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