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 - 2008 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 = "20081215";
  21
  22 #include <linux/module.h>
  23
  24 #include <linux/fs.h>
  25 #include <linux/kernel.h>
  26 #include <linux/sched.h>
  27 #include <linux/mm.h>
  28 #include <linux/init.h>
  29 #include <linux/string.h>
  30 #include <linux/slab.h>
  31 #include <linux/errno.h>
  32 #include <linux/mtio.h>
  33 #include <linux/cdrom.h>
  34 #include <linux/ioctl.h>
  35 #include <linux/fcntl.h>
  36 #include <linux/spinlock.h>
  37 #include <linux/blkdev.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/cdev.h>
  40 #include <linux/delay.h>
  41 #include <linux/mutex.h>
  42 #include <linux/smp_lock.h>
  43
  44 #include <asm/uaccess.h>
  45 #include <asm/dma.h>
  46 #include <asm/system.h>
  47
  48 #include <scsi/scsi.h>
  49 #include <scsi/scsi_dbg.h>
  50 #include <scsi/scsi_device.h>
  51 #include <scsi/scsi_driver.h>
  52 #include <scsi/scsi_eh.h>
  53 #include <scsi/scsi_host.h>
  54 #include <scsi/scsi_ioctl.h>
  55 #include <scsi/sg.h>
  56
  57
  58 /* The driver prints some debugging information on the console if DEBUG
  59    is defined and non-zero. */
  60 #define DEBUG 0
  61
  62 #if DEBUG
  63 /* The message level for the debug messages is currently set to KERN_NOTICE
  64    so that people can easily see the messages. Later when the debugging messages
  65    in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
  66 #define ST_DEB_MSG  KERN_NOTICE
  67 #define DEB(a) a
  68 #define DEBC(a) if (debugging) { a ; }
  69 #else
  70 #define DEB(a)
  71 #define DEBC(a)
  72 #endif
  73
  74 #define ST_KILOBYTE 1024
  75
  76 #include "st_options.h"
  77 #include "st.h"
  78
  79 static int buffer_kbs;
  80 static int max_sg_segs;
  81 static int try_direct_io = TRY_DIRECT_IO;
  82 static int try_rdio = 1;
  83 static int try_wdio = 1;
  84
  85 static int st_dev_max;
  86 static int st_nr_dev;
  87
  88 static struct class *st_sysfs_class;
  89
  90 MODULE_AUTHOR("Kai Makisara");
  91 MODULE_DESCRIPTION("SCSI tape (st) driver");
  92 MODULE_LICENSE("GPL");
  93 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_TAPE_MAJOR);
  94 MODULE_ALIAS_SCSI_DEVICE(TYPE_TAPE);
  95
  96 /* Set 'perm' (4th argument) to 0 to disable module_param's definition
  97  * of sysfs parameters (which module_param doesn't yet support).
  98  * Sysfs parameters defined explicitly later.
  99  */
 100 module_param_named(buffer_kbs, buffer_kbs, int, 0);
 101 MODULE_PARM_DESC(buffer_kbs, "Default driver buffer size for fixed block mode (KB; 32)");
 102 module_param_named(max_sg_segs, max_sg_segs, int, 0);
 103 MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (256)");
 104 module_param_named(try_direct_io, try_direct_io, int, 0);
 105 MODULE_PARM_DESC(try_direct_io, "Try direct I/O between user buffer and tape drive (1)");
 106
 107 /* Extra parameters for testing */
 108 module_param_named(try_rdio, try_rdio, int, 0);
 109 MODULE_PARM_DESC(try_rdio, "Try direct read i/o when possible");
 110 module_param_named(try_wdio, try_wdio, int, 0);
 111 MODULE_PARM_DESC(try_wdio, "Try direct write i/o when possible");
 112
 113 #ifndef MODULE
 114 static int write_threshold_kbs;  /* retained for compatibility */
 115 static struct st_dev_parm {
 116         char *name;
 117         int *val;
 118 } parms[] __initdata = {
 119         {
 120                 "buffer_kbs", &buffer_kbs
 121         },
 122         {       /* Retained for compatibility with 2.4 */
 123                 "write_threshold_kbs", &write_threshold_kbs
 124         },
 125         {
 126                 "max_sg_segs", NULL
 127         },
 128         {
 129                 "try_direct_io", &try_direct_io
 130         }
 131 };
 132 #endif
 133
 134 /* Restrict the number of modes so that names for all are assigned */
 135 #if ST_NBR_MODES > 16
 136 #error "Maximum number of modes is 16"
 137 #endif
 138 /* Bit reversed order to get same names for same minors with all
 139    mode counts */
 140 static const char *st_formats[] = {
 141         "",  "r", "k", "s", "l", "t", "o", "u",
 142         "m", "v", "p", "x", "a", "y", "q", "z"};
 143
 144 /* The default definitions have been moved to st_options.h */
 145
 146 #define ST_FIXED_BUFFER_SIZE (ST_FIXED_BUFFER_BLOCKS * ST_KILOBYTE)
 147
 148 /* The buffer size should fit into the 24 bits for length in the
 149    6-byte SCSI read and write commands. */
 150 #if ST_FIXED_BUFFER_SIZE >= (2 << 24 - 1)
 151 #error "Buffer size should not exceed (2 << 24 - 1) bytes!"
 152 #endif
 153
 154 static int debugging = DEBUG;
 155
 156 #define MAX_RETRIES 0
 157 #define MAX_WRITE_RETRIES 0
 158 #define MAX_READY_RETRIES 0
 159 #define NO_TAPE  NOT_READY
 160
 161 #define ST_TIMEOUT (900 * HZ)
 162 #define ST_LONG_TIMEOUT (14000 * HZ)
 163
 164 /* Remove mode bits and auto-rewind bit (7) */
 165 #define TAPE_NR(x) ( ((iminor(x) & ~255) >> (ST_NBR_MODE_BITS + 1)) | \
 166     (iminor(x) & ~(-1 << ST_MODE_SHIFT)) )
 167 #define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
 168
 169 /* Construct the minor number from the device (d), mode (m), and non-rewind (n) data */
 170 #define TAPE_MINOR(d, m, n) (((d & ~(255 >> (ST_NBR_MODE_BITS + 1))) << (ST_NBR_MODE_BITS + 1)) | \
 171   (d & (255 >> (ST_NBR_MODE_BITS + 1))) | (m << ST_MODE_SHIFT) | ((n != 0) << 7) )
 172
 173 /* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
 174    24 bits) */
 175 #define SET_DENS_AND_BLK 0x10001
 176
 177 static DEFINE_RWLOCK(st_dev_arr_lock);
 178
 179 static int st_fixed_buffer_size = ST_FIXED_BUFFER_SIZE;
 180 static int st_max_sg_segs = ST_MAX_SG;
 181
 182 static struct scsi_tape **scsi_tapes = NULL;
 183
 184 static int modes_defined;
 185
 186 static int enlarge_buffer(struct st_buffer *, int, int);
 187 static void clear_buffer(struct st_buffer *);
 188 static void normalize_buffer(struct st_buffer *);
 189 static int append_to_buffer(const char __user *, struct st_buffer *, int);
 190 static int from_buffer(struct st_buffer *, char __user *, int);
 191 static void move_buffer_data(struct st_buffer *, int);
 192
 193 static int sgl_map_user_pages(struct st_buffer *, const unsigned int,
 194                               unsigned long, size_t, int);
 195 static int sgl_unmap_user_pages(struct st_buffer *, const unsigned int, int);
 196
 197 static int st_probe(struct device *);
 198 static int st_remove(struct device *);
 199
 200 static int do_create_sysfs_files(void);
 201 static void do_remove_sysfs_files(void);
 202 static int do_create_class_files(struct scsi_tape *, int, int);
 203
 204 static struct scsi_driver st_template = {
 205         .owner                  = THIS_MODULE,
 206         .gendrv = {
 207                 .name           = "st",
 208                 .probe          = st_probe,
 209                 .remove         = st_remove,
 210         },
 211 };
 212
 213 static int st_compression(struct scsi_tape *, int);
 214
 215 static int find_partition(struct scsi_tape *);
 216 static int switch_partition(struct scsi_tape *);
 217
 218 static int st_int_ioctl(struct scsi_tape *, unsigned int, unsigned long);
 219
 220 static void scsi_tape_release(struct kref *);
 221
 222 #define to_scsi_tape(obj) container_of(obj, struct scsi_tape, kref)
 223
 224 static DEFINE_MUTEX(st_ref_mutex);
 225
 226 \f
 227 #include "osst_detect.h"
 228 #ifndef SIGS_FROM_OSST
 229 #define SIGS_FROM_OSST \
 230         {"OnStream", "SC-", "", "osst"}, \
 231         {"OnStream", "DI-", "", "osst"}, \
 232         {"OnStream", "DP-", "", "osst"}, \
 233         {"OnStream", "USB", "", "osst"}, \
 234         {"OnStream", "FW-", "", "osst"}
 235 #endif
 236
 237 static struct scsi_tape *scsi_tape_get(int dev)
 238 {
 239         struct scsi_tape *STp = NULL;
 240
 241         mutex_lock(&st_ref_mutex);
 242         write_lock(&st_dev_arr_lock);
 243
 244         if (dev < st_dev_max && scsi_tapes != NULL)
 245                 STp = scsi_tapes[dev];
 246         if (!STp) goto out;
 247
 248         kref_get(&STp->kref);
 249
 250         if (!STp->device)
 251                 goto out_put;
 252
 253         if (scsi_device_get(STp->device))
 254                 goto out_put;
 255
 256         goto out;
 257
 258 out_put:
 259         kref_put(&STp->kref, scsi_tape_release);
 260         STp = NULL;
 261 out:
 262         write_unlock(&st_dev_arr_lock);
 263         mutex_unlock(&st_ref_mutex);
 264         return STp;
 265 }
 266
 267 static void scsi_tape_put(struct scsi_tape *STp)
 268 {
 269         struct scsi_device *sdev = STp->device;
 270
 271         mutex_lock(&st_ref_mutex);
 272         kref_put(&STp->kref, scsi_tape_release);
 273         scsi_device_put(sdev);
 274         mutex_unlock(&st_ref_mutex);
 275 }
 276
 277 struct st_reject_data {
 278         char *vendor;
 279         char *model;
 280         char *rev;
 281         char *driver_hint; /* Name of the correct driver, NULL if unknown */
 282 };
 283
 284 static struct st_reject_data reject_list[] = {
 285         /* {"XXX", "Yy-", "", NULL},  example */
 286         SIGS_FROM_OSST,
 287         {NULL, }};
 288
 289 /* If the device signature is on the list of incompatible drives, the
 290    function returns a pointer to the name of the correct driver (if known) */
 291 static char * st_incompatible(struct scsi_device* SDp)
 292 {
 293         struct st_reject_data *rp;
 294
 295         for (rp=&(reject_list[0]); rp->vendor != NULL; rp++)
 296                 if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
 297                     !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
 298                     !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) {
 299                         if (rp->driver_hint)
 300                                 return rp->driver_hint;
 301                         else
 302                                 return "unknown";
 303                 }
 304         return NULL;
 305 }
 306 \f
 307
 308 static inline char *tape_name(struct scsi_tape *tape)
 309 {
 310         return tape->disk->disk_name;
 311 }
 312
 313
 314 static void st_analyze_sense(struct st_request *SRpnt, struct st_cmdstatus *s)
 315 {
 316         const u8 *ucp;
 317         const u8 *sense = SRpnt->sense;
 318
 319         s->have_sense = scsi_normalize_sense(SRpnt->sense,
 320                                 SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
 321         s->flags = 0;
 322
 323         if (s->have_sense) {
 324                 s->deferred = 0;
 325                 s->remainder_valid =
 326                         scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
 327                 switch (sense[0] & 0x7f) {
 328                 case 0x71:
 329                         s->deferred = 1;
 330                 case 0x70:
 331                         s->fixed_format = 1;
 332                         s->flags = sense[2] & 0xe0;
 333                         break;
 334                 case 0x73:
 335                         s->deferred = 1;
 336                 case 0x72:
 337                         s->fixed_format = 0;
 338                         ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
 339                         s->flags = ucp ? (ucp[3] & 0xe0) : 0;
 340                         break;
 341                 }
 342         }
 343 }
 344
 345
 346 /* Convert the result to success code */
 347 static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
 348 {
 349         int result = SRpnt->result;
 350         u8 scode;
 351         DEB(const char *stp;)
 352         char *name = tape_name(STp);
 353         struct st_cmdstatus *cmdstatp;
 354
 355         if (!result)
 356                 return 0;
 357
 358         cmdstatp = &STp->buffer->cmdstat;
 359         st_analyze_sense(SRpnt, cmdstatp);
 360
 361         if (cmdstatp->have_sense)
 362                 scode = STp->buffer->cmdstat.sense_hdr.sense_key;
 363         else
 364                 scode = 0;
 365
 366         DEB(
 367         if (debugging) {
 368                 printk(ST_DEB_MSG "%s: Error: %x, cmd: %x %x %x %x %x %x\n",
 369                        name, result,
 370                        SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
 371                        SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
 372                 if (cmdstatp->have_sense)
 373                          __scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 374         } ) /* end DEB */
 375         if (!debugging) { /* Abnormal conditions for tape */
 376                 if (!cmdstatp->have_sense)
 377                         printk(KERN_WARNING
 378                                "%s: Error %x (driver bt 0x%x, host bt 0x%x).\n",
 379                                name, result, driver_byte(result),
 380                                host_byte(result));
 381                 else if (cmdstatp->have_sense &&
 382                          scode != NO_SENSE &&
 383                          scode != RECOVERED_ERROR &&
 384                          /* scode != UNIT_ATTENTION && */
 385                          scode != BLANK_CHECK &&
 386                          scode != VOLUME_OVERFLOW &&
 387                          SRpnt->cmd[0] != MODE_SENSE &&
 388                          SRpnt->cmd[0] != TEST_UNIT_READY) {
 389
 390                         __scsi_print_sense(name, SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
 391                 }
 392         }
 393
 394         if (cmdstatp->fixed_format &&
 395             STp->cln_mode >= EXTENDED_SENSE_START) {  /* Only fixed format sense */
 396                 if (STp->cln_sense_value)
 397                         STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 398                                                STp->cln_sense_mask) == STp->cln_sense_value);
 399                 else
 400                         STp->cleaning_req |= ((SRpnt->sense[STp->cln_mode] &
 401                                                STp->cln_sense_mask) != 0);
 402         }
 403         if (cmdstatp->have_sense &&
 404             cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
 405                 STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
 406
 407         STp->pos_unknown |= STp->device->was_reset;
 408
 409         if (cmdstatp->have_sense &&
 410             scode == RECOVERED_ERROR
 411 #if ST_RECOVERED_WRITE_FATAL
 412             && SRpnt->cmd[0] != WRITE_6
 413             && SRpnt->cmd[0] != WRITE_FILEMARKS
 414 #endif
 415             ) {
 416                 STp->recover_count++;
 417                 STp->recover_reg++;
 418
 419                 DEB(
 420                 if (debugging) {
 421                         if (SRpnt->cmd[0] == READ_6)
 422                                 stp = "read";
 423                         else if (SRpnt->cmd[0] == WRITE_6)
 424                                 stp = "write";
 425                         else
 426                                 stp = "ioctl";
 427                         printk(ST_DEB_MSG "%s: Recovered %s error (%d).\n", name, stp,
 428                                STp->recover_count);
 429                 } ) /* end DEB */
 430
 431                 if (cmdstatp->flags == 0)
 432                         return 0;
 433         }
 434         return (-EIO);
 435 }
 436
 437 static struct st_request *st_allocate_request(struct scsi_tape *stp)
 438 {
 439         struct st_request *streq;
 440
 441         streq = kzalloc(sizeof(*streq), GFP_KERNEL);
 442         if (streq)
 443                 streq->stp = stp;
 444         else {
 445                 DEBC(printk(KERN_ERR "%s: Can't get SCSI request.\n",
 446                             tape_name(stp)););
 447                 if (signal_pending(current))
 448                         stp->buffer->syscall_result = -EINTR;
 449                 else
 450                         stp->buffer->syscall_result = -EBUSY;
 451         }
 452
 453         return streq;
 454 }
 455
 456 static void st_release_request(struct st_request *streq)
 457 {
 458         kfree(streq);
 459 }
 460
 461 static void st_scsi_execute_end(struct request *req, int uptodate)
 462 {
 463         struct st_request *SRpnt = req->end_io_data;
 464         struct scsi_tape *STp = SRpnt->stp;
 465
 466         STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
 467         STp->buffer->cmdstat.residual = req->resid_len;
 468
 469         if (SRpnt->waiting)
 470                 complete(SRpnt->waiting);
 471
 472         blk_rq_unmap_user(SRpnt->bio);
 473         __blk_put_request(req->q, req);
 474 }
 475
 476 static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
 477                            int data_direction, void *buffer, unsigned bufflen,
 478                            int timeout, int retries)
 479 {
 480         struct request *req;
 481         struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 482         int err = 0;
 483         int write = (data_direction == DMA_TO_DEVICE);
 484
 485         req = blk_get_request(SRpnt->stp->device->request_queue, write,
 486                               GFP_KERNEL);
 487         if (!req)
 488                 return DRIVER_ERROR << 24;
 489
 490         req->cmd_type = REQ_TYPE_BLOCK_PC;
 491         req->cmd_flags |= REQ_QUIET;
 492
 493         mdata->null_mapped = 1;
 494
 495         if (bufflen) {
 496                 err = blk_rq_map_user(req->q, req, mdata, NULL, bufflen,
 497                                       GFP_KERNEL);
 498                 if (err) {
 499                         blk_put_request(req);
 500                         return DRIVER_ERROR << 24;
 501                 }
 502         }
 503
 504         SRpnt->bio = req->bio;
 505         req->cmd_len = COMMAND_SIZE(cmd[0]);
 506         memset(req->cmd, 0, BLK_MAX_CDB);
 507         memcpy(req->cmd, cmd, req->cmd_len);
 508         req->sense = SRpnt->sense;
 509         req->sense_len = 0;
 510         req->timeout = timeout;
 511         req->retries = retries;
 512         req->end_io_data = SRpnt;
 513
 514         blk_execute_rq_nowait(req->q, NULL, req, 1, st_scsi_execute_end);
 515         return 0;
 516 }
 517
 518 /* Do the scsi command. Waits until command performed if do_wait is true.
 519    Otherwise write_behind_check() is used to check that the command
 520    has finished. */
 521 static struct st_request *
 522 st_do_scsi(struct st_request * SRpnt, struct scsi_tape * STp, unsigned char *cmd,
 523            int bytes, int direction, int timeout, int retries, int do_wait)
 524 {
 525         struct completion *waiting;
 526         struct rq_map_data *mdata = &STp->buffer->map_data;
 527         int ret;
 528
 529         /* if async, make sure there's no command outstanding */
 530         if (!do_wait && ((STp->buffer)->last_SRpnt)) {
 531                 printk(KERN_ERR "%s: Async command already active.\n",
 532                        tape_name(STp));
 533                 if (signal_pending(current))
 534                         (STp->buffer)->syscall_result = (-EINTR);
 535                 else
 536                         (STp->buffer)->syscall_result = (-EBUSY);
 537                 return NULL;
 538         }
 539
 540         if (!SRpnt) {
 541                 SRpnt = st_allocate_request(STp);
 542                 if (!SRpnt)
 543                         return NULL;
 544         }
 545
 546         /* If async IO, set last_SRpnt. This ptr tells write_behind_check
 547            which IO is outstanding. It's nulled out when the IO completes. */
 548         if (!do_wait)
 549                 (STp->buffer)->last_SRpnt = SRpnt;
 550
 551         waiting = &STp->wait;
 552         init_completion(waiting);
 553         SRpnt->waiting = waiting;
 554
 555         if (STp->buffer->do_dio) {
 556                 mdata->page_order = 0;
 557                 mdata->nr_entries = STp->buffer->sg_segs;
 558                 mdata->pages = STp->buffer->mapped_pages;
 559         } else {
 560                 mdata->page_order = STp->buffer->reserved_page_order;
 561                 mdata->nr_entries =
 562                         DIV_ROUND_UP(bytes, PAGE_SIZE << mdata->page_order);
 563                 mdata->pages = STp->buffer->reserved_pages;
 564                 mdata->offset = 0;
 565         }
 566
 567         memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
 568         STp->buffer->cmdstat.have_sense = 0;
 569         STp->buffer->syscall_result = 0;
 570
 571         ret = st_scsi_execute(SRpnt, cmd, direction, NULL, bytes, timeout,
 572                               retries);
 573         if (ret) {
 574                 /* could not allocate the buffer or request was too large */
 575                 (STp->buffer)->syscall_result = (-EBUSY);
 576                 (STp->buffer)->last_SRpnt = NULL;
 577         } else if (do_wait) {
 578                 wait_for_completion(waiting);
 579                 SRpnt->waiting = NULL;
 580                 (STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 581         }
 582
 583         return SRpnt;
 584 }
 585
 586
 587 /* Handle the write-behind checking (waits for completion). Returns -ENOSPC if
 588    write has been correct but EOM early warning reached, -EIO if write ended in
 589    error or zero if write successful. Asynchronous writes are used only in
 590    variable block mode. */
 591 static int write_behind_check(struct scsi_tape * STp)
 592 {
 593         int retval = 0;
 594         struct st_buffer *STbuffer;
 595         struct st_partstat *STps;
 596         struct st_cmdstatus *cmdstatp;
 597         struct st_request *SRpnt;
 598
 599         STbuffer = STp->buffer;
 600         if (!STbuffer->writing)
 601                 return 0;
 602
 603         DEB(
 604         if (STp->write_pending)
 605                 STp->nbr_waits++;
 606         else
 607                 STp->nbr_finished++;
 608         ) /* end DEB */
 609
 610         wait_for_completion(&(STp->wait));
 611         SRpnt = STbuffer->last_SRpnt;
 612         STbuffer->last_SRpnt = NULL;
 613         SRpnt->waiting = NULL;
 614
 615         (STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 616         st_release_request(SRpnt);
 617
 618         STbuffer->buffer_bytes -= STbuffer->writing;
 619         STps = &(STp->ps[STp->partition]);
 620         if (STps->drv_block >= 0) {
 621                 if (STp->block_size == 0)
 622                         STps->drv_block++;
 623                 else
 624                         STps->drv_block += STbuffer->writing / STp->block_size;
 625         }
 626
 627         cmdstatp = &STbuffer->cmdstat;
 628         if (STbuffer->syscall_result) {
 629                 retval = -EIO;
 630                 if (cmdstatp->have_sense && !cmdstatp->deferred &&
 631                     (cmdstatp->flags & SENSE_EOM) &&
 632                     (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 633                      cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR)) {
 634                         /* EOM at write-behind, has all data been written? */
 635                         if (!cmdstatp->remainder_valid ||
 636                             cmdstatp->uremainder64 == 0)
 637                                 retval = -ENOSPC;
 638                 }
 639                 if (retval == -EIO)
 640                         STps->drv_block = -1;
 641         }
 642         STbuffer->writing = 0;
 643
 644         DEB(if (debugging && retval)
 645             printk(ST_DEB_MSG "%s: Async write error %x, return value %d.\n",
 646                    tape_name(STp), STbuffer->cmdstat.midlevel_result, retval);) /* end DEB */
 647
 648         return retval;
 649 }
 650
 651
 652 /* Step over EOF if it has been inadvertently crossed (ioctl not used because
 653    it messes up the block number). */
 654 static int cross_eof(struct scsi_tape * STp, int forward)
 655 {
 656         struct st_request *SRpnt;
 657         unsigned char cmd[MAX_COMMAND_SIZE];
 658
 659         cmd[0] = SPACE;
 660         cmd[1] = 0x01;          /* Space FileMarks */
 661         if (forward) {
 662                 cmd[2] = cmd[3] = 0;
 663                 cmd[4] = 1;
 664         } else
 665                 cmd[2] = cmd[3] = cmd[4] = 0xff;        /* -1 filemarks */
 666         cmd[5] = 0;
 667
 668         DEBC(printk(ST_DEB_MSG "%s: Stepping over filemark %s.\n",
 669                    tape_name(STp), forward ? "forward" : "backward"));
 670
 671         SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
 672                            STp->device->request_queue->rq_timeout,
 673                            MAX_RETRIES, 1);
 674         if (!SRpnt)
 675                 return (STp->buffer)->syscall_result;
 676
 677         st_release_request(SRpnt);
 678         SRpnt = NULL;
 679
 680         if ((STp->buffer)->cmdstat.midlevel_result != 0)
 681                 printk(KERN_ERR "%s: Stepping over filemark %s failed.\n",
 682                    tape_name(STp), forward ? "forward" : "backward");
 683
 684         return (STp->buffer)->syscall_result;
 685 }
 686
 687
 688 /* Flush the write buffer (never need to write if variable blocksize). */
 689 static int st_flush_write_buffer(struct scsi_tape * STp)
 690 {
 691         int transfer, blks;
 692         int result;
 693         unsigned char cmd[MAX_COMMAND_SIZE];
 694         struct st_request *SRpnt;
 695         struct st_partstat *STps;
 696
 697         result = write_behind_check(STp);
 698         if (result)
 699                 return result;
 700
 701         result = 0;
 702         if (STp->dirty == 1) {
 703
 704                 transfer = STp->buffer->buffer_bytes;
 705                 DEBC(printk(ST_DEB_MSG "%s: Flushing %d bytes.\n",
 706                                tape_name(STp), transfer));
 707
 708                 memset(cmd, 0, MAX_COMMAND_SIZE);
 709                 cmd[0] = WRITE_6;
 710                 cmd[1] = 1;
 711                 blks = transfer / STp->block_size;
 712                 cmd[2] = blks >> 16;
 713                 cmd[3] = blks >> 8;
 714                 cmd[4] = blks;
 715
 716                 SRpnt = st_do_scsi(NULL, STp, cmd, transfer, DMA_TO_DEVICE,
 717                                    STp->device->request_queue->rq_timeout,
 718                                    MAX_WRITE_RETRIES, 1);
 719                 if (!SRpnt)
 720                         return (STp->buffer)->syscall_result;
 721
 722                 STps = &(STp->ps[STp->partition]);
 723                 if ((STp->buffer)->syscall_result != 0) {
 724                         struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 725
 726                         if (cmdstatp->have_sense && !cmdstatp->deferred &&
 727                             (cmdstatp->flags & SENSE_EOM) &&
 728                             (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
 729                              cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
 730                             (!cmdstatp->remainder_valid ||
 731                              cmdstatp->uremainder64 == 0)) { /* All written at EOM early warning */
 732                                 STp->dirty = 0;
 733                                 (STp->buffer)->buffer_bytes = 0;
 734                                 if (STps->drv_block >= 0)
 735                                         STps->drv_block += blks;
 736                                 result = (-ENOSPC);
 737                         } else {
 738                                 printk(KERN_ERR "%s: Error on flush.\n",
 739                                        tape_name(STp));
 740                                 STps->drv_block = (-1);
 741                                 result = (-EIO);
 742                         }
 743                 } else {
 744                         if (STps->drv_block >= 0)
 745                                 STps->drv_block += blks;
 746                         STp->dirty = 0;
 747                         (STp->buffer)->buffer_bytes = 0;
 748                 }
 749                 st_release_request(SRpnt);
 750                 SRpnt = NULL;
 751         }
 752         return result;
 753 }
 754
 755
 756 /* Flush the tape buffer. The tape will be positioned correctly unless
 757    seek_next is true. */
 758 static int flush_buffer(struct scsi_tape *STp, int seek_next)
 759 {
 760         int backspace, result;
 761         struct st_buffer *STbuffer;
 762         struct st_partstat *STps;
 763
 764         STbuffer = STp->buffer;
 765
 766         /*
 767          * If there was a bus reset, block further access
 768          * to this device.
 769          */
 770         if (STp->pos_unknown)
 771                 return (-EIO);
 772
 773         if (STp->ready != ST_READY)
 774                 return 0;
 775         STps = &(STp->ps[STp->partition]);
 776         if (STps->rw == ST_WRITING)     /* Writing */
 777                 return st_flush_write_buffer(STp);
 778
 779         if (STp->block_size == 0)
 780                 return 0;
 781
 782         backspace = ((STp->buffer)->buffer_bytes +
 783                      (STp->buffer)->read_pointer) / STp->block_size -
 784             ((STp->buffer)->read_pointer + STp->block_size - 1) /
 785             STp->block_size;
 786         (STp->buffer)->buffer_bytes = 0;
 787         (STp->buffer)->read_pointer = 0;
 788         result = 0;
 789         if (!seek_next) {
 790                 if (STps->eof == ST_FM_HIT) {
 791                         result = cross_eof(STp, 0);     /* Back over the EOF hit */
 792                         if (!result)
 793                                 STps->eof = ST_NOEOF;
 794                         else {
 795                                 if (STps->drv_file >= 0)
 796                                         STps->drv_file++;
 797                                 STps->drv_block = 0;
 798                         }
 799                 }
 800                 if (!result && backspace > 0)
 801                         result = st_int_ioctl(STp, MTBSR, backspace);
 802         } else if (STps->eof == ST_FM_HIT) {
 803                 if (STps->drv_file >= 0)
 804                         STps->drv_file++;
 805                 STps->drv_block = 0;
 806                 STps->eof = ST_NOEOF;
 807         }
 808         return result;
 809
 810 }
 811 \f
 812 /* Set the mode parameters */
 813 static int set_mode_densblk(struct scsi_tape * STp, struct st_modedef * STm)
 814 {
 815         int set_it = 0;
 816         unsigned long arg;
 817         char *name = tape_name(STp);
 818
 819         if (!STp->density_changed &&
 820             STm->default_density >= 0 &&
 821             STm->default_density != STp->density) {
 822                 arg = STm->default_density;
 823                 set_it = 1;
 824         } else
 825                 arg = STp->density;
 826         arg <<= MT_ST_DENSITY_SHIFT;
 827         if (!STp->blksize_changed &&
 828             STm->default_blksize >= 0 &&
 829             STm->default_blksize != STp->block_size) {
 830                 arg |= STm->default_blksize;
 831                 set_it = 1;
 832         } else
 833                 arg |= STp->block_size;
 834         if (set_it &&
 835             st_int_ioctl(STp, SET_DENS_AND_BLK, arg)) {
 836                 printk(KERN_WARNING
 837                        "%s: Can't set default block size to %d bytes and density %x.\n",
 838                        name, STm->default_blksize, STm->default_density);
 839                 if (modes_defined)
 840                         return (-EINVAL);
 841         }
 842         return 0;
 843 }
 844
 845
 846 /* Lock or unlock the drive door. Don't use when st_request allocated. */
 847 static int do_door_lock(struct scsi_tape * STp, int do_lock)
 848 {
 849         int retval, cmd;
 850         DEB(char *name = tape_name(STp);)
 851
 852
 853         cmd = do_lock ? SCSI_IOCTL_DOORLOCK : SCSI_IOCTL_DOORUNLOCK;
 854         DEBC(printk(ST_DEB_MSG "%s: %socking drive door.\n", name,
 855                     do_lock ? "L" : "Unl"));
 856         retval = scsi_ioctl(STp->device, cmd, NULL);
 857         if (!retval) {
 858                 STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
 859         }
 860         else {
 861                 STp->door_locked = ST_LOCK_FAILS;
 862         }
 863         return retval;
 864 }
 865
 866
 867 /* Set the internal state after reset */
 868 static void reset_state(struct scsi_tape *STp)
 869 {
 870         int i;
 871         struct st_partstat *STps;
 872
 873         STp->pos_unknown = 0;
 874         for (i = 0; i < ST_NBR_PARTITIONS; i++) {
 875                 STps = &(STp->ps[i]);
 876                 STps->rw = ST_IDLE;
 877                 STps->eof = ST_NOEOF;
 878                 STps->at_sm = 0;
 879                 STps->last_block_valid = 0;
 880                 STps->drv_block = -1;
 881                 STps->drv_file = -1;
 882         }
 883         if (STp->can_partitions) {
 884                 STp->partition = find_partition(STp);
 885                 if (STp->partition < 0)
 886                         STp->partition = 0;
 887                 STp->new_partition = STp->partition;
 888         }
 889 }
 890 \f
 891 /* Test if the drive is ready. Returns either one of the codes below or a negative system
 892    error code. */
 893 #define CHKRES_READY       0
 894 #define CHKRES_NEW_SESSION 1
 895 #define CHKRES_NOT_READY   2
 896 #define CHKRES_NO_TAPE     3
 897
 898 #define MAX_ATTENTIONS    10
 899
 900 static int test_ready(struct scsi_tape *STp, int do_wait)
 901 {
 902         int attentions, waits, max_wait, scode;
 903         int retval = CHKRES_READY, new_session = 0;
 904         unsigned char cmd[MAX_COMMAND_SIZE];
 905         struct st_request *SRpnt = NULL;
 906         struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
 907
 908         max_wait = do_wait ? ST_BLOCK_SECONDS : 0;
 909
 910         for (attentions=waits=0; ; ) {
 911                 memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
 912                 cmd[0] = TEST_UNIT_READY;
 913                 SRpnt = st_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
 914                                    STp->long_timeout, MAX_READY_RETRIES, 1);
 915
 916                 if (!SRpnt) {
 917                         retval = (STp->buffer)->syscall_result;
 918                         break;
 919                 }
 920
 921                 if (cmdstatp->have_sense) {
 922
 923                         scode = cmdstatp->sense_hdr.sense_key;
 924
 925                         if (scode == UNIT_ATTENTION) { /* New media? */
 926                                 new_session = 1;
 927                                 if (attentions < MAX_ATTENTIONS) {
 928                                         attentions++;
 929                                         continue;
 930                                 }
 931                                 else {
 932                                         retval = (-EIO);
 933                                         break;
 934                                 }
 935                         }
 936
 937                         if (scode == NOT_READY) {
 938                                 if (waits < max_wait) {
 939                                         if (msleep_interruptible(1000)) {
 940                                                 retval = (-EINTR);
 941                                                 break;
 942                                         }
 943                                         waits++;
 944                                         continue;
 945                                 }
 946                                 else {
 947                                         if ((STp->device)->scsi_level >= SCSI_2 &&
 948                                             cmdstatp->sense_hdr.asc == 0x3a)    /* Check ASC */
 949                                                 retval = CHKRES_NO_TAPE;
 950                                         else
 951                                                 retval = CHKRES_NOT_READY;
 952                                         break;
 953                                 }
 954                         }
 955                 }
 956
 957                 retval = (STp->buffer)->syscall_result;
 958                 if (!retval)
 959                         retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
 960                 break;
 961         }
 962
 963         if (SRpnt != NULL)
 964                 st_release_request(SRpnt);
 965         return retval;
 966 }
 967
 968
 969 /* See if the drive is ready and gather information about the tape. Return values:
 970    < 0   negative error code from errno.h
 971    0     drive ready
 972    1     drive not ready (possibly no tape)
 973 */
 974 static int check_tape(struct scsi_tape *STp, struct file *filp)
 975 {
 976         int i, retval, new_session = 0, do_wait;
 977         unsigned char cmd[MAX_COMMAND_SIZE], saved_cleaning;
 978         unsigned short st_flags = filp->f_flags;
 979         struct st_request *SRpnt = NULL;
 980         struct st_modedef *STm;
 981         struct st_partstat *STps;
 982         char *name = tape_name(STp);
 983         struct inode *inode = filp->f_path.dentry->d_inode;
 984         int mode = TAPE_MODE(inode);
 985
 986         STp->ready = ST_READY;
 987
 988         if (mode != STp->current_mode) {
 989                 DEBC(printk(ST_DEB_MSG "%s: Mode change from %d to %d.\n",
 990                                name, STp->current_mode, mode));
 991                 new_session = 1;
 992                 STp->current_mode = mode;
 993         }
 994         STm = &(STp->modes[STp->current_mode]);
 995
 996         saved_cleaning = STp->cleaning_req;
 997         STp->cleaning_req = 0;
 998
 999         do_wait = ((filp->f_flags & O_NONBLOCK) == 0);
1000         retval = test_ready(STp, do_wait);
1001
1002         if (retval < 0)
1003             goto err_out;
1004
1005         if (retval == CHKRES_NEW_SESSION) {
1006                 STp->pos_unknown = 0;
1007                 STp->partition = STp->new_partition = 0;
1008                 if (STp->can_partitions)
1009                         STp->nbr_partitions = 1; /* This guess will be updated later
1010                                                     if necessary */
1011                 for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1012                         STps = &(STp->ps[i]);
1013                         STps->rw = ST_IDLE;
1014                         STps->eof = ST_NOEOF;
1015                         STps->at_sm = 0;
1016                         STps->last_block_valid = 0;
1017                         STps->drv_block = 0;
1018                         STps->drv_file = 0;
1019                 }
1020                 new_session = 1;
1021         }
1022         else {
1023                 STp->cleaning_req |= saved_cleaning;
1024
1025                 if (retval == CHKRES_NOT_READY || retval == CHKRES_NO_TAPE) {
1026                         if (retval == CHKRES_NO_TAPE)
1027                                 STp->ready = ST_NO_TAPE;
1028                         else
1029                                 STp->ready = ST_NOT_READY;
1030
1031                         STp->density = 0;       /* Clear the erroneous "residue" */
1032                         STp->write_prot = 0;
1033                         STp->block_size = 0;
1034                         STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
1035                         STp->partition = STp->new_partition = 0;
1036                         STp->door_locked = ST_UNLOCKED;
1037                         return CHKRES_NOT_READY;
1038                 }
1039         }
1040
1041         if (STp->omit_blklims)
1042                 STp->min_block = STp->max_block = (-1);
1043         else {
1044                 memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1045                 cmd[0] = READ_BLOCK_LIMITS;
1046
1047                 SRpnt = st_do_scsi(SRpnt, STp, cmd, 6, DMA_FROM_DEVICE,
1048                                    STp->device->request_queue->rq_timeout,
1049                                    MAX_READY_RETRIES, 1);
1050                 if (!SRpnt) {
1051                         retval = (STp->buffer)->syscall_result;
1052                         goto err_out;
1053                 }
1054
1055                 if (!SRpnt->result && !STp->buffer->cmdstat.have_sense) {
1056                         STp->max_block = ((STp->buffer)->b_data[1] << 16) |
1057                             ((STp->buffer)->b_data[2] << 8) | (STp->buffer)->b_data[3];
1058                         STp->min_block = ((STp->buffer)->b_data[4] << 8) |
1059                             (STp->buffer)->b_data[5];
1060                         if ( DEB( debugging || ) !STp->inited)
1061                                 printk(KERN_INFO
1062                                        "%s: Block limits %d - %d bytes.\n", name,
1063                                        STp->min_block, STp->max_block);
1064                 } else {
1065                         STp->min_block = STp->max_block = (-1);
1066                         DEBC(printk(ST_DEB_MSG "%s: Can't read block limits.\n",
1067                                        name));
1068                 }
1069         }
1070
1071         memset((void *) &cmd[0], 0, MAX_COMMAND_SIZE);
1072         cmd[0] = MODE_SENSE;
1073         cmd[4] = 12;
1074
1075         SRpnt = st_do_scsi(SRpnt, STp, cmd, 12, DMA_FROM_DEVICE,
1076                            STp->device->request_queue->rq_timeout,
1077                            MAX_READY_RETRIES, 1);
1078         if (!SRpnt) {
1079                 retval = (STp->buffer)->syscall_result;
1080                 goto err_out;
1081         }
1082
1083         if ((STp->buffer)->syscall_result != 0) {
1084                 DEBC(printk(ST_DEB_MSG "%s: No Mode Sense.\n", name));
1085                 STp->block_size = ST_DEFAULT_BLOCK;     /* Educated guess (?) */
1086                 (STp->buffer)->syscall_result = 0;      /* Prevent error propagation */
1087                 STp->drv_write_prot = 0;
1088         } else {
1089                 DEBC(printk(ST_DEB_MSG
1090                             "%s: Mode sense. Length %d, medium %x, WBS %x, BLL %d\n",
1091                             name,
1092                             (STp->buffer)->b_data[0], (STp->buffer)->b_data[1],
1093                             (STp->buffer)->b_data[2], (STp->buffer)->b_data[3]));
1094
1095                 if ((STp->buffer)->b_data[3] >= 8) {
1096                         STp->drv_buffer = ((STp->buffer)->b_data[2] >> 4) & 7;
1097                         STp->density = (STp->buffer)->b_data[4];
1098                         STp->block_size = (STp->buffer)->b_data[9] * 65536 +
1099                             (STp->buffer)->b_data[10] * 256 + (STp->buffer)->b_data[11];
1100                         DEBC(printk(ST_DEB_MSG
1101                                     "%s: Density %x, tape length: %x, drv buffer: %d\n",
1102                                     name, STp->density, (STp->buffer)->b_data[5] * 65536 +
1103                                     (STp->buffer)->b_data[6] * 256 + (STp->buffer)->b_data[7],
1104                                     STp->drv_buffer));
1105                 }
1106                 STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0;
1107         }
1108         st_release_request(SRpnt);
1109         SRpnt = NULL;
1110         STp->inited = 1;
1111
1112         if (STp->block_size > 0)
1113                 (STp->buffer)->buffer_blocks =
1114                         (STp->buffer)->buffer_size / STp->block_size;
1115         else
1116                 (STp->buffer)->buffer_blocks = 1;
1117         (STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
1118
1119         DEBC(printk(ST_DEB_MSG
1120                        "%s: Block size: %d, buffer size: %d (%d blocks).\n", name,
1121                        STp->block_size, (STp->buffer)->buffer_size,
1122                        (STp->buffer)->buffer_blocks));
1123
1124         if (STp->drv_write_prot) {
1125                 STp->write_prot = 1;
1126
1127                 DEBC(printk(ST_DEB_MSG "%s: Write protected\n", name));
1128
1129                 if (do_wait &&
1130                     ((st_flags & O_ACCMODE) == O_WRONLY ||
1131                      (st_flags & O_ACCMODE) == O_RDWR)) {
1132                         retval = (-EROFS);
1133                         goto err_out;
1134                 }
1135         }
1136
1137         if (STp->can_partitions && STp->nbr_partitions < 1) {
1138                 /* This code is reached when the device is opened for the first time
1139                    after the driver has been initialized with tape in the drive and the
1140                    partition support has been enabled. */
1141                 DEBC(printk(ST_DEB_MSG
1142                             "%s: Updating partition number in status.\n", name));
1143                 if ((STp->partition = find_partition(STp)) < 0) {
1144                         retval = STp->partition;
1145                         goto err_out;
1146                 }
1147                 STp->new_partition = STp->partition;
1148                 STp->nbr_partitions = 1; /* This guess will be updated when necessary */
1149         }
1150
1151         if (new_session) {      /* Change the drive parameters for the new mode */
1152                 STp->density_changed = STp->blksize_changed = 0;
1153                 STp->compression_changed = 0;
1154                 if (!(STm->defaults_for_writes) &&
1155                     (retval = set_mode_densblk(STp, STm)) < 0)
1156                     goto err_out;
1157
1158                 if (STp->default_drvbuffer != 0xff) {
1159                         if (st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer))
1160                                 printk(KERN_WARNING
1161                                        "%s: Can't set default drive buffering to %d.\n",
1162                                        name, STp->default_drvbuffer);
1163                 }
1164         }
1165
1166         return CHKRES_READY;
1167
1168  err_out:
1169         return retval;
1170 }
1171
1172
1173 \f/* Open the device. Needs to take the BKL only because of incrementing the SCSI host
1174    module count. */
1175 static int st_open(struct inode *inode, struct file *filp)
1176 {
1177         int i, retval = (-EIO);
1178         struct scsi_tape *STp;
1179         struct st_partstat *STps;
1180         int dev = TAPE_NR(inode);
1181         char *name;
1182
1183         lock_kernel();
1184         /*
1185          * We really want to do nonseekable_open(inode, filp); here, but some
1186          * versions of tar incorrectly call lseek on tapes and bail out if that
1187          * fails.  So we disallow pread() and pwrite(), but permit lseeks.
1188          */
1189         filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
1190
1191         if (!(STp = scsi_tape_get(dev))) {
1192                 unlock_kernel();
1193                 return -ENXIO;
1194         }
1195
1196         write_lock(&st_dev_arr_lock);
1197         filp->private_data = STp;
1198         name = tape_name(STp);
1199
1200         if (STp->in_use) {
1201                 write_unlock(&st_dev_arr_lock);
1202                 scsi_tape_put(STp);
1203                 unlock_kernel();
1204                 DEB( printk(ST_DEB_MSG "%s: Device already in use.\n", name); )
1205                 return (-EBUSY);
1206         }
1207
1208         STp->in_use = 1;
1209         write_unlock(&st_dev_arr_lock);
1210         STp->rew_at_close = STp->autorew_dev = (iminor(inode) & 0x80) == 0;
1211
1212         if (!scsi_block_when_processing_errors(STp->device)) {
1213                 retval = (-ENXIO);
1214                 goto err_out;
1215         }
1216
1217         /* See that we have at least a one page buffer available */
1218         if (!enlarge_buffer(STp->buffer, PAGE_SIZE, STp->restr_dma)) {
1219                 printk(KERN_WARNING "%s: Can't allocate one page tape buffer.\n",
1220                        name);
1221                 retval = (-EOVERFLOW);
1222                 goto err_out;
1223         }
1224
1225         (STp->buffer)->cleared = 0;
1226         (STp->buffer)->writing = 0;
1227         (STp->buffer)->syscall_result = 0;
1228
1229         STp->write_prot = ((filp->f_flags & O_ACCMODE) == O_RDONLY);
1230
1231         STp->dirty = 0;
1232         for (i = 0; i < ST_NBR_PARTITIONS; i++) {
1233                 STps = &(STp->ps[i]);
1234                 STps->rw = ST_IDLE;
1235         }
1236         STp->try_dio_now = STp->try_dio;
1237         STp->recover_count = 0;
1238         DEB( STp->nbr_waits = STp->nbr_finished = 0;
1239              STp->nbr_requests = STp->nbr_dio = STp->nbr_pages = 0; )
1240
1241         retval = check_tape(STp, filp);
1242         if (retval < 0)
1243                 goto err_out;
1244         if ((filp->f_flags & O_NONBLOCK) == 0 &&
1245             retval != CHKRES_READY) {
1246                 if (STp->ready == NO_TAPE)
1247                         retval = (-ENOMEDIUM);
1248                 else
1249                         retval = (-EIO);
1250                 goto err_out;
1251         }
1252         unlock_kernel();
1253         return 0;
1254
1255  err_out:
1256         normalize_buffer(STp->buffer);
1257         STp->in_use = 0;
1258         scsi_tape_put(STp);
1259         unlock_kernel();
1260         return retval;
1261
1262 }
1263 \f
1264
1265 /* Flush the tape buffer before close */
1266 static int st_flush(struct file *filp, fl_owner_t id)
1267 {
1268         int result = 0, result2;
1269         unsigned char cmd[MAX_COMMAND_SIZE];
1270         struct st_request *SRpnt;
1271         struct scsi_tape *STp = filp->private_data;
1272         struct st_modedef *STm = &(STp->modes[STp->current_mode]);
1273         struct st_partstat *STps = &(STp->ps[STp->partition]);
1274         char *name = tape_name(STp);
1275
1276         if (file_count(filp) > 1)
1277                 return 0;
1278
1279         if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1280                 result = st_flush_write_buffer(STp);
1281                 if (result != 0 && result != (-ENOSPC))
1282                         goto out;
1283         }
1284
1285         if (STp->can_partitions &&
1286             (result2 = switch_partition(STp)) < 0) {
1287                 DEBC(printk(ST_DEB_MSG
1288                                "%s: switch_partition at close failed.\n", name));
1289                 if (result == 0)
1290                         result = result2;
1291                 goto out;
1292         }
1293
1294         DEBC( if (STp->nbr_requests)
1295                 printk(KERN_DEBUG "%s: Number of r/w requests %d, dio used in %d, pages %d.\n",
1296                        name, STp->nbr_requests, STp->nbr_dio, STp->nbr_pages));
1297
1298         if (STps->rw == ST_WRITING && !STp->pos_unknown) {
1299                 struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1300
1301                 DEBC(printk(ST_DEB_MSG "%s: Async write waits %d, finished %d.\n",
1302                             name, STp->nbr_waits, STp->nbr_finished);
1303                 )
1304
1305                 memset(cmd, 0, MAX_COMMAND_SIZE);
1306                 cmd[0] = WRITE_FILEMARKS;
1307                 cmd[4] = 1 + STp->two_fm;
1308
1309                 SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
1310                                    STp->device->request_queue->rq_timeout,
1311                                    MAX_WRITE_RETRIES, 1);
1312                 if (!SRpnt) {
1313                         result = (STp->buffer)->syscall_result;
1314                         goto out;
1315                 }
1316
1317                 if (STp->buffer->syscall_result == 0 ||
1318                     (cmdstatp->have_sense && !cmdstatp->deferred &&
1319                      (cmdstatp->flags & SENSE_EOM) &&
1320                      (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
1321                       cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) &&
1322                      (!cmdstatp->remainder_valid || cmdstatp->uremainder64 == 0))) {
1323                         /* Write successful at EOM */
1324                         st_release_request(SRpnt);
1325                         SRpnt = NULL;
1326                         if (STps->drv_file >= 0)
1327                                 STps->drv_file++;
1328                         STps->drv_block = 0;
1329                         if (STp->two_fm)
1330                                 cross_eof(STp, 0);
1331                         STps->eof = ST_FM;
1332                 }
1333                 else { /* Write error */
1334                         st_release_request(SRpnt);
1335                         SRpnt = NULL;
1336                         printk(KERN_ERR "%s: Error on write filemark.\n", name);
1337                         if (result == 0)
1338                                 result = (-EIO);
1339                 }
1340
1341                 DEBC(printk(ST_DEB_MSG "%s: Buffer flushed, %d EOF(s) written\n",
1342                             name, cmd[4]));
1343         } else if (!STp->rew_at_close) {
1344                 STps = &(STp->ps[STp->partition]);
1345                 if (!STm->sysv || STps->rw != ST_READING) {
1346                         if (STp->can_bsr)
1347                                 result = flush_buffer(STp, 0);
1348                         else if (STps->eof == ST_FM_HIT) {
1349                                 result = cross_eof(STp, 0);
1350                                 if (result) {
1351                                         if (STps->drv_file >= 0)
1352                                                 STps->drv_file++;
1353                                         STps->drv_block = 0;
1354                                         STps->eof = ST_FM;
1355                                 } else
1356                                         STps->eof = ST_NOEOF;
1357                         }
1358                 } else if ((STps->eof == ST_NOEOF &&
1359                             !(result = cross_eof(STp, 1))) ||
1360                            STps->eof == ST_FM_HIT) {
1361                         if (STps->drv_file >= 0)
1362                                 STps->drv_file++;
1363                         STps->drv_block = 0;
1364                         STps->eof = ST_FM;
1365                 }
1366         }
1367
1368       out:
1369         if (STp->rew_at_close) {
1370                 result2 = st_int_ioctl(STp, MTREW, 1);
1371                 if (result == 0)
1372                         result = result2;
1373         }
1374         return result;
1375 }
1376
1377
1378 /* Close the device and release it. BKL is not needed: this is the only thread
1379    accessing this tape. */
1380 static int st_release(struct inode *inode, struct file *filp)
1381 {
1382         int result = 0;
1383         struct scsi_tape *STp = filp->private_data;
1384
1385         if (STp->door_locked == ST_LOCKED_AUTO)
1386                 do_door_lock(STp, 0);
1387
1388         normalize_buffer(STp->buffer);
1389         write_lock(&st_dev_arr_lock);
1390         STp->in_use = 0;
1391         write_unlock(&st_dev_arr_lock);
1392         scsi_tape_put(STp);
1393
1394         return result;
1395 }
1396 \f
1397 /* The checks common to both reading and writing */
1398 static ssize_t rw_checks(struct scsi_tape *STp, struct file *filp, size_t count)
1399 {
1400         ssize_t retval = 0;
1401
1402         /*
1403          * If we are in the middle of error recovery, don't let anyone
1404          * else try and use this device.  Also, if error recovery fails, it
1405          * may try and take the device offline, in which case all further
1406          * access to the device is prohibited.
1407          */
1408         if (!scsi_block_when_processing_errors(STp->device)) {
1409                 retval = (-ENXIO);
1410                 goto out;
1411         }
1412
1413         if (STp->ready != ST_READY) {
1414                 if (STp->ready == ST_NO_TAPE)
1415                         retval = (-ENOMEDIUM);
1416                 else
1417                         retval = (-EIO);
1418                 goto out;
1419         }
1420
1421         if (! STp->modes[STp->current_mode].defined) {
1422                 retval = (-ENXIO);
1423                 goto out;
1424         }
1425
1426
1427         /*
1428          * If there was a bus reset, block further access
1429          * to this device.
1430          */
1431         if (STp->pos_unknown) {
1432                 retval = (-EIO);
1433                 goto out;
1434         }
1435
1436         if (count == 0)
1437                 goto out;
1438
1439         DEB(
1440         if (!STp->in_use) {
1441                 printk(ST_DEB_MSG "%s: Incorrect device.\n", tape_name(STp));
1442                 retval = (-EIO);
1443                 goto out;
1444         } ) /* end DEB */
1445
1446         if (STp->can_partitions &&
1447             (retval = switch_partition(STp)) < 0)
1448                 goto out;
1449
1450         if (STp->block_size == 0 && STp->max_block > 0 &&
1451             (count < STp->min_block || count > STp->max_block)) {
1452                 retval = (-EINVAL);
1453                 goto out;
1454         }
1455
1456         if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED &&
1457             !do_door_lock(STp, 1))
1458                 STp->door_locked = ST_LOCKED_AUTO;
1459
1460  out:
1461         return retval;
1462 }
1463
1464
1465 static int setup_buffering(struct scsi_tape *STp, const char __user *buf,
1466                            size_t count, int is_read)
1467 {
1468         int i, bufsize, retval = 0;
1469         struct st_buffer *STbp = STp->buffer;
1470
1471         if (is_read)
1472                 i = STp->try_dio_now && try_rdio;
1473         else
1474                 i = STp->try_dio_now && try_wdio;
1475
1476         if (i && ((unsigned long)buf & queue_dma_alignment(
1477                                         STp->device->request_queue)) == 0) {
1478                 i = sgl_map_user_pages(STbp, STbp->use_sg, (unsigned long)buf,
1479                                        count, (is_read ? READ : WRITE));
1480                 if (i > 0) {
1481                         STbp->do_dio = i;
1482                         STbp->buffer_bytes = 0;   /* can be used as transfer counter */
1483                 }
1484                 else
1485                         STbp->do_dio = 0;  /* fall back to buffering with any error */
1486                 STbp->sg_segs = STbp->do_dio;
1487                 DEB(
1488                      if (STbp->do_dio) {
1489                         STp->nbr_dio++;
1490                         STp->nbr_pages += STbp->do_dio;
1491                      }
1492                 )
1493         } else
1494                 STbp->do_dio = 0;
1495         DEB( STp->nbr_requests++; )
1496
1497         if (!STbp->do_dio) {
1498                 if (STp->block_size)
1499                         bufsize = STp->block_size > st_fixed_buffer_size ?
1500                                 STp->block_size : st_fixed_buffer_size;
1501                 else {
1502                         bufsize = count;
1503                         /* Make sure that data from previous user is not leaked even if
1504                            HBA does not return correct residual */
1505                         if (is_read && STp->sili && !STbp->cleared)
1506                                 clear_buffer(STbp);
1507                 }
1508
1509                 if (bufsize > STbp->buffer_size &&
1510                     !enlarge_buffer(STbp, bufsize, STp->restr_dma)) {
1511                         printk(KERN_WARNING "%s: Can't allocate %d byte tape buffer.\n",
1512                                tape_name(STp), bufsize);
1513                         retval = (-EOVERFLOW);
1514                         goto out;
1515                 }
1516                 if (STp->block_size)
1517                         STbp->buffer_blocks = bufsize / STp->block_size;
1518         }
1519
1520  out:
1521         return retval;
1522 }
1523
1524
1525 /* Can be called more than once after each setup_buffer() */
1526 static void release_buffering(struct scsi_tape *STp, int is_read)
1527 {
1528         struct st_buffer *STbp;
1529
1530         STbp = STp->buffer;
1531         if (STbp->do_dio) {
1532                 sgl_unmap_user_pages(STbp, STbp->do_dio, is_read);
1533                 STbp->do_dio = 0;
1534                 STbp->sg_segs = 0;
1535         }
1536 }
1537
1538
1539 /* Write command */
1540 static ssize_t
1541 st_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
1542 {
1543         ssize_t total;
1544         ssize_t i, do_count, blks, transfer;
1545         ssize_t retval;
1546         int undone, retry_eot = 0, scode;
1547         int async_write;
1548         unsigned char cmd[MAX_COMMAND_SIZE];
1549         const char __user *b_point;
1550         struct st_request *SRpnt = NULL;
1551         struct scsi_tape *STp = filp->private_data;
1552         struct st_modedef *STm;
1553         struct st_partstat *STps;
1554         struct st_buffer *STbp;
1555         char *name = tape_name(STp);
1556
1557         if (mutex_lock_interruptible(&STp->lock))
1558                 return -ERESTARTSYS;
1559
1560         retval = rw_checks(STp, filp, count);
1561         if (retval || count == 0)
1562                 goto out;
1563
1564         /* Write must be integral number of blocks */
1565         if (STp->block_size != 0 && (count % STp->block_size) != 0) {
1566                 printk(KERN_WARNING "%s: Write not multiple of tape block size.\n",
1567                        name);
1568                 retval = (-EINVAL);
1569                 goto out;
1570         }
1571
1572         STm = &(STp->modes[STp->current_mode]);
1573         STps = &(STp->ps[STp->partition]);
1574
1575         if (STp->write_prot) {
1576                 retval = (-EACCES);
1577                 goto out;
1578         }
1579
1580
1581         if (STps->rw == ST_READING) {
1582                 retval = flush_buffer(STp, 0);
1583                 if (retval)
1584                         goto out;
1585                 STps->rw = ST_WRITING;
1586         } else if (STps->rw != ST_WRITING &&
1587                    STps->drv_file == 0 && STps->drv_block == 0) {
1588                 if ((retval = set_mode_densblk(STp, STm)) < 0)
1589                         goto out;
1590                 if (STm->default_compression != ST_DONT_TOUCH &&
1591                     !(STp->compression_changed)) {
1592                         if (st_compression(STp, (STm->default_compression == ST_YES))) {
1593                                 printk(KERN_WARNING "%s: Can't set default compression.\n",
1594                                        name);
1595                                 if (modes_defined) {
1596                                         retval = (-EINVAL);
1597                                         goto out;
1598                                 }
1599                         }
1600                 }
1601         }
1602
1603         STbp = STp->buffer;
1604         i = write_behind_check(STp);
1605         if (i) {
1606                 if (i == -ENOSPC)
1607                         STps->eof = ST_EOM_OK;
1608                 else
1609                         STps->eof = ST_EOM_ERROR;
1610         }
1611
1612         if (STps->eof == ST_EOM_OK) {
1613                 STps->eof = ST_EOD_1;  /* allow next write */
1614                 retval = (-ENOSPC);
1615                 goto out;
1616         }
1617         else if (STps->eof == ST_EOM_ERROR) {
1618                 retval = (-EIO);
1619                 goto out;
1620         }
1621
1622         /* Check the buffer readability in cases where copy_user might catch
1623            the problems after some tape movement. */
1624         if (STp->block_size != 0 &&
1625             !STbp->do_dio &&
1626             (copy_from_user(&i, buf, 1) != 0 ||
1627              copy_from_user(&i, buf + count - 1, 1) != 0)) {
1628                 retval = (-EFAULT);
1629                 goto out;
1630         }
1631
1632         retval = setup_buffering(STp, buf, count, 0);
1633         if (retval)
1634                 goto out;
1635
1636         total = count;
1637
1638         memset(cmd, 0, MAX_COMMAND_SIZE);
1639         cmd[0] = WRITE_6;
1640         cmd[1] = (STp->block_size != 0);
1641
1642         STps->rw = ST_WRITING;
1643
1644         b_point = buf;
1645         while (count > 0 && !retry_eot) {
1646
1647                 if (STbp->do_dio) {
1648                         do_count = count;
1649                 }
1650                 else {
1651                         if (STp->block_size == 0)
1652                                 do_count = count;
1653                         else {
1654                                 do_count = STbp->buffer_blocks * STp->block_size -
1655                                         STbp->buffer_bytes;
1656                                 if (do_count > count)
1657                                         do_count = count;
1658                         }
1659
1660                         i = append_to_buffer(b_point, STbp, do_count);
1661                         if (i) {
1662                                 retval = i;
1663                                 goto out;
1664                         }
1665                 }
1666                 count -= do_count;
1667                 b_point += do_count;
1668
1669                 async_write = STp->block_size == 0 && !STbp->do_dio &&
1670                         STm->do_async_writes && STps->eof < ST_EOM_OK;
1671
1672                 if (STp->block_size != 0 && STm->do_buffer_writes &&
1673                     !(STp->try_dio_now && try_wdio) && STps->eof < ST_EOM_OK &&
1674                     STbp->buffer_bytes < STbp->buffer_size) {
1675                         STp->dirty = 1;
1676                         /* Don't write a buffer that is not full enough. */
1677                         if (!async_write && count == 0)
1678                                 break;
1679                 }
1680
1681         retry_write:
1682                 if (STp->block_size == 0)
1683                         blks = transfer = do_count;
1684                 else {
1685                         if (!STbp->do_dio)
1686                                 blks = STbp->buffer_bytes;
1687                         else
1688                                 blks = do_count;
1689                         blks /= STp->block_size;
1690                         transfer = blks * STp->block_size;
1691                 }
1692                 cmd[2] = blks >> 16;
1693                 cmd[3] = blks >> 8;
1694                 cmd[4] = blks;
1695
1696                 SRpnt = st_do_scsi(SRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
1697                                    STp->device->request_queue->rq_timeout,
1698                                    MAX_WRITE_RETRIES, !async_write);
1699                 if (!SRpnt) {
1700                         retval = STbp->syscall_result;
1701                         goto out;
1702                 }
1703                 if (async_write && !STbp->syscall_result) {
1704                         STbp->writing = transfer;
1705                         STp->dirty = !(STbp->writing ==
1706                                        STbp->buffer_bytes);
1707                         SRpnt = NULL;  /* Prevent releasing this request! */
1708                         DEB( STp->write_pending = 1; )
1709                         break;
1710                 }
1711
1712                 if (STbp->syscall_result != 0) {
1713                         struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1714
1715                         DEBC(printk(ST_DEB_MSG "%s: Error on write:\n", name));
1716                         if (cmdstatp->have_sense && (cmdstatp->flags & SENSE_EOM)) {
1717                                 scode = cmdstatp->sense_hdr.sense_key;
1718                                 if (cmdstatp->remainder_valid)
1719                                         undone = (int)cmdstatp->uremainder64;
1720                                 else if (STp->block_size == 0 &&
1721                                          scode == VOLUME_OVERFLOW)
1722                                         undone = transfer;
1723                                 else
1724                                         undone = 0;
1725                                 if (STp->block_size != 0)
1726                                         undone *= STp->block_size;
1727                                 if (undone <= do_count) {
1728                                         /* Only data from this write is not written */
1729                                         count += undone;
1730                                         b_point -= undone;
1731                                         do_count -= undone;
1732                                         if (STp->block_size)
1733                                                 blks = (transfer - undone) / STp->block_size;
1734                                         STps->eof = ST_EOM_OK;
1735                                         /* Continue in fixed block mode if all written
1736                                            in this request but still something left to write
1737                                            (retval left to zero)
1738                                         */
1739                                         if (STp->block_size == 0 ||
1740                                             undone > 0 || count == 0)
1741                                                 retval = (-ENOSPC); /* EOM within current request */
1742                                         DEBC(printk(ST_DEB_MSG
1743                                                        "%s: EOM with %d bytes unwritten.\n",
1744                                                        name, (int)count));
1745                                 } else {
1746                                         /* EOT within data buffered earlier (possible only
1747                                            in fixed block mode without direct i/o) */
1748                                         if (!retry_eot && !cmdstatp->deferred &&
1749                                             (scode == NO_SENSE || scode == RECOVERED_ERROR)) {
1750                                                 move_buffer_data(STp->buffer, transfer - undone);
1751                                                 retry_eot = 1;
1752                                                 if (STps->drv_block >= 0) {
1753                                                         STps->drv_block += (transfer - undone) /
1754                                                                 STp->block_size;
1755                                                 }
1756                                                 STps->eof = ST_EOM_OK;
1757                                                 DEBC(printk(ST_DEB_MSG
1758                                                             "%s: Retry write of %d bytes at EOM.\n",
1759                                                             name, STp->buffer->buffer_bytes));
1760                                                 goto retry_write;
1761                                         }
1762                                         else {
1763                                                 /* Either error within data buffered by driver or
1764                                                    failed retry */
1765                                                 count -= do_count;
1766                                                 blks = do_count = 0;
1767                                                 STps->eof = ST_EOM_ERROR;
1768                                                 STps->drv_block = (-1); /* Too cautious? */
1769                                                 retval = (-EIO);        /* EOM for old data */
1770                                                 DEBC(printk(ST_DEB_MSG
1771                                                             "%s: EOM with lost data.\n",
1772                                                             name));
1773                                         }
1774                                 }
1775                         } else {
1776                                 count += do_count;
1777                                 STps->drv_block = (-1);         /* Too cautious? */
1778                                 retval = STbp->syscall_result;
1779                         }
1780
1781                 }
1782
1783                 if (STps->drv_block >= 0) {
1784                         if (STp->block_size == 0)
1785                                 STps->drv_block += (do_count > 0);
1786                         else
1787                                 STps->drv_block += blks;
1788                 }
1789
1790                 STbp->buffer_bytes = 0;
1791                 STp->dirty = 0;
1792
1793                 if (retval || retry_eot) {
1794                         if (count < total)
1795                                 retval = total - count;
1796                         goto out;
1797                 }
1798         }
1799
1800         if (STps->eof == ST_EOD_1)
1801                 STps->eof = ST_EOM_OK;
1802         else if (STps->eof != ST_EOM_OK)
1803                 STps->eof = ST_NOEOF;
1804         retval = total - count;
1805
1806  out:
1807         if (SRpnt != NULL)
1808                 st_release_request(SRpnt);
1809         release_buffering(STp, 0);
1810         mutex_unlock(&STp->lock);
1811
1812         return retval;
1813 }
1814 \f
1815 /* Read data from the tape. Returns zero in the normal case, one if the
1816    eof status has changed, and the negative error code in case of a
1817    fatal error. Otherwise updates the buffer and the eof state.
1818
1819    Does release user buffer mapping if it is set.
1820 */
1821 static long read_tape(struct scsi_tape *STp, long count,
1822                       struct st_request ** aSRpnt)
1823 {
1824         int transfer, blks, bytes;
1825         unsigned char cmd[MAX_COMMAND_SIZE];
1826         struct st_request *SRpnt;
1827         struct st_modedef *STm;
1828         struct st_partstat *STps;
1829         struct st_buffer *STbp;
1830         int retval = 0;
1831         char *name = tape_name(STp);
1832
1833         if (count == 0)
1834                 return 0;
1835
1836         STm = &(STp->modes[STp->current_mode]);
1837         STps = &(STp->ps[STp->partition]);
1838         if (STps->eof == ST_FM_HIT)
1839                 return 1;
1840         STbp = STp->buffer;
1841
1842         if (STp->block_size == 0)
1843                 blks = bytes = count;
1844         else {
1845                 if (!(STp->try_dio_now && try_rdio) && STm->do_read_ahead) {
1846                         blks = (STp->buffer)->buffer_blocks;
1847                         bytes = blks * STp->block_size;
1848                 } else {
1849                         bytes = count;
1850                         if (!STbp->do_dio && bytes > (STp->buffer)->buffer_size)
1851                                 bytes = (STp->buffer)->buffer_size;
1852                         blks = bytes / STp->block_size;
1853                         bytes = blks * STp->block_size;
1854                 }
1855         }
1856
1857         memset(cmd, 0, MAX_COMMAND_SIZE);
1858         cmd[0] = READ_6;
1859         cmd[1] = (STp->block_size != 0);
1860         if (!cmd[1] && STp->sili)
1861                 cmd[1] |= 2;
1862         cmd[2] = blks >> 16;
1863         cmd[3] = blks >> 8;
1864         cmd[4] = blks;
1865
1866         SRpnt = *aSRpnt;
1867         SRpnt = st_do_scsi(SRpnt, STp, cmd, bytes, DMA_FROM_DEVICE,
1868                            STp->device->request_queue->rq_timeout,
1869                            MAX_RETRIES, 1);
1870         release_buffering(STp, 1);
1871         *aSRpnt = SRpnt;
1872         if (!SRpnt)
1873                 return STbp->syscall_result;
1874
1875         STbp->read_pointer = 0;
1876         STps->at_sm = 0;
1877
1878         /* Something to check */
1879         if (STbp->syscall_result) {
1880                 struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
1881
1882                 retval = 1;
1883                 DEBC(printk(ST_DEB_MSG "%s: Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
1884                             name,
1885                             SRpnt->sense[0], SRpnt->sense[1],
1886                             SRpnt->sense[2], SRpnt->sense[3],
1887                             SRpnt->sense[4], SRpnt->sense[5],
1888                             SRpnt->sense[6], SRpnt->sense[7]));
1889                 if (cmdstatp->have_sense) {
1890
1891                         if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
1892                                 cmdstatp->flags &= 0xcf;        /* No need for EOM in this case */
1893
1894                         if (cmdstatp->flags != 0) { /* EOF, EOM, or ILI */
1895                                 /* Compute the residual count */
1896                                 if (cmdstatp->remainder_valid)
1897                                         transfer = (int)cmdstatp->uremainder64;
1898                                 else
1899                                         transfer = 0;
1900                                 if (STp->block_size == 0 &&
1901                                     cmdstatp->sense_hdr.sense_key == MEDIUM_ERROR)
1902                                         transfer = bytes;
1903
1904                                 if (cmdstatp->flags & SENSE_ILI) {      /* ILI */
1905                                         if (STp->block_size == 0) {
1906                                                 if (transfer <= 0) {
1907                                                         if (transfer < 0)
1908                                                                 printk(KERN_NOTICE
1909                                                                        "%s: Failed to read %d byte block with %d byte transfer.\n",
1910                                                                        name, bytes - transfer, bytes);
1911                                                         if (STps->drv_block >= 0)
1912                                                                 STps->drv_block += 1;
1913                                                         STbp->buffer_bytes = 0;
1914                                                         return (-ENOMEM);
1915                                                 }
1916                                                 STbp->buffer_bytes = bytes - transfer;
1917                                         } else {
1918                                                 st_release_request(SRpnt);
1919                                                 SRpnt = *aSRpnt = NULL;
1920                                                 if (transfer == blks) { /* We did not get anything, error */
1921                                                         printk(KERN_NOTICE "%s: Incorrect block size.\n", name);
1922                                                         if (STps->drv_block >= 0)
1923                                                                 STps->drv_block += blks - transfer + 1;
1924                                                         st_int_ioctl(STp, MTBSR, 1);
1925                                                         return (-EIO);
1926                                                 }
1927                                                 /* We have some data, deliver it */
1928                                                 STbp->buffer_bytes = (blks - transfer) *
1929                                                     STp->block_size;
1930                                                 DEBC(printk(ST_DEB_MSG
1931                                                             "%s: ILI but enough data received %ld %d.\n",
1932                                                             name, count, STbp->buffer_bytes));
1933                                                 if (STps->drv_block >= 0)
1934                                                         STps->drv_block += 1;
1935                                                 if (st_int_ioctl(STp, MTBSR, 1))
1936                                                         return (-EIO);
1937                                         }
1938                                 } else if (cmdstatp->flags & SENSE_FMK) {       /* FM overrides EOM */
1939                                         if (STps->eof != ST_FM_HIT)
1940                                                 STps->eof = ST_FM_HIT;
1941                                         else
1942                                                 STps->eof = ST_EOD_2;
1943                                         if (STp->block_size == 0)
1944                                                 STbp->buffer_bytes = 0;
1945                                         else
1946                                                 STbp->buffer_bytes =
1947                                                     bytes - transfer * STp->block_size;
1948                                         DEBC(printk(ST_DEB_MSG
1949                                                     "%s: EOF detected (%d bytes read).\n",
1950                                                     name, STbp->buffer_bytes));
1951                                 } else if (cmdstatp->flags & SENSE_EOM) {
1952                                         if (STps->eof == ST_FM)
1953                                                 STps->eof = ST_EOD_1;
1954                                         else
1955                                                 STps->eof = ST_EOM_OK;
1956                                         if (STp->block_size == 0)
1957                                                 STbp->buffer_bytes = bytes - transfer;
1958                                         else
1959                                                 STbp->buffer_bytes =
1960                                                     bytes - transfer * STp->block_size;
1961
1962                                         DEBC(printk(ST_DEB_MSG "%s: EOM detected (%d bytes read).\n",
1963                                                     name, STbp->buffer_bytes));
1964                                 }
1965                         }
1966                         /* end of EOF, EOM, ILI test */
1967                         else {  /* nonzero sense key */
1968                                 DEBC(printk(ST_DEB_MSG
1969                                             "%s: Tape error while reading.\n", name));
1970                                 STps->drv_block = (-1);
1971                                 if (STps->eof == ST_FM &&
1972                                     cmdstatp->sense_hdr.sense_key == BLANK_CHECK) {
1973                                         DEBC(printk(ST_DEB_MSG
1974                                                     "%s: Zero returned for first BLANK CHECK after EOF.\n",
1975                                                     name));
1976                                         STps->eof = ST_EOD_2;   /* First BLANK_CHECK after FM */
1977                                 } else  /* Some other extended sense code */
1978                                         retval = (-EIO);
1979                         }
1980
1981                         if (STbp->buffer_bytes < 0)  /* Caused by bogus sense data */
1982                                 STbp->buffer_bytes = 0;
1983                 }
1984                 /* End of extended sense test */
1985                 else {          /* Non-extended sense */
1986                         retval = STbp->syscall_result;
1987                 }
1988
1989         }
1990         /* End of error handling */
1991         else {                  /* Read successful */
1992                 STbp->buffer_bytes = bytes;
1993                 if (STp->sili) /* In fixed block mode residual is always zero here */
1994                         STbp->buffer_bytes -= STp->buffer->cmdstat.residual;
1995         }
1996
1997         if (STps->drv_block >= 0) {
1998                 if (STp->block_size == 0)
1999                         STps->drv_block++;
2000                 else
2001                         STps->drv_block += STbp->buffer_bytes / STp->block_size;
2002         }
2003         return retval;
2004 }
2005 \f
2006
2007 /* Read command */
2008 static ssize_t
2009 st_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
2010 {
2011         ssize_t total;
2012         ssize_t retval = 0;
2013         ssize_t i, transfer;
2014         int special, do_dio = 0;
2015         struct st_request *SRpnt = NULL;
2016         struct scsi_tape *STp = filp->private_data;
2017         struct st_modedef *STm;
2018         struct st_partstat *STps;
2019         struct st_buffer *STbp = STp->buffer;
2020         DEB( char *name = tape_name(STp); )
2021
2022         if (mutex_lock_interruptible(&STp->lock))
2023                 return -ERESTARTSYS;
2024
2025         retval = rw_checks(STp, filp, count);
2026         if (retval || count == 0)
2027                 goto out;
2028
2029         STm = &(STp->modes[STp->current_mode]);
2030         if (STp->block_size != 0 && (count % STp->block_size) != 0) {
2031                 if (!STm->do_read_ahead) {
2032                         retval = (-EINVAL);     /* Read must be integral number of blocks */
2033                         goto out;
2034                 }
2035                 STp->try_dio_now = 0;  /* Direct i/o can't handle split blocks */
2036         }
2037
2038         STps = &(STp->ps[STp->partition]);
2039         if (STps->rw == ST_WRITING) {
2040                 retval = flush_buffer(STp, 0);
2041                 if (retval)
2042                         goto out;
2043                 STps->rw = ST_READING;
2044         }
2045         DEB(
2046         if (debugging && STps->eof != ST_NOEOF)
2047                 printk(ST_DEB_MSG "%s: EOF/EOM flag up (%d). Bytes %d\n", name,
2048                        STps->eof, STbp->buffer_bytes);
2049         ) /* end DEB */
2050
2051         retval = setup_buffering(STp, buf, count, 1);
2052         if (retval)
2053                 goto out;
2054         do_dio = STbp->do_dio;
2055
2056         if (STbp->buffer_bytes == 0 &&
2057             STps->eof >= ST_EOD_1) {
2058                 if (STps->eof < ST_EOD) {
2059                         STps->eof += 1;
2060                         retval = 0;
2061                         goto out;
2062                 }
2063                 retval = (-EIO);        /* EOM or Blank Check */
2064                 goto out;
2065         }
2066
2067         if (do_dio) {
2068                 /* Check the buffer writability before any tape movement. Don't alter
2069                    buffer data. */
2070                 if (copy_from_user(&i, buf, 1) != 0 ||
2071                     copy_to_user(buf, &i, 1) != 0 ||
2072                     copy_from_user(&i, buf + count - 1, 1) != 0 ||
2073                     copy_to_user(buf + count - 1, &i, 1) != 0) {
2074                         retval = (-EFAULT);
2075                         goto out;
2076                 }
2077         }
2078
2079         STps->rw = ST_READING;
2080
2081
2082         /* Loop until enough data in buffer or a special condition found */
2083         for (total = 0, special = 0; total < count && !special;) {
2084
2085                 /* Get new data if the buffer is empty */
2086                 if (STbp->buffer_bytes == 0) {
2087                         special = read_tape(STp, count - total, &SRpnt);
2088                         if (special < 0) {      /* No need to continue read */
2089                                 retval = special;
2090                                 goto out;
2091                         }
2092                 }
2093
2094                 /* Move the data from driver buffer to user buffer */
2095                 if (STbp->buffer_bytes > 0) {
2096                         DEB(
2097                         if (debugging && STps->eof != ST_NOEOF)
2098                                 printk(ST_DEB_MSG
2099                                        "%s: EOF up (%d). Left %d, needed %d.\n", name,
2100                                        STps->eof, STbp->buffer_bytes,
2101                                        (int)(count - total));
2102                         ) /* end DEB */
2103                         transfer = STbp->buffer_bytes < count - total ?
2104                             STbp->buffer_bytes : count - total;
2105                         if (!do_dio) {
2106                                 i = from_buffer(STbp, buf, transfer);
2107                                 if (i) {
2108                                         retval = i;
2109                                         goto out;
2110                                 }
2111                         }
2112                         buf += transfer;
2113                         total += transfer;
2114                 }
2115
2116                 if (STp->block_size == 0)
2117                         break;  /* Read only one variable length block */
2118
2119         }                       /* for (total = 0, special = 0;
2120                                    total < count && !special; ) */
2121
2122         /* Change the eof state if no data from tape or buffer */
2123         if (total == 0) {
2124                 if (STps->eof == ST_FM_HIT) {
2125                         STps->eof = ST_FM;
2126                         STps->drv_block = 0;
2127                         if (STps->drv_file >= 0)
2128                                 STps->drv_file++;
2129                 } else if (STps->eof == ST_EOD_1) {
2130                         STps->eof = ST_EOD_2;
2131                         STps->drv_block = 0;
2132                         if (STps->drv_file >= 0)
2133                                 STps->drv_file++;
2134                 } else if (STps->eof == ST_EOD_2)
2135                         STps->eof = ST_EOD;
2136         } else if (STps->eof == ST_FM)
2137                 STps->eof = ST_NOEOF;
2138         retval = total;
2139
2140  out:
2141         if (SRpnt != NULL) {
2142                 st_release_request(SRpnt);
2143                 SRpnt = NULL;
2144         }
2145         if (do_dio) {
2146                 release_buffering(STp, 1);
2147                 STbp->buffer_bytes = 0;
2148         }
2149         mutex_unlock(&STp->lock);
2150
2151         return retval;
2152 }
2153 \f
2154
2155
2156 DEB(
2157 /* Set the driver options */
2158 static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm, char *name)
2159 {
2160         if (debugging) {
2161                 printk(KERN_INFO
2162                        "%s: Mode %d options: buffer writes: %d, async writes: %d, read ahead: %d\n",
2163                        name, STp->current_mode, STm->do_buffer_writes, STm->do_async_writes,
2164                        STm->do_read_ahead);
2165                 printk(KERN_INFO
2166                        "%s:    can bsr: %d, two FMs: %d, fast mteom: %d, auto lock: %d,\n",
2167                        name, STp->can_bsr, STp->two_fm, STp->fast_mteom, STp->do_auto_lock);
2168                 printk(KERN_INFO
2169                        "%s:    defs for wr: %d, no block limits: %d, partitions: %d, s2 log: %d\n",
2170                        name, STm->defaults_for_writes, STp->omit_blklims, STp->can_partitions,
2171                        STp->scsi2_logical);
2172                 printk(KERN_INFO
2173                        "%s:    sysv: %d nowait: %d sili: %d\n", name, STm->sysv, STp->immediate,
2174                         STp->sili);
2175                 printk(KERN_INFO "%s:    debugging: %d\n",
2176                        name, debugging);
2177         }
2178 }
2179         )
2180
2181
2182 static int st_set_options(struct scsi_tape *STp, long options)
2183 {
2184         int value;
2185         long code;
2186         struct st_modedef *STm;
2187         char *name = tape_name(STp);
2188         struct cdev *cd0, *cd1;
2189
2190         STm = &(STp->modes[STp->current_mode]);
2191         if (!STm->defined) {
2192                 cd0 = STm->cdevs[0]; cd1 = STm->cdevs[1];
2193                 memcpy(STm, &(STp->modes[0]), sizeof(struct st_modedef));
2194                 STm->cdevs[0] = cd0; STm->cdevs[1] = cd1;
2195                 modes_defined = 1;
2196                 DEBC(printk(ST_DEB_MSG
2197                             "%s: Initialized mode %d definition from mode 0\n",
2198                             name, STp->current_mode));
2199         }
2200
2201         code = options & MT_ST_OPTIONS;
2202         if (code == MT_ST_BOOLEANS) {
2203                 STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
2204                 STm->do_async_writes = (options & MT_ST_ASYNC_WRITES) != 0;
2205                 STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
2206                 STm->do_read_ahead = (options & MT_ST_READ_AHEAD) != 0;
2207                 STp->two_fm = (options & MT_ST_TWO_FM) != 0;
2208                 STp->fast_mteom = (options & MT_ST_FAST_MTEOM) != 0;
2209                 STp->do_auto_lock = (options & MT_ST_AUTO_LOCK) != 0;
2210                 STp->can_bsr = (options & MT_ST_CAN_BSR) != 0;
2211                 STp->omit_blklims = (options & MT_ST_NO_BLKLIMS) != 0;
2212                 if ((STp->device)->scsi_level >= SCSI_2)
2213                         STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
2214                 STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0;
2215                 STp->immediate = (options & MT_ST_NOWAIT) != 0;
2216                 STm->sysv = (options & MT_ST_SYSV) != 0;
2217                 STp->sili = (options & MT_ST_SILI) != 0;
2218                 DEB( debugging = (options & MT_ST_DEBUGGING) != 0;
2219                      st_log_options(STp, STm, name); )
2220         } else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
2221                 value = (code == MT_ST_SETBOOLEANS);
2222                 if ((options & MT_ST_BUFFER_WRITES) != 0)
2223                         STm->do_buffer_writes = value;
2224                 if ((options & MT_ST_ASYNC_WRITES) != 0)
2225                         STm->do_async_writes = value;
2226                 if ((options & MT_ST_DEF_WRITES) != 0)
2227                         STm->defaults_for_writes = value;
2228                 if ((options & MT_ST_READ_AHEAD) != 0)
2229                         STm->do_read_ahead = value;
2230                 if ((options & MT_ST_TWO_FM) != 0)
2231                         STp->two_fm = value;
2232                 if ((options & MT_ST_FAST_MTEOM) != 0)
2233                         STp->fast_mteom = value;
2234                 if ((options & MT_ST_AUTO_LOCK) != 0)
2235                         STp->do_auto_lock = value;
2236                 if ((options & MT_ST_CAN_BSR) != 0)
2237                         STp->can_bsr = value;
2238                 if ((options & MT_ST_NO_BLKLIMS) != 0)
2239                         STp->omit_blklims = value;
2240                 if ((STp->device)->scsi_level >= SCSI_2 &&
2241                     (options & MT_ST_CAN_PARTITIONS) != 0)
2242                         STp->can_partitions = value;
2243                 if ((options & MT_ST_SCSI2LOGICAL) != 0)
2244                         STp->scsi2_logical = value;
2245                 if ((options & MT_ST_NOWAIT) != 0)
2246                         STp->immediate = value;
2247                 if ((options & MT_ST_SYSV) != 0)
2248                         STm->sysv = value;
2249                 if ((options & MT_ST_SILI) != 0)
2250                         STp->sili = value;
2251                 DEB(
2252                 if ((options & MT_ST_DEBUGGING) != 0)
2253                         debugging = value;
2254                         st_log_options(STp, STm, name); )
2255         } else if (code == MT_ST_WRITE_THRESHOLD) {
2256                 /* Retained for compatibility */
2257         } else if (code == MT_ST_DEF_BLKSIZE) {
2258                 value = (options & ~MT_ST_OPTIONS);
2259                 if (value == ~MT_ST_OPTIONS) {
2260                         STm->default_blksize = (-1);
2261                         DEBC( printk(KERN_INFO "%s: Default block size disabled.\n", name));
2262                 } else {
2263                         STm->default_blksize = value;
2264                         DEBC( printk(KERN_INFO "%s: Default block size set to %d bytes.\n",
2265                                name, STm->default_blksize));
2266                         if (STp->ready == ST_READY) {
2267                                 STp->blksize_changed = 0;
2268                                 set_mode_densblk(STp, STm);
2269                         }
2270                 }
2271         } else if (code == MT_ST_TIMEOUTS) {
2272                 value = (options & ~MT_ST_OPTIONS);
2273                 if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
2274                         STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
2275                         DEBC( printk(KERN_INFO "%s: Long timeout set to %d seconds.\n", name,
2276                                (value & ~MT_ST_SET_LONG_TIMEOUT)));
2277                 } else {
2278                         blk_queue_rq_timeout(STp->device->request_queue,
2279                                              value * HZ);
2280                         DEBC( printk(KERN_INFO "%s: Normal timeout set to %d seconds.\n",
2281                                 name, value) );
2282                 }
2283         } else if (code == MT_ST_SET_CLN) {
2284                 value = (options & ~MT_ST_OPTIONS) & 0xff;
2285                 if (value != 0 &&
2286                         (value < EXTENDED_SENSE_START ||
2287                                 value >= SCSI_SENSE_BUFFERSIZE))
2288                         return (-EINVAL);
2289                 STp->cln_mode = value;
2290                 STp->cln_sense_mask = (options >> 8) & 0xff;
2291                 STp->cln_sense_value = (options >> 16) & 0xff;
2292                 printk(KERN_INFO
2293                        "%s: Cleaning request mode %d, mask %02x, value %02x\n",
2294                        name, value, STp->cln_sense_mask, STp->cln_sense_value);
2295         } else if (code == MT_ST_DEF_OPTIONS) {
2296                 code = (options & ~MT_ST_CLEAR_DEFAULT);
2297                 value = (options & MT_ST_CLEAR_DEFAULT);
2298                 if (code == MT_ST_DEF_DENSITY) {
2299                         if (value == MT_ST_CLEAR_DEFAULT) {
2300                                 STm->default_density = (-1);
2301                                 DEBC( printk(KERN_INFO "%s: Density default disabled.\n",
2302                                        name));
2303                         } else {
2304                                 STm->default_density = value & 0xff;
2305                                 DEBC( printk(KERN_INFO "%s: Density default set to %x\n",
2306                                        name, STm->default_density));
2307                                 if (STp->ready == ST_READY) {
2308                                         STp->density_changed = 0;
2309                                         set_mode_densblk(STp, STm);
2310                                 }
2311                         }
2312                 } else if (code == MT_ST_DEF_DRVBUFFER) {
2313                         if (value == MT_ST_CLEAR_DEFAULT) {
2314                                 STp->default_drvbuffer = 0xff;
2315                                 DEBC( printk(KERN_INFO
2316                                        "%s: Drive buffer default disabled.\n", name));
2317                         } else {
2318                                 STp->default_drvbuffer = value & 7;
2319                                 DEBC( printk(KERN_INFO
2320                                        "%s: Drive buffer default set to %x\n",
2321                                        name, STp->default_drvbuffer));
2322                                 if (STp->ready == ST_READY)
2323                                         st_int_ioctl(STp, MTSETDRVBUFFER, STp->default_drvbuffer);
2324                         }
2325                 } else if (code == MT_ST_DEF_COMPRESSION) {
2326                         if (value == MT_ST_CLEAR_DEFAULT) {
2327                                 STm->default_compression = ST_DONT_TOUCH;
2328                                 DEBC( printk(KERN_INFO
2329                                        "%s: Compression default disabled.\n", name));
2330                         } else {
2331                                 if ((value & 0xff00) != 0) {
2332                                         STp->c_algo = (value & 0xff00) >> 8;
2333                                         DEBC( printk(KERN_INFO "%s: Compression algorithm set to 0x%x.\n",
2334                                                name, STp->c_algo));
2335                                 }
2336                                 if ((value & 0xff) != 0xff) {
2337                                         STm->default_compression = (value & 1 ? ST_YES : ST_NO);
2338                                         DEBC( printk(KERN_INFO "%s: Compression default set to %x\n",
2339                                                name, (value & 1)));
2340                                         if (STp->ready == ST_READY) {
2341                                                 STp->compression_changed = 0;
2342                                                 st_compression(STp, (STm->default_compression == ST_YES));
2343                                         }
2344                                 }
2345                         }
2346                 }
2347         } else
2348                 return (-EIO);
2349
2350         return 0;
2351 }
2352 \f
2353 #define MODE_HEADER_LENGTH  4
2354
2355 /* Mode header and page byte offsets */
2356 #define MH_OFF_DATA_LENGTH     0
2357 #define MH_OFF_MEDIUM_TYPE     1
2358 #define MH_OFF_DEV_SPECIFIC    2
2359 #define MH_OFF_BDESCS_LENGTH   3
2360 #define MP_OFF_PAGE_NBR        0
2361 #define MP_OFF_PAGE_LENGTH     1
2362
2363 /* Mode header and page bit masks */
2364 #define MH_BIT_WP              0x80
2365 #define MP_MSK_PAGE_NBR        0x3f
2366
2367 /* Don't return block descriptors */
2368 #define MODE_SENSE_OMIT_BDESCS 0x08
2369
2370 #define MODE_SELECT_PAGE_FORMAT 0x10
2371
2372 /* Read a mode page into the tape buffer. The block descriptors are included
2373    if incl_block_descs is true. The page control is ored to the page number
2374    parameter, if necessary. */
2375 static int read_mode_page(struct scsi_tape *STp, int page, int omit_block_descs)
2376 {
2377         unsigned char cmd[MAX_COMMAND_SIZE];
2378         struct st_request *SRpnt;
2379
2380         memset(cmd, 0, MAX_COMMAND_SIZE);
2381         cmd[0] = MODE_SENSE;
2382         if (omit_block_descs)
2383                 cmd[1] = MODE_SENSE_OMIT_BDESCS;
2384         cmd[2] = page;
2385         cmd[4] = 255;
2386
2387         SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_FROM_DEVICE,
2388                            STp->device->request_queue->rq_timeout, 0, 1);
2389         if (SRpnt == NULL)
2390                 return (STp->buffer)->syscall_result;
2391
2392         st_release_request(SRpnt);
2393
2394         return STp->buffer->syscall_result;
2395 }
2396
2397
2398 /* Send the mode page in the tape buffer to the drive. Assumes that the mode data
2399    in the buffer is correctly formatted. The long timeout is used if slow is non-zero. */
2400 static int write_mode_page(struct scsi_tape *STp, int page, int slow)
2401 {
2402         int pgo;
2403         unsigned char cmd[MAX_COMMAND_SIZE];
2404         struct st_request *SRpnt;
2405         int timeout;
2406
2407         memset(cmd, 0, MAX_COMMAND_SIZE);
2408         cmd[0] = MODE_SELECT;
2409         cmd[1] = MODE_SELECT_PAGE_FORMAT;
2410         pgo = MODE_HEADER_LENGTH + (STp->buffer)->b_data[MH_OFF_BDESCS_LENGTH];
2411         cmd[4] = pgo + (STp->buffer)->b_data[pgo + MP_OFF_PAGE_LENGTH] + 2;
2412
2413         /* Clear reserved fields */
2414         (STp->buffer)->b_data[MH_OFF_DATA_LENGTH] = 0;
2415         (STp->buffer)->b_data[MH_OFF_MEDIUM_TYPE] = 0;
2416         (STp->buffer)->b_data[MH_OFF_DEV_SPECIFIC] &= ~MH_BIT_WP;
2417         (STp->buffer)->b_data[pgo + MP_OFF_PAGE_NBR] &= MP_MSK_PAGE_NBR;
2418
2419         timeout = slow ?
2420                 STp->long_timeout : STp->device->request_queue->rq_timeout;
2421         SRpnt = st_do_scsi(NULL, STp, cmd, cmd[4], DMA_TO_DEVICE,
2422                            timeout, 0, 1);
2423         if (SRpnt == NULL)
2424                 return (STp->buffer)->syscall_result;
2425
2426         st_release_request(SRpnt);
2427
2428         return STp->buffer->syscall_result;
2429 }
2430
2431
2432 #define COMPRESSION_PAGE        0x0f
2433 #define COMPRESSION_PAGE_LENGTH 16
2434
2435 #define CP_OFF_DCE_DCC          2
2436 #define CP_OFF_C_ALGO           7
2437
2438 #define DCE_MASK  0x80
2439 #define DCC_MASK  0x40
2440 #define RED_MASK  0x60
2441
2442
2443 /* Control the compression with mode page 15. Algorithm not changed if zero.
2444
2445    The block descriptors are read and written because Sony SDT-7000 does not
2446    work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
2447    Including block descriptors should not cause any harm to other drives. */
2448
2449 static int st_compression(struct scsi_tape * STp, int state)
2450 {
2451         int retval;
2452         int mpoffs;  /* Offset to mode page start */
2453         unsigned char *b_data = (STp->buffer)->b_data;
2454         DEB( char *name = tape_name(STp); )
2455
2456         if (STp->ready != ST_READY)
2457                 return (-EIO);
2458
2459         /* Read the current page contents */
2460         retval = read_mode_page(STp, COMPRESSION_PAGE, 0);
2461         if (retval) {
2462                 DEBC(printk(ST_DEB_MSG "%s: Compression mode page not supported.\n",
2463                             name));
2464                 return (-EIO);
2465         }
2466
2467         mpoffs = MODE_HEADER_LENGTH + b_data[MH_OFF_BDESCS_LENGTH];
2468         DEBC(printk(ST_DEB_MSG "%s: Compression state is %d.\n", name,
2469                     (b_data[mpoffs + CP_OFF_DCE_DCC] & DCE_MASK ? 1 : 0)));
2470
2471         /* Check if compression can be changed */
2472         if ((b_data[mpoffs + CP_OFF_DCE_DCC] & DCC_MASK) == 0) {
2473                 DEBC(printk(ST_DEB_MSG "%s: Compression not supported.\n", name));
2474                 return (-EIO);
2475         }
2476
2477         /* Do the change */
2478         if (state) {
2479                 b_data[mpoffs + CP_OFF_DCE_DCC] |= DCE_MASK;
2480                 if (STp->c_algo != 0)
2481                         b_data[mpoffs + CP_OFF_C_ALGO] = STp->c_algo;
2482         }
2483         else {
2484                 b_data[mpoffs + CP_OFF_DCE_DCC] &= ~DCE_MASK;
2485                 if (STp->c_algo != 0)
2486                         b_data[mpoffs + CP_OFF_C_ALGO] = 0; /* no compression */
2487         }
2488
2489         retval = write_mode_page(STp, COMPRESSION_PAGE, 0);
2490         if (retval) {
2491                 DEBC(printk(ST_DEB_MSG "%s: Compression change failed.\n", name));
2492                 return (-EIO);
2493         }
2494         DEBC(printk(ST_DEB_MSG "%s: Compression state changed to %d.\n",
2495                        name, state));
2496
2497         STp->compression_changed = 1;
2498         return 0;
2499 }
2500
2501
2502 /* Process the load and unload commands (does unload if the load code is zero) */
2503 static int do_load_unload(struct scsi_tape *STp, struct file *filp, int load_code)
2504 {
2505         int retval = (-EIO), timeout;
2506         DEB( char *name = tape_name(STp); )
2507         unsigned char cmd[MAX_COMMAND_SIZE];
2508         struct st_partstat *STps;
2509         struct st_request *SRpnt;
2510
2511         if (STp->ready != ST_READY && !load_code) {
2512                 if (STp->ready == ST_NO_TAPE)
2513                         return (-ENOMEDIUM);
2514                 else
2515                         return (-EIO);
2516         }
2517
2518         memset(cmd, 0, MAX_COMMAND_SIZE);
2519         cmd[0] = START_STOP;
2520         if (load_code)
2521                 cmd[4] |= 1;
2522         /*
2523          * If arg >= 1 && arg <= 6 Enhanced load/unload in HP C1553A
2524          */
2525         if (load_code >= 1 + MT_ST_HPLOADER_OFFSET
2526             && load_code <= 6 + MT_ST_HPLOADER_OFFSET) {
2527                 DEBC(printk(ST_DEB_MSG "%s: Enhanced %sload slot %2d.\n",
2528                             name, (cmd[4]) ? "" : "un",
2529                             load_code - MT_ST_HPLOADER_OFFSET));
2530                 cmd[3] = load_code - MT_ST_HPLOADER_OFFSET; /* MediaID field of C1553A */
2531         }
2532         if (STp->immediate) {
2533                 cmd[1] = 1;     /* Don't wait for completion */
2534                 timeout = STp->device->request_queue->rq_timeout;
2535         }
2536         else
2537                 timeout = STp->long_timeout;
2538
2539         DEBC(
2540                 if (!load_code)
2541                 printk(ST_DEB_MSG "%s: Unloading tape.\n", name);
2542                 else
2543                 printk(ST_DEB_MSG "%s: Loading tape.\n", name);
2544                 );
2545
2546         SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE,
2547                            timeout, MAX_RETRIES, 1);
2548         if (!SRpnt)
2549                 return (STp->buffer)->syscall_result;
2550
2551         retval = (STp->buffer)->syscall_result;
2552         st_release_request(SRpnt);
2553
2554         if (!retval) {  /* SCSI command successful */
2555
2556                 if (!load_code) {
2557                         STp->rew_at_close = 0;
2558                         STp->ready = ST_NO_TAPE;
2559                 }
2560                 else {
2561                         STp->rew_at_close = STp->autorew_dev;
2562                         retval = check_tape(STp, filp);
2563                         if (retval > 0)
2564                                 retval = 0;
2565                 }
2566         }
2567         else {
2568                 STps = &(STp->ps[STp->partition]);
2569                 STps->drv_file = STps->drv_block = (-1);
2570         }
2571
2572         return retval;
2573 }
2574 \f
2575 #if DEBUG
2576 #define ST_DEB_FORWARD  0
2577 #define ST_DEB_BACKWARD 1
2578 static void deb_space_print(char *name, int direction, char *units, unsigned char *cmd)
2579 {
2580         s32 sc;
2581
2582         sc = cmd[2] & 0x80 ? 0xff000000 : 0;
2583         sc |= (cmd[2] << 16) | (cmd[3] << 8) | cmd[4];
2584         if (direction)
2585                 sc = -sc;
2586         printk(ST_DEB_MSG "%s: Spacing tape %s over %d %s.\n", name,
2587                direction ? "backward" : "forward", sc, units);
2588 }
2589 #endif
2590
2591
2592 /* Internal ioctl function */
2593 static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
2594 {
2595         int timeout;
2596         long ltmp;
2597         int ioctl_result;
2598         int chg_eof = 1;
2599         unsigned char cmd[MAX_COMMAND_SIZE];
2600         struct st_request *SRpnt;
2601         struct st_partstat *STps;
2602         int fileno, blkno, at_sm, undone;
2603         int datalen = 0, direction = DMA_NONE;
2604         char *name = tape_name(STp);
2605
2606         WARN_ON(STp->buffer->do_dio != 0);
2607         if (STp->ready != ST_READY) {
2608                 if (STp->ready == ST_NO_TAPE)
2609                         return (-ENOMEDIUM);
2610                 else
2611                         return (-EIO);
2612         }
2613         timeout = STp->long_timeout;
2614         STps = &(STp->ps[STp->partition]);
2615         fileno = STps->drv_file;
2616         blkno = STps->drv_block;
2617         at_sm = STps->at_sm;
2618
2619         memset(cmd, 0, MAX_COMMAND_SIZE);
2620         switch (cmd_in) {
2621         case MTFSFM:
2622                 chg_eof = 0;    /* Changed from the FSF after this */
2623         case MTFSF:
2624                 cmd[0] = SPACE;
2625                 cmd[1] = 0x01;  /* Space FileMarks */
2626                 cmd[2] = (arg >> 16);
2627                 cmd[3] = (arg >> 8);
2628                 cmd[4] = arg;
2629                 DEBC(deb_space_print(name, ST_DEB_FORWARD, "filemarks", cmd);)
2630                 if (fileno >= 0)
2631                         fileno += arg;
2632                 blkno = 0;
2633                 at_sm &= (arg == 0);
2634                 break;
2635         case MTBSFM:
2636                 chg_eof = 0;    /* Changed from the FSF after this */
2637         case MTBSF:
2638                 cmd[0] = SPACE;
2639                 cmd[1] = 0x01;  /* Space FileMarks */
2640                 ltmp = (-arg);
2641                 cmd[2] = (ltmp >> 16);
2642                 cmd[3] = (ltmp >> 8);
2643                 cmd[4] = ltmp;
2644                 DEBC(deb_space_print(name, ST_DEB_BACKWARD, "filemarks", cmd);)
2645                 if (fileno >= 0)
2646                         fileno -= arg;
2647                 blkno = (-1);   /* We can't know the block number */
2648                 at_sm &= (arg == 0);
2649                 break;
2650         case MTFSR:
2651                 cmd[0] = SPACE;
2652                 cmd[1] = 0x00;  /* Space Blocks */
2653                 cmd[2] = (arg >> 16);
2654                 cmd[3] = (arg >> 8);
2655                 cmd[4] = arg;
2656                 DEBC(deb_space_print(name, ST_DEB_FORWARD, "blocks", cmd);)
2657                 if (blkno >= 0)
2658                         blkno += arg;
2659                 at_sm &= (arg == 0);
2660                 break;
2661         case MTBSR:
2662                 cmd[0] = SPACE;
2663                 cmd[1] = 0x00;  /* Space Blocks */
2664                 ltmp = (-arg);
2665                 cmd[2] = (ltmp >> 16);
2666                 cmd[3] = (ltmp >> 8);
2667                 cmd[4] = ltmp;
2668                 DEBC(deb_space_print(name, ST_DEB_BACKWARD, "blocks", cmd);)
2669                 if (blkno >= 0)
2670                         blkno -= arg;
2671                 at_sm &= (arg == 0);
2672                 break;
2673         case MTFSS:
2674                 cmd[0] = SPACE;
2675                 cmd[1] = 0x04;  /* Space Setmarks */
2676                 cmd[2] = (arg >> 16);
2677                 cmd[3] = (arg >> 8);
2678                 cmd[4] = arg;
2679                 DEBC(deb_space_print(name, ST_DEB_FORWARD, "setmarks", cmd);)
2680                 if (arg != 0) {
2681                         blkno = fileno = (-1);
2682                         at_sm = 1;
2683                 }
2684                 break;
2685         case MTBSS:
2686                 cmd[0] = SPACE;
2687                 cmd[1] = 0x04;  /* Space Setmarks */
2688                 ltmp = (-arg);
2689                 cmd[2] = (ltmp >> 16);
2690                 cmd[3] = (ltmp >> 8);
2691                 cmd[4] = ltmp;
2692                 DEBC(deb_space_print(name, ST_DEB_BACKWARD, "setmarks", cmd);)
2693                 if (arg != 0) {
2694                         blkno = fileno = (-1);
2695                         at_sm = 1;
2696                 }
2697                 break;
2698         case MTWEOF:
2699         case MTWSM:
2700                 if (STp->write_prot)
2701                         return (-EACCES);
2702                 cmd[0] = WRITE_FILEMARKS;
2703                 if (cmd_in == MTWSM)
2704                         cmd[1] = 2;
2705                 cmd[2] = (arg >> 16);
2706                 cmd[3] = (arg >> 8);
2707                 cmd[4] = arg;
2708                 timeout = STp->device->request_queue->rq_timeout;
2709                 DEBC(
2710                      if (cmd_in == MTWEOF)
2711                                printk(ST_DEB_MSG "%s: Writing %d filemarks.\n", name,
2712                                  cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
2713                      else
2714                                 printk(ST_DEB_MSG "%s: Writing %d setmarks.\n", name,
2715                                  cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
2716                 )
2717                 if (fileno >= 0)
2718                         fileno += arg;
2719                 blkno = 0;
2720                 at_sm = (cmd_in == MTWSM);
2721                 break;
2722         case MTREW:
2723                 cmd[0] = REZERO_UNIT;
2724                 if (STp->immediate) {
2725                         cmd[1] = 1;     /* Don't wait for completion */
2726                         timeout = STp->device->request_queue->rq_timeout;
2727                 }
2728                 DEBC(printk(ST_DEB_MSG "%s: Rewinding tape.\n", name));
2729                 fileno = blkno = at_sm = 0;
2730                 break;
2731         case MTNOP:
2732                 DEBC(printk(ST_DEB_MSG "%s: No op on tape.\n", name));
2733                 return 0;       /* Should do something ? */
2734                 break;
2735         case MTRETEN:
2736                 cmd[0] = START_STOP;
2737                 if (STp->immediate) {
2738                         cmd[1] = 1;     /* Don't wait for completion */
2739                         timeout = STp->device->request_queue->rq_timeout;
2740                 }
2741                 cmd[4] = 3;
2742                 DEBC(printk(ST_DEB_MSG "%s: Retensioning tape.\n", name));
2743                 fileno = blkno = at_sm = 0;
2744                 break;
2745         case MTEOM:
2746                 if (!STp->fast_mteom) {
2747                         /* space to the end of tape */
2748                         ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
2749                         fileno = STps->drv_file;
2750                         if (STps->eof >= ST_EOD_1)
2751                                 return 0;
2752                         /* The next lines would hide the number of spaced FileMarks
2753                            That's why I inserted the previous lines. I had no luck
2754                            with detecting EOM with FSF, so we go now to EOM.
2755                            Joerg Weule */
2756                 } else
2757                         fileno = (-1);
2758                 cmd[0] = SPACE;
2759                 cmd[1] = 3;
2760                 DEBC(printk(ST_DEB_MSG "%s: Spacing to end of recorded medium.\n",
2761                             name));
2762                 blkno = -1;
2763                 at_sm = 0;
2764                 break;
2765         case MTERASE:
2766                 if (STp->write_prot)
2767                         return (-EACCES);
2768                 cmd[0] = ERASE;
2769                 cmd[1] = (arg ? 1 : 0); /* Long erase with non-zero argument */
2770                 if (STp->immediate) {
2771                         cmd[1] |= 2;    /* Don't wait for completion */
2772                         timeout = STp->device->request_queue->rq_timeout;
2773                 }
2774                 else
2775                         timeout = STp->long_timeout * 8;
2776
2777                 DEBC(printk(ST_DEB_MSG "%s: Erasing tape.\n", name));
2778                 fileno = blkno = at_sm = 0;
2779                 break;
2780         case MTSETBLK:          /* Set block length */
2781         case MTSETDENSITY:      /* Set tape density */
2782         case MTSETDRVBUFFER:    /* Set drive buffering */
2783         case SET_DENS_AND_BLK:  /* Set density and block size */
2784                 chg_eof = 0;
2785                 if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
2786                         return (-EIO);  /* Not allowed if data in buffer */
2787                 if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
2788                     (arg & MT_ST_BLKSIZE_MASK) != 0 &&
2789                     STp->max_block > 0 &&
2790                     ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
2791                      (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
2792                         printk(KERN_WARNING "%s: Illegal block size.\n", name);
2793                         return (-EINVAL);
2794                 }
2795                 cmd[0] = MODE_SELECT;
2796                 if ((STp->use_pf & USE_PF))
2797                         cmd[1] = MODE_SELECT_PAGE_FORMAT;
2798                 cmd[4] = datalen = 12;
2799                 direction = DMA_TO_DEVICE;
2800
2801                 memset((STp->buffer)->b_data, 0, 12);
2802                 if (cmd_in == MTSETDRVBUFFER)
2803                         (STp->buffer)->b_data[2] = (arg & 7) << 4;
2804                 else
2805                         (STp->buffer)->b_data[2] =
2806                             STp->drv_buffer << 4;
2807                 (STp->buffer)->b_data[3] = 8;   /* block descriptor length */
2808                 if (cmd_in == MTSETDENSITY) {
2809                         (STp->buffer)->b_data[4] = arg;
2810                         STp->density_changed = 1;       /* At least we tried ;-) */
2811                 } else if (cmd_in == SET_DENS_AND_BLK)
2812                         (STp->buffer)->b_data[4] = arg >> 24;
2813                 else
2814                         (STp->buffer)->b_data[4] = STp->density;
2815                 if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2816                         ltmp = arg & MT_ST_BLKSIZE_MASK;
2817                         if (cmd_in == MTSETBLK)
2818                                 STp->blksize_changed = 1; /* At least we tried ;-) */
2819                 } else
2820                         ltmp = STp->block_size;
2821                 (STp->buffer)->b_data[9] = (ltmp >> 16);
2822                 (STp->buffer)->b_data[10] = (ltmp >> 8);
2823                 (STp->buffer)->b_data[11] = ltmp;
2824                 timeout = STp->device->request_queue->rq_timeout;
2825                 DEBC(
2826                         if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
2827                                 printk(ST_DEB_MSG
2828                                        "%s: Setting block size to %d bytes.\n", name,
2829                                        (STp->buffer)->b_data[9] * 65536 +
2830                                        (STp->buffer)->b_data[10] * 256 +
2831                                        (STp->buffer)->b_data[11]);
2832                         if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
2833                                 printk(ST_DEB_MSG
2834                                        "%s: Setting density code to %x.\n", name,
2835                                        (STp->buffer)->b_data[4]);
2836                         if (cmd_in == MTSETDRVBUFFER)
2837                                 printk(ST_DEB_MSG
2838                                        "%s: Setting drive buffer code to %d.\n", name,
2839                                     ((STp->buffer)->b_data[2] >> 4) & 7);
2840                 )
2841                 break;
2842         default:
2843                 return (-ENOSYS);
2844         }
2845
2846         SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
2847                            timeout, MAX_RETRIES, 1);
2848         if (!SRpnt)
2849                 return (STp->buffer)->syscall_result;
2850
2851         ioctl_result = (STp->buffer)->syscall_result;
2852
2853         if (!ioctl_result) {    /* SCSI command successful */
2854                 st_release_request(SRpnt);
2855                 SRpnt = NULL;
2856                 STps->drv_block = blkno;
2857                 STps->drv_file = fileno;
2858                 STps->at_sm = at_sm;
2859
2860                 if (cmd_in == MTBSFM)
2861                         ioctl_result = st_int_ioctl(STp, MTFSF, 1);
2862                 else if (cmd_in == MTFSFM)
2863                         ioctl_result = st_int_ioctl(STp, MTBSF, 1);
2864
2865                 if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
2866                         STp->block_size = arg & MT_ST_BLKSIZE_MASK;
2867                         if (STp->block_size != 0) {
2868                                 (STp->buffer)->buffer_blocks =
2869                                     (STp->buffer)->buffer_size / STp->block_size;
2870                         }
2871                         (STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
2872                         if (cmd_in == SET_DENS_AND_BLK)
2873                                 STp->density = arg >> MT_ST_DENSITY_SHIFT;
2874                 } else if (cmd_in == MTSETDRVBUFFER)
2875                         STp->drv_buffer = (arg & 7);
2876                 else if (cmd_in == MTSETDENSITY)
2877                         STp->density = arg;
2878
2879                 if (cmd_in == MTEOM)
2880                         STps->eof = ST_EOD;
2881                 else if (cmd_in == MTFSF)
2882                         STps->eof = ST_FM;
2883                 else if (chg_eof)
2884                         STps->eof = ST_NOEOF;
2885
2886                 if (cmd_in == MTWEOF)
2887                         STps->rw = ST_IDLE;
2888         } else { /* SCSI command was not completely successful. Don't return
2889                     from this block without releasing the SCSI command block! */
2890                 struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
2891
2892                 if (cmdstatp->flags & SENSE_EOM) {
2893                         if (cmd_in != MTBSF && cmd_in != MTBSFM &&
2894                             cmd_in != MTBSR && cmd_in != MTBSS)
2895                                 STps->eof = ST_EOM_OK;
2896                         STps->drv_block = 0;
2897                 }
2898
2899                 if (cmdstatp->remainder_valid)
2900                         undone = (int)cmdstatp->uremainder64;
2901                 else
2902                         undone = 0;
2903
2904                 if (cmd_in == MTWEOF &&
2905                     cmdstatp->have_sense &&
2906                     (cmdstatp->flags & SENSE_EOM)) {
2907                         if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
2908                             cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
2909                                 ioctl_result = 0;       /* EOF(s) written successfully at EOM */
2910                                 STps->eof = ST_NOEOF;
2911                         } else {  /* Writing EOF(s) failed */
2912                                 if (fileno >= 0)
2913                                         fileno -= undone;
2914                                 if (undone < arg)
2915                                         STps->eof = ST_NOEOF;
2916                         }
2917                         STps->drv_file = fileno;
2918                 } else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
2919                         if (fileno >= 0)
2920                                 STps->drv_file = fileno - undone;
2921                         else
2922                                 STps->drv_file = fileno;
2923                         STps->drv_block = -1;
2924                         STps->eof = ST_NOEOF;
2925                 } else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
2926                         if (arg > 0 && undone < 0)  /* Some drives get this wrong */
2927                                 undone = (-undone);
2928                         if (STps->drv_file >= 0)
2929                                 STps->drv_file = fileno + undone;
2930                         STps->drv_block = 0;
2931                         STps->eof = ST_NOEOF;
2932                 } else if (cmd_in == MTFSR) {
2933                         if (cmdstatp->flags & SENSE_FMK) {      /* Hit filemark */
2934                                 if (STps->drv_file >= 0)
2935                                         STps->drv_file++;
2936                                 STps->drv_block = 0;
2937                                 STps->eof = ST_FM;
2938                         } else {
2939                                 if (blkno >= undone)
2940                                         STps->drv_block = blkno - undone;
2941                                 else
2942                                         STps->drv_block = (-1);
2943                                 STps->eof = ST_NOEOF;
2944                         }
2945                 } else if (cmd_in == MTBSR) {
2946                         if (cmdstatp->flags & SENSE_FMK) {      /* Hit filemark */
2947                                 STps->drv_file--;
2948                                 STps->drv_block = (-1);
2949                         } else {
2950                                 if (arg > 0 && undone < 0)  /* Some drives get this wrong */
2951                                         undone = (-undone);
2952                                 if (STps->drv_block >= 0)
2953                                         STps->drv_block = blkno + undone;
2954                         }
2955                         STps->eof = ST_NOEOF;
2956                 } else if (cmd_in == MTEOM) {
2957                         STps->drv_file = (-1);
2958                         STps->drv_block = (-1);
2959                         STps->eof = ST_EOD;
2960                 } else if (cmd_in == MTSETBLK ||
2961                            cmd_in == MTSETDENSITY ||
2962                            cmd_in == MTSETDRVBUFFER ||
2963                            cmd_in == SET_DENS_AND_BLK) {
2964                         if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
2965                             !(STp->use_pf & PF_TESTED)) {
2966                                 /* Try the other possible state of Page Format if not
2967                                    already tried */
2968                                 STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
2969                                 st_release_request(SRpnt);
2970                                 SRpnt = NULL;
2971                                 return st_int_ioctl(STp, cmd_in, arg);
2972                         }
2973                 } else if (chg_eof)
2974                         STps->eof = ST_NOEOF;
2975
2976                 if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
2977                         STps->eof = ST_EOD;
2978
2979                 st_release_request(SRpnt);
2980                 SRpnt = NULL;
2981         }
2982
2983         return ioctl_result;
2984 }
2985 \f
2986
2987 /* Get the tape position. If bt == 2, arg points into a kernel space mt_loc
2988    structure. */
2989
2990 static int get_location(struct scsi_tape *STp, unsigned int *block, int *partition,
2991                         int logical)
2992 {
2993         int result;
2994         unsigned char scmd[MAX_COMMAND_SIZE];
2995         struct st_request *SRpnt;
2996         DEB( char *name = tape_name(STp); )
2997
2998         if (STp->ready != ST_READY)
2999                 return (-EIO);
3000
3001         memset(scmd, 0, MAX_COMMAND_SIZE);
3002         if ((STp->device)->scsi_level < SCSI_2) {
3003                 scmd[0] = QFA_REQUEST_BLOCK;
3004                 scmd[4] = 3;
3005         } else {
3006                 scmd[0] = READ_POSITION;
3007                 if (!logical && !STp->scsi2_logical)
3008                         scmd[1] = 1;
3009         }
3010         SRpnt = st_do_scsi(NULL, STp, scmd, 20, DMA_FROM_DEVICE,
3011                            STp->device->request_queue->rq_timeout,
3012                            MAX_READY_RETRIES, 1);
3013         if (!SRpnt)
3014                 return (STp->buffer)->syscall_result;
3015
3016         if ((STp->buffer)->syscall_result != 0 ||
3017             (STp->device->scsi_level >= SCSI_2 &&
3018              ((STp->buffer)->b_data[0] & 4) != 0)) {
3019                 *block = *partition = 0;
3020                 DEBC(printk(ST_DEB_MSG "%s: Can't read tape position.\n", name));
3021                 result = (-EIO);
3022         } else {
3023                 result = 0;
3024                 if ((STp->device)->scsi_level < SCSI_2) {
3025                         *block = ((STp->buffer)->b_data[0] << 16)
3026                             + ((STp->buffer)->b_data[1] << 8)
3027                             + (STp->buffer)->b_data[2];
3028                         *partition = 0;
3029                 } else {
3030                         *block = ((STp->buffer)->b_data[4] << 24)
3031                             + ((STp->buffer)->b_data[5] << 16)
3032                             + ((STp->buffer)->b_data[6] << 8)
3033                             + (STp->buffer)->b_data[7];
3034                         *partition = (STp->buffer)->b_data[1];
3035                         if (((STp->buffer)->b_data[0] & 0x80) &&
3036                             (STp->buffer)->b_data[1] == 0)      /* BOP of partition 0 */
3037                                 STp->ps[0].drv_block = STp->ps[0].drv_file = 0;
3038                 }
3039                 DEBC(printk(ST_DEB_MSG "%s: Got tape pos. blk %d part %d.\n", name,
3040                             *block, *partition));
3041         }
3042         st_release_request(SRpnt);
3043         SRpnt = NULL;
3044
3045         return result;
3046 }
3047
3048
3049 /* Set the tape block and partition. Negative partition means that only the
3050    block should be set in vendor specific way. */
3051 static int set_location(struct scsi_tape *STp, unsigned int block, int partition,
3052                         int logical)
3053 {
3054         struct st_partstat *STps;
3055         int result, p;
3056         unsigned int blk;
3057         int timeout;
3058         unsigned char scmd[MAX_COMMAND_SIZE];
3059         struct st_request *SRpnt;
3060         DEB( char *name = tape_name(STp); )
3061
3062         if (STp->ready != ST_READY)
3063                 return (-EIO);
3064         timeout = STp->long_timeout;
3065         STps = &(STp->ps[STp->partition]);
3066
3067         DEBC(printk(ST_DEB_MSG "%s: Setting block to %d and partition to %d.\n",
3068                     name, block, partition));
3069         DEB(if (partition < 0)
3070                 return (-EIO); )
3071
3072         /* Update the location at the partition we are leaving */
3073         if ((!STp->can_partitions && partition != 0) ||
3074             partition >= ST_NBR_PARTITIONS)
3075                 return (-EINVAL);
3076         if (partition != STp->partition) {
3077                 if (get_location(STp, &blk, &p, 1))
3078                         STps->last_block_valid = 0;
3079                 else {
3080                         STps->last_block_valid = 1;
3081                         STps->last_block_visited = blk;
3082                         DEBC(printk(ST_DEB_MSG
3083                                     "%s: Visited block %d for partition %d saved.\n",
3084                                     name, blk, STp->partition));
3085                 }
3086         }
3087
3088         memset(scmd, 0, MAX_COMMAND_SIZE);
3089         if ((STp->device)->scsi_level < SCSI_2) {
3090                 scmd[0] = QFA_SEEK_BLOCK;
3091                 scmd[2] = (block >> 16);
3092                 scmd[3] = (block >> 8);
3093                 scmd[4] = block;
3094                 scmd[5] = 0;
3095         } else {
3096                 scmd[0] = SEEK_10;
3097                 scmd[3] = (block >> 24);
3098                 scmd[4] = (block >> 16);
3099                 scmd[5] = (block >> 8);
3100                 scmd[6] = block;
3101                 if (!logical && !STp->scsi2_logical)
3102                         scmd[1] = 4;
3103                 if (STp->partition != partition) {
3104                         scmd[1] |= 2;
3105                         scmd[8] = partition;
3106                         DEBC(printk(ST_DEB_MSG
3107                                     "%s: Trying to change partition from %d to %d\n",
3108                                     name, STp->partition, partition));
3109                 }
3110         }
3111         if (STp->immediate) {
3112                 scmd[1] |= 1;           /* Don't wait for completion */
3113                 timeout = STp->device->request_queue->rq_timeout;
3114         }
3115
3116         SRpnt = st_do_scsi(NULL, STp, scmd, 0, DMA_NONE,
3117                            timeout, MAX_READY_RETRIES, 1);
3118         if (!SRpnt)
3119                 return (STp->buffer)->syscall_result;
3120
3121         STps->drv_block = STps->drv_file = (-1);
3122         STps->eof = ST_NOEOF;
3123         if ((STp->buffer)->syscall_result != 0) {
3124                 result = (-EIO);
3125                 if (STp->can_partitions &&
3126                     (STp->device)->scsi_level >= SCSI_2 &&
3127                     (p = find_partition(STp)) >= 0)
3128                         STp->partition = p;
3129         } else {
3130                 if (STp->can_partitions) {
3131                         STp->partition = partition;
3132                         STps = &(STp->ps[partition]);
3133                         if (!STps->last_block_valid ||
3134                             STps->last_block_visited != block) {
3135                                 STps->at_sm = 0;
3136                                 STps->rw = ST_IDLE;
3137                         }
3138                 } else
3139                         STps->at_sm = 0;
3140                 if (block == 0)
3141                         STps->drv_block = STps->drv_file = 0;
3142                 result = 0;
3143         }
3144
3145         st_release_request(SRpnt);
3146         SRpnt = NULL;
3147
3148         return result;
3149 }
3150
3151
3152 /* Find the current partition number for the drive status. Called from open and
3153    returns either partition number of negative error code. */
3154 static int find_partition(struct scsi_tape *STp)
3155 {
3156         int i, partition;
3157         unsigned int block;
3158
3159         if ((i = get_location(STp, &block, &partition, 1)) < 0)
3160                 return i;
3161         if (partition >= ST_NBR_PARTITIONS)
3162                 return (-EIO);
3163         return partition;
3164 }
3165
3166
3167 /* Change the partition if necessary */
3168 static int switch_partition(struct scsi_tape *STp)
3169 {
3170         struct st_partstat *STps;
3171
3172         if (STp->partition == STp->new_partition)
3173                 return 0;
3174         STps = &(STp->ps[STp->new_partition]);
3175         if (!STps->last_block_valid)
3176                 STps->last_block_visited = 0;
3177         return set_location(STp, STps->last_block_visited, STp->new_partition, 1);
3178 }
3179 \f
3180 /* Functions for reading and writing the medium partition mode page. */
3181
3182 #define PART_PAGE   0x11
3183 #define PART_PAGE_FIXED_LENGTH 8
3184
3185 #define PP_OFF_MAX_ADD_PARTS   2
3186 #define PP_OFF_NBR_ADD_PARTS   3
3187 #define PP_OFF_FLAGS           4
3188 #define PP_OFF_PART_UNITS      6
3189 #define PP_OFF_RESERVED        7
3190
3191 #define PP_BIT_IDP             0x20
3192 #define PP_MSK_PSUM_MB         0x10
3193
3194 /* Get the number of partitions on the tape. As a side effect reads the
3195    mode page into the tape buffer. */
3196 static int nbr_partitions(struct scsi_tape *STp)
3197 {
3198         int result;
3199         DEB( char *name = tape_name(STp); )
3200
3201         if (STp->ready != ST_READY)
3202                 return (-EIO);
3203
3204         result = read_mode_page(STp, PART_PAGE, 1);
3205
3206         if (result) {
3207                 DEBC(printk(ST_DEB_MSG "%s: Can't read medium partition page.\n",
3208                             name));
3209                 result = (-EIO);
3210         } else {
3211                 result = (STp->buffer)->b_data[MODE_HEADER_LENGTH +
3212                                               PP_OFF_NBR_ADD_PARTS] + 1;
3213                 DEBC(printk(ST_DEB_MSG "%s: Number of partitions %d.\n", name, result));
3214         }
3215
3216         return result;
3217 }
3218
3219
3220 /* Partition the tape into two partitions if size > 0 or one partition if
3221    size == 0.
3222
3223    The block descriptors are read and written because Sony SDT-7000 does not
3224    work without this (suggestion from Michael Schaefer <Michael.Schaefer@dlr.de>).
3225
3226    My HP C1533A drive returns only one partition size field. This is used to
3227    set the size of partition 1. There is no size field for the default partition.
3228    Michael Schaefer's Sony SDT-7000 returns two descriptors and the second is
3229    used to set the size of partition 1 (this is what the SCSI-3 standard specifies).
3230    The following algorithm is used to accommodate both drives: if the number of
3231    partition size fields is greater than the maximum number of additional partitions
3232    in the mode page, the second field is used. Otherwise the first field is used.
3233
3234    For Seagate DDS drives the page length must be 8 when no partitions is defined
3235    and 10 when 1 partition is defined (information from Eric Lee Green). This is
3236    is acceptable also to some other old drives and enforced if the first partition
3237    size field is used for the first additional partition size.
3238  */
3239 static int partition_tape(struct scsi_tape *STp, int size)
3240 {
3241         char *name = tape_name(STp);
3242         int result;
3243         int pgo, psd_cnt, psdo;
3244         unsigned char *bp;
3245
3246         result = read_mode_page(STp, PART_PAGE, 0);
3247         if (result) {
3248                 DEBC(printk(ST_DEB_MSG "%s: Can't read partition mode page.\n", name));
3249                 return result;
3250         }
3251         /* The mode page is in the buffer. Let's modify it and write it. */
3252         bp = (STp->buffer)->b_data;
3253         pgo = MODE_HEADER_LENGTH + bp[MH_OFF_BDESCS_LENGTH];
3254         DEBC(printk(ST_DEB_MSG "%s: Partition page length is %d bytes.\n",
3255                     name, bp[pgo + MP_OFF_PAGE_LENGTH] + 2));
3256
3257         psd_cnt = (bp[pgo + MP_OFF_PAGE_LENGTH] + 2 - PART_PAGE_FIXED_LENGTH) / 2;
3258         psdo = pgo + PART_PAGE_FIXED_LENGTH;
3259         if (psd_cnt > bp[pgo + PP_OFF_MAX_ADD_PARTS]) {
3260                 bp[psdo] = bp[psdo + 1] = 0xff;  /* Rest of the tape */
3261                 psdo += 2;
3262         }
3263         memset(bp + psdo, 0, bp[pgo + PP_OFF_NBR_ADD_PARTS] * 2);
3264
3265         DEBC(printk("%s: psd_cnt %d, max.parts %d, nbr_parts %d\n", name,
3266                     psd_cnt, bp[pgo + PP_OFF_MAX_ADD_PARTS],
3267                     bp[pgo + PP_OFF_NBR_ADD_PARTS]));
3268
3269         if (size <= 0) {
3270                 bp[pgo + PP_OFF_NBR_ADD_PARTS] = 0;
3271                 if (psd_cnt <= bp[pgo + PP_OFF_MAX_ADD_PARTS])
3272                     bp[pgo + MP_OFF_PAGE_LENGTH] = 6;
3273                 DEBC(printk(ST_DEB_MSG "%s: Formatting tape with one partition.\n",
3274                             name));
3275         } else {
3276                 bp[psdo] = (size >> 8) & 0xff;
3277                 bp[psdo + 1] = size & 0xff;
3278                 bp[pgo + 3] = 1;
3279                 if (bp[pgo + MP_OFF_PAGE_LENGTH] < 8)
3280                     bp[pgo + MP_OFF_PAGE_LENGTH] = 8;
3281                 DEBC(printk(ST_DEB_MSG
3282                             "%s: Formatting tape with two partitions (1 = %d MB).\n",
3283                             name, size));
3284         }
3285         bp[pgo + PP_OFF_PART_UNITS] = 0;
3286         bp[pgo + PP_OFF_RESERVED] = 0;
3287         bp[pgo + PP_OFF_FLAGS] = PP_BIT_IDP | PP_MSK_PSUM_MB;
3288
3289         result = write_mode_page(STp, PART_PAGE, 1);
3290         if (result) {
3291                 printk(KERN_INFO "%s: Partitioning of tape failed.\n", name);
3292                 result = (-EIO);
3293         }
3294
3295         return result;
3296 }
3297 \f
3298
3299
3300 /* The ioctl command */
3301 static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
3302 {
3303         int i, cmd_nr, cmd_type, bt;
3304         int retval = 0;
3305         unsigned int blk;
3306         struct scsi_tape *STp = file->private_data;
3307         struct st_modedef *STm;
3308         struct st_partstat *STps;
3309         char *name = tape_name(STp);
3310         void __user *p = (void __user *)arg;
3311
3312         if (mutex_lock_interruptible(&STp->lock))
3313                 return -ERESTARTSYS;
3314
3315         DEB(
3316         if (debugging && !STp->in_use) {
3317                 printk(ST_DEB_MSG "%s: Incorrect device.\n", name);
3318                 retval = (-EIO);
3319                 goto out;
3320         } ) /* end DEB */
3321
3322         STm = &(STp->modes[STp->current_mode]);
3323         STps = &(STp->ps[STp->partition]);
3324
3325         /*
3326          * If we are in the middle of error recovery, don't let anyone
3327          * else try and use this device.  Also, if error recovery fails, it
3328          * may try and take the device offline, in which case all further
3329          * access to the device is prohibited.
3330          */
3331         retval = scsi_nonblockable_ioctl(STp->device, cmd_in, p,
3332                                         file->f_flags & O_NDELAY);
3333         if (!scsi_block_when_processing_errors(STp->device) || retval != -ENODEV)
3334                 goto out;
3335         retval = 0;
3336
3337         cmd_type = _IOC_TYPE(cmd_in);
3338         cmd_nr = _IOC_NR(cmd_in);
3339
3340         if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
3341                 struct mtop mtc;
3342
3343                 if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
3344                         retval = (-EINVAL);
3345                         goto out;
3346                 }
3347
3348                 i = copy_from_user(&mtc, p, sizeof(struct mtop));
3349                 if (i) {
3350                         retval = (-EFAULT);
3351                         goto out;
3352                 }
3353
3354                 if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
3355                         printk(KERN_WARNING
3356                                "%s: MTSETDRVBUFFER only allowed for root.\n", name);
3357                         retval = (-EPERM);
3358                         goto out;
3359                 }
3360                 if (!STm->defined &&
3361                     (mtc.mt_op != MTSETDRVBUFFER &&
3362                      (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
3363                         retval = (-ENXIO);
3364                         goto out;
3365                 }
3366
3367                 if (!STp->pos_unknown) {
3368
3369                         if (STps->eof == ST_FM_HIT) {
3370                                 if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3371                                     mtc.mt_op == MTEOM) {
3372                                         mtc.mt_count -= 1;
3373                                         if (STps->drv_file >= 0)
3374                                                 STps->drv_file += 1;
3375                                 } else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
3376                                         mtc.mt_count += 1;
3377                                         if (STps->drv_file >= 0)
3378                                                 STps->drv_file += 1;
3379                                 }
3380                         }
3381
3382                         if (mtc.mt_op == MTSEEK) {
3383                                 /* Old position must be restored if partition will be
3384                                    changed */
3385                                 i = !STp->can_partitions ||
3386                                     (STp->new_partition != STp->partition);
3387                         } else {
3388                                 i = mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3389                                     mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM ||
3390                                     mtc.mt_op == MTLOCK || mtc.mt_op == MTLOAD ||
3391                                     mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM ||
3392                                     mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM ||
3393                                     mtc.mt_op == MTCOMPRESSION;
3394                         }
3395                         i = flush_buffer(STp, i);
3396                         if (i < 0) {
3397                                 retval = i;
3398                                 goto out;
3399                         }
3400                         if (STps->rw == ST_WRITING &&
3401                             (mtc.mt_op == MTREW || mtc.mt_op == MTOFFL ||
3402                              mtc.mt_op == MTSEEK ||
3403                              mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)) {
3404                                 i = st_int_ioctl(STp, MTWEOF, 1);
3405                                 if (i < 0) {
3406                                         retval = i;
3407                                         goto out;
3408                                 }
3409                                 if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM)
3410                                         mtc.mt_count++;
3411                                 STps->rw = ST_IDLE;
3412                              }
3413
3414                 } else {
3415                         /*
3416                          * If there was a bus reset, block further access
3417                          * to this device.  If the user wants to rewind the tape,
3418                          * then reset the flag and allow access again.
3419                          */
3420                         if (mtc.mt_op != MTREW &&
3421                             mtc.mt_op != MTOFFL &&
3422                             mtc.mt_op != MTRETEN &&
3423                             mtc.mt_op != MTERASE &&
3424                             mtc.mt_op != MTSEEK &&
3425                             mtc.mt_op != MTEOM) {
3426                                 retval = (-EIO);
3427                                 goto out;
3428                         }
3429                         reset_state(STp);
3430                         /* remove this when the midlevel properly clears was_reset */
3431                         STp->device->was_reset = 0;
3432                 }
3433
3434                 if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK &&
3435                     mtc.mt_op != MTSETDENSITY && mtc.mt_op != MTWSM &&
3436                     mtc.mt_op != MTSETDRVBUFFER && mtc.mt_op != MTSETPART)
3437                         STps->rw = ST_IDLE;     /* Prevent automatic WEOF and fsf */
3438
3439                 if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
3440                         do_door_lock(STp, 0);   /* Ignore result! */
3441
3442                 if (mtc.mt_op == MTSETDRVBUFFER &&
3443                     (mtc.mt_count & MT_ST_OPTIONS) != 0) {
3444                         retval = st_set_options(STp, mtc.mt_count);
3445                         goto out;
3446                 }
3447
3448                 if (mtc.mt_op == MTSETPART) {
3449                         if (!STp->can_partitions ||
3450                             mtc.mt_count < 0 || mtc.mt_count >= ST_NBR_PARTITIONS) {
3451                                 retval = (-EINVAL);
3452                                 goto out;
3453                         }
3454                         if (mtc.mt_count >= STp->nbr_partitions &&
3455                             (STp->nbr_partitions = nbr_partitions(STp)) < 0) {
3456                                 retval = (-EIO);
3457                                 goto out;
3458                         }
3459                         if (mtc.mt_count >= STp->nbr_partitions) {
3460                                 retval = (-EINVAL);
3461                                 goto out;
3462                         }
3463                         STp->new_partition = mtc.mt_count;
3464                         retval = 0;
3465                         goto out;
3466                 }
3467
3468                 if (mtc.mt_op == MTMKPART) {
3469                         if (!STp->can_partitions) {
3470                                 retval = (-EINVAL);
3471                                 goto out;
3472                         }
3473                         if ((i = st_int_ioctl(STp, MTREW, 0)) < 0 ||
3474                             (i = partition_tape(STp, mtc.mt_count)) < 0) {
3475                                 retval = i;
3476                                 goto out;
3477                         }
3478                         for (i = 0; i < ST_NBR_PARTITIONS; i++) {
3479                                 STp->ps[i].rw = ST_IDLE;
3480                                 STp->ps[i].at_sm = 0;
3481                                 STp->ps[i].last_block_valid = 0;
3482                         }
3483                         STp->partition = STp->new_partition = 0;
3484                         STp->nbr_partitions = 1;        /* Bad guess ?-) */
3485                         STps->drv_block = STps->drv_file = 0;
3486                         retval = 0;
3487                         goto out;
3488                 }
3489
3490                 if (mtc.mt_op == MTSEEK) {
3491                         i = set_location(STp, mtc.mt_count, STp->new_partition, 0);
3492                         if (!STp->can_partitions)
3493                                 STp->ps[0].rw = ST_IDLE;
3494                         retval = i;
3495                         goto out;
3496                 }
3497
3498                 if (mtc.mt_op == MTUNLOAD || mtc.mt_op == MTOFFL) {
3499                         retval = do_load_unload(STp, file, 0);
3500                         goto out;
3501                 }
3502
3503                 if (mtc.mt_op == MTLOAD) {
3504                         retval = do_load_unload(STp, file, max(1, mtc.mt_count));
3505                         goto out;
3506                 }
3507
3508                 if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
3509                         retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
3510                         goto out;
3511                 }
3512
3513                 if (STp->can_partitions && STp->ready == ST_READY &&
3514                     (i = switch_partition(STp)) < 0) {
3515                         retval = i;
3516                         goto out;
3517                 }
3518
3519                 if (mtc.mt_op == MTCOMPRESSION)
3520                         retval = st_compression(STp, (mtc.mt_count & 1));
3521                 else
3522                         retval = st_int_ioctl(STp, mtc.mt_op, mtc.mt_count);
3523                 goto out;
3524         }
3525         if (!STm->defined) {
3526                 retval = (-ENXIO);
3527                 goto out;
3528         }
3529
3530         if ((i = flush_buffer(STp, 0)) < 0) {
3531                 retval = i;
3532                 goto out;
3533         }
3534         if (STp->can_partitions &&
3535             (i = switch_partition(STp)) < 0) {
3536                 retval = i;
3537                 goto out;
3538         }
3539
3540         if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
3541                 struct mtget mt_status;
3542
3543                 if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
3544                          retval = (-EINVAL);
3545                          goto out;
3546                 }
3547
3548                 mt_status.mt_type = STp->tape_type;
3549                 mt_status.mt_dsreg =
3550                     ((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
3551                     ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
3552                 mt_status.mt_blkno = STps->drv_block;
3553                 mt_status.mt_fileno = STps->drv_file;
3554                 if (STp->block_size != 0) {
3555                         if (STps->rw == ST_WRITING)
3556                                 mt_status.mt_blkno +=
3557                                     (STp->buffer)->buffer_bytes / STp->block_size;
3558                         else if (STps->rw == ST_READING)
3559                                 mt_status.mt_blkno -=
3560                                         ((STp->buffer)->buffer_bytes +
3561                                          STp->block_size - 1) / STp->block_size;
3562                 }
3563
3564                 mt_status.mt_gstat = 0;
3565                 if (STp->drv_write_prot)
3566                         mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
3567                 if (mt_status.mt_blkno == 0) {
3568                         if (mt_status.mt_fileno == 0)
3569                                 mt_status.mt_gstat |= GMT_BOT(0xffffffff);
3570                         else
3571                                 mt_status.mt_gstat |= GMT_EOF(0xffffffff);
3572                 }
3573                 mt_status.mt_erreg = (STp->recover_reg << MT_ST_SOFTERR_SHIFT);
3574                 mt_status.mt_resid = STp->partition;
3575                 if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
3576                         mt_status.mt_gstat |= GMT_EOT(0xffffffff);
3577                 else if (STps->eof >= ST_EOM_OK)
3578                         mt_status.mt_gstat |= GMT_EOD(0xffffffff);
3579                 if (STp->density == 1)
3580                         mt_status.mt_gstat |= GMT_D_800(0xffffffff);
3581                 else if (STp->density == 2)
3582                         mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
3583                 else if (STp->density == 3)
3584                         mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
3585                 if (STp->ready == ST_READY)
3586                         mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
3587                 if (STp->ready == ST_NO_TAPE)
3588                         mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
3589                 if (STps->at_sm)
3590                         mt_status.mt_gstat |= GMT_SM(0xffffffff);
3591                 if (STm->do_async_writes ||
3592                     (STm->do_buffer_writes && STp->block_size != 0) ||
3593                     STp->drv_buffer != 0)
3594                         mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
3595                 if (STp->cleaning_req)
3596                         mt_status.mt_gstat |= GMT_CLN(0xffffffff);
3597
3598                 i = copy_to_user(p, &mt_status, sizeof(struct mtget));
3599                 if (i) {
3600                         retval = (-EFAULT);
3601                         goto out;
3602                 }
3603
3604                 STp->recover_reg = 0;           /* Clear after read */
3605                 retval = 0;
3606                 goto out;
3607         }                       /* End of MTIOCGET */
3608         if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
3609                 struct mtpos mt_pos;
3610                 if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
3611                          retval = (-EINVAL);
3612                          goto out;
3613                 }
3614                 if ((i = get_location(STp, &blk, &bt, 0)) < 0) {
3615                         retval = i;
3616                         goto out;
3617                 }
3618                 mt_pos.mt_blkno = blk;
3619                 i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
3620                 if (i)
3621                         retval = (-EFAULT);
3622                 goto out;
3623         }
3624         mutex_unlock(&STp->lock);
3625         switch (cmd_in) {
3626                 case SCSI_IOCTL_GET_IDLUN:
3627                 case SCSI_IOCTL_GET_BUS_NUMBER:
3628                         break;
3629                 default:
3630                         if ((cmd_in == SG_IO ||
3631                              cmd_in == SCSI_IOCTL_SEND_COMMAND ||
3632                              cmd_in == CDROM_SEND_PACKET) &&
3633                             !capable(CAP_SYS_RAWIO))
3634                                 i = -EPERM;
3635                         else
3636                                 i = scsi_cmd_ioctl(STp->disk->queue, STp->disk,
3637                                                    file->f_mode, cmd_in, p);
3638                         if (i != -ENOTTY)
3639                                 return i;
3640                         break;
3641         }
3642         retval = scsi_ioctl(STp->device, cmd_in, p);
3643         if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
3644                 STp->rew_at_close = 0;
3645                 STp->ready = ST_NO_TAPE;
3646         }
3647         return retval;
3648
3649  out:
3650         mutex_unlock(&STp->lock);
3651         return retval;
3652 }
3653
3654 #ifdef CONFIG_COMPAT
3655 static long st_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
3656 {
3657         struct scsi_tape *STp = file->private_data;
3658         struct scsi_device *sdev = STp->device;
3659         int ret = -ENOIOCTLCMD;
3660         if (sdev->host->hostt->compat_ioctl) {
3661
3662                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
3663
3664         }
3665         return ret;
3666 }
3667 #endif
3668
3669 \f
3670
3671 /* Try to allocate a new tape buffer. Calling function must not hold
3672    dev_arr_lock. */
3673 static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
3674 {
3675         struct st_buffer *tb;
3676
3677         tb = kzalloc(sizeof(struct st_buffer), GFP_ATOMIC);
3678         if (!tb) {
3679                 printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
3680                 return NULL;
3681         }
3682         tb->frp_segs = 0;
3683         tb->use_sg = max_sg;
3684         tb->dma = need_dma;
3685         tb->buffer_size = 0;
3686
3687         tb->reserved_pages = kzalloc(max_sg * sizeof(struct page *),
3688                                      GFP_ATOMIC);
3689         if (!tb->reserved_pages) {
3690                 kfree(tb);
3691                 return NULL;
3692         }
3693
3694         return tb;
3695 }
3696
3697
3698 /* Try to allocate enough space in the tape buffer */
3699 #define ST_MAX_ORDER 6
3700
3701 static int enlarge_buffer(struct st_buffer * STbuffer, int new_size, int need_dma)
3702 {
3703         int segs, nbr, max_segs, b_size, order, got;
3704         gfp_t priority;
3705
3706         if (new_size <= STbuffer->buffer_size)
3707                 return 1;
3708
3709         if (STbuffer->buffer_size <= PAGE_SIZE)
3710                 normalize_buffer(STbuffer);  /* Avoid extra segment */
3711
3712         max_segs = STbuffer->use_sg;
3713         nbr = max_segs - STbuffer->frp_segs;
3714         if (nbr <= 0)
3715                 return 0;
3716
3717         priority = GFP_KERNEL | __GFP_NOWARN;
3718         if (need_dma)
3719                 priority |= GFP_DMA;
3720
3721         if (STbuffer->cleared)
3722                 priority |= __GFP_ZERO;
3723
3724         if (STbuffer->frp_segs) {
3725                 order = STbuffer->reserved_page_order;
3726                 b_size = PAGE_SIZE << order;
3727         } else {
3728                 for (b_size = PAGE_SIZE, order = 0;
3729                      order < ST_MAX_ORDER && b_size < new_size;
3730                      order++, b_size *= 2)
3731                         ;  /* empty */
3732         }
3733         if (max_segs * (PAGE_SIZE << order) < new_size) {
3734                 if (order == ST_MAX_ORDER)
3735                         return 0;
3736                 normalize_buffer(STbuffer);
3737                 return enlarge_buffer(STbuffer, new_size, need_dma);
3738         }
3739
3740         for (segs = STbuffer->frp_segs, got = STbuffer->buffer_size;
3741              segs < max_segs && got < new_size;) {
3742                 struct page *page;
3743
3744                 page = alloc_pages(priority, order);
3745                 if (!page) {
3746                         DEB(STbuffer->buffer_size = got);
3747                         normalize_buffer(STbuffer);
3748                         return 0;
3749                 }
3750
3751                 STbuffer->frp_segs += 1;
3752                 got += b_size;
3753                 STbuffer->buffer_size = got;
3754                 STbuffer->reserved_pages[segs] = page;
3755                 segs++;
3756         }
3757         STbuffer->b_data = page_address(STbuffer->reserved_pages[0]);
3758         STbuffer->reserved_page_order = order;
3759
3760         return 1;
3761 }
3762
3763
3764 /* Make sure that no data from previous user is in the internal buffer */
3765 static void clear_buffer(struct st_buffer * st_bp)
3766 {
3767         int i;
3768
3769         for (i=0; i < st_bp->frp_segs; i++)
3770                 memset(page_address(st_bp->reserved_pages[i]), 0,
3771                        PAGE_SIZE << st_bp->reserved_page_order);
3772         st_bp->cleared = 1;
3773 }
3774
3775
3776 /* Release the extra buffer */
3777 static void normalize_buffer(struct st_buffer * STbuffer)
3778 {
3779         int i, order = STbuffer->reserved_page_order;
3780
3781         for (i = 0; i < STbuffer->frp_segs; i++) {
3782                 __free_pages(STbuffer->reserved_pages[i], order);
3783                 STbuffer->buffer_size -= (PAGE_SIZE << order);
3784         }
3785         STbuffer->frp_segs = 0;
3786         STbuffer->sg_segs = 0;
3787         STbuffer->reserved_page_order = 0;
3788         STbuffer->map_data.offset = 0;
3789 }
3790
3791
3792 /* Move data from the user buffer to the tape buffer. Returns zero (success) or
3793    negative error code. */
3794 static int append_to_buffer(const char __user *ubp, struct st_buffer * st_bp, int do_count)
3795 {
3796         int i, cnt, res, offset;
3797         int length = PAGE_SIZE << st_bp->reserved_page_order;
3798
3799         for (i = 0, offset = st_bp->buffer_bytes;
3800              i < st_bp->frp_segs && offset >= length; i++)
3801                 offset -= length;
3802         if (i == st_bp->frp_segs) {     /* Should never happen */
3803                 printk(KERN_WARNING "st: append_to_buffer offset overflow.\n");
3804                 return (-EIO);
3805         }
3806         for (; i < st_bp->frp_segs && do_count > 0; i++) {
3807                 struct page *page = st_bp->reserved_pages[i];
3808                 cnt = length - offset < do_count ? length - offset : do_count;
3809                 res = copy_from_user(page_address(page) + offset, ubp, cnt);
3810                 if (res)
3811                         return (-EFAULT);
3812                 do_count -= cnt;
3813                 st_bp->buffer_bytes += cnt;
3814                 ubp += cnt;
3815                 offset = 0;
3816         }
3817         if (do_count) /* Should never happen */
3818                 return (-EIO);
3819
3820         return 0;
3821 }
3822
3823
3824 /* Move data from the tape buffer to the user buffer. Returns zero (success) or
3825    negative error code. */
3826 static int from_buffer(struct st_buffer * st_bp, char __user *ubp, int do_count)
3827 {
3828         int i, cnt, res, offset;
3829         int length = PAGE_SIZE << st_bp->reserved_page_order;
3830
3831         for (i = 0, offset = st_bp->read_pointer;
3832              i < st_bp->frp_segs && offset >= length; i++)
3833                 offset -= length;
3834         if (i == st_bp->frp_segs) {     /* Should never happen */
3835                 printk(KERN_WARNING "st: from_buffer offset overflow.\n");
3836                 return (-EIO);
3837         }
3838         for (; i < st_bp->frp_segs && do_count > 0; i++) {
3839                 struct page *page = st_bp->reserved_pages[i];
3840                 cnt = length - offset < do_count ? length - offset : do_count;
3841                 res = copy_to_user(ubp, page_address(page) + offset, cnt);
3842                 if (res)
3843                         return (-EFAULT);
3844                 do_count -= cnt;
3845                 st_bp->buffer_bytes -= cnt;
3846                 st_bp->read_pointer += cnt;
3847                 ubp += cnt;
3848                 offset = 0;
3849         }
3850         if (do_count) /* Should never happen */
3851                 return (-EIO);
3852
3853         return 0;
3854 }
3855
3856
3857 /* Move data towards start of buffer */
3858 static void move_buffer_data(struct st_buffer * st_bp, int offset)
3859 {
3860         int src_seg, dst_seg, src_offset = 0, dst_offset;
3861         int count, total;
3862         int length = PAGE_SIZE << st_bp->reserved_page_order;
3863
3864         if (offset == 0)
3865                 return;
3866
3867         total=st_bp->buffer_bytes - offset;
3868         for (src_seg=0; src_seg < st_bp->frp_segs; src_seg++) {
3869                 src_offset = offset;
3870                 if (src_offset < length)
3871                         break;
3872                 offset -= length;
3873         }
3874
3875         st_bp->buffer_bytes = st_bp->read_pointer = total;
3876         for (dst_seg=dst_offset=0; total > 0; ) {
3877                 struct page *dpage = st_bp->reserved_pages[dst_seg];
3878                 struct page *spage = st_bp->reserved_pages[src_seg];
3879
3880                 count = min(length - dst_offset, length - src_offset);
3881                 memmove(page_address(dpage) + dst_offset,
3882                         page_address(spage) + src_offset, count);
3883                 src_offset += count;
3884                 if (src_offset >= length) {
3885                         src_seg++;
3886                         src_offset = 0;
3887                 }
3888                 dst_offset += count;
3889                 if (dst_offset >= length) {
3890                         dst_seg++;
3891                         dst_offset = 0;
3892                 }
3893                 total -= count;
3894         }
3895 }
3896
3897 /* Validate the options from command line or module parameters */
3898 static void validate_options(void)
3899 {
3900         if (buffer_kbs > 0)
3901                 st_fixed_buffer_size = buffer_kbs * ST_KILOBYTE;
3902         if (max_sg_segs >= ST_FIRST_SG)
3903                 st_max_sg_segs = max_sg_segs;
3904 }
3905
3906 #ifndef MODULE
3907 /* Set the boot options. Syntax is defined in Documenation/scsi/st.txt.
3908  */
3909 static int __init st_setup(char *str)
3910 {
3911         int i, len, ints[5];
3912         char *stp;
3913
3914         stp = get_options(str, ARRAY_SIZE(ints), ints);
3915
3916         if (ints[0] > 0) {
3917                 for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
3918                         if (parms[i].val)
3919                                 *parms[i].val = ints[i + 1];
3920         } else {
3921                 while (stp != NULL) {
3922                         for (i = 0; i < ARRAY_SIZE(parms); i++) {
3923                                 len = strlen(parms[i].name);
3924                                 if (!strncmp(stp, parms[i].name, len) &&
3925                                     (*(stp + len) == ':' || *(stp + len) == '=')) {
3926                                         if (parms[i].val)
3927                                                 *parms[i].val =
3928                                                         simple_strtoul(stp + len + 1, NULL, 0);
3929                                         else
3930                                                 printk(KERN_WARNING "st: Obsolete parameter %s\n",
3931                                                        parms[i].name);
3932                                         break;
3933                                 }
3934                         }
3935                         if (i >= ARRAY_SIZE(parms))
3936                                  printk(KERN_WARNING "st: invalid parameter in '%s'\n",
3937                                         stp);
3938                         stp = strchr(stp, ',');
3939                         if (stp)
3940                                 stp++;
3941                 }
3942         }
3943
3944         validate_options();
3945
3946         return 1;
3947 }
3948
3949 __setup("st=", st_setup);
3950
3951 #endif
3952
3953 static const struct file_operations st_fops =
3954 {
3955         .owner =        THIS_MODULE,
3956         .read =         st_read,
3957         .write =        st_write,
3958         .unlocked_ioctl = st_ioctl,
3959 #ifdef CONFIG_COMPAT
3960         .compat_ioctl = st_compat_ioctl,
3961 #endif
3962         .open =         st_open,
3963         .flush =        st_flush,
3964         .release =      st_release,
3965         .llseek =       noop_llseek,
3966 };
3967
3968 static int st_probe(struct device *dev)
3969 {
3970         struct scsi_device *SDp = to_scsi_device(dev);
3971         struct gendisk *disk = NULL;
3972         struct cdev *cdev = NULL;
3973         struct scsi_tape *tpnt = NULL;
3974         struct st_modedef *STm;
3975         struct st_partstat *STps;
3976         struct st_buffer *buffer;
3977         int i, j, mode, dev_num, error;
3978         char *stp;
3979
3980         if (SDp->type != TYPE_TAPE)
3981                 return -ENODEV;
3982         if ((stp = st_incompatible(SDp))) {
3983                 sdev_printk(KERN_INFO, SDp, "Found incompatible tape\n");
3984                 printk(KERN_INFO "st: The suggested driver is %s.\n", stp);
3985                 return -ENODEV;
3986         }
3987
3988         i = queue_max_segments(SDp->request_queue);
3989         if (st_max_sg_segs < i)
3990                 i = st_max_sg_segs;
3991         buffer = new_tape_buffer((SDp->host)->unchecked_isa_dma, i);
3992         if (buffer == NULL) {
3993                 printk(KERN_ERR
3994                        "st: Can't allocate new tape buffer. Device not attached.\n");
3995                 goto out;
3996         }
3997
3998         disk = alloc_disk(1);
3999         if (!disk) {
4000                 printk(KERN_ERR "st: out of memory. Device not attached.\n");
4001                 goto out_buffer_free;
4002         }
4003
4004         write_lock(&st_dev_arr_lock);
4005         if (st_nr_dev >= st_dev_max) {
4006                 struct scsi_tape **tmp_da;
4007                 int tmp_dev_max;
4008
4009                 tmp_dev_max = max(st_nr_dev * 2, 8);
4010                 if (tmp_dev_max > ST_MAX_TAPES)
4011                         tmp_dev_max = ST_MAX_TAPES;
4012                 if (tmp_dev_max <= st_nr_dev) {
4013                         write_unlock(&st_dev_arr_lock);
4014                         printk(KERN_ERR "st: Too many tape devices (max. %d).\n",
4015                                ST_MAX_TAPES);
4016                         goto out_put_disk;
4017                 }
4018
4019                 tmp_da = kzalloc(tmp_dev_max * sizeof(struct scsi_tape *), GFP_ATOMIC);
4020                 if (tmp_da == NULL) {
4021                         write_unlock(&st_dev_arr_lock);
4022                         printk(KERN_ERR "st: Can't extend device array.\n");
4023                         goto out_put_disk;
4024                 }
4025
4026                 if (scsi_tapes != NULL) {
4027                         memcpy(tmp_da, scsi_tapes,
4028                                st_dev_max * sizeof(struct scsi_tape *));
4029                         kfree(scsi_tapes);
4030                 }
4031                 scsi_tapes = tmp_da;
4032
4033                 st_dev_max = tmp_dev_max;
4034         }
4035
4036         for (i = 0; i < st_dev_max; i++)
4037                 if (scsi_tapes[i] == NULL)
4038                         break;
4039         if (i >= st_dev_max)
4040                 panic("scsi_devices corrupt (st)");
4041
4042         tpnt = kzalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
4043         if (tpnt == NULL) {
4044                 write_unlock(&st_dev_arr_lock);
4045                 printk(KERN_ERR "st: Can't allocate device descriptor.\n");
4046                 goto out_put_disk;
4047         }
4048         kref_init(&tpnt->kref);
4049         tpnt->disk = disk;
4050         sprintf(disk->disk_name, "st%d", i);
4051         disk->private_data = &tpnt->driver;
4052         disk->queue = SDp->request_queue;
4053         tpnt->driver = &st_template;
4054         scsi_tapes[i] = tpnt;
4055         dev_num = i;
4056
4057         tpnt->device = SDp;
4058         if (SDp->scsi_level <= 2)
4059                 tpnt->tape_type = MT_ISSCSI1;
4060         else
4061                 tpnt->tape_type = MT_ISSCSI2;
4062
4063         tpnt->buffer = buffer;
4064         tpnt->buffer->last_SRpnt = NULL;
4065
4066         tpnt->inited = 0;
4067         tpnt->dirty = 0;
4068         tpnt->in_use = 0;
4069         tpnt->drv_buffer = 1;   /* Try buffering if no mode sense */
4070         tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
4071         tpnt->use_pf = (SDp->scsi_level >= SCSI_2);
4072         tpnt->density = 0;
4073         tpnt->do_auto_lock = ST_AUTO_LOCK;
4074         tpnt->can_bsr = (SDp->scsi_level > 2 ? 1 : ST_IN_FILE_POS); /* BSR mandatory in SCSI3 */
4075         tpnt->can_partitions = 0;
4076         tpnt->two_fm = ST_TWO_FM;
4077         tpnt->fast_mteom = ST_FAST_MTEOM;
4078         tpnt->scsi2_logical = ST_SCSI2LOGICAL;
4079         tpnt->sili = ST_SILI;
4080         tpnt->immediate = ST_NOWAIT;
4081         tpnt->default_drvbuffer = 0xff;         /* No forced buffering */
4082         tpnt->partition = 0;
4083         tpnt->new_partition = 0;
4084         tpnt->nbr_partitions = 0;
4085         blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
4086         tpnt->long_timeout = ST_LONG_TIMEOUT;
4087         tpnt->try_dio = try_direct_io && !SDp->host->unchecked_isa_dma;
4088
4089         for (i = 0; i < ST_NBR_MODES; i++) {
4090                 STm = &(tpnt->modes[i]);
4091                 STm->defined = 0;
4092                 STm->sysv = ST_SYSV;
4093                 STm->defaults_for_writes = 0;
4094                 STm->do_async_writes = ST_ASYNC_WRITES;
4095                 STm->do_buffer_writes = ST_BUFFER_WRITES;
4096                 STm->do_read_ahead = ST_READ_AHEAD;
4097                 STm->default_compression = ST_DONT_TOUCH;
4098                 STm->default_blksize = (-1);    /* No forced size */
4099                 STm->default_density = (-1);    /* No forced density */
4100         }
4101
4102         for (i = 0; i < ST_NBR_PARTITIONS; i++) {
4103                 STps = &(tpnt->ps[i]);
4104                 STps->rw = ST_IDLE;
4105                 STps->eof = ST_NOEOF;
4106                 STps->at_sm = 0;
4107                 STps->last_block_valid = 0;
4108                 STps->drv_block = (-1);
4109                 STps->drv_file = (-1);
4110         }
4111
4112         tpnt->current_mode = 0;
4113         tpnt->modes[0].defined = 1;
4114
4115         tpnt->density_changed = tpnt->compression_changed =
4116             tpnt->blksize_changed = 0;
4117         mutex_init(&tpnt->lock);
4118
4119         st_nr_dev++;
4120         write_unlock(&st_dev_arr_lock);
4121
4122         for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4123                 STm = &(tpnt->modes[mode]);
4124                 for (j=0; j < 2; j++) {
4125                         cdev = cdev_alloc();
4126                         if (!cdev) {
4127                                 printk(KERN_ERR
4128                                        "st%d: out of memory. Device not attached.\n",
4129                                        dev_num);
4130                                 goto out_free_tape;
4131                         }
4132                         cdev->owner = THIS_MODULE;
4133                         cdev->ops = &st_fops;
4134
4135                         error = cdev_add(cdev,
4136                                          MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(dev_num, mode, j)),
4137                                          1);
4138                         if (error) {
4139                                 printk(KERN_ERR "st%d: Can't add %s-rewind mode %d\n",
4140                                        dev_num, j ? "non" : "auto", mode);
4141                                 printk(KERN_ERR "st%d: Device not attached.\n", dev_num);
4142                                 goto out_free_tape;
4143                         }
4144                         STm->cdevs[j] = cdev;
4145
4146                 }
4147                 error = do_create_class_files(tpnt, dev_num, mode);
4148                 if (error)
4149                         goto out_free_tape;
4150         }
4151
4152         sdev_printk(KERN_NOTICE, SDp,
4153                     "Attached scsi tape %s\n", tape_name(tpnt));
4154         sdev_printk(KERN_INFO, SDp, "%s: try direct i/o: %s (alignment %d B)\n",
4155                     tape_name(tpnt), tpnt->try_dio ? "yes" : "no",
4156                     queue_dma_alignment(SDp->request_queue) + 1);
4157
4158         return 0;
4159
4160 out_free_tape:
4161         for (mode=0; mode < ST_NBR_MODES; mode++) {
4162                 STm = &(tpnt->modes[mode]);
4163                 sysfs_remove_link(&tpnt->device->sdev_gendev.kobj,
4164                                   "tape");
4165                 for (j=0; j < 2; j++) {
4166                         if (STm->cdevs[j]) {
4167                                 if (cdev == STm->cdevs[j])
4168                                         cdev = NULL;
4169                                         device_destroy(st_sysfs_class,
4170                                                        MKDEV(SCSI_TAPE_MAJOR,
4171                                                              TAPE_MINOR(i, mode, j)));
4172                                 cdev_del(STm->cdevs[j]);
4173                         }
4174                 }
4175         }
4176         if (cdev)
4177                 cdev_del(cdev);
4178         write_lock(&st_dev_arr_lock);
4179         scsi_tapes[dev_num] = NULL;
4180         st_nr_dev--;
4181         write_unlock(&st_dev_arr_lock);
4182 out_put_disk:
4183         put_disk(disk);
4184         kfree(tpnt);
4185 out_buffer_free:
4186         kfree(buffer);
4187 out:
4188         return -ENODEV;
4189 };
4190
4191
4192 static int st_remove(struct device *dev)
4193 {
4194         struct scsi_device *SDp = to_scsi_device(dev);
4195         struct scsi_tape *tpnt;
4196         int i, j, mode;
4197
4198         write_lock(&st_dev_arr_lock);
4199         for (i = 0; i < st_dev_max; i++) {
4200                 tpnt = scsi_tapes[i];
4201                 if (tpnt != NULL && tpnt->device == SDp) {
4202                         scsi_tapes[i] = NULL;
4203                         st_nr_dev--;
4204                         write_unlock(&st_dev_arr_lock);
4205                         sysfs_remove_link(&tpnt->device->sdev_gendev.kobj,
4206                                           "tape");
4207                         for (mode = 0; mode < ST_NBR_MODES; ++mode) {
4208                                 for (j=0; j < 2; j++) {
4209                                         device_destroy(st_sysfs_class,
4210                                                        MKDEV(SCSI_TAPE_MAJOR,
4211                                                              TAPE_MINOR(i, mode, j)));
4212                                         cdev_del(tpnt->modes[mode].cdevs[j]);
4213                                         tpnt->modes[mode].cdevs[j] = NULL;
4214                                 }
4215                         }
4216
4217                         mutex_lock(&st_ref_mutex);
4218                         kref_put(&tpnt->kref, scsi_tape_release);
4219                         mutex_unlock(&st_ref_mutex);
4220                         return 0;
4221                 }
4222         }
4223
4224         write_unlock(&st_dev_arr_lock);
4225         return 0;
4226 }
4227
4228 /**
4229  *      scsi_tape_release - Called to free the Scsi_Tape structure
4230  *      @kref: pointer to embedded kref
4231  *
4232  *      st_ref_mutex must be held entering this routine.  Because it is
4233  *      called on last put, you should always use the scsi_tape_get()
4234  *      scsi_tape_put() helpers which manipulate the semaphore directly
4235  *      and never do a direct kref_put().
4236  **/
4237 static void scsi_tape_release(struct kref *kref)
4238 {
4239         struct scsi_tape *tpnt = to_scsi_tape(kref);
4240         struct gendisk *disk = tpnt->disk;
4241
4242         tpnt->device = NULL;
4243
4244         if (tpnt->buffer) {
4245                 normalize_buffer(tpnt->buffer);
4246                 kfree(tpnt->buffer->reserved_pages);
4247                 kfree(tpnt->buffer);
4248         }
4249
4250         disk->private_data = NULL;
4251         put_disk(disk);
4252         kfree(tpnt);
4253         return;
4254 }
4255
4256 static int __init init_st(void)
4257 {
4258         int err;
4259
4260         validate_options();
4261
4262         printk(KERN_INFO "st: Version %s, fixed bufsize %d, s/g segs %d\n",
4263                 verstr, st_fixed_buffer_size, st_max_sg_segs);
4264
4265         st_sysfs_class = class_create(THIS_MODULE, "scsi_tape");
4266         if (IS_ERR(st_sysfs_class)) {
4267                 printk(KERN_ERR "Unable create sysfs class for SCSI tapes\n");
4268                 return PTR_ERR(st_sysfs_class);
4269         }
4270
4271         err = register_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4272                                      ST_MAX_TAPE_ENTRIES, "st");
4273         if (err) {
4274                 printk(KERN_ERR "Unable to get major %d for SCSI tapes\n",
4275                        SCSI_TAPE_MAJOR);
4276                 goto err_class;
4277         }
4278
4279         err = scsi_register_driver(&st_template.gendrv);
4280         if (err)
4281                 goto err_chrdev;
4282
4283         err = do_create_sysfs_files();
4284         if (err)
4285                 goto err_scsidrv;
4286
4287         return 0;
4288
4289 err_scsidrv:
4290         scsi_unregister_driver(&st_template.gendrv);
4291 err_chrdev:
4292         unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4293                                  ST_MAX_TAPE_ENTRIES);
4294 err_class:
4295         class_destroy(st_sysfs_class);
4296         return err;
4297 }
4298
4299 static void __exit exit_st(void)
4300 {
4301         do_remove_sysfs_files();
4302         scsi_unregister_driver(&st_template.gendrv);
4303         unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
4304                                  ST_MAX_TAPE_ENTRIES);
4305         class_destroy(st_sysfs_class);
4306         kfree(scsi_tapes);
4307         printk(KERN_INFO "st: Unloaded.\n");
4308 }
4309
4310 module_init(init_st);
4311 module_exit(exit_st);
4312
4313
4314 /* The sysfs driver interface. Read-only at the moment */
4315 static ssize_t st_try_direct_io_show(struct device_driver *ddp, char *buf)
4316 {
4317         return snprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
4318 }
4319 static DRIVER_ATTR(try_direct_io, S_IRUGO, st_try_direct_io_show, NULL);
4320
4321 static ssize_t st_fixed_buffer_size_show(struct device_driver *ddp, char *buf)
4322 {
4323         return snprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
4324 }
4325 static DRIVER_ATTR(fixed_buffer_size, S_IRUGO, st_fixed_buffer_size_show, NULL);
4326
4327 static ssize_t st_max_sg_segs_show(struct device_driver *ddp, char *buf)
4328 {
4329         return snprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
4330 }
4331 static DRIVER_ATTR(max_sg_segs, S_IRUGO, st_max_sg_segs_show, NULL);
4332
4333 static ssize_t st_version_show(struct device_driver *ddd, char *buf)
4334 {
4335         return snprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
4336 }
4337 static DRIVER_ATTR(version, S_IRUGO, st_version_show, NULL);
4338
4339 static int do_create_sysfs_files(void)
4340 {
4341         struct device_driver *sysfs = &st_template.gendrv;
4342         int err;
4343
4344         err = driver_create_file(sysfs, &driver_attr_try_direct_io);
4345         if (err)
4346                 return err;
4347         err = driver_create_file(sysfs, &driver_attr_fixed_buffer_size);
4348         if (err)
4349                 goto err_try_direct_io;
4350         err = driver_create_file(sysfs, &driver_attr_max_sg_segs);
4351         if (err)
4352                 goto err_attr_fixed_buf;
4353         err = driver_create_file(sysfs, &driver_attr_version);
4354         if (err)
4355                 goto err_attr_max_sg;
4356
4357         return 0;
4358
4359 err_attr_max_sg:
4360         driver_remove_file(sysfs, &driver_attr_max_sg_segs);
4361 err_attr_fixed_buf:
4362         driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
4363 err_try_direct_io:
4364         driver_remove_file(sysfs, &driver_attr_try_direct_io);
4365         return err;
4366 }
4367
4368 static void do_remove_sysfs_files(void)
4369 {
4370         struct device_driver *sysfs = &st_template.gendrv;
4371
4372         driver_remove_file(sysfs, &driver_attr_version);
4373         driver_remove_file(sysfs, &driver_attr_max_sg_segs);
4374         driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
4375         driver_remove_file(sysfs, &driver_attr_try_direct_io);
4376 }
4377
4378
4379 /* The sysfs simple class interface */
4380 static ssize_t
4381 st_defined_show(struct device *dev, struct device_attribute *attr, char *buf)
4382 {
4383         struct st_modedef *STm = dev_get_drvdata(dev);
4384         ssize_t l = 0;
4385
4386         l = snprintf(buf, PAGE_SIZE, "%d\n", STm->defined);
4387         return l;
4388 }
4389
4390 DEVICE_ATTR(defined, S_IRUGO, st_defined_show, NULL);
4391
4392 static ssize_t
4393 st_defblk_show(struct device *dev, struct device_attribute *attr, char *buf)
4394 {
4395         struct st_modedef *STm = dev_get_drvdata(dev);
4396         ssize_t l = 0;
4397
4398         l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_blksize);
4399         return l;
4400 }
4401
4402 DEVICE_ATTR(default_blksize, S_IRUGO, st_defblk_show, NULL);
4403
4404 static ssize_t
4405 st_defdensity_show(struct device *dev, struct device_attribute *attr, char *buf)
4406 {
4407         struct st_modedef *STm = dev_get_drvdata(dev);
4408         ssize_t l = 0;
4409         char *fmt;
4410
4411         fmt = STm->default_density >= 0 ? "0x%02x\n" : "%d\n";
4412         l = snprintf(buf, PAGE_SIZE, fmt, STm->default_density);
4413         return l;
4414 }
4415
4416 DEVICE_ATTR(default_density, S_IRUGO, st_defdensity_show, NULL);
4417
4418 static ssize_t
4419 st_defcompression_show(struct device *dev, struct device_attribute *attr,
4420                        char *buf)
4421 {
4422         struct st_modedef *STm = dev_get_drvdata(dev);
4423         ssize_t l = 0;
4424
4425         l = snprintf(buf, PAGE_SIZE, "%d\n", STm->default_compression - 1);
4426         return l;
4427 }
4428
4429 DEVICE_ATTR(default_compression, S_IRUGO, st_defcompression_show, NULL);
4430
4431 static ssize_t
4432 st_options_show(struct device *dev, struct device_attribute *attr, char *buf)
4433 {
4434         struct st_modedef *STm = dev_get_drvdata(dev);
4435         struct scsi_tape *STp;
4436         int i, j, options;
4437         ssize_t l = 0;
4438
4439         for (i=0; i < st_dev_max; i++) {
4440                 for (j=0; j < ST_NBR_MODES; j++)
4441                         if (&scsi_tapes[i]->modes[j] == STm)
4442                                 break;
4443                 if (j < ST_NBR_MODES)
4444                         break;
4445         }
4446         if (i == st_dev_max)
4447                 return 0;  /* should never happen */
4448
4449         STp = scsi_tapes[i];
4450
4451         options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
4452         options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
4453         options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
4454         DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
4455         options |= STp->two_fm ? MT_ST_TWO_FM : 0;
4456         options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
4457         options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
4458         options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
4459         options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
4460         options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
4461         options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
4462         options |= STm->sysv ? MT_ST_SYSV : 0;
4463         options |= STp->immediate ? MT_ST_NOWAIT : 0;
4464         options |= STp->sili ? MT_ST_SILI : 0;
4465
4466         l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
4467         return l;
4468 }
4469
4470 DEVICE_ATTR(options, S_IRUGO, st_options_show, NULL);
4471
4472 static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
4473 {
4474         int i, rew, error;
4475         char name[10];
4476         struct device *st_class_member;
4477
4478         for (rew=0; rew < 2; rew++) {
4479                 /* Make sure that the minor numbers corresponding to the four
4480                    first modes always get the same names */
4481                 i = mode << (4 - ST_NBR_MODE_BITS);
4482                 snprintf(name, 10, "%s%s%s", rew ? "n" : "",
4483                          STp->disk->disk_name, st_formats[i]);
4484                 st_class_member =
4485                         device_create(st_sysfs_class, &STp->device->sdev_gendev,
4486                                       MKDEV(SCSI_TAPE_MAJOR,
4487                                             TAPE_MINOR(dev_num, mode, rew)),
4488                                       &STp->modes[mode], "%s", name);
4489                 if (IS_ERR(st_class_member)) {
4490                         printk(KERN_WARNING "st%d: device_create failed\n",
4491                                dev_num);
4492                         error = PTR_ERR(st_class_member);
4493                         goto out;
4494                 }
4495
4496                 error = device_create_file(st_class_member,
4497                                            &dev_attr_defined);
4498                 if (error) goto out;
4499                 error = device_create_file(st_class_member,
4500                                            &dev_attr_default_blksize);
4501                 if (error) goto out;
4502                 error = device_create_file(st_class_member,
4503                                            &dev_attr_default_density);
4504                 if (error) goto out;
4505                 error = device_create_file(st_class_member,
4506                                            &dev_attr_default_compression);
4507                 if (error) goto out;
4508                 error = device_create_file(st_class_member,
4509                                            &dev_attr_options);
4510                 if (error) goto out;
4511
4512                 if (mode == 0 && rew == 0) {
4513                         error = sysfs_create_link(&STp->device->sdev_gendev.kobj,
4514                                                   &st_class_member->kobj,
4515                                                   "tape");
4516                         if (error) {
4517                                 printk(KERN_ERR
4518                                        "st%d: Can't create sysfs link from SCSI device.\n",
4519                                        dev_num);
4520                                 goto out;
4521                         }
4522                 }
4523         }
4524
4525         return 0;
4526
4527 out:
4528         return error;
4529 }
4530
4531 /* The following functions may be useful for a larger audience. */
4532 static int sgl_map_user_pages(struct st_buffer *STbp,
4533                               const unsigned int max_pages, unsigned long uaddr,
4534                               size_t count, int rw)
4535 {
4536         unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
4537         unsigned long start = uaddr >> PAGE_SHIFT;
4538         const int nr_pages = end - start;
4539         int res, i, j;
4540         struct page **pages;
4541         struct rq_map_data *mdata = &STbp->map_data;
4542
4543         /* User attempted Overflow! */
4544         if ((uaddr + count) < uaddr)
4545                 return -EINVAL;
4546
4547         /* Too big */
4548         if (nr_pages > max_pages)
4549                 return -ENOMEM;
4550
4551         /* Hmm? */
4552         if (count == 0)
4553                 return 0;
4554
4555         if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_KERNEL)) == NULL)
4556                 return -ENOMEM;
4557
4558         /* Try to fault in all of the necessary pages */
4559         down_read(&current->mm->mmap_sem);
4560         /* rw==READ means read from drive, write into memory area */
4561         res = get_user_pages(
4562                 current,
4563                 current->mm,
4564                 uaddr,
4565                 nr_pages,
4566                 rw == READ,
4567                 0, /* don't force */
4568                 pages,
4569                 NULL);
4570         up_read(&current->mm->mmap_sem);
4571
4572         /* Errors and no page mapped should return here */
4573         if (res < nr_pages)
4574                 goto out_unmap;
4575
4576         for (i=0; i < nr_pages; i++) {
4577                 /* FIXME: flush superflous for rw==READ,
4578                  * probably wrong function for rw==WRITE
4579                  */
4580                 flush_dcache_page(pages[i]);
4581         }
4582
4583         mdata->offset = uaddr & ~PAGE_MASK;
4584         STbp->mapped_pages = pages;
4585
4586         return nr_pages;
4587  out_unmap:
4588         if (res > 0) {
4589                 for (j=0; j < res; j++)
4590                         page_cache_release(pages[j]);
4591                 res = 0;
4592         }
4593         kfree(pages);
4594         return res;
4595 }
4596
4597
4598 /* And unmap them... */
4599 static int sgl_unmap_user_pages(struct st_buffer *STbp,
4600                                 const unsigned int nr_pages, int dirtied)
4601 {
4602         int i;
4603
4604         for (i=0; i < nr_pages; i++) {
4605                 struct page *page = STbp->mapped_pages[i];
4606
4607                 if (dirtied)
4608                         SetPageDirty(page);
4609                 /* FIXME: cache flush missing for rw==READ
4610                  * FIXME: call the correct reference counting function
4611                  */
4612                 page_cache_release(page);
4613         }
4614         kfree(STbp->mapped_pages);
4615         STbp->mapped_pages = NULL;
4616
4617         return 0;
4618 }