drivers/scsi/st.c

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