp->buffer)->b_data[0] & 4) != 0)) {
3140		*block = *partition = 0;
3141		DEBC_printk(STp, " Can't read tape position.\n");
3142		result = (-EIO);
3143	} else {
3144		result = 0;
3145		if ((STp->device)->scsi_level < SCSI_2) {
3146			*block = ((STp->buffer)->b_data[0] << 16)
3147			    + ((STp->buffer)->b_data[1] << 8)
3148			    + (STp->buffer)->b_data[2];
3149			*partition = 0;
3150		} else {
3151			*block = ((STp->buffer)->b_data[4] << 24)
3152			    + ((STp->buffer)->b_data[5] << 16)
3153			    + ((STp->buffer)->b_data[6] << 8)
3154			    + (STp->buffer)->b_data[7];
3155			*partition = (STp->buffer)->b_data[1];
3156			if (((STp->buffer)->b_data[0] & 0x80) &&
3157			    (STp->buffer)->b_data[1] == 0)	/* BOP of partition 0 */
3158				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3159		}
3160		DEBC_printk(STp, "Got tape pos. blk %d part %d.\n",
3161			    *block, *partition);
3162	}
3163	st_release_request(SRpnt);
3164	SRpnt = NULL;
3165
3166	return result;
3167}
3168
3169
3170/* Set the tape block and partition. Negative partition means that only the
3171   block should be set in vendor specific way. */
3172static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3173			int logical)
3174{
3175	struct st_partstat *STps;
3176	int result, p;
3177	unsigned int blk;
3178	int timeout;
3179	unsigned char scmd[MAX_COMMAND_SIZE];
3180	struct st_request *SRpnt;
3181
3182	if (STp->ready != ST_READY)
3183		return (-EIO);
3184	timeout = STp->long_timeout;
3185	STps = &(STp->ps[STp->partition]);
3186
3187	DEBC_printk(STp, "Setting block to %d and partition to %d.\n",
3188		    block, partition);
3189	DEB(if (partition < 0)
3190		return (-EIO); )
3191
3192	/* Update the location at the partition we are leaving */
3193	if ((!STp->can_partitions && partition != 0) ||
3194	    partition >= ST_NBR_PARTITIONS)
3195		return (-EINVAL);
3196	if (partition != STp->partition) {
3197		if (get_location(STp, &blk, &p, 1))
3198			STps->last_block_valid = 0;
3199		else {
3200			STps->last_block_valid = 1;
3201			STps->last_block_visited = blk;
3202			DEBC_printk(STp, "Visited block %d for "
3203				    "partition %d saved.\n",
3204				    blk, STp->partition);
3205		}
3206	}
3207
3208	memset(scmd, 0, MAX_COMMAND_SIZE);
3209	if ((STp->device)->scsi_level < SCSI_2) {
3210		scmd[0] = QFA_SEEK_BLOCK;
3211		scmd[2] = (block >> 16);
3212		scmd[3] = (block >> 8);
3213		scmd[4] = block;
3214		scmd[5] = 0;
3215	} else {
3216		scmd[0] = SEEK_10;
3217		scmd[3] = (block >> 24);
3218		scmd[4] = (block >> 16);
3219		scmd[5] = (block >> 8);
3220		scmd[6] = block;
3221		if (!logical && !STp->scsi2_logical)
3222			scmd[1] = 4;
3223		if (STp->partition != partition) {
3224			scmd[1] |= 2;
3225			scmd[8] = partition;
3226			DEBC_printk(STp, "Trying to change partition "
3227				    "from %d to %d\n", STp->partition,
3228				    partition);
3229		}
3230	}
3231	if (STp->immediate) {
3232		scmd[1] |= 1;		/* Don't wait for completion */
3233		timeout = STp->device->request_queue->rq_timeout;
3234	}
3235
3236	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3237			   timeout, MAX_READY_RETRIES, 1);
3238	if (!SRpnt)
3239		return (STp->buffer)->syscall_result;
3240
3241	STps->drv_block = STps->drv_file = (-1);
3242	STps->eof = ST_NOEOF;
3243	if ((STp->buffer)->syscall_result != 0) {
3244		result = (-EIO);
3245		if (STp->can_partitions &&
3246		    (STp->device)->scsi_level >= SCSI_2 &&
3247		    (p = find_partition(STp)) >= 0)
3248			STp->partition = p;
3249	} else {
3250		if (STp->can_partitions) {
3251			STp->partition = partition;
3252			STps = &(STp->ps[partition]);
3253			if (!STps->last_block_valid ||
3254			    STps->last_block_visited != block) {
3255				STps->at_sm = 0;
3256				STps->rw = ST_IDLE;
3257			}
3258		} else
3259			STps->at_sm = 0;
3260		if (block == 0)
3261			STps->drv_block = STps->drv_file = 0;
3262		result = 0;
3263	}
3264
3265	st_release_request(SRpnt);
3266	SRpnt = NULL;
3267
3268	return result;
3269}
3270
3271
3272/* Find the current partition number for the drive status. Called from open and
3273   returns either partition number of negative error code. */
3274static int find_partition(struct scsi_tape *STp)
3275{
3276	int i, partition;
3277	unsigned int block;
3278
3279	if ((i = get_location(STp, &block, &partition, 1)) < 0)
3280		return i;
3281	if (partition >= ST_NBR_PARTITIONS)
3282		return (-EIO);
3283	return partition;
3284}
3285
3286
3287/* Change the partition if necessary */
3288static int switch_partition(struct scsi_tape *STp)
3289{
3290	struct st_partstat *STps;
3291
3292	if (STp->partition == STp->new_partition)
3293		return 0;
3294	STps = &(STp->ps[STp->new_partition]);
3295	if (!STps->last_block_valid)
3296		STps->last_block_visited = 0;
3297	return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3298}
3299
3300/* Functions for reading and writing the medium partition mode page. */
3301
3302#define PART_PAGE   0x11
3303#define PART_PAGE_FIXED_LENGTH 8
3304
3305#define PP_OFF_MAX_ADD_PARTS   2
3306#define PP_OFF_NBR_ADD_PARTS   3
3307#define PP_OFF_FLAGS           4
3308#define PP_OFF_PART_UNITS      6
3309#define PP_OFF_RESERVED        7
3310
3311#define PP_BIT_IDP             0x20
3312#define PP_BIT_FDP             0x80
3313#define PP_MSK_PSUM_MB         0x10
3314#define PP_MSK_PSUM_UNITS      0x18
3315#define PP_MSK_POFM            0x04
3316
3317/* Get the number of partitions on the tape. As a side effect reads the
3318   mode page into the tape buffer. */
3319static int nbr_partitions(struct scsi_tape *STp)
3320{
3321	int result;
3322
3323	if (STp->ready != ST_READY)
3324		return (-EIO);
3325
3326	result = read_mode_page(STp, PART_PAGE, 1);
3327
3328	if (result) {
3329		DEBC_printk(STp, "Can't read medium partition page.\n");
3330		result = (-EIO);
3331	} else {
3332		result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3333					      PP_OFF_NBR_ADD_PARTS] + 1;
3334		DEBC_printk(STp, "Number of partitions %d.\n", result);
3335	}
3336
3337	return result;
3338}
3339
3340
3341static int format_medium(struct scsi_tape *STp, int format)
3342{
3343	int result = 0;
3344	int timeout = STp->long_timeout;
3345	unsigned char scmd[MAX_COMMAND_SIZE];
3346	struct st_request *SRpnt;
3347
3348	memset(scmd, 0, MAX_COMMAND_SIZE);
3349	scmd[0] = FORMAT_UNIT;
3350	scmd[2] = format;
3351	if (STp->immediate) {
3352		scmd[1] |= 1;		/* Don't wait for completion */
3353		timeout = STp->device->request_queue->rq_timeout;
3354	}
3355	DEBC_printk(STp, "Sending FORMAT MEDIUM\n");
3356	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3357			   timeout, MAX_RETRIES, 1);
3358	if (!SRpnt)
3359		result = STp->buffer->syscall_result;
3360	return result;
3361}
3362
3363
3364/* Partition the tape into two partitions if size > 0 or one partition if
3365   size == 0.
3366
3367   The block descriptors are read and written because Sony SDT-7000 does not
3368   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3369
3370   My HP C1533A drive returns only one partition size field. This is used to
3371   set the size of partition 1. There is no size field for the default partition.
3372   Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3373   used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3374   The following algorithm is used to accommodate both drives: if the number of
3375   partition size fields is greater than the maximum number of additional partitions
3376   in the mode page, the second field is used. Otherwise the first field is used.
3377
3378   For Seagate DDS drives the page length must be 8 when no partitions is defined
3379   and 10 when 1 partition is defined (information from Eric Lee Green). This is
3380   is acceptable also to some other old drives and enforced if the first partition
3381   size field is used for the first additional partition size.
3382
3383   For drives that advertize SCSI-3 or newer, use the SSC-3 methods.
3384 */
3385static int partition_tape(struct scsi_tape *STp, int size)
3386{
3387	int result;
3388	int target_partition;
3389	bool scsi3 = STp->device->scsi_level >= SCSI_3, needs_format = false;
3390	int pgo, psd_cnt, psdo;
3391	int psum = PP_MSK_PSUM_MB, units = 0;
3392	unsigned char *bp;
3393
3394	result = read_mode_page(STp, PART_PAGE, 0);
3395	if (result) {
3396		DEBC_printk(STp, "Can't read partition mode page.\n");
3397		return result;
3398	}
3399	target_partition = 1;
3400	if (size < 0) {
3401		target_partition = 0;
3402		size = -size;
3403	}
3404
3405	/* The mode page is in the buffer. Let's modify it and write it. */
3406	bp = (STp->buffer)->b_data;
3407	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3408	DEBC_printk(STp, "Partition page length is %d bytes.\n",
3409		    bp[pgo + MP_OFF_PAGE_LENGTH] + 2);
3410
3411	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
3412
3413	if (scsi3) {
3414		needs_format = (bp[pgo + PP_OFF_FLAGS] & PP_MSK_POFM) != 0;
3415		if (needs_format && size == 0) {
3416			/* No need to write the mode page when clearing
3417			 *  partitioning
3418			 */
3419			DEBC_printk(STp, "Formatting tape with one partition.\n");
3420			result = format_medium(STp, 0);
3421			goto out;
3422		}
3423		if (needs_format)  /* Leave the old value for HP DATs claiming SCSI_3 */
3424			psd_cnt = 2;
3425		if ((bp[pgo + PP_OFF_FLAGS] & PP_MSK_PSUM_UNITS) == PP_MSK_PSUM_UNITS) {
3426			/* Use units scaling for large partitions if the device
3427			 * suggests it and no precision lost. Required for IBM
3428			 * TS1140/50 drives that don't support MB units.
3429			 */
3430			if (size >= 1000 && (size % 1000) == 0) {
3431				size /= 1000;
3432				psum = PP_MSK_PSUM_UNITS;
3433				units = 9; /* GB */
3434			}
3435		}
3436		/* Try it anyway if too large to specify in MB */
3437		if (psum == PP_MSK_PSUM_MB && size >= 65534) {
3438			size /= 1000;
3439			psum = PP_MSK_PSUM_UNITS;
3440			units = 9;  /* GB */
3441		}
3442	}
3443
3444	if (size >= 65535 ||  /* Does not fit into two bytes */
3445	    (target_partition == 0 && psd_cnt < 2)) {
3446		result = -EINVAL;
3447		goto out;
3448	}
3449
3450	psdo = pgo + PART_PAGE_FIXED_LENGTH;
3451	/* The second condition is for HP DDS which use only one partition size
3452	 * descriptor
3453	 */
3454	if (target_partition > 0 &&
3455	    (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS] ||
3456	     bp[pgo + PP_OFF_MAX_ADD_PARTS] != 1)) {
3457		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest to partition 0 */
3458		psdo += 2;
3459	}
3460	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3461
3462	DEBC_printk(STp, "psd_cnt %d, max.parts %d, nbr_parts %d\n",
3463		    psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3464		    bp[pgo + PP_OFF_NBR_ADD_PARTS]);
3465
3466	if (size == 0) {
3467		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3468		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3469		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3470		DEBC_printk(STp, "Formatting tape with one partition.\n");
3471	} else {
3472		bp[psdo] = (size >> 8) & 0xff;
3473		bp[psdo + 1] = size & 0xff;
3474		if (target_partition == 0)
3475			bp[psdo + 2] = bp[psdo + 3] = 0xff;
3476		bp[pgo + 3] = 1;
3477		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3478		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3479		DEBC_printk(STp,
3480			    "Formatting tape with two partitions (%i = %d MB).\n",
3481			    target_partition, units > 0 ? size * 1000 : size);
3482	}
3483	bp[pgo + PP_OFF_PART_UNITS] = 0;
3484	bp[pgo + PP_OFF_RESERVED] = 0;
3485	if (size != 1 || units != 0) {
3486		bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | psum |
3487			(bp[pgo + PP_OFF_FLAGS] & 0x07);
3488		bp[pgo + PP_OFF_PART_UNITS] = units;
3489	} else
3490		bp[pgo + PP_OFF_FLAGS] = PP_BIT_FDP |
3491			(bp[pgo + PP_OFF_FLAGS] & 0x1f);
3492	bp[pgo + MP_OFF_PAGE_LENGTH] = 6 + psd_cnt * 2;
3493
3494	result = write_mode_page(STp, PART_PAGE, 1);
3495
3496	if (!result && needs_format)
3497		result = format_medium(STp, 1);
3498
3499	if (result) {
3500		st_printk(KERN_INFO, STp, "Partitioning of tape failed.\n");
3501		result = (-EIO);
3502	}
3503
3504out:
3505	return result;
3506}
3507
3508
3509
3510/* The ioctl command */
3511static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3512{
3513	void __user *p = (void __user *)arg;
3514	int i, cmd_nr, cmd_type, bt;
3515	int retval = 0;
3516	unsigned int blk;
3517	bool cmd_mtiocget;
3518	struct scsi_tape *STp = file->private_data;
3519	struct st_modedef *STm;
3520	struct st_partstat *STps;
3521
3522	if (mutex_lock_interruptible(&STp->lock))
3523		return -ERESTARTSYS;
3524
3525	DEB(
3526	if (debugging && !STp->in_use) {
3527		st_printk(ST_DEB_MSG, STp, "Incorrect device.\n");
3528		retval = (-EIO);
3529		goto out;
3530	} ) /* end DEB */
3531
3532	STm = &(STp->modes[STp->current_mode]);
3533	STps = &(STp->ps[STp->partition]);
3534
3535	/*
3536	 * If we are in the middle of error recovery, don't let anyone
3537	 * else try and use this device.  Also, if error recovery fails, it
3538	 * may try and take the device offline, in which case all further
3539	 * access to the device is prohibited.
3540	 */
3541	retval = scsi_ioctl_block_when_processing_errors(STp->device, cmd_in,
3542			file->f_flags & O_NDELAY);
3543	if (retval)
3544		goto out;
3545
3546	cmd_type = _IOC_TYPE(cmd_in);
3547	cmd_nr = _IOC_NR(cmd_in);
3548
3549	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3550		struct mtop mtc;
3551
3552		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3553			retval = (-EINVAL);
3554			goto out;
3555		}
3556
3557		i = copy_from_user(&mtc, p, sizeof(struct mtop));
3558		if (i) {
3559			retval = (-EFAULT);
3560			goto out;
3561		}
3562
3563		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3564			st_printk(KERN_WARNING, STp,
3565				  "MTSETDRVBUFFER only allowed for root.\n");
3566			retval = (-EPERM);
3567			goto out;
3568		}
3569		if (!STm->defined &&
3570		    (mtc.mt_op != MTSETDRVBUFFER &&
3571		     (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3572			retval = (-ENXIO);
3573			goto out;
3574		}
3575
3576		if (!STp->pos_unknown) {
3577
3578			if (STps->eof == ST_FM_HIT) {
3579				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3580                                    mtc.mt_op == MTEOM) {
3581					mtc.mt_count -= 1;
3582					if (STps->drv_file >= 0)
3583						STps->drv_file += 1;
3584				} else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3585					mtc.mt_count += 1;
3586					if (STps->drv_file >= 0)
3587						STps->drv_file += 1;
3588				}
3589			}
3590
3591			if (mtc.mt_op == MTSEEK) {
3592				/* Old position must be restored if partition will be
3593                                   changed */
3594				i = !STp->can_partitions ||
3595				    (STp->new_partition != STp->partition);
3596			} else {
3597				i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3598				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3599				    mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3600				    mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3601				    mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3602				    mtc.mt_op == MTCOMPRESSION;
3603			}
3604			i = flush_buffer(STp, i);
3605			if (i < 0) {
3606				retval = i;
3607				goto out;
3608			}
3609			if (STps->rw == ST_WRITING &&
3610			    (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3611			     mtc.mt_op == MTSEEK ||
3612			     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3613				i = st_int_ioctl(STp, MTWEOF, 1);
3614				if (i < 0) {
3615					retval = i;
3616					goto out;
3617				}
3618				if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3619					mtc.mt_count++;
3620				STps->rw = ST_IDLE;
3621			     }
3622
3623		} else {
3624			/*
3625			 * If there was a bus reset, block further access
3626			 * to this device.  If the user wants to rewind the tape,
3627			 * then reset the flag and allow access again.
3628			 */
3629			if (mtc.mt_op != MTREW &&
3630			    mtc.mt_op != MTOFFL &&
3631			    mtc.mt_op != MTLOAD &&
3632			    mtc.mt_op != MTRETEN &&
3633			    mtc.mt_op != MTERASE &&
3634			    mtc.mt_op != MTSEEK &&
3635			    mtc.mt_op != MTEOM) {
3636				retval = (-EIO);
3637				goto out;
3638			}
3639			reset_state(STp);
3640			/* remove this when the midlevel properly clears was_reset */
3641			STp->device->was_reset = 0;
3642		}
3643
3644		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3645		    mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3646		    mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3647			STps->rw = ST_IDLE;	/* Prevent automatic WEOF and fsf */
3648
3649		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3650			do_door_lock(STp, 0);	/* Ignore result! */
3651
3652		if (mtc.mt_op == MTSETDRVBUFFER &&
3653		    (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3654			retval = st_set_options(STp, mtc.mt_count);
3655			goto out;
3656		}
3657
3658		if (mtc.mt_op == MTSETPART) {
3659			if (!STp->can_partitions ||
3660			    mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3661				retval = (-EINVAL);
3662				goto out;
3663			}
3664			if (mtc.mt_count >= STp->nbr_partitions &&
3665			    (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3666				retval = (-EIO);
3667				goto out;
3668			}
3669			if (mtc.mt_count >= STp->nbr_partitions) {
3670				retval = (-EINVAL);
3671				goto out;
3672			}
3673			STp->new_partition = mtc.mt_count;
3674			retval = 0;
3675			goto out;
3676		}
3677
3678		if (mtc.mt_op == MTMKPART) {
3679			if (!STp->can_partitions) {
3680				retval = (-EINVAL);
3681				goto out;
3682			}
3683			i = do_load_unload(STp, file, 1);
3684			if (i < 0) {
3685				retval = i;
3686				goto out;
3687			}
3688			i = partition_tape(STp, mtc.mt_count);
3689			if (i < 0) {
3690				retval = i;
3691				goto out;
3692			}
3693			for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3694				STp->ps[i].rw = ST_IDLE;
3695				STp->ps[i].at_sm = 0;
3696				STp->ps[i].last_block_valid = 0;
3697			}
3698			STp->partition = STp->new_partition = 0;
3699			STp->nbr_partitions = mtc.mt_count != 0 ? 2 : 1;
3700			STps->drv_block = STps->drv_file = 0;
3701			retval = 0;
3702			goto out;
3703		}
3704
3705		if (mtc.mt_op == MTSEEK) {
3706			i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3707			if (!STp->can_partitions)
3708				STp->ps[0].rw = ST_IDLE;
3709			retval = i;
3710			goto out;
3711		}
3712
3713		if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3714			retval = do_load_unload(STp, file, 0);
3715			goto out;
3716		}
3717
3718		if (mtc.mt_op == MTLOAD) {
3719			retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3720			goto out;
3721		}
3722
3723		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3724			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3725			goto out;
3726		}
3727
3728		if (STp->can_partitions && STp->ready == ST_READY &&
3729		    (i = switch_partition(STp)) < 0) {
3730			retval = i;
3731			goto out;
3732		}
3733
3734		if (mtc.mt_op == MTCOMPRESSION)
3735			retval = st_compression(STp, (mtc.mt_count & 1));
3736		else
3737			retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3738		goto out;
3739	}
3740	if (!STm->defined) {
3741		retval = (-ENXIO);
3742		goto out;
3743	}
3744
3745	cmd_mtiocget = cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET);
3746
3747	if ((i = flush_buffer(STp, 0)) < 0) {
3748		if (cmd_mtiocget && STp->pos_unknown) {
3749			/* flush fails -> modify status accordingly */
3750			reset_state(STp);
3751			STp->pos_unknown = 1;
3752		} else { /* return error */
3753			retval = i;
3754			goto out;
3755		}
3756	} else { /* flush_buffer succeeds */
3757		if (STp->can_partitions) {
3758			i = switch_partition(STp);
3759			if (i < 0) {
3760				retval = i;
3761				goto out;
3762			}
3763		}
3764	}
3765
3766	if (cmd_mtiocget) {
3767		struct mtget mt_status;
3768
3769		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3770			 retval = (-EINVAL);
3771			 goto out;
3772		}
3773
3774		mt_status.mt_type = STp->tape_type;
3775		mt_status.mt_dsreg =
3776		    ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3777		    ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3778		mt_status.mt_blkno = STps->drv_block;
3779		mt_status.mt_fileno = STps->drv_file;
3780		if (STp->block_size != 0 && mt_status.mt_blkno >= 0) {
3781			if (STps->rw == ST_WRITING)
3782				mt_status.mt_blkno +=
3783				    (STp->buffer)->buffer_bytes / STp->block_size;
3784			else if (STps->rw == ST_READING)
3785				mt_status.mt_blkno -=
3786                                        ((STp->buffer)->buffer_bytes +
3787                                         STp->block_size - 1) / STp->block_size;
3788		}
3789
3790		mt_status.mt_gstat = 0;
3791		if (STp->drv_write_prot)
3792			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3793		if (mt_status.mt_blkno == 0) {
3794			if (mt_status.mt_fileno == 0)
3795				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3796			else
3797				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3798		}
3799		mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3800		mt_status.mt_resid = STp->partition;
3801		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3802			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3803		else if (STps->eof >= ST_EOM_OK)
3804			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3805		if (STp->density == 1)
3806			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3807		else if (STp->density == 2)
3808			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3809		else if (STp->density == 3)
3810			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3811		if (STp->ready == ST_READY)
3812			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3813		if (STp->ready == ST_NO_TAPE)
3814			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3815		if (STps->at_sm)
3816			mt_status.mt_gstat |= GMT_SM(0xffffffff);
3817		if (STm->do_async_writes ||
3818                    (STm->do_buffer_writes && STp->block_size != 0) ||
3819		    STp->drv_buffer != 0)
3820			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3821		if (STp->cleaning_req)
3822			mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3823
3824		retval = put_user_mtget(p, &mt_status);
3825		if (retval)
3826			goto out;
3827
3828		STp->recover_reg = 0;		/* Clear after read */
3829		goto out;
3830	}			/* End of MTIOCGET */
3831	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3832		struct mtpos mt_pos;
3833		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3834			 retval = (-EINVAL);
3835			 goto out;
3836		}
3837		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3838			retval = i;
3839			goto out;
3840		}
3841		mt_pos.mt_blkno = blk;
3842		retval = put_user_mtpos(p, &mt_pos);
3843		goto out;
3844	}
3845	mutex_unlock(&STp->lock);
3846
3847	switch (cmd_in) {
3848	case SG_IO:
3849	case SCSI_IOCTL_SEND_COMMAND:
3850	case CDROM_SEND_PACKET:
3851		if (!capable(CAP_SYS_RAWIO))
3852			return -EPERM;
3853		break;
3854	default:
3855		break;
3856	}
 
 
 
3857
3858	retval = scsi_ioctl(STp->device, file->f_mode & FMODE_WRITE, cmd_in, p);
3859	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) {
3860		/* unload */
3861		STp->rew_at_close = 0;
3862		STp->ready = ST_NO_TAPE;
 
 
 
 
 
 
 
3863	}
3864	return retval;
3865
3866 out:
3867	mutex_unlock(&STp->lock);
3868	return retval;
3869}
3870
 
 
 
 
 
 
 
 
 
 
 
 
 
3871#ifdef CONFIG_COMPAT
3872static long st_compat_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3873{
 
 
 
 
3874	/* argument conversion is handled using put_user_mtpos/put_user_mtget */
3875	switch (cmd_in) {
3876	case MTIOCPOS32:
3877		cmd_in = MTIOCPOS;
3878		break;
3879	case MTIOCGET32:
3880		cmd_in = MTIOCGET;
3881		break;
3882	}
3883
3884	return st_ioctl(file, cmd_in, arg);
 
 
 
 
3885}
3886#endif
3887
3888
3889
3890/* Try to allocate a new tape buffer. Calling function must not hold
3891   dev_arr_lock. */
3892static struct st_buffer *new_tape_buffer(int max_sg)
3893{
3894	struct st_buffer *tb;
3895
3896	tb = kzalloc(sizeof(struct st_buffer), GFP_KERNEL);
3897	if (!tb) {
3898		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3899		return NULL;
3900	}
3901	tb->frp_segs = 0;
3902	tb->use_sg = max_sg;
 
3903	tb->buffer_size = 0;
3904
3905	tb->reserved_pages = kcalloc(max_sg, sizeof(struct page *),
3906				     GFP_KERNEL);
3907	if (!tb->reserved_pages) {
3908		kfree(tb);
3909		return NULL;
3910	}
3911
3912	return tb;
3913}
3914
3915
3916/* Try to allocate enough space in the tape buffer */
3917#define ST_MAX_ORDER 6
3918
3919static int enlarge_buffer(struct st_buffer * STbuffer, int new_size)
3920{
3921	int segs, max_segs, b_size, order, got;
3922	gfp_t priority;
3923
3924	if (new_size <= STbuffer->buffer_size)
3925		return 1;
3926
3927	if (STbuffer->buffer_size <= PAGE_SIZE)
3928		normalize_buffer(STbuffer);  /* Avoid extra segment */
3929
3930	max_segs = STbuffer->use_sg;
3931
3932	priority = GFP_KERNEL | __GFP_NOWARN;
 
 
3933
3934	if (STbuffer->cleared)
3935		priority |= __GFP_ZERO;
3936
3937	if (STbuffer->frp_segs) {
3938		order = STbuffer->reserved_page_order;
3939		b_size = PAGE_SIZE << order;
3940	} else {
3941		for (b_size = PAGE_SIZE, order = 0;
3942		     order < ST_MAX_ORDER &&
3943			     max_segs * (PAGE_SIZE << order) < new_size;
3944		     order++, b_size *= 2)
3945			;  /* empty */
3946		STbuffer->reserved_page_order = order;
3947	}
3948	if (max_segs * (PAGE_SIZE << order) < new_size) {
3949		if (order == ST_MAX_ORDER)
3950			return 0;
3951		normalize_buffer(STbuffer);
3952		return enlarge_buffer(STbuffer, new_size);
3953	}
3954
3955	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3956	     segs < max_segs && got < new_size;) {
3957		struct page *page;
3958
3959		page = alloc_pages(priority, order);
3960		if (!page) {
3961			DEB(STbuffer->buffer_size = got);
3962			normalize_buffer(STbuffer);
3963			return 0;
3964		}
3965
3966		STbuffer->frp_segs += 1;
3967		got += b_size;
3968		STbuffer->buffer_size = got;
3969		STbuffer->reserved_pages[segs] = page;
3970		segs++;
3971	}
3972	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3973
3974	return 1;
3975}
3976
3977
3978/* Make sure that no data from previous user is in the internal buffer */
3979static void clear_buffer(struct st_buffer * st_bp)
3980{
3981	int i;
3982
3983	for (i=0; i < st_bp->frp_segs; i++)
3984		memset(page_address(st_bp->reserved_pages[i]), 0,
3985		       PAGE_SIZE << st_bp->reserved_page_order);
3986	st_bp->cleared = 1;
3987}
3988
3989
3990/* Release the extra buffer */
3991static void normalize_buffer(struct st_buffer * STbuffer)
3992{
3993	int i, order = STbuffer->reserved_page_order;
3994
3995	for (i = 0; i < STbuffer->frp_segs; i++) {
3996		__free_pages(STbuffer->reserved_pages[i], order);
3997		STbuffer->buffer_size -= (PAGE_SIZE << order);
3998	}
3999	STbuffer->frp_segs = 0;
4000	STbuffer->sg_segs = 0;
4001	STbuffer->reserved_page_order = 0;
4002	STbuffer->map_data.offset = 0;
4003}
4004
4005
4006/* Move data from the user buffer to the tape buffer. Returns zero (success) or
4007   negative error code. */
4008static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
4009{
4010	int i, cnt, res, offset;
4011	int length = PAGE_SIZE << st_bp->reserved_page_order;
4012
4013	for (i = 0, offset = st_bp->buffer_bytes;
4014	     i < st_bp->frp_segs && offset >= length; i++)
4015		offset -= length;
4016	if (i == st_bp->frp_segs) {	/* Should never happen */
4017		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
4018		return (-EIO);
4019	}
4020	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4021		struct page *page = st_bp->reserved_pages[i];
4022		cnt = length - offset < do_count ? length - offset : do_count;
4023		res = copy_from_user(page_address(page) + offset, ubp, cnt);
4024		if (res)
4025			return (-EFAULT);
4026		do_count -= cnt;
4027		st_bp->buffer_bytes += cnt;
4028		ubp += cnt;
4029		offset = 0;
4030	}
4031	if (do_count) /* Should never happen */
4032		return (-EIO);
4033
4034	return 0;
4035}
4036
4037
4038/* Move data from the tape buffer to the user buffer. Returns zero (success) or
4039   negative error code. */
4040static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
4041{
4042	int i, cnt, res, offset;
4043	int length = PAGE_SIZE << st_bp->reserved_page_order;
4044
4045	for (i = 0, offset = st_bp->read_pointer;
4046	     i < st_bp->frp_segs && offset >= length; i++)
4047		offset -= length;
4048	if (i == st_bp->frp_segs) {	/* Should never happen */
4049		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
4050		return (-EIO);
4051	}
4052	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4053		struct page *page = st_bp->reserved_pages[i];
4054		cnt = length - offset < do_count ? length - offset : do_count;
4055		res = copy_to_user(ubp, page_address(page) + offset, cnt);
4056		if (res)
4057			return (-EFAULT);
4058		do_count -= cnt;
4059		st_bp->buffer_bytes -= cnt;
4060		st_bp->read_pointer += cnt;
4061		ubp += cnt;
4062		offset = 0;
4063	}
4064	if (do_count) /* Should never happen */
4065		return (-EIO);
4066
4067	return 0;
4068}
4069
4070
4071/* Move data towards start of buffer */
4072static void move_buffer_data(struct st_buffer * st_bp, int offset)
4073{
4074	int src_seg, dst_seg, src_offset = 0, dst_offset;
4075	int count, total;
4076	int length = PAGE_SIZE << st_bp->reserved_page_order;
4077
4078	if (offset == 0)
4079		return;
4080
4081	total=st_bp->buffer_bytes - offset;
4082	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
4083		src_offset = offset;
4084		if (src_offset < length)
4085			break;
4086		offset -= length;
4087	}
4088
4089	st_bp->buffer_bytes = st_bp->read_pointer = total;
4090	for (dst_seg=dst_offset=0; total > 0; ) {
4091		struct page *dpage = st_bp->reserved_pages[dst_seg];
4092		struct page *spage = st_bp->reserved_pages[src_seg];
4093
4094		count = min(length - dst_offset, length - src_offset);
4095		memmove(page_address(dpage) + dst_offset,
4096			page_address(spage) + src_offset, count);
4097		src_offset += count;
4098		if (src_offset >= length) {
4099			src_seg++;
4100			src_offset = 0;
4101		}
4102		dst_offset += count;
4103		if (dst_offset >= length) {
4104			dst_seg++;
4105			dst_offset = 0;
4106		}
4107		total -= count;
4108	}
4109}
4110
4111/* Validate the options from command line or module parameters */
4112static void validate_options(void)
4113{
4114	if (buffer_kbs > 0)
4115		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
4116	if (max_sg_segs >= ST_FIRST_SG)
4117		st_max_sg_segs = max_sg_segs;
4118}
4119
4120#ifndef MODULE
4121/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
4122 */
4123static int __init st_setup(char *str)
4124{
4125	int i, len, ints[5];
4126	char *stp;
4127
4128	stp = get_options(str, ARRAY_SIZE(ints), ints);
4129
4130	if (ints[0] > 0) {
4131		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
4132			if (parms[i].val)
4133				*parms[i].val = ints[i + 1];
4134	} else {
4135		while (stp != NULL) {
4136			for (i = 0; i < ARRAY_SIZE(parms); i++) {
4137				len = strlen(parms[i].name);
4138				if (!strncmp(stp, parms[i].name, len) &&
4139				    (*(stp + len) == ':' || *(stp + len) == '=')) {
4140					if (parms[i].val)
4141						*parms[i].val =
4142							simple_strtoul(stp + len + 1, NULL, 0);
4143					else
4144						printk(KERN_WARNING "st: Obsolete parameter %s\n",
4145						       parms[i].name);
4146					break;
4147				}
4148			}
4149			if (i >= ARRAY_SIZE(parms))
4150				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
4151					stp);
4152			stp = strchr(stp, ',');
4153			if (stp)
4154				stp++;
4155		}
4156	}
4157
4158	validate_options();
4159
4160	return 1;
4161}
4162
4163__setup("st=", st_setup);
4164
4165#endif
4166
4167static const struct file_operations st_fops =
4168{
4169	.owner =	THIS_MODULE,
4170	.read =		st_read,
4171	.write =	st_write,
4172	.unlocked_ioctl = st_ioctl,
4173#ifdef CONFIG_COMPAT
4174	.compat_ioctl = st_compat_ioctl,
4175#endif
4176	.open =		st_open,
4177	.flush =	st_flush,
4178	.release =	st_release,
4179	.llseek =	noop_llseek,
4180};
4181
4182static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
4183{
4184	int i, error;
4185	dev_t cdev_devno;
4186	struct cdev *cdev;
4187	struct device *dev;
4188	struct st_modedef *STm = &(tape->modes[mode]);
4189	char name[10];
4190	int dev_num = tape->index;
4191
4192	cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
4193
4194	cdev = cdev_alloc();
4195	if (!cdev) {
4196		pr_err("st%d: out of memory. Device not attached.\n", dev_num);
4197		error = -ENOMEM;
4198		goto out;
4199	}
4200	cdev->owner = THIS_MODULE;
4201	cdev->ops = &st_fops;
4202	STm->cdevs[rew] = cdev;
4203
4204	error = cdev_add(cdev, cdev_devno, 1);
4205	if (error) {
4206		pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
4207		       rew ? "non" : "auto", mode);
4208		pr_err("st%d: Device not attached.\n", dev_num);
4209		goto out_free;
4210	}
4211
4212	i = mode << (4 - ST_NBR_MODE_BITS);
4213	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4214		 tape->name, st_formats[i]);
4215
4216	dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
4217			    cdev_devno, &tape->modes[mode], "%s", name);
4218	if (IS_ERR(dev)) {
4219		pr_err("st%d: device_create failed\n", dev_num);
4220		error = PTR_ERR(dev);
4221		goto out_free;
4222	}
4223
4224	STm->devs[rew] = dev;
4225
4226	return 0;
4227out_free:
4228	cdev_del(STm->cdevs[rew]);
4229out:
4230	STm->cdevs[rew] = NULL;
4231	STm->devs[rew] = NULL;
4232	return error;
4233}
4234
4235static int create_cdevs(struct scsi_tape *tape)
4236{
4237	int mode, error;
4238	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4239		error = create_one_cdev(tape, mode, 0);
4240		if (error)
4241			return error;
4242		error = create_one_cdev(tape, mode, 1);
4243		if (error)
4244			return error;
4245	}
4246
4247	return sysfs_create_link(&tape->device->sdev_gendev.kobj,
4248				 &tape->modes[0].devs[0]->kobj, "tape");
4249}
4250
4251static void remove_cdevs(struct scsi_tape *tape)
4252{
4253	int mode, rew;
4254	sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
4255	for (mode = 0; mode < ST_NBR_MODES; mode++) {
4256		struct st_modedef *STm = &(tape->modes[mode]);
4257		for (rew = 0; rew < 2; rew++) {
4258			if (STm->cdevs[rew])
4259				cdev_del(STm->cdevs[rew]);
4260			if (STm->devs[rew])
4261				device_unregister(STm->devs[rew]);
4262		}
4263	}
4264}
4265
4266static int st_probe(struct device *dev)
4267{
4268	struct scsi_device *SDp = to_scsi_device(dev);
 
4269	struct scsi_tape *tpnt = NULL;
4270	struct st_modedef *STm;
4271	struct st_partstat *STps;
4272	struct st_buffer *buffer;
4273	int i, error;
 
4274
4275	if (SDp->type != TYPE_TAPE)
4276		return -ENODEV;
4277	if (st_incompatible(SDp)) {
4278		sdev_printk(KERN_INFO, SDp,
4279			    "OnStream tapes are no longer supported;\n");
4280		sdev_printk(KERN_INFO, SDp,
4281			    "please mail to linux-scsi@vger.kernel.org.\n");
4282		return -ENODEV;
4283	}
4284
4285	scsi_autopm_get_device(SDp);
4286	i = queue_max_segments(SDp->request_queue);
4287	if (st_max_sg_segs < i)
4288		i = st_max_sg_segs;
4289	buffer = new_tape_buffer(i);
4290	if (buffer == NULL) {
4291		sdev_printk(KERN_ERR, SDp,
4292			    "st: Can't allocate new tape buffer. "
4293			    "Device not attached.\n");
4294		goto out;
4295	}
4296
 
 
 
 
 
 
 
4297	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_KERNEL);
4298	if (tpnt == NULL) {
4299		sdev_printk(KERN_ERR, SDp,
4300			    "st: Can't allocate device descriptor.\n");
4301		goto out_buffer_free;
4302	}
4303	kref_init(&tpnt->kref);
 
 
 
 
 
 
 
 
4304
4305	tpnt->device = SDp;
4306	if (SDp->scsi_level <= 2)
4307		tpnt->tape_type = MT_ISSCSI1;
4308	else
4309		tpnt->tape_type = MT_ISSCSI2;
4310
4311	tpnt->buffer = buffer;
4312	tpnt->buffer->last_SRpnt = NULL;
4313
4314	tpnt->inited = 0;
4315	tpnt->dirty = 0;
4316	tpnt->in_use = 0;
4317	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
 
4318	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4319	tpnt->density = 0;
4320	tpnt->do_auto_lock = ST_AUTO_LOCK;
4321	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4322	tpnt->can_partitions = 0;
4323	tpnt->two_fm = ST_TWO_FM;
4324	tpnt->fast_mteom = ST_FAST_MTEOM;
4325	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4326	tpnt->sili = ST_SILI;
4327	tpnt->immediate = ST_NOWAIT;
4328	tpnt->immediate_filemark = 0;
4329	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4330	tpnt->partition = 0;
4331	tpnt->new_partition = 0;
4332	tpnt->nbr_partitions = 0;
4333	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4334	tpnt->long_timeout = ST_LONG_TIMEOUT;
4335	tpnt->try_dio = try_direct_io;
4336	tpnt->first_tur = 1;
4337
4338	for (i = 0; i < ST_NBR_MODES; i++) {
4339		STm = &(tpnt->modes[i]);
4340		STm->defined = 0;
4341		STm->sysv = ST_SYSV;
4342		STm->defaults_for_writes = 0;
4343		STm->do_async_writes = ST_ASYNC_WRITES;
4344		STm->do_buffer_writes = ST_BUFFER_WRITES;
4345		STm->do_read_ahead = ST_READ_AHEAD;
4346		STm->default_compression = ST_DONT_TOUCH;
4347		STm->default_blksize = (-1);	/* No forced size */
4348		STm->default_density = (-1);	/* No forced density */
4349		STm->tape = tpnt;
4350	}
4351
4352	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4353		STps = &(tpnt->ps[i]);
4354		STps->rw = ST_IDLE;
4355		STps->eof = ST_NOEOF;
4356		STps->at_sm = 0;
4357		STps->last_block_valid = 0;
4358		STps->drv_block = (-1);
4359		STps->drv_file = (-1);
4360	}
4361
4362	tpnt->current_mode = 0;
4363	tpnt->modes[0].defined = 1;
4364
4365	tpnt->density_changed = tpnt->compression_changed =
4366	    tpnt->blksize_changed = 0;
4367	mutex_init(&tpnt->lock);
4368
4369	idr_preload(GFP_KERNEL);
4370	spin_lock(&st_index_lock);
4371	error = idr_alloc(&st_index_idr, tpnt, 0, ST_MAX_TAPES + 1, GFP_NOWAIT);
4372	spin_unlock(&st_index_lock);
4373	idr_preload_end();
4374	if (error < 0) {
4375		pr_warn("st: idr allocation failed: %d\n", error);
4376		goto out_free_tape;
4377	}
4378	tpnt->index = error;
4379	sprintf(tpnt->name, "st%d", tpnt->index);
4380	tpnt->stats = kzalloc(sizeof(struct scsi_tape_stats), GFP_KERNEL);
4381	if (tpnt->stats == NULL) {
4382		sdev_printk(KERN_ERR, SDp,
4383			    "st: Can't allocate statistics.\n");
4384		goto out_idr_remove;
4385	}
4386
4387	dev_set_drvdata(dev, tpnt);
4388
4389
4390	error = create_cdevs(tpnt);
4391	if (error)
4392		goto out_remove_devs;
4393	scsi_autopm_put_device(SDp);
4394
4395	sdev_printk(KERN_NOTICE, SDp,
4396		    "Attached scsi tape %s\n", tpnt->name);
4397	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4398		    tpnt->name, tpnt->try_dio ? "yes" : "no",
4399		    queue_dma_alignment(SDp->request_queue) + 1);
4400
4401	return 0;
4402
4403out_remove_devs:
4404	remove_cdevs(tpnt);
4405	kfree(tpnt->stats);
4406out_idr_remove:
4407	spin_lock(&st_index_lock);
4408	idr_remove(&st_index_idr, tpnt->index);
4409	spin_unlock(&st_index_lock);
4410out_free_tape:
 
 
 
4411	kfree(tpnt);
4412out_buffer_free:
4413	kfree(buffer);
4414out:
4415	scsi_autopm_put_device(SDp);
4416	return -ENODEV;
4417};
4418
4419
4420static int st_remove(struct device *dev)
4421{
4422	struct scsi_tape *tpnt = dev_get_drvdata(dev);
4423	int index = tpnt->index;
4424
4425	scsi_autopm_get_device(to_scsi_device(dev));
4426	remove_cdevs(tpnt);
4427
4428	mutex_lock(&st_ref_mutex);
4429	kref_put(&tpnt->kref, scsi_tape_release);
4430	mutex_unlock(&st_ref_mutex);
4431	spin_lock(&st_index_lock);
4432	idr_remove(&st_index_idr, index);
4433	spin_unlock(&st_index_lock);
4434	return 0;
4435}
4436
4437/**
4438 *      scsi_tape_release - Called to free the Scsi_Tape structure
4439 *      @kref: pointer to embedded kref
4440 *
4441 *      st_ref_mutex must be held entering this routine.  Because it is
4442 *      called on last put, you should always use the scsi_tape_get()
4443 *      scsi_tape_put() helpers which manipulate the semaphore directly
4444 *      and never do a direct kref_put().
4445 **/
4446static void scsi_tape_release(struct kref *kref)
4447{
4448	struct scsi_tape *tpnt = to_scsi_tape(kref);
 
4449
4450	tpnt->device = NULL;
4451
4452	if (tpnt->buffer) {
4453		normalize_buffer(tpnt->buffer);
4454		kfree(tpnt->buffer->reserved_pages);
4455		kfree(tpnt->buffer);
4456	}
4457
 
 
4458	kfree(tpnt->stats);
4459	kfree(tpnt);
4460	return;
4461}
4462
4463static const struct class st_sysfs_class = {
4464	.name = "scsi_tape",
4465	.dev_groups = st_dev_groups,
4466};
4467
4468static int __init init_st(void)
4469{
4470	int err;
4471
4472	validate_options();
4473
4474	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4475		verstr, st_fixed_buffer_size, st_max_sg_segs);
4476
4477	debugging = (debug_flag > 0) ? debug_flag : NO_DEBUG;
4478	if (debugging) {
4479		printk(KERN_INFO "st: Debugging enabled debug_flag = %d\n",
4480			debugging);
4481	}
4482
4483	err = class_register(&st_sysfs_class);
4484	if (err) {
4485		pr_err("Unable register sysfs class for SCSI tapes\n");
4486		return err;
4487	}
4488
4489	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4490				     ST_MAX_TAPE_ENTRIES, "st");
4491	if (err) {
4492		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4493		       SCSI_TAPE_MAJOR);
4494		goto err_class;
4495	}
4496
4497	err = scsi_register_driver(&st_template.gendrv);
4498	if (err)
4499		goto err_chrdev;
4500
4501	return 0;
4502
4503err_chrdev:
4504	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4505				 ST_MAX_TAPE_ENTRIES);
4506err_class:
4507	class_unregister(&st_sysfs_class);
4508	return err;
4509}
4510
4511static void __exit exit_st(void)
4512{
4513	scsi_unregister_driver(&st_template.gendrv);
4514	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4515				 ST_MAX_TAPE_ENTRIES);
4516	class_unregister(&st_sysfs_class);
4517	idr_destroy(&st_index_idr);
4518	printk(KERN_INFO "st: Unloaded.\n");
4519}
4520
4521module_init(init_st);
4522module_exit(exit_st);
4523
4524
4525/* The sysfs driver interface. Read-only at the moment */
4526static ssize_t try_direct_io_show(struct device_driver *ddp, char *buf)
4527{
4528	return scnprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4529}
4530static DRIVER_ATTR_RO(try_direct_io);
4531
4532static ssize_t fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4533{
4534	return scnprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4535}
4536static DRIVER_ATTR_RO(fixed_buffer_size);
4537
4538static ssize_t max_sg_segs_show(struct device_driver *ddp, char *buf)
4539{
4540	return scnprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4541}
4542static DRIVER_ATTR_RO(max_sg_segs);
4543
4544static ssize_t version_show(struct device_driver *ddd, char *buf)
4545{
4546	return scnprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4547}
4548static DRIVER_ATTR_RO(version);
4549
4550#if DEBUG
4551static ssize_t debug_flag_store(struct device_driver *ddp,
4552	const char *buf, size_t count)
4553{
4554/* We only care what the first byte of the data is the rest is unused.
4555 * if it's a '1' we turn on debug and if it's a '0' we disable it. All
4556 * other values have -EINVAL returned if they are passed in.
4557 */
4558	if (count > 0) {
4559		if (buf[0] == '0') {
4560			debugging = NO_DEBUG;
4561			return count;
4562		} else if (buf[0] == '1') {
4563			debugging = 1;
4564			return count;
4565		}
4566	}
4567	return -EINVAL;
4568}
4569
4570static ssize_t debug_flag_show(struct device_driver *ddp, char *buf)
4571{
4572	return scnprintf(buf, PAGE_SIZE, "%d\n", debugging);
4573}
4574static DRIVER_ATTR_RW(debug_flag);
4575#endif
4576
4577static struct attribute *st_drv_attrs[] = {
4578	&driver_attr_try_direct_io.attr,
4579	&driver_attr_fixed_buffer_size.attr,
4580	&driver_attr_max_sg_segs.attr,
4581	&driver_attr_version.attr,
4582#if DEBUG
4583	&driver_attr_debug_flag.attr,
4584#endif
4585	NULL,
4586};
4587ATTRIBUTE_GROUPS(st_drv);
4588
4589/* The sysfs simple class interface */
4590static ssize_t
4591defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4592{
4593	struct st_modedef *STm = dev_get_drvdata(dev);
4594	ssize_t l = 0;
4595
4596	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4597	return l;
4598}
4599static DEVICE_ATTR_RO(defined);
4600
4601static ssize_t
4602default_blksize_show(struct device *dev, struct device_attribute *attr,
4603		     char *buf)
4604{
4605	struct st_modedef *STm = dev_get_drvdata(dev);
4606	ssize_t l = 0;
4607
4608	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4609	return l;
4610}
4611static DEVICE_ATTR_RO(default_blksize);
4612
4613static ssize_t
4614default_density_show(struct device *dev, struct device_attribute *attr,
4615		     char *buf)
4616{
4617	struct st_modedef *STm = dev_get_drvdata(dev);
4618	ssize_t l = 0;
4619	char *fmt;
4620
4621	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4622	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4623	return l;
4624}
4625static DEVICE_ATTR_RO(default_density);
4626
4627static ssize_t
4628default_compression_show(struct device *dev, struct device_attribute *attr,
4629			 char *buf)
4630{
4631	struct st_modedef *STm = dev_get_drvdata(dev);
4632	ssize_t l = 0;
4633
4634	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4635	return l;
4636}
4637static DEVICE_ATTR_RO(default_compression);
4638
4639static ssize_t
4640options_show(struct device *dev, struct device_attribute *attr, char *buf)
4641{
4642	struct st_modedef *STm = dev_get_drvdata(dev);
4643	struct scsi_tape *STp = STm->tape;
4644	int options;
4645	ssize_t l = 0;
4646
4647	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4648	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4649	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4650	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4651	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4652	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4653	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4654	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4655	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4656	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4657	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4658	options |= STm->sysv ? MT_ST_SYSV : 0;
4659	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4660	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4661	options |= STp->sili ? MT_ST_SILI : 0;
4662
4663	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4664	return l;
4665}
4666static DEVICE_ATTR_RO(options);
4667
4668/* Support for tape stats */
4669
4670/**
4671 * read_cnt_show - return read count - count of reads made from tape drive
4672 * @dev: struct device
4673 * @attr: attribute structure
4674 * @buf: buffer to return formatted data in
4675 */
4676static ssize_t read_cnt_show(struct device *dev,
4677	struct device_attribute *attr, char *buf)
4678{
4679	struct st_modedef *STm = dev_get_drvdata(dev);
4680
4681	return sprintf(buf, "%lld",
4682		       (long long)atomic64_read(&STm->tape->stats->read_cnt));
4683}
4684static DEVICE_ATTR_RO(read_cnt);
4685
4686/**
4687 * read_byte_cnt_show - return read byte count - tape drives
4688 * may use blocks less than 512 bytes this gives the raw byte count of
4689 * of data read from the tape drive.
4690 * @dev: struct device
4691 * @attr: attribute structure
4692 * @buf: buffer to return formatted data in
4693 */
4694static ssize_t read_byte_cnt_show(struct device *dev,
4695	struct device_attribute *attr, char *buf)
4696{
4697	struct st_modedef *STm = dev_get_drvdata(dev);
4698
4699	return sprintf(buf, "%lld",
4700		       (long long)atomic64_read(&STm->tape->stats->read_byte_cnt));
4701}
4702static DEVICE_ATTR_RO(read_byte_cnt);
4703
4704/**
4705 * read_ns_show - return read ns - overall time spent waiting on reads in ns.
4706 * @dev: struct device
4707 * @attr: attribute structure
4708 * @buf: buffer to return formatted data in
4709 */
4710static ssize_t read_ns_show(struct device *dev,
4711	struct device_attribute *attr, char *buf)
4712{
4713	struct st_modedef *STm = dev_get_drvdata(dev);
4714
4715	return sprintf(buf, "%lld",
4716		       (long long)atomic64_read(&STm->tape->stats->tot_read_time));
4717}
4718static DEVICE_ATTR_RO(read_ns);
4719
4720/**
4721 * write_cnt_show - write count - number of user calls
4722 * to write(2) that have written data to tape.
4723 * @dev: struct device
4724 * @attr: attribute structure
4725 * @buf: buffer to return formatted data in
4726 */
4727static ssize_t write_cnt_show(struct device *dev,
4728	struct device_attribute *attr, char *buf)
4729{
4730	struct st_modedef *STm = dev_get_drvdata(dev);
4731
4732	return sprintf(buf, "%lld",
4733		       (long long)atomic64_read(&STm->tape->stats->write_cnt));
4734}
4735static DEVICE_ATTR_RO(write_cnt);
4736
4737/**
4738 * write_byte_cnt_show - write byte count - raw count of
4739 * bytes written to tape.
4740 * @dev: struct device
4741 * @attr: attribute structure
4742 * @buf: buffer to return formatted data in
4743 */
4744static ssize_t write_byte_cnt_show(struct device *dev,
4745	struct device_attribute *attr, char *buf)
4746{
4747	struct st_modedef *STm = dev_get_drvdata(dev);
4748
4749	return sprintf(buf, "%lld",
4750		       (long long)atomic64_read(&STm->tape->stats->write_byte_cnt));
4751}
4752static DEVICE_ATTR_RO(write_byte_cnt);
4753
4754/**
4755 * write_ns_show - write ns - number of nanoseconds waiting on write
4756 * requests to complete.
4757 * @dev: struct device
4758 * @attr: attribute structure
4759 * @buf: buffer to return formatted data in
4760 */
4761static ssize_t write_ns_show(struct device *dev,
4762	struct device_attribute *attr, char *buf)
4763{
4764	struct st_modedef *STm = dev_get_drvdata(dev);
4765
4766	return sprintf(buf, "%lld",
4767		       (long long)atomic64_read(&STm->tape->stats->tot_write_time));
4768}
4769static DEVICE_ATTR_RO(write_ns);
4770
4771/**
4772 * in_flight_show - number of I/Os currently in flight -
4773 * in most cases this will be either 0 or 1. It may be higher if someone
4774 * has also issued other SCSI commands such as via an ioctl.
4775 * @dev: struct device
4776 * @attr: attribute structure
4777 * @buf: buffer to return formatted data in
4778 */
4779static ssize_t in_flight_show(struct device *dev,
4780	struct device_attribute *attr, char *buf)
4781{
4782	struct st_modedef *STm = dev_get_drvdata(dev);
4783
4784	return sprintf(buf, "%lld",
4785		       (long long)atomic64_read(&STm->tape->stats->in_flight));
4786}
4787static DEVICE_ATTR_RO(in_flight);
4788
4789/**
4790 * io_ns_show - io wait ns - this is the number of ns spent
4791 * waiting on all I/O to complete. This includes tape movement commands
4792 * such as rewinding, seeking to end of file or tape, it also includes
4793 * read and write. To determine the time spent on tape movement
4794 * subtract the read and write ns from this value.
4795 * @dev: struct device
4796 * @attr: attribute structure
4797 * @buf: buffer to return formatted data in
4798 */
4799static ssize_t io_ns_show(struct device *dev,
4800	struct device_attribute *attr, char *buf)
4801{
4802	struct st_modedef *STm = dev_get_drvdata(dev);
4803
4804	return sprintf(buf, "%lld",
4805		       (long long)atomic64_read(&STm->tape->stats->tot_io_time));
4806}
4807static DEVICE_ATTR_RO(io_ns);
4808
4809/**
4810 * other_cnt_show - other io count - this is the number of
4811 * I/O requests other than read and write requests.
4812 * Typically these are tape movement requests but will include driver
4813 * tape movement. This includes only requests issued by the st driver.
4814 * @dev: struct device
4815 * @attr: attribute structure
4816 * @buf: buffer to return formatted data in
4817 */
4818static ssize_t other_cnt_show(struct device *dev,
4819	struct device_attribute *attr, char *buf)
4820{
4821	struct st_modedef *STm = dev_get_drvdata(dev);
4822
4823	return sprintf(buf, "%lld",
4824		       (long long)atomic64_read(&STm->tape->stats->other_cnt));
4825}
4826static DEVICE_ATTR_RO(other_cnt);
4827
4828/**
4829 * resid_cnt_show - A count of the number of times we get a residual
4830 * count - this should indicate someone issuing reads larger than the
4831 * block size on tape.
4832 * @dev: struct device
4833 * @attr: attribute structure
4834 * @buf: buffer to return formatted data in
4835 */
4836static ssize_t resid_cnt_show(struct device *dev,
4837	struct device_attribute *attr, char *buf)
4838{
4839	struct st_modedef *STm = dev_get_drvdata(dev);
4840
4841	return sprintf(buf, "%lld",
4842		       (long long)atomic64_read(&STm->tape->stats->resid_cnt));
4843}
4844static DEVICE_ATTR_RO(resid_cnt);
4845
4846static struct attribute *st_dev_attrs[] = {
4847	&dev_attr_defined.attr,
4848	&dev_attr_default_blksize.attr,
4849	&dev_attr_default_density.attr,
4850	&dev_attr_default_compression.attr,
4851	&dev_attr_options.attr,
4852	NULL,
4853};
4854
4855static struct attribute *st_stats_attrs[] = {
4856	&dev_attr_read_cnt.attr,
4857	&dev_attr_read_byte_cnt.attr,
4858	&dev_attr_read_ns.attr,
4859	&dev_attr_write_cnt.attr,
4860	&dev_attr_write_byte_cnt.attr,
4861	&dev_attr_write_ns.attr,
4862	&dev_attr_in_flight.attr,
4863	&dev_attr_io_ns.attr,
4864	&dev_attr_other_cnt.attr,
4865	&dev_attr_resid_cnt.attr,
4866	NULL,
4867};
4868
4869static struct attribute_group stats_group = {
4870	.name = "stats",
4871	.attrs = st_stats_attrs,
4872};
4873
4874static struct attribute_group st_group = {
4875	.attrs = st_dev_attrs,
4876};
4877
4878static const struct attribute_group *st_dev_groups[] = {
4879	&st_group,
4880	&stats_group,
4881	NULL,
4882};
4883
4884/* The following functions may be useful for a larger audience. */
4885static int sgl_map_user_pages(struct st_buffer *STbp,
4886			      const unsigned int max_pages, unsigned long uaddr,
4887			      size_t count, int rw)
4888{
4889	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4890	unsigned long start = uaddr >> PAGE_SHIFT;
4891	const int nr_pages = end - start;
4892	int res, i;
4893	struct page **pages;
4894	struct rq_map_data *mdata = &STbp->map_data;
4895
4896	/* User attempted Overflow! */
4897	if ((uaddr + count) < uaddr)
4898		return -EINVAL;
4899
4900	/* Too big */
4901        if (nr_pages > max_pages)
4902		return -ENOMEM;
4903
4904	/* Hmm? */
4905	if (count == 0)
4906		return 0;
4907
4908	pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
4909	if (pages == NULL)
4910		return -ENOMEM;
4911
4912        /* Try to fault in all of the necessary pages */
4913        /* rw==READ means read from drive, write into memory area */
4914	res = pin_user_pages_fast(uaddr, nr_pages, rw == READ ? FOLL_WRITE : 0,
4915				  pages);
4916
4917	/* Errors and no page mapped should return here */
4918	if (res < nr_pages)
4919		goto out_unmap;
4920
4921        for (i=0; i < nr_pages; i++) {
4922                /* FIXME: flush superflous for rw==READ,
4923                 * probably wrong function for rw==WRITE
4924                 */
4925		flush_dcache_page(pages[i]);
4926        }
4927
4928	mdata->offset = uaddr & ~PAGE_MASK;
4929	STbp->mapped_pages = pages;
4930
4931	return nr_pages;
4932 out_unmap:
4933	if (res > 0) {
4934		unpin_user_pages(pages, res);
4935		res = 0;
4936	}
4937	kfree(pages);
4938	return res;
4939}
4940
4941
4942/* And unmap them... */
4943static int sgl_unmap_user_pages(struct st_buffer *STbp,
4944				const unsigned int nr_pages, int dirtied)
4945{
4946	/* FIXME: cache flush missing for rw==READ */
4947	unpin_user_pages_dirty_lock(STbp->mapped_pages, nr_pages, dirtied);
4948
4949	kfree(STbp->mapped_pages);
4950	STbp->mapped_pages = NULL;
4951
4952	return 0;
4953}
v5.9
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3   SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
   4   file Documentation/scsi/st.rst for more information.
   5
   6   History:
   7   Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
   8   Contribution and ideas from several people including (in alphabetical
   9   order) Klaus Ehrenfried, Eugene Exarevsky, Eric Lee Green, Wolfgang Denk,
  10   Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
  11   Michael Schaefer, J"org Weule, and Eric Youngdale.
  12
  13   Copyright 1992 - 2016 Kai Makisara
  14   email Kai.Makisara@kolumbus.fi
  15
  16   Some small formal changes - aeb, 950809
  17
  18   Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
  19 */
  20
  21static const char *verstr = "20160209";
  22
  23#include <linux/module.h>
  24
  25#include <linux/compat.h>
  26#include <linux/fs.h>
  27#include <linux/kernel.h>
  28#include <linux/sched/signal.h>
  29#include <linux/mm.h>
  30#include <linux/init.h>
  31#include <linux/string.h>
  32#include <linux/slab.h>
  33#include <linux/errno.h>
  34#include <linux/mtio.h>
 
  35#include <linux/cdrom.h>
  36#include <linux/ioctl.h>
  37#include <linux/fcntl.h>
  38#include <linux/spinlock.h>
  39#include <linux/blkdev.h>
  40#include <linux/moduleparam.h>
  41#include <linux/cdev.h>
  42#include <linux/idr.h>
  43#include <linux/delay.h>
  44#include <linux/mutex.h>
  45
  46#include <linux/uaccess.h>
  47#include <asm/dma.h>
  48#include <asm/unaligned.h>
  49
  50#include <scsi/scsi.h>
  51#include <scsi/scsi_dbg.h>
  52#include <scsi/scsi_device.h>
  53#include <scsi/scsi_driver.h>
  54#include <scsi/scsi_eh.h>
  55#include <scsi/scsi_host.h>
  56#include <scsi/scsi_ioctl.h>
  57#include <scsi/sg.h>
  58
  59
  60/* The driver prints some debugging information on the console if DEBUG
  61   is defined and non-zero. */
  62#define DEBUG 1
  63#define NO_DEBUG 0
  64
  65#define ST_DEB_MSG  KERN_NOTICE
  66#if DEBUG
  67/* The message level for the debug messages is currently set to KERN_NOTICE
  68   so that people can easily see the messages. Later when the debugging messages
  69   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
  70#define DEB(a) a
  71#define DEBC(a) if (debugging) { a ; }
  72#else
  73#define DEB(a)
  74#define DEBC(a)
  75#endif
  76
  77#define ST_KILOBYTE 1024
  78
  79#include "st_options.h"
  80#include "st.h"
  81
  82static int buffer_kbs;
  83static int max_sg_segs;
  84static int try_direct_io = TRY_DIRECT_IO;
  85static int try_rdio = 1;
  86static int try_wdio = 1;
  87static int debug_flag;
  88
  89static struct class st_sysfs_class;
  90static const struct attribute_group *st_dev_groups[];
  91static const struct attribute_group *st_drv_groups[];
  92
  93MODULE_AUTHOR("Kai Makisara");
  94MODULE_DESCRIPTION("SCSI tape (st) driver");
  95MODULE_LICENSE("GPL");
  96MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  97MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  98
  99/* Set 'perm' (4th argument) to 0 to disable module_param's definition
 100 * of sysfs parameters (which module_param doesn't yet support).
 101 * Sysfs parameters defined explicitly later.
 102 */
 103module_param_named(buffer_kbs, buffer_kbs, int, 0);
 104MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
 105module_param_named(max_sg_segs, max_sg_segs, int, 0);
 106MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 107module_param_named(try_direct_io, try_direct_io, int, 0);
 108MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 109module_param_named(debug_flag, debug_flag, int, 0);
 110MODULE_PARM_DESC(debug_flag, "Enable DEBUG, same as setting debugging=1");
 111
 112
 113/* Extra parameters for testing */
 114module_param_named(try_rdio, try_rdio, int, 0);
 115MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 116module_param_named(try_wdio, try_wdio, int, 0);
 117MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 118
 119#ifndef MODULE
 120static int write_threshold_kbs;  /* retained for compatibility */
 121static struct st_dev_parm {
 122	char *name;
 123	int *val;
 124} parms[] __initdata = {
 125	{
 126		"buffer_kbs", &buffer_kbs
 127	},
 128	{       /* Retained for compatibility with 2.4 */
 129		"write_threshold_kbs", &write_threshold_kbs
 130	},
 131	{
 132		"max_sg_segs", NULL
 133	},
 134	{
 135		"try_direct_io", &try_direct_io
 136	},
 137	{
 138		"debug_flag", &debug_flag
 139	}
 140};
 141#endif
 142
 143/* Restrict the number of modes so that names for all are assigned */
 144#if ST_NBR_MODES > 16
 145#error "Maximum number of modes is 16"
 146#endif
 147/* Bit reversed order to get same names for same minors with all
 148   mode counts */
 149static const char *st_formats[] = {
 150	"",  "r", "k", "s", "l", "t", "o", "u",
 151	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 152
 153/* The default definitions have been moved to st_options.h */
 154
 155#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 156
 157/* The buffer size should fit into the 24 bits for length in the
 158   6-byte SCSI read and write commands. */
 159#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 160#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 161#endif
 162
 163static int debugging = DEBUG;
 164
 165#define MAX_RETRIES 0
 166#define MAX_WRITE_RETRIES 0
 167#define MAX_READY_RETRIES 0
 168#define NO_TAPE  NOT_READY
 169
 170#define ST_TIMEOUT (900 * HZ)
 171#define ST_LONG_TIMEOUT (14000 * HZ)
 172
 173/* Remove mode bits and auto-rewind bit (7) */
 174#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 175	(iminor(x) & ((1 << ST_MODE_SHIFT)-1)))
 176#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 177
 178/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 179#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 180  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 181
 182/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 183   24 bits) */
 184#define SET_DENS_AND_BLK 0x10001
 185
 186static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 187static int st_max_sg_segs = ST_MAX_SG;
 188
 189static int modes_defined;
 190
 191static int enlarge_buffer(struct st_buffer *, int, int);
 192static void clear_buffer(struct st_buffer *);
 193static void normalize_buffer(struct st_buffer *);
 194static int append_to_buffer(const char __user *, struct st_buffer *, int);
 195static int from_buffer(struct st_buffer *, char __user *, int);
 196static void move_buffer_data(struct st_buffer *, int);
 197
 198static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 199			      unsigned long, size_t, int);
 200static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 201
 202static int st_probe(struct device *);
 203static int st_remove(struct device *);
 204
 205static struct scsi_driver st_template = {
 206	.gendrv = {
 207		.name		= "st",
 208		.owner		= THIS_MODULE,
 209		.probe		= st_probe,
 210		.remove		= st_remove,
 211		.groups		= st_drv_groups,
 212	},
 213};
 214
 215static int st_compression(struct scsi_tape *, int);
 216
 217static int find_partition(struct scsi_tape *);
 218static int switch_partition(struct scsi_tape *);
 219
 220static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 221
 222static void scsi_tape_release(struct kref *);
 223
 224#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 225
 226static DEFINE_MUTEX(st_ref_mutex);
 227static DEFINE_SPINLOCK(st_index_lock);
 228static DEFINE_SPINLOCK(st_use_lock);
 229static DEFINE_IDR(st_index_idr);
 230
 231
 232
 233#ifndef SIGS_FROM_OSST
 234#define SIGS_FROM_OSST \
 235	{"OnStream", "SC-", "", "osst"}, \
 236	{"OnStream", "DI-", "", "osst"}, \
 237	{"OnStream", "DP-", "", "osst"}, \
 238	{"OnStream", "USB", "", "osst"}, \
 239	{"OnStream", "FW-", "", "osst"}
 240#endif
 241
 242static struct scsi_tape *scsi_tape_get(int dev)
 243{
 244	struct scsi_tape *STp = NULL;
 245
 246	mutex_lock(&st_ref_mutex);
 247	spin_lock(&st_index_lock);
 248
 249	STp = idr_find(&st_index_idr, dev);
 250	if (!STp) goto out;
 251
 252	kref_get(&STp->kref);
 253
 254	if (!STp->device)
 255		goto out_put;
 256
 257	if (scsi_device_get(STp->device))
 258		goto out_put;
 259
 260	goto out;
 261
 262out_put:
 263	kref_put(&STp->kref, scsi_tape_release);
 264	STp = NULL;
 265out:
 266	spin_unlock(&st_index_lock);
 267	mutex_unlock(&st_ref_mutex);
 268	return STp;
 269}
 270
 271static void scsi_tape_put(struct scsi_tape *STp)
 272{
 273	struct scsi_device *sdev = STp->device;
 274
 275	mutex_lock(&st_ref_mutex);
 276	kref_put(&STp->kref, scsi_tape_release);
 277	scsi_device_put(sdev);
 278	mutex_unlock(&st_ref_mutex);
 279}
 280
 281struct st_reject_data {
 282	char *vendor;
 283	char *model;
 284	char *rev;
 285	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 286};
 287
 288static struct st_reject_data reject_list[] = {
 289	/* {"XXX", "Yy-", "", NULL},  example */
 290	SIGS_FROM_OSST,
 291	{NULL, }};
 292
 293/* If the device signature is on the list of incompatible drives, the
 294   function returns a pointer to the name of the correct driver (if known) */
 295static char * st_incompatible(struct scsi_device* SDp)
 296{
 297	struct st_reject_data *rp;
 298
 299	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 300		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 301		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 302		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 303			if (rp->driver_hint)
 304				return rp->driver_hint;
 305			else
 306				return "unknown";
 307		}
 308	return NULL;
 309}
 310
 311
 312static inline char *tape_name(struct scsi_tape *tape)
 313{
 314	return tape->disk->disk_name;
 315}
 316
 317#define st_printk(prefix, t, fmt, a...) \
 318	sdev_prefix_printk(prefix, (t)->device, tape_name(t), fmt, ##a)
 319#ifdef DEBUG
 320#define DEBC_printk(t, fmt, a...) \
 321	if (debugging) { st_printk(ST_DEB_MSG, t, fmt, ##a ); }
 322#else
 323#define DEBC_printk(t, fmt, a...)
 324#endif
 325
 326static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 327{
 328	const u8 *ucp;
 329	const u8 *sense = SRpnt->sense;
 330
 331	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 332				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 333	s->flags = 0;
 334
 335	if (s->have_sense) {
 336		s->deferred = 0;
 337		s->remainder_valid =
 338			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 339		switch (sense[0] & 0x7f) {
 340		case 0x71:
 341			s->deferred = 1;
 342			fallthrough;
 343		case 0x70:
 344			s->fixed_format = 1;
 345			s->flags = sense[2] & 0xe0;
 346			break;
 347		case 0x73:
 348			s->deferred = 1;
 349			fallthrough;
 350		case 0x72:
 351			s->fixed_format = 0;
 352			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 353			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 354			break;
 355		}
 356	}
 357}
 358
 359
 360/* Convert the result to success code */
 361static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 362{
 363	int result = SRpnt->result;
 364	u8 scode;
 365	DEB(const char *stp;)
 366	char *name = tape_name(STp);
 367	struct st_cmdstatus *cmdstatp;
 368
 369	if (!result)
 370		return 0;
 371
 372	cmdstatp = &STp->buffer->cmdstat;
 373	st_analyze_sense(SRpnt, cmdstatp);
 374
 375	if (cmdstatp->have_sense)
 376		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 377	else
 378		scode = 0;
 379
 380	DEB(
 381	if (debugging) {
 382		st_printk(ST_DEB_MSG, STp,
 383			    "Error: %x, cmd: %x %x %x %x %x %x\n", result,
 384			    SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 385			    SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 386		if (cmdstatp->have_sense)
 387			__scsi_print_sense(STp->device, name,
 388					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 389	} ) /* end DEB */
 390	if (!debugging) { /* Abnormal conditions for tape */
 391		if (!cmdstatp->have_sense)
 392			st_printk(KERN_WARNING, STp,
 393			       "Error %x (driver bt 0x%x, host bt 0x%x).\n",
 394			       result, driver_byte(result), host_byte(result));
 395		else if (cmdstatp->have_sense &&
 396			 scode != NO_SENSE &&
 397			 scode != RECOVERED_ERROR &&
 398			 /* scode != UNIT_ATTENTION && */
 399			 scode != BLANK_CHECK &&
 400			 scode != VOLUME_OVERFLOW &&
 401			 SRpnt->cmd[0] != MODE_SENSE &&
 402			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 403
 404			__scsi_print_sense(STp->device, name,
 405					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 406		}
 407	}
 408
 409	if (cmdstatp->fixed_format &&
 410	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 411		if (STp->cln_sense_value)
 412			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 413					       STp->cln_sense_mask) == STp->cln_sense_value);
 414		else
 415			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 416					       STp->cln_sense_mask) != 0);
 417	}
 418	if (cmdstatp->have_sense &&
 419	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 420		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 
 
 421
 422	STp->pos_unknown |= STp->device->was_reset;
 423
 424	if (cmdstatp->have_sense &&
 425	    scode == RECOVERED_ERROR
 426#if ST_RECOVERED_WRITE_FATAL
 427	    && SRpnt->cmd[0] != WRITE_6
 428	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 429#endif
 430	    ) {
 431		STp->recover_count++;
 432		STp->recover_reg++;
 433
 434		DEB(
 435		if (debugging) {
 436			if (SRpnt->cmd[0] == READ_6)
 437				stp = "read";
 438			else if (SRpnt->cmd[0] == WRITE_6)
 439				stp = "write";
 440			else
 441				stp = "ioctl";
 442			st_printk(ST_DEB_MSG, STp,
 443				  "Recovered %s error (%d).\n",
 444				  stp, STp->recover_count);
 445		} ) /* end DEB */
 446
 447		if (cmdstatp->flags == 0)
 448			return 0;
 449	}
 450	return (-EIO);
 451}
 452
 453static struct st_request *st_allocate_request(struct scsi_tape *stp)
 454{
 455	struct st_request *streq;
 456
 457	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 458	if (streq)
 459		streq->stp = stp;
 460	else {
 461		st_printk(KERN_ERR, stp,
 462			  "Can't get SCSI request.\n");
 463		if (signal_pending(current))
 464			stp->buffer->syscall_result = -EINTR;
 465		else
 466			stp->buffer->syscall_result = -EBUSY;
 467	}
 468
 469	return streq;
 470}
 471
 472static void st_release_request(struct st_request *streq)
 473{
 474	kfree(streq);
 475}
 476
 477static void st_do_stats(struct scsi_tape *STp, struct request *req)
 478{
 
 479	ktime_t now;
 480
 481	now = ktime_get();
 482	if (scsi_req(req)->cmd[0] == WRITE_6) {
 483		now = ktime_sub(now, STp->stats->write_time);
 484		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 485		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 486		atomic64_inc(&STp->stats->write_cnt);
 487		if (scsi_req(req)->result) {
 488			atomic64_add(atomic_read(&STp->stats->last_write_size)
 489				- STp->buffer->cmdstat.residual,
 490				&STp->stats->write_byte_cnt);
 491			if (STp->buffer->cmdstat.residual > 0)
 492				atomic64_inc(&STp->stats->resid_cnt);
 493		} else
 494			atomic64_add(atomic_read(&STp->stats->last_write_size),
 495				&STp->stats->write_byte_cnt);
 496	} else if (scsi_req(req)->cmd[0] == READ_6) {
 497		now = ktime_sub(now, STp->stats->read_time);
 498		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 499		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 500		atomic64_inc(&STp->stats->read_cnt);
 501		if (scsi_req(req)->result) {
 502			atomic64_add(atomic_read(&STp->stats->last_read_size)
 503				- STp->buffer->cmdstat.residual,
 504				&STp->stats->read_byte_cnt);
 505			if (STp->buffer->cmdstat.residual > 0)
 506				atomic64_inc(&STp->stats->resid_cnt);
 507		} else
 508			atomic64_add(atomic_read(&STp->stats->last_read_size),
 509				&STp->stats->read_byte_cnt);
 510	} else {
 511		now = ktime_sub(now, STp->stats->other_time);
 512		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 513		atomic64_inc(&STp->stats->other_cnt);
 514	}
 515	atomic64_dec(&STp->stats->in_flight);
 516}
 517
 518static void st_scsi_execute_end(struct request *req, blk_status_t status)
 
 519{
 
 520	struct st_request *SRpnt = req->end_io_data;
 521	struct scsi_request *rq = scsi_req(req);
 522	struct scsi_tape *STp = SRpnt->stp;
 523	struct bio *tmp;
 524
 525	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 526	STp->buffer->cmdstat.residual = rq->resid_len;
 527
 528	st_do_stats(STp, req);
 529
 530	tmp = SRpnt->bio;
 531	if (rq->sense_len)
 532		memcpy(SRpnt->sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
 533	if (SRpnt->waiting)
 534		complete(SRpnt->waiting);
 535
 536	blk_rq_unmap_user(tmp);
 537	blk_put_request(req);
 
 538}
 539
 540static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 541			   int data_direction, void *buffer, unsigned bufflen,
 542			   int timeout, int retries)
 543{
 544	struct request *req;
 545	struct scsi_request *rq;
 546	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 547	int err = 0;
 548	struct scsi_tape *STp = SRpnt->stp;
 
 549
 550	req = blk_get_request(SRpnt->stp->device->request_queue,
 551			data_direction == DMA_TO_DEVICE ?
 552			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 553	if (IS_ERR(req))
 554		return DRIVER_ERROR << 24;
 555	rq = scsi_req(req);
 556	req->rq_flags |= RQF_QUIET;
 557
 558	mdata->null_mapped = 1;
 559
 560	if (bufflen) {
 561		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 562				      GFP_KERNEL);
 563		if (err) {
 564			blk_put_request(req);
 565			return DRIVER_ERROR << 24;
 566		}
 567	}
 568
 569	atomic64_inc(&STp->stats->in_flight);
 570	if (cmd[0] == WRITE_6) {
 571		atomic_set(&STp->stats->last_write_size, bufflen);
 572		STp->stats->write_time = ktime_get();
 573	} else if (cmd[0] == READ_6) {
 574		atomic_set(&STp->stats->last_read_size, bufflen);
 575		STp->stats->read_time = ktime_get();
 576	} else {
 577		STp->stats->other_time = ktime_get();
 578	}
 579
 580	SRpnt->bio = req->bio;
 581	rq->cmd_len = COMMAND_SIZE(cmd[0]);
 582	memset(rq->cmd, 0, BLK_MAX_CDB);
 583	memcpy(rq->cmd, cmd, rq->cmd_len);
 584	req->timeout = timeout;
 585	rq->retries = retries;
 
 586	req->end_io_data = SRpnt;
 587
 588	blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
 589	return 0;
 590}
 591
 592/* Do the scsi command. Waits until command performed if do_wait is true.
 593   Otherwise write_behind_check() is used to check that the command
 594   has finished. */
 595static struct st_request *
 596st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 597	   int bytes, int direction, int timeout, int retries, int do_wait)
 598{
 599	struct completion *waiting;
 600	struct rq_map_data *mdata = &STp->buffer->map_data;
 601	int ret;
 602
 603	/* if async, make sure there's no command outstanding */
 604	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 605		st_printk(KERN_ERR, STp,
 606			  "Async command already active.\n");
 607		if (signal_pending(current))
 608			(STp->buffer)->syscall_result = (-EINTR);
 609		else
 610			(STp->buffer)->syscall_result = (-EBUSY);
 611		return NULL;
 612	}
 613
 614	if (!SRpnt) {
 615		SRpnt = st_allocate_request(STp);
 616		if (!SRpnt)
 617			return NULL;
 618	}
 619
 620	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 621	   which IO is outstanding. It's nulled out when the IO completes. */
 622	if (!do_wait)
 623		(STp->buffer)->last_SRpnt = SRpnt;
 624
 625	waiting = &STp->wait;
 626	init_completion(waiting);
 627	SRpnt->waiting = waiting;
 628
 629	if (STp->buffer->do_dio) {
 630		mdata->page_order = 0;
 631		mdata->nr_entries = STp->buffer->sg_segs;
 632		mdata->pages = STp->buffer->mapped_pages;
 633	} else {
 634		mdata->page_order = STp->buffer->reserved_page_order;
 635		mdata->nr_entries =
 636			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 637		mdata->pages = STp->buffer->reserved_pages;
 638		mdata->offset = 0;
 639	}
 640
 641	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 642	STp->buffer->cmdstat.have_sense = 0;
 643	STp->buffer->syscall_result = 0;
 644
 645	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 646			      retries);
 647	if (ret) {
 648		/* could not allocate the buffer or request was too large */
 649		(STp->buffer)->syscall_result = (-EBUSY);
 650		(STp->buffer)->last_SRpnt = NULL;
 651	} else if (do_wait) {
 652		wait_for_completion(waiting);
 653		SRpnt->waiting = NULL;
 654		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 655	}
 656
 657	return SRpnt;
 658}
 659
 660
 661/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 662   write has been correct but EOM early warning reached, -EIO if write ended in
 663   error or zero if write successful. Asynchronous writes are used only in
 664   variable block mode. */
 665static int write_behind_check(struct scsi_tape * STp)
 666{
 667	int retval = 0;
 668	struct st_buffer *STbuffer;
 669	struct st_partstat *STps;
 670	struct st_cmdstatus *cmdstatp;
 671	struct st_request *SRpnt;
 672
 673	STbuffer = STp->buffer;
 674	if (!STbuffer->writing)
 675		return 0;
 676
 677	DEB(
 678	if (STp->write_pending)
 679		STp->nbr_waits++;
 680	else
 681		STp->nbr_finished++;
 682	) /* end DEB */
 683
 684	wait_for_completion(&(STp->wait));
 685	SRpnt = STbuffer->last_SRpnt;
 686	STbuffer->last_SRpnt = NULL;
 687	SRpnt->waiting = NULL;
 688
 689	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 690	st_release_request(SRpnt);
 691
 692	STbuffer->buffer_bytes -= STbuffer->writing;
 693	STps = &(STp->ps[STp->partition]);
 694	if (STps->drv_block >= 0) {
 695		if (STp->block_size == 0)
 696			STps->drv_block++;
 697		else
 698			STps->drv_block += STbuffer->writing / STp->block_size;
 699	}
 700
 701	cmdstatp = &STbuffer->cmdstat;
 702	if (STbuffer->syscall_result) {
 703		retval = -EIO;
 704		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 705		    (cmdstatp->flags & SENSE_EOM) &&
 706		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 707		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 708			/* EOM at write-behind, has all data been written? */
 709			if (!cmdstatp->remainder_valid ||
 710			    cmdstatp->uremainder64 == 0)
 711				retval = -ENOSPC;
 712		}
 713		if (retval == -EIO)
 714			STps->drv_block = -1;
 715	}
 716	STbuffer->writing = 0;
 717
 718	DEB(if (debugging && retval)
 719		    st_printk(ST_DEB_MSG, STp,
 720				"Async write error %x, return value %d.\n",
 721				STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 722
 723	return retval;
 724}
 725
 726
 727/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 728   it messes up the block number). */
 729static int cross_eof(struct scsi_tape * STp, int forward)
 730{
 731	struct st_request *SRpnt;
 732	unsigned char cmd[MAX_COMMAND_SIZE];
 733
 734	cmd[0] = SPACE;
 735	cmd[1] = 0x01;		/* Space FileMarks */
 736	if (forward) {
 737		cmd[2] = cmd[3] = 0;
 738		cmd[4] = 1;
 739	} else
 740		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 741	cmd[5] = 0;
 742
 743	DEBC_printk(STp, "Stepping over filemark %s.\n",
 744		    forward ? "forward" : "backward");
 745
 746	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 747			   STp->device->request_queue->rq_timeout,
 748			   MAX_RETRIES, 1);
 749	if (!SRpnt)
 750		return (STp->buffer)->syscall_result;
 751
 752	st_release_request(SRpnt);
 753	SRpnt = NULL;
 754
 755	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 756		st_printk(KERN_ERR, STp,
 757			  "Stepping over filemark %s failed.\n",
 758			  forward ? "forward" : "backward");
 759
 760	return (STp->buffer)->syscall_result;
 761}
 762
 763
 764/* Flush the write buffer (never need to write if variable blocksize). */
 765static int st_flush_write_buffer(struct scsi_tape * STp)
 766{
 767	int transfer, blks;
 768	int result;
 769	unsigned char cmd[MAX_COMMAND_SIZE];
 770	struct st_request *SRpnt;
 771	struct st_partstat *STps;
 772
 773	result = write_behind_check(STp);
 774	if (result)
 775		return result;
 776
 777	result = 0;
 778	if (STp->dirty == 1) {
 779
 780		transfer = STp->buffer->buffer_bytes;
 781		DEBC_printk(STp, "Flushing %d bytes.\n", transfer);
 782
 783		memset(cmd, 0, MAX_COMMAND_SIZE);
 784		cmd[0] = WRITE_6;
 785		cmd[1] = 1;
 786		blks = transfer / STp->block_size;
 787		cmd[2] = blks >> 16;
 788		cmd[3] = blks >> 8;
 789		cmd[4] = blks;
 790
 791		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 792				   STp->device->request_queue->rq_timeout,
 793				   MAX_WRITE_RETRIES, 1);
 794		if (!SRpnt)
 795			return (STp->buffer)->syscall_result;
 796
 797		STps = &(STp->ps[STp->partition]);
 798		if ((STp->buffer)->syscall_result != 0) {
 799			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 800
 801			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 802			    (cmdstatp->flags & SENSE_EOM) &&
 803			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 804			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 805			    (!cmdstatp->remainder_valid ||
 806			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 807				STp->dirty = 0;
 808				(STp->buffer)->buffer_bytes = 0;
 809				if (STps->drv_block >= 0)
 810					STps->drv_block += blks;
 811				result = (-ENOSPC);
 812			} else {
 813				st_printk(KERN_ERR, STp, "Error on flush.\n");
 814				STps->drv_block = (-1);
 815				result = (-EIO);
 816			}
 817		} else {
 818			if (STps->drv_block >= 0)
 819				STps->drv_block += blks;
 820			STp->dirty = 0;
 821			(STp->buffer)->buffer_bytes = 0;
 822		}
 823		st_release_request(SRpnt);
 824		SRpnt = NULL;
 825	}
 826	return result;
 827}
 828
 829
 830/* Flush the tape buffer. The tape will be positioned correctly unless
 831   seek_next is true. */
 832static int flush_buffer(struct scsi_tape *STp, int seek_next)
 833{
 834	int backspace, result;
 835	struct st_partstat *STps;
 836
 
 
 
 837	/*
 838	 * If there was a bus reset, block further access
 839	 * to this device.
 840	 */
 841	if (STp->pos_unknown)
 842		return (-EIO);
 843
 844	if (STp->ready != ST_READY)
 845		return 0;
 846	STps = &(STp->ps[STp->partition]);
 847	if (STps->rw == ST_WRITING)	/* Writing */
 848		return st_flush_write_buffer(STp);
 849
 850	if (STp->block_size == 0)
 851		return 0;
 852
 853	backspace = ((STp->buffer)->buffer_bytes +
 854		     (STp->buffer)->read_pointer) / STp->block_size -
 855	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 856	    STp->block_size;
 857	(STp->buffer)->buffer_bytes = 0;
 858	(STp->buffer)->read_pointer = 0;
 859	result = 0;
 860	if (!seek_next) {
 861		if (STps->eof == ST_FM_HIT) {
 862			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 863			if (!result)
 864				STps->eof = ST_NOEOF;
 865			else {
 866				if (STps->drv_file >= 0)
 867					STps->drv_file++;
 868				STps->drv_block = 0;
 869			}
 870		}
 871		if (!result && backspace > 0)
 872			result = st_int_ioctl(STp, MTBSR, backspace);
 873	} else if (STps->eof == ST_FM_HIT) {
 874		if (STps->drv_file >= 0)
 875			STps->drv_file++;
 876		STps->drv_block = 0;
 877		STps->eof = ST_NOEOF;
 878	}
 879	return result;
 880
 881}
 882
 883/* Set the mode parameters */
 884static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 885{
 886	int set_it = 0;
 887	unsigned long arg;
 888
 889	if (!STp->density_changed &&
 890	    STm->default_density >= 0 &&
 891	    STm->default_density != STp->density) {
 892		arg = STm->default_density;
 893		set_it = 1;
 894	} else
 895		arg = STp->density;
 896	arg <<= MT_ST_DENSITY_SHIFT;
 897	if (!STp->blksize_changed &&
 898	    STm->default_blksize >= 0 &&
 899	    STm->default_blksize != STp->block_size) {
 900		arg |= STm->default_blksize;
 901		set_it = 1;
 902	} else
 903		arg |= STp->block_size;
 904	if (set_it &&
 905	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 906		st_printk(KERN_WARNING, STp,
 907			  "Can't set default block size to %d bytes "
 908			  "and density %x.\n",
 909			  STm->default_blksize, STm->default_density);
 910		if (modes_defined)
 911			return (-EINVAL);
 912	}
 913	return 0;
 914}
 915
 916
 917/* Lock or unlock the drive door. Don't use when st_request allocated. */
 918static int do_door_lock(struct scsi_tape * STp, int do_lock)
 919{
 920	int retval;
 921
 922	DEBC_printk(STp, "%socking drive door.\n", do_lock ? "L" : "Unl");
 923
 924	retval = scsi_set_medium_removal(STp->device,
 925			do_lock ? SCSI_REMOVAL_PREVENT : SCSI_REMOVAL_ALLOW);
 926	if (!retval)
 927		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 928	else
 929		STp->door_locked = ST_LOCK_FAILS;
 930	return retval;
 931}
 932
 933
 934/* Set the internal state after reset */
 935static void reset_state(struct scsi_tape *STp)
 936{
 937	int i;
 938	struct st_partstat *STps;
 939
 940	STp->pos_unknown = 0;
 941	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 942		STps = &(STp->ps[i]);
 943		STps->rw = ST_IDLE;
 944		STps->eof = ST_NOEOF;
 945		STps->at_sm = 0;
 946		STps->last_block_valid = 0;
 947		STps->drv_block = -1;
 948		STps->drv_file = -1;
 949	}
 950	if (STp->can_partitions) {
 951		STp->partition = find_partition(STp);
 952		if (STp->partition < 0)
 953			STp->partition = 0;
 954		STp->new_partition = STp->partition;
 955	}
 956}
 957
 958/* Test if the drive is ready. Returns either one of the codes below or a negative system
 959   error code. */
 960#define CHKRES_READY       0
 961#define CHKRES_NEW_SESSION 1
 962#define CHKRES_NOT_READY   2
 963#define CHKRES_NO_TAPE     3
 964
 965#define MAX_ATTENTIONS    10
 966
 967static int test_ready(struct scsi_tape *STp, int do_wait)
 968{
 969	int attentions, waits, max_wait, scode;
 970	int retval = CHKRES_READY, new_session = 0;
 971	unsigned char cmd[MAX_COMMAND_SIZE];
 972	struct st_request *SRpnt = NULL;
 973	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 974
 975	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 976
 977	for (attentions=waits=0; ; ) {
 978		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 979		cmd[0] = TEST_UNIT_READY;
 980		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 981				   STp->long_timeout, MAX_READY_RETRIES, 1);
 982
 983		if (!SRpnt) {
 984			retval = (STp->buffer)->syscall_result;
 985			break;
 986		}
 987
 988		if (cmdstatp->have_sense) {
 989
 990			scode = cmdstatp->sense_hdr.sense_key;
 991
 992			if (scode == UNIT_ATTENTION) { /* New media? */
 993				new_session = 1;
 
 
 
 994				if (attentions < MAX_ATTENTIONS) {
 995					attentions++;
 996					continue;
 997				}
 998				else {
 999					retval = (-EIO);
1000					break;
1001				}
1002			}
1003
1004			if (scode == NOT_READY) {
1005				if (waits < max_wait) {
1006					if (msleep_interruptible(1000)) {
1007						retval = (-EINTR);
1008						break;
1009					}
1010					waits++;
1011					continue;
1012				}
1013				else {
1014					if ((STp->device)->scsi_level >= SCSI_2 &&
1015					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
1016						retval = CHKRES_NO_TAPE;
1017					else
1018						retval = CHKRES_NOT_READY;
1019					break;
1020				}
1021			}
1022		}
1023
1024		retval = (STp->buffer)->syscall_result;
1025		if (!retval)
1026			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
1027		break;
1028	}
 
 
 
 
 
1029
1030	if (SRpnt != NULL)
1031		st_release_request(SRpnt);
1032	return retval;
1033}
1034
1035
1036/* See if the drive is ready and gather information about the tape. Return values:
1037   < 0   negative error code from errno.h
1038   0     drive ready
1039   1     drive not ready (possibly no tape)
1040*/
1041static int check_tape(struct scsi_tape *STp, struct file *filp)
1042{
1043	int i, retval, new_session = 0, do_wait;
1044	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
1045	unsigned short st_flags = filp->f_flags;
1046	struct st_request *SRpnt = NULL;
1047	struct st_modedef *STm;
1048	struct st_partstat *STps;
1049	struct inode *inode = file_inode(filp);
1050	int mode = TAPE_MODE(inode);
1051
1052	STp->ready = ST_READY;
1053
1054	if (mode != STp->current_mode) {
1055		DEBC_printk(STp, "Mode change from %d to %d.\n",
1056			    STp->current_mode, mode);
1057		new_session = 1;
1058		STp->current_mode = mode;
1059	}
1060	STm = &(STp->modes[STp->current_mode]);
1061
1062	saved_cleaning = STp->cleaning_req;
1063	STp->cleaning_req = 0;
1064
1065	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1066	retval = test_ready(STp, do_wait);
1067
1068	if (retval < 0)
1069	    goto err_out;
1070
1071	if (retval == CHKRES_NEW_SESSION) {
1072		STp->pos_unknown = 0;
1073		STp->partition = STp->new_partition = 0;
1074		if (STp->can_partitions)
1075			STp->nbr_partitions = 1; /* This guess will be updated later
1076                                                    if necessary */
1077		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1078			STps = &(STp->ps[i]);
1079			STps->rw = ST_IDLE;
1080			STps->eof = ST_NOEOF;
1081			STps->at_sm = 0;
1082			STps->last_block_valid = 0;
1083			STps->drv_block = 0;
1084			STps->drv_file = 0;
1085		}
1086		new_session = 1;
1087	}
1088	else {
1089		STp->cleaning_req |= saved_cleaning;
1090
1091		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1092			if (retval == CHKRES_NO_TAPE)
1093				STp->ready = ST_NO_TAPE;
1094			else
1095				STp->ready = ST_NOT_READY;
1096
1097			STp->density = 0;	/* Clear the erroneous "residue" */
1098			STp->write_prot = 0;
1099			STp->block_size = 0;
1100			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1101			STp->partition = STp->new_partition = 0;
1102			STp->door_locked = ST_UNLOCKED;
1103			return CHKRES_NOT_READY;
1104		}
1105	}
1106
1107	if (STp->omit_blklims)
1108		STp->min_block = STp->max_block = (-1);
1109	else {
1110		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1111		cmd[0] = READ_BLOCK_LIMITS;
1112
1113		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1114				   STp->device->request_queue->rq_timeout,
1115				   MAX_READY_RETRIES, 1);
1116		if (!SRpnt) {
1117			retval = (STp->buffer)->syscall_result;
1118			goto err_out;
1119		}
1120
1121		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1122			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1123			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1124			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1125			    (STp->buffer)->b_data[5];
1126			if ( DEB( debugging || ) !STp->inited)
1127				st_printk(KERN_INFO, STp,
1128					  "Block limits %d - %d bytes.\n",
1129					  STp->min_block, STp->max_block);
1130		} else {
1131			STp->min_block = STp->max_block = (-1);
1132			DEBC_printk(STp, "Can't read block limits.\n");
1133		}
1134	}
1135
1136	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1137	cmd[0] = MODE_SENSE;
1138	cmd[4] = 12;
1139
1140	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1141			   STp->device->request_queue->rq_timeout,
1142			   MAX_READY_RETRIES, 1);
1143	if (!SRpnt) {
1144		retval = (STp->buffer)->syscall_result;
1145		goto err_out;
1146	}
1147
1148	if ((STp->buffer)->syscall_result != 0) {
1149		DEBC_printk(STp, "No Mode Sense.\n");
1150		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1151		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1152		STp->drv_write_prot = 0;
1153	} else {
1154		DEBC_printk(STp,"Mode sense. Length %d, "
1155			    "medium %x, WBS %x, BLL %d\n",
1156			    (STp->buffer)->b_data[0],
1157			    (STp->buffer)->b_data[1],
1158			    (STp->buffer)->b_data[2],
1159			    (STp->buffer)->b_data[3]);
1160
1161		if ((STp->buffer)->b_data[3] >= 8) {
1162			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1163			STp->density = (STp->buffer)->b_data[4];
1164			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1165			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1166			DEBC_printk(STp, "Density %x, tape length: %x, "
1167				    "drv buffer: %d\n",
1168				    STp->density,
1169				    (STp->buffer)->b_data[5] * 65536 +
1170				    (STp->buffer)->b_data[6] * 256 +
1171				    (STp->buffer)->b_data[7],
1172				    STp->drv_buffer);
1173		}
1174		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1175		if (!STp->drv_buffer && STp->immediate_filemark) {
1176			st_printk(KERN_WARNING, STp,
1177				  "non-buffered tape: disabling "
1178				  "writing immediate filemarks\n");
1179			STp->immediate_filemark = 0;
1180		}
1181	}
1182	st_release_request(SRpnt);
1183	SRpnt = NULL;
1184	STp->inited = 1;
1185
1186	if (STp->block_size > 0)
1187		(STp->buffer)->buffer_blocks =
1188			(STp->buffer)->buffer_size / STp->block_size;
1189	else
1190		(STp->buffer)->buffer_blocks = 1;
1191	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1192
1193	DEBC_printk(STp, "Block size: %d, buffer size: %d (%d blocks).\n",
1194		    STp->block_size, (STp->buffer)->buffer_size,
1195		    (STp->buffer)->buffer_blocks);
1196
1197	if (STp->drv_write_prot) {
1198		STp->write_prot = 1;
1199
1200		DEBC_printk(STp, "Write protected\n");
1201
1202		if (do_wait &&
1203		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1204		     (st_flags & O_ACCMODE) == O_RDWR)) {
1205			retval = (-EROFS);
1206			goto err_out;
1207		}
1208	}
1209
1210	if (STp->can_partitions && STp->nbr_partitions < 1) {
1211		/* This code is reached when the device is opened for the first time
1212		   after the driver has been initialized with tape in the drive and the
1213		   partition support has been enabled. */
1214		DEBC_printk(STp, "Updating partition number in status.\n");
1215		if ((STp->partition = find_partition(STp)) < 0) {
1216			retval = STp->partition;
1217			goto err_out;
1218		}
1219		STp->new_partition = STp->partition;
1220		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1221	}
1222
1223	if (new_session) {	/* Change the drive parameters for the new mode */
1224		STp->density_changed = STp->blksize_changed = 0;
1225		STp->compression_changed = 0;
1226		if (!(STm->defaults_for_writes) &&
1227		    (retval = set_mode_densblk(STp, STm)) < 0)
1228		    goto err_out;
1229
1230		if (STp->default_drvbuffer != 0xff) {
1231			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1232				st_printk(KERN_WARNING, STp,
1233					  "Can't set default drive "
1234					  "buffering to %d.\n",
1235					  STp->default_drvbuffer);
1236		}
1237	}
1238
1239	return CHKRES_READY;
1240
1241 err_out:
1242	return retval;
1243}
1244
1245
1246/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1247   module count. */
1248static int st_open(struct inode *inode, struct file *filp)
1249{
1250	int i, retval = (-EIO);
1251	int resumed = 0;
1252	struct scsi_tape *STp;
1253	struct st_partstat *STps;
1254	int dev = TAPE_NR(inode);
1255
1256	/*
1257	 * We really want to do nonseekable_open(inode, filp); here, but some
1258	 * versions of tar incorrectly call lseek on tapes and bail out if that
1259	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1260	 */
1261	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1262
1263	if (!(STp = scsi_tape_get(dev))) {
1264		return -ENXIO;
1265	}
1266
1267	filp->private_data = STp;
1268
1269	spin_lock(&st_use_lock);
1270	if (STp->in_use) {
1271		spin_unlock(&st_use_lock);
 
1272		scsi_tape_put(STp);
1273		DEBC_printk(STp, "Device already in use.\n");
1274		return (-EBUSY);
1275	}
1276
1277	STp->in_use = 1;
1278	spin_unlock(&st_use_lock);
1279	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1280
1281	if (scsi_autopm_get_device(STp->device) < 0) {
1282		retval = -EIO;
1283		goto err_out;
1284	}
1285	resumed = 1;
1286	if (!scsi_block_when_processing_errors(STp->device)) {
1287		retval = (-ENXIO);
1288		goto err_out;
1289	}
1290
1291	/* See that we have at least a one page buffer available */
1292	if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1293		st_printk(KERN_WARNING, STp,
1294			  "Can't allocate one page tape buffer.\n");
1295		retval = (-EOVERFLOW);
1296		goto err_out;
1297	}
1298
1299	(STp->buffer)->cleared = 0;
1300	(STp->buffer)->writing = 0;
1301	(STp->buffer)->syscall_result = 0;
1302
1303	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1304
1305	STp->dirty = 0;
1306	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1307		STps = &(STp->ps[i]);
1308		STps->rw = ST_IDLE;
1309	}
1310	STp->try_dio_now = STp->try_dio;
1311	STp->recover_count = 0;
1312	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1313	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1314
1315	retval = check_tape(STp, filp);
1316	if (retval < 0)
1317		goto err_out;
1318	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1319	    retval != CHKRES_READY) {
1320		if (STp->ready == NO_TAPE)
1321			retval = (-ENOMEDIUM);
1322		else
1323			retval = (-EIO);
1324		goto err_out;
1325	}
1326	return 0;
1327
1328 err_out:
1329	normalize_buffer(STp->buffer);
1330	spin_lock(&st_use_lock);
1331	STp->in_use = 0;
1332	spin_unlock(&st_use_lock);
1333	if (resumed)
1334		scsi_autopm_put_device(STp->device);
1335	scsi_tape_put(STp);
1336	return retval;
1337
1338}
1339
1340
1341/* Flush the tape buffer before close */
1342static int st_flush(struct file *filp, fl_owner_t id)
1343{
1344	int result = 0, result2;
1345	unsigned char cmd[MAX_COMMAND_SIZE];
1346	struct st_request *SRpnt;
1347	struct scsi_tape *STp = filp->private_data;
1348	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1349	struct st_partstat *STps = &(STp->ps[STp->partition]);
1350
1351	if (file_count(filp) > 1)
1352		return 0;
1353
1354	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1355		result = st_flush_write_buffer(STp);
1356		if (result != 0 && result != (-ENOSPC))
1357			goto out;
1358	}
1359
1360	if (STp->can_partitions &&
1361	    (result2 = switch_partition(STp)) < 0) {
1362		DEBC_printk(STp, "switch_partition at close failed.\n");
1363		if (result == 0)
1364			result = result2;
1365		goto out;
1366	}
1367
1368	DEBC( if (STp->nbr_requests)
1369		st_printk(KERN_DEBUG, STp,
1370			  "Number of r/w requests %d, dio used in %d, "
1371			  "pages %d.\n", STp->nbr_requests, STp->nbr_dio,
1372			  STp->nbr_pages));
1373
1374	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1375		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1376
1377#if DEBUG
1378		DEBC_printk(STp, "Async write waits %d, finished %d.\n",
1379			    STp->nbr_waits, STp->nbr_finished);
1380#endif
1381		memset(cmd, 0, MAX_COMMAND_SIZE);
1382		cmd[0] = WRITE_FILEMARKS;
1383		if (STp->immediate_filemark)
1384			cmd[1] = 1;
1385		cmd[4] = 1 + STp->two_fm;
1386
1387		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1388				   STp->device->request_queue->rq_timeout,
1389				   MAX_WRITE_RETRIES, 1);
1390		if (!SRpnt) {
1391			result = (STp->buffer)->syscall_result;
1392			goto out;
1393		}
1394
1395		if (STp->buffer->syscall_result == 0 ||
1396		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1397		     (cmdstatp->flags & SENSE_EOM) &&
1398		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1399		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1400		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1401			/* Write successful at EOM */
1402			st_release_request(SRpnt);
1403			SRpnt = NULL;
1404			if (STps->drv_file >= 0)
1405				STps->drv_file++;
1406			STps->drv_block = 0;
1407			if (STp->two_fm)
1408				cross_eof(STp, 0);
1409			STps->eof = ST_FM;
1410		}
1411		else { /* Write error */
1412			st_release_request(SRpnt);
1413			SRpnt = NULL;
1414			st_printk(KERN_ERR, STp,
1415				  "Error on write filemark.\n");
1416			if (result == 0)
1417				result = (-EIO);
1418		}
1419
1420		DEBC_printk(STp, "Buffer flushed, %d EOF(s) written\n", cmd[4]);
1421	} else if (!STp->rew_at_close) {
1422		STps = &(STp->ps[STp->partition]);
1423		if (!STm->sysv || STps->rw != ST_READING) {
1424			if (STp->can_bsr)
1425				result = flush_buffer(STp, 0);
1426			else if (STps->eof == ST_FM_HIT) {
1427				result = cross_eof(STp, 0);
1428				if (result) {
1429					if (STps->drv_file >= 0)
1430						STps->drv_file++;
1431					STps->drv_block = 0;
1432					STps->eof = ST_FM;
1433				} else
1434					STps->eof = ST_NOEOF;
1435			}
1436		} else if ((STps->eof == ST_NOEOF &&
1437			    !(result = cross_eof(STp, 1))) ||
1438			   STps->eof == ST_FM_HIT) {
1439			if (STps->drv_file >= 0)
1440				STps->drv_file++;
1441			STps->drv_block = 0;
1442			STps->eof = ST_FM;
1443		}
1444	}
1445
1446      out:
1447	if (STp->rew_at_close) {
1448		result2 = st_int_ioctl(STp, MTREW, 1);
1449		if (result == 0)
1450			result = result2;
1451	}
1452	return result;
1453}
1454
1455
1456/* Close the device and release it. BKL is not needed: this is the only thread
1457   accessing this tape. */
1458static int st_release(struct inode *inode, struct file *filp)
1459{
1460	struct scsi_tape *STp = filp->private_data;
1461
1462	if (STp->door_locked == ST_LOCKED_AUTO)
1463		do_door_lock(STp, 0);
1464
1465	normalize_buffer(STp->buffer);
1466	spin_lock(&st_use_lock);
1467	STp->in_use = 0;
1468	spin_unlock(&st_use_lock);
1469	scsi_autopm_put_device(STp->device);
1470	scsi_tape_put(STp);
1471
1472	return 0;
1473}
1474
1475/* The checks common to both reading and writing */
1476static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1477{
1478	ssize_t retval = 0;
1479
1480	/*
1481	 * If we are in the middle of error recovery, don't let anyone
1482	 * else try and use this device.  Also, if error recovery fails, it
1483	 * may try and take the device offline, in which case all further
1484	 * access to the device is prohibited.
1485	 */
1486	if (!scsi_block_when_processing_errors(STp->device)) {
1487		retval = (-ENXIO);
1488		goto out;
1489	}
1490
1491	if (STp->ready != ST_READY) {
1492		if (STp->ready == ST_NO_TAPE)
1493			retval = (-ENOMEDIUM);
1494		else
1495			retval = (-EIO);
1496		goto out;
1497	}
1498
1499	if (! STp->modes[STp->current_mode].defined) {
1500		retval = (-ENXIO);
1501		goto out;
1502	}
1503
1504
1505	/*
1506	 * If there was a bus reset, block further access
1507	 * to this device.
1508	 */
1509	if (STp->pos_unknown) {
1510		retval = (-EIO);
1511		goto out;
1512	}
1513
1514	if (count == 0)
1515		goto out;
1516
1517	DEB(
1518	if (!STp->in_use) {
1519		st_printk(ST_DEB_MSG, STp,
1520			  "Incorrect device.\n");
1521		retval = (-EIO);
1522		goto out;
1523	} ) /* end DEB */
1524
1525	if (STp->can_partitions &&
1526	    (retval = switch_partition(STp)) < 0)
1527		goto out;
1528
1529	if (STp->block_size == 0 && STp->max_block > 0 &&
1530	    (count < STp->min_block || count > STp->max_block)) {
1531		retval = (-EINVAL);
1532		goto out;
1533	}
1534
1535	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1536	    !do_door_lock(STp, 1))
1537		STp->door_locked = ST_LOCKED_AUTO;
1538
1539 out:
1540	return retval;
1541}
1542
1543
1544static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1545			   size_t count, int is_read)
1546{
1547	int i, bufsize, retval = 0;
1548	struct st_buffer *STbp = STp->buffer;
1549
1550	if (is_read)
1551		i = STp->try_dio_now && try_rdio;
1552	else
1553		i = STp->try_dio_now && try_wdio;
1554
1555	if (i && ((unsigned long)buf & queue_dma_alignment(
1556					STp->device->request_queue)) == 0) {
1557		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1558				       count, (is_read ? READ : WRITE));
1559		if (i > 0) {
1560			STbp->do_dio = i;
1561			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1562		}
1563		else
1564			STbp->do_dio = 0;  /* fall back to buffering with any error */
1565		STbp->sg_segs = STbp->do_dio;
1566		DEB(
1567		     if (STbp->do_dio) {
1568			STp->nbr_dio++;
1569			STp->nbr_pages += STbp->do_dio;
1570		     }
1571		)
1572	} else
1573		STbp->do_dio = 0;
1574	DEB( STp->nbr_requests++; )
1575
1576	if (!STbp->do_dio) {
1577		if (STp->block_size)
1578			bufsize = STp->block_size > st_fixed_buffer_size ?
1579				STp->block_size : st_fixed_buffer_size;
1580		else {
1581			bufsize = count;
1582			/* Make sure that data from previous user is not leaked even if
1583			   HBA does not return correct residual */
1584			if (is_read && STp->sili && !STbp->cleared)
1585				clear_buffer(STbp);
1586		}
1587
1588		if (bufsize > STbp->buffer_size &&
1589		    !enlarge_buffer(STbp, bufsize, 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 = sign_extend32(get_unaligned_be24(&cmd[2]), 23);
2684	if (direction)
2685		sc = -sc;
2686	st_printk(ST_DEB_MSG, STp, "Spacing tape %s over %d %s.\n",
2687		  direction ? "backward" : "forward", sc, units);
2688}
2689#else
2690#define ST_DEB_FORWARD  0
2691#define ST_DEB_BACKWARD 1
2692static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd) {}
2693#endif
2694
2695
2696/* Internal ioctl function */
2697static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2698{
2699	int timeout;
2700	long ltmp;
2701	int ioctl_result;
2702	int chg_eof = 1;
2703	unsigned char cmd[MAX_COMMAND_SIZE];
2704	struct st_request *SRpnt;
2705	struct st_partstat *STps;
2706	int fileno, blkno, at_sm, undone;
2707	int datalen = 0, direction = DMA_NONE;
2708
2709	WARN_ON(STp->buffer->do_dio != 0);
2710	if (STp->ready != ST_READY) {
2711		if (STp->ready == ST_NO_TAPE)
2712			return (-ENOMEDIUM);
2713		else
2714			return (-EIO);
2715	}
2716	timeout = STp->long_timeout;
2717	STps = &(STp->ps[STp->partition]);
2718	fileno = STps->drv_file;
2719	blkno = STps->drv_block;
2720	at_sm = STps->at_sm;
2721
2722	memset(cmd, 0, MAX_COMMAND_SIZE);
2723	switch (cmd_in) {
2724	case MTFSFM:
2725		chg_eof = 0;	/* Changed from the FSF after this */
2726		fallthrough;
2727	case MTFSF:
2728		cmd[0] = SPACE;
2729		cmd[1] = 0x01;	/* Space FileMarks */
2730		cmd[2] = (arg >> 16);
2731		cmd[3] = (arg >> 8);
2732		cmd[4] = arg;
2733		deb_space_print(STp, ST_DEB_FORWARD, "filemarks", cmd);
2734		if (fileno >= 0)
2735			fileno += arg;
2736		blkno = 0;
2737		at_sm &= (arg == 0);
2738		break;
2739	case MTBSFM:
2740		chg_eof = 0;	/* Changed from the FSF after this */
2741		fallthrough;
2742	case MTBSF:
2743		cmd[0] = SPACE;
2744		cmd[1] = 0x01;	/* Space FileMarks */
2745		ltmp = (-arg);
2746		cmd[2] = (ltmp >> 16);
2747		cmd[3] = (ltmp >> 8);
2748		cmd[4] = ltmp;
2749		deb_space_print(STp, ST_DEB_BACKWARD, "filemarks", cmd);
2750		if (fileno >= 0)
2751			fileno -= arg;
2752		blkno = (-1);	/* We can't know the block number */
2753		at_sm &= (arg == 0);
2754		break;
2755	case MTFSR:
2756		cmd[0] = SPACE;
2757		cmd[1] = 0x00;	/* Space Blocks */
2758		cmd[2] = (arg >> 16);
2759		cmd[3] = (arg >> 8);
2760		cmd[4] = arg;
2761		deb_space_print(STp, ST_DEB_FORWARD, "blocks", cmd);
2762		if (blkno >= 0)
2763			blkno += arg;
2764		at_sm &= (arg == 0);
2765		break;
2766	case MTBSR:
2767		cmd[0] = SPACE;
2768		cmd[1] = 0x00;	/* Space Blocks */
2769		ltmp = (-arg);
2770		cmd[2] = (ltmp >> 16);
2771		cmd[3] = (ltmp >> 8);
2772		cmd[4] = ltmp;
2773		deb_space_print(STp, ST_DEB_BACKWARD, "blocks", cmd);
2774		if (blkno >= 0)
2775			blkno -= arg;
2776		at_sm &= (arg == 0);
2777		break;
2778	case MTFSS:
2779		cmd[0] = SPACE;
2780		cmd[1] = 0x04;	/* Space Setmarks */
2781		cmd[2] = (arg >> 16);
2782		cmd[3] = (arg >> 8);
2783		cmd[4] = arg;
2784		deb_space_print(STp, ST_DEB_FORWARD, "setmarks", cmd);
2785		if (arg != 0) {
2786			blkno = fileno = (-1);
2787			at_sm = 1;
2788		}
2789		break;
2790	case MTBSS:
2791		cmd[0] = SPACE;
2792		cmd[1] = 0x04;	/* Space Setmarks */
2793		ltmp = (-arg);
2794		cmd[2] = (ltmp >> 16);
2795		cmd[3] = (ltmp >> 8);
2796		cmd[4] = ltmp;
2797		deb_space_print(STp, ST_DEB_BACKWARD, "setmarks", cmd);
2798		if (arg != 0) {
2799			blkno = fileno = (-1);
2800			at_sm = 1;
2801		}
2802		break;
2803	case MTWEOF:
2804	case MTWEOFI:
2805	case MTWSM:
2806		if (STp->write_prot)
2807			return (-EACCES);
2808		cmd[0] = WRITE_FILEMARKS;
2809		if (cmd_in == MTWSM)
2810			cmd[1] = 2;
2811		if (cmd_in == MTWEOFI ||
2812		    (cmd_in == MTWEOF && STp->immediate_filemark))
2813			cmd[1] |= 1;
2814		cmd[2] = (arg >> 16);
2815		cmd[3] = (arg >> 8);
2816		cmd[4] = arg;
2817		timeout = STp->device->request_queue->rq_timeout;
2818		DEBC(
2819			if (cmd_in != MTWSM)
2820				st_printk(ST_DEB_MSG, STp,
2821					  "Writing %d filemarks.\n",
2822					  cmd[2] * 65536 +
2823					  cmd[3] * 256 +
2824					  cmd[4]);
2825			else
2826				st_printk(ST_DEB_MSG, STp,
2827					  "Writing %d setmarks.\n",
2828					  cmd[2] * 65536 +
2829					  cmd[3] * 256 +
2830					  cmd[4]);
2831		)
2832		if (fileno >= 0)
2833			fileno += arg;
2834		blkno = 0;
2835		at_sm = (cmd_in == MTWSM);
2836		break;
2837	case MTREW:
2838		cmd[0] = REZERO_UNIT;
2839		if (STp->immediate) {
2840			cmd[1] = 1;	/* Don't wait for completion */
2841			timeout = STp->device->request_queue->rq_timeout;
2842		}
2843		DEBC_printk(STp, "Rewinding tape.\n");
2844		fileno = blkno = at_sm = 0;
2845		break;
2846	case MTNOP:
2847		DEBC_printk(STp, "No op on tape.\n");
2848		return 0;	/* Should do something ? */
2849		break;
2850	case MTRETEN:
2851		cmd[0] = START_STOP;
2852		if (STp->immediate) {
2853			cmd[1] = 1;	/* Don't wait for completion */
2854			timeout = STp->device->request_queue->rq_timeout;
2855		}
2856		cmd[4] = 3;
2857		DEBC_printk(STp, "Retensioning tape.\n");
2858		fileno = blkno = at_sm = 0;
2859		break;
2860	case MTEOM:
2861		if (!STp->fast_mteom) {
2862			/* space to the end of tape */
2863			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2864			fileno = STps->drv_file;
2865			if (STps->eof >= ST_EOD_1)
2866				return 0;
2867			/* The next lines would hide the number of spaced FileMarks
2868			   That's why I inserted the previous lines. I had no luck
2869			   with detecting EOM with FSF, so we go now to EOM.
2870			   Joerg Weule */
2871		} else
2872			fileno = (-1);
2873		cmd[0] = SPACE;
2874		cmd[1] = 3;
2875		DEBC_printk(STp, "Spacing to end of recorded medium.\n");
2876		blkno = -1;
2877		at_sm = 0;
2878		break;
2879	case MTERASE:
2880		if (STp->write_prot)
2881			return (-EACCES);
2882		cmd[0] = ERASE;
2883		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
2884		if (STp->immediate) {
2885			cmd[1] |= 2;	/* Don't wait for completion */
2886			timeout = STp->device->request_queue->rq_timeout;
2887		}
2888		else
2889			timeout = STp->long_timeout * 8;
2890
2891		DEBC_printk(STp, "Erasing tape.\n");
2892		fileno = blkno = at_sm = 0;
2893		break;
2894	case MTSETBLK:		/* Set block length */
2895	case MTSETDENSITY:	/* Set tape density */
2896	case MTSETDRVBUFFER:	/* Set drive buffering */
2897	case SET_DENS_AND_BLK:	/* Set density and block size */
2898		chg_eof = 0;
2899		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2900			return (-EIO);	/* Not allowed if data in buffer */
2901		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2902		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2903		    STp->max_block > 0 &&
2904		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2905		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2906			st_printk(KERN_WARNING, STp, "Illegal block size.\n");
2907			return (-EINVAL);
2908		}
2909		cmd[0] = MODE_SELECT;
2910		if ((STp->use_pf & USE_PF))
2911			cmd[1] = MODE_SELECT_PAGE_FORMAT;
2912		cmd[4] = datalen = 12;
2913		direction = DMA_TO_DEVICE;
2914
2915		memset((STp->buffer)->b_data, 0, 12);
2916		if (cmd_in == MTSETDRVBUFFER)
2917			(STp->buffer)->b_data[2] = (arg & 7) << 4;
2918		else
2919			(STp->buffer)->b_data[2] =
2920			    STp->drv_buffer << 4;
2921		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
2922		if (cmd_in == MTSETDENSITY) {
2923			(STp->buffer)->b_data[4] = arg;
2924			STp->density_changed = 1;	/* At least we tried ;-) */
2925		} else if (cmd_in == SET_DENS_AND_BLK)
2926			(STp->buffer)->b_data[4] = arg >> 24;
2927		else
2928			(STp->buffer)->b_data[4] = STp->density;
2929		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2930			ltmp = arg & MT_ST_BLKSIZE_MASK;
2931			if (cmd_in == MTSETBLK)
2932				STp->blksize_changed = 1; /* At least we tried ;-) */
2933		} else
2934			ltmp = STp->block_size;
2935		(STp->buffer)->b_data[9] = (ltmp >> 16);
2936		(STp->buffer)->b_data[10] = (ltmp >> 8);
2937		(STp->buffer)->b_data[11] = ltmp;
2938		timeout = STp->device->request_queue->rq_timeout;
2939		DEBC(
2940			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2941				st_printk(ST_DEB_MSG, STp,
2942					  "Setting block size to %d bytes.\n",
2943					  (STp->buffer)->b_data[9] * 65536 +
2944					  (STp->buffer)->b_data[10] * 256 +
2945					  (STp->buffer)->b_data[11]);
2946			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2947				st_printk(ST_DEB_MSG, STp,
2948					  "Setting density code to %x.\n",
2949					  (STp->buffer)->b_data[4]);
2950			if (cmd_in == MTSETDRVBUFFER)
2951				st_printk(ST_DEB_MSG, STp,
2952					  "Setting drive buffer code to %d.\n",
2953					  ((STp->buffer)->b_data[2] >> 4) & 7);
2954		)
2955		break;
2956	default:
2957		return (-ENOSYS);
2958	}
2959
2960	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2961			   timeout, MAX_RETRIES, 1);
2962	if (!SRpnt)
2963		return (STp->buffer)->syscall_result;
2964
2965	ioctl_result = (STp->buffer)->syscall_result;
2966
2967	if (!ioctl_result) {	/* SCSI command successful */
2968		st_release_request(SRpnt);
2969		SRpnt = NULL;
2970		STps->drv_block = blkno;
2971		STps->drv_file = fileno;
2972		STps->at_sm = at_sm;
2973
2974		if (cmd_in == MTBSFM)
2975			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2976		else if (cmd_in == MTFSFM)
2977			ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2978
2979		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2980			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2981			if (STp->block_size != 0) {
2982				(STp->buffer)->buffer_blocks =
2983				    (STp->buffer)->buffer_size / STp->block_size;
2984			}
2985			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2986			if (cmd_in == SET_DENS_AND_BLK)
2987				STp->density = arg >> MT_ST_DENSITY_SHIFT;
2988		} else if (cmd_in == MTSETDRVBUFFER)
2989			STp->drv_buffer = (arg & 7);
2990		else if (cmd_in == MTSETDENSITY)
2991			STp->density = arg;
2992
2993		if (cmd_in == MTEOM)
2994			STps->eof = ST_EOD;
2995		else if (cmd_in == MTFSF)
2996			STps->eof = ST_FM;
2997		else if (chg_eof)
2998			STps->eof = ST_NOEOF;
2999
3000		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
3001			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
3002	} else { /* SCSI command was not completely successful. Don't return
3003                    from this block without releasing the SCSI command block! */
3004		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
3005
3006		if (cmdstatp->flags & SENSE_EOM) {
3007			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
3008			    cmd_in != MTBSR && cmd_in != MTBSS)
3009				STps->eof = ST_EOM_OK;
3010			STps->drv_block = 0;
3011		}
3012
3013		if (cmdstatp->remainder_valid)
3014			undone = (int)cmdstatp->uremainder64;
3015		else
3016			undone = 0;
3017
3018		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
3019		    cmdstatp->have_sense &&
3020		    (cmdstatp->flags & SENSE_EOM)) {
3021			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
3022			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
3023				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
3024				STps->eof = ST_NOEOF;
3025			} else {  /* Writing EOF(s) failed */
3026				if (fileno >= 0)
3027					fileno -= undone;
3028				if (undone < arg)
3029					STps->eof = ST_NOEOF;
3030			}
3031			STps->drv_file = fileno;
3032		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
3033			if (fileno >= 0)
3034				STps->drv_file = fileno - undone;
3035			else
3036				STps->drv_file = fileno;
3037			STps->drv_block = -1;
3038			STps->eof = ST_NOEOF;
3039		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
3040			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3041				undone = (-undone);
3042			if (STps->drv_file >= 0)
3043				STps->drv_file = fileno + undone;
3044			STps->drv_block = 0;
3045			STps->eof = ST_NOEOF;
3046		} else if (cmd_in == MTFSR) {
3047			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3048				if (STps->drv_file >= 0)
3049					STps->drv_file++;
3050				STps->drv_block = 0;
3051				STps->eof = ST_FM;
3052			} else {
3053				if (blkno >= undone)
3054					STps->drv_block = blkno - undone;
3055				else
3056					STps->drv_block = (-1);
3057				STps->eof = ST_NOEOF;
3058			}
3059		} else if (cmd_in == MTBSR) {
3060			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3061				STps->drv_file--;
3062				STps->drv_block = (-1);
3063			} else {
3064				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3065					undone = (-undone);
3066				if (STps->drv_block >= 0)
3067					STps->drv_block = blkno + undone;
3068			}
3069			STps->eof = ST_NOEOF;
3070		} else if (cmd_in == MTEOM) {
3071			STps->drv_file = (-1);
3072			STps->drv_block = (-1);
3073			STps->eof = ST_EOD;
3074		} else if (cmd_in == MTSETBLK ||
3075			   cmd_in == MTSETDENSITY ||
3076			   cmd_in == MTSETDRVBUFFER ||
3077			   cmd_in == SET_DENS_AND_BLK) {
3078			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
3079			    !(STp->use_pf & PF_TESTED)) {
3080				/* Try the other possible state of Page Format if not
3081				   already tried */
3082				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
3083				st_release_request(SRpnt);
3084				SRpnt = NULL;
3085				return st_int_ioctl(STp, cmd_in, arg);
3086			}
3087		} else if (chg_eof)
3088			STps->eof = ST_NOEOF;
3089
3090		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
3091			STps->eof = ST_EOD;
3092
3093		st_release_request(SRpnt);
3094		SRpnt = NULL;
3095	}
3096
3097	return ioctl_result;
3098}
3099
3100
3101/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
3102   structure. */
3103
3104static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
3105			int logical)
3106{
3107	int result;
3108	unsigned char scmd[MAX_COMMAND_SIZE];
3109	struct st_request *SRpnt;
3110
3111	if (STp->ready != ST_READY)
3112		return (-EIO);
3113
3114	memset(scmd, 0, MAX_COMMAND_SIZE);
3115	if ((STp->device)->scsi_level < SCSI_2) {
3116		scmd[0] = QFA_REQUEST_BLOCK;
3117		scmd[4] = 3;
3118	} else {
3119		scmd[0] = READ_POSITION;
3120		if (!logical && !STp->scsi2_logical)
3121			scmd[1] = 1;
3122	}
3123	SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3124			   STp->device->request_queue->rq_timeout,
3125			   MAX_READY_RETRIES, 1);
3126	if (!SRpnt)
3127		return (STp->buffer)->syscall_result;
3128
3129	if ((STp->buffer)->syscall_result != 0 ||
3130	    (STp->device->scsi_level >= SCSI_2 &&
3131	     ((STp->buffer)->b_data[0] & 4) != 0)) {
3132		*block = *partition = 0;
3133		DEBC_printk(STp, " Can't read tape position.\n");
3134		result = (-EIO);
3135	} else {
3136		result = 0;
3137		if ((STp->device)->scsi_level < SCSI_2) {
3138			*block = ((STp->buffer)->b_data[0] << 16)
3139			    + ((STp->buffer)->b_data[1] << 8)
3140			    + (STp->buffer)->b_data[2];
3141			*partition = 0;
3142		} else {
3143			*block = ((STp->buffer)->b_data[4] << 24)
3144			    + ((STp->buffer)->b_data[5] << 16)
3145			    + ((STp->buffer)->b_data[6] << 8)
3146			    + (STp->buffer)->b_data[7];
3147			*partition = (STp->buffer)->b_data[1];
3148			if (((STp->buffer)->b_data[0] & 0x80) &&
3149			    (STp->buffer)->b_data[1] == 0)	/* BOP of partition 0 */
3150				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3151		}
3152		DEBC_printk(STp, "Got tape pos. blk %d part %d.\n",
3153			    *block, *partition);
3154	}
3155	st_release_request(SRpnt);
3156	SRpnt = NULL;
3157
3158	return result;
3159}
3160
3161
3162/* Set the tape block and partition. Negative partition means that only the
3163   block should be set in vendor specific way. */
3164static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3165			int logical)
3166{
3167	struct st_partstat *STps;
3168	int result, p;
3169	unsigned int blk;
3170	int timeout;
3171	unsigned char scmd[MAX_COMMAND_SIZE];
3172	struct st_request *SRpnt;
3173
3174	if (STp->ready != ST_READY)
3175		return (-EIO);
3176	timeout = STp->long_timeout;
3177	STps = &(STp->ps[STp->partition]);
3178
3179	DEBC_printk(STp, "Setting block to %d and partition to %d.\n",
3180		    block, partition);
3181	DEB(if (partition < 0)
3182		return (-EIO); )
3183
3184	/* Update the location at the partition we are leaving */
3185	if ((!STp->can_partitions && partition != 0) ||
3186	    partition >= ST_NBR_PARTITIONS)
3187		return (-EINVAL);
3188	if (partition != STp->partition) {
3189		if (get_location(STp, &blk, &p, 1))
3190			STps->last_block_valid = 0;
3191		else {
3192			STps->last_block_valid = 1;
3193			STps->last_block_visited = blk;
3194			DEBC_printk(STp, "Visited block %d for "
3195				    "partition %d saved.\n",
3196				    blk, STp->partition);
3197		}
3198	}
3199
3200	memset(scmd, 0, MAX_COMMAND_SIZE);
3201	if ((STp->device)->scsi_level < SCSI_2) {
3202		scmd[0] = QFA_SEEK_BLOCK;
3203		scmd[2] = (block >> 16);
3204		scmd[3] = (block >> 8);
3205		scmd[4] = block;
3206		scmd[5] = 0;
3207	} else {
3208		scmd[0] = SEEK_10;
3209		scmd[3] = (block >> 24);
3210		scmd[4] = (block >> 16);
3211		scmd[5] = (block >> 8);
3212		scmd[6] = block;
3213		if (!logical && !STp->scsi2_logical)
3214			scmd[1] = 4;
3215		if (STp->partition != partition) {
3216			scmd[1] |= 2;
3217			scmd[8] = partition;
3218			DEBC_printk(STp, "Trying to change partition "
3219				    "from %d to %d\n", STp->partition,
3220				    partition);
3221		}
3222	}
3223	if (STp->immediate) {
3224		scmd[1] |= 1;		/* Don't wait for completion */
3225		timeout = STp->device->request_queue->rq_timeout;
3226	}
3227
3228	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3229			   timeout, MAX_READY_RETRIES, 1);
3230	if (!SRpnt)
3231		return (STp->buffer)->syscall_result;
3232
3233	STps->drv_block = STps->drv_file = (-1);
3234	STps->eof = ST_NOEOF;
3235	if ((STp->buffer)->syscall_result != 0) {
3236		result = (-EIO);
3237		if (STp->can_partitions &&
3238		    (STp->device)->scsi_level >= SCSI_2 &&
3239		    (p = find_partition(STp)) >= 0)
3240			STp->partition = p;
3241	} else {
3242		if (STp->can_partitions) {
3243			STp->partition = partition;
3244			STps = &(STp->ps[partition]);
3245			if (!STps->last_block_valid ||
3246			    STps->last_block_visited != block) {
3247				STps->at_sm = 0;
3248				STps->rw = ST_IDLE;
3249			}
3250		} else
3251			STps->at_sm = 0;
3252		if (block == 0)
3253			STps->drv_block = STps->drv_file = 0;
3254		result = 0;
3255	}
3256
3257	st_release_request(SRpnt);
3258	SRpnt = NULL;
3259
3260	return result;
3261}
3262
3263
3264/* Find the current partition number for the drive status. Called from open and
3265   returns either partition number of negative error code. */
3266static int find_partition(struct scsi_tape *STp)
3267{
3268	int i, partition;
3269	unsigned int block;
3270
3271	if ((i = get_location(STp, &block, &partition, 1)) < 0)
3272		return i;
3273	if (partition >= ST_NBR_PARTITIONS)
3274		return (-EIO);
3275	return partition;
3276}
3277
3278
3279/* Change the partition if necessary */
3280static int switch_partition(struct scsi_tape *STp)
3281{
3282	struct st_partstat *STps;
3283
3284	if (STp->partition == STp->new_partition)
3285		return 0;
3286	STps = &(STp->ps[STp->new_partition]);
3287	if (!STps->last_block_valid)
3288		STps->last_block_visited = 0;
3289	return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3290}
3291
3292/* Functions for reading and writing the medium partition mode page. */
3293
3294#define PART_PAGE   0x11
3295#define PART_PAGE_FIXED_LENGTH 8
3296
3297#define PP_OFF_MAX_ADD_PARTS   2
3298#define PP_OFF_NBR_ADD_PARTS   3
3299#define PP_OFF_FLAGS           4
3300#define PP_OFF_PART_UNITS      6
3301#define PP_OFF_RESERVED        7
3302
3303#define PP_BIT_IDP             0x20
3304#define PP_BIT_FDP             0x80
3305#define PP_MSK_PSUM_MB         0x10
3306#define PP_MSK_PSUM_UNITS      0x18
3307#define PP_MSK_POFM            0x04
3308
3309/* Get the number of partitions on the tape. As a side effect reads the
3310   mode page into the tape buffer. */
3311static int nbr_partitions(struct scsi_tape *STp)
3312{
3313	int result;
3314
3315	if (STp->ready != ST_READY)
3316		return (-EIO);
3317
3318	result = read_mode_page(STp, PART_PAGE, 1);
3319
3320	if (result) {
3321		DEBC_printk(STp, "Can't read medium partition page.\n");
3322		result = (-EIO);
3323	} else {
3324		result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3325					      PP_OFF_NBR_ADD_PARTS] + 1;
3326		DEBC_printk(STp, "Number of partitions %d.\n", result);
3327	}
3328
3329	return result;
3330}
3331
3332
3333static int format_medium(struct scsi_tape *STp, int format)
3334{
3335	int result = 0;
3336	int timeout = STp->long_timeout;
3337	unsigned char scmd[MAX_COMMAND_SIZE];
3338	struct st_request *SRpnt;
3339
3340	memset(scmd, 0, MAX_COMMAND_SIZE);
3341	scmd[0] = FORMAT_UNIT;
3342	scmd[2] = format;
3343	if (STp->immediate) {
3344		scmd[1] |= 1;		/* Don't wait for completion */
3345		timeout = STp->device->request_queue->rq_timeout;
3346	}
3347	DEBC_printk(STp, "Sending FORMAT MEDIUM\n");
3348	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3349			   timeout, MAX_RETRIES, 1);
3350	if (!SRpnt)
3351		result = STp->buffer->syscall_result;
3352	return result;
3353}
3354
3355
3356/* Partition the tape into two partitions if size > 0 or one partition if
3357   size == 0.
3358
3359   The block descriptors are read and written because Sony SDT-7000 does not
3360   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3361
3362   My HP C1533A drive returns only one partition size field. This is used to
3363   set the size of partition 1. There is no size field for the default partition.
3364   Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3365   used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3366   The following algorithm is used to accommodate both drives: if the number of
3367   partition size fields is greater than the maximum number of additional partitions
3368   in the mode page, the second field is used. Otherwise the first field is used.
3369
3370   For Seagate DDS drives the page length must be 8 when no partitions is defined
3371   and 10 when 1 partition is defined (information from Eric Lee Green). This is
3372   is acceptable also to some other old drives and enforced if the first partition
3373   size field is used for the first additional partition size.
3374
3375   For drives that advertize SCSI-3 or newer, use the SSC-3 methods.
3376 */
3377static int partition_tape(struct scsi_tape *STp, int size)
3378{
3379	int result;
3380	int target_partition;
3381	bool scsi3 = STp->device->scsi_level >= SCSI_3, needs_format = false;
3382	int pgo, psd_cnt, psdo;
3383	int psum = PP_MSK_PSUM_MB, units = 0;
3384	unsigned char *bp;
3385
3386	result = read_mode_page(STp, PART_PAGE, 0);
3387	if (result) {
3388		DEBC_printk(STp, "Can't read partition mode page.\n");
3389		return result;
3390	}
3391	target_partition = 1;
3392	if (size < 0) {
3393		target_partition = 0;
3394		size = -size;
3395	}
3396
3397	/* The mode page is in the buffer. Let's modify it and write it. */
3398	bp = (STp->buffer)->b_data;
3399	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3400	DEBC_printk(STp, "Partition page length is %d bytes.\n",
3401		    bp[pgo + MP_OFF_PAGE_LENGTH] + 2);
3402
3403	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
3404
3405	if (scsi3) {
3406		needs_format = (bp[pgo + PP_OFF_FLAGS] & PP_MSK_POFM) != 0;
3407		if (needs_format && size == 0) {
3408			/* No need to write the mode page when clearing
3409			 *  partitioning
3410			 */
3411			DEBC_printk(STp, "Formatting tape with one partition.\n");
3412			result = format_medium(STp, 0);
3413			goto out;
3414		}
3415		if (needs_format)  /* Leave the old value for HP DATs claiming SCSI_3 */
3416			psd_cnt = 2;
3417		if ((bp[pgo + PP_OFF_FLAGS] & PP_MSK_PSUM_UNITS) == PP_MSK_PSUM_UNITS) {
3418			/* Use units scaling for large partitions if the device
3419			 * suggests it and no precision lost. Required for IBM
3420			 * TS1140/50 drives that don't support MB units.
3421			 */
3422			if (size >= 1000 && (size % 1000) == 0) {
3423				size /= 1000;
3424				psum = PP_MSK_PSUM_UNITS;
3425				units = 9; /* GB */
3426			}
3427		}
3428		/* Try it anyway if too large to specify in MB */
3429		if (psum == PP_MSK_PSUM_MB && size >= 65534) {
3430			size /= 1000;
3431			psum = PP_MSK_PSUM_UNITS;
3432			units = 9;  /* GB */
3433		}
3434	}
3435
3436	if (size >= 65535 ||  /* Does not fit into two bytes */
3437	    (target_partition == 0 && psd_cnt < 2)) {
3438		result = -EINVAL;
3439		goto out;
3440	}
3441
3442	psdo = pgo + PART_PAGE_FIXED_LENGTH;
3443	/* The second condition is for HP DDS which use only one partition size
3444	 * descriptor
3445	 */
3446	if (target_partition > 0 &&
3447	    (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS] ||
3448	     bp[pgo + PP_OFF_MAX_ADD_PARTS] != 1)) {
3449		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest to partition 0 */
3450		psdo += 2;
3451	}
3452	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3453
3454	DEBC_printk(STp, "psd_cnt %d, max.parts %d, nbr_parts %d\n",
3455		    psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3456		    bp[pgo + PP_OFF_NBR_ADD_PARTS]);
3457
3458	if (size == 0) {
3459		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3460		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3461		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3462		DEBC_printk(STp, "Formatting tape with one partition.\n");
3463	} else {
3464		bp[psdo] = (size >> 8) & 0xff;
3465		bp[psdo + 1] = size & 0xff;
3466		if (target_partition == 0)
3467			bp[psdo + 2] = bp[psdo + 3] = 0xff;
3468		bp[pgo + 3] = 1;
3469		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3470		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3471		DEBC_printk(STp,
3472			    "Formatting tape with two partitions (%i = %d MB).\n",
3473			    target_partition, units > 0 ? size * 1000 : size);
3474	}
3475	bp[pgo + PP_OFF_PART_UNITS] = 0;
3476	bp[pgo + PP_OFF_RESERVED] = 0;
3477	if (size != 1 || units != 0) {
3478		bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | psum |
3479			(bp[pgo + PP_OFF_FLAGS] & 0x07);
3480		bp[pgo + PP_OFF_PART_UNITS] = units;
3481	} else
3482		bp[pgo + PP_OFF_FLAGS] = PP_BIT_FDP |
3483			(bp[pgo + PP_OFF_FLAGS] & 0x1f);
3484	bp[pgo + MP_OFF_PAGE_LENGTH] = 6 + psd_cnt * 2;
3485
3486	result = write_mode_page(STp, PART_PAGE, 1);
3487
3488	if (!result && needs_format)
3489		result = format_medium(STp, 1);
3490
3491	if (result) {
3492		st_printk(KERN_INFO, STp, "Partitioning of tape failed.\n");
3493		result = (-EIO);
3494	}
3495
3496out:
3497	return result;
3498}
3499
3500
3501
3502/* The ioctl command */
3503static long st_ioctl_common(struct file *file, unsigned int cmd_in, void __user *p)
3504{
 
3505	int i, cmd_nr, cmd_type, bt;
3506	int retval = 0;
3507	unsigned int blk;
 
3508	struct scsi_tape *STp = file->private_data;
3509	struct st_modedef *STm;
3510	struct st_partstat *STps;
3511
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		retval = put_user_mtget(p, &mt_status);
3803		if (retval)
3804			goto out;
3805
3806		STp->recover_reg = 0;		/* Clear after read */
3807		goto out;
3808	}			/* End of MTIOCGET */
3809	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3810		struct mtpos mt_pos;
3811		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3812			 retval = (-EINVAL);
3813			 goto out;
3814		}
3815		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3816			retval = i;
3817			goto out;
3818		}
3819		mt_pos.mt_blkno = blk;
3820		retval = put_user_mtpos(p, &mt_pos);
3821		goto out;
3822	}
3823	mutex_unlock(&STp->lock);
 
3824	switch (cmd_in) {
3825		case SCSI_IOCTL_STOP_UNIT:
3826			/* unload */
3827			retval = scsi_ioctl(STp->device, cmd_in, p);
3828			if (!retval) {
3829				STp->rew_at_close = 0;
3830				STp->ready = ST_NO_TAPE;
3831			}
3832			return retval;
3833
3834		case SCSI_IOCTL_GET_IDLUN:
3835		case SCSI_IOCTL_GET_BUS_NUMBER:
3836			break;
3837
3838		default:
3839			if ((cmd_in == SG_IO ||
3840			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3841			     cmd_in == CDROM_SEND_PACKET) &&
3842			    !capable(CAP_SYS_RAWIO))
3843				i = -EPERM;
3844			else
3845				i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3846						   file->f_mode, cmd_in, p);
3847			if (i != -ENOTTY)
3848				return i;
3849			break;
3850	}
3851	return -ENOTTY;
3852
3853 out:
3854	mutex_unlock(&STp->lock);
3855	return retval;
3856}
3857
3858static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3859{
3860	void __user *p = (void __user *)arg;
3861	struct scsi_tape *STp = file->private_data;
3862	int ret;
3863
3864	ret = st_ioctl_common(file, cmd_in, p);
3865	if (ret != -ENOTTY)
3866		return ret;
3867
3868	return scsi_ioctl(STp->device, cmd_in, p);
3869}
3870
3871#ifdef CONFIG_COMPAT
3872static long st_compat_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3873{
3874	void __user *p = compat_ptr(arg);
3875	struct scsi_tape *STp = file->private_data;
3876	int ret;
3877
3878	/* argument conversion is handled using put_user_mtpos/put_user_mtget */
3879	switch (cmd_in) {
3880	case MTIOCPOS32:
3881		return st_ioctl_common(file, MTIOCPOS, p);
 
3882	case MTIOCGET32:
3883		return st_ioctl_common(file, MTIOCGET, p);
 
3884	}
3885
3886	ret = st_ioctl_common(file, cmd_in, p);
3887	if (ret != -ENOTTY)
3888		return ret;
3889
3890	return scsi_compat_ioctl(STp->device, cmd_in, p);
3891}
3892#endif
3893
3894
3895
3896/* Try to allocate a new tape buffer. Calling function must not hold
3897   dev_arr_lock. */
3898static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
3899{
3900	struct st_buffer *tb;
3901
3902	tb = kzalloc(sizeof(struct st_buffer), GFP_KERNEL);
3903	if (!tb) {
3904		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3905		return NULL;
3906	}
3907	tb->frp_segs = 0;
3908	tb->use_sg = max_sg;
3909	tb->dma = need_dma;
3910	tb->buffer_size = 0;
3911
3912	tb->reserved_pages = kcalloc(max_sg, sizeof(struct page *),
3913				     GFP_KERNEL);
3914	if (!tb->reserved_pages) {
3915		kfree(tb);
3916		return NULL;
3917	}
3918
3919	return tb;
3920}
3921
3922
3923/* Try to allocate enough space in the tape buffer */
3924#define ST_MAX_ORDER 6
3925
3926static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
3927{
3928	int segs, max_segs, b_size, order, got;
3929	gfp_t priority;
3930
3931	if (new_size <= STbuffer->buffer_size)
3932		return 1;
3933
3934	if (STbuffer->buffer_size <= PAGE_SIZE)
3935		normalize_buffer(STbuffer);  /* Avoid extra segment */
3936
3937	max_segs = STbuffer->use_sg;
3938
3939	priority = GFP_KERNEL | __GFP_NOWARN;
3940	if (need_dma)
3941		priority |= GFP_DMA;
3942
3943	if (STbuffer->cleared)
3944		priority |= __GFP_ZERO;
3945
3946	if (STbuffer->frp_segs) {
3947		order = STbuffer->reserved_page_order;
3948		b_size = PAGE_SIZE << order;
3949	} else {
3950		for (b_size = PAGE_SIZE, order = 0;
3951		     order < ST_MAX_ORDER &&
3952			     max_segs * (PAGE_SIZE << order) < new_size;
3953		     order++, b_size *= 2)
3954			;  /* empty */
3955		STbuffer->reserved_page_order = order;
3956	}
3957	if (max_segs * (PAGE_SIZE << order) < new_size) {
3958		if (order == ST_MAX_ORDER)
3959			return 0;
3960		normalize_buffer(STbuffer);
3961		return enlarge_buffer(STbuffer, new_size, need_dma);
3962	}
3963
3964	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3965	     segs < max_segs && got < new_size;) {
3966		struct page *page;
3967
3968		page = alloc_pages(priority, order);
3969		if (!page) {
3970			DEB(STbuffer->buffer_size = got);
3971			normalize_buffer(STbuffer);
3972			return 0;
3973		}
3974
3975		STbuffer->frp_segs += 1;
3976		got += b_size;
3977		STbuffer->buffer_size = got;
3978		STbuffer->reserved_pages[segs] = page;
3979		segs++;
3980	}
3981	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3982
3983	return 1;
3984}
3985
3986
3987/* Make sure that no data from previous user is in the internal buffer */
3988static void clear_buffer(struct st_buffer * st_bp)
3989{
3990	int i;
3991
3992	for (i=0; i < st_bp->frp_segs; i++)
3993		memset(page_address(st_bp->reserved_pages[i]), 0,
3994		       PAGE_SIZE << st_bp->reserved_page_order);
3995	st_bp->cleared = 1;
3996}
3997
3998
3999/* Release the extra buffer */
4000static void normalize_buffer(struct st_buffer * STbuffer)
4001{
4002	int i, order = STbuffer->reserved_page_order;
4003
4004	for (i = 0; i < STbuffer->frp_segs; i++) {
4005		__free_pages(STbuffer->reserved_pages[i], order);
4006		STbuffer->buffer_size -= (PAGE_SIZE << order);
4007	}
4008	STbuffer->frp_segs = 0;
4009	STbuffer->sg_segs = 0;
4010	STbuffer->reserved_page_order = 0;
4011	STbuffer->map_data.offset = 0;
4012}
4013
4014
4015/* Move data from the user buffer to the tape buffer. Returns zero (success) or
4016   negative error code. */
4017static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
4018{
4019	int i, cnt, res, offset;
4020	int length = PAGE_SIZE << st_bp->reserved_page_order;
4021
4022	for (i = 0, offset = st_bp->buffer_bytes;
4023	     i < st_bp->frp_segs && offset >= length; i++)
4024		offset -= length;
4025	if (i == st_bp->frp_segs) {	/* Should never happen */
4026		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
4027		return (-EIO);
4028	}
4029	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4030		struct page *page = st_bp->reserved_pages[i];
4031		cnt = length - offset < do_count ? length - offset : do_count;
4032		res = copy_from_user(page_address(page) + offset, ubp, cnt);
4033		if (res)
4034			return (-EFAULT);
4035		do_count -= cnt;
4036		st_bp->buffer_bytes += cnt;
4037		ubp += cnt;
4038		offset = 0;
4039	}
4040	if (do_count) /* Should never happen */
4041		return (-EIO);
4042
4043	return 0;
4044}
4045
4046
4047/* Move data from the tape buffer to the user buffer. Returns zero (success) or
4048   negative error code. */
4049static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
4050{
4051	int i, cnt, res, offset;
4052	int length = PAGE_SIZE << st_bp->reserved_page_order;
4053
4054	for (i = 0, offset = st_bp->read_pointer;
4055	     i < st_bp->frp_segs && offset >= length; i++)
4056		offset -= length;
4057	if (i == st_bp->frp_segs) {	/* Should never happen */
4058		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
4059		return (-EIO);
4060	}
4061	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4062		struct page *page = st_bp->reserved_pages[i];
4063		cnt = length - offset < do_count ? length - offset : do_count;
4064		res = copy_to_user(ubp, page_address(page) + offset, cnt);
4065		if (res)
4066			return (-EFAULT);
4067		do_count -= cnt;
4068		st_bp->buffer_bytes -= cnt;
4069		st_bp->read_pointer += cnt;
4070		ubp += cnt;
4071		offset = 0;
4072	}
4073	if (do_count) /* Should never happen */
4074		return (-EIO);
4075
4076	return 0;
4077}
4078
4079
4080/* Move data towards start of buffer */
4081static void move_buffer_data(struct st_buffer * st_bp, int offset)
4082{
4083	int src_seg, dst_seg, src_offset = 0, dst_offset;
4084	int count, total;
4085	int length = PAGE_SIZE << st_bp->reserved_page_order;
4086
4087	if (offset == 0)
4088		return;
4089
4090	total=st_bp->buffer_bytes - offset;
4091	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
4092		src_offset = offset;
4093		if (src_offset < length)
4094			break;
4095		offset -= length;
4096	}
4097
4098	st_bp->buffer_bytes = st_bp->read_pointer = total;
4099	for (dst_seg=dst_offset=0; total > 0; ) {
4100		struct page *dpage = st_bp->reserved_pages[dst_seg];
4101		struct page *spage = st_bp->reserved_pages[src_seg];
4102
4103		count = min(length - dst_offset, length - src_offset);
4104		memmove(page_address(dpage) + dst_offset,
4105			page_address(spage) + src_offset, count);
4106		src_offset += count;
4107		if (src_offset >= length) {
4108			src_seg++;
4109			src_offset = 0;
4110		}
4111		dst_offset += count;
4112		if (dst_offset >= length) {
4113			dst_seg++;
4114			dst_offset = 0;
4115		}
4116		total -= count;
4117	}
4118}
4119
4120/* Validate the options from command line or module parameters */
4121static void validate_options(void)
4122{
4123	if (buffer_kbs > 0)
4124		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
4125	if (max_sg_segs >= ST_FIRST_SG)
4126		st_max_sg_segs = max_sg_segs;
4127}
4128
4129#ifndef MODULE
4130/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
4131 */
4132static int __init st_setup(char *str)
4133{
4134	int i, len, ints[5];
4135	char *stp;
4136
4137	stp = get_options(str, ARRAY_SIZE(ints), ints);
4138
4139	if (ints[0] > 0) {
4140		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
4141			if (parms[i].val)
4142				*parms[i].val = ints[i + 1];
4143	} else {
4144		while (stp != NULL) {
4145			for (i = 0; i < ARRAY_SIZE(parms); i++) {
4146				len = strlen(parms[i].name);
4147				if (!strncmp(stp, parms[i].name, len) &&
4148				    (*(stp + len) == ':' || *(stp + len) == '=')) {
4149					if (parms[i].val)
4150						*parms[i].val =
4151							simple_strtoul(stp + len + 1, NULL, 0);
4152					else
4153						printk(KERN_WARNING "st: Obsolete parameter %s\n",
4154						       parms[i].name);
4155					break;
4156				}
4157			}
4158			if (i >= ARRAY_SIZE(parms))
4159				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
4160					stp);
4161			stp = strchr(stp, ',');
4162			if (stp)
4163				stp++;
4164		}
4165	}
4166
4167	validate_options();
4168
4169	return 1;
4170}
4171
4172__setup("st=", st_setup);
4173
4174#endif
4175
4176static const struct file_operations st_fops =
4177{
4178	.owner =	THIS_MODULE,
4179	.read =		st_read,
4180	.write =	st_write,
4181	.unlocked_ioctl = st_ioctl,
4182#ifdef CONFIG_COMPAT
4183	.compat_ioctl = st_compat_ioctl,
4184#endif
4185	.open =		st_open,
4186	.flush =	st_flush,
4187	.release =	st_release,
4188	.llseek =	noop_llseek,
4189};
4190
4191static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
4192{
4193	int i, error;
4194	dev_t cdev_devno;
4195	struct cdev *cdev;
4196	struct device *dev;
4197	struct st_modedef *STm = &(tape->modes[mode]);
4198	char name[10];
4199	int dev_num = tape->index;
4200
4201	cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
4202
4203	cdev = cdev_alloc();
4204	if (!cdev) {
4205		pr_err("st%d: out of memory. Device not attached.\n", dev_num);
4206		error = -ENOMEM;
4207		goto out;
4208	}
4209	cdev->owner = THIS_MODULE;
4210	cdev->ops = &st_fops;
4211	STm->cdevs[rew] = cdev;
4212
4213	error = cdev_add(cdev, cdev_devno, 1);
4214	if (error) {
4215		pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
4216		       rew ? "non" : "auto", mode);
4217		pr_err("st%d: Device not attached.\n", dev_num);
4218		goto out_free;
4219	}
4220
4221	i = mode << (4 - ST_NBR_MODE_BITS);
4222	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4223		 tape->disk->disk_name, st_formats[i]);
4224
4225	dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
4226			    cdev_devno, &tape->modes[mode], "%s", name);
4227	if (IS_ERR(dev)) {
4228		pr_err("st%d: device_create failed\n", dev_num);
4229		error = PTR_ERR(dev);
4230		goto out_free;
4231	}
4232
4233	STm->devs[rew] = dev;
4234
4235	return 0;
4236out_free:
4237	cdev_del(STm->cdevs[rew]);
4238out:
4239	STm->cdevs[rew] = NULL;
4240	STm->devs[rew] = NULL;
4241	return error;
4242}
4243
4244static int create_cdevs(struct scsi_tape *tape)
4245{
4246	int mode, error;
4247	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4248		error = create_one_cdev(tape, mode, 0);
4249		if (error)
4250			return error;
4251		error = create_one_cdev(tape, mode, 1);
4252		if (error)
4253			return error;
4254	}
4255
4256	return sysfs_create_link(&tape->device->sdev_gendev.kobj,
4257				 &tape->modes[0].devs[0]->kobj, "tape");
4258}
4259
4260static void remove_cdevs(struct scsi_tape *tape)
4261{
4262	int mode, rew;
4263	sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
4264	for (mode = 0; mode < ST_NBR_MODES; mode++) {
4265		struct st_modedef *STm = &(tape->modes[mode]);
4266		for (rew = 0; rew < 2; rew++) {
4267			if (STm->cdevs[rew])
4268				cdev_del(STm->cdevs[rew]);
4269			if (STm->devs[rew])
4270				device_unregister(STm->devs[rew]);
4271		}
4272	}
4273}
4274
4275static int st_probe(struct device *dev)
4276{
4277	struct scsi_device *SDp = to_scsi_device(dev);
4278	struct gendisk *disk = NULL;
4279	struct scsi_tape *tpnt = NULL;
4280	struct st_modedef *STm;
4281	struct st_partstat *STps;
4282	struct st_buffer *buffer;
4283	int i, error;
4284	char *stp;
4285
4286	if (SDp->type != TYPE_TAPE)
4287		return -ENODEV;
4288	if ((stp = st_incompatible(SDp))) {
4289		sdev_printk(KERN_INFO, SDp,
4290			    "OnStream tapes are no longer supported;\n");
4291		sdev_printk(KERN_INFO, SDp,
4292			    "please mail to linux-scsi@vger.kernel.org.\n");
4293		return -ENODEV;
4294	}
4295
4296	scsi_autopm_get_device(SDp);
4297	i = queue_max_segments(SDp->request_queue);
4298	if (st_max_sg_segs < i)
4299		i = st_max_sg_segs;
4300	buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
4301	if (buffer == NULL) {
4302		sdev_printk(KERN_ERR, SDp,
4303			    "st: Can't allocate new tape buffer. "
4304			    "Device not attached.\n");
4305		goto out;
4306	}
4307
4308	disk = alloc_disk(1);
4309	if (!disk) {
4310		sdev_printk(KERN_ERR, SDp,
4311			    "st: out of memory. Device not attached.\n");
4312		goto out_buffer_free;
4313	}
4314
4315	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_KERNEL);
4316	if (tpnt == NULL) {
4317		sdev_printk(KERN_ERR, SDp,
4318			    "st: Can't allocate device descriptor.\n");
4319		goto out_put_disk;
4320	}
4321	kref_init(&tpnt->kref);
4322	tpnt->disk = disk;
4323	disk->private_data = &tpnt->driver;
4324	/* SCSI tape doesn't register this gendisk via add_disk().  Manually
4325	 * take queue reference that release_disk() expects. */
4326	if (!blk_get_queue(SDp->request_queue))
4327		goto out_put_disk;
4328	disk->queue = SDp->request_queue;
4329	tpnt->driver = &st_template;
4330
4331	tpnt->device = SDp;
4332	if (SDp->scsi_level <= 2)
4333		tpnt->tape_type = MT_ISSCSI1;
4334	else
4335		tpnt->tape_type = MT_ISSCSI2;
4336
4337	tpnt->buffer = buffer;
4338	tpnt->buffer->last_SRpnt = NULL;
4339
4340	tpnt->inited = 0;
4341	tpnt->dirty = 0;
4342	tpnt->in_use = 0;
4343	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
4344	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4345	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4346	tpnt->density = 0;
4347	tpnt->do_auto_lock = ST_AUTO_LOCK;
4348	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4349	tpnt->can_partitions = 0;
4350	tpnt->two_fm = ST_TWO_FM;
4351	tpnt->fast_mteom = ST_FAST_MTEOM;
4352	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4353	tpnt->sili = ST_SILI;
4354	tpnt->immediate = ST_NOWAIT;
4355	tpnt->immediate_filemark = 0;
4356	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4357	tpnt->partition = 0;
4358	tpnt->new_partition = 0;
4359	tpnt->nbr_partitions = 0;
4360	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4361	tpnt->long_timeout = ST_LONG_TIMEOUT;
4362	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
 
4363
4364	for (i = 0; i < ST_NBR_MODES; i++) {
4365		STm = &(tpnt->modes[i]);
4366		STm->defined = 0;
4367		STm->sysv = ST_SYSV;
4368		STm->defaults_for_writes = 0;
4369		STm->do_async_writes = ST_ASYNC_WRITES;
4370		STm->do_buffer_writes = ST_BUFFER_WRITES;
4371		STm->do_read_ahead = ST_READ_AHEAD;
4372		STm->default_compression = ST_DONT_TOUCH;
4373		STm->default_blksize = (-1);	/* No forced size */
4374		STm->default_density = (-1);	/* No forced density */
4375		STm->tape = tpnt;
4376	}
4377
4378	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4379		STps = &(tpnt->ps[i]);
4380		STps->rw = ST_IDLE;
4381		STps->eof = ST_NOEOF;
4382		STps->at_sm = 0;
4383		STps->last_block_valid = 0;
4384		STps->drv_block = (-1);
4385		STps->drv_file = (-1);
4386	}
4387
4388	tpnt->current_mode = 0;
4389	tpnt->modes[0].defined = 1;
4390
4391	tpnt->density_changed = tpnt->compression_changed =
4392	    tpnt->blksize_changed = 0;
4393	mutex_init(&tpnt->lock);
4394
4395	idr_preload(GFP_KERNEL);
4396	spin_lock(&st_index_lock);
4397	error = idr_alloc(&st_index_idr, tpnt, 0, ST_MAX_TAPES + 1, GFP_NOWAIT);
4398	spin_unlock(&st_index_lock);
4399	idr_preload_end();
4400	if (error < 0) {
4401		pr_warn("st: idr allocation failed: %d\n", error);
4402		goto out_put_queue;
4403	}
4404	tpnt->index = error;
4405	sprintf(disk->disk_name, "st%d", tpnt->index);
4406	tpnt->stats = kzalloc(sizeof(struct scsi_tape_stats), GFP_KERNEL);
4407	if (tpnt->stats == NULL) {
4408		sdev_printk(KERN_ERR, SDp,
4409			    "st: Can't allocate statistics.\n");
4410		goto out_idr_remove;
4411	}
4412
4413	dev_set_drvdata(dev, tpnt);
4414
4415
4416	error = create_cdevs(tpnt);
4417	if (error)
4418		goto out_remove_devs;
4419	scsi_autopm_put_device(SDp);
4420
4421	sdev_printk(KERN_NOTICE, SDp,
4422		    "Attached scsi tape %s\n", tape_name(tpnt));
4423	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4424		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4425		    queue_dma_alignment(SDp->request_queue) + 1);
4426
4427	return 0;
4428
4429out_remove_devs:
4430	remove_cdevs(tpnt);
4431	kfree(tpnt->stats);
4432out_idr_remove:
4433	spin_lock(&st_index_lock);
4434	idr_remove(&st_index_idr, tpnt->index);
4435	spin_unlock(&st_index_lock);
4436out_put_queue:
4437	blk_put_queue(disk->queue);
4438out_put_disk:
4439	put_disk(disk);
4440	kfree(tpnt);
4441out_buffer_free:
4442	kfree(buffer);
4443out:
4444	scsi_autopm_put_device(SDp);
4445	return -ENODEV;
4446};
4447
4448
4449static int st_remove(struct device *dev)
4450{
4451	struct scsi_tape *tpnt = dev_get_drvdata(dev);
4452	int index = tpnt->index;
4453
4454	scsi_autopm_get_device(to_scsi_device(dev));
4455	remove_cdevs(tpnt);
4456
4457	mutex_lock(&st_ref_mutex);
4458	kref_put(&tpnt->kref, scsi_tape_release);
4459	mutex_unlock(&st_ref_mutex);
4460	spin_lock(&st_index_lock);
4461	idr_remove(&st_index_idr, index);
4462	spin_unlock(&st_index_lock);
4463	return 0;
4464}
4465
4466/**
4467 *      scsi_tape_release - Called to free the Scsi_Tape structure
4468 *      @kref: pointer to embedded kref
4469 *
4470 *      st_ref_mutex must be held entering this routine.  Because it is
4471 *      called on last put, you should always use the scsi_tape_get()
4472 *      scsi_tape_put() helpers which manipulate the semaphore directly
4473 *      and never do a direct kref_put().
4474 **/
4475static void scsi_tape_release(struct kref *kref)
4476{
4477	struct scsi_tape *tpnt = to_scsi_tape(kref);
4478	struct gendisk *disk = tpnt->disk;
4479
4480	tpnt->device = NULL;
4481
4482	if (tpnt->buffer) {
4483		normalize_buffer(tpnt->buffer);
4484		kfree(tpnt->buffer->reserved_pages);
4485		kfree(tpnt->buffer);
4486	}
4487
4488	disk->private_data = NULL;
4489	put_disk(disk);
4490	kfree(tpnt->stats);
4491	kfree(tpnt);
4492	return;
4493}
4494
4495static struct class st_sysfs_class = {
4496	.name = "scsi_tape",
4497	.dev_groups = st_dev_groups,
4498};
4499
4500static int __init init_st(void)
4501{
4502	int err;
4503
4504	validate_options();
4505
4506	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4507		verstr, st_fixed_buffer_size, st_max_sg_segs);
4508
4509	debugging = (debug_flag > 0) ? debug_flag : NO_DEBUG;
4510	if (debugging) {
4511		printk(KERN_INFO "st: Debugging enabled debug_flag = %d\n",
4512			debugging);
4513	}
4514
4515	err = class_register(&st_sysfs_class);
4516	if (err) {
4517		pr_err("Unable register sysfs class for SCSI tapes\n");
4518		return err;
4519	}
4520
4521	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4522				     ST_MAX_TAPE_ENTRIES, "st");
4523	if (err) {
4524		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4525		       SCSI_TAPE_MAJOR);
4526		goto err_class;
4527	}
4528
4529	err = scsi_register_driver(&st_template.gendrv);
4530	if (err)
4531		goto err_chrdev;
4532
4533	return 0;
4534
4535err_chrdev:
4536	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4537				 ST_MAX_TAPE_ENTRIES);
4538err_class:
4539	class_unregister(&st_sysfs_class);
4540	return err;
4541}
4542
4543static void __exit exit_st(void)
4544{
4545	scsi_unregister_driver(&st_template.gendrv);
4546	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4547				 ST_MAX_TAPE_ENTRIES);
4548	class_unregister(&st_sysfs_class);
4549	idr_destroy(&st_index_idr);
4550	printk(KERN_INFO "st: Unloaded.\n");
4551}
4552
4553module_init(init_st);
4554module_exit(exit_st);
4555
4556
4557/* The sysfs driver interface. Read-only at the moment */
4558static ssize_t try_direct_io_show(struct device_driver *ddp, char *buf)
4559{
4560	return scnprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4561}
4562static DRIVER_ATTR_RO(try_direct_io);
4563
4564static ssize_t fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4565{
4566	return scnprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4567}
4568static DRIVER_ATTR_RO(fixed_buffer_size);
4569
4570static ssize_t max_sg_segs_show(struct device_driver *ddp, char *buf)
4571{
4572	return scnprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4573}
4574static DRIVER_ATTR_RO(max_sg_segs);
4575
4576static ssize_t version_show(struct device_driver *ddd, char *buf)
4577{
4578	return scnprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4579}
4580static DRIVER_ATTR_RO(version);
4581
4582#if DEBUG
4583static ssize_t debug_flag_store(struct device_driver *ddp,
4584	const char *buf, size_t count)
4585{
4586/* We only care what the first byte of the data is the rest is unused.
4587 * if it's a '1' we turn on debug and if it's a '0' we disable it. All
4588 * other values have -EINVAL returned if they are passed in.
4589 */
4590	if (count > 0) {
4591		if (buf[0] == '0') {
4592			debugging = NO_DEBUG;
4593			return count;
4594		} else if (buf[0] == '1') {
4595			debugging = 1;
4596			return count;
4597		}
4598	}
4599	return -EINVAL;
4600}
4601
4602static ssize_t debug_flag_show(struct device_driver *ddp, char *buf)
4603{
4604	return scnprintf(buf, PAGE_SIZE, "%d\n", debugging);
4605}
4606static DRIVER_ATTR_RW(debug_flag);
4607#endif
4608
4609static struct attribute *st_drv_attrs[] = {
4610	&driver_attr_try_direct_io.attr,
4611	&driver_attr_fixed_buffer_size.attr,
4612	&driver_attr_max_sg_segs.attr,
4613	&driver_attr_version.attr,
4614#if DEBUG
4615	&driver_attr_debug_flag.attr,
4616#endif
4617	NULL,
4618};
4619ATTRIBUTE_GROUPS(st_drv);
4620
4621/* The sysfs simple class interface */
4622static ssize_t
4623defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4624{
4625	struct st_modedef *STm = dev_get_drvdata(dev);
4626	ssize_t l = 0;
4627
4628	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4629	return l;
4630}
4631static DEVICE_ATTR_RO(defined);
4632
4633static ssize_t
4634default_blksize_show(struct device *dev, struct device_attribute *attr,
4635		     char *buf)
4636{
4637	struct st_modedef *STm = dev_get_drvdata(dev);
4638	ssize_t l = 0;
4639
4640	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4641	return l;
4642}
4643static DEVICE_ATTR_RO(default_blksize);
4644
4645static ssize_t
4646default_density_show(struct device *dev, struct device_attribute *attr,
4647		     char *buf)
4648{
4649	struct st_modedef *STm = dev_get_drvdata(dev);
4650	ssize_t l = 0;
4651	char *fmt;
4652
4653	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4654	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4655	return l;
4656}
4657static DEVICE_ATTR_RO(default_density);
4658
4659static ssize_t
4660default_compression_show(struct device *dev, struct device_attribute *attr,
4661			 char *buf)
4662{
4663	struct st_modedef *STm = dev_get_drvdata(dev);
4664	ssize_t l = 0;
4665
4666	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4667	return l;
4668}
4669static DEVICE_ATTR_RO(default_compression);
4670
4671static ssize_t
4672options_show(struct device *dev, struct device_attribute *attr, char *buf)
4673{
4674	struct st_modedef *STm = dev_get_drvdata(dev);
4675	struct scsi_tape *STp = STm->tape;
4676	int options;
4677	ssize_t l = 0;
4678
4679	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4680	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4681	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4682	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4683	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4684	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4685	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4686	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4687	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4688	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4689	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4690	options |= STm->sysv ? MT_ST_SYSV : 0;
4691	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4692	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4693	options |= STp->sili ? MT_ST_SILI : 0;
4694
4695	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4696	return l;
4697}
4698static DEVICE_ATTR_RO(options);
4699
4700/* Support for tape stats */
4701
4702/**
4703 * read_cnt_show - return read count - count of reads made from tape drive
4704 * @dev: struct device
4705 * @attr: attribute structure
4706 * @buf: buffer to return formatted data in
4707 */
4708static ssize_t read_cnt_show(struct device *dev,
4709	struct device_attribute *attr, char *buf)
4710{
4711	struct st_modedef *STm = dev_get_drvdata(dev);
4712
4713	return sprintf(buf, "%lld",
4714		       (long long)atomic64_read(&STm->tape->stats->read_cnt));
4715}
4716static DEVICE_ATTR_RO(read_cnt);
4717
4718/**
4719 * read_byte_cnt_show - return read byte count - tape drives
4720 * may use blocks less than 512 bytes this gives the raw byte count of
4721 * of data read from the tape drive.
4722 * @dev: struct device
4723 * @attr: attribute structure
4724 * @buf: buffer to return formatted data in
4725 */
4726static ssize_t read_byte_cnt_show(struct device *dev,
4727	struct device_attribute *attr, char *buf)
4728{
4729	struct st_modedef *STm = dev_get_drvdata(dev);
4730
4731	return sprintf(buf, "%lld",
4732		       (long long)atomic64_read(&STm->tape->stats->read_byte_cnt));
4733}
4734static DEVICE_ATTR_RO(read_byte_cnt);
4735
4736/**
4737 * read_ns_show - return read ns - overall time spent waiting on reads in ns.
4738 * @dev: struct device
4739 * @attr: attribute structure
4740 * @buf: buffer to return formatted data in
4741 */
4742static ssize_t read_ns_show(struct device *dev,
4743	struct device_attribute *attr, char *buf)
4744{
4745	struct st_modedef *STm = dev_get_drvdata(dev);
4746
4747	return sprintf(buf, "%lld",
4748		       (long long)atomic64_read(&STm->tape->stats->tot_read_time));
4749}
4750static DEVICE_ATTR_RO(read_ns);
4751
4752/**
4753 * write_cnt_show - write count - number of user calls
4754 * to write(2) that have written data to tape.
4755 * @dev: struct device
4756 * @attr: attribute structure
4757 * @buf: buffer to return formatted data in
4758 */
4759static ssize_t write_cnt_show(struct device *dev,
4760	struct device_attribute *attr, char *buf)
4761{
4762	struct st_modedef *STm = dev_get_drvdata(dev);
4763
4764	return sprintf(buf, "%lld",
4765		       (long long)atomic64_read(&STm->tape->stats->write_cnt));
4766}
4767static DEVICE_ATTR_RO(write_cnt);
4768
4769/**
4770 * write_byte_cnt_show - write byte count - raw count of
4771 * bytes written to tape.
4772 * @dev: struct device
4773 * @attr: attribute structure
4774 * @buf: buffer to return formatted data in
4775 */
4776static ssize_t write_byte_cnt_show(struct device *dev,
4777	struct device_attribute *attr, char *buf)
4778{
4779	struct st_modedef *STm = dev_get_drvdata(dev);
4780
4781	return sprintf(buf, "%lld",
4782		       (long long)atomic64_read(&STm->tape->stats->write_byte_cnt));
4783}
4784static DEVICE_ATTR_RO(write_byte_cnt);
4785
4786/**
4787 * write_ns_show - write ns - number of nanoseconds waiting on write
4788 * requests to complete.
4789 * @dev: struct device
4790 * @attr: attribute structure
4791 * @buf: buffer to return formatted data in
4792 */
4793static ssize_t write_ns_show(struct device *dev,
4794	struct device_attribute *attr, char *buf)
4795{
4796	struct st_modedef *STm = dev_get_drvdata(dev);
4797
4798	return sprintf(buf, "%lld",
4799		       (long long)atomic64_read(&STm->tape->stats->tot_write_time));
4800}
4801static DEVICE_ATTR_RO(write_ns);
4802
4803/**
4804 * in_flight_show - number of I/Os currently in flight -
4805 * in most cases this will be either 0 or 1. It may be higher if someone
4806 * has also issued other SCSI commands such as via an ioctl.
4807 * @dev: struct device
4808 * @attr: attribute structure
4809 * @buf: buffer to return formatted data in
4810 */
4811static ssize_t in_flight_show(struct device *dev,
4812	struct device_attribute *attr, char *buf)
4813{
4814	struct st_modedef *STm = dev_get_drvdata(dev);
4815
4816	return sprintf(buf, "%lld",
4817		       (long long)atomic64_read(&STm->tape->stats->in_flight));
4818}
4819static DEVICE_ATTR_RO(in_flight);
4820
4821/**
4822 * io_ns_show - io wait ns - this is the number of ns spent
4823 * waiting on all I/O to complete. This includes tape movement commands
4824 * such as rewinding, seeking to end of file or tape, it also includes
4825 * read and write. To determine the time spent on tape movement
4826 * subtract the read and write ns from this value.
4827 * @dev: struct device
4828 * @attr: attribute structure
4829 * @buf: buffer to return formatted data in
4830 */
4831static ssize_t io_ns_show(struct device *dev,
4832	struct device_attribute *attr, char *buf)
4833{
4834	struct st_modedef *STm = dev_get_drvdata(dev);
4835
4836	return sprintf(buf, "%lld",
4837		       (long long)atomic64_read(&STm->tape->stats->tot_io_time));
4838}
4839static DEVICE_ATTR_RO(io_ns);
4840
4841/**
4842 * other_cnt_show - other io count - this is the number of
4843 * I/O requests other than read and write requests.
4844 * Typically these are tape movement requests but will include driver
4845 * tape movement. This includes only requests issued by the st driver.
4846 * @dev: struct device
4847 * @attr: attribute structure
4848 * @buf: buffer to return formatted data in
4849 */
4850static ssize_t other_cnt_show(struct device *dev,
4851	struct device_attribute *attr, char *buf)
4852{
4853	struct st_modedef *STm = dev_get_drvdata(dev);
4854
4855	return sprintf(buf, "%lld",
4856		       (long long)atomic64_read(&STm->tape->stats->other_cnt));
4857}
4858static DEVICE_ATTR_RO(other_cnt);
4859
4860/**
4861 * resid_cnt_show - A count of the number of times we get a residual
4862 * count - this should indicate someone issuing reads larger than the
4863 * block size on tape.
4864 * @dev: struct device
4865 * @attr: attribute structure
4866 * @buf: buffer to return formatted data in
4867 */
4868static ssize_t resid_cnt_show(struct device *dev,
4869	struct device_attribute *attr, char *buf)
4870{
4871	struct st_modedef *STm = dev_get_drvdata(dev);
4872
4873	return sprintf(buf, "%lld",
4874		       (long long)atomic64_read(&STm->tape->stats->resid_cnt));
4875}
4876static DEVICE_ATTR_RO(resid_cnt);
4877
4878static struct attribute *st_dev_attrs[] = {
4879	&dev_attr_defined.attr,
4880	&dev_attr_default_blksize.attr,
4881	&dev_attr_default_density.attr,
4882	&dev_attr_default_compression.attr,
4883	&dev_attr_options.attr,
4884	NULL,
4885};
4886
4887static struct attribute *st_stats_attrs[] = {
4888	&dev_attr_read_cnt.attr,
4889	&dev_attr_read_byte_cnt.attr,
4890	&dev_attr_read_ns.attr,
4891	&dev_attr_write_cnt.attr,
4892	&dev_attr_write_byte_cnt.attr,
4893	&dev_attr_write_ns.attr,
4894	&dev_attr_in_flight.attr,
4895	&dev_attr_io_ns.attr,
4896	&dev_attr_other_cnt.attr,
4897	&dev_attr_resid_cnt.attr,
4898	NULL,
4899};
4900
4901static struct attribute_group stats_group = {
4902	.name = "stats",
4903	.attrs = st_stats_attrs,
4904};
4905
4906static struct attribute_group st_group = {
4907	.attrs = st_dev_attrs,
4908};
4909
4910static const struct attribute_group *st_dev_groups[] = {
4911	&st_group,
4912	&stats_group,
4913	NULL,
4914};
4915
4916/* The following functions may be useful for a larger audience. */
4917static int sgl_map_user_pages(struct st_buffer *STbp,
4918			      const unsigned int max_pages, unsigned long uaddr,
4919			      size_t count, int rw)
4920{
4921	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4922	unsigned long start = uaddr >> PAGE_SHIFT;
4923	const int nr_pages = end - start;
4924	int res, i;
4925	struct page **pages;
4926	struct rq_map_data *mdata = &STbp->map_data;
4927
4928	/* User attempted Overflow! */
4929	if ((uaddr + count) < uaddr)
4930		return -EINVAL;
4931
4932	/* Too big */
4933        if (nr_pages > max_pages)
4934		return -ENOMEM;
4935
4936	/* Hmm? */
4937	if (count == 0)
4938		return 0;
4939
4940	pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
4941	if (pages == NULL)
4942		return -ENOMEM;
4943
4944        /* Try to fault in all of the necessary pages */
4945        /* rw==READ means read from drive, write into memory area */
4946	res = pin_user_pages_fast(uaddr, nr_pages, rw == READ ? FOLL_WRITE : 0,
4947				  pages);
4948
4949	/* Errors and no page mapped should return here */
4950	if (res < nr_pages)
4951		goto out_unmap;
4952
4953        for (i=0; i < nr_pages; i++) {
4954                /* FIXME: flush superflous for rw==READ,
4955                 * probably wrong function for rw==WRITE
4956                 */
4957		flush_dcache_page(pages[i]);
4958        }
4959
4960	mdata->offset = uaddr & ~PAGE_MASK;
4961	STbp->mapped_pages = pages;
4962
4963	return nr_pages;
4964 out_unmap:
4965	if (res > 0) {
4966		unpin_user_pages(pages, res);
4967		res = 0;
4968	}
4969	kfree(pages);
4970	return res;
4971}
4972
4973
4974/* And unmap them... */
4975static int sgl_unmap_user_pages(struct st_buffer *STbp,
4976				const unsigned int nr_pages, int dirtied)
4977{
4978	/* FIXME: cache flush missing for rw==READ */
4979	unpin_user_pages_dirty_lock(STbp->mapped_pages, nr_pages, dirtied);
4980
4981	kfree(STbp->mapped_pages);
4982	STbp->mapped_pages = NULL;
4983
4984	return 0;
4985}