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v4.10.11
 
   1/*
   2   SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
   3   file Documentation/scsi/st.txt for more information.
   4
   5   History:
   6   Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
   7   Contribution and ideas from several people including (in alphabetical
   8   order) Klaus Ehrenfried, Eugene Exarevsky, Eric Lee Green, Wolfgang Denk,
   9   Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
  10   Michael Schaefer, J"org Weule, and Eric Youngdale.
  11
  12   Copyright 1992 - 2016 Kai Makisara
  13   email Kai.Makisara@kolumbus.fi
  14
  15   Some small formal changes - aeb, 950809
  16
  17   Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
  18 */
  19
  20static const char *verstr = "20160209";
  21
  22#include <linux/module.h>
  23
  24#include <linux/fs.h>
  25#include <linux/kernel.h>
  26#include <linux/sched.h>
  27#include <linux/mm.h>
  28#include <linux/init.h>
  29#include <linux/string.h>
  30#include <linux/slab.h>
  31#include <linux/errno.h>
  32#include <linux/mtio.h>
  33#include <linux/cdrom.h>
  34#include <linux/ioctl.h>
  35#include <linux/fcntl.h>
  36#include <linux/spinlock.h>
  37#include <linux/blkdev.h>
  38#include <linux/moduleparam.h>
  39#include <linux/cdev.h>
  40#include <linux/idr.h>
  41#include <linux/delay.h>
  42#include <linux/mutex.h>
  43
  44#include <linux/uaccess.h>
  45#include <asm/dma.h>
  46
  47#include <scsi/scsi.h>
  48#include <scsi/scsi_dbg.h>
  49#include <scsi/scsi_device.h>
  50#include <scsi/scsi_driver.h>
  51#include <scsi/scsi_eh.h>
  52#include <scsi/scsi_host.h>
  53#include <scsi/scsi_ioctl.h>
  54#include <scsi/sg.h>
  55
  56
  57/* The driver prints some debugging information on the console if DEBUG
  58   is defined and non-zero. */
  59#define DEBUG 1
  60#define NO_DEBUG 0
  61
  62#define ST_DEB_MSG  KERN_NOTICE
  63#if DEBUG
  64/* The message level for the debug messages is currently set to KERN_NOTICE
  65   so that people can easily see the messages. Later when the debugging messages
  66   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
  67#define DEB(a) a
  68#define DEBC(a) if (debugging) { a ; }
  69#else
  70#define DEB(a)
  71#define DEBC(a)
  72#endif
  73
  74#define ST_KILOBYTE 1024
  75
  76#include "st_options.h"
  77#include "st.h"
  78
  79static int buffer_kbs;
  80static int max_sg_segs;
  81static int try_direct_io = TRY_DIRECT_IO;
  82static int try_rdio = 1;
  83static int try_wdio = 1;
  84static int debug_flag;
  85
  86static struct class st_sysfs_class;
  87static const struct attribute_group *st_dev_groups[];
  88static const struct attribute_group *st_drv_groups[];
  89
  90MODULE_AUTHOR("Kai Makisara");
  91MODULE_DESCRIPTION("SCSI tape (st) driver");
  92MODULE_LICENSE("GPL");
  93MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  94MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  95
  96/* Set 'perm' (4th argument) to 0 to disable module_param's definition
  97 * of sysfs parameters (which module_param doesn't yet support).
  98 * Sysfs parameters defined explicitly later.
  99 */
 100module_param_named(buffer_kbs, buffer_kbs, int, 0);
 101MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
 102module_param_named(max_sg_segs, max_sg_segs, int, 0);
 103MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 104module_param_named(try_direct_io, try_direct_io, int, 0);
 105MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 106module_param_named(debug_flag, debug_flag, int, 0);
 107MODULE_PARM_DESC(debug_flag, "Enable DEBUG, same as setting debugging=1");
 108
 109
 110/* Extra parameters for testing */
 111module_param_named(try_rdio, try_rdio, int, 0);
 112MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 113module_param_named(try_wdio, try_wdio, int, 0);
 114MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 115
 116#ifndef MODULE
 117static int write_threshold_kbs;  /* retained for compatibility */
 118static struct st_dev_parm {
 119	char *name;
 120	int *val;
 121} parms[] __initdata = {
 122	{
 123		"buffer_kbs", &buffer_kbs
 124	},
 125	{       /* Retained for compatibility with 2.4 */
 126		"write_threshold_kbs", &write_threshold_kbs
 127	},
 128	{
 129		"max_sg_segs", NULL
 130	},
 131	{
 132		"try_direct_io", &try_direct_io
 133	},
 134	{
 135		"debug_flag", &debug_flag
 136	}
 137};
 138#endif
 139
 140/* Restrict the number of modes so that names for all are assigned */
 141#if ST_NBR_MODES > 16
 142#error "Maximum number of modes is 16"
 143#endif
 144/* Bit reversed order to get same names for same minors with all
 145   mode counts */
 146static const char *st_formats[] = {
 147	"",  "r", "k", "s", "l", "t", "o", "u",
 148	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 149
 150/* The default definitions have been moved to st_options.h */
 151
 152#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 153
 154/* The buffer size should fit into the 24 bits for length in the
 155   6-byte SCSI read and write commands. */
 156#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 157#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 158#endif
 159
 160static int debugging = DEBUG;
 161
 162#define MAX_RETRIES 0
 163#define MAX_WRITE_RETRIES 0
 164#define MAX_READY_RETRIES 0
 165#define NO_TAPE  NOT_READY
 166
 167#define ST_TIMEOUT (900 * HZ)
 168#define ST_LONG_TIMEOUT (14000 * HZ)
 169
 170/* Remove mode bits and auto-rewind bit (7) */
 171#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 172    (iminor(x) & ~(-1 << ST_MODE_SHIFT)) )
 173#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 174
 175/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 176#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 177  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 178
 179/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 180   24 bits) */
 181#define SET_DENS_AND_BLK 0x10001
 182
 183static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 184static int st_max_sg_segs = ST_MAX_SG;
 185
 186static int modes_defined;
 187
 188static int enlarge_buffer(struct st_buffer *, int, int);
 189static void clear_buffer(struct st_buffer *);
 190static void normalize_buffer(struct st_buffer *);
 191static int append_to_buffer(const char __user *, struct st_buffer *, int);
 192static int from_buffer(struct st_buffer *, char __user *, int);
 193static void move_buffer_data(struct st_buffer *, int);
 194
 195static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 196			      unsigned long, size_t, int);
 197static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 198
 199static int st_probe(struct device *);
 200static int st_remove(struct device *);
 201
 202static struct scsi_driver st_template = {
 203	.gendrv = {
 204		.name		= "st",
 205		.owner		= THIS_MODULE,
 206		.probe		= st_probe,
 207		.remove		= st_remove,
 208		.groups		= st_drv_groups,
 209	},
 210};
 211
 212static int st_compression(struct scsi_tape *, int);
 213
 214static int find_partition(struct scsi_tape *);
 215static int switch_partition(struct scsi_tape *);
 216
 217static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 218
 219static void scsi_tape_release(struct kref *);
 220
 221#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 222
 223static DEFINE_MUTEX(st_ref_mutex);
 224static DEFINE_SPINLOCK(st_index_lock);
 225static DEFINE_SPINLOCK(st_use_lock);
 226static DEFINE_IDR(st_index_idr);
 227
 228
 229
 230#include "osst_detect.h"
 231#ifndef SIGS_FROM_OSST
 232#define SIGS_FROM_OSST \
 233	{"OnStream", "SC-", "", "osst"}, \
 234	{"OnStream", "DI-", "", "osst"}, \
 235	{"OnStream", "DP-", "", "osst"}, \
 236	{"OnStream", "USB", "", "osst"}, \
 237	{"OnStream", "FW-", "", "osst"}
 238#endif
 239
 240static struct scsi_tape *scsi_tape_get(int dev)
 241{
 242	struct scsi_tape *STp = NULL;
 243
 244	mutex_lock(&st_ref_mutex);
 245	spin_lock(&st_index_lock);
 246
 247	STp = idr_find(&st_index_idr, dev);
 248	if (!STp) goto out;
 249
 250	kref_get(&STp->kref);
 251
 252	if (!STp->device)
 253		goto out_put;
 254
 255	if (scsi_device_get(STp->device))
 256		goto out_put;
 257
 258	goto out;
 259
 260out_put:
 261	kref_put(&STp->kref, scsi_tape_release);
 262	STp = NULL;
 263out:
 264	spin_unlock(&st_index_lock);
 265	mutex_unlock(&st_ref_mutex);
 266	return STp;
 267}
 268
 269static void scsi_tape_put(struct scsi_tape *STp)
 270{
 271	struct scsi_device *sdev = STp->device;
 272
 273	mutex_lock(&st_ref_mutex);
 274	kref_put(&STp->kref, scsi_tape_release);
 275	scsi_device_put(sdev);
 276	mutex_unlock(&st_ref_mutex);
 277}
 278
 279struct st_reject_data {
 280	char *vendor;
 281	char *model;
 282	char *rev;
 283	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 284};
 285
 286static struct st_reject_data reject_list[] = {
 287	/* {"XXX", "Yy-", "", NULL},  example */
 288	SIGS_FROM_OSST,
 289	{NULL, }};
 290
 291/* If the device signature is on the list of incompatible drives, the
 292   function returns a pointer to the name of the correct driver (if known) */
 293static char * st_incompatible(struct scsi_device* SDp)
 294{
 295	struct st_reject_data *rp;
 296
 297	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 298		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 299		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 300		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 301			if (rp->driver_hint)
 302				return rp->driver_hint;
 303			else
 304				return "unknown";
 305		}
 306	return NULL;
 307}
 308
 309
 310static inline char *tape_name(struct scsi_tape *tape)
 311{
 312	return tape->disk->disk_name;
 313}
 314
 315#define st_printk(prefix, t, fmt, a...) \
 316	sdev_prefix_printk(prefix, (t)->device, tape_name(t), fmt, ##a)
 317#ifdef DEBUG
 318#define DEBC_printk(t, fmt, a...) \
 319	if (debugging) { st_printk(ST_DEB_MSG, t, fmt, ##a ); }
 320#else
 321#define DEBC_printk(t, fmt, a...)
 322#endif
 323
 324static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 325{
 326	const u8 *ucp;
 327	const u8 *sense = SRpnt->sense;
 328
 329	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 330				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 331	s->flags = 0;
 332
 333	if (s->have_sense) {
 334		s->deferred = 0;
 335		s->remainder_valid =
 336			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 337		switch (sense[0] & 0x7f) {
 338		case 0x71:
 339			s->deferred = 1;
 
 340		case 0x70:
 341			s->fixed_format = 1;
 342			s->flags = sense[2] & 0xe0;
 343			break;
 344		case 0x73:
 345			s->deferred = 1;
 
 346		case 0x72:
 347			s->fixed_format = 0;
 348			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 349			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 350			break;
 351		}
 352	}
 353}
 354
 355
 356/* Convert the result to success code */
 357static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 358{
 359	int result = SRpnt->result;
 360	u8 scode;
 361	DEB(const char *stp;)
 362	char *name = tape_name(STp);
 363	struct st_cmdstatus *cmdstatp;
 364
 365	if (!result)
 366		return 0;
 367
 368	cmdstatp = &STp->buffer->cmdstat;
 369	st_analyze_sense(SRpnt, cmdstatp);
 370
 371	if (cmdstatp->have_sense)
 372		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 373	else
 374		scode = 0;
 375
 376	DEB(
 377	if (debugging) {
 378		st_printk(ST_DEB_MSG, STp,
 379			    "Error: %x, cmd: %x %x %x %x %x %x\n", result,
 380			    SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 381			    SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 382		if (cmdstatp->have_sense)
 383			__scsi_print_sense(STp->device, name,
 384					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 385	} ) /* end DEB */
 386	if (!debugging) { /* Abnormal conditions for tape */
 387		if (!cmdstatp->have_sense)
 388			st_printk(KERN_WARNING, STp,
 389			       "Error %x (driver bt 0x%x, host bt 0x%x).\n",
 390			       result, driver_byte(result), host_byte(result));
 391		else if (cmdstatp->have_sense &&
 392			 scode != NO_SENSE &&
 393			 scode != RECOVERED_ERROR &&
 394			 /* scode != UNIT_ATTENTION && */
 395			 scode != BLANK_CHECK &&
 396			 scode != VOLUME_OVERFLOW &&
 397			 SRpnt->cmd[0] != MODE_SENSE &&
 398			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 399
 400			__scsi_print_sense(STp->device, name,
 401					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 402		}
 403	}
 404
 405	if (cmdstatp->fixed_format &&
 406	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 407		if (STp->cln_sense_value)
 408			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 409					       STp->cln_sense_mask) == STp->cln_sense_value);
 410		else
 411			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 412					       STp->cln_sense_mask) != 0);
 413	}
 414	if (cmdstatp->have_sense &&
 415	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 416		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 417
 418	STp->pos_unknown |= STp->device->was_reset;
 419
 420	if (cmdstatp->have_sense &&
 421	    scode == RECOVERED_ERROR
 422#if ST_RECOVERED_WRITE_FATAL
 423	    && SRpnt->cmd[0] != WRITE_6
 424	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 425#endif
 426	    ) {
 427		STp->recover_count++;
 428		STp->recover_reg++;
 429
 430		DEB(
 431		if (debugging) {
 432			if (SRpnt->cmd[0] == READ_6)
 433				stp = "read";
 434			else if (SRpnt->cmd[0] == WRITE_6)
 435				stp = "write";
 436			else
 437				stp = "ioctl";
 438			st_printk(ST_DEB_MSG, STp,
 439				  "Recovered %s error (%d).\n",
 440				  stp, STp->recover_count);
 441		} ) /* end DEB */
 442
 443		if (cmdstatp->flags == 0)
 444			return 0;
 445	}
 446	return (-EIO);
 447}
 448
 449static struct st_request *st_allocate_request(struct scsi_tape *stp)
 450{
 451	struct st_request *streq;
 452
 453	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 454	if (streq)
 455		streq->stp = stp;
 456	else {
 457		st_printk(KERN_ERR, stp,
 458			  "Can't get SCSI request.\n");
 459		if (signal_pending(current))
 460			stp->buffer->syscall_result = -EINTR;
 461		else
 462			stp->buffer->syscall_result = -EBUSY;
 463	}
 464
 465	return streq;
 466}
 467
 468static void st_release_request(struct st_request *streq)
 469{
 470	kfree(streq);
 471}
 472
 473static void st_do_stats(struct scsi_tape *STp, struct request *req)
 474{
 475	ktime_t now;
 476
 477	now = ktime_get();
 478	if (req->cmd[0] == WRITE_6) {
 479		now = ktime_sub(now, STp->stats->write_time);
 480		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 481		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 482		atomic64_inc(&STp->stats->write_cnt);
 483		if (req->errors) {
 484			atomic64_add(atomic_read(&STp->stats->last_write_size)
 485				- STp->buffer->cmdstat.residual,
 486				&STp->stats->write_byte_cnt);
 487			if (STp->buffer->cmdstat.residual > 0)
 488				atomic64_inc(&STp->stats->resid_cnt);
 489		} else
 490			atomic64_add(atomic_read(&STp->stats->last_write_size),
 491				&STp->stats->write_byte_cnt);
 492	} else if (req->cmd[0] == READ_6) {
 493		now = ktime_sub(now, STp->stats->read_time);
 494		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 495		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 496		atomic64_inc(&STp->stats->read_cnt);
 497		if (req->errors) {
 498			atomic64_add(atomic_read(&STp->stats->last_read_size)
 499				- STp->buffer->cmdstat.residual,
 500				&STp->stats->read_byte_cnt);
 501			if (STp->buffer->cmdstat.residual > 0)
 502				atomic64_inc(&STp->stats->resid_cnt);
 503		} else
 504			atomic64_add(atomic_read(&STp->stats->last_read_size),
 505				&STp->stats->read_byte_cnt);
 506	} else {
 507		now = ktime_sub(now, STp->stats->other_time);
 508		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 509		atomic64_inc(&STp->stats->other_cnt);
 510	}
 511	atomic64_dec(&STp->stats->in_flight);
 512}
 513
 514static void st_scsi_execute_end(struct request *req, int uptodate)
 515{
 516	struct st_request *SRpnt = req->end_io_data;
 
 517	struct scsi_tape *STp = SRpnt->stp;
 518	struct bio *tmp;
 519
 520	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
 521	STp->buffer->cmdstat.residual = req->resid_len;
 522
 523	st_do_stats(STp, req);
 524
 525	tmp = SRpnt->bio;
 
 
 526	if (SRpnt->waiting)
 527		complete(SRpnt->waiting);
 528
 529	blk_rq_unmap_user(tmp);
 530	__blk_put_request(req->q, req);
 531}
 532
 533static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 534			   int data_direction, void *buffer, unsigned bufflen,
 535			   int timeout, int retries)
 536{
 537	struct request *req;
 
 538	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 539	int err = 0;
 540	int write = (data_direction == DMA_TO_DEVICE);
 541	struct scsi_tape *STp = SRpnt->stp;
 542
 543	req = blk_get_request(SRpnt->stp->device->request_queue, write,
 544			      GFP_KERNEL);
 
 545	if (IS_ERR(req))
 546		return DRIVER_ERROR << 24;
 547
 548	blk_rq_set_block_pc(req);
 549	req->rq_flags |= RQF_QUIET;
 550
 551	mdata->null_mapped = 1;
 552
 553	if (bufflen) {
 554		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 555				      GFP_KERNEL);
 556		if (err) {
 557			blk_put_request(req);
 558			return DRIVER_ERROR << 24;
 559		}
 560	}
 561
 562	atomic64_inc(&STp->stats->in_flight);
 563	if (cmd[0] == WRITE_6) {
 564		atomic_set(&STp->stats->last_write_size, bufflen);
 565		STp->stats->write_time = ktime_get();
 566	} else if (cmd[0] == READ_6) {
 567		atomic_set(&STp->stats->last_read_size, bufflen);
 568		STp->stats->read_time = ktime_get();
 569	} else {
 570		STp->stats->other_time = ktime_get();
 571	}
 572
 573	SRpnt->bio = req->bio;
 574	req->cmd_len = COMMAND_SIZE(cmd[0]);
 575	memset(req->cmd, 0, BLK_MAX_CDB);
 576	memcpy(req->cmd, cmd, req->cmd_len);
 577	req->sense = SRpnt->sense;
 578	req->sense_len = 0;
 579	req->timeout = timeout;
 580	req->retries = retries;
 581	req->end_io_data = SRpnt;
 582
 583	blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
 584	return 0;
 585}
 586
 587/* Do the scsi command. Waits until command performed if do_wait is true.
 588   Otherwise write_behind_check() is used to check that the command
 589   has finished. */
 590static struct st_request *
 591st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 592	   int bytes, int direction, int timeout, int retries, int do_wait)
 593{
 594	struct completion *waiting;
 595	struct rq_map_data *mdata = &STp->buffer->map_data;
 596	int ret;
 597
 598	/* if async, make sure there's no command outstanding */
 599	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 600		st_printk(KERN_ERR, STp,
 601			  "Async command already active.\n");
 602		if (signal_pending(current))
 603			(STp->buffer)->syscall_result = (-EINTR);
 604		else
 605			(STp->buffer)->syscall_result = (-EBUSY);
 606		return NULL;
 607	}
 608
 609	if (!SRpnt) {
 610		SRpnt = st_allocate_request(STp);
 611		if (!SRpnt)
 612			return NULL;
 613	}
 614
 615	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 616	   which IO is outstanding. It's nulled out when the IO completes. */
 617	if (!do_wait)
 618		(STp->buffer)->last_SRpnt = SRpnt;
 619
 620	waiting = &STp->wait;
 621	init_completion(waiting);
 622	SRpnt->waiting = waiting;
 623
 624	if (STp->buffer->do_dio) {
 625		mdata->page_order = 0;
 626		mdata->nr_entries = STp->buffer->sg_segs;
 627		mdata->pages = STp->buffer->mapped_pages;
 628	} else {
 629		mdata->page_order = STp->buffer->reserved_page_order;
 630		mdata->nr_entries =
 631			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 632		mdata->pages = STp->buffer->reserved_pages;
 633		mdata->offset = 0;
 634	}
 635
 636	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 637	STp->buffer->cmdstat.have_sense = 0;
 638	STp->buffer->syscall_result = 0;
 639
 640	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 641			      retries);
 642	if (ret) {
 643		/* could not allocate the buffer or request was too large */
 644		(STp->buffer)->syscall_result = (-EBUSY);
 645		(STp->buffer)->last_SRpnt = NULL;
 646	} else if (do_wait) {
 647		wait_for_completion(waiting);
 648		SRpnt->waiting = NULL;
 649		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 650	}
 651
 652	return SRpnt;
 653}
 654
 655
 656/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 657   write has been correct but EOM early warning reached, -EIO if write ended in
 658   error or zero if write successful. Asynchronous writes are used only in
 659   variable block mode. */
 660static int write_behind_check(struct scsi_tape * STp)
 661{
 662	int retval = 0;
 663	struct st_buffer *STbuffer;
 664	struct st_partstat *STps;
 665	struct st_cmdstatus *cmdstatp;
 666	struct st_request *SRpnt;
 667
 668	STbuffer = STp->buffer;
 669	if (!STbuffer->writing)
 670		return 0;
 671
 672	DEB(
 673	if (STp->write_pending)
 674		STp->nbr_waits++;
 675	else
 676		STp->nbr_finished++;
 677	) /* end DEB */
 678
 679	wait_for_completion(&(STp->wait));
 680	SRpnt = STbuffer->last_SRpnt;
 681	STbuffer->last_SRpnt = NULL;
 682	SRpnt->waiting = NULL;
 683
 684	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 685	st_release_request(SRpnt);
 686
 687	STbuffer->buffer_bytes -= STbuffer->writing;
 688	STps = &(STp->ps[STp->partition]);
 689	if (STps->drv_block >= 0) {
 690		if (STp->block_size == 0)
 691			STps->drv_block++;
 692		else
 693			STps->drv_block += STbuffer->writing / STp->block_size;
 694	}
 695
 696	cmdstatp = &STbuffer->cmdstat;
 697	if (STbuffer->syscall_result) {
 698		retval = -EIO;
 699		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 700		    (cmdstatp->flags & SENSE_EOM) &&
 701		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 702		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 703			/* EOM at write-behind, has all data been written? */
 704			if (!cmdstatp->remainder_valid ||
 705			    cmdstatp->uremainder64 == 0)
 706				retval = -ENOSPC;
 707		}
 708		if (retval == -EIO)
 709			STps->drv_block = -1;
 710	}
 711	STbuffer->writing = 0;
 712
 713	DEB(if (debugging && retval)
 714		    st_printk(ST_DEB_MSG, STp,
 715				"Async write error %x, return value %d.\n",
 716				STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 717
 718	return retval;
 719}
 720
 721
 722/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 723   it messes up the block number). */
 724static int cross_eof(struct scsi_tape * STp, int forward)
 725{
 726	struct st_request *SRpnt;
 727	unsigned char cmd[MAX_COMMAND_SIZE];
 728
 729	cmd[0] = SPACE;
 730	cmd[1] = 0x01;		/* Space FileMarks */
 731	if (forward) {
 732		cmd[2] = cmd[3] = 0;
 733		cmd[4] = 1;
 734	} else
 735		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 736	cmd[5] = 0;
 737
 738	DEBC_printk(STp, "Stepping over filemark %s.\n",
 739		    forward ? "forward" : "backward");
 740
 741	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 742			   STp->device->request_queue->rq_timeout,
 743			   MAX_RETRIES, 1);
 744	if (!SRpnt)
 745		return (STp->buffer)->syscall_result;
 746
 747	st_release_request(SRpnt);
 748	SRpnt = NULL;
 749
 750	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 751		st_printk(KERN_ERR, STp,
 752			  "Stepping over filemark %s failed.\n",
 753			  forward ? "forward" : "backward");
 754
 755	return (STp->buffer)->syscall_result;
 756}
 757
 758
 759/* Flush the write buffer (never need to write if variable blocksize). */
 760static int st_flush_write_buffer(struct scsi_tape * STp)
 761{
 762	int transfer, blks;
 763	int result;
 764	unsigned char cmd[MAX_COMMAND_SIZE];
 765	struct st_request *SRpnt;
 766	struct st_partstat *STps;
 767
 768	result = write_behind_check(STp);
 769	if (result)
 770		return result;
 771
 772	result = 0;
 773	if (STp->dirty == 1) {
 774
 775		transfer = STp->buffer->buffer_bytes;
 776		DEBC_printk(STp, "Flushing %d bytes.\n", transfer);
 777
 778		memset(cmd, 0, MAX_COMMAND_SIZE);
 779		cmd[0] = WRITE_6;
 780		cmd[1] = 1;
 781		blks = transfer / STp->block_size;
 782		cmd[2] = blks >> 16;
 783		cmd[3] = blks >> 8;
 784		cmd[4] = blks;
 785
 786		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 787				   STp->device->request_queue->rq_timeout,
 788				   MAX_WRITE_RETRIES, 1);
 789		if (!SRpnt)
 790			return (STp->buffer)->syscall_result;
 791
 792		STps = &(STp->ps[STp->partition]);
 793		if ((STp->buffer)->syscall_result != 0) {
 794			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 795
 796			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 797			    (cmdstatp->flags & SENSE_EOM) &&
 798			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 799			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 800			    (!cmdstatp->remainder_valid ||
 801			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 802				STp->dirty = 0;
 803				(STp->buffer)->buffer_bytes = 0;
 804				if (STps->drv_block >= 0)
 805					STps->drv_block += blks;
 806				result = (-ENOSPC);
 807			} else {
 808				st_printk(KERN_ERR, STp, "Error on flush.\n");
 809				STps->drv_block = (-1);
 810				result = (-EIO);
 811			}
 812		} else {
 813			if (STps->drv_block >= 0)
 814				STps->drv_block += blks;
 815			STp->dirty = 0;
 816			(STp->buffer)->buffer_bytes = 0;
 817		}
 818		st_release_request(SRpnt);
 819		SRpnt = NULL;
 820	}
 821	return result;
 822}
 823
 824
 825/* Flush the tape buffer. The tape will be positioned correctly unless
 826   seek_next is true. */
 827static int flush_buffer(struct scsi_tape *STp, int seek_next)
 828{
 829	int backspace, result;
 830	struct st_buffer *STbuffer;
 831	struct st_partstat *STps;
 832
 833	STbuffer = STp->buffer;
 834
 835	/*
 836	 * If there was a bus reset, block further access
 837	 * to this device.
 838	 */
 839	if (STp->pos_unknown)
 840		return (-EIO);
 841
 842	if (STp->ready != ST_READY)
 843		return 0;
 844	STps = &(STp->ps[STp->partition]);
 845	if (STps->rw == ST_WRITING)	/* Writing */
 846		return st_flush_write_buffer(STp);
 847
 848	if (STp->block_size == 0)
 849		return 0;
 850
 851	backspace = ((STp->buffer)->buffer_bytes +
 852		     (STp->buffer)->read_pointer) / STp->block_size -
 853	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 854	    STp->block_size;
 855	(STp->buffer)->buffer_bytes = 0;
 856	(STp->buffer)->read_pointer = 0;
 857	result = 0;
 858	if (!seek_next) {
 859		if (STps->eof == ST_FM_HIT) {
 860			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 861			if (!result)
 862				STps->eof = ST_NOEOF;
 863			else {
 864				if (STps->drv_file >= 0)
 865					STps->drv_file++;
 866				STps->drv_block = 0;
 867			}
 868		}
 869		if (!result && backspace > 0)
 870			result = st_int_ioctl(STp, MTBSR, backspace);
 871	} else if (STps->eof == ST_FM_HIT) {
 872		if (STps->drv_file >= 0)
 873			STps->drv_file++;
 874		STps->drv_block = 0;
 875		STps->eof = ST_NOEOF;
 876	}
 877	return result;
 878
 879}
 880
 881/* Set the mode parameters */
 882static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 883{
 884	int set_it = 0;
 885	unsigned long arg;
 886
 887	if (!STp->density_changed &&
 888	    STm->default_density >= 0 &&
 889	    STm->default_density != STp->density) {
 890		arg = STm->default_density;
 891		set_it = 1;
 892	} else
 893		arg = STp->density;
 894	arg <<= MT_ST_DENSITY_SHIFT;
 895	if (!STp->blksize_changed &&
 896	    STm->default_blksize >= 0 &&
 897	    STm->default_blksize != STp->block_size) {
 898		arg |= STm->default_blksize;
 899		set_it = 1;
 900	} else
 901		arg |= STp->block_size;
 902	if (set_it &&
 903	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 904		st_printk(KERN_WARNING, STp,
 905			  "Can't set default block size to %d bytes "
 906			  "and density %x.\n",
 907			  STm->default_blksize, STm->default_density);
 908		if (modes_defined)
 909			return (-EINVAL);
 910	}
 911	return 0;
 912}
 913
 914
 915/* Lock or unlock the drive door. Don't use when st_request allocated. */
 916static int do_door_lock(struct scsi_tape * STp, int do_lock)
 917{
 918	int retval;
 919
 920	DEBC_printk(STp, "%socking drive door.\n", do_lock ? "L" : "Unl");
 921
 922	retval = scsi_set_medium_removal(STp->device,
 923			do_lock ? SCSI_REMOVAL_PREVENT : SCSI_REMOVAL_ALLOW);
 924	if (!retval)
 925		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 926	else
 927		STp->door_locked = ST_LOCK_FAILS;
 928	return retval;
 929}
 930
 931
 932/* Set the internal state after reset */
 933static void reset_state(struct scsi_tape *STp)
 934{
 935	int i;
 936	struct st_partstat *STps;
 937
 938	STp->pos_unknown = 0;
 939	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 940		STps = &(STp->ps[i]);
 941		STps->rw = ST_IDLE;
 942		STps->eof = ST_NOEOF;
 943		STps->at_sm = 0;
 944		STps->last_block_valid = 0;
 945		STps->drv_block = -1;
 946		STps->drv_file = -1;
 947	}
 948	if (STp->can_partitions) {
 949		STp->partition = find_partition(STp);
 950		if (STp->partition < 0)
 951			STp->partition = 0;
 952		STp->new_partition = STp->partition;
 953	}
 954}
 955
 956/* Test if the drive is ready. Returns either one of the codes below or a negative system
 957   error code. */
 958#define CHKRES_READY       0
 959#define CHKRES_NEW_SESSION 1
 960#define CHKRES_NOT_READY   2
 961#define CHKRES_NO_TAPE     3
 962
 963#define MAX_ATTENTIONS    10
 964
 965static int test_ready(struct scsi_tape *STp, int do_wait)
 966{
 967	int attentions, waits, max_wait, scode;
 968	int retval = CHKRES_READY, new_session = 0;
 969	unsigned char cmd[MAX_COMMAND_SIZE];
 970	struct st_request *SRpnt = NULL;
 971	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 972
 973	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 974
 975	for (attentions=waits=0; ; ) {
 976		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 977		cmd[0] = TEST_UNIT_READY;
 978		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 979				   STp->long_timeout, MAX_READY_RETRIES, 1);
 980
 981		if (!SRpnt) {
 982			retval = (STp->buffer)->syscall_result;
 983			break;
 984		}
 985
 986		if (cmdstatp->have_sense) {
 987
 988			scode = cmdstatp->sense_hdr.sense_key;
 989
 990			if (scode == UNIT_ATTENTION) { /* New media? */
 991				new_session = 1;
 992				if (attentions < MAX_ATTENTIONS) {
 993					attentions++;
 994					continue;
 995				}
 996				else {
 997					retval = (-EIO);
 998					break;
 999				}
1000			}
1001
1002			if (scode == NOT_READY) {
1003				if (waits < max_wait) {
1004					if (msleep_interruptible(1000)) {
1005						retval = (-EINTR);
1006						break;
1007					}
1008					waits++;
1009					continue;
1010				}
1011				else {
1012					if ((STp->device)->scsi_level >= SCSI_2 &&
1013					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
1014						retval = CHKRES_NO_TAPE;
1015					else
1016						retval = CHKRES_NOT_READY;
1017					break;
1018				}
1019			}
1020		}
1021
1022		retval = (STp->buffer)->syscall_result;
1023		if (!retval)
1024			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
1025		break;
1026	}
1027
1028	if (SRpnt != NULL)
1029		st_release_request(SRpnt);
1030	return retval;
1031}
1032
1033
1034/* See if the drive is ready and gather information about the tape. Return values:
1035   < 0   negative error code from errno.h
1036   0     drive ready
1037   1     drive not ready (possibly no tape)
1038*/
1039static int check_tape(struct scsi_tape *STp, struct file *filp)
1040{
1041	int i, retval, new_session = 0, do_wait;
1042	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
1043	unsigned short st_flags = filp->f_flags;
1044	struct st_request *SRpnt = NULL;
1045	struct st_modedef *STm;
1046	struct st_partstat *STps;
1047	struct inode *inode = file_inode(filp);
1048	int mode = TAPE_MODE(inode);
1049
1050	STp->ready = ST_READY;
1051
1052	if (mode != STp->current_mode) {
1053		DEBC_printk(STp, "Mode change from %d to %d.\n",
1054			    STp->current_mode, mode);
1055		new_session = 1;
1056		STp->current_mode = mode;
1057	}
1058	STm = &(STp->modes[STp->current_mode]);
1059
1060	saved_cleaning = STp->cleaning_req;
1061	STp->cleaning_req = 0;
1062
1063	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1064	retval = test_ready(STp, do_wait);
1065
1066	if (retval < 0)
1067	    goto err_out;
1068
1069	if (retval == CHKRES_NEW_SESSION) {
1070		STp->pos_unknown = 0;
1071		STp->partition = STp->new_partition = 0;
1072		if (STp->can_partitions)
1073			STp->nbr_partitions = 1; /* This guess will be updated later
1074                                                    if necessary */
1075		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1076			STps = &(STp->ps[i]);
1077			STps->rw = ST_IDLE;
1078			STps->eof = ST_NOEOF;
1079			STps->at_sm = 0;
1080			STps->last_block_valid = 0;
1081			STps->drv_block = 0;
1082			STps->drv_file = 0;
1083		}
1084		new_session = 1;
1085	}
1086	else {
1087		STp->cleaning_req |= saved_cleaning;
1088
1089		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1090			if (retval == CHKRES_NO_TAPE)
1091				STp->ready = ST_NO_TAPE;
1092			else
1093				STp->ready = ST_NOT_READY;
1094
1095			STp->density = 0;	/* Clear the erroneous "residue" */
1096			STp->write_prot = 0;
1097			STp->block_size = 0;
1098			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1099			STp->partition = STp->new_partition = 0;
1100			STp->door_locked = ST_UNLOCKED;
1101			return CHKRES_NOT_READY;
1102		}
1103	}
1104
1105	if (STp->omit_blklims)
1106		STp->min_block = STp->max_block = (-1);
1107	else {
1108		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1109		cmd[0] = READ_BLOCK_LIMITS;
1110
1111		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1112				   STp->device->request_queue->rq_timeout,
1113				   MAX_READY_RETRIES, 1);
1114		if (!SRpnt) {
1115			retval = (STp->buffer)->syscall_result;
1116			goto err_out;
1117		}
1118
1119		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1120			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1121			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1122			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1123			    (STp->buffer)->b_data[5];
1124			if ( DEB( debugging || ) !STp->inited)
1125				st_printk(KERN_INFO, STp,
1126					  "Block limits %d - %d bytes.\n",
1127					  STp->min_block, STp->max_block);
1128		} else {
1129			STp->min_block = STp->max_block = (-1);
1130			DEBC_printk(STp, "Can't read block limits.\n");
1131		}
1132	}
1133
1134	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1135	cmd[0] = MODE_SENSE;
1136	cmd[4] = 12;
1137
1138	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1139			   STp->device->request_queue->rq_timeout,
1140			   MAX_READY_RETRIES, 1);
1141	if (!SRpnt) {
1142		retval = (STp->buffer)->syscall_result;
1143		goto err_out;
1144	}
1145
1146	if ((STp->buffer)->syscall_result != 0) {
1147		DEBC_printk(STp, "No Mode Sense.\n");
1148		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1149		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1150		STp->drv_write_prot = 0;
1151	} else {
1152		DEBC_printk(STp,"Mode sense. Length %d, "
1153			    "medium %x, WBS %x, BLL %d\n",
1154			    (STp->buffer)->b_data[0],
1155			    (STp->buffer)->b_data[1],
1156			    (STp->buffer)->b_data[2],
1157			    (STp->buffer)->b_data[3]);
1158
1159		if ((STp->buffer)->b_data[3] >= 8) {
1160			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1161			STp->density = (STp->buffer)->b_data[4];
1162			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1163			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1164			DEBC_printk(STp, "Density %x, tape length: %x, "
1165				    "drv buffer: %d\n",
1166				    STp->density,
1167				    (STp->buffer)->b_data[5] * 65536 +
1168				    (STp->buffer)->b_data[6] * 256 +
1169				    (STp->buffer)->b_data[7],
1170				    STp->drv_buffer);
1171		}
1172		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1173		if (!STp->drv_buffer && STp->immediate_filemark) {
1174			st_printk(KERN_WARNING, STp,
1175				  "non-buffered tape: disabling "
1176				  "writing immediate filemarks\n");
1177			STp->immediate_filemark = 0;
1178		}
1179	}
1180	st_release_request(SRpnt);
1181	SRpnt = NULL;
1182	STp->inited = 1;
1183
1184	if (STp->block_size > 0)
1185		(STp->buffer)->buffer_blocks =
1186			(STp->buffer)->buffer_size / STp->block_size;
1187	else
1188		(STp->buffer)->buffer_blocks = 1;
1189	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1190
1191	DEBC_printk(STp, "Block size: %d, buffer size: %d (%d blocks).\n",
1192		    STp->block_size, (STp->buffer)->buffer_size,
1193		    (STp->buffer)->buffer_blocks);
1194
1195	if (STp->drv_write_prot) {
1196		STp->write_prot = 1;
1197
1198		DEBC_printk(STp, "Write protected\n");
1199
1200		if (do_wait &&
1201		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1202		     (st_flags & O_ACCMODE) == O_RDWR)) {
1203			retval = (-EROFS);
1204			goto err_out;
1205		}
1206	}
1207
1208	if (STp->can_partitions && STp->nbr_partitions < 1) {
1209		/* This code is reached when the device is opened for the first time
1210		   after the driver has been initialized with tape in the drive and the
1211		   partition support has been enabled. */
1212		DEBC_printk(STp, "Updating partition number in status.\n");
1213		if ((STp->partition = find_partition(STp)) < 0) {
1214			retval = STp->partition;
1215			goto err_out;
1216		}
1217		STp->new_partition = STp->partition;
1218		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1219	}
1220
1221	if (new_session) {	/* Change the drive parameters for the new mode */
1222		STp->density_changed = STp->blksize_changed = 0;
1223		STp->compression_changed = 0;
1224		if (!(STm->defaults_for_writes) &&
1225		    (retval = set_mode_densblk(STp, STm)) < 0)
1226		    goto err_out;
1227
1228		if (STp->default_drvbuffer != 0xff) {
1229			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1230				st_printk(KERN_WARNING, STp,
1231					  "Can't set default drive "
1232					  "buffering to %d.\n",
1233					  STp->default_drvbuffer);
1234		}
1235	}
1236
1237	return CHKRES_READY;
1238
1239 err_out:
1240	return retval;
1241}
1242
1243
1244/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1245   module count. */
1246static int st_open(struct inode *inode, struct file *filp)
1247{
1248	int i, retval = (-EIO);
1249	int resumed = 0;
1250	struct scsi_tape *STp;
1251	struct st_partstat *STps;
1252	int dev = TAPE_NR(inode);
1253
1254	/*
1255	 * We really want to do nonseekable_open(inode, filp); here, but some
1256	 * versions of tar incorrectly call lseek on tapes and bail out if that
1257	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1258	 */
1259	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1260
1261	if (!(STp = scsi_tape_get(dev))) {
1262		return -ENXIO;
1263	}
1264
1265	filp->private_data = STp;
1266
1267	spin_lock(&st_use_lock);
1268	if (STp->in_use) {
1269		spin_unlock(&st_use_lock);
1270		scsi_tape_put(STp);
1271		DEBC_printk(STp, "Device already in use.\n");
1272		return (-EBUSY);
1273	}
1274
1275	STp->in_use = 1;
1276	spin_unlock(&st_use_lock);
1277	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1278
1279	if (scsi_autopm_get_device(STp->device) < 0) {
1280		retval = -EIO;
1281		goto err_out;
1282	}
1283	resumed = 1;
1284	if (!scsi_block_when_processing_errors(STp->device)) {
1285		retval = (-ENXIO);
1286		goto err_out;
1287	}
1288
1289	/* See that we have at least a one page buffer available */
1290	if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1291		st_printk(KERN_WARNING, STp,
1292			  "Can't allocate one page tape buffer.\n");
1293		retval = (-EOVERFLOW);
1294		goto err_out;
1295	}
1296
1297	(STp->buffer)->cleared = 0;
1298	(STp->buffer)->writing = 0;
1299	(STp->buffer)->syscall_result = 0;
1300
1301	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1302
1303	STp->dirty = 0;
1304	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1305		STps = &(STp->ps[i]);
1306		STps->rw = ST_IDLE;
1307	}
1308	STp->try_dio_now = STp->try_dio;
1309	STp->recover_count = 0;
1310	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1311	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1312
1313	retval = check_tape(STp, filp);
1314	if (retval < 0)
1315		goto err_out;
1316	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1317	    retval != CHKRES_READY) {
1318		if (STp->ready == NO_TAPE)
1319			retval = (-ENOMEDIUM);
1320		else
1321			retval = (-EIO);
1322		goto err_out;
1323	}
1324	return 0;
1325
1326 err_out:
1327	normalize_buffer(STp->buffer);
1328	spin_lock(&st_use_lock);
1329	STp->in_use = 0;
1330	spin_unlock(&st_use_lock);
1331	if (resumed)
1332		scsi_autopm_put_device(STp->device);
1333	scsi_tape_put(STp);
1334	return retval;
1335
1336}
1337
1338
1339/* Flush the tape buffer before close */
1340static int st_flush(struct file *filp, fl_owner_t id)
1341{
1342	int result = 0, result2;
1343	unsigned char cmd[MAX_COMMAND_SIZE];
1344	struct st_request *SRpnt;
1345	struct scsi_tape *STp = filp->private_data;
1346	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1347	struct st_partstat *STps = &(STp->ps[STp->partition]);
1348
1349	if (file_count(filp) > 1)
1350		return 0;
1351
1352	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1353		result = st_flush_write_buffer(STp);
1354		if (result != 0 && result != (-ENOSPC))
1355			goto out;
1356	}
1357
1358	if (STp->can_partitions &&
1359	    (result2 = switch_partition(STp)) < 0) {
1360		DEBC_printk(STp, "switch_partition at close failed.\n");
1361		if (result == 0)
1362			result = result2;
1363		goto out;
1364	}
1365
1366	DEBC( if (STp->nbr_requests)
1367		st_printk(KERN_DEBUG, STp,
1368			  "Number of r/w requests %d, dio used in %d, "
1369			  "pages %d.\n", STp->nbr_requests, STp->nbr_dio,
1370			  STp->nbr_pages));
1371
1372	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1373		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1374
1375#if DEBUG
1376		DEBC_printk(STp, "Async write waits %d, finished %d.\n",
1377			    STp->nbr_waits, STp->nbr_finished);
1378#endif
1379		memset(cmd, 0, MAX_COMMAND_SIZE);
1380		cmd[0] = WRITE_FILEMARKS;
1381		if (STp->immediate_filemark)
1382			cmd[1] = 1;
1383		cmd[4] = 1 + STp->two_fm;
1384
1385		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1386				   STp->device->request_queue->rq_timeout,
1387				   MAX_WRITE_RETRIES, 1);
1388		if (!SRpnt) {
1389			result = (STp->buffer)->syscall_result;
1390			goto out;
1391		}
1392
1393		if (STp->buffer->syscall_result == 0 ||
1394		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1395		     (cmdstatp->flags & SENSE_EOM) &&
1396		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1397		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1398		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1399			/* Write successful at EOM */
1400			st_release_request(SRpnt);
1401			SRpnt = NULL;
1402			if (STps->drv_file >= 0)
1403				STps->drv_file++;
1404			STps->drv_block = 0;
1405			if (STp->two_fm)
1406				cross_eof(STp, 0);
1407			STps->eof = ST_FM;
1408		}
1409		else { /* Write error */
1410			st_release_request(SRpnt);
1411			SRpnt = NULL;
1412			st_printk(KERN_ERR, STp,
1413				  "Error on write filemark.\n");
1414			if (result == 0)
1415				result = (-EIO);
1416		}
1417
1418		DEBC_printk(STp, "Buffer flushed, %d EOF(s) written\n", cmd[4]);
1419	} else if (!STp->rew_at_close) {
1420		STps = &(STp->ps[STp->partition]);
1421		if (!STm->sysv || STps->rw != ST_READING) {
1422			if (STp->can_bsr)
1423				result = flush_buffer(STp, 0);
1424			else if (STps->eof == ST_FM_HIT) {
1425				result = cross_eof(STp, 0);
1426				if (result) {
1427					if (STps->drv_file >= 0)
1428						STps->drv_file++;
1429					STps->drv_block = 0;
1430					STps->eof = ST_FM;
1431				} else
1432					STps->eof = ST_NOEOF;
1433			}
1434		} else if ((STps->eof == ST_NOEOF &&
1435			    !(result = cross_eof(STp, 1))) ||
1436			   STps->eof == ST_FM_HIT) {
1437			if (STps->drv_file >= 0)
1438				STps->drv_file++;
1439			STps->drv_block = 0;
1440			STps->eof = ST_FM;
1441		}
1442	}
1443
1444      out:
1445	if (STp->rew_at_close) {
1446		result2 = st_int_ioctl(STp, MTREW, 1);
1447		if (result == 0)
1448			result = result2;
1449	}
1450	return result;
1451}
1452
1453
1454/* Close the device and release it. BKL is not needed: this is the only thread
1455   accessing this tape. */
1456static int st_release(struct inode *inode, struct file *filp)
1457{
1458	int result = 0;
1459	struct scsi_tape *STp = filp->private_data;
1460
1461	if (STp->door_locked == ST_LOCKED_AUTO)
1462		do_door_lock(STp, 0);
1463
1464	normalize_buffer(STp->buffer);
1465	spin_lock(&st_use_lock);
1466	STp->in_use = 0;
1467	spin_unlock(&st_use_lock);
1468	scsi_autopm_put_device(STp->device);
1469	scsi_tape_put(STp);
1470
1471	return result;
1472}
1473
1474/* The checks common to both reading and writing */
1475static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1476{
1477	ssize_t retval = 0;
1478
1479	/*
1480	 * If we are in the middle of error recovery, don't let anyone
1481	 * else try and use this device.  Also, if error recovery fails, it
1482	 * may try and take the device offline, in which case all further
1483	 * access to the device is prohibited.
1484	 */
1485	if (!scsi_block_when_processing_errors(STp->device)) {
1486		retval = (-ENXIO);
1487		goto out;
1488	}
1489
1490	if (STp->ready != ST_READY) {
1491		if (STp->ready == ST_NO_TAPE)
1492			retval = (-ENOMEDIUM);
1493		else
1494			retval = (-EIO);
1495		goto out;
1496	}
1497
1498	if (! STp->modes[STp->current_mode].defined) {
1499		retval = (-ENXIO);
1500		goto out;
1501	}
1502
1503
1504	/*
1505	 * If there was a bus reset, block further access
1506	 * to this device.
1507	 */
1508	if (STp->pos_unknown) {
1509		retval = (-EIO);
1510		goto out;
1511	}
1512
1513	if (count == 0)
1514		goto out;
1515
1516	DEB(
1517	if (!STp->in_use) {
1518		st_printk(ST_DEB_MSG, STp,
1519			  "Incorrect device.\n");
1520		retval = (-EIO);
1521		goto out;
1522	} ) /* end DEB */
1523
1524	if (STp->can_partitions &&
1525	    (retval = switch_partition(STp)) < 0)
1526		goto out;
1527
1528	if (STp->block_size == 0 && STp->max_block > 0 &&
1529	    (count < STp->min_block || count > STp->max_block)) {
1530		retval = (-EINVAL);
1531		goto out;
1532	}
1533
1534	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1535	    !do_door_lock(STp, 1))
1536		STp->door_locked = ST_LOCKED_AUTO;
1537
1538 out:
1539	return retval;
1540}
1541
1542
1543static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1544			   size_t count, int is_read)
1545{
1546	int i, bufsize, retval = 0;
1547	struct st_buffer *STbp = STp->buffer;
1548
1549	if (is_read)
1550		i = STp->try_dio_now && try_rdio;
1551	else
1552		i = STp->try_dio_now && try_wdio;
1553
1554	if (i && ((unsigned long)buf & queue_dma_alignment(
1555					STp->device->request_queue)) == 0) {
1556		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1557				       count, (is_read ? READ : WRITE));
1558		if (i > 0) {
1559			STbp->do_dio = i;
1560			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1561		}
1562		else
1563			STbp->do_dio = 0;  /* fall back to buffering with any error */
1564		STbp->sg_segs = STbp->do_dio;
1565		DEB(
1566		     if (STbp->do_dio) {
1567			STp->nbr_dio++;
1568			STp->nbr_pages += STbp->do_dio;
1569		     }
1570		)
1571	} else
1572		STbp->do_dio = 0;
1573	DEB( STp->nbr_requests++; )
1574
1575	if (!STbp->do_dio) {
1576		if (STp->block_size)
1577			bufsize = STp->block_size > st_fixed_buffer_size ?
1578				STp->block_size : st_fixed_buffer_size;
1579		else {
1580			bufsize = count;
1581			/* Make sure that data from previous user is not leaked even if
1582			   HBA does not return correct residual */
1583			if (is_read && STp->sili && !STbp->cleared)
1584				clear_buffer(STbp);
1585		}
1586
1587		if (bufsize > STbp->buffer_size &&
1588		    !enlarge_buffer(STbp, bufsize, STp->restr_dma)) {
1589			st_printk(KERN_WARNING, STp,
1590				  "Can't allocate %d byte tape buffer.\n",
1591				  bufsize);
1592			retval = (-EOVERFLOW);
1593			goto out;
1594		}
1595		if (STp->block_size)
1596			STbp->buffer_blocks = bufsize / STp->block_size;
1597	}
1598
1599 out:
1600	return retval;
1601}
1602
1603
1604/* Can be called more than once after each setup_buffer() */
1605static void release_buffering(struct scsi_tape *STp, int is_read)
1606{
1607	struct st_buffer *STbp;
1608
1609	STbp = STp->buffer;
1610	if (STbp->do_dio) {
1611		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1612		STbp->do_dio = 0;
1613		STbp->sg_segs = 0;
1614	}
1615}
1616
1617
1618/* Write command */
1619static ssize_t
1620st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1621{
1622	ssize_t total;
1623	ssize_t i, do_count, blks, transfer;
1624	ssize_t retval;
1625	int undone, retry_eot = 0, scode;
1626	int async_write;
1627	unsigned char cmd[MAX_COMMAND_SIZE];
1628	const char __user *b_point;
1629	struct st_request *SRpnt = NULL;
1630	struct scsi_tape *STp = filp->private_data;
1631	struct st_modedef *STm;
1632	struct st_partstat *STps;
1633	struct st_buffer *STbp;
1634
1635	if (mutex_lock_interruptible(&STp->lock))
1636		return -ERESTARTSYS;
1637
1638	retval = rw_checks(STp, filp, count);
1639	if (retval || count == 0)
1640		goto out;
1641
1642	/* Write must be integral number of blocks */
1643	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1644		st_printk(KERN_WARNING, STp,
1645			  "Write not multiple of tape block size.\n");
1646		retval = (-EINVAL);
1647		goto out;
1648	}
1649
1650	STm = &(STp->modes[STp->current_mode]);
1651	STps = &(STp->ps[STp->partition]);
1652
1653	if (STp->write_prot) {
1654		retval = (-EACCES);
1655		goto out;
1656	}
1657
1658
1659	if (STps->rw == ST_READING) {
1660		retval = flush_buffer(STp, 0);
1661		if (retval)
1662			goto out;
1663		STps->rw = ST_WRITING;
1664	} else if (STps->rw != ST_WRITING &&
1665		   STps->drv_file == 0 && STps->drv_block == 0) {
1666		if ((retval = set_mode_densblk(STp, STm)) < 0)
1667			goto out;
1668		if (STm->default_compression != ST_DONT_TOUCH &&
1669		    !(STp->compression_changed)) {
1670			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1671				st_printk(KERN_WARNING, STp,
1672					  "Can't set default compression.\n");
1673				if (modes_defined) {
1674					retval = (-EINVAL);
1675					goto out;
1676				}
1677			}
1678		}
1679	}
1680
1681	STbp = STp->buffer;
1682	i = write_behind_check(STp);
1683	if (i) {
1684		if (i == -ENOSPC)
1685			STps->eof = ST_EOM_OK;
1686		else
1687			STps->eof = ST_EOM_ERROR;
1688	}
1689
1690	if (STps->eof == ST_EOM_OK) {
1691		STps->eof = ST_EOD_1;  /* allow next write */
1692		retval = (-ENOSPC);
1693		goto out;
1694	}
1695	else if (STps->eof == ST_EOM_ERROR) {
1696		retval = (-EIO);
1697		goto out;
1698	}
1699
1700	/* Check the buffer readability in cases where copy_user might catch
1701	   the problems after some tape movement. */
1702	if (STp->block_size != 0 &&
1703	    !STbp->do_dio &&
1704	    (copy_from_user(&i, buf, 1) != 0 ||
1705	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1706		retval = (-EFAULT);
1707		goto out;
1708	}
1709
1710	retval = setup_buffering(STp, buf, count, 0);
1711	if (retval)
1712		goto out;
1713
1714	total = count;
1715
1716	memset(cmd, 0, MAX_COMMAND_SIZE);
1717	cmd[0] = WRITE_6;
1718	cmd[1] = (STp->block_size != 0);
1719
1720	STps->rw = ST_WRITING;
1721
1722	b_point = buf;
1723	while (count > 0 && !retry_eot) {
1724
1725		if (STbp->do_dio) {
1726			do_count = count;
1727		}
1728		else {
1729			if (STp->block_size == 0)
1730				do_count = count;
1731			else {
1732				do_count = STbp->buffer_blocks * STp->block_size -
1733					STbp->buffer_bytes;
1734				if (do_count > count)
1735					do_count = count;
1736			}
1737
1738			i = append_to_buffer(b_point, STbp, do_count);
1739			if (i) {
1740				retval = i;
1741				goto out;
1742			}
1743		}
1744		count -= do_count;
1745		b_point += do_count;
1746
1747		async_write = STp->block_size == 0 && !STbp->do_dio &&
1748			STm->do_async_writes && STps->eof < ST_EOM_OK;
1749
1750		if (STp->block_size != 0 && STm->do_buffer_writes &&
1751		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1752		    STbp->buffer_bytes < STbp->buffer_size) {
1753			STp->dirty = 1;
1754			/* Don't write a buffer that is not full enough. */
1755			if (!async_write && count == 0)
1756				break;
1757		}
1758
1759	retry_write:
1760		if (STp->block_size == 0)
1761			blks = transfer = do_count;
1762		else {
1763			if (!STbp->do_dio)
1764				blks = STbp->buffer_bytes;
1765			else
1766				blks = do_count;
1767			blks /= STp->block_size;
1768			transfer = blks * STp->block_size;
1769		}
1770		cmd[2] = blks >> 16;
1771		cmd[3] = blks >> 8;
1772		cmd[4] = blks;
1773
1774		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1775				   STp->device->request_queue->rq_timeout,
1776				   MAX_WRITE_RETRIES, !async_write);
1777		if (!SRpnt) {
1778			retval = STbp->syscall_result;
1779			goto out;
1780		}
1781		if (async_write && !STbp->syscall_result) {
1782			STbp->writing = transfer;
1783			STp->dirty = !(STbp->writing ==
1784				       STbp->buffer_bytes);
1785			SRpnt = NULL;  /* Prevent releasing this request! */
1786			DEB( STp->write_pending = 1; )
1787			break;
1788		}
1789
1790		if (STbp->syscall_result != 0) {
1791			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1792
1793			DEBC_printk(STp, "Error on write:\n");
1794			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1795				scode = cmdstatp->sense_hdr.sense_key;
1796				if (cmdstatp->remainder_valid)
1797					undone = (int)cmdstatp->uremainder64;
1798				else if (STp->block_size == 0 &&
1799					 scode == VOLUME_OVERFLOW)
1800					undone = transfer;
1801				else
1802					undone = 0;
1803				if (STp->block_size != 0)
1804					undone *= STp->block_size;
1805				if (undone <= do_count) {
1806					/* Only data from this write is not written */
1807					count += undone;
1808					b_point -= undone;
1809					do_count -= undone;
1810					if (STp->block_size)
1811						blks = (transfer - undone) / STp->block_size;
1812					STps->eof = ST_EOM_OK;
1813					/* Continue in fixed block mode if all written
1814					   in this request but still something left to write
1815					   (retval left to zero)
1816					*/
1817					if (STp->block_size == 0 ||
1818					    undone > 0 || count == 0)
1819						retval = (-ENOSPC); /* EOM within current request */
1820					DEBC_printk(STp, "EOM with %d "
1821						    "bytes unwritten.\n",
1822						    (int)count);
1823				} else {
1824					/* EOT within data buffered earlier (possible only
1825					   in fixed block mode without direct i/o) */
1826					if (!retry_eot && !cmdstatp->deferred &&
1827					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1828						move_buffer_data(STp->buffer, transfer - undone);
1829						retry_eot = 1;
1830						if (STps->drv_block >= 0) {
1831							STps->drv_block += (transfer - undone) /
1832								STp->block_size;
1833						}
1834						STps->eof = ST_EOM_OK;
1835						DEBC_printk(STp, "Retry "
1836							    "write of %d "
1837							    "bytes at EOM.\n",
1838							    STp->buffer->buffer_bytes);
1839						goto retry_write;
1840					}
1841					else {
1842						/* Either error within data buffered by driver or
1843						   failed retry */
1844						count -= do_count;
1845						blks = do_count = 0;
1846						STps->eof = ST_EOM_ERROR;
1847						STps->drv_block = (-1); /* Too cautious? */
1848						retval = (-EIO);	/* EOM for old data */
1849						DEBC_printk(STp, "EOM with "
1850							    "lost data.\n");
1851					}
1852				}
1853			} else {
1854				count += do_count;
1855				STps->drv_block = (-1);		/* Too cautious? */
1856				retval = STbp->syscall_result;
1857			}
1858
1859		}
1860
1861		if (STps->drv_block >= 0) {
1862			if (STp->block_size == 0)
1863				STps->drv_block += (do_count > 0);
1864			else
1865				STps->drv_block += blks;
1866		}
1867
1868		STbp->buffer_bytes = 0;
1869		STp->dirty = 0;
1870
1871		if (retval || retry_eot) {
1872			if (count < total)
1873				retval = total - count;
1874			goto out;
1875		}
1876	}
1877
1878	if (STps->eof == ST_EOD_1)
1879		STps->eof = ST_EOM_OK;
1880	else if (STps->eof != ST_EOM_OK)
1881		STps->eof = ST_NOEOF;
1882	retval = total - count;
1883
1884 out:
1885	if (SRpnt != NULL)
1886		st_release_request(SRpnt);
1887	release_buffering(STp, 0);
1888	mutex_unlock(&STp->lock);
1889
1890	return retval;
1891}
1892
1893/* Read data from the tape. Returns zero in the normal case, one if the
1894   eof status has changed, and the negative error code in case of a
1895   fatal error. Otherwise updates the buffer and the eof state.
1896
1897   Does release user buffer mapping if it is set.
1898*/
1899static long read_tape(struct scsi_tape *STp, long count,
1900		      struct st_request ** aSRpnt)
1901{
1902	int transfer, blks, bytes;
1903	unsigned char cmd[MAX_COMMAND_SIZE];
1904	struct st_request *SRpnt;
1905	struct st_modedef *STm;
1906	struct st_partstat *STps;
1907	struct st_buffer *STbp;
1908	int retval = 0;
1909
1910	if (count == 0)
1911		return 0;
1912
1913	STm = &(STp->modes[STp->current_mode]);
1914	STps = &(STp->ps[STp->partition]);
1915	if (STps->eof == ST_FM_HIT)
1916		return 1;
1917	STbp = STp->buffer;
1918
1919	if (STp->block_size == 0)
1920		blks = bytes = count;
1921	else {
1922		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1923			blks = (STp->buffer)->buffer_blocks;
1924			bytes = blks * STp->block_size;
1925		} else {
1926			bytes = count;
1927			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1928				bytes = (STp->buffer)->buffer_size;
1929			blks = bytes / STp->block_size;
1930			bytes = blks * STp->block_size;
1931		}
1932	}
1933
1934	memset(cmd, 0, MAX_COMMAND_SIZE);
1935	cmd[0] = READ_6;
1936	cmd[1] = (STp->block_size != 0);
1937	if (!cmd[1] && STp->sili)
1938		cmd[1] |= 2;
1939	cmd[2] = blks >> 16;
1940	cmd[3] = blks >> 8;
1941	cmd[4] = blks;
1942
1943	SRpnt = *aSRpnt;
1944	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1945			   STp->device->request_queue->rq_timeout,
1946			   MAX_RETRIES, 1);
1947	release_buffering(STp, 1);
1948	*aSRpnt = SRpnt;
1949	if (!SRpnt)
1950		return STbp->syscall_result;
1951
1952	STbp->read_pointer = 0;
1953	STps->at_sm = 0;
1954
1955	/* Something to check */
1956	if (STbp->syscall_result) {
1957		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1958
1959		retval = 1;
1960		DEBC_printk(STp,
1961			    "Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1962			    SRpnt->sense[0], SRpnt->sense[1],
1963			    SRpnt->sense[2], SRpnt->sense[3],
1964			    SRpnt->sense[4], SRpnt->sense[5],
1965			    SRpnt->sense[6], SRpnt->sense[7]);
1966		if (cmdstatp->have_sense) {
1967
1968			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1969				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1970
1971			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1972				/* Compute the residual count */
1973				if (cmdstatp->remainder_valid)
1974					transfer = (int)cmdstatp->uremainder64;
1975				else
1976					transfer = 0;
1977				if (cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR) {
1978					if (STp->block_size == 0)
1979						transfer = bytes;
1980					/* Some drives set ILI with MEDIUM ERROR */
1981					cmdstatp->flags &= ~SENSE_ILI;
1982				}
1983
1984				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1985					if (STp->block_size == 0 &&
1986					    transfer < 0) {
1987						st_printk(KERN_NOTICE, STp,
1988							  "Failed to read %d "
1989							  "byte block with %d "
1990							  "byte transfer.\n",
1991							  bytes - transfer,
1992							  bytes);
1993						if (STps->drv_block >= 0)
1994							STps->drv_block += 1;
1995						STbp->buffer_bytes = 0;
1996						return (-ENOMEM);
1997					} else if (STp->block_size == 0) {
1998						STbp->buffer_bytes = bytes - transfer;
1999					} else {
2000						st_release_request(SRpnt);
2001						SRpnt = *aSRpnt = NULL;
2002						if (transfer == blks) {	/* We did not get anything, error */
2003							st_printk(KERN_NOTICE, STp,
2004								  "Incorrect "
2005								  "block size.\n");
2006							if (STps->drv_block >= 0)
2007								STps->drv_block += blks - transfer + 1;
2008							st_int_ioctl(STp, MTBSR, 1);
2009							return (-EIO);
2010						}
2011						/* We have some data, deliver it */
2012						STbp->buffer_bytes = (blks - transfer) *
2013						    STp->block_size;
2014						DEBC_printk(STp, "ILI but "
2015							    "enough data "
2016							    "received %ld "
2017							    "%d.\n", count,
2018							    STbp->buffer_bytes);
2019						if (STps->drv_block >= 0)
2020							STps->drv_block += 1;
2021						if (st_int_ioctl(STp, MTBSR, 1))
2022							return (-EIO);
2023					}
2024				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
2025					if (STps->eof != ST_FM_HIT)
2026						STps->eof = ST_FM_HIT;
2027					else
2028						STps->eof = ST_EOD_2;
2029					if (STp->block_size == 0)
2030						STbp->buffer_bytes = 0;
2031					else
2032						STbp->buffer_bytes =
2033						    bytes - transfer * STp->block_size;
2034					DEBC_printk(STp, "EOF detected (%d "
2035						    "bytes read).\n",
2036						    STbp->buffer_bytes);
2037				} else if (cmdstatp->flags & SENSE_EOM) {
2038					if (STps->eof == ST_FM)
2039						STps->eof = ST_EOD_1;
2040					else
2041						STps->eof = ST_EOM_OK;
2042					if (STp->block_size == 0)
2043						STbp->buffer_bytes = bytes - transfer;
2044					else
2045						STbp->buffer_bytes =
2046						    bytes - transfer * STp->block_size;
2047
2048					DEBC_printk(STp, "EOM detected (%d "
2049						    "bytes read).\n",
2050						    STbp->buffer_bytes);
2051				}
2052			}
2053			/* end of EOF, EOM, ILI test */
2054			else {	/* nonzero sense key */
2055				DEBC_printk(STp, "Tape error while reading.\n");
2056				STps->drv_block = (-1);
2057				if (STps->eof == ST_FM &&
2058				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
2059					DEBC_printk(STp, "Zero returned for "
2060						    "first BLANK CHECK "
2061						    "after EOF.\n");
2062					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
2063				} else	/* Some other extended sense code */
2064					retval = (-EIO);
2065			}
2066
2067			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
2068				STbp->buffer_bytes = 0;
2069		}
2070		/* End of extended sense test */
2071		else {		/* Non-extended sense */
2072			retval = STbp->syscall_result;
2073		}
2074
2075	}
2076	/* End of error handling */
2077	else {			/* Read successful */
2078		STbp->buffer_bytes = bytes;
2079		if (STp->sili) /* In fixed block mode residual is always zero here */
2080			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
2081	}
2082
2083	if (STps->drv_block >= 0) {
2084		if (STp->block_size == 0)
2085			STps->drv_block++;
2086		else
2087			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2088	}
2089	return retval;
2090}
2091
2092
2093/* Read command */
2094static ssize_t
2095st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2096{
2097	ssize_t total;
2098	ssize_t retval = 0;
2099	ssize_t i, transfer;
2100	int special, do_dio = 0;
2101	struct st_request *SRpnt = NULL;
2102	struct scsi_tape *STp = filp->private_data;
2103	struct st_modedef *STm;
2104	struct st_partstat *STps;
2105	struct st_buffer *STbp = STp->buffer;
2106
2107	if (mutex_lock_interruptible(&STp->lock))
2108		return -ERESTARTSYS;
2109
2110	retval = rw_checks(STp, filp, count);
2111	if (retval || count == 0)
2112		goto out;
2113
2114	STm = &(STp->modes[STp->current_mode]);
2115	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2116		if (!STm->do_read_ahead) {
2117			retval = (-EINVAL);	/* Read must be integral number of blocks */
2118			goto out;
2119		}
2120		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2121	}
2122
2123	STps = &(STp->ps[STp->partition]);
2124	if (STps->rw == ST_WRITING) {
2125		retval = flush_buffer(STp, 0);
2126		if (retval)
2127			goto out;
2128		STps->rw = ST_READING;
2129	}
2130	DEB(
2131	if (debugging && STps->eof != ST_NOEOF)
2132		st_printk(ST_DEB_MSG, STp,
2133			  "EOF/EOM flag up (%d). Bytes %d\n",
2134			  STps->eof, STbp->buffer_bytes);
2135	) /* end DEB */
2136
2137	retval = setup_buffering(STp, buf, count, 1);
2138	if (retval)
2139		goto out;
2140	do_dio = STbp->do_dio;
2141
2142	if (STbp->buffer_bytes == 0 &&
2143	    STps->eof >= ST_EOD_1) {
2144		if (STps->eof < ST_EOD) {
2145			STps->eof += 1;
2146			retval = 0;
2147			goto out;
2148		}
2149		retval = (-EIO);	/* EOM or Blank Check */
2150		goto out;
2151	}
2152
2153	if (do_dio) {
2154		/* Check the buffer writability before any tape movement. Don't alter
2155		   buffer data. */
2156		if (copy_from_user(&i, buf, 1) != 0 ||
2157		    copy_to_user(buf, &i, 1) != 0 ||
2158		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2159		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2160			retval = (-EFAULT);
2161			goto out;
2162		}
2163	}
2164
2165	STps->rw = ST_READING;
2166
2167
2168	/* Loop until enough data in buffer or a special condition found */
2169	for (total = 0, special = 0; total < count && !special;) {
2170
2171		/* Get new data if the buffer is empty */
2172		if (STbp->buffer_bytes == 0) {
2173			special = read_tape(STp, count - total, &SRpnt);
2174			if (special < 0) {	/* No need to continue read */
2175				retval = special;
2176				goto out;
2177			}
2178		}
2179
2180		/* Move the data from driver buffer to user buffer */
2181		if (STbp->buffer_bytes > 0) {
2182			DEB(
2183			if (debugging && STps->eof != ST_NOEOF)
2184				st_printk(ST_DEB_MSG, STp,
2185					  "EOF up (%d). Left %d, needed %d.\n",
2186					  STps->eof, STbp->buffer_bytes,
2187					  (int)(count - total));
2188			) /* end DEB */
2189			transfer = STbp->buffer_bytes < count - total ?
2190			    STbp->buffer_bytes : count - total;
2191			if (!do_dio) {
2192				i = from_buffer(STbp, buf, transfer);
2193				if (i) {
2194					retval = i;
2195					goto out;
2196				}
2197			}
2198			buf += transfer;
2199			total += transfer;
2200		}
2201
2202		if (STp->block_size == 0)
2203			break;	/* Read only one variable length block */
2204
2205	}			/* for (total = 0, special = 0;
2206                                   total < count && !special; ) */
2207
2208	/* Change the eof state if no data from tape or buffer */
2209	if (total == 0) {
2210		if (STps->eof == ST_FM_HIT) {
2211			STps->eof = ST_FM;
2212			STps->drv_block = 0;
2213			if (STps->drv_file >= 0)
2214				STps->drv_file++;
2215		} else if (STps->eof == ST_EOD_1) {
2216			STps->eof = ST_EOD_2;
2217			STps->drv_block = 0;
2218			if (STps->drv_file >= 0)
2219				STps->drv_file++;
2220		} else if (STps->eof == ST_EOD_2)
2221			STps->eof = ST_EOD;
2222	} else if (STps->eof == ST_FM)
2223		STps->eof = ST_NOEOF;
2224	retval = total;
2225
2226 out:
2227	if (SRpnt != NULL) {
2228		st_release_request(SRpnt);
2229		SRpnt = NULL;
2230	}
2231	if (do_dio) {
2232		release_buffering(STp, 1);
2233		STbp->buffer_bytes = 0;
2234	}
2235	mutex_unlock(&STp->lock);
2236
2237	return retval;
2238}
2239
2240
2241
2242DEB(
2243/* Set the driver options */
2244static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm)
2245{
2246	if (debugging) {
2247		st_printk(KERN_INFO, STp,
2248			  "Mode %d options: buffer writes: %d, "
2249			  "async writes: %d, read ahead: %d\n",
2250			  STp->current_mode, STm->do_buffer_writes,
2251			  STm->do_async_writes, STm->do_read_ahead);
2252		st_printk(KERN_INFO, STp,
2253			  "    can bsr: %d, two FMs: %d, "
2254			  "fast mteom: %d, auto lock: %d,\n",
2255			  STp->can_bsr, STp->two_fm, STp->fast_mteom,
2256			  STp->do_auto_lock);
2257		st_printk(KERN_INFO, STp,
2258			  "    defs for wr: %d, no block limits: %d, "
2259			  "partitions: %d, s2 log: %d\n",
2260			  STm->defaults_for_writes, STp->omit_blklims,
2261			  STp->can_partitions, STp->scsi2_logical);
2262		st_printk(KERN_INFO, STp,
2263			  "    sysv: %d nowait: %d sili: %d "
2264			  "nowait_filemark: %d\n",
2265			  STm->sysv, STp->immediate, STp->sili,
2266			  STp->immediate_filemark);
2267		st_printk(KERN_INFO, STp, "    debugging: %d\n", debugging);
2268	}
2269}
2270	)
2271
2272
2273static int st_set_options(struct scsi_tape *STp, long options)
2274{
2275	int value;
2276	long code;
2277	struct st_modedef *STm;
2278	struct cdev *cd0, *cd1;
2279	struct device *d0, *d1;
2280
2281	STm = &(STp->modes[STp->current_mode]);
2282	if (!STm->defined) {
2283		cd0 = STm->cdevs[0];
2284		cd1 = STm->cdevs[1];
2285		d0  = STm->devs[0];
2286		d1  = STm->devs[1];
2287		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2288		STm->cdevs[0] = cd0;
2289		STm->cdevs[1] = cd1;
2290		STm->devs[0]  = d0;
2291		STm->devs[1]  = d1;
2292		modes_defined = 1;
2293		DEBC_printk(STp, "Initialized mode %d definition from mode 0\n",
2294			    STp->current_mode);
2295	}
2296
2297	code = options & MT_ST_OPTIONS;
2298	if (code == MT_ST_BOOLEANS) {
2299		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2300		STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2301		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2302		STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2303		STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2304		STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2305		STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2306		STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2307		STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2308		if ((STp->device)->scsi_level >= SCSI_2)
2309			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2310		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2311		STp->immediate = (options & MT_ST_NOWAIT) != 0;
2312		STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
2313		STm->sysv = (options & MT_ST_SYSV) != 0;
2314		STp->sili = (options & MT_ST_SILI) != 0;
2315		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2316		     st_log_options(STp, STm); )
2317	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2318		value = (code == MT_ST_SETBOOLEANS);
2319		if ((options & MT_ST_BUFFER_WRITES) != 0)
2320			STm->do_buffer_writes = value;
2321		if ((options & MT_ST_ASYNC_WRITES) != 0)
2322			STm->do_async_writes = value;
2323		if ((options & MT_ST_DEF_WRITES) != 0)
2324			STm->defaults_for_writes = value;
2325		if ((options & MT_ST_READ_AHEAD) != 0)
2326			STm->do_read_ahead = value;
2327		if ((options & MT_ST_TWO_FM) != 0)
2328			STp->two_fm = value;
2329		if ((options & MT_ST_FAST_MTEOM) != 0)
2330			STp->fast_mteom = value;
2331		if ((options & MT_ST_AUTO_LOCK) != 0)
2332			STp->do_auto_lock = value;
2333		if ((options & MT_ST_CAN_BSR) != 0)
2334			STp->can_bsr = value;
2335		if ((options & MT_ST_NO_BLKLIMS) != 0)
2336			STp->omit_blklims = value;
2337		if ((STp->device)->scsi_level >= SCSI_2 &&
2338		    (options & MT_ST_CAN_PARTITIONS) != 0)
2339			STp->can_partitions = value;
2340		if ((options & MT_ST_SCSI2LOGICAL) != 0)
2341			STp->scsi2_logical = value;
2342		if ((options & MT_ST_NOWAIT) != 0)
2343			STp->immediate = value;
2344		if ((options & MT_ST_NOWAIT_EOF) != 0)
2345			STp->immediate_filemark = value;
2346		if ((options & MT_ST_SYSV) != 0)
2347			STm->sysv = value;
2348		if ((options & MT_ST_SILI) != 0)
2349			STp->sili = value;
2350		DEB(
2351		if ((options & MT_ST_DEBUGGING) != 0)
2352			debugging = value;
2353			st_log_options(STp, STm); )
2354	} else if (code == MT_ST_WRITE_THRESHOLD) {
2355		/* Retained for compatibility */
2356	} else if (code == MT_ST_DEF_BLKSIZE) {
2357		value = (options & ~MT_ST_OPTIONS);
2358		if (value == ~MT_ST_OPTIONS) {
2359			STm->default_blksize = (-1);
2360			DEBC_printk(STp, "Default block size disabled.\n");
2361		} else {
2362			STm->default_blksize = value;
2363			DEBC_printk(STp,"Default block size set to "
2364				    "%d bytes.\n", STm->default_blksize);
2365			if (STp->ready == ST_READY) {
2366				STp->blksize_changed = 0;
2367				set_mode_densblk(STp, STm);
2368			}
2369		}
2370	} else if (code == MT_ST_TIMEOUTS) {
2371		value = (options & ~MT_ST_OPTIONS);
2372		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2373			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2374			DEBC_printk(STp, "Long timeout set to %d seconds.\n",
2375				    (value & ~MT_ST_SET_LONG_TIMEOUT));
2376		} else {
2377			blk_queue_rq_timeout(STp->device->request_queue,
2378					     value * HZ);
2379			DEBC_printk(STp, "Normal timeout set to %d seconds.\n",
2380				    value);
2381		}
2382	} else if (code == MT_ST_SET_CLN) {
2383		value = (options & ~MT_ST_OPTIONS) & 0xff;
2384		if (value != 0 &&
2385			(value < EXTENDED_SENSE_START ||
2386				value >= SCSI_SENSE_BUFFERSIZE))
2387			return (-EINVAL);
2388		STp->cln_mode = value;
2389		STp->cln_sense_mask = (options >> 8) & 0xff;
2390		STp->cln_sense_value = (options >> 16) & 0xff;
2391		st_printk(KERN_INFO, STp,
2392			  "Cleaning request mode %d, mask %02x, value %02x\n",
2393			  value, STp->cln_sense_mask, STp->cln_sense_value);
2394	} else if (code == MT_ST_DEF_OPTIONS) {
2395		code = (options & ~MT_ST_CLEAR_DEFAULT);
2396		value = (options & MT_ST_CLEAR_DEFAULT);
2397		if (code == MT_ST_DEF_DENSITY) {
2398			if (value == MT_ST_CLEAR_DEFAULT) {
2399				STm->default_density = (-1);
2400				DEBC_printk(STp,
2401					    "Density default disabled.\n");
2402			} else {
2403				STm->default_density = value & 0xff;
2404				DEBC_printk(STp, "Density default set to %x\n",
2405					    STm->default_density);
2406				if (STp->ready == ST_READY) {
2407					STp->density_changed = 0;
2408					set_mode_densblk(STp, STm);
2409				}
2410			}
2411		} else if (code == MT_ST_DEF_DRVBUFFER) {
2412			if (value == MT_ST_CLEAR_DEFAULT) {
2413				STp->default_drvbuffer = 0xff;
2414				DEBC_printk(STp,
2415					    "Drive buffer default disabled.\n");
2416			} else {
2417				STp->default_drvbuffer = value & 7;
2418				DEBC_printk(STp,
2419					    "Drive buffer default set to %x\n",
2420					    STp->default_drvbuffer);
2421				if (STp->ready == ST_READY)
2422					st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2423			}
2424		} else if (code == MT_ST_DEF_COMPRESSION) {
2425			if (value == MT_ST_CLEAR_DEFAULT) {
2426				STm->default_compression = ST_DONT_TOUCH;
2427				DEBC_printk(STp,
2428					    "Compression default disabled.\n");
2429			} else {
2430				if ((value & 0xff00) != 0) {
2431					STp->c_algo = (value & 0xff00) >> 8;
2432					DEBC_printk(STp, "Compression "
2433						    "algorithm set to 0x%x.\n",
2434						    STp->c_algo);
2435				}
2436				if ((value & 0xff) != 0xff) {
2437					STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2438					DEBC_printk(STp, "Compression default "
2439						    "set to %x\n",
2440						    (value & 1));
2441					if (STp->ready == ST_READY) {
2442						STp->compression_changed = 0;
2443						st_compression(STp, (STm->default_compression == ST_YES));
2444					}
2445				}
2446			}
2447		}
2448	} else
2449		return (-EIO);
2450
2451	return 0;
2452}
2453
2454#define MODE_HEADER_LENGTH  4
2455
2456/* Mode header and page byte offsets */
2457#define MH_OFF_DATA_LENGTH     0
2458#define MH_OFF_MEDIUM_TYPE     1
2459#define MH_OFF_DEV_SPECIFIC    2
2460#define MH_OFF_BDESCS_LENGTH   3
2461#define MP_OFF_PAGE_NBR        0
2462#define MP_OFF_PAGE_LENGTH     1
2463
2464/* Mode header and page bit masks */
2465#define MH_BIT_WP              0x80
2466#define MP_MSK_PAGE_NBR        0x3f
2467
2468/* Don't return block descriptors */
2469#define MODE_SENSE_OMIT_BDESCS 0x08
2470
2471#define MODE_SELECT_PAGE_FORMAT 0x10
2472
2473/* Read a mode page into the tape buffer. The block descriptors are included
2474   if incl_block_descs is true. The page control is ored to the page number
2475   parameter, if necessary. */
2476static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2477{
2478	unsigned char cmd[MAX_COMMAND_SIZE];
2479	struct st_request *SRpnt;
2480
2481	memset(cmd, 0, MAX_COMMAND_SIZE);
2482	cmd[0] = MODE_SENSE;
2483	if (omit_block_descs)
2484		cmd[1] = MODE_SENSE_OMIT_BDESCS;
2485	cmd[2] = page;
2486	cmd[4] = 255;
2487
2488	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2489			   STp->device->request_queue->rq_timeout, 0, 1);
2490	if (SRpnt == NULL)
2491		return (STp->buffer)->syscall_result;
2492
2493	st_release_request(SRpnt);
2494
2495	return STp->buffer->syscall_result;
2496}
2497
2498
2499/* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2500   in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2501static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2502{
2503	int pgo;
2504	unsigned char cmd[MAX_COMMAND_SIZE];
2505	struct st_request *SRpnt;
2506	int timeout;
2507
2508	memset(cmd, 0, MAX_COMMAND_SIZE);
2509	cmd[0] = MODE_SELECT;
2510	cmd[1] = MODE_SELECT_PAGE_FORMAT;
2511	pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2512	cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2513
2514	/* Clear reserved fields */
2515	(STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2516	(STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2517	(STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2518	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2519
2520	timeout = slow ?
2521		STp->long_timeout : STp->device->request_queue->rq_timeout;
2522	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2523			   timeout, 0, 1);
2524	if (SRpnt == NULL)
2525		return (STp->buffer)->syscall_result;
2526
2527	st_release_request(SRpnt);
2528
2529	return STp->buffer->syscall_result;
2530}
2531
2532
2533#define COMPRESSION_PAGE        0x0f
2534#define COMPRESSION_PAGE_LENGTH 16
2535
2536#define CP_OFF_DCE_DCC          2
2537#define CP_OFF_C_ALGO           7
2538
2539#define DCE_MASK  0x80
2540#define DCC_MASK  0x40
2541#define RED_MASK  0x60
2542
2543
2544/* Control the compression with mode page 15. Algorithm not changed if zero.
2545
2546   The block descriptors are read and written because Sony SDT-7000 does not
2547   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2548   Including block descriptors should not cause any harm to other drives. */
2549
2550static int st_compression(struct scsi_tape * STp, int state)
2551{
2552	int retval;
2553	int mpoffs;  /* Offset to mode page start */
2554	unsigned char *b_data = (STp->buffer)->b_data;
2555
2556	if (STp->ready != ST_READY)
2557		return (-EIO);
2558
2559	/* Read the current page contents */
2560	retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2561	if (retval) {
2562		DEBC_printk(STp, "Compression mode page not supported.\n");
2563		return (-EIO);
2564	}
2565
2566	mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2567	DEBC_printk(STp, "Compression state is %d.\n",
2568		    (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0));
2569
2570	/* Check if compression can be changed */
2571	if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2572		DEBC_printk(STp, "Compression not supported.\n");
2573		return (-EIO);
2574	}
2575
2576	/* Do the change */
2577	if (state) {
2578		b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2579		if (STp->c_algo != 0)
2580			b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2581	}
2582	else {
2583		b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2584		if (STp->c_algo != 0)
2585			b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2586	}
2587
2588	retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2589	if (retval) {
2590		DEBC_printk(STp, "Compression change failed.\n");
2591		return (-EIO);
2592	}
2593	DEBC_printk(STp, "Compression state changed to %d.\n", state);
2594
2595	STp->compression_changed = 1;
2596	return 0;
2597}
2598
2599
2600/* Process the load and unload commands (does unload if the load code is zero) */
2601static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2602{
2603	int retval = (-EIO), timeout;
2604	unsigned char cmd[MAX_COMMAND_SIZE];
2605	struct st_partstat *STps;
2606	struct st_request *SRpnt;
2607
2608	if (STp->ready != ST_READY && !load_code) {
2609		if (STp->ready == ST_NO_TAPE)
2610			return (-ENOMEDIUM);
2611		else
2612			return (-EIO);
2613	}
2614
2615	memset(cmd, 0, MAX_COMMAND_SIZE);
2616	cmd[0] = START_STOP;
2617	if (load_code)
2618		cmd[4] |= 1;
2619	/*
2620	 * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2621	 */
2622	if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2623	    && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2624		DEBC_printk(STp, " Enhanced %sload slot %2d.\n",
2625			    (cmd[4]) ? "" : "un",
2626			    load_code - MT_ST_HPLOADER_OFFSET);
2627		cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2628	}
2629	if (STp->immediate) {
2630		cmd[1] = 1;	/* Don't wait for completion */
2631		timeout = STp->device->request_queue->rq_timeout;
2632	}
2633	else
2634		timeout = STp->long_timeout;
2635
2636	DEBC(
2637		if (!load_code)
2638			st_printk(ST_DEB_MSG, STp, "Unloading tape.\n");
2639		else
2640			st_printk(ST_DEB_MSG, STp, "Loading tape.\n");
2641		);
2642
2643	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2644			   timeout, MAX_RETRIES, 1);
2645	if (!SRpnt)
2646		return (STp->buffer)->syscall_result;
2647
2648	retval = (STp->buffer)->syscall_result;
2649	st_release_request(SRpnt);
2650
2651	if (!retval) {	/* SCSI command successful */
2652
2653		if (!load_code) {
2654			STp->rew_at_close = 0;
2655			STp->ready = ST_NO_TAPE;
2656		}
2657		else {
2658			STp->rew_at_close = STp->autorew_dev;
2659			retval = check_tape(STp, filp);
2660			if (retval > 0)
2661				retval = 0;
2662		}
2663	}
2664	else {
2665		STps = &(STp->ps[STp->partition]);
2666		STps->drv_file = STps->drv_block = (-1);
2667	}
2668
2669	return retval;
2670}
2671
2672#if DEBUG
2673#define ST_DEB_FORWARD  0
2674#define ST_DEB_BACKWARD 1
2675static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd)
2676{
2677	s32 sc;
2678
2679	if (!debugging)
2680		return;
2681
2682	sc = cmd[2] & 0x80 ? 0xff000000 : 0;
2683	sc |= (cmd[2] << 16) | (cmd[3] << 8) | cmd[4];
2684	if (direction)
2685		sc = -sc;
2686	st_printk(ST_DEB_MSG, STp, "Spacing tape %s over %d %s.\n",
2687		  direction ? "backward" : "forward", sc, units);
2688}
2689#else
2690#define ST_DEB_FORWARD  0
2691#define ST_DEB_BACKWARD 1
2692static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd) {}
2693#endif
2694
2695
2696/* Internal ioctl function */
2697static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2698{
2699	int timeout;
2700	long ltmp;
2701	int ioctl_result;
2702	int chg_eof = 1;
2703	unsigned char cmd[MAX_COMMAND_SIZE];
2704	struct st_request *SRpnt;
2705	struct st_partstat *STps;
2706	int fileno, blkno, at_sm, undone;
2707	int datalen = 0, direction = DMA_NONE;
2708
2709	WARN_ON(STp->buffer->do_dio != 0);
2710	if (STp->ready != ST_READY) {
2711		if (STp->ready == ST_NO_TAPE)
2712			return (-ENOMEDIUM);
2713		else
2714			return (-EIO);
2715	}
2716	timeout = STp->long_timeout;
2717	STps = &(STp->ps[STp->partition]);
2718	fileno = STps->drv_file;
2719	blkno = STps->drv_block;
2720	at_sm = STps->at_sm;
2721
2722	memset(cmd, 0, MAX_COMMAND_SIZE);
2723	switch (cmd_in) {
2724	case MTFSFM:
2725		chg_eof = 0;	/* Changed from the FSF after this */
 
2726	case MTFSF:
2727		cmd[0] = SPACE;
2728		cmd[1] = 0x01;	/* Space FileMarks */
2729		cmd[2] = (arg >> 16);
2730		cmd[3] = (arg >> 8);
2731		cmd[4] = arg;
2732		deb_space_print(STp, ST_DEB_FORWARD, "filemarks", cmd);
2733		if (fileno >= 0)
2734			fileno += arg;
2735		blkno = 0;
2736		at_sm &= (arg == 0);
2737		break;
2738	case MTBSFM:
2739		chg_eof = 0;	/* Changed from the FSF after this */
 
2740	case MTBSF:
2741		cmd[0] = SPACE;
2742		cmd[1] = 0x01;	/* Space FileMarks */
2743		ltmp = (-arg);
2744		cmd[2] = (ltmp >> 16);
2745		cmd[3] = (ltmp >> 8);
2746		cmd[4] = ltmp;
2747		deb_space_print(STp, ST_DEB_BACKWARD, "filemarks", cmd);
2748		if (fileno >= 0)
2749			fileno -= arg;
2750		blkno = (-1);	/* We can't know the block number */
2751		at_sm &= (arg == 0);
2752		break;
2753	case MTFSR:
2754		cmd[0] = SPACE;
2755		cmd[1] = 0x00;	/* Space Blocks */
2756		cmd[2] = (arg >> 16);
2757		cmd[3] = (arg >> 8);
2758		cmd[4] = arg;
2759		deb_space_print(STp, ST_DEB_FORWARD, "blocks", cmd);
2760		if (blkno >= 0)
2761			blkno += arg;
2762		at_sm &= (arg == 0);
2763		break;
2764	case MTBSR:
2765		cmd[0] = SPACE;
2766		cmd[1] = 0x00;	/* Space Blocks */
2767		ltmp = (-arg);
2768		cmd[2] = (ltmp >> 16);
2769		cmd[3] = (ltmp >> 8);
2770		cmd[4] = ltmp;
2771		deb_space_print(STp, ST_DEB_BACKWARD, "blocks", cmd);
2772		if (blkno >= 0)
2773			blkno -= arg;
2774		at_sm &= (arg == 0);
2775		break;
2776	case MTFSS:
2777		cmd[0] = SPACE;
2778		cmd[1] = 0x04;	/* Space Setmarks */
2779		cmd[2] = (arg >> 16);
2780		cmd[3] = (arg >> 8);
2781		cmd[4] = arg;
2782		deb_space_print(STp, ST_DEB_FORWARD, "setmarks", cmd);
2783		if (arg != 0) {
2784			blkno = fileno = (-1);
2785			at_sm = 1;
2786		}
2787		break;
2788	case MTBSS:
2789		cmd[0] = SPACE;
2790		cmd[1] = 0x04;	/* Space Setmarks */
2791		ltmp = (-arg);
2792		cmd[2] = (ltmp >> 16);
2793		cmd[3] = (ltmp >> 8);
2794		cmd[4] = ltmp;
2795		deb_space_print(STp, ST_DEB_BACKWARD, "setmarks", cmd);
2796		if (arg != 0) {
2797			blkno = fileno = (-1);
2798			at_sm = 1;
2799		}
2800		break;
2801	case MTWEOF:
2802	case MTWEOFI:
2803	case MTWSM:
2804		if (STp->write_prot)
2805			return (-EACCES);
2806		cmd[0] = WRITE_FILEMARKS;
2807		if (cmd_in == MTWSM)
2808			cmd[1] = 2;
2809		if (cmd_in == MTWEOFI ||
2810		    (cmd_in == MTWEOF && STp->immediate_filemark))
2811			cmd[1] |= 1;
2812		cmd[2] = (arg >> 16);
2813		cmd[3] = (arg >> 8);
2814		cmd[4] = arg;
2815		timeout = STp->device->request_queue->rq_timeout;
2816		DEBC(
2817			if (cmd_in != MTWSM)
2818				st_printk(ST_DEB_MSG, STp,
2819					  "Writing %d filemarks.\n",
2820					  cmd[2] * 65536 +
2821					  cmd[3] * 256 +
2822					  cmd[4]);
2823			else
2824				st_printk(ST_DEB_MSG, STp,
2825					  "Writing %d setmarks.\n",
2826					  cmd[2] * 65536 +
2827					  cmd[3] * 256 +
2828					  cmd[4]);
2829		)
2830		if (fileno >= 0)
2831			fileno += arg;
2832		blkno = 0;
2833		at_sm = (cmd_in == MTWSM);
2834		break;
2835	case MTREW:
2836		cmd[0] = REZERO_UNIT;
2837		if (STp->immediate) {
2838			cmd[1] = 1;	/* Don't wait for completion */
2839			timeout = STp->device->request_queue->rq_timeout;
2840		}
2841		DEBC_printk(STp, "Rewinding tape.\n");
2842		fileno = blkno = at_sm = 0;
2843		break;
2844	case MTNOP:
2845		DEBC_printk(STp, "No op on tape.\n");
2846		return 0;	/* Should do something ? */
2847		break;
2848	case MTRETEN:
2849		cmd[0] = START_STOP;
2850		if (STp->immediate) {
2851			cmd[1] = 1;	/* Don't wait for completion */
2852			timeout = STp->device->request_queue->rq_timeout;
2853		}
2854		cmd[4] = 3;
2855		DEBC_printk(STp, "Retensioning tape.\n");
2856		fileno = blkno = at_sm = 0;
2857		break;
2858	case MTEOM:
2859		if (!STp->fast_mteom) {
2860			/* space to the end of tape */
2861			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2862			fileno = STps->drv_file;
2863			if (STps->eof >= ST_EOD_1)
2864				return 0;
2865			/* The next lines would hide the number of spaced FileMarks
2866			   That's why I inserted the previous lines. I had no luck
2867			   with detecting EOM with FSF, so we go now to EOM.
2868			   Joerg Weule */
2869		} else
2870			fileno = (-1);
2871		cmd[0] = SPACE;
2872		cmd[1] = 3;
2873		DEBC_printk(STp, "Spacing to end of recorded medium.\n");
2874		blkno = -1;
2875		at_sm = 0;
2876		break;
2877	case MTERASE:
2878		if (STp->write_prot)
2879			return (-EACCES);
2880		cmd[0] = ERASE;
2881		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
2882		if (STp->immediate) {
2883			cmd[1] |= 2;	/* Don't wait for completion */
2884			timeout = STp->device->request_queue->rq_timeout;
2885		}
2886		else
2887			timeout = STp->long_timeout * 8;
2888
2889		DEBC_printk(STp, "Erasing tape.\n");
2890		fileno = blkno = at_sm = 0;
2891		break;
2892	case MTSETBLK:		/* Set block length */
2893	case MTSETDENSITY:	/* Set tape density */
2894	case MTSETDRVBUFFER:	/* Set drive buffering */
2895	case SET_DENS_AND_BLK:	/* Set density and block size */
2896		chg_eof = 0;
2897		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2898			return (-EIO);	/* Not allowed if data in buffer */
2899		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2900		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2901		    STp->max_block > 0 &&
2902		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2903		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2904			st_printk(KERN_WARNING, STp, "Illegal block size.\n");
2905			return (-EINVAL);
2906		}
2907		cmd[0] = MODE_SELECT;
2908		if ((STp->use_pf & USE_PF))
2909			cmd[1] = MODE_SELECT_PAGE_FORMAT;
2910		cmd[4] = datalen = 12;
2911		direction = DMA_TO_DEVICE;
2912
2913		memset((STp->buffer)->b_data, 0, 12);
2914		if (cmd_in == MTSETDRVBUFFER)
2915			(STp->buffer)->b_data[2] = (arg & 7) << 4;
2916		else
2917			(STp->buffer)->b_data[2] =
2918			    STp->drv_buffer << 4;
2919		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
2920		if (cmd_in == MTSETDENSITY) {
2921			(STp->buffer)->b_data[4] = arg;
2922			STp->density_changed = 1;	/* At least we tried ;-) */
2923		} else if (cmd_in == SET_DENS_AND_BLK)
2924			(STp->buffer)->b_data[4] = arg >> 24;
2925		else
2926			(STp->buffer)->b_data[4] = STp->density;
2927		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2928			ltmp = arg & MT_ST_BLKSIZE_MASK;
2929			if (cmd_in == MTSETBLK)
2930				STp->blksize_changed = 1; /* At least we tried ;-) */
2931		} else
2932			ltmp = STp->block_size;
2933		(STp->buffer)->b_data[9] = (ltmp >> 16);
2934		(STp->buffer)->b_data[10] = (ltmp >> 8);
2935		(STp->buffer)->b_data[11] = ltmp;
2936		timeout = STp->device->request_queue->rq_timeout;
2937		DEBC(
2938			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2939				st_printk(ST_DEB_MSG, STp,
2940					  "Setting block size to %d bytes.\n",
2941					  (STp->buffer)->b_data[9] * 65536 +
2942					  (STp->buffer)->b_data[10] * 256 +
2943					  (STp->buffer)->b_data[11]);
2944			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2945				st_printk(ST_DEB_MSG, STp,
2946					  "Setting density code to %x.\n",
2947					  (STp->buffer)->b_data[4]);
2948			if (cmd_in == MTSETDRVBUFFER)
2949				st_printk(ST_DEB_MSG, STp,
2950					  "Setting drive buffer code to %d.\n",
2951					  ((STp->buffer)->b_data[2] >> 4) & 7);
2952		)
2953		break;
2954	default:
2955		return (-ENOSYS);
2956	}
2957
2958	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2959			   timeout, MAX_RETRIES, 1);
2960	if (!SRpnt)
2961		return (STp->buffer)->syscall_result;
2962
2963	ioctl_result = (STp->buffer)->syscall_result;
2964
2965	if (!ioctl_result) {	/* SCSI command successful */
2966		st_release_request(SRpnt);
2967		SRpnt = NULL;
2968		STps->drv_block = blkno;
2969		STps->drv_file = fileno;
2970		STps->at_sm = at_sm;
2971
2972		if (cmd_in == MTBSFM)
2973			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2974		else if (cmd_in == MTFSFM)
2975			ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2976
2977		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2978			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2979			if (STp->block_size != 0) {
2980				(STp->buffer)->buffer_blocks =
2981				    (STp->buffer)->buffer_size / STp->block_size;
2982			}
2983			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2984			if (cmd_in == SET_DENS_AND_BLK)
2985				STp->density = arg >> MT_ST_DENSITY_SHIFT;
2986		} else if (cmd_in == MTSETDRVBUFFER)
2987			STp->drv_buffer = (arg & 7);
2988		else if (cmd_in == MTSETDENSITY)
2989			STp->density = arg;
2990
2991		if (cmd_in == MTEOM)
2992			STps->eof = ST_EOD;
2993		else if (cmd_in == MTFSF)
2994			STps->eof = ST_FM;
2995		else if (chg_eof)
2996			STps->eof = ST_NOEOF;
2997
2998		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
2999			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
3000	} else { /* SCSI command was not completely successful. Don't return
3001                    from this block without releasing the SCSI command block! */
3002		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
3003
3004		if (cmdstatp->flags & SENSE_EOM) {
3005			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
3006			    cmd_in != MTBSR && cmd_in != MTBSS)
3007				STps->eof = ST_EOM_OK;
3008			STps->drv_block = 0;
3009		}
3010
3011		if (cmdstatp->remainder_valid)
3012			undone = (int)cmdstatp->uremainder64;
3013		else
3014			undone = 0;
3015
3016		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
3017		    cmdstatp->have_sense &&
3018		    (cmdstatp->flags & SENSE_EOM)) {
3019			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
3020			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
3021				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
3022				STps->eof = ST_NOEOF;
3023			} else {  /* Writing EOF(s) failed */
3024				if (fileno >= 0)
3025					fileno -= undone;
3026				if (undone < arg)
3027					STps->eof = ST_NOEOF;
3028			}
3029			STps->drv_file = fileno;
3030		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
3031			if (fileno >= 0)
3032				STps->drv_file = fileno - undone;
3033			else
3034				STps->drv_file = fileno;
3035			STps->drv_block = -1;
3036			STps->eof = ST_NOEOF;
3037		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
3038			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3039				undone = (-undone);
3040			if (STps->drv_file >= 0)
3041				STps->drv_file = fileno + undone;
3042			STps->drv_block = 0;
3043			STps->eof = ST_NOEOF;
3044		} else if (cmd_in == MTFSR) {
3045			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3046				if (STps->drv_file >= 0)
3047					STps->drv_file++;
3048				STps->drv_block = 0;
3049				STps->eof = ST_FM;
3050			} else {
3051				if (blkno >= undone)
3052					STps->drv_block = blkno - undone;
3053				else
3054					STps->drv_block = (-1);
3055				STps->eof = ST_NOEOF;
3056			}
3057		} else if (cmd_in == MTBSR) {
3058			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3059				STps->drv_file--;
3060				STps->drv_block = (-1);
3061			} else {
3062				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3063					undone = (-undone);
3064				if (STps->drv_block >= 0)
3065					STps->drv_block = blkno + undone;
3066			}
3067			STps->eof = ST_NOEOF;
3068		} else if (cmd_in == MTEOM) {
3069			STps->drv_file = (-1);
3070			STps->drv_block = (-1);
3071			STps->eof = ST_EOD;
3072		} else if (cmd_in == MTSETBLK ||
3073			   cmd_in == MTSETDENSITY ||
3074			   cmd_in == MTSETDRVBUFFER ||
3075			   cmd_in == SET_DENS_AND_BLK) {
3076			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
3077			    !(STp->use_pf & PF_TESTED)) {
3078				/* Try the other possible state of Page Format if not
3079				   already tried */
3080				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
3081				st_release_request(SRpnt);
3082				SRpnt = NULL;
3083				return st_int_ioctl(STp, cmd_in, arg);
3084			}
3085		} else if (chg_eof)
3086			STps->eof = ST_NOEOF;
3087
3088		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
3089			STps->eof = ST_EOD;
3090
3091		st_release_request(SRpnt);
3092		SRpnt = NULL;
3093	}
3094
3095	return ioctl_result;
3096}
3097
3098
3099/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
3100   structure. */
3101
3102static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
3103			int logical)
3104{
3105	int result;
3106	unsigned char scmd[MAX_COMMAND_SIZE];
3107	struct st_request *SRpnt;
3108
3109	if (STp->ready != ST_READY)
3110		return (-EIO);
3111
3112	memset(scmd, 0, MAX_COMMAND_SIZE);
3113	if ((STp->device)->scsi_level < SCSI_2) {
3114		scmd[0] = QFA_REQUEST_BLOCK;
3115		scmd[4] = 3;
3116	} else {
3117		scmd[0] = READ_POSITION;
3118		if (!logical && !STp->scsi2_logical)
3119			scmd[1] = 1;
3120	}
3121	SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3122			   STp->device->request_queue->rq_timeout,
3123			   MAX_READY_RETRIES, 1);
3124	if (!SRpnt)
3125		return (STp->buffer)->syscall_result;
3126
3127	if ((STp->buffer)->syscall_result != 0 ||
3128	    (STp->device->scsi_level >= SCSI_2 &&
3129	     ((STp->buffer)->b_data[0] & 4) != 0)) {
3130		*block = *partition = 0;
3131		DEBC_printk(STp, " Can't read tape position.\n");
3132		result = (-EIO);
3133	} else {
3134		result = 0;
3135		if ((STp->device)->scsi_level < SCSI_2) {
3136			*block = ((STp->buffer)->b_data[0] << 16)
3137			    + ((STp->buffer)->b_data[1] << 8)
3138			    + (STp->buffer)->b_data[2];
3139			*partition = 0;
3140		} else {
3141			*block = ((STp->buffer)->b_data[4] << 24)
3142			    + ((STp->buffer)->b_data[5] << 16)
3143			    + ((STp->buffer)->b_data[6] << 8)
3144			    + (STp->buffer)->b_data[7];
3145			*partition = (STp->buffer)->b_data[1];
3146			if (((STp->buffer)->b_data[0] & 0x80) &&
3147			    (STp->buffer)->b_data[1] == 0)	/* BOP of partition 0 */
3148				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3149		}
3150		DEBC_printk(STp, "Got tape pos. blk %d part %d.\n",
3151			    *block, *partition);
3152	}
3153	st_release_request(SRpnt);
3154	SRpnt = NULL;
3155
3156	return result;
3157}
3158
3159
3160/* Set the tape block and partition. Negative partition means that only the
3161   block should be set in vendor specific way. */
3162static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3163			int logical)
3164{
3165	struct st_partstat *STps;
3166	int result, p;
3167	unsigned int blk;
3168	int timeout;
3169	unsigned char scmd[MAX_COMMAND_SIZE];
3170	struct st_request *SRpnt;
3171
3172	if (STp->ready != ST_READY)
3173		return (-EIO);
3174	timeout = STp->long_timeout;
3175	STps = &(STp->ps[STp->partition]);
3176
3177	DEBC_printk(STp, "Setting block to %d and partition to %d.\n",
3178		    block, partition);
3179	DEB(if (partition < 0)
3180		return (-EIO); )
3181
3182	/* Update the location at the partition we are leaving */
3183	if ((!STp->can_partitions && partition != 0) ||
3184	    partition >= ST_NBR_PARTITIONS)
3185		return (-EINVAL);
3186	if (partition != STp->partition) {
3187		if (get_location(STp, &blk, &p, 1))
3188			STps->last_block_valid = 0;
3189		else {
3190			STps->last_block_valid = 1;
3191			STps->last_block_visited = blk;
3192			DEBC_printk(STp, "Visited block %d for "
3193				    "partition %d saved.\n",
3194				    blk, STp->partition);
3195		}
3196	}
3197
3198	memset(scmd, 0, MAX_COMMAND_SIZE);
3199	if ((STp->device)->scsi_level < SCSI_2) {
3200		scmd[0] = QFA_SEEK_BLOCK;
3201		scmd[2] = (block >> 16);
3202		scmd[3] = (block >> 8);
3203		scmd[4] = block;
3204		scmd[5] = 0;
3205	} else {
3206		scmd[0] = SEEK_10;
3207		scmd[3] = (block >> 24);
3208		scmd[4] = (block >> 16);
3209		scmd[5] = (block >> 8);
3210		scmd[6] = block;
3211		if (!logical && !STp->scsi2_logical)
3212			scmd[1] = 4;
3213		if (STp->partition != partition) {
3214			scmd[1] |= 2;
3215			scmd[8] = partition;
3216			DEBC_printk(STp, "Trying to change partition "
3217				    "from %d to %d\n", STp->partition,
3218				    partition);
3219		}
3220	}
3221	if (STp->immediate) {
3222		scmd[1] |= 1;		/* Don't wait for completion */
3223		timeout = STp->device->request_queue->rq_timeout;
3224	}
3225
3226	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3227			   timeout, MAX_READY_RETRIES, 1);
3228	if (!SRpnt)
3229		return (STp->buffer)->syscall_result;
3230
3231	STps->drv_block = STps->drv_file = (-1);
3232	STps->eof = ST_NOEOF;
3233	if ((STp->buffer)->syscall_result != 0) {
3234		result = (-EIO);
3235		if (STp->can_partitions &&
3236		    (STp->device)->scsi_level >= SCSI_2 &&
3237		    (p = find_partition(STp)) >= 0)
3238			STp->partition = p;
3239	} else {
3240		if (STp->can_partitions) {
3241			STp->partition = partition;
3242			STps = &(STp->ps[partition]);
3243			if (!STps->last_block_valid ||
3244			    STps->last_block_visited != block) {
3245				STps->at_sm = 0;
3246				STps->rw = ST_IDLE;
3247			}
3248		} else
3249			STps->at_sm = 0;
3250		if (block == 0)
3251			STps->drv_block = STps->drv_file = 0;
3252		result = 0;
3253	}
3254
3255	st_release_request(SRpnt);
3256	SRpnt = NULL;
3257
3258	return result;
3259}
3260
3261
3262/* Find the current partition number for the drive status. Called from open and
3263   returns either partition number of negative error code. */
3264static int find_partition(struct scsi_tape *STp)
3265{
3266	int i, partition;
3267	unsigned int block;
3268
3269	if ((i = get_location(STp, &block, &partition, 1)) < 0)
3270		return i;
3271	if (partition >= ST_NBR_PARTITIONS)
3272		return (-EIO);
3273	return partition;
3274}
3275
3276
3277/* Change the partition if necessary */
3278static int switch_partition(struct scsi_tape *STp)
3279{
3280	struct st_partstat *STps;
3281
3282	if (STp->partition == STp->new_partition)
3283		return 0;
3284	STps = &(STp->ps[STp->new_partition]);
3285	if (!STps->last_block_valid)
3286		STps->last_block_visited = 0;
3287	return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3288}
3289
3290/* Functions for reading and writing the medium partition mode page. */
3291
3292#define PART_PAGE   0x11
3293#define PART_PAGE_FIXED_LENGTH 8
3294
3295#define PP_OFF_MAX_ADD_PARTS   2
3296#define PP_OFF_NBR_ADD_PARTS   3
3297#define PP_OFF_FLAGS           4
3298#define PP_OFF_PART_UNITS      6
3299#define PP_OFF_RESERVED        7
3300
3301#define PP_BIT_IDP             0x20
3302#define PP_BIT_FDP             0x80
3303#define PP_MSK_PSUM_MB         0x10
3304#define PP_MSK_PSUM_UNITS      0x18
3305#define PP_MSK_POFM            0x04
3306
3307/* Get the number of partitions on the tape. As a side effect reads the
3308   mode page into the tape buffer. */
3309static int nbr_partitions(struct scsi_tape *STp)
3310{
3311	int result;
3312
3313	if (STp->ready != ST_READY)
3314		return (-EIO);
3315
3316	result = read_mode_page(STp, PART_PAGE, 1);
3317
3318	if (result) {
3319		DEBC_printk(STp, "Can't read medium partition page.\n");
3320		result = (-EIO);
3321	} else {
3322		result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3323					      PP_OFF_NBR_ADD_PARTS] + 1;
3324		DEBC_printk(STp, "Number of partitions %d.\n", result);
3325	}
3326
3327	return result;
3328}
3329
3330
3331static int format_medium(struct scsi_tape *STp, int format)
3332{
3333	int result = 0;
3334	int timeout = STp->long_timeout;
3335	unsigned char scmd[MAX_COMMAND_SIZE];
3336	struct st_request *SRpnt;
3337
3338	memset(scmd, 0, MAX_COMMAND_SIZE);
3339	scmd[0] = FORMAT_UNIT;
3340	scmd[2] = format;
3341	if (STp->immediate) {
3342		scmd[1] |= 1;		/* Don't wait for completion */
3343		timeout = STp->device->request_queue->rq_timeout;
3344	}
3345	DEBC_printk(STp, "Sending FORMAT MEDIUM\n");
3346	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3347			   timeout, MAX_RETRIES, 1);
3348	if (!SRpnt)
3349		result = STp->buffer->syscall_result;
3350	return result;
3351}
3352
3353
3354/* Partition the tape into two partitions if size > 0 or one partition if
3355   size == 0.
3356
3357   The block descriptors are read and written because Sony SDT-7000 does not
3358   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3359
3360   My HP C1533A drive returns only one partition size field. This is used to
3361   set the size of partition 1. There is no size field for the default partition.
3362   Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3363   used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3364   The following algorithm is used to accommodate both drives: if the number of
3365   partition size fields is greater than the maximum number of additional partitions
3366   in the mode page, the second field is used. Otherwise the first field is used.
3367
3368   For Seagate DDS drives the page length must be 8 when no partitions is defined
3369   and 10 when 1 partition is defined (information from Eric Lee Green). This is
3370   is acceptable also to some other old drives and enforced if the first partition
3371   size field is used for the first additional partition size.
3372
3373   For drives that advertize SCSI-3 or newer, use the SSC-3 methods.
3374 */
3375static int partition_tape(struct scsi_tape *STp, int size)
3376{
3377	int result;
3378	int target_partition;
3379	bool scsi3 = STp->device->scsi_level >= SCSI_3, needs_format = false;
3380	int pgo, psd_cnt, psdo;
3381	int psum = PP_MSK_PSUM_MB, units = 0;
3382	unsigned char *bp;
3383
3384	result = read_mode_page(STp, PART_PAGE, 0);
3385	if (result) {
3386		DEBC_printk(STp, "Can't read partition mode page.\n");
3387		return result;
3388	}
3389	target_partition = 1;
3390	if (size < 0) {
3391		target_partition = 0;
3392		size = -size;
3393	}
3394
3395	/* The mode page is in the buffer. Let's modify it and write it. */
3396	bp = (STp->buffer)->b_data;
3397	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3398	DEBC_printk(STp, "Partition page length is %d bytes.\n",
3399		    bp[pgo + MP_OFF_PAGE_LENGTH] + 2);
3400
3401	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
3402
3403	if (scsi3) {
3404		needs_format = (bp[pgo + PP_OFF_FLAGS] & PP_MSK_POFM) != 0;
3405		if (needs_format && size == 0) {
3406			/* No need to write the mode page when clearing
3407			 *  partitioning
3408			 */
3409			DEBC_printk(STp, "Formatting tape with one partition.\n");
3410			result = format_medium(STp, 0);
3411			goto out;
3412		}
3413		if (needs_format)  /* Leave the old value for HP DATs claiming SCSI_3 */
3414			psd_cnt = 2;
3415		if ((bp[pgo + PP_OFF_FLAGS] & PP_MSK_PSUM_UNITS) == PP_MSK_PSUM_UNITS) {
3416			/* Use units scaling for large partitions if the device
3417			 * suggests it and no precision lost. Required for IBM
3418			 * TS1140/50 drives that don't support MB units.
3419			 */
3420			if (size >= 1000 && (size % 1000) == 0) {
3421				size /= 1000;
3422				psum = PP_MSK_PSUM_UNITS;
3423				units = 9; /* GB */
3424			}
3425		}
3426		/* Try it anyway if too large to specify in MB */
3427		if (psum == PP_MSK_PSUM_MB && size >= 65534) {
3428			size /= 1000;
3429			psum = PP_MSK_PSUM_UNITS;
3430			units = 9;  /* GB */
3431		}
3432	}
3433
3434	if (size >= 65535 ||  /* Does not fit into two bytes */
3435	    (target_partition == 0 && psd_cnt < 2)) {
3436		result = -EINVAL;
3437		goto out;
3438	}
3439
3440	psdo = pgo + PART_PAGE_FIXED_LENGTH;
3441	/* The second condition is for HP DDS which use only one partition size
3442	 * descriptor
3443	 */
3444	if (target_partition > 0 &&
3445	    (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS] ||
3446	     bp[pgo + PP_OFF_MAX_ADD_PARTS] != 1)) {
3447		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest to partition 0 */
3448		psdo += 2;
3449	}
3450	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3451
3452	DEBC_printk(STp, "psd_cnt %d, max.parts %d, nbr_parts %d\n",
3453		    psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3454		    bp[pgo + PP_OFF_NBR_ADD_PARTS]);
3455
3456	if (size == 0) {
3457		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3458		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3459		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3460		DEBC_printk(STp, "Formatting tape with one partition.\n");
3461	} else {
3462		bp[psdo] = (size >> 8) & 0xff;
3463		bp[psdo + 1] = size & 0xff;
3464		if (target_partition == 0)
3465			bp[psdo + 2] = bp[psdo + 3] = 0xff;
3466		bp[pgo + 3] = 1;
3467		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3468		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3469		DEBC_printk(STp,
3470			    "Formatting tape with two partitions (%i = %d MB).\n",
3471			    target_partition, units > 0 ? size * 1000 : size);
3472	}
3473	bp[pgo + PP_OFF_PART_UNITS] = 0;
3474	bp[pgo + PP_OFF_RESERVED] = 0;
3475	if (size != 1 || units != 0) {
3476		bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | psum |
3477			(bp[pgo + PP_OFF_FLAGS] & 0x07);
3478		bp[pgo + PP_OFF_PART_UNITS] = units;
3479	} else
3480		bp[pgo + PP_OFF_FLAGS] = PP_BIT_FDP |
3481			(bp[pgo + PP_OFF_FLAGS] & 0x1f);
3482	bp[pgo + MP_OFF_PAGE_LENGTH] = 6 + psd_cnt * 2;
3483
3484	result = write_mode_page(STp, PART_PAGE, 1);
3485
3486	if (!result && needs_format)
3487		result = format_medium(STp, 1);
3488
3489	if (result) {
3490		st_printk(KERN_INFO, STp, "Partitioning of tape failed.\n");
3491		result = (-EIO);
3492	}
3493
3494out:
3495	return result;
3496}
3497
3498
3499
3500/* The ioctl command */
3501static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3502{
3503	int i, cmd_nr, cmd_type, bt;
3504	int retval = 0;
3505	unsigned int blk;
3506	struct scsi_tape *STp = file->private_data;
3507	struct st_modedef *STm;
3508	struct st_partstat *STps;
3509	void __user *p = (void __user *)arg;
3510
3511	if (mutex_lock_interruptible(&STp->lock))
3512		return -ERESTARTSYS;
3513
3514	DEB(
3515	if (debugging && !STp->in_use) {
3516		st_printk(ST_DEB_MSG, STp, "Incorrect device.\n");
3517		retval = (-EIO);
3518		goto out;
3519	} ) /* end DEB */
3520
3521	STm = &(STp->modes[STp->current_mode]);
3522	STps = &(STp->ps[STp->partition]);
3523
3524	/*
3525	 * If we are in the middle of error recovery, don't let anyone
3526	 * else try and use this device.  Also, if error recovery fails, it
3527	 * may try and take the device offline, in which case all further
3528	 * access to the device is prohibited.
3529	 */
3530	retval = scsi_ioctl_block_when_processing_errors(STp->device, cmd_in,
3531			file->f_flags & O_NDELAY);
3532	if (retval)
3533		goto out;
3534
3535	cmd_type = _IOC_TYPE(cmd_in);
3536	cmd_nr = _IOC_NR(cmd_in);
3537
3538	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3539		struct mtop mtc;
3540
3541		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3542			retval = (-EINVAL);
3543			goto out;
3544		}
3545
3546		i = copy_from_user(&mtc, p, sizeof(struct mtop));
3547		if (i) {
3548			retval = (-EFAULT);
3549			goto out;
3550		}
3551
3552		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3553			st_printk(KERN_WARNING, STp,
3554				  "MTSETDRVBUFFER only allowed for root.\n");
3555			retval = (-EPERM);
3556			goto out;
3557		}
3558		if (!STm->defined &&
3559		    (mtc.mt_op != MTSETDRVBUFFER &&
3560		     (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3561			retval = (-ENXIO);
3562			goto out;
3563		}
3564
3565		if (!STp->pos_unknown) {
3566
3567			if (STps->eof == ST_FM_HIT) {
3568				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3569                                    mtc.mt_op == MTEOM) {
3570					mtc.mt_count -= 1;
3571					if (STps->drv_file >= 0)
3572						STps->drv_file += 1;
3573				} else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3574					mtc.mt_count += 1;
3575					if (STps->drv_file >= 0)
3576						STps->drv_file += 1;
3577				}
3578			}
3579
3580			if (mtc.mt_op == MTSEEK) {
3581				/* Old position must be restored if partition will be
3582                                   changed */
3583				i = !STp->can_partitions ||
3584				    (STp->new_partition != STp->partition);
3585			} else {
3586				i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3587				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3588				    mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3589				    mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3590				    mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3591				    mtc.mt_op == MTCOMPRESSION;
3592			}
3593			i = flush_buffer(STp, i);
3594			if (i < 0) {
3595				retval = i;
3596				goto out;
3597			}
3598			if (STps->rw == ST_WRITING &&
3599			    (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3600			     mtc.mt_op == MTSEEK ||
3601			     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3602				i = st_int_ioctl(STp, MTWEOF, 1);
3603				if (i < 0) {
3604					retval = i;
3605					goto out;
3606				}
3607				if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3608					mtc.mt_count++;
3609				STps->rw = ST_IDLE;
3610			     }
3611
3612		} else {
3613			/*
3614			 * If there was a bus reset, block further access
3615			 * to this device.  If the user wants to rewind the tape,
3616			 * then reset the flag and allow access again.
3617			 */
3618			if (mtc.mt_op != MTREW &&
3619			    mtc.mt_op != MTOFFL &&
3620			    mtc.mt_op != MTRETEN &&
3621			    mtc.mt_op != MTERASE &&
3622			    mtc.mt_op != MTSEEK &&
3623			    mtc.mt_op != MTEOM) {
3624				retval = (-EIO);
3625				goto out;
3626			}
3627			reset_state(STp);
3628			/* remove this when the midlevel properly clears was_reset */
3629			STp->device->was_reset = 0;
3630		}
3631
3632		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3633		    mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3634		    mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3635			STps->rw = ST_IDLE;	/* Prevent automatic WEOF and fsf */
3636
3637		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3638			do_door_lock(STp, 0);	/* Ignore result! */
3639
3640		if (mtc.mt_op == MTSETDRVBUFFER &&
3641		    (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3642			retval = st_set_options(STp, mtc.mt_count);
3643			goto out;
3644		}
3645
3646		if (mtc.mt_op == MTSETPART) {
3647			if (!STp->can_partitions ||
3648			    mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3649				retval = (-EINVAL);
3650				goto out;
3651			}
3652			if (mtc.mt_count >= STp->nbr_partitions &&
3653			    (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3654				retval = (-EIO);
3655				goto out;
3656			}
3657			if (mtc.mt_count >= STp->nbr_partitions) {
3658				retval = (-EINVAL);
3659				goto out;
3660			}
3661			STp->new_partition = mtc.mt_count;
3662			retval = 0;
3663			goto out;
3664		}
3665
3666		if (mtc.mt_op == MTMKPART) {
3667			if (!STp->can_partitions) {
3668				retval = (-EINVAL);
3669				goto out;
3670			}
3671			i = do_load_unload(STp, file, 1);
3672			if (i < 0) {
3673				retval = i;
3674				goto out;
3675			}
3676			i = partition_tape(STp, mtc.mt_count);
3677			if (i < 0) {
3678				retval = i;
3679				goto out;
3680			}
3681			for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3682				STp->ps[i].rw = ST_IDLE;
3683				STp->ps[i].at_sm = 0;
3684				STp->ps[i].last_block_valid = 0;
3685			}
3686			STp->partition = STp->new_partition = 0;
3687			STp->nbr_partitions = mtc.mt_count != 0 ? 2 : 1;
3688			STps->drv_block = STps->drv_file = 0;
3689			retval = 0;
3690			goto out;
3691		}
3692
3693		if (mtc.mt_op == MTSEEK) {
3694			i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3695			if (!STp->can_partitions)
3696				STp->ps[0].rw = ST_IDLE;
3697			retval = i;
3698			goto out;
3699		}
3700
3701		if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3702			retval = do_load_unload(STp, file, 0);
3703			goto out;
3704		}
3705
3706		if (mtc.mt_op == MTLOAD) {
3707			retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3708			goto out;
3709		}
3710
3711		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3712			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3713			goto out;
3714		}
3715
3716		if (STp->can_partitions && STp->ready == ST_READY &&
3717		    (i = switch_partition(STp)) < 0) {
3718			retval = i;
3719			goto out;
3720		}
3721
3722		if (mtc.mt_op == MTCOMPRESSION)
3723			retval = st_compression(STp, (mtc.mt_count & 1));
3724		else
3725			retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3726		goto out;
3727	}
3728	if (!STm->defined) {
3729		retval = (-ENXIO);
3730		goto out;
3731	}
3732
3733	if ((i = flush_buffer(STp, 0)) < 0) {
3734		retval = i;
3735		goto out;
3736	}
3737	if (STp->can_partitions &&
3738	    (i = switch_partition(STp)) < 0) {
3739		retval = i;
3740		goto out;
3741	}
3742
3743	if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
3744		struct mtget mt_status;
3745
3746		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3747			 retval = (-EINVAL);
3748			 goto out;
3749		}
3750
3751		mt_status.mt_type = STp->tape_type;
3752		mt_status.mt_dsreg =
3753		    ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3754		    ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3755		mt_status.mt_blkno = STps->drv_block;
3756		mt_status.mt_fileno = STps->drv_file;
3757		if (STp->block_size != 0) {
3758			if (STps->rw == ST_WRITING)
3759				mt_status.mt_blkno +=
3760				    (STp->buffer)->buffer_bytes / STp->block_size;
3761			else if (STps->rw == ST_READING)
3762				mt_status.mt_blkno -=
3763                                        ((STp->buffer)->buffer_bytes +
3764                                         STp->block_size - 1) / STp->block_size;
3765		}
3766
3767		mt_status.mt_gstat = 0;
3768		if (STp->drv_write_prot)
3769			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3770		if (mt_status.mt_blkno == 0) {
3771			if (mt_status.mt_fileno == 0)
3772				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3773			else
3774				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3775		}
3776		mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3777		mt_status.mt_resid = STp->partition;
3778		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3779			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3780		else if (STps->eof >= ST_EOM_OK)
3781			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3782		if (STp->density == 1)
3783			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3784		else if (STp->density == 2)
3785			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3786		else if (STp->density == 3)
3787			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3788		if (STp->ready == ST_READY)
3789			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3790		if (STp->ready == ST_NO_TAPE)
3791			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3792		if (STps->at_sm)
3793			mt_status.mt_gstat |= GMT_SM(0xffffffff);
3794		if (STm->do_async_writes ||
3795                    (STm->do_buffer_writes && STp->block_size != 0) ||
3796		    STp->drv_buffer != 0)
3797			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3798		if (STp->cleaning_req)
3799			mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3800
3801		i = copy_to_user(p, &mt_status, sizeof(struct mtget));
3802		if (i) {
3803			retval = (-EFAULT);
3804			goto out;
3805		}
3806
3807		STp->recover_reg = 0;		/* Clear after read */
3808		retval = 0;
3809		goto out;
3810	}			/* End of MTIOCGET */
3811	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3812		struct mtpos mt_pos;
3813		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3814			 retval = (-EINVAL);
3815			 goto out;
3816		}
3817		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3818			retval = i;
3819			goto out;
3820		}
3821		mt_pos.mt_blkno = blk;
3822		i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
3823		if (i)
3824			retval = (-EFAULT);
3825		goto out;
3826	}
3827	mutex_unlock(&STp->lock);
3828	switch (cmd_in) {
3829		case SCSI_IOCTL_GET_IDLUN:
3830		case SCSI_IOCTL_GET_BUS_NUMBER:
3831			break;
3832		default:
3833			if ((cmd_in == SG_IO ||
3834			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3835			     cmd_in == CDROM_SEND_PACKET) &&
3836			    !capable(CAP_SYS_RAWIO))
3837				i = -EPERM;
3838			else
3839				i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3840						   file->f_mode, cmd_in, p);
3841			if (i != -ENOTTY)
3842				return i;
3843			break;
3844	}
3845	retval = scsi_ioctl(STp->device, cmd_in, p);
3846	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
3847		STp->rew_at_close = 0;
3848		STp->ready = ST_NO_TAPE;
3849	}
3850	return retval;
3851
3852 out:
3853	mutex_unlock(&STp->lock);
3854	return retval;
3855}
3856
3857#ifdef CONFIG_COMPAT
3858static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3859{
3860	struct scsi_tape *STp = file->private_data;
3861	struct scsi_device *sdev = STp->device;
3862	int ret = -ENOIOCTLCMD;
3863	if (sdev->host->hostt->compat_ioctl) { 
3864
3865		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
3866
3867	}
3868	return ret;
3869}
3870#endif
3871
3872
3873
3874/* Try to allocate a new tape buffer. Calling function must not hold
3875   dev_arr_lock. */
3876static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
3877{
3878	struct st_buffer *tb;
3879
3880	tb = kzalloc(sizeof(struct st_buffer), GFP_ATOMIC);
3881	if (!tb) {
3882		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3883		return NULL;
3884	}
3885	tb->frp_segs = 0;
3886	tb->use_sg = max_sg;
3887	tb->dma = need_dma;
3888	tb->buffer_size = 0;
3889
3890	tb->reserved_pages = kzalloc(max_sg * sizeof(struct page *),
3891				     GFP_ATOMIC);
3892	if (!tb->reserved_pages) {
3893		kfree(tb);
3894		return NULL;
3895	}
3896
3897	return tb;
3898}
3899
3900
3901/* Try to allocate enough space in the tape buffer */
3902#define ST_MAX_ORDER 6
3903
3904static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
3905{
3906	int segs, max_segs, b_size, order, got;
3907	gfp_t priority;
3908
3909	if (new_size <= STbuffer->buffer_size)
3910		return 1;
3911
3912	if (STbuffer->buffer_size <= PAGE_SIZE)
3913		normalize_buffer(STbuffer);  /* Avoid extra segment */
3914
3915	max_segs = STbuffer->use_sg;
3916
3917	priority = GFP_KERNEL | __GFP_NOWARN;
3918	if (need_dma)
3919		priority |= GFP_DMA;
3920
3921	if (STbuffer->cleared)
3922		priority |= __GFP_ZERO;
3923
3924	if (STbuffer->frp_segs) {
3925		order = STbuffer->reserved_page_order;
3926		b_size = PAGE_SIZE << order;
3927	} else {
3928		for (b_size = PAGE_SIZE, order = 0;
3929		     order < ST_MAX_ORDER &&
3930			     max_segs * (PAGE_SIZE << order) < new_size;
3931		     order++, b_size *= 2)
3932			;  /* empty */
3933		STbuffer->reserved_page_order = order;
3934	}
3935	if (max_segs * (PAGE_SIZE << order) < new_size) {
3936		if (order == ST_MAX_ORDER)
3937			return 0;
3938		normalize_buffer(STbuffer);
3939		return enlarge_buffer(STbuffer, new_size, need_dma);
3940	}
3941
3942	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3943	     segs < max_segs && got < new_size;) {
3944		struct page *page;
3945
3946		page = alloc_pages(priority, order);
3947		if (!page) {
3948			DEB(STbuffer->buffer_size = got);
3949			normalize_buffer(STbuffer);
3950			return 0;
3951		}
3952
3953		STbuffer->frp_segs += 1;
3954		got += b_size;
3955		STbuffer->buffer_size = got;
3956		STbuffer->reserved_pages[segs] = page;
3957		segs++;
3958	}
3959	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3960
3961	return 1;
3962}
3963
3964
3965/* Make sure that no data from previous user is in the internal buffer */
3966static void clear_buffer(struct st_buffer * st_bp)
3967{
3968	int i;
3969
3970	for (i=0; i < st_bp->frp_segs; i++)
3971		memset(page_address(st_bp->reserved_pages[i]), 0,
3972		       PAGE_SIZE << st_bp->reserved_page_order);
3973	st_bp->cleared = 1;
3974}
3975
3976
3977/* Release the extra buffer */
3978static void normalize_buffer(struct st_buffer * STbuffer)
3979{
3980	int i, order = STbuffer->reserved_page_order;
3981
3982	for (i = 0; i < STbuffer->frp_segs; i++) {
3983		__free_pages(STbuffer->reserved_pages[i], order);
3984		STbuffer->buffer_size -= (PAGE_SIZE << order);
3985	}
3986	STbuffer->frp_segs = 0;
3987	STbuffer->sg_segs = 0;
3988	STbuffer->reserved_page_order = 0;
3989	STbuffer->map_data.offset = 0;
3990}
3991
3992
3993/* Move data from the user buffer to the tape buffer. Returns zero (success) or
3994   negative error code. */
3995static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3996{
3997	int i, cnt, res, offset;
3998	int length = PAGE_SIZE << st_bp->reserved_page_order;
3999
4000	for (i = 0, offset = st_bp->buffer_bytes;
4001	     i < st_bp->frp_segs && offset >= length; i++)
4002		offset -= length;
4003	if (i == st_bp->frp_segs) {	/* Should never happen */
4004		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
4005		return (-EIO);
4006	}
4007	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4008		struct page *page = st_bp->reserved_pages[i];
4009		cnt = length - offset < do_count ? length - offset : do_count;
4010		res = copy_from_user(page_address(page) + offset, ubp, cnt);
4011		if (res)
4012			return (-EFAULT);
4013		do_count -= cnt;
4014		st_bp->buffer_bytes += cnt;
4015		ubp += cnt;
4016		offset = 0;
4017	}
4018	if (do_count) /* Should never happen */
4019		return (-EIO);
4020
4021	return 0;
4022}
4023
4024
4025/* Move data from the tape buffer to the user buffer. Returns zero (success) or
4026   negative error code. */
4027static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
4028{
4029	int i, cnt, res, offset;
4030	int length = PAGE_SIZE << st_bp->reserved_page_order;
4031
4032	for (i = 0, offset = st_bp->read_pointer;
4033	     i < st_bp->frp_segs && offset >= length; i++)
4034		offset -= length;
4035	if (i == st_bp->frp_segs) {	/* Should never happen */
4036		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
4037		return (-EIO);
4038	}
4039	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4040		struct page *page = st_bp->reserved_pages[i];
4041		cnt = length - offset < do_count ? length - offset : do_count;
4042		res = copy_to_user(ubp, page_address(page) + offset, cnt);
4043		if (res)
4044			return (-EFAULT);
4045		do_count -= cnt;
4046		st_bp->buffer_bytes -= cnt;
4047		st_bp->read_pointer += cnt;
4048		ubp += cnt;
4049		offset = 0;
4050	}
4051	if (do_count) /* Should never happen */
4052		return (-EIO);
4053
4054	return 0;
4055}
4056
4057
4058/* Move data towards start of buffer */
4059static void move_buffer_data(struct st_buffer * st_bp, int offset)
4060{
4061	int src_seg, dst_seg, src_offset = 0, dst_offset;
4062	int count, total;
4063	int length = PAGE_SIZE << st_bp->reserved_page_order;
4064
4065	if (offset == 0)
4066		return;
4067
4068	total=st_bp->buffer_bytes - offset;
4069	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
4070		src_offset = offset;
4071		if (src_offset < length)
4072			break;
4073		offset -= length;
4074	}
4075
4076	st_bp->buffer_bytes = st_bp->read_pointer = total;
4077	for (dst_seg=dst_offset=0; total > 0; ) {
4078		struct page *dpage = st_bp->reserved_pages[dst_seg];
4079		struct page *spage = st_bp->reserved_pages[src_seg];
4080
4081		count = min(length - dst_offset, length - src_offset);
4082		memmove(page_address(dpage) + dst_offset,
4083			page_address(spage) + src_offset, count);
4084		src_offset += count;
4085		if (src_offset >= length) {
4086			src_seg++;
4087			src_offset = 0;
4088		}
4089		dst_offset += count;
4090		if (dst_offset >= length) {
4091			dst_seg++;
4092			dst_offset = 0;
4093		}
4094		total -= count;
4095	}
4096}
4097
4098/* Validate the options from command line or module parameters */
4099static void validate_options(void)
4100{
4101	if (buffer_kbs > 0)
4102		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
4103	if (max_sg_segs >= ST_FIRST_SG)
4104		st_max_sg_segs = max_sg_segs;
4105}
4106
4107#ifndef MODULE
4108/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
4109 */
4110static int __init st_setup(char *str)
4111{
4112	int i, len, ints[5];
4113	char *stp;
4114
4115	stp = get_options(str, ARRAY_SIZE(ints), ints);
4116
4117	if (ints[0] > 0) {
4118		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
4119			if (parms[i].val)
4120				*parms[i].val = ints[i + 1];
4121	} else {
4122		while (stp != NULL) {
4123			for (i = 0; i < ARRAY_SIZE(parms); i++) {
4124				len = strlen(parms[i].name);
4125				if (!strncmp(stp, parms[i].name, len) &&
4126				    (*(stp + len) == ':' || *(stp + len) == '=')) {
4127					if (parms[i].val)
4128						*parms[i].val =
4129							simple_strtoul(stp + len + 1, NULL, 0);
4130					else
4131						printk(KERN_WARNING "st: Obsolete parameter %s\n",
4132						       parms[i].name);
4133					break;
4134				}
4135			}
4136			if (i >= ARRAY_SIZE(parms))
4137				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
4138					stp);
4139			stp = strchr(stp, ',');
4140			if (stp)
4141				stp++;
4142		}
4143	}
4144
4145	validate_options();
4146
4147	return 1;
4148}
4149
4150__setup("st=", st_setup);
4151
4152#endif
4153
4154static const struct file_operations st_fops =
4155{
4156	.owner =	THIS_MODULE,
4157	.read =		st_read,
4158	.write =	st_write,
4159	.unlocked_ioctl = st_ioctl,
4160#ifdef CONFIG_COMPAT
4161	.compat_ioctl = st_compat_ioctl,
4162#endif
4163	.open =		st_open,
4164	.flush =	st_flush,
4165	.release =	st_release,
4166	.llseek =	noop_llseek,
4167};
4168
4169static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
4170{
4171	int i, error;
4172	dev_t cdev_devno;
4173	struct cdev *cdev;
4174	struct device *dev;
4175	struct st_modedef *STm = &(tape->modes[mode]);
4176	char name[10];
4177	int dev_num = tape->index;
4178
4179	cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
4180
4181	cdev = cdev_alloc();
4182	if (!cdev) {
4183		pr_err("st%d: out of memory. Device not attached.\n", dev_num);
4184		error = -ENOMEM;
4185		goto out;
4186	}
4187	cdev->owner = THIS_MODULE;
4188	cdev->ops = &st_fops;
4189	STm->cdevs[rew] = cdev;
4190
4191	error = cdev_add(cdev, cdev_devno, 1);
4192	if (error) {
4193		pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
4194		       rew ? "non" : "auto", mode);
4195		pr_err("st%d: Device not attached.\n", dev_num);
4196		goto out_free;
4197	}
4198
4199	i = mode << (4 - ST_NBR_MODE_BITS);
4200	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4201		 tape->disk->disk_name, st_formats[i]);
4202
4203	dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
4204			    cdev_devno, &tape->modes[mode], "%s", name);
4205	if (IS_ERR(dev)) {
4206		pr_err("st%d: device_create failed\n", dev_num);
4207		error = PTR_ERR(dev);
4208		goto out_free;
4209	}
4210
4211	STm->devs[rew] = dev;
4212
4213	return 0;
4214out_free:
4215	cdev_del(STm->cdevs[rew]);
4216out:
4217	STm->cdevs[rew] = NULL;
4218	STm->devs[rew] = NULL;
4219	return error;
4220}
4221
4222static int create_cdevs(struct scsi_tape *tape)
4223{
4224	int mode, error;
4225	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4226		error = create_one_cdev(tape, mode, 0);
4227		if (error)
4228			return error;
4229		error = create_one_cdev(tape, mode, 1);
4230		if (error)
4231			return error;
4232	}
4233
4234	return sysfs_create_link(&tape->device->sdev_gendev.kobj,
4235				 &tape->modes[0].devs[0]->kobj, "tape");
4236}
4237
4238static void remove_cdevs(struct scsi_tape *tape)
4239{
4240	int mode, rew;
4241	sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
4242	for (mode = 0; mode < ST_NBR_MODES; mode++) {
4243		struct st_modedef *STm = &(tape->modes[mode]);
4244		for (rew = 0; rew < 2; rew++) {
4245			if (STm->cdevs[rew])
4246				cdev_del(STm->cdevs[rew]);
4247			if (STm->devs[rew])
4248				device_unregister(STm->devs[rew]);
4249		}
4250	}
4251}
4252
4253static int st_probe(struct device *dev)
4254{
4255	struct scsi_device *SDp = to_scsi_device(dev);
4256	struct gendisk *disk = NULL;
4257	struct scsi_tape *tpnt = NULL;
4258	struct st_modedef *STm;
4259	struct st_partstat *STps;
4260	struct st_buffer *buffer;
4261	int i, error;
4262	char *stp;
4263
4264	if (SDp->type != TYPE_TAPE)
4265		return -ENODEV;
4266	if ((stp = st_incompatible(SDp))) {
4267		sdev_printk(KERN_INFO, SDp, "Found incompatible tape\n");
4268		sdev_printk(KERN_INFO, SDp,
4269			    "st: The suggested driver is %s.\n", stp);
 
 
4270		return -ENODEV;
4271	}
4272
4273	scsi_autopm_get_device(SDp);
4274	i = queue_max_segments(SDp->request_queue);
4275	if (st_max_sg_segs < i)
4276		i = st_max_sg_segs;
4277	buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
4278	if (buffer == NULL) {
4279		sdev_printk(KERN_ERR, SDp,
4280			    "st: Can't allocate new tape buffer. "
4281			    "Device not attached.\n");
4282		goto out;
4283	}
4284
4285	disk = alloc_disk(1);
4286	if (!disk) {
4287		sdev_printk(KERN_ERR, SDp,
4288			    "st: out of memory. Device not attached.\n");
4289		goto out_buffer_free;
4290	}
4291
4292	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
4293	if (tpnt == NULL) {
4294		sdev_printk(KERN_ERR, SDp,
4295			    "st: Can't allocate device descriptor.\n");
4296		goto out_put_disk;
4297	}
4298	kref_init(&tpnt->kref);
4299	tpnt->disk = disk;
4300	disk->private_data = &tpnt->driver;
4301	disk->queue = SDp->request_queue;
4302	/* SCSI tape doesn't register this gendisk via add_disk().  Manually
4303	 * take queue reference that release_disk() expects. */
4304	if (!blk_get_queue(disk->queue))
4305		goto out_put_disk;
 
4306	tpnt->driver = &st_template;
4307
4308	tpnt->device = SDp;
4309	if (SDp->scsi_level <= 2)
4310		tpnt->tape_type = MT_ISSCSI1;
4311	else
4312		tpnt->tape_type = MT_ISSCSI2;
4313
4314	tpnt->buffer = buffer;
4315	tpnt->buffer->last_SRpnt = NULL;
4316
4317	tpnt->inited = 0;
4318	tpnt->dirty = 0;
4319	tpnt->in_use = 0;
4320	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
4321	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4322	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4323	tpnt->density = 0;
4324	tpnt->do_auto_lock = ST_AUTO_LOCK;
4325	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4326	tpnt->can_partitions = 0;
4327	tpnt->two_fm = ST_TWO_FM;
4328	tpnt->fast_mteom = ST_FAST_MTEOM;
4329	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4330	tpnt->sili = ST_SILI;
4331	tpnt->immediate = ST_NOWAIT;
4332	tpnt->immediate_filemark = 0;
4333	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4334	tpnt->partition = 0;
4335	tpnt->new_partition = 0;
4336	tpnt->nbr_partitions = 0;
4337	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4338	tpnt->long_timeout = ST_LONG_TIMEOUT;
4339	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
4340
4341	for (i = 0; i < ST_NBR_MODES; i++) {
4342		STm = &(tpnt->modes[i]);
4343		STm->defined = 0;
4344		STm->sysv = ST_SYSV;
4345		STm->defaults_for_writes = 0;
4346		STm->do_async_writes = ST_ASYNC_WRITES;
4347		STm->do_buffer_writes = ST_BUFFER_WRITES;
4348		STm->do_read_ahead = ST_READ_AHEAD;
4349		STm->default_compression = ST_DONT_TOUCH;
4350		STm->default_blksize = (-1);	/* No forced size */
4351		STm->default_density = (-1);	/* No forced density */
4352		STm->tape = tpnt;
4353	}
4354
4355	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4356		STps = &(tpnt->ps[i]);
4357		STps->rw = ST_IDLE;
4358		STps->eof = ST_NOEOF;
4359		STps->at_sm = 0;
4360		STps->last_block_valid = 0;
4361		STps->drv_block = (-1);
4362		STps->drv_file = (-1);
4363	}
4364
4365	tpnt->current_mode = 0;
4366	tpnt->modes[0].defined = 1;
4367
4368	tpnt->density_changed = tpnt->compression_changed =
4369	    tpnt->blksize_changed = 0;
4370	mutex_init(&tpnt->lock);
4371
4372	idr_preload(GFP_KERNEL);
4373	spin_lock(&st_index_lock);
4374	error = idr_alloc(&st_index_idr, tpnt, 0, ST_MAX_TAPES + 1, GFP_NOWAIT);
4375	spin_unlock(&st_index_lock);
4376	idr_preload_end();
4377	if (error < 0) {
4378		pr_warn("st: idr allocation failed: %d\n", error);
4379		goto out_put_queue;
4380	}
4381	tpnt->index = error;
4382	sprintf(disk->disk_name, "st%d", tpnt->index);
4383	tpnt->stats = kzalloc(sizeof(struct scsi_tape_stats), GFP_KERNEL);
4384	if (tpnt->stats == NULL) {
4385		sdev_printk(KERN_ERR, SDp,
4386			    "st: Can't allocate statistics.\n");
4387		goto out_idr_remove;
4388	}
4389
4390	dev_set_drvdata(dev, tpnt);
4391
4392
4393	error = create_cdevs(tpnt);
4394	if (error)
4395		goto out_remove_devs;
4396	scsi_autopm_put_device(SDp);
4397
4398	sdev_printk(KERN_NOTICE, SDp,
4399		    "Attached scsi tape %s\n", tape_name(tpnt));
4400	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4401		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4402		    queue_dma_alignment(SDp->request_queue) + 1);
4403
4404	return 0;
4405
4406out_remove_devs:
4407	remove_cdevs(tpnt);
4408	kfree(tpnt->stats);
4409out_idr_remove:
4410	spin_lock(&st_index_lock);
4411	idr_remove(&st_index_idr, tpnt->index);
4412	spin_unlock(&st_index_lock);
4413out_put_queue:
4414	blk_put_queue(disk->queue);
4415out_put_disk:
4416	put_disk(disk);
4417	kfree(tpnt);
4418out_buffer_free:
4419	kfree(buffer);
4420out:
4421	scsi_autopm_put_device(SDp);
4422	return -ENODEV;
4423};
4424
4425
4426static int st_remove(struct device *dev)
4427{
4428	struct scsi_tape *tpnt = dev_get_drvdata(dev);
4429	int index = tpnt->index;
4430
4431	scsi_autopm_get_device(to_scsi_device(dev));
4432	remove_cdevs(tpnt);
4433
4434	mutex_lock(&st_ref_mutex);
4435	kref_put(&tpnt->kref, scsi_tape_release);
4436	mutex_unlock(&st_ref_mutex);
4437	spin_lock(&st_index_lock);
4438	idr_remove(&st_index_idr, index);
4439	spin_unlock(&st_index_lock);
4440	return 0;
4441}
4442
4443/**
4444 *      scsi_tape_release - Called to free the Scsi_Tape structure
4445 *      @kref: pointer to embedded kref
4446 *
4447 *      st_ref_mutex must be held entering this routine.  Because it is
4448 *      called on last put, you should always use the scsi_tape_get()
4449 *      scsi_tape_put() helpers which manipulate the semaphore directly
4450 *      and never do a direct kref_put().
4451 **/
4452static void scsi_tape_release(struct kref *kref)
4453{
4454	struct scsi_tape *tpnt = to_scsi_tape(kref);
4455	struct gendisk *disk = tpnt->disk;
4456
4457	tpnt->device = NULL;
4458
4459	if (tpnt->buffer) {
4460		normalize_buffer(tpnt->buffer);
4461		kfree(tpnt->buffer->reserved_pages);
4462		kfree(tpnt->buffer);
4463	}
4464
4465	disk->private_data = NULL;
4466	put_disk(disk);
4467	kfree(tpnt->stats);
4468	kfree(tpnt);
4469	return;
4470}
4471
4472static struct class st_sysfs_class = {
4473	.name = "scsi_tape",
4474	.dev_groups = st_dev_groups,
4475};
4476
4477static int __init init_st(void)
4478{
4479	int err;
4480
4481	validate_options();
4482
4483	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4484		verstr, st_fixed_buffer_size, st_max_sg_segs);
4485
4486	debugging = (debug_flag > 0) ? debug_flag : NO_DEBUG;
4487	if (debugging) {
4488		printk(KERN_INFO "st: Debugging enabled debug_flag = %d\n",
4489			debugging);
4490	}
4491
4492	err = class_register(&st_sysfs_class);
4493	if (err) {
4494		pr_err("Unable register sysfs class for SCSI tapes\n");
4495		return err;
4496	}
4497
4498	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4499				     ST_MAX_TAPE_ENTRIES, "st");
4500	if (err) {
4501		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4502		       SCSI_TAPE_MAJOR);
4503		goto err_class;
4504	}
4505
4506	err = scsi_register_driver(&st_template.gendrv);
4507	if (err)
4508		goto err_chrdev;
4509
4510	return 0;
4511
4512err_chrdev:
4513	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4514				 ST_MAX_TAPE_ENTRIES);
4515err_class:
4516	class_unregister(&st_sysfs_class);
4517	return err;
4518}
4519
4520static void __exit exit_st(void)
4521{
4522	scsi_unregister_driver(&st_template.gendrv);
4523	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4524				 ST_MAX_TAPE_ENTRIES);
4525	class_unregister(&st_sysfs_class);
4526	idr_destroy(&st_index_idr);
4527	printk(KERN_INFO "st: Unloaded.\n");
4528}
4529
4530module_init(init_st);
4531module_exit(exit_st);
4532
4533
4534/* The sysfs driver interface. Read-only at the moment */
4535static ssize_t try_direct_io_show(struct device_driver *ddp, char *buf)
4536{
4537	return scnprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4538}
4539static DRIVER_ATTR_RO(try_direct_io);
4540
4541static ssize_t fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4542{
4543	return scnprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4544}
4545static DRIVER_ATTR_RO(fixed_buffer_size);
4546
4547static ssize_t max_sg_segs_show(struct device_driver *ddp, char *buf)
4548{
4549	return scnprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4550}
4551static DRIVER_ATTR_RO(max_sg_segs);
4552
4553static ssize_t version_show(struct device_driver *ddd, char *buf)
4554{
4555	return scnprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4556}
4557static DRIVER_ATTR_RO(version);
4558
4559#if DEBUG
4560static ssize_t debug_flag_store(struct device_driver *ddp,
4561	const char *buf, size_t count)
4562{
4563/* We only care what the first byte of the data is the rest is unused.
4564 * if it's a '1' we turn on debug and if it's a '0' we disable it. All
4565 * other values have -EINVAL returned if they are passed in.
4566 */
4567	if (count > 0) {
4568		if (buf[0] == '0') {
4569			debugging = NO_DEBUG;
4570			return count;
4571		} else if (buf[0] == '1') {
4572			debugging = 1;
4573			return count;
4574		}
4575	}
4576	return -EINVAL;
4577}
4578
4579static ssize_t debug_flag_show(struct device_driver *ddp, char *buf)
4580{
4581	return scnprintf(buf, PAGE_SIZE, "%d\n", debugging);
4582}
4583static DRIVER_ATTR_RW(debug_flag);
4584#endif
4585
4586static struct attribute *st_drv_attrs[] = {
4587	&driver_attr_try_direct_io.attr,
4588	&driver_attr_fixed_buffer_size.attr,
4589	&driver_attr_max_sg_segs.attr,
4590	&driver_attr_version.attr,
4591#if DEBUG
4592	&driver_attr_debug_flag.attr,
4593#endif
4594	NULL,
4595};
4596ATTRIBUTE_GROUPS(st_drv);
4597
4598/* The sysfs simple class interface */
4599static ssize_t
4600defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4601{
4602	struct st_modedef *STm = dev_get_drvdata(dev);
4603	ssize_t l = 0;
4604
4605	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4606	return l;
4607}
4608static DEVICE_ATTR_RO(defined);
4609
4610static ssize_t
4611default_blksize_show(struct device *dev, struct device_attribute *attr,
4612		     char *buf)
4613{
4614	struct st_modedef *STm = dev_get_drvdata(dev);
4615	ssize_t l = 0;
4616
4617	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4618	return l;
4619}
4620static DEVICE_ATTR_RO(default_blksize);
4621
4622static ssize_t
4623default_density_show(struct device *dev, struct device_attribute *attr,
4624		     char *buf)
4625{
4626	struct st_modedef *STm = dev_get_drvdata(dev);
4627	ssize_t l = 0;
4628	char *fmt;
4629
4630	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4631	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4632	return l;
4633}
4634static DEVICE_ATTR_RO(default_density);
4635
4636static ssize_t
4637default_compression_show(struct device *dev, struct device_attribute *attr,
4638			 char *buf)
4639{
4640	struct st_modedef *STm = dev_get_drvdata(dev);
4641	ssize_t l = 0;
4642
4643	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4644	return l;
4645}
4646static DEVICE_ATTR_RO(default_compression);
4647
4648static ssize_t
4649options_show(struct device *dev, struct device_attribute *attr, char *buf)
4650{
4651	struct st_modedef *STm = dev_get_drvdata(dev);
4652	struct scsi_tape *STp = STm->tape;
4653	int options;
4654	ssize_t l = 0;
4655
4656	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4657	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4658	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4659	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4660	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4661	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4662	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4663	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4664	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4665	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4666	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4667	options |= STm->sysv ? MT_ST_SYSV : 0;
4668	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4669	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4670	options |= STp->sili ? MT_ST_SILI : 0;
4671
4672	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4673	return l;
4674}
4675static DEVICE_ATTR_RO(options);
4676
4677/* Support for tape stats */
4678
4679/**
4680 * read_cnt_show - return read count - count of reads made from tape drive
4681 * @dev: struct device
4682 * @attr: attribute structure
4683 * @buf: buffer to return formatted data in
4684 */
4685static ssize_t read_cnt_show(struct device *dev,
4686	struct device_attribute *attr, char *buf)
4687{
4688	struct st_modedef *STm = dev_get_drvdata(dev);
4689
4690	return sprintf(buf, "%lld",
4691		       (long long)atomic64_read(&STm->tape->stats->read_cnt));
4692}
4693static DEVICE_ATTR_RO(read_cnt);
4694
4695/**
4696 * read_byte_cnt_show - return read byte count - tape drives
4697 * may use blocks less than 512 bytes this gives the raw byte count of
4698 * of data read from the tape drive.
4699 * @dev: struct device
4700 * @attr: attribute structure
4701 * @buf: buffer to return formatted data in
4702 */
4703static ssize_t read_byte_cnt_show(struct device *dev,
4704	struct device_attribute *attr, char *buf)
4705{
4706	struct st_modedef *STm = dev_get_drvdata(dev);
4707
4708	return sprintf(buf, "%lld",
4709		       (long long)atomic64_read(&STm->tape->stats->read_byte_cnt));
4710}
4711static DEVICE_ATTR_RO(read_byte_cnt);
4712
4713/**
4714 * read_us_show - return read us - overall time spent waiting on reads in ns.
4715 * @dev: struct device
4716 * @attr: attribute structure
4717 * @buf: buffer to return formatted data in
4718 */
4719static ssize_t read_ns_show(struct device *dev,
4720	struct device_attribute *attr, char *buf)
4721{
4722	struct st_modedef *STm = dev_get_drvdata(dev);
4723
4724	return sprintf(buf, "%lld",
4725		       (long long)atomic64_read(&STm->tape->stats->tot_read_time));
4726}
4727static DEVICE_ATTR_RO(read_ns);
4728
4729/**
4730 * write_cnt_show - write count - number of user calls
4731 * to write(2) that have written data to tape.
4732 * @dev: struct device
4733 * @attr: attribute structure
4734 * @buf: buffer to return formatted data in
4735 */
4736static ssize_t write_cnt_show(struct device *dev,
4737	struct device_attribute *attr, char *buf)
4738{
4739	struct st_modedef *STm = dev_get_drvdata(dev);
4740
4741	return sprintf(buf, "%lld",
4742		       (long long)atomic64_read(&STm->tape->stats->write_cnt));
4743}
4744static DEVICE_ATTR_RO(write_cnt);
4745
4746/**
4747 * write_byte_cnt_show - write byte count - raw count of
4748 * bytes written to tape.
4749 * @dev: struct device
4750 * @attr: attribute structure
4751 * @buf: buffer to return formatted data in
4752 */
4753static ssize_t write_byte_cnt_show(struct device *dev,
4754	struct device_attribute *attr, char *buf)
4755{
4756	struct st_modedef *STm = dev_get_drvdata(dev);
4757
4758	return sprintf(buf, "%lld",
4759		       (long long)atomic64_read(&STm->tape->stats->write_byte_cnt));
4760}
4761static DEVICE_ATTR_RO(write_byte_cnt);
4762
4763/**
4764 * write_ns_show - write ns - number of nanoseconds waiting on write
4765 * requests to complete.
4766 * @dev: struct device
4767 * @attr: attribute structure
4768 * @buf: buffer to return formatted data in
4769 */
4770static ssize_t write_ns_show(struct device *dev,
4771	struct device_attribute *attr, char *buf)
4772{
4773	struct st_modedef *STm = dev_get_drvdata(dev);
4774
4775	return sprintf(buf, "%lld",
4776		       (long long)atomic64_read(&STm->tape->stats->tot_write_time));
4777}
4778static DEVICE_ATTR_RO(write_ns);
4779
4780/**
4781 * in_flight_show - number of I/Os currently in flight -
4782 * in most cases this will be either 0 or 1. It may be higher if someone
4783 * has also issued other SCSI commands such as via an ioctl.
4784 * @dev: struct device
4785 * @attr: attribute structure
4786 * @buf: buffer to return formatted data in
4787 */
4788static ssize_t in_flight_show(struct device *dev,
4789	struct device_attribute *attr, char *buf)
4790{
4791	struct st_modedef *STm = dev_get_drvdata(dev);
4792
4793	return sprintf(buf, "%lld",
4794		       (long long)atomic64_read(&STm->tape->stats->in_flight));
4795}
4796static DEVICE_ATTR_RO(in_flight);
4797
4798/**
4799 * io_ns_show - io wait ns - this is the number of ns spent
4800 * waiting on all I/O to complete. This includes tape movement commands
4801 * such as rewinding, seeking to end of file or tape, it also includes
4802 * read and write. To determine the time spent on tape movement
4803 * subtract the read and write ns from this value.
4804 * @dev: struct device
4805 * @attr: attribute structure
4806 * @buf: buffer to return formatted data in
4807 */
4808static ssize_t io_ns_show(struct device *dev,
4809	struct device_attribute *attr, char *buf)
4810{
4811	struct st_modedef *STm = dev_get_drvdata(dev);
4812
4813	return sprintf(buf, "%lld",
4814		       (long long)atomic64_read(&STm->tape->stats->tot_io_time));
4815}
4816static DEVICE_ATTR_RO(io_ns);
4817
4818/**
4819 * other_cnt_show - other io count - this is the number of
4820 * I/O requests other than read and write requests.
4821 * Typically these are tape movement requests but will include driver
4822 * tape movement. This includes only requests issued by the st driver.
4823 * @dev: struct device
4824 * @attr: attribute structure
4825 * @buf: buffer to return formatted data in
4826 */
4827static ssize_t other_cnt_show(struct device *dev,
4828	struct device_attribute *attr, char *buf)
4829{
4830	struct st_modedef *STm = dev_get_drvdata(dev);
4831
4832	return sprintf(buf, "%lld",
4833		       (long long)atomic64_read(&STm->tape->stats->other_cnt));
4834}
4835static DEVICE_ATTR_RO(other_cnt);
4836
4837/**
4838 * resid_cnt_show - A count of the number of times we get a residual
4839 * count - this should indicate someone issuing reads larger than the
4840 * block size on tape.
4841 * @dev: struct device
4842 * @attr: attribute structure
4843 * @buf: buffer to return formatted data in
4844 */
4845static ssize_t resid_cnt_show(struct device *dev,
4846	struct device_attribute *attr, char *buf)
4847{
4848	struct st_modedef *STm = dev_get_drvdata(dev);
4849
4850	return sprintf(buf, "%lld",
4851		       (long long)atomic64_read(&STm->tape->stats->resid_cnt));
4852}
4853static DEVICE_ATTR_RO(resid_cnt);
4854
4855static struct attribute *st_dev_attrs[] = {
4856	&dev_attr_defined.attr,
4857	&dev_attr_default_blksize.attr,
4858	&dev_attr_default_density.attr,
4859	&dev_attr_default_compression.attr,
4860	&dev_attr_options.attr,
4861	NULL,
4862};
4863
4864static struct attribute *st_stats_attrs[] = {
4865	&dev_attr_read_cnt.attr,
4866	&dev_attr_read_byte_cnt.attr,
4867	&dev_attr_read_ns.attr,
4868	&dev_attr_write_cnt.attr,
4869	&dev_attr_write_byte_cnt.attr,
4870	&dev_attr_write_ns.attr,
4871	&dev_attr_in_flight.attr,
4872	&dev_attr_io_ns.attr,
4873	&dev_attr_other_cnt.attr,
4874	&dev_attr_resid_cnt.attr,
4875	NULL,
4876};
4877
4878static struct attribute_group stats_group = {
4879	.name = "stats",
4880	.attrs = st_stats_attrs,
4881};
4882
4883static struct attribute_group st_group = {
4884	.attrs = st_dev_attrs,
4885};
4886
4887static const struct attribute_group *st_dev_groups[] = {
4888	&st_group,
4889	&stats_group,
4890	NULL,
4891};
4892
4893/* The following functions may be useful for a larger audience. */
4894static int sgl_map_user_pages(struct st_buffer *STbp,
4895			      const unsigned int max_pages, unsigned long uaddr,
4896			      size_t count, int rw)
4897{
4898	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4899	unsigned long start = uaddr >> PAGE_SHIFT;
4900	const int nr_pages = end - start;
4901	int res, i, j;
4902	struct page **pages;
4903	struct rq_map_data *mdata = &STbp->map_data;
4904
4905	/* User attempted Overflow! */
4906	if ((uaddr + count) < uaddr)
4907		return -EINVAL;
4908
4909	/* Too big */
4910        if (nr_pages > max_pages)
4911		return -ENOMEM;
4912
4913	/* Hmm? */
4914	if (count == 0)
4915		return 0;
4916
4917	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_KERNEL)) == NULL)
 
4918		return -ENOMEM;
4919
4920        /* Try to fault in all of the necessary pages */
4921        /* rw==READ means read from drive, write into memory area */
4922	res = get_user_pages_unlocked(
4923		uaddr,
4924		nr_pages,
4925		pages,
4926		rw == READ ? FOLL_WRITE : 0); /* don't force */
4927
4928	/* Errors and no page mapped should return here */
4929	if (res < nr_pages)
4930		goto out_unmap;
4931
4932        for (i=0; i < nr_pages; i++) {
4933                /* FIXME: flush superflous for rw==READ,
4934                 * probably wrong function for rw==WRITE
4935                 */
4936		flush_dcache_page(pages[i]);
4937        }
4938
4939	mdata->offset = uaddr & ~PAGE_MASK;
4940	STbp->mapped_pages = pages;
4941
4942	return nr_pages;
4943 out_unmap:
4944	if (res > 0) {
4945		for (j=0; j < res; j++)
4946			put_page(pages[j]);
4947		res = 0;
4948	}
4949	kfree(pages);
4950	return res;
4951}
4952
4953
4954/* And unmap them... */
4955static int sgl_unmap_user_pages(struct st_buffer *STbp,
4956				const unsigned int nr_pages, int dirtied)
4957{
4958	int i;
4959
4960	for (i=0; i < nr_pages; i++) {
4961		struct page *page = STbp->mapped_pages[i];
4962
4963		if (dirtied)
4964			SetPageDirty(page);
4965		/* FIXME: cache flush missing for rw==READ
4966		 * FIXME: call the correct reference counting function
4967		 */
4968		put_page(page);
4969	}
4970	kfree(STbp->mapped_pages);
4971	STbp->mapped_pages = NULL;
4972
4973	return 0;
4974}
v5.4
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3   SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
   4   file Documentation/scsi/st.txt for more information.
   5
   6   History:
   7   Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
   8   Contribution and ideas from several people including (in alphabetical
   9   order) Klaus Ehrenfried, Eugene Exarevsky, Eric Lee Green, Wolfgang Denk,
  10   Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
  11   Michael Schaefer, J"org Weule, and Eric Youngdale.
  12
  13   Copyright 1992 - 2016 Kai Makisara
  14   email Kai.Makisara@kolumbus.fi
  15
  16   Some small formal changes - aeb, 950809
  17
  18   Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
  19 */
  20
  21static const char *verstr = "20160209";
  22
  23#include <linux/module.h>
  24
  25#include <linux/fs.h>
  26#include <linux/kernel.h>
  27#include <linux/sched/signal.h>
  28#include <linux/mm.h>
  29#include <linux/init.h>
  30#include <linux/string.h>
  31#include <linux/slab.h>
  32#include <linux/errno.h>
  33#include <linux/mtio.h>
  34#include <linux/cdrom.h>
  35#include <linux/ioctl.h>
  36#include <linux/fcntl.h>
  37#include <linux/spinlock.h>
  38#include <linux/blkdev.h>
  39#include <linux/moduleparam.h>
  40#include <linux/cdev.h>
  41#include <linux/idr.h>
  42#include <linux/delay.h>
  43#include <linux/mutex.h>
  44
  45#include <linux/uaccess.h>
  46#include <asm/dma.h>
  47
  48#include <scsi/scsi.h>
  49#include <scsi/scsi_dbg.h>
  50#include <scsi/scsi_device.h>
  51#include <scsi/scsi_driver.h>
  52#include <scsi/scsi_eh.h>
  53#include <scsi/scsi_host.h>
  54#include <scsi/scsi_ioctl.h>
  55#include <scsi/sg.h>
  56
  57
  58/* The driver prints some debugging information on the console if DEBUG
  59   is defined and non-zero. */
  60#define DEBUG 1
  61#define NO_DEBUG 0
  62
  63#define ST_DEB_MSG  KERN_NOTICE
  64#if DEBUG
  65/* The message level for the debug messages is currently set to KERN_NOTICE
  66   so that people can easily see the messages. Later when the debugging messages
  67   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
  68#define DEB(a) a
  69#define DEBC(a) if (debugging) { a ; }
  70#else
  71#define DEB(a)
  72#define DEBC(a)
  73#endif
  74
  75#define ST_KILOBYTE 1024
  76
  77#include "st_options.h"
  78#include "st.h"
  79
  80static int buffer_kbs;
  81static int max_sg_segs;
  82static int try_direct_io = TRY_DIRECT_IO;
  83static int try_rdio = 1;
  84static int try_wdio = 1;
  85static int debug_flag;
  86
  87static struct class st_sysfs_class;
  88static const struct attribute_group *st_dev_groups[];
  89static const struct attribute_group *st_drv_groups[];
  90
  91MODULE_AUTHOR("Kai Makisara");
  92MODULE_DESCRIPTION("SCSI tape (st) driver");
  93MODULE_LICENSE("GPL");
  94MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  95MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  96
  97/* Set 'perm' (4th argument) to 0 to disable module_param's definition
  98 * of sysfs parameters (which module_param doesn't yet support).
  99 * Sysfs parameters defined explicitly later.
 100 */
 101module_param_named(buffer_kbs, buffer_kbs, int, 0);
 102MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
 103module_param_named(max_sg_segs, max_sg_segs, int, 0);
 104MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 105module_param_named(try_direct_io, try_direct_io, int, 0);
 106MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 107module_param_named(debug_flag, debug_flag, int, 0);
 108MODULE_PARM_DESC(debug_flag, "Enable DEBUG, same as setting debugging=1");
 109
 110
 111/* Extra parameters for testing */
 112module_param_named(try_rdio, try_rdio, int, 0);
 113MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 114module_param_named(try_wdio, try_wdio, int, 0);
 115MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 116
 117#ifndef MODULE
 118static int write_threshold_kbs;  /* retained for compatibility */
 119static struct st_dev_parm {
 120	char *name;
 121	int *val;
 122} parms[] __initdata = {
 123	{
 124		"buffer_kbs", &buffer_kbs
 125	},
 126	{       /* Retained for compatibility with 2.4 */
 127		"write_threshold_kbs", &write_threshold_kbs
 128	},
 129	{
 130		"max_sg_segs", NULL
 131	},
 132	{
 133		"try_direct_io", &try_direct_io
 134	},
 135	{
 136		"debug_flag", &debug_flag
 137	}
 138};
 139#endif
 140
 141/* Restrict the number of modes so that names for all are assigned */
 142#if ST_NBR_MODES > 16
 143#error "Maximum number of modes is 16"
 144#endif
 145/* Bit reversed order to get same names for same minors with all
 146   mode counts */
 147static const char *st_formats[] = {
 148	"",  "r", "k", "s", "l", "t", "o", "u",
 149	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 150
 151/* The default definitions have been moved to st_options.h */
 152
 153#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 154
 155/* The buffer size should fit into the 24 bits for length in the
 156   6-byte SCSI read and write commands. */
 157#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 158#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 159#endif
 160
 161static int debugging = DEBUG;
 162
 163#define MAX_RETRIES 0
 164#define MAX_WRITE_RETRIES 0
 165#define MAX_READY_RETRIES 0
 166#define NO_TAPE  NOT_READY
 167
 168#define ST_TIMEOUT (900 * HZ)
 169#define ST_LONG_TIMEOUT (14000 * HZ)
 170
 171/* Remove mode bits and auto-rewind bit (7) */
 172#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 173	(iminor(x) & ((1 << ST_MODE_SHIFT)-1)))
 174#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 175
 176/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 177#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 178  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 179
 180/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 181   24 bits) */
 182#define SET_DENS_AND_BLK 0x10001
 183
 184static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 185static int st_max_sg_segs = ST_MAX_SG;
 186
 187static int modes_defined;
 188
 189static int enlarge_buffer(struct st_buffer *, int, int);
 190static void clear_buffer(struct st_buffer *);
 191static void normalize_buffer(struct st_buffer *);
 192static int append_to_buffer(const char __user *, struct st_buffer *, int);
 193static int from_buffer(struct st_buffer *, char __user *, int);
 194static void move_buffer_data(struct st_buffer *, int);
 195
 196static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 197			      unsigned long, size_t, int);
 198static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 199
 200static int st_probe(struct device *);
 201static int st_remove(struct device *);
 202
 203static struct scsi_driver st_template = {
 204	.gendrv = {
 205		.name		= "st",
 206		.owner		= THIS_MODULE,
 207		.probe		= st_probe,
 208		.remove		= st_remove,
 209		.groups		= st_drv_groups,
 210	},
 211};
 212
 213static int st_compression(struct scsi_tape *, int);
 214
 215static int find_partition(struct scsi_tape *);
 216static int switch_partition(struct scsi_tape *);
 217
 218static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 219
 220static void scsi_tape_release(struct kref *);
 221
 222#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 223
 224static DEFINE_MUTEX(st_ref_mutex);
 225static DEFINE_SPINLOCK(st_index_lock);
 226static DEFINE_SPINLOCK(st_use_lock);
 227static DEFINE_IDR(st_index_idr);
 228
 229
 230
 
 231#ifndef SIGS_FROM_OSST
 232#define SIGS_FROM_OSST \
 233	{"OnStream", "SC-", "", "osst"}, \
 234	{"OnStream", "DI-", "", "osst"}, \
 235	{"OnStream", "DP-", "", "osst"}, \
 236	{"OnStream", "USB", "", "osst"}, \
 237	{"OnStream", "FW-", "", "osst"}
 238#endif
 239
 240static struct scsi_tape *scsi_tape_get(int dev)
 241{
 242	struct scsi_tape *STp = NULL;
 243
 244	mutex_lock(&st_ref_mutex);
 245	spin_lock(&st_index_lock);
 246
 247	STp = idr_find(&st_index_idr, dev);
 248	if (!STp) goto out;
 249
 250	kref_get(&STp->kref);
 251
 252	if (!STp->device)
 253		goto out_put;
 254
 255	if (scsi_device_get(STp->device))
 256		goto out_put;
 257
 258	goto out;
 259
 260out_put:
 261	kref_put(&STp->kref, scsi_tape_release);
 262	STp = NULL;
 263out:
 264	spin_unlock(&st_index_lock);
 265	mutex_unlock(&st_ref_mutex);
 266	return STp;
 267}
 268
 269static void scsi_tape_put(struct scsi_tape *STp)
 270{
 271	struct scsi_device *sdev = STp->device;
 272
 273	mutex_lock(&st_ref_mutex);
 274	kref_put(&STp->kref, scsi_tape_release);
 275	scsi_device_put(sdev);
 276	mutex_unlock(&st_ref_mutex);
 277}
 278
 279struct st_reject_data {
 280	char *vendor;
 281	char *model;
 282	char *rev;
 283	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 284};
 285
 286static struct st_reject_data reject_list[] = {
 287	/* {"XXX", "Yy-", "", NULL},  example */
 288	SIGS_FROM_OSST,
 289	{NULL, }};
 290
 291/* If the device signature is on the list of incompatible drives, the
 292   function returns a pointer to the name of the correct driver (if known) */
 293static char * st_incompatible(struct scsi_device* SDp)
 294{
 295	struct st_reject_data *rp;
 296
 297	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 298		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 299		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 300		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 301			if (rp->driver_hint)
 302				return rp->driver_hint;
 303			else
 304				return "unknown";
 305		}
 306	return NULL;
 307}
 308
 309
 310static inline char *tape_name(struct scsi_tape *tape)
 311{
 312	return tape->disk->disk_name;
 313}
 314
 315#define st_printk(prefix, t, fmt, a...) \
 316	sdev_prefix_printk(prefix, (t)->device, tape_name(t), fmt, ##a)
 317#ifdef DEBUG
 318#define DEBC_printk(t, fmt, a...) \
 319	if (debugging) { st_printk(ST_DEB_MSG, t, fmt, ##a ); }
 320#else
 321#define DEBC_printk(t, fmt, a...)
 322#endif
 323
 324static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 325{
 326	const u8 *ucp;
 327	const u8 *sense = SRpnt->sense;
 328
 329	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 330				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 331	s->flags = 0;
 332
 333	if (s->have_sense) {
 334		s->deferred = 0;
 335		s->remainder_valid =
 336			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 337		switch (sense[0] & 0x7f) {
 338		case 0x71:
 339			s->deferred = 1;
 340			/* fall through */
 341		case 0x70:
 342			s->fixed_format = 1;
 343			s->flags = sense[2] & 0xe0;
 344			break;
 345		case 0x73:
 346			s->deferred = 1;
 347			/* fall through */
 348		case 0x72:
 349			s->fixed_format = 0;
 350			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 351			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 352			break;
 353		}
 354	}
 355}
 356
 357
 358/* Convert the result to success code */
 359static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 360{
 361	int result = SRpnt->result;
 362	u8 scode;
 363	DEB(const char *stp;)
 364	char *name = tape_name(STp);
 365	struct st_cmdstatus *cmdstatp;
 366
 367	if (!result)
 368		return 0;
 369
 370	cmdstatp = &STp->buffer->cmdstat;
 371	st_analyze_sense(SRpnt, cmdstatp);
 372
 373	if (cmdstatp->have_sense)
 374		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 375	else
 376		scode = 0;
 377
 378	DEB(
 379	if (debugging) {
 380		st_printk(ST_DEB_MSG, STp,
 381			    "Error: %x, cmd: %x %x %x %x %x %x\n", result,
 382			    SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 383			    SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 384		if (cmdstatp->have_sense)
 385			__scsi_print_sense(STp->device, name,
 386					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 387	} ) /* end DEB */
 388	if (!debugging) { /* Abnormal conditions for tape */
 389		if (!cmdstatp->have_sense)
 390			st_printk(KERN_WARNING, STp,
 391			       "Error %x (driver bt 0x%x, host bt 0x%x).\n",
 392			       result, driver_byte(result), host_byte(result));
 393		else if (cmdstatp->have_sense &&
 394			 scode != NO_SENSE &&
 395			 scode != RECOVERED_ERROR &&
 396			 /* scode != UNIT_ATTENTION && */
 397			 scode != BLANK_CHECK &&
 398			 scode != VOLUME_OVERFLOW &&
 399			 SRpnt->cmd[0] != MODE_SENSE &&
 400			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 401
 402			__scsi_print_sense(STp->device, name,
 403					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 404		}
 405	}
 406
 407	if (cmdstatp->fixed_format &&
 408	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 409		if (STp->cln_sense_value)
 410			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 411					       STp->cln_sense_mask) == STp->cln_sense_value);
 412		else
 413			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 414					       STp->cln_sense_mask) != 0);
 415	}
 416	if (cmdstatp->have_sense &&
 417	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 418		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 419
 420	STp->pos_unknown |= STp->device->was_reset;
 421
 422	if (cmdstatp->have_sense &&
 423	    scode == RECOVERED_ERROR
 424#if ST_RECOVERED_WRITE_FATAL
 425	    && SRpnt->cmd[0] != WRITE_6
 426	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 427#endif
 428	    ) {
 429		STp->recover_count++;
 430		STp->recover_reg++;
 431
 432		DEB(
 433		if (debugging) {
 434			if (SRpnt->cmd[0] == READ_6)
 435				stp = "read";
 436			else if (SRpnt->cmd[0] == WRITE_6)
 437				stp = "write";
 438			else
 439				stp = "ioctl";
 440			st_printk(ST_DEB_MSG, STp,
 441				  "Recovered %s error (%d).\n",
 442				  stp, STp->recover_count);
 443		} ) /* end DEB */
 444
 445		if (cmdstatp->flags == 0)
 446			return 0;
 447	}
 448	return (-EIO);
 449}
 450
 451static struct st_request *st_allocate_request(struct scsi_tape *stp)
 452{
 453	struct st_request *streq;
 454
 455	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 456	if (streq)
 457		streq->stp = stp;
 458	else {
 459		st_printk(KERN_ERR, stp,
 460			  "Can't get SCSI request.\n");
 461		if (signal_pending(current))
 462			stp->buffer->syscall_result = -EINTR;
 463		else
 464			stp->buffer->syscall_result = -EBUSY;
 465	}
 466
 467	return streq;
 468}
 469
 470static void st_release_request(struct st_request *streq)
 471{
 472	kfree(streq);
 473}
 474
 475static void st_do_stats(struct scsi_tape *STp, struct request *req)
 476{
 477	ktime_t now;
 478
 479	now = ktime_get();
 480	if (scsi_req(req)->cmd[0] == WRITE_6) {
 481		now = ktime_sub(now, STp->stats->write_time);
 482		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 483		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 484		atomic64_inc(&STp->stats->write_cnt);
 485		if (scsi_req(req)->result) {
 486			atomic64_add(atomic_read(&STp->stats->last_write_size)
 487				- STp->buffer->cmdstat.residual,
 488				&STp->stats->write_byte_cnt);
 489			if (STp->buffer->cmdstat.residual > 0)
 490				atomic64_inc(&STp->stats->resid_cnt);
 491		} else
 492			atomic64_add(atomic_read(&STp->stats->last_write_size),
 493				&STp->stats->write_byte_cnt);
 494	} else if (scsi_req(req)->cmd[0] == READ_6) {
 495		now = ktime_sub(now, STp->stats->read_time);
 496		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 497		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 498		atomic64_inc(&STp->stats->read_cnt);
 499		if (scsi_req(req)->result) {
 500			atomic64_add(atomic_read(&STp->stats->last_read_size)
 501				- STp->buffer->cmdstat.residual,
 502				&STp->stats->read_byte_cnt);
 503			if (STp->buffer->cmdstat.residual > 0)
 504				atomic64_inc(&STp->stats->resid_cnt);
 505		} else
 506			atomic64_add(atomic_read(&STp->stats->last_read_size),
 507				&STp->stats->read_byte_cnt);
 508	} else {
 509		now = ktime_sub(now, STp->stats->other_time);
 510		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 511		atomic64_inc(&STp->stats->other_cnt);
 512	}
 513	atomic64_dec(&STp->stats->in_flight);
 514}
 515
 516static void st_scsi_execute_end(struct request *req, blk_status_t status)
 517{
 518	struct st_request *SRpnt = req->end_io_data;
 519	struct scsi_request *rq = scsi_req(req);
 520	struct scsi_tape *STp = SRpnt->stp;
 521	struct bio *tmp;
 522
 523	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 524	STp->buffer->cmdstat.residual = rq->resid_len;
 525
 526	st_do_stats(STp, req);
 527
 528	tmp = SRpnt->bio;
 529	if (rq->sense_len)
 530		memcpy(SRpnt->sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
 531	if (SRpnt->waiting)
 532		complete(SRpnt->waiting);
 533
 534	blk_rq_unmap_user(tmp);
 535	blk_put_request(req);
 536}
 537
 538static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 539			   int data_direction, void *buffer, unsigned bufflen,
 540			   int timeout, int retries)
 541{
 542	struct request *req;
 543	struct scsi_request *rq;
 544	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 545	int err = 0;
 
 546	struct scsi_tape *STp = SRpnt->stp;
 547
 548	req = blk_get_request(SRpnt->stp->device->request_queue,
 549			data_direction == DMA_TO_DEVICE ?
 550			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
 551	if (IS_ERR(req))
 552		return DRIVER_ERROR << 24;
 553	rq = scsi_req(req);
 
 554	req->rq_flags |= RQF_QUIET;
 555
 556	mdata->null_mapped = 1;
 557
 558	if (bufflen) {
 559		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 560				      GFP_KERNEL);
 561		if (err) {
 562			blk_put_request(req);
 563			return DRIVER_ERROR << 24;
 564		}
 565	}
 566
 567	atomic64_inc(&STp->stats->in_flight);
 568	if (cmd[0] == WRITE_6) {
 569		atomic_set(&STp->stats->last_write_size, bufflen);
 570		STp->stats->write_time = ktime_get();
 571	} else if (cmd[0] == READ_6) {
 572		atomic_set(&STp->stats->last_read_size, bufflen);
 573		STp->stats->read_time = ktime_get();
 574	} else {
 575		STp->stats->other_time = ktime_get();
 576	}
 577
 578	SRpnt->bio = req->bio;
 579	rq->cmd_len = COMMAND_SIZE(cmd[0]);
 580	memset(rq->cmd, 0, BLK_MAX_CDB);
 581	memcpy(rq->cmd, cmd, rq->cmd_len);
 
 
 582	req->timeout = timeout;
 583	rq->retries = retries;
 584	req->end_io_data = SRpnt;
 585
 586	blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
 587	return 0;
 588}
 589
 590/* Do the scsi command. Waits until command performed if do_wait is true.
 591   Otherwise write_behind_check() is used to check that the command
 592   has finished. */
 593static struct st_request *
 594st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 595	   int bytes, int direction, int timeout, int retries, int do_wait)
 596{
 597	struct completion *waiting;
 598	struct rq_map_data *mdata = &STp->buffer->map_data;
 599	int ret;
 600
 601	/* if async, make sure there's no command outstanding */
 602	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 603		st_printk(KERN_ERR, STp,
 604			  "Async command already active.\n");
 605		if (signal_pending(current))
 606			(STp->buffer)->syscall_result = (-EINTR);
 607		else
 608			(STp->buffer)->syscall_result = (-EBUSY);
 609		return NULL;
 610	}
 611
 612	if (!SRpnt) {
 613		SRpnt = st_allocate_request(STp);
 614		if (!SRpnt)
 615			return NULL;
 616	}
 617
 618	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 619	   which IO is outstanding. It's nulled out when the IO completes. */
 620	if (!do_wait)
 621		(STp->buffer)->last_SRpnt = SRpnt;
 622
 623	waiting = &STp->wait;
 624	init_completion(waiting);
 625	SRpnt->waiting = waiting;
 626
 627	if (STp->buffer->do_dio) {
 628		mdata->page_order = 0;
 629		mdata->nr_entries = STp->buffer->sg_segs;
 630		mdata->pages = STp->buffer->mapped_pages;
 631	} else {
 632		mdata->page_order = STp->buffer->reserved_page_order;
 633		mdata->nr_entries =
 634			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 635		mdata->pages = STp->buffer->reserved_pages;
 636		mdata->offset = 0;
 637	}
 638
 639	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 640	STp->buffer->cmdstat.have_sense = 0;
 641	STp->buffer->syscall_result = 0;
 642
 643	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 644			      retries);
 645	if (ret) {
 646		/* could not allocate the buffer or request was too large */
 647		(STp->buffer)->syscall_result = (-EBUSY);
 648		(STp->buffer)->last_SRpnt = NULL;
 649	} else if (do_wait) {
 650		wait_for_completion(waiting);
 651		SRpnt->waiting = NULL;
 652		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 653	}
 654
 655	return SRpnt;
 656}
 657
 658
 659/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 660   write has been correct but EOM early warning reached, -EIO if write ended in
 661   error or zero if write successful. Asynchronous writes are used only in
 662   variable block mode. */
 663static int write_behind_check(struct scsi_tape * STp)
 664{
 665	int retval = 0;
 666	struct st_buffer *STbuffer;
 667	struct st_partstat *STps;
 668	struct st_cmdstatus *cmdstatp;
 669	struct st_request *SRpnt;
 670
 671	STbuffer = STp->buffer;
 672	if (!STbuffer->writing)
 673		return 0;
 674
 675	DEB(
 676	if (STp->write_pending)
 677		STp->nbr_waits++;
 678	else
 679		STp->nbr_finished++;
 680	) /* end DEB */
 681
 682	wait_for_completion(&(STp->wait));
 683	SRpnt = STbuffer->last_SRpnt;
 684	STbuffer->last_SRpnt = NULL;
 685	SRpnt->waiting = NULL;
 686
 687	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 688	st_release_request(SRpnt);
 689
 690	STbuffer->buffer_bytes -= STbuffer->writing;
 691	STps = &(STp->ps[STp->partition]);
 692	if (STps->drv_block >= 0) {
 693		if (STp->block_size == 0)
 694			STps->drv_block++;
 695		else
 696			STps->drv_block += STbuffer->writing / STp->block_size;
 697	}
 698
 699	cmdstatp = &STbuffer->cmdstat;
 700	if (STbuffer->syscall_result) {
 701		retval = -EIO;
 702		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 703		    (cmdstatp->flags & SENSE_EOM) &&
 704		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 705		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 706			/* EOM at write-behind, has all data been written? */
 707			if (!cmdstatp->remainder_valid ||
 708			    cmdstatp->uremainder64 == 0)
 709				retval = -ENOSPC;
 710		}
 711		if (retval == -EIO)
 712			STps->drv_block = -1;
 713	}
 714	STbuffer->writing = 0;
 715
 716	DEB(if (debugging && retval)
 717		    st_printk(ST_DEB_MSG, STp,
 718				"Async write error %x, return value %d.\n",
 719				STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 720
 721	return retval;
 722}
 723
 724
 725/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 726   it messes up the block number). */
 727static int cross_eof(struct scsi_tape * STp, int forward)
 728{
 729	struct st_request *SRpnt;
 730	unsigned char cmd[MAX_COMMAND_SIZE];
 731
 732	cmd[0] = SPACE;
 733	cmd[1] = 0x01;		/* Space FileMarks */
 734	if (forward) {
 735		cmd[2] = cmd[3] = 0;
 736		cmd[4] = 1;
 737	} else
 738		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 739	cmd[5] = 0;
 740
 741	DEBC_printk(STp, "Stepping over filemark %s.\n",
 742		    forward ? "forward" : "backward");
 743
 744	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 745			   STp->device->request_queue->rq_timeout,
 746			   MAX_RETRIES, 1);
 747	if (!SRpnt)
 748		return (STp->buffer)->syscall_result;
 749
 750	st_release_request(SRpnt);
 751	SRpnt = NULL;
 752
 753	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 754		st_printk(KERN_ERR, STp,
 755			  "Stepping over filemark %s failed.\n",
 756			  forward ? "forward" : "backward");
 757
 758	return (STp->buffer)->syscall_result;
 759}
 760
 761
 762/* Flush the write buffer (never need to write if variable blocksize). */
 763static int st_flush_write_buffer(struct scsi_tape * STp)
 764{
 765	int transfer, blks;
 766	int result;
 767	unsigned char cmd[MAX_COMMAND_SIZE];
 768	struct st_request *SRpnt;
 769	struct st_partstat *STps;
 770
 771	result = write_behind_check(STp);
 772	if (result)
 773		return result;
 774
 775	result = 0;
 776	if (STp->dirty == 1) {
 777
 778		transfer = STp->buffer->buffer_bytes;
 779		DEBC_printk(STp, "Flushing %d bytes.\n", transfer);
 780
 781		memset(cmd, 0, MAX_COMMAND_SIZE);
 782		cmd[0] = WRITE_6;
 783		cmd[1] = 1;
 784		blks = transfer / STp->block_size;
 785		cmd[2] = blks >> 16;
 786		cmd[3] = blks >> 8;
 787		cmd[4] = blks;
 788
 789		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 790				   STp->device->request_queue->rq_timeout,
 791				   MAX_WRITE_RETRIES, 1);
 792		if (!SRpnt)
 793			return (STp->buffer)->syscall_result;
 794
 795		STps = &(STp->ps[STp->partition]);
 796		if ((STp->buffer)->syscall_result != 0) {
 797			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 798
 799			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 800			    (cmdstatp->flags & SENSE_EOM) &&
 801			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 802			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 803			    (!cmdstatp->remainder_valid ||
 804			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 805				STp->dirty = 0;
 806				(STp->buffer)->buffer_bytes = 0;
 807				if (STps->drv_block >= 0)
 808					STps->drv_block += blks;
 809				result = (-ENOSPC);
 810			} else {
 811				st_printk(KERN_ERR, STp, "Error on flush.\n");
 812				STps->drv_block = (-1);
 813				result = (-EIO);
 814			}
 815		} else {
 816			if (STps->drv_block >= 0)
 817				STps->drv_block += blks;
 818			STp->dirty = 0;
 819			(STp->buffer)->buffer_bytes = 0;
 820		}
 821		st_release_request(SRpnt);
 822		SRpnt = NULL;
 823	}
 824	return result;
 825}
 826
 827
 828/* Flush the tape buffer. The tape will be positioned correctly unless
 829   seek_next is true. */
 830static int flush_buffer(struct scsi_tape *STp, int seek_next)
 831{
 832	int backspace, result;
 
 833	struct st_partstat *STps;
 834
 
 
 835	/*
 836	 * If there was a bus reset, block further access
 837	 * to this device.
 838	 */
 839	if (STp->pos_unknown)
 840		return (-EIO);
 841
 842	if (STp->ready != ST_READY)
 843		return 0;
 844	STps = &(STp->ps[STp->partition]);
 845	if (STps->rw == ST_WRITING)	/* Writing */
 846		return st_flush_write_buffer(STp);
 847
 848	if (STp->block_size == 0)
 849		return 0;
 850
 851	backspace = ((STp->buffer)->buffer_bytes +
 852		     (STp->buffer)->read_pointer) / STp->block_size -
 853	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 854	    STp->block_size;
 855	(STp->buffer)->buffer_bytes = 0;
 856	(STp->buffer)->read_pointer = 0;
 857	result = 0;
 858	if (!seek_next) {
 859		if (STps->eof == ST_FM_HIT) {
 860			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 861			if (!result)
 862				STps->eof = ST_NOEOF;
 863			else {
 864				if (STps->drv_file >= 0)
 865					STps->drv_file++;
 866				STps->drv_block = 0;
 867			}
 868		}
 869		if (!result && backspace > 0)
 870			result = st_int_ioctl(STp, MTBSR, backspace);
 871	} else if (STps->eof == ST_FM_HIT) {
 872		if (STps->drv_file >= 0)
 873			STps->drv_file++;
 874		STps->drv_block = 0;
 875		STps->eof = ST_NOEOF;
 876	}
 877	return result;
 878
 879}
 880
 881/* Set the mode parameters */
 882static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 883{
 884	int set_it = 0;
 885	unsigned long arg;
 886
 887	if (!STp->density_changed &&
 888	    STm->default_density >= 0 &&
 889	    STm->default_density != STp->density) {
 890		arg = STm->default_density;
 891		set_it = 1;
 892	} else
 893		arg = STp->density;
 894	arg <<= MT_ST_DENSITY_SHIFT;
 895	if (!STp->blksize_changed &&
 896	    STm->default_blksize >= 0 &&
 897	    STm->default_blksize != STp->block_size) {
 898		arg |= STm->default_blksize;
 899		set_it = 1;
 900	} else
 901		arg |= STp->block_size;
 902	if (set_it &&
 903	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 904		st_printk(KERN_WARNING, STp,
 905			  "Can't set default block size to %d bytes "
 906			  "and density %x.\n",
 907			  STm->default_blksize, STm->default_density);
 908		if (modes_defined)
 909			return (-EINVAL);
 910	}
 911	return 0;
 912}
 913
 914
 915/* Lock or unlock the drive door. Don't use when st_request allocated. */
 916static int do_door_lock(struct scsi_tape * STp, int do_lock)
 917{
 918	int retval;
 919
 920	DEBC_printk(STp, "%socking drive door.\n", do_lock ? "L" : "Unl");
 921
 922	retval = scsi_set_medium_removal(STp->device,
 923			do_lock ? SCSI_REMOVAL_PREVENT : SCSI_REMOVAL_ALLOW);
 924	if (!retval)
 925		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 926	else
 927		STp->door_locked = ST_LOCK_FAILS;
 928	return retval;
 929}
 930
 931
 932/* Set the internal state after reset */
 933static void reset_state(struct scsi_tape *STp)
 934{
 935	int i;
 936	struct st_partstat *STps;
 937
 938	STp->pos_unknown = 0;
 939	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 940		STps = &(STp->ps[i]);
 941		STps->rw = ST_IDLE;
 942		STps->eof = ST_NOEOF;
 943		STps->at_sm = 0;
 944		STps->last_block_valid = 0;
 945		STps->drv_block = -1;
 946		STps->drv_file = -1;
 947	}
 948	if (STp->can_partitions) {
 949		STp->partition = find_partition(STp);
 950		if (STp->partition < 0)
 951			STp->partition = 0;
 952		STp->new_partition = STp->partition;
 953	}
 954}
 955
 956/* Test if the drive is ready. Returns either one of the codes below or a negative system
 957   error code. */
 958#define CHKRES_READY       0
 959#define CHKRES_NEW_SESSION 1
 960#define CHKRES_NOT_READY   2
 961#define CHKRES_NO_TAPE     3
 962
 963#define MAX_ATTENTIONS    10
 964
 965static int test_ready(struct scsi_tape *STp, int do_wait)
 966{
 967	int attentions, waits, max_wait, scode;
 968	int retval = CHKRES_READY, new_session = 0;
 969	unsigned char cmd[MAX_COMMAND_SIZE];
 970	struct st_request *SRpnt = NULL;
 971	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 972
 973	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 974
 975	for (attentions=waits=0; ; ) {
 976		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 977		cmd[0] = TEST_UNIT_READY;
 978		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 979				   STp->long_timeout, MAX_READY_RETRIES, 1);
 980
 981		if (!SRpnt) {
 982			retval = (STp->buffer)->syscall_result;
 983			break;
 984		}
 985
 986		if (cmdstatp->have_sense) {
 987
 988			scode = cmdstatp->sense_hdr.sense_key;
 989
 990			if (scode == UNIT_ATTENTION) { /* New media? */
 991				new_session = 1;
 992				if (attentions < MAX_ATTENTIONS) {
 993					attentions++;
 994					continue;
 995				}
 996				else {
 997					retval = (-EIO);
 998					break;
 999				}
1000			}
1001
1002			if (scode == NOT_READY) {
1003				if (waits < max_wait) {
1004					if (msleep_interruptible(1000)) {
1005						retval = (-EINTR);
1006						break;
1007					}
1008					waits++;
1009					continue;
1010				}
1011				else {
1012					if ((STp->device)->scsi_level >= SCSI_2 &&
1013					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
1014						retval = CHKRES_NO_TAPE;
1015					else
1016						retval = CHKRES_NOT_READY;
1017					break;
1018				}
1019			}
1020		}
1021
1022		retval = (STp->buffer)->syscall_result;
1023		if (!retval)
1024			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
1025		break;
1026	}
1027
1028	if (SRpnt != NULL)
1029		st_release_request(SRpnt);
1030	return retval;
1031}
1032
1033
1034/* See if the drive is ready and gather information about the tape. Return values:
1035   < 0   negative error code from errno.h
1036   0     drive ready
1037   1     drive not ready (possibly no tape)
1038*/
1039static int check_tape(struct scsi_tape *STp, struct file *filp)
1040{
1041	int i, retval, new_session = 0, do_wait;
1042	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
1043	unsigned short st_flags = filp->f_flags;
1044	struct st_request *SRpnt = NULL;
1045	struct st_modedef *STm;
1046	struct st_partstat *STps;
1047	struct inode *inode = file_inode(filp);
1048	int mode = TAPE_MODE(inode);
1049
1050	STp->ready = ST_READY;
1051
1052	if (mode != STp->current_mode) {
1053		DEBC_printk(STp, "Mode change from %d to %d.\n",
1054			    STp->current_mode, mode);
1055		new_session = 1;
1056		STp->current_mode = mode;
1057	}
1058	STm = &(STp->modes[STp->current_mode]);
1059
1060	saved_cleaning = STp->cleaning_req;
1061	STp->cleaning_req = 0;
1062
1063	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1064	retval = test_ready(STp, do_wait);
1065
1066	if (retval < 0)
1067	    goto err_out;
1068
1069	if (retval == CHKRES_NEW_SESSION) {
1070		STp->pos_unknown = 0;
1071		STp->partition = STp->new_partition = 0;
1072		if (STp->can_partitions)
1073			STp->nbr_partitions = 1; /* This guess will be updated later
1074                                                    if necessary */
1075		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1076			STps = &(STp->ps[i]);
1077			STps->rw = ST_IDLE;
1078			STps->eof = ST_NOEOF;
1079			STps->at_sm = 0;
1080			STps->last_block_valid = 0;
1081			STps->drv_block = 0;
1082			STps->drv_file = 0;
1083		}
1084		new_session = 1;
1085	}
1086	else {
1087		STp->cleaning_req |= saved_cleaning;
1088
1089		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1090			if (retval == CHKRES_NO_TAPE)
1091				STp->ready = ST_NO_TAPE;
1092			else
1093				STp->ready = ST_NOT_READY;
1094
1095			STp->density = 0;	/* Clear the erroneous "residue" */
1096			STp->write_prot = 0;
1097			STp->block_size = 0;
1098			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1099			STp->partition = STp->new_partition = 0;
1100			STp->door_locked = ST_UNLOCKED;
1101			return CHKRES_NOT_READY;
1102		}
1103	}
1104
1105	if (STp->omit_blklims)
1106		STp->min_block = STp->max_block = (-1);
1107	else {
1108		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1109		cmd[0] = READ_BLOCK_LIMITS;
1110
1111		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1112				   STp->device->request_queue->rq_timeout,
1113				   MAX_READY_RETRIES, 1);
1114		if (!SRpnt) {
1115			retval = (STp->buffer)->syscall_result;
1116			goto err_out;
1117		}
1118
1119		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1120			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1121			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1122			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1123			    (STp->buffer)->b_data[5];
1124			if ( DEB( debugging || ) !STp->inited)
1125				st_printk(KERN_INFO, STp,
1126					  "Block limits %d - %d bytes.\n",
1127					  STp->min_block, STp->max_block);
1128		} else {
1129			STp->min_block = STp->max_block = (-1);
1130			DEBC_printk(STp, "Can't read block limits.\n");
1131		}
1132	}
1133
1134	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1135	cmd[0] = MODE_SENSE;
1136	cmd[4] = 12;
1137
1138	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1139			   STp->device->request_queue->rq_timeout,
1140			   MAX_READY_RETRIES, 1);
1141	if (!SRpnt) {
1142		retval = (STp->buffer)->syscall_result;
1143		goto err_out;
1144	}
1145
1146	if ((STp->buffer)->syscall_result != 0) {
1147		DEBC_printk(STp, "No Mode Sense.\n");
1148		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1149		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1150		STp->drv_write_prot = 0;
1151	} else {
1152		DEBC_printk(STp,"Mode sense. Length %d, "
1153			    "medium %x, WBS %x, BLL %d\n",
1154			    (STp->buffer)->b_data[0],
1155			    (STp->buffer)->b_data[1],
1156			    (STp->buffer)->b_data[2],
1157			    (STp->buffer)->b_data[3]);
1158
1159		if ((STp->buffer)->b_data[3] >= 8) {
1160			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1161			STp->density = (STp->buffer)->b_data[4];
1162			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1163			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1164			DEBC_printk(STp, "Density %x, tape length: %x, "
1165				    "drv buffer: %d\n",
1166				    STp->density,
1167				    (STp->buffer)->b_data[5] * 65536 +
1168				    (STp->buffer)->b_data[6] * 256 +
1169				    (STp->buffer)->b_data[7],
1170				    STp->drv_buffer);
1171		}
1172		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1173		if (!STp->drv_buffer && STp->immediate_filemark) {
1174			st_printk(KERN_WARNING, STp,
1175				  "non-buffered tape: disabling "
1176				  "writing immediate filemarks\n");
1177			STp->immediate_filemark = 0;
1178		}
1179	}
1180	st_release_request(SRpnt);
1181	SRpnt = NULL;
1182	STp->inited = 1;
1183
1184	if (STp->block_size > 0)
1185		(STp->buffer)->buffer_blocks =
1186			(STp->buffer)->buffer_size / STp->block_size;
1187	else
1188		(STp->buffer)->buffer_blocks = 1;
1189	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1190
1191	DEBC_printk(STp, "Block size: %d, buffer size: %d (%d blocks).\n",
1192		    STp->block_size, (STp->buffer)->buffer_size,
1193		    (STp->buffer)->buffer_blocks);
1194
1195	if (STp->drv_write_prot) {
1196		STp->write_prot = 1;
1197
1198		DEBC_printk(STp, "Write protected\n");
1199
1200		if (do_wait &&
1201		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1202		     (st_flags & O_ACCMODE) == O_RDWR)) {
1203			retval = (-EROFS);
1204			goto err_out;
1205		}
1206	}
1207
1208	if (STp->can_partitions && STp->nbr_partitions < 1) {
1209		/* This code is reached when the device is opened for the first time
1210		   after the driver has been initialized with tape in the drive and the
1211		   partition support has been enabled. */
1212		DEBC_printk(STp, "Updating partition number in status.\n");
1213		if ((STp->partition = find_partition(STp)) < 0) {
1214			retval = STp->partition;
1215			goto err_out;
1216		}
1217		STp->new_partition = STp->partition;
1218		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1219	}
1220
1221	if (new_session) {	/* Change the drive parameters for the new mode */
1222		STp->density_changed = STp->blksize_changed = 0;
1223		STp->compression_changed = 0;
1224		if (!(STm->defaults_for_writes) &&
1225		    (retval = set_mode_densblk(STp, STm)) < 0)
1226		    goto err_out;
1227
1228		if (STp->default_drvbuffer != 0xff) {
1229			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1230				st_printk(KERN_WARNING, STp,
1231					  "Can't set default drive "
1232					  "buffering to %d.\n",
1233					  STp->default_drvbuffer);
1234		}
1235	}
1236
1237	return CHKRES_READY;
1238
1239 err_out:
1240	return retval;
1241}
1242
1243
1244/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1245   module count. */
1246static int st_open(struct inode *inode, struct file *filp)
1247{
1248	int i, retval = (-EIO);
1249	int resumed = 0;
1250	struct scsi_tape *STp;
1251	struct st_partstat *STps;
1252	int dev = TAPE_NR(inode);
1253
1254	/*
1255	 * We really want to do nonseekable_open(inode, filp); here, but some
1256	 * versions of tar incorrectly call lseek on tapes and bail out if that
1257	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1258	 */
1259	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1260
1261	if (!(STp = scsi_tape_get(dev))) {
1262		return -ENXIO;
1263	}
1264
1265	filp->private_data = STp;
1266
1267	spin_lock(&st_use_lock);
1268	if (STp->in_use) {
1269		spin_unlock(&st_use_lock);
1270		scsi_tape_put(STp);
1271		DEBC_printk(STp, "Device already in use.\n");
1272		return (-EBUSY);
1273	}
1274
1275	STp->in_use = 1;
1276	spin_unlock(&st_use_lock);
1277	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1278
1279	if (scsi_autopm_get_device(STp->device) < 0) {
1280		retval = -EIO;
1281		goto err_out;
1282	}
1283	resumed = 1;
1284	if (!scsi_block_when_processing_errors(STp->device)) {
1285		retval = (-ENXIO);
1286		goto err_out;
1287	}
1288
1289	/* See that we have at least a one page buffer available */
1290	if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1291		st_printk(KERN_WARNING, STp,
1292			  "Can't allocate one page tape buffer.\n");
1293		retval = (-EOVERFLOW);
1294		goto err_out;
1295	}
1296
1297	(STp->buffer)->cleared = 0;
1298	(STp->buffer)->writing = 0;
1299	(STp->buffer)->syscall_result = 0;
1300
1301	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1302
1303	STp->dirty = 0;
1304	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1305		STps = &(STp->ps[i]);
1306		STps->rw = ST_IDLE;
1307	}
1308	STp->try_dio_now = STp->try_dio;
1309	STp->recover_count = 0;
1310	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1311	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1312
1313	retval = check_tape(STp, filp);
1314	if (retval < 0)
1315		goto err_out;
1316	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1317	    retval != CHKRES_READY) {
1318		if (STp->ready == NO_TAPE)
1319			retval = (-ENOMEDIUM);
1320		else
1321			retval = (-EIO);
1322		goto err_out;
1323	}
1324	return 0;
1325
1326 err_out:
1327	normalize_buffer(STp->buffer);
1328	spin_lock(&st_use_lock);
1329	STp->in_use = 0;
1330	spin_unlock(&st_use_lock);
1331	if (resumed)
1332		scsi_autopm_put_device(STp->device);
1333	scsi_tape_put(STp);
1334	return retval;
1335
1336}
1337
1338
1339/* Flush the tape buffer before close */
1340static int st_flush(struct file *filp, fl_owner_t id)
1341{
1342	int result = 0, result2;
1343	unsigned char cmd[MAX_COMMAND_SIZE];
1344	struct st_request *SRpnt;
1345	struct scsi_tape *STp = filp->private_data;
1346	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1347	struct st_partstat *STps = &(STp->ps[STp->partition]);
1348
1349	if (file_count(filp) > 1)
1350		return 0;
1351
1352	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1353		result = st_flush_write_buffer(STp);
1354		if (result != 0 && result != (-ENOSPC))
1355			goto out;
1356	}
1357
1358	if (STp->can_partitions &&
1359	    (result2 = switch_partition(STp)) < 0) {
1360		DEBC_printk(STp, "switch_partition at close failed.\n");
1361		if (result == 0)
1362			result = result2;
1363		goto out;
1364	}
1365
1366	DEBC( if (STp->nbr_requests)
1367		st_printk(KERN_DEBUG, STp,
1368			  "Number of r/w requests %d, dio used in %d, "
1369			  "pages %d.\n", STp->nbr_requests, STp->nbr_dio,
1370			  STp->nbr_pages));
1371
1372	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1373		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1374
1375#if DEBUG
1376		DEBC_printk(STp, "Async write waits %d, finished %d.\n",
1377			    STp->nbr_waits, STp->nbr_finished);
1378#endif
1379		memset(cmd, 0, MAX_COMMAND_SIZE);
1380		cmd[0] = WRITE_FILEMARKS;
1381		if (STp->immediate_filemark)
1382			cmd[1] = 1;
1383		cmd[4] = 1 + STp->two_fm;
1384
1385		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1386				   STp->device->request_queue->rq_timeout,
1387				   MAX_WRITE_RETRIES, 1);
1388		if (!SRpnt) {
1389			result = (STp->buffer)->syscall_result;
1390			goto out;
1391		}
1392
1393		if (STp->buffer->syscall_result == 0 ||
1394		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1395		     (cmdstatp->flags & SENSE_EOM) &&
1396		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1397		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1398		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1399			/* Write successful at EOM */
1400			st_release_request(SRpnt);
1401			SRpnt = NULL;
1402			if (STps->drv_file >= 0)
1403				STps->drv_file++;
1404			STps->drv_block = 0;
1405			if (STp->two_fm)
1406				cross_eof(STp, 0);
1407			STps->eof = ST_FM;
1408		}
1409		else { /* Write error */
1410			st_release_request(SRpnt);
1411			SRpnt = NULL;
1412			st_printk(KERN_ERR, STp,
1413				  "Error on write filemark.\n");
1414			if (result == 0)
1415				result = (-EIO);
1416		}
1417
1418		DEBC_printk(STp, "Buffer flushed, %d EOF(s) written\n", cmd[4]);
1419	} else if (!STp->rew_at_close) {
1420		STps = &(STp->ps[STp->partition]);
1421		if (!STm->sysv || STps->rw != ST_READING) {
1422			if (STp->can_bsr)
1423				result = flush_buffer(STp, 0);
1424			else if (STps->eof == ST_FM_HIT) {
1425				result = cross_eof(STp, 0);
1426				if (result) {
1427					if (STps->drv_file >= 0)
1428						STps->drv_file++;
1429					STps->drv_block = 0;
1430					STps->eof = ST_FM;
1431				} else
1432					STps->eof = ST_NOEOF;
1433			}
1434		} else if ((STps->eof == ST_NOEOF &&
1435			    !(result = cross_eof(STp, 1))) ||
1436			   STps->eof == ST_FM_HIT) {
1437			if (STps->drv_file >= 0)
1438				STps->drv_file++;
1439			STps->drv_block = 0;
1440			STps->eof = ST_FM;
1441		}
1442	}
1443
1444      out:
1445	if (STp->rew_at_close) {
1446		result2 = st_int_ioctl(STp, MTREW, 1);
1447		if (result == 0)
1448			result = result2;
1449	}
1450	return result;
1451}
1452
1453
1454/* Close the device and release it. BKL is not needed: this is the only thread
1455   accessing this tape. */
1456static int st_release(struct inode *inode, struct file *filp)
1457{
1458	int result = 0;
1459	struct scsi_tape *STp = filp->private_data;
1460
1461	if (STp->door_locked == ST_LOCKED_AUTO)
1462		do_door_lock(STp, 0);
1463
1464	normalize_buffer(STp->buffer);
1465	spin_lock(&st_use_lock);
1466	STp->in_use = 0;
1467	spin_unlock(&st_use_lock);
1468	scsi_autopm_put_device(STp->device);
1469	scsi_tape_put(STp);
1470
1471	return result;
1472}
1473
1474/* The checks common to both reading and writing */
1475static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1476{
1477	ssize_t retval = 0;
1478
1479	/*
1480	 * If we are in the middle of error recovery, don't let anyone
1481	 * else try and use this device.  Also, if error recovery fails, it
1482	 * may try and take the device offline, in which case all further
1483	 * access to the device is prohibited.
1484	 */
1485	if (!scsi_block_when_processing_errors(STp->device)) {
1486		retval = (-ENXIO);
1487		goto out;
1488	}
1489
1490	if (STp->ready != ST_READY) {
1491		if (STp->ready == ST_NO_TAPE)
1492			retval = (-ENOMEDIUM);
1493		else
1494			retval = (-EIO);
1495		goto out;
1496	}
1497
1498	if (! STp->modes[STp->current_mode].defined) {
1499		retval = (-ENXIO);
1500		goto out;
1501	}
1502
1503
1504	/*
1505	 * If there was a bus reset, block further access
1506	 * to this device.
1507	 */
1508	if (STp->pos_unknown) {
1509		retval = (-EIO);
1510		goto out;
1511	}
1512
1513	if (count == 0)
1514		goto out;
1515
1516	DEB(
1517	if (!STp->in_use) {
1518		st_printk(ST_DEB_MSG, STp,
1519			  "Incorrect device.\n");
1520		retval = (-EIO);
1521		goto out;
1522	} ) /* end DEB */
1523
1524	if (STp->can_partitions &&
1525	    (retval = switch_partition(STp)) < 0)
1526		goto out;
1527
1528	if (STp->block_size == 0 && STp->max_block > 0 &&
1529	    (count < STp->min_block || count > STp->max_block)) {
1530		retval = (-EINVAL);
1531		goto out;
1532	}
1533
1534	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1535	    !do_door_lock(STp, 1))
1536		STp->door_locked = ST_LOCKED_AUTO;
1537
1538 out:
1539	return retval;
1540}
1541
1542
1543static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1544			   size_t count, int is_read)
1545{
1546	int i, bufsize, retval = 0;
1547	struct st_buffer *STbp = STp->buffer;
1548
1549	if (is_read)
1550		i = STp->try_dio_now && try_rdio;
1551	else
1552		i = STp->try_dio_now && try_wdio;
1553
1554	if (i && ((unsigned long)buf & queue_dma_alignment(
1555					STp->device->request_queue)) == 0) {
1556		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1557				       count, (is_read ? READ : WRITE));
1558		if (i > 0) {
1559			STbp->do_dio = i;
1560			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1561		}
1562		else
1563			STbp->do_dio = 0;  /* fall back to buffering with any error */
1564		STbp->sg_segs = STbp->do_dio;
1565		DEB(
1566		     if (STbp->do_dio) {
1567			STp->nbr_dio++;
1568			STp->nbr_pages += STbp->do_dio;
1569		     }
1570		)
1571	} else
1572		STbp->do_dio = 0;
1573	DEB( STp->nbr_requests++; )
1574
1575	if (!STbp->do_dio) {
1576		if (STp->block_size)
1577			bufsize = STp->block_size > st_fixed_buffer_size ?
1578				STp->block_size : st_fixed_buffer_size;
1579		else {
1580			bufsize = count;
1581			/* Make sure that data from previous user is not leaked even if
1582			   HBA does not return correct residual */
1583			if (is_read && STp->sili && !STbp->cleared)
1584				clear_buffer(STbp);
1585		}
1586
1587		if (bufsize > STbp->buffer_size &&
1588		    !enlarge_buffer(STbp, bufsize, STp->restr_dma)) {
1589			st_printk(KERN_WARNING, STp,
1590				  "Can't allocate %d byte tape buffer.\n",
1591				  bufsize);
1592			retval = (-EOVERFLOW);
1593			goto out;
1594		}
1595		if (STp->block_size)
1596			STbp->buffer_blocks = bufsize / STp->block_size;
1597	}
1598
1599 out:
1600	return retval;
1601}
1602
1603
1604/* Can be called more than once after each setup_buffer() */
1605static void release_buffering(struct scsi_tape *STp, int is_read)
1606{
1607	struct st_buffer *STbp;
1608
1609	STbp = STp->buffer;
1610	if (STbp->do_dio) {
1611		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1612		STbp->do_dio = 0;
1613		STbp->sg_segs = 0;
1614	}
1615}
1616
1617
1618/* Write command */
1619static ssize_t
1620st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1621{
1622	ssize_t total;
1623	ssize_t i, do_count, blks, transfer;
1624	ssize_t retval;
1625	int undone, retry_eot = 0, scode;
1626	int async_write;
1627	unsigned char cmd[MAX_COMMAND_SIZE];
1628	const char __user *b_point;
1629	struct st_request *SRpnt = NULL;
1630	struct scsi_tape *STp = filp->private_data;
1631	struct st_modedef *STm;
1632	struct st_partstat *STps;
1633	struct st_buffer *STbp;
1634
1635	if (mutex_lock_interruptible(&STp->lock))
1636		return -ERESTARTSYS;
1637
1638	retval = rw_checks(STp, filp, count);
1639	if (retval || count == 0)
1640		goto out;
1641
1642	/* Write must be integral number of blocks */
1643	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1644		st_printk(KERN_WARNING, STp,
1645			  "Write not multiple of tape block size.\n");
1646		retval = (-EINVAL);
1647		goto out;
1648	}
1649
1650	STm = &(STp->modes[STp->current_mode]);
1651	STps = &(STp->ps[STp->partition]);
1652
1653	if (STp->write_prot) {
1654		retval = (-EACCES);
1655		goto out;
1656	}
1657
1658
1659	if (STps->rw == ST_READING) {
1660		retval = flush_buffer(STp, 0);
1661		if (retval)
1662			goto out;
1663		STps->rw = ST_WRITING;
1664	} else if (STps->rw != ST_WRITING &&
1665		   STps->drv_file == 0 && STps->drv_block == 0) {
1666		if ((retval = set_mode_densblk(STp, STm)) < 0)
1667			goto out;
1668		if (STm->default_compression != ST_DONT_TOUCH &&
1669		    !(STp->compression_changed)) {
1670			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1671				st_printk(KERN_WARNING, STp,
1672					  "Can't set default compression.\n");
1673				if (modes_defined) {
1674					retval = (-EINVAL);
1675					goto out;
1676				}
1677			}
1678		}
1679	}
1680
1681	STbp = STp->buffer;
1682	i = write_behind_check(STp);
1683	if (i) {
1684		if (i == -ENOSPC)
1685			STps->eof = ST_EOM_OK;
1686		else
1687			STps->eof = ST_EOM_ERROR;
1688	}
1689
1690	if (STps->eof == ST_EOM_OK) {
1691		STps->eof = ST_EOD_1;  /* allow next write */
1692		retval = (-ENOSPC);
1693		goto out;
1694	}
1695	else if (STps->eof == ST_EOM_ERROR) {
1696		retval = (-EIO);
1697		goto out;
1698	}
1699
1700	/* Check the buffer readability in cases where copy_user might catch
1701	   the problems after some tape movement. */
1702	if (STp->block_size != 0 &&
1703	    !STbp->do_dio &&
1704	    (copy_from_user(&i, buf, 1) != 0 ||
1705	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1706		retval = (-EFAULT);
1707		goto out;
1708	}
1709
1710	retval = setup_buffering(STp, buf, count, 0);
1711	if (retval)
1712		goto out;
1713
1714	total = count;
1715
1716	memset(cmd, 0, MAX_COMMAND_SIZE);
1717	cmd[0] = WRITE_6;
1718	cmd[1] = (STp->block_size != 0);
1719
1720	STps->rw = ST_WRITING;
1721
1722	b_point = buf;
1723	while (count > 0 && !retry_eot) {
1724
1725		if (STbp->do_dio) {
1726			do_count = count;
1727		}
1728		else {
1729			if (STp->block_size == 0)
1730				do_count = count;
1731			else {
1732				do_count = STbp->buffer_blocks * STp->block_size -
1733					STbp->buffer_bytes;
1734				if (do_count > count)
1735					do_count = count;
1736			}
1737
1738			i = append_to_buffer(b_point, STbp, do_count);
1739			if (i) {
1740				retval = i;
1741				goto out;
1742			}
1743		}
1744		count -= do_count;
1745		b_point += do_count;
1746
1747		async_write = STp->block_size == 0 && !STbp->do_dio &&
1748			STm->do_async_writes && STps->eof < ST_EOM_OK;
1749
1750		if (STp->block_size != 0 && STm->do_buffer_writes &&
1751		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1752		    STbp->buffer_bytes < STbp->buffer_size) {
1753			STp->dirty = 1;
1754			/* Don't write a buffer that is not full enough. */
1755			if (!async_write && count == 0)
1756				break;
1757		}
1758
1759	retry_write:
1760		if (STp->block_size == 0)
1761			blks = transfer = do_count;
1762		else {
1763			if (!STbp->do_dio)
1764				blks = STbp->buffer_bytes;
1765			else
1766				blks = do_count;
1767			blks /= STp->block_size;
1768			transfer = blks * STp->block_size;
1769		}
1770		cmd[2] = blks >> 16;
1771		cmd[3] = blks >> 8;
1772		cmd[4] = blks;
1773
1774		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1775				   STp->device->request_queue->rq_timeout,
1776				   MAX_WRITE_RETRIES, !async_write);
1777		if (!SRpnt) {
1778			retval = STbp->syscall_result;
1779			goto out;
1780		}
1781		if (async_write && !STbp->syscall_result) {
1782			STbp->writing = transfer;
1783			STp->dirty = !(STbp->writing ==
1784				       STbp->buffer_bytes);
1785			SRpnt = NULL;  /* Prevent releasing this request! */
1786			DEB( STp->write_pending = 1; )
1787			break;
1788		}
1789
1790		if (STbp->syscall_result != 0) {
1791			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1792
1793			DEBC_printk(STp, "Error on write:\n");
1794			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1795				scode = cmdstatp->sense_hdr.sense_key;
1796				if (cmdstatp->remainder_valid)
1797					undone = (int)cmdstatp->uremainder64;
1798				else if (STp->block_size == 0 &&
1799					 scode == VOLUME_OVERFLOW)
1800					undone = transfer;
1801				else
1802					undone = 0;
1803				if (STp->block_size != 0)
1804					undone *= STp->block_size;
1805				if (undone <= do_count) {
1806					/* Only data from this write is not written */
1807					count += undone;
1808					b_point -= undone;
1809					do_count -= undone;
1810					if (STp->block_size)
1811						blks = (transfer - undone) / STp->block_size;
1812					STps->eof = ST_EOM_OK;
1813					/* Continue in fixed block mode if all written
1814					   in this request but still something left to write
1815					   (retval left to zero)
1816					*/
1817					if (STp->block_size == 0 ||
1818					    undone > 0 || count == 0)
1819						retval = (-ENOSPC); /* EOM within current request */
1820					DEBC_printk(STp, "EOM with %d "
1821						    "bytes unwritten.\n",
1822						    (int)count);
1823				} else {
1824					/* EOT within data buffered earlier (possible only
1825					   in fixed block mode without direct i/o) */
1826					if (!retry_eot && !cmdstatp->deferred &&
1827					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1828						move_buffer_data(STp->buffer, transfer - undone);
1829						retry_eot = 1;
1830						if (STps->drv_block >= 0) {
1831							STps->drv_block += (transfer - undone) /
1832								STp->block_size;
1833						}
1834						STps->eof = ST_EOM_OK;
1835						DEBC_printk(STp, "Retry "
1836							    "write of %d "
1837							    "bytes at EOM.\n",
1838							    STp->buffer->buffer_bytes);
1839						goto retry_write;
1840					}
1841					else {
1842						/* Either error within data buffered by driver or
1843						   failed retry */
1844						count -= do_count;
1845						blks = do_count = 0;
1846						STps->eof = ST_EOM_ERROR;
1847						STps->drv_block = (-1); /* Too cautious? */
1848						retval = (-EIO);	/* EOM for old data */
1849						DEBC_printk(STp, "EOM with "
1850							    "lost data.\n");
1851					}
1852				}
1853			} else {
1854				count += do_count;
1855				STps->drv_block = (-1);		/* Too cautious? */
1856				retval = STbp->syscall_result;
1857			}
1858
1859		}
1860
1861		if (STps->drv_block >= 0) {
1862			if (STp->block_size == 0)
1863				STps->drv_block += (do_count > 0);
1864			else
1865				STps->drv_block += blks;
1866		}
1867
1868		STbp->buffer_bytes = 0;
1869		STp->dirty = 0;
1870
1871		if (retval || retry_eot) {
1872			if (count < total)
1873				retval = total - count;
1874			goto out;
1875		}
1876	}
1877
1878	if (STps->eof == ST_EOD_1)
1879		STps->eof = ST_EOM_OK;
1880	else if (STps->eof != ST_EOM_OK)
1881		STps->eof = ST_NOEOF;
1882	retval = total - count;
1883
1884 out:
1885	if (SRpnt != NULL)
1886		st_release_request(SRpnt);
1887	release_buffering(STp, 0);
1888	mutex_unlock(&STp->lock);
1889
1890	return retval;
1891}
1892
1893/* Read data from the tape. Returns zero in the normal case, one if the
1894   eof status has changed, and the negative error code in case of a
1895   fatal error. Otherwise updates the buffer and the eof state.
1896
1897   Does release user buffer mapping if it is set.
1898*/
1899static long read_tape(struct scsi_tape *STp, long count,
1900		      struct st_request ** aSRpnt)
1901{
1902	int transfer, blks, bytes;
1903	unsigned char cmd[MAX_COMMAND_SIZE];
1904	struct st_request *SRpnt;
1905	struct st_modedef *STm;
1906	struct st_partstat *STps;
1907	struct st_buffer *STbp;
1908	int retval = 0;
1909
1910	if (count == 0)
1911		return 0;
1912
1913	STm = &(STp->modes[STp->current_mode]);
1914	STps = &(STp->ps[STp->partition]);
1915	if (STps->eof == ST_FM_HIT)
1916		return 1;
1917	STbp = STp->buffer;
1918
1919	if (STp->block_size == 0)
1920		blks = bytes = count;
1921	else {
1922		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1923			blks = (STp->buffer)->buffer_blocks;
1924			bytes = blks * STp->block_size;
1925		} else {
1926			bytes = count;
1927			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1928				bytes = (STp->buffer)->buffer_size;
1929			blks = bytes / STp->block_size;
1930			bytes = blks * STp->block_size;
1931		}
1932	}
1933
1934	memset(cmd, 0, MAX_COMMAND_SIZE);
1935	cmd[0] = READ_6;
1936	cmd[1] = (STp->block_size != 0);
1937	if (!cmd[1] && STp->sili)
1938		cmd[1] |= 2;
1939	cmd[2] = blks >> 16;
1940	cmd[3] = blks >> 8;
1941	cmd[4] = blks;
1942
1943	SRpnt = *aSRpnt;
1944	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1945			   STp->device->request_queue->rq_timeout,
1946			   MAX_RETRIES, 1);
1947	release_buffering(STp, 1);
1948	*aSRpnt = SRpnt;
1949	if (!SRpnt)
1950		return STbp->syscall_result;
1951
1952	STbp->read_pointer = 0;
1953	STps->at_sm = 0;
1954
1955	/* Something to check */
1956	if (STbp->syscall_result) {
1957		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1958
1959		retval = 1;
1960		DEBC_printk(STp,
1961			    "Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1962			    SRpnt->sense[0], SRpnt->sense[1],
1963			    SRpnt->sense[2], SRpnt->sense[3],
1964			    SRpnt->sense[4], SRpnt->sense[5],
1965			    SRpnt->sense[6], SRpnt->sense[7]);
1966		if (cmdstatp->have_sense) {
1967
1968			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1969				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1970
1971			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1972				/* Compute the residual count */
1973				if (cmdstatp->remainder_valid)
1974					transfer = (int)cmdstatp->uremainder64;
1975				else
1976					transfer = 0;
1977				if (cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR) {
1978					if (STp->block_size == 0)
1979						transfer = bytes;
1980					/* Some drives set ILI with MEDIUM ERROR */
1981					cmdstatp->flags &= ~SENSE_ILI;
1982				}
1983
1984				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1985					if (STp->block_size == 0 &&
1986					    transfer < 0) {
1987						st_printk(KERN_NOTICE, STp,
1988							  "Failed to read %d "
1989							  "byte block with %d "
1990							  "byte transfer.\n",
1991							  bytes - transfer,
1992							  bytes);
1993						if (STps->drv_block >= 0)
1994							STps->drv_block += 1;
1995						STbp->buffer_bytes = 0;
1996						return (-ENOMEM);
1997					} else if (STp->block_size == 0) {
1998						STbp->buffer_bytes = bytes - transfer;
1999					} else {
2000						st_release_request(SRpnt);
2001						SRpnt = *aSRpnt = NULL;
2002						if (transfer == blks) {	/* We did not get anything, error */
2003							st_printk(KERN_NOTICE, STp,
2004								  "Incorrect "
2005								  "block size.\n");
2006							if (STps->drv_block >= 0)
2007								STps->drv_block += blks - transfer + 1;
2008							st_int_ioctl(STp, MTBSR, 1);
2009							return (-EIO);
2010						}
2011						/* We have some data, deliver it */
2012						STbp->buffer_bytes = (blks - transfer) *
2013						    STp->block_size;
2014						DEBC_printk(STp, "ILI but "
2015							    "enough data "
2016							    "received %ld "
2017							    "%d.\n", count,
2018							    STbp->buffer_bytes);
2019						if (STps->drv_block >= 0)
2020							STps->drv_block += 1;
2021						if (st_int_ioctl(STp, MTBSR, 1))
2022							return (-EIO);
2023					}
2024				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
2025					if (STps->eof != ST_FM_HIT)
2026						STps->eof = ST_FM_HIT;
2027					else
2028						STps->eof = ST_EOD_2;
2029					if (STp->block_size == 0)
2030						STbp->buffer_bytes = 0;
2031					else
2032						STbp->buffer_bytes =
2033						    bytes - transfer * STp->block_size;
2034					DEBC_printk(STp, "EOF detected (%d "
2035						    "bytes read).\n",
2036						    STbp->buffer_bytes);
2037				} else if (cmdstatp->flags & SENSE_EOM) {
2038					if (STps->eof == ST_FM)
2039						STps->eof = ST_EOD_1;
2040					else
2041						STps->eof = ST_EOM_OK;
2042					if (STp->block_size == 0)
2043						STbp->buffer_bytes = bytes - transfer;
2044					else
2045						STbp->buffer_bytes =
2046						    bytes - transfer * STp->block_size;
2047
2048					DEBC_printk(STp, "EOM detected (%d "
2049						    "bytes read).\n",
2050						    STbp->buffer_bytes);
2051				}
2052			}
2053			/* end of EOF, EOM, ILI test */
2054			else {	/* nonzero sense key */
2055				DEBC_printk(STp, "Tape error while reading.\n");
2056				STps->drv_block = (-1);
2057				if (STps->eof == ST_FM &&
2058				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
2059					DEBC_printk(STp, "Zero returned for "
2060						    "first BLANK CHECK "
2061						    "after EOF.\n");
2062					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
2063				} else	/* Some other extended sense code */
2064					retval = (-EIO);
2065			}
2066
2067			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
2068				STbp->buffer_bytes = 0;
2069		}
2070		/* End of extended sense test */
2071		else {		/* Non-extended sense */
2072			retval = STbp->syscall_result;
2073		}
2074
2075	}
2076	/* End of error handling */
2077	else {			/* Read successful */
2078		STbp->buffer_bytes = bytes;
2079		if (STp->sili) /* In fixed block mode residual is always zero here */
2080			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
2081	}
2082
2083	if (STps->drv_block >= 0) {
2084		if (STp->block_size == 0)
2085			STps->drv_block++;
2086		else
2087			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2088	}
2089	return retval;
2090}
2091
2092
2093/* Read command */
2094static ssize_t
2095st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2096{
2097	ssize_t total;
2098	ssize_t retval = 0;
2099	ssize_t i, transfer;
2100	int special, do_dio = 0;
2101	struct st_request *SRpnt = NULL;
2102	struct scsi_tape *STp = filp->private_data;
2103	struct st_modedef *STm;
2104	struct st_partstat *STps;
2105	struct st_buffer *STbp = STp->buffer;
2106
2107	if (mutex_lock_interruptible(&STp->lock))
2108		return -ERESTARTSYS;
2109
2110	retval = rw_checks(STp, filp, count);
2111	if (retval || count == 0)
2112		goto out;
2113
2114	STm = &(STp->modes[STp->current_mode]);
2115	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2116		if (!STm->do_read_ahead) {
2117			retval = (-EINVAL);	/* Read must be integral number of blocks */
2118			goto out;
2119		}
2120		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2121	}
2122
2123	STps = &(STp->ps[STp->partition]);
2124	if (STps->rw == ST_WRITING) {
2125		retval = flush_buffer(STp, 0);
2126		if (retval)
2127			goto out;
2128		STps->rw = ST_READING;
2129	}
2130	DEB(
2131	if (debugging && STps->eof != ST_NOEOF)
2132		st_printk(ST_DEB_MSG, STp,
2133			  "EOF/EOM flag up (%d). Bytes %d\n",
2134			  STps->eof, STbp->buffer_bytes);
2135	) /* end DEB */
2136
2137	retval = setup_buffering(STp, buf, count, 1);
2138	if (retval)
2139		goto out;
2140	do_dio = STbp->do_dio;
2141
2142	if (STbp->buffer_bytes == 0 &&
2143	    STps->eof >= ST_EOD_1) {
2144		if (STps->eof < ST_EOD) {
2145			STps->eof += 1;
2146			retval = 0;
2147			goto out;
2148		}
2149		retval = (-EIO);	/* EOM or Blank Check */
2150		goto out;
2151	}
2152
2153	if (do_dio) {
2154		/* Check the buffer writability before any tape movement. Don't alter
2155		   buffer data. */
2156		if (copy_from_user(&i, buf, 1) != 0 ||
2157		    copy_to_user(buf, &i, 1) != 0 ||
2158		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2159		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2160			retval = (-EFAULT);
2161			goto out;
2162		}
2163	}
2164
2165	STps->rw = ST_READING;
2166
2167
2168	/* Loop until enough data in buffer or a special condition found */
2169	for (total = 0, special = 0; total < count && !special;) {
2170
2171		/* Get new data if the buffer is empty */
2172		if (STbp->buffer_bytes == 0) {
2173			special = read_tape(STp, count - total, &SRpnt);
2174			if (special < 0) {	/* No need to continue read */
2175				retval = special;
2176				goto out;
2177			}
2178		}
2179
2180		/* Move the data from driver buffer to user buffer */
2181		if (STbp->buffer_bytes > 0) {
2182			DEB(
2183			if (debugging && STps->eof != ST_NOEOF)
2184				st_printk(ST_DEB_MSG, STp,
2185					  "EOF up (%d). Left %d, needed %d.\n",
2186					  STps->eof, STbp->buffer_bytes,
2187					  (int)(count - total));
2188			) /* end DEB */
2189			transfer = STbp->buffer_bytes < count - total ?
2190			    STbp->buffer_bytes : count - total;
2191			if (!do_dio) {
2192				i = from_buffer(STbp, buf, transfer);
2193				if (i) {
2194					retval = i;
2195					goto out;
2196				}
2197			}
2198			buf += transfer;
2199			total += transfer;
2200		}
2201
2202		if (STp->block_size == 0)
2203			break;	/* Read only one variable length block */
2204
2205	}			/* for (total = 0, special = 0;
2206                                   total < count && !special; ) */
2207
2208	/* Change the eof state if no data from tape or buffer */
2209	if (total == 0) {
2210		if (STps->eof == ST_FM_HIT) {
2211			STps->eof = ST_FM;
2212			STps->drv_block = 0;
2213			if (STps->drv_file >= 0)
2214				STps->drv_file++;
2215		} else if (STps->eof == ST_EOD_1) {
2216			STps->eof = ST_EOD_2;
2217			STps->drv_block = 0;
2218			if (STps->drv_file >= 0)
2219				STps->drv_file++;
2220		} else if (STps->eof == ST_EOD_2)
2221			STps->eof = ST_EOD;
2222	} else if (STps->eof == ST_FM)
2223		STps->eof = ST_NOEOF;
2224	retval = total;
2225
2226 out:
2227	if (SRpnt != NULL) {
2228		st_release_request(SRpnt);
2229		SRpnt = NULL;
2230	}
2231	if (do_dio) {
2232		release_buffering(STp, 1);
2233		STbp->buffer_bytes = 0;
2234	}
2235	mutex_unlock(&STp->lock);
2236
2237	return retval;
2238}
2239
2240
2241
2242DEB(
2243/* Set the driver options */
2244static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm)
2245{
2246	if (debugging) {
2247		st_printk(KERN_INFO, STp,
2248			  "Mode %d options: buffer writes: %d, "
2249			  "async writes: %d, read ahead: %d\n",
2250			  STp->current_mode, STm->do_buffer_writes,
2251			  STm->do_async_writes, STm->do_read_ahead);
2252		st_printk(KERN_INFO, STp,
2253			  "    can bsr: %d, two FMs: %d, "
2254			  "fast mteom: %d, auto lock: %d,\n",
2255			  STp->can_bsr, STp->two_fm, STp->fast_mteom,
2256			  STp->do_auto_lock);
2257		st_printk(KERN_INFO, STp,
2258			  "    defs for wr: %d, no block limits: %d, "
2259			  "partitions: %d, s2 log: %d\n",
2260			  STm->defaults_for_writes, STp->omit_blklims,
2261			  STp->can_partitions, STp->scsi2_logical);
2262		st_printk(KERN_INFO, STp,
2263			  "    sysv: %d nowait: %d sili: %d "
2264			  "nowait_filemark: %d\n",
2265			  STm->sysv, STp->immediate, STp->sili,
2266			  STp->immediate_filemark);
2267		st_printk(KERN_INFO, STp, "    debugging: %d\n", debugging);
2268	}
2269}
2270	)
2271
2272
2273static int st_set_options(struct scsi_tape *STp, long options)
2274{
2275	int value;
2276	long code;
2277	struct st_modedef *STm;
2278	struct cdev *cd0, *cd1;
2279	struct device *d0, *d1;
2280
2281	STm = &(STp->modes[STp->current_mode]);
2282	if (!STm->defined) {
2283		cd0 = STm->cdevs[0];
2284		cd1 = STm->cdevs[1];
2285		d0  = STm->devs[0];
2286		d1  = STm->devs[1];
2287		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2288		STm->cdevs[0] = cd0;
2289		STm->cdevs[1] = cd1;
2290		STm->devs[0]  = d0;
2291		STm->devs[1]  = d1;
2292		modes_defined = 1;
2293		DEBC_printk(STp, "Initialized mode %d definition from mode 0\n",
2294			    STp->current_mode);
2295	}
2296
2297	code = options & MT_ST_OPTIONS;
2298	if (code == MT_ST_BOOLEANS) {
2299		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2300		STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2301		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2302		STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2303		STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2304		STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2305		STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2306		STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2307		STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2308		if ((STp->device)->scsi_level >= SCSI_2)
2309			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2310		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2311		STp->immediate = (options & MT_ST_NOWAIT) != 0;
2312		STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
2313		STm->sysv = (options & MT_ST_SYSV) != 0;
2314		STp->sili = (options & MT_ST_SILI) != 0;
2315		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2316		     st_log_options(STp, STm); )
2317	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2318		value = (code == MT_ST_SETBOOLEANS);
2319		if ((options & MT_ST_BUFFER_WRITES) != 0)
2320			STm->do_buffer_writes = value;
2321		if ((options & MT_ST_ASYNC_WRITES) != 0)
2322			STm->do_async_writes = value;
2323		if ((options & MT_ST_DEF_WRITES) != 0)
2324			STm->defaults_for_writes = value;
2325		if ((options & MT_ST_READ_AHEAD) != 0)
2326			STm->do_read_ahead = value;
2327		if ((options & MT_ST_TWO_FM) != 0)
2328			STp->two_fm = value;
2329		if ((options & MT_ST_FAST_MTEOM) != 0)
2330			STp->fast_mteom = value;
2331		if ((options & MT_ST_AUTO_LOCK) != 0)
2332			STp->do_auto_lock = value;
2333		if ((options & MT_ST_CAN_BSR) != 0)
2334			STp->can_bsr = value;
2335		if ((options & MT_ST_NO_BLKLIMS) != 0)
2336			STp->omit_blklims = value;
2337		if ((STp->device)->scsi_level >= SCSI_2 &&
2338		    (options & MT_ST_CAN_PARTITIONS) != 0)
2339			STp->can_partitions = value;
2340		if ((options & MT_ST_SCSI2LOGICAL) != 0)
2341			STp->scsi2_logical = value;
2342		if ((options & MT_ST_NOWAIT) != 0)
2343			STp->immediate = value;
2344		if ((options & MT_ST_NOWAIT_EOF) != 0)
2345			STp->immediate_filemark = value;
2346		if ((options & MT_ST_SYSV) != 0)
2347			STm->sysv = value;
2348		if ((options & MT_ST_SILI) != 0)
2349			STp->sili = value;
2350		DEB(
2351		if ((options & MT_ST_DEBUGGING) != 0)
2352			debugging = value;
2353			st_log_options(STp, STm); )
2354	} else if (code == MT_ST_WRITE_THRESHOLD) {
2355		/* Retained for compatibility */
2356	} else if (code == MT_ST_DEF_BLKSIZE) {
2357		value = (options & ~MT_ST_OPTIONS);
2358		if (value == ~MT_ST_OPTIONS) {
2359			STm->default_blksize = (-1);
2360			DEBC_printk(STp, "Default block size disabled.\n");
2361		} else {
2362			STm->default_blksize = value;
2363			DEBC_printk(STp,"Default block size set to "
2364				    "%d bytes.\n", STm->default_blksize);
2365			if (STp->ready == ST_READY) {
2366				STp->blksize_changed = 0;
2367				set_mode_densblk(STp, STm);
2368			}
2369		}
2370	} else if (code == MT_ST_TIMEOUTS) {
2371		value = (options & ~MT_ST_OPTIONS);
2372		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2373			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2374			DEBC_printk(STp, "Long timeout set to %d seconds.\n",
2375				    (value & ~MT_ST_SET_LONG_TIMEOUT));
2376		} else {
2377			blk_queue_rq_timeout(STp->device->request_queue,
2378					     value * HZ);
2379			DEBC_printk(STp, "Normal timeout set to %d seconds.\n",
2380				    value);
2381		}
2382	} else if (code == MT_ST_SET_CLN) {
2383		value = (options & ~MT_ST_OPTIONS) & 0xff;
2384		if (value != 0 &&
2385			(value < EXTENDED_SENSE_START ||
2386				value >= SCSI_SENSE_BUFFERSIZE))
2387			return (-EINVAL);
2388		STp->cln_mode = value;
2389		STp->cln_sense_mask = (options >> 8) & 0xff;
2390		STp->cln_sense_value = (options >> 16) & 0xff;
2391		st_printk(KERN_INFO, STp,
2392			  "Cleaning request mode %d, mask %02x, value %02x\n",
2393			  value, STp->cln_sense_mask, STp->cln_sense_value);
2394	} else if (code == MT_ST_DEF_OPTIONS) {
2395		code = (options & ~MT_ST_CLEAR_DEFAULT);
2396		value = (options & MT_ST_CLEAR_DEFAULT);
2397		if (code == MT_ST_DEF_DENSITY) {
2398			if (value == MT_ST_CLEAR_DEFAULT) {
2399				STm->default_density = (-1);
2400				DEBC_printk(STp,
2401					    "Density default disabled.\n");
2402			} else {
2403				STm->default_density = value & 0xff;
2404				DEBC_printk(STp, "Density default set to %x\n",
2405					    STm->default_density);
2406				if (STp->ready == ST_READY) {
2407					STp->density_changed = 0;
2408					set_mode_densblk(STp, STm);
2409				}
2410			}
2411		} else if (code == MT_ST_DEF_DRVBUFFER) {
2412			if (value == MT_ST_CLEAR_DEFAULT) {
2413				STp->default_drvbuffer = 0xff;
2414				DEBC_printk(STp,
2415					    "Drive buffer default disabled.\n");
2416			} else {
2417				STp->default_drvbuffer = value & 7;
2418				DEBC_printk(STp,
2419					    "Drive buffer default set to %x\n",
2420					    STp->default_drvbuffer);
2421				if (STp->ready == ST_READY)
2422					st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2423			}
2424		} else if (code == MT_ST_DEF_COMPRESSION) {
2425			if (value == MT_ST_CLEAR_DEFAULT) {
2426				STm->default_compression = ST_DONT_TOUCH;
2427				DEBC_printk(STp,
2428					    "Compression default disabled.\n");
2429			} else {
2430				if ((value & 0xff00) != 0) {
2431					STp->c_algo = (value & 0xff00) >> 8;
2432					DEBC_printk(STp, "Compression "
2433						    "algorithm set to 0x%x.\n",
2434						    STp->c_algo);
2435				}
2436				if ((value & 0xff) != 0xff) {
2437					STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2438					DEBC_printk(STp, "Compression default "
2439						    "set to %x\n",
2440						    (value & 1));
2441					if (STp->ready == ST_READY) {
2442						STp->compression_changed = 0;
2443						st_compression(STp, (STm->default_compression == ST_YES));
2444					}
2445				}
2446			}
2447		}
2448	} else
2449		return (-EIO);
2450
2451	return 0;
2452}
2453
2454#define MODE_HEADER_LENGTH  4
2455
2456/* Mode header and page byte offsets */
2457#define MH_OFF_DATA_LENGTH     0
2458#define MH_OFF_MEDIUM_TYPE     1
2459#define MH_OFF_DEV_SPECIFIC    2
2460#define MH_OFF_BDESCS_LENGTH   3
2461#define MP_OFF_PAGE_NBR        0
2462#define MP_OFF_PAGE_LENGTH     1
2463
2464/* Mode header and page bit masks */
2465#define MH_BIT_WP              0x80
2466#define MP_MSK_PAGE_NBR        0x3f
2467
2468/* Don't return block descriptors */
2469#define MODE_SENSE_OMIT_BDESCS 0x08
2470
2471#define MODE_SELECT_PAGE_FORMAT 0x10
2472
2473/* Read a mode page into the tape buffer. The block descriptors are included
2474   if incl_block_descs is true. The page control is ored to the page number
2475   parameter, if necessary. */
2476static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2477{
2478	unsigned char cmd[MAX_COMMAND_SIZE];
2479	struct st_request *SRpnt;
2480
2481	memset(cmd, 0, MAX_COMMAND_SIZE);
2482	cmd[0] = MODE_SENSE;
2483	if (omit_block_descs)
2484		cmd[1] = MODE_SENSE_OMIT_BDESCS;
2485	cmd[2] = page;
2486	cmd[4] = 255;
2487
2488	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2489			   STp->device->request_queue->rq_timeout, 0, 1);
2490	if (SRpnt == NULL)
2491		return (STp->buffer)->syscall_result;
2492
2493	st_release_request(SRpnt);
2494
2495	return STp->buffer->syscall_result;
2496}
2497
2498
2499/* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2500   in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2501static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2502{
2503	int pgo;
2504	unsigned char cmd[MAX_COMMAND_SIZE];
2505	struct st_request *SRpnt;
2506	int timeout;
2507
2508	memset(cmd, 0, MAX_COMMAND_SIZE);
2509	cmd[0] = MODE_SELECT;
2510	cmd[1] = MODE_SELECT_PAGE_FORMAT;
2511	pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2512	cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2513
2514	/* Clear reserved fields */
2515	(STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2516	(STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2517	(STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2518	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2519
2520	timeout = slow ?
2521		STp->long_timeout : STp->device->request_queue->rq_timeout;
2522	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2523			   timeout, 0, 1);
2524	if (SRpnt == NULL)
2525		return (STp->buffer)->syscall_result;
2526
2527	st_release_request(SRpnt);
2528
2529	return STp->buffer->syscall_result;
2530}
2531
2532
2533#define COMPRESSION_PAGE        0x0f
2534#define COMPRESSION_PAGE_LENGTH 16
2535
2536#define CP_OFF_DCE_DCC          2
2537#define CP_OFF_C_ALGO           7
2538
2539#define DCE_MASK  0x80
2540#define DCC_MASK  0x40
2541#define RED_MASK  0x60
2542
2543
2544/* Control the compression with mode page 15. Algorithm not changed if zero.
2545
2546   The block descriptors are read and written because Sony SDT-7000 does not
2547   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2548   Including block descriptors should not cause any harm to other drives. */
2549
2550static int st_compression(struct scsi_tape * STp, int state)
2551{
2552	int retval;
2553	int mpoffs;  /* Offset to mode page start */
2554	unsigned char *b_data = (STp->buffer)->b_data;
2555
2556	if (STp->ready != ST_READY)
2557		return (-EIO);
2558
2559	/* Read the current page contents */
2560	retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2561	if (retval) {
2562		DEBC_printk(STp, "Compression mode page not supported.\n");
2563		return (-EIO);
2564	}
2565
2566	mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2567	DEBC_printk(STp, "Compression state is %d.\n",
2568		    (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0));
2569
2570	/* Check if compression can be changed */
2571	if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2572		DEBC_printk(STp, "Compression not supported.\n");
2573		return (-EIO);
2574	}
2575
2576	/* Do the change */
2577	if (state) {
2578		b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2579		if (STp->c_algo != 0)
2580			b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2581	}
2582	else {
2583		b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2584		if (STp->c_algo != 0)
2585			b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2586	}
2587
2588	retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2589	if (retval) {
2590		DEBC_printk(STp, "Compression change failed.\n");
2591		return (-EIO);
2592	}
2593	DEBC_printk(STp, "Compression state changed to %d.\n", state);
2594
2595	STp->compression_changed = 1;
2596	return 0;
2597}
2598
2599
2600/* Process the load and unload commands (does unload if the load code is zero) */
2601static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2602{
2603	int retval = (-EIO), timeout;
2604	unsigned char cmd[MAX_COMMAND_SIZE];
2605	struct st_partstat *STps;
2606	struct st_request *SRpnt;
2607
2608	if (STp->ready != ST_READY && !load_code) {
2609		if (STp->ready == ST_NO_TAPE)
2610			return (-ENOMEDIUM);
2611		else
2612			return (-EIO);
2613	}
2614
2615	memset(cmd, 0, MAX_COMMAND_SIZE);
2616	cmd[0] = START_STOP;
2617	if (load_code)
2618		cmd[4] |= 1;
2619	/*
2620	 * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2621	 */
2622	if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2623	    && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2624		DEBC_printk(STp, " Enhanced %sload slot %2d.\n",
2625			    (cmd[4]) ? "" : "un",
2626			    load_code - MT_ST_HPLOADER_OFFSET);
2627		cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2628	}
2629	if (STp->immediate) {
2630		cmd[1] = 1;	/* Don't wait for completion */
2631		timeout = STp->device->request_queue->rq_timeout;
2632	}
2633	else
2634		timeout = STp->long_timeout;
2635
2636	DEBC(
2637		if (!load_code)
2638			st_printk(ST_DEB_MSG, STp, "Unloading tape.\n");
2639		else
2640			st_printk(ST_DEB_MSG, STp, "Loading tape.\n");
2641		);
2642
2643	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2644			   timeout, MAX_RETRIES, 1);
2645	if (!SRpnt)
2646		return (STp->buffer)->syscall_result;
2647
2648	retval = (STp->buffer)->syscall_result;
2649	st_release_request(SRpnt);
2650
2651	if (!retval) {	/* SCSI command successful */
2652
2653		if (!load_code) {
2654			STp->rew_at_close = 0;
2655			STp->ready = ST_NO_TAPE;
2656		}
2657		else {
2658			STp->rew_at_close = STp->autorew_dev;
2659			retval = check_tape(STp, filp);
2660			if (retval > 0)
2661				retval = 0;
2662		}
2663	}
2664	else {
2665		STps = &(STp->ps[STp->partition]);
2666		STps->drv_file = STps->drv_block = (-1);
2667	}
2668
2669	return retval;
2670}
2671
2672#if DEBUG
2673#define ST_DEB_FORWARD  0
2674#define ST_DEB_BACKWARD 1
2675static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd)
2676{
2677	s32 sc;
2678
2679	if (!debugging)
2680		return;
2681
2682	sc = cmd[2] & 0x80 ? 0xff000000 : 0;
2683	sc |= (cmd[2] << 16) | (cmd[3] << 8) | cmd[4];
2684	if (direction)
2685		sc = -sc;
2686	st_printk(ST_DEB_MSG, STp, "Spacing tape %s over %d %s.\n",
2687		  direction ? "backward" : "forward", sc, units);
2688}
2689#else
2690#define ST_DEB_FORWARD  0
2691#define ST_DEB_BACKWARD 1
2692static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd) {}
2693#endif
2694
2695
2696/* Internal ioctl function */
2697static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2698{
2699	int timeout;
2700	long ltmp;
2701	int ioctl_result;
2702	int chg_eof = 1;
2703	unsigned char cmd[MAX_COMMAND_SIZE];
2704	struct st_request *SRpnt;
2705	struct st_partstat *STps;
2706	int fileno, blkno, at_sm, undone;
2707	int datalen = 0, direction = DMA_NONE;
2708
2709	WARN_ON(STp->buffer->do_dio != 0);
2710	if (STp->ready != ST_READY) {
2711		if (STp->ready == ST_NO_TAPE)
2712			return (-ENOMEDIUM);
2713		else
2714			return (-EIO);
2715	}
2716	timeout = STp->long_timeout;
2717	STps = &(STp->ps[STp->partition]);
2718	fileno = STps->drv_file;
2719	blkno = STps->drv_block;
2720	at_sm = STps->at_sm;
2721
2722	memset(cmd, 0, MAX_COMMAND_SIZE);
2723	switch (cmd_in) {
2724	case MTFSFM:
2725		chg_eof = 0;	/* Changed from the FSF after this */
2726		/* fall through */
2727	case MTFSF:
2728		cmd[0] = SPACE;
2729		cmd[1] = 0x01;	/* Space FileMarks */
2730		cmd[2] = (arg >> 16);
2731		cmd[3] = (arg >> 8);
2732		cmd[4] = arg;
2733		deb_space_print(STp, ST_DEB_FORWARD, "filemarks", cmd);
2734		if (fileno >= 0)
2735			fileno += arg;
2736		blkno = 0;
2737		at_sm &= (arg == 0);
2738		break;
2739	case MTBSFM:
2740		chg_eof = 0;	/* Changed from the FSF after this */
2741		/* fall through */
2742	case MTBSF:
2743		cmd[0] = SPACE;
2744		cmd[1] = 0x01;	/* Space FileMarks */
2745		ltmp = (-arg);
2746		cmd[2] = (ltmp >> 16);
2747		cmd[3] = (ltmp >> 8);
2748		cmd[4] = ltmp;
2749		deb_space_print(STp, ST_DEB_BACKWARD, "filemarks", cmd);
2750		if (fileno >= 0)
2751			fileno -= arg;
2752		blkno = (-1);	/* We can't know the block number */
2753		at_sm &= (arg == 0);
2754		break;
2755	case MTFSR:
2756		cmd[0] = SPACE;
2757		cmd[1] = 0x00;	/* Space Blocks */
2758		cmd[2] = (arg >> 16);
2759		cmd[3] = (arg >> 8);
2760		cmd[4] = arg;
2761		deb_space_print(STp, ST_DEB_FORWARD, "blocks", cmd);
2762		if (blkno >= 0)
2763			blkno += arg;
2764		at_sm &= (arg == 0);
2765		break;
2766	case MTBSR:
2767		cmd[0] = SPACE;
2768		cmd[1] = 0x00;	/* Space Blocks */
2769		ltmp = (-arg);
2770		cmd[2] = (ltmp >> 16);
2771		cmd[3] = (ltmp >> 8);
2772		cmd[4] = ltmp;
2773		deb_space_print(STp, ST_DEB_BACKWARD, "blocks", cmd);
2774		if (blkno >= 0)
2775			blkno -= arg;
2776		at_sm &= (arg == 0);
2777		break;
2778	case MTFSS:
2779		cmd[0] = SPACE;
2780		cmd[1] = 0x04;	/* Space Setmarks */
2781		cmd[2] = (arg >> 16);
2782		cmd[3] = (arg >> 8);
2783		cmd[4] = arg;
2784		deb_space_print(STp, ST_DEB_FORWARD, "setmarks", cmd);
2785		if (arg != 0) {
2786			blkno = fileno = (-1);
2787			at_sm = 1;
2788		}
2789		break;
2790	case MTBSS:
2791		cmd[0] = SPACE;
2792		cmd[1] = 0x04;	/* Space Setmarks */
2793		ltmp = (-arg);
2794		cmd[2] = (ltmp >> 16);
2795		cmd[3] = (ltmp >> 8);
2796		cmd[4] = ltmp;
2797		deb_space_print(STp, ST_DEB_BACKWARD, "setmarks", cmd);
2798		if (arg != 0) {
2799			blkno = fileno = (-1);
2800			at_sm = 1;
2801		}
2802		break;
2803	case MTWEOF:
2804	case MTWEOFI:
2805	case MTWSM:
2806		if (STp->write_prot)
2807			return (-EACCES);
2808		cmd[0] = WRITE_FILEMARKS;
2809		if (cmd_in == MTWSM)
2810			cmd[1] = 2;
2811		if (cmd_in == MTWEOFI ||
2812		    (cmd_in == MTWEOF && STp->immediate_filemark))
2813			cmd[1] |= 1;
2814		cmd[2] = (arg >> 16);
2815		cmd[3] = (arg >> 8);
2816		cmd[4] = arg;
2817		timeout = STp->device->request_queue->rq_timeout;
2818		DEBC(
2819			if (cmd_in != MTWSM)
2820				st_printk(ST_DEB_MSG, STp,
2821					  "Writing %d filemarks.\n",
2822					  cmd[2] * 65536 +
2823					  cmd[3] * 256 +
2824					  cmd[4]);
2825			else
2826				st_printk(ST_DEB_MSG, STp,
2827					  "Writing %d setmarks.\n",
2828					  cmd[2] * 65536 +
2829					  cmd[3] * 256 +
2830					  cmd[4]);
2831		)
2832		if (fileno >= 0)
2833			fileno += arg;
2834		blkno = 0;
2835		at_sm = (cmd_in == MTWSM);
2836		break;
2837	case MTREW:
2838		cmd[0] = REZERO_UNIT;
2839		if (STp->immediate) {
2840			cmd[1] = 1;	/* Don't wait for completion */
2841			timeout = STp->device->request_queue->rq_timeout;
2842		}
2843		DEBC_printk(STp, "Rewinding tape.\n");
2844		fileno = blkno = at_sm = 0;
2845		break;
2846	case MTNOP:
2847		DEBC_printk(STp, "No op on tape.\n");
2848		return 0;	/* Should do something ? */
2849		break;
2850	case MTRETEN:
2851		cmd[0] = START_STOP;
2852		if (STp->immediate) {
2853			cmd[1] = 1;	/* Don't wait for completion */
2854			timeout = STp->device->request_queue->rq_timeout;
2855		}
2856		cmd[4] = 3;
2857		DEBC_printk(STp, "Retensioning tape.\n");
2858		fileno = blkno = at_sm = 0;
2859		break;
2860	case MTEOM:
2861		if (!STp->fast_mteom) {
2862			/* space to the end of tape */
2863			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2864			fileno = STps->drv_file;
2865			if (STps->eof >= ST_EOD_1)
2866				return 0;
2867			/* The next lines would hide the number of spaced FileMarks
2868			   That's why I inserted the previous lines. I had no luck
2869			   with detecting EOM with FSF, so we go now to EOM.
2870			   Joerg Weule */
2871		} else
2872			fileno = (-1);
2873		cmd[0] = SPACE;
2874		cmd[1] = 3;
2875		DEBC_printk(STp, "Spacing to end of recorded medium.\n");
2876		blkno = -1;
2877		at_sm = 0;
2878		break;
2879	case MTERASE:
2880		if (STp->write_prot)
2881			return (-EACCES);
2882		cmd[0] = ERASE;
2883		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
2884		if (STp->immediate) {
2885			cmd[1] |= 2;	/* Don't wait for completion */
2886			timeout = STp->device->request_queue->rq_timeout;
2887		}
2888		else
2889			timeout = STp->long_timeout * 8;
2890
2891		DEBC_printk(STp, "Erasing tape.\n");
2892		fileno = blkno = at_sm = 0;
2893		break;
2894	case MTSETBLK:		/* Set block length */
2895	case MTSETDENSITY:	/* Set tape density */
2896	case MTSETDRVBUFFER:	/* Set drive buffering */
2897	case SET_DENS_AND_BLK:	/* Set density and block size */
2898		chg_eof = 0;
2899		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2900			return (-EIO);	/* Not allowed if data in buffer */
2901		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2902		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2903		    STp->max_block > 0 &&
2904		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2905		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2906			st_printk(KERN_WARNING, STp, "Illegal block size.\n");
2907			return (-EINVAL);
2908		}
2909		cmd[0] = MODE_SELECT;
2910		if ((STp->use_pf & USE_PF))
2911			cmd[1] = MODE_SELECT_PAGE_FORMAT;
2912		cmd[4] = datalen = 12;
2913		direction = DMA_TO_DEVICE;
2914
2915		memset((STp->buffer)->b_data, 0, 12);
2916		if (cmd_in == MTSETDRVBUFFER)
2917			(STp->buffer)->b_data[2] = (arg & 7) << 4;
2918		else
2919			(STp->buffer)->b_data[2] =
2920			    STp->drv_buffer << 4;
2921		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
2922		if (cmd_in == MTSETDENSITY) {
2923			(STp->buffer)->b_data[4] = arg;
2924			STp->density_changed = 1;	/* At least we tried ;-) */
2925		} else if (cmd_in == SET_DENS_AND_BLK)
2926			(STp->buffer)->b_data[4] = arg >> 24;
2927		else
2928			(STp->buffer)->b_data[4] = STp->density;
2929		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2930			ltmp = arg & MT_ST_BLKSIZE_MASK;
2931			if (cmd_in == MTSETBLK)
2932				STp->blksize_changed = 1; /* At least we tried ;-) */
2933		} else
2934			ltmp = STp->block_size;
2935		(STp->buffer)->b_data[9] = (ltmp >> 16);
2936		(STp->buffer)->b_data[10] = (ltmp >> 8);
2937		(STp->buffer)->b_data[11] = ltmp;
2938		timeout = STp->device->request_queue->rq_timeout;
2939		DEBC(
2940			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2941				st_printk(ST_DEB_MSG, STp,
2942					  "Setting block size to %d bytes.\n",
2943					  (STp->buffer)->b_data[9] * 65536 +
2944					  (STp->buffer)->b_data[10] * 256 +
2945					  (STp->buffer)->b_data[11]);
2946			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2947				st_printk(ST_DEB_MSG, STp,
2948					  "Setting density code to %x.\n",
2949					  (STp->buffer)->b_data[4]);
2950			if (cmd_in == MTSETDRVBUFFER)
2951				st_printk(ST_DEB_MSG, STp,
2952					  "Setting drive buffer code to %d.\n",
2953					  ((STp->buffer)->b_data[2] >> 4) & 7);
2954		)
2955		break;
2956	default:
2957		return (-ENOSYS);
2958	}
2959
2960	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2961			   timeout, MAX_RETRIES, 1);
2962	if (!SRpnt)
2963		return (STp->buffer)->syscall_result;
2964
2965	ioctl_result = (STp->buffer)->syscall_result;
2966
2967	if (!ioctl_result) {	/* SCSI command successful */
2968		st_release_request(SRpnt);
2969		SRpnt = NULL;
2970		STps->drv_block = blkno;
2971		STps->drv_file = fileno;
2972		STps->at_sm = at_sm;
2973
2974		if (cmd_in == MTBSFM)
2975			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2976		else if (cmd_in == MTFSFM)
2977			ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2978
2979		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2980			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2981			if (STp->block_size != 0) {
2982				(STp->buffer)->buffer_blocks =
2983				    (STp->buffer)->buffer_size / STp->block_size;
2984			}
2985			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2986			if (cmd_in == SET_DENS_AND_BLK)
2987				STp->density = arg >> MT_ST_DENSITY_SHIFT;
2988		} else if (cmd_in == MTSETDRVBUFFER)
2989			STp->drv_buffer = (arg & 7);
2990		else if (cmd_in == MTSETDENSITY)
2991			STp->density = arg;
2992
2993		if (cmd_in == MTEOM)
2994			STps->eof = ST_EOD;
2995		else if (cmd_in == MTFSF)
2996			STps->eof = ST_FM;
2997		else if (chg_eof)
2998			STps->eof = ST_NOEOF;
2999
3000		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
3001			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
3002	} else { /* SCSI command was not completely successful. Don't return
3003                    from this block without releasing the SCSI command block! */
3004		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
3005
3006		if (cmdstatp->flags & SENSE_EOM) {
3007			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
3008			    cmd_in != MTBSR && cmd_in != MTBSS)
3009				STps->eof = ST_EOM_OK;
3010			STps->drv_block = 0;
3011		}
3012
3013		if (cmdstatp->remainder_valid)
3014			undone = (int)cmdstatp->uremainder64;
3015		else
3016			undone = 0;
3017
3018		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
3019		    cmdstatp->have_sense &&
3020		    (cmdstatp->flags & SENSE_EOM)) {
3021			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
3022			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
3023				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
3024				STps->eof = ST_NOEOF;
3025			} else {  /* Writing EOF(s) failed */
3026				if (fileno >= 0)
3027					fileno -= undone;
3028				if (undone < arg)
3029					STps->eof = ST_NOEOF;
3030			}
3031			STps->drv_file = fileno;
3032		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
3033			if (fileno >= 0)
3034				STps->drv_file = fileno - undone;
3035			else
3036				STps->drv_file = fileno;
3037			STps->drv_block = -1;
3038			STps->eof = ST_NOEOF;
3039		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
3040			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3041				undone = (-undone);
3042			if (STps->drv_file >= 0)
3043				STps->drv_file = fileno + undone;
3044			STps->drv_block = 0;
3045			STps->eof = ST_NOEOF;
3046		} else if (cmd_in == MTFSR) {
3047			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3048				if (STps->drv_file >= 0)
3049					STps->drv_file++;
3050				STps->drv_block = 0;
3051				STps->eof = ST_FM;
3052			} else {
3053				if (blkno >= undone)
3054					STps->drv_block = blkno - undone;
3055				else
3056					STps->drv_block = (-1);
3057				STps->eof = ST_NOEOF;
3058			}
3059		} else if (cmd_in == MTBSR) {
3060			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3061				STps->drv_file--;
3062				STps->drv_block = (-1);
3063			} else {
3064				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3065					undone = (-undone);
3066				if (STps->drv_block >= 0)
3067					STps->drv_block = blkno + undone;
3068			}
3069			STps->eof = ST_NOEOF;
3070		} else if (cmd_in == MTEOM) {
3071			STps->drv_file = (-1);
3072			STps->drv_block = (-1);
3073			STps->eof = ST_EOD;
3074		} else if (cmd_in == MTSETBLK ||
3075			   cmd_in == MTSETDENSITY ||
3076			   cmd_in == MTSETDRVBUFFER ||
3077			   cmd_in == SET_DENS_AND_BLK) {
3078			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
3079			    !(STp->use_pf & PF_TESTED)) {
3080				/* Try the other possible state of Page Format if not
3081				   already tried */
3082				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
3083				st_release_request(SRpnt);
3084				SRpnt = NULL;
3085				return st_int_ioctl(STp, cmd_in, arg);
3086			}
3087		} else if (chg_eof)
3088			STps->eof = ST_NOEOF;
3089
3090		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
3091			STps->eof = ST_EOD;
3092
3093		st_release_request(SRpnt);
3094		SRpnt = NULL;
3095	}
3096
3097	return ioctl_result;
3098}
3099
3100
3101/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
3102   structure. */
3103
3104static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
3105			int logical)
3106{
3107	int result;
3108	unsigned char scmd[MAX_COMMAND_SIZE];
3109	struct st_request *SRpnt;
3110
3111	if (STp->ready != ST_READY)
3112		return (-EIO);
3113
3114	memset(scmd, 0, MAX_COMMAND_SIZE);
3115	if ((STp->device)->scsi_level < SCSI_2) {
3116		scmd[0] = QFA_REQUEST_BLOCK;
3117		scmd[4] = 3;
3118	} else {
3119		scmd[0] = READ_POSITION;
3120		if (!logical && !STp->scsi2_logical)
3121			scmd[1] = 1;
3122	}
3123	SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3124			   STp->device->request_queue->rq_timeout,
3125			   MAX_READY_RETRIES, 1);
3126	if (!SRpnt)
3127		return (STp->buffer)->syscall_result;
3128
3129	if ((STp->buffer)->syscall_result != 0 ||
3130	    (STp->device->scsi_level >= SCSI_2 &&
3131	     ((STp->buffer)->b_data[0] & 4) != 0)) {
3132		*block = *partition = 0;
3133		DEBC_printk(STp, " Can't read tape position.\n");
3134		result = (-EIO);
3135	} else {
3136		result = 0;
3137		if ((STp->device)->scsi_level < SCSI_2) {
3138			*block = ((STp->buffer)->b_data[0] << 16)
3139			    + ((STp->buffer)->b_data[1] << 8)
3140			    + (STp->buffer)->b_data[2];
3141			*partition = 0;
3142		} else {
3143			*block = ((STp->buffer)->b_data[4] << 24)
3144			    + ((STp->buffer)->b_data[5] << 16)
3145			    + ((STp->buffer)->b_data[6] << 8)
3146			    + (STp->buffer)->b_data[7];
3147			*partition = (STp->buffer)->b_data[1];
3148			if (((STp->buffer)->b_data[0] & 0x80) &&
3149			    (STp->buffer)->b_data[1] == 0)	/* BOP of partition 0 */
3150				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3151		}
3152		DEBC_printk(STp, "Got tape pos. blk %d part %d.\n",
3153			    *block, *partition);
3154	}
3155	st_release_request(SRpnt);
3156	SRpnt = NULL;
3157
3158	return result;
3159}
3160
3161
3162/* Set the tape block and partition. Negative partition means that only the
3163   block should be set in vendor specific way. */
3164static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3165			int logical)
3166{
3167	struct st_partstat *STps;
3168	int result, p;
3169	unsigned int blk;
3170	int timeout;
3171	unsigned char scmd[MAX_COMMAND_SIZE];
3172	struct st_request *SRpnt;
3173
3174	if (STp->ready != ST_READY)
3175		return (-EIO);
3176	timeout = STp->long_timeout;
3177	STps = &(STp->ps[STp->partition]);
3178
3179	DEBC_printk(STp, "Setting block to %d and partition to %d.\n",
3180		    block, partition);
3181	DEB(if (partition < 0)
3182		return (-EIO); )
3183
3184	/* Update the location at the partition we are leaving */
3185	if ((!STp->can_partitions && partition != 0) ||
3186	    partition >= ST_NBR_PARTITIONS)
3187		return (-EINVAL);
3188	if (partition != STp->partition) {
3189		if (get_location(STp, &blk, &p, 1))
3190			STps->last_block_valid = 0;
3191		else {
3192			STps->last_block_valid = 1;
3193			STps->last_block_visited = blk;
3194			DEBC_printk(STp, "Visited block %d for "
3195				    "partition %d saved.\n",
3196				    blk, STp->partition);
3197		}
3198	}
3199
3200	memset(scmd, 0, MAX_COMMAND_SIZE);
3201	if ((STp->device)->scsi_level < SCSI_2) {
3202		scmd[0] = QFA_SEEK_BLOCK;
3203		scmd[2] = (block >> 16);
3204		scmd[3] = (block >> 8);
3205		scmd[4] = block;
3206		scmd[5] = 0;
3207	} else {
3208		scmd[0] = SEEK_10;
3209		scmd[3] = (block >> 24);
3210		scmd[4] = (block >> 16);
3211		scmd[5] = (block >> 8);
3212		scmd[6] = block;
3213		if (!logical && !STp->scsi2_logical)
3214			scmd[1] = 4;
3215		if (STp->partition != partition) {
3216			scmd[1] |= 2;
3217			scmd[8] = partition;
3218			DEBC_printk(STp, "Trying to change partition "
3219				    "from %d to %d\n", STp->partition,
3220				    partition);
3221		}
3222	}
3223	if (STp->immediate) {
3224		scmd[1] |= 1;		/* Don't wait for completion */
3225		timeout = STp->device->request_queue->rq_timeout;
3226	}
3227
3228	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3229			   timeout, MAX_READY_RETRIES, 1);
3230	if (!SRpnt)
3231		return (STp->buffer)->syscall_result;
3232
3233	STps->drv_block = STps->drv_file = (-1);
3234	STps->eof = ST_NOEOF;
3235	if ((STp->buffer)->syscall_result != 0) {
3236		result = (-EIO);
3237		if (STp->can_partitions &&
3238		    (STp->device)->scsi_level >= SCSI_2 &&
3239		    (p = find_partition(STp)) >= 0)
3240			STp->partition = p;
3241	} else {
3242		if (STp->can_partitions) {
3243			STp->partition = partition;
3244			STps = &(STp->ps[partition]);
3245			if (!STps->last_block_valid ||
3246			    STps->last_block_visited != block) {
3247				STps->at_sm = 0;
3248				STps->rw = ST_IDLE;
3249			}
3250		} else
3251			STps->at_sm = 0;
3252		if (block == 0)
3253			STps->drv_block = STps->drv_file = 0;
3254		result = 0;
3255	}
3256
3257	st_release_request(SRpnt);
3258	SRpnt = NULL;
3259
3260	return result;
3261}
3262
3263
3264/* Find the current partition number for the drive status. Called from open and
3265   returns either partition number of negative error code. */
3266static int find_partition(struct scsi_tape *STp)
3267{
3268	int i, partition;
3269	unsigned int block;
3270
3271	if ((i = get_location(STp, &block, &partition, 1)) < 0)
3272		return i;
3273	if (partition >= ST_NBR_PARTITIONS)
3274		return (-EIO);
3275	return partition;
3276}
3277
3278
3279/* Change the partition if necessary */
3280static int switch_partition(struct scsi_tape *STp)
3281{
3282	struct st_partstat *STps;
3283
3284	if (STp->partition == STp->new_partition)
3285		return 0;
3286	STps = &(STp->ps[STp->new_partition]);
3287	if (!STps->last_block_valid)
3288		STps->last_block_visited = 0;
3289	return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3290}
3291
3292/* Functions for reading and writing the medium partition mode page. */
3293
3294#define PART_PAGE   0x11
3295#define PART_PAGE_FIXED_LENGTH 8
3296
3297#define PP_OFF_MAX_ADD_PARTS   2
3298#define PP_OFF_NBR_ADD_PARTS   3
3299#define PP_OFF_FLAGS           4
3300#define PP_OFF_PART_UNITS      6
3301#define PP_OFF_RESERVED        7
3302
3303#define PP_BIT_IDP             0x20
3304#define PP_BIT_FDP             0x80
3305#define PP_MSK_PSUM_MB         0x10
3306#define PP_MSK_PSUM_UNITS      0x18
3307#define PP_MSK_POFM            0x04
3308
3309/* Get the number of partitions on the tape. As a side effect reads the
3310   mode page into the tape buffer. */
3311static int nbr_partitions(struct scsi_tape *STp)
3312{
3313	int result;
3314
3315	if (STp->ready != ST_READY)
3316		return (-EIO);
3317
3318	result = read_mode_page(STp, PART_PAGE, 1);
3319
3320	if (result) {
3321		DEBC_printk(STp, "Can't read medium partition page.\n");
3322		result = (-EIO);
3323	} else {
3324		result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3325					      PP_OFF_NBR_ADD_PARTS] + 1;
3326		DEBC_printk(STp, "Number of partitions %d.\n", result);
3327	}
3328
3329	return result;
3330}
3331
3332
3333static int format_medium(struct scsi_tape *STp, int format)
3334{
3335	int result = 0;
3336	int timeout = STp->long_timeout;
3337	unsigned char scmd[MAX_COMMAND_SIZE];
3338	struct st_request *SRpnt;
3339
3340	memset(scmd, 0, MAX_COMMAND_SIZE);
3341	scmd[0] = FORMAT_UNIT;
3342	scmd[2] = format;
3343	if (STp->immediate) {
3344		scmd[1] |= 1;		/* Don't wait for completion */
3345		timeout = STp->device->request_queue->rq_timeout;
3346	}
3347	DEBC_printk(STp, "Sending FORMAT MEDIUM\n");
3348	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3349			   timeout, MAX_RETRIES, 1);
3350	if (!SRpnt)
3351		result = STp->buffer->syscall_result;
3352	return result;
3353}
3354
3355
3356/* Partition the tape into two partitions if size > 0 or one partition if
3357   size == 0.
3358
3359   The block descriptors are read and written because Sony SDT-7000 does not
3360   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3361
3362   My HP C1533A drive returns only one partition size field. This is used to
3363   set the size of partition 1. There is no size field for the default partition.
3364   Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3365   used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3366   The following algorithm is used to accommodate both drives: if the number of
3367   partition size fields is greater than the maximum number of additional partitions
3368   in the mode page, the second field is used. Otherwise the first field is used.
3369
3370   For Seagate DDS drives the page length must be 8 when no partitions is defined
3371   and 10 when 1 partition is defined (information from Eric Lee Green). This is
3372   is acceptable also to some other old drives and enforced if the first partition
3373   size field is used for the first additional partition size.
3374
3375   For drives that advertize SCSI-3 or newer, use the SSC-3 methods.
3376 */
3377static int partition_tape(struct scsi_tape *STp, int size)
3378{
3379	int result;
3380	int target_partition;
3381	bool scsi3 = STp->device->scsi_level >= SCSI_3, needs_format = false;
3382	int pgo, psd_cnt, psdo;
3383	int psum = PP_MSK_PSUM_MB, units = 0;
3384	unsigned char *bp;
3385
3386	result = read_mode_page(STp, PART_PAGE, 0);
3387	if (result) {
3388		DEBC_printk(STp, "Can't read partition mode page.\n");
3389		return result;
3390	}
3391	target_partition = 1;
3392	if (size < 0) {
3393		target_partition = 0;
3394		size = -size;
3395	}
3396
3397	/* The mode page is in the buffer. Let's modify it and write it. */
3398	bp = (STp->buffer)->b_data;
3399	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3400	DEBC_printk(STp, "Partition page length is %d bytes.\n",
3401		    bp[pgo + MP_OFF_PAGE_LENGTH] + 2);
3402
3403	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
3404
3405	if (scsi3) {
3406		needs_format = (bp[pgo + PP_OFF_FLAGS] & PP_MSK_POFM) != 0;
3407		if (needs_format && size == 0) {
3408			/* No need to write the mode page when clearing
3409			 *  partitioning
3410			 */
3411			DEBC_printk(STp, "Formatting tape with one partition.\n");
3412			result = format_medium(STp, 0);
3413			goto out;
3414		}
3415		if (needs_format)  /* Leave the old value for HP DATs claiming SCSI_3 */
3416			psd_cnt = 2;
3417		if ((bp[pgo + PP_OFF_FLAGS] & PP_MSK_PSUM_UNITS) == PP_MSK_PSUM_UNITS) {
3418			/* Use units scaling for large partitions if the device
3419			 * suggests it and no precision lost. Required for IBM
3420			 * TS1140/50 drives that don't support MB units.
3421			 */
3422			if (size >= 1000 && (size % 1000) == 0) {
3423				size /= 1000;
3424				psum = PP_MSK_PSUM_UNITS;
3425				units = 9; /* GB */
3426			}
3427		}
3428		/* Try it anyway if too large to specify in MB */
3429		if (psum == PP_MSK_PSUM_MB && size >= 65534) {
3430			size /= 1000;
3431			psum = PP_MSK_PSUM_UNITS;
3432			units = 9;  /* GB */
3433		}
3434	}
3435
3436	if (size >= 65535 ||  /* Does not fit into two bytes */
3437	    (target_partition == 0 && psd_cnt < 2)) {
3438		result = -EINVAL;
3439		goto out;
3440	}
3441
3442	psdo = pgo + PART_PAGE_FIXED_LENGTH;
3443	/* The second condition is for HP DDS which use only one partition size
3444	 * descriptor
3445	 */
3446	if (target_partition > 0 &&
3447	    (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS] ||
3448	     bp[pgo + PP_OFF_MAX_ADD_PARTS] != 1)) {
3449		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest to partition 0 */
3450		psdo += 2;
3451	}
3452	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3453
3454	DEBC_printk(STp, "psd_cnt %d, max.parts %d, nbr_parts %d\n",
3455		    psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3456		    bp[pgo + PP_OFF_NBR_ADD_PARTS]);
3457
3458	if (size == 0) {
3459		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3460		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3461		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3462		DEBC_printk(STp, "Formatting tape with one partition.\n");
3463	} else {
3464		bp[psdo] = (size >> 8) & 0xff;
3465		bp[psdo + 1] = size & 0xff;
3466		if (target_partition == 0)
3467			bp[psdo + 2] = bp[psdo + 3] = 0xff;
3468		bp[pgo + 3] = 1;
3469		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3470		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3471		DEBC_printk(STp,
3472			    "Formatting tape with two partitions (%i = %d MB).\n",
3473			    target_partition, units > 0 ? size * 1000 : size);
3474	}
3475	bp[pgo + PP_OFF_PART_UNITS] = 0;
3476	bp[pgo + PP_OFF_RESERVED] = 0;
3477	if (size != 1 || units != 0) {
3478		bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | psum |
3479			(bp[pgo + PP_OFF_FLAGS] & 0x07);
3480		bp[pgo + PP_OFF_PART_UNITS] = units;
3481	} else
3482		bp[pgo + PP_OFF_FLAGS] = PP_BIT_FDP |
3483			(bp[pgo + PP_OFF_FLAGS] & 0x1f);
3484	bp[pgo + MP_OFF_PAGE_LENGTH] = 6 + psd_cnt * 2;
3485
3486	result = write_mode_page(STp, PART_PAGE, 1);
3487
3488	if (!result && needs_format)
3489		result = format_medium(STp, 1);
3490
3491	if (result) {
3492		st_printk(KERN_INFO, STp, "Partitioning of tape failed.\n");
3493		result = (-EIO);
3494	}
3495
3496out:
3497	return result;
3498}
3499
3500
3501
3502/* The ioctl command */
3503static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3504{
3505	int i, cmd_nr, cmd_type, bt;
3506	int retval = 0;
3507	unsigned int blk;
3508	struct scsi_tape *STp = file->private_data;
3509	struct st_modedef *STm;
3510	struct st_partstat *STps;
3511	void __user *p = (void __user *)arg;
3512
3513	if (mutex_lock_interruptible(&STp->lock))
3514		return -ERESTARTSYS;
3515
3516	DEB(
3517	if (debugging && !STp->in_use) {
3518		st_printk(ST_DEB_MSG, STp, "Incorrect device.\n");
3519		retval = (-EIO);
3520		goto out;
3521	} ) /* end DEB */
3522
3523	STm = &(STp->modes[STp->current_mode]);
3524	STps = &(STp->ps[STp->partition]);
3525
3526	/*
3527	 * If we are in the middle of error recovery, don't let anyone
3528	 * else try and use this device.  Also, if error recovery fails, it
3529	 * may try and take the device offline, in which case all further
3530	 * access to the device is prohibited.
3531	 */
3532	retval = scsi_ioctl_block_when_processing_errors(STp->device, cmd_in,
3533			file->f_flags & O_NDELAY);
3534	if (retval)
3535		goto out;
3536
3537	cmd_type = _IOC_TYPE(cmd_in);
3538	cmd_nr = _IOC_NR(cmd_in);
3539
3540	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3541		struct mtop mtc;
3542
3543		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3544			retval = (-EINVAL);
3545			goto out;
3546		}
3547
3548		i = copy_from_user(&mtc, p, sizeof(struct mtop));
3549		if (i) {
3550			retval = (-EFAULT);
3551			goto out;
3552		}
3553
3554		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3555			st_printk(KERN_WARNING, STp,
3556				  "MTSETDRVBUFFER only allowed for root.\n");
3557			retval = (-EPERM);
3558			goto out;
3559		}
3560		if (!STm->defined &&
3561		    (mtc.mt_op != MTSETDRVBUFFER &&
3562		     (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3563			retval = (-ENXIO);
3564			goto out;
3565		}
3566
3567		if (!STp->pos_unknown) {
3568
3569			if (STps->eof == ST_FM_HIT) {
3570				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3571                                    mtc.mt_op == MTEOM) {
3572					mtc.mt_count -= 1;
3573					if (STps->drv_file >= 0)
3574						STps->drv_file += 1;
3575				} else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3576					mtc.mt_count += 1;
3577					if (STps->drv_file >= 0)
3578						STps->drv_file += 1;
3579				}
3580			}
3581
3582			if (mtc.mt_op == MTSEEK) {
3583				/* Old position must be restored if partition will be
3584                                   changed */
3585				i = !STp->can_partitions ||
3586				    (STp->new_partition != STp->partition);
3587			} else {
3588				i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3589				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3590				    mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3591				    mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3592				    mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3593				    mtc.mt_op == MTCOMPRESSION;
3594			}
3595			i = flush_buffer(STp, i);
3596			if (i < 0) {
3597				retval = i;
3598				goto out;
3599			}
3600			if (STps->rw == ST_WRITING &&
3601			    (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3602			     mtc.mt_op == MTSEEK ||
3603			     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3604				i = st_int_ioctl(STp, MTWEOF, 1);
3605				if (i < 0) {
3606					retval = i;
3607					goto out;
3608				}
3609				if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3610					mtc.mt_count++;
3611				STps->rw = ST_IDLE;
3612			     }
3613
3614		} else {
3615			/*
3616			 * If there was a bus reset, block further access
3617			 * to this device.  If the user wants to rewind the tape,
3618			 * then reset the flag and allow access again.
3619			 */
3620			if (mtc.mt_op != MTREW &&
3621			    mtc.mt_op != MTOFFL &&
3622			    mtc.mt_op != MTRETEN &&
3623			    mtc.mt_op != MTERASE &&
3624			    mtc.mt_op != MTSEEK &&
3625			    mtc.mt_op != MTEOM) {
3626				retval = (-EIO);
3627				goto out;
3628			}
3629			reset_state(STp);
3630			/* remove this when the midlevel properly clears was_reset */
3631			STp->device->was_reset = 0;
3632		}
3633
3634		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3635		    mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3636		    mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3637			STps->rw = ST_IDLE;	/* Prevent automatic WEOF and fsf */
3638
3639		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3640			do_door_lock(STp, 0);	/* Ignore result! */
3641
3642		if (mtc.mt_op == MTSETDRVBUFFER &&
3643		    (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3644			retval = st_set_options(STp, mtc.mt_count);
3645			goto out;
3646		}
3647
3648		if (mtc.mt_op == MTSETPART) {
3649			if (!STp->can_partitions ||
3650			    mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3651				retval = (-EINVAL);
3652				goto out;
3653			}
3654			if (mtc.mt_count >= STp->nbr_partitions &&
3655			    (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3656				retval = (-EIO);
3657				goto out;
3658			}
3659			if (mtc.mt_count >= STp->nbr_partitions) {
3660				retval = (-EINVAL);
3661				goto out;
3662			}
3663			STp->new_partition = mtc.mt_count;
3664			retval = 0;
3665			goto out;
3666		}
3667
3668		if (mtc.mt_op == MTMKPART) {
3669			if (!STp->can_partitions) {
3670				retval = (-EINVAL);
3671				goto out;
3672			}
3673			i = do_load_unload(STp, file, 1);
3674			if (i < 0) {
3675				retval = i;
3676				goto out;
3677			}
3678			i = partition_tape(STp, mtc.mt_count);
3679			if (i < 0) {
3680				retval = i;
3681				goto out;
3682			}
3683			for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3684				STp->ps[i].rw = ST_IDLE;
3685				STp->ps[i].at_sm = 0;
3686				STp->ps[i].last_block_valid = 0;
3687			}
3688			STp->partition = STp->new_partition = 0;
3689			STp->nbr_partitions = mtc.mt_count != 0 ? 2 : 1;
3690			STps->drv_block = STps->drv_file = 0;
3691			retval = 0;
3692			goto out;
3693		}
3694
3695		if (mtc.mt_op == MTSEEK) {
3696			i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3697			if (!STp->can_partitions)
3698				STp->ps[0].rw = ST_IDLE;
3699			retval = i;
3700			goto out;
3701		}
3702
3703		if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3704			retval = do_load_unload(STp, file, 0);
3705			goto out;
3706		}
3707
3708		if (mtc.mt_op == MTLOAD) {
3709			retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3710			goto out;
3711		}
3712
3713		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3714			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3715			goto out;
3716		}
3717
3718		if (STp->can_partitions && STp->ready == ST_READY &&
3719		    (i = switch_partition(STp)) < 0) {
3720			retval = i;
3721			goto out;
3722		}
3723
3724		if (mtc.mt_op == MTCOMPRESSION)
3725			retval = st_compression(STp, (mtc.mt_count & 1));
3726		else
3727			retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3728		goto out;
3729	}
3730	if (!STm->defined) {
3731		retval = (-ENXIO);
3732		goto out;
3733	}
3734
3735	if ((i = flush_buffer(STp, 0)) < 0) {
3736		retval = i;
3737		goto out;
3738	}
3739	if (STp->can_partitions &&
3740	    (i = switch_partition(STp)) < 0) {
3741		retval = i;
3742		goto out;
3743	}
3744
3745	if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
3746		struct mtget mt_status;
3747
3748		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3749			 retval = (-EINVAL);
3750			 goto out;
3751		}
3752
3753		mt_status.mt_type = STp->tape_type;
3754		mt_status.mt_dsreg =
3755		    ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3756		    ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3757		mt_status.mt_blkno = STps->drv_block;
3758		mt_status.mt_fileno = STps->drv_file;
3759		if (STp->block_size != 0) {
3760			if (STps->rw == ST_WRITING)
3761				mt_status.mt_blkno +=
3762				    (STp->buffer)->buffer_bytes / STp->block_size;
3763			else if (STps->rw == ST_READING)
3764				mt_status.mt_blkno -=
3765                                        ((STp->buffer)->buffer_bytes +
3766                                         STp->block_size - 1) / STp->block_size;
3767		}
3768
3769		mt_status.mt_gstat = 0;
3770		if (STp->drv_write_prot)
3771			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3772		if (mt_status.mt_blkno == 0) {
3773			if (mt_status.mt_fileno == 0)
3774				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3775			else
3776				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3777		}
3778		mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3779		mt_status.mt_resid = STp->partition;
3780		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3781			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3782		else if (STps->eof >= ST_EOM_OK)
3783			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3784		if (STp->density == 1)
3785			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3786		else if (STp->density == 2)
3787			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3788		else if (STp->density == 3)
3789			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3790		if (STp->ready == ST_READY)
3791			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3792		if (STp->ready == ST_NO_TAPE)
3793			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3794		if (STps->at_sm)
3795			mt_status.mt_gstat |= GMT_SM(0xffffffff);
3796		if (STm->do_async_writes ||
3797                    (STm->do_buffer_writes && STp->block_size != 0) ||
3798		    STp->drv_buffer != 0)
3799			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3800		if (STp->cleaning_req)
3801			mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3802
3803		i = copy_to_user(p, &mt_status, sizeof(struct mtget));
3804		if (i) {
3805			retval = (-EFAULT);
3806			goto out;
3807		}
3808
3809		STp->recover_reg = 0;		/* Clear after read */
3810		retval = 0;
3811		goto out;
3812	}			/* End of MTIOCGET */
3813	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3814		struct mtpos mt_pos;
3815		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3816			 retval = (-EINVAL);
3817			 goto out;
3818		}
3819		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3820			retval = i;
3821			goto out;
3822		}
3823		mt_pos.mt_blkno = blk;
3824		i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
3825		if (i)
3826			retval = (-EFAULT);
3827		goto out;
3828	}
3829	mutex_unlock(&STp->lock);
3830	switch (cmd_in) {
3831		case SCSI_IOCTL_GET_IDLUN:
3832		case SCSI_IOCTL_GET_BUS_NUMBER:
3833			break;
3834		default:
3835			if ((cmd_in == SG_IO ||
3836			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3837			     cmd_in == CDROM_SEND_PACKET) &&
3838			    !capable(CAP_SYS_RAWIO))
3839				i = -EPERM;
3840			else
3841				i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3842						   file->f_mode, cmd_in, p);
3843			if (i != -ENOTTY)
3844				return i;
3845			break;
3846	}
3847	retval = scsi_ioctl(STp->device, cmd_in, p);
3848	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
3849		STp->rew_at_close = 0;
3850		STp->ready = ST_NO_TAPE;
3851	}
3852	return retval;
3853
3854 out:
3855	mutex_unlock(&STp->lock);
3856	return retval;
3857}
3858
3859#ifdef CONFIG_COMPAT
3860static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3861{
3862	struct scsi_tape *STp = file->private_data;
3863	struct scsi_device *sdev = STp->device;
3864	int ret = -ENOIOCTLCMD;
3865	if (sdev->host->hostt->compat_ioctl) { 
3866
3867		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
3868
3869	}
3870	return ret;
3871}
3872#endif
3873
3874
3875
3876/* Try to allocate a new tape buffer. Calling function must not hold
3877   dev_arr_lock. */
3878static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
3879{
3880	struct st_buffer *tb;
3881
3882	tb = kzalloc(sizeof(struct st_buffer), GFP_KERNEL);
3883	if (!tb) {
3884		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3885		return NULL;
3886	}
3887	tb->frp_segs = 0;
3888	tb->use_sg = max_sg;
3889	tb->dma = need_dma;
3890	tb->buffer_size = 0;
3891
3892	tb->reserved_pages = kcalloc(max_sg, sizeof(struct page *),
3893				     GFP_KERNEL);
3894	if (!tb->reserved_pages) {
3895		kfree(tb);
3896		return NULL;
3897	}
3898
3899	return tb;
3900}
3901
3902
3903/* Try to allocate enough space in the tape buffer */
3904#define ST_MAX_ORDER 6
3905
3906static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
3907{
3908	int segs, max_segs, b_size, order, got;
3909	gfp_t priority;
3910
3911	if (new_size <= STbuffer->buffer_size)
3912		return 1;
3913
3914	if (STbuffer->buffer_size <= PAGE_SIZE)
3915		normalize_buffer(STbuffer);  /* Avoid extra segment */
3916
3917	max_segs = STbuffer->use_sg;
3918
3919	priority = GFP_KERNEL | __GFP_NOWARN;
3920	if (need_dma)
3921		priority |= GFP_DMA;
3922
3923	if (STbuffer->cleared)
3924		priority |= __GFP_ZERO;
3925
3926	if (STbuffer->frp_segs) {
3927		order = STbuffer->reserved_page_order;
3928		b_size = PAGE_SIZE << order;
3929	} else {
3930		for (b_size = PAGE_SIZE, order = 0;
3931		     order < ST_MAX_ORDER &&
3932			     max_segs * (PAGE_SIZE << order) < new_size;
3933		     order++, b_size *= 2)
3934			;  /* empty */
3935		STbuffer->reserved_page_order = order;
3936	}
3937	if (max_segs * (PAGE_SIZE << order) < new_size) {
3938		if (order == ST_MAX_ORDER)
3939			return 0;
3940		normalize_buffer(STbuffer);
3941		return enlarge_buffer(STbuffer, new_size, need_dma);
3942	}
3943
3944	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3945	     segs < max_segs && got < new_size;) {
3946		struct page *page;
3947
3948		page = alloc_pages(priority, order);
3949		if (!page) {
3950			DEB(STbuffer->buffer_size = got);
3951			normalize_buffer(STbuffer);
3952			return 0;
3953		}
3954
3955		STbuffer->frp_segs += 1;
3956		got += b_size;
3957		STbuffer->buffer_size = got;
3958		STbuffer->reserved_pages[segs] = page;
3959		segs++;
3960	}
3961	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3962
3963	return 1;
3964}
3965
3966
3967/* Make sure that no data from previous user is in the internal buffer */
3968static void clear_buffer(struct st_buffer * st_bp)
3969{
3970	int i;
3971
3972	for (i=0; i < st_bp->frp_segs; i++)
3973		memset(page_address(st_bp->reserved_pages[i]), 0,
3974		       PAGE_SIZE << st_bp->reserved_page_order);
3975	st_bp->cleared = 1;
3976}
3977
3978
3979/* Release the extra buffer */
3980static void normalize_buffer(struct st_buffer * STbuffer)
3981{
3982	int i, order = STbuffer->reserved_page_order;
3983
3984	for (i = 0; i < STbuffer->frp_segs; i++) {
3985		__free_pages(STbuffer->reserved_pages[i], order);
3986		STbuffer->buffer_size -= (PAGE_SIZE << order);
3987	}
3988	STbuffer->frp_segs = 0;
3989	STbuffer->sg_segs = 0;
3990	STbuffer->reserved_page_order = 0;
3991	STbuffer->map_data.offset = 0;
3992}
3993
3994
3995/* Move data from the user buffer to the tape buffer. Returns zero (success) or
3996   negative error code. */
3997static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3998{
3999	int i, cnt, res, offset;
4000	int length = PAGE_SIZE << st_bp->reserved_page_order;
4001
4002	for (i = 0, offset = st_bp->buffer_bytes;
4003	     i < st_bp->frp_segs && offset >= length; i++)
4004		offset -= length;
4005	if (i == st_bp->frp_segs) {	/* Should never happen */
4006		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
4007		return (-EIO);
4008	}
4009	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4010		struct page *page = st_bp->reserved_pages[i];
4011		cnt = length - offset < do_count ? length - offset : do_count;
4012		res = copy_from_user(page_address(page) + offset, ubp, cnt);
4013		if (res)
4014			return (-EFAULT);
4015		do_count -= cnt;
4016		st_bp->buffer_bytes += cnt;
4017		ubp += cnt;
4018		offset = 0;
4019	}
4020	if (do_count) /* Should never happen */
4021		return (-EIO);
4022
4023	return 0;
4024}
4025
4026
4027/* Move data from the tape buffer to the user buffer. Returns zero (success) or
4028   negative error code. */
4029static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
4030{
4031	int i, cnt, res, offset;
4032	int length = PAGE_SIZE << st_bp->reserved_page_order;
4033
4034	for (i = 0, offset = st_bp->read_pointer;
4035	     i < st_bp->frp_segs && offset >= length; i++)
4036		offset -= length;
4037	if (i == st_bp->frp_segs) {	/* Should never happen */
4038		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
4039		return (-EIO);
4040	}
4041	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4042		struct page *page = st_bp->reserved_pages[i];
4043		cnt = length - offset < do_count ? length - offset : do_count;
4044		res = copy_to_user(ubp, page_address(page) + offset, cnt);
4045		if (res)
4046			return (-EFAULT);
4047		do_count -= cnt;
4048		st_bp->buffer_bytes -= cnt;
4049		st_bp->read_pointer += cnt;
4050		ubp += cnt;
4051		offset = 0;
4052	}
4053	if (do_count) /* Should never happen */
4054		return (-EIO);
4055
4056	return 0;
4057}
4058
4059
4060/* Move data towards start of buffer */
4061static void move_buffer_data(struct st_buffer * st_bp, int offset)
4062{
4063	int src_seg, dst_seg, src_offset = 0, dst_offset;
4064	int count, total;
4065	int length = PAGE_SIZE << st_bp->reserved_page_order;
4066
4067	if (offset == 0)
4068		return;
4069
4070	total=st_bp->buffer_bytes - offset;
4071	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
4072		src_offset = offset;
4073		if (src_offset < length)
4074			break;
4075		offset -= length;
4076	}
4077
4078	st_bp->buffer_bytes = st_bp->read_pointer = total;
4079	for (dst_seg=dst_offset=0; total > 0; ) {
4080		struct page *dpage = st_bp->reserved_pages[dst_seg];
4081		struct page *spage = st_bp->reserved_pages[src_seg];
4082
4083		count = min(length - dst_offset, length - src_offset);
4084		memmove(page_address(dpage) + dst_offset,
4085			page_address(spage) + src_offset, count);
4086		src_offset += count;
4087		if (src_offset >= length) {
4088			src_seg++;
4089			src_offset = 0;
4090		}
4091		dst_offset += count;
4092		if (dst_offset >= length) {
4093			dst_seg++;
4094			dst_offset = 0;
4095		}
4096		total -= count;
4097	}
4098}
4099
4100/* Validate the options from command line or module parameters */
4101static void validate_options(void)
4102{
4103	if (buffer_kbs > 0)
4104		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
4105	if (max_sg_segs >= ST_FIRST_SG)
4106		st_max_sg_segs = max_sg_segs;
4107}
4108
4109#ifndef MODULE
4110/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
4111 */
4112static int __init st_setup(char *str)
4113{
4114	int i, len, ints[5];
4115	char *stp;
4116
4117	stp = get_options(str, ARRAY_SIZE(ints), ints);
4118
4119	if (ints[0] > 0) {
4120		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
4121			if (parms[i].val)
4122				*parms[i].val = ints[i + 1];
4123	} else {
4124		while (stp != NULL) {
4125			for (i = 0; i < ARRAY_SIZE(parms); i++) {
4126				len = strlen(parms[i].name);
4127				if (!strncmp(stp, parms[i].name, len) &&
4128				    (*(stp + len) == ':' || *(stp + len) == '=')) {
4129					if (parms[i].val)
4130						*parms[i].val =
4131							simple_strtoul(stp + len + 1, NULL, 0);
4132					else
4133						printk(KERN_WARNING "st: Obsolete parameter %s\n",
4134						       parms[i].name);
4135					break;
4136				}
4137			}
4138			if (i >= ARRAY_SIZE(parms))
4139				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
4140					stp);
4141			stp = strchr(stp, ',');
4142			if (stp)
4143				stp++;
4144		}
4145	}
4146
4147	validate_options();
4148
4149	return 1;
4150}
4151
4152__setup("st=", st_setup);
4153
4154#endif
4155
4156static const struct file_operations st_fops =
4157{
4158	.owner =	THIS_MODULE,
4159	.read =		st_read,
4160	.write =	st_write,
4161	.unlocked_ioctl = st_ioctl,
4162#ifdef CONFIG_COMPAT
4163	.compat_ioctl = st_compat_ioctl,
4164#endif
4165	.open =		st_open,
4166	.flush =	st_flush,
4167	.release =	st_release,
4168	.llseek =	noop_llseek,
4169};
4170
4171static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
4172{
4173	int i, error;
4174	dev_t cdev_devno;
4175	struct cdev *cdev;
4176	struct device *dev;
4177	struct st_modedef *STm = &(tape->modes[mode]);
4178	char name[10];
4179	int dev_num = tape->index;
4180
4181	cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
4182
4183	cdev = cdev_alloc();
4184	if (!cdev) {
4185		pr_err("st%d: out of memory. Device not attached.\n", dev_num);
4186		error = -ENOMEM;
4187		goto out;
4188	}
4189	cdev->owner = THIS_MODULE;
4190	cdev->ops = &st_fops;
4191	STm->cdevs[rew] = cdev;
4192
4193	error = cdev_add(cdev, cdev_devno, 1);
4194	if (error) {
4195		pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
4196		       rew ? "non" : "auto", mode);
4197		pr_err("st%d: Device not attached.\n", dev_num);
4198		goto out_free;
4199	}
4200
4201	i = mode << (4 - ST_NBR_MODE_BITS);
4202	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4203		 tape->disk->disk_name, st_formats[i]);
4204
4205	dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
4206			    cdev_devno, &tape->modes[mode], "%s", name);
4207	if (IS_ERR(dev)) {
4208		pr_err("st%d: device_create failed\n", dev_num);
4209		error = PTR_ERR(dev);
4210		goto out_free;
4211	}
4212
4213	STm->devs[rew] = dev;
4214
4215	return 0;
4216out_free:
4217	cdev_del(STm->cdevs[rew]);
4218out:
4219	STm->cdevs[rew] = NULL;
4220	STm->devs[rew] = NULL;
4221	return error;
4222}
4223
4224static int create_cdevs(struct scsi_tape *tape)
4225{
4226	int mode, error;
4227	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4228		error = create_one_cdev(tape, mode, 0);
4229		if (error)
4230			return error;
4231		error = create_one_cdev(tape, mode, 1);
4232		if (error)
4233			return error;
4234	}
4235
4236	return sysfs_create_link(&tape->device->sdev_gendev.kobj,
4237				 &tape->modes[0].devs[0]->kobj, "tape");
4238}
4239
4240static void remove_cdevs(struct scsi_tape *tape)
4241{
4242	int mode, rew;
4243	sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
4244	for (mode = 0; mode < ST_NBR_MODES; mode++) {
4245		struct st_modedef *STm = &(tape->modes[mode]);
4246		for (rew = 0; rew < 2; rew++) {
4247			if (STm->cdevs[rew])
4248				cdev_del(STm->cdevs[rew]);
4249			if (STm->devs[rew])
4250				device_unregister(STm->devs[rew]);
4251		}
4252	}
4253}
4254
4255static int st_probe(struct device *dev)
4256{
4257	struct scsi_device *SDp = to_scsi_device(dev);
4258	struct gendisk *disk = NULL;
4259	struct scsi_tape *tpnt = NULL;
4260	struct st_modedef *STm;
4261	struct st_partstat *STps;
4262	struct st_buffer *buffer;
4263	int i, error;
4264	char *stp;
4265
4266	if (SDp->type != TYPE_TAPE)
4267		return -ENODEV;
4268	if ((stp = st_incompatible(SDp))) {
 
4269		sdev_printk(KERN_INFO, SDp,
4270			    "OnStream tapes are no longer supported;\n");
4271		sdev_printk(KERN_INFO, SDp,
4272			    "please mail to linux-scsi@vger.kernel.org.\n");
4273		return -ENODEV;
4274	}
4275
4276	scsi_autopm_get_device(SDp);
4277	i = queue_max_segments(SDp->request_queue);
4278	if (st_max_sg_segs < i)
4279		i = st_max_sg_segs;
4280	buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
4281	if (buffer == NULL) {
4282		sdev_printk(KERN_ERR, SDp,
4283			    "st: Can't allocate new tape buffer. "
4284			    "Device not attached.\n");
4285		goto out;
4286	}
4287
4288	disk = alloc_disk(1);
4289	if (!disk) {
4290		sdev_printk(KERN_ERR, SDp,
4291			    "st: out of memory. Device not attached.\n");
4292		goto out_buffer_free;
4293	}
4294
4295	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_KERNEL);
4296	if (tpnt == NULL) {
4297		sdev_printk(KERN_ERR, SDp,
4298			    "st: Can't allocate device descriptor.\n");
4299		goto out_put_disk;
4300	}
4301	kref_init(&tpnt->kref);
4302	tpnt->disk = disk;
4303	disk->private_data = &tpnt->driver;
 
4304	/* SCSI tape doesn't register this gendisk via add_disk().  Manually
4305	 * take queue reference that release_disk() expects. */
4306	if (!blk_get_queue(SDp->request_queue))
4307		goto out_put_disk;
4308	disk->queue = SDp->request_queue;
4309	tpnt->driver = &st_template;
4310
4311	tpnt->device = SDp;
4312	if (SDp->scsi_level <= 2)
4313		tpnt->tape_type = MT_ISSCSI1;
4314	else
4315		tpnt->tape_type = MT_ISSCSI2;
4316
4317	tpnt->buffer = buffer;
4318	tpnt->buffer->last_SRpnt = NULL;
4319
4320	tpnt->inited = 0;
4321	tpnt->dirty = 0;
4322	tpnt->in_use = 0;
4323	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
4324	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4325	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4326	tpnt->density = 0;
4327	tpnt->do_auto_lock = ST_AUTO_LOCK;
4328	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4329	tpnt->can_partitions = 0;
4330	tpnt->two_fm = ST_TWO_FM;
4331	tpnt->fast_mteom = ST_FAST_MTEOM;
4332	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4333	tpnt->sili = ST_SILI;
4334	tpnt->immediate = ST_NOWAIT;
4335	tpnt->immediate_filemark = 0;
4336	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4337	tpnt->partition = 0;
4338	tpnt->new_partition = 0;
4339	tpnt->nbr_partitions = 0;
4340	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4341	tpnt->long_timeout = ST_LONG_TIMEOUT;
4342	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
4343
4344	for (i = 0; i < ST_NBR_MODES; i++) {
4345		STm = &(tpnt->modes[i]);
4346		STm->defined = 0;
4347		STm->sysv = ST_SYSV;
4348		STm->defaults_for_writes = 0;
4349		STm->do_async_writes = ST_ASYNC_WRITES;
4350		STm->do_buffer_writes = ST_BUFFER_WRITES;
4351		STm->do_read_ahead = ST_READ_AHEAD;
4352		STm->default_compression = ST_DONT_TOUCH;
4353		STm->default_blksize = (-1);	/* No forced size */
4354		STm->default_density = (-1);	/* No forced density */
4355		STm->tape = tpnt;
4356	}
4357
4358	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4359		STps = &(tpnt->ps[i]);
4360		STps->rw = ST_IDLE;
4361		STps->eof = ST_NOEOF;
4362		STps->at_sm = 0;
4363		STps->last_block_valid = 0;
4364		STps->drv_block = (-1);
4365		STps->drv_file = (-1);
4366	}
4367
4368	tpnt->current_mode = 0;
4369	tpnt->modes[0].defined = 1;
4370
4371	tpnt->density_changed = tpnt->compression_changed =
4372	    tpnt->blksize_changed = 0;
4373	mutex_init(&tpnt->lock);
4374
4375	idr_preload(GFP_KERNEL);
4376	spin_lock(&st_index_lock);
4377	error = idr_alloc(&st_index_idr, tpnt, 0, ST_MAX_TAPES + 1, GFP_NOWAIT);
4378	spin_unlock(&st_index_lock);
4379	idr_preload_end();
4380	if (error < 0) {
4381		pr_warn("st: idr allocation failed: %d\n", error);
4382		goto out_put_queue;
4383	}
4384	tpnt->index = error;
4385	sprintf(disk->disk_name, "st%d", tpnt->index);
4386	tpnt->stats = kzalloc(sizeof(struct scsi_tape_stats), GFP_KERNEL);
4387	if (tpnt->stats == NULL) {
4388		sdev_printk(KERN_ERR, SDp,
4389			    "st: Can't allocate statistics.\n");
4390		goto out_idr_remove;
4391	}
4392
4393	dev_set_drvdata(dev, tpnt);
4394
4395
4396	error = create_cdevs(tpnt);
4397	if (error)
4398		goto out_remove_devs;
4399	scsi_autopm_put_device(SDp);
4400
4401	sdev_printk(KERN_NOTICE, SDp,
4402		    "Attached scsi tape %s\n", tape_name(tpnt));
4403	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4404		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4405		    queue_dma_alignment(SDp->request_queue) + 1);
4406
4407	return 0;
4408
4409out_remove_devs:
4410	remove_cdevs(tpnt);
4411	kfree(tpnt->stats);
4412out_idr_remove:
4413	spin_lock(&st_index_lock);
4414	idr_remove(&st_index_idr, tpnt->index);
4415	spin_unlock(&st_index_lock);
4416out_put_queue:
4417	blk_put_queue(disk->queue);
4418out_put_disk:
4419	put_disk(disk);
4420	kfree(tpnt);
4421out_buffer_free:
4422	kfree(buffer);
4423out:
4424	scsi_autopm_put_device(SDp);
4425	return -ENODEV;
4426};
4427
4428
4429static int st_remove(struct device *dev)
4430{
4431	struct scsi_tape *tpnt = dev_get_drvdata(dev);
4432	int index = tpnt->index;
4433
4434	scsi_autopm_get_device(to_scsi_device(dev));
4435	remove_cdevs(tpnt);
4436
4437	mutex_lock(&st_ref_mutex);
4438	kref_put(&tpnt->kref, scsi_tape_release);
4439	mutex_unlock(&st_ref_mutex);
4440	spin_lock(&st_index_lock);
4441	idr_remove(&st_index_idr, index);
4442	spin_unlock(&st_index_lock);
4443	return 0;
4444}
4445
4446/**
4447 *      scsi_tape_release - Called to free the Scsi_Tape structure
4448 *      @kref: pointer to embedded kref
4449 *
4450 *      st_ref_mutex must be held entering this routine.  Because it is
4451 *      called on last put, you should always use the scsi_tape_get()
4452 *      scsi_tape_put() helpers which manipulate the semaphore directly
4453 *      and never do a direct kref_put().
4454 **/
4455static void scsi_tape_release(struct kref *kref)
4456{
4457	struct scsi_tape *tpnt = to_scsi_tape(kref);
4458	struct gendisk *disk = tpnt->disk;
4459
4460	tpnt->device = NULL;
4461
4462	if (tpnt->buffer) {
4463		normalize_buffer(tpnt->buffer);
4464		kfree(tpnt->buffer->reserved_pages);
4465		kfree(tpnt->buffer);
4466	}
4467
4468	disk->private_data = NULL;
4469	put_disk(disk);
4470	kfree(tpnt->stats);
4471	kfree(tpnt);
4472	return;
4473}
4474
4475static struct class st_sysfs_class = {
4476	.name = "scsi_tape",
4477	.dev_groups = st_dev_groups,
4478};
4479
4480static int __init init_st(void)
4481{
4482	int err;
4483
4484	validate_options();
4485
4486	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4487		verstr, st_fixed_buffer_size, st_max_sg_segs);
4488
4489	debugging = (debug_flag > 0) ? debug_flag : NO_DEBUG;
4490	if (debugging) {
4491		printk(KERN_INFO "st: Debugging enabled debug_flag = %d\n",
4492			debugging);
4493	}
4494
4495	err = class_register(&st_sysfs_class);
4496	if (err) {
4497		pr_err("Unable register sysfs class for SCSI tapes\n");
4498		return err;
4499	}
4500
4501	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4502				     ST_MAX_TAPE_ENTRIES, "st");
4503	if (err) {
4504		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4505		       SCSI_TAPE_MAJOR);
4506		goto err_class;
4507	}
4508
4509	err = scsi_register_driver(&st_template.gendrv);
4510	if (err)
4511		goto err_chrdev;
4512
4513	return 0;
4514
4515err_chrdev:
4516	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4517				 ST_MAX_TAPE_ENTRIES);
4518err_class:
4519	class_unregister(&st_sysfs_class);
4520	return err;
4521}
4522
4523static void __exit exit_st(void)
4524{
4525	scsi_unregister_driver(&st_template.gendrv);
4526	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4527				 ST_MAX_TAPE_ENTRIES);
4528	class_unregister(&st_sysfs_class);
4529	idr_destroy(&st_index_idr);
4530	printk(KERN_INFO "st: Unloaded.\n");
4531}
4532
4533module_init(init_st);
4534module_exit(exit_st);
4535
4536
4537/* The sysfs driver interface. Read-only at the moment */
4538static ssize_t try_direct_io_show(struct device_driver *ddp, char *buf)
4539{
4540	return scnprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4541}
4542static DRIVER_ATTR_RO(try_direct_io);
4543
4544static ssize_t fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4545{
4546	return scnprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4547}
4548static DRIVER_ATTR_RO(fixed_buffer_size);
4549
4550static ssize_t max_sg_segs_show(struct device_driver *ddp, char *buf)
4551{
4552	return scnprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4553}
4554static DRIVER_ATTR_RO(max_sg_segs);
4555
4556static ssize_t version_show(struct device_driver *ddd, char *buf)
4557{
4558	return scnprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4559}
4560static DRIVER_ATTR_RO(version);
4561
4562#if DEBUG
4563static ssize_t debug_flag_store(struct device_driver *ddp,
4564	const char *buf, size_t count)
4565{
4566/* We only care what the first byte of the data is the rest is unused.
4567 * if it's a '1' we turn on debug and if it's a '0' we disable it. All
4568 * other values have -EINVAL returned if they are passed in.
4569 */
4570	if (count > 0) {
4571		if (buf[0] == '0') {
4572			debugging = NO_DEBUG;
4573			return count;
4574		} else if (buf[0] == '1') {
4575			debugging = 1;
4576			return count;
4577		}
4578	}
4579	return -EINVAL;
4580}
4581
4582static ssize_t debug_flag_show(struct device_driver *ddp, char *buf)
4583{
4584	return scnprintf(buf, PAGE_SIZE, "%d\n", debugging);
4585}
4586static DRIVER_ATTR_RW(debug_flag);
4587#endif
4588
4589static struct attribute *st_drv_attrs[] = {
4590	&driver_attr_try_direct_io.attr,
4591	&driver_attr_fixed_buffer_size.attr,
4592	&driver_attr_max_sg_segs.attr,
4593	&driver_attr_version.attr,
4594#if DEBUG
4595	&driver_attr_debug_flag.attr,
4596#endif
4597	NULL,
4598};
4599ATTRIBUTE_GROUPS(st_drv);
4600
4601/* The sysfs simple class interface */
4602static ssize_t
4603defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4604{
4605	struct st_modedef *STm = dev_get_drvdata(dev);
4606	ssize_t l = 0;
4607
4608	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4609	return l;
4610}
4611static DEVICE_ATTR_RO(defined);
4612
4613static ssize_t
4614default_blksize_show(struct device *dev, struct device_attribute *attr,
4615		     char *buf)
4616{
4617	struct st_modedef *STm = dev_get_drvdata(dev);
4618	ssize_t l = 0;
4619
4620	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4621	return l;
4622}
4623static DEVICE_ATTR_RO(default_blksize);
4624
4625static ssize_t
4626default_density_show(struct device *dev, struct device_attribute *attr,
4627		     char *buf)
4628{
4629	struct st_modedef *STm = dev_get_drvdata(dev);
4630	ssize_t l = 0;
4631	char *fmt;
4632
4633	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4634	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4635	return l;
4636}
4637static DEVICE_ATTR_RO(default_density);
4638
4639static ssize_t
4640default_compression_show(struct device *dev, struct device_attribute *attr,
4641			 char *buf)
4642{
4643	struct st_modedef *STm = dev_get_drvdata(dev);
4644	ssize_t l = 0;
4645
4646	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4647	return l;
4648}
4649static DEVICE_ATTR_RO(default_compression);
4650
4651static ssize_t
4652options_show(struct device *dev, struct device_attribute *attr, char *buf)
4653{
4654	struct st_modedef *STm = dev_get_drvdata(dev);
4655	struct scsi_tape *STp = STm->tape;
4656	int options;
4657	ssize_t l = 0;
4658
4659	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4660	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4661	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4662	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4663	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4664	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4665	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4666	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4667	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4668	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4669	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4670	options |= STm->sysv ? MT_ST_SYSV : 0;
4671	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4672	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4673	options |= STp->sili ? MT_ST_SILI : 0;
4674
4675	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4676	return l;
4677}
4678static DEVICE_ATTR_RO(options);
4679
4680/* Support for tape stats */
4681
4682/**
4683 * read_cnt_show - return read count - count of reads made from tape drive
4684 * @dev: struct device
4685 * @attr: attribute structure
4686 * @buf: buffer to return formatted data in
4687 */
4688static ssize_t read_cnt_show(struct device *dev,
4689	struct device_attribute *attr, char *buf)
4690{
4691	struct st_modedef *STm = dev_get_drvdata(dev);
4692
4693	return sprintf(buf, "%lld",
4694		       (long long)atomic64_read(&STm->tape->stats->read_cnt));
4695}
4696static DEVICE_ATTR_RO(read_cnt);
4697
4698/**
4699 * read_byte_cnt_show - return read byte count - tape drives
4700 * may use blocks less than 512 bytes this gives the raw byte count of
4701 * of data read from the tape drive.
4702 * @dev: struct device
4703 * @attr: attribute structure
4704 * @buf: buffer to return formatted data in
4705 */
4706static ssize_t read_byte_cnt_show(struct device *dev,
4707	struct device_attribute *attr, char *buf)
4708{
4709	struct st_modedef *STm = dev_get_drvdata(dev);
4710
4711	return sprintf(buf, "%lld",
4712		       (long long)atomic64_read(&STm->tape->stats->read_byte_cnt));
4713}
4714static DEVICE_ATTR_RO(read_byte_cnt);
4715
4716/**
4717 * read_ns_show - return read ns - overall time spent waiting on reads in ns.
4718 * @dev: struct device
4719 * @attr: attribute structure
4720 * @buf: buffer to return formatted data in
4721 */
4722static ssize_t read_ns_show(struct device *dev,
4723	struct device_attribute *attr, char *buf)
4724{
4725	struct st_modedef *STm = dev_get_drvdata(dev);
4726
4727	return sprintf(buf, "%lld",
4728		       (long long)atomic64_read(&STm->tape->stats->tot_read_time));
4729}
4730static DEVICE_ATTR_RO(read_ns);
4731
4732/**
4733 * write_cnt_show - write count - number of user calls
4734 * to write(2) that have written data to tape.
4735 * @dev: struct device
4736 * @attr: attribute structure
4737 * @buf: buffer to return formatted data in
4738 */
4739static ssize_t write_cnt_show(struct device *dev,
4740	struct device_attribute *attr, char *buf)
4741{
4742	struct st_modedef *STm = dev_get_drvdata(dev);
4743
4744	return sprintf(buf, "%lld",
4745		       (long long)atomic64_read(&STm->tape->stats->write_cnt));
4746}
4747static DEVICE_ATTR_RO(write_cnt);
4748
4749/**
4750 * write_byte_cnt_show - write byte count - raw count of
4751 * bytes written to tape.
4752 * @dev: struct device
4753 * @attr: attribute structure
4754 * @buf: buffer to return formatted data in
4755 */
4756static ssize_t write_byte_cnt_show(struct device *dev,
4757	struct device_attribute *attr, char *buf)
4758{
4759	struct st_modedef *STm = dev_get_drvdata(dev);
4760
4761	return sprintf(buf, "%lld",
4762		       (long long)atomic64_read(&STm->tape->stats->write_byte_cnt));
4763}
4764static DEVICE_ATTR_RO(write_byte_cnt);
4765
4766/**
4767 * write_ns_show - write ns - number of nanoseconds waiting on write
4768 * requests to complete.
4769 * @dev: struct device
4770 * @attr: attribute structure
4771 * @buf: buffer to return formatted data in
4772 */
4773static ssize_t write_ns_show(struct device *dev,
4774	struct device_attribute *attr, char *buf)
4775{
4776	struct st_modedef *STm = dev_get_drvdata(dev);
4777
4778	return sprintf(buf, "%lld",
4779		       (long long)atomic64_read(&STm->tape->stats->tot_write_time));
4780}
4781static DEVICE_ATTR_RO(write_ns);
4782
4783/**
4784 * in_flight_show - number of I/Os currently in flight -
4785 * in most cases this will be either 0 or 1. It may be higher if someone
4786 * has also issued other SCSI commands such as via an ioctl.
4787 * @dev: struct device
4788 * @attr: attribute structure
4789 * @buf: buffer to return formatted data in
4790 */
4791static ssize_t in_flight_show(struct device *dev,
4792	struct device_attribute *attr, char *buf)
4793{
4794	struct st_modedef *STm = dev_get_drvdata(dev);
4795
4796	return sprintf(buf, "%lld",
4797		       (long long)atomic64_read(&STm->tape->stats->in_flight));
4798}
4799static DEVICE_ATTR_RO(in_flight);
4800
4801/**
4802 * io_ns_show - io wait ns - this is the number of ns spent
4803 * waiting on all I/O to complete. This includes tape movement commands
4804 * such as rewinding, seeking to end of file or tape, it also includes
4805 * read and write. To determine the time spent on tape movement
4806 * subtract the read and write ns from this value.
4807 * @dev: struct device
4808 * @attr: attribute structure
4809 * @buf: buffer to return formatted data in
4810 */
4811static ssize_t io_ns_show(struct device *dev,
4812	struct device_attribute *attr, char *buf)
4813{
4814	struct st_modedef *STm = dev_get_drvdata(dev);
4815
4816	return sprintf(buf, "%lld",
4817		       (long long)atomic64_read(&STm->tape->stats->tot_io_time));
4818}
4819static DEVICE_ATTR_RO(io_ns);
4820
4821/**
4822 * other_cnt_show - other io count - this is the number of
4823 * I/O requests other than read and write requests.
4824 * Typically these are tape movement requests but will include driver
4825 * tape movement. This includes only requests issued by the st driver.
4826 * @dev: struct device
4827 * @attr: attribute structure
4828 * @buf: buffer to return formatted data in
4829 */
4830static ssize_t other_cnt_show(struct device *dev,
4831	struct device_attribute *attr, char *buf)
4832{
4833	struct st_modedef *STm = dev_get_drvdata(dev);
4834
4835	return sprintf(buf, "%lld",
4836		       (long long)atomic64_read(&STm->tape->stats->other_cnt));
4837}
4838static DEVICE_ATTR_RO(other_cnt);
4839
4840/**
4841 * resid_cnt_show - A count of the number of times we get a residual
4842 * count - this should indicate someone issuing reads larger than the
4843 * block size on tape.
4844 * @dev: struct device
4845 * @attr: attribute structure
4846 * @buf: buffer to return formatted data in
4847 */
4848static ssize_t resid_cnt_show(struct device *dev,
4849	struct device_attribute *attr, char *buf)
4850{
4851	struct st_modedef *STm = dev_get_drvdata(dev);
4852
4853	return sprintf(buf, "%lld",
4854		       (long long)atomic64_read(&STm->tape->stats->resid_cnt));
4855}
4856static DEVICE_ATTR_RO(resid_cnt);
4857
4858static struct attribute *st_dev_attrs[] = {
4859	&dev_attr_defined.attr,
4860	&dev_attr_default_blksize.attr,
4861	&dev_attr_default_density.attr,
4862	&dev_attr_default_compression.attr,
4863	&dev_attr_options.attr,
4864	NULL,
4865};
4866
4867static struct attribute *st_stats_attrs[] = {
4868	&dev_attr_read_cnt.attr,
4869	&dev_attr_read_byte_cnt.attr,
4870	&dev_attr_read_ns.attr,
4871	&dev_attr_write_cnt.attr,
4872	&dev_attr_write_byte_cnt.attr,
4873	&dev_attr_write_ns.attr,
4874	&dev_attr_in_flight.attr,
4875	&dev_attr_io_ns.attr,
4876	&dev_attr_other_cnt.attr,
4877	&dev_attr_resid_cnt.attr,
4878	NULL,
4879};
4880
4881static struct attribute_group stats_group = {
4882	.name = "stats",
4883	.attrs = st_stats_attrs,
4884};
4885
4886static struct attribute_group st_group = {
4887	.attrs = st_dev_attrs,
4888};
4889
4890static const struct attribute_group *st_dev_groups[] = {
4891	&st_group,
4892	&stats_group,
4893	NULL,
4894};
4895
4896/* The following functions may be useful for a larger audience. */
4897static int sgl_map_user_pages(struct st_buffer *STbp,
4898			      const unsigned int max_pages, unsigned long uaddr,
4899			      size_t count, int rw)
4900{
4901	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4902	unsigned long start = uaddr >> PAGE_SHIFT;
4903	const int nr_pages = end - start;
4904	int res, i, j;
4905	struct page **pages;
4906	struct rq_map_data *mdata = &STbp->map_data;
4907
4908	/* User attempted Overflow! */
4909	if ((uaddr + count) < uaddr)
4910		return -EINVAL;
4911
4912	/* Too big */
4913        if (nr_pages > max_pages)
4914		return -ENOMEM;
4915
4916	/* Hmm? */
4917	if (count == 0)
4918		return 0;
4919
4920	pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
4921	if (pages == NULL)
4922		return -ENOMEM;
4923
4924        /* Try to fault in all of the necessary pages */
4925        /* rw==READ means read from drive, write into memory area */
4926	res = get_user_pages_fast(uaddr, nr_pages, rw == READ ? FOLL_WRITE : 0,
4927				  pages);
 
 
 
4928
4929	/* Errors and no page mapped should return here */
4930	if (res < nr_pages)
4931		goto out_unmap;
4932
4933        for (i=0; i < nr_pages; i++) {
4934                /* FIXME: flush superflous for rw==READ,
4935                 * probably wrong function for rw==WRITE
4936                 */
4937		flush_dcache_page(pages[i]);
4938        }
4939
4940	mdata->offset = uaddr & ~PAGE_MASK;
4941	STbp->mapped_pages = pages;
4942
4943	return nr_pages;
4944 out_unmap:
4945	if (res > 0) {
4946		for (j=0; j < res; j++)
4947			put_page(pages[j]);
4948		res = 0;
4949	}
4950	kfree(pages);
4951	return res;
4952}
4953
4954
4955/* And unmap them... */
4956static int sgl_unmap_user_pages(struct st_buffer *STbp,
4957				const unsigned int nr_pages, int dirtied)
4958{
4959	int i;
4960
4961	for (i=0; i < nr_pages; i++) {
4962		struct page *page = STbp->mapped_pages[i];
4963
4964		if (dirtied)
4965			SetPageDirty(page);
4966		/* FIXME: cache flush missing for rw==READ
4967		 * FIXME: call the correct reference counting function
4968		 */
4969		put_page(page);
4970	}
4971	kfree(STbp->mapped_pages);
4972	STbp->mapped_pages = NULL;
4973
4974	return 0;
4975}