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v4.17
   1/*
   2   SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
   3   file Documentation/scsi/st.txt for more information.
   4
   5   History:
   6   Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
   7   Contribution and ideas from several people including (in alphabetical
   8   order) Klaus Ehrenfried, Eugene Exarevsky, Eric Lee Green, Wolfgang Denk,
   9   Steve Hirsch, Andreas Koppenh"ofer, Michael Leodolter, Eyal Lebedinsky,
  10   Michael Schaefer, J"org Weule, and Eric Youngdale.
  11
  12   Copyright 1992 - 2016 Kai Makisara
  13   email Kai.Makisara@kolumbus.fi
  14
  15   Some small formal changes - aeb, 950809
  16
  17   Last modified: 18-JAN-1998 Richard Gooch <rgooch@atnf.csiro.au> Devfs support
  18 */
  19
  20static const char *verstr = "20160209";
  21
  22#include <linux/module.h>
  23
  24#include <linux/fs.h>
  25#include <linux/kernel.h>
  26#include <linux/sched/signal.h>
  27#include <linux/mm.h>
  28#include <linux/init.h>
  29#include <linux/string.h>
  30#include <linux/slab.h>
  31#include <linux/errno.h>
  32#include <linux/mtio.h>
  33#include <linux/cdrom.h>
  34#include <linux/ioctl.h>
  35#include <linux/fcntl.h>
  36#include <linux/spinlock.h>
  37#include <linux/blkdev.h>
  38#include <linux/moduleparam.h>
  39#include <linux/cdev.h>
  40#include <linux/idr.h>
  41#include <linux/delay.h>
  42#include <linux/mutex.h>
  43
  44#include <linux/uaccess.h>
  45#include <asm/dma.h>
  46
  47#include <scsi/scsi.h>
  48#include <scsi/scsi_dbg.h>
  49#include <scsi/scsi_device.h>
  50#include <scsi/scsi_driver.h>
  51#include <scsi/scsi_eh.h>
  52#include <scsi/scsi_host.h>
  53#include <scsi/scsi_ioctl.h>
  54#include <scsi/sg.h>
  55
  56
  57/* The driver prints some debugging information on the console if DEBUG
  58   is defined and non-zero. */
  59#define DEBUG 1
  60#define NO_DEBUG 0
  61
  62#define ST_DEB_MSG  KERN_NOTICE
  63#if DEBUG
  64/* The message level for the debug messages is currently set to KERN_NOTICE
  65   so that people can easily see the messages. Later when the debugging messages
  66   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
 
  67#define DEB(a) a
  68#define DEBC(a) if (debugging) { a ; }
  69#else
  70#define DEB(a)
  71#define DEBC(a)
  72#endif
  73
  74#define ST_KILOBYTE 1024
  75
  76#include "st_options.h"
  77#include "st.h"
  78
  79static int buffer_kbs;
  80static int max_sg_segs;
  81static int try_direct_io = TRY_DIRECT_IO;
  82static int try_rdio = 1;
  83static int try_wdio = 1;
  84static int debug_flag;
  85
  86static struct class st_sysfs_class;
  87static const struct attribute_group *st_dev_groups[];
  88static const struct attribute_group *st_drv_groups[];
  89
  90MODULE_AUTHOR("Kai Makisara");
  91MODULE_DESCRIPTION("SCSI tape (st) driver");
  92MODULE_LICENSE("GPL");
  93MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  94MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  95
  96/* Set 'perm' (4th argument) to 0 to disable module_param's definition
  97 * of sysfs parameters (which module_param doesn't yet support).
  98 * Sysfs parameters defined explicitly later.
  99 */
 100module_param_named(buffer_kbs, buffer_kbs, int, 0);
 101MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
 102module_param_named(max_sg_segs, max_sg_segs, int, 0);
 103MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 104module_param_named(try_direct_io, try_direct_io, int, 0);
 105MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 106module_param_named(debug_flag, debug_flag, int, 0);
 107MODULE_PARM_DESC(debug_flag, "Enable DEBUG, same as setting debugging=1");
 108
 109
 110/* Extra parameters for testing */
 111module_param_named(try_rdio, try_rdio, int, 0);
 112MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 113module_param_named(try_wdio, try_wdio, int, 0);
 114MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 115
 116#ifndef MODULE
 117static int write_threshold_kbs;  /* retained for compatibility */
 118static struct st_dev_parm {
 119	char *name;
 120	int *val;
 121} parms[] __initdata = {
 122	{
 123		"buffer_kbs", &buffer_kbs
 124	},
 125	{       /* Retained for compatibility with 2.4 */
 126		"write_threshold_kbs", &write_threshold_kbs
 127	},
 128	{
 129		"max_sg_segs", NULL
 130	},
 131	{
 132		"try_direct_io", &try_direct_io
 133	},
 134	{
 135		"debug_flag", &debug_flag
 136	}
 137};
 138#endif
 139
 140/* Restrict the number of modes so that names for all are assigned */
 141#if ST_NBR_MODES > 16
 142#error "Maximum number of modes is 16"
 143#endif
 144/* Bit reversed order to get same names for same minors with all
 145   mode counts */
 146static const char *st_formats[] = {
 147	"",  "r", "k", "s", "l", "t", "o", "u",
 148	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 149
 150/* The default definitions have been moved to st_options.h */
 151
 152#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 153
 154/* The buffer size should fit into the 24 bits for length in the
 155   6-byte SCSI read and write commands. */
 156#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 157#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 158#endif
 159
 160static int debugging = DEBUG;
 161
 162#define MAX_RETRIES 0
 163#define MAX_WRITE_RETRIES 0
 164#define MAX_READY_RETRIES 0
 165#define NO_TAPE  NOT_READY
 166
 167#define ST_TIMEOUT (900 * HZ)
 168#define ST_LONG_TIMEOUT (14000 * HZ)
 169
 170/* Remove mode bits and auto-rewind bit (7) */
 171#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 172    (iminor(x) & ~(-1 << ST_MODE_SHIFT)) )
 173#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 174
 175/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 176#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 177  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 178
 179/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 180   24 bits) */
 181#define SET_DENS_AND_BLK 0x10001
 182
 183static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 184static int st_max_sg_segs = ST_MAX_SG;
 185
 186static int modes_defined;
 187
 188static int enlarge_buffer(struct st_buffer *, int, int);
 189static void clear_buffer(struct st_buffer *);
 190static void normalize_buffer(struct st_buffer *);
 191static int append_to_buffer(const char __user *, struct st_buffer *, int);
 192static int from_buffer(struct st_buffer *, char __user *, int);
 193static void move_buffer_data(struct st_buffer *, int);
 194
 195static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 196			      unsigned long, size_t, int);
 197static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 198
 199static int st_probe(struct device *);
 200static int st_remove(struct device *);
 201
 
 
 
 202static struct scsi_driver st_template = {
 
 203	.gendrv = {
 204		.name		= "st",
 205		.owner		= THIS_MODULE,
 206		.probe		= st_probe,
 207		.remove		= st_remove,
 208		.groups		= st_drv_groups,
 209	},
 210};
 211
 212static int st_compression(struct scsi_tape *, int);
 213
 214static int find_partition(struct scsi_tape *);
 215static int switch_partition(struct scsi_tape *);
 216
 217static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 218
 219static void scsi_tape_release(struct kref *);
 220
 221#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 222
 223static DEFINE_MUTEX(st_ref_mutex);
 224static DEFINE_SPINLOCK(st_index_lock);
 225static DEFINE_SPINLOCK(st_use_lock);
 226static DEFINE_IDR(st_index_idr);
 227
 228
 229
 230#include "osst_detect.h"
 231#ifndef SIGS_FROM_OSST
 232#define SIGS_FROM_OSST \
 233	{"OnStream", "SC-", "", "osst"}, \
 234	{"OnStream", "DI-", "", "osst"}, \
 235	{"OnStream", "DP-", "", "osst"}, \
 236	{"OnStream", "USB", "", "osst"}, \
 237	{"OnStream", "FW-", "", "osst"}
 238#endif
 239
 240static struct scsi_tape *scsi_tape_get(int dev)
 241{
 242	struct scsi_tape *STp = NULL;
 243
 244	mutex_lock(&st_ref_mutex);
 245	spin_lock(&st_index_lock);
 246
 247	STp = idr_find(&st_index_idr, dev);
 248	if (!STp) goto out;
 249
 250	kref_get(&STp->kref);
 251
 252	if (!STp->device)
 253		goto out_put;
 254
 255	if (scsi_device_get(STp->device))
 256		goto out_put;
 257
 258	goto out;
 259
 260out_put:
 261	kref_put(&STp->kref, scsi_tape_release);
 262	STp = NULL;
 263out:
 264	spin_unlock(&st_index_lock);
 265	mutex_unlock(&st_ref_mutex);
 266	return STp;
 267}
 268
 269static void scsi_tape_put(struct scsi_tape *STp)
 270{
 271	struct scsi_device *sdev = STp->device;
 272
 273	mutex_lock(&st_ref_mutex);
 274	kref_put(&STp->kref, scsi_tape_release);
 275	scsi_device_put(sdev);
 276	mutex_unlock(&st_ref_mutex);
 277}
 278
 279struct st_reject_data {
 280	char *vendor;
 281	char *model;
 282	char *rev;
 283	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 284};
 285
 286static struct st_reject_data reject_list[] = {
 287	/* {"XXX", "Yy-", "", NULL},  example */
 288	SIGS_FROM_OSST,
 289	{NULL, }};
 290
 291/* If the device signature is on the list of incompatible drives, the
 292   function returns a pointer to the name of the correct driver (if known) */
 293static char * st_incompatible(struct scsi_device* SDp)
 294{
 295	struct st_reject_data *rp;
 296
 297	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 298		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 299		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 300		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 301			if (rp->driver_hint)
 302				return rp->driver_hint;
 303			else
 304				return "unknown";
 305		}
 306	return NULL;
 307}
 308
 309
 310static inline char *tape_name(struct scsi_tape *tape)
 311{
 312	return tape->disk->disk_name;
 313}
 314
 315#define st_printk(prefix, t, fmt, a...) \
 316	sdev_prefix_printk(prefix, (t)->device, tape_name(t), fmt, ##a)
 317#ifdef DEBUG
 318#define DEBC_printk(t, fmt, a...) \
 319	if (debugging) { st_printk(ST_DEB_MSG, t, fmt, ##a ); }
 320#else
 321#define DEBC_printk(t, fmt, a...)
 322#endif
 323
 324static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 325{
 326	const u8 *ucp;
 327	const u8 *sense = SRpnt->sense;
 328
 329	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 330				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 331	s->flags = 0;
 332
 333	if (s->have_sense) {
 334		s->deferred = 0;
 335		s->remainder_valid =
 336			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 337		switch (sense[0] & 0x7f) {
 338		case 0x71:
 339			s->deferred = 1;
 340		case 0x70:
 341			s->fixed_format = 1;
 342			s->flags = sense[2] & 0xe0;
 343			break;
 344		case 0x73:
 345			s->deferred = 1;
 346		case 0x72:
 347			s->fixed_format = 0;
 348			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 349			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 350			break;
 351		}
 352	}
 353}
 354
 355
 356/* Convert the result to success code */
 357static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 358{
 359	int result = SRpnt->result;
 360	u8 scode;
 361	DEB(const char *stp;)
 362	char *name = tape_name(STp);
 363	struct st_cmdstatus *cmdstatp;
 364
 365	if (!result)
 366		return 0;
 367
 368	cmdstatp = &STp->buffer->cmdstat;
 369	st_analyze_sense(SRpnt, cmdstatp);
 370
 371	if (cmdstatp->have_sense)
 372		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 373	else
 374		scode = 0;
 375
 376	DEB(
 377	if (debugging) {
 378		st_printk(ST_DEB_MSG, STp,
 379			    "Error: %x, cmd: %x %x %x %x %x %x\n", result,
 380			    SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 381			    SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 382		if (cmdstatp->have_sense)
 383			__scsi_print_sense(STp->device, name,
 384					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 385	} ) /* end DEB */
 386	if (!debugging) { /* Abnormal conditions for tape */
 387		if (!cmdstatp->have_sense)
 388			st_printk(KERN_WARNING, STp,
 389			       "Error %x (driver bt 0x%x, host bt 0x%x).\n",
 390			       result, driver_byte(result), host_byte(result));
 
 391		else if (cmdstatp->have_sense &&
 392			 scode != NO_SENSE &&
 393			 scode != RECOVERED_ERROR &&
 394			 /* scode != UNIT_ATTENTION && */
 395			 scode != BLANK_CHECK &&
 396			 scode != VOLUME_OVERFLOW &&
 397			 SRpnt->cmd[0] != MODE_SENSE &&
 398			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 399
 400			__scsi_print_sense(STp->device, name,
 401					   SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 402		}
 403	}
 404
 405	if (cmdstatp->fixed_format &&
 406	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 407		if (STp->cln_sense_value)
 408			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 409					       STp->cln_sense_mask) == STp->cln_sense_value);
 410		else
 411			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 412					       STp->cln_sense_mask) != 0);
 413	}
 414	if (cmdstatp->have_sense &&
 415	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 416		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 417
 418	STp->pos_unknown |= STp->device->was_reset;
 419
 420	if (cmdstatp->have_sense &&
 421	    scode == RECOVERED_ERROR
 422#if ST_RECOVERED_WRITE_FATAL
 423	    && SRpnt->cmd[0] != WRITE_6
 424	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 425#endif
 426	    ) {
 427		STp->recover_count++;
 428		STp->recover_reg++;
 429
 430		DEB(
 431		if (debugging) {
 432			if (SRpnt->cmd[0] == READ_6)
 433				stp = "read";
 434			else if (SRpnt->cmd[0] == WRITE_6)
 435				stp = "write";
 436			else
 437				stp = "ioctl";
 438			st_printk(ST_DEB_MSG, STp,
 439				  "Recovered %s error (%d).\n",
 440				  stp, STp->recover_count);
 441		} ) /* end DEB */
 442
 443		if (cmdstatp->flags == 0)
 444			return 0;
 445	}
 446	return (-EIO);
 447}
 448
 449static struct st_request *st_allocate_request(struct scsi_tape *stp)
 450{
 451	struct st_request *streq;
 452
 453	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 454	if (streq)
 455		streq->stp = stp;
 456	else {
 457		st_printk(KERN_ERR, stp,
 458			  "Can't get SCSI request.\n");
 459		if (signal_pending(current))
 460			stp->buffer->syscall_result = -EINTR;
 461		else
 462			stp->buffer->syscall_result = -EBUSY;
 463	}
 464
 465	return streq;
 466}
 467
 468static void st_release_request(struct st_request *streq)
 469{
 470	kfree(streq);
 471}
 472
 473static void st_do_stats(struct scsi_tape *STp, struct request *req)
 474{
 475	ktime_t now;
 476
 477	now = ktime_get();
 478	if (scsi_req(req)->cmd[0] == WRITE_6) {
 479		now = ktime_sub(now, STp->stats->write_time);
 480		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 481		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 482		atomic64_inc(&STp->stats->write_cnt);
 483		if (scsi_req(req)->result) {
 484			atomic64_add(atomic_read(&STp->stats->last_write_size)
 485				- STp->buffer->cmdstat.residual,
 486				&STp->stats->write_byte_cnt);
 487			if (STp->buffer->cmdstat.residual > 0)
 488				atomic64_inc(&STp->stats->resid_cnt);
 489		} else
 490			atomic64_add(atomic_read(&STp->stats->last_write_size),
 491				&STp->stats->write_byte_cnt);
 492	} else if (scsi_req(req)->cmd[0] == READ_6) {
 493		now = ktime_sub(now, STp->stats->read_time);
 494		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 495		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 496		atomic64_inc(&STp->stats->read_cnt);
 497		if (scsi_req(req)->result) {
 498			atomic64_add(atomic_read(&STp->stats->last_read_size)
 499				- STp->buffer->cmdstat.residual,
 500				&STp->stats->read_byte_cnt);
 501			if (STp->buffer->cmdstat.residual > 0)
 502				atomic64_inc(&STp->stats->resid_cnt);
 503		} else
 504			atomic64_add(atomic_read(&STp->stats->last_read_size),
 505				&STp->stats->read_byte_cnt);
 506	} else {
 507		now = ktime_sub(now, STp->stats->other_time);
 508		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 509		atomic64_inc(&STp->stats->other_cnt);
 510	}
 511	atomic64_dec(&STp->stats->in_flight);
 512}
 513
 514static void st_scsi_execute_end(struct request *req, blk_status_t status)
 515{
 516	struct st_request *SRpnt = req->end_io_data;
 517	struct scsi_request *rq = scsi_req(req);
 518	struct scsi_tape *STp = SRpnt->stp;
 519	struct bio *tmp;
 520
 521	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 522	STp->buffer->cmdstat.residual = rq->resid_len;
 523
 524	st_do_stats(STp, req);
 525
 526	tmp = SRpnt->bio;
 527	if (rq->sense_len)
 528		memcpy(SRpnt->sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
 529	if (SRpnt->waiting)
 530		complete(SRpnt->waiting);
 531
 532	blk_rq_unmap_user(tmp);
 533	__blk_put_request(req->q, req);
 534}
 535
 536static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 537			   int data_direction, void *buffer, unsigned bufflen,
 538			   int timeout, int retries)
 539{
 540	struct request *req;
 541	struct scsi_request *rq;
 542	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 543	int err = 0;
 544	struct scsi_tape *STp = SRpnt->stp;
 545
 546	req = blk_get_request(SRpnt->stp->device->request_queue,
 547			data_direction == DMA_TO_DEVICE ?
 548			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, GFP_KERNEL);
 549	if (IS_ERR(req))
 550		return DRIVER_ERROR << 24;
 551	rq = scsi_req(req);
 552	req->rq_flags |= RQF_QUIET;
 
 553
 554	mdata->null_mapped = 1;
 555
 556	if (bufflen) {
 557		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 558				      GFP_KERNEL);
 559		if (err) {
 560			blk_put_request(req);
 561			return DRIVER_ERROR << 24;
 562		}
 563	}
 564
 565	atomic64_inc(&STp->stats->in_flight);
 566	if (cmd[0] == WRITE_6) {
 567		atomic_set(&STp->stats->last_write_size, bufflen);
 568		STp->stats->write_time = ktime_get();
 569	} else if (cmd[0] == READ_6) {
 570		atomic_set(&STp->stats->last_read_size, bufflen);
 571		STp->stats->read_time = ktime_get();
 572	} else {
 573		STp->stats->other_time = ktime_get();
 574	}
 575
 576	SRpnt->bio = req->bio;
 577	rq->cmd_len = COMMAND_SIZE(cmd[0]);
 578	memset(rq->cmd, 0, BLK_MAX_CDB);
 579	memcpy(rq->cmd, cmd, rq->cmd_len);
 
 
 580	req->timeout = timeout;
 581	rq->retries = retries;
 582	req->end_io_data = SRpnt;
 583
 584	blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
 585	return 0;
 586}
 587
 588/* Do the scsi command. Waits until command performed if do_wait is true.
 589   Otherwise write_behind_check() is used to check that the command
 590   has finished. */
 591static struct st_request *
 592st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 593	   int bytes, int direction, int timeout, int retries, int do_wait)
 594{
 595	struct completion *waiting;
 596	struct rq_map_data *mdata = &STp->buffer->map_data;
 597	int ret;
 598
 599	/* if async, make sure there's no command outstanding */
 600	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 601		st_printk(KERN_ERR, STp,
 602			  "Async command already active.\n");
 603		if (signal_pending(current))
 604			(STp->buffer)->syscall_result = (-EINTR);
 605		else
 606			(STp->buffer)->syscall_result = (-EBUSY);
 607		return NULL;
 608	}
 609
 610	if (!SRpnt) {
 611		SRpnt = st_allocate_request(STp);
 612		if (!SRpnt)
 613			return NULL;
 614	}
 615
 616	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 617	   which IO is outstanding. It's nulled out when the IO completes. */
 618	if (!do_wait)
 619		(STp->buffer)->last_SRpnt = SRpnt;
 620
 621	waiting = &STp->wait;
 622	init_completion(waiting);
 623	SRpnt->waiting = waiting;
 624
 625	if (STp->buffer->do_dio) {
 626		mdata->page_order = 0;
 627		mdata->nr_entries = STp->buffer->sg_segs;
 628		mdata->pages = STp->buffer->mapped_pages;
 629	} else {
 630		mdata->page_order = STp->buffer->reserved_page_order;
 631		mdata->nr_entries =
 632			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 633		mdata->pages = STp->buffer->reserved_pages;
 634		mdata->offset = 0;
 635	}
 636
 637	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 638	STp->buffer->cmdstat.have_sense = 0;
 639	STp->buffer->syscall_result = 0;
 640
 641	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 642			      retries);
 643	if (ret) {
 644		/* could not allocate the buffer or request was too large */
 645		(STp->buffer)->syscall_result = (-EBUSY);
 646		(STp->buffer)->last_SRpnt = NULL;
 647	} else if (do_wait) {
 648		wait_for_completion(waiting);
 649		SRpnt->waiting = NULL;
 650		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 651	}
 652
 653	return SRpnt;
 654}
 655
 656
 657/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 658   write has been correct but EOM early warning reached, -EIO if write ended in
 659   error or zero if write successful. Asynchronous writes are used only in
 660   variable block mode. */
 661static int write_behind_check(struct scsi_tape * STp)
 662{
 663	int retval = 0;
 664	struct st_buffer *STbuffer;
 665	struct st_partstat *STps;
 666	struct st_cmdstatus *cmdstatp;
 667	struct st_request *SRpnt;
 668
 669	STbuffer = STp->buffer;
 670	if (!STbuffer->writing)
 671		return 0;
 672
 673	DEB(
 674	if (STp->write_pending)
 675		STp->nbr_waits++;
 676	else
 677		STp->nbr_finished++;
 678	) /* end DEB */
 679
 680	wait_for_completion(&(STp->wait));
 681	SRpnt = STbuffer->last_SRpnt;
 682	STbuffer->last_SRpnt = NULL;
 683	SRpnt->waiting = NULL;
 684
 685	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 686	st_release_request(SRpnt);
 687
 688	STbuffer->buffer_bytes -= STbuffer->writing;
 689	STps = &(STp->ps[STp->partition]);
 690	if (STps->drv_block >= 0) {
 691		if (STp->block_size == 0)
 692			STps->drv_block++;
 693		else
 694			STps->drv_block += STbuffer->writing / STp->block_size;
 695	}
 696
 697	cmdstatp = &STbuffer->cmdstat;
 698	if (STbuffer->syscall_result) {
 699		retval = -EIO;
 700		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 701		    (cmdstatp->flags & SENSE_EOM) &&
 702		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 703		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 704			/* EOM at write-behind, has all data been written? */
 705			if (!cmdstatp->remainder_valid ||
 706			    cmdstatp->uremainder64 == 0)
 707				retval = -ENOSPC;
 708		}
 709		if (retval == -EIO)
 710			STps->drv_block = -1;
 711	}
 712	STbuffer->writing = 0;
 713
 714	DEB(if (debugging && retval)
 715		    st_printk(ST_DEB_MSG, STp,
 716				"Async write error %x, return value %d.\n",
 717				STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 718
 719	return retval;
 720}
 721
 722
 723/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 724   it messes up the block number). */
 725static int cross_eof(struct scsi_tape * STp, int forward)
 726{
 727	struct st_request *SRpnt;
 728	unsigned char cmd[MAX_COMMAND_SIZE];
 729
 730	cmd[0] = SPACE;
 731	cmd[1] = 0x01;		/* Space FileMarks */
 732	if (forward) {
 733		cmd[2] = cmd[3] = 0;
 734		cmd[4] = 1;
 735	} else
 736		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 737	cmd[5] = 0;
 738
 739	DEBC_printk(STp, "Stepping over filemark %s.\n",
 740		    forward ? "forward" : "backward");
 741
 742	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 743			   STp->device->request_queue->rq_timeout,
 744			   MAX_RETRIES, 1);
 745	if (!SRpnt)
 746		return (STp->buffer)->syscall_result;
 747
 748	st_release_request(SRpnt);
 749	SRpnt = NULL;
 750
 751	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 752		st_printk(KERN_ERR, STp,
 753			  "Stepping over filemark %s failed.\n",
 754			  forward ? "forward" : "backward");
 755
 756	return (STp->buffer)->syscall_result;
 757}
 758
 759
 760/* Flush the write buffer (never need to write if variable blocksize). */
 761static int st_flush_write_buffer(struct scsi_tape * STp)
 762{
 763	int transfer, blks;
 764	int result;
 765	unsigned char cmd[MAX_COMMAND_SIZE];
 766	struct st_request *SRpnt;
 767	struct st_partstat *STps;
 768
 769	result = write_behind_check(STp);
 770	if (result)
 771		return result;
 772
 773	result = 0;
 774	if (STp->dirty == 1) {
 775
 776		transfer = STp->buffer->buffer_bytes;
 777		DEBC_printk(STp, "Flushing %d bytes.\n", transfer);
 
 778
 779		memset(cmd, 0, MAX_COMMAND_SIZE);
 780		cmd[0] = WRITE_6;
 781		cmd[1] = 1;
 782		blks = transfer / STp->block_size;
 783		cmd[2] = blks >> 16;
 784		cmd[3] = blks >> 8;
 785		cmd[4] = blks;
 786
 787		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 788				   STp->device->request_queue->rq_timeout,
 789				   MAX_WRITE_RETRIES, 1);
 790		if (!SRpnt)
 791			return (STp->buffer)->syscall_result;
 792
 793		STps = &(STp->ps[STp->partition]);
 794		if ((STp->buffer)->syscall_result != 0) {
 795			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 796
 797			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 798			    (cmdstatp->flags & SENSE_EOM) &&
 799			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 800			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 801			    (!cmdstatp->remainder_valid ||
 802			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 803				STp->dirty = 0;
 804				(STp->buffer)->buffer_bytes = 0;
 805				if (STps->drv_block >= 0)
 806					STps->drv_block += blks;
 807				result = (-ENOSPC);
 808			} else {
 809				st_printk(KERN_ERR, STp, "Error on flush.\n");
 
 810				STps->drv_block = (-1);
 811				result = (-EIO);
 812			}
 813		} else {
 814			if (STps->drv_block >= 0)
 815				STps->drv_block += blks;
 816			STp->dirty = 0;
 817			(STp->buffer)->buffer_bytes = 0;
 818		}
 819		st_release_request(SRpnt);
 820		SRpnt = NULL;
 821	}
 822	return result;
 823}
 824
 825
 826/* Flush the tape buffer. The tape will be positioned correctly unless
 827   seek_next is true. */
 828static int flush_buffer(struct scsi_tape *STp, int seek_next)
 829{
 830	int backspace, result;
 831	struct st_buffer *STbuffer;
 832	struct st_partstat *STps;
 833
 834	STbuffer = STp->buffer;
 835
 836	/*
 837	 * If there was a bus reset, block further access
 838	 * to this device.
 839	 */
 840	if (STp->pos_unknown)
 841		return (-EIO);
 842
 843	if (STp->ready != ST_READY)
 844		return 0;
 845	STps = &(STp->ps[STp->partition]);
 846	if (STps->rw == ST_WRITING)	/* Writing */
 847		return st_flush_write_buffer(STp);
 848
 849	if (STp->block_size == 0)
 850		return 0;
 851
 852	backspace = ((STp->buffer)->buffer_bytes +
 853		     (STp->buffer)->read_pointer) / STp->block_size -
 854	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 855	    STp->block_size;
 856	(STp->buffer)->buffer_bytes = 0;
 857	(STp->buffer)->read_pointer = 0;
 858	result = 0;
 859	if (!seek_next) {
 860		if (STps->eof == ST_FM_HIT) {
 861			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 862			if (!result)
 863				STps->eof = ST_NOEOF;
 864			else {
 865				if (STps->drv_file >= 0)
 866					STps->drv_file++;
 867				STps->drv_block = 0;
 868			}
 869		}
 870		if (!result && backspace > 0)
 871			result = st_int_ioctl(STp, MTBSR, backspace);
 872	} else if (STps->eof == ST_FM_HIT) {
 873		if (STps->drv_file >= 0)
 874			STps->drv_file++;
 875		STps->drv_block = 0;
 876		STps->eof = ST_NOEOF;
 877	}
 878	return result;
 879
 880}
 881
 882/* Set the mode parameters */
 883static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 884{
 885	int set_it = 0;
 886	unsigned long arg;
 
 887
 888	if (!STp->density_changed &&
 889	    STm->default_density >= 0 &&
 890	    STm->default_density != STp->density) {
 891		arg = STm->default_density;
 892		set_it = 1;
 893	} else
 894		arg = STp->density;
 895	arg <<= MT_ST_DENSITY_SHIFT;
 896	if (!STp->blksize_changed &&
 897	    STm->default_blksize >= 0 &&
 898	    STm->default_blksize != STp->block_size) {
 899		arg |= STm->default_blksize;
 900		set_it = 1;
 901	} else
 902		arg |= STp->block_size;
 903	if (set_it &&
 904	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 905		st_printk(KERN_WARNING, STp,
 906			  "Can't set default block size to %d bytes "
 907			  "and density %x.\n",
 908			  STm->default_blksize, STm->default_density);
 909		if (modes_defined)
 910			return (-EINVAL);
 911	}
 912	return 0;
 913}
 914
 915
 916/* Lock or unlock the drive door. Don't use when st_request allocated. */
 917static int do_door_lock(struct scsi_tape * STp, int do_lock)
 918{
 919	int retval;
 
 920
 921	DEBC_printk(STp, "%socking drive door.\n", do_lock ? "L" : "Unl");
 922
 923	retval = scsi_set_medium_removal(STp->device,
 924			do_lock ? SCSI_REMOVAL_PREVENT : SCSI_REMOVAL_ALLOW);
 925	if (!retval)
 
 
 926		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 927	else
 
 928		STp->door_locked = ST_LOCK_FAILS;
 
 929	return retval;
 930}
 931
 932
 933/* Set the internal state after reset */
 934static void reset_state(struct scsi_tape *STp)
 935{
 936	int i;
 937	struct st_partstat *STps;
 938
 939	STp->pos_unknown = 0;
 940	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 941		STps = &(STp->ps[i]);
 942		STps->rw = ST_IDLE;
 943		STps->eof = ST_NOEOF;
 944		STps->at_sm = 0;
 945		STps->last_block_valid = 0;
 946		STps->drv_block = -1;
 947		STps->drv_file = -1;
 948	}
 949	if (STp->can_partitions) {
 950		STp->partition = find_partition(STp);
 951		if (STp->partition < 0)
 952			STp->partition = 0;
 953		STp->new_partition = STp->partition;
 954	}
 955}
 956
 957/* Test if the drive is ready. Returns either one of the codes below or a negative system
 958   error code. */
 959#define CHKRES_READY       0
 960#define CHKRES_NEW_SESSION 1
 961#define CHKRES_NOT_READY   2
 962#define CHKRES_NO_TAPE     3
 963
 964#define MAX_ATTENTIONS    10
 965
 966static int test_ready(struct scsi_tape *STp, int do_wait)
 967{
 968	int attentions, waits, max_wait, scode;
 969	int retval = CHKRES_READY, new_session = 0;
 970	unsigned char cmd[MAX_COMMAND_SIZE];
 971	struct st_request *SRpnt = NULL;
 972	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 973
 974	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 975
 976	for (attentions=waits=0; ; ) {
 977		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 978		cmd[0] = TEST_UNIT_READY;
 979		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 980				   STp->long_timeout, MAX_READY_RETRIES, 1);
 981
 982		if (!SRpnt) {
 983			retval = (STp->buffer)->syscall_result;
 984			break;
 985		}
 986
 987		if (cmdstatp->have_sense) {
 988
 989			scode = cmdstatp->sense_hdr.sense_key;
 990
 991			if (scode == UNIT_ATTENTION) { /* New media? */
 992				new_session = 1;
 993				if (attentions < MAX_ATTENTIONS) {
 994					attentions++;
 995					continue;
 996				}
 997				else {
 998					retval = (-EIO);
 999					break;
1000				}
1001			}
1002
1003			if (scode == NOT_READY) {
1004				if (waits < max_wait) {
1005					if (msleep_interruptible(1000)) {
1006						retval = (-EINTR);
1007						break;
1008					}
1009					waits++;
1010					continue;
1011				}
1012				else {
1013					if ((STp->device)->scsi_level >= SCSI_2 &&
1014					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
1015						retval = CHKRES_NO_TAPE;
1016					else
1017						retval = CHKRES_NOT_READY;
1018					break;
1019				}
1020			}
1021		}
1022
1023		retval = (STp->buffer)->syscall_result;
1024		if (!retval)
1025			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
1026		break;
1027	}
1028
1029	if (SRpnt != NULL)
1030		st_release_request(SRpnt);
1031	return retval;
1032}
1033
1034
1035/* See if the drive is ready and gather information about the tape. Return values:
1036   < 0   negative error code from errno.h
1037   0     drive ready
1038   1     drive not ready (possibly no tape)
1039*/
1040static int check_tape(struct scsi_tape *STp, struct file *filp)
1041{
1042	int i, retval, new_session = 0, do_wait;
1043	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
1044	unsigned short st_flags = filp->f_flags;
1045	struct st_request *SRpnt = NULL;
1046	struct st_modedef *STm;
1047	struct st_partstat *STps;
 
1048	struct inode *inode = file_inode(filp);
1049	int mode = TAPE_MODE(inode);
1050
1051	STp->ready = ST_READY;
1052
1053	if (mode != STp->current_mode) {
1054		DEBC_printk(STp, "Mode change from %d to %d.\n",
1055			    STp->current_mode, mode);
1056		new_session = 1;
1057		STp->current_mode = mode;
1058	}
1059	STm = &(STp->modes[STp->current_mode]);
1060
1061	saved_cleaning = STp->cleaning_req;
1062	STp->cleaning_req = 0;
1063
1064	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1065	retval = test_ready(STp, do_wait);
1066
1067	if (retval < 0)
1068	    goto err_out;
1069
1070	if (retval == CHKRES_NEW_SESSION) {
1071		STp->pos_unknown = 0;
1072		STp->partition = STp->new_partition = 0;
1073		if (STp->can_partitions)
1074			STp->nbr_partitions = 1; /* This guess will be updated later
1075                                                    if necessary */
1076		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1077			STps = &(STp->ps[i]);
1078			STps->rw = ST_IDLE;
1079			STps->eof = ST_NOEOF;
1080			STps->at_sm = 0;
1081			STps->last_block_valid = 0;
1082			STps->drv_block = 0;
1083			STps->drv_file = 0;
1084		}
1085		new_session = 1;
1086	}
1087	else {
1088		STp->cleaning_req |= saved_cleaning;
1089
1090		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1091			if (retval == CHKRES_NO_TAPE)
1092				STp->ready = ST_NO_TAPE;
1093			else
1094				STp->ready = ST_NOT_READY;
1095
1096			STp->density = 0;	/* Clear the erroneous "residue" */
1097			STp->write_prot = 0;
1098			STp->block_size = 0;
1099			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1100			STp->partition = STp->new_partition = 0;
1101			STp->door_locked = ST_UNLOCKED;
1102			return CHKRES_NOT_READY;
1103		}
1104	}
1105
1106	if (STp->omit_blklims)
1107		STp->min_block = STp->max_block = (-1);
1108	else {
1109		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1110		cmd[0] = READ_BLOCK_LIMITS;
1111
1112		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1113				   STp->device->request_queue->rq_timeout,
1114				   MAX_READY_RETRIES, 1);
1115		if (!SRpnt) {
1116			retval = (STp->buffer)->syscall_result;
1117			goto err_out;
1118		}
1119
1120		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1121			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1122			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1123			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1124			    (STp->buffer)->b_data[5];
1125			if ( DEB( debugging || ) !STp->inited)
1126				st_printk(KERN_INFO, STp,
1127					  "Block limits %d - %d bytes.\n",
1128					  STp->min_block, STp->max_block);
1129		} else {
1130			STp->min_block = STp->max_block = (-1);
1131			DEBC_printk(STp, "Can't read block limits.\n");
 
1132		}
1133	}
1134
1135	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1136	cmd[0] = MODE_SENSE;
1137	cmd[4] = 12;
1138
1139	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1140			   STp->device->request_queue->rq_timeout,
1141			   MAX_READY_RETRIES, 1);
1142	if (!SRpnt) {
1143		retval = (STp->buffer)->syscall_result;
1144		goto err_out;
1145	}
1146
1147	if ((STp->buffer)->syscall_result != 0) {
1148		DEBC_printk(STp, "No Mode Sense.\n");
1149		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1150		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1151		STp->drv_write_prot = 0;
1152	} else {
1153		DEBC_printk(STp,"Mode sense. Length %d, "
1154			    "medium %x, WBS %x, BLL %d\n",
1155			    (STp->buffer)->b_data[0],
1156			    (STp->buffer)->b_data[1],
1157			    (STp->buffer)->b_data[2],
1158			    (STp->buffer)->b_data[3]);
1159
1160		if ((STp->buffer)->b_data[3] >= 8) {
1161			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1162			STp->density = (STp->buffer)->b_data[4];
1163			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1164			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1165			DEBC_printk(STp, "Density %x, tape length: %x, "
1166				    "drv buffer: %d\n",
1167				    STp->density,
1168				    (STp->buffer)->b_data[5] * 65536 +
1169				    (STp->buffer)->b_data[6] * 256 +
1170				    (STp->buffer)->b_data[7],
1171				    STp->drv_buffer);
1172		}
1173		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1174		if (!STp->drv_buffer && STp->immediate_filemark) {
1175			st_printk(KERN_WARNING, STp,
1176				  "non-buffered tape: disabling "
1177				  "writing immediate filemarks\n");
1178			STp->immediate_filemark = 0;
1179		}
1180	}
1181	st_release_request(SRpnt);
1182	SRpnt = NULL;
1183	STp->inited = 1;
1184
1185	if (STp->block_size > 0)
1186		(STp->buffer)->buffer_blocks =
1187			(STp->buffer)->buffer_size / STp->block_size;
1188	else
1189		(STp->buffer)->buffer_blocks = 1;
1190	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1191
1192	DEBC_printk(STp, "Block size: %d, buffer size: %d (%d blocks).\n",
1193		    STp->block_size, (STp->buffer)->buffer_size,
1194		    (STp->buffer)->buffer_blocks);
 
1195
1196	if (STp->drv_write_prot) {
1197		STp->write_prot = 1;
1198
1199		DEBC_printk(STp, "Write protected\n");
1200
1201		if (do_wait &&
1202		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1203		     (st_flags & O_ACCMODE) == O_RDWR)) {
1204			retval = (-EROFS);
1205			goto err_out;
1206		}
1207	}
1208
1209	if (STp->can_partitions && STp->nbr_partitions < 1) {
1210		/* This code is reached when the device is opened for the first time
1211		   after the driver has been initialized with tape in the drive and the
1212		   partition support has been enabled. */
1213		DEBC_printk(STp, "Updating partition number in status.\n");
 
1214		if ((STp->partition = find_partition(STp)) < 0) {
1215			retval = STp->partition;
1216			goto err_out;
1217		}
1218		STp->new_partition = STp->partition;
1219		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1220	}
1221
1222	if (new_session) {	/* Change the drive parameters for the new mode */
1223		STp->density_changed = STp->blksize_changed = 0;
1224		STp->compression_changed = 0;
1225		if (!(STm->defaults_for_writes) &&
1226		    (retval = set_mode_densblk(STp, STm)) < 0)
1227		    goto err_out;
1228
1229		if (STp->default_drvbuffer != 0xff) {
1230			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1231				st_printk(KERN_WARNING, STp,
1232					  "Can't set default drive "
1233					  "buffering to %d.\n",
1234					  STp->default_drvbuffer);
1235		}
1236	}
1237
1238	return CHKRES_READY;
1239
1240 err_out:
1241	return retval;
1242}
1243
1244
1245/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1246   module count. */
1247static int st_open(struct inode *inode, struct file *filp)
1248{
1249	int i, retval = (-EIO);
1250	int resumed = 0;
1251	struct scsi_tape *STp;
1252	struct st_partstat *STps;
1253	int dev = TAPE_NR(inode);
 
1254
1255	/*
1256	 * We really want to do nonseekable_open(inode, filp); here, but some
1257	 * versions of tar incorrectly call lseek on tapes and bail out if that
1258	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1259	 */
1260	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1261
1262	if (!(STp = scsi_tape_get(dev))) {
1263		return -ENXIO;
1264	}
1265
1266	filp->private_data = STp;
 
1267
1268	spin_lock(&st_use_lock);
1269	if (STp->in_use) {
1270		spin_unlock(&st_use_lock);
1271		scsi_tape_put(STp);
1272		DEBC_printk(STp, "Device already in use.\n");
1273		return (-EBUSY);
1274	}
1275
1276	STp->in_use = 1;
1277	spin_unlock(&st_use_lock);
1278	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1279
1280	if (scsi_autopm_get_device(STp->device) < 0) {
1281		retval = -EIO;
1282		goto err_out;
1283	}
1284	resumed = 1;
1285	if (!scsi_block_when_processing_errors(STp->device)) {
1286		retval = (-ENXIO);
1287		goto err_out;
1288	}
1289
1290	/* See that we have at least a one page buffer available */
1291	if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1292		st_printk(KERN_WARNING, STp,
1293			  "Can't allocate one page tape buffer.\n");
1294		retval = (-EOVERFLOW);
1295		goto err_out;
1296	}
1297
1298	(STp->buffer)->cleared = 0;
1299	(STp->buffer)->writing = 0;
1300	(STp->buffer)->syscall_result = 0;
1301
1302	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1303
1304	STp->dirty = 0;
1305	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1306		STps = &(STp->ps[i]);
1307		STps->rw = ST_IDLE;
1308	}
1309	STp->try_dio_now = STp->try_dio;
1310	STp->recover_count = 0;
1311	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1312	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1313
1314	retval = check_tape(STp, filp);
1315	if (retval < 0)
1316		goto err_out;
1317	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1318	    retval != CHKRES_READY) {
1319		if (STp->ready == NO_TAPE)
1320			retval = (-ENOMEDIUM);
1321		else
1322			retval = (-EIO);
1323		goto err_out;
1324	}
1325	return 0;
1326
1327 err_out:
1328	normalize_buffer(STp->buffer);
1329	spin_lock(&st_use_lock);
1330	STp->in_use = 0;
1331	spin_unlock(&st_use_lock);
 
1332	if (resumed)
1333		scsi_autopm_put_device(STp->device);
1334	scsi_tape_put(STp);
1335	return retval;
1336
1337}
1338
1339
1340/* Flush the tape buffer before close */
1341static int st_flush(struct file *filp, fl_owner_t id)
1342{
1343	int result = 0, result2;
1344	unsigned char cmd[MAX_COMMAND_SIZE];
1345	struct st_request *SRpnt;
1346	struct scsi_tape *STp = filp->private_data;
1347	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1348	struct st_partstat *STps = &(STp->ps[STp->partition]);
 
1349
1350	if (file_count(filp) > 1)
1351		return 0;
1352
1353	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1354		result = st_flush_write_buffer(STp);
1355		if (result != 0 && result != (-ENOSPC))
1356			goto out;
1357	}
1358
1359	if (STp->can_partitions &&
1360	    (result2 = switch_partition(STp)) < 0) {
1361		DEBC_printk(STp, "switch_partition at close failed.\n");
 
1362		if (result == 0)
1363			result = result2;
1364		goto out;
1365	}
1366
1367	DEBC( if (STp->nbr_requests)
1368		st_printk(KERN_DEBUG, STp,
1369			  "Number of r/w requests %d, dio used in %d, "
1370			  "pages %d.\n", STp->nbr_requests, STp->nbr_dio,
1371			  STp->nbr_pages));
1372
1373	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1374		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1375
1376#if DEBUG
1377		DEBC_printk(STp, "Async write waits %d, finished %d.\n",
1378			    STp->nbr_waits, STp->nbr_finished);
1379#endif
1380		memset(cmd, 0, MAX_COMMAND_SIZE);
1381		cmd[0] = WRITE_FILEMARKS;
1382		if (STp->immediate_filemark)
1383			cmd[1] = 1;
1384		cmd[4] = 1 + STp->two_fm;
1385
1386		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1387				   STp->device->request_queue->rq_timeout,
1388				   MAX_WRITE_RETRIES, 1);
1389		if (!SRpnt) {
1390			result = (STp->buffer)->syscall_result;
1391			goto out;
1392		}
1393
1394		if (STp->buffer->syscall_result == 0 ||
1395		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1396		     (cmdstatp->flags & SENSE_EOM) &&
1397		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1398		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1399		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1400			/* Write successful at EOM */
1401			st_release_request(SRpnt);
1402			SRpnt = NULL;
1403			if (STps->drv_file >= 0)
1404				STps->drv_file++;
1405			STps->drv_block = 0;
1406			if (STp->two_fm)
1407				cross_eof(STp, 0);
1408			STps->eof = ST_FM;
1409		}
1410		else { /* Write error */
1411			st_release_request(SRpnt);
1412			SRpnt = NULL;
1413			st_printk(KERN_ERR, STp,
1414				  "Error on write filemark.\n");
1415			if (result == 0)
1416				result = (-EIO);
1417		}
1418
1419		DEBC_printk(STp, "Buffer flushed, %d EOF(s) written\n", cmd[4]);
 
1420	} else if (!STp->rew_at_close) {
1421		STps = &(STp->ps[STp->partition]);
1422		if (!STm->sysv || STps->rw != ST_READING) {
1423			if (STp->can_bsr)
1424				result = flush_buffer(STp, 0);
1425			else if (STps->eof == ST_FM_HIT) {
1426				result = cross_eof(STp, 0);
1427				if (result) {
1428					if (STps->drv_file >= 0)
1429						STps->drv_file++;
1430					STps->drv_block = 0;
1431					STps->eof = ST_FM;
1432				} else
1433					STps->eof = ST_NOEOF;
1434			}
1435		} else if ((STps->eof == ST_NOEOF &&
1436			    !(result = cross_eof(STp, 1))) ||
1437			   STps->eof == ST_FM_HIT) {
1438			if (STps->drv_file >= 0)
1439				STps->drv_file++;
1440			STps->drv_block = 0;
1441			STps->eof = ST_FM;
1442		}
1443	}
1444
1445      out:
1446	if (STp->rew_at_close) {
1447		result2 = st_int_ioctl(STp, MTREW, 1);
1448		if (result == 0)
1449			result = result2;
1450	}
1451	return result;
1452}
1453
1454
1455/* Close the device and release it. BKL is not needed: this is the only thread
1456   accessing this tape. */
1457static int st_release(struct inode *inode, struct file *filp)
1458{
1459	int result = 0;
1460	struct scsi_tape *STp = filp->private_data;
1461
1462	if (STp->door_locked == ST_LOCKED_AUTO)
1463		do_door_lock(STp, 0);
1464
1465	normalize_buffer(STp->buffer);
1466	spin_lock(&st_use_lock);
1467	STp->in_use = 0;
1468	spin_unlock(&st_use_lock);
1469	scsi_autopm_put_device(STp->device);
1470	scsi_tape_put(STp);
1471
1472	return result;
1473}
1474
1475/* The checks common to both reading and writing */
1476static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1477{
1478	ssize_t retval = 0;
1479
1480	/*
1481	 * If we are in the middle of error recovery, don't let anyone
1482	 * else try and use this device.  Also, if error recovery fails, it
1483	 * may try and take the device offline, in which case all further
1484	 * access to the device is prohibited.
1485	 */
1486	if (!scsi_block_when_processing_errors(STp->device)) {
1487		retval = (-ENXIO);
1488		goto out;
1489	}
1490
1491	if (STp->ready != ST_READY) {
1492		if (STp->ready == ST_NO_TAPE)
1493			retval = (-ENOMEDIUM);
1494		else
1495			retval = (-EIO);
1496		goto out;
1497	}
1498
1499	if (! STp->modes[STp->current_mode].defined) {
1500		retval = (-ENXIO);
1501		goto out;
1502	}
1503
1504
1505	/*
1506	 * If there was a bus reset, block further access
1507	 * to this device.
1508	 */
1509	if (STp->pos_unknown) {
1510		retval = (-EIO);
1511		goto out;
1512	}
1513
1514	if (count == 0)
1515		goto out;
1516
1517	DEB(
1518	if (!STp->in_use) {
1519		st_printk(ST_DEB_MSG, STp,
1520			  "Incorrect device.\n");
1521		retval = (-EIO);
1522		goto out;
1523	} ) /* end DEB */
1524
1525	if (STp->can_partitions &&
1526	    (retval = switch_partition(STp)) < 0)
1527		goto out;
1528
1529	if (STp->block_size == 0 && STp->max_block > 0 &&
1530	    (count < STp->min_block || count > STp->max_block)) {
1531		retval = (-EINVAL);
1532		goto out;
1533	}
1534
1535	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1536	    !do_door_lock(STp, 1))
1537		STp->door_locked = ST_LOCKED_AUTO;
1538
1539 out:
1540	return retval;
1541}
1542
1543
1544static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1545			   size_t count, int is_read)
1546{
1547	int i, bufsize, retval = 0;
1548	struct st_buffer *STbp = STp->buffer;
1549
1550	if (is_read)
1551		i = STp->try_dio_now && try_rdio;
1552	else
1553		i = STp->try_dio_now && try_wdio;
1554
1555	if (i && ((unsigned long)buf & queue_dma_alignment(
1556					STp->device->request_queue)) == 0) {
1557		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1558				       count, (is_read ? READ : WRITE));
1559		if (i > 0) {
1560			STbp->do_dio = i;
1561			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1562		}
1563		else
1564			STbp->do_dio = 0;  /* fall back to buffering with any error */
1565		STbp->sg_segs = STbp->do_dio;
1566		DEB(
1567		     if (STbp->do_dio) {
1568			STp->nbr_dio++;
1569			STp->nbr_pages += STbp->do_dio;
1570		     }
1571		)
1572	} else
1573		STbp->do_dio = 0;
1574	DEB( STp->nbr_requests++; )
1575
1576	if (!STbp->do_dio) {
1577		if (STp->block_size)
1578			bufsize = STp->block_size > st_fixed_buffer_size ?
1579				STp->block_size : st_fixed_buffer_size;
1580		else {
1581			bufsize = count;
1582			/* Make sure that data from previous user is not leaked even if
1583			   HBA does not return correct residual */
1584			if (is_read && STp->sili && !STbp->cleared)
1585				clear_buffer(STbp);
1586		}
1587
1588		if (bufsize > STbp->buffer_size &&
1589		    !enlarge_buffer(STbp, bufsize, STp->restr_dma)) {
1590			st_printk(KERN_WARNING, STp,
1591				  "Can't allocate %d byte tape buffer.\n",
1592				  bufsize);
1593			retval = (-EOVERFLOW);
1594			goto out;
1595		}
1596		if (STp->block_size)
1597			STbp->buffer_blocks = bufsize / STp->block_size;
1598	}
1599
1600 out:
1601	return retval;
1602}
1603
1604
1605/* Can be called more than once after each setup_buffer() */
1606static void release_buffering(struct scsi_tape *STp, int is_read)
1607{
1608	struct st_buffer *STbp;
1609
1610	STbp = STp->buffer;
1611	if (STbp->do_dio) {
1612		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1613		STbp->do_dio = 0;
1614		STbp->sg_segs = 0;
1615	}
1616}
1617
1618
1619/* Write command */
1620static ssize_t
1621st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1622{
1623	ssize_t total;
1624	ssize_t i, do_count, blks, transfer;
1625	ssize_t retval;
1626	int undone, retry_eot = 0, scode;
1627	int async_write;
1628	unsigned char cmd[MAX_COMMAND_SIZE];
1629	const char __user *b_point;
1630	struct st_request *SRpnt = NULL;
1631	struct scsi_tape *STp = filp->private_data;
1632	struct st_modedef *STm;
1633	struct st_partstat *STps;
1634	struct st_buffer *STbp;
 
1635
1636	if (mutex_lock_interruptible(&STp->lock))
1637		return -ERESTARTSYS;
1638
1639	retval = rw_checks(STp, filp, count);
1640	if (retval || count == 0)
1641		goto out;
1642
1643	/* Write must be integral number of blocks */
1644	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1645		st_printk(KERN_WARNING, STp,
1646			  "Write not multiple of tape block size.\n");
1647		retval = (-EINVAL);
1648		goto out;
1649	}
1650
1651	STm = &(STp->modes[STp->current_mode]);
1652	STps = &(STp->ps[STp->partition]);
1653
1654	if (STp->write_prot) {
1655		retval = (-EACCES);
1656		goto out;
1657	}
1658
1659
1660	if (STps->rw == ST_READING) {
1661		retval = flush_buffer(STp, 0);
1662		if (retval)
1663			goto out;
1664		STps->rw = ST_WRITING;
1665	} else if (STps->rw != ST_WRITING &&
1666		   STps->drv_file == 0 && STps->drv_block == 0) {
1667		if ((retval = set_mode_densblk(STp, STm)) < 0)
1668			goto out;
1669		if (STm->default_compression != ST_DONT_TOUCH &&
1670		    !(STp->compression_changed)) {
1671			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1672				st_printk(KERN_WARNING, STp,
1673					  "Can't set default compression.\n");
1674				if (modes_defined) {
1675					retval = (-EINVAL);
1676					goto out;
1677				}
1678			}
1679		}
1680	}
1681
1682	STbp = STp->buffer;
1683	i = write_behind_check(STp);
1684	if (i) {
1685		if (i == -ENOSPC)
1686			STps->eof = ST_EOM_OK;
1687		else
1688			STps->eof = ST_EOM_ERROR;
1689	}
1690
1691	if (STps->eof == ST_EOM_OK) {
1692		STps->eof = ST_EOD_1;  /* allow next write */
1693		retval = (-ENOSPC);
1694		goto out;
1695	}
1696	else if (STps->eof == ST_EOM_ERROR) {
1697		retval = (-EIO);
1698		goto out;
1699	}
1700
1701	/* Check the buffer readability in cases where copy_user might catch
1702	   the problems after some tape movement. */
1703	if (STp->block_size != 0 &&
1704	    !STbp->do_dio &&
1705	    (copy_from_user(&i, buf, 1) != 0 ||
1706	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1707		retval = (-EFAULT);
1708		goto out;
1709	}
1710
1711	retval = setup_buffering(STp, buf, count, 0);
1712	if (retval)
1713		goto out;
1714
1715	total = count;
1716
1717	memset(cmd, 0, MAX_COMMAND_SIZE);
1718	cmd[0] = WRITE_6;
1719	cmd[1] = (STp->block_size != 0);
1720
1721	STps->rw = ST_WRITING;
1722
1723	b_point = buf;
1724	while (count > 0 && !retry_eot) {
1725
1726		if (STbp->do_dio) {
1727			do_count = count;
1728		}
1729		else {
1730			if (STp->block_size == 0)
1731				do_count = count;
1732			else {
1733				do_count = STbp->buffer_blocks * STp->block_size -
1734					STbp->buffer_bytes;
1735				if (do_count > count)
1736					do_count = count;
1737			}
1738
1739			i = append_to_buffer(b_point, STbp, do_count);
1740			if (i) {
1741				retval = i;
1742				goto out;
1743			}
1744		}
1745		count -= do_count;
1746		b_point += do_count;
1747
1748		async_write = STp->block_size == 0 && !STbp->do_dio &&
1749			STm->do_async_writes && STps->eof < ST_EOM_OK;
1750
1751		if (STp->block_size != 0 && STm->do_buffer_writes &&
1752		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1753		    STbp->buffer_bytes < STbp->buffer_size) {
1754			STp->dirty = 1;
1755			/* Don't write a buffer that is not full enough. */
1756			if (!async_write && count == 0)
1757				break;
1758		}
1759
1760	retry_write:
1761		if (STp->block_size == 0)
1762			blks = transfer = do_count;
1763		else {
1764			if (!STbp->do_dio)
1765				blks = STbp->buffer_bytes;
1766			else
1767				blks = do_count;
1768			blks /= STp->block_size;
1769			transfer = blks * STp->block_size;
1770		}
1771		cmd[2] = blks >> 16;
1772		cmd[3] = blks >> 8;
1773		cmd[4] = blks;
1774
1775		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1776				   STp->device->request_queue->rq_timeout,
1777				   MAX_WRITE_RETRIES, !async_write);
1778		if (!SRpnt) {
1779			retval = STbp->syscall_result;
1780			goto out;
1781		}
1782		if (async_write && !STbp->syscall_result) {
1783			STbp->writing = transfer;
1784			STp->dirty = !(STbp->writing ==
1785				       STbp->buffer_bytes);
1786			SRpnt = NULL;  /* Prevent releasing this request! */
1787			DEB( STp->write_pending = 1; )
1788			break;
1789		}
1790
1791		if (STbp->syscall_result != 0) {
1792			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1793
1794			DEBC_printk(STp, "Error on write:\n");
1795			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1796				scode = cmdstatp->sense_hdr.sense_key;
1797				if (cmdstatp->remainder_valid)
1798					undone = (int)cmdstatp->uremainder64;
1799				else if (STp->block_size == 0 &&
1800					 scode == VOLUME_OVERFLOW)
1801					undone = transfer;
1802				else
1803					undone = 0;
1804				if (STp->block_size != 0)
1805					undone *= STp->block_size;
1806				if (undone <= do_count) {
1807					/* Only data from this write is not written */
1808					count += undone;
1809					b_point -= undone;
1810					do_count -= undone;
1811					if (STp->block_size)
1812						blks = (transfer - undone) / STp->block_size;
1813					STps->eof = ST_EOM_OK;
1814					/* Continue in fixed block mode if all written
1815					   in this request but still something left to write
1816					   (retval left to zero)
1817					*/
1818					if (STp->block_size == 0 ||
1819					    undone > 0 || count == 0)
1820						retval = (-ENOSPC); /* EOM within current request */
1821					DEBC_printk(STp, "EOM with %d "
1822						    "bytes unwritten.\n",
1823						    (int)count);
1824				} else {
1825					/* EOT within data buffered earlier (possible only
1826					   in fixed block mode without direct i/o) */
1827					if (!retry_eot && !cmdstatp->deferred &&
1828					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1829						move_buffer_data(STp->buffer, transfer - undone);
1830						retry_eot = 1;
1831						if (STps->drv_block >= 0) {
1832							STps->drv_block += (transfer - undone) /
1833								STp->block_size;
1834						}
1835						STps->eof = ST_EOM_OK;
1836						DEBC_printk(STp, "Retry "
1837							    "write of %d "
1838							    "bytes at EOM.\n",
1839							    STp->buffer->buffer_bytes);
1840						goto retry_write;
1841					}
1842					else {
1843						/* Either error within data buffered by driver or
1844						   failed retry */
1845						count -= do_count;
1846						blks = do_count = 0;
1847						STps->eof = ST_EOM_ERROR;
1848						STps->drv_block = (-1); /* Too cautious? */
1849						retval = (-EIO);	/* EOM for old data */
1850						DEBC_printk(STp, "EOM with "
1851							    "lost data.\n");
 
1852					}
1853				}
1854			} else {
1855				count += do_count;
1856				STps->drv_block = (-1);		/* Too cautious? */
1857				retval = STbp->syscall_result;
1858			}
1859
1860		}
1861
1862		if (STps->drv_block >= 0) {
1863			if (STp->block_size == 0)
1864				STps->drv_block += (do_count > 0);
1865			else
1866				STps->drv_block += blks;
1867		}
1868
1869		STbp->buffer_bytes = 0;
1870		STp->dirty = 0;
1871
1872		if (retval || retry_eot) {
1873			if (count < total)
1874				retval = total - count;
1875			goto out;
1876		}
1877	}
1878
1879	if (STps->eof == ST_EOD_1)
1880		STps->eof = ST_EOM_OK;
1881	else if (STps->eof != ST_EOM_OK)
1882		STps->eof = ST_NOEOF;
1883	retval = total - count;
1884
1885 out:
1886	if (SRpnt != NULL)
1887		st_release_request(SRpnt);
1888	release_buffering(STp, 0);
1889	mutex_unlock(&STp->lock);
1890
1891	return retval;
1892}
1893
1894/* Read data from the tape. Returns zero in the normal case, one if the
1895   eof status has changed, and the negative error code in case of a
1896   fatal error. Otherwise updates the buffer and the eof state.
1897
1898   Does release user buffer mapping if it is set.
1899*/
1900static long read_tape(struct scsi_tape *STp, long count,
1901		      struct st_request ** aSRpnt)
1902{
1903	int transfer, blks, bytes;
1904	unsigned char cmd[MAX_COMMAND_SIZE];
1905	struct st_request *SRpnt;
1906	struct st_modedef *STm;
1907	struct st_partstat *STps;
1908	struct st_buffer *STbp;
1909	int retval = 0;
 
1910
1911	if (count == 0)
1912		return 0;
1913
1914	STm = &(STp->modes[STp->current_mode]);
1915	STps = &(STp->ps[STp->partition]);
1916	if (STps->eof == ST_FM_HIT)
1917		return 1;
1918	STbp = STp->buffer;
1919
1920	if (STp->block_size == 0)
1921		blks = bytes = count;
1922	else {
1923		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1924			blks = (STp->buffer)->buffer_blocks;
1925			bytes = blks * STp->block_size;
1926		} else {
1927			bytes = count;
1928			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1929				bytes = (STp->buffer)->buffer_size;
1930			blks = bytes / STp->block_size;
1931			bytes = blks * STp->block_size;
1932		}
1933	}
1934
1935	memset(cmd, 0, MAX_COMMAND_SIZE);
1936	cmd[0] = READ_6;
1937	cmd[1] = (STp->block_size != 0);
1938	if (!cmd[1] && STp->sili)
1939		cmd[1] |= 2;
1940	cmd[2] = blks >> 16;
1941	cmd[3] = blks >> 8;
1942	cmd[4] = blks;
1943
1944	SRpnt = *aSRpnt;
1945	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1946			   STp->device->request_queue->rq_timeout,
1947			   MAX_RETRIES, 1);
1948	release_buffering(STp, 1);
1949	*aSRpnt = SRpnt;
1950	if (!SRpnt)
1951		return STbp->syscall_result;
1952
1953	STbp->read_pointer = 0;
1954	STps->at_sm = 0;
1955
1956	/* Something to check */
1957	if (STbp->syscall_result) {
1958		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1959
1960		retval = 1;
1961		DEBC_printk(STp,
1962			    "Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1963			    SRpnt->sense[0], SRpnt->sense[1],
1964			    SRpnt->sense[2], SRpnt->sense[3],
1965			    SRpnt->sense[4], SRpnt->sense[5],
1966			    SRpnt->sense[6], SRpnt->sense[7]);
1967		if (cmdstatp->have_sense) {
1968
1969			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1970				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1971
1972			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1973				/* Compute the residual count */
1974				if (cmdstatp->remainder_valid)
1975					transfer = (int)cmdstatp->uremainder64;
1976				else
1977					transfer = 0;
1978				if (cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR) {
1979					if (STp->block_size == 0)
1980						transfer = bytes;
1981					/* Some drives set ILI with MEDIUM ERROR */
1982					cmdstatp->flags &= ~SENSE_ILI;
1983				}
1984
1985				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1986					if (STp->block_size == 0 &&
1987					    transfer < 0) {
1988						st_printk(KERN_NOTICE, STp,
1989							  "Failed to read %d "
1990							  "byte block with %d "
1991							  "byte transfer.\n",
1992							  bytes - transfer,
1993							  bytes);
1994						if (STps->drv_block >= 0)
1995							STps->drv_block += 1;
1996						STbp->buffer_bytes = 0;
1997						return (-ENOMEM);
1998					} else if (STp->block_size == 0) {
1999						STbp->buffer_bytes = bytes - transfer;
2000					} else {
2001						st_release_request(SRpnt);
2002						SRpnt = *aSRpnt = NULL;
2003						if (transfer == blks) {	/* We did not get anything, error */
2004							st_printk(KERN_NOTICE, STp,
2005								  "Incorrect "
2006								  "block size.\n");
2007							if (STps->drv_block >= 0)
2008								STps->drv_block += blks - transfer + 1;
2009							st_int_ioctl(STp, MTBSR, 1);
2010							return (-EIO);
2011						}
2012						/* We have some data, deliver it */
2013						STbp->buffer_bytes = (blks - transfer) *
2014						    STp->block_size;
2015						DEBC_printk(STp, "ILI but "
2016							    "enough data "
2017							    "received %ld "
2018							    "%d.\n", count,
2019							    STbp->buffer_bytes);
2020						if (STps->drv_block >= 0)
2021							STps->drv_block += 1;
2022						if (st_int_ioctl(STp, MTBSR, 1))
2023							return (-EIO);
2024					}
2025				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
2026					if (STps->eof != ST_FM_HIT)
2027						STps->eof = ST_FM_HIT;
2028					else
2029						STps->eof = ST_EOD_2;
2030					if (STp->block_size == 0)
2031						STbp->buffer_bytes = 0;
2032					else
2033						STbp->buffer_bytes =
2034						    bytes - transfer * STp->block_size;
2035					DEBC_printk(STp, "EOF detected (%d "
2036						    "bytes read).\n",
2037						    STbp->buffer_bytes);
2038				} else if (cmdstatp->flags & SENSE_EOM) {
2039					if (STps->eof == ST_FM)
2040						STps->eof = ST_EOD_1;
2041					else
2042						STps->eof = ST_EOM_OK;
2043					if (STp->block_size == 0)
2044						STbp->buffer_bytes = bytes - transfer;
2045					else
2046						STbp->buffer_bytes =
2047						    bytes - transfer * STp->block_size;
2048
2049					DEBC_printk(STp, "EOM detected (%d "
2050						    "bytes read).\n",
2051						    STbp->buffer_bytes);
2052				}
2053			}
2054			/* end of EOF, EOM, ILI test */
2055			else {	/* nonzero sense key */
2056				DEBC_printk(STp, "Tape error while reading.\n");
 
2057				STps->drv_block = (-1);
2058				if (STps->eof == ST_FM &&
2059				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
2060					DEBC_printk(STp, "Zero returned for "
2061						    "first BLANK CHECK "
2062						    "after EOF.\n");
2063					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
2064				} else	/* Some other extended sense code */
2065					retval = (-EIO);
2066			}
2067
2068			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
2069				STbp->buffer_bytes = 0;
2070		}
2071		/* End of extended sense test */
2072		else {		/* Non-extended sense */
2073			retval = STbp->syscall_result;
2074		}
2075
2076	}
2077	/* End of error handling */
2078	else {			/* Read successful */
2079		STbp->buffer_bytes = bytes;
2080		if (STp->sili) /* In fixed block mode residual is always zero here */
2081			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
2082	}
2083
2084	if (STps->drv_block >= 0) {
2085		if (STp->block_size == 0)
2086			STps->drv_block++;
2087		else
2088			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2089	}
2090	return retval;
2091}
2092
2093
2094/* Read command */
2095static ssize_t
2096st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2097{
2098	ssize_t total;
2099	ssize_t retval = 0;
2100	ssize_t i, transfer;
2101	int special, do_dio = 0;
2102	struct st_request *SRpnt = NULL;
2103	struct scsi_tape *STp = filp->private_data;
2104	struct st_modedef *STm;
2105	struct st_partstat *STps;
2106	struct st_buffer *STbp = STp->buffer;
 
2107
2108	if (mutex_lock_interruptible(&STp->lock))
2109		return -ERESTARTSYS;
2110
2111	retval = rw_checks(STp, filp, count);
2112	if (retval || count == 0)
2113		goto out;
2114
2115	STm = &(STp->modes[STp->current_mode]);
2116	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2117		if (!STm->do_read_ahead) {
2118			retval = (-EINVAL);	/* Read must be integral number of blocks */
2119			goto out;
2120		}
2121		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2122	}
2123
2124	STps = &(STp->ps[STp->partition]);
2125	if (STps->rw == ST_WRITING) {
2126		retval = flush_buffer(STp, 0);
2127		if (retval)
2128			goto out;
2129		STps->rw = ST_READING;
2130	}
2131	DEB(
2132	if (debugging && STps->eof != ST_NOEOF)
2133		st_printk(ST_DEB_MSG, STp,
2134			  "EOF/EOM flag up (%d). Bytes %d\n",
2135			  STps->eof, STbp->buffer_bytes);
2136	) /* end DEB */
2137
2138	retval = setup_buffering(STp, buf, count, 1);
2139	if (retval)
2140		goto out;
2141	do_dio = STbp->do_dio;
2142
2143	if (STbp->buffer_bytes == 0 &&
2144	    STps->eof >= ST_EOD_1) {
2145		if (STps->eof < ST_EOD) {
2146			STps->eof += 1;
2147			retval = 0;
2148			goto out;
2149		}
2150		retval = (-EIO);	/* EOM or Blank Check */
2151		goto out;
2152	}
2153
2154	if (do_dio) {
2155		/* Check the buffer writability before any tape movement. Don't alter
2156		   buffer data. */
2157		if (copy_from_user(&i, buf, 1) != 0 ||
2158		    copy_to_user(buf, &i, 1) != 0 ||
2159		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2160		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2161			retval = (-EFAULT);
2162			goto out;
2163		}
2164	}
2165
2166	STps->rw = ST_READING;
2167
2168
2169	/* Loop until enough data in buffer or a special condition found */
2170	for (total = 0, special = 0; total < count && !special;) {
2171
2172		/* Get new data if the buffer is empty */
2173		if (STbp->buffer_bytes == 0) {
2174			special = read_tape(STp, count - total, &SRpnt);
2175			if (special < 0) {	/* No need to continue read */
2176				retval = special;
2177				goto out;
2178			}
2179		}
2180
2181		/* Move the data from driver buffer to user buffer */
2182		if (STbp->buffer_bytes > 0) {
2183			DEB(
2184			if (debugging && STps->eof != ST_NOEOF)
2185				st_printk(ST_DEB_MSG, STp,
2186					  "EOF up (%d). Left %d, needed %d.\n",
2187					  STps->eof, STbp->buffer_bytes,
2188					  (int)(count - total));
2189			) /* end DEB */
2190			transfer = STbp->buffer_bytes < count - total ?
2191			    STbp->buffer_bytes : count - total;
2192			if (!do_dio) {
2193				i = from_buffer(STbp, buf, transfer);
2194				if (i) {
2195					retval = i;
2196					goto out;
2197				}
2198			}
2199			buf += transfer;
2200			total += transfer;
2201		}
2202
2203		if (STp->block_size == 0)
2204			break;	/* Read only one variable length block */
2205
2206	}			/* for (total = 0, special = 0;
2207                                   total < count && !special; ) */
2208
2209	/* Change the eof state if no data from tape or buffer */
2210	if (total == 0) {
2211		if (STps->eof == ST_FM_HIT) {
2212			STps->eof = ST_FM;
2213			STps->drv_block = 0;
2214			if (STps->drv_file >= 0)
2215				STps->drv_file++;
2216		} else if (STps->eof == ST_EOD_1) {
2217			STps->eof = ST_EOD_2;
2218			STps->drv_block = 0;
2219			if (STps->drv_file >= 0)
2220				STps->drv_file++;
2221		} else if (STps->eof == ST_EOD_2)
2222			STps->eof = ST_EOD;
2223	} else if (STps->eof == ST_FM)
2224		STps->eof = ST_NOEOF;
2225	retval = total;
2226
2227 out:
2228	if (SRpnt != NULL) {
2229		st_release_request(SRpnt);
2230		SRpnt = NULL;
2231	}
2232	if (do_dio) {
2233		release_buffering(STp, 1);
2234		STbp->buffer_bytes = 0;
2235	}
2236	mutex_unlock(&STp->lock);
2237
2238	return retval;
2239}
2240
2241
2242
2243DEB(
2244/* Set the driver options */
2245static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm)
2246{
2247	if (debugging) {
2248		st_printk(KERN_INFO, STp,
2249			  "Mode %d options: buffer writes: %d, "
2250			  "async writes: %d, read ahead: %d\n",
2251			  STp->current_mode, STm->do_buffer_writes,
2252			  STm->do_async_writes, STm->do_read_ahead);
2253		st_printk(KERN_INFO, STp,
2254			  "    can bsr: %d, two FMs: %d, "
2255			  "fast mteom: %d, auto lock: %d,\n",
2256			  STp->can_bsr, STp->two_fm, STp->fast_mteom,
2257			  STp->do_auto_lock);
2258		st_printk(KERN_INFO, STp,
2259			  "    defs for wr: %d, no block limits: %d, "
2260			  "partitions: %d, s2 log: %d\n",
2261			  STm->defaults_for_writes, STp->omit_blklims,
2262			  STp->can_partitions, STp->scsi2_logical);
2263		st_printk(KERN_INFO, STp,
2264			  "    sysv: %d nowait: %d sili: %d "
2265			  "nowait_filemark: %d\n",
2266			  STm->sysv, STp->immediate, STp->sili,
2267			  STp->immediate_filemark);
2268		st_printk(KERN_INFO, STp, "    debugging: %d\n", debugging);
2269	}
2270}
2271	)
2272
2273
2274static int st_set_options(struct scsi_tape *STp, long options)
2275{
2276	int value;
2277	long code;
2278	struct st_modedef *STm;
 
2279	struct cdev *cd0, *cd1;
2280	struct device *d0, *d1;
2281
2282	STm = &(STp->modes[STp->current_mode]);
2283	if (!STm->defined) {
2284		cd0 = STm->cdevs[0];
2285		cd1 = STm->cdevs[1];
2286		d0  = STm->devs[0];
2287		d1  = STm->devs[1];
2288		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2289		STm->cdevs[0] = cd0;
2290		STm->cdevs[1] = cd1;
2291		STm->devs[0]  = d0;
2292		STm->devs[1]  = d1;
2293		modes_defined = 1;
2294		DEBC_printk(STp, "Initialized mode %d definition from mode 0\n",
2295			    STp->current_mode);
 
2296	}
2297
2298	code = options & MT_ST_OPTIONS;
2299	if (code == MT_ST_BOOLEANS) {
2300		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2301		STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2302		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2303		STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2304		STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2305		STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2306		STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2307		STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2308		STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2309		if ((STp->device)->scsi_level >= SCSI_2)
2310			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2311		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2312		STp->immediate = (options & MT_ST_NOWAIT) != 0;
2313		STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
2314		STm->sysv = (options & MT_ST_SYSV) != 0;
2315		STp->sili = (options & MT_ST_SILI) != 0;
2316		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2317		     st_log_options(STp, STm); )
2318	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2319		value = (code == MT_ST_SETBOOLEANS);
2320		if ((options & MT_ST_BUFFER_WRITES) != 0)
2321			STm->do_buffer_writes = value;
2322		if ((options & MT_ST_ASYNC_WRITES) != 0)
2323			STm->do_async_writes = value;
2324		if ((options & MT_ST_DEF_WRITES) != 0)
2325			STm->defaults_for_writes = value;
2326		if ((options & MT_ST_READ_AHEAD) != 0)
2327			STm->do_read_ahead = value;
2328		if ((options & MT_ST_TWO_FM) != 0)
2329			STp->two_fm = value;
2330		if ((options & MT_ST_FAST_MTEOM) != 0)
2331			STp->fast_mteom = value;
2332		if ((options & MT_ST_AUTO_LOCK) != 0)
2333			STp->do_auto_lock = value;
2334		if ((options & MT_ST_CAN_BSR) != 0)
2335			STp->can_bsr = value;
2336		if ((options & MT_ST_NO_BLKLIMS) != 0)
2337			STp->omit_blklims = value;
2338		if ((STp->device)->scsi_level >= SCSI_2 &&
2339		    (options & MT_ST_CAN_PARTITIONS) != 0)
2340			STp->can_partitions = value;
2341		if ((options & MT_ST_SCSI2LOGICAL) != 0)
2342			STp->scsi2_logical = value;
2343		if ((options & MT_ST_NOWAIT) != 0)
2344			STp->immediate = value;
2345		if ((options & MT_ST_NOWAIT_EOF) != 0)
2346			STp->immediate_filemark = value;
2347		if ((options & MT_ST_SYSV) != 0)
2348			STm->sysv = value;
2349		if ((options & MT_ST_SILI) != 0)
2350			STp->sili = value;
2351		DEB(
2352		if ((options & MT_ST_DEBUGGING) != 0)
2353			debugging = value;
2354			st_log_options(STp, STm); )
2355	} else if (code == MT_ST_WRITE_THRESHOLD) {
2356		/* Retained for compatibility */
2357	} else if (code == MT_ST_DEF_BLKSIZE) {
2358		value = (options & ~MT_ST_OPTIONS);
2359		if (value == ~MT_ST_OPTIONS) {
2360			STm->default_blksize = (-1);
2361			DEBC_printk(STp, "Default block size disabled.\n");
2362		} else {
2363			STm->default_blksize = value;
2364			DEBC_printk(STp,"Default block size set to "
2365				    "%d bytes.\n", STm->default_blksize);
2366			if (STp->ready == ST_READY) {
2367				STp->blksize_changed = 0;
2368				set_mode_densblk(STp, STm);
2369			}
2370		}
2371	} else if (code == MT_ST_TIMEOUTS) {
2372		value = (options & ~MT_ST_OPTIONS);
2373		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2374			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2375			DEBC_printk(STp, "Long timeout set to %d seconds.\n",
2376				    (value & ~MT_ST_SET_LONG_TIMEOUT));
2377		} else {
2378			blk_queue_rq_timeout(STp->device->request_queue,
2379					     value * HZ);
2380			DEBC_printk(STp, "Normal timeout set to %d seconds.\n",
2381				    value);
2382		}
2383	} else if (code == MT_ST_SET_CLN) {
2384		value = (options & ~MT_ST_OPTIONS) & 0xff;
2385		if (value != 0 &&
2386			(value < EXTENDED_SENSE_START ||
2387				value >= SCSI_SENSE_BUFFERSIZE))
2388			return (-EINVAL);
2389		STp->cln_mode = value;
2390		STp->cln_sense_mask = (options >> 8) & 0xff;
2391		STp->cln_sense_value = (options >> 16) & 0xff;
2392		st_printk(KERN_INFO, STp,
2393			  "Cleaning request mode %d, mask %02x, value %02x\n",
2394			  value, STp->cln_sense_mask, STp->cln_sense_value);
2395	} else if (code == MT_ST_DEF_OPTIONS) {
2396		code = (options & ~MT_ST_CLEAR_DEFAULT);
2397		value = (options & MT_ST_CLEAR_DEFAULT);
2398		if (code == MT_ST_DEF_DENSITY) {
2399			if (value == MT_ST_CLEAR_DEFAULT) {
2400				STm->default_density = (-1);
2401				DEBC_printk(STp,
2402					    "Density default disabled.\n");
2403			} else {
2404				STm->default_density = value & 0xff;
2405				DEBC_printk(STp, "Density default set to %x\n",
2406					    STm->default_density);
2407				if (STp->ready == ST_READY) {
2408					STp->density_changed = 0;
2409					set_mode_densblk(STp, STm);
2410				}
2411			}
2412		} else if (code == MT_ST_DEF_DRVBUFFER) {
2413			if (value == MT_ST_CLEAR_DEFAULT) {
2414				STp->default_drvbuffer = 0xff;
2415				DEBC_printk(STp,
2416					    "Drive buffer default disabled.\n");
2417			} else {
2418				STp->default_drvbuffer = value & 7;
2419				DEBC_printk(STp,
2420					    "Drive buffer default set to %x\n",
2421					    STp->default_drvbuffer);
2422				if (STp->ready == ST_READY)
2423					st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2424			}
2425		} else if (code == MT_ST_DEF_COMPRESSION) {
2426			if (value == MT_ST_CLEAR_DEFAULT) {
2427				STm->default_compression = ST_DONT_TOUCH;
2428				DEBC_printk(STp,
2429					    "Compression default disabled.\n");
2430			} else {
2431				if ((value & 0xff00) != 0) {
2432					STp->c_algo = (value & 0xff00) >> 8;
2433					DEBC_printk(STp, "Compression "
2434						    "algorithm set to 0x%x.\n",
2435						    STp->c_algo);
2436				}
2437				if ((value & 0xff) != 0xff) {
2438					STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2439					DEBC_printk(STp, "Compression default "
2440						    "set to %x\n",
2441						    (value & 1));
2442					if (STp->ready == ST_READY) {
2443						STp->compression_changed = 0;
2444						st_compression(STp, (STm->default_compression == ST_YES));
2445					}
2446				}
2447			}
2448		}
2449	} else
2450		return (-EIO);
2451
2452	return 0;
2453}
2454
2455#define MODE_HEADER_LENGTH  4
2456
2457/* Mode header and page byte offsets */
2458#define MH_OFF_DATA_LENGTH     0
2459#define MH_OFF_MEDIUM_TYPE     1
2460#define MH_OFF_DEV_SPECIFIC    2
2461#define MH_OFF_BDESCS_LENGTH   3
2462#define MP_OFF_PAGE_NBR        0
2463#define MP_OFF_PAGE_LENGTH     1
2464
2465/* Mode header and page bit masks */
2466#define MH_BIT_WP              0x80
2467#define MP_MSK_PAGE_NBR        0x3f
2468
2469/* Don't return block descriptors */
2470#define MODE_SENSE_OMIT_BDESCS 0x08
2471
2472#define MODE_SELECT_PAGE_FORMAT 0x10
2473
2474/* Read a mode page into the tape buffer. The block descriptors are included
2475   if incl_block_descs is true. The page control is ored to the page number
2476   parameter, if necessary. */
2477static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2478{
2479	unsigned char cmd[MAX_COMMAND_SIZE];
2480	struct st_request *SRpnt;
2481
2482	memset(cmd, 0, MAX_COMMAND_SIZE);
2483	cmd[0] = MODE_SENSE;
2484	if (omit_block_descs)
2485		cmd[1] = MODE_SENSE_OMIT_BDESCS;
2486	cmd[2] = page;
2487	cmd[4] = 255;
2488
2489	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2490			   STp->device->request_queue->rq_timeout, 0, 1);
2491	if (SRpnt == NULL)
2492		return (STp->buffer)->syscall_result;
2493
2494	st_release_request(SRpnt);
2495
2496	return STp->buffer->syscall_result;
2497}
2498
2499
2500/* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2501   in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2502static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2503{
2504	int pgo;
2505	unsigned char cmd[MAX_COMMAND_SIZE];
2506	struct st_request *SRpnt;
2507	int timeout;
2508
2509	memset(cmd, 0, MAX_COMMAND_SIZE);
2510	cmd[0] = MODE_SELECT;
2511	cmd[1] = MODE_SELECT_PAGE_FORMAT;
2512	pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2513	cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2514
2515	/* Clear reserved fields */
2516	(STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2517	(STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2518	(STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2519	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2520
2521	timeout = slow ?
2522		STp->long_timeout : STp->device->request_queue->rq_timeout;
2523	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2524			   timeout, 0, 1);
2525	if (SRpnt == NULL)
2526		return (STp->buffer)->syscall_result;
2527
2528	st_release_request(SRpnt);
2529
2530	return STp->buffer->syscall_result;
2531}
2532
2533
2534#define COMPRESSION_PAGE        0x0f
2535#define COMPRESSION_PAGE_LENGTH 16
2536
2537#define CP_OFF_DCE_DCC          2
2538#define CP_OFF_C_ALGO           7
2539
2540#define DCE_MASK  0x80
2541#define DCC_MASK  0x40
2542#define RED_MASK  0x60
2543
2544
2545/* Control the compression with mode page 15. Algorithm not changed if zero.
2546
2547   The block descriptors are read and written because Sony SDT-7000 does not
2548   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2549   Including block descriptors should not cause any harm to other drives. */
2550
2551static int st_compression(struct scsi_tape * STp, int state)
2552{
2553	int retval;
2554	int mpoffs;  /* Offset to mode page start */
2555	unsigned char *b_data = (STp->buffer)->b_data;
 
2556
2557	if (STp->ready != ST_READY)
2558		return (-EIO);
2559
2560	/* Read the current page contents */
2561	retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2562	if (retval) {
2563		DEBC_printk(STp, "Compression mode page not supported.\n");
 
2564		return (-EIO);
2565	}
2566
2567	mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2568	DEBC_printk(STp, "Compression state is %d.\n",
2569		    (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0));
2570
2571	/* Check if compression can be changed */
2572	if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2573		DEBC_printk(STp, "Compression not supported.\n");
2574		return (-EIO);
2575	}
2576
2577	/* Do the change */
2578	if (state) {
2579		b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2580		if (STp->c_algo != 0)
2581			b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2582	}
2583	else {
2584		b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2585		if (STp->c_algo != 0)
2586			b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2587	}
2588
2589	retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2590	if (retval) {
2591		DEBC_printk(STp, "Compression change failed.\n");
2592		return (-EIO);
2593	}
2594	DEBC_printk(STp, "Compression state changed to %d.\n", state);
 
2595
2596	STp->compression_changed = 1;
2597	return 0;
2598}
2599
2600
2601/* Process the load and unload commands (does unload if the load code is zero) */
2602static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2603{
2604	int retval = (-EIO), timeout;
 
2605	unsigned char cmd[MAX_COMMAND_SIZE];
2606	struct st_partstat *STps;
2607	struct st_request *SRpnt;
2608
2609	if (STp->ready != ST_READY && !load_code) {
2610		if (STp->ready == ST_NO_TAPE)
2611			return (-ENOMEDIUM);
2612		else
2613			return (-EIO);
2614	}
2615
2616	memset(cmd, 0, MAX_COMMAND_SIZE);
2617	cmd[0] = START_STOP;
2618	if (load_code)
2619		cmd[4] |= 1;
2620	/*
2621	 * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2622	 */
2623	if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2624	    && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2625		DEBC_printk(STp, " Enhanced %sload slot %2d.\n",
2626			    (cmd[4]) ? "" : "un",
2627			    load_code - MT_ST_HPLOADER_OFFSET);
2628		cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2629	}
2630	if (STp->immediate) {
2631		cmd[1] = 1;	/* Don't wait for completion */
2632		timeout = STp->device->request_queue->rq_timeout;
2633	}
2634	else
2635		timeout = STp->long_timeout;
2636
2637	DEBC(
2638		if (!load_code)
2639			st_printk(ST_DEB_MSG, STp, "Unloading tape.\n");
2640		else
2641			st_printk(ST_DEB_MSG, STp, "Loading tape.\n");
2642		);
2643
2644	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2645			   timeout, MAX_RETRIES, 1);
2646	if (!SRpnt)
2647		return (STp->buffer)->syscall_result;
2648
2649	retval = (STp->buffer)->syscall_result;
2650	st_release_request(SRpnt);
2651
2652	if (!retval) {	/* SCSI command successful */
2653
2654		if (!load_code) {
2655			STp->rew_at_close = 0;
2656			STp->ready = ST_NO_TAPE;
2657		}
2658		else {
2659			STp->rew_at_close = STp->autorew_dev;
2660			retval = check_tape(STp, filp);
2661			if (retval > 0)
2662				retval = 0;
2663		}
2664	}
2665	else {
2666		STps = &(STp->ps[STp->partition]);
2667		STps->drv_file = STps->drv_block = (-1);
2668	}
2669
2670	return retval;
2671}
2672
2673#if DEBUG
2674#define ST_DEB_FORWARD  0
2675#define ST_DEB_BACKWARD 1
2676static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd)
2677{
2678	s32 sc;
2679
2680	if (!debugging)
2681		return;
2682
2683	sc = cmd[2] & 0x80 ? 0xff000000 : 0;
2684	sc |= (cmd[2] << 16) | (cmd[3] << 8) | cmd[4];
2685	if (direction)
2686		sc = -sc;
2687	st_printk(ST_DEB_MSG, STp, "Spacing tape %s over %d %s.\n",
2688		  direction ? "backward" : "forward", sc, units);
2689}
2690#else
2691#define ST_DEB_FORWARD  0
2692#define ST_DEB_BACKWARD 1
2693static void deb_space_print(struct scsi_tape *STp, int direction, char *units, unsigned char *cmd) {}
2694#endif
2695
2696
2697/* Internal ioctl function */
2698static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2699{
2700	int timeout;
2701	long ltmp;
2702	int ioctl_result;
2703	int chg_eof = 1;
2704	unsigned char cmd[MAX_COMMAND_SIZE];
2705	struct st_request *SRpnt;
2706	struct st_partstat *STps;
2707	int fileno, blkno, at_sm, undone;
2708	int datalen = 0, direction = DMA_NONE;
 
2709
2710	WARN_ON(STp->buffer->do_dio != 0);
2711	if (STp->ready != ST_READY) {
2712		if (STp->ready == ST_NO_TAPE)
2713			return (-ENOMEDIUM);
2714		else
2715			return (-EIO);
2716	}
2717	timeout = STp->long_timeout;
2718	STps = &(STp->ps[STp->partition]);
2719	fileno = STps->drv_file;
2720	blkno = STps->drv_block;
2721	at_sm = STps->at_sm;
2722
2723	memset(cmd, 0, MAX_COMMAND_SIZE);
2724	switch (cmd_in) {
2725	case MTFSFM:
2726		chg_eof = 0;	/* Changed from the FSF after this */
2727	case MTFSF:
2728		cmd[0] = SPACE;
2729		cmd[1] = 0x01;	/* Space FileMarks */
2730		cmd[2] = (arg >> 16);
2731		cmd[3] = (arg >> 8);
2732		cmd[4] = arg;
2733		deb_space_print(STp, ST_DEB_FORWARD, "filemarks", cmd);
2734		if (fileno >= 0)
2735			fileno += arg;
2736		blkno = 0;
2737		at_sm &= (arg == 0);
2738		break;
2739	case MTBSFM:
2740		chg_eof = 0;	/* Changed from the FSF after this */
2741	case MTBSF:
2742		cmd[0] = SPACE;
2743		cmd[1] = 0x01;	/* Space FileMarks */
2744		ltmp = (-arg);
2745		cmd[2] = (ltmp >> 16);
2746		cmd[3] = (ltmp >> 8);
2747		cmd[4] = ltmp;
2748		deb_space_print(STp, ST_DEB_BACKWARD, "filemarks", cmd);
2749		if (fileno >= 0)
2750			fileno -= arg;
2751		blkno = (-1);	/* We can't know the block number */
2752		at_sm &= (arg == 0);
2753		break;
2754	case MTFSR:
2755		cmd[0] = SPACE;
2756		cmd[1] = 0x00;	/* Space Blocks */
2757		cmd[2] = (arg >> 16);
2758		cmd[3] = (arg >> 8);
2759		cmd[4] = arg;
2760		deb_space_print(STp, ST_DEB_FORWARD, "blocks", cmd);
2761		if (blkno >= 0)
2762			blkno += arg;
2763		at_sm &= (arg == 0);
2764		break;
2765	case MTBSR:
2766		cmd[0] = SPACE;
2767		cmd[1] = 0x00;	/* Space Blocks */
2768		ltmp = (-arg);
2769		cmd[2] = (ltmp >> 16);
2770		cmd[3] = (ltmp >> 8);
2771		cmd[4] = ltmp;
2772		deb_space_print(STp, ST_DEB_BACKWARD, "blocks", cmd);
2773		if (blkno >= 0)
2774			blkno -= arg;
2775		at_sm &= (arg == 0);
2776		break;
2777	case MTFSS:
2778		cmd[0] = SPACE;
2779		cmd[1] = 0x04;	/* Space Setmarks */
2780		cmd[2] = (arg >> 16);
2781		cmd[3] = (arg >> 8);
2782		cmd[4] = arg;
2783		deb_space_print(STp, ST_DEB_FORWARD, "setmarks", cmd);
2784		if (arg != 0) {
2785			blkno = fileno = (-1);
2786			at_sm = 1;
2787		}
2788		break;
2789	case MTBSS:
2790		cmd[0] = SPACE;
2791		cmd[1] = 0x04;	/* Space Setmarks */
2792		ltmp = (-arg);
2793		cmd[2] = (ltmp >> 16);
2794		cmd[3] = (ltmp >> 8);
2795		cmd[4] = ltmp;
2796		deb_space_print(STp, ST_DEB_BACKWARD, "setmarks", cmd);
2797		if (arg != 0) {
2798			blkno = fileno = (-1);
2799			at_sm = 1;
2800		}
2801		break;
2802	case MTWEOF:
2803	case MTWEOFI:
2804	case MTWSM:
2805		if (STp->write_prot)
2806			return (-EACCES);
2807		cmd[0] = WRITE_FILEMARKS;
2808		if (cmd_in == MTWSM)
2809			cmd[1] = 2;
2810		if (cmd_in == MTWEOFI ||
2811		    (cmd_in == MTWEOF && STp->immediate_filemark))
2812			cmd[1] |= 1;
2813		cmd[2] = (arg >> 16);
2814		cmd[3] = (arg >> 8);
2815		cmd[4] = arg;
2816		timeout = STp->device->request_queue->rq_timeout;
2817		DEBC(
2818			if (cmd_in != MTWSM)
2819				st_printk(ST_DEB_MSG, STp,
2820					  "Writing %d filemarks.\n",
2821					  cmd[2] * 65536 +
2822					  cmd[3] * 256 +
2823					  cmd[4]);
2824			else
2825				st_printk(ST_DEB_MSG, STp,
2826					  "Writing %d setmarks.\n",
2827					  cmd[2] * 65536 +
2828					  cmd[3] * 256 +
2829					  cmd[4]);
2830		)
2831		if (fileno >= 0)
2832			fileno += arg;
2833		blkno = 0;
2834		at_sm = (cmd_in == MTWSM);
2835		break;
2836	case MTREW:
2837		cmd[0] = REZERO_UNIT;
2838		if (STp->immediate) {
2839			cmd[1] = 1;	/* Don't wait for completion */
2840			timeout = STp->device->request_queue->rq_timeout;
2841		}
2842		DEBC_printk(STp, "Rewinding tape.\n");
2843		fileno = blkno = at_sm = 0;
2844		break;
2845	case MTNOP:
2846		DEBC_printk(STp, "No op on tape.\n");
2847		return 0;	/* Should do something ? */
2848		break;
2849	case MTRETEN:
2850		cmd[0] = START_STOP;
2851		if (STp->immediate) {
2852			cmd[1] = 1;	/* Don't wait for completion */
2853			timeout = STp->device->request_queue->rq_timeout;
2854		}
2855		cmd[4] = 3;
2856		DEBC_printk(STp, "Retensioning tape.\n");
2857		fileno = blkno = at_sm = 0;
2858		break;
2859	case MTEOM:
2860		if (!STp->fast_mteom) {
2861			/* space to the end of tape */
2862			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2863			fileno = STps->drv_file;
2864			if (STps->eof >= ST_EOD_1)
2865				return 0;
2866			/* The next lines would hide the number of spaced FileMarks
2867			   That's why I inserted the previous lines. I had no luck
2868			   with detecting EOM with FSF, so we go now to EOM.
2869			   Joerg Weule */
2870		} else
2871			fileno = (-1);
2872		cmd[0] = SPACE;
2873		cmd[1] = 3;
2874		DEBC_printk(STp, "Spacing to end of recorded medium.\n");
 
2875		blkno = -1;
2876		at_sm = 0;
2877		break;
2878	case MTERASE:
2879		if (STp->write_prot)
2880			return (-EACCES);
2881		cmd[0] = ERASE;
2882		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
2883		if (STp->immediate) {
2884			cmd[1] |= 2;	/* Don't wait for completion */
2885			timeout = STp->device->request_queue->rq_timeout;
2886		}
2887		else
2888			timeout = STp->long_timeout * 8;
2889
2890		DEBC_printk(STp, "Erasing tape.\n");
2891		fileno = blkno = at_sm = 0;
2892		break;
2893	case MTSETBLK:		/* Set block length */
2894	case MTSETDENSITY:	/* Set tape density */
2895	case MTSETDRVBUFFER:	/* Set drive buffering */
2896	case SET_DENS_AND_BLK:	/* Set density and block size */
2897		chg_eof = 0;
2898		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2899			return (-EIO);	/* Not allowed if data in buffer */
2900		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2901		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2902		    STp->max_block > 0 &&
2903		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2904		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2905			st_printk(KERN_WARNING, STp, "Illegal block size.\n");
2906			return (-EINVAL);
2907		}
2908		cmd[0] = MODE_SELECT;
2909		if ((STp->use_pf & USE_PF))
2910			cmd[1] = MODE_SELECT_PAGE_FORMAT;
2911		cmd[4] = datalen = 12;
2912		direction = DMA_TO_DEVICE;
2913
2914		memset((STp->buffer)->b_data, 0, 12);
2915		if (cmd_in == MTSETDRVBUFFER)
2916			(STp->buffer)->b_data[2] = (arg & 7) << 4;
2917		else
2918			(STp->buffer)->b_data[2] =
2919			    STp->drv_buffer << 4;
2920		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
2921		if (cmd_in == MTSETDENSITY) {
2922			(STp->buffer)->b_data[4] = arg;
2923			STp->density_changed = 1;	/* At least we tried ;-) */
2924		} else if (cmd_in == SET_DENS_AND_BLK)
2925			(STp->buffer)->b_data[4] = arg >> 24;
2926		else
2927			(STp->buffer)->b_data[4] = STp->density;
2928		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2929			ltmp = arg & MT_ST_BLKSIZE_MASK;
2930			if (cmd_in == MTSETBLK)
2931				STp->blksize_changed = 1; /* At least we tried ;-) */
2932		} else
2933			ltmp = STp->block_size;
2934		(STp->buffer)->b_data[9] = (ltmp >> 16);
2935		(STp->buffer)->b_data[10] = (ltmp >> 8);
2936		(STp->buffer)->b_data[11] = ltmp;
2937		timeout = STp->device->request_queue->rq_timeout;
2938		DEBC(
2939			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2940				st_printk(ST_DEB_MSG, STp,
2941					  "Setting block size to %d bytes.\n",
2942					  (STp->buffer)->b_data[9] * 65536 +
2943					  (STp->buffer)->b_data[10] * 256 +
2944					  (STp->buffer)->b_data[11]);
2945			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2946				st_printk(ST_DEB_MSG, STp,
2947					  "Setting density code to %x.\n",
2948					  (STp->buffer)->b_data[4]);
2949			if (cmd_in == MTSETDRVBUFFER)
2950				st_printk(ST_DEB_MSG, STp,
2951					  "Setting drive buffer code to %d.\n",
2952					  ((STp->buffer)->b_data[2] >> 4) & 7);
2953		)
2954		break;
2955	default:
2956		return (-ENOSYS);
2957	}
2958
2959	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2960			   timeout, MAX_RETRIES, 1);
2961	if (!SRpnt)
2962		return (STp->buffer)->syscall_result;
2963
2964	ioctl_result = (STp->buffer)->syscall_result;
2965
2966	if (!ioctl_result) {	/* SCSI command successful */
2967		st_release_request(SRpnt);
2968		SRpnt = NULL;
2969		STps->drv_block = blkno;
2970		STps->drv_file = fileno;
2971		STps->at_sm = at_sm;
2972
2973		if (cmd_in == MTBSFM)
2974			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2975		else if (cmd_in == MTFSFM)
2976			ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2977
2978		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2979			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2980			if (STp->block_size != 0) {
2981				(STp->buffer)->buffer_blocks =
2982				    (STp->buffer)->buffer_size / STp->block_size;
2983			}
2984			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2985			if (cmd_in == SET_DENS_AND_BLK)
2986				STp->density = arg >> MT_ST_DENSITY_SHIFT;
2987		} else if (cmd_in == MTSETDRVBUFFER)
2988			STp->drv_buffer = (arg & 7);
2989		else if (cmd_in == MTSETDENSITY)
2990			STp->density = arg;
2991
2992		if (cmd_in == MTEOM)
2993			STps->eof = ST_EOD;
2994		else if (cmd_in == MTFSF)
2995			STps->eof = ST_FM;
2996		else if (chg_eof)
2997			STps->eof = ST_NOEOF;
2998
2999		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
3000			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
3001	} else { /* SCSI command was not completely successful. Don't return
3002                    from this block without releasing the SCSI command block! */
3003		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
3004
3005		if (cmdstatp->flags & SENSE_EOM) {
3006			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
3007			    cmd_in != MTBSR && cmd_in != MTBSS)
3008				STps->eof = ST_EOM_OK;
3009			STps->drv_block = 0;
3010		}
3011
3012		if (cmdstatp->remainder_valid)
3013			undone = (int)cmdstatp->uremainder64;
3014		else
3015			undone = 0;
3016
3017		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
3018		    cmdstatp->have_sense &&
3019		    (cmdstatp->flags & SENSE_EOM)) {
3020			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
3021			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
3022				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
3023				STps->eof = ST_NOEOF;
3024			} else {  /* Writing EOF(s) failed */
3025				if (fileno >= 0)
3026					fileno -= undone;
3027				if (undone < arg)
3028					STps->eof = ST_NOEOF;
3029			}
3030			STps->drv_file = fileno;
3031		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
3032			if (fileno >= 0)
3033				STps->drv_file = fileno - undone;
3034			else
3035				STps->drv_file = fileno;
3036			STps->drv_block = -1;
3037			STps->eof = ST_NOEOF;
3038		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
3039			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3040				undone = (-undone);
3041			if (STps->drv_file >= 0)
3042				STps->drv_file = fileno + undone;
3043			STps->drv_block = 0;
3044			STps->eof = ST_NOEOF;
3045		} else if (cmd_in == MTFSR) {
3046			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3047				if (STps->drv_file >= 0)
3048					STps->drv_file++;
3049				STps->drv_block = 0;
3050				STps->eof = ST_FM;
3051			} else {
3052				if (blkno >= undone)
3053					STps->drv_block = blkno - undone;
3054				else
3055					STps->drv_block = (-1);
3056				STps->eof = ST_NOEOF;
3057			}
3058		} else if (cmd_in == MTBSR) {
3059			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
3060				STps->drv_file--;
3061				STps->drv_block = (-1);
3062			} else {
3063				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
3064					undone = (-undone);
3065				if (STps->drv_block >= 0)
3066					STps->drv_block = blkno + undone;
3067			}
3068			STps->eof = ST_NOEOF;
3069		} else if (cmd_in == MTEOM) {
3070			STps->drv_file = (-1);
3071			STps->drv_block = (-1);
3072			STps->eof = ST_EOD;
3073		} else if (cmd_in == MTSETBLK ||
3074			   cmd_in == MTSETDENSITY ||
3075			   cmd_in == MTSETDRVBUFFER ||
3076			   cmd_in == SET_DENS_AND_BLK) {
3077			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
3078			    !(STp->use_pf & PF_TESTED)) {
3079				/* Try the other possible state of Page Format if not
3080				   already tried */
3081				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
3082				st_release_request(SRpnt);
3083				SRpnt = NULL;
3084				return st_int_ioctl(STp, cmd_in, arg);
3085			}
3086		} else if (chg_eof)
3087			STps->eof = ST_NOEOF;
3088
3089		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
3090			STps->eof = ST_EOD;
3091
3092		st_release_request(SRpnt);
3093		SRpnt = NULL;
3094	}
3095
3096	return ioctl_result;
3097}
3098
3099
3100/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
3101   structure. */
3102
3103static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
3104			int logical)
3105{
3106	int result;
3107	unsigned char scmd[MAX_COMMAND_SIZE];
3108	struct st_request *SRpnt;
 
3109
3110	if (STp->ready != ST_READY)
3111		return (-EIO);
3112
3113	memset(scmd, 0, MAX_COMMAND_SIZE);
3114	if ((STp->device)->scsi_level < SCSI_2) {
3115		scmd[0] = QFA_REQUEST_BLOCK;
3116		scmd[4] = 3;
3117	} else {
3118		scmd[0] = READ_POSITION;
3119		if (!logical && !STp->scsi2_logical)
3120			scmd[1] = 1;
3121	}
3122	SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3123			   STp->device->request_queue->rq_timeout,
3124			   MAX_READY_RETRIES, 1);
3125	if (!SRpnt)
3126		return (STp->buffer)->syscall_result;
3127
3128	if ((STp->buffer)->syscall_result != 0 ||
3129	    (STp->device->scsi_level >= SCSI_2 &&
3130	     ((STp->buffer)->b_data[0] & 4) != 0)) {
3131		*block = *partition = 0;
3132		DEBC_printk(STp, " Can't read tape position.\n");
3133		result = (-EIO);
3134	} else {
3135		result = 0;
3136		if ((STp->device)->scsi_level < SCSI_2) {
3137			*block = ((STp->buffer)->b_data[0] << 16)
3138			    + ((STp->buffer)->b_data[1] << 8)
3139			    + (STp->buffer)->b_data[2];
3140			*partition = 0;
3141		} else {
3142			*block = ((STp->buffer)->b_data[4] << 24)
3143			    + ((STp->buffer)->b_data[5] << 16)
3144			    + ((STp->buffer)->b_data[6] << 8)
3145			    + (STp->buffer)->b_data[7];
3146			*partition = (STp->buffer)->b_data[1];
3147			if (((STp->buffer)->b_data[0] & 0x80) &&
3148			    (STp->buffer)->b_data[1] == 0)	/* BOP of partition 0 */
3149				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3150		}
3151		DEBC_printk(STp, "Got tape pos. blk %d part %d.\n",
3152			    *block, *partition);
3153	}
3154	st_release_request(SRpnt);
3155	SRpnt = NULL;
3156
3157	return result;
3158}
3159
3160
3161/* Set the tape block and partition. Negative partition means that only the
3162   block should be set in vendor specific way. */
3163static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3164			int logical)
3165{
3166	struct st_partstat *STps;
3167	int result, p;
3168	unsigned int blk;
3169	int timeout;
3170	unsigned char scmd[MAX_COMMAND_SIZE];
3171	struct st_request *SRpnt;
 
3172
3173	if (STp->ready != ST_READY)
3174		return (-EIO);
3175	timeout = STp->long_timeout;
3176	STps = &(STp->ps[STp->partition]);
3177
3178	DEBC_printk(STp, "Setting block to %d and partition to %d.\n",
3179		    block, partition);
3180	DEB(if (partition < 0)
3181		return (-EIO); )
3182
3183	/* Update the location at the partition we are leaving */
3184	if ((!STp->can_partitions && partition != 0) ||
3185	    partition >= ST_NBR_PARTITIONS)
3186		return (-EINVAL);
3187	if (partition != STp->partition) {
3188		if (get_location(STp, &blk, &p, 1))
3189			STps->last_block_valid = 0;
3190		else {
3191			STps->last_block_valid = 1;
3192			STps->last_block_visited = blk;
3193			DEBC_printk(STp, "Visited block %d for "
3194				    "partition %d saved.\n",
3195				    blk, STp->partition);
3196		}
3197	}
3198
3199	memset(scmd, 0, MAX_COMMAND_SIZE);
3200	if ((STp->device)->scsi_level < SCSI_2) {
3201		scmd[0] = QFA_SEEK_BLOCK;
3202		scmd[2] = (block >> 16);
3203		scmd[3] = (block >> 8);
3204		scmd[4] = block;
3205		scmd[5] = 0;
3206	} else {
3207		scmd[0] = SEEK_10;
3208		scmd[3] = (block >> 24);
3209		scmd[4] = (block >> 16);
3210		scmd[5] = (block >> 8);
3211		scmd[6] = block;
3212		if (!logical && !STp->scsi2_logical)
3213			scmd[1] = 4;
3214		if (STp->partition != partition) {
3215			scmd[1] |= 2;
3216			scmd[8] = partition;
3217			DEBC_printk(STp, "Trying to change partition "
3218				    "from %d to %d\n", STp->partition,
3219				    partition);
3220		}
3221	}
3222	if (STp->immediate) {
3223		scmd[1] |= 1;		/* Don't wait for completion */
3224		timeout = STp->device->request_queue->rq_timeout;
3225	}
3226
3227	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3228			   timeout, MAX_READY_RETRIES, 1);
3229	if (!SRpnt)
3230		return (STp->buffer)->syscall_result;
3231
3232	STps->drv_block = STps->drv_file = (-1);
3233	STps->eof = ST_NOEOF;
3234	if ((STp->buffer)->syscall_result != 0) {
3235		result = (-EIO);
3236		if (STp->can_partitions &&
3237		    (STp->device)->scsi_level >= SCSI_2 &&
3238		    (p = find_partition(STp)) >= 0)
3239			STp->partition = p;
3240	} else {
3241		if (STp->can_partitions) {
3242			STp->partition = partition;
3243			STps = &(STp->ps[partition]);
3244			if (!STps->last_block_valid ||
3245			    STps->last_block_visited != block) {
3246				STps->at_sm = 0;
3247				STps->rw = ST_IDLE;
3248			}
3249		} else
3250			STps->at_sm = 0;
3251		if (block == 0)
3252			STps->drv_block = STps->drv_file = 0;
3253		result = 0;
3254	}
3255
3256	st_release_request(SRpnt);
3257	SRpnt = NULL;
3258
3259	return result;
3260}
3261
3262
3263/* Find the current partition number for the drive status. Called from open and
3264   returns either partition number of negative error code. */
3265static int find_partition(struct scsi_tape *STp)
3266{
3267	int i, partition;
3268	unsigned int block;
3269
3270	if ((i = get_location(STp, &block, &partition, 1)) < 0)
3271		return i;
3272	if (partition >= ST_NBR_PARTITIONS)
3273		return (-EIO);
3274	return partition;
3275}
3276
3277
3278/* Change the partition if necessary */
3279static int switch_partition(struct scsi_tape *STp)
3280{
3281	struct st_partstat *STps;
3282
3283	if (STp->partition == STp->new_partition)
3284		return 0;
3285	STps = &(STp->ps[STp->new_partition]);
3286	if (!STps->last_block_valid)
3287		STps->last_block_visited = 0;
3288	return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3289}
3290
3291/* Functions for reading and writing the medium partition mode page. */
3292
3293#define PART_PAGE   0x11
3294#define PART_PAGE_FIXED_LENGTH 8
3295
3296#define PP_OFF_MAX_ADD_PARTS   2
3297#define PP_OFF_NBR_ADD_PARTS   3
3298#define PP_OFF_FLAGS           4
3299#define PP_OFF_PART_UNITS      6
3300#define PP_OFF_RESERVED        7
3301
3302#define PP_BIT_IDP             0x20
3303#define PP_BIT_FDP             0x80
3304#define PP_MSK_PSUM_MB         0x10
3305#define PP_MSK_PSUM_UNITS      0x18
3306#define PP_MSK_POFM            0x04
3307
3308/* Get the number of partitions on the tape. As a side effect reads the
3309   mode page into the tape buffer. */
3310static int nbr_partitions(struct scsi_tape *STp)
3311{
3312	int result;
 
3313
3314	if (STp->ready != ST_READY)
3315		return (-EIO);
3316
3317	result = read_mode_page(STp, PART_PAGE, 1);
3318
3319	if (result) {
3320		DEBC_printk(STp, "Can't read medium partition page.\n");
 
3321		result = (-EIO);
3322	} else {
3323		result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3324					      PP_OFF_NBR_ADD_PARTS] + 1;
3325		DEBC_printk(STp, "Number of partitions %d.\n", result);
3326	}
3327
3328	return result;
3329}
3330
3331
3332static int format_medium(struct scsi_tape *STp, int format)
3333{
3334	int result = 0;
3335	int timeout = STp->long_timeout;
3336	unsigned char scmd[MAX_COMMAND_SIZE];
3337	struct st_request *SRpnt;
3338
3339	memset(scmd, 0, MAX_COMMAND_SIZE);
3340	scmd[0] = FORMAT_UNIT;
3341	scmd[2] = format;
3342	if (STp->immediate) {
3343		scmd[1] |= 1;		/* Don't wait for completion */
3344		timeout = STp->device->request_queue->rq_timeout;
3345	}
3346	DEBC_printk(STp, "Sending FORMAT MEDIUM\n");
3347	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3348			   timeout, MAX_RETRIES, 1);
3349	if (!SRpnt)
3350		result = STp->buffer->syscall_result;
3351	return result;
3352}
3353
3354
3355/* Partition the tape into two partitions if size > 0 or one partition if
3356   size == 0.
3357
3358   The block descriptors are read and written because Sony SDT-7000 does not
3359   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3360
3361   My HP C1533A drive returns only one partition size field. This is used to
3362   set the size of partition 1. There is no size field for the default partition.
3363   Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3364   used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3365   The following algorithm is used to accommodate both drives: if the number of
3366   partition size fields is greater than the maximum number of additional partitions
3367   in the mode page, the second field is used. Otherwise the first field is used.
3368
3369   For Seagate DDS drives the page length must be 8 when no partitions is defined
3370   and 10 when 1 partition is defined (information from Eric Lee Green). This is
3371   is acceptable also to some other old drives and enforced if the first partition
3372   size field is used for the first additional partition size.
3373
3374   For drives that advertize SCSI-3 or newer, use the SSC-3 methods.
3375 */
3376static int partition_tape(struct scsi_tape *STp, int size)
3377{
 
3378	int result;
3379	int target_partition;
3380	bool scsi3 = STp->device->scsi_level >= SCSI_3, needs_format = false;
3381	int pgo, psd_cnt, psdo;
3382	int psum = PP_MSK_PSUM_MB, units = 0;
3383	unsigned char *bp;
3384
3385	result = read_mode_page(STp, PART_PAGE, 0);
3386	if (result) {
3387		DEBC_printk(STp, "Can't read partition mode page.\n");
3388		return result;
3389	}
3390	target_partition = 1;
3391	if (size < 0) {
3392		target_partition = 0;
3393		size = -size;
3394	}
3395
3396	/* The mode page is in the buffer. Let's modify it and write it. */
3397	bp = (STp->buffer)->b_data;
3398	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3399	DEBC_printk(STp, "Partition page length is %d bytes.\n",
3400		    bp[pgo + MP_OFF_PAGE_LENGTH] + 2);
3401
3402	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
3403
3404	if (scsi3) {
3405		needs_format = (bp[pgo + PP_OFF_FLAGS] & PP_MSK_POFM) != 0;
3406		if (needs_format && size == 0) {
3407			/* No need to write the mode page when clearing
3408			 *  partitioning
3409			 */
3410			DEBC_printk(STp, "Formatting tape with one partition.\n");
3411			result = format_medium(STp, 0);
3412			goto out;
3413		}
3414		if (needs_format)  /* Leave the old value for HP DATs claiming SCSI_3 */
3415			psd_cnt = 2;
3416		if ((bp[pgo + PP_OFF_FLAGS] & PP_MSK_PSUM_UNITS) == PP_MSK_PSUM_UNITS) {
3417			/* Use units scaling for large partitions if the device
3418			 * suggests it and no precision lost. Required for IBM
3419			 * TS1140/50 drives that don't support MB units.
3420			 */
3421			if (size >= 1000 && (size % 1000) == 0) {
3422				size /= 1000;
3423				psum = PP_MSK_PSUM_UNITS;
3424				units = 9; /* GB */
3425			}
3426		}
3427		/* Try it anyway if too large to specify in MB */
3428		if (psum == PP_MSK_PSUM_MB && size >= 65534) {
3429			size /= 1000;
3430			psum = PP_MSK_PSUM_UNITS;
3431			units = 9;  /* GB */
3432		}
3433	}
3434
3435	if (size >= 65535 ||  /* Does not fit into two bytes */
3436	    (target_partition == 0 && psd_cnt < 2)) {
3437		result = -EINVAL;
3438		goto out;
3439	}
3440
3441	psdo = pgo + PART_PAGE_FIXED_LENGTH;
3442	/* The second condition is for HP DDS which use only one partition size
3443	 * descriptor
3444	 */
3445	if (target_partition > 0 &&
3446	    (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS] ||
3447	     bp[pgo + PP_OFF_MAX_ADD_PARTS] != 1)) {
3448		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest to partition 0 */
3449		psdo += 2;
3450	}
3451	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3452
3453	DEBC_printk(STp, "psd_cnt %d, max.parts %d, nbr_parts %d\n",
3454		    psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3455		    bp[pgo + PP_OFF_NBR_ADD_PARTS]);
3456
3457	if (size == 0) {
3458		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3459		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3460		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3461		DEBC_printk(STp, "Formatting tape with one partition.\n");
 
3462	} else {
3463		bp[psdo] = (size >> 8) & 0xff;
3464		bp[psdo + 1] = size & 0xff;
3465		if (target_partition == 0)
3466			bp[psdo + 2] = bp[psdo + 3] = 0xff;
3467		bp[pgo + 3] = 1;
3468		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3469		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3470		DEBC_printk(STp,
3471			    "Formatting tape with two partitions (%i = %d MB).\n",
3472			    target_partition, units > 0 ? size * 1000 : size);
3473	}
3474	bp[pgo + PP_OFF_PART_UNITS] = 0;
3475	bp[pgo + PP_OFF_RESERVED] = 0;
3476	if (size != 1 || units != 0) {
3477		bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | psum |
3478			(bp[pgo + PP_OFF_FLAGS] & 0x07);
3479		bp[pgo + PP_OFF_PART_UNITS] = units;
3480	} else
3481		bp[pgo + PP_OFF_FLAGS] = PP_BIT_FDP |
3482			(bp[pgo + PP_OFF_FLAGS] & 0x1f);
3483	bp[pgo + MP_OFF_PAGE_LENGTH] = 6 + psd_cnt * 2;
3484
3485	result = write_mode_page(STp, PART_PAGE, 1);
3486
3487	if (!result && needs_format)
3488		result = format_medium(STp, 1);
3489
3490	if (result) {
3491		st_printk(KERN_INFO, STp, "Partitioning of tape failed.\n");
3492		result = (-EIO);
3493	}
3494
3495out:
3496	return result;
3497}
3498
3499
3500
3501/* The ioctl command */
3502static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3503{
3504	int i, cmd_nr, cmd_type, bt;
3505	int retval = 0;
3506	unsigned int blk;
3507	struct scsi_tape *STp = file->private_data;
3508	struct st_modedef *STm;
3509	struct st_partstat *STps;
 
3510	void __user *p = (void __user *)arg;
3511
3512	if (mutex_lock_interruptible(&STp->lock))
3513		return -ERESTARTSYS;
3514
3515	DEB(
3516	if (debugging && !STp->in_use) {
3517		st_printk(ST_DEB_MSG, STp, "Incorrect device.\n");
3518		retval = (-EIO);
3519		goto out;
3520	} ) /* end DEB */
3521
3522	STm = &(STp->modes[STp->current_mode]);
3523	STps = &(STp->ps[STp->partition]);
3524
3525	/*
3526	 * If we are in the middle of error recovery, don't let anyone
3527	 * else try and use this device.  Also, if error recovery fails, it
3528	 * may try and take the device offline, in which case all further
3529	 * access to the device is prohibited.
3530	 */
3531	retval = scsi_ioctl_block_when_processing_errors(STp->device, cmd_in,
3532			file->f_flags & O_NDELAY);
3533	if (retval)
3534		goto out;
 
3535
3536	cmd_type = _IOC_TYPE(cmd_in);
3537	cmd_nr = _IOC_NR(cmd_in);
3538
3539	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3540		struct mtop mtc;
3541
3542		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3543			retval = (-EINVAL);
3544			goto out;
3545		}
3546
3547		i = copy_from_user(&mtc, p, sizeof(struct mtop));
3548		if (i) {
3549			retval = (-EFAULT);
3550			goto out;
3551		}
3552
3553		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3554			st_printk(KERN_WARNING, STp,
3555				  "MTSETDRVBUFFER only allowed for root.\n");
3556			retval = (-EPERM);
3557			goto out;
3558		}
3559		if (!STm->defined &&
3560		    (mtc.mt_op != MTSETDRVBUFFER &&
3561		     (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3562			retval = (-ENXIO);
3563			goto out;
3564		}
3565
3566		if (!STp->pos_unknown) {
3567
3568			if (STps->eof == ST_FM_HIT) {
3569				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3570                                    mtc.mt_op == MTEOM) {
3571					mtc.mt_count -= 1;
3572					if (STps->drv_file >= 0)
3573						STps->drv_file += 1;
3574				} else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3575					mtc.mt_count += 1;
3576					if (STps->drv_file >= 0)
3577						STps->drv_file += 1;
3578				}
3579			}
3580
3581			if (mtc.mt_op == MTSEEK) {
3582				/* Old position must be restored if partition will be
3583                                   changed */
3584				i = !STp->can_partitions ||
3585				    (STp->new_partition != STp->partition);
3586			} else {
3587				i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3588				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3589				    mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3590				    mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3591				    mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3592				    mtc.mt_op == MTCOMPRESSION;
3593			}
3594			i = flush_buffer(STp, i);
3595			if (i < 0) {
3596				retval = i;
3597				goto out;
3598			}
3599			if (STps->rw == ST_WRITING &&
3600			    (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3601			     mtc.mt_op == MTSEEK ||
3602			     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3603				i = st_int_ioctl(STp, MTWEOF, 1);
3604				if (i < 0) {
3605					retval = i;
3606					goto out;
3607				}
3608				if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3609					mtc.mt_count++;
3610				STps->rw = ST_IDLE;
3611			     }
3612
3613		} else {
3614			/*
3615			 * If there was a bus reset, block further access
3616			 * to this device.  If the user wants to rewind the tape,
3617			 * then reset the flag and allow access again.
3618			 */
3619			if (mtc.mt_op != MTREW &&
3620			    mtc.mt_op != MTOFFL &&
3621			    mtc.mt_op != MTRETEN &&
3622			    mtc.mt_op != MTERASE &&
3623			    mtc.mt_op != MTSEEK &&
3624			    mtc.mt_op != MTEOM) {
3625				retval = (-EIO);
3626				goto out;
3627			}
3628			reset_state(STp);
3629			/* remove this when the midlevel properly clears was_reset */
3630			STp->device->was_reset = 0;
3631		}
3632
3633		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3634		    mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3635		    mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3636			STps->rw = ST_IDLE;	/* Prevent automatic WEOF and fsf */
3637
3638		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3639			do_door_lock(STp, 0);	/* Ignore result! */
3640
3641		if (mtc.mt_op == MTSETDRVBUFFER &&
3642		    (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3643			retval = st_set_options(STp, mtc.mt_count);
3644			goto out;
3645		}
3646
3647		if (mtc.mt_op == MTSETPART) {
3648			if (!STp->can_partitions ||
3649			    mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3650				retval = (-EINVAL);
3651				goto out;
3652			}
3653			if (mtc.mt_count >= STp->nbr_partitions &&
3654			    (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3655				retval = (-EIO);
3656				goto out;
3657			}
3658			if (mtc.mt_count >= STp->nbr_partitions) {
3659				retval = (-EINVAL);
3660				goto out;
3661			}
3662			STp->new_partition = mtc.mt_count;
3663			retval = 0;
3664			goto out;
3665		}
3666
3667		if (mtc.mt_op == MTMKPART) {
3668			if (!STp->can_partitions) {
3669				retval = (-EINVAL);
3670				goto out;
3671			}
3672			i = do_load_unload(STp, file, 1);
3673			if (i < 0) {
3674				retval = i;
3675				goto out;
3676			}
3677			i = partition_tape(STp, mtc.mt_count);
3678			if (i < 0) {
3679				retval = i;
3680				goto out;
3681			}
3682			for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3683				STp->ps[i].rw = ST_IDLE;
3684				STp->ps[i].at_sm = 0;
3685				STp->ps[i].last_block_valid = 0;
3686			}
3687			STp->partition = STp->new_partition = 0;
3688			STp->nbr_partitions = mtc.mt_count != 0 ? 2 : 1;
3689			STps->drv_block = STps->drv_file = 0;
3690			retval = 0;
3691			goto out;
3692		}
3693
3694		if (mtc.mt_op == MTSEEK) {
3695			i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3696			if (!STp->can_partitions)
3697				STp->ps[0].rw = ST_IDLE;
3698			retval = i;
3699			goto out;
3700		}
3701
3702		if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3703			retval = do_load_unload(STp, file, 0);
3704			goto out;
3705		}
3706
3707		if (mtc.mt_op == MTLOAD) {
3708			retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3709			goto out;
3710		}
3711
3712		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3713			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3714			goto out;
3715		}
3716
3717		if (STp->can_partitions && STp->ready == ST_READY &&
3718		    (i = switch_partition(STp)) < 0) {
3719			retval = i;
3720			goto out;
3721		}
3722
3723		if (mtc.mt_op == MTCOMPRESSION)
3724			retval = st_compression(STp, (mtc.mt_count & 1));
3725		else
3726			retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3727		goto out;
3728	}
3729	if (!STm->defined) {
3730		retval = (-ENXIO);
3731		goto out;
3732	}
3733
3734	if ((i = flush_buffer(STp, 0)) < 0) {
3735		retval = i;
3736		goto out;
3737	}
3738	if (STp->can_partitions &&
3739	    (i = switch_partition(STp)) < 0) {
3740		retval = i;
3741		goto out;
3742	}
3743
3744	if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
3745		struct mtget mt_status;
3746
3747		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3748			 retval = (-EINVAL);
3749			 goto out;
3750		}
3751
3752		mt_status.mt_type = STp->tape_type;
3753		mt_status.mt_dsreg =
3754		    ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3755		    ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3756		mt_status.mt_blkno = STps->drv_block;
3757		mt_status.mt_fileno = STps->drv_file;
3758		if (STp->block_size != 0) {
3759			if (STps->rw == ST_WRITING)
3760				mt_status.mt_blkno +=
3761				    (STp->buffer)->buffer_bytes / STp->block_size;
3762			else if (STps->rw == ST_READING)
3763				mt_status.mt_blkno -=
3764                                        ((STp->buffer)->buffer_bytes +
3765                                         STp->block_size - 1) / STp->block_size;
3766		}
3767
3768		mt_status.mt_gstat = 0;
3769		if (STp->drv_write_prot)
3770			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3771		if (mt_status.mt_blkno == 0) {
3772			if (mt_status.mt_fileno == 0)
3773				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3774			else
3775				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3776		}
3777		mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3778		mt_status.mt_resid = STp->partition;
3779		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3780			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3781		else if (STps->eof >= ST_EOM_OK)
3782			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3783		if (STp->density == 1)
3784			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3785		else if (STp->density == 2)
3786			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3787		else if (STp->density == 3)
3788			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3789		if (STp->ready == ST_READY)
3790			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3791		if (STp->ready == ST_NO_TAPE)
3792			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3793		if (STps->at_sm)
3794			mt_status.mt_gstat |= GMT_SM(0xffffffff);
3795		if (STm->do_async_writes ||
3796                    (STm->do_buffer_writes && STp->block_size != 0) ||
3797		    STp->drv_buffer != 0)
3798			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3799		if (STp->cleaning_req)
3800			mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3801
3802		i = copy_to_user(p, &mt_status, sizeof(struct mtget));
3803		if (i) {
3804			retval = (-EFAULT);
3805			goto out;
3806		}
3807
3808		STp->recover_reg = 0;		/* Clear after read */
3809		retval = 0;
3810		goto out;
3811	}			/* End of MTIOCGET */
3812	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3813		struct mtpos mt_pos;
3814		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3815			 retval = (-EINVAL);
3816			 goto out;
3817		}
3818		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3819			retval = i;
3820			goto out;
3821		}
3822		mt_pos.mt_blkno = blk;
3823		i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
3824		if (i)
3825			retval = (-EFAULT);
3826		goto out;
3827	}
3828	mutex_unlock(&STp->lock);
3829	switch (cmd_in) {
3830		case SCSI_IOCTL_GET_IDLUN:
3831		case SCSI_IOCTL_GET_BUS_NUMBER:
3832			break;
3833		default:
3834			if ((cmd_in == SG_IO ||
3835			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3836			     cmd_in == CDROM_SEND_PACKET) &&
3837			    !capable(CAP_SYS_RAWIO))
3838				i = -EPERM;
3839			else
3840				i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3841						   file->f_mode, cmd_in, p);
3842			if (i != -ENOTTY)
3843				return i;
3844			break;
3845	}
3846	retval = scsi_ioctl(STp->device, cmd_in, p);
3847	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
3848		STp->rew_at_close = 0;
3849		STp->ready = ST_NO_TAPE;
3850	}
3851	return retval;
3852
3853 out:
3854	mutex_unlock(&STp->lock);
3855	return retval;
3856}
3857
3858#ifdef CONFIG_COMPAT
3859static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3860{
3861	struct scsi_tape *STp = file->private_data;
3862	struct scsi_device *sdev = STp->device;
3863	int ret = -ENOIOCTLCMD;
3864	if (sdev->host->hostt->compat_ioctl) { 
3865
3866		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
3867
3868	}
3869	return ret;
3870}
3871#endif
3872
3873
3874
3875/* Try to allocate a new tape buffer. Calling function must not hold
3876   dev_arr_lock. */
3877static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
3878{
3879	struct st_buffer *tb;
3880
3881	tb = kzalloc(sizeof(struct st_buffer), GFP_ATOMIC);
3882	if (!tb) {
3883		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3884		return NULL;
3885	}
3886	tb->frp_segs = 0;
3887	tb->use_sg = max_sg;
3888	tb->dma = need_dma;
3889	tb->buffer_size = 0;
3890
3891	tb->reserved_pages = kzalloc(max_sg * sizeof(struct page *),
3892				     GFP_ATOMIC);
3893	if (!tb->reserved_pages) {
3894		kfree(tb);
3895		return NULL;
3896	}
3897
3898	return tb;
3899}
3900
3901
3902/* Try to allocate enough space in the tape buffer */
3903#define ST_MAX_ORDER 6
3904
3905static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
3906{
3907	int segs, max_segs, b_size, order, got;
3908	gfp_t priority;
3909
3910	if (new_size <= STbuffer->buffer_size)
3911		return 1;
3912
3913	if (STbuffer->buffer_size <= PAGE_SIZE)
3914		normalize_buffer(STbuffer);  /* Avoid extra segment */
3915
3916	max_segs = STbuffer->use_sg;
3917
3918	priority = GFP_KERNEL | __GFP_NOWARN;
3919	if (need_dma)
3920		priority |= GFP_DMA;
3921
3922	if (STbuffer->cleared)
3923		priority |= __GFP_ZERO;
3924
3925	if (STbuffer->frp_segs) {
3926		order = STbuffer->reserved_page_order;
3927		b_size = PAGE_SIZE << order;
3928	} else {
3929		for (b_size = PAGE_SIZE, order = 0;
3930		     order < ST_MAX_ORDER &&
3931			     max_segs * (PAGE_SIZE << order) < new_size;
3932		     order++, b_size *= 2)
3933			;  /* empty */
3934		STbuffer->reserved_page_order = order;
3935	}
3936	if (max_segs * (PAGE_SIZE << order) < new_size) {
3937		if (order == ST_MAX_ORDER)
3938			return 0;
3939		normalize_buffer(STbuffer);
3940		return enlarge_buffer(STbuffer, new_size, need_dma);
3941	}
3942
3943	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3944	     segs < max_segs && got < new_size;) {
3945		struct page *page;
3946
3947		page = alloc_pages(priority, order);
3948		if (!page) {
3949			DEB(STbuffer->buffer_size = got);
3950			normalize_buffer(STbuffer);
3951			return 0;
3952		}
3953
3954		STbuffer->frp_segs += 1;
3955		got += b_size;
3956		STbuffer->buffer_size = got;
3957		STbuffer->reserved_pages[segs] = page;
3958		segs++;
3959	}
3960	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3961
3962	return 1;
3963}
3964
3965
3966/* Make sure that no data from previous user is in the internal buffer */
3967static void clear_buffer(struct st_buffer * st_bp)
3968{
3969	int i;
3970
3971	for (i=0; i < st_bp->frp_segs; i++)
3972		memset(page_address(st_bp->reserved_pages[i]), 0,
3973		       PAGE_SIZE << st_bp->reserved_page_order);
3974	st_bp->cleared = 1;
3975}
3976
3977
3978/* Release the extra buffer */
3979static void normalize_buffer(struct st_buffer * STbuffer)
3980{
3981	int i, order = STbuffer->reserved_page_order;
3982
3983	for (i = 0; i < STbuffer->frp_segs; i++) {
3984		__free_pages(STbuffer->reserved_pages[i], order);
3985		STbuffer->buffer_size -= (PAGE_SIZE << order);
3986	}
3987	STbuffer->frp_segs = 0;
3988	STbuffer->sg_segs = 0;
3989	STbuffer->reserved_page_order = 0;
3990	STbuffer->map_data.offset = 0;
3991}
3992
3993
3994/* Move data from the user buffer to the tape buffer. Returns zero (success) or
3995   negative error code. */
3996static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3997{
3998	int i, cnt, res, offset;
3999	int length = PAGE_SIZE << st_bp->reserved_page_order;
4000
4001	for (i = 0, offset = st_bp->buffer_bytes;
4002	     i < st_bp->frp_segs && offset >= length; i++)
4003		offset -= length;
4004	if (i == st_bp->frp_segs) {	/* Should never happen */
4005		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
4006		return (-EIO);
4007	}
4008	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4009		struct page *page = st_bp->reserved_pages[i];
4010		cnt = length - offset < do_count ? length - offset : do_count;
4011		res = copy_from_user(page_address(page) + offset, ubp, cnt);
4012		if (res)
4013			return (-EFAULT);
4014		do_count -= cnt;
4015		st_bp->buffer_bytes += cnt;
4016		ubp += cnt;
4017		offset = 0;
4018	}
4019	if (do_count) /* Should never happen */
4020		return (-EIO);
4021
4022	return 0;
4023}
4024
4025
4026/* Move data from the tape buffer to the user buffer. Returns zero (success) or
4027   negative error code. */
4028static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
4029{
4030	int i, cnt, res, offset;
4031	int length = PAGE_SIZE << st_bp->reserved_page_order;
4032
4033	for (i = 0, offset = st_bp->read_pointer;
4034	     i < st_bp->frp_segs && offset >= length; i++)
4035		offset -= length;
4036	if (i == st_bp->frp_segs) {	/* Should never happen */
4037		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
4038		return (-EIO);
4039	}
4040	for (; i < st_bp->frp_segs && do_count > 0; i++) {
4041		struct page *page = st_bp->reserved_pages[i];
4042		cnt = length - offset < do_count ? length - offset : do_count;
4043		res = copy_to_user(ubp, page_address(page) + offset, cnt);
4044		if (res)
4045			return (-EFAULT);
4046		do_count -= cnt;
4047		st_bp->buffer_bytes -= cnt;
4048		st_bp->read_pointer += cnt;
4049		ubp += cnt;
4050		offset = 0;
4051	}
4052	if (do_count) /* Should never happen */
4053		return (-EIO);
4054
4055	return 0;
4056}
4057
4058
4059/* Move data towards start of buffer */
4060static void move_buffer_data(struct st_buffer * st_bp, int offset)
4061{
4062	int src_seg, dst_seg, src_offset = 0, dst_offset;
4063	int count, total;
4064	int length = PAGE_SIZE << st_bp->reserved_page_order;
4065
4066	if (offset == 0)
4067		return;
4068
4069	total=st_bp->buffer_bytes - offset;
4070	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
4071		src_offset = offset;
4072		if (src_offset < length)
4073			break;
4074		offset -= length;
4075	}
4076
4077	st_bp->buffer_bytes = st_bp->read_pointer = total;
4078	for (dst_seg=dst_offset=0; total > 0; ) {
4079		struct page *dpage = st_bp->reserved_pages[dst_seg];
4080		struct page *spage = st_bp->reserved_pages[src_seg];
4081
4082		count = min(length - dst_offset, length - src_offset);
4083		memmove(page_address(dpage) + dst_offset,
4084			page_address(spage) + src_offset, count);
4085		src_offset += count;
4086		if (src_offset >= length) {
4087			src_seg++;
4088			src_offset = 0;
4089		}
4090		dst_offset += count;
4091		if (dst_offset >= length) {
4092			dst_seg++;
4093			dst_offset = 0;
4094		}
4095		total -= count;
4096	}
4097}
4098
4099/* Validate the options from command line or module parameters */
4100static void validate_options(void)
4101{
4102	if (buffer_kbs > 0)
4103		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
4104	if (max_sg_segs >= ST_FIRST_SG)
4105		st_max_sg_segs = max_sg_segs;
4106}
4107
4108#ifndef MODULE
4109/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
4110 */
4111static int __init st_setup(char *str)
4112{
4113	int i, len, ints[5];
4114	char *stp;
4115
4116	stp = get_options(str, ARRAY_SIZE(ints), ints);
4117
4118	if (ints[0] > 0) {
4119		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
4120			if (parms[i].val)
4121				*parms[i].val = ints[i + 1];
4122	} else {
4123		while (stp != NULL) {
4124			for (i = 0; i < ARRAY_SIZE(parms); i++) {
4125				len = strlen(parms[i].name);
4126				if (!strncmp(stp, parms[i].name, len) &&
4127				    (*(stp + len) == ':' || *(stp + len) == '=')) {
4128					if (parms[i].val)
4129						*parms[i].val =
4130							simple_strtoul(stp + len + 1, NULL, 0);
4131					else
4132						printk(KERN_WARNING "st: Obsolete parameter %s\n",
4133						       parms[i].name);
4134					break;
4135				}
4136			}
4137			if (i >= ARRAY_SIZE(parms))
4138				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
4139					stp);
4140			stp = strchr(stp, ',');
4141			if (stp)
4142				stp++;
4143		}
4144	}
4145
4146	validate_options();
4147
4148	return 1;
4149}
4150
4151__setup("st=", st_setup);
4152
4153#endif
4154
4155static const struct file_operations st_fops =
4156{
4157	.owner =	THIS_MODULE,
4158	.read =		st_read,
4159	.write =	st_write,
4160	.unlocked_ioctl = st_ioctl,
4161#ifdef CONFIG_COMPAT
4162	.compat_ioctl = st_compat_ioctl,
4163#endif
4164	.open =		st_open,
4165	.flush =	st_flush,
4166	.release =	st_release,
4167	.llseek =	noop_llseek,
4168};
4169
4170static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
4171{
4172	int i, error;
4173	dev_t cdev_devno;
4174	struct cdev *cdev;
4175	struct device *dev;
4176	struct st_modedef *STm = &(tape->modes[mode]);
4177	char name[10];
4178	int dev_num = tape->index;
4179
4180	cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
4181
4182	cdev = cdev_alloc();
4183	if (!cdev) {
4184		pr_err("st%d: out of memory. Device not attached.\n", dev_num);
4185		error = -ENOMEM;
4186		goto out;
4187	}
4188	cdev->owner = THIS_MODULE;
4189	cdev->ops = &st_fops;
4190	STm->cdevs[rew] = cdev;
4191
4192	error = cdev_add(cdev, cdev_devno, 1);
4193	if (error) {
4194		pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
4195		       rew ? "non" : "auto", mode);
4196		pr_err("st%d: Device not attached.\n", dev_num);
4197		goto out_free;
4198	}
 
4199
4200	i = mode << (4 - ST_NBR_MODE_BITS);
4201	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4202		 tape->disk->disk_name, st_formats[i]);
4203
4204	dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
4205			    cdev_devno, &tape->modes[mode], "%s", name);
4206	if (IS_ERR(dev)) {
4207		pr_err("st%d: device_create failed\n", dev_num);
4208		error = PTR_ERR(dev);
4209		goto out_free;
4210	}
4211
4212	STm->devs[rew] = dev;
4213
4214	return 0;
4215out_free:
4216	cdev_del(STm->cdevs[rew]);
4217out:
4218	STm->cdevs[rew] = NULL;
4219	STm->devs[rew] = NULL;
4220	return error;
4221}
4222
4223static int create_cdevs(struct scsi_tape *tape)
4224{
4225	int mode, error;
4226	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4227		error = create_one_cdev(tape, mode, 0);
4228		if (error)
4229			return error;
4230		error = create_one_cdev(tape, mode, 1);
4231		if (error)
4232			return error;
4233	}
4234
4235	return sysfs_create_link(&tape->device->sdev_gendev.kobj,
4236				 &tape->modes[0].devs[0]->kobj, "tape");
4237}
4238
4239static void remove_cdevs(struct scsi_tape *tape)
4240{
4241	int mode, rew;
4242	sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
4243	for (mode = 0; mode < ST_NBR_MODES; mode++) {
4244		struct st_modedef *STm = &(tape->modes[mode]);
4245		for (rew = 0; rew < 2; rew++) {
4246			if (STm->cdevs[rew])
4247				cdev_del(STm->cdevs[rew]);
4248			if (STm->devs[rew])
4249				device_unregister(STm->devs[rew]);
4250		}
4251	}
4252}
4253
4254static int st_probe(struct device *dev)
4255{
4256	struct scsi_device *SDp = to_scsi_device(dev);
4257	struct gendisk *disk = NULL;
4258	struct scsi_tape *tpnt = NULL;
4259	struct st_modedef *STm;
4260	struct st_partstat *STps;
4261	struct st_buffer *buffer;
4262	int i, error;
4263	char *stp;
4264
4265	if (SDp->type != TYPE_TAPE)
4266		return -ENODEV;
4267	if ((stp = st_incompatible(SDp))) {
4268		sdev_printk(KERN_INFO, SDp, "Found incompatible tape\n");
4269		sdev_printk(KERN_INFO, SDp,
4270			    "st: The suggested driver is %s.\n", stp);
4271		return -ENODEV;
4272	}
4273
4274	scsi_autopm_get_device(SDp);
4275	i = queue_max_segments(SDp->request_queue);
4276	if (st_max_sg_segs < i)
4277		i = st_max_sg_segs;
4278	buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
4279	if (buffer == NULL) {
4280		sdev_printk(KERN_ERR, SDp,
4281			    "st: Can't allocate new tape buffer. "
4282			    "Device not attached.\n");
4283		goto out;
4284	}
4285
4286	disk = alloc_disk(1);
4287	if (!disk) {
4288		sdev_printk(KERN_ERR, SDp,
4289			    "st: out of memory. Device not attached.\n");
4290		goto out_buffer_free;
4291	}
4292
4293	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
4294	if (tpnt == NULL) {
4295		sdev_printk(KERN_ERR, SDp,
4296			    "st: Can't allocate device descriptor.\n");
4297		goto out_put_disk;
4298	}
4299	kref_init(&tpnt->kref);
4300	tpnt->disk = disk;
4301	disk->private_data = &tpnt->driver;
 
4302	/* SCSI tape doesn't register this gendisk via add_disk().  Manually
4303	 * take queue reference that release_disk() expects. */
4304	if (!blk_get_queue(SDp->request_queue))
4305		goto out_put_disk;
4306	disk->queue = SDp->request_queue;
4307	tpnt->driver = &st_template;
4308
4309	tpnt->device = SDp;
4310	if (SDp->scsi_level <= 2)
4311		tpnt->tape_type = MT_ISSCSI1;
4312	else
4313		tpnt->tape_type = MT_ISSCSI2;
4314
4315	tpnt->buffer = buffer;
4316	tpnt->buffer->last_SRpnt = NULL;
4317
4318	tpnt->inited = 0;
4319	tpnt->dirty = 0;
4320	tpnt->in_use = 0;
4321	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
4322	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4323	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4324	tpnt->density = 0;
4325	tpnt->do_auto_lock = ST_AUTO_LOCK;
4326	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4327	tpnt->can_partitions = 0;
4328	tpnt->two_fm = ST_TWO_FM;
4329	tpnt->fast_mteom = ST_FAST_MTEOM;
4330	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4331	tpnt->sili = ST_SILI;
4332	tpnt->immediate = ST_NOWAIT;
4333	tpnt->immediate_filemark = 0;
4334	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4335	tpnt->partition = 0;
4336	tpnt->new_partition = 0;
4337	tpnt->nbr_partitions = 0;
4338	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4339	tpnt->long_timeout = ST_LONG_TIMEOUT;
4340	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
4341
4342	for (i = 0; i < ST_NBR_MODES; i++) {
4343		STm = &(tpnt->modes[i]);
4344		STm->defined = 0;
4345		STm->sysv = ST_SYSV;
4346		STm->defaults_for_writes = 0;
4347		STm->do_async_writes = ST_ASYNC_WRITES;
4348		STm->do_buffer_writes = ST_BUFFER_WRITES;
4349		STm->do_read_ahead = ST_READ_AHEAD;
4350		STm->default_compression = ST_DONT_TOUCH;
4351		STm->default_blksize = (-1);	/* No forced size */
4352		STm->default_density = (-1);	/* No forced density */
4353		STm->tape = tpnt;
4354	}
4355
4356	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4357		STps = &(tpnt->ps[i]);
4358		STps->rw = ST_IDLE;
4359		STps->eof = ST_NOEOF;
4360		STps->at_sm = 0;
4361		STps->last_block_valid = 0;
4362		STps->drv_block = (-1);
4363		STps->drv_file = (-1);
4364	}
4365
4366	tpnt->current_mode = 0;
4367	tpnt->modes[0].defined = 1;
4368
4369	tpnt->density_changed = tpnt->compression_changed =
4370	    tpnt->blksize_changed = 0;
4371	mutex_init(&tpnt->lock);
4372
4373	idr_preload(GFP_KERNEL);
4374	spin_lock(&st_index_lock);
4375	error = idr_alloc(&st_index_idr, tpnt, 0, ST_MAX_TAPES + 1, GFP_NOWAIT);
4376	spin_unlock(&st_index_lock);
4377	idr_preload_end();
4378	if (error < 0) {
4379		pr_warn("st: idr allocation failed: %d\n", error);
4380		goto out_put_queue;
4381	}
4382	tpnt->index = error;
4383	sprintf(disk->disk_name, "st%d", tpnt->index);
4384	tpnt->stats = kzalloc(sizeof(struct scsi_tape_stats), GFP_KERNEL);
4385	if (tpnt->stats == NULL) {
4386		sdev_printk(KERN_ERR, SDp,
4387			    "st: Can't allocate statistics.\n");
4388		goto out_idr_remove;
4389	}
4390
4391	dev_set_drvdata(dev, tpnt);
4392
4393
4394	error = create_cdevs(tpnt);
4395	if (error)
4396		goto out_remove_devs;
4397	scsi_autopm_put_device(SDp);
4398
4399	sdev_printk(KERN_NOTICE, SDp,
4400		    "Attached scsi tape %s\n", tape_name(tpnt));
4401	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4402		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4403		    queue_dma_alignment(SDp->request_queue) + 1);
4404
4405	return 0;
4406
4407out_remove_devs:
4408	remove_cdevs(tpnt);
4409	kfree(tpnt->stats);
4410out_idr_remove:
4411	spin_lock(&st_index_lock);
4412	idr_remove(&st_index_idr, tpnt->index);
4413	spin_unlock(&st_index_lock);
4414out_put_queue:
4415	blk_put_queue(disk->queue);
4416out_put_disk:
4417	put_disk(disk);
4418	kfree(tpnt);
4419out_buffer_free:
4420	kfree(buffer);
4421out:
4422	scsi_autopm_put_device(SDp);
4423	return -ENODEV;
4424};
4425
4426
4427static int st_remove(struct device *dev)
4428{
4429	struct scsi_tape *tpnt = dev_get_drvdata(dev);
4430	int index = tpnt->index;
4431
4432	scsi_autopm_get_device(to_scsi_device(dev));
4433	remove_cdevs(tpnt);
4434
4435	mutex_lock(&st_ref_mutex);
4436	kref_put(&tpnt->kref, scsi_tape_release);
4437	mutex_unlock(&st_ref_mutex);
4438	spin_lock(&st_index_lock);
4439	idr_remove(&st_index_idr, index);
4440	spin_unlock(&st_index_lock);
4441	return 0;
4442}
4443
4444/**
4445 *      scsi_tape_release - Called to free the Scsi_Tape structure
4446 *      @kref: pointer to embedded kref
4447 *
4448 *      st_ref_mutex must be held entering this routine.  Because it is
4449 *      called on last put, you should always use the scsi_tape_get()
4450 *      scsi_tape_put() helpers which manipulate the semaphore directly
4451 *      and never do a direct kref_put().
4452 **/
4453static void scsi_tape_release(struct kref *kref)
4454{
4455	struct scsi_tape *tpnt = to_scsi_tape(kref);
4456	struct gendisk *disk = tpnt->disk;
4457
4458	tpnt->device = NULL;
4459
4460	if (tpnt->buffer) {
4461		normalize_buffer(tpnt->buffer);
4462		kfree(tpnt->buffer->reserved_pages);
4463		kfree(tpnt->buffer);
4464	}
4465
4466	disk->private_data = NULL;
4467	put_disk(disk);
4468	kfree(tpnt->stats);
4469	kfree(tpnt);
4470	return;
4471}
4472
4473static struct class st_sysfs_class = {
4474	.name = "scsi_tape",
4475	.dev_groups = st_dev_groups,
4476};
4477
4478static int __init init_st(void)
4479{
4480	int err;
4481
4482	validate_options();
4483
4484	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4485		verstr, st_fixed_buffer_size, st_max_sg_segs);
4486
4487	debugging = (debug_flag > 0) ? debug_flag : NO_DEBUG;
4488	if (debugging) {
4489		printk(KERN_INFO "st: Debugging enabled debug_flag = %d\n",
4490			debugging);
4491	}
4492
4493	err = class_register(&st_sysfs_class);
4494	if (err) {
4495		pr_err("Unable register sysfs class for SCSI tapes\n");
4496		return err;
4497	}
4498
4499	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4500				     ST_MAX_TAPE_ENTRIES, "st");
4501	if (err) {
4502		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4503		       SCSI_TAPE_MAJOR);
4504		goto err_class;
4505	}
4506
4507	err = scsi_register_driver(&st_template.gendrv);
4508	if (err)
4509		goto err_chrdev;
4510
 
 
 
 
4511	return 0;
4512
 
 
4513err_chrdev:
4514	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4515				 ST_MAX_TAPE_ENTRIES);
4516err_class:
4517	class_unregister(&st_sysfs_class);
4518	return err;
4519}
4520
4521static void __exit exit_st(void)
4522{
 
4523	scsi_unregister_driver(&st_template.gendrv);
4524	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4525				 ST_MAX_TAPE_ENTRIES);
4526	class_unregister(&st_sysfs_class);
4527	idr_destroy(&st_index_idr);
4528	printk(KERN_INFO "st: Unloaded.\n");
4529}
4530
4531module_init(init_st);
4532module_exit(exit_st);
4533
4534
4535/* The sysfs driver interface. Read-only at the moment */
4536static ssize_t try_direct_io_show(struct device_driver *ddp, char *buf)
4537{
4538	return scnprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4539}
4540static DRIVER_ATTR_RO(try_direct_io);
4541
4542static ssize_t fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4543{
4544	return scnprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4545}
4546static DRIVER_ATTR_RO(fixed_buffer_size);
4547
4548static ssize_t max_sg_segs_show(struct device_driver *ddp, char *buf)
4549{
4550	return scnprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4551}
4552static DRIVER_ATTR_RO(max_sg_segs);
4553
4554static ssize_t version_show(struct device_driver *ddd, char *buf)
4555{
4556	return scnprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4557}
4558static DRIVER_ATTR_RO(version);
4559
4560#if DEBUG
4561static ssize_t debug_flag_store(struct device_driver *ddp,
4562	const char *buf, size_t count)
4563{
4564/* We only care what the first byte of the data is the rest is unused.
4565 * if it's a '1' we turn on debug and if it's a '0' we disable it. All
4566 * other values have -EINVAL returned if they are passed in.
4567 */
4568	if (count > 0) {
4569		if (buf[0] == '0') {
4570			debugging = NO_DEBUG;
4571			return count;
4572		} else if (buf[0] == '1') {
4573			debugging = 1;
4574			return count;
4575		}
4576	}
4577	return -EINVAL;
 
 
 
 
 
 
 
 
 
 
 
4578}
4579
4580static ssize_t debug_flag_show(struct device_driver *ddp, char *buf)
4581{
4582	return scnprintf(buf, PAGE_SIZE, "%d\n", debugging);
4583}
4584static DRIVER_ATTR_RW(debug_flag);
4585#endif
4586
4587static struct attribute *st_drv_attrs[] = {
4588	&driver_attr_try_direct_io.attr,
4589	&driver_attr_fixed_buffer_size.attr,
4590	&driver_attr_max_sg_segs.attr,
4591	&driver_attr_version.attr,
4592#if DEBUG
4593	&driver_attr_debug_flag.attr,
4594#endif
4595	NULL,
4596};
4597ATTRIBUTE_GROUPS(st_drv);
4598
4599/* The sysfs simple class interface */
4600static ssize_t
4601defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4602{
4603	struct st_modedef *STm = dev_get_drvdata(dev);
4604	ssize_t l = 0;
4605
4606	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4607	return l;
4608}
4609static DEVICE_ATTR_RO(defined);
4610
4611static ssize_t
4612default_blksize_show(struct device *dev, struct device_attribute *attr,
4613		     char *buf)
4614{
4615	struct st_modedef *STm = dev_get_drvdata(dev);
4616	ssize_t l = 0;
4617
4618	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4619	return l;
4620}
4621static DEVICE_ATTR_RO(default_blksize);
4622
4623static ssize_t
4624default_density_show(struct device *dev, struct device_attribute *attr,
4625		     char *buf)
4626{
4627	struct st_modedef *STm = dev_get_drvdata(dev);
4628	ssize_t l = 0;
4629	char *fmt;
4630
4631	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4632	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4633	return l;
4634}
4635static DEVICE_ATTR_RO(default_density);
4636
4637static ssize_t
4638default_compression_show(struct device *dev, struct device_attribute *attr,
4639			 char *buf)
4640{
4641	struct st_modedef *STm = dev_get_drvdata(dev);
4642	ssize_t l = 0;
4643
4644	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4645	return l;
4646}
4647static DEVICE_ATTR_RO(default_compression);
4648
4649static ssize_t
4650options_show(struct device *dev, struct device_attribute *attr, char *buf)
4651{
4652	struct st_modedef *STm = dev_get_drvdata(dev);
4653	struct scsi_tape *STp = STm->tape;
4654	int options;
4655	ssize_t l = 0;
4656
4657	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4658	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4659	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4660	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4661	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4662	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4663	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4664	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4665	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4666	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4667	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4668	options |= STm->sysv ? MT_ST_SYSV : 0;
4669	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4670	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4671	options |= STp->sili ? MT_ST_SILI : 0;
4672
4673	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4674	return l;
4675}
4676static DEVICE_ATTR_RO(options);
4677
4678/* Support for tape stats */
4679
4680/**
4681 * read_cnt_show - return read count - count of reads made from tape drive
4682 * @dev: struct device
4683 * @attr: attribute structure
4684 * @buf: buffer to return formatted data in
4685 */
4686static ssize_t read_cnt_show(struct device *dev,
4687	struct device_attribute *attr, char *buf)
4688{
4689	struct st_modedef *STm = dev_get_drvdata(dev);
4690
4691	return sprintf(buf, "%lld",
4692		       (long long)atomic64_read(&STm->tape->stats->read_cnt));
4693}
4694static DEVICE_ATTR_RO(read_cnt);
4695
4696/**
4697 * read_byte_cnt_show - return read byte count - tape drives
4698 * may use blocks less than 512 bytes this gives the raw byte count of
4699 * of data read from the tape drive.
4700 * @dev: struct device
4701 * @attr: attribute structure
4702 * @buf: buffer to return formatted data in
4703 */
4704static ssize_t read_byte_cnt_show(struct device *dev,
4705	struct device_attribute *attr, char *buf)
4706{
4707	struct st_modedef *STm = dev_get_drvdata(dev);
4708
4709	return sprintf(buf, "%lld",
4710		       (long long)atomic64_read(&STm->tape->stats->read_byte_cnt));
4711}
4712static DEVICE_ATTR_RO(read_byte_cnt);
4713
4714/**
4715 * read_ns_show - return read ns - overall time spent waiting on reads in ns.
4716 * @dev: struct device
4717 * @attr: attribute structure
4718 * @buf: buffer to return formatted data in
4719 */
4720static ssize_t read_ns_show(struct device *dev,
4721	struct device_attribute *attr, char *buf)
4722{
4723	struct st_modedef *STm = dev_get_drvdata(dev);
4724
4725	return sprintf(buf, "%lld",
4726		       (long long)atomic64_read(&STm->tape->stats->tot_read_time));
4727}
4728static DEVICE_ATTR_RO(read_ns);
4729
4730/**
4731 * write_cnt_show - write count - number of user calls
4732 * to write(2) that have written data to tape.
4733 * @dev: struct device
4734 * @attr: attribute structure
4735 * @buf: buffer to return formatted data in
4736 */
4737static ssize_t write_cnt_show(struct device *dev,
4738	struct device_attribute *attr, char *buf)
4739{
4740	struct st_modedef *STm = dev_get_drvdata(dev);
4741
4742	return sprintf(buf, "%lld",
4743		       (long long)atomic64_read(&STm->tape->stats->write_cnt));
4744}
4745static DEVICE_ATTR_RO(write_cnt);
4746
4747/**
4748 * write_byte_cnt_show - write byte count - raw count of
4749 * bytes written to tape.
4750 * @dev: struct device
4751 * @attr: attribute structure
4752 * @buf: buffer to return formatted data in
4753 */
4754static ssize_t write_byte_cnt_show(struct device *dev,
4755	struct device_attribute *attr, char *buf)
4756{
4757	struct st_modedef *STm = dev_get_drvdata(dev);
4758
4759	return sprintf(buf, "%lld",
4760		       (long long)atomic64_read(&STm->tape->stats->write_byte_cnt));
4761}
4762static DEVICE_ATTR_RO(write_byte_cnt);
4763
4764/**
4765 * write_ns_show - write ns - number of nanoseconds waiting on write
4766 * requests to complete.
4767 * @dev: struct device
4768 * @attr: attribute structure
4769 * @buf: buffer to return formatted data in
4770 */
4771static ssize_t write_ns_show(struct device *dev,
4772	struct device_attribute *attr, char *buf)
4773{
4774	struct st_modedef *STm = dev_get_drvdata(dev);
4775
4776	return sprintf(buf, "%lld",
4777		       (long long)atomic64_read(&STm->tape->stats->tot_write_time));
4778}
4779static DEVICE_ATTR_RO(write_ns);
4780
4781/**
4782 * in_flight_show - number of I/Os currently in flight -
4783 * in most cases this will be either 0 or 1. It may be higher if someone
4784 * has also issued other SCSI commands such as via an ioctl.
4785 * @dev: struct device
4786 * @attr: attribute structure
4787 * @buf: buffer to return formatted data in
4788 */
4789static ssize_t in_flight_show(struct device *dev,
4790	struct device_attribute *attr, char *buf)
4791{
4792	struct st_modedef *STm = dev_get_drvdata(dev);
4793
4794	return sprintf(buf, "%lld",
4795		       (long long)atomic64_read(&STm->tape->stats->in_flight));
4796}
4797static DEVICE_ATTR_RO(in_flight);
4798
4799/**
4800 * io_ns_show - io wait ns - this is the number of ns spent
4801 * waiting on all I/O to complete. This includes tape movement commands
4802 * such as rewinding, seeking to end of file or tape, it also includes
4803 * read and write. To determine the time spent on tape movement
4804 * subtract the read and write ns from this value.
4805 * @dev: struct device
4806 * @attr: attribute structure
4807 * @buf: buffer to return formatted data in
4808 */
4809static ssize_t io_ns_show(struct device *dev,
4810	struct device_attribute *attr, char *buf)
4811{
4812	struct st_modedef *STm = dev_get_drvdata(dev);
4813
4814	return sprintf(buf, "%lld",
4815		       (long long)atomic64_read(&STm->tape->stats->tot_io_time));
4816}
4817static DEVICE_ATTR_RO(io_ns);
4818
4819/**
4820 * other_cnt_show - other io count - this is the number of
4821 * I/O requests other than read and write requests.
4822 * Typically these are tape movement requests but will include driver
4823 * tape movement. This includes only requests issued by the st driver.
4824 * @dev: struct device
4825 * @attr: attribute structure
4826 * @buf: buffer to return formatted data in
4827 */
4828static ssize_t other_cnt_show(struct device *dev,
4829	struct device_attribute *attr, char *buf)
4830{
4831	struct st_modedef *STm = dev_get_drvdata(dev);
4832
4833	return sprintf(buf, "%lld",
4834		       (long long)atomic64_read(&STm->tape->stats->other_cnt));
4835}
4836static DEVICE_ATTR_RO(other_cnt);
4837
4838/**
4839 * resid_cnt_show - A count of the number of times we get a residual
4840 * count - this should indicate someone issuing reads larger than the
4841 * block size on tape.
4842 * @dev: struct device
4843 * @attr: attribute structure
4844 * @buf: buffer to return formatted data in
4845 */
4846static ssize_t resid_cnt_show(struct device *dev,
4847	struct device_attribute *attr, char *buf)
4848{
4849	struct st_modedef *STm = dev_get_drvdata(dev);
4850
4851	return sprintf(buf, "%lld",
4852		       (long long)atomic64_read(&STm->tape->stats->resid_cnt));
4853}
4854static DEVICE_ATTR_RO(resid_cnt);
4855
4856static struct attribute *st_dev_attrs[] = {
4857	&dev_attr_defined.attr,
4858	&dev_attr_default_blksize.attr,
4859	&dev_attr_default_density.attr,
4860	&dev_attr_default_compression.attr,
4861	&dev_attr_options.attr,
4862	NULL,
4863};
4864
4865static struct attribute *st_stats_attrs[] = {
4866	&dev_attr_read_cnt.attr,
4867	&dev_attr_read_byte_cnt.attr,
4868	&dev_attr_read_ns.attr,
4869	&dev_attr_write_cnt.attr,
4870	&dev_attr_write_byte_cnt.attr,
4871	&dev_attr_write_ns.attr,
4872	&dev_attr_in_flight.attr,
4873	&dev_attr_io_ns.attr,
4874	&dev_attr_other_cnt.attr,
4875	&dev_attr_resid_cnt.attr,
4876	NULL,
4877};
4878
4879static struct attribute_group stats_group = {
4880	.name = "stats",
4881	.attrs = st_stats_attrs,
4882};
4883
4884static struct attribute_group st_group = {
4885	.attrs = st_dev_attrs,
4886};
4887
4888static const struct attribute_group *st_dev_groups[] = {
4889	&st_group,
4890	&stats_group,
4891	NULL,
4892};
4893
4894/* The following functions may be useful for a larger audience. */
4895static int sgl_map_user_pages(struct st_buffer *STbp,
4896			      const unsigned int max_pages, unsigned long uaddr,
4897			      size_t count, int rw)
4898{
4899	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4900	unsigned long start = uaddr >> PAGE_SHIFT;
4901	const int nr_pages = end - start;
4902	int res, i, j;
4903	struct page **pages;
4904	struct rq_map_data *mdata = &STbp->map_data;
4905
4906	/* User attempted Overflow! */
4907	if ((uaddr + count) < uaddr)
4908		return -EINVAL;
4909
4910	/* Too big */
4911        if (nr_pages > max_pages)
4912		return -ENOMEM;
4913
4914	/* Hmm? */
4915	if (count == 0)
4916		return 0;
4917
4918	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_KERNEL)) == NULL)
4919		return -ENOMEM;
4920
4921        /* Try to fault in all of the necessary pages */
 
4922        /* rw==READ means read from drive, write into memory area */
4923	res = get_user_pages_fast(uaddr, nr_pages, rw == READ, pages);
 
 
 
 
 
 
 
 
 
4924
4925	/* Errors and no page mapped should return here */
4926	if (res < nr_pages)
4927		goto out_unmap;
4928
4929        for (i=0; i < nr_pages; i++) {
4930                /* FIXME: flush superflous for rw==READ,
4931                 * probably wrong function for rw==WRITE
4932                 */
4933		flush_dcache_page(pages[i]);
4934        }
4935
4936	mdata->offset = uaddr & ~PAGE_MASK;
4937	STbp->mapped_pages = pages;
4938
4939	return nr_pages;
4940 out_unmap:
4941	if (res > 0) {
4942		for (j=0; j < res; j++)
4943			put_page(pages[j]);
4944		res = 0;
4945	}
4946	kfree(pages);
4947	return res;
4948}
4949
4950
4951/* And unmap them... */
4952static int sgl_unmap_user_pages(struct st_buffer *STbp,
4953				const unsigned int nr_pages, int dirtied)
4954{
4955	int i;
4956
4957	for (i=0; i < nr_pages; i++) {
4958		struct page *page = STbp->mapped_pages[i];
4959
4960		if (dirtied)
4961			SetPageDirty(page);
4962		/* FIXME: cache flush missing for rw==READ
4963		 * FIXME: call the correct reference counting function
4964		 */
4965		put_page(page);
4966	}
4967	kfree(STbp->mapped_pages);
4968	STbp->mapped_pages = NULL;
4969
4970	return 0;
4971}
v3.15
   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 - 2010 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 = "20101219";
  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 <asm/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 0
 
  60
 
  61#if DEBUG
  62/* The message level for the debug messages is currently set to KERN_NOTICE
  63   so that people can easily see the messages. Later when the debugging messages
  64   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
  65#define ST_DEB_MSG  KERN_NOTICE
  66#define DEB(a) a
  67#define DEBC(a) if (debugging) { a ; }
  68#else
  69#define DEB(a)
  70#define DEBC(a)
  71#endif
  72
  73#define ST_KILOBYTE 1024
  74
  75#include "st_options.h"
  76#include "st.h"
  77
  78static int buffer_kbs;
  79static int max_sg_segs;
  80static int try_direct_io = TRY_DIRECT_IO;
  81static int try_rdio = 1;
  82static int try_wdio = 1;
 
  83
  84static struct class st_sysfs_class;
  85static const struct attribute_group *st_dev_groups[];
 
  86
  87MODULE_AUTHOR("Kai Makisara");
  88MODULE_DESCRIPTION("SCSI tape (st) driver");
  89MODULE_LICENSE("GPL");
  90MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  91MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  92
  93/* Set 'perm' (4th argument) to 0 to disable module_param's definition
  94 * of sysfs parameters (which module_param doesn't yet support).
  95 * Sysfs parameters defined explicitly later.
  96 */
  97module_param_named(buffer_kbs, buffer_kbs, int, 0);
  98MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
  99module_param_named(max_sg_segs, max_sg_segs, int, 0);
 100MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 101module_param_named(try_direct_io, try_direct_io, int, 0);
 102MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 
 
 
 103
 104/* Extra parameters for testing */
 105module_param_named(try_rdio, try_rdio, int, 0);
 106MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 107module_param_named(try_wdio, try_wdio, int, 0);
 108MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 109
 110#ifndef MODULE
 111static int write_threshold_kbs;  /* retained for compatibility */
 112static struct st_dev_parm {
 113	char *name;
 114	int *val;
 115} parms[] __initdata = {
 116	{
 117		"buffer_kbs", &buffer_kbs
 118	},
 119	{       /* Retained for compatibility with 2.4 */
 120		"write_threshold_kbs", &write_threshold_kbs
 121	},
 122	{
 123		"max_sg_segs", NULL
 124	},
 125	{
 126		"try_direct_io", &try_direct_io
 
 
 
 127	}
 128};
 129#endif
 130
 131/* Restrict the number of modes so that names for all are assigned */
 132#if ST_NBR_MODES > 16
 133#error "Maximum number of modes is 16"
 134#endif
 135/* Bit reversed order to get same names for same minors with all
 136   mode counts */
 137static const char *st_formats[] = {
 138	"",  "r", "k", "s", "l", "t", "o", "u",
 139	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 140
 141/* The default definitions have been moved to st_options.h */
 142
 143#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 144
 145/* The buffer size should fit into the 24 bits for length in the
 146   6-byte SCSI read and write commands. */
 147#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 148#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 149#endif
 150
 151static int debugging = DEBUG;
 152
 153#define MAX_RETRIES 0
 154#define MAX_WRITE_RETRIES 0
 155#define MAX_READY_RETRIES 0
 156#define NO_TAPE  NOT_READY
 157
 158#define ST_TIMEOUT (900 * HZ)
 159#define ST_LONG_TIMEOUT (14000 * HZ)
 160
 161/* Remove mode bits and auto-rewind bit (7) */
 162#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 163    (iminor(x) & ~(-1 << ST_MODE_SHIFT)) )
 164#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 165
 166/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 167#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 168  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 169
 170/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 171   24 bits) */
 172#define SET_DENS_AND_BLK 0x10001
 173
 174static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 175static int st_max_sg_segs = ST_MAX_SG;
 176
 177static int modes_defined;
 178
 179static int enlarge_buffer(struct st_buffer *, int, int);
 180static void clear_buffer(struct st_buffer *);
 181static void normalize_buffer(struct st_buffer *);
 182static int append_to_buffer(const char __user *, struct st_buffer *, int);
 183static int from_buffer(struct st_buffer *, char __user *, int);
 184static void move_buffer_data(struct st_buffer *, int);
 185
 186static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 187			      unsigned long, size_t, int);
 188static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 189
 190static int st_probe(struct device *);
 191static int st_remove(struct device *);
 192
 193static int do_create_sysfs_files(void);
 194static void do_remove_sysfs_files(void);
 195
 196static struct scsi_driver st_template = {
 197	.owner			= THIS_MODULE,
 198	.gendrv = {
 199		.name		= "st",
 
 200		.probe		= st_probe,
 201		.remove		= st_remove,
 
 202	},
 203};
 204
 205static int st_compression(struct scsi_tape *, int);
 206
 207static int find_partition(struct scsi_tape *);
 208static int switch_partition(struct scsi_tape *);
 209
 210static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 211
 212static void scsi_tape_release(struct kref *);
 213
 214#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 215
 216static DEFINE_MUTEX(st_ref_mutex);
 217static DEFINE_SPINLOCK(st_index_lock);
 218static DEFINE_SPINLOCK(st_use_lock);
 219static DEFINE_IDR(st_index_idr);
 220
 221
 222
 223#include "osst_detect.h"
 224#ifndef SIGS_FROM_OSST
 225#define SIGS_FROM_OSST \
 226	{"OnStream", "SC-", "", "osst"}, \
 227	{"OnStream", "DI-", "", "osst"}, \
 228	{"OnStream", "DP-", "", "osst"}, \
 229	{"OnStream", "USB", "", "osst"}, \
 230	{"OnStream", "FW-", "", "osst"}
 231#endif
 232
 233static struct scsi_tape *scsi_tape_get(int dev)
 234{
 235	struct scsi_tape *STp = NULL;
 236
 237	mutex_lock(&st_ref_mutex);
 238	spin_lock(&st_index_lock);
 239
 240	STp = idr_find(&st_index_idr, dev);
 241	if (!STp) goto out;
 242
 243	kref_get(&STp->kref);
 244
 245	if (!STp->device)
 246		goto out_put;
 247
 248	if (scsi_device_get(STp->device))
 249		goto out_put;
 250
 251	goto out;
 252
 253out_put:
 254	kref_put(&STp->kref, scsi_tape_release);
 255	STp = NULL;
 256out:
 257	spin_unlock(&st_index_lock);
 258	mutex_unlock(&st_ref_mutex);
 259	return STp;
 260}
 261
 262static void scsi_tape_put(struct scsi_tape *STp)
 263{
 264	struct scsi_device *sdev = STp->device;
 265
 266	mutex_lock(&st_ref_mutex);
 267	kref_put(&STp->kref, scsi_tape_release);
 268	scsi_device_put(sdev);
 269	mutex_unlock(&st_ref_mutex);
 270}
 271
 272struct st_reject_data {
 273	char *vendor;
 274	char *model;
 275	char *rev;
 276	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 277};
 278
 279static struct st_reject_data reject_list[] = {
 280	/* {"XXX", "Yy-", "", NULL},  example */
 281	SIGS_FROM_OSST,
 282	{NULL, }};
 283
 284/* If the device signature is on the list of incompatible drives, the
 285   function returns a pointer to the name of the correct driver (if known) */
 286static char * st_incompatible(struct scsi_device* SDp)
 287{
 288	struct st_reject_data *rp;
 289
 290	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 291		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 292		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 293		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 294			if (rp->driver_hint)
 295				return rp->driver_hint;
 296			else
 297				return "unknown";
 298		}
 299	return NULL;
 300}
 301
 302
 303static inline char *tape_name(struct scsi_tape *tape)
 304{
 305	return tape->disk->disk_name;
 306}
 307
 
 
 
 
 
 
 
 
 308
 309static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 310{
 311	const u8 *ucp;
 312	const u8 *sense = SRpnt->sense;
 313
 314	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 315				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 316	s->flags = 0;
 317
 318	if (s->have_sense) {
 319		s->deferred = 0;
 320		s->remainder_valid =
 321			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 322		switch (sense[0] & 0x7f) {
 323		case 0x71:
 324			s->deferred = 1;
 325		case 0x70:
 326			s->fixed_format = 1;
 327			s->flags = sense[2] & 0xe0;
 328			break;
 329		case 0x73:
 330			s->deferred = 1;
 331		case 0x72:
 332			s->fixed_format = 0;
 333			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 334			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 335			break;
 336		}
 337	}
 338}
 339
 340
 341/* Convert the result to success code */
 342static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 343{
 344	int result = SRpnt->result;
 345	u8 scode;
 346	DEB(const char *stp;)
 347	char *name = tape_name(STp);
 348	struct st_cmdstatus *cmdstatp;
 349
 350	if (!result)
 351		return 0;
 352
 353	cmdstatp = &STp->buffer->cmdstat;
 354	st_analyze_sense(SRpnt, cmdstatp);
 355
 356	if (cmdstatp->have_sense)
 357		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 358	else
 359		scode = 0;
 360
 361        DEB(
 362        if (debugging) {
 363                printk(ST_DEB_MSG "%s: Error: %x, cmd: %x %x %x %x %x %x\n",
 364		       name, result,
 365		       SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 366		       SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 367		if (cmdstatp->have_sense)
 368			 __scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 
 369	} ) /* end DEB */
 370	if (!debugging) { /* Abnormal conditions for tape */
 371		if (!cmdstatp->have_sense)
 372			printk(KERN_WARNING
 373			       "%s: Error %x (driver bt 0x%x, host bt 0x%x).\n",
 374			       name, result, driver_byte(result),
 375			       host_byte(result));
 376		else if (cmdstatp->have_sense &&
 377			 scode != NO_SENSE &&
 378			 scode != RECOVERED_ERROR &&
 379			 /* scode != UNIT_ATTENTION && */
 380			 scode != BLANK_CHECK &&
 381			 scode != VOLUME_OVERFLOW &&
 382			 SRpnt->cmd[0] != MODE_SENSE &&
 383			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 384
 385			__scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 
 386		}
 387	}
 388
 389	if (cmdstatp->fixed_format &&
 390	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 391		if (STp->cln_sense_value)
 392			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 393					       STp->cln_sense_mask) == STp->cln_sense_value);
 394		else
 395			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 396					       STp->cln_sense_mask) != 0);
 397	}
 398	if (cmdstatp->have_sense &&
 399	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 400		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 401
 402	STp->pos_unknown |= STp->device->was_reset;
 403
 404	if (cmdstatp->have_sense &&
 405	    scode == RECOVERED_ERROR
 406#if ST_RECOVERED_WRITE_FATAL
 407	    && SRpnt->cmd[0] != WRITE_6
 408	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 409#endif
 410	    ) {
 411		STp->recover_count++;
 412		STp->recover_reg++;
 413
 414                DEB(
 415		if (debugging) {
 416			if (SRpnt->cmd[0] == READ_6)
 417				stp = "read";
 418			else if (SRpnt->cmd[0] == WRITE_6)
 419				stp = "write";
 420			else
 421				stp = "ioctl";
 422			printk(ST_DEB_MSG "%s: Recovered %s error (%d).\n", name, stp,
 423			       STp->recover_count);
 
 424		} ) /* end DEB */
 425
 426		if (cmdstatp->flags == 0)
 427			return 0;
 428	}
 429	return (-EIO);
 430}
 431
 432static struct st_request *st_allocate_request(struct scsi_tape *stp)
 433{
 434	struct st_request *streq;
 435
 436	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 437	if (streq)
 438		streq->stp = stp;
 439	else {
 440		DEBC(printk(KERN_ERR "%s: Can't get SCSI request.\n",
 441			    tape_name(stp)););
 442		if (signal_pending(current))
 443			stp->buffer->syscall_result = -EINTR;
 444		else
 445			stp->buffer->syscall_result = -EBUSY;
 446	}
 447
 448	return streq;
 449}
 450
 451static void st_release_request(struct st_request *streq)
 452{
 453	kfree(streq);
 454}
 455
 456static void st_scsi_execute_end(struct request *req, int uptodate)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 457{
 458	struct st_request *SRpnt = req->end_io_data;
 
 459	struct scsi_tape *STp = SRpnt->stp;
 460	struct bio *tmp;
 461
 462	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
 463	STp->buffer->cmdstat.residual = req->resid_len;
 
 
 464
 465	tmp = SRpnt->bio;
 
 
 466	if (SRpnt->waiting)
 467		complete(SRpnt->waiting);
 468
 469	blk_rq_unmap_user(tmp);
 470	__blk_put_request(req->q, req);
 471}
 472
 473static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 474			   int data_direction, void *buffer, unsigned bufflen,
 475			   int timeout, int retries)
 476{
 477	struct request *req;
 
 478	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 479	int err = 0;
 480	int write = (data_direction == DMA_TO_DEVICE);
 481
 482	req = blk_get_request(SRpnt->stp->device->request_queue, write,
 483			      GFP_KERNEL);
 484	if (!req)
 
 485		return DRIVER_ERROR << 24;
 486
 487	req->cmd_type = REQ_TYPE_BLOCK_PC;
 488	req->cmd_flags |= REQ_QUIET;
 489
 490	mdata->null_mapped = 1;
 491
 492	if (bufflen) {
 493		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 494				      GFP_KERNEL);
 495		if (err) {
 496			blk_put_request(req);
 497			return DRIVER_ERROR << 24;
 498		}
 499	}
 500
 
 
 
 
 
 
 
 
 
 
 
 501	SRpnt->bio = req->bio;
 502	req->cmd_len = COMMAND_SIZE(cmd[0]);
 503	memset(req->cmd, 0, BLK_MAX_CDB);
 504	memcpy(req->cmd, cmd, req->cmd_len);
 505	req->sense = SRpnt->sense;
 506	req->sense_len = 0;
 507	req->timeout = timeout;
 508	req->retries = retries;
 509	req->end_io_data = SRpnt;
 510
 511	blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
 512	return 0;
 513}
 514
 515/* Do the scsi command. Waits until command performed if do_wait is true.
 516   Otherwise write_behind_check() is used to check that the command
 517   has finished. */
 518static struct st_request *
 519st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 520	   int bytes, int direction, int timeout, int retries, int do_wait)
 521{
 522	struct completion *waiting;
 523	struct rq_map_data *mdata = &STp->buffer->map_data;
 524	int ret;
 525
 526	/* if async, make sure there's no command outstanding */
 527	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 528		printk(KERN_ERR "%s: Async command already active.\n",
 529		       tape_name(STp));
 530		if (signal_pending(current))
 531			(STp->buffer)->syscall_result = (-EINTR);
 532		else
 533			(STp->buffer)->syscall_result = (-EBUSY);
 534		return NULL;
 535	}
 536
 537	if (!SRpnt) {
 538		SRpnt = st_allocate_request(STp);
 539		if (!SRpnt)
 540			return NULL;
 541	}
 542
 543	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 544	   which IO is outstanding. It's nulled out when the IO completes. */
 545	if (!do_wait)
 546		(STp->buffer)->last_SRpnt = SRpnt;
 547
 548	waiting = &STp->wait;
 549	init_completion(waiting);
 550	SRpnt->waiting = waiting;
 551
 552	if (STp->buffer->do_dio) {
 553		mdata->page_order = 0;
 554		mdata->nr_entries = STp->buffer->sg_segs;
 555		mdata->pages = STp->buffer->mapped_pages;
 556	} else {
 557		mdata->page_order = STp->buffer->reserved_page_order;
 558		mdata->nr_entries =
 559			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 560		mdata->pages = STp->buffer->reserved_pages;
 561		mdata->offset = 0;
 562	}
 563
 564	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 565	STp->buffer->cmdstat.have_sense = 0;
 566	STp->buffer->syscall_result = 0;
 567
 568	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 569			      retries);
 570	if (ret) {
 571		/* could not allocate the buffer or request was too large */
 572		(STp->buffer)->syscall_result = (-EBUSY);
 573		(STp->buffer)->last_SRpnt = NULL;
 574	} else if (do_wait) {
 575		wait_for_completion(waiting);
 576		SRpnt->waiting = NULL;
 577		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 578	}
 579
 580	return SRpnt;
 581}
 582
 583
 584/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 585   write has been correct but EOM early warning reached, -EIO if write ended in
 586   error or zero if write successful. Asynchronous writes are used only in
 587   variable block mode. */
 588static int write_behind_check(struct scsi_tape * STp)
 589{
 590	int retval = 0;
 591	struct st_buffer *STbuffer;
 592	struct st_partstat *STps;
 593	struct st_cmdstatus *cmdstatp;
 594	struct st_request *SRpnt;
 595
 596	STbuffer = STp->buffer;
 597	if (!STbuffer->writing)
 598		return 0;
 599
 600        DEB(
 601	if (STp->write_pending)
 602		STp->nbr_waits++;
 603	else
 604		STp->nbr_finished++;
 605        ) /* end DEB */
 606
 607	wait_for_completion(&(STp->wait));
 608	SRpnt = STbuffer->last_SRpnt;
 609	STbuffer->last_SRpnt = NULL;
 610	SRpnt->waiting = NULL;
 611
 612	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 613	st_release_request(SRpnt);
 614
 615	STbuffer->buffer_bytes -= STbuffer->writing;
 616	STps = &(STp->ps[STp->partition]);
 617	if (STps->drv_block >= 0) {
 618		if (STp->block_size == 0)
 619			STps->drv_block++;
 620		else
 621			STps->drv_block += STbuffer->writing / STp->block_size;
 622	}
 623
 624	cmdstatp = &STbuffer->cmdstat;
 625	if (STbuffer->syscall_result) {
 626		retval = -EIO;
 627		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 628		    (cmdstatp->flags & SENSE_EOM) &&
 629		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 630		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 631			/* EOM at write-behind, has all data been written? */
 632			if (!cmdstatp->remainder_valid ||
 633			    cmdstatp->uremainder64 == 0)
 634				retval = -ENOSPC;
 635		}
 636		if (retval == -EIO)
 637			STps->drv_block = -1;
 638	}
 639	STbuffer->writing = 0;
 640
 641	DEB(if (debugging && retval)
 642	    printk(ST_DEB_MSG "%s: Async write error %x, return value %d.\n",
 643		   tape_name(STp), STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 
 644
 645	return retval;
 646}
 647
 648
 649/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 650   it messes up the block number). */
 651static int cross_eof(struct scsi_tape * STp, int forward)
 652{
 653	struct st_request *SRpnt;
 654	unsigned char cmd[MAX_COMMAND_SIZE];
 655
 656	cmd[0] = SPACE;
 657	cmd[1] = 0x01;		/* Space FileMarks */
 658	if (forward) {
 659		cmd[2] = cmd[3] = 0;
 660		cmd[4] = 1;
 661	} else
 662		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 663	cmd[5] = 0;
 664
 665        DEBC(printk(ST_DEB_MSG "%s: Stepping over filemark %s.\n",
 666		   tape_name(STp), forward ? "forward" : "backward"));
 667
 668	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 669			   STp->device->request_queue->rq_timeout,
 670			   MAX_RETRIES, 1);
 671	if (!SRpnt)
 672		return (STp->buffer)->syscall_result;
 673
 674	st_release_request(SRpnt);
 675	SRpnt = NULL;
 676
 677	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 678		printk(KERN_ERR "%s: Stepping over filemark %s failed.\n",
 679		   tape_name(STp), forward ? "forward" : "backward");
 
 680
 681	return (STp->buffer)->syscall_result;
 682}
 683
 684
 685/* Flush the write buffer (never need to write if variable blocksize). */
 686static int st_flush_write_buffer(struct scsi_tape * STp)
 687{
 688	int transfer, blks;
 689	int result;
 690	unsigned char cmd[MAX_COMMAND_SIZE];
 691	struct st_request *SRpnt;
 692	struct st_partstat *STps;
 693
 694	result = write_behind_check(STp);
 695	if (result)
 696		return result;
 697
 698	result = 0;
 699	if (STp->dirty == 1) {
 700
 701		transfer = STp->buffer->buffer_bytes;
 702                DEBC(printk(ST_DEB_MSG "%s: Flushing %d bytes.\n",
 703                               tape_name(STp), transfer));
 704
 705		memset(cmd, 0, MAX_COMMAND_SIZE);
 706		cmd[0] = WRITE_6;
 707		cmd[1] = 1;
 708		blks = transfer / STp->block_size;
 709		cmd[2] = blks >> 16;
 710		cmd[3] = blks >> 8;
 711		cmd[4] = blks;
 712
 713		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 714				   STp->device->request_queue->rq_timeout,
 715				   MAX_WRITE_RETRIES, 1);
 716		if (!SRpnt)
 717			return (STp->buffer)->syscall_result;
 718
 719		STps = &(STp->ps[STp->partition]);
 720		if ((STp->buffer)->syscall_result != 0) {
 721			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 722
 723			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 724			    (cmdstatp->flags & SENSE_EOM) &&
 725			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 726			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 727			    (!cmdstatp->remainder_valid ||
 728			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 729				STp->dirty = 0;
 730				(STp->buffer)->buffer_bytes = 0;
 731				if (STps->drv_block >= 0)
 732					STps->drv_block += blks;
 733				result = (-ENOSPC);
 734			} else {
 735				printk(KERN_ERR "%s: Error on flush.\n",
 736                                       tape_name(STp));
 737				STps->drv_block = (-1);
 738				result = (-EIO);
 739			}
 740		} else {
 741			if (STps->drv_block >= 0)
 742				STps->drv_block += blks;
 743			STp->dirty = 0;
 744			(STp->buffer)->buffer_bytes = 0;
 745		}
 746		st_release_request(SRpnt);
 747		SRpnt = NULL;
 748	}
 749	return result;
 750}
 751
 752
 753/* Flush the tape buffer. The tape will be positioned correctly unless
 754   seek_next is true. */
 755static int flush_buffer(struct scsi_tape *STp, int seek_next)
 756{
 757	int backspace, result;
 758	struct st_buffer *STbuffer;
 759	struct st_partstat *STps;
 760
 761	STbuffer = STp->buffer;
 762
 763	/*
 764	 * If there was a bus reset, block further access
 765	 * to this device.
 766	 */
 767	if (STp->pos_unknown)
 768		return (-EIO);
 769
 770	if (STp->ready != ST_READY)
 771		return 0;
 772	STps = &(STp->ps[STp->partition]);
 773	if (STps->rw == ST_WRITING)	/* Writing */
 774		return st_flush_write_buffer(STp);
 775
 776	if (STp->block_size == 0)
 777		return 0;
 778
 779	backspace = ((STp->buffer)->buffer_bytes +
 780		     (STp->buffer)->read_pointer) / STp->block_size -
 781	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 782	    STp->block_size;
 783	(STp->buffer)->buffer_bytes = 0;
 784	(STp->buffer)->read_pointer = 0;
 785	result = 0;
 786	if (!seek_next) {
 787		if (STps->eof == ST_FM_HIT) {
 788			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 789			if (!result)
 790				STps->eof = ST_NOEOF;
 791			else {
 792				if (STps->drv_file >= 0)
 793					STps->drv_file++;
 794				STps->drv_block = 0;
 795			}
 796		}
 797		if (!result && backspace > 0)
 798			result = st_int_ioctl(STp, MTBSR, backspace);
 799	} else if (STps->eof == ST_FM_HIT) {
 800		if (STps->drv_file >= 0)
 801			STps->drv_file++;
 802		STps->drv_block = 0;
 803		STps->eof = ST_NOEOF;
 804	}
 805	return result;
 806
 807}
 808
 809/* Set the mode parameters */
 810static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 811{
 812	int set_it = 0;
 813	unsigned long arg;
 814	char *name = tape_name(STp);
 815
 816	if (!STp->density_changed &&
 817	    STm->default_density >= 0 &&
 818	    STm->default_density != STp->density) {
 819		arg = STm->default_density;
 820		set_it = 1;
 821	} else
 822		arg = STp->density;
 823	arg <<= MT_ST_DENSITY_SHIFT;
 824	if (!STp->blksize_changed &&
 825	    STm->default_blksize >= 0 &&
 826	    STm->default_blksize != STp->block_size) {
 827		arg |= STm->default_blksize;
 828		set_it = 1;
 829	} else
 830		arg |= STp->block_size;
 831	if (set_it &&
 832	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 833		printk(KERN_WARNING
 834		       "%s: Can't set default block size to %d bytes and density %x.\n",
 835		       name, STm->default_blksize, STm->default_density);
 
 836		if (modes_defined)
 837			return (-EINVAL);
 838	}
 839	return 0;
 840}
 841
 842
 843/* Lock or unlock the drive door. Don't use when st_request allocated. */
 844static int do_door_lock(struct scsi_tape * STp, int do_lock)
 845{
 846	int retval, cmd;
 847	DEB(char *name = tape_name(STp);)
 848
 
 849
 850	cmd = do_lock ? SCSI_IOCTL_DOORLOCK : SCSI_IOCTL_DOORUNLOCK;
 851	DEBC(printk(ST_DEB_MSG "%s: %socking drive door.\n", name,
 852		    do_lock ? "L" : "Unl"));
 853	retval = scsi_ioctl(STp->device, cmd, NULL);
 854	if (!retval) {
 855		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 856	}
 857	else {
 858		STp->door_locked = ST_LOCK_FAILS;
 859	}
 860	return retval;
 861}
 862
 863
 864/* Set the internal state after reset */
 865static void reset_state(struct scsi_tape *STp)
 866{
 867	int i;
 868	struct st_partstat *STps;
 869
 870	STp->pos_unknown = 0;
 871	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 872		STps = &(STp->ps[i]);
 873		STps->rw = ST_IDLE;
 874		STps->eof = ST_NOEOF;
 875		STps->at_sm = 0;
 876		STps->last_block_valid = 0;
 877		STps->drv_block = -1;
 878		STps->drv_file = -1;
 879	}
 880	if (STp->can_partitions) {
 881		STp->partition = find_partition(STp);
 882		if (STp->partition < 0)
 883			STp->partition = 0;
 884		STp->new_partition = STp->partition;
 885	}
 886}
 887
 888/* Test if the drive is ready. Returns either one of the codes below or a negative system
 889   error code. */
 890#define CHKRES_READY       0
 891#define CHKRES_NEW_SESSION 1
 892#define CHKRES_NOT_READY   2
 893#define CHKRES_NO_TAPE     3
 894
 895#define MAX_ATTENTIONS    10
 896
 897static int test_ready(struct scsi_tape *STp, int do_wait)
 898{
 899	int attentions, waits, max_wait, scode;
 900	int retval = CHKRES_READY, new_session = 0;
 901	unsigned char cmd[MAX_COMMAND_SIZE];
 902	struct st_request *SRpnt = NULL;
 903	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 904
 905	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 906
 907	for (attentions=waits=0; ; ) {
 908		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 909		cmd[0] = TEST_UNIT_READY;
 910		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 911				   STp->long_timeout, MAX_READY_RETRIES, 1);
 912
 913		if (!SRpnt) {
 914			retval = (STp->buffer)->syscall_result;
 915			break;
 916		}
 917
 918		if (cmdstatp->have_sense) {
 919
 920			scode = cmdstatp->sense_hdr.sense_key;
 921
 922			if (scode == UNIT_ATTENTION) { /* New media? */
 923				new_session = 1;
 924				if (attentions < MAX_ATTENTIONS) {
 925					attentions++;
 926					continue;
 927				}
 928				else {
 929					retval = (-EIO);
 930					break;
 931				}
 932			}
 933
 934			if (scode == NOT_READY) {
 935				if (waits < max_wait) {
 936					if (msleep_interruptible(1000)) {
 937						retval = (-EINTR);
 938						break;
 939					}
 940					waits++;
 941					continue;
 942				}
 943				else {
 944					if ((STp->device)->scsi_level >= SCSI_2 &&
 945					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
 946						retval = CHKRES_NO_TAPE;
 947					else
 948						retval = CHKRES_NOT_READY;
 949					break;
 950				}
 951			}
 952		}
 953
 954		retval = (STp->buffer)->syscall_result;
 955		if (!retval)
 956			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
 957		break;
 958	}
 959
 960	if (SRpnt != NULL)
 961		st_release_request(SRpnt);
 962	return retval;
 963}
 964
 965
 966/* See if the drive is ready and gather information about the tape. Return values:
 967   < 0   negative error code from errno.h
 968   0     drive ready
 969   1     drive not ready (possibly no tape)
 970*/
 971static int check_tape(struct scsi_tape *STp, struct file *filp)
 972{
 973	int i, retval, new_session = 0, do_wait;
 974	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
 975	unsigned short st_flags = filp->f_flags;
 976	struct st_request *SRpnt = NULL;
 977	struct st_modedef *STm;
 978	struct st_partstat *STps;
 979	char *name = tape_name(STp);
 980	struct inode *inode = file_inode(filp);
 981	int mode = TAPE_MODE(inode);
 982
 983	STp->ready = ST_READY;
 984
 985	if (mode != STp->current_mode) {
 986                DEBC(printk(ST_DEB_MSG "%s: Mode change from %d to %d.\n",
 987			       name, STp->current_mode, mode));
 988		new_session = 1;
 989		STp->current_mode = mode;
 990	}
 991	STm = &(STp->modes[STp->current_mode]);
 992
 993	saved_cleaning = STp->cleaning_req;
 994	STp->cleaning_req = 0;
 995
 996	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
 997	retval = test_ready(STp, do_wait);
 998
 999	if (retval < 0)
1000	    goto err_out;
1001
1002	if (retval == CHKRES_NEW_SESSION) {
1003		STp->pos_unknown = 0;
1004		STp->partition = STp->new_partition = 0;
1005		if (STp->can_partitions)
1006			STp->nbr_partitions = 1; /* This guess will be updated later
1007                                                    if necessary */
1008		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1009			STps = &(STp->ps[i]);
1010			STps->rw = ST_IDLE;
1011			STps->eof = ST_NOEOF;
1012			STps->at_sm = 0;
1013			STps->last_block_valid = 0;
1014			STps->drv_block = 0;
1015			STps->drv_file = 0;
1016		}
1017		new_session = 1;
1018	}
1019	else {
1020		STp->cleaning_req |= saved_cleaning;
1021
1022		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1023			if (retval == CHKRES_NO_TAPE)
1024				STp->ready = ST_NO_TAPE;
1025			else
1026				STp->ready = ST_NOT_READY;
1027
1028			STp->density = 0;	/* Clear the erroneous "residue" */
1029			STp->write_prot = 0;
1030			STp->block_size = 0;
1031			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1032			STp->partition = STp->new_partition = 0;
1033			STp->door_locked = ST_UNLOCKED;
1034			return CHKRES_NOT_READY;
1035		}
1036	}
1037
1038	if (STp->omit_blklims)
1039		STp->min_block = STp->max_block = (-1);
1040	else {
1041		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1042		cmd[0] = READ_BLOCK_LIMITS;
1043
1044		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1045				   STp->device->request_queue->rq_timeout,
1046				   MAX_READY_RETRIES, 1);
1047		if (!SRpnt) {
1048			retval = (STp->buffer)->syscall_result;
1049			goto err_out;
1050		}
1051
1052		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1053			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1054			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1055			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1056			    (STp->buffer)->b_data[5];
1057			if ( DEB( debugging || ) !STp->inited)
1058				printk(KERN_INFO
1059                                       "%s: Block limits %d - %d bytes.\n", name,
1060                                       STp->min_block, STp->max_block);
1061		} else {
1062			STp->min_block = STp->max_block = (-1);
1063                        DEBC(printk(ST_DEB_MSG "%s: Can't read block limits.\n",
1064                                       name));
1065		}
1066	}
1067
1068	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1069	cmd[0] = MODE_SENSE;
1070	cmd[4] = 12;
1071
1072	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1073			   STp->device->request_queue->rq_timeout,
1074			   MAX_READY_RETRIES, 1);
1075	if (!SRpnt) {
1076		retval = (STp->buffer)->syscall_result;
1077		goto err_out;
1078	}
1079
1080	if ((STp->buffer)->syscall_result != 0) {
1081                DEBC(printk(ST_DEB_MSG "%s: No Mode Sense.\n", name));
1082		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1083		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1084		STp->drv_write_prot = 0;
1085	} else {
1086                DEBC(printk(ST_DEB_MSG
1087                            "%s: Mode sense. Length %d, medium %x, WBS %x, BLL %d\n",
1088                            name,
1089                            (STp->buffer)->b_data[0], (STp->buffer)->b_data[1],
1090                            (STp->buffer)->b_data[2], (STp->buffer)->b_data[3]));
 
1091
1092		if ((STp->buffer)->b_data[3] >= 8) {
1093			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1094			STp->density = (STp->buffer)->b_data[4];
1095			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1096			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1097                        DEBC(printk(ST_DEB_MSG
1098                                    "%s: Density %x, tape length: %x, drv buffer: %d\n",
1099                                    name, STp->density, (STp->buffer)->b_data[5] * 65536 +
1100                                    (STp->buffer)->b_data[6] * 256 + (STp->buffer)->b_data[7],
1101                                    STp->drv_buffer));
 
 
1102		}
1103		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1104		if (!STp->drv_buffer && STp->immediate_filemark) {
1105			printk(KERN_WARNING
1106			    "%s: non-buffered tape: disabling writing immediate filemarks\n",
1107			    name);
1108			STp->immediate_filemark = 0;
1109		}
1110	}
1111	st_release_request(SRpnt);
1112	SRpnt = NULL;
1113        STp->inited = 1;
1114
1115	if (STp->block_size > 0)
1116		(STp->buffer)->buffer_blocks =
1117                        (STp->buffer)->buffer_size / STp->block_size;
1118	else
1119		(STp->buffer)->buffer_blocks = 1;
1120	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1121
1122        DEBC(printk(ST_DEB_MSG
1123                       "%s: Block size: %d, buffer size: %d (%d blocks).\n", name,
1124		       STp->block_size, (STp->buffer)->buffer_size,
1125		       (STp->buffer)->buffer_blocks));
1126
1127	if (STp->drv_write_prot) {
1128		STp->write_prot = 1;
1129
1130                DEBC(printk(ST_DEB_MSG "%s: Write protected\n", name));
1131
1132		if (do_wait &&
1133		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1134		     (st_flags & O_ACCMODE) == O_RDWR)) {
1135			retval = (-EROFS);
1136			goto err_out;
1137		}
1138	}
1139
1140	if (STp->can_partitions && STp->nbr_partitions < 1) {
1141		/* This code is reached when the device is opened for the first time
1142		   after the driver has been initialized with tape in the drive and the
1143		   partition support has been enabled. */
1144                DEBC(printk(ST_DEB_MSG
1145                            "%s: Updating partition number in status.\n", name));
1146		if ((STp->partition = find_partition(STp)) < 0) {
1147			retval = STp->partition;
1148			goto err_out;
1149		}
1150		STp->new_partition = STp->partition;
1151		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1152	}
1153
1154	if (new_session) {	/* Change the drive parameters for the new mode */
1155		STp->density_changed = STp->blksize_changed = 0;
1156		STp->compression_changed = 0;
1157		if (!(STm->defaults_for_writes) &&
1158		    (retval = set_mode_densblk(STp, STm)) < 0)
1159		    goto err_out;
1160
1161		if (STp->default_drvbuffer != 0xff) {
1162			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1163				printk(KERN_WARNING
1164                                       "%s: Can't set default drive buffering to %d.\n",
1165				       name, STp->default_drvbuffer);
 
1166		}
1167	}
1168
1169	return CHKRES_READY;
1170
1171 err_out:
1172	return retval;
1173}
1174
1175
1176/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1177   module count. */
1178static int st_open(struct inode *inode, struct file *filp)
1179{
1180	int i, retval = (-EIO);
1181	int resumed = 0;
1182	struct scsi_tape *STp;
1183	struct st_partstat *STps;
1184	int dev = TAPE_NR(inode);
1185	char *name;
1186
1187	/*
1188	 * We really want to do nonseekable_open(inode, filp); here, but some
1189	 * versions of tar incorrectly call lseek on tapes and bail out if that
1190	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1191	 */
1192	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1193
1194	if (!(STp = scsi_tape_get(dev))) {
1195		return -ENXIO;
1196	}
1197
1198	filp->private_data = STp;
1199	name = tape_name(STp);
1200
1201	spin_lock(&st_use_lock);
1202	if (STp->in_use) {
1203		spin_unlock(&st_use_lock);
1204		scsi_tape_put(STp);
1205		DEB( printk(ST_DEB_MSG "%s: Device already in use.\n", name); )
1206		return (-EBUSY);
1207	}
1208
1209	STp->in_use = 1;
1210	spin_unlock(&st_use_lock);
1211	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1212
1213	if (scsi_autopm_get_device(STp->device) < 0) {
1214		retval = -EIO;
1215		goto err_out;
1216	}
1217	resumed = 1;
1218	if (!scsi_block_when_processing_errors(STp->device)) {
1219		retval = (-ENXIO);
1220		goto err_out;
1221	}
1222
1223	/* See that we have at least a one page buffer available */
1224	if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1225		printk(KERN_WARNING "%s: Can't allocate one page tape buffer.\n",
1226		       name);
1227		retval = (-EOVERFLOW);
1228		goto err_out;
1229	}
1230
1231	(STp->buffer)->cleared = 0;
1232	(STp->buffer)->writing = 0;
1233	(STp->buffer)->syscall_result = 0;
1234
1235	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1236
1237	STp->dirty = 0;
1238	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1239		STps = &(STp->ps[i]);
1240		STps->rw = ST_IDLE;
1241	}
1242	STp->try_dio_now = STp->try_dio;
1243	STp->recover_count = 0;
1244	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1245	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1246
1247	retval = check_tape(STp, filp);
1248	if (retval < 0)
1249		goto err_out;
1250	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1251	    retval != CHKRES_READY) {
1252		if (STp->ready == NO_TAPE)
1253			retval = (-ENOMEDIUM);
1254		else
1255			retval = (-EIO);
1256		goto err_out;
1257	}
1258	return 0;
1259
1260 err_out:
1261	normalize_buffer(STp->buffer);
1262	spin_lock(&st_use_lock);
1263	STp->in_use = 0;
1264	spin_unlock(&st_use_lock);
1265	scsi_tape_put(STp);
1266	if (resumed)
1267		scsi_autopm_put_device(STp->device);
 
1268	return retval;
1269
1270}
1271
1272
1273/* Flush the tape buffer before close */
1274static int st_flush(struct file *filp, fl_owner_t id)
1275{
1276	int result = 0, result2;
1277	unsigned char cmd[MAX_COMMAND_SIZE];
1278	struct st_request *SRpnt;
1279	struct scsi_tape *STp = filp->private_data;
1280	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1281	struct st_partstat *STps = &(STp->ps[STp->partition]);
1282	char *name = tape_name(STp);
1283
1284	if (file_count(filp) > 1)
1285		return 0;
1286
1287	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1288		result = st_flush_write_buffer(STp);
1289		if (result != 0 && result != (-ENOSPC))
1290			goto out;
1291	}
1292
1293	if (STp->can_partitions &&
1294	    (result2 = switch_partition(STp)) < 0) {
1295                DEBC(printk(ST_DEB_MSG
1296                               "%s: switch_partition at close failed.\n", name));
1297		if (result == 0)
1298			result = result2;
1299		goto out;
1300	}
1301
1302	DEBC( if (STp->nbr_requests)
1303		printk(KERN_DEBUG "%s: Number of r/w requests %d, dio used in %d, pages %d.\n",
1304		       name, STp->nbr_requests, STp->nbr_dio, STp->nbr_pages));
 
 
1305
1306	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1307		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1308
1309                DEBC(printk(ST_DEB_MSG "%s: Async write waits %d, finished %d.\n",
1310                            name, STp->nbr_waits, STp->nbr_finished);
1311		)
1312
1313		memset(cmd, 0, MAX_COMMAND_SIZE);
1314		cmd[0] = WRITE_FILEMARKS;
1315		if (STp->immediate_filemark)
1316			cmd[1] = 1;
1317		cmd[4] = 1 + STp->two_fm;
1318
1319		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1320				   STp->device->request_queue->rq_timeout,
1321				   MAX_WRITE_RETRIES, 1);
1322		if (!SRpnt) {
1323			result = (STp->buffer)->syscall_result;
1324			goto out;
1325		}
1326
1327		if (STp->buffer->syscall_result == 0 ||
1328		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1329		     (cmdstatp->flags & SENSE_EOM) &&
1330		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1331		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1332		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1333			/* Write successful at EOM */
1334			st_release_request(SRpnt);
1335			SRpnt = NULL;
1336			if (STps->drv_file >= 0)
1337				STps->drv_file++;
1338			STps->drv_block = 0;
1339			if (STp->two_fm)
1340				cross_eof(STp, 0);
1341			STps->eof = ST_FM;
1342		}
1343		else { /* Write error */
1344			st_release_request(SRpnt);
1345			SRpnt = NULL;
1346			printk(KERN_ERR "%s: Error on write filemark.\n", name);
 
1347			if (result == 0)
1348				result = (-EIO);
1349		}
1350
1351                DEBC(printk(ST_DEB_MSG "%s: Buffer flushed, %d EOF(s) written\n",
1352                            name, cmd[4]));
1353	} else if (!STp->rew_at_close) {
1354		STps = &(STp->ps[STp->partition]);
1355		if (!STm->sysv || STps->rw != ST_READING) {
1356			if (STp->can_bsr)
1357				result = flush_buffer(STp, 0);
1358			else if (STps->eof == ST_FM_HIT) {
1359				result = cross_eof(STp, 0);
1360				if (result) {
1361					if (STps->drv_file >= 0)
1362						STps->drv_file++;
1363					STps->drv_block = 0;
1364					STps->eof = ST_FM;
1365				} else
1366					STps->eof = ST_NOEOF;
1367			}
1368		} else if ((STps->eof == ST_NOEOF &&
1369			    !(result = cross_eof(STp, 1))) ||
1370			   STps->eof == ST_FM_HIT) {
1371			if (STps->drv_file >= 0)
1372				STps->drv_file++;
1373			STps->drv_block = 0;
1374			STps->eof = ST_FM;
1375		}
1376	}
1377
1378      out:
1379	if (STp->rew_at_close) {
1380		result2 = st_int_ioctl(STp, MTREW, 1);
1381		if (result == 0)
1382			result = result2;
1383	}
1384	return result;
1385}
1386
1387
1388/* Close the device and release it. BKL is not needed: this is the only thread
1389   accessing this tape. */
1390static int st_release(struct inode *inode, struct file *filp)
1391{
1392	int result = 0;
1393	struct scsi_tape *STp = filp->private_data;
1394
1395	if (STp->door_locked == ST_LOCKED_AUTO)
1396		do_door_lock(STp, 0);
1397
1398	normalize_buffer(STp->buffer);
1399	spin_lock(&st_use_lock);
1400	STp->in_use = 0;
1401	spin_unlock(&st_use_lock);
1402	scsi_autopm_put_device(STp->device);
1403	scsi_tape_put(STp);
1404
1405	return result;
1406}
1407
1408/* The checks common to both reading and writing */
1409static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1410{
1411	ssize_t retval = 0;
1412
1413	/*
1414	 * If we are in the middle of error recovery, don't let anyone
1415	 * else try and use this device.  Also, if error recovery fails, it
1416	 * may try and take the device offline, in which case all further
1417	 * access to the device is prohibited.
1418	 */
1419	if (!scsi_block_when_processing_errors(STp->device)) {
1420		retval = (-ENXIO);
1421		goto out;
1422	}
1423
1424	if (STp->ready != ST_READY) {
1425		if (STp->ready == ST_NO_TAPE)
1426			retval = (-ENOMEDIUM);
1427		else
1428			retval = (-EIO);
1429		goto out;
1430	}
1431
1432	if (! STp->modes[STp->current_mode].defined) {
1433		retval = (-ENXIO);
1434		goto out;
1435	}
1436
1437
1438	/*
1439	 * If there was a bus reset, block further access
1440	 * to this device.
1441	 */
1442	if (STp->pos_unknown) {
1443		retval = (-EIO);
1444		goto out;
1445	}
1446
1447	if (count == 0)
1448		goto out;
1449
1450        DEB(
1451	if (!STp->in_use) {
1452		printk(ST_DEB_MSG "%s: Incorrect device.\n", tape_name(STp));
 
1453		retval = (-EIO);
1454		goto out;
1455	} ) /* end DEB */
1456
1457	if (STp->can_partitions &&
1458	    (retval = switch_partition(STp)) < 0)
1459		goto out;
1460
1461	if (STp->block_size == 0 && STp->max_block > 0 &&
1462	    (count < STp->min_block || count > STp->max_block)) {
1463		retval = (-EINVAL);
1464		goto out;
1465	}
1466
1467	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1468	    !do_door_lock(STp, 1))
1469		STp->door_locked = ST_LOCKED_AUTO;
1470
1471 out:
1472	return retval;
1473}
1474
1475
1476static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1477			   size_t count, int is_read)
1478{
1479	int i, bufsize, retval = 0;
1480	struct st_buffer *STbp = STp->buffer;
1481
1482	if (is_read)
1483		i = STp->try_dio_now && try_rdio;
1484	else
1485		i = STp->try_dio_now && try_wdio;
1486
1487	if (i && ((unsigned long)buf & queue_dma_alignment(
1488					STp->device->request_queue)) == 0) {
1489		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1490				       count, (is_read ? READ : WRITE));
1491		if (i > 0) {
1492			STbp->do_dio = i;
1493			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1494		}
1495		else
1496			STbp->do_dio = 0;  /* fall back to buffering with any error */
1497		STbp->sg_segs = STbp->do_dio;
1498		DEB(
1499		     if (STbp->do_dio) {
1500			STp->nbr_dio++;
1501			STp->nbr_pages += STbp->do_dio;
1502		     }
1503		)
1504	} else
1505		STbp->do_dio = 0;
1506	DEB( STp->nbr_requests++; )
1507
1508	if (!STbp->do_dio) {
1509		if (STp->block_size)
1510			bufsize = STp->block_size > st_fixed_buffer_size ?
1511				STp->block_size : st_fixed_buffer_size;
1512		else {
1513			bufsize = count;
1514			/* Make sure that data from previous user is not leaked even if
1515			   HBA does not return correct residual */
1516			if (is_read && STp->sili && !STbp->cleared)
1517				clear_buffer(STbp);
1518		}
1519
1520		if (bufsize > STbp->buffer_size &&
1521		    !enlarge_buffer(STbp, bufsize, STp->restr_dma)) {
1522			printk(KERN_WARNING "%s: Can't allocate %d byte tape buffer.\n",
1523			       tape_name(STp), bufsize);
 
1524			retval = (-EOVERFLOW);
1525			goto out;
1526		}
1527		if (STp->block_size)
1528			STbp->buffer_blocks = bufsize / STp->block_size;
1529	}
1530
1531 out:
1532	return retval;
1533}
1534
1535
1536/* Can be called more than once after each setup_buffer() */
1537static void release_buffering(struct scsi_tape *STp, int is_read)
1538{
1539	struct st_buffer *STbp;
1540
1541	STbp = STp->buffer;
1542	if (STbp->do_dio) {
1543		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1544		STbp->do_dio = 0;
1545		STbp->sg_segs = 0;
1546	}
1547}
1548
1549
1550/* Write command */
1551static ssize_t
1552st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1553{
1554	ssize_t total;
1555	ssize_t i, do_count, blks, transfer;
1556	ssize_t retval;
1557	int undone, retry_eot = 0, scode;
1558	int async_write;
1559	unsigned char cmd[MAX_COMMAND_SIZE];
1560	const char __user *b_point;
1561	struct st_request *SRpnt = NULL;
1562	struct scsi_tape *STp = filp->private_data;
1563	struct st_modedef *STm;
1564	struct st_partstat *STps;
1565	struct st_buffer *STbp;
1566	char *name = tape_name(STp);
1567
1568	if (mutex_lock_interruptible(&STp->lock))
1569		return -ERESTARTSYS;
1570
1571	retval = rw_checks(STp, filp, count);
1572	if (retval || count == 0)
1573		goto out;
1574
1575	/* Write must be integral number of blocks */
1576	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1577		printk(KERN_WARNING "%s: Write not multiple of tape block size.\n",
1578		       name);
1579		retval = (-EINVAL);
1580		goto out;
1581	}
1582
1583	STm = &(STp->modes[STp->current_mode]);
1584	STps = &(STp->ps[STp->partition]);
1585
1586	if (STp->write_prot) {
1587		retval = (-EACCES);
1588		goto out;
1589	}
1590
1591
1592	if (STps->rw == ST_READING) {
1593		retval = flush_buffer(STp, 0);
1594		if (retval)
1595			goto out;
1596		STps->rw = ST_WRITING;
1597	} else if (STps->rw != ST_WRITING &&
1598		   STps->drv_file == 0 && STps->drv_block == 0) {
1599		if ((retval = set_mode_densblk(STp, STm)) < 0)
1600			goto out;
1601		if (STm->default_compression != ST_DONT_TOUCH &&
1602		    !(STp->compression_changed)) {
1603			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1604				printk(KERN_WARNING "%s: Can't set default compression.\n",
1605				       name);
1606				if (modes_defined) {
1607					retval = (-EINVAL);
1608					goto out;
1609				}
1610			}
1611		}
1612	}
1613
1614	STbp = STp->buffer;
1615	i = write_behind_check(STp);
1616	if (i) {
1617		if (i == -ENOSPC)
1618			STps->eof = ST_EOM_OK;
1619		else
1620			STps->eof = ST_EOM_ERROR;
1621	}
1622
1623	if (STps->eof == ST_EOM_OK) {
1624		STps->eof = ST_EOD_1;  /* allow next write */
1625		retval = (-ENOSPC);
1626		goto out;
1627	}
1628	else if (STps->eof == ST_EOM_ERROR) {
1629		retval = (-EIO);
1630		goto out;
1631	}
1632
1633	/* Check the buffer readability in cases where copy_user might catch
1634	   the problems after some tape movement. */
1635	if (STp->block_size != 0 &&
1636	    !STbp->do_dio &&
1637	    (copy_from_user(&i, buf, 1) != 0 ||
1638	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1639		retval = (-EFAULT);
1640		goto out;
1641	}
1642
1643	retval = setup_buffering(STp, buf, count, 0);
1644	if (retval)
1645		goto out;
1646
1647	total = count;
1648
1649	memset(cmd, 0, MAX_COMMAND_SIZE);
1650	cmd[0] = WRITE_6;
1651	cmd[1] = (STp->block_size != 0);
1652
1653	STps->rw = ST_WRITING;
1654
1655	b_point = buf;
1656	while (count > 0 && !retry_eot) {
1657
1658		if (STbp->do_dio) {
1659			do_count = count;
1660		}
1661		else {
1662			if (STp->block_size == 0)
1663				do_count = count;
1664			else {
1665				do_count = STbp->buffer_blocks * STp->block_size -
1666					STbp->buffer_bytes;
1667				if (do_count > count)
1668					do_count = count;
1669			}
1670
1671			i = append_to_buffer(b_point, STbp, do_count);
1672			if (i) {
1673				retval = i;
1674				goto out;
1675			}
1676		}
1677		count -= do_count;
1678		b_point += do_count;
1679
1680		async_write = STp->block_size == 0 && !STbp->do_dio &&
1681			STm->do_async_writes && STps->eof < ST_EOM_OK;
1682
1683		if (STp->block_size != 0 && STm->do_buffer_writes &&
1684		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1685		    STbp->buffer_bytes < STbp->buffer_size) {
1686			STp->dirty = 1;
1687			/* Don't write a buffer that is not full enough. */
1688			if (!async_write && count == 0)
1689				break;
1690		}
1691
1692	retry_write:
1693		if (STp->block_size == 0)
1694			blks = transfer = do_count;
1695		else {
1696			if (!STbp->do_dio)
1697				blks = STbp->buffer_bytes;
1698			else
1699				blks = do_count;
1700			blks /= STp->block_size;
1701			transfer = blks * STp->block_size;
1702		}
1703		cmd[2] = blks >> 16;
1704		cmd[3] = blks >> 8;
1705		cmd[4] = blks;
1706
1707		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1708				   STp->device->request_queue->rq_timeout,
1709				   MAX_WRITE_RETRIES, !async_write);
1710		if (!SRpnt) {
1711			retval = STbp->syscall_result;
1712			goto out;
1713		}
1714		if (async_write && !STbp->syscall_result) {
1715			STbp->writing = transfer;
1716			STp->dirty = !(STbp->writing ==
1717				       STbp->buffer_bytes);
1718			SRpnt = NULL;  /* Prevent releasing this request! */
1719			DEB( STp->write_pending = 1; )
1720			break;
1721		}
1722
1723		if (STbp->syscall_result != 0) {
1724			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1725
1726                        DEBC(printk(ST_DEB_MSG "%s: Error on write:\n", name));
1727			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1728				scode = cmdstatp->sense_hdr.sense_key;
1729				if (cmdstatp->remainder_valid)
1730					undone = (int)cmdstatp->uremainder64;
1731				else if (STp->block_size == 0 &&
1732					 scode == VOLUME_OVERFLOW)
1733					undone = transfer;
1734				else
1735					undone = 0;
1736				if (STp->block_size != 0)
1737					undone *= STp->block_size;
1738				if (undone <= do_count) {
1739					/* Only data from this write is not written */
1740					count += undone;
1741					b_point -= undone;
1742					do_count -= undone;
1743					if (STp->block_size)
1744						blks = (transfer - undone) / STp->block_size;
1745					STps->eof = ST_EOM_OK;
1746					/* Continue in fixed block mode if all written
1747					   in this request but still something left to write
1748					   (retval left to zero)
1749					*/
1750					if (STp->block_size == 0 ||
1751					    undone > 0 || count == 0)
1752						retval = (-ENOSPC); /* EOM within current request */
1753                                        DEBC(printk(ST_DEB_MSG
1754                                                       "%s: EOM with %d bytes unwritten.\n",
1755						       name, (int)count));
1756				} else {
1757					/* EOT within data buffered earlier (possible only
1758					   in fixed block mode without direct i/o) */
1759					if (!retry_eot && !cmdstatp->deferred &&
1760					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1761						move_buffer_data(STp->buffer, transfer - undone);
1762						retry_eot = 1;
1763						if (STps->drv_block >= 0) {
1764							STps->drv_block += (transfer - undone) /
1765								STp->block_size;
1766						}
1767						STps->eof = ST_EOM_OK;
1768						DEBC(printk(ST_DEB_MSG
1769							    "%s: Retry write of %d bytes at EOM.\n",
1770							    name, STp->buffer->buffer_bytes));
 
1771						goto retry_write;
1772					}
1773					else {
1774						/* Either error within data buffered by driver or
1775						   failed retry */
1776						count -= do_count;
1777						blks = do_count = 0;
1778						STps->eof = ST_EOM_ERROR;
1779						STps->drv_block = (-1); /* Too cautious? */
1780						retval = (-EIO);	/* EOM for old data */
1781						DEBC(printk(ST_DEB_MSG
1782							    "%s: EOM with lost data.\n",
1783							    name));
1784					}
1785				}
1786			} else {
1787				count += do_count;
1788				STps->drv_block = (-1);		/* Too cautious? */
1789				retval = STbp->syscall_result;
1790			}
1791
1792		}
1793
1794		if (STps->drv_block >= 0) {
1795			if (STp->block_size == 0)
1796				STps->drv_block += (do_count > 0);
1797			else
1798				STps->drv_block += blks;
1799		}
1800
1801		STbp->buffer_bytes = 0;
1802		STp->dirty = 0;
1803
1804		if (retval || retry_eot) {
1805			if (count < total)
1806				retval = total - count;
1807			goto out;
1808		}
1809	}
1810
1811	if (STps->eof == ST_EOD_1)
1812		STps->eof = ST_EOM_OK;
1813	else if (STps->eof != ST_EOM_OK)
1814		STps->eof = ST_NOEOF;
1815	retval = total - count;
1816
1817 out:
1818	if (SRpnt != NULL)
1819		st_release_request(SRpnt);
1820	release_buffering(STp, 0);
1821	mutex_unlock(&STp->lock);
1822
1823	return retval;
1824}
1825
1826/* Read data from the tape. Returns zero in the normal case, one if the
1827   eof status has changed, and the negative error code in case of a
1828   fatal error. Otherwise updates the buffer and the eof state.
1829
1830   Does release user buffer mapping if it is set.
1831*/
1832static long read_tape(struct scsi_tape *STp, long count,
1833		      struct st_request ** aSRpnt)
1834{
1835	int transfer, blks, bytes;
1836	unsigned char cmd[MAX_COMMAND_SIZE];
1837	struct st_request *SRpnt;
1838	struct st_modedef *STm;
1839	struct st_partstat *STps;
1840	struct st_buffer *STbp;
1841	int retval = 0;
1842	char *name = tape_name(STp);
1843
1844	if (count == 0)
1845		return 0;
1846
1847	STm = &(STp->modes[STp->current_mode]);
1848	STps = &(STp->ps[STp->partition]);
1849	if (STps->eof == ST_FM_HIT)
1850		return 1;
1851	STbp = STp->buffer;
1852
1853	if (STp->block_size == 0)
1854		blks = bytes = count;
1855	else {
1856		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1857			blks = (STp->buffer)->buffer_blocks;
1858			bytes = blks * STp->block_size;
1859		} else {
1860			bytes = count;
1861			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1862				bytes = (STp->buffer)->buffer_size;
1863			blks = bytes / STp->block_size;
1864			bytes = blks * STp->block_size;
1865		}
1866	}
1867
1868	memset(cmd, 0, MAX_COMMAND_SIZE);
1869	cmd[0] = READ_6;
1870	cmd[1] = (STp->block_size != 0);
1871	if (!cmd[1] && STp->sili)
1872		cmd[1] |= 2;
1873	cmd[2] = blks >> 16;
1874	cmd[3] = blks >> 8;
1875	cmd[4] = blks;
1876
1877	SRpnt = *aSRpnt;
1878	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1879			   STp->device->request_queue->rq_timeout,
1880			   MAX_RETRIES, 1);
1881	release_buffering(STp, 1);
1882	*aSRpnt = SRpnt;
1883	if (!SRpnt)
1884		return STbp->syscall_result;
1885
1886	STbp->read_pointer = 0;
1887	STps->at_sm = 0;
1888
1889	/* Something to check */
1890	if (STbp->syscall_result) {
1891		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1892
1893		retval = 1;
1894		DEBC(printk(ST_DEB_MSG "%s: Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1895                            name,
1896                            SRpnt->sense[0], SRpnt->sense[1],
1897                            SRpnt->sense[2], SRpnt->sense[3],
1898                            SRpnt->sense[4], SRpnt->sense[5],
1899                            SRpnt->sense[6], SRpnt->sense[7]));
1900		if (cmdstatp->have_sense) {
1901
1902			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1903				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1904
1905			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1906				/* Compute the residual count */
1907				if (cmdstatp->remainder_valid)
1908					transfer = (int)cmdstatp->uremainder64;
1909				else
1910					transfer = 0;
1911				if (STp->block_size == 0 &&
1912				    cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR)
1913					transfer = bytes;
 
 
 
1914
1915				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1916					if (STp->block_size == 0) {
1917						if (transfer <= 0) {
1918							if (transfer < 0)
1919								printk(KERN_NOTICE
1920								       "%s: Failed to read %d byte block with %d byte transfer.\n",
1921								       name, bytes - transfer, bytes);
1922							if (STps->drv_block >= 0)
1923								STps->drv_block += 1;
1924							STbp->buffer_bytes = 0;
1925							return (-ENOMEM);
1926						}
 
 
1927						STbp->buffer_bytes = bytes - transfer;
1928					} else {
1929						st_release_request(SRpnt);
1930						SRpnt = *aSRpnt = NULL;
1931						if (transfer == blks) {	/* We did not get anything, error */
1932							printk(KERN_NOTICE "%s: Incorrect block size.\n", name);
 
 
1933							if (STps->drv_block >= 0)
1934								STps->drv_block += blks - transfer + 1;
1935							st_int_ioctl(STp, MTBSR, 1);
1936							return (-EIO);
1937						}
1938						/* We have some data, deliver it */
1939						STbp->buffer_bytes = (blks - transfer) *
1940						    STp->block_size;
1941                                                DEBC(printk(ST_DEB_MSG
1942                                                            "%s: ILI but enough data received %ld %d.\n",
1943                                                            name, count, STbp->buffer_bytes));
 
 
1944						if (STps->drv_block >= 0)
1945							STps->drv_block += 1;
1946						if (st_int_ioctl(STp, MTBSR, 1))
1947							return (-EIO);
1948					}
1949				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
1950					if (STps->eof != ST_FM_HIT)
1951						STps->eof = ST_FM_HIT;
1952					else
1953						STps->eof = ST_EOD_2;
1954					if (STp->block_size == 0)
1955						STbp->buffer_bytes = 0;
1956					else
1957						STbp->buffer_bytes =
1958						    bytes - transfer * STp->block_size;
1959                                        DEBC(printk(ST_DEB_MSG
1960                                                    "%s: EOF detected (%d bytes read).\n",
1961                                                    name, STbp->buffer_bytes));
1962				} else if (cmdstatp->flags & SENSE_EOM) {
1963					if (STps->eof == ST_FM)
1964						STps->eof = ST_EOD_1;
1965					else
1966						STps->eof = ST_EOM_OK;
1967					if (STp->block_size == 0)
1968						STbp->buffer_bytes = bytes - transfer;
1969					else
1970						STbp->buffer_bytes =
1971						    bytes - transfer * STp->block_size;
1972
1973                                        DEBC(printk(ST_DEB_MSG "%s: EOM detected (%d bytes read).\n",
1974                                                    name, STbp->buffer_bytes));
 
1975				}
1976			}
1977			/* end of EOF, EOM, ILI test */ 
1978			else {	/* nonzero sense key */
1979                                DEBC(printk(ST_DEB_MSG
1980                                            "%s: Tape error while reading.\n", name));
1981				STps->drv_block = (-1);
1982				if (STps->eof == ST_FM &&
1983				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
1984                                        DEBC(printk(ST_DEB_MSG
1985                                                    "%s: Zero returned for first BLANK CHECK after EOF.\n",
1986                                                    name));
1987					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
1988				} else	/* Some other extended sense code */
1989					retval = (-EIO);
1990			}
1991
1992			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
1993				STbp->buffer_bytes = 0;
1994		}
1995		/* End of extended sense test */ 
1996		else {		/* Non-extended sense */
1997			retval = STbp->syscall_result;
1998		}
1999
2000	}
2001	/* End of error handling */ 
2002	else {			/* Read successful */
2003		STbp->buffer_bytes = bytes;
2004		if (STp->sili) /* In fixed block mode residual is always zero here */
2005			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
2006	}
2007
2008	if (STps->drv_block >= 0) {
2009		if (STp->block_size == 0)
2010			STps->drv_block++;
2011		else
2012			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2013	}
2014	return retval;
2015}
2016
2017
2018/* Read command */
2019static ssize_t
2020st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2021{
2022	ssize_t total;
2023	ssize_t retval = 0;
2024	ssize_t i, transfer;
2025	int special, do_dio = 0;
2026	struct st_request *SRpnt = NULL;
2027	struct scsi_tape *STp = filp->private_data;
2028	struct st_modedef *STm;
2029	struct st_partstat *STps;
2030	struct st_buffer *STbp = STp->buffer;
2031	DEB( char *name = tape_name(STp); )
2032
2033	if (mutex_lock_interruptible(&STp->lock))
2034		return -ERESTARTSYS;
2035
2036	retval = rw_checks(STp, filp, count);
2037	if (retval || count == 0)
2038		goto out;
2039
2040	STm = &(STp->modes[STp->current_mode]);
2041	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2042		if (!STm->do_read_ahead) {
2043			retval = (-EINVAL);	/* Read must be integral number of blocks */
2044			goto out;
2045		}
2046		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2047	}
2048
2049	STps = &(STp->ps[STp->partition]);
2050	if (STps->rw == ST_WRITING) {
2051		retval = flush_buffer(STp, 0);
2052		if (retval)
2053			goto out;
2054		STps->rw = ST_READING;
2055	}
2056        DEB(
2057	if (debugging && STps->eof != ST_NOEOF)
2058		printk(ST_DEB_MSG "%s: EOF/EOM flag up (%d). Bytes %d\n", name,
2059		       STps->eof, STbp->buffer_bytes);
2060        ) /* end DEB */
 
2061
2062	retval = setup_buffering(STp, buf, count, 1);
2063	if (retval)
2064		goto out;
2065	do_dio = STbp->do_dio;
2066
2067	if (STbp->buffer_bytes == 0 &&
2068	    STps->eof >= ST_EOD_1) {
2069		if (STps->eof < ST_EOD) {
2070			STps->eof += 1;
2071			retval = 0;
2072			goto out;
2073		}
2074		retval = (-EIO);	/* EOM or Blank Check */
2075		goto out;
2076	}
2077
2078	if (do_dio) {
2079		/* Check the buffer writability before any tape movement. Don't alter
2080		   buffer data. */
2081		if (copy_from_user(&i, buf, 1) != 0 ||
2082		    copy_to_user(buf, &i, 1) != 0 ||
2083		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2084		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2085			retval = (-EFAULT);
2086			goto out;
2087		}
2088	}
2089
2090	STps->rw = ST_READING;
2091
2092
2093	/* Loop until enough data in buffer or a special condition found */
2094	for (total = 0, special = 0; total < count && !special;) {
2095
2096		/* Get new data if the buffer is empty */
2097		if (STbp->buffer_bytes == 0) {
2098			special = read_tape(STp, count - total, &SRpnt);
2099			if (special < 0) {	/* No need to continue read */
2100				retval = special;
2101				goto out;
2102			}
2103		}
2104
2105		/* Move the data from driver buffer to user buffer */
2106		if (STbp->buffer_bytes > 0) {
2107                        DEB(
2108			if (debugging && STps->eof != ST_NOEOF)
2109				printk(ST_DEB_MSG
2110                                       "%s: EOF up (%d). Left %d, needed %d.\n", name,
2111				       STps->eof, STbp->buffer_bytes,
2112                                       (int)(count - total));
2113                        ) /* end DEB */
2114			transfer = STbp->buffer_bytes < count - total ?
2115			    STbp->buffer_bytes : count - total;
2116			if (!do_dio) {
2117				i = from_buffer(STbp, buf, transfer);
2118				if (i) {
2119					retval = i;
2120					goto out;
2121				}
2122			}
2123			buf += transfer;
2124			total += transfer;
2125		}
2126
2127		if (STp->block_size == 0)
2128			break;	/* Read only one variable length block */
2129
2130	}			/* for (total = 0, special = 0;
2131                                   total < count && !special; ) */
2132
2133	/* Change the eof state if no data from tape or buffer */
2134	if (total == 0) {
2135		if (STps->eof == ST_FM_HIT) {
2136			STps->eof = ST_FM;
2137			STps->drv_block = 0;
2138			if (STps->drv_file >= 0)
2139				STps->drv_file++;
2140		} else if (STps->eof == ST_EOD_1) {
2141			STps->eof = ST_EOD_2;
2142			STps->drv_block = 0;
2143			if (STps->drv_file >= 0)
2144				STps->drv_file++;
2145		} else if (STps->eof == ST_EOD_2)
2146			STps->eof = ST_EOD;
2147	} else if (STps->eof == ST_FM)
2148		STps->eof = ST_NOEOF;
2149	retval = total;
2150
2151 out:
2152	if (SRpnt != NULL) {
2153		st_release_request(SRpnt);
2154		SRpnt = NULL;
2155	}
2156	if (do_dio) {
2157		release_buffering(STp, 1);
2158		STbp->buffer_bytes = 0;
2159	}
2160	mutex_unlock(&STp->lock);
2161
2162	return retval;
2163}
2164
2165
2166
2167DEB(
2168/* Set the driver options */
2169static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm, char *name)
2170{
2171	if (debugging) {
2172		printk(KERN_INFO
2173		       "%s: Mode %d options: buffer writes: %d, async writes: %d, read ahead: %d\n",
2174		       name, STp->current_mode, STm->do_buffer_writes, STm->do_async_writes,
2175		       STm->do_read_ahead);
2176		printk(KERN_INFO
2177		       "%s:    can bsr: %d, two FMs: %d, fast mteom: %d, auto lock: %d,\n",
2178		       name, STp->can_bsr, STp->two_fm, STp->fast_mteom, STp->do_auto_lock);
2179		printk(KERN_INFO
2180		       "%s:    defs for wr: %d, no block limits: %d, partitions: %d, s2 log: %d\n",
2181		       name, STm->defaults_for_writes, STp->omit_blklims, STp->can_partitions,
2182		       STp->scsi2_logical);
2183		printk(KERN_INFO
2184		       "%s:    sysv: %d nowait: %d sili: %d nowait_filemark: %d\n",
2185		       name, STm->sysv, STp->immediate, STp->sili,
2186		       STp->immediate_filemark);
2187		printk(KERN_INFO "%s:    debugging: %d\n",
2188		       name, debugging);
 
 
 
 
2189	}
2190}
2191	)
2192
2193
2194static int st_set_options(struct scsi_tape *STp, long options)
2195{
2196	int value;
2197	long code;
2198	struct st_modedef *STm;
2199	char *name = tape_name(STp);
2200	struct cdev *cd0, *cd1;
2201	struct device *d0, *d1;
2202
2203	STm = &(STp->modes[STp->current_mode]);
2204	if (!STm->defined) {
2205		cd0 = STm->cdevs[0];
2206		cd1 = STm->cdevs[1];
2207		d0  = STm->devs[0];
2208		d1  = STm->devs[1];
2209		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2210		STm->cdevs[0] = cd0;
2211		STm->cdevs[1] = cd1;
2212		STm->devs[0]  = d0;
2213		STm->devs[1]  = d1;
2214		modes_defined = 1;
2215                DEBC(printk(ST_DEB_MSG
2216                            "%s: Initialized mode %d definition from mode 0\n",
2217                            name, STp->current_mode));
2218	}
2219
2220	code = options & MT_ST_OPTIONS;
2221	if (code == MT_ST_BOOLEANS) {
2222		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2223		STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2224		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2225		STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2226		STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2227		STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2228		STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2229		STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2230		STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2231		if ((STp->device)->scsi_level >= SCSI_2)
2232			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2233		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2234		STp->immediate = (options & MT_ST_NOWAIT) != 0;
2235		STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0;
2236		STm->sysv = (options & MT_ST_SYSV) != 0;
2237		STp->sili = (options & MT_ST_SILI) != 0;
2238		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2239		     st_log_options(STp, STm, name); )
2240	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2241		value = (code == MT_ST_SETBOOLEANS);
2242		if ((options & MT_ST_BUFFER_WRITES) != 0)
2243			STm->do_buffer_writes = value;
2244		if ((options & MT_ST_ASYNC_WRITES) != 0)
2245			STm->do_async_writes = value;
2246		if ((options & MT_ST_DEF_WRITES) != 0)
2247			STm->defaults_for_writes = value;
2248		if ((options & MT_ST_READ_AHEAD) != 0)
2249			STm->do_read_ahead = value;
2250		if ((options & MT_ST_TWO_FM) != 0)
2251			STp->two_fm = value;
2252		if ((options & MT_ST_FAST_MTEOM) != 0)
2253			STp->fast_mteom = value;
2254		if ((options & MT_ST_AUTO_LOCK) != 0)
2255			STp->do_auto_lock = value;
2256		if ((options & MT_ST_CAN_BSR) != 0)
2257			STp->can_bsr = value;
2258		if ((options & MT_ST_NO_BLKLIMS) != 0)
2259			STp->omit_blklims = value;
2260		if ((STp->device)->scsi_level >= SCSI_2 &&
2261		    (options & MT_ST_CAN_PARTITIONS) != 0)
2262			STp->can_partitions = value;
2263		if ((options & MT_ST_SCSI2LOGICAL) != 0)
2264			STp->scsi2_logical = value;
2265		if ((options & MT_ST_NOWAIT) != 0)
2266			STp->immediate = value;
2267		if ((options & MT_ST_NOWAIT_EOF) != 0)
2268			STp->immediate_filemark = value;
2269		if ((options & MT_ST_SYSV) != 0)
2270			STm->sysv = value;
2271		if ((options & MT_ST_SILI) != 0)
2272			STp->sili = value;
2273                DEB(
2274		if ((options & MT_ST_DEBUGGING) != 0)
2275			debugging = value;
2276			st_log_options(STp, STm, name); )
2277	} else if (code == MT_ST_WRITE_THRESHOLD) {
2278		/* Retained for compatibility */
2279	} else if (code == MT_ST_DEF_BLKSIZE) {
2280		value = (options & ~MT_ST_OPTIONS);
2281		if (value == ~MT_ST_OPTIONS) {
2282			STm->default_blksize = (-1);
2283			DEBC( printk(KERN_INFO "%s: Default block size disabled.\n", name));
2284		} else {
2285			STm->default_blksize = value;
2286			DEBC( printk(KERN_INFO "%s: Default block size set to %d bytes.\n",
2287			       name, STm->default_blksize));
2288			if (STp->ready == ST_READY) {
2289				STp->blksize_changed = 0;
2290				set_mode_densblk(STp, STm);
2291			}
2292		}
2293	} else if (code == MT_ST_TIMEOUTS) {
2294		value = (options & ~MT_ST_OPTIONS);
2295		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2296			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2297			DEBC( printk(KERN_INFO "%s: Long timeout set to %d seconds.\n", name,
2298			       (value & ~MT_ST_SET_LONG_TIMEOUT)));
2299		} else {
2300			blk_queue_rq_timeout(STp->device->request_queue,
2301					     value * HZ);
2302			DEBC( printk(KERN_INFO "%s: Normal timeout set to %d seconds.\n",
2303				name, value) );
2304		}
2305	} else if (code == MT_ST_SET_CLN) {
2306		value = (options & ~MT_ST_OPTIONS) & 0xff;
2307		if (value != 0 &&
2308			(value < EXTENDED_SENSE_START ||
2309				value >= SCSI_SENSE_BUFFERSIZE))
2310			return (-EINVAL);
2311		STp->cln_mode = value;
2312		STp->cln_sense_mask = (options >> 8) & 0xff;
2313		STp->cln_sense_value = (options >> 16) & 0xff;
2314		printk(KERN_INFO
2315		       "%s: Cleaning request mode %d, mask %02x, value %02x\n",
2316		       name, value, STp->cln_sense_mask, STp->cln_sense_value);
2317	} else if (code == MT_ST_DEF_OPTIONS) {
2318		code = (options & ~MT_ST_CLEAR_DEFAULT);
2319		value = (options & MT_ST_CLEAR_DEFAULT);
2320		if (code == MT_ST_DEF_DENSITY) {
2321			if (value == MT_ST_CLEAR_DEFAULT) {
2322				STm->default_density = (-1);
2323				DEBC( printk(KERN_INFO "%s: Density default disabled.\n",
2324                                       name));
2325			} else {
2326				STm->default_density = value & 0xff;
2327				DEBC( printk(KERN_INFO "%s: Density default set to %x\n",
2328				       name, STm->default_density));
2329				if (STp->ready == ST_READY) {
2330					STp->density_changed = 0;
2331					set_mode_densblk(STp, STm);
2332				}
2333			}
2334		} else if (code == MT_ST_DEF_DRVBUFFER) {
2335			if (value == MT_ST_CLEAR_DEFAULT) {
2336				STp->default_drvbuffer = 0xff;
2337				DEBC( printk(KERN_INFO
2338                                       "%s: Drive buffer default disabled.\n", name));
2339			} else {
2340				STp->default_drvbuffer = value & 7;
2341				DEBC( printk(KERN_INFO
2342                                       "%s: Drive buffer default set to %x\n",
2343				       name, STp->default_drvbuffer));
2344				if (STp->ready == ST_READY)
2345					st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2346			}
2347		} else if (code == MT_ST_DEF_COMPRESSION) {
2348			if (value == MT_ST_CLEAR_DEFAULT) {
2349				STm->default_compression = ST_DONT_TOUCH;
2350				DEBC( printk(KERN_INFO
2351                                       "%s: Compression default disabled.\n", name));
2352			} else {
2353				if ((value & 0xff00) != 0) {
2354					STp->c_algo = (value & 0xff00) >> 8;
2355					DEBC( printk(KERN_INFO "%s: Compression algorithm set to 0x%x.\n",
2356					       name, STp->c_algo));
 
2357				}
2358				if ((value & 0xff) != 0xff) {
2359					STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2360					DEBC( printk(KERN_INFO "%s: Compression default set to %x\n",
2361					       name, (value & 1)));
 
2362					if (STp->ready == ST_READY) {
2363						STp->compression_changed = 0;
2364						st_compression(STp, (STm->default_compression == ST_YES));
2365					}
2366				}
2367			}
2368		}
2369	} else
2370		return (-EIO);
2371
2372	return 0;
2373}
2374
2375#define MODE_HEADER_LENGTH  4
2376
2377/* Mode header and page byte offsets */
2378#define MH_OFF_DATA_LENGTH     0
2379#define MH_OFF_MEDIUM_TYPE     1
2380#define MH_OFF_DEV_SPECIFIC    2
2381#define MH_OFF_BDESCS_LENGTH   3
2382#define MP_OFF_PAGE_NBR        0
2383#define MP_OFF_PAGE_LENGTH     1
2384
2385/* Mode header and page bit masks */
2386#define MH_BIT_WP              0x80
2387#define MP_MSK_PAGE_NBR        0x3f
2388
2389/* Don't return block descriptors */
2390#define MODE_SENSE_OMIT_BDESCS 0x08
2391
2392#define MODE_SELECT_PAGE_FORMAT 0x10
2393
2394/* Read a mode page into the tape buffer. The block descriptors are included
2395   if incl_block_descs is true. The page control is ored to the page number
2396   parameter, if necessary. */
2397static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2398{
2399	unsigned char cmd[MAX_COMMAND_SIZE];
2400	struct st_request *SRpnt;
2401
2402	memset(cmd, 0, MAX_COMMAND_SIZE);
2403	cmd[0] = MODE_SENSE;
2404	if (omit_block_descs)
2405		cmd[1] = MODE_SENSE_OMIT_BDESCS;
2406	cmd[2] = page;
2407	cmd[4] = 255;
2408
2409	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2410			   STp->device->request_queue->rq_timeout, 0, 1);
2411	if (SRpnt == NULL)
2412		return (STp->buffer)->syscall_result;
2413
2414	st_release_request(SRpnt);
2415
2416	return STp->buffer->syscall_result;
2417}
2418
2419
2420/* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2421   in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2422static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2423{
2424	int pgo;
2425	unsigned char cmd[MAX_COMMAND_SIZE];
2426	struct st_request *SRpnt;
2427	int timeout;
2428
2429	memset(cmd, 0, MAX_COMMAND_SIZE);
2430	cmd[0] = MODE_SELECT;
2431	cmd[1] = MODE_SELECT_PAGE_FORMAT;
2432	pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2433	cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2434
2435	/* Clear reserved fields */
2436	(STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2437	(STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2438	(STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2439	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2440
2441	timeout = slow ?
2442		STp->long_timeout : STp->device->request_queue->rq_timeout;
2443	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2444			   timeout, 0, 1);
2445	if (SRpnt == NULL)
2446		return (STp->buffer)->syscall_result;
2447
2448	st_release_request(SRpnt);
2449
2450	return STp->buffer->syscall_result;
2451}
2452
2453
2454#define COMPRESSION_PAGE        0x0f
2455#define COMPRESSION_PAGE_LENGTH 16
2456
2457#define CP_OFF_DCE_DCC          2
2458#define CP_OFF_C_ALGO           7
2459
2460#define DCE_MASK  0x80
2461#define DCC_MASK  0x40
2462#define RED_MASK  0x60
2463
2464
2465/* Control the compression with mode page 15. Algorithm not changed if zero.
2466
2467   The block descriptors are read and written because Sony SDT-7000 does not
2468   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2469   Including block descriptors should not cause any harm to other drives. */
2470
2471static int st_compression(struct scsi_tape * STp, int state)
2472{
2473	int retval;
2474	int mpoffs;  /* Offset to mode page start */
2475	unsigned char *b_data = (STp->buffer)->b_data;
2476	DEB( char *name = tape_name(STp); )
2477
2478	if (STp->ready != ST_READY)
2479		return (-EIO);
2480
2481	/* Read the current page contents */
2482	retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2483	if (retval) {
2484                DEBC(printk(ST_DEB_MSG "%s: Compression mode page not supported.\n",
2485                            name));
2486		return (-EIO);
2487	}
2488
2489	mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2490        DEBC(printk(ST_DEB_MSG "%s: Compression state is %d.\n", name,
2491                    (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0)));
2492
2493	/* Check if compression can be changed */
2494	if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2495                DEBC(printk(ST_DEB_MSG "%s: Compression not supported.\n", name));
2496		return (-EIO);
2497	}
2498
2499	/* Do the change */
2500	if (state) {
2501		b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2502		if (STp->c_algo != 0)
2503			b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2504	}
2505	else {
2506		b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2507		if (STp->c_algo != 0)
2508			b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2509	}
2510
2511	retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2512	if (retval) {
2513                DEBC(printk(ST_DEB_MSG "%s: Compression change failed.\n", name));
2514		return (-EIO);
2515	}
2516        DEBC(printk(ST_DEB_MSG "%s: Compression state changed to %d.\n",
2517		       name, state));
2518
2519	STp->compression_changed = 1;
2520	return 0;
2521}
2522
2523
2524/* Process the load and unload commands (does unload if the load code is zero) */
2525static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2526{
2527	int retval = (-EIO), timeout;
2528	DEB( char *name = tape_name(STp); )
2529	unsigned char cmd[MAX_COMMAND_SIZE];
2530	struct st_partstat *STps;
2531	struct st_request *SRpnt;
2532
2533	if (STp->ready != ST_READY && !load_code) {
2534		if (STp->ready == ST_NO_TAPE)
2535			return (-ENOMEDIUM);
2536		else
2537			return (-EIO);
2538	}
2539
2540	memset(cmd, 0, MAX_COMMAND_SIZE);
2541	cmd[0] = START_STOP;
2542	if (load_code)
2543		cmd[4] |= 1;
2544	/*
2545	 * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2546	 */
2547	if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2548	    && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2549		DEBC(printk(ST_DEB_MSG "%s: Enhanced %sload slot %2d.\n",
2550			    name, (cmd[4]) ? "" : "un",
2551			    load_code - MT_ST_HPLOADER_OFFSET));
2552		cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2553	}
2554	if (STp->immediate) {
2555		cmd[1] = 1;	/* Don't wait for completion */
2556		timeout = STp->device->request_queue->rq_timeout;
2557	}
2558	else
2559		timeout = STp->long_timeout;
2560
2561	DEBC(
2562		if (!load_code)
2563		printk(ST_DEB_MSG "%s: Unloading tape.\n", name);
2564		else
2565		printk(ST_DEB_MSG "%s: Loading tape.\n", name);
2566		);
2567
2568	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2569			   timeout, MAX_RETRIES, 1);
2570	if (!SRpnt)
2571		return (STp->buffer)->syscall_result;
2572
2573	retval = (STp->buffer)->syscall_result;
2574	st_release_request(SRpnt);
2575
2576	if (!retval) {	/* SCSI command successful */
2577
2578		if (!load_code) {
2579			STp->rew_at_close = 0;
2580			STp->ready = ST_NO_TAPE;
2581		}
2582		else {
2583			STp->rew_at_close = STp->autorew_dev;
2584			retval = check_tape(STp, filp);
2585			if (retval > 0)
2586				retval = 0;
2587		}
2588	}
2589	else {
2590		STps = &(STp->ps[STp->partition]);
2591		STps->drv_file = STps->drv_block = (-1);
2592	}
2593
2594	return retval;
2595}
2596
2597#if DEBUG
2598#define ST_DEB_FORWARD  0
2599#define ST_DEB_BACKWARD 1
2600static void deb_space_print(char *name, int direction, char *units, unsigned char *cmd)
2601{
2602	s32 sc;
2603
 
 
 
2604	sc = cmd[2] & 0x80 ? 0xff000000 : 0;
2605	sc |= (cmd[2] << 16) | (cmd[3] << 8) | cmd[4];
2606	if (direction)
2607		sc = -sc;
2608	printk(ST_DEB_MSG "%s: Spacing tape %s over %d %s.\n", name,
2609	       direction ? "backward" : "forward", sc, units);
2610}
 
 
 
 
2611#endif
2612
2613
2614/* Internal ioctl function */
2615static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2616{
2617	int timeout;
2618	long ltmp;
2619	int ioctl_result;
2620	int chg_eof = 1;
2621	unsigned char cmd[MAX_COMMAND_SIZE];
2622	struct st_request *SRpnt;
2623	struct st_partstat *STps;
2624	int fileno, blkno, at_sm, undone;
2625	int datalen = 0, direction = DMA_NONE;
2626	char *name = tape_name(STp);
2627
2628	WARN_ON(STp->buffer->do_dio != 0);
2629	if (STp->ready != ST_READY) {
2630		if (STp->ready == ST_NO_TAPE)
2631			return (-ENOMEDIUM);
2632		else
2633			return (-EIO);
2634	}
2635	timeout = STp->long_timeout;
2636	STps = &(STp->ps[STp->partition]);
2637	fileno = STps->drv_file;
2638	blkno = STps->drv_block;
2639	at_sm = STps->at_sm;
2640
2641	memset(cmd, 0, MAX_COMMAND_SIZE);
2642	switch (cmd_in) {
2643	case MTFSFM:
2644		chg_eof = 0;	/* Changed from the FSF after this */
2645	case MTFSF:
2646		cmd[0] = SPACE;
2647		cmd[1] = 0x01;	/* Space FileMarks */
2648		cmd[2] = (arg >> 16);
2649		cmd[3] = (arg >> 8);
2650		cmd[4] = arg;
2651                DEBC(deb_space_print(name, ST_DEB_FORWARD, "filemarks", cmd);)
2652		if (fileno >= 0)
2653			fileno += arg;
2654		blkno = 0;
2655		at_sm &= (arg == 0);
2656		break;
2657	case MTBSFM:
2658		chg_eof = 0;	/* Changed from the FSF after this */
2659	case MTBSF:
2660		cmd[0] = SPACE;
2661		cmd[1] = 0x01;	/* Space FileMarks */
2662		ltmp = (-arg);
2663		cmd[2] = (ltmp >> 16);
2664		cmd[3] = (ltmp >> 8);
2665		cmd[4] = ltmp;
2666                DEBC(deb_space_print(name, ST_DEB_BACKWARD, "filemarks", cmd);)
2667		if (fileno >= 0)
2668			fileno -= arg;
2669		blkno = (-1);	/* We can't know the block number */
2670		at_sm &= (arg == 0);
2671		break;
2672	case MTFSR:
2673		cmd[0] = SPACE;
2674		cmd[1] = 0x00;	/* Space Blocks */
2675		cmd[2] = (arg >> 16);
2676		cmd[3] = (arg >> 8);
2677		cmd[4] = arg;
2678                DEBC(deb_space_print(name, ST_DEB_FORWARD, "blocks", cmd);)
2679		if (blkno >= 0)
2680			blkno += arg;
2681		at_sm &= (arg == 0);
2682		break;
2683	case MTBSR:
2684		cmd[0] = SPACE;
2685		cmd[1] = 0x00;	/* Space Blocks */
2686		ltmp = (-arg);
2687		cmd[2] = (ltmp >> 16);
2688		cmd[3] = (ltmp >> 8);
2689		cmd[4] = ltmp;
2690                DEBC(deb_space_print(name, ST_DEB_BACKWARD, "blocks", cmd);)
2691		if (blkno >= 0)
2692			blkno -= arg;
2693		at_sm &= (arg == 0);
2694		break;
2695	case MTFSS:
2696		cmd[0] = SPACE;
2697		cmd[1] = 0x04;	/* Space Setmarks */
2698		cmd[2] = (arg >> 16);
2699		cmd[3] = (arg >> 8);
2700		cmd[4] = arg;
2701                DEBC(deb_space_print(name, ST_DEB_FORWARD, "setmarks", cmd);)
2702		if (arg != 0) {
2703			blkno = fileno = (-1);
2704			at_sm = 1;
2705		}
2706		break;
2707	case MTBSS:
2708		cmd[0] = SPACE;
2709		cmd[1] = 0x04;	/* Space Setmarks */
2710		ltmp = (-arg);
2711		cmd[2] = (ltmp >> 16);
2712		cmd[3] = (ltmp >> 8);
2713		cmd[4] = ltmp;
2714                DEBC(deb_space_print(name, ST_DEB_BACKWARD, "setmarks", cmd);)
2715		if (arg != 0) {
2716			blkno = fileno = (-1);
2717			at_sm = 1;
2718		}
2719		break;
2720	case MTWEOF:
2721	case MTWEOFI:
2722	case MTWSM:
2723		if (STp->write_prot)
2724			return (-EACCES);
2725		cmd[0] = WRITE_FILEMARKS;
2726		if (cmd_in == MTWSM)
2727			cmd[1] = 2;
2728		if (cmd_in == MTWEOFI ||
2729		    (cmd_in == MTWEOF && STp->immediate_filemark))
2730			cmd[1] |= 1;
2731		cmd[2] = (arg >> 16);
2732		cmd[3] = (arg >> 8);
2733		cmd[4] = arg;
2734		timeout = STp->device->request_queue->rq_timeout;
2735                DEBC(
2736		     if (cmd_in != MTWSM)
2737                               printk(ST_DEB_MSG "%s: Writing %d filemarks.\n", name,
2738				 cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
2739                     else
2740				printk(ST_DEB_MSG "%s: Writing %d setmarks.\n", name,
2741				 cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
 
 
 
 
 
 
2742		)
2743		if (fileno >= 0)
2744			fileno += arg;
2745		blkno = 0;
2746		at_sm = (cmd_in == MTWSM);
2747		break;
2748	case MTREW:
2749		cmd[0] = REZERO_UNIT;
2750		if (STp->immediate) {
2751			cmd[1] = 1;	/* Don't wait for completion */
2752			timeout = STp->device->request_queue->rq_timeout;
2753		}
2754                DEBC(printk(ST_DEB_MSG "%s: Rewinding tape.\n", name));
2755		fileno = blkno = at_sm = 0;
2756		break;
2757	case MTNOP:
2758                DEBC(printk(ST_DEB_MSG "%s: No op on tape.\n", name));
2759		return 0;	/* Should do something ? */
2760		break;
2761	case MTRETEN:
2762		cmd[0] = START_STOP;
2763		if (STp->immediate) {
2764			cmd[1] = 1;	/* Don't wait for completion */
2765			timeout = STp->device->request_queue->rq_timeout;
2766		}
2767		cmd[4] = 3;
2768                DEBC(printk(ST_DEB_MSG "%s: Retensioning tape.\n", name));
2769		fileno = blkno = at_sm = 0;
2770		break;
2771	case MTEOM:
2772		if (!STp->fast_mteom) {
2773			/* space to the end of tape */
2774			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2775			fileno = STps->drv_file;
2776			if (STps->eof >= ST_EOD_1)
2777				return 0;
2778			/* The next lines would hide the number of spaced FileMarks
2779			   That's why I inserted the previous lines. I had no luck
2780			   with detecting EOM with FSF, so we go now to EOM.
2781			   Joerg Weule */
2782		} else
2783			fileno = (-1);
2784		cmd[0] = SPACE;
2785		cmd[1] = 3;
2786                DEBC(printk(ST_DEB_MSG "%s: Spacing to end of recorded medium.\n",
2787                            name));
2788		blkno = -1;
2789		at_sm = 0;
2790		break;
2791	case MTERASE:
2792		if (STp->write_prot)
2793			return (-EACCES);
2794		cmd[0] = ERASE;
2795		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
2796		if (STp->immediate) {
2797			cmd[1] |= 2;	/* Don't wait for completion */
2798			timeout = STp->device->request_queue->rq_timeout;
2799		}
2800		else
2801			timeout = STp->long_timeout * 8;
2802
2803                DEBC(printk(ST_DEB_MSG "%s: Erasing tape.\n", name));
2804		fileno = blkno = at_sm = 0;
2805		break;
2806	case MTSETBLK:		/* Set block length */
2807	case MTSETDENSITY:	/* Set tape density */
2808	case MTSETDRVBUFFER:	/* Set drive buffering */
2809	case SET_DENS_AND_BLK:	/* Set density and block size */
2810		chg_eof = 0;
2811		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2812			return (-EIO);	/* Not allowed if data in buffer */
2813		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2814		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2815		    STp->max_block > 0 &&
2816		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2817		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2818			printk(KERN_WARNING "%s: Illegal block size.\n", name);
2819			return (-EINVAL);
2820		}
2821		cmd[0] = MODE_SELECT;
2822		if ((STp->use_pf & USE_PF))
2823			cmd[1] = MODE_SELECT_PAGE_FORMAT;
2824		cmd[4] = datalen = 12;
2825		direction = DMA_TO_DEVICE;
2826
2827		memset((STp->buffer)->b_data, 0, 12);
2828		if (cmd_in == MTSETDRVBUFFER)
2829			(STp->buffer)->b_data[2] = (arg & 7) << 4;
2830		else
2831			(STp->buffer)->b_data[2] =
2832			    STp->drv_buffer << 4;
2833		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
2834		if (cmd_in == MTSETDENSITY) {
2835			(STp->buffer)->b_data[4] = arg;
2836			STp->density_changed = 1;	/* At least we tried ;-) */
2837		} else if (cmd_in == SET_DENS_AND_BLK)
2838			(STp->buffer)->b_data[4] = arg >> 24;
2839		else
2840			(STp->buffer)->b_data[4] = STp->density;
2841		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2842			ltmp = arg & MT_ST_BLKSIZE_MASK;
2843			if (cmd_in == MTSETBLK)
2844				STp->blksize_changed = 1; /* At least we tried ;-) */
2845		} else
2846			ltmp = STp->block_size;
2847		(STp->buffer)->b_data[9] = (ltmp >> 16);
2848		(STp->buffer)->b_data[10] = (ltmp >> 8);
2849		(STp->buffer)->b_data[11] = ltmp;
2850		timeout = STp->device->request_queue->rq_timeout;
2851                DEBC(
2852			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2853				printk(ST_DEB_MSG
2854                                       "%s: Setting block size to %d bytes.\n", name,
2855				       (STp->buffer)->b_data[9] * 65536 +
2856				       (STp->buffer)->b_data[10] * 256 +
2857				       (STp->buffer)->b_data[11]);
2858			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2859				printk(ST_DEB_MSG
2860                                       "%s: Setting density code to %x.\n", name,
2861				       (STp->buffer)->b_data[4]);
2862			if (cmd_in == MTSETDRVBUFFER)
2863				printk(ST_DEB_MSG
2864                                       "%s: Setting drive buffer code to %d.\n", name,
2865				    ((STp->buffer)->b_data[2] >> 4) & 7);
2866		)
2867		break;
2868	default:
2869		return (-ENOSYS);
2870	}
2871
2872	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2873			   timeout, MAX_RETRIES, 1);
2874	if (!SRpnt)
2875		return (STp->buffer)->syscall_result;
2876
2877	ioctl_result = (STp->buffer)->syscall_result;
2878
2879	if (!ioctl_result) {	/* SCSI command successful */
2880		st_release_request(SRpnt);
2881		SRpnt = NULL;
2882		STps->drv_block = blkno;
2883		STps->drv_file = fileno;
2884		STps->at_sm = at_sm;
2885
2886		if (cmd_in == MTBSFM)
2887			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2888		else if (cmd_in == MTFSFM)
2889			ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2890
2891		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2892			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2893			if (STp->block_size != 0) {
2894				(STp->buffer)->buffer_blocks =
2895				    (STp->buffer)->buffer_size / STp->block_size;
2896			}
2897			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2898			if (cmd_in == SET_DENS_AND_BLK)
2899				STp->density = arg >> MT_ST_DENSITY_SHIFT;
2900		} else if (cmd_in == MTSETDRVBUFFER)
2901			STp->drv_buffer = (arg & 7);
2902		else if (cmd_in == MTSETDENSITY)
2903			STp->density = arg;
2904
2905		if (cmd_in == MTEOM)
2906			STps->eof = ST_EOD;
2907		else if (cmd_in == MTFSF)
2908			STps->eof = ST_FM;
2909		else if (chg_eof)
2910			STps->eof = ST_NOEOF;
2911
2912		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
2913			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
2914	} else { /* SCSI command was not completely successful. Don't return
2915                    from this block without releasing the SCSI command block! */
2916		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
2917
2918		if (cmdstatp->flags & SENSE_EOM) {
2919			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
2920			    cmd_in != MTBSR && cmd_in != MTBSS)
2921				STps->eof = ST_EOM_OK;
2922			STps->drv_block = 0;
2923		}
2924
2925		if (cmdstatp->remainder_valid)
2926			undone = (int)cmdstatp->uremainder64;
2927		else
2928			undone = 0;
2929
2930		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
2931		    cmdstatp->have_sense &&
2932		    (cmdstatp->flags & SENSE_EOM)) {
2933			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
2934			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
2935				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
2936				STps->eof = ST_NOEOF;
2937			} else {  /* Writing EOF(s) failed */
2938				if (fileno >= 0)
2939					fileno -= undone;
2940				if (undone < arg)
2941					STps->eof = ST_NOEOF;
2942			}
2943			STps->drv_file = fileno;
2944		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
2945			if (fileno >= 0)
2946				STps->drv_file = fileno - undone;
2947			else
2948				STps->drv_file = fileno;
2949			STps->drv_block = -1;
2950			STps->eof = ST_NOEOF;
2951		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
2952			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
2953				undone = (-undone);
2954			if (STps->drv_file >= 0)
2955				STps->drv_file = fileno + undone;
2956			STps->drv_block = 0;
2957			STps->eof = ST_NOEOF;
2958		} else if (cmd_in == MTFSR) {
2959			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
2960				if (STps->drv_file >= 0)
2961					STps->drv_file++;
2962				STps->drv_block = 0;
2963				STps->eof = ST_FM;
2964			} else {
2965				if (blkno >= undone)
2966					STps->drv_block = blkno - undone;
2967				else
2968					STps->drv_block = (-1);
2969				STps->eof = ST_NOEOF;
2970			}
2971		} else if (cmd_in == MTBSR) {
2972			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
2973				STps->drv_file--;
2974				STps->drv_block = (-1);
2975			} else {
2976				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
2977					undone = (-undone);
2978				if (STps->drv_block >= 0)
2979					STps->drv_block = blkno + undone;
2980			}
2981			STps->eof = ST_NOEOF;
2982		} else if (cmd_in == MTEOM) {
2983			STps->drv_file = (-1);
2984			STps->drv_block = (-1);
2985			STps->eof = ST_EOD;
2986		} else if (cmd_in == MTSETBLK ||
2987			   cmd_in == MTSETDENSITY ||
2988			   cmd_in == MTSETDRVBUFFER ||
2989			   cmd_in == SET_DENS_AND_BLK) {
2990			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
2991			    !(STp->use_pf & PF_TESTED)) {
2992				/* Try the other possible state of Page Format if not
2993				   already tried */
2994				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
2995				st_release_request(SRpnt);
2996				SRpnt = NULL;
2997				return st_int_ioctl(STp, cmd_in, arg);
2998			}
2999		} else if (chg_eof)
3000			STps->eof = ST_NOEOF;
3001
3002		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
3003			STps->eof = ST_EOD;
3004
3005		st_release_request(SRpnt);
3006		SRpnt = NULL;
3007	}
3008
3009	return ioctl_result;
3010}
3011
3012
3013/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
3014   structure. */
3015
3016static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
3017			int logical)
3018{
3019	int result;
3020	unsigned char scmd[MAX_COMMAND_SIZE];
3021	struct st_request *SRpnt;
3022	DEB( char *name = tape_name(STp); )
3023
3024	if (STp->ready != ST_READY)
3025		return (-EIO);
3026
3027	memset(scmd, 0, MAX_COMMAND_SIZE);
3028	if ((STp->device)->scsi_level < SCSI_2) {
3029		scmd[0] = QFA_REQUEST_BLOCK;
3030		scmd[4] = 3;
3031	} else {
3032		scmd[0] = READ_POSITION;
3033		if (!logical && !STp->scsi2_logical)
3034			scmd[1] = 1;
3035	}
3036	SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3037			   STp->device->request_queue->rq_timeout,
3038			   MAX_READY_RETRIES, 1);
3039	if (!SRpnt)
3040		return (STp->buffer)->syscall_result;
3041
3042	if ((STp->buffer)->syscall_result != 0 ||
3043	    (STp->device->scsi_level >= SCSI_2 &&
3044	     ((STp->buffer)->b_data[0] & 4) != 0)) {
3045		*block = *partition = 0;
3046                DEBC(printk(ST_DEB_MSG "%s: Can't read tape position.\n", name));
3047		result = (-EIO);
3048	} else {
3049		result = 0;
3050		if ((STp->device)->scsi_level < SCSI_2) {
3051			*block = ((STp->buffer)->b_data[0] << 16)
3052			    + ((STp->buffer)->b_data[1] << 8)
3053			    + (STp->buffer)->b_data[2];
3054			*partition = 0;
3055		} else {
3056			*block = ((STp->buffer)->b_data[4] << 24)
3057			    + ((STp->buffer)->b_data[5] << 16)
3058			    + ((STp->buffer)->b_data[6] << 8)
3059			    + (STp->buffer)->b_data[7];
3060			*partition = (STp->buffer)->b_data[1];
3061			if (((STp->buffer)->b_data[0] & 0x80) &&
3062			    (STp->buffer)->b_data[1] == 0)	/* BOP of partition 0 */
3063				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3064		}
3065                DEBC(printk(ST_DEB_MSG "%s: Got tape pos. blk %d part %d.\n", name,
3066                            *block, *partition));
3067	}
3068	st_release_request(SRpnt);
3069	SRpnt = NULL;
3070
3071	return result;
3072}
3073
3074
3075/* Set the tape block and partition. Negative partition means that only the
3076   block should be set in vendor specific way. */
3077static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3078			int logical)
3079{
3080	struct st_partstat *STps;
3081	int result, p;
3082	unsigned int blk;
3083	int timeout;
3084	unsigned char scmd[MAX_COMMAND_SIZE];
3085	struct st_request *SRpnt;
3086	DEB( char *name = tape_name(STp); )
3087
3088	if (STp->ready != ST_READY)
3089		return (-EIO);
3090	timeout = STp->long_timeout;
3091	STps = &(STp->ps[STp->partition]);
3092
3093        DEBC(printk(ST_DEB_MSG "%s: Setting block to %d and partition to %d.\n",
3094                    name, block, partition));
3095	DEB(if (partition < 0)
3096		return (-EIO); )
3097
3098	/* Update the location at the partition we are leaving */
3099	if ((!STp->can_partitions && partition != 0) ||
3100	    partition >= ST_NBR_PARTITIONS)
3101		return (-EINVAL);
3102	if (partition != STp->partition) {
3103		if (get_location(STp, &blk, &p, 1))
3104			STps->last_block_valid = 0;
3105		else {
3106			STps->last_block_valid = 1;
3107			STps->last_block_visited = blk;
3108                        DEBC(printk(ST_DEB_MSG
3109                                    "%s: Visited block %d for partition %d saved.\n",
3110                                    name, blk, STp->partition));
3111		}
3112	}
3113
3114	memset(scmd, 0, MAX_COMMAND_SIZE);
3115	if ((STp->device)->scsi_level < SCSI_2) {
3116		scmd[0] = QFA_SEEK_BLOCK;
3117		scmd[2] = (block >> 16);
3118		scmd[3] = (block >> 8);
3119		scmd[4] = block;
3120		scmd[5] = 0;
3121	} else {
3122		scmd[0] = SEEK_10;
3123		scmd[3] = (block >> 24);
3124		scmd[4] = (block >> 16);
3125		scmd[5] = (block >> 8);
3126		scmd[6] = block;
3127		if (!logical && !STp->scsi2_logical)
3128			scmd[1] = 4;
3129		if (STp->partition != partition) {
3130			scmd[1] |= 2;
3131			scmd[8] = partition;
3132                        DEBC(printk(ST_DEB_MSG
3133                                    "%s: Trying to change partition from %d to %d\n",
3134                                    name, STp->partition, partition));
3135		}
3136	}
3137	if (STp->immediate) {
3138		scmd[1] |= 1;		/* Don't wait for completion */
3139		timeout = STp->device->request_queue->rq_timeout;
3140	}
3141
3142	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3143			   timeout, MAX_READY_RETRIES, 1);
3144	if (!SRpnt)
3145		return (STp->buffer)->syscall_result;
3146
3147	STps->drv_block = STps->drv_file = (-1);
3148	STps->eof = ST_NOEOF;
3149	if ((STp->buffer)->syscall_result != 0) {
3150		result = (-EIO);
3151		if (STp->can_partitions &&
3152		    (STp->device)->scsi_level >= SCSI_2 &&
3153		    (p = find_partition(STp)) >= 0)
3154			STp->partition = p;
3155	} else {
3156		if (STp->can_partitions) {
3157			STp->partition = partition;
3158			STps = &(STp->ps[partition]);
3159			if (!STps->last_block_valid ||
3160			    STps->last_block_visited != block) {
3161				STps->at_sm = 0;
3162				STps->rw = ST_IDLE;
3163			}
3164		} else
3165			STps->at_sm = 0;
3166		if (block == 0)
3167			STps->drv_block = STps->drv_file = 0;
3168		result = 0;
3169	}
3170
3171	st_release_request(SRpnt);
3172	SRpnt = NULL;
3173
3174	return result;
3175}
3176
3177
3178/* Find the current partition number for the drive status. Called from open and
3179   returns either partition number of negative error code. */
3180static int find_partition(struct scsi_tape *STp)
3181{
3182	int i, partition;
3183	unsigned int block;
3184
3185	if ((i = get_location(STp, &block, &partition, 1)) < 0)
3186		return i;
3187	if (partition >= ST_NBR_PARTITIONS)
3188		return (-EIO);
3189	return partition;
3190}
3191
3192
3193/* Change the partition if necessary */
3194static int switch_partition(struct scsi_tape *STp)
3195{
3196	struct st_partstat *STps;
3197
3198	if (STp->partition == STp->new_partition)
3199		return 0;
3200	STps = &(STp->ps[STp->new_partition]);
3201	if (!STps->last_block_valid)
3202		STps->last_block_visited = 0;
3203	return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3204}
3205
3206/* Functions for reading and writing the medium partition mode page. */
3207
3208#define PART_PAGE   0x11
3209#define PART_PAGE_FIXED_LENGTH 8
3210
3211#define PP_OFF_MAX_ADD_PARTS   2
3212#define PP_OFF_NBR_ADD_PARTS   3
3213#define PP_OFF_FLAGS           4
3214#define PP_OFF_PART_UNITS      6
3215#define PP_OFF_RESERVED        7
3216
3217#define PP_BIT_IDP             0x20
 
3218#define PP_MSK_PSUM_MB         0x10
 
 
3219
3220/* Get the number of partitions on the tape. As a side effect reads the
3221   mode page into the tape buffer. */
3222static int nbr_partitions(struct scsi_tape *STp)
3223{
3224	int result;
3225	DEB( char *name = tape_name(STp); )
3226
3227	if (STp->ready != ST_READY)
3228		return (-EIO);
3229
3230	result = read_mode_page(STp, PART_PAGE, 1);
3231
3232	if (result) {
3233                DEBC(printk(ST_DEB_MSG "%s: Can't read medium partition page.\n",
3234                            name));
3235		result = (-EIO);
3236	} else {
3237		result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3238					      PP_OFF_NBR_ADD_PARTS] + 1;
3239                DEBC(printk(ST_DEB_MSG "%s: Number of partitions %d.\n", name, result));
3240	}
3241
3242	return result;
3243}
3244
3245
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3246/* Partition the tape into two partitions if size > 0 or one partition if
3247   size == 0.
3248
3249   The block descriptors are read and written because Sony SDT-7000 does not
3250   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3251
3252   My HP C1533A drive returns only one partition size field. This is used to
3253   set the size of partition 1. There is no size field for the default partition.
3254   Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3255   used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3256   The following algorithm is used to accommodate both drives: if the number of
3257   partition size fields is greater than the maximum number of additional partitions
3258   in the mode page, the second field is used. Otherwise the first field is used.
3259
3260   For Seagate DDS drives the page length must be 8 when no partitions is defined
3261   and 10 when 1 partition is defined (information from Eric Lee Green). This is
3262   is acceptable also to some other old drives and enforced if the first partition
3263   size field is used for the first additional partition size.
 
 
3264 */
3265static int partition_tape(struct scsi_tape *STp, int size)
3266{
3267	char *name = tape_name(STp);
3268	int result;
 
 
3269	int pgo, psd_cnt, psdo;
 
3270	unsigned char *bp;
3271
3272	result = read_mode_page(STp, PART_PAGE, 0);
3273	if (result) {
3274		DEBC(printk(ST_DEB_MSG "%s: Can't read partition mode page.\n", name));
3275		return result;
3276	}
 
 
 
 
 
 
3277	/* The mode page is in the buffer. Let's modify it and write it. */
3278	bp = (STp->buffer)->b_data;
3279	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3280	DEBC(printk(ST_DEB_MSG "%s: Partition page length is %d bytes.\n",
3281		    name, bp[pgo + MP_OFF_PAGE_LENGTH] + 2));
3282
3283	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3284	psdo = pgo + PART_PAGE_FIXED_LENGTH;
3285	if (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS]) {
3286		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest of the tape */
 
 
 
 
 
3287		psdo += 2;
3288	}
3289	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3290
3291	DEBC(printk("%s: psd_cnt %d, max.parts %d, nbr_parts %d\n", name,
3292		    psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3293		    bp[pgo + PP_OFF_NBR_ADD_PARTS]));
3294
3295	if (size <= 0) {
3296		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3297		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3298		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3299                DEBC(printk(ST_DEB_MSG "%s: Formatting tape with one partition.\n",
3300                            name));
3301	} else {
3302		bp[psdo] = (size >> 8) & 0xff;
3303		bp[psdo + 1] = size & 0xff;
 
 
3304		bp[pgo + 3] = 1;
3305		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3306		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3307                DEBC(printk(ST_DEB_MSG
3308                            "%s: Formatting tape with two partitions (1 = %d MB).\n",
3309                            name, size));
3310	}
3311	bp[pgo + PP_OFF_PART_UNITS] = 0;
3312	bp[pgo + PP_OFF_RESERVED] = 0;
3313	bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | PP_MSK_PSUM_MB;
 
 
 
 
 
 
 
3314
3315	result = write_mode_page(STp, PART_PAGE, 1);
 
 
 
 
3316	if (result) {
3317		printk(KERN_INFO "%s: Partitioning of tape failed.\n", name);
3318		result = (-EIO);
3319	}
3320
 
3321	return result;
3322}
3323
3324
3325
3326/* The ioctl command */
3327static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3328{
3329	int i, cmd_nr, cmd_type, bt;
3330	int retval = 0;
3331	unsigned int blk;
3332	struct scsi_tape *STp = file->private_data;
3333	struct st_modedef *STm;
3334	struct st_partstat *STps;
3335	char *name = tape_name(STp);
3336	void __user *p = (void __user *)arg;
3337
3338	if (mutex_lock_interruptible(&STp->lock))
3339		return -ERESTARTSYS;
3340
3341        DEB(
3342	if (debugging && !STp->in_use) {
3343		printk(ST_DEB_MSG "%s: Incorrect device.\n", name);
3344		retval = (-EIO);
3345		goto out;
3346	} ) /* end DEB */
3347
3348	STm = &(STp->modes[STp->current_mode]);
3349	STps = &(STp->ps[STp->partition]);
3350
3351	/*
3352	 * If we are in the middle of error recovery, don't let anyone
3353	 * else try and use this device.  Also, if error recovery fails, it
3354	 * may try and take the device offline, in which case all further
3355	 * access to the device is prohibited.
3356	 */
3357	retval = scsi_nonblockable_ioctl(STp->device, cmd_in, p,
3358					file->f_flags & O_NDELAY);
3359	if (!scsi_block_when_processing_errors(STp->device) || retval != -ENODEV)
3360		goto out;
3361	retval = 0;
3362
3363	cmd_type = _IOC_TYPE(cmd_in);
3364	cmd_nr = _IOC_NR(cmd_in);
3365
3366	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3367		struct mtop mtc;
3368
3369		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3370			retval = (-EINVAL);
3371			goto out;
3372		}
3373
3374		i = copy_from_user(&mtc, p, sizeof(struct mtop));
3375		if (i) {
3376			retval = (-EFAULT);
3377			goto out;
3378		}
3379
3380		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3381			printk(KERN_WARNING
3382                               "%s: MTSETDRVBUFFER only allowed for root.\n", name);
3383			retval = (-EPERM);
3384			goto out;
3385		}
3386		if (!STm->defined &&
3387		    (mtc.mt_op != MTSETDRVBUFFER &&
3388		     (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3389			retval = (-ENXIO);
3390			goto out;
3391		}
3392
3393		if (!STp->pos_unknown) {
3394
3395			if (STps->eof == ST_FM_HIT) {
3396				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3397                                    mtc.mt_op == MTEOM) {
3398					mtc.mt_count -= 1;
3399					if (STps->drv_file >= 0)
3400						STps->drv_file += 1;
3401				} else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3402					mtc.mt_count += 1;
3403					if (STps->drv_file >= 0)
3404						STps->drv_file += 1;
3405				}
3406			}
3407
3408			if (mtc.mt_op == MTSEEK) {
3409				/* Old position must be restored if partition will be
3410                                   changed */
3411				i = !STp->can_partitions ||
3412				    (STp->new_partition != STp->partition);
3413			} else {
3414				i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3415				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3416				    mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3417				    mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3418				    mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3419				    mtc.mt_op == MTCOMPRESSION;
3420			}
3421			i = flush_buffer(STp, i);
3422			if (i < 0) {
3423				retval = i;
3424				goto out;
3425			}
3426			if (STps->rw == ST_WRITING &&
3427			    (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3428			     mtc.mt_op == MTSEEK ||
3429			     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3430				i = st_int_ioctl(STp, MTWEOF, 1);
3431				if (i < 0) {
3432					retval = i;
3433					goto out;
3434				}
3435				if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3436					mtc.mt_count++;
3437				STps->rw = ST_IDLE;
3438			     }
3439
3440		} else {
3441			/*
3442			 * If there was a bus reset, block further access
3443			 * to this device.  If the user wants to rewind the tape,
3444			 * then reset the flag and allow access again.
3445			 */
3446			if (mtc.mt_op != MTREW &&
3447			    mtc.mt_op != MTOFFL &&
3448			    mtc.mt_op != MTRETEN &&
3449			    mtc.mt_op != MTERASE &&
3450			    mtc.mt_op != MTSEEK &&
3451			    mtc.mt_op != MTEOM) {
3452				retval = (-EIO);
3453				goto out;
3454			}
3455			reset_state(STp);
3456			/* remove this when the midlevel properly clears was_reset */
3457			STp->device->was_reset = 0;
3458		}
3459
3460		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3461		    mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3462		    mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3463			STps->rw = ST_IDLE;	/* Prevent automatic WEOF and fsf */
3464
3465		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3466			do_door_lock(STp, 0);	/* Ignore result! */
3467
3468		if (mtc.mt_op == MTSETDRVBUFFER &&
3469		    (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3470			retval = st_set_options(STp, mtc.mt_count);
3471			goto out;
3472		}
3473
3474		if (mtc.mt_op == MTSETPART) {
3475			if (!STp->can_partitions ||
3476			    mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3477				retval = (-EINVAL);
3478				goto out;
3479			}
3480			if (mtc.mt_count >= STp->nbr_partitions &&
3481			    (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3482				retval = (-EIO);
3483				goto out;
3484			}
3485			if (mtc.mt_count >= STp->nbr_partitions) {
3486				retval = (-EINVAL);
3487				goto out;
3488			}
3489			STp->new_partition = mtc.mt_count;
3490			retval = 0;
3491			goto out;
3492		}
3493
3494		if (mtc.mt_op == MTMKPART) {
3495			if (!STp->can_partitions) {
3496				retval = (-EINVAL);
3497				goto out;
3498			}
3499			if ((i = st_int_ioctl(STp, MTREW, 0)) < 0 ||
3500			    (i = partition_tape(STp, mtc.mt_count)) < 0) {
 
 
 
 
 
3501				retval = i;
3502				goto out;
3503			}
3504			for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3505				STp->ps[i].rw = ST_IDLE;
3506				STp->ps[i].at_sm = 0;
3507				STp->ps[i].last_block_valid = 0;
3508			}
3509			STp->partition = STp->new_partition = 0;
3510			STp->nbr_partitions = 1;	/* Bad guess ?-) */
3511			STps->drv_block = STps->drv_file = 0;
3512			retval = 0;
3513			goto out;
3514		}
3515
3516		if (mtc.mt_op == MTSEEK) {
3517			i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3518			if (!STp->can_partitions)
3519				STp->ps[0].rw = ST_IDLE;
3520			retval = i;
3521			goto out;
3522		}
3523
3524		if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3525			retval = do_load_unload(STp, file, 0);
3526			goto out;
3527		}
3528
3529		if (mtc.mt_op == MTLOAD) {
3530			retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3531			goto out;
3532		}
3533
3534		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3535			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3536			goto out;
3537		}
3538
3539		if (STp->can_partitions && STp->ready == ST_READY &&
3540		    (i = switch_partition(STp)) < 0) {
3541			retval = i;
3542			goto out;
3543		}
3544
3545		if (mtc.mt_op == MTCOMPRESSION)
3546			retval = st_compression(STp, (mtc.mt_count & 1));
3547		else
3548			retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3549		goto out;
3550	}
3551	if (!STm->defined) {
3552		retval = (-ENXIO);
3553		goto out;
3554	}
3555
3556	if ((i = flush_buffer(STp, 0)) < 0) {
3557		retval = i;
3558		goto out;
3559	}
3560	if (STp->can_partitions &&
3561	    (i = switch_partition(STp)) < 0) {
3562		retval = i;
3563		goto out;
3564	}
3565
3566	if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
3567		struct mtget mt_status;
3568
3569		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3570			 retval = (-EINVAL);
3571			 goto out;
3572		}
3573
3574		mt_status.mt_type = STp->tape_type;
3575		mt_status.mt_dsreg =
3576		    ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3577		    ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3578		mt_status.mt_blkno = STps->drv_block;
3579		mt_status.mt_fileno = STps->drv_file;
3580		if (STp->block_size != 0) {
3581			if (STps->rw == ST_WRITING)
3582				mt_status.mt_blkno +=
3583				    (STp->buffer)->buffer_bytes / STp->block_size;
3584			else if (STps->rw == ST_READING)
3585				mt_status.mt_blkno -=
3586                                        ((STp->buffer)->buffer_bytes +
3587                                         STp->block_size - 1) / STp->block_size;
3588		}
3589
3590		mt_status.mt_gstat = 0;
3591		if (STp->drv_write_prot)
3592			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3593		if (mt_status.mt_blkno == 0) {
3594			if (mt_status.mt_fileno == 0)
3595				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3596			else
3597				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3598		}
3599		mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3600		mt_status.mt_resid = STp->partition;
3601		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3602			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3603		else if (STps->eof >= ST_EOM_OK)
3604			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3605		if (STp->density == 1)
3606			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3607		else if (STp->density == 2)
3608			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3609		else if (STp->density == 3)
3610			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3611		if (STp->ready == ST_READY)
3612			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3613		if (STp->ready == ST_NO_TAPE)
3614			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3615		if (STps->at_sm)
3616			mt_status.mt_gstat |= GMT_SM(0xffffffff);
3617		if (STm->do_async_writes ||
3618                    (STm->do_buffer_writes && STp->block_size != 0) ||
3619		    STp->drv_buffer != 0)
3620			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3621		if (STp->cleaning_req)
3622			mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3623
3624		i = copy_to_user(p, &mt_status, sizeof(struct mtget));
3625		if (i) {
3626			retval = (-EFAULT);
3627			goto out;
3628		}
3629
3630		STp->recover_reg = 0;		/* Clear after read */
3631		retval = 0;
3632		goto out;
3633	}			/* End of MTIOCGET */
3634	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3635		struct mtpos mt_pos;
3636		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3637			 retval = (-EINVAL);
3638			 goto out;
3639		}
3640		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3641			retval = i;
3642			goto out;
3643		}
3644		mt_pos.mt_blkno = blk;
3645		i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
3646		if (i)
3647			retval = (-EFAULT);
3648		goto out;
3649	}
3650	mutex_unlock(&STp->lock);
3651	switch (cmd_in) {
3652		case SCSI_IOCTL_GET_IDLUN:
3653		case SCSI_IOCTL_GET_BUS_NUMBER:
3654			break;
3655		default:
3656			if ((cmd_in == SG_IO ||
3657			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3658			     cmd_in == CDROM_SEND_PACKET) &&
3659			    !capable(CAP_SYS_RAWIO))
3660				i = -EPERM;
3661			else
3662				i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3663						   file->f_mode, cmd_in, p);
3664			if (i != -ENOTTY)
3665				return i;
3666			break;
3667	}
3668	retval = scsi_ioctl(STp->device, cmd_in, p);
3669	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
3670		STp->rew_at_close = 0;
3671		STp->ready = ST_NO_TAPE;
3672	}
3673	return retval;
3674
3675 out:
3676	mutex_unlock(&STp->lock);
3677	return retval;
3678}
3679
3680#ifdef CONFIG_COMPAT
3681static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3682{
3683	struct scsi_tape *STp = file->private_data;
3684	struct scsi_device *sdev = STp->device;
3685	int ret = -ENOIOCTLCMD;
3686	if (sdev->host->hostt->compat_ioctl) { 
3687
3688		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
3689
3690	}
3691	return ret;
3692}
3693#endif
3694
3695
3696
3697/* Try to allocate a new tape buffer. Calling function must not hold
3698   dev_arr_lock. */
3699static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
3700{
3701	struct st_buffer *tb;
3702
3703	tb = kzalloc(sizeof(struct st_buffer), GFP_ATOMIC);
3704	if (!tb) {
3705		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3706		return NULL;
3707	}
3708	tb->frp_segs = 0;
3709	tb->use_sg = max_sg;
3710	tb->dma = need_dma;
3711	tb->buffer_size = 0;
3712
3713	tb->reserved_pages = kzalloc(max_sg * sizeof(struct page *),
3714				     GFP_ATOMIC);
3715	if (!tb->reserved_pages) {
3716		kfree(tb);
3717		return NULL;
3718	}
3719
3720	return tb;
3721}
3722
3723
3724/* Try to allocate enough space in the tape buffer */
3725#define ST_MAX_ORDER 6
3726
3727static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
3728{
3729	int segs, max_segs, b_size, order, got;
3730	gfp_t priority;
3731
3732	if (new_size <= STbuffer->buffer_size)
3733		return 1;
3734
3735	if (STbuffer->buffer_size <= PAGE_SIZE)
3736		normalize_buffer(STbuffer);  /* Avoid extra segment */
3737
3738	max_segs = STbuffer->use_sg;
3739
3740	priority = GFP_KERNEL | __GFP_NOWARN;
3741	if (need_dma)
3742		priority |= GFP_DMA;
3743
3744	if (STbuffer->cleared)
3745		priority |= __GFP_ZERO;
3746
3747	if (STbuffer->frp_segs) {
3748		order = STbuffer->reserved_page_order;
3749		b_size = PAGE_SIZE << order;
3750	} else {
3751		for (b_size = PAGE_SIZE, order = 0;
3752		     order < ST_MAX_ORDER &&
3753			     max_segs * (PAGE_SIZE << order) < new_size;
3754		     order++, b_size *= 2)
3755			;  /* empty */
3756		STbuffer->reserved_page_order = order;
3757	}
3758	if (max_segs * (PAGE_SIZE << order) < new_size) {
3759		if (order == ST_MAX_ORDER)
3760			return 0;
3761		normalize_buffer(STbuffer);
3762		return enlarge_buffer(STbuffer, new_size, need_dma);
3763	}
3764
3765	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3766	     segs < max_segs && got < new_size;) {
3767		struct page *page;
3768
3769		page = alloc_pages(priority, order);
3770		if (!page) {
3771			DEB(STbuffer->buffer_size = got);
3772			normalize_buffer(STbuffer);
3773			return 0;
3774		}
3775
3776		STbuffer->frp_segs += 1;
3777		got += b_size;
3778		STbuffer->buffer_size = got;
3779		STbuffer->reserved_pages[segs] = page;
3780		segs++;
3781	}
3782	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3783
3784	return 1;
3785}
3786
3787
3788/* Make sure that no data from previous user is in the internal buffer */
3789static void clear_buffer(struct st_buffer * st_bp)
3790{
3791	int i;
3792
3793	for (i=0; i < st_bp->frp_segs; i++)
3794		memset(page_address(st_bp->reserved_pages[i]), 0,
3795		       PAGE_SIZE << st_bp->reserved_page_order);
3796	st_bp->cleared = 1;
3797}
3798
3799
3800/* Release the extra buffer */
3801static void normalize_buffer(struct st_buffer * STbuffer)
3802{
3803	int i, order = STbuffer->reserved_page_order;
3804
3805	for (i = 0; i < STbuffer->frp_segs; i++) {
3806		__free_pages(STbuffer->reserved_pages[i], order);
3807		STbuffer->buffer_size -= (PAGE_SIZE << order);
3808	}
3809	STbuffer->frp_segs = 0;
3810	STbuffer->sg_segs = 0;
3811	STbuffer->reserved_page_order = 0;
3812	STbuffer->map_data.offset = 0;
3813}
3814
3815
3816/* Move data from the user buffer to the tape buffer. Returns zero (success) or
3817   negative error code. */
3818static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3819{
3820	int i, cnt, res, offset;
3821	int length = PAGE_SIZE << st_bp->reserved_page_order;
3822
3823	for (i = 0, offset = st_bp->buffer_bytes;
3824	     i < st_bp->frp_segs && offset >= length; i++)
3825		offset -= length;
3826	if (i == st_bp->frp_segs) {	/* Should never happen */
3827		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
3828		return (-EIO);
3829	}
3830	for (; i < st_bp->frp_segs && do_count > 0; i++) {
3831		struct page *page = st_bp->reserved_pages[i];
3832		cnt = length - offset < do_count ? length - offset : do_count;
3833		res = copy_from_user(page_address(page) + offset, ubp, cnt);
3834		if (res)
3835			return (-EFAULT);
3836		do_count -= cnt;
3837		st_bp->buffer_bytes += cnt;
3838		ubp += cnt;
3839		offset = 0;
3840	}
3841	if (do_count) /* Should never happen */
3842		return (-EIO);
3843
3844	return 0;
3845}
3846
3847
3848/* Move data from the tape buffer to the user buffer. Returns zero (success) or
3849   negative error code. */
3850static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
3851{
3852	int i, cnt, res, offset;
3853	int length = PAGE_SIZE << st_bp->reserved_page_order;
3854
3855	for (i = 0, offset = st_bp->read_pointer;
3856	     i < st_bp->frp_segs && offset >= length; i++)
3857		offset -= length;
3858	if (i == st_bp->frp_segs) {	/* Should never happen */
3859		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
3860		return (-EIO);
3861	}
3862	for (; i < st_bp->frp_segs && do_count > 0; i++) {
3863		struct page *page = st_bp->reserved_pages[i];
3864		cnt = length - offset < do_count ? length - offset : do_count;
3865		res = copy_to_user(ubp, page_address(page) + offset, cnt);
3866		if (res)
3867			return (-EFAULT);
3868		do_count -= cnt;
3869		st_bp->buffer_bytes -= cnt;
3870		st_bp->read_pointer += cnt;
3871		ubp += cnt;
3872		offset = 0;
3873	}
3874	if (do_count) /* Should never happen */
3875		return (-EIO);
3876
3877	return 0;
3878}
3879
3880
3881/* Move data towards start of buffer */
3882static void move_buffer_data(struct st_buffer * st_bp, int offset)
3883{
3884	int src_seg, dst_seg, src_offset = 0, dst_offset;
3885	int count, total;
3886	int length = PAGE_SIZE << st_bp->reserved_page_order;
3887
3888	if (offset == 0)
3889		return;
3890
3891	total=st_bp->buffer_bytes - offset;
3892	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
3893		src_offset = offset;
3894		if (src_offset < length)
3895			break;
3896		offset -= length;
3897	}
3898
3899	st_bp->buffer_bytes = st_bp->read_pointer = total;
3900	for (dst_seg=dst_offset=0; total > 0; ) {
3901		struct page *dpage = st_bp->reserved_pages[dst_seg];
3902		struct page *spage = st_bp->reserved_pages[src_seg];
3903
3904		count = min(length - dst_offset, length - src_offset);
3905		memmove(page_address(dpage) + dst_offset,
3906			page_address(spage) + src_offset, count);
3907		src_offset += count;
3908		if (src_offset >= length) {
3909			src_seg++;
3910			src_offset = 0;
3911		}
3912		dst_offset += count;
3913		if (dst_offset >= length) {
3914			dst_seg++;
3915			dst_offset = 0;
3916		}
3917		total -= count;
3918	}
3919}
3920
3921/* Validate the options from command line or module parameters */
3922static void validate_options(void)
3923{
3924	if (buffer_kbs > 0)
3925		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
3926	if (max_sg_segs >= ST_FIRST_SG)
3927		st_max_sg_segs = max_sg_segs;
3928}
3929
3930#ifndef MODULE
3931/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
3932 */
3933static int __init st_setup(char *str)
3934{
3935	int i, len, ints[5];
3936	char *stp;
3937
3938	stp = get_options(str, ARRAY_SIZE(ints), ints);
3939
3940	if (ints[0] > 0) {
3941		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
3942			if (parms[i].val)
3943				*parms[i].val = ints[i + 1];
3944	} else {
3945		while (stp != NULL) {
3946			for (i = 0; i < ARRAY_SIZE(parms); i++) {
3947				len = strlen(parms[i].name);
3948				if (!strncmp(stp, parms[i].name, len) &&
3949				    (*(stp + len) == ':' || *(stp + len) == '=')) {
3950					if (parms[i].val)
3951						*parms[i].val =
3952							simple_strtoul(stp + len + 1, NULL, 0);
3953					else
3954						printk(KERN_WARNING "st: Obsolete parameter %s\n",
3955						       parms[i].name);
3956					break;
3957				}
3958			}
3959			if (i >= ARRAY_SIZE(parms))
3960				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
3961					stp);
3962			stp = strchr(stp, ',');
3963			if (stp)
3964				stp++;
3965		}
3966	}
3967
3968	validate_options();
3969
3970	return 1;
3971}
3972
3973__setup("st=", st_setup);
3974
3975#endif
3976
3977static const struct file_operations st_fops =
3978{
3979	.owner =	THIS_MODULE,
3980	.read =		st_read,
3981	.write =	st_write,
3982	.unlocked_ioctl = st_ioctl,
3983#ifdef CONFIG_COMPAT
3984	.compat_ioctl = st_compat_ioctl,
3985#endif
3986	.open =		st_open,
3987	.flush =	st_flush,
3988	.release =	st_release,
3989	.llseek =	noop_llseek,
3990};
3991
3992static int create_one_cdev(struct scsi_tape *tape, int mode, int rew)
3993{
3994	int i, error;
3995	dev_t cdev_devno;
3996	struct cdev *cdev;
3997	struct device *dev;
3998	struct st_modedef *STm = &(tape->modes[mode]);
3999	char name[10];
4000	int dev_num = tape->index;
4001
4002	cdev_devno = MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, rew));
4003
4004	cdev = cdev_alloc();
4005	if (!cdev) {
4006		pr_err("st%d: out of memory. Device not attached.\n", dev_num);
4007		error = -ENOMEM;
4008		goto out;
4009	}
4010	cdev->owner = THIS_MODULE;
4011	cdev->ops = &st_fops;
 
4012
4013	error = cdev_add(cdev, cdev_devno, 1);
4014	if (error) {
4015		pr_err("st%d: Can't add %s-rewind mode %d\n", dev_num,
4016		       rew ? "non" : "auto", mode);
4017		pr_err("st%d: Device not attached.\n", dev_num);
4018		goto out_free;
4019	}
4020	STm->cdevs[rew] = cdev;
4021
4022	i = mode << (4 - ST_NBR_MODE_BITS);
4023	snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4024		 tape->disk->disk_name, st_formats[i]);
4025
4026	dev = device_create(&st_sysfs_class, &tape->device->sdev_gendev,
4027			    cdev_devno, &tape->modes[mode], "%s", name);
4028	if (IS_ERR(dev)) {
4029		pr_err("st%d: device_create failed\n", dev_num);
4030		error = PTR_ERR(dev);
4031		goto out_free;
4032	}
4033
4034	STm->devs[rew] = dev;
4035
4036	return 0;
4037out_free:
4038	cdev_del(STm->cdevs[rew]);
 
4039	STm->cdevs[rew] = NULL;
4040out:
4041	return error;
4042}
4043
4044static int create_cdevs(struct scsi_tape *tape)
4045{
4046	int mode, error;
4047	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4048		error = create_one_cdev(tape, mode, 0);
4049		if (error)
4050			return error;
4051		error = create_one_cdev(tape, mode, 1);
4052		if (error)
4053			return error;
4054	}
4055
4056	return sysfs_create_link(&tape->device->sdev_gendev.kobj,
4057				 &tape->modes[0].devs[0]->kobj, "tape");
4058}
4059
4060static void remove_cdevs(struct scsi_tape *tape)
4061{
4062	int mode, rew;
4063	sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
4064	for (mode = 0; mode < ST_NBR_MODES; mode++) {
4065		struct st_modedef *STm = &(tape->modes[mode]);
4066		for (rew = 0; rew < 2; rew++) {
4067			if (STm->cdevs[rew])
4068				cdev_del(STm->cdevs[rew]);
4069			if (STm->devs[rew])
4070				device_unregister(STm->devs[rew]);
4071		}
4072	}
4073}
4074
4075static int st_probe(struct device *dev)
4076{
4077	struct scsi_device *SDp = to_scsi_device(dev);
4078	struct gendisk *disk = NULL;
4079	struct scsi_tape *tpnt = NULL;
4080	struct st_modedef *STm;
4081	struct st_partstat *STps;
4082	struct st_buffer *buffer;
4083	int i, error;
4084	char *stp;
4085
4086	if (SDp->type != TYPE_TAPE)
4087		return -ENODEV;
4088	if ((stp = st_incompatible(SDp))) {
4089		sdev_printk(KERN_INFO, SDp, "Found incompatible tape\n");
4090		printk(KERN_INFO "st: The suggested driver is %s.\n", stp);
 
4091		return -ENODEV;
4092	}
4093
 
4094	i = queue_max_segments(SDp->request_queue);
4095	if (st_max_sg_segs < i)
4096		i = st_max_sg_segs;
4097	buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
4098	if (buffer == NULL) {
4099		printk(KERN_ERR
4100		       "st: Can't allocate new tape buffer. Device not attached.\n");
 
4101		goto out;
4102	}
4103
4104	disk = alloc_disk(1);
4105	if (!disk) {
4106		printk(KERN_ERR "st: out of memory. Device not attached.\n");
 
4107		goto out_buffer_free;
4108	}
4109
4110	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
4111	if (tpnt == NULL) {
4112		printk(KERN_ERR "st: Can't allocate device descriptor.\n");
 
4113		goto out_put_disk;
4114	}
4115	kref_init(&tpnt->kref);
4116	tpnt->disk = disk;
4117	disk->private_data = &tpnt->driver;
4118	disk->queue = SDp->request_queue;
4119	/* SCSI tape doesn't register this gendisk via add_disk().  Manually
4120	 * take queue reference that release_disk() expects. */
4121	if (!blk_get_queue(disk->queue))
4122		goto out_put_disk;
 
4123	tpnt->driver = &st_template;
4124
4125	tpnt->device = SDp;
4126	if (SDp->scsi_level <= 2)
4127		tpnt->tape_type = MT_ISSCSI1;
4128	else
4129		tpnt->tape_type = MT_ISSCSI2;
4130
4131	tpnt->buffer = buffer;
4132	tpnt->buffer->last_SRpnt = NULL;
4133
4134	tpnt->inited = 0;
4135	tpnt->dirty = 0;
4136	tpnt->in_use = 0;
4137	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
4138	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4139	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4140	tpnt->density = 0;
4141	tpnt->do_auto_lock = ST_AUTO_LOCK;
4142	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4143	tpnt->can_partitions = 0;
4144	tpnt->two_fm = ST_TWO_FM;
4145	tpnt->fast_mteom = ST_FAST_MTEOM;
4146	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4147	tpnt->sili = ST_SILI;
4148	tpnt->immediate = ST_NOWAIT;
4149	tpnt->immediate_filemark = 0;
4150	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4151	tpnt->partition = 0;
4152	tpnt->new_partition = 0;
4153	tpnt->nbr_partitions = 0;
4154	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4155	tpnt->long_timeout = ST_LONG_TIMEOUT;
4156	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
4157
4158	for (i = 0; i < ST_NBR_MODES; i++) {
4159		STm = &(tpnt->modes[i]);
4160		STm->defined = 0;
4161		STm->sysv = ST_SYSV;
4162		STm->defaults_for_writes = 0;
4163		STm->do_async_writes = ST_ASYNC_WRITES;
4164		STm->do_buffer_writes = ST_BUFFER_WRITES;
4165		STm->do_read_ahead = ST_READ_AHEAD;
4166		STm->default_compression = ST_DONT_TOUCH;
4167		STm->default_blksize = (-1);	/* No forced size */
4168		STm->default_density = (-1);	/* No forced density */
4169		STm->tape = tpnt;
4170	}
4171
4172	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4173		STps = &(tpnt->ps[i]);
4174		STps->rw = ST_IDLE;
4175		STps->eof = ST_NOEOF;
4176		STps->at_sm = 0;
4177		STps->last_block_valid = 0;
4178		STps->drv_block = (-1);
4179		STps->drv_file = (-1);
4180	}
4181
4182	tpnt->current_mode = 0;
4183	tpnt->modes[0].defined = 1;
4184
4185	tpnt->density_changed = tpnt->compression_changed =
4186	    tpnt->blksize_changed = 0;
4187	mutex_init(&tpnt->lock);
4188
4189	idr_preload(GFP_KERNEL);
4190	spin_lock(&st_index_lock);
4191	error = idr_alloc(&st_index_idr, tpnt, 0, ST_MAX_TAPES + 1, GFP_NOWAIT);
4192	spin_unlock(&st_index_lock);
4193	idr_preload_end();
4194	if (error < 0) {
4195		pr_warn("st: idr allocation failed: %d\n", error);
4196		goto out_put_queue;
4197	}
4198	tpnt->index = error;
4199	sprintf(disk->disk_name, "st%d", tpnt->index);
 
 
 
 
 
 
4200
4201	dev_set_drvdata(dev, tpnt);
4202
4203
4204	error = create_cdevs(tpnt);
4205	if (error)
4206		goto out_remove_devs;
4207	scsi_autopm_put_device(SDp);
4208
4209	sdev_printk(KERN_NOTICE, SDp,
4210		    "Attached scsi tape %s\n", tape_name(tpnt));
4211	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4212		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4213		    queue_dma_alignment(SDp->request_queue) + 1);
4214
4215	return 0;
4216
4217out_remove_devs:
4218	remove_cdevs(tpnt);
 
 
4219	spin_lock(&st_index_lock);
4220	idr_remove(&st_index_idr, tpnt->index);
4221	spin_unlock(&st_index_lock);
4222out_put_queue:
4223	blk_put_queue(disk->queue);
4224out_put_disk:
4225	put_disk(disk);
4226	kfree(tpnt);
4227out_buffer_free:
4228	kfree(buffer);
4229out:
 
4230	return -ENODEV;
4231};
4232
4233
4234static int st_remove(struct device *dev)
4235{
4236	struct scsi_tape *tpnt = dev_get_drvdata(dev);
4237	int index = tpnt->index;
4238
4239	scsi_autopm_get_device(to_scsi_device(dev));
4240	remove_cdevs(tpnt);
4241
4242	mutex_lock(&st_ref_mutex);
4243	kref_put(&tpnt->kref, scsi_tape_release);
4244	mutex_unlock(&st_ref_mutex);
4245	spin_lock(&st_index_lock);
4246	idr_remove(&st_index_idr, index);
4247	spin_unlock(&st_index_lock);
4248	return 0;
4249}
4250
4251/**
4252 *      scsi_tape_release - Called to free the Scsi_Tape structure
4253 *      @kref: pointer to embedded kref
4254 *
4255 *      st_ref_mutex must be held entering this routine.  Because it is
4256 *      called on last put, you should always use the scsi_tape_get()
4257 *      scsi_tape_put() helpers which manipulate the semaphore directly
4258 *      and never do a direct kref_put().
4259 **/
4260static void scsi_tape_release(struct kref *kref)
4261{
4262	struct scsi_tape *tpnt = to_scsi_tape(kref);
4263	struct gendisk *disk = tpnt->disk;
4264
4265	tpnt->device = NULL;
4266
4267	if (tpnt->buffer) {
4268		normalize_buffer(tpnt->buffer);
4269		kfree(tpnt->buffer->reserved_pages);
4270		kfree(tpnt->buffer);
4271	}
4272
4273	disk->private_data = NULL;
4274	put_disk(disk);
 
4275	kfree(tpnt);
4276	return;
4277}
4278
4279static struct class st_sysfs_class = {
4280	.name = "scsi_tape",
4281	.dev_groups = st_dev_groups,
4282};
4283
4284static int __init init_st(void)
4285{
4286	int err;
4287
4288	validate_options();
4289
4290	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4291		verstr, st_fixed_buffer_size, st_max_sg_segs);
4292
 
 
 
 
 
 
4293	err = class_register(&st_sysfs_class);
4294	if (err) {
4295		pr_err("Unable register sysfs class for SCSI tapes\n");
4296		return err;
4297	}
4298
4299	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4300				     ST_MAX_TAPE_ENTRIES, "st");
4301	if (err) {
4302		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4303		       SCSI_TAPE_MAJOR);
4304		goto err_class;
4305	}
4306
4307	err = scsi_register_driver(&st_template.gendrv);
4308	if (err)
4309		goto err_chrdev;
4310
4311	err = do_create_sysfs_files();
4312	if (err)
4313		goto err_scsidrv;
4314
4315	return 0;
4316
4317err_scsidrv:
4318	scsi_unregister_driver(&st_template.gendrv);
4319err_chrdev:
4320	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4321				 ST_MAX_TAPE_ENTRIES);
4322err_class:
4323	class_unregister(&st_sysfs_class);
4324	return err;
4325}
4326
4327static void __exit exit_st(void)
4328{
4329	do_remove_sysfs_files();
4330	scsi_unregister_driver(&st_template.gendrv);
4331	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4332				 ST_MAX_TAPE_ENTRIES);
4333	class_unregister(&st_sysfs_class);
 
4334	printk(KERN_INFO "st: Unloaded.\n");
4335}
4336
4337module_init(init_st);
4338module_exit(exit_st);
4339
4340
4341/* The sysfs driver interface. Read-only at the moment */
4342static ssize_t st_try_direct_io_show(struct device_driver *ddp, char *buf)
4343{
4344	return snprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4345}
4346static DRIVER_ATTR(try_direct_io, S_IRUGO, st_try_direct_io_show, NULL);
4347
4348static ssize_t st_fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4349{
4350	return snprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4351}
4352static DRIVER_ATTR(fixed_buffer_size, S_IRUGO, st_fixed_buffer_size_show, NULL);
4353
4354static ssize_t st_max_sg_segs_show(struct device_driver *ddp, char *buf)
4355{
4356	return snprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4357}
4358static DRIVER_ATTR(max_sg_segs, S_IRUGO, st_max_sg_segs_show, NULL);
4359
4360static ssize_t st_version_show(struct device_driver *ddd, char *buf)
4361{
4362	return snprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4363}
4364static DRIVER_ATTR(version, S_IRUGO, st_version_show, NULL);
4365
4366static int do_create_sysfs_files(void)
 
 
4367{
4368	struct device_driver *sysfs = &st_template.gendrv;
4369	int err;
4370
4371	err = driver_create_file(sysfs, &driver_attr_try_direct_io);
4372	if (err)
4373		return err;
4374	err = driver_create_file(sysfs, &driver_attr_fixed_buffer_size);
4375	if (err)
4376		goto err_try_direct_io;
4377	err = driver_create_file(sysfs, &driver_attr_max_sg_segs);
4378	if (err)
4379		goto err_attr_fixed_buf;
4380	err = driver_create_file(sysfs, &driver_attr_version);
4381	if (err)
4382		goto err_attr_max_sg;
4383
4384	return 0;
4385
4386err_attr_max_sg:
4387	driver_remove_file(sysfs, &driver_attr_max_sg_segs);
4388err_attr_fixed_buf:
4389	driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
4390err_try_direct_io:
4391	driver_remove_file(sysfs, &driver_attr_try_direct_io);
4392	return err;
4393}
4394
4395static void do_remove_sysfs_files(void)
4396{
4397	struct device_driver *sysfs = &st_template.gendrv;
 
 
 
4398
4399	driver_remove_file(sysfs, &driver_attr_version);
4400	driver_remove_file(sysfs, &driver_attr_max_sg_segs);
4401	driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
4402	driver_remove_file(sysfs, &driver_attr_try_direct_io);
4403}
 
 
 
 
 
 
4404
4405/* The sysfs simple class interface */
4406static ssize_t
4407defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4408{
4409	struct st_modedef *STm = dev_get_drvdata(dev);
4410	ssize_t l = 0;
4411
4412	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4413	return l;
4414}
4415static DEVICE_ATTR_RO(defined);
4416
4417static ssize_t
4418default_blksize_show(struct device *dev, struct device_attribute *attr,
4419		     char *buf)
4420{
4421	struct st_modedef *STm = dev_get_drvdata(dev);
4422	ssize_t l = 0;
4423
4424	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4425	return l;
4426}
4427static DEVICE_ATTR_RO(default_blksize);
4428
4429static ssize_t
4430default_density_show(struct device *dev, struct device_attribute *attr,
4431		     char *buf)
4432{
4433	struct st_modedef *STm = dev_get_drvdata(dev);
4434	ssize_t l = 0;
4435	char *fmt;
4436
4437	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4438	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4439	return l;
4440}
4441static DEVICE_ATTR_RO(default_density);
4442
4443static ssize_t
4444default_compression_show(struct device *dev, struct device_attribute *attr,
4445			 char *buf)
4446{
4447	struct st_modedef *STm = dev_get_drvdata(dev);
4448	ssize_t l = 0;
4449
4450	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4451	return l;
4452}
4453static DEVICE_ATTR_RO(default_compression);
4454
4455static ssize_t
4456options_show(struct device *dev, struct device_attribute *attr, char *buf)
4457{
4458	struct st_modedef *STm = dev_get_drvdata(dev);
4459	struct scsi_tape *STp = STm->tape;
4460	int options;
4461	ssize_t l = 0;
4462
4463	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4464	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4465	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4466	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4467	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4468	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4469	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4470	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4471	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4472	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4473	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4474	options |= STm->sysv ? MT_ST_SYSV : 0;
4475	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4476	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4477	options |= STp->sili ? MT_ST_SILI : 0;
4478
4479	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4480	return l;
4481}
4482static DEVICE_ATTR_RO(options);
4483
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4484static struct attribute *st_dev_attrs[] = {
4485	&dev_attr_defined.attr,
4486	&dev_attr_default_blksize.attr,
4487	&dev_attr_default_density.attr,
4488	&dev_attr_default_compression.attr,
4489	&dev_attr_options.attr,
4490	NULL,
4491};
4492ATTRIBUTE_GROUPS(st_dev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4493
4494/* The following functions may be useful for a larger audience. */
4495static int sgl_map_user_pages(struct st_buffer *STbp,
4496			      const unsigned int max_pages, unsigned long uaddr,
4497			      size_t count, int rw)
4498{
4499	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4500	unsigned long start = uaddr >> PAGE_SHIFT;
4501	const int nr_pages = end - start;
4502	int res, i, j;
4503	struct page **pages;
4504	struct rq_map_data *mdata = &STbp->map_data;
4505
4506	/* User attempted Overflow! */
4507	if ((uaddr + count) < uaddr)
4508		return -EINVAL;
4509
4510	/* Too big */
4511        if (nr_pages > max_pages)
4512		return -ENOMEM;
4513
4514	/* Hmm? */
4515	if (count == 0)
4516		return 0;
4517
4518	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_KERNEL)) == NULL)
4519		return -ENOMEM;
4520
4521        /* Try to fault in all of the necessary pages */
4522	down_read(&current->mm->mmap_sem);
4523        /* rw==READ means read from drive, write into memory area */
4524	res = get_user_pages(
4525		current,
4526		current->mm,
4527		uaddr,
4528		nr_pages,
4529		rw == READ,
4530		0, /* don't force */
4531		pages,
4532		NULL);
4533	up_read(&current->mm->mmap_sem);
4534
4535	/* Errors and no page mapped should return here */
4536	if (res < nr_pages)
4537		goto out_unmap;
4538
4539        for (i=0; i < nr_pages; i++) {
4540                /* FIXME: flush superflous for rw==READ,
4541                 * probably wrong function for rw==WRITE
4542                 */
4543		flush_dcache_page(pages[i]);
4544        }
4545
4546	mdata->offset = uaddr & ~PAGE_MASK;
4547	STbp->mapped_pages = pages;
4548
4549	return nr_pages;
4550 out_unmap:
4551	if (res > 0) {
4552		for (j=0; j < res; j++)
4553			page_cache_release(pages[j]);
4554		res = 0;
4555	}
4556	kfree(pages);
4557	return res;
4558}
4559
4560
4561/* And unmap them... */
4562static int sgl_unmap_user_pages(struct st_buffer *STbp,
4563				const unsigned int nr_pages, int dirtied)
4564{
4565	int i;
4566
4567	for (i=0; i < nr_pages; i++) {
4568		struct page *page = STbp->mapped_pages[i];
4569
4570		if (dirtied)
4571			SetPageDirty(page);
4572		/* FIXME: cache flush missing for rw==READ
4573		 * FIXME: call the correct reference counting function
4574		 */
4575		page_cache_release(page);
4576	}
4577	kfree(STbp->mapped_pages);
4578	STbp->mapped_pages = NULL;
4579
4580	return 0;
4581}