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v3.1
   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/delay.h>
  41#include <linux/mutex.h>
  42
  43#include <asm/uaccess.h>
  44#include <asm/dma.h>
  45#include <asm/system.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 DEFINE_MUTEX(st_mutex);
  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;
  84
  85static int st_dev_max;
  86static int st_nr_dev;
  87
  88static struct class *st_sysfs_class;
  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)");
 106
 107/* Extra parameters for testing */
 108module_param_named(try_rdio, try_rdio, int, 0);
 109MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 110module_param_named(try_wdio, try_wdio, int, 0);
 111MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 112
 113#ifndef MODULE
 114static int write_threshold_kbs;  /* retained for compatibility */
 115static struct st_dev_parm {
 116	char *name;
 117	int *val;
 118} parms[] __initdata = {
 119	{
 120		"buffer_kbs", &buffer_kbs
 121	},
 122	{       /* Retained for compatibility with 2.4 */
 123		"write_threshold_kbs", &write_threshold_kbs
 124	},
 125	{
 126		"max_sg_segs", NULL
 127	},
 128	{
 129		"try_direct_io", &try_direct_io
 130	}
 131};
 132#endif
 133
 134/* Restrict the number of modes so that names for all are assigned */
 135#if ST_NBR_MODES > 16
 136#error "Maximum number of modes is 16"
 137#endif
 138/* Bit reversed order to get same names for same minors with all
 139   mode counts */
 140static const char *st_formats[] = {
 141	"",  "r", "k", "s", "l", "t", "o", "u",
 142	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 143
 144/* The default definitions have been moved to st_options.h */
 145
 146#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 147
 148/* The buffer size should fit into the 24 bits for length in the
 149   6-byte SCSI read and write commands. */
 150#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 151#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 152#endif
 153
 154static int debugging = DEBUG;
 155
 156#define MAX_RETRIES 0
 157#define MAX_WRITE_RETRIES 0
 158#define MAX_READY_RETRIES 0
 159#define NO_TAPE  NOT_READY
 160
 161#define ST_TIMEOUT (900 * HZ)
 162#define ST_LONG_TIMEOUT (14000 * HZ)
 163
 164/* Remove mode bits and auto-rewind bit (7) */
 165#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 166    (iminor(x) & ~(-1 << ST_MODE_SHIFT)) )
 167#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 168
 169/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 170#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 171  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 172
 173/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 174   24 bits) */
 175#define SET_DENS_AND_BLK 0x10001
 176
 177static DEFINE_RWLOCK(st_dev_arr_lock);
 178
 179static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 180static int st_max_sg_segs = ST_MAX_SG;
 181
 182static struct scsi_tape **scsi_tapes = NULL;
 183
 184static int modes_defined;
 185
 186static int enlarge_buffer(struct st_buffer *, int, int);
 187static void clear_buffer(struct st_buffer *);
 188static void normalize_buffer(struct st_buffer *);
 189static int append_to_buffer(const char __user *, struct st_buffer *, int);
 190static int from_buffer(struct st_buffer *, char __user *, int);
 191static void move_buffer_data(struct st_buffer *, int);
 192
 193static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 194			      unsigned long, size_t, int);
 195static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 196
 197static int st_probe(struct device *);
 198static int st_remove(struct device *);
 199
 200static int do_create_sysfs_files(void);
 201static void do_remove_sysfs_files(void);
 202static int do_create_class_files(struct scsi_tape *, int, int);
 203
 204static struct scsi_driver st_template = {
 205	.owner			= THIS_MODULE,
 206	.gendrv = {
 207		.name		= "st",
 208		.probe		= st_probe,
 209		.remove		= st_remove,
 210	},
 211};
 212
 213static int st_compression(struct scsi_tape *, int);
 214
 215static int find_partition(struct scsi_tape *);
 216static int switch_partition(struct scsi_tape *);
 217
 218static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 219
 220static void scsi_tape_release(struct kref *);
 221
 222#define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 223
 224static DEFINE_MUTEX(st_ref_mutex);
 225
 226
 227#include "osst_detect.h"
 228#ifndef SIGS_FROM_OSST
 229#define SIGS_FROM_OSST \
 230	{"OnStream", "SC-", "", "osst"}, \
 231	{"OnStream", "DI-", "", "osst"}, \
 232	{"OnStream", "DP-", "", "osst"}, \
 233	{"OnStream", "USB", "", "osst"}, \
 234	{"OnStream", "FW-", "", "osst"}
 235#endif
 236
 237static struct scsi_tape *scsi_tape_get(int dev)
 238{
 239	struct scsi_tape *STp = NULL;
 240
 241	mutex_lock(&st_ref_mutex);
 242	write_lock(&st_dev_arr_lock);
 243
 244	if (dev < st_dev_max && scsi_tapes != NULL)
 245		STp = scsi_tapes[dev];
 246	if (!STp) goto out;
 247
 248	kref_get(&STp->kref);
 249
 250	if (!STp->device)
 251		goto out_put;
 252
 253	if (scsi_device_get(STp->device))
 254		goto out_put;
 255
 256	goto out;
 257
 258out_put:
 259	kref_put(&STp->kref, scsi_tape_release);
 260	STp = NULL;
 261out:
 262	write_unlock(&st_dev_arr_lock);
 263	mutex_unlock(&st_ref_mutex);
 264	return STp;
 265}
 266
 267static void scsi_tape_put(struct scsi_tape *STp)
 268{
 269	struct scsi_device *sdev = STp->device;
 270
 271	mutex_lock(&st_ref_mutex);
 272	kref_put(&STp->kref, scsi_tape_release);
 273	scsi_device_put(sdev);
 274	mutex_unlock(&st_ref_mutex);
 275}
 276
 277struct st_reject_data {
 278	char *vendor;
 279	char *model;
 280	char *rev;
 281	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 282};
 283
 284static struct st_reject_data reject_list[] = {
 285	/* {"XXX", "Yy-", "", NULL},  example */
 286	SIGS_FROM_OSST,
 287	{NULL, }};
 288
 289/* If the device signature is on the list of incompatible drives, the
 290   function returns a pointer to the name of the correct driver (if known) */
 291static char * st_incompatible(struct scsi_device* SDp)
 292{
 293	struct st_reject_data *rp;
 294
 295	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 296		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 297		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 298		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 299			if (rp->driver_hint)
 300				return rp->driver_hint;
 301			else
 302				return "unknown";
 303		}
 304	return NULL;
 305}
 306
 307
 308static inline char *tape_name(struct scsi_tape *tape)
 309{
 310	return tape->disk->disk_name;
 311}
 312
 313
 314static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 315{
 316	const u8 *ucp;
 317	const u8 *sense = SRpnt->sense;
 318
 319	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 320				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 321	s->flags = 0;
 322
 323	if (s->have_sense) {
 324		s->deferred = 0;
 325		s->remainder_valid =
 326			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 327		switch (sense[0] & 0x7f) {
 328		case 0x71:
 329			s->deferred = 1;
 330		case 0x70:
 331			s->fixed_format = 1;
 332			s->flags = sense[2] & 0xe0;
 333			break;
 334		case 0x73:
 335			s->deferred = 1;
 336		case 0x72:
 337			s->fixed_format = 0;
 338			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 339			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 340			break;
 341		}
 342	}
 343}
 344
 345
 346/* Convert the result to success code */
 347static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 348{
 349	int result = SRpnt->result;
 350	u8 scode;
 351	DEB(const char *stp;)
 352	char *name = tape_name(STp);
 353	struct st_cmdstatus *cmdstatp;
 354
 355	if (!result)
 356		return 0;
 357
 358	cmdstatp = &STp->buffer->cmdstat;
 359	st_analyze_sense(SRpnt, cmdstatp);
 360
 361	if (cmdstatp->have_sense)
 362		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 363	else
 364		scode = 0;
 365
 366        DEB(
 367        if (debugging) {
 368                printk(ST_DEB_MSG "%s: Error: %x, cmd: %x %x %x %x %x %x\n",
 369		       name, result,
 370		       SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 371		       SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 372		if (cmdstatp->have_sense)
 373			 __scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 374	} ) /* end DEB */
 375	if (!debugging) { /* Abnormal conditions for tape */
 376		if (!cmdstatp->have_sense)
 377			printk(KERN_WARNING
 378			       "%s: Error %x (driver bt 0x%x, host bt 0x%x).\n",
 379			       name, result, driver_byte(result),
 380			       host_byte(result));
 381		else if (cmdstatp->have_sense &&
 382			 scode != NO_SENSE &&
 383			 scode != RECOVERED_ERROR &&
 384			 /* scode != UNIT_ATTENTION && */
 385			 scode != BLANK_CHECK &&
 386			 scode != VOLUME_OVERFLOW &&
 387			 SRpnt->cmd[0] != MODE_SENSE &&
 388			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 389
 390			__scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 391		}
 392	}
 393
 394	if (cmdstatp->fixed_format &&
 395	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 396		if (STp->cln_sense_value)
 397			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 398					       STp->cln_sense_mask) == STp->cln_sense_value);
 399		else
 400			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 401					       STp->cln_sense_mask) != 0);
 402	}
 403	if (cmdstatp->have_sense &&
 404	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 405		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 406
 407	STp->pos_unknown |= STp->device->was_reset;
 408
 409	if (cmdstatp->have_sense &&
 410	    scode == RECOVERED_ERROR
 411#if ST_RECOVERED_WRITE_FATAL
 412	    && SRpnt->cmd[0] != WRITE_6
 413	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 414#endif
 415	    ) {
 416		STp->recover_count++;
 417		STp->recover_reg++;
 418
 419                DEB(
 420		if (debugging) {
 421			if (SRpnt->cmd[0] == READ_6)
 422				stp = "read";
 423			else if (SRpnt->cmd[0] == WRITE_6)
 424				stp = "write";
 425			else
 426				stp = "ioctl";
 427			printk(ST_DEB_MSG "%s: Recovered %s error (%d).\n", name, stp,
 428			       STp->recover_count);
 429		} ) /* end DEB */
 430
 431		if (cmdstatp->flags == 0)
 432			return 0;
 433	}
 434	return (-EIO);
 435}
 436
 437static struct st_request *st_allocate_request(struct scsi_tape *stp)
 438{
 439	struct st_request *streq;
 440
 441	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 442	if (streq)
 443		streq->stp = stp;
 444	else {
 445		DEBC(printk(KERN_ERR "%s: Can't get SCSI request.\n",
 446			    tape_name(stp)););
 447		if (signal_pending(current))
 448			stp->buffer->syscall_result = -EINTR;
 449		else
 450			stp->buffer->syscall_result = -EBUSY;
 451	}
 452
 453	return streq;
 454}
 455
 456static void st_release_request(struct st_request *streq)
 457{
 458	kfree(streq);
 459}
 460
 461static void st_scsi_execute_end(struct request *req, int uptodate)
 462{
 463	struct st_request *SRpnt = req->end_io_data;
 464	struct scsi_tape *STp = SRpnt->stp;
 
 465
 466	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
 467	STp->buffer->cmdstat.residual = req->resid_len;
 468
 
 469	if (SRpnt->waiting)
 470		complete(SRpnt->waiting);
 471
 472	blk_rq_unmap_user(SRpnt->bio);
 473	__blk_put_request(req->q, req);
 474}
 475
 476static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 477			   int data_direction, void *buffer, unsigned bufflen,
 478			   int timeout, int retries)
 479{
 480	struct request *req;
 481	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 482	int err = 0;
 483	int write = (data_direction == DMA_TO_DEVICE);
 484
 485	req = blk_get_request(SRpnt->stp->device->request_queue, write,
 486			      GFP_KERNEL);
 487	if (!req)
 488		return DRIVER_ERROR << 24;
 489
 490	req->cmd_type = REQ_TYPE_BLOCK_PC;
 491	req->cmd_flags |= REQ_QUIET;
 492
 493	mdata->null_mapped = 1;
 494
 495	if (bufflen) {
 496		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 497				      GFP_KERNEL);
 498		if (err) {
 499			blk_put_request(req);
 500			return DRIVER_ERROR << 24;
 501		}
 502	}
 503
 504	SRpnt->bio = req->bio;
 505	req->cmd_len = COMMAND_SIZE(cmd[0]);
 506	memset(req->cmd, 0, BLK_MAX_CDB);
 507	memcpy(req->cmd, cmd, req->cmd_len);
 508	req->sense = SRpnt->sense;
 509	req->sense_len = 0;
 510	req->timeout = timeout;
 511	req->retries = retries;
 512	req->end_io_data = SRpnt;
 513
 514	blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
 515	return 0;
 516}
 517
 518/* Do the scsi command. Waits until command performed if do_wait is true.
 519   Otherwise write_behind_check() is used to check that the command
 520   has finished. */
 521static struct st_request *
 522st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 523	   int bytes, int direction, int timeout, int retries, int do_wait)
 524{
 525	struct completion *waiting;
 526	struct rq_map_data *mdata = &STp->buffer->map_data;
 527	int ret;
 528
 529	/* if async, make sure there's no command outstanding */
 530	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 531		printk(KERN_ERR "%s: Async command already active.\n",
 532		       tape_name(STp));
 533		if (signal_pending(current))
 534			(STp->buffer)->syscall_result = (-EINTR);
 535		else
 536			(STp->buffer)->syscall_result = (-EBUSY);
 537		return NULL;
 538	}
 539
 540	if (!SRpnt) {
 541		SRpnt = st_allocate_request(STp);
 542		if (!SRpnt)
 543			return NULL;
 544	}
 545
 546	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 547	   which IO is outstanding. It's nulled out when the IO completes. */
 548	if (!do_wait)
 549		(STp->buffer)->last_SRpnt = SRpnt;
 550
 551	waiting = &STp->wait;
 552	init_completion(waiting);
 553	SRpnt->waiting = waiting;
 554
 555	if (STp->buffer->do_dio) {
 556		mdata->page_order = 0;
 557		mdata->nr_entries = STp->buffer->sg_segs;
 558		mdata->pages = STp->buffer->mapped_pages;
 559	} else {
 560		mdata->page_order = STp->buffer->reserved_page_order;
 561		mdata->nr_entries =
 562			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 563		mdata->pages = STp->buffer->reserved_pages;
 564		mdata->offset = 0;
 565	}
 566
 567	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 568	STp->buffer->cmdstat.have_sense = 0;
 569	STp->buffer->syscall_result = 0;
 570
 571	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 572			      retries);
 573	if (ret) {
 574		/* could not allocate the buffer or request was too large */
 575		(STp->buffer)->syscall_result = (-EBUSY);
 576		(STp->buffer)->last_SRpnt = NULL;
 577	} else if (do_wait) {
 578		wait_for_completion(waiting);
 579		SRpnt->waiting = NULL;
 580		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 581	}
 582
 583	return SRpnt;
 584}
 585
 586
 587/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 588   write has been correct but EOM early warning reached, -EIO if write ended in
 589   error or zero if write successful. Asynchronous writes are used only in
 590   variable block mode. */
 591static int write_behind_check(struct scsi_tape * STp)
 592{
 593	int retval = 0;
 594	struct st_buffer *STbuffer;
 595	struct st_partstat *STps;
 596	struct st_cmdstatus *cmdstatp;
 597	struct st_request *SRpnt;
 598
 599	STbuffer = STp->buffer;
 600	if (!STbuffer->writing)
 601		return 0;
 602
 603        DEB(
 604	if (STp->write_pending)
 605		STp->nbr_waits++;
 606	else
 607		STp->nbr_finished++;
 608        ) /* end DEB */
 609
 610	wait_for_completion(&(STp->wait));
 611	SRpnt = STbuffer->last_SRpnt;
 612	STbuffer->last_SRpnt = NULL;
 613	SRpnt->waiting = NULL;
 614
 615	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 616	st_release_request(SRpnt);
 617
 618	STbuffer->buffer_bytes -= STbuffer->writing;
 619	STps = &(STp->ps[STp->partition]);
 620	if (STps->drv_block >= 0) {
 621		if (STp->block_size == 0)
 622			STps->drv_block++;
 623		else
 624			STps->drv_block += STbuffer->writing / STp->block_size;
 625	}
 626
 627	cmdstatp = &STbuffer->cmdstat;
 628	if (STbuffer->syscall_result) {
 629		retval = -EIO;
 630		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 631		    (cmdstatp->flags & SENSE_EOM) &&
 632		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 633		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 634			/* EOM at write-behind, has all data been written? */
 635			if (!cmdstatp->remainder_valid ||
 636			    cmdstatp->uremainder64 == 0)
 637				retval = -ENOSPC;
 638		}
 639		if (retval == -EIO)
 640			STps->drv_block = -1;
 641	}
 642	STbuffer->writing = 0;
 643
 644	DEB(if (debugging && retval)
 645	    printk(ST_DEB_MSG "%s: Async write error %x, return value %d.\n",
 646		   tape_name(STp), STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 647
 648	return retval;
 649}
 650
 651
 652/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 653   it messes up the block number). */
 654static int cross_eof(struct scsi_tape * STp, int forward)
 655{
 656	struct st_request *SRpnt;
 657	unsigned char cmd[MAX_COMMAND_SIZE];
 658
 659	cmd[0] = SPACE;
 660	cmd[1] = 0x01;		/* Space FileMarks */
 661	if (forward) {
 662		cmd[2] = cmd[3] = 0;
 663		cmd[4] = 1;
 664	} else
 665		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 666	cmd[5] = 0;
 667
 668        DEBC(printk(ST_DEB_MSG "%s: Stepping over filemark %s.\n",
 669		   tape_name(STp), forward ? "forward" : "backward"));
 670
 671	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 672			   STp->device->request_queue->rq_timeout,
 673			   MAX_RETRIES, 1);
 674	if (!SRpnt)
 675		return (STp->buffer)->syscall_result;
 676
 677	st_release_request(SRpnt);
 678	SRpnt = NULL;
 679
 680	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 681		printk(KERN_ERR "%s: Stepping over filemark %s failed.\n",
 682		   tape_name(STp), forward ? "forward" : "backward");
 683
 684	return (STp->buffer)->syscall_result;
 685}
 686
 687
 688/* Flush the write buffer (never need to write if variable blocksize). */
 689static int st_flush_write_buffer(struct scsi_tape * STp)
 690{
 691	int transfer, blks;
 692	int result;
 693	unsigned char cmd[MAX_COMMAND_SIZE];
 694	struct st_request *SRpnt;
 695	struct st_partstat *STps;
 696
 697	result = write_behind_check(STp);
 698	if (result)
 699		return result;
 700
 701	result = 0;
 702	if (STp->dirty == 1) {
 703
 704		transfer = STp->buffer->buffer_bytes;
 705                DEBC(printk(ST_DEB_MSG "%s: Flushing %d bytes.\n",
 706                               tape_name(STp), transfer));
 707
 708		memset(cmd, 0, MAX_COMMAND_SIZE);
 709		cmd[0] = WRITE_6;
 710		cmd[1] = 1;
 711		blks = transfer / STp->block_size;
 712		cmd[2] = blks >> 16;
 713		cmd[3] = blks >> 8;
 714		cmd[4] = blks;
 715
 716		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 717				   STp->device->request_queue->rq_timeout,
 718				   MAX_WRITE_RETRIES, 1);
 719		if (!SRpnt)
 720			return (STp->buffer)->syscall_result;
 721
 722		STps = &(STp->ps[STp->partition]);
 723		if ((STp->buffer)->syscall_result != 0) {
 724			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 725
 726			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 727			    (cmdstatp->flags & SENSE_EOM) &&
 728			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 729			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 730			    (!cmdstatp->remainder_valid ||
 731			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 732				STp->dirty = 0;
 733				(STp->buffer)->buffer_bytes = 0;
 734				if (STps->drv_block >= 0)
 735					STps->drv_block += blks;
 736				result = (-ENOSPC);
 737			} else {
 738				printk(KERN_ERR "%s: Error on flush.\n",
 739                                       tape_name(STp));
 740				STps->drv_block = (-1);
 741				result = (-EIO);
 742			}
 743		} else {
 744			if (STps->drv_block >= 0)
 745				STps->drv_block += blks;
 746			STp->dirty = 0;
 747			(STp->buffer)->buffer_bytes = 0;
 748		}
 749		st_release_request(SRpnt);
 750		SRpnt = NULL;
 751	}
 752	return result;
 753}
 754
 755
 756/* Flush the tape buffer. The tape will be positioned correctly unless
 757   seek_next is true. */
 758static int flush_buffer(struct scsi_tape *STp, int seek_next)
 759{
 760	int backspace, result;
 761	struct st_buffer *STbuffer;
 762	struct st_partstat *STps;
 763
 764	STbuffer = STp->buffer;
 765
 766	/*
 767	 * If there was a bus reset, block further access
 768	 * to this device.
 769	 */
 770	if (STp->pos_unknown)
 771		return (-EIO);
 772
 773	if (STp->ready != ST_READY)
 774		return 0;
 775	STps = &(STp->ps[STp->partition]);
 776	if (STps->rw == ST_WRITING)	/* Writing */
 777		return st_flush_write_buffer(STp);
 778
 779	if (STp->block_size == 0)
 780		return 0;
 781
 782	backspace = ((STp->buffer)->buffer_bytes +
 783		     (STp->buffer)->read_pointer) / STp->block_size -
 784	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 785	    STp->block_size;
 786	(STp->buffer)->buffer_bytes = 0;
 787	(STp->buffer)->read_pointer = 0;
 788	result = 0;
 789	if (!seek_next) {
 790		if (STps->eof == ST_FM_HIT) {
 791			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 792			if (!result)
 793				STps->eof = ST_NOEOF;
 794			else {
 795				if (STps->drv_file >= 0)
 796					STps->drv_file++;
 797				STps->drv_block = 0;
 798			}
 799		}
 800		if (!result && backspace > 0)
 801			result = st_int_ioctl(STp, MTBSR, backspace);
 802	} else if (STps->eof == ST_FM_HIT) {
 803		if (STps->drv_file >= 0)
 804			STps->drv_file++;
 805		STps->drv_block = 0;
 806		STps->eof = ST_NOEOF;
 807	}
 808	return result;
 809
 810}
 811
 812/* Set the mode parameters */
 813static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 814{
 815	int set_it = 0;
 816	unsigned long arg;
 817	char *name = tape_name(STp);
 818
 819	if (!STp->density_changed &&
 820	    STm->default_density >= 0 &&
 821	    STm->default_density != STp->density) {
 822		arg = STm->default_density;
 823		set_it = 1;
 824	} else
 825		arg = STp->density;
 826	arg <<= MT_ST_DENSITY_SHIFT;
 827	if (!STp->blksize_changed &&
 828	    STm->default_blksize >= 0 &&
 829	    STm->default_blksize != STp->block_size) {
 830		arg |= STm->default_blksize;
 831		set_it = 1;
 832	} else
 833		arg |= STp->block_size;
 834	if (set_it &&
 835	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 836		printk(KERN_WARNING
 837		       "%s: Can't set default block size to %d bytes and density %x.\n",
 838		       name, STm->default_blksize, STm->default_density);
 839		if (modes_defined)
 840			return (-EINVAL);
 841	}
 842	return 0;
 843}
 844
 845
 846/* Lock or unlock the drive door. Don't use when st_request allocated. */
 847static int do_door_lock(struct scsi_tape * STp, int do_lock)
 848{
 849	int retval, cmd;
 850	DEB(char *name = tape_name(STp);)
 851
 852
 853	cmd = do_lock ? SCSI_IOCTL_DOORLOCK : SCSI_IOCTL_DOORUNLOCK;
 854	DEBC(printk(ST_DEB_MSG "%s: %socking drive door.\n", name,
 855		    do_lock ? "L" : "Unl"));
 856	retval = scsi_ioctl(STp->device, cmd, NULL);
 857	if (!retval) {
 858		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 859	}
 860	else {
 861		STp->door_locked = ST_LOCK_FAILS;
 862	}
 863	return retval;
 864}
 865
 866
 867/* Set the internal state after reset */
 868static void reset_state(struct scsi_tape *STp)
 869{
 870	int i;
 871	struct st_partstat *STps;
 872
 873	STp->pos_unknown = 0;
 874	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 875		STps = &(STp->ps[i]);
 876		STps->rw = ST_IDLE;
 877		STps->eof = ST_NOEOF;
 878		STps->at_sm = 0;
 879		STps->last_block_valid = 0;
 880		STps->drv_block = -1;
 881		STps->drv_file = -1;
 882	}
 883	if (STp->can_partitions) {
 884		STp->partition = find_partition(STp);
 885		if (STp->partition < 0)
 886			STp->partition = 0;
 887		STp->new_partition = STp->partition;
 888	}
 889}
 890
 891/* Test if the drive is ready. Returns either one of the codes below or a negative system
 892   error code. */
 893#define CHKRES_READY       0
 894#define CHKRES_NEW_SESSION 1
 895#define CHKRES_NOT_READY   2
 896#define CHKRES_NO_TAPE     3
 897
 898#define MAX_ATTENTIONS    10
 899
 900static int test_ready(struct scsi_tape *STp, int do_wait)
 901{
 902	int attentions, waits, max_wait, scode;
 903	int retval = CHKRES_READY, new_session = 0;
 904	unsigned char cmd[MAX_COMMAND_SIZE];
 905	struct st_request *SRpnt = NULL;
 906	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 907
 908	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 909
 910	for (attentions=waits=0; ; ) {
 911		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 912		cmd[0] = TEST_UNIT_READY;
 913		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 914				   STp->long_timeout, MAX_READY_RETRIES, 1);
 915
 916		if (!SRpnt) {
 917			retval = (STp->buffer)->syscall_result;
 918			break;
 919		}
 920
 921		if (cmdstatp->have_sense) {
 922
 923			scode = cmdstatp->sense_hdr.sense_key;
 924
 925			if (scode == UNIT_ATTENTION) { /* New media? */
 926				new_session = 1;
 927				if (attentions < MAX_ATTENTIONS) {
 928					attentions++;
 929					continue;
 930				}
 931				else {
 932					retval = (-EIO);
 933					break;
 934				}
 935			}
 936
 937			if (scode == NOT_READY) {
 938				if (waits < max_wait) {
 939					if (msleep_interruptible(1000)) {
 940						retval = (-EINTR);
 941						break;
 942					}
 943					waits++;
 944					continue;
 945				}
 946				else {
 947					if ((STp->device)->scsi_level >= SCSI_2 &&
 948					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
 949						retval = CHKRES_NO_TAPE;
 950					else
 951						retval = CHKRES_NOT_READY;
 952					break;
 953				}
 954			}
 955		}
 956
 957		retval = (STp->buffer)->syscall_result;
 958		if (!retval)
 959			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
 960		break;
 961	}
 962
 963	if (SRpnt != NULL)
 964		st_release_request(SRpnt);
 965	return retval;
 966}
 967
 968
 969/* See if the drive is ready and gather information about the tape. Return values:
 970   < 0   negative error code from errno.h
 971   0     drive ready
 972   1     drive not ready (possibly no tape)
 973*/
 974static int check_tape(struct scsi_tape *STp, struct file *filp)
 975{
 976	int i, retval, new_session = 0, do_wait;
 977	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
 978	unsigned short st_flags = filp->f_flags;
 979	struct st_request *SRpnt = NULL;
 980	struct st_modedef *STm;
 981	struct st_partstat *STps;
 982	char *name = tape_name(STp);
 983	struct inode *inode = filp->f_path.dentry->d_inode;
 984	int mode = TAPE_MODE(inode);
 985
 986	STp->ready = ST_READY;
 987
 988	if (mode != STp->current_mode) {
 989                DEBC(printk(ST_DEB_MSG "%s: Mode change from %d to %d.\n",
 990			       name, STp->current_mode, mode));
 991		new_session = 1;
 992		STp->current_mode = mode;
 993	}
 994	STm = &(STp->modes[STp->current_mode]);
 995
 996	saved_cleaning = STp->cleaning_req;
 997	STp->cleaning_req = 0;
 998
 999	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1000	retval = test_ready(STp, do_wait);
1001
1002	if (retval < 0)
1003	    goto err_out;
1004
1005	if (retval == CHKRES_NEW_SESSION) {
1006		STp->pos_unknown = 0;
1007		STp->partition = STp->new_partition = 0;
1008		if (STp->can_partitions)
1009			STp->nbr_partitions = 1; /* This guess will be updated later
1010                                                    if necessary */
1011		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1012			STps = &(STp->ps[i]);
1013			STps->rw = ST_IDLE;
1014			STps->eof = ST_NOEOF;
1015			STps->at_sm = 0;
1016			STps->last_block_valid = 0;
1017			STps->drv_block = 0;
1018			STps->drv_file = 0;
1019		}
1020		new_session = 1;
1021	}
1022	else {
1023		STp->cleaning_req |= saved_cleaning;
1024
1025		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1026			if (retval == CHKRES_NO_TAPE)
1027				STp->ready = ST_NO_TAPE;
1028			else
1029				STp->ready = ST_NOT_READY;
1030
1031			STp->density = 0;	/* Clear the erroneous "residue" */
1032			STp->write_prot = 0;
1033			STp->block_size = 0;
1034			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1035			STp->partition = STp->new_partition = 0;
1036			STp->door_locked = ST_UNLOCKED;
1037			return CHKRES_NOT_READY;
1038		}
1039	}
1040
1041	if (STp->omit_blklims)
1042		STp->min_block = STp->max_block = (-1);
1043	else {
1044		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1045		cmd[0] = READ_BLOCK_LIMITS;
1046
1047		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1048				   STp->device->request_queue->rq_timeout,
1049				   MAX_READY_RETRIES, 1);
1050		if (!SRpnt) {
1051			retval = (STp->buffer)->syscall_result;
1052			goto err_out;
1053		}
1054
1055		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1056			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1057			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1058			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1059			    (STp->buffer)->b_data[5];
1060			if ( DEB( debugging || ) !STp->inited)
1061				printk(KERN_INFO
1062                                       "%s: Block limits %d - %d bytes.\n", name,
1063                                       STp->min_block, STp->max_block);
1064		} else {
1065			STp->min_block = STp->max_block = (-1);
1066                        DEBC(printk(ST_DEB_MSG "%s: Can't read block limits.\n",
1067                                       name));
1068		}
1069	}
1070
1071	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1072	cmd[0] = MODE_SENSE;
1073	cmd[4] = 12;
1074
1075	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1076			   STp->device->request_queue->rq_timeout,
1077			   MAX_READY_RETRIES, 1);
1078	if (!SRpnt) {
1079		retval = (STp->buffer)->syscall_result;
1080		goto err_out;
1081	}
1082
1083	if ((STp->buffer)->syscall_result != 0) {
1084                DEBC(printk(ST_DEB_MSG "%s: No Mode Sense.\n", name));
1085		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1086		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1087		STp->drv_write_prot = 0;
1088	} else {
1089                DEBC(printk(ST_DEB_MSG
1090                            "%s: Mode sense. Length %d, medium %x, WBS %x, BLL %d\n",
1091                            name,
1092                            (STp->buffer)->b_data[0], (STp->buffer)->b_data[1],
1093                            (STp->buffer)->b_data[2], (STp->buffer)->b_data[3]));
1094
1095		if ((STp->buffer)->b_data[3] >= 8) {
1096			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1097			STp->density = (STp->buffer)->b_data[4];
1098			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1099			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1100                        DEBC(printk(ST_DEB_MSG
1101                                    "%s: Density %x, tape length: %x, drv buffer: %d\n",
1102                                    name, STp->density, (STp->buffer)->b_data[5] * 65536 +
1103                                    (STp->buffer)->b_data[6] * 256 + (STp->buffer)->b_data[7],
1104                                    STp->drv_buffer));
1105		}
1106		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
 
 
 
 
 
 
1107	}
1108	st_release_request(SRpnt);
1109	SRpnt = NULL;
1110        STp->inited = 1;
1111
1112	if (STp->block_size > 0)
1113		(STp->buffer)->buffer_blocks =
1114                        (STp->buffer)->buffer_size / STp->block_size;
1115	else
1116		(STp->buffer)->buffer_blocks = 1;
1117	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1118
1119        DEBC(printk(ST_DEB_MSG
1120                       "%s: Block size: %d, buffer size: %d (%d blocks).\n", name,
1121		       STp->block_size, (STp->buffer)->buffer_size,
1122		       (STp->buffer)->buffer_blocks));
1123
1124	if (STp->drv_write_prot) {
1125		STp->write_prot = 1;
1126
1127                DEBC(printk(ST_DEB_MSG "%s: Write protected\n", name));
1128
1129		if (do_wait &&
1130		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1131		     (st_flags & O_ACCMODE) == O_RDWR)) {
1132			retval = (-EROFS);
1133			goto err_out;
1134		}
1135	}
1136
1137	if (STp->can_partitions && STp->nbr_partitions < 1) {
1138		/* This code is reached when the device is opened for the first time
1139		   after the driver has been initialized with tape in the drive and the
1140		   partition support has been enabled. */
1141                DEBC(printk(ST_DEB_MSG
1142                            "%s: Updating partition number in status.\n", name));
1143		if ((STp->partition = find_partition(STp)) < 0) {
1144			retval = STp->partition;
1145			goto err_out;
1146		}
1147		STp->new_partition = STp->partition;
1148		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1149	}
1150
1151	if (new_session) {	/* Change the drive parameters for the new mode */
1152		STp->density_changed = STp->blksize_changed = 0;
1153		STp->compression_changed = 0;
1154		if (!(STm->defaults_for_writes) &&
1155		    (retval = set_mode_densblk(STp, STm)) < 0)
1156		    goto err_out;
1157
1158		if (STp->default_drvbuffer != 0xff) {
1159			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1160				printk(KERN_WARNING
1161                                       "%s: Can't set default drive buffering to %d.\n",
1162				       name, STp->default_drvbuffer);
1163		}
1164	}
1165
1166	return CHKRES_READY;
1167
1168 err_out:
1169	return retval;
1170}
1171
1172
1173/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1174   module count. */
1175static int st_open(struct inode *inode, struct file *filp)
1176{
1177	int i, retval = (-EIO);
 
1178	struct scsi_tape *STp;
1179	struct st_partstat *STps;
1180	int dev = TAPE_NR(inode);
1181	char *name;
1182
1183	mutex_lock(&st_mutex);
1184	/*
1185	 * We really want to do nonseekable_open(inode, filp); here, but some
1186	 * versions of tar incorrectly call lseek on tapes and bail out if that
1187	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1188	 */
1189	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1190
1191	if (!(STp = scsi_tape_get(dev))) {
1192		mutex_unlock(&st_mutex);
1193		return -ENXIO;
1194	}
1195
1196	write_lock(&st_dev_arr_lock);
1197	filp->private_data = STp;
1198	name = tape_name(STp);
1199
1200	if (STp->in_use) {
1201		write_unlock(&st_dev_arr_lock);
1202		scsi_tape_put(STp);
1203		mutex_unlock(&st_mutex);
1204		DEB( printk(ST_DEB_MSG "%s: Device already in use.\n", name); )
1205		return (-EBUSY);
1206	}
1207
1208	STp->in_use = 1;
1209	write_unlock(&st_dev_arr_lock);
1210	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1211
 
 
 
 
 
1212	if (!scsi_block_when_processing_errors(STp->device)) {
1213		retval = (-ENXIO);
1214		goto err_out;
1215	}
1216
1217	/* See that we have at least a one page buffer available */
1218	if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1219		printk(KERN_WARNING "%s: Can't allocate one page tape buffer.\n",
1220		       name);
1221		retval = (-EOVERFLOW);
1222		goto err_out;
1223	}
1224
1225	(STp->buffer)->cleared = 0;
1226	(STp->buffer)->writing = 0;
1227	(STp->buffer)->syscall_result = 0;
1228
1229	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1230
1231	STp->dirty = 0;
1232	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1233		STps = &(STp->ps[i]);
1234		STps->rw = ST_IDLE;
1235	}
1236	STp->try_dio_now = STp->try_dio;
1237	STp->recover_count = 0;
1238	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1239	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1240
1241	retval = check_tape(STp, filp);
1242	if (retval < 0)
1243		goto err_out;
1244	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1245	    retval != CHKRES_READY) {
1246		if (STp->ready == NO_TAPE)
1247			retval = (-ENOMEDIUM);
1248		else
1249			retval = (-EIO);
1250		goto err_out;
1251	}
1252	mutex_unlock(&st_mutex);
1253	return 0;
1254
1255 err_out:
1256	normalize_buffer(STp->buffer);
1257	STp->in_use = 0;
1258	scsi_tape_put(STp);
 
 
1259	mutex_unlock(&st_mutex);
1260	return retval;
1261
1262}
1263
1264
1265/* Flush the tape buffer before close */
1266static int st_flush(struct file *filp, fl_owner_t id)
1267{
1268	int result = 0, result2;
1269	unsigned char cmd[MAX_COMMAND_SIZE];
1270	struct st_request *SRpnt;
1271	struct scsi_tape *STp = filp->private_data;
1272	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1273	struct st_partstat *STps = &(STp->ps[STp->partition]);
1274	char *name = tape_name(STp);
1275
1276	if (file_count(filp) > 1)
1277		return 0;
1278
1279	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1280		result = st_flush_write_buffer(STp);
1281		if (result != 0 && result != (-ENOSPC))
1282			goto out;
1283	}
1284
1285	if (STp->can_partitions &&
1286	    (result2 = switch_partition(STp)) < 0) {
1287                DEBC(printk(ST_DEB_MSG
1288                               "%s: switch_partition at close failed.\n", name));
1289		if (result == 0)
1290			result = result2;
1291		goto out;
1292	}
1293
1294	DEBC( if (STp->nbr_requests)
1295		printk(KERN_DEBUG "%s: Number of r/w requests %d, dio used in %d, pages %d.\n",
1296		       name, STp->nbr_requests, STp->nbr_dio, STp->nbr_pages));
1297
1298	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1299		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1300
1301                DEBC(printk(ST_DEB_MSG "%s: Async write waits %d, finished %d.\n",
1302                            name, STp->nbr_waits, STp->nbr_finished);
1303		)
1304
1305		memset(cmd, 0, MAX_COMMAND_SIZE);
1306		cmd[0] = WRITE_FILEMARKS;
 
 
1307		cmd[4] = 1 + STp->two_fm;
1308
1309		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1310				   STp->device->request_queue->rq_timeout,
1311				   MAX_WRITE_RETRIES, 1);
1312		if (!SRpnt) {
1313			result = (STp->buffer)->syscall_result;
1314			goto out;
1315		}
1316
1317		if (STp->buffer->syscall_result == 0 ||
1318		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1319		     (cmdstatp->flags & SENSE_EOM) &&
1320		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1321		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1322		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1323			/* Write successful at EOM */
1324			st_release_request(SRpnt);
1325			SRpnt = NULL;
1326			if (STps->drv_file >= 0)
1327				STps->drv_file++;
1328			STps->drv_block = 0;
1329			if (STp->two_fm)
1330				cross_eof(STp, 0);
1331			STps->eof = ST_FM;
1332		}
1333		else { /* Write error */
1334			st_release_request(SRpnt);
1335			SRpnt = NULL;
1336			printk(KERN_ERR "%s: Error on write filemark.\n", name);
1337			if (result == 0)
1338				result = (-EIO);
1339		}
1340
1341                DEBC(printk(ST_DEB_MSG "%s: Buffer flushed, %d EOF(s) written\n",
1342                            name, cmd[4]));
1343	} else if (!STp->rew_at_close) {
1344		STps = &(STp->ps[STp->partition]);
1345		if (!STm->sysv || STps->rw != ST_READING) {
1346			if (STp->can_bsr)
1347				result = flush_buffer(STp, 0);
1348			else if (STps->eof == ST_FM_HIT) {
1349				result = cross_eof(STp, 0);
1350				if (result) {
1351					if (STps->drv_file >= 0)
1352						STps->drv_file++;
1353					STps->drv_block = 0;
1354					STps->eof = ST_FM;
1355				} else
1356					STps->eof = ST_NOEOF;
1357			}
1358		} else if ((STps->eof == ST_NOEOF &&
1359			    !(result = cross_eof(STp, 1))) ||
1360			   STps->eof == ST_FM_HIT) {
1361			if (STps->drv_file >= 0)
1362				STps->drv_file++;
1363			STps->drv_block = 0;
1364			STps->eof = ST_FM;
1365		}
1366	}
1367
1368      out:
1369	if (STp->rew_at_close) {
1370		result2 = st_int_ioctl(STp, MTREW, 1);
1371		if (result == 0)
1372			result = result2;
1373	}
1374	return result;
1375}
1376
1377
1378/* Close the device and release it. BKL is not needed: this is the only thread
1379   accessing this tape. */
1380static int st_release(struct inode *inode, struct file *filp)
1381{
1382	int result = 0;
1383	struct scsi_tape *STp = filp->private_data;
1384
1385	if (STp->door_locked == ST_LOCKED_AUTO)
1386		do_door_lock(STp, 0);
1387
1388	normalize_buffer(STp->buffer);
1389	write_lock(&st_dev_arr_lock);
1390	STp->in_use = 0;
1391	write_unlock(&st_dev_arr_lock);
 
1392	scsi_tape_put(STp);
1393
1394	return result;
1395}
1396
1397/* The checks common to both reading and writing */
1398static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1399{
1400	ssize_t retval = 0;
1401
1402	/*
1403	 * If we are in the middle of error recovery, don't let anyone
1404	 * else try and use this device.  Also, if error recovery fails, it
1405	 * may try and take the device offline, in which case all further
1406	 * access to the device is prohibited.
1407	 */
1408	if (!scsi_block_when_processing_errors(STp->device)) {
1409		retval = (-ENXIO);
1410		goto out;
1411	}
1412
1413	if (STp->ready != ST_READY) {
1414		if (STp->ready == ST_NO_TAPE)
1415			retval = (-ENOMEDIUM);
1416		else
1417			retval = (-EIO);
1418		goto out;
1419	}
1420
1421	if (! STp->modes[STp->current_mode].defined) {
1422		retval = (-ENXIO);
1423		goto out;
1424	}
1425
1426
1427	/*
1428	 * If there was a bus reset, block further access
1429	 * to this device.
1430	 */
1431	if (STp->pos_unknown) {
1432		retval = (-EIO);
1433		goto out;
1434	}
1435
1436	if (count == 0)
1437		goto out;
1438
1439        DEB(
1440	if (!STp->in_use) {
1441		printk(ST_DEB_MSG "%s: Incorrect device.\n", tape_name(STp));
1442		retval = (-EIO);
1443		goto out;
1444	} ) /* end DEB */
1445
1446	if (STp->can_partitions &&
1447	    (retval = switch_partition(STp)) < 0)
1448		goto out;
1449
1450	if (STp->block_size == 0 && STp->max_block > 0 &&
1451	    (count < STp->min_block || count > STp->max_block)) {
1452		retval = (-EINVAL);
1453		goto out;
1454	}
1455
1456	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1457	    !do_door_lock(STp, 1))
1458		STp->door_locked = ST_LOCKED_AUTO;
1459
1460 out:
1461	return retval;
1462}
1463
1464
1465static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1466			   size_t count, int is_read)
1467{
1468	int i, bufsize, retval = 0;
1469	struct st_buffer *STbp = STp->buffer;
1470
1471	if (is_read)
1472		i = STp->try_dio_now && try_rdio;
1473	else
1474		i = STp->try_dio_now && try_wdio;
1475
1476	if (i && ((unsigned long)buf & queue_dma_alignment(
1477					STp->device->request_queue)) == 0) {
1478		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1479				       count, (is_read ? READ : WRITE));
1480		if (i > 0) {
1481			STbp->do_dio = i;
1482			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1483		}
1484		else
1485			STbp->do_dio = 0;  /* fall back to buffering with any error */
1486		STbp->sg_segs = STbp->do_dio;
1487		DEB(
1488		     if (STbp->do_dio) {
1489			STp->nbr_dio++;
1490			STp->nbr_pages += STbp->do_dio;
1491		     }
1492		)
1493	} else
1494		STbp->do_dio = 0;
1495	DEB( STp->nbr_requests++; )
1496
1497	if (!STbp->do_dio) {
1498		if (STp->block_size)
1499			bufsize = STp->block_size > st_fixed_buffer_size ?
1500				STp->block_size : st_fixed_buffer_size;
1501		else {
1502			bufsize = count;
1503			/* Make sure that data from previous user is not leaked even if
1504			   HBA does not return correct residual */
1505			if (is_read && STp->sili && !STbp->cleared)
1506				clear_buffer(STbp);
1507		}
1508
1509		if (bufsize > STbp->buffer_size &&
1510		    !enlarge_buffer(STbp, bufsize, STp->restr_dma)) {
1511			printk(KERN_WARNING "%s: Can't allocate %d byte tape buffer.\n",
1512			       tape_name(STp), bufsize);
1513			retval = (-EOVERFLOW);
1514			goto out;
1515		}
1516		if (STp->block_size)
1517			STbp->buffer_blocks = bufsize / STp->block_size;
1518	}
1519
1520 out:
1521	return retval;
1522}
1523
1524
1525/* Can be called more than once after each setup_buffer() */
1526static void release_buffering(struct scsi_tape *STp, int is_read)
1527{
1528	struct st_buffer *STbp;
1529
1530	STbp = STp->buffer;
1531	if (STbp->do_dio) {
1532		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1533		STbp->do_dio = 0;
1534		STbp->sg_segs = 0;
1535	}
1536}
1537
1538
1539/* Write command */
1540static ssize_t
1541st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1542{
1543	ssize_t total;
1544	ssize_t i, do_count, blks, transfer;
1545	ssize_t retval;
1546	int undone, retry_eot = 0, scode;
1547	int async_write;
1548	unsigned char cmd[MAX_COMMAND_SIZE];
1549	const char __user *b_point;
1550	struct st_request *SRpnt = NULL;
1551	struct scsi_tape *STp = filp->private_data;
1552	struct st_modedef *STm;
1553	struct st_partstat *STps;
1554	struct st_buffer *STbp;
1555	char *name = tape_name(STp);
1556
1557	if (mutex_lock_interruptible(&STp->lock))
1558		return -ERESTARTSYS;
1559
1560	retval = rw_checks(STp, filp, count);
1561	if (retval || count == 0)
1562		goto out;
1563
1564	/* Write must be integral number of blocks */
1565	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1566		printk(KERN_WARNING "%s: Write not multiple of tape block size.\n",
1567		       name);
1568		retval = (-EINVAL);
1569		goto out;
1570	}
1571
1572	STm = &(STp->modes[STp->current_mode]);
1573	STps = &(STp->ps[STp->partition]);
1574
1575	if (STp->write_prot) {
1576		retval = (-EACCES);
1577		goto out;
1578	}
1579
1580
1581	if (STps->rw == ST_READING) {
1582		retval = flush_buffer(STp, 0);
1583		if (retval)
1584			goto out;
1585		STps->rw = ST_WRITING;
1586	} else if (STps->rw != ST_WRITING &&
1587		   STps->drv_file == 0 && STps->drv_block == 0) {
1588		if ((retval = set_mode_densblk(STp, STm)) < 0)
1589			goto out;
1590		if (STm->default_compression != ST_DONT_TOUCH &&
1591		    !(STp->compression_changed)) {
1592			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1593				printk(KERN_WARNING "%s: Can't set default compression.\n",
1594				       name);
1595				if (modes_defined) {
1596					retval = (-EINVAL);
1597					goto out;
1598				}
1599			}
1600		}
1601	}
1602
1603	STbp = STp->buffer;
1604	i = write_behind_check(STp);
1605	if (i) {
1606		if (i == -ENOSPC)
1607			STps->eof = ST_EOM_OK;
1608		else
1609			STps->eof = ST_EOM_ERROR;
1610	}
1611
1612	if (STps->eof == ST_EOM_OK) {
1613		STps->eof = ST_EOD_1;  /* allow next write */
1614		retval = (-ENOSPC);
1615		goto out;
1616	}
1617	else if (STps->eof == ST_EOM_ERROR) {
1618		retval = (-EIO);
1619		goto out;
1620	}
1621
1622	/* Check the buffer readability in cases where copy_user might catch
1623	   the problems after some tape movement. */
1624	if (STp->block_size != 0 &&
1625	    !STbp->do_dio &&
1626	    (copy_from_user(&i, buf, 1) != 0 ||
1627	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1628		retval = (-EFAULT);
1629		goto out;
1630	}
1631
1632	retval = setup_buffering(STp, buf, count, 0);
1633	if (retval)
1634		goto out;
1635
1636	total = count;
1637
1638	memset(cmd, 0, MAX_COMMAND_SIZE);
1639	cmd[0] = WRITE_6;
1640	cmd[1] = (STp->block_size != 0);
1641
1642	STps->rw = ST_WRITING;
1643
1644	b_point = buf;
1645	while (count > 0 && !retry_eot) {
1646
1647		if (STbp->do_dio) {
1648			do_count = count;
1649		}
1650		else {
1651			if (STp->block_size == 0)
1652				do_count = count;
1653			else {
1654				do_count = STbp->buffer_blocks * STp->block_size -
1655					STbp->buffer_bytes;
1656				if (do_count > count)
1657					do_count = count;
1658			}
1659
1660			i = append_to_buffer(b_point, STbp, do_count);
1661			if (i) {
1662				retval = i;
1663				goto out;
1664			}
1665		}
1666		count -= do_count;
1667		b_point += do_count;
1668
1669		async_write = STp->block_size == 0 && !STbp->do_dio &&
1670			STm->do_async_writes && STps->eof < ST_EOM_OK;
1671
1672		if (STp->block_size != 0 && STm->do_buffer_writes &&
1673		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1674		    STbp->buffer_bytes < STbp->buffer_size) {
1675			STp->dirty = 1;
1676			/* Don't write a buffer that is not full enough. */
1677			if (!async_write && count == 0)
1678				break;
1679		}
1680
1681	retry_write:
1682		if (STp->block_size == 0)
1683			blks = transfer = do_count;
1684		else {
1685			if (!STbp->do_dio)
1686				blks = STbp->buffer_bytes;
1687			else
1688				blks = do_count;
1689			blks /= STp->block_size;
1690			transfer = blks * STp->block_size;
1691		}
1692		cmd[2] = blks >> 16;
1693		cmd[3] = blks >> 8;
1694		cmd[4] = blks;
1695
1696		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1697				   STp->device->request_queue->rq_timeout,
1698				   MAX_WRITE_RETRIES, !async_write);
1699		if (!SRpnt) {
1700			retval = STbp->syscall_result;
1701			goto out;
1702		}
1703		if (async_write && !STbp->syscall_result) {
1704			STbp->writing = transfer;
1705			STp->dirty = !(STbp->writing ==
1706				       STbp->buffer_bytes);
1707			SRpnt = NULL;  /* Prevent releasing this request! */
1708			DEB( STp->write_pending = 1; )
1709			break;
1710		}
1711
1712		if (STbp->syscall_result != 0) {
1713			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1714
1715                        DEBC(printk(ST_DEB_MSG "%s: Error on write:\n", name));
1716			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1717				scode = cmdstatp->sense_hdr.sense_key;
1718				if (cmdstatp->remainder_valid)
1719					undone = (int)cmdstatp->uremainder64;
1720				else if (STp->block_size == 0 &&
1721					 scode == VOLUME_OVERFLOW)
1722					undone = transfer;
1723				else
1724					undone = 0;
1725				if (STp->block_size != 0)
1726					undone *= STp->block_size;
1727				if (undone <= do_count) {
1728					/* Only data from this write is not written */
1729					count += undone;
1730					b_point -= undone;
1731					do_count -= undone;
1732					if (STp->block_size)
1733						blks = (transfer - undone) / STp->block_size;
1734					STps->eof = ST_EOM_OK;
1735					/* Continue in fixed block mode if all written
1736					   in this request but still something left to write
1737					   (retval left to zero)
1738					*/
1739					if (STp->block_size == 0 ||
1740					    undone > 0 || count == 0)
1741						retval = (-ENOSPC); /* EOM within current request */
1742                                        DEBC(printk(ST_DEB_MSG
1743                                                       "%s: EOM with %d bytes unwritten.\n",
1744						       name, (int)count));
1745				} else {
1746					/* EOT within data buffered earlier (possible only
1747					   in fixed block mode without direct i/o) */
1748					if (!retry_eot && !cmdstatp->deferred &&
1749					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1750						move_buffer_data(STp->buffer, transfer - undone);
1751						retry_eot = 1;
1752						if (STps->drv_block >= 0) {
1753							STps->drv_block += (transfer - undone) /
1754								STp->block_size;
1755						}
1756						STps->eof = ST_EOM_OK;
1757						DEBC(printk(ST_DEB_MSG
1758							    "%s: Retry write of %d bytes at EOM.\n",
1759							    name, STp->buffer->buffer_bytes));
1760						goto retry_write;
1761					}
1762					else {
1763						/* Either error within data buffered by driver or
1764						   failed retry */
1765						count -= do_count;
1766						blks = do_count = 0;
1767						STps->eof = ST_EOM_ERROR;
1768						STps->drv_block = (-1); /* Too cautious? */
1769						retval = (-EIO);	/* EOM for old data */
1770						DEBC(printk(ST_DEB_MSG
1771							    "%s: EOM with lost data.\n",
1772							    name));
1773					}
1774				}
1775			} else {
1776				count += do_count;
1777				STps->drv_block = (-1);		/* Too cautious? */
1778				retval = STbp->syscall_result;
1779			}
1780
1781		}
1782
1783		if (STps->drv_block >= 0) {
1784			if (STp->block_size == 0)
1785				STps->drv_block += (do_count > 0);
1786			else
1787				STps->drv_block += blks;
1788		}
1789
1790		STbp->buffer_bytes = 0;
1791		STp->dirty = 0;
1792
1793		if (retval || retry_eot) {
1794			if (count < total)
1795				retval = total - count;
1796			goto out;
1797		}
1798	}
1799
1800	if (STps->eof == ST_EOD_1)
1801		STps->eof = ST_EOM_OK;
1802	else if (STps->eof != ST_EOM_OK)
1803		STps->eof = ST_NOEOF;
1804	retval = total - count;
1805
1806 out:
1807	if (SRpnt != NULL)
1808		st_release_request(SRpnt);
1809	release_buffering(STp, 0);
1810	mutex_unlock(&STp->lock);
1811
1812	return retval;
1813}
1814
1815/* Read data from the tape. Returns zero in the normal case, one if the
1816   eof status has changed, and the negative error code in case of a
1817   fatal error. Otherwise updates the buffer and the eof state.
1818
1819   Does release user buffer mapping if it is set.
1820*/
1821static long read_tape(struct scsi_tape *STp, long count,
1822		      struct st_request ** aSRpnt)
1823{
1824	int transfer, blks, bytes;
1825	unsigned char cmd[MAX_COMMAND_SIZE];
1826	struct st_request *SRpnt;
1827	struct st_modedef *STm;
1828	struct st_partstat *STps;
1829	struct st_buffer *STbp;
1830	int retval = 0;
1831	char *name = tape_name(STp);
1832
1833	if (count == 0)
1834		return 0;
1835
1836	STm = &(STp->modes[STp->current_mode]);
1837	STps = &(STp->ps[STp->partition]);
1838	if (STps->eof == ST_FM_HIT)
1839		return 1;
1840	STbp = STp->buffer;
1841
1842	if (STp->block_size == 0)
1843		blks = bytes = count;
1844	else {
1845		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1846			blks = (STp->buffer)->buffer_blocks;
1847			bytes = blks * STp->block_size;
1848		} else {
1849			bytes = count;
1850			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1851				bytes = (STp->buffer)->buffer_size;
1852			blks = bytes / STp->block_size;
1853			bytes = blks * STp->block_size;
1854		}
1855	}
1856
1857	memset(cmd, 0, MAX_COMMAND_SIZE);
1858	cmd[0] = READ_6;
1859	cmd[1] = (STp->block_size != 0);
1860	if (!cmd[1] && STp->sili)
1861		cmd[1] |= 2;
1862	cmd[2] = blks >> 16;
1863	cmd[3] = blks >> 8;
1864	cmd[4] = blks;
1865
1866	SRpnt = *aSRpnt;
1867	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1868			   STp->device->request_queue->rq_timeout,
1869			   MAX_RETRIES, 1);
1870	release_buffering(STp, 1);
1871	*aSRpnt = SRpnt;
1872	if (!SRpnt)
1873		return STbp->syscall_result;
1874
1875	STbp->read_pointer = 0;
1876	STps->at_sm = 0;
1877
1878	/* Something to check */
1879	if (STbp->syscall_result) {
1880		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1881
1882		retval = 1;
1883		DEBC(printk(ST_DEB_MSG "%s: Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1884                            name,
1885                            SRpnt->sense[0], SRpnt->sense[1],
1886                            SRpnt->sense[2], SRpnt->sense[3],
1887                            SRpnt->sense[4], SRpnt->sense[5],
1888                            SRpnt->sense[6], SRpnt->sense[7]));
1889		if (cmdstatp->have_sense) {
1890
1891			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1892				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1893
1894			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1895				/* Compute the residual count */
1896				if (cmdstatp->remainder_valid)
1897					transfer = (int)cmdstatp->uremainder64;
1898				else
1899					transfer = 0;
1900				if (STp->block_size == 0 &&
1901				    cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR)
1902					transfer = bytes;
1903
1904				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1905					if (STp->block_size == 0) {
1906						if (transfer <= 0) {
1907							if (transfer < 0)
1908								printk(KERN_NOTICE
1909								       "%s: Failed to read %d byte block with %d byte transfer.\n",
1910								       name, bytes - transfer, bytes);
1911							if (STps->drv_block >= 0)
1912								STps->drv_block += 1;
1913							STbp->buffer_bytes = 0;
1914							return (-ENOMEM);
1915						}
1916						STbp->buffer_bytes = bytes - transfer;
1917					} else {
1918						st_release_request(SRpnt);
1919						SRpnt = *aSRpnt = NULL;
1920						if (transfer == blks) {	/* We did not get anything, error */
1921							printk(KERN_NOTICE "%s: Incorrect block size.\n", name);
1922							if (STps->drv_block >= 0)
1923								STps->drv_block += blks - transfer + 1;
1924							st_int_ioctl(STp, MTBSR, 1);
1925							return (-EIO);
1926						}
1927						/* We have some data, deliver it */
1928						STbp->buffer_bytes = (blks - transfer) *
1929						    STp->block_size;
1930                                                DEBC(printk(ST_DEB_MSG
1931                                                            "%s: ILI but enough data received %ld %d.\n",
1932                                                            name, count, STbp->buffer_bytes));
1933						if (STps->drv_block >= 0)
1934							STps->drv_block += 1;
1935						if (st_int_ioctl(STp, MTBSR, 1))
1936							return (-EIO);
1937					}
1938				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
1939					if (STps->eof != ST_FM_HIT)
1940						STps->eof = ST_FM_HIT;
1941					else
1942						STps->eof = ST_EOD_2;
1943					if (STp->block_size == 0)
1944						STbp->buffer_bytes = 0;
1945					else
1946						STbp->buffer_bytes =
1947						    bytes - transfer * STp->block_size;
1948                                        DEBC(printk(ST_DEB_MSG
1949                                                    "%s: EOF detected (%d bytes read).\n",
1950                                                    name, STbp->buffer_bytes));
1951				} else if (cmdstatp->flags & SENSE_EOM) {
1952					if (STps->eof == ST_FM)
1953						STps->eof = ST_EOD_1;
1954					else
1955						STps->eof = ST_EOM_OK;
1956					if (STp->block_size == 0)
1957						STbp->buffer_bytes = bytes - transfer;
1958					else
1959						STbp->buffer_bytes =
1960						    bytes - transfer * STp->block_size;
1961
1962                                        DEBC(printk(ST_DEB_MSG "%s: EOM detected (%d bytes read).\n",
1963                                                    name, STbp->buffer_bytes));
1964				}
1965			}
1966			/* end of EOF, EOM, ILI test */ 
1967			else {	/* nonzero sense key */
1968                                DEBC(printk(ST_DEB_MSG
1969                                            "%s: Tape error while reading.\n", name));
1970				STps->drv_block = (-1);
1971				if (STps->eof == ST_FM &&
1972				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
1973                                        DEBC(printk(ST_DEB_MSG
1974                                                    "%s: Zero returned for first BLANK CHECK after EOF.\n",
1975                                                    name));
1976					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
1977				} else	/* Some other extended sense code */
1978					retval = (-EIO);
1979			}
1980
1981			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
1982				STbp->buffer_bytes = 0;
1983		}
1984		/* End of extended sense test */ 
1985		else {		/* Non-extended sense */
1986			retval = STbp->syscall_result;
1987		}
1988
1989	}
1990	/* End of error handling */ 
1991	else {			/* Read successful */
1992		STbp->buffer_bytes = bytes;
1993		if (STp->sili) /* In fixed block mode residual is always zero here */
1994			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
1995	}
1996
1997	if (STps->drv_block >= 0) {
1998		if (STp->block_size == 0)
1999			STps->drv_block++;
2000		else
2001			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2002	}
2003	return retval;
2004}
2005
2006
2007/* Read command */
2008static ssize_t
2009st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2010{
2011	ssize_t total;
2012	ssize_t retval = 0;
2013	ssize_t i, transfer;
2014	int special, do_dio = 0;
2015	struct st_request *SRpnt = NULL;
2016	struct scsi_tape *STp = filp->private_data;
2017	struct st_modedef *STm;
2018	struct st_partstat *STps;
2019	struct st_buffer *STbp = STp->buffer;
2020	DEB( char *name = tape_name(STp); )
2021
2022	if (mutex_lock_interruptible(&STp->lock))
2023		return -ERESTARTSYS;
2024
2025	retval = rw_checks(STp, filp, count);
2026	if (retval || count == 0)
2027		goto out;
2028
2029	STm = &(STp->modes[STp->current_mode]);
2030	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2031		if (!STm->do_read_ahead) {
2032			retval = (-EINVAL);	/* Read must be integral number of blocks */
2033			goto out;
2034		}
2035		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2036	}
2037
2038	STps = &(STp->ps[STp->partition]);
2039	if (STps->rw == ST_WRITING) {
2040		retval = flush_buffer(STp, 0);
2041		if (retval)
2042			goto out;
2043		STps->rw = ST_READING;
2044	}
2045        DEB(
2046	if (debugging && STps->eof != ST_NOEOF)
2047		printk(ST_DEB_MSG "%s: EOF/EOM flag up (%d). Bytes %d\n", name,
2048		       STps->eof, STbp->buffer_bytes);
2049        ) /* end DEB */
2050
2051	retval = setup_buffering(STp, buf, count, 1);
2052	if (retval)
2053		goto out;
2054	do_dio = STbp->do_dio;
2055
2056	if (STbp->buffer_bytes == 0 &&
2057	    STps->eof >= ST_EOD_1) {
2058		if (STps->eof < ST_EOD) {
2059			STps->eof += 1;
2060			retval = 0;
2061			goto out;
2062		}
2063		retval = (-EIO);	/* EOM or Blank Check */
2064		goto out;
2065	}
2066
2067	if (do_dio) {
2068		/* Check the buffer writability before any tape movement. Don't alter
2069		   buffer data. */
2070		if (copy_from_user(&i, buf, 1) != 0 ||
2071		    copy_to_user(buf, &i, 1) != 0 ||
2072		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2073		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2074			retval = (-EFAULT);
2075			goto out;
2076		}
2077	}
2078
2079	STps->rw = ST_READING;
2080
2081
2082	/* Loop until enough data in buffer or a special condition found */
2083	for (total = 0, special = 0; total < count && !special;) {
2084
2085		/* Get new data if the buffer is empty */
2086		if (STbp->buffer_bytes == 0) {
2087			special = read_tape(STp, count - total, &SRpnt);
2088			if (special < 0) {	/* No need to continue read */
2089				retval = special;
2090				goto out;
2091			}
2092		}
2093
2094		/* Move the data from driver buffer to user buffer */
2095		if (STbp->buffer_bytes > 0) {
2096                        DEB(
2097			if (debugging && STps->eof != ST_NOEOF)
2098				printk(ST_DEB_MSG
2099                                       "%s: EOF up (%d). Left %d, needed %d.\n", name,
2100				       STps->eof, STbp->buffer_bytes,
2101                                       (int)(count - total));
2102                        ) /* end DEB */
2103			transfer = STbp->buffer_bytes < count - total ?
2104			    STbp->buffer_bytes : count - total;
2105			if (!do_dio) {
2106				i = from_buffer(STbp, buf, transfer);
2107				if (i) {
2108					retval = i;
2109					goto out;
2110				}
2111			}
2112			buf += transfer;
2113			total += transfer;
2114		}
2115
2116		if (STp->block_size == 0)
2117			break;	/* Read only one variable length block */
2118
2119	}			/* for (total = 0, special = 0;
2120                                   total < count && !special; ) */
2121
2122	/* Change the eof state if no data from tape or buffer */
2123	if (total == 0) {
2124		if (STps->eof == ST_FM_HIT) {
2125			STps->eof = ST_FM;
2126			STps->drv_block = 0;
2127			if (STps->drv_file >= 0)
2128				STps->drv_file++;
2129		} else if (STps->eof == ST_EOD_1) {
2130			STps->eof = ST_EOD_2;
2131			STps->drv_block = 0;
2132			if (STps->drv_file >= 0)
2133				STps->drv_file++;
2134		} else if (STps->eof == ST_EOD_2)
2135			STps->eof = ST_EOD;
2136	} else if (STps->eof == ST_FM)
2137		STps->eof = ST_NOEOF;
2138	retval = total;
2139
2140 out:
2141	if (SRpnt != NULL) {
2142		st_release_request(SRpnt);
2143		SRpnt = NULL;
2144	}
2145	if (do_dio) {
2146		release_buffering(STp, 1);
2147		STbp->buffer_bytes = 0;
2148	}
2149	mutex_unlock(&STp->lock);
2150
2151	return retval;
2152}
2153
2154
2155
2156DEB(
2157/* Set the driver options */
2158static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm, char *name)
2159{
2160	if (debugging) {
2161		printk(KERN_INFO
2162		       "%s: Mode %d options: buffer writes: %d, async writes: %d, read ahead: %d\n",
2163		       name, STp->current_mode, STm->do_buffer_writes, STm->do_async_writes,
2164		       STm->do_read_ahead);
2165		printk(KERN_INFO
2166		       "%s:    can bsr: %d, two FMs: %d, fast mteom: %d, auto lock: %d,\n",
2167		       name, STp->can_bsr, STp->two_fm, STp->fast_mteom, STp->do_auto_lock);
2168		printk(KERN_INFO
2169		       "%s:    defs for wr: %d, no block limits: %d, partitions: %d, s2 log: %d\n",
2170		       name, STm->defaults_for_writes, STp->omit_blklims, STp->can_partitions,
2171		       STp->scsi2_logical);
2172		printk(KERN_INFO
2173		       "%s:    sysv: %d nowait: %d sili: %d\n", name, STm->sysv, STp->immediate,
2174			STp->sili);
 
2175		printk(KERN_INFO "%s:    debugging: %d\n",
2176		       name, debugging);
2177	}
2178}
2179	)
2180
2181
2182static int st_set_options(struct scsi_tape *STp, long options)
2183{
2184	int value;
2185	long code;
2186	struct st_modedef *STm;
2187	char *name = tape_name(STp);
2188	struct cdev *cd0, *cd1;
2189
2190	STm = &(STp->modes[STp->current_mode]);
2191	if (!STm->defined) {
2192		cd0 = STm->cdevs[0]; cd1 = STm->cdevs[1];
2193		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2194		STm->cdevs[0] = cd0; STm->cdevs[1] = cd1;
2195		modes_defined = 1;
2196                DEBC(printk(ST_DEB_MSG
2197                            "%s: Initialized mode %d definition from mode 0\n",
2198                            name, STp->current_mode));
2199	}
2200
2201	code = options & MT_ST_OPTIONS;
2202	if (code == MT_ST_BOOLEANS) {
2203		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2204		STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2205		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2206		STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2207		STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2208		STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2209		STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2210		STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2211		STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2212		if ((STp->device)->scsi_level >= SCSI_2)
2213			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2214		STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2215		STp->immediate = (options & MT_ST_NOWAIT) != 0;
 
2216		STm->sysv = (options & MT_ST_SYSV) != 0;
2217		STp->sili = (options & MT_ST_SILI) != 0;
2218		DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2219		     st_log_options(STp, STm, name); )
2220	} else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2221		value = (code == MT_ST_SETBOOLEANS);
2222		if ((options & MT_ST_BUFFER_WRITES) != 0)
2223			STm->do_buffer_writes = value;
2224		if ((options & MT_ST_ASYNC_WRITES) != 0)
2225			STm->do_async_writes = value;
2226		if ((options & MT_ST_DEF_WRITES) != 0)
2227			STm->defaults_for_writes = value;
2228		if ((options & MT_ST_READ_AHEAD) != 0)
2229			STm->do_read_ahead = value;
2230		if ((options & MT_ST_TWO_FM) != 0)
2231			STp->two_fm = value;
2232		if ((options & MT_ST_FAST_MTEOM) != 0)
2233			STp->fast_mteom = value;
2234		if ((options & MT_ST_AUTO_LOCK) != 0)
2235			STp->do_auto_lock = value;
2236		if ((options & MT_ST_CAN_BSR) != 0)
2237			STp->can_bsr = value;
2238		if ((options & MT_ST_NO_BLKLIMS) != 0)
2239			STp->omit_blklims = value;
2240		if ((STp->device)->scsi_level >= SCSI_2 &&
2241		    (options & MT_ST_CAN_PARTITIONS) != 0)
2242			STp->can_partitions = value;
2243		if ((options & MT_ST_SCSI2LOGICAL) != 0)
2244			STp->scsi2_logical = value;
2245		if ((options & MT_ST_NOWAIT) != 0)
2246			STp->immediate = value;
 
 
2247		if ((options & MT_ST_SYSV) != 0)
2248			STm->sysv = value;
2249		if ((options & MT_ST_SILI) != 0)
2250			STp->sili = value;
2251                DEB(
2252		if ((options & MT_ST_DEBUGGING) != 0)
2253			debugging = value;
2254			st_log_options(STp, STm, name); )
2255	} else if (code == MT_ST_WRITE_THRESHOLD) {
2256		/* Retained for compatibility */
2257	} else if (code == MT_ST_DEF_BLKSIZE) {
2258		value = (options & ~MT_ST_OPTIONS);
2259		if (value == ~MT_ST_OPTIONS) {
2260			STm->default_blksize = (-1);
2261			DEBC( printk(KERN_INFO "%s: Default block size disabled.\n", name));
2262		} else {
2263			STm->default_blksize = value;
2264			DEBC( printk(KERN_INFO "%s: Default block size set to %d bytes.\n",
2265			       name, STm->default_blksize));
2266			if (STp->ready == ST_READY) {
2267				STp->blksize_changed = 0;
2268				set_mode_densblk(STp, STm);
2269			}
2270		}
2271	} else if (code == MT_ST_TIMEOUTS) {
2272		value = (options & ~MT_ST_OPTIONS);
2273		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2274			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2275			DEBC( printk(KERN_INFO "%s: Long timeout set to %d seconds.\n", name,
2276			       (value & ~MT_ST_SET_LONG_TIMEOUT)));
2277		} else {
2278			blk_queue_rq_timeout(STp->device->request_queue,
2279					     value * HZ);
2280			DEBC( printk(KERN_INFO "%s: Normal timeout set to %d seconds.\n",
2281				name, value) );
2282		}
2283	} else if (code == MT_ST_SET_CLN) {
2284		value = (options & ~MT_ST_OPTIONS) & 0xff;
2285		if (value != 0 &&
2286			(value < EXTENDED_SENSE_START ||
2287				value >= SCSI_SENSE_BUFFERSIZE))
2288			return (-EINVAL);
2289		STp->cln_mode = value;
2290		STp->cln_sense_mask = (options >> 8) & 0xff;
2291		STp->cln_sense_value = (options >> 16) & 0xff;
2292		printk(KERN_INFO
2293		       "%s: Cleaning request mode %d, mask %02x, value %02x\n",
2294		       name, value, STp->cln_sense_mask, STp->cln_sense_value);
2295	} else if (code == MT_ST_DEF_OPTIONS) {
2296		code = (options & ~MT_ST_CLEAR_DEFAULT);
2297		value = (options & MT_ST_CLEAR_DEFAULT);
2298		if (code == MT_ST_DEF_DENSITY) {
2299			if (value == MT_ST_CLEAR_DEFAULT) {
2300				STm->default_density = (-1);
2301				DEBC( printk(KERN_INFO "%s: Density default disabled.\n",
2302                                       name));
2303			} else {
2304				STm->default_density = value & 0xff;
2305				DEBC( printk(KERN_INFO "%s: Density default set to %x\n",
2306				       name, STm->default_density));
2307				if (STp->ready == ST_READY) {
2308					STp->density_changed = 0;
2309					set_mode_densblk(STp, STm);
2310				}
2311			}
2312		} else if (code == MT_ST_DEF_DRVBUFFER) {
2313			if (value == MT_ST_CLEAR_DEFAULT) {
2314				STp->default_drvbuffer = 0xff;
2315				DEBC( printk(KERN_INFO
2316                                       "%s: Drive buffer default disabled.\n", name));
2317			} else {
2318				STp->default_drvbuffer = value & 7;
2319				DEBC( printk(KERN_INFO
2320                                       "%s: Drive buffer default set to %x\n",
2321				       name, STp->default_drvbuffer));
2322				if (STp->ready == ST_READY)
2323					st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2324			}
2325		} else if (code == MT_ST_DEF_COMPRESSION) {
2326			if (value == MT_ST_CLEAR_DEFAULT) {
2327				STm->default_compression = ST_DONT_TOUCH;
2328				DEBC( printk(KERN_INFO
2329                                       "%s: Compression default disabled.\n", name));
2330			} else {
2331				if ((value & 0xff00) != 0) {
2332					STp->c_algo = (value & 0xff00) >> 8;
2333					DEBC( printk(KERN_INFO "%s: Compression algorithm set to 0x%x.\n",
2334					       name, STp->c_algo));
2335				}
2336				if ((value & 0xff) != 0xff) {
2337					STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2338					DEBC( printk(KERN_INFO "%s: Compression default set to %x\n",
2339					       name, (value & 1)));
2340					if (STp->ready == ST_READY) {
2341						STp->compression_changed = 0;
2342						st_compression(STp, (STm->default_compression == ST_YES));
2343					}
2344				}
2345			}
2346		}
2347	} else
2348		return (-EIO);
2349
2350	return 0;
2351}
2352
2353#define MODE_HEADER_LENGTH  4
2354
2355/* Mode header and page byte offsets */
2356#define MH_OFF_DATA_LENGTH     0
2357#define MH_OFF_MEDIUM_TYPE     1
2358#define MH_OFF_DEV_SPECIFIC    2
2359#define MH_OFF_BDESCS_LENGTH   3
2360#define MP_OFF_PAGE_NBR        0
2361#define MP_OFF_PAGE_LENGTH     1
2362
2363/* Mode header and page bit masks */
2364#define MH_BIT_WP              0x80
2365#define MP_MSK_PAGE_NBR        0x3f
2366
2367/* Don't return block descriptors */
2368#define MODE_SENSE_OMIT_BDESCS 0x08
2369
2370#define MODE_SELECT_PAGE_FORMAT 0x10
2371
2372/* Read a mode page into the tape buffer. The block descriptors are included
2373   if incl_block_descs is true. The page control is ored to the page number
2374   parameter, if necessary. */
2375static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2376{
2377	unsigned char cmd[MAX_COMMAND_SIZE];
2378	struct st_request *SRpnt;
2379
2380	memset(cmd, 0, MAX_COMMAND_SIZE);
2381	cmd[0] = MODE_SENSE;
2382	if (omit_block_descs)
2383		cmd[1] = MODE_SENSE_OMIT_BDESCS;
2384	cmd[2] = page;
2385	cmd[4] = 255;
2386
2387	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2388			   STp->device->request_queue->rq_timeout, 0, 1);
2389	if (SRpnt == NULL)
2390		return (STp->buffer)->syscall_result;
2391
2392	st_release_request(SRpnt);
2393
2394	return STp->buffer->syscall_result;
2395}
2396
2397
2398/* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2399   in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2400static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2401{
2402	int pgo;
2403	unsigned char cmd[MAX_COMMAND_SIZE];
2404	struct st_request *SRpnt;
2405	int timeout;
2406
2407	memset(cmd, 0, MAX_COMMAND_SIZE);
2408	cmd[0] = MODE_SELECT;
2409	cmd[1] = MODE_SELECT_PAGE_FORMAT;
2410	pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2411	cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2412
2413	/* Clear reserved fields */
2414	(STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2415	(STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2416	(STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2417	(STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2418
2419	timeout = slow ?
2420		STp->long_timeout : STp->device->request_queue->rq_timeout;
2421	SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2422			   timeout, 0, 1);
2423	if (SRpnt == NULL)
2424		return (STp->buffer)->syscall_result;
2425
2426	st_release_request(SRpnt);
2427
2428	return STp->buffer->syscall_result;
2429}
2430
2431
2432#define COMPRESSION_PAGE        0x0f
2433#define COMPRESSION_PAGE_LENGTH 16
2434
2435#define CP_OFF_DCE_DCC          2
2436#define CP_OFF_C_ALGO           7
2437
2438#define DCE_MASK  0x80
2439#define DCC_MASK  0x40
2440#define RED_MASK  0x60
2441
2442
2443/* Control the compression with mode page 15. Algorithm not changed if zero.
2444
2445   The block descriptors are read and written because Sony SDT-7000 does not
2446   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2447   Including block descriptors should not cause any harm to other drives. */
2448
2449static int st_compression(struct scsi_tape * STp, int state)
2450{
2451	int retval;
2452	int mpoffs;  /* Offset to mode page start */
2453	unsigned char *b_data = (STp->buffer)->b_data;
2454	DEB( char *name = tape_name(STp); )
2455
2456	if (STp->ready != ST_READY)
2457		return (-EIO);
2458
2459	/* Read the current page contents */
2460	retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2461	if (retval) {
2462                DEBC(printk(ST_DEB_MSG "%s: Compression mode page not supported.\n",
2463                            name));
2464		return (-EIO);
2465	}
2466
2467	mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2468        DEBC(printk(ST_DEB_MSG "%s: Compression state is %d.\n", name,
2469                    (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0)));
2470
2471	/* Check if compression can be changed */
2472	if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2473                DEBC(printk(ST_DEB_MSG "%s: Compression not supported.\n", name));
2474		return (-EIO);
2475	}
2476
2477	/* Do the change */
2478	if (state) {
2479		b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2480		if (STp->c_algo != 0)
2481			b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2482	}
2483	else {
2484		b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2485		if (STp->c_algo != 0)
2486			b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2487	}
2488
2489	retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2490	if (retval) {
2491                DEBC(printk(ST_DEB_MSG "%s: Compression change failed.\n", name));
2492		return (-EIO);
2493	}
2494        DEBC(printk(ST_DEB_MSG "%s: Compression state changed to %d.\n",
2495		       name, state));
2496
2497	STp->compression_changed = 1;
2498	return 0;
2499}
2500
2501
2502/* Process the load and unload commands (does unload if the load code is zero) */
2503static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2504{
2505	int retval = (-EIO), timeout;
2506	DEB( char *name = tape_name(STp); )
2507	unsigned char cmd[MAX_COMMAND_SIZE];
2508	struct st_partstat *STps;
2509	struct st_request *SRpnt;
2510
2511	if (STp->ready != ST_READY && !load_code) {
2512		if (STp->ready == ST_NO_TAPE)
2513			return (-ENOMEDIUM);
2514		else
2515			return (-EIO);
2516	}
2517
2518	memset(cmd, 0, MAX_COMMAND_SIZE);
2519	cmd[0] = START_STOP;
2520	if (load_code)
2521		cmd[4] |= 1;
2522	/*
2523	 * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2524	 */
2525	if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2526	    && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2527		DEBC(printk(ST_DEB_MSG "%s: Enhanced %sload slot %2d.\n",
2528			    name, (cmd[4]) ? "" : "un",
2529			    load_code - MT_ST_HPLOADER_OFFSET));
2530		cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2531	}
2532	if (STp->immediate) {
2533		cmd[1] = 1;	/* Don't wait for completion */
2534		timeout = STp->device->request_queue->rq_timeout;
2535	}
2536	else
2537		timeout = STp->long_timeout;
2538
2539	DEBC(
2540		if (!load_code)
2541		printk(ST_DEB_MSG "%s: Unloading tape.\n", name);
2542		else
2543		printk(ST_DEB_MSG "%s: Loading tape.\n", name);
2544		);
2545
2546	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2547			   timeout, MAX_RETRIES, 1);
2548	if (!SRpnt)
2549		return (STp->buffer)->syscall_result;
2550
2551	retval = (STp->buffer)->syscall_result;
2552	st_release_request(SRpnt);
2553
2554	if (!retval) {	/* SCSI command successful */
2555
2556		if (!load_code) {
2557			STp->rew_at_close = 0;
2558			STp->ready = ST_NO_TAPE;
2559		}
2560		else {
2561			STp->rew_at_close = STp->autorew_dev;
2562			retval = check_tape(STp, filp);
2563			if (retval > 0)
2564				retval = 0;
2565		}
2566	}
2567	else {
2568		STps = &(STp->ps[STp->partition]);
2569		STps->drv_file = STps->drv_block = (-1);
2570	}
2571
2572	return retval;
2573}
2574
2575#if DEBUG
2576#define ST_DEB_FORWARD  0
2577#define ST_DEB_BACKWARD 1
2578static void deb_space_print(char *name, int direction, char *units, unsigned char *cmd)
2579{
2580	s32 sc;
2581
2582	sc = cmd[2] & 0x80 ? 0xff000000 : 0;
2583	sc |= (cmd[2] << 16) | (cmd[3] << 8) | cmd[4];
2584	if (direction)
2585		sc = -sc;
2586	printk(ST_DEB_MSG "%s: Spacing tape %s over %d %s.\n", name,
2587	       direction ? "backward" : "forward", sc, units);
2588}
2589#endif
2590
2591
2592/* Internal ioctl function */
2593static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2594{
2595	int timeout;
2596	long ltmp;
2597	int ioctl_result;
2598	int chg_eof = 1;
2599	unsigned char cmd[MAX_COMMAND_SIZE];
2600	struct st_request *SRpnt;
2601	struct st_partstat *STps;
2602	int fileno, blkno, at_sm, undone;
2603	int datalen = 0, direction = DMA_NONE;
2604	char *name = tape_name(STp);
2605
2606	WARN_ON(STp->buffer->do_dio != 0);
2607	if (STp->ready != ST_READY) {
2608		if (STp->ready == ST_NO_TAPE)
2609			return (-ENOMEDIUM);
2610		else
2611			return (-EIO);
2612	}
2613	timeout = STp->long_timeout;
2614	STps = &(STp->ps[STp->partition]);
2615	fileno = STps->drv_file;
2616	blkno = STps->drv_block;
2617	at_sm = STps->at_sm;
2618
2619	memset(cmd, 0, MAX_COMMAND_SIZE);
2620	switch (cmd_in) {
2621	case MTFSFM:
2622		chg_eof = 0;	/* Changed from the FSF after this */
2623	case MTFSF:
2624		cmd[0] = SPACE;
2625		cmd[1] = 0x01;	/* Space FileMarks */
2626		cmd[2] = (arg >> 16);
2627		cmd[3] = (arg >> 8);
2628		cmd[4] = arg;
2629                DEBC(deb_space_print(name, ST_DEB_FORWARD, "filemarks", cmd);)
2630		if (fileno >= 0)
2631			fileno += arg;
2632		blkno = 0;
2633		at_sm &= (arg == 0);
2634		break;
2635	case MTBSFM:
2636		chg_eof = 0;	/* Changed from the FSF after this */
2637	case MTBSF:
2638		cmd[0] = SPACE;
2639		cmd[1] = 0x01;	/* Space FileMarks */
2640		ltmp = (-arg);
2641		cmd[2] = (ltmp >> 16);
2642		cmd[3] = (ltmp >> 8);
2643		cmd[4] = ltmp;
2644                DEBC(deb_space_print(name, ST_DEB_BACKWARD, "filemarks", cmd);)
2645		if (fileno >= 0)
2646			fileno -= arg;
2647		blkno = (-1);	/* We can't know the block number */
2648		at_sm &= (arg == 0);
2649		break;
2650	case MTFSR:
2651		cmd[0] = SPACE;
2652		cmd[1] = 0x00;	/* Space Blocks */
2653		cmd[2] = (arg >> 16);
2654		cmd[3] = (arg >> 8);
2655		cmd[4] = arg;
2656                DEBC(deb_space_print(name, ST_DEB_FORWARD, "blocks", cmd);)
2657		if (blkno >= 0)
2658			blkno += arg;
2659		at_sm &= (arg == 0);
2660		break;
2661	case MTBSR:
2662		cmd[0] = SPACE;
2663		cmd[1] = 0x00;	/* Space Blocks */
2664		ltmp = (-arg);
2665		cmd[2] = (ltmp >> 16);
2666		cmd[3] = (ltmp >> 8);
2667		cmd[4] = ltmp;
2668                DEBC(deb_space_print(name, ST_DEB_BACKWARD, "blocks", cmd);)
2669		if (blkno >= 0)
2670			blkno -= arg;
2671		at_sm &= (arg == 0);
2672		break;
2673	case MTFSS:
2674		cmd[0] = SPACE;
2675		cmd[1] = 0x04;	/* Space Setmarks */
2676		cmd[2] = (arg >> 16);
2677		cmd[3] = (arg >> 8);
2678		cmd[4] = arg;
2679                DEBC(deb_space_print(name, ST_DEB_FORWARD, "setmarks", cmd);)
2680		if (arg != 0) {
2681			blkno = fileno = (-1);
2682			at_sm = 1;
2683		}
2684		break;
2685	case MTBSS:
2686		cmd[0] = SPACE;
2687		cmd[1] = 0x04;	/* Space Setmarks */
2688		ltmp = (-arg);
2689		cmd[2] = (ltmp >> 16);
2690		cmd[3] = (ltmp >> 8);
2691		cmd[4] = ltmp;
2692                DEBC(deb_space_print(name, ST_DEB_BACKWARD, "setmarks", cmd);)
2693		if (arg != 0) {
2694			blkno = fileno = (-1);
2695			at_sm = 1;
2696		}
2697		break;
2698	case MTWEOF:
2699	case MTWEOFI:
2700	case MTWSM:
2701		if (STp->write_prot)
2702			return (-EACCES);
2703		cmd[0] = WRITE_FILEMARKS;
2704		if (cmd_in == MTWSM)
2705			cmd[1] = 2;
2706		if (cmd_in == MTWEOFI)
 
2707			cmd[1] |= 1;
2708		cmd[2] = (arg >> 16);
2709		cmd[3] = (arg >> 8);
2710		cmd[4] = arg;
2711		timeout = STp->device->request_queue->rq_timeout;
2712                DEBC(
2713		     if (cmd_in != MTWSM)
2714                               printk(ST_DEB_MSG "%s: Writing %d filemarks.\n", name,
2715				 cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
2716                     else
2717				printk(ST_DEB_MSG "%s: Writing %d setmarks.\n", name,
2718				 cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
2719		)
2720		if (fileno >= 0)
2721			fileno += arg;
2722		blkno = 0;
2723		at_sm = (cmd_in == MTWSM);
2724		break;
2725	case MTREW:
2726		cmd[0] = REZERO_UNIT;
2727		if (STp->immediate) {
2728			cmd[1] = 1;	/* Don't wait for completion */
2729			timeout = STp->device->request_queue->rq_timeout;
2730		}
2731                DEBC(printk(ST_DEB_MSG "%s: Rewinding tape.\n", name));
2732		fileno = blkno = at_sm = 0;
2733		break;
2734	case MTNOP:
2735                DEBC(printk(ST_DEB_MSG "%s: No op on tape.\n", name));
2736		return 0;	/* Should do something ? */
2737		break;
2738	case MTRETEN:
2739		cmd[0] = START_STOP;
2740		if (STp->immediate) {
2741			cmd[1] = 1;	/* Don't wait for completion */
2742			timeout = STp->device->request_queue->rq_timeout;
2743		}
2744		cmd[4] = 3;
2745                DEBC(printk(ST_DEB_MSG "%s: Retensioning tape.\n", name));
2746		fileno = blkno = at_sm = 0;
2747		break;
2748	case MTEOM:
2749		if (!STp->fast_mteom) {
2750			/* space to the end of tape */
2751			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2752			fileno = STps->drv_file;
2753			if (STps->eof >= ST_EOD_1)
2754				return 0;
2755			/* The next lines would hide the number of spaced FileMarks
2756			   That's why I inserted the previous lines. I had no luck
2757			   with detecting EOM with FSF, so we go now to EOM.
2758			   Joerg Weule */
2759		} else
2760			fileno = (-1);
2761		cmd[0] = SPACE;
2762		cmd[1] = 3;
2763                DEBC(printk(ST_DEB_MSG "%s: Spacing to end of recorded medium.\n",
2764                            name));
2765		blkno = -1;
2766		at_sm = 0;
2767		break;
2768	case MTERASE:
2769		if (STp->write_prot)
2770			return (-EACCES);
2771		cmd[0] = ERASE;
2772		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
2773		if (STp->immediate) {
2774			cmd[1] |= 2;	/* Don't wait for completion */
2775			timeout = STp->device->request_queue->rq_timeout;
2776		}
2777		else
2778			timeout = STp->long_timeout * 8;
2779
2780                DEBC(printk(ST_DEB_MSG "%s: Erasing tape.\n", name));
2781		fileno = blkno = at_sm = 0;
2782		break;
2783	case MTSETBLK:		/* Set block length */
2784	case MTSETDENSITY:	/* Set tape density */
2785	case MTSETDRVBUFFER:	/* Set drive buffering */
2786	case SET_DENS_AND_BLK:	/* Set density and block size */
2787		chg_eof = 0;
2788		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2789			return (-EIO);	/* Not allowed if data in buffer */
2790		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2791		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2792		    STp->max_block > 0 &&
2793		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2794		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2795			printk(KERN_WARNING "%s: Illegal block size.\n", name);
2796			return (-EINVAL);
2797		}
2798		cmd[0] = MODE_SELECT;
2799		if ((STp->use_pf & USE_PF))
2800			cmd[1] = MODE_SELECT_PAGE_FORMAT;
2801		cmd[4] = datalen = 12;
2802		direction = DMA_TO_DEVICE;
2803
2804		memset((STp->buffer)->b_data, 0, 12);
2805		if (cmd_in == MTSETDRVBUFFER)
2806			(STp->buffer)->b_data[2] = (arg & 7) << 4;
2807		else
2808			(STp->buffer)->b_data[2] =
2809			    STp->drv_buffer << 4;
2810		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
2811		if (cmd_in == MTSETDENSITY) {
2812			(STp->buffer)->b_data[4] = arg;
2813			STp->density_changed = 1;	/* At least we tried ;-) */
2814		} else if (cmd_in == SET_DENS_AND_BLK)
2815			(STp->buffer)->b_data[4] = arg >> 24;
2816		else
2817			(STp->buffer)->b_data[4] = STp->density;
2818		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2819			ltmp = arg & MT_ST_BLKSIZE_MASK;
2820			if (cmd_in == MTSETBLK)
2821				STp->blksize_changed = 1; /* At least we tried ;-) */
2822		} else
2823			ltmp = STp->block_size;
2824		(STp->buffer)->b_data[9] = (ltmp >> 16);
2825		(STp->buffer)->b_data[10] = (ltmp >> 8);
2826		(STp->buffer)->b_data[11] = ltmp;
2827		timeout = STp->device->request_queue->rq_timeout;
2828                DEBC(
2829			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2830				printk(ST_DEB_MSG
2831                                       "%s: Setting block size to %d bytes.\n", name,
2832				       (STp->buffer)->b_data[9] * 65536 +
2833				       (STp->buffer)->b_data[10] * 256 +
2834				       (STp->buffer)->b_data[11]);
2835			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2836				printk(ST_DEB_MSG
2837                                       "%s: Setting density code to %x.\n", name,
2838				       (STp->buffer)->b_data[4]);
2839			if (cmd_in == MTSETDRVBUFFER)
2840				printk(ST_DEB_MSG
2841                                       "%s: Setting drive buffer code to %d.\n", name,
2842				    ((STp->buffer)->b_data[2] >> 4) & 7);
2843		)
2844		break;
2845	default:
2846		return (-ENOSYS);
2847	}
2848
2849	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2850			   timeout, MAX_RETRIES, 1);
2851	if (!SRpnt)
2852		return (STp->buffer)->syscall_result;
2853
2854	ioctl_result = (STp->buffer)->syscall_result;
2855
2856	if (!ioctl_result) {	/* SCSI command successful */
2857		st_release_request(SRpnt);
2858		SRpnt = NULL;
2859		STps->drv_block = blkno;
2860		STps->drv_file = fileno;
2861		STps->at_sm = at_sm;
2862
2863		if (cmd_in == MTBSFM)
2864			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2865		else if (cmd_in == MTFSFM)
2866			ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2867
2868		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2869			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2870			if (STp->block_size != 0) {
2871				(STp->buffer)->buffer_blocks =
2872				    (STp->buffer)->buffer_size / STp->block_size;
2873			}
2874			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2875			if (cmd_in == SET_DENS_AND_BLK)
2876				STp->density = arg >> MT_ST_DENSITY_SHIFT;
2877		} else if (cmd_in == MTSETDRVBUFFER)
2878			STp->drv_buffer = (arg & 7);
2879		else if (cmd_in == MTSETDENSITY)
2880			STp->density = arg;
2881
2882		if (cmd_in == MTEOM)
2883			STps->eof = ST_EOD;
2884		else if (cmd_in == MTFSF)
2885			STps->eof = ST_FM;
2886		else if (chg_eof)
2887			STps->eof = ST_NOEOF;
2888
2889		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
2890			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
2891	} else { /* SCSI command was not completely successful. Don't return
2892                    from this block without releasing the SCSI command block! */
2893		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
2894
2895		if (cmdstatp->flags & SENSE_EOM) {
2896			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
2897			    cmd_in != MTBSR && cmd_in != MTBSS)
2898				STps->eof = ST_EOM_OK;
2899			STps->drv_block = 0;
2900		}
2901
2902		if (cmdstatp->remainder_valid)
2903			undone = (int)cmdstatp->uremainder64;
2904		else
2905			undone = 0;
2906
2907		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
2908		    cmdstatp->have_sense &&
2909		    (cmdstatp->flags & SENSE_EOM)) {
2910			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
2911			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
2912				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
2913				STps->eof = ST_NOEOF;
2914			} else {  /* Writing EOF(s) failed */
2915				if (fileno >= 0)
2916					fileno -= undone;
2917				if (undone < arg)
2918					STps->eof = ST_NOEOF;
2919			}
2920			STps->drv_file = fileno;
2921		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
2922			if (fileno >= 0)
2923				STps->drv_file = fileno - undone;
2924			else
2925				STps->drv_file = fileno;
2926			STps->drv_block = -1;
2927			STps->eof = ST_NOEOF;
2928		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
2929			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
2930				undone = (-undone);
2931			if (STps->drv_file >= 0)
2932				STps->drv_file = fileno + undone;
2933			STps->drv_block = 0;
2934			STps->eof = ST_NOEOF;
2935		} else if (cmd_in == MTFSR) {
2936			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
2937				if (STps->drv_file >= 0)
2938					STps->drv_file++;
2939				STps->drv_block = 0;
2940				STps->eof = ST_FM;
2941			} else {
2942				if (blkno >= undone)
2943					STps->drv_block = blkno - undone;
2944				else
2945					STps->drv_block = (-1);
2946				STps->eof = ST_NOEOF;
2947			}
2948		} else if (cmd_in == MTBSR) {
2949			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
2950				STps->drv_file--;
2951				STps->drv_block = (-1);
2952			} else {
2953				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
2954					undone = (-undone);
2955				if (STps->drv_block >= 0)
2956					STps->drv_block = blkno + undone;
2957			}
2958			STps->eof = ST_NOEOF;
2959		} else if (cmd_in == MTEOM) {
2960			STps->drv_file = (-1);
2961			STps->drv_block = (-1);
2962			STps->eof = ST_EOD;
2963		} else if (cmd_in == MTSETBLK ||
2964			   cmd_in == MTSETDENSITY ||
2965			   cmd_in == MTSETDRVBUFFER ||
2966			   cmd_in == SET_DENS_AND_BLK) {
2967			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
2968			    !(STp->use_pf & PF_TESTED)) {
2969				/* Try the other possible state of Page Format if not
2970				   already tried */
2971				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
2972				st_release_request(SRpnt);
2973				SRpnt = NULL;
2974				return st_int_ioctl(STp, cmd_in, arg);
2975			}
2976		} else if (chg_eof)
2977			STps->eof = ST_NOEOF;
2978
2979		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
2980			STps->eof = ST_EOD;
2981
2982		st_release_request(SRpnt);
2983		SRpnt = NULL;
2984	}
2985
2986	return ioctl_result;
2987}
2988
2989
2990/* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
2991   structure. */
2992
2993static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
2994			int logical)
2995{
2996	int result;
2997	unsigned char scmd[MAX_COMMAND_SIZE];
2998	struct st_request *SRpnt;
2999	DEB( char *name = tape_name(STp); )
3000
3001	if (STp->ready != ST_READY)
3002		return (-EIO);
3003
3004	memset(scmd, 0, MAX_COMMAND_SIZE);
3005	if ((STp->device)->scsi_level < SCSI_2) {
3006		scmd[0] = QFA_REQUEST_BLOCK;
3007		scmd[4] = 3;
3008	} else {
3009		scmd[0] = READ_POSITION;
3010		if (!logical && !STp->scsi2_logical)
3011			scmd[1] = 1;
3012	}
3013	SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3014			   STp->device->request_queue->rq_timeout,
3015			   MAX_READY_RETRIES, 1);
3016	if (!SRpnt)
3017		return (STp->buffer)->syscall_result;
3018
3019	if ((STp->buffer)->syscall_result != 0 ||
3020	    (STp->device->scsi_level >= SCSI_2 &&
3021	     ((STp->buffer)->b_data[0] & 4) != 0)) {
3022		*block = *partition = 0;
3023                DEBC(printk(ST_DEB_MSG "%s: Can't read tape position.\n", name));
3024		result = (-EIO);
3025	} else {
3026		result = 0;
3027		if ((STp->device)->scsi_level < SCSI_2) {
3028			*block = ((STp->buffer)->b_data[0] << 16)
3029			    + ((STp->buffer)->b_data[1] << 8)
3030			    + (STp->buffer)->b_data[2];
3031			*partition = 0;
3032		} else {
3033			*block = ((STp->buffer)->b_data[4] << 24)
3034			    + ((STp->buffer)->b_data[5] << 16)
3035			    + ((STp->buffer)->b_data[6] << 8)
3036			    + (STp->buffer)->b_data[7];
3037			*partition = (STp->buffer)->b_data[1];
3038			if (((STp->buffer)->b_data[0] & 0x80) &&
3039			    (STp->buffer)->b_data[1] == 0)	/* BOP of partition 0 */
3040				STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3041		}
3042                DEBC(printk(ST_DEB_MSG "%s: Got tape pos. blk %d part %d.\n", name,
3043                            *block, *partition));
3044	}
3045	st_release_request(SRpnt);
3046	SRpnt = NULL;
3047
3048	return result;
3049}
3050
3051
3052/* Set the tape block and partition. Negative partition means that only the
3053   block should be set in vendor specific way. */
3054static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3055			int logical)
3056{
3057	struct st_partstat *STps;
3058	int result, p;
3059	unsigned int blk;
3060	int timeout;
3061	unsigned char scmd[MAX_COMMAND_SIZE];
3062	struct st_request *SRpnt;
3063	DEB( char *name = tape_name(STp); )
3064
3065	if (STp->ready != ST_READY)
3066		return (-EIO);
3067	timeout = STp->long_timeout;
3068	STps = &(STp->ps[STp->partition]);
3069
3070        DEBC(printk(ST_DEB_MSG "%s: Setting block to %d and partition to %d.\n",
3071                    name, block, partition));
3072	DEB(if (partition < 0)
3073		return (-EIO); )
3074
3075	/* Update the location at the partition we are leaving */
3076	if ((!STp->can_partitions && partition != 0) ||
3077	    partition >= ST_NBR_PARTITIONS)
3078		return (-EINVAL);
3079	if (partition != STp->partition) {
3080		if (get_location(STp, &blk, &p, 1))
3081			STps->last_block_valid = 0;
3082		else {
3083			STps->last_block_valid = 1;
3084			STps->last_block_visited = blk;
3085                        DEBC(printk(ST_DEB_MSG
3086                                    "%s: Visited block %d for partition %d saved.\n",
3087                                    name, blk, STp->partition));
3088		}
3089	}
3090
3091	memset(scmd, 0, MAX_COMMAND_SIZE);
3092	if ((STp->device)->scsi_level < SCSI_2) {
3093		scmd[0] = QFA_SEEK_BLOCK;
3094		scmd[2] = (block >> 16);
3095		scmd[3] = (block >> 8);
3096		scmd[4] = block;
3097		scmd[5] = 0;
3098	} else {
3099		scmd[0] = SEEK_10;
3100		scmd[3] = (block >> 24);
3101		scmd[4] = (block >> 16);
3102		scmd[5] = (block >> 8);
3103		scmd[6] = block;
3104		if (!logical && !STp->scsi2_logical)
3105			scmd[1] = 4;
3106		if (STp->partition != partition) {
3107			scmd[1] |= 2;
3108			scmd[8] = partition;
3109                        DEBC(printk(ST_DEB_MSG
3110                                    "%s: Trying to change partition from %d to %d\n",
3111                                    name, STp->partition, partition));
3112		}
3113	}
3114	if (STp->immediate) {
3115		scmd[1] |= 1;		/* Don't wait for completion */
3116		timeout = STp->device->request_queue->rq_timeout;
3117	}
3118
3119	SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3120			   timeout, MAX_READY_RETRIES, 1);
3121	if (!SRpnt)
3122		return (STp->buffer)->syscall_result;
3123
3124	STps->drv_block = STps->drv_file = (-1);
3125	STps->eof = ST_NOEOF;
3126	if ((STp->buffer)->syscall_result != 0) {
3127		result = (-EIO);
3128		if (STp->can_partitions &&
3129		    (STp->device)->scsi_level >= SCSI_2 &&
3130		    (p = find_partition(STp)) >= 0)
3131			STp->partition = p;
3132	} else {
3133		if (STp->can_partitions) {
3134			STp->partition = partition;
3135			STps = &(STp->ps[partition]);
3136			if (!STps->last_block_valid ||
3137			    STps->last_block_visited != block) {
3138				STps->at_sm = 0;
3139				STps->rw = ST_IDLE;
3140			}
3141		} else
3142			STps->at_sm = 0;
3143		if (block == 0)
3144			STps->drv_block = STps->drv_file = 0;
3145		result = 0;
3146	}
3147
3148	st_release_request(SRpnt);
3149	SRpnt = NULL;
3150
3151	return result;
3152}
3153
3154
3155/* Find the current partition number for the drive status. Called from open and
3156   returns either partition number of negative error code. */
3157static int find_partition(struct scsi_tape *STp)
3158{
3159	int i, partition;
3160	unsigned int block;
3161
3162	if ((i = get_location(STp, &block, &partition, 1)) < 0)
3163		return i;
3164	if (partition >= ST_NBR_PARTITIONS)
3165		return (-EIO);
3166	return partition;
3167}
3168
3169
3170/* Change the partition if necessary */
3171static int switch_partition(struct scsi_tape *STp)
3172{
3173	struct st_partstat *STps;
3174
3175	if (STp->partition == STp->new_partition)
3176		return 0;
3177	STps = &(STp->ps[STp->new_partition]);
3178	if (!STps->last_block_valid)
3179		STps->last_block_visited = 0;
3180	return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3181}
3182
3183/* Functions for reading and writing the medium partition mode page. */
3184
3185#define PART_PAGE   0x11
3186#define PART_PAGE_FIXED_LENGTH 8
3187
3188#define PP_OFF_MAX_ADD_PARTS   2
3189#define PP_OFF_NBR_ADD_PARTS   3
3190#define PP_OFF_FLAGS           4
3191#define PP_OFF_PART_UNITS      6
3192#define PP_OFF_RESERVED        7
3193
3194#define PP_BIT_IDP             0x20
3195#define PP_MSK_PSUM_MB         0x10
3196
3197/* Get the number of partitions on the tape. As a side effect reads the
3198   mode page into the tape buffer. */
3199static int nbr_partitions(struct scsi_tape *STp)
3200{
3201	int result;
3202	DEB( char *name = tape_name(STp); )
3203
3204	if (STp->ready != ST_READY)
3205		return (-EIO);
3206
3207	result = read_mode_page(STp, PART_PAGE, 1);
3208
3209	if (result) {
3210                DEBC(printk(ST_DEB_MSG "%s: Can't read medium partition page.\n",
3211                            name));
3212		result = (-EIO);
3213	} else {
3214		result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3215					      PP_OFF_NBR_ADD_PARTS] + 1;
3216                DEBC(printk(ST_DEB_MSG "%s: Number of partitions %d.\n", name, result));
3217	}
3218
3219	return result;
3220}
3221
3222
3223/* Partition the tape into two partitions if size > 0 or one partition if
3224   size == 0.
3225
3226   The block descriptors are read and written because Sony SDT-7000 does not
3227   work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3228
3229   My HP C1533A drive returns only one partition size field. This is used to
3230   set the size of partition 1. There is no size field for the default partition.
3231   Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3232   used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3233   The following algorithm is used to accommodate both drives: if the number of
3234   partition size fields is greater than the maximum number of additional partitions
3235   in the mode page, the second field is used. Otherwise the first field is used.
3236
3237   For Seagate DDS drives the page length must be 8 when no partitions is defined
3238   and 10 when 1 partition is defined (information from Eric Lee Green). This is
3239   is acceptable also to some other old drives and enforced if the first partition
3240   size field is used for the first additional partition size.
3241 */
3242static int partition_tape(struct scsi_tape *STp, int size)
3243{
3244	char *name = tape_name(STp);
3245	int result;
3246	int pgo, psd_cnt, psdo;
3247	unsigned char *bp;
3248
3249	result = read_mode_page(STp, PART_PAGE, 0);
3250	if (result) {
3251		DEBC(printk(ST_DEB_MSG "%s: Can't read partition mode page.\n", name));
3252		return result;
3253	}
3254	/* The mode page is in the buffer. Let's modify it and write it. */
3255	bp = (STp->buffer)->b_data;
3256	pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3257	DEBC(printk(ST_DEB_MSG "%s: Partition page length is %d bytes.\n",
3258		    name, bp[pgo + MP_OFF_PAGE_LENGTH] + 2));
3259
3260	psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
3261	psdo = pgo + PART_PAGE_FIXED_LENGTH;
3262	if (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS]) {
3263		bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest of the tape */
3264		psdo += 2;
3265	}
3266	memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3267
3268	DEBC(printk("%s: psd_cnt %d, max.parts %d, nbr_parts %d\n", name,
3269		    psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3270		    bp[pgo + PP_OFF_NBR_ADD_PARTS]));
3271
3272	if (size <= 0) {
3273		bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3274		if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3275		    bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3276                DEBC(printk(ST_DEB_MSG "%s: Formatting tape with one partition.\n",
3277                            name));
3278	} else {
3279		bp[psdo] = (size >> 8) & 0xff;
3280		bp[psdo + 1] = size & 0xff;
3281		bp[pgo + 3] = 1;
3282		if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3283		    bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3284                DEBC(printk(ST_DEB_MSG
3285                            "%s: Formatting tape with two partitions (1 = %d MB).\n",
3286                            name, size));
3287	}
3288	bp[pgo + PP_OFF_PART_UNITS] = 0;
3289	bp[pgo + PP_OFF_RESERVED] = 0;
3290	bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | PP_MSK_PSUM_MB;
3291
3292	result = write_mode_page(STp, PART_PAGE, 1);
3293	if (result) {
3294		printk(KERN_INFO "%s: Partitioning of tape failed.\n", name);
3295		result = (-EIO);
3296	}
3297
3298	return result;
3299}
3300
3301
3302
3303/* The ioctl command */
3304static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3305{
3306	int i, cmd_nr, cmd_type, bt;
3307	int retval = 0;
3308	unsigned int blk;
3309	struct scsi_tape *STp = file->private_data;
3310	struct st_modedef *STm;
3311	struct st_partstat *STps;
3312	char *name = tape_name(STp);
3313	void __user *p = (void __user *)arg;
3314
3315	if (mutex_lock_interruptible(&STp->lock))
3316		return -ERESTARTSYS;
3317
3318        DEB(
3319	if (debugging && !STp->in_use) {
3320		printk(ST_DEB_MSG "%s: Incorrect device.\n", name);
3321		retval = (-EIO);
3322		goto out;
3323	} ) /* end DEB */
3324
3325	STm = &(STp->modes[STp->current_mode]);
3326	STps = &(STp->ps[STp->partition]);
3327
3328	/*
3329	 * If we are in the middle of error recovery, don't let anyone
3330	 * else try and use this device.  Also, if error recovery fails, it
3331	 * may try and take the device offline, in which case all further
3332	 * access to the device is prohibited.
3333	 */
3334	retval = scsi_nonblockable_ioctl(STp->device, cmd_in, p,
3335					file->f_flags & O_NDELAY);
3336	if (!scsi_block_when_processing_errors(STp->device) || retval != -ENODEV)
3337		goto out;
3338	retval = 0;
3339
3340	cmd_type = _IOC_TYPE(cmd_in);
3341	cmd_nr = _IOC_NR(cmd_in);
3342
3343	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3344		struct mtop mtc;
3345
3346		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3347			retval = (-EINVAL);
3348			goto out;
3349		}
3350
3351		i = copy_from_user(&mtc, p, sizeof(struct mtop));
3352		if (i) {
3353			retval = (-EFAULT);
3354			goto out;
3355		}
3356
3357		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3358			printk(KERN_WARNING
3359                               "%s: MTSETDRVBUFFER only allowed for root.\n", name);
3360			retval = (-EPERM);
3361			goto out;
3362		}
3363		if (!STm->defined &&
3364		    (mtc.mt_op != MTSETDRVBUFFER &&
3365		     (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3366			retval = (-ENXIO);
3367			goto out;
3368		}
3369
3370		if (!STp->pos_unknown) {
3371
3372			if (STps->eof == ST_FM_HIT) {
3373				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3374                                    mtc.mt_op == MTEOM) {
3375					mtc.mt_count -= 1;
3376					if (STps->drv_file >= 0)
3377						STps->drv_file += 1;
3378				} else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3379					mtc.mt_count += 1;
3380					if (STps->drv_file >= 0)
3381						STps->drv_file += 1;
3382				}
3383			}
3384
3385			if (mtc.mt_op == MTSEEK) {
3386				/* Old position must be restored if partition will be
3387                                   changed */
3388				i = !STp->can_partitions ||
3389				    (STp->new_partition != STp->partition);
3390			} else {
3391				i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3392				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3393				    mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3394				    mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3395				    mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3396				    mtc.mt_op == MTCOMPRESSION;
3397			}
3398			i = flush_buffer(STp, i);
3399			if (i < 0) {
3400				retval = i;
3401				goto out;
3402			}
3403			if (STps->rw == ST_WRITING &&
3404			    (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3405			     mtc.mt_op == MTSEEK ||
3406			     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3407				i = st_int_ioctl(STp, MTWEOF, 1);
3408				if (i < 0) {
3409					retval = i;
3410					goto out;
3411				}
3412				if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3413					mtc.mt_count++;
3414				STps->rw = ST_IDLE;
3415			     }
3416
3417		} else {
3418			/*
3419			 * If there was a bus reset, block further access
3420			 * to this device.  If the user wants to rewind the tape,
3421			 * then reset the flag and allow access again.
3422			 */
3423			if (mtc.mt_op != MTREW &&
3424			    mtc.mt_op != MTOFFL &&
3425			    mtc.mt_op != MTRETEN &&
3426			    mtc.mt_op != MTERASE &&
3427			    mtc.mt_op != MTSEEK &&
3428			    mtc.mt_op != MTEOM) {
3429				retval = (-EIO);
3430				goto out;
3431			}
3432			reset_state(STp);
3433			/* remove this when the midlevel properly clears was_reset */
3434			STp->device->was_reset = 0;
3435		}
3436
3437		if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3438		    mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3439		    mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3440			STps->rw = ST_IDLE;	/* Prevent automatic WEOF and fsf */
3441
3442		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3443			do_door_lock(STp, 0);	/* Ignore result! */
3444
3445		if (mtc.mt_op == MTSETDRVBUFFER &&
3446		    (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3447			retval = st_set_options(STp, mtc.mt_count);
3448			goto out;
3449		}
3450
3451		if (mtc.mt_op == MTSETPART) {
3452			if (!STp->can_partitions ||
3453			    mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3454				retval = (-EINVAL);
3455				goto out;
3456			}
3457			if (mtc.mt_count >= STp->nbr_partitions &&
3458			    (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3459				retval = (-EIO);
3460				goto out;
3461			}
3462			if (mtc.mt_count >= STp->nbr_partitions) {
3463				retval = (-EINVAL);
3464				goto out;
3465			}
3466			STp->new_partition = mtc.mt_count;
3467			retval = 0;
3468			goto out;
3469		}
3470
3471		if (mtc.mt_op == MTMKPART) {
3472			if (!STp->can_partitions) {
3473				retval = (-EINVAL);
3474				goto out;
3475			}
3476			if ((i = st_int_ioctl(STp, MTREW, 0)) < 0 ||
3477			    (i = partition_tape(STp, mtc.mt_count)) < 0) {
3478				retval = i;
3479				goto out;
3480			}
3481			for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3482				STp->ps[i].rw = ST_IDLE;
3483				STp->ps[i].at_sm = 0;
3484				STp->ps[i].last_block_valid = 0;
3485			}
3486			STp->partition = STp->new_partition = 0;
3487			STp->nbr_partitions = 1;	/* Bad guess ?-) */
3488			STps->drv_block = STps->drv_file = 0;
3489			retval = 0;
3490			goto out;
3491		}
3492
3493		if (mtc.mt_op == MTSEEK) {
3494			i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3495			if (!STp->can_partitions)
3496				STp->ps[0].rw = ST_IDLE;
3497			retval = i;
3498			goto out;
3499		}
3500
3501		if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3502			retval = do_load_unload(STp, file, 0);
3503			goto out;
3504		}
3505
3506		if (mtc.mt_op == MTLOAD) {
3507			retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3508			goto out;
3509		}
3510
3511		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3512			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3513			goto out;
3514		}
3515
3516		if (STp->can_partitions && STp->ready == ST_READY &&
3517		    (i = switch_partition(STp)) < 0) {
3518			retval = i;
3519			goto out;
3520		}
3521
3522		if (mtc.mt_op == MTCOMPRESSION)
3523			retval = st_compression(STp, (mtc.mt_count & 1));
3524		else
3525			retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3526		goto out;
3527	}
3528	if (!STm->defined) {
3529		retval = (-ENXIO);
3530		goto out;
3531	}
3532
3533	if ((i = flush_buffer(STp, 0)) < 0) {
3534		retval = i;
3535		goto out;
3536	}
3537	if (STp->can_partitions &&
3538	    (i = switch_partition(STp)) < 0) {
3539		retval = i;
3540		goto out;
3541	}
3542
3543	if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
3544		struct mtget mt_status;
3545
3546		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3547			 retval = (-EINVAL);
3548			 goto out;
3549		}
3550
3551		mt_status.mt_type = STp->tape_type;
3552		mt_status.mt_dsreg =
3553		    ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3554		    ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3555		mt_status.mt_blkno = STps->drv_block;
3556		mt_status.mt_fileno = STps->drv_file;
3557		if (STp->block_size != 0) {
3558			if (STps->rw == ST_WRITING)
3559				mt_status.mt_blkno +=
3560				    (STp->buffer)->buffer_bytes / STp->block_size;
3561			else if (STps->rw == ST_READING)
3562				mt_status.mt_blkno -=
3563                                        ((STp->buffer)->buffer_bytes +
3564                                         STp->block_size - 1) / STp->block_size;
3565		}
3566
3567		mt_status.mt_gstat = 0;
3568		if (STp->drv_write_prot)
3569			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3570		if (mt_status.mt_blkno == 0) {
3571			if (mt_status.mt_fileno == 0)
3572				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3573			else
3574				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3575		}
3576		mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3577		mt_status.mt_resid = STp->partition;
3578		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3579			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3580		else if (STps->eof >= ST_EOM_OK)
3581			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3582		if (STp->density == 1)
3583			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3584		else if (STp->density == 2)
3585			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3586		else if (STp->density == 3)
3587			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3588		if (STp->ready == ST_READY)
3589			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3590		if (STp->ready == ST_NO_TAPE)
3591			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3592		if (STps->at_sm)
3593			mt_status.mt_gstat |= GMT_SM(0xffffffff);
3594		if (STm->do_async_writes ||
3595                    (STm->do_buffer_writes && STp->block_size != 0) ||
3596		    STp->drv_buffer != 0)
3597			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3598		if (STp->cleaning_req)
3599			mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3600
3601		i = copy_to_user(p, &mt_status, sizeof(struct mtget));
3602		if (i) {
3603			retval = (-EFAULT);
3604			goto out;
3605		}
3606
3607		STp->recover_reg = 0;		/* Clear after read */
3608		retval = 0;
3609		goto out;
3610	}			/* End of MTIOCGET */
3611	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3612		struct mtpos mt_pos;
3613		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3614			 retval = (-EINVAL);
3615			 goto out;
3616		}
3617		if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3618			retval = i;
3619			goto out;
3620		}
3621		mt_pos.mt_blkno = blk;
3622		i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
3623		if (i)
3624			retval = (-EFAULT);
3625		goto out;
3626	}
3627	mutex_unlock(&STp->lock);
3628	switch (cmd_in) {
3629		case SCSI_IOCTL_GET_IDLUN:
3630		case SCSI_IOCTL_GET_BUS_NUMBER:
3631			break;
3632		default:
3633			if ((cmd_in == SG_IO ||
3634			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3635			     cmd_in == CDROM_SEND_PACKET) &&
3636			    !capable(CAP_SYS_RAWIO))
3637				i = -EPERM;
3638			else
3639				i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3640						   file->f_mode, cmd_in, p);
3641			if (i != -ENOTTY)
3642				return i;
3643			break;
3644	}
3645	retval = scsi_ioctl(STp->device, cmd_in, p);
3646	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
3647		STp->rew_at_close = 0;
3648		STp->ready = ST_NO_TAPE;
3649	}
3650	return retval;
3651
3652 out:
3653	mutex_unlock(&STp->lock);
3654	return retval;
3655}
3656
3657#ifdef CONFIG_COMPAT
3658static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3659{
3660	struct scsi_tape *STp = file->private_data;
3661	struct scsi_device *sdev = STp->device;
3662	int ret = -ENOIOCTLCMD;
3663	if (sdev->host->hostt->compat_ioctl) { 
3664
3665		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
3666
3667	}
3668	return ret;
3669}
3670#endif
3671
3672
3673
3674/* Try to allocate a new tape buffer. Calling function must not hold
3675   dev_arr_lock. */
3676static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
3677{
3678	struct st_buffer *tb;
3679
3680	tb = kzalloc(sizeof(struct st_buffer), GFP_ATOMIC);
3681	if (!tb) {
3682		printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3683		return NULL;
3684	}
3685	tb->frp_segs = 0;
3686	tb->use_sg = max_sg;
3687	tb->dma = need_dma;
3688	tb->buffer_size = 0;
3689
3690	tb->reserved_pages = kzalloc(max_sg * sizeof(struct page *),
3691				     GFP_ATOMIC);
3692	if (!tb->reserved_pages) {
3693		kfree(tb);
3694		return NULL;
3695	}
3696
3697	return tb;
3698}
3699
3700
3701/* Try to allocate enough space in the tape buffer */
3702#define ST_MAX_ORDER 6
3703
3704static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
3705{
3706	int segs, nbr, max_segs, b_size, order, got;
3707	gfp_t priority;
3708
3709	if (new_size <= STbuffer->buffer_size)
3710		return 1;
3711
3712	if (STbuffer->buffer_size <= PAGE_SIZE)
3713		normalize_buffer(STbuffer);  /* Avoid extra segment */
3714
3715	max_segs = STbuffer->use_sg;
3716	nbr = max_segs - STbuffer->frp_segs;
3717	if (nbr <= 0)
3718		return 0;
3719
3720	priority = GFP_KERNEL | __GFP_NOWARN;
3721	if (need_dma)
3722		priority |= GFP_DMA;
3723
3724	if (STbuffer->cleared)
3725		priority |= __GFP_ZERO;
3726
3727	if (STbuffer->frp_segs) {
3728		order = STbuffer->reserved_page_order;
3729		b_size = PAGE_SIZE << order;
3730	} else {
3731		for (b_size = PAGE_SIZE, order = 0;
3732		     order < ST_MAX_ORDER &&
3733			     max_segs * (PAGE_SIZE << order) < new_size;
3734		     order++, b_size *= 2)
3735			;  /* empty */
3736		STbuffer->reserved_page_order = order;
3737	}
3738	if (max_segs * (PAGE_SIZE << order) < new_size) {
3739		if (order == ST_MAX_ORDER)
3740			return 0;
3741		normalize_buffer(STbuffer);
3742		return enlarge_buffer(STbuffer, new_size, need_dma);
3743	}
3744
3745	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3746	     segs < max_segs && got < new_size;) {
3747		struct page *page;
3748
3749		page = alloc_pages(priority, order);
3750		if (!page) {
3751			DEB(STbuffer->buffer_size = got);
3752			normalize_buffer(STbuffer);
3753			return 0;
3754		}
3755
3756		STbuffer->frp_segs += 1;
3757		got += b_size;
3758		STbuffer->buffer_size = got;
3759		STbuffer->reserved_pages[segs] = page;
3760		segs++;
3761	}
3762	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3763
3764	return 1;
3765}
3766
3767
3768/* Make sure that no data from previous user is in the internal buffer */
3769static void clear_buffer(struct st_buffer * st_bp)
3770{
3771	int i;
3772
3773	for (i=0; i < st_bp->frp_segs; i++)
3774		memset(page_address(st_bp->reserved_pages[i]), 0,
3775		       PAGE_SIZE << st_bp->reserved_page_order);
3776	st_bp->cleared = 1;
3777}
3778
3779
3780/* Release the extra buffer */
3781static void normalize_buffer(struct st_buffer * STbuffer)
3782{
3783	int i, order = STbuffer->reserved_page_order;
3784
3785	for (i = 0; i < STbuffer->frp_segs; i++) {
3786		__free_pages(STbuffer->reserved_pages[i], order);
3787		STbuffer->buffer_size -= (PAGE_SIZE << order);
3788	}
3789	STbuffer->frp_segs = 0;
3790	STbuffer->sg_segs = 0;
3791	STbuffer->reserved_page_order = 0;
3792	STbuffer->map_data.offset = 0;
3793}
3794
3795
3796/* Move data from the user buffer to the tape buffer. Returns zero (success) or
3797   negative error code. */
3798static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3799{
3800	int i, cnt, res, offset;
3801	int length = PAGE_SIZE << st_bp->reserved_page_order;
3802
3803	for (i = 0, offset = st_bp->buffer_bytes;
3804	     i < st_bp->frp_segs && offset >= length; i++)
3805		offset -= length;
3806	if (i == st_bp->frp_segs) {	/* Should never happen */
3807		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
3808		return (-EIO);
3809	}
3810	for (; i < st_bp->frp_segs && do_count > 0; i++) {
3811		struct page *page = st_bp->reserved_pages[i];
3812		cnt = length - offset < do_count ? length - offset : do_count;
3813		res = copy_from_user(page_address(page) + offset, ubp, cnt);
3814		if (res)
3815			return (-EFAULT);
3816		do_count -= cnt;
3817		st_bp->buffer_bytes += cnt;
3818		ubp += cnt;
3819		offset = 0;
3820	}
3821	if (do_count) /* Should never happen */
3822		return (-EIO);
3823
3824	return 0;
3825}
3826
3827
3828/* Move data from the tape buffer to the user buffer. Returns zero (success) or
3829   negative error code. */
3830static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
3831{
3832	int i, cnt, res, offset;
3833	int length = PAGE_SIZE << st_bp->reserved_page_order;
3834
3835	for (i = 0, offset = st_bp->read_pointer;
3836	     i < st_bp->frp_segs && offset >= length; i++)
3837		offset -= length;
3838	if (i == st_bp->frp_segs) {	/* Should never happen */
3839		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
3840		return (-EIO);
3841	}
3842	for (; i < st_bp->frp_segs && do_count > 0; i++) {
3843		struct page *page = st_bp->reserved_pages[i];
3844		cnt = length - offset < do_count ? length - offset : do_count;
3845		res = copy_to_user(ubp, page_address(page) + offset, cnt);
3846		if (res)
3847			return (-EFAULT);
3848		do_count -= cnt;
3849		st_bp->buffer_bytes -= cnt;
3850		st_bp->read_pointer += cnt;
3851		ubp += cnt;
3852		offset = 0;
3853	}
3854	if (do_count) /* Should never happen */
3855		return (-EIO);
3856
3857	return 0;
3858}
3859
3860
3861/* Move data towards start of buffer */
3862static void move_buffer_data(struct st_buffer * st_bp, int offset)
3863{
3864	int src_seg, dst_seg, src_offset = 0, dst_offset;
3865	int count, total;
3866	int length = PAGE_SIZE << st_bp->reserved_page_order;
3867
3868	if (offset == 0)
3869		return;
3870
3871	total=st_bp->buffer_bytes - offset;
3872	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
3873		src_offset = offset;
3874		if (src_offset < length)
3875			break;
3876		offset -= length;
3877	}
3878
3879	st_bp->buffer_bytes = st_bp->read_pointer = total;
3880	for (dst_seg=dst_offset=0; total > 0; ) {
3881		struct page *dpage = st_bp->reserved_pages[dst_seg];
3882		struct page *spage = st_bp->reserved_pages[src_seg];
3883
3884		count = min(length - dst_offset, length - src_offset);
3885		memmove(page_address(dpage) + dst_offset,
3886			page_address(spage) + src_offset, count);
3887		src_offset += count;
3888		if (src_offset >= length) {
3889			src_seg++;
3890			src_offset = 0;
3891		}
3892		dst_offset += count;
3893		if (dst_offset >= length) {
3894			dst_seg++;
3895			dst_offset = 0;
3896		}
3897		total -= count;
3898	}
3899}
3900
3901/* Validate the options from command line or module parameters */
3902static void validate_options(void)
3903{
3904	if (buffer_kbs > 0)
3905		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
3906	if (max_sg_segs >= ST_FIRST_SG)
3907		st_max_sg_segs = max_sg_segs;
3908}
3909
3910#ifndef MODULE
3911/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
3912 */
3913static int __init st_setup(char *str)
3914{
3915	int i, len, ints[5];
3916	char *stp;
3917
3918	stp = get_options(str, ARRAY_SIZE(ints), ints);
3919
3920	if (ints[0] > 0) {
3921		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
3922			if (parms[i].val)
3923				*parms[i].val = ints[i + 1];
3924	} else {
3925		while (stp != NULL) {
3926			for (i = 0; i < ARRAY_SIZE(parms); i++) {
3927				len = strlen(parms[i].name);
3928				if (!strncmp(stp, parms[i].name, len) &&
3929				    (*(stp + len) == ':' || *(stp + len) == '=')) {
3930					if (parms[i].val)
3931						*parms[i].val =
3932							simple_strtoul(stp + len + 1, NULL, 0);
3933					else
3934						printk(KERN_WARNING "st: Obsolete parameter %s\n",
3935						       parms[i].name);
3936					break;
3937				}
3938			}
3939			if (i >= ARRAY_SIZE(parms))
3940				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
3941					stp);
3942			stp = strchr(stp, ',');
3943			if (stp)
3944				stp++;
3945		}
3946	}
3947
3948	validate_options();
3949
3950	return 1;
3951}
3952
3953__setup("st=", st_setup);
3954
3955#endif
3956
3957static const struct file_operations st_fops =
3958{
3959	.owner =	THIS_MODULE,
3960	.read =		st_read,
3961	.write =	st_write,
3962	.unlocked_ioctl = st_ioctl,
3963#ifdef CONFIG_COMPAT
3964	.compat_ioctl = st_compat_ioctl,
3965#endif
3966	.open =		st_open,
3967	.flush =	st_flush,
3968	.release =	st_release,
3969	.llseek =	noop_llseek,
3970};
3971
3972static int st_probe(struct device *dev)
3973{
3974	struct scsi_device *SDp = to_scsi_device(dev);
3975	struct gendisk *disk = NULL;
3976	struct cdev *cdev = NULL;
3977	struct scsi_tape *tpnt = NULL;
3978	struct st_modedef *STm;
3979	struct st_partstat *STps;
3980	struct st_buffer *buffer;
3981	int i, j, mode, dev_num, error;
3982	char *stp;
3983
3984	if (SDp->type != TYPE_TAPE)
3985		return -ENODEV;
3986	if ((stp = st_incompatible(SDp))) {
3987		sdev_printk(KERN_INFO, SDp, "Found incompatible tape\n");
3988		printk(KERN_INFO "st: The suggested driver is %s.\n", stp);
3989		return -ENODEV;
3990	}
3991
3992	i = queue_max_segments(SDp->request_queue);
3993	if (st_max_sg_segs < i)
3994		i = st_max_sg_segs;
3995	buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
3996	if (buffer == NULL) {
3997		printk(KERN_ERR
3998		       "st: Can't allocate new tape buffer. Device not attached.\n");
3999		goto out;
4000	}
4001
4002	disk = alloc_disk(1);
4003	if (!disk) {
4004		printk(KERN_ERR "st: out of memory. Device not attached.\n");
4005		goto out_buffer_free;
4006	}
4007
4008	write_lock(&st_dev_arr_lock);
4009	if (st_nr_dev >= st_dev_max) {
4010		struct scsi_tape **tmp_da;
4011		int tmp_dev_max;
4012
4013		tmp_dev_max = max(st_nr_dev * 2, 8);
4014		if (tmp_dev_max > ST_MAX_TAPES)
4015			tmp_dev_max = ST_MAX_TAPES;
4016		if (tmp_dev_max <= st_nr_dev) {
4017			write_unlock(&st_dev_arr_lock);
4018			printk(KERN_ERR "st: Too many tape devices (max. %d).\n",
4019			       ST_MAX_TAPES);
4020			goto out_put_disk;
4021		}
4022
4023		tmp_da = kzalloc(tmp_dev_max * sizeof(struct scsi_tape *), GFP_ATOMIC);
4024		if (tmp_da == NULL) {
4025			write_unlock(&st_dev_arr_lock);
4026			printk(KERN_ERR "st: Can't extend device array.\n");
4027			goto out_put_disk;
4028		}
4029
4030		if (scsi_tapes != NULL) {
4031			memcpy(tmp_da, scsi_tapes,
4032			       st_dev_max * sizeof(struct scsi_tape *));
4033			kfree(scsi_tapes);
4034		}
4035		scsi_tapes = tmp_da;
4036
4037		st_dev_max = tmp_dev_max;
4038	}
4039
4040	for (i = 0; i < st_dev_max; i++)
4041		if (scsi_tapes[i] == NULL)
4042			break;
4043	if (i >= st_dev_max)
4044		panic("scsi_devices corrupt (st)");
4045
4046	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
4047	if (tpnt == NULL) {
4048		write_unlock(&st_dev_arr_lock);
4049		printk(KERN_ERR "st: Can't allocate device descriptor.\n");
4050		goto out_put_disk;
4051	}
4052	kref_init(&tpnt->kref);
4053	tpnt->disk = disk;
4054	sprintf(disk->disk_name, "st%d", i);
4055	disk->private_data = &tpnt->driver;
4056	disk->queue = SDp->request_queue;
4057	tpnt->driver = &st_template;
4058	scsi_tapes[i] = tpnt;
4059	dev_num = i;
4060
4061	tpnt->device = SDp;
4062	if (SDp->scsi_level <= 2)
4063		tpnt->tape_type = MT_ISSCSI1;
4064	else
4065		tpnt->tape_type = MT_ISSCSI2;
4066
4067	tpnt->buffer = buffer;
4068	tpnt->buffer->last_SRpnt = NULL;
4069
4070	tpnt->inited = 0;
4071	tpnt->dirty = 0;
4072	tpnt->in_use = 0;
4073	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
4074	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4075	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4076	tpnt->density = 0;
4077	tpnt->do_auto_lock = ST_AUTO_LOCK;
4078	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4079	tpnt->can_partitions = 0;
4080	tpnt->two_fm = ST_TWO_FM;
4081	tpnt->fast_mteom = ST_FAST_MTEOM;
4082	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4083	tpnt->sili = ST_SILI;
4084	tpnt->immediate = ST_NOWAIT;
 
4085	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4086	tpnt->partition = 0;
4087	tpnt->new_partition = 0;
4088	tpnt->nbr_partitions = 0;
4089	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4090	tpnt->long_timeout = ST_LONG_TIMEOUT;
4091	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
4092
4093	for (i = 0; i < ST_NBR_MODES; i++) {
4094		STm = &(tpnt->modes[i]);
4095		STm->defined = 0;
4096		STm->sysv = ST_SYSV;
4097		STm->defaults_for_writes = 0;
4098		STm->do_async_writes = ST_ASYNC_WRITES;
4099		STm->do_buffer_writes = ST_BUFFER_WRITES;
4100		STm->do_read_ahead = ST_READ_AHEAD;
4101		STm->default_compression = ST_DONT_TOUCH;
4102		STm->default_blksize = (-1);	/* No forced size */
4103		STm->default_density = (-1);	/* No forced density */
4104	}
4105
4106	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4107		STps = &(tpnt->ps[i]);
4108		STps->rw = ST_IDLE;
4109		STps->eof = ST_NOEOF;
4110		STps->at_sm = 0;
4111		STps->last_block_valid = 0;
4112		STps->drv_block = (-1);
4113		STps->drv_file = (-1);
4114	}
4115
4116	tpnt->current_mode = 0;
4117	tpnt->modes[0].defined = 1;
4118
4119	tpnt->density_changed = tpnt->compression_changed =
4120	    tpnt->blksize_changed = 0;
4121	mutex_init(&tpnt->lock);
4122
4123	st_nr_dev++;
4124	write_unlock(&st_dev_arr_lock);
4125
4126	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4127		STm = &(tpnt->modes[mode]);
4128		for (j=0; j < 2; j++) {
4129			cdev = cdev_alloc();
4130			if (!cdev) {
4131				printk(KERN_ERR
4132				       "st%d: out of memory. Device not attached.\n",
4133				       dev_num);
4134				goto out_free_tape;
4135			}
4136			cdev->owner = THIS_MODULE;
4137			cdev->ops = &st_fops;
4138
4139			error = cdev_add(cdev,
4140					 MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, j)),
4141					 1);
4142			if (error) {
4143				printk(KERN_ERR "st%d: Can't add %s-rewind mode %d\n",
4144				       dev_num, j ? "non" : "auto", mode);
4145				printk(KERN_ERR "st%d: Device not attached.\n", dev_num);
4146				goto out_free_tape;
4147			}
4148			STm->cdevs[j] = cdev;
4149
4150		}
4151		error = do_create_class_files(tpnt, dev_num, mode);
4152		if (error)
4153			goto out_free_tape;
4154	}
 
4155
4156	sdev_printk(KERN_NOTICE, SDp,
4157		    "Attached scsi tape %s\n", tape_name(tpnt));
4158	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4159		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4160		    queue_dma_alignment(SDp->request_queue) + 1);
4161
4162	return 0;
4163
4164out_free_tape:
4165	for (mode=0; mode < ST_NBR_MODES; mode++) {
4166		STm = &(tpnt->modes[mode]);
4167		sysfs_remove_link(&tpnt->device->sdev_gendev.kobj,
4168				  "tape");
4169		for (j=0; j < 2; j++) {
4170			if (STm->cdevs[j]) {
4171				if (cdev == STm->cdevs[j])
4172					cdev = NULL;
4173					device_destroy(st_sysfs_class,
4174						       MKDEV(SCSI_TAPE_MAJOR,
4175							     TAPE_MINOR(i, mode, j)));
4176				cdev_del(STm->cdevs[j]);
4177			}
4178		}
4179	}
4180	if (cdev)
4181		cdev_del(cdev);
4182	write_lock(&st_dev_arr_lock);
4183	scsi_tapes[dev_num] = NULL;
4184	st_nr_dev--;
4185	write_unlock(&st_dev_arr_lock);
4186out_put_disk:
4187	put_disk(disk);
4188	kfree(tpnt);
4189out_buffer_free:
4190	kfree(buffer);
4191out:
4192	return -ENODEV;
4193};
4194
4195
4196static int st_remove(struct device *dev)
4197{
4198	struct scsi_device *SDp = to_scsi_device(dev);
4199	struct scsi_tape *tpnt;
4200	int i, j, mode;
4201
 
4202	write_lock(&st_dev_arr_lock);
4203	for (i = 0; i < st_dev_max; i++) {
4204		tpnt = scsi_tapes[i];
4205		if (tpnt != NULL && tpnt->device == SDp) {
4206			scsi_tapes[i] = NULL;
4207			st_nr_dev--;
4208			write_unlock(&st_dev_arr_lock);
4209			sysfs_remove_link(&tpnt->device->sdev_gendev.kobj,
4210					  "tape");
4211			for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4212				for (j=0; j < 2; j++) {
4213					device_destroy(st_sysfs_class,
4214						       MKDEV(SCSI_TAPE_MAJOR,
4215							     TAPE_MINOR(i, mode, j)));
4216					cdev_del(tpnt->modes[mode].cdevs[j]);
4217					tpnt->modes[mode].cdevs[j] = NULL;
4218				}
4219			}
4220
4221			mutex_lock(&st_ref_mutex);
4222			kref_put(&tpnt->kref, scsi_tape_release);
4223			mutex_unlock(&st_ref_mutex);
4224			return 0;
4225		}
4226	}
4227
4228	write_unlock(&st_dev_arr_lock);
4229	return 0;
4230}
4231
4232/**
4233 *      scsi_tape_release - Called to free the Scsi_Tape structure
4234 *      @kref: pointer to embedded kref
4235 *
4236 *      st_ref_mutex must be held entering this routine.  Because it is
4237 *      called on last put, you should always use the scsi_tape_get()
4238 *      scsi_tape_put() helpers which manipulate the semaphore directly
4239 *      and never do a direct kref_put().
4240 **/
4241static void scsi_tape_release(struct kref *kref)
4242{
4243	struct scsi_tape *tpnt = to_scsi_tape(kref);
4244	struct gendisk *disk = tpnt->disk;
4245
4246	tpnt->device = NULL;
4247
4248	if (tpnt->buffer) {
4249		normalize_buffer(tpnt->buffer);
4250		kfree(tpnt->buffer->reserved_pages);
4251		kfree(tpnt->buffer);
4252	}
4253
4254	disk->private_data = NULL;
4255	put_disk(disk);
4256	kfree(tpnt);
4257	return;
4258}
4259
4260static int __init init_st(void)
4261{
4262	int err;
4263
4264	validate_options();
4265
4266	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4267		verstr, st_fixed_buffer_size, st_max_sg_segs);
4268
4269	st_sysfs_class = class_create(THIS_MODULE, "scsi_tape");
4270	if (IS_ERR(st_sysfs_class)) {
4271		printk(KERN_ERR "Unable create sysfs class for SCSI tapes\n");
4272		return PTR_ERR(st_sysfs_class);
4273	}
4274
4275	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4276				     ST_MAX_TAPE_ENTRIES, "st");
4277	if (err) {
4278		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4279		       SCSI_TAPE_MAJOR);
4280		goto err_class;
4281	}
4282
4283	err = scsi_register_driver(&st_template.gendrv);
4284	if (err)
4285		goto err_chrdev;
4286
4287	err = do_create_sysfs_files();
4288	if (err)
4289		goto err_scsidrv;
4290
4291	return 0;
4292
4293err_scsidrv:
4294	scsi_unregister_driver(&st_template.gendrv);
4295err_chrdev:
4296	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4297				 ST_MAX_TAPE_ENTRIES);
4298err_class:
4299	class_destroy(st_sysfs_class);
4300	return err;
4301}
4302
4303static void __exit exit_st(void)
4304{
4305	do_remove_sysfs_files();
4306	scsi_unregister_driver(&st_template.gendrv);
4307	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4308				 ST_MAX_TAPE_ENTRIES);
4309	class_destroy(st_sysfs_class);
4310	kfree(scsi_tapes);
4311	printk(KERN_INFO "st: Unloaded.\n");
4312}
4313
4314module_init(init_st);
4315module_exit(exit_st);
4316
4317
4318/* The sysfs driver interface. Read-only at the moment */
4319static ssize_t st_try_direct_io_show(struct device_driver *ddp, char *buf)
4320{
4321	return snprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4322}
4323static DRIVER_ATTR(try_direct_io, S_IRUGO, st_try_direct_io_show, NULL);
4324
4325static ssize_t st_fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4326{
4327	return snprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4328}
4329static DRIVER_ATTR(fixed_buffer_size, S_IRUGO, st_fixed_buffer_size_show, NULL);
4330
4331static ssize_t st_max_sg_segs_show(struct device_driver *ddp, char *buf)
4332{
4333	return snprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4334}
4335static DRIVER_ATTR(max_sg_segs, S_IRUGO, st_max_sg_segs_show, NULL);
4336
4337static ssize_t st_version_show(struct device_driver *ddd, char *buf)
4338{
4339	return snprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4340}
4341static DRIVER_ATTR(version, S_IRUGO, st_version_show, NULL);
4342
4343static int do_create_sysfs_files(void)
4344{
4345	struct device_driver *sysfs = &st_template.gendrv;
4346	int err;
4347
4348	err = driver_create_file(sysfs, &driver_attr_try_direct_io);
4349	if (err)
4350		return err;
4351	err = driver_create_file(sysfs, &driver_attr_fixed_buffer_size);
4352	if (err)
4353		goto err_try_direct_io;
4354	err = driver_create_file(sysfs, &driver_attr_max_sg_segs);
4355	if (err)
4356		goto err_attr_fixed_buf;
4357	err = driver_create_file(sysfs, &driver_attr_version);
4358	if (err)
4359		goto err_attr_max_sg;
4360
4361	return 0;
4362
4363err_attr_max_sg:
4364	driver_remove_file(sysfs, &driver_attr_max_sg_segs);
4365err_attr_fixed_buf:
4366	driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
4367err_try_direct_io:
4368	driver_remove_file(sysfs, &driver_attr_try_direct_io);
4369	return err;
4370}
4371
4372static void do_remove_sysfs_files(void)
4373{
4374	struct device_driver *sysfs = &st_template.gendrv;
4375
4376	driver_remove_file(sysfs, &driver_attr_version);
4377	driver_remove_file(sysfs, &driver_attr_max_sg_segs);
4378	driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
4379	driver_remove_file(sysfs, &driver_attr_try_direct_io);
4380}
4381
4382
4383/* The sysfs simple class interface */
4384static ssize_t
4385st_defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4386{
4387	struct st_modedef *STm = dev_get_drvdata(dev);
4388	ssize_t l = 0;
4389
4390	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4391	return l;
4392}
4393
4394DEVICE_ATTR(defined, S_IRUGO, st_defined_show, NULL);
4395
4396static ssize_t
4397st_defblk_show(struct device *dev, struct device_attribute *attr, char *buf)
4398{
4399	struct st_modedef *STm = dev_get_drvdata(dev);
4400	ssize_t l = 0;
4401
4402	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4403	return l;
4404}
4405
4406DEVICE_ATTR(default_blksize, S_IRUGO, st_defblk_show, NULL);
4407
4408static ssize_t
4409st_defdensity_show(struct device *dev, struct device_attribute *attr, char *buf)
4410{
4411	struct st_modedef *STm = dev_get_drvdata(dev);
4412	ssize_t l = 0;
4413	char *fmt;
4414
4415	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4416	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4417	return l;
4418}
4419
4420DEVICE_ATTR(default_density, S_IRUGO, st_defdensity_show, NULL);
4421
4422static ssize_t
4423st_defcompression_show(struct device *dev, struct device_attribute *attr,
4424		       char *buf)
4425{
4426	struct st_modedef *STm = dev_get_drvdata(dev);
4427	ssize_t l = 0;
4428
4429	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4430	return l;
4431}
4432
4433DEVICE_ATTR(default_compression, S_IRUGO, st_defcompression_show, NULL);
4434
4435static ssize_t
4436st_options_show(struct device *dev, struct device_attribute *attr, char *buf)
4437{
4438	struct st_modedef *STm = dev_get_drvdata(dev);
4439	struct scsi_tape *STp;
4440	int i, j, options;
4441	ssize_t l = 0;
4442
4443	for (i=0; i < st_dev_max; i++) {
4444		for (j=0; j < ST_NBR_MODES; j++)
4445			if (&scsi_tapes[i]->modes[j] == STm)
4446				break;
4447		if (j < ST_NBR_MODES)
4448			break;
4449	}
4450	if (i == st_dev_max)
4451		return 0;  /* should never happen */
4452
4453	STp = scsi_tapes[i];
4454
4455	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4456	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4457	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4458	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4459	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4460	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4461	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4462	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4463	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4464	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4465	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4466	options |= STm->sysv ? MT_ST_SYSV : 0;
4467	options |= STp->immediate ? MT_ST_NOWAIT : 0;
 
4468	options |= STp->sili ? MT_ST_SILI : 0;
4469
4470	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4471	return l;
4472}
4473
4474DEVICE_ATTR(options, S_IRUGO, st_options_show, NULL);
4475
4476static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
4477{
4478	int i, rew, error;
4479	char name[10];
4480	struct device *st_class_member;
4481
4482	for (rew=0; rew < 2; rew++) {
4483		/* Make sure that the minor numbers corresponding to the four
4484		   first modes always get the same names */
4485		i = mode << (4 - ST_NBR_MODE_BITS);
4486		snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4487			 STp->disk->disk_name, st_formats[i]);
4488		st_class_member =
4489			device_create(st_sysfs_class, &STp->device->sdev_gendev,
4490				      MKDEV(SCSI_TAPE_MAJOR,
4491					    TAPE_MINOR(dev_num, mode, rew)),
4492				      &STp->modes[mode], "%s", name);
4493		if (IS_ERR(st_class_member)) {
4494			printk(KERN_WARNING "st%d: device_create failed\n",
4495			       dev_num);
4496			error = PTR_ERR(st_class_member);
4497			goto out;
4498		}
4499
4500		error = device_create_file(st_class_member,
4501					   &dev_attr_defined);
4502		if (error) goto out;
4503		error = device_create_file(st_class_member,
4504					   &dev_attr_default_blksize);
4505		if (error) goto out;
4506		error = device_create_file(st_class_member,
4507					   &dev_attr_default_density);
4508		if (error) goto out;
4509		error = device_create_file(st_class_member,
4510					   &dev_attr_default_compression);
4511		if (error) goto out;
4512		error = device_create_file(st_class_member,
4513					   &dev_attr_options);
4514		if (error) goto out;
4515
4516		if (mode == 0 && rew == 0) {
4517			error = sysfs_create_link(&STp->device->sdev_gendev.kobj,
4518						  &st_class_member->kobj,
4519						  "tape");
4520			if (error) {
4521				printk(KERN_ERR
4522				       "st%d: Can't create sysfs link from SCSI device.\n",
4523				       dev_num);
4524				goto out;
4525			}
4526		}
4527	}
4528
4529	return 0;
4530
4531out:
4532	return error;
4533}
4534
4535/* The following functions may be useful for a larger audience. */
4536static int sgl_map_user_pages(struct st_buffer *STbp,
4537			      const unsigned int max_pages, unsigned long uaddr,
4538			      size_t count, int rw)
4539{
4540	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4541	unsigned long start = uaddr >> PAGE_SHIFT;
4542	const int nr_pages = end - start;
4543	int res, i, j;
4544	struct page **pages;
4545	struct rq_map_data *mdata = &STbp->map_data;
4546
4547	/* User attempted Overflow! */
4548	if ((uaddr + count) < uaddr)
4549		return -EINVAL;
4550
4551	/* Too big */
4552        if (nr_pages > max_pages)
4553		return -ENOMEM;
4554
4555	/* Hmm? */
4556	if (count == 0)
4557		return 0;
4558
4559	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_KERNEL)) == NULL)
4560		return -ENOMEM;
4561
4562        /* Try to fault in all of the necessary pages */
4563	down_read(&current->mm->mmap_sem);
4564        /* rw==READ means read from drive, write into memory area */
4565	res = get_user_pages(
4566		current,
4567		current->mm,
4568		uaddr,
4569		nr_pages,
4570		rw == READ,
4571		0, /* don't force */
4572		pages,
4573		NULL);
4574	up_read(&current->mm->mmap_sem);
4575
4576	/* Errors and no page mapped should return here */
4577	if (res < nr_pages)
4578		goto out_unmap;
4579
4580        for (i=0; i < nr_pages; i++) {
4581                /* FIXME: flush superflous for rw==READ,
4582                 * probably wrong function for rw==WRITE
4583                 */
4584		flush_dcache_page(pages[i]);
4585        }
4586
4587	mdata->offset = uaddr & ~PAGE_MASK;
4588	STbp->mapped_pages = pages;
4589
4590	return nr_pages;
4591 out_unmap:
4592	if (res > 0) {
4593		for (j=0; j < res; j++)
4594			page_cache_release(pages[j]);
4595		res = 0;
4596	}
4597	kfree(pages);
4598	return res;
4599}
4600
4601
4602/* And unmap them... */
4603static int sgl_unmap_user_pages(struct st_buffer *STbp,
4604				const unsigned int nr_pages, int dirtied)
4605{
4606	int i;
4607
4608	for (i=0; i < nr_pages; i++) {
4609		struct page *page = STbp->mapped_pages[i];
4610
4611		if (dirtied)
4612			SetPageDirty(page);
4613		/* FIXME: cache flush missing for rw==READ
4614		 * FIXME: call the correct reference counting function
4615		 */
4616		page_cache_release(page);
4617	}
4618	kfree(STbp->mapped_pages);
4619	STbp->mapped_pages = NULL;
4620
4621	return 0;
4622}
v3.5.6
   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/delay.h>
  41#include <linux/mutex.h>
  42
  43#include <asm/uaccess.h>
  44#include <asm/dma.h>
 
  45
  46#include <scsi/scsi.h>
  47#include <scsi/scsi_dbg.h>
  48#include <scsi/scsi_device.h>
  49#include <scsi/scsi_driver.h>
  50#include <scsi/scsi_eh.h>
  51#include <scsi/scsi_host.h>
  52#include <scsi/scsi_ioctl.h>
  53#include <scsi/sg.h>
  54
  55
  56/* The driver prints some debugging information on the console if DEBUG
  57   is defined and non-zero. */
  58#define DEBUG 0
  59
  60#if DEBUG
  61/* The message level for the debug messages is currently set to KERN_NOTICE
  62   so that people can easily see the messages. Later when the debugging messages
  63   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
  64#define ST_DEB_MSG  KERN_NOTICE
  65#define DEB(a) a
  66#define DEBC(a) if (debugging) { a ; }
  67#else
  68#define DEB(a)
  69#define DEBC(a)
  70#endif
  71
  72#define ST_KILOBYTE 1024
  73
  74#include "st_options.h"
  75#include "st.h"
  76
  77static DEFINE_MUTEX(st_mutex);
  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 int st_dev_max;
  85static int st_nr_dev;
  86
  87static struct class *st_sysfs_class;
  88
  89MODULE_AUTHOR("Kai Makisara");
  90MODULE_DESCRIPTION("SCSI tape (st) driver");
  91MODULE_LICENSE("GPL");
  92MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  93MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  94
  95/* Set 'perm' (4th argument) to 0 to disable module_param's definition
  96 * of sysfs parameters (which module_param doesn't yet support).
  97 * Sysfs parameters defined explicitly later.
  98 */
  99module_param_named(buffer_kbs, buffer_kbs, int, 0);
 100MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
 101module_param_named(max_sg_segs, max_sg_segs, int, 0);
 102MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 103module_param_named(try_direct_io, try_direct_io, int, 0);
 104MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 105
 106/* Extra parameters for testing */
 107module_param_named(try_rdio, try_rdio, int, 0);
 108MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 109module_param_named(try_wdio, try_wdio, int, 0);
 110MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 111
 112#ifndef MODULE
 113static int write_threshold_kbs;  /* retained for compatibility */
 114static struct st_dev_parm {
 115	char *name;
 116	int *val;
 117} parms[] __initdata = {
 118	{
 119		"buffer_kbs", &buffer_kbs
 120	},
 121	{       /* Retained for compatibility with 2.4 */
 122		"write_threshold_kbs", &write_threshold_kbs
 123	},
 124	{
 125		"max_sg_segs", NULL
 126	},
 127	{
 128		"try_direct_io", &try_direct_io
 129	}
 130};
 131#endif
 132
 133/* Restrict the number of modes so that names for all are assigned */
 134#if ST_NBR_MODES > 16
 135#error "Maximum number of modes is 16"
 136#endif
 137/* Bit reversed order to get same names for same minors with all
 138   mode counts */
 139static const char *st_formats[] = {
 140	"",  "r", "k", "s", "l", "t", "o", "u",
 141	"m", "v", "p", "x", "a", "y", "q", "z"}; 
 142
 143/* The default definitions have been moved to st_options.h */
 144
 145#define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 146
 147/* The buffer size should fit into the 24 bits for length in the
 148   6-byte SCSI read and write commands. */
 149#if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 150#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 151#endif
 152
 153static int debugging = DEBUG;
 154
 155#define MAX_RETRIES 0
 156#define MAX_WRITE_RETRIES 0
 157#define MAX_READY_RETRIES 0
 158#define NO_TAPE  NOT_READY
 159
 160#define ST_TIMEOUT (900 * HZ)
 161#define ST_LONG_TIMEOUT (14000 * HZ)
 162
 163/* Remove mode bits and auto-rewind bit (7) */
 164#define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 165    (iminor(x) & ~(-1 << ST_MODE_SHIFT)) )
 166#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 167
 168/* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 169#define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 170  (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 171
 172/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 173   24 bits) */
 174#define SET_DENS_AND_BLK 0x10001
 175
 176static DEFINE_RWLOCK(st_dev_arr_lock);
 177
 178static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 179static int st_max_sg_segs = ST_MAX_SG;
 180
 181static struct scsi_tape **scsi_tapes = NULL;
 182
 183static int modes_defined;
 184
 185static int enlarge_buffer(struct st_buffer *, int, int);
 186static void clear_buffer(struct st_buffer *);
 187static void normalize_buffer(struct st_buffer *);
 188static int append_to_buffer(const char __user *, struct st_buffer *, int);
 189static int from_buffer(struct st_buffer *, char __user *, int);
 190static void move_buffer_data(struct st_buffer *, int);
 191
 192static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 193			      unsigned long, size_t, int);
 194static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 195
 196static int st_probe(struct device *);
 197static int st_remove(struct device *);
 198
 199static int do_create_sysfs_files(void);
 200static void do_remove_sysfs_files(void);
 201static int do_create_class_files(struct scsi_tape *, int, int);
 202
 203static struct scsi_driver st_template = {
 204	.owner			= THIS_MODULE,
 205	.gendrv = {
 206		.name		= "st",
 207		.probe		= st_probe,
 208		.remove		= st_remove,
 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);
 224
 225
 226#include "osst_detect.h"
 227#ifndef SIGS_FROM_OSST
 228#define SIGS_FROM_OSST \
 229	{"OnStream", "SC-", "", "osst"}, \
 230	{"OnStream", "DI-", "", "osst"}, \
 231	{"OnStream", "DP-", "", "osst"}, \
 232	{"OnStream", "USB", "", "osst"}, \
 233	{"OnStream", "FW-", "", "osst"}
 234#endif
 235
 236static struct scsi_tape *scsi_tape_get(int dev)
 237{
 238	struct scsi_tape *STp = NULL;
 239
 240	mutex_lock(&st_ref_mutex);
 241	write_lock(&st_dev_arr_lock);
 242
 243	if (dev < st_dev_max && scsi_tapes != NULL)
 244		STp = scsi_tapes[dev];
 245	if (!STp) goto out;
 246
 247	kref_get(&STp->kref);
 248
 249	if (!STp->device)
 250		goto out_put;
 251
 252	if (scsi_device_get(STp->device))
 253		goto out_put;
 254
 255	goto out;
 256
 257out_put:
 258	kref_put(&STp->kref, scsi_tape_release);
 259	STp = NULL;
 260out:
 261	write_unlock(&st_dev_arr_lock);
 262	mutex_unlock(&st_ref_mutex);
 263	return STp;
 264}
 265
 266static void scsi_tape_put(struct scsi_tape *STp)
 267{
 268	struct scsi_device *sdev = STp->device;
 269
 270	mutex_lock(&st_ref_mutex);
 271	kref_put(&STp->kref, scsi_tape_release);
 272	scsi_device_put(sdev);
 273	mutex_unlock(&st_ref_mutex);
 274}
 275
 276struct st_reject_data {
 277	char *vendor;
 278	char *model;
 279	char *rev;
 280	char *driver_hint; /* Name of the correct driver, NULL if unknown */
 281};
 282
 283static struct st_reject_data reject_list[] = {
 284	/* {"XXX", "Yy-", "", NULL},  example */
 285	SIGS_FROM_OSST,
 286	{NULL, }};
 287
 288/* If the device signature is on the list of incompatible drives, the
 289   function returns a pointer to the name of the correct driver (if known) */
 290static char * st_incompatible(struct scsi_device* SDp)
 291{
 292	struct st_reject_data *rp;
 293
 294	for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 295		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 296		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 297		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 298			if (rp->driver_hint)
 299				return rp->driver_hint;
 300			else
 301				return "unknown";
 302		}
 303	return NULL;
 304}
 305
 306
 307static inline char *tape_name(struct scsi_tape *tape)
 308{
 309	return tape->disk->disk_name;
 310}
 311
 312
 313static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 314{
 315	const u8 *ucp;
 316	const u8 *sense = SRpnt->sense;
 317
 318	s->have_sense = scsi_normalize_sense(SRpnt->sense,
 319				SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 320	s->flags = 0;
 321
 322	if (s->have_sense) {
 323		s->deferred = 0;
 324		s->remainder_valid =
 325			scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 326		switch (sense[0] & 0x7f) {
 327		case 0x71:
 328			s->deferred = 1;
 329		case 0x70:
 330			s->fixed_format = 1;
 331			s->flags = sense[2] & 0xe0;
 332			break;
 333		case 0x73:
 334			s->deferred = 1;
 335		case 0x72:
 336			s->fixed_format = 0;
 337			ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 338			s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 339			break;
 340		}
 341	}
 342}
 343
 344
 345/* Convert the result to success code */
 346static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 347{
 348	int result = SRpnt->result;
 349	u8 scode;
 350	DEB(const char *stp;)
 351	char *name = tape_name(STp);
 352	struct st_cmdstatus *cmdstatp;
 353
 354	if (!result)
 355		return 0;
 356
 357	cmdstatp = &STp->buffer->cmdstat;
 358	st_analyze_sense(SRpnt, cmdstatp);
 359
 360	if (cmdstatp->have_sense)
 361		scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 362	else
 363		scode = 0;
 364
 365        DEB(
 366        if (debugging) {
 367                printk(ST_DEB_MSG "%s: Error: %x, cmd: %x %x %x %x %x %x\n",
 368		       name, result,
 369		       SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 370		       SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 371		if (cmdstatp->have_sense)
 372			 __scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 373	} ) /* end DEB */
 374	if (!debugging) { /* Abnormal conditions for tape */
 375		if (!cmdstatp->have_sense)
 376			printk(KERN_WARNING
 377			       "%s: Error %x (driver bt 0x%x, host bt 0x%x).\n",
 378			       name, result, driver_byte(result),
 379			       host_byte(result));
 380		else if (cmdstatp->have_sense &&
 381			 scode != NO_SENSE &&
 382			 scode != RECOVERED_ERROR &&
 383			 /* scode != UNIT_ATTENTION && */
 384			 scode != BLANK_CHECK &&
 385			 scode != VOLUME_OVERFLOW &&
 386			 SRpnt->cmd[0] != MODE_SENSE &&
 387			 SRpnt->cmd[0] != TEST_UNIT_READY) {
 388
 389			__scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 390		}
 391	}
 392
 393	if (cmdstatp->fixed_format &&
 394	    STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 395		if (STp->cln_sense_value)
 396			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 397					       STp->cln_sense_mask) == STp->cln_sense_value);
 398		else
 399			STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 400					       STp->cln_sense_mask) != 0);
 401	}
 402	if (cmdstatp->have_sense &&
 403	    cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 404		STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 405
 406	STp->pos_unknown |= STp->device->was_reset;
 407
 408	if (cmdstatp->have_sense &&
 409	    scode == RECOVERED_ERROR
 410#if ST_RECOVERED_WRITE_FATAL
 411	    && SRpnt->cmd[0] != WRITE_6
 412	    && SRpnt->cmd[0] != WRITE_FILEMARKS
 413#endif
 414	    ) {
 415		STp->recover_count++;
 416		STp->recover_reg++;
 417
 418                DEB(
 419		if (debugging) {
 420			if (SRpnt->cmd[0] == READ_6)
 421				stp = "read";
 422			else if (SRpnt->cmd[0] == WRITE_6)
 423				stp = "write";
 424			else
 425				stp = "ioctl";
 426			printk(ST_DEB_MSG "%s: Recovered %s error (%d).\n", name, stp,
 427			       STp->recover_count);
 428		} ) /* end DEB */
 429
 430		if (cmdstatp->flags == 0)
 431			return 0;
 432	}
 433	return (-EIO);
 434}
 435
 436static struct st_request *st_allocate_request(struct scsi_tape *stp)
 437{
 438	struct st_request *streq;
 439
 440	streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 441	if (streq)
 442		streq->stp = stp;
 443	else {
 444		DEBC(printk(KERN_ERR "%s: Can't get SCSI request.\n",
 445			    tape_name(stp)););
 446		if (signal_pending(current))
 447			stp->buffer->syscall_result = -EINTR;
 448		else
 449			stp->buffer->syscall_result = -EBUSY;
 450	}
 451
 452	return streq;
 453}
 454
 455static void st_release_request(struct st_request *streq)
 456{
 457	kfree(streq);
 458}
 459
 460static void st_scsi_execute_end(struct request *req, int uptodate)
 461{
 462	struct st_request *SRpnt = req->end_io_data;
 463	struct scsi_tape *STp = SRpnt->stp;
 464	struct bio *tmp;
 465
 466	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
 467	STp->buffer->cmdstat.residual = req->resid_len;
 468
 469	tmp = SRpnt->bio;
 470	if (SRpnt->waiting)
 471		complete(SRpnt->waiting);
 472
 473	blk_rq_unmap_user(tmp);
 474	__blk_put_request(req->q, req);
 475}
 476
 477static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 478			   int data_direction, void *buffer, unsigned bufflen,
 479			   int timeout, int retries)
 480{
 481	struct request *req;
 482	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 483	int err = 0;
 484	int write = (data_direction == DMA_TO_DEVICE);
 485
 486	req = blk_get_request(SRpnt->stp->device->request_queue, write,
 487			      GFP_KERNEL);
 488	if (!req)
 489		return DRIVER_ERROR << 24;
 490
 491	req->cmd_type = REQ_TYPE_BLOCK_PC;
 492	req->cmd_flags |= REQ_QUIET;
 493
 494	mdata->null_mapped = 1;
 495
 496	if (bufflen) {
 497		err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 498				      GFP_KERNEL);
 499		if (err) {
 500			blk_put_request(req);
 501			return DRIVER_ERROR << 24;
 502		}
 503	}
 504
 505	SRpnt->bio = req->bio;
 506	req->cmd_len = COMMAND_SIZE(cmd[0]);
 507	memset(req->cmd, 0, BLK_MAX_CDB);
 508	memcpy(req->cmd, cmd, req->cmd_len);
 509	req->sense = SRpnt->sense;
 510	req->sense_len = 0;
 511	req->timeout = timeout;
 512	req->retries = retries;
 513	req->end_io_data = SRpnt;
 514
 515	blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
 516	return 0;
 517}
 518
 519/* Do the scsi command. Waits until command performed if do_wait is true.
 520   Otherwise write_behind_check() is used to check that the command
 521   has finished. */
 522static struct st_request *
 523st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 524	   int bytes, int direction, int timeout, int retries, int do_wait)
 525{
 526	struct completion *waiting;
 527	struct rq_map_data *mdata = &STp->buffer->map_data;
 528	int ret;
 529
 530	/* if async, make sure there's no command outstanding */
 531	if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 532		printk(KERN_ERR "%s: Async command already active.\n",
 533		       tape_name(STp));
 534		if (signal_pending(current))
 535			(STp->buffer)->syscall_result = (-EINTR);
 536		else
 537			(STp->buffer)->syscall_result = (-EBUSY);
 538		return NULL;
 539	}
 540
 541	if (!SRpnt) {
 542		SRpnt = st_allocate_request(STp);
 543		if (!SRpnt)
 544			return NULL;
 545	}
 546
 547	/* If async IO, set last_SRpnt. This ptr tells write_behind_check
 548	   which IO is outstanding. It's nulled out when the IO completes. */
 549	if (!do_wait)
 550		(STp->buffer)->last_SRpnt = SRpnt;
 551
 552	waiting = &STp->wait;
 553	init_completion(waiting);
 554	SRpnt->waiting = waiting;
 555
 556	if (STp->buffer->do_dio) {
 557		mdata->page_order = 0;
 558		mdata->nr_entries = STp->buffer->sg_segs;
 559		mdata->pages = STp->buffer->mapped_pages;
 560	} else {
 561		mdata->page_order = STp->buffer->reserved_page_order;
 562		mdata->nr_entries =
 563			DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 564		mdata->pages = STp->buffer->reserved_pages;
 565		mdata->offset = 0;
 566	}
 567
 568	memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 569	STp->buffer->cmdstat.have_sense = 0;
 570	STp->buffer->syscall_result = 0;
 571
 572	ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 573			      retries);
 574	if (ret) {
 575		/* could not allocate the buffer or request was too large */
 576		(STp->buffer)->syscall_result = (-EBUSY);
 577		(STp->buffer)->last_SRpnt = NULL;
 578	} else if (do_wait) {
 579		wait_for_completion(waiting);
 580		SRpnt->waiting = NULL;
 581		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 582	}
 583
 584	return SRpnt;
 585}
 586
 587
 588/* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 589   write has been correct but EOM early warning reached, -EIO if write ended in
 590   error or zero if write successful. Asynchronous writes are used only in
 591   variable block mode. */
 592static int write_behind_check(struct scsi_tape * STp)
 593{
 594	int retval = 0;
 595	struct st_buffer *STbuffer;
 596	struct st_partstat *STps;
 597	struct st_cmdstatus *cmdstatp;
 598	struct st_request *SRpnt;
 599
 600	STbuffer = STp->buffer;
 601	if (!STbuffer->writing)
 602		return 0;
 603
 604        DEB(
 605	if (STp->write_pending)
 606		STp->nbr_waits++;
 607	else
 608		STp->nbr_finished++;
 609        ) /* end DEB */
 610
 611	wait_for_completion(&(STp->wait));
 612	SRpnt = STbuffer->last_SRpnt;
 613	STbuffer->last_SRpnt = NULL;
 614	SRpnt->waiting = NULL;
 615
 616	(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 617	st_release_request(SRpnt);
 618
 619	STbuffer->buffer_bytes -= STbuffer->writing;
 620	STps = &(STp->ps[STp->partition]);
 621	if (STps->drv_block >= 0) {
 622		if (STp->block_size == 0)
 623			STps->drv_block++;
 624		else
 625			STps->drv_block += STbuffer->writing / STp->block_size;
 626	}
 627
 628	cmdstatp = &STbuffer->cmdstat;
 629	if (STbuffer->syscall_result) {
 630		retval = -EIO;
 631		if (cmdstatp->have_sense && !cmdstatp->deferred &&
 632		    (cmdstatp->flags & SENSE_EOM) &&
 633		    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 634		     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 635			/* EOM at write-behind, has all data been written? */
 636			if (!cmdstatp->remainder_valid ||
 637			    cmdstatp->uremainder64 == 0)
 638				retval = -ENOSPC;
 639		}
 640		if (retval == -EIO)
 641			STps->drv_block = -1;
 642	}
 643	STbuffer->writing = 0;
 644
 645	DEB(if (debugging && retval)
 646	    printk(ST_DEB_MSG "%s: Async write error %x, return value %d.\n",
 647		   tape_name(STp), STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 648
 649	return retval;
 650}
 651
 652
 653/* Step over EOF if it has been inadvertently crossed (ioctl not used because
 654   it messes up the block number). */
 655static int cross_eof(struct scsi_tape * STp, int forward)
 656{
 657	struct st_request *SRpnt;
 658	unsigned char cmd[MAX_COMMAND_SIZE];
 659
 660	cmd[0] = SPACE;
 661	cmd[1] = 0x01;		/* Space FileMarks */
 662	if (forward) {
 663		cmd[2] = cmd[3] = 0;
 664		cmd[4] = 1;
 665	} else
 666		cmd[2] = cmd[3] = cmd[4] = 0xff;	/* -1 filemarks */
 667	cmd[5] = 0;
 668
 669        DEBC(printk(ST_DEB_MSG "%s: Stepping over filemark %s.\n",
 670		   tape_name(STp), forward ? "forward" : "backward"));
 671
 672	SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 673			   STp->device->request_queue->rq_timeout,
 674			   MAX_RETRIES, 1);
 675	if (!SRpnt)
 676		return (STp->buffer)->syscall_result;
 677
 678	st_release_request(SRpnt);
 679	SRpnt = NULL;
 680
 681	if ((STp->buffer)->cmdstat.midlevel_result != 0)
 682		printk(KERN_ERR "%s: Stepping over filemark %s failed.\n",
 683		   tape_name(STp), forward ? "forward" : "backward");
 684
 685	return (STp->buffer)->syscall_result;
 686}
 687
 688
 689/* Flush the write buffer (never need to write if variable blocksize). */
 690static int st_flush_write_buffer(struct scsi_tape * STp)
 691{
 692	int transfer, blks;
 693	int result;
 694	unsigned char cmd[MAX_COMMAND_SIZE];
 695	struct st_request *SRpnt;
 696	struct st_partstat *STps;
 697
 698	result = write_behind_check(STp);
 699	if (result)
 700		return result;
 701
 702	result = 0;
 703	if (STp->dirty == 1) {
 704
 705		transfer = STp->buffer->buffer_bytes;
 706                DEBC(printk(ST_DEB_MSG "%s: Flushing %d bytes.\n",
 707                               tape_name(STp), transfer));
 708
 709		memset(cmd, 0, MAX_COMMAND_SIZE);
 710		cmd[0] = WRITE_6;
 711		cmd[1] = 1;
 712		blks = transfer / STp->block_size;
 713		cmd[2] = blks >> 16;
 714		cmd[3] = blks >> 8;
 715		cmd[4] = blks;
 716
 717		SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 718				   STp->device->request_queue->rq_timeout,
 719				   MAX_WRITE_RETRIES, 1);
 720		if (!SRpnt)
 721			return (STp->buffer)->syscall_result;
 722
 723		STps = &(STp->ps[STp->partition]);
 724		if ((STp->buffer)->syscall_result != 0) {
 725			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 726
 727			if (cmdstatp->have_sense && !cmdstatp->deferred &&
 728			    (cmdstatp->flags & SENSE_EOM) &&
 729			    (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 730			     cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 731			    (!cmdstatp->remainder_valid ||
 732			     cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 733				STp->dirty = 0;
 734				(STp->buffer)->buffer_bytes = 0;
 735				if (STps->drv_block >= 0)
 736					STps->drv_block += blks;
 737				result = (-ENOSPC);
 738			} else {
 739				printk(KERN_ERR "%s: Error on flush.\n",
 740                                       tape_name(STp));
 741				STps->drv_block = (-1);
 742				result = (-EIO);
 743			}
 744		} else {
 745			if (STps->drv_block >= 0)
 746				STps->drv_block += blks;
 747			STp->dirty = 0;
 748			(STp->buffer)->buffer_bytes = 0;
 749		}
 750		st_release_request(SRpnt);
 751		SRpnt = NULL;
 752	}
 753	return result;
 754}
 755
 756
 757/* Flush the tape buffer. The tape will be positioned correctly unless
 758   seek_next is true. */
 759static int flush_buffer(struct scsi_tape *STp, int seek_next)
 760{
 761	int backspace, result;
 762	struct st_buffer *STbuffer;
 763	struct st_partstat *STps;
 764
 765	STbuffer = STp->buffer;
 766
 767	/*
 768	 * If there was a bus reset, block further access
 769	 * to this device.
 770	 */
 771	if (STp->pos_unknown)
 772		return (-EIO);
 773
 774	if (STp->ready != ST_READY)
 775		return 0;
 776	STps = &(STp->ps[STp->partition]);
 777	if (STps->rw == ST_WRITING)	/* Writing */
 778		return st_flush_write_buffer(STp);
 779
 780	if (STp->block_size == 0)
 781		return 0;
 782
 783	backspace = ((STp->buffer)->buffer_bytes +
 784		     (STp->buffer)->read_pointer) / STp->block_size -
 785	    ((STp->buffer)->read_pointer + STp->block_size - 1) /
 786	    STp->block_size;
 787	(STp->buffer)->buffer_bytes = 0;
 788	(STp->buffer)->read_pointer = 0;
 789	result = 0;
 790	if (!seek_next) {
 791		if (STps->eof == ST_FM_HIT) {
 792			result = cross_eof(STp, 0);	/* Back over the EOF hit */
 793			if (!result)
 794				STps->eof = ST_NOEOF;
 795			else {
 796				if (STps->drv_file >= 0)
 797					STps->drv_file++;
 798				STps->drv_block = 0;
 799			}
 800		}
 801		if (!result && backspace > 0)
 802			result = st_int_ioctl(STp, MTBSR, backspace);
 803	} else if (STps->eof == ST_FM_HIT) {
 804		if (STps->drv_file >= 0)
 805			STps->drv_file++;
 806		STps->drv_block = 0;
 807		STps->eof = ST_NOEOF;
 808	}
 809	return result;
 810
 811}
 812
 813/* Set the mode parameters */
 814static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 815{
 816	int set_it = 0;
 817	unsigned long arg;
 818	char *name = tape_name(STp);
 819
 820	if (!STp->density_changed &&
 821	    STm->default_density >= 0 &&
 822	    STm->default_density != STp->density) {
 823		arg = STm->default_density;
 824		set_it = 1;
 825	} else
 826		arg = STp->density;
 827	arg <<= MT_ST_DENSITY_SHIFT;
 828	if (!STp->blksize_changed &&
 829	    STm->default_blksize >= 0 &&
 830	    STm->default_blksize != STp->block_size) {
 831		arg |= STm->default_blksize;
 832		set_it = 1;
 833	} else
 834		arg |= STp->block_size;
 835	if (set_it &&
 836	    st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 837		printk(KERN_WARNING
 838		       "%s: Can't set default block size to %d bytes and density %x.\n",
 839		       name, STm->default_blksize, STm->default_density);
 840		if (modes_defined)
 841			return (-EINVAL);
 842	}
 843	return 0;
 844}
 845
 846
 847/* Lock or unlock the drive door. Don't use when st_request allocated. */
 848static int do_door_lock(struct scsi_tape * STp, int do_lock)
 849{
 850	int retval, cmd;
 851	DEB(char *name = tape_name(STp);)
 852
 853
 854	cmd = do_lock ? SCSI_IOCTL_DOORLOCK : SCSI_IOCTL_DOORUNLOCK;
 855	DEBC(printk(ST_DEB_MSG "%s: %socking drive door.\n", name,
 856		    do_lock ? "L" : "Unl"));
 857	retval = scsi_ioctl(STp->device, cmd, NULL);
 858	if (!retval) {
 859		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 860	}
 861	else {
 862		STp->door_locked = ST_LOCK_FAILS;
 863	}
 864	return retval;
 865}
 866
 867
 868/* Set the internal state after reset */
 869static void reset_state(struct scsi_tape *STp)
 870{
 871	int i;
 872	struct st_partstat *STps;
 873
 874	STp->pos_unknown = 0;
 875	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 876		STps = &(STp->ps[i]);
 877		STps->rw = ST_IDLE;
 878		STps->eof = ST_NOEOF;
 879		STps->at_sm = 0;
 880		STps->last_block_valid = 0;
 881		STps->drv_block = -1;
 882		STps->drv_file = -1;
 883	}
 884	if (STp->can_partitions) {
 885		STp->partition = find_partition(STp);
 886		if (STp->partition < 0)
 887			STp->partition = 0;
 888		STp->new_partition = STp->partition;
 889	}
 890}
 891
 892/* Test if the drive is ready. Returns either one of the codes below or a negative system
 893   error code. */
 894#define CHKRES_READY       0
 895#define CHKRES_NEW_SESSION 1
 896#define CHKRES_NOT_READY   2
 897#define CHKRES_NO_TAPE     3
 898
 899#define MAX_ATTENTIONS    10
 900
 901static int test_ready(struct scsi_tape *STp, int do_wait)
 902{
 903	int attentions, waits, max_wait, scode;
 904	int retval = CHKRES_READY, new_session = 0;
 905	unsigned char cmd[MAX_COMMAND_SIZE];
 906	struct st_request *SRpnt = NULL;
 907	struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 908
 909	max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 910
 911	for (attentions=waits=0; ; ) {
 912		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 913		cmd[0] = TEST_UNIT_READY;
 914		SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 915				   STp->long_timeout, MAX_READY_RETRIES, 1);
 916
 917		if (!SRpnt) {
 918			retval = (STp->buffer)->syscall_result;
 919			break;
 920		}
 921
 922		if (cmdstatp->have_sense) {
 923
 924			scode = cmdstatp->sense_hdr.sense_key;
 925
 926			if (scode == UNIT_ATTENTION) { /* New media? */
 927				new_session = 1;
 928				if (attentions < MAX_ATTENTIONS) {
 929					attentions++;
 930					continue;
 931				}
 932				else {
 933					retval = (-EIO);
 934					break;
 935				}
 936			}
 937
 938			if (scode == NOT_READY) {
 939				if (waits < max_wait) {
 940					if (msleep_interruptible(1000)) {
 941						retval = (-EINTR);
 942						break;
 943					}
 944					waits++;
 945					continue;
 946				}
 947				else {
 948					if ((STp->device)->scsi_level >= SCSI_2 &&
 949					    cmdstatp->sense_hdr.asc == 0x3a)	/* Check ASC */
 950						retval = CHKRES_NO_TAPE;
 951					else
 952						retval = CHKRES_NOT_READY;
 953					break;
 954				}
 955			}
 956		}
 957
 958		retval = (STp->buffer)->syscall_result;
 959		if (!retval)
 960			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
 961		break;
 962	}
 963
 964	if (SRpnt != NULL)
 965		st_release_request(SRpnt);
 966	return retval;
 967}
 968
 969
 970/* See if the drive is ready and gather information about the tape. Return values:
 971   < 0   negative error code from errno.h
 972   0     drive ready
 973   1     drive not ready (possibly no tape)
 974*/
 975static int check_tape(struct scsi_tape *STp, struct file *filp)
 976{
 977	int i, retval, new_session = 0, do_wait;
 978	unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
 979	unsigned short st_flags = filp->f_flags;
 980	struct st_request *SRpnt = NULL;
 981	struct st_modedef *STm;
 982	struct st_partstat *STps;
 983	char *name = tape_name(STp);
 984	struct inode *inode = filp->f_path.dentry->d_inode;
 985	int mode = TAPE_MODE(inode);
 986
 987	STp->ready = ST_READY;
 988
 989	if (mode != STp->current_mode) {
 990                DEBC(printk(ST_DEB_MSG "%s: Mode change from %d to %d.\n",
 991			       name, STp->current_mode, mode));
 992		new_session = 1;
 993		STp->current_mode = mode;
 994	}
 995	STm = &(STp->modes[STp->current_mode]);
 996
 997	saved_cleaning = STp->cleaning_req;
 998	STp->cleaning_req = 0;
 999
1000	do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1001	retval = test_ready(STp, do_wait);
1002
1003	if (retval < 0)
1004	    goto err_out;
1005
1006	if (retval == CHKRES_NEW_SESSION) {
1007		STp->pos_unknown = 0;
1008		STp->partition = STp->new_partition = 0;
1009		if (STp->can_partitions)
1010			STp->nbr_partitions = 1; /* This guess will be updated later
1011                                                    if necessary */
1012		for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1013			STps = &(STp->ps[i]);
1014			STps->rw = ST_IDLE;
1015			STps->eof = ST_NOEOF;
1016			STps->at_sm = 0;
1017			STps->last_block_valid = 0;
1018			STps->drv_block = 0;
1019			STps->drv_file = 0;
1020		}
1021		new_session = 1;
1022	}
1023	else {
1024		STp->cleaning_req |= saved_cleaning;
1025
1026		if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1027			if (retval == CHKRES_NO_TAPE)
1028				STp->ready = ST_NO_TAPE;
1029			else
1030				STp->ready = ST_NOT_READY;
1031
1032			STp->density = 0;	/* Clear the erroneous "residue" */
1033			STp->write_prot = 0;
1034			STp->block_size = 0;
1035			STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1036			STp->partition = STp->new_partition = 0;
1037			STp->door_locked = ST_UNLOCKED;
1038			return CHKRES_NOT_READY;
1039		}
1040	}
1041
1042	if (STp->omit_blklims)
1043		STp->min_block = STp->max_block = (-1);
1044	else {
1045		memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1046		cmd[0] = READ_BLOCK_LIMITS;
1047
1048		SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1049				   STp->device->request_queue->rq_timeout,
1050				   MAX_READY_RETRIES, 1);
1051		if (!SRpnt) {
1052			retval = (STp->buffer)->syscall_result;
1053			goto err_out;
1054		}
1055
1056		if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1057			STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1058			    ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1059			STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1060			    (STp->buffer)->b_data[5];
1061			if ( DEB( debugging || ) !STp->inited)
1062				printk(KERN_INFO
1063                                       "%s: Block limits %d - %d bytes.\n", name,
1064                                       STp->min_block, STp->max_block);
1065		} else {
1066			STp->min_block = STp->max_block = (-1);
1067                        DEBC(printk(ST_DEB_MSG "%s: Can't read block limits.\n",
1068                                       name));
1069		}
1070	}
1071
1072	memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1073	cmd[0] = MODE_SENSE;
1074	cmd[4] = 12;
1075
1076	SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1077			   STp->device->request_queue->rq_timeout,
1078			   MAX_READY_RETRIES, 1);
1079	if (!SRpnt) {
1080		retval = (STp->buffer)->syscall_result;
1081		goto err_out;
1082	}
1083
1084	if ((STp->buffer)->syscall_result != 0) {
1085                DEBC(printk(ST_DEB_MSG "%s: No Mode Sense.\n", name));
1086		STp->block_size = ST_DEFAULT_BLOCK;	/* Educated guess (?) */
1087		(STp->buffer)->syscall_result = 0;	/* Prevent error propagation */
1088		STp->drv_write_prot = 0;
1089	} else {
1090                DEBC(printk(ST_DEB_MSG
1091                            "%s: Mode sense. Length %d, medium %x, WBS %x, BLL %d\n",
1092                            name,
1093                            (STp->buffer)->b_data[0], (STp->buffer)->b_data[1],
1094                            (STp->buffer)->b_data[2], (STp->buffer)->b_data[3]));
1095
1096		if ((STp->buffer)->b_data[3] >= 8) {
1097			STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1098			STp->density = (STp->buffer)->b_data[4];
1099			STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1100			    (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1101                        DEBC(printk(ST_DEB_MSG
1102                                    "%s: Density %x, tape length: %x, drv buffer: %d\n",
1103                                    name, STp->density, (STp->buffer)->b_data[5] * 65536 +
1104                                    (STp->buffer)->b_data[6] * 256 + (STp->buffer)->b_data[7],
1105                                    STp->drv_buffer));
1106		}
1107		STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1108		if (!STp->drv_buffer && STp->immediate_filemark) {
1109			printk(KERN_WARNING
1110			    "%s: non-buffered tape: disabling writing immediate filemarks\n",
1111			    name);
1112			STp->immediate_filemark = 0;
1113		}
1114	}
1115	st_release_request(SRpnt);
1116	SRpnt = NULL;
1117        STp->inited = 1;
1118
1119	if (STp->block_size > 0)
1120		(STp->buffer)->buffer_blocks =
1121                        (STp->buffer)->buffer_size / STp->block_size;
1122	else
1123		(STp->buffer)->buffer_blocks = 1;
1124	(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1125
1126        DEBC(printk(ST_DEB_MSG
1127                       "%s: Block size: %d, buffer size: %d (%d blocks).\n", name,
1128		       STp->block_size, (STp->buffer)->buffer_size,
1129		       (STp->buffer)->buffer_blocks));
1130
1131	if (STp->drv_write_prot) {
1132		STp->write_prot = 1;
1133
1134                DEBC(printk(ST_DEB_MSG "%s: Write protected\n", name));
1135
1136		if (do_wait &&
1137		    ((st_flags & O_ACCMODE) == O_WRONLY ||
1138		     (st_flags & O_ACCMODE) == O_RDWR)) {
1139			retval = (-EROFS);
1140			goto err_out;
1141		}
1142	}
1143
1144	if (STp->can_partitions && STp->nbr_partitions < 1) {
1145		/* This code is reached when the device is opened for the first time
1146		   after the driver has been initialized with tape in the drive and the
1147		   partition support has been enabled. */
1148                DEBC(printk(ST_DEB_MSG
1149                            "%s: Updating partition number in status.\n", name));
1150		if ((STp->partition = find_partition(STp)) < 0) {
1151			retval = STp->partition;
1152			goto err_out;
1153		}
1154		STp->new_partition = STp->partition;
1155		STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1156	}
1157
1158	if (new_session) {	/* Change the drive parameters for the new mode */
1159		STp->density_changed = STp->blksize_changed = 0;
1160		STp->compression_changed = 0;
1161		if (!(STm->defaults_for_writes) &&
1162		    (retval = set_mode_densblk(STp, STm)) < 0)
1163		    goto err_out;
1164
1165		if (STp->default_drvbuffer != 0xff) {
1166			if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1167				printk(KERN_WARNING
1168                                       "%s: Can't set default drive buffering to %d.\n",
1169				       name, STp->default_drvbuffer);
1170		}
1171	}
1172
1173	return CHKRES_READY;
1174
1175 err_out:
1176	return retval;
1177}
1178
1179
1180/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1181   module count. */
1182static int st_open(struct inode *inode, struct file *filp)
1183{
1184	int i, retval = (-EIO);
1185	int resumed = 0;
1186	struct scsi_tape *STp;
1187	struct st_partstat *STps;
1188	int dev = TAPE_NR(inode);
1189	char *name;
1190
1191	mutex_lock(&st_mutex);
1192	/*
1193	 * We really want to do nonseekable_open(inode, filp); here, but some
1194	 * versions of tar incorrectly call lseek on tapes and bail out if that
1195	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1196	 */
1197	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1198
1199	if (!(STp = scsi_tape_get(dev))) {
1200		mutex_unlock(&st_mutex);
1201		return -ENXIO;
1202	}
1203
1204	write_lock(&st_dev_arr_lock);
1205	filp->private_data = STp;
1206	name = tape_name(STp);
1207
1208	if (STp->in_use) {
1209		write_unlock(&st_dev_arr_lock);
1210		scsi_tape_put(STp);
1211		mutex_unlock(&st_mutex);
1212		DEB( printk(ST_DEB_MSG "%s: Device already in use.\n", name); )
1213		return (-EBUSY);
1214	}
1215
1216	STp->in_use = 1;
1217	write_unlock(&st_dev_arr_lock);
1218	STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1219
1220	if (scsi_autopm_get_device(STp->device) < 0) {
1221		retval = -EIO;
1222		goto err_out;
1223	}
1224	resumed = 1;
1225	if (!scsi_block_when_processing_errors(STp->device)) {
1226		retval = (-ENXIO);
1227		goto err_out;
1228	}
1229
1230	/* See that we have at least a one page buffer available */
1231	if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1232		printk(KERN_WARNING "%s: Can't allocate one page tape buffer.\n",
1233		       name);
1234		retval = (-EOVERFLOW);
1235		goto err_out;
1236	}
1237
1238	(STp->buffer)->cleared = 0;
1239	(STp->buffer)->writing = 0;
1240	(STp->buffer)->syscall_result = 0;
1241
1242	STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1243
1244	STp->dirty = 0;
1245	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1246		STps = &(STp->ps[i]);
1247		STps->rw = ST_IDLE;
1248	}
1249	STp->try_dio_now = STp->try_dio;
1250	STp->recover_count = 0;
1251	DEB( STp->nbr_waits = STp->nbr_finished = 0;
1252	     STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1253
1254	retval = check_tape(STp, filp);
1255	if (retval < 0)
1256		goto err_out;
1257	if ((filp->f_flags & O_NONBLOCK) == 0 &&
1258	    retval != CHKRES_READY) {
1259		if (STp->ready == NO_TAPE)
1260			retval = (-ENOMEDIUM);
1261		else
1262			retval = (-EIO);
1263		goto err_out;
1264	}
1265	mutex_unlock(&st_mutex);
1266	return 0;
1267
1268 err_out:
1269	normalize_buffer(STp->buffer);
1270	STp->in_use = 0;
1271	scsi_tape_put(STp);
1272	if (resumed)
1273		scsi_autopm_put_device(STp->device);
1274	mutex_unlock(&st_mutex);
1275	return retval;
1276
1277}
1278
1279
1280/* Flush the tape buffer before close */
1281static int st_flush(struct file *filp, fl_owner_t id)
1282{
1283	int result = 0, result2;
1284	unsigned char cmd[MAX_COMMAND_SIZE];
1285	struct st_request *SRpnt;
1286	struct scsi_tape *STp = filp->private_data;
1287	struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1288	struct st_partstat *STps = &(STp->ps[STp->partition]);
1289	char *name = tape_name(STp);
1290
1291	if (file_count(filp) > 1)
1292		return 0;
1293
1294	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1295		result = st_flush_write_buffer(STp);
1296		if (result != 0 && result != (-ENOSPC))
1297			goto out;
1298	}
1299
1300	if (STp->can_partitions &&
1301	    (result2 = switch_partition(STp)) < 0) {
1302                DEBC(printk(ST_DEB_MSG
1303                               "%s: switch_partition at close failed.\n", name));
1304		if (result == 0)
1305			result = result2;
1306		goto out;
1307	}
1308
1309	DEBC( if (STp->nbr_requests)
1310		printk(KERN_DEBUG "%s: Number of r/w requests %d, dio used in %d, pages %d.\n",
1311		       name, STp->nbr_requests, STp->nbr_dio, STp->nbr_pages));
1312
1313	if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1314		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1315
1316                DEBC(printk(ST_DEB_MSG "%s: Async write waits %d, finished %d.\n",
1317                            name, STp->nbr_waits, STp->nbr_finished);
1318		)
1319
1320		memset(cmd, 0, MAX_COMMAND_SIZE);
1321		cmd[0] = WRITE_FILEMARKS;
1322		if (STp->immediate_filemark)
1323			cmd[1] = 1;
1324		cmd[4] = 1 + STp->two_fm;
1325
1326		SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1327				   STp->device->request_queue->rq_timeout,
1328				   MAX_WRITE_RETRIES, 1);
1329		if (!SRpnt) {
1330			result = (STp->buffer)->syscall_result;
1331			goto out;
1332		}
1333
1334		if (STp->buffer->syscall_result == 0 ||
1335		    (cmdstatp->have_sense && !cmdstatp->deferred &&
1336		     (cmdstatp->flags & SENSE_EOM) &&
1337		     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1338		      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1339		     (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1340			/* Write successful at EOM */
1341			st_release_request(SRpnt);
1342			SRpnt = NULL;
1343			if (STps->drv_file >= 0)
1344				STps->drv_file++;
1345			STps->drv_block = 0;
1346			if (STp->two_fm)
1347				cross_eof(STp, 0);
1348			STps->eof = ST_FM;
1349		}
1350		else { /* Write error */
1351			st_release_request(SRpnt);
1352			SRpnt = NULL;
1353			printk(KERN_ERR "%s: Error on write filemark.\n", name);
1354			if (result == 0)
1355				result = (-EIO);
1356		}
1357
1358                DEBC(printk(ST_DEB_MSG "%s: Buffer flushed, %d EOF(s) written\n",
1359                            name, cmd[4]));
1360	} else if (!STp->rew_at_close) {
1361		STps = &(STp->ps[STp->partition]);
1362		if (!STm->sysv || STps->rw != ST_READING) {
1363			if (STp->can_bsr)
1364				result = flush_buffer(STp, 0);
1365			else if (STps->eof == ST_FM_HIT) {
1366				result = cross_eof(STp, 0);
1367				if (result) {
1368					if (STps->drv_file >= 0)
1369						STps->drv_file++;
1370					STps->drv_block = 0;
1371					STps->eof = ST_FM;
1372				} else
1373					STps->eof = ST_NOEOF;
1374			}
1375		} else if ((STps->eof == ST_NOEOF &&
1376			    !(result = cross_eof(STp, 1))) ||
1377			   STps->eof == ST_FM_HIT) {
1378			if (STps->drv_file >= 0)
1379				STps->drv_file++;
1380			STps->drv_block = 0;
1381			STps->eof = ST_FM;
1382		}
1383	}
1384
1385      out:
1386	if (STp->rew_at_close) {
1387		result2 = st_int_ioctl(STp, MTREW, 1);
1388		if (result == 0)
1389			result = result2;
1390	}
1391	return result;
1392}
1393
1394
1395/* Close the device and release it. BKL is not needed: this is the only thread
1396   accessing this tape. */
1397static int st_release(struct inode *inode, struct file *filp)
1398{
1399	int result = 0;
1400	struct scsi_tape *STp = filp->private_data;
1401
1402	if (STp->door_locked == ST_LOCKED_AUTO)
1403		do_door_lock(STp, 0);
1404
1405	normalize_buffer(STp->buffer);
1406	write_lock(&st_dev_arr_lock);
1407	STp->in_use = 0;
1408	write_unlock(&st_dev_arr_lock);
1409	scsi_autopm_put_device(STp->device);
1410	scsi_tape_put(STp);
1411
1412	return result;
1413}
1414
1415/* The checks common to both reading and writing */
1416static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1417{
1418	ssize_t retval = 0;
1419
1420	/*
1421	 * If we are in the middle of error recovery, don't let anyone
1422	 * else try and use this device.  Also, if error recovery fails, it
1423	 * may try and take the device offline, in which case all further
1424	 * access to the device is prohibited.
1425	 */
1426	if (!scsi_block_when_processing_errors(STp->device)) {
1427		retval = (-ENXIO);
1428		goto out;
1429	}
1430
1431	if (STp->ready != ST_READY) {
1432		if (STp->ready == ST_NO_TAPE)
1433			retval = (-ENOMEDIUM);
1434		else
1435			retval = (-EIO);
1436		goto out;
1437	}
1438
1439	if (! STp->modes[STp->current_mode].defined) {
1440		retval = (-ENXIO);
1441		goto out;
1442	}
1443
1444
1445	/*
1446	 * If there was a bus reset, block further access
1447	 * to this device.
1448	 */
1449	if (STp->pos_unknown) {
1450		retval = (-EIO);
1451		goto out;
1452	}
1453
1454	if (count == 0)
1455		goto out;
1456
1457        DEB(
1458	if (!STp->in_use) {
1459		printk(ST_DEB_MSG "%s: Incorrect device.\n", tape_name(STp));
1460		retval = (-EIO);
1461		goto out;
1462	} ) /* end DEB */
1463
1464	if (STp->can_partitions &&
1465	    (retval = switch_partition(STp)) < 0)
1466		goto out;
1467
1468	if (STp->block_size == 0 && STp->max_block > 0 &&
1469	    (count < STp->min_block || count > STp->max_block)) {
1470		retval = (-EINVAL);
1471		goto out;
1472	}
1473
1474	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1475	    !do_door_lock(STp, 1))
1476		STp->door_locked = ST_LOCKED_AUTO;
1477
1478 out:
1479	return retval;
1480}
1481
1482
1483static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1484			   size_t count, int is_read)
1485{
1486	int i, bufsize, retval = 0;
1487	struct st_buffer *STbp = STp->buffer;
1488
1489	if (is_read)
1490		i = STp->try_dio_now && try_rdio;
1491	else
1492		i = STp->try_dio_now && try_wdio;
1493
1494	if (i && ((unsigned long)buf & queue_dma_alignment(
1495					STp->device->request_queue)) == 0) {
1496		i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1497				       count, (is_read ? READ : WRITE));
1498		if (i > 0) {
1499			STbp->do_dio = i;
1500			STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1501		}
1502		else
1503			STbp->do_dio = 0;  /* fall back to buffering with any error */
1504		STbp->sg_segs = STbp->do_dio;
1505		DEB(
1506		     if (STbp->do_dio) {
1507			STp->nbr_dio++;
1508			STp->nbr_pages += STbp->do_dio;
1509		     }
1510		)
1511	} else
1512		STbp->do_dio = 0;
1513	DEB( STp->nbr_requests++; )
1514
1515	if (!STbp->do_dio) {
1516		if (STp->block_size)
1517			bufsize = STp->block_size > st_fixed_buffer_size ?
1518				STp->block_size : st_fixed_buffer_size;
1519		else {
1520			bufsize = count;
1521			/* Make sure that data from previous user is not leaked even if
1522			   HBA does not return correct residual */
1523			if (is_read && STp->sili && !STbp->cleared)
1524				clear_buffer(STbp);
1525		}
1526
1527		if (bufsize > STbp->buffer_size &&
1528		    !enlarge_buffer(STbp, bufsize, STp->restr_dma)) {
1529			printk(KERN_WARNING "%s: Can't allocate %d byte tape buffer.\n",
1530			       tape_name(STp), bufsize);
1531			retval = (-EOVERFLOW);
1532			goto out;
1533		}
1534		if (STp->block_size)
1535			STbp->buffer_blocks = bufsize / STp->block_size;
1536	}
1537
1538 out:
1539	return retval;
1540}
1541
1542
1543/* Can be called more than once after each setup_buffer() */
1544static void release_buffering(struct scsi_tape *STp, int is_read)
1545{
1546	struct st_buffer *STbp;
1547
1548	STbp = STp->buffer;
1549	if (STbp->do_dio) {
1550		sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1551		STbp->do_dio = 0;
1552		STbp->sg_segs = 0;
1553	}
1554}
1555
1556
1557/* Write command */
1558static ssize_t
1559st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1560{
1561	ssize_t total;
1562	ssize_t i, do_count, blks, transfer;
1563	ssize_t retval;
1564	int undone, retry_eot = 0, scode;
1565	int async_write;
1566	unsigned char cmd[MAX_COMMAND_SIZE];
1567	const char __user *b_point;
1568	struct st_request *SRpnt = NULL;
1569	struct scsi_tape *STp = filp->private_data;
1570	struct st_modedef *STm;
1571	struct st_partstat *STps;
1572	struct st_buffer *STbp;
1573	char *name = tape_name(STp);
1574
1575	if (mutex_lock_interruptible(&STp->lock))
1576		return -ERESTARTSYS;
1577
1578	retval = rw_checks(STp, filp, count);
1579	if (retval || count == 0)
1580		goto out;
1581
1582	/* Write must be integral number of blocks */
1583	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1584		printk(KERN_WARNING "%s: Write not multiple of tape block size.\n",
1585		       name);
1586		retval = (-EINVAL);
1587		goto out;
1588	}
1589
1590	STm = &(STp->modes[STp->current_mode]);
1591	STps = &(STp->ps[STp->partition]);
1592
1593	if (STp->write_prot) {
1594		retval = (-EACCES);
1595		goto out;
1596	}
1597
1598
1599	if (STps->rw == ST_READING) {
1600		retval = flush_buffer(STp, 0);
1601		if (retval)
1602			goto out;
1603		STps->rw = ST_WRITING;
1604	} else if (STps->rw != ST_WRITING &&
1605		   STps->drv_file == 0 && STps->drv_block == 0) {
1606		if ((retval = set_mode_densblk(STp, STm)) < 0)
1607			goto out;
1608		if (STm->default_compression != ST_DONT_TOUCH &&
1609		    !(STp->compression_changed)) {
1610			if (st_compression(STp, (STm->default_compression == ST_YES))) {
1611				printk(KERN_WARNING "%s: Can't set default compression.\n",
1612				       name);
1613				if (modes_defined) {
1614					retval = (-EINVAL);
1615					goto out;
1616				}
1617			}
1618		}
1619	}
1620
1621	STbp = STp->buffer;
1622	i = write_behind_check(STp);
1623	if (i) {
1624		if (i == -ENOSPC)
1625			STps->eof = ST_EOM_OK;
1626		else
1627			STps->eof = ST_EOM_ERROR;
1628	}
1629
1630	if (STps->eof == ST_EOM_OK) {
1631		STps->eof = ST_EOD_1;  /* allow next write */
1632		retval = (-ENOSPC);
1633		goto out;
1634	}
1635	else if (STps->eof == ST_EOM_ERROR) {
1636		retval = (-EIO);
1637		goto out;
1638	}
1639
1640	/* Check the buffer readability in cases where copy_user might catch
1641	   the problems after some tape movement. */
1642	if (STp->block_size != 0 &&
1643	    !STbp->do_dio &&
1644	    (copy_from_user(&i, buf, 1) != 0 ||
1645	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
1646		retval = (-EFAULT);
1647		goto out;
1648	}
1649
1650	retval = setup_buffering(STp, buf, count, 0);
1651	if (retval)
1652		goto out;
1653
1654	total = count;
1655
1656	memset(cmd, 0, MAX_COMMAND_SIZE);
1657	cmd[0] = WRITE_6;
1658	cmd[1] = (STp->block_size != 0);
1659
1660	STps->rw = ST_WRITING;
1661
1662	b_point = buf;
1663	while (count > 0 && !retry_eot) {
1664
1665		if (STbp->do_dio) {
1666			do_count = count;
1667		}
1668		else {
1669			if (STp->block_size == 0)
1670				do_count = count;
1671			else {
1672				do_count = STbp->buffer_blocks * STp->block_size -
1673					STbp->buffer_bytes;
1674				if (do_count > count)
1675					do_count = count;
1676			}
1677
1678			i = append_to_buffer(b_point, STbp, do_count);
1679			if (i) {
1680				retval = i;
1681				goto out;
1682			}
1683		}
1684		count -= do_count;
1685		b_point += do_count;
1686
1687		async_write = STp->block_size == 0 && !STbp->do_dio &&
1688			STm->do_async_writes && STps->eof < ST_EOM_OK;
1689
1690		if (STp->block_size != 0 && STm->do_buffer_writes &&
1691		    !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1692		    STbp->buffer_bytes < STbp->buffer_size) {
1693			STp->dirty = 1;
1694			/* Don't write a buffer that is not full enough. */
1695			if (!async_write && count == 0)
1696				break;
1697		}
1698
1699	retry_write:
1700		if (STp->block_size == 0)
1701			blks = transfer = do_count;
1702		else {
1703			if (!STbp->do_dio)
1704				blks = STbp->buffer_bytes;
1705			else
1706				blks = do_count;
1707			blks /= STp->block_size;
1708			transfer = blks * STp->block_size;
1709		}
1710		cmd[2] = blks >> 16;
1711		cmd[3] = blks >> 8;
1712		cmd[4] = blks;
1713
1714		SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1715				   STp->device->request_queue->rq_timeout,
1716				   MAX_WRITE_RETRIES, !async_write);
1717		if (!SRpnt) {
1718			retval = STbp->syscall_result;
1719			goto out;
1720		}
1721		if (async_write && !STbp->syscall_result) {
1722			STbp->writing = transfer;
1723			STp->dirty = !(STbp->writing ==
1724				       STbp->buffer_bytes);
1725			SRpnt = NULL;  /* Prevent releasing this request! */
1726			DEB( STp->write_pending = 1; )
1727			break;
1728		}
1729
1730		if (STbp->syscall_result != 0) {
1731			struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1732
1733                        DEBC(printk(ST_DEB_MSG "%s: Error on write:\n", name));
1734			if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1735				scode = cmdstatp->sense_hdr.sense_key;
1736				if (cmdstatp->remainder_valid)
1737					undone = (int)cmdstatp->uremainder64;
1738				else if (STp->block_size == 0 &&
1739					 scode == VOLUME_OVERFLOW)
1740					undone = transfer;
1741				else
1742					undone = 0;
1743				if (STp->block_size != 0)
1744					undone *= STp->block_size;
1745				if (undone <= do_count) {
1746					/* Only data from this write is not written */
1747					count += undone;
1748					b_point -= undone;
1749					do_count -= undone;
1750					if (STp->block_size)
1751						blks = (transfer - undone) / STp->block_size;
1752					STps->eof = ST_EOM_OK;
1753					/* Continue in fixed block mode if all written
1754					   in this request but still something left to write
1755					   (retval left to zero)
1756					*/
1757					if (STp->block_size == 0 ||
1758					    undone > 0 || count == 0)
1759						retval = (-ENOSPC); /* EOM within current request */
1760                                        DEBC(printk(ST_DEB_MSG
1761                                                       "%s: EOM with %d bytes unwritten.\n",
1762						       name, (int)count));
1763				} else {
1764					/* EOT within data buffered earlier (possible only
1765					   in fixed block mode without direct i/o) */
1766					if (!retry_eot && !cmdstatp->deferred &&
1767					    (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1768						move_buffer_data(STp->buffer, transfer - undone);
1769						retry_eot = 1;
1770						if (STps->drv_block >= 0) {
1771							STps->drv_block += (transfer - undone) /
1772								STp->block_size;
1773						}
1774						STps->eof = ST_EOM_OK;
1775						DEBC(printk(ST_DEB_MSG
1776							    "%s: Retry write of %d bytes at EOM.\n",
1777							    name, STp->buffer->buffer_bytes));
1778						goto retry_write;
1779					}
1780					else {
1781						/* Either error within data buffered by driver or
1782						   failed retry */
1783						count -= do_count;
1784						blks = do_count = 0;
1785						STps->eof = ST_EOM_ERROR;
1786						STps->drv_block = (-1); /* Too cautious? */
1787						retval = (-EIO);	/* EOM for old data */
1788						DEBC(printk(ST_DEB_MSG
1789							    "%s: EOM with lost data.\n",
1790							    name));
1791					}
1792				}
1793			} else {
1794				count += do_count;
1795				STps->drv_block = (-1);		/* Too cautious? */
1796				retval = STbp->syscall_result;
1797			}
1798
1799		}
1800
1801		if (STps->drv_block >= 0) {
1802			if (STp->block_size == 0)
1803				STps->drv_block += (do_count > 0);
1804			else
1805				STps->drv_block += blks;
1806		}
1807
1808		STbp->buffer_bytes = 0;
1809		STp->dirty = 0;
1810
1811		if (retval || retry_eot) {
1812			if (count < total)
1813				retval = total - count;
1814			goto out;
1815		}
1816	}
1817
1818	if (STps->eof == ST_EOD_1)
1819		STps->eof = ST_EOM_OK;
1820	else if (STps->eof != ST_EOM_OK)
1821		STps->eof = ST_NOEOF;
1822	retval = total - count;
1823
1824 out:
1825	if (SRpnt != NULL)
1826		st_release_request(SRpnt);
1827	release_buffering(STp, 0);
1828	mutex_unlock(&STp->lock);
1829
1830	return retval;
1831}
1832
1833/* Read data from the tape. Returns zero in the normal case, one if the
1834   eof status has changed, and the negative error code in case of a
1835   fatal error. Otherwise updates the buffer and the eof state.
1836
1837   Does release user buffer mapping if it is set.
1838*/
1839static long read_tape(struct scsi_tape *STp, long count,
1840		      struct st_request ** aSRpnt)
1841{
1842	int transfer, blks, bytes;
1843	unsigned char cmd[MAX_COMMAND_SIZE];
1844	struct st_request *SRpnt;
1845	struct st_modedef *STm;
1846	struct st_partstat *STps;
1847	struct st_buffer *STbp;
1848	int retval = 0;
1849	char *name = tape_name(STp);
1850
1851	if (count == 0)
1852		return 0;
1853
1854	STm = &(STp->modes[STp->current_mode]);
1855	STps = &(STp->ps[STp->partition]);
1856	if (STps->eof == ST_FM_HIT)
1857		return 1;
1858	STbp = STp->buffer;
1859
1860	if (STp->block_size == 0)
1861		blks = bytes = count;
1862	else {
1863		if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1864			blks = (STp->buffer)->buffer_blocks;
1865			bytes = blks * STp->block_size;
1866		} else {
1867			bytes = count;
1868			if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1869				bytes = (STp->buffer)->buffer_size;
1870			blks = bytes / STp->block_size;
1871			bytes = blks * STp->block_size;
1872		}
1873	}
1874
1875	memset(cmd, 0, MAX_COMMAND_SIZE);
1876	cmd[0] = READ_6;
1877	cmd[1] = (STp->block_size != 0);
1878	if (!cmd[1] && STp->sili)
1879		cmd[1] |= 2;
1880	cmd[2] = blks >> 16;
1881	cmd[3] = blks >> 8;
1882	cmd[4] = blks;
1883
1884	SRpnt = *aSRpnt;
1885	SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1886			   STp->device->request_queue->rq_timeout,
1887			   MAX_RETRIES, 1);
1888	release_buffering(STp, 1);
1889	*aSRpnt = SRpnt;
1890	if (!SRpnt)
1891		return STbp->syscall_result;
1892
1893	STbp->read_pointer = 0;
1894	STps->at_sm = 0;
1895
1896	/* Something to check */
1897	if (STbp->syscall_result) {
1898		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1899
1900		retval = 1;
1901		DEBC(printk(ST_DEB_MSG "%s: Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1902                            name,
1903                            SRpnt->sense[0], SRpnt->sense[1],
1904                            SRpnt->sense[2], SRpnt->sense[3],
1905                            SRpnt->sense[4], SRpnt->sense[5],
1906                            SRpnt->sense[6], SRpnt->sense[7]));
1907		if (cmdstatp->have_sense) {
1908
1909			if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1910				cmdstatp->flags &= 0xcf;	/* No need for EOM in this case */
1911
1912			if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1913				/* Compute the residual count */
1914				if (cmdstatp->remainder_valid)
1915					transfer = (int)cmdstatp->uremainder64;
1916				else
1917					transfer = 0;
1918				if (STp->block_size == 0 &&
1919				    cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR)
1920					transfer = bytes;
1921
1922				if (cmdstatp->flags & SENSE_ILI) {	/* ILI */
1923					if (STp->block_size == 0) {
1924						if (transfer <= 0) {
1925							if (transfer < 0)
1926								printk(KERN_NOTICE
1927								       "%s: Failed to read %d byte block with %d byte transfer.\n",
1928								       name, bytes - transfer, bytes);
1929							if (STps->drv_block >= 0)
1930								STps->drv_block += 1;
1931							STbp->buffer_bytes = 0;
1932							return (-ENOMEM);
1933						}
1934						STbp->buffer_bytes = bytes - transfer;
1935					} else {
1936						st_release_request(SRpnt);
1937						SRpnt = *aSRpnt = NULL;
1938						if (transfer == blks) {	/* We did not get anything, error */
1939							printk(KERN_NOTICE "%s: Incorrect block size.\n", name);
1940							if (STps->drv_block >= 0)
1941								STps->drv_block += blks - transfer + 1;
1942							st_int_ioctl(STp, MTBSR, 1);
1943							return (-EIO);
1944						}
1945						/* We have some data, deliver it */
1946						STbp->buffer_bytes = (blks - transfer) *
1947						    STp->block_size;
1948                                                DEBC(printk(ST_DEB_MSG
1949                                                            "%s: ILI but enough data received %ld %d.\n",
1950                                                            name, count, STbp->buffer_bytes));
1951						if (STps->drv_block >= 0)
1952							STps->drv_block += 1;
1953						if (st_int_ioctl(STp, MTBSR, 1))
1954							return (-EIO);
1955					}
1956				} else if (cmdstatp->flags & SENSE_FMK) {	/* FM overrides EOM */
1957					if (STps->eof != ST_FM_HIT)
1958						STps->eof = ST_FM_HIT;
1959					else
1960						STps->eof = ST_EOD_2;
1961					if (STp->block_size == 0)
1962						STbp->buffer_bytes = 0;
1963					else
1964						STbp->buffer_bytes =
1965						    bytes - transfer * STp->block_size;
1966                                        DEBC(printk(ST_DEB_MSG
1967                                                    "%s: EOF detected (%d bytes read).\n",
1968                                                    name, STbp->buffer_bytes));
1969				} else if (cmdstatp->flags & SENSE_EOM) {
1970					if (STps->eof == ST_FM)
1971						STps->eof = ST_EOD_1;
1972					else
1973						STps->eof = ST_EOM_OK;
1974					if (STp->block_size == 0)
1975						STbp->buffer_bytes = bytes - transfer;
1976					else
1977						STbp->buffer_bytes =
1978						    bytes - transfer * STp->block_size;
1979
1980                                        DEBC(printk(ST_DEB_MSG "%s: EOM detected (%d bytes read).\n",
1981                                                    name, STbp->buffer_bytes));
1982				}
1983			}
1984			/* end of EOF, EOM, ILI test */ 
1985			else {	/* nonzero sense key */
1986                                DEBC(printk(ST_DEB_MSG
1987                                            "%s: Tape error while reading.\n", name));
1988				STps->drv_block = (-1);
1989				if (STps->eof == ST_FM &&
1990				    cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
1991                                        DEBC(printk(ST_DEB_MSG
1992                                                    "%s: Zero returned for first BLANK CHECK after EOF.\n",
1993                                                    name));
1994					STps->eof = ST_EOD_2;	/* First BLANK_CHECK after FM */
1995				} else	/* Some other extended sense code */
1996					retval = (-EIO);
1997			}
1998
1999			if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
2000				STbp->buffer_bytes = 0;
2001		}
2002		/* End of extended sense test */ 
2003		else {		/* Non-extended sense */
2004			retval = STbp->syscall_result;
2005		}
2006
2007	}
2008	/* End of error handling */ 
2009	else {			/* Read successful */
2010		STbp->buffer_bytes = bytes;
2011		if (STp->sili) /* In fixed block mode residual is always zero here */
2012			STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
2013	}
2014
2015	if (STps->drv_block >= 0) {
2016		if (STp->block_size == 0)
2017			STps->drv_block++;
2018		else
2019			STps->drv_block += STbp->buffer_bytes / STp->block_size;
2020	}
2021	return retval;
2022}
2023
2024
2025/* Read command */
2026static ssize_t
2027st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2028{
2029	ssize_t total;
2030	ssize_t retval = 0;
2031	ssize_t i, transfer;
2032	int special, do_dio = 0;
2033	struct st_request *SRpnt = NULL;
2034	struct scsi_tape *STp = filp->private_data;
2035	struct st_modedef *STm;
2036	struct st_partstat *STps;
2037	struct st_buffer *STbp = STp->buffer;
2038	DEB( char *name = tape_name(STp); )
2039
2040	if (mutex_lock_interruptible(&STp->lock))
2041		return -ERESTARTSYS;
2042
2043	retval = rw_checks(STp, filp, count);
2044	if (retval || count == 0)
2045		goto out;
2046
2047	STm = &(STp->modes[STp->current_mode]);
2048	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2049		if (!STm->do_read_ahead) {
2050			retval = (-EINVAL);	/* Read must be integral number of blocks */
2051			goto out;
2052		}
2053		STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2054	}
2055
2056	STps = &(STp->ps[STp->partition]);
2057	if (STps->rw == ST_WRITING) {
2058		retval = flush_buffer(STp, 0);
2059		if (retval)
2060			goto out;
2061		STps->rw = ST_READING;
2062	}
2063        DEB(
2064	if (debugging && STps->eof != ST_NOEOF)
2065		printk(ST_DEB_MSG "%s: EOF/EOM flag up (%d). Bytes %d\n", name,
2066		       STps->eof, STbp->buffer_bytes);
2067        ) /* end DEB */
2068
2069	retval = setup_buffering(STp, buf, count, 1);
2070	if (retval)
2071		goto out;
2072	do_dio = STbp->do_dio;
2073
2074	if (STbp->buffer_bytes == 0 &&
2075	    STps->eof >= ST_EOD_1) {
2076		if (STps->eof < ST_EOD) {
2077			STps->eof += 1;
2078			retval = 0;
2079			goto out;
2080		}
2081		retval = (-EIO);	/* EOM or Blank Check */
2082		goto out;
2083	}
2084
2085	if (do_dio) {
2086		/* Check the buffer writability before any tape movement. Don't alter
2087		   buffer data. */
2088		if (copy_from_user(&i, buf, 1) != 0 ||
2089		    copy_to_user(buf, &i, 1) != 0 ||
2090		    copy_from_user(&i, buf + count - 1, 1) != 0 ||
2091		    copy_to_user(buf + count - 1, &i, 1) != 0) {
2092			retval = (-EFAULT);
2093			goto out;
2094		}
2095	}
2096
2097	STps->rw = ST_READING;
2098
2099
2100	/* Loop until enough data in buffer or a special condition found */
2101	for (total = 0, special = 0; total < count && !special;) {
2102
2103		/* Get new data if the buffer is empty */
2104		if (STbp->buffer_bytes == 0) {
2105			special = read_tape(STp, count - total, &SRpnt);
2106			if (special < 0) {	/* No need to continue read */
2107				retval = special;
2108				goto out;
2109			}
2110		}
2111
2112		/* Move the data from driver buffer to user buffer */
2113		if (STbp->buffer_bytes > 0) {
2114                        DEB(
2115			if (debugging && STps->eof != ST_NOEOF)
2116				printk(ST_DEB_MSG
2117                                       "%s: EOF up (%d). Left %d, needed %d.\n", name,
2118				       STps->eof, STbp->buffer_bytes,
2119                                       (int)(count - total));
2120                        ) /* end DEB */
2121			transfer = STbp->buffer_bytes < count - total ?
2122			    STbp->buffer_bytes : count - total;
2123			if (!do_dio) {
2124				i = from_buffer(STbp, buf, transfer);
2125				if (i) {
2126					retval = i;
2127					goto out;
2128				}
2129			}
2130			buf += transfer;
2131			total += transfer;
2132		}
2133
2134		if (STp->block_size == 0)
2135			break;	/* Read only one variable length block */
2136
2137	}			/* for (total = 0, special = 0;
2138                                   total < count && !special; ) */
2139
2140	/* Change the eof state if no data from tape or buffer */
2141	if (total == 0) {
2142		if (STps->eof == ST_FM_HIT) {
2143			STps->eof = ST_FM;
2144			STps->drv_block = 0;
2145			if (STps->drv_file >= 0)
2146				STps->drv_file++;
2147		} else if (STps->eof == ST_EOD_1) {
2148			STps->eof = ST_EOD_2;
2149			STps->drv_block = 0;
2150			if (STps->drv_file >= 0)
2151				STps->drv_file++;
2152		} else if (STps->eof == ST_EOD_2)
2153			STps->eof = ST_EOD;
2154	} else if (STps->eof == ST_FM)
2155		STps->eof = ST_NOEOF;
2156	retval = total;
2157
2158 out:
2159	if (SRpnt != NULL) {
2160		st_release_request(SRpnt);
2161		SRpnt = NULL;
2162	}
2163	if (do_dio) {
2164		release_buffering(STp, 1);
2165		STbp->buffer_bytes = 0;
2166	}
2167	mutex_unlock(&STp->lock);
2168
2169	return retval;
2170}
2171
2172
2173
2174DEB(
2175/* Set the driver options */
2176static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm, char *name)
2177{
2178	if (debugging) {
2179		printk(KERN_INFO
2180		       "%s: Mode %d options: buffer writes: %d, async writes: %d, read ahead: %d\n",
2181		       name, STp->current_mode, STm->do_buffer_writes, STm->do_async_writes,
2182		       STm->do_read_ahead);
2183		printk(KERN_INFO
2184		       "%s:    can bsr: %d, two FMs: %d, fast mteom: %d, auto lock: %d,\n",
2185		       name, STp->can_bsr, STp->two_fm, STp->fast_mteom, STp->do_auto_lock);
2186		printk(KERN_INFO
2187		       "%s:    defs for wr: %d, no block limits: %d, partitions: %d, s2 log: %d\n",
2188		       name, STm->defaults_for_writes, STp->omit_blklims, STp->can_partitions,
2189		       STp->scsi2_logical);
2190		printk(KERN_INFO
2191		       "%s:    sysv: %d nowait: %d sili: %d nowait_filemark: %d\n",
2192		       name, STm->sysv, STp->immediate, STp->sili,
2193		       STp->immediate_filemark);
2194		printk(KERN_INFO "%s:    debugging: %d\n",
2195		       name, debugging);
2196	}
2197}
2198	)
2199
2200
2201static int st_set_options(struct scsi_tape *STp, long options)
2202{
2203	int value;
2204	long code;
2205	struct st_modedef *STm;
2206	char *name = tape_name(STp);
2207	struct cdev *cd0, *cd1;
2208
2209	STm = &(STp->modes[STp->current_mode]);
2210	if (!STm->defined) {
2211		cd0 = STm->cdevs[0]; cd1 = STm->cdevs[1];
2212		memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2213		STm->cdevs[0] = cd0; STm->cdevs[1] = cd1;
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, nbr, 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	nbr = max_segs - STbuffer->frp_segs;
3740	if (nbr <= 0)
3741		return 0;
3742
3743	priority = GFP_KERNEL | __GFP_NOWARN;
3744	if (need_dma)
3745		priority |= GFP_DMA;
3746
3747	if (STbuffer->cleared)
3748		priority |= __GFP_ZERO;
3749
3750	if (STbuffer->frp_segs) {
3751		order = STbuffer->reserved_page_order;
3752		b_size = PAGE_SIZE << order;
3753	} else {
3754		for (b_size = PAGE_SIZE, order = 0;
3755		     order < ST_MAX_ORDER &&
3756			     max_segs * (PAGE_SIZE << order) < new_size;
3757		     order++, b_size *= 2)
3758			;  /* empty */
3759		STbuffer->reserved_page_order = order;
3760	}
3761	if (max_segs * (PAGE_SIZE << order) < new_size) {
3762		if (order == ST_MAX_ORDER)
3763			return 0;
3764		normalize_buffer(STbuffer);
3765		return enlarge_buffer(STbuffer, new_size, need_dma);
3766	}
3767
3768	for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3769	     segs < max_segs && got < new_size;) {
3770		struct page *page;
3771
3772		page = alloc_pages(priority, order);
3773		if (!page) {
3774			DEB(STbuffer->buffer_size = got);
3775			normalize_buffer(STbuffer);
3776			return 0;
3777		}
3778
3779		STbuffer->frp_segs += 1;
3780		got += b_size;
3781		STbuffer->buffer_size = got;
3782		STbuffer->reserved_pages[segs] = page;
3783		segs++;
3784	}
3785	STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3786
3787	return 1;
3788}
3789
3790
3791/* Make sure that no data from previous user is in the internal buffer */
3792static void clear_buffer(struct st_buffer * st_bp)
3793{
3794	int i;
3795
3796	for (i=0; i < st_bp->frp_segs; i++)
3797		memset(page_address(st_bp->reserved_pages[i]), 0,
3798		       PAGE_SIZE << st_bp->reserved_page_order);
3799	st_bp->cleared = 1;
3800}
3801
3802
3803/* Release the extra buffer */
3804static void normalize_buffer(struct st_buffer * STbuffer)
3805{
3806	int i, order = STbuffer->reserved_page_order;
3807
3808	for (i = 0; i < STbuffer->frp_segs; i++) {
3809		__free_pages(STbuffer->reserved_pages[i], order);
3810		STbuffer->buffer_size -= (PAGE_SIZE << order);
3811	}
3812	STbuffer->frp_segs = 0;
3813	STbuffer->sg_segs = 0;
3814	STbuffer->reserved_page_order = 0;
3815	STbuffer->map_data.offset = 0;
3816}
3817
3818
3819/* Move data from the user buffer to the tape buffer. Returns zero (success) or
3820   negative error code. */
3821static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3822{
3823	int i, cnt, res, offset;
3824	int length = PAGE_SIZE << st_bp->reserved_page_order;
3825
3826	for (i = 0, offset = st_bp->buffer_bytes;
3827	     i < st_bp->frp_segs && offset >= length; i++)
3828		offset -= length;
3829	if (i == st_bp->frp_segs) {	/* Should never happen */
3830		printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
3831		return (-EIO);
3832	}
3833	for (; i < st_bp->frp_segs && do_count > 0; i++) {
3834		struct page *page = st_bp->reserved_pages[i];
3835		cnt = length - offset < do_count ? length - offset : do_count;
3836		res = copy_from_user(page_address(page) + offset, ubp, cnt);
3837		if (res)
3838			return (-EFAULT);
3839		do_count -= cnt;
3840		st_bp->buffer_bytes += cnt;
3841		ubp += cnt;
3842		offset = 0;
3843	}
3844	if (do_count) /* Should never happen */
3845		return (-EIO);
3846
3847	return 0;
3848}
3849
3850
3851/* Move data from the tape buffer to the user buffer. Returns zero (success) or
3852   negative error code. */
3853static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
3854{
3855	int i, cnt, res, offset;
3856	int length = PAGE_SIZE << st_bp->reserved_page_order;
3857
3858	for (i = 0, offset = st_bp->read_pointer;
3859	     i < st_bp->frp_segs && offset >= length; i++)
3860		offset -= length;
3861	if (i == st_bp->frp_segs) {	/* Should never happen */
3862		printk(KERN_WARNING "st: from_buffer offset overflow.\n");
3863		return (-EIO);
3864	}
3865	for (; i < st_bp->frp_segs && do_count > 0; i++) {
3866		struct page *page = st_bp->reserved_pages[i];
3867		cnt = length - offset < do_count ? length - offset : do_count;
3868		res = copy_to_user(ubp, page_address(page) + offset, cnt);
3869		if (res)
3870			return (-EFAULT);
3871		do_count -= cnt;
3872		st_bp->buffer_bytes -= cnt;
3873		st_bp->read_pointer += cnt;
3874		ubp += cnt;
3875		offset = 0;
3876	}
3877	if (do_count) /* Should never happen */
3878		return (-EIO);
3879
3880	return 0;
3881}
3882
3883
3884/* Move data towards start of buffer */
3885static void move_buffer_data(struct st_buffer * st_bp, int offset)
3886{
3887	int src_seg, dst_seg, src_offset = 0, dst_offset;
3888	int count, total;
3889	int length = PAGE_SIZE << st_bp->reserved_page_order;
3890
3891	if (offset == 0)
3892		return;
3893
3894	total=st_bp->buffer_bytes - offset;
3895	for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
3896		src_offset = offset;
3897		if (src_offset < length)
3898			break;
3899		offset -= length;
3900	}
3901
3902	st_bp->buffer_bytes = st_bp->read_pointer = total;
3903	for (dst_seg=dst_offset=0; total > 0; ) {
3904		struct page *dpage = st_bp->reserved_pages[dst_seg];
3905		struct page *spage = st_bp->reserved_pages[src_seg];
3906
3907		count = min(length - dst_offset, length - src_offset);
3908		memmove(page_address(dpage) + dst_offset,
3909			page_address(spage) + src_offset, count);
3910		src_offset += count;
3911		if (src_offset >= length) {
3912			src_seg++;
3913			src_offset = 0;
3914		}
3915		dst_offset += count;
3916		if (dst_offset >= length) {
3917			dst_seg++;
3918			dst_offset = 0;
3919		}
3920		total -= count;
3921	}
3922}
3923
3924/* Validate the options from command line or module parameters */
3925static void validate_options(void)
3926{
3927	if (buffer_kbs > 0)
3928		st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
3929	if (max_sg_segs >= ST_FIRST_SG)
3930		st_max_sg_segs = max_sg_segs;
3931}
3932
3933#ifndef MODULE
3934/* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
3935 */
3936static int __init st_setup(char *str)
3937{
3938	int i, len, ints[5];
3939	char *stp;
3940
3941	stp = get_options(str, ARRAY_SIZE(ints), ints);
3942
3943	if (ints[0] > 0) {
3944		for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
3945			if (parms[i].val)
3946				*parms[i].val = ints[i + 1];
3947	} else {
3948		while (stp != NULL) {
3949			for (i = 0; i < ARRAY_SIZE(parms); i++) {
3950				len = strlen(parms[i].name);
3951				if (!strncmp(stp, parms[i].name, len) &&
3952				    (*(stp + len) == ':' || *(stp + len) == '=')) {
3953					if (parms[i].val)
3954						*parms[i].val =
3955							simple_strtoul(stp + len + 1, NULL, 0);
3956					else
3957						printk(KERN_WARNING "st: Obsolete parameter %s\n",
3958						       parms[i].name);
3959					break;
3960				}
3961			}
3962			if (i >= ARRAY_SIZE(parms))
3963				 printk(KERN_WARNING "st: invalid parameter in '%s'\n",
3964					stp);
3965			stp = strchr(stp, ',');
3966			if (stp)
3967				stp++;
3968		}
3969	}
3970
3971	validate_options();
3972
3973	return 1;
3974}
3975
3976__setup("st=", st_setup);
3977
3978#endif
3979
3980static const struct file_operations st_fops =
3981{
3982	.owner =	THIS_MODULE,
3983	.read =		st_read,
3984	.write =	st_write,
3985	.unlocked_ioctl = st_ioctl,
3986#ifdef CONFIG_COMPAT
3987	.compat_ioctl = st_compat_ioctl,
3988#endif
3989	.open =		st_open,
3990	.flush =	st_flush,
3991	.release =	st_release,
3992	.llseek =	noop_llseek,
3993};
3994
3995static int st_probe(struct device *dev)
3996{
3997	struct scsi_device *SDp = to_scsi_device(dev);
3998	struct gendisk *disk = NULL;
3999	struct cdev *cdev = NULL;
4000	struct scsi_tape *tpnt = NULL;
4001	struct st_modedef *STm;
4002	struct st_partstat *STps;
4003	struct st_buffer *buffer;
4004	int i, j, mode, dev_num, error;
4005	char *stp;
4006
4007	if (SDp->type != TYPE_TAPE)
4008		return -ENODEV;
4009	if ((stp = st_incompatible(SDp))) {
4010		sdev_printk(KERN_INFO, SDp, "Found incompatible tape\n");
4011		printk(KERN_INFO "st: The suggested driver is %s.\n", stp);
4012		return -ENODEV;
4013	}
4014
4015	i = queue_max_segments(SDp->request_queue);
4016	if (st_max_sg_segs < i)
4017		i = st_max_sg_segs;
4018	buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
4019	if (buffer == NULL) {
4020		printk(KERN_ERR
4021		       "st: Can't allocate new tape buffer. Device not attached.\n");
4022		goto out;
4023	}
4024
4025	disk = alloc_disk(1);
4026	if (!disk) {
4027		printk(KERN_ERR "st: out of memory. Device not attached.\n");
4028		goto out_buffer_free;
4029	}
4030
4031	write_lock(&st_dev_arr_lock);
4032	if (st_nr_dev >= st_dev_max) {
4033		struct scsi_tape **tmp_da;
4034		int tmp_dev_max;
4035
4036		tmp_dev_max = max(st_nr_dev * 2, 8);
4037		if (tmp_dev_max > ST_MAX_TAPES)
4038			tmp_dev_max = ST_MAX_TAPES;
4039		if (tmp_dev_max <= st_nr_dev) {
4040			write_unlock(&st_dev_arr_lock);
4041			printk(KERN_ERR "st: Too many tape devices (max. %d).\n",
4042			       ST_MAX_TAPES);
4043			goto out_put_disk;
4044		}
4045
4046		tmp_da = kzalloc(tmp_dev_max * sizeof(struct scsi_tape *), GFP_ATOMIC);
4047		if (tmp_da == NULL) {
4048			write_unlock(&st_dev_arr_lock);
4049			printk(KERN_ERR "st: Can't extend device array.\n");
4050			goto out_put_disk;
4051		}
4052
4053		if (scsi_tapes != NULL) {
4054			memcpy(tmp_da, scsi_tapes,
4055			       st_dev_max * sizeof(struct scsi_tape *));
4056			kfree(scsi_tapes);
4057		}
4058		scsi_tapes = tmp_da;
4059
4060		st_dev_max = tmp_dev_max;
4061	}
4062
4063	for (i = 0; i < st_dev_max; i++)
4064		if (scsi_tapes[i] == NULL)
4065			break;
4066	if (i >= st_dev_max)
4067		panic("scsi_devices corrupt (st)");
4068
4069	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
4070	if (tpnt == NULL) {
4071		write_unlock(&st_dev_arr_lock);
4072		printk(KERN_ERR "st: Can't allocate device descriptor.\n");
4073		goto out_put_disk;
4074	}
4075	kref_init(&tpnt->kref);
4076	tpnt->disk = disk;
4077	sprintf(disk->disk_name, "st%d", i);
4078	disk->private_data = &tpnt->driver;
4079	disk->queue = SDp->request_queue;
4080	tpnt->driver = &st_template;
4081	scsi_tapes[i] = tpnt;
4082	dev_num = i;
4083
4084	tpnt->device = SDp;
4085	if (SDp->scsi_level <= 2)
4086		tpnt->tape_type = MT_ISSCSI1;
4087	else
4088		tpnt->tape_type = MT_ISSCSI2;
4089
4090	tpnt->buffer = buffer;
4091	tpnt->buffer->last_SRpnt = NULL;
4092
4093	tpnt->inited = 0;
4094	tpnt->dirty = 0;
4095	tpnt->in_use = 0;
4096	tpnt->drv_buffer = 1;	/* Try buffering if no mode sense */
4097	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4098	tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4099	tpnt->density = 0;
4100	tpnt->do_auto_lock = ST_AUTO_LOCK;
4101	tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4102	tpnt->can_partitions = 0;
4103	tpnt->two_fm = ST_TWO_FM;
4104	tpnt->fast_mteom = ST_FAST_MTEOM;
4105	tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4106	tpnt->sili = ST_SILI;
4107	tpnt->immediate = ST_NOWAIT;
4108	tpnt->immediate_filemark = 0;
4109	tpnt->default_drvbuffer = 0xff;		/* No forced buffering */
4110	tpnt->partition = 0;
4111	tpnt->new_partition = 0;
4112	tpnt->nbr_partitions = 0;
4113	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4114	tpnt->long_timeout = ST_LONG_TIMEOUT;
4115	tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
4116
4117	for (i = 0; i < ST_NBR_MODES; i++) {
4118		STm = &(tpnt->modes[i]);
4119		STm->defined = 0;
4120		STm->sysv = ST_SYSV;
4121		STm->defaults_for_writes = 0;
4122		STm->do_async_writes = ST_ASYNC_WRITES;
4123		STm->do_buffer_writes = ST_BUFFER_WRITES;
4124		STm->do_read_ahead = ST_READ_AHEAD;
4125		STm->default_compression = ST_DONT_TOUCH;
4126		STm->default_blksize = (-1);	/* No forced size */
4127		STm->default_density = (-1);	/* No forced density */
4128	}
4129
4130	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4131		STps = &(tpnt->ps[i]);
4132		STps->rw = ST_IDLE;
4133		STps->eof = ST_NOEOF;
4134		STps->at_sm = 0;
4135		STps->last_block_valid = 0;
4136		STps->drv_block = (-1);
4137		STps->drv_file = (-1);
4138	}
4139
4140	tpnt->current_mode = 0;
4141	tpnt->modes[0].defined = 1;
4142
4143	tpnt->density_changed = tpnt->compression_changed =
4144	    tpnt->blksize_changed = 0;
4145	mutex_init(&tpnt->lock);
4146
4147	st_nr_dev++;
4148	write_unlock(&st_dev_arr_lock);
4149
4150	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4151		STm = &(tpnt->modes[mode]);
4152		for (j=0; j < 2; j++) {
4153			cdev = cdev_alloc();
4154			if (!cdev) {
4155				printk(KERN_ERR
4156				       "st%d: out of memory. Device not attached.\n",
4157				       dev_num);
4158				goto out_free_tape;
4159			}
4160			cdev->owner = THIS_MODULE;
4161			cdev->ops = &st_fops;
4162
4163			error = cdev_add(cdev,
4164					 MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, j)),
4165					 1);
4166			if (error) {
4167				printk(KERN_ERR "st%d: Can't add %s-rewind mode %d\n",
4168				       dev_num, j ? "non" : "auto", mode);
4169				printk(KERN_ERR "st%d: Device not attached.\n", dev_num);
4170				goto out_free_tape;
4171			}
4172			STm->cdevs[j] = cdev;
4173
4174		}
4175		error = do_create_class_files(tpnt, dev_num, mode);
4176		if (error)
4177			goto out_free_tape;
4178	}
4179	scsi_autopm_put_device(SDp);
4180
4181	sdev_printk(KERN_NOTICE, SDp,
4182		    "Attached scsi tape %s\n", tape_name(tpnt));
4183	sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4184		    tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4185		    queue_dma_alignment(SDp->request_queue) + 1);
4186
4187	return 0;
4188
4189out_free_tape:
4190	for (mode=0; mode < ST_NBR_MODES; mode++) {
4191		STm = &(tpnt->modes[mode]);
4192		sysfs_remove_link(&tpnt->device->sdev_gendev.kobj,
4193				  "tape");
4194		for (j=0; j < 2; j++) {
4195			if (STm->cdevs[j]) {
4196				if (cdev == STm->cdevs[j])
4197					cdev = NULL;
4198					device_destroy(st_sysfs_class,
4199						       MKDEV(SCSI_TAPE_MAJOR,
4200							     TAPE_MINOR(i, mode, j)));
4201				cdev_del(STm->cdevs[j]);
4202			}
4203		}
4204	}
4205	if (cdev)
4206		cdev_del(cdev);
4207	write_lock(&st_dev_arr_lock);
4208	scsi_tapes[dev_num] = NULL;
4209	st_nr_dev--;
4210	write_unlock(&st_dev_arr_lock);
4211out_put_disk:
4212	put_disk(disk);
4213	kfree(tpnt);
4214out_buffer_free:
4215	kfree(buffer);
4216out:
4217	return -ENODEV;
4218};
4219
4220
4221static int st_remove(struct device *dev)
4222{
4223	struct scsi_device *SDp = to_scsi_device(dev);
4224	struct scsi_tape *tpnt;
4225	int i, j, mode;
4226
4227	scsi_autopm_get_device(SDp);
4228	write_lock(&st_dev_arr_lock);
4229	for (i = 0; i < st_dev_max; i++) {
4230		tpnt = scsi_tapes[i];
4231		if (tpnt != NULL && tpnt->device == SDp) {
4232			scsi_tapes[i] = NULL;
4233			st_nr_dev--;
4234			write_unlock(&st_dev_arr_lock);
4235			sysfs_remove_link(&tpnt->device->sdev_gendev.kobj,
4236					  "tape");
4237			for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4238				for (j=0; j < 2; j++) {
4239					device_destroy(st_sysfs_class,
4240						       MKDEV(SCSI_TAPE_MAJOR,
4241							     TAPE_MINOR(i, mode, j)));
4242					cdev_del(tpnt->modes[mode].cdevs[j]);
4243					tpnt->modes[mode].cdevs[j] = NULL;
4244				}
4245			}
4246
4247			mutex_lock(&st_ref_mutex);
4248			kref_put(&tpnt->kref, scsi_tape_release);
4249			mutex_unlock(&st_ref_mutex);
4250			return 0;
4251		}
4252	}
4253
4254	write_unlock(&st_dev_arr_lock);
4255	return 0;
4256}
4257
4258/**
4259 *      scsi_tape_release - Called to free the Scsi_Tape structure
4260 *      @kref: pointer to embedded kref
4261 *
4262 *      st_ref_mutex must be held entering this routine.  Because it is
4263 *      called on last put, you should always use the scsi_tape_get()
4264 *      scsi_tape_put() helpers which manipulate the semaphore directly
4265 *      and never do a direct kref_put().
4266 **/
4267static void scsi_tape_release(struct kref *kref)
4268{
4269	struct scsi_tape *tpnt = to_scsi_tape(kref);
4270	struct gendisk *disk = tpnt->disk;
4271
4272	tpnt->device = NULL;
4273
4274	if (tpnt->buffer) {
4275		normalize_buffer(tpnt->buffer);
4276		kfree(tpnt->buffer->reserved_pages);
4277		kfree(tpnt->buffer);
4278	}
4279
4280	disk->private_data = NULL;
4281	put_disk(disk);
4282	kfree(tpnt);
4283	return;
4284}
4285
4286static int __init init_st(void)
4287{
4288	int err;
4289
4290	validate_options();
4291
4292	printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4293		verstr, st_fixed_buffer_size, st_max_sg_segs);
4294
4295	st_sysfs_class = class_create(THIS_MODULE, "scsi_tape");
4296	if (IS_ERR(st_sysfs_class)) {
4297		printk(KERN_ERR "Unable create sysfs class for SCSI tapes\n");
4298		return PTR_ERR(st_sysfs_class);
4299	}
4300
4301	err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4302				     ST_MAX_TAPE_ENTRIES, "st");
4303	if (err) {
4304		printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4305		       SCSI_TAPE_MAJOR);
4306		goto err_class;
4307	}
4308
4309	err = scsi_register_driver(&st_template.gendrv);
4310	if (err)
4311		goto err_chrdev;
4312
4313	err = do_create_sysfs_files();
4314	if (err)
4315		goto err_scsidrv;
4316
4317	return 0;
4318
4319err_scsidrv:
4320	scsi_unregister_driver(&st_template.gendrv);
4321err_chrdev:
4322	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4323				 ST_MAX_TAPE_ENTRIES);
4324err_class:
4325	class_destroy(st_sysfs_class);
4326	return err;
4327}
4328
4329static void __exit exit_st(void)
4330{
4331	do_remove_sysfs_files();
4332	scsi_unregister_driver(&st_template.gendrv);
4333	unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4334				 ST_MAX_TAPE_ENTRIES);
4335	class_destroy(st_sysfs_class);
4336	kfree(scsi_tapes);
4337	printk(KERN_INFO "st: Unloaded.\n");
4338}
4339
4340module_init(init_st);
4341module_exit(exit_st);
4342
4343
4344/* The sysfs driver interface. Read-only at the moment */
4345static ssize_t st_try_direct_io_show(struct device_driver *ddp, char *buf)
4346{
4347	return snprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4348}
4349static DRIVER_ATTR(try_direct_io, S_IRUGO, st_try_direct_io_show, NULL);
4350
4351static ssize_t st_fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4352{
4353	return snprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4354}
4355static DRIVER_ATTR(fixed_buffer_size, S_IRUGO, st_fixed_buffer_size_show, NULL);
4356
4357static ssize_t st_max_sg_segs_show(struct device_driver *ddp, char *buf)
4358{
4359	return snprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4360}
4361static DRIVER_ATTR(max_sg_segs, S_IRUGO, st_max_sg_segs_show, NULL);
4362
4363static ssize_t st_version_show(struct device_driver *ddd, char *buf)
4364{
4365	return snprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4366}
4367static DRIVER_ATTR(version, S_IRUGO, st_version_show, NULL);
4368
4369static int do_create_sysfs_files(void)
4370{
4371	struct device_driver *sysfs = &st_template.gendrv;
4372	int err;
4373
4374	err = driver_create_file(sysfs, &driver_attr_try_direct_io);
4375	if (err)
4376		return err;
4377	err = driver_create_file(sysfs, &driver_attr_fixed_buffer_size);
4378	if (err)
4379		goto err_try_direct_io;
4380	err = driver_create_file(sysfs, &driver_attr_max_sg_segs);
4381	if (err)
4382		goto err_attr_fixed_buf;
4383	err = driver_create_file(sysfs, &driver_attr_version);
4384	if (err)
4385		goto err_attr_max_sg;
4386
4387	return 0;
4388
4389err_attr_max_sg:
4390	driver_remove_file(sysfs, &driver_attr_max_sg_segs);
4391err_attr_fixed_buf:
4392	driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
4393err_try_direct_io:
4394	driver_remove_file(sysfs, &driver_attr_try_direct_io);
4395	return err;
4396}
4397
4398static void do_remove_sysfs_files(void)
4399{
4400	struct device_driver *sysfs = &st_template.gendrv;
4401
4402	driver_remove_file(sysfs, &driver_attr_version);
4403	driver_remove_file(sysfs, &driver_attr_max_sg_segs);
4404	driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
4405	driver_remove_file(sysfs, &driver_attr_try_direct_io);
4406}
4407
4408
4409/* The sysfs simple class interface */
4410static ssize_t
4411st_defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4412{
4413	struct st_modedef *STm = dev_get_drvdata(dev);
4414	ssize_t l = 0;
4415
4416	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4417	return l;
4418}
4419
4420DEVICE_ATTR(defined, S_IRUGO, st_defined_show, NULL);
4421
4422static ssize_t
4423st_defblk_show(struct device *dev, struct device_attribute *attr, char *buf)
4424{
4425	struct st_modedef *STm = dev_get_drvdata(dev);
4426	ssize_t l = 0;
4427
4428	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4429	return l;
4430}
4431
4432DEVICE_ATTR(default_blksize, S_IRUGO, st_defblk_show, NULL);
4433
4434static ssize_t
4435st_defdensity_show(struct device *dev, struct device_attribute *attr, char *buf)
4436{
4437	struct st_modedef *STm = dev_get_drvdata(dev);
4438	ssize_t l = 0;
4439	char *fmt;
4440
4441	fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4442	l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4443	return l;
4444}
4445
4446DEVICE_ATTR(default_density, S_IRUGO, st_defdensity_show, NULL);
4447
4448static ssize_t
4449st_defcompression_show(struct device *dev, struct device_attribute *attr,
4450		       char *buf)
4451{
4452	struct st_modedef *STm = dev_get_drvdata(dev);
4453	ssize_t l = 0;
4454
4455	l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4456	return l;
4457}
4458
4459DEVICE_ATTR(default_compression, S_IRUGO, st_defcompression_show, NULL);
4460
4461static ssize_t
4462st_options_show(struct device *dev, struct device_attribute *attr, char *buf)
4463{
4464	struct st_modedef *STm = dev_get_drvdata(dev);
4465	struct scsi_tape *STp;
4466	int i, j, options;
4467	ssize_t l = 0;
4468
4469	for (i=0; i < st_dev_max; i++) {
4470		for (j=0; j < ST_NBR_MODES; j++)
4471			if (&scsi_tapes[i]->modes[j] == STm)
4472				break;
4473		if (j < ST_NBR_MODES)
4474			break;
4475	}
4476	if (i == st_dev_max)
4477		return 0;  /* should never happen */
4478
4479	STp = scsi_tapes[i];
4480
4481	options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4482	options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4483	options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4484	DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4485	options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4486	options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4487	options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4488	options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4489	options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4490	options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4491	options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4492	options |= STm->sysv ? MT_ST_SYSV : 0;
4493	options |= STp->immediate ? MT_ST_NOWAIT : 0;
4494	options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0;
4495	options |= STp->sili ? MT_ST_SILI : 0;
4496
4497	l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4498	return l;
4499}
4500
4501DEVICE_ATTR(options, S_IRUGO, st_options_show, NULL);
4502
4503static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
4504{
4505	int i, rew, error;
4506	char name[10];
4507	struct device *st_class_member;
4508
4509	for (rew=0; rew < 2; rew++) {
4510		/* Make sure that the minor numbers corresponding to the four
4511		   first modes always get the same names */
4512		i = mode << (4 - ST_NBR_MODE_BITS);
4513		snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4514			 STp->disk->disk_name, st_formats[i]);
4515		st_class_member =
4516			device_create(st_sysfs_class, &STp->device->sdev_gendev,
4517				      MKDEV(SCSI_TAPE_MAJOR,
4518					    TAPE_MINOR(dev_num, mode, rew)),
4519				      &STp->modes[mode], "%s", name);
4520		if (IS_ERR(st_class_member)) {
4521			printk(KERN_WARNING "st%d: device_create failed\n",
4522			       dev_num);
4523			error = PTR_ERR(st_class_member);
4524			goto out;
4525		}
4526
4527		error = device_create_file(st_class_member,
4528					   &dev_attr_defined);
4529		if (error) goto out;
4530		error = device_create_file(st_class_member,
4531					   &dev_attr_default_blksize);
4532		if (error) goto out;
4533		error = device_create_file(st_class_member,
4534					   &dev_attr_default_density);
4535		if (error) goto out;
4536		error = device_create_file(st_class_member,
4537					   &dev_attr_default_compression);
4538		if (error) goto out;
4539		error = device_create_file(st_class_member,
4540					   &dev_attr_options);
4541		if (error) goto out;
4542
4543		if (mode == 0 && rew == 0) {
4544			error = sysfs_create_link(&STp->device->sdev_gendev.kobj,
4545						  &st_class_member->kobj,
4546						  "tape");
4547			if (error) {
4548				printk(KERN_ERR
4549				       "st%d: Can't create sysfs link from SCSI device.\n",
4550				       dev_num);
4551				goto out;
4552			}
4553		}
4554	}
4555
4556	return 0;
4557
4558out:
4559	return error;
4560}
4561
4562/* The following functions may be useful for a larger audience. */
4563static int sgl_map_user_pages(struct st_buffer *STbp,
4564			      const unsigned int max_pages, unsigned long uaddr,
4565			      size_t count, int rw)
4566{
4567	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4568	unsigned long start = uaddr >> PAGE_SHIFT;
4569	const int nr_pages = end - start;
4570	int res, i, j;
4571	struct page **pages;
4572	struct rq_map_data *mdata = &STbp->map_data;
4573
4574	/* User attempted Overflow! */
4575	if ((uaddr + count) < uaddr)
4576		return -EINVAL;
4577
4578	/* Too big */
4579        if (nr_pages > max_pages)
4580		return -ENOMEM;
4581
4582	/* Hmm? */
4583	if (count == 0)
4584		return 0;
4585
4586	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_KERNEL)) == NULL)
4587		return -ENOMEM;
4588
4589        /* Try to fault in all of the necessary pages */
4590	down_read(&current->mm->mmap_sem);
4591        /* rw==READ means read from drive, write into memory area */
4592	res = get_user_pages(
4593		current,
4594		current->mm,
4595		uaddr,
4596		nr_pages,
4597		rw == READ,
4598		0, /* don't force */
4599		pages,
4600		NULL);
4601	up_read(&current->mm->mmap_sem);
4602
4603	/* Errors and no page mapped should return here */
4604	if (res < nr_pages)
4605		goto out_unmap;
4606
4607        for (i=0; i < nr_pages; i++) {
4608                /* FIXME: flush superflous for rw==READ,
4609                 * probably wrong function for rw==WRITE
4610                 */
4611		flush_dcache_page(pages[i]);
4612        }
4613
4614	mdata->offset = uaddr & ~PAGE_MASK;
4615	STbp->mapped_pages = pages;
4616
4617	return nr_pages;
4618 out_unmap:
4619	if (res > 0) {
4620		for (j=0; j < res; j++)
4621			page_cache_release(pages[j]);
4622		res = 0;
4623	}
4624	kfree(pages);
4625	return res;
4626}
4627
4628
4629/* And unmap them... */
4630static int sgl_unmap_user_pages(struct st_buffer *STbp,
4631				const unsigned int nr_pages, int dirtied)
4632{
4633	int i;
4634
4635	for (i=0; i < nr_pages; i++) {
4636		struct page *page = STbp->mapped_pages[i];
4637
4638		if (dirtied)
4639			SetPageDirty(page);
4640		/* FIXME: cache flush missing for rw==READ
4641		 * FIXME: call the correct reference counting function
4642		 */
4643		page_cache_release(page);
4644	}
4645	kfree(STbp->mapped_pages);
4646	STbp->mapped_pages = NULL;
4647
4648	return 0;
4649}