drivers/scsi/sd.c

   1 /*
   2  *      sd.c Copyright (C) 1992 Drew Eckhardt
   3  *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
   4  *
   5  *      Linux scsi disk driver
   6  *              Initial versions: Drew Eckhardt
   7  *              Subsequent revisions: Eric Youngdale
   8  *      Modification history:
   9  *       - Drew Eckhardt <drew@colorado.edu> original
  10  *       - Eric Youngdale <eric@andante.org> add scatter-gather, multiple
  11  *         outstanding request, and other enhancements.
  12  *         Support loadable low-level scsi drivers.
  13  *       - Jirka Hanika <geo@ff.cuni.cz> support more scsi disks using
  14  *         eight major numbers.
  15  *       - Richard Gooch <rgooch@atnf.csiro.au> support devfs.
  16  *       - Torben Mathiasen <tmm@image.dk> Resource allocation fixes in
  17  *         sd_init and cleanups.
  18  *       - Alex Davis <letmein@erols.com> Fix problem where partition info
  19  *         not being read in sd_open. Fix problem where removable media
  20  *         could be ejected after sd_open.
  21  *       - Douglas Gilbert <dgilbert@interlog.com> cleanup for lk 2.5.x
  22  *       - Badari Pulavarty <pbadari@us.ibm.com>, Matthew Wilcox
  23  *         <willy@debian.org>, Kurt Garloff <garloff@suse.de>:
  24  *         Support 32k/1M disks.
  25  *
  26  *      Logging policy (needs CONFIG_SCSI_LOGGING defined):
  27  *       - setting up transfer: SCSI_LOG_HLQUEUE levels 1 and 2
  28  *       - end of transfer (bh + scsi_lib): SCSI_LOG_HLCOMPLETE level 1
  29  *       - entering sd_ioctl: SCSI_LOG_IOCTL level 1
  30  *       - entering other commands: SCSI_LOG_HLQUEUE level 3
  31  *      Note: when the logging level is set by the user, it must be greater
  32  *      than the level indicated above to trigger output.
  33  */
  34
  35 #include <linux/module.h>
  36 #include <linux/fs.h>
  37 #include <linux/kernel.h>
  38 #include <linux/mm.h>
  39 #include <linux/bio.h>
  40 #include <linux/genhd.h>
  41 #include <linux/hdreg.h>
  42 #include <linux/errno.h>
  43 #include <linux/idr.h>
  44 #include <linux/interrupt.h>
  45 #include <linux/init.h>
  46 #include <linux/blkdev.h>
  47 #include <linux/blkpg.h>
  48 #include <linux/delay.h>
  49 #include <linux/mutex.h>
  50 #include <linux/string_helpers.h>
  51 #include <linux/async.h>
  52 #include <linux/slab.h>
  53 #include <linux/pm_runtime.h>
  54 #include <linux/pr.h>
  55 #include <asm/uaccess.h>
  56 #include <asm/unaligned.h>
  57
  58 #include <scsi/scsi.h>
  59 #include <scsi/scsi_cmnd.h>
  60 #include <scsi/scsi_dbg.h>
  61 #include <scsi/scsi_device.h>
  62 #include <scsi/scsi_driver.h>
  63 #include <scsi/scsi_eh.h>
  64 #include <scsi/scsi_host.h>
  65 #include <scsi/scsi_ioctl.h>
  66 #include <scsi/scsicam.h>
  67
  68 #include "sd.h"
  69 #include "scsi_priv.h"
  70 #include "scsi_logging.h"
  71
  72 MODULE_AUTHOR("Eric Youngdale");
  73 MODULE_DESCRIPTION("SCSI disk (sd) driver");
  74 MODULE_LICENSE("GPL");
  75
  76 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK0_MAJOR);
  77 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK1_MAJOR);
  78 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK2_MAJOR);
  79 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK3_MAJOR);
  80 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK4_MAJOR);
  81 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK5_MAJOR);
  82 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK6_MAJOR);
  83 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK7_MAJOR);
  84 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK8_MAJOR);
  85 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK9_MAJOR);
  86 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK10_MAJOR);
  87 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK11_MAJOR);
  88 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK12_MAJOR);
  89 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK13_MAJOR);
  90 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK14_MAJOR);
  91 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
  92 MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
  93 MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
  94 MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
  95
  96 #if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
  97 #define SD_MINORS       16
  98 #else
  99 #define SD_MINORS       0
 100 #endif
 101
 102 static void sd_config_discard(struct scsi_disk *, unsigned int);
 103 static void sd_config_write_same(struct scsi_disk *);
 104 static int  sd_revalidate_disk(struct gendisk *);
 105 static void sd_unlock_native_capacity(struct gendisk *disk);
 106 static int  sd_probe(struct device *);
 107 static int  sd_remove(struct device *);
 108 static void sd_shutdown(struct device *);
 109 static int sd_suspend_system(struct device *);
 110 static int sd_suspend_runtime(struct device *);
 111 static int sd_resume(struct device *);
 112 static void sd_rescan(struct device *);
 113 static int sd_init_command(struct scsi_cmnd *SCpnt);
 114 static void sd_uninit_command(struct scsi_cmnd *SCpnt);
 115 static int sd_done(struct scsi_cmnd *);
 116 static int sd_eh_action(struct scsi_cmnd *, int);
 117 static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
 118 static void scsi_disk_release(struct device *cdev);
 119 static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
 120 static void sd_print_result(const struct scsi_disk *, const char *, int);
 121
 122 static DEFINE_SPINLOCK(sd_index_lock);
 123 static DEFINE_IDA(sd_index_ida);
 124
 125 /* This semaphore is used to mediate the 0->1 reference get in the
 126  * face of object destruction (i.e. we can't allow a get on an
 127  * object after last put) */
 128 static DEFINE_MUTEX(sd_ref_mutex);
 129
 130 static struct kmem_cache *sd_cdb_cache;
 131 static mempool_t *sd_cdb_pool;
 132
 133 static const char *sd_cache_types[] = {
 134         "write through", "none", "write back",
 135         "write back, no read (daft)"
 136 };
 137
 138 static void sd_set_flush_flag(struct scsi_disk *sdkp)
 139 {
 140         unsigned flush = 0;
 141
 142         if (sdkp->WCE) {
 143                 flush |= REQ_FLUSH;
 144                 if (sdkp->DPOFUA)
 145                         flush |= REQ_FUA;
 146         }
 147
 148         blk_queue_flush(sdkp->disk->queue, flush);
 149 }
 150
 151 static ssize_t
 152 cache_type_store(struct device *dev, struct device_attribute *attr,
 153                  const char *buf, size_t count)
 154 {
 155         int i, ct = -1, rcd, wce, sp;
 156         struct scsi_disk *sdkp = to_scsi_disk(dev);
 157         struct scsi_device *sdp = sdkp->device;
 158         char buffer[64];
 159         char *buffer_data;
 160         struct scsi_mode_data data;
 161         struct scsi_sense_hdr sshdr;
 162         static const char temp[] = "temporary ";
 163         int len;
 164
 165         if (sdp->type != TYPE_DISK)
 166                 /* no cache control on RBC devices; theoretically they
 167                  * can do it, but there's probably so many exceptions
 168                  * it's not worth the risk */
 169                 return -EINVAL;
 170
 171         if (strncmp(buf, temp, sizeof(temp) - 1) == 0) {
 172                 buf += sizeof(temp) - 1;
 173                 sdkp->cache_override = 1;
 174         } else {
 175                 sdkp->cache_override = 0;
 176         }
 177
 178         for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {
 179                 len = strlen(sd_cache_types[i]);
 180                 if (strncmp(sd_cache_types[i], buf, len) == 0 &&
 181                     buf[len] == '\n') {
 182                         ct = i;
 183                         break;
 184                 }
 185         }
 186         if (ct < 0)
 187                 return -EINVAL;
 188         rcd = ct & 0x01 ? 1 : 0;
 189         wce = (ct & 0x02) && !sdkp->write_prot ? 1 : 0;
 190
 191         if (sdkp->cache_override) {
 192                 sdkp->WCE = wce;
 193                 sdkp->RCD = rcd;
 194                 sd_set_flush_flag(sdkp);
 195                 return count;
 196         }
 197
 198         if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
 199                             SD_MAX_RETRIES, &data, NULL))
 200                 return -EINVAL;
 201         len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
 202                   data.block_descriptor_length);
 203         buffer_data = buffer + data.header_length +
 204                 data.block_descriptor_length;
 205         buffer_data[2] &= ~0x05;
 206         buffer_data[2] |= wce << 2 | rcd;
 207         sp = buffer_data[0] & 0x80 ? 1 : 0;
 208         buffer_data[0] &= ~0x80;
 209
 210         /*
 211          * Ensure WP, DPOFUA, and RESERVED fields are cleared in
 212          * received mode parameter buffer before doing MODE SELECT.
 213          */
 214         data.device_specific = 0;
 215
 216         if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
 217                              SD_MAX_RETRIES, &data, &sshdr)) {
 218                 if (scsi_sense_valid(&sshdr))
 219                         sd_print_sense_hdr(sdkp, &sshdr);
 220                 return -EINVAL;
 221         }
 222         revalidate_disk(sdkp->disk);
 223         return count;
 224 }
 225
 226 static ssize_t
 227 manage_start_stop_show(struct device *dev, struct device_attribute *attr,
 228                        char *buf)
 229 {
 230         struct scsi_disk *sdkp = to_scsi_disk(dev);
 231         struct scsi_device *sdp = sdkp->device;
 232
 233         return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
 234 }
 235
 236 static ssize_t
 237 manage_start_stop_store(struct device *dev, struct device_attribute *attr,
 238                         const char *buf, size_t count)
 239 {
 240         struct scsi_disk *sdkp = to_scsi_disk(dev);
 241         struct scsi_device *sdp = sdkp->device;
 242         bool v;
 243
 244         if (!capable(CAP_SYS_ADMIN))
 245                 return -EACCES;
 246
 247         if (kstrtobool(buf, &v))
 248                 return -EINVAL;
 249
 250         sdp->manage_start_stop = v;
 251
 252         return count;
 253 }
 254 static DEVICE_ATTR_RW(manage_start_stop);
 255
 256 static ssize_t
 257 allow_restart_show(struct device *dev, struct device_attribute *attr, char *buf)
 258 {
 259         struct scsi_disk *sdkp = to_scsi_disk(dev);
 260
 261         return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
 262 }
 263
 264 static ssize_t
 265 allow_restart_store(struct device *dev, struct device_attribute *attr,
 266                     const char *buf, size_t count)
 267 {
 268         bool v;
 269         struct scsi_disk *sdkp = to_scsi_disk(dev);
 270         struct scsi_device *sdp = sdkp->device;
 271
 272         if (!capable(CAP_SYS_ADMIN))
 273                 return -EACCES;
 274
 275         if (sdp->type != TYPE_DISK)
 276                 return -EINVAL;
 277
 278         if (kstrtobool(buf, &v))
 279                 return -EINVAL;
 280
 281         sdp->allow_restart = v;
 282
 283         return count;
 284 }
 285 static DEVICE_ATTR_RW(allow_restart);
 286
 287 static ssize_t
 288 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
 289 {
 290         struct scsi_disk *sdkp = to_scsi_disk(dev);
 291         int ct = sdkp->RCD + 2*sdkp->WCE;
 292
 293         return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
 294 }
 295 static DEVICE_ATTR_RW(cache_type);
 296
 297 static ssize_t
 298 FUA_show(struct device *dev, struct device_attribute *attr, char *buf)
 299 {
 300         struct scsi_disk *sdkp = to_scsi_disk(dev);
 301
 302         return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
 303 }
 304 static DEVICE_ATTR_RO(FUA);
 305
 306 static ssize_t
 307 protection_type_show(struct device *dev, struct device_attribute *attr,
 308                      char *buf)
 309 {
 310         struct scsi_disk *sdkp = to_scsi_disk(dev);
 311
 312         return snprintf(buf, 20, "%u\n", sdkp->protection_type);
 313 }
 314
 315 static ssize_t
 316 protection_type_store(struct device *dev, struct device_attribute *attr,
 317                       const char *buf, size_t count)
 318 {
 319         struct scsi_disk *sdkp = to_scsi_disk(dev);
 320         unsigned int val;
 321         int err;
 322
 323         if (!capable(CAP_SYS_ADMIN))
 324                 return -EACCES;
 325
 326         err = kstrtouint(buf, 10, &val);
 327
 328         if (err)
 329                 return err;
 330
 331         if (val >= 0 && val <= SD_DIF_TYPE3_PROTECTION)
 332                 sdkp->protection_type = val;
 333
 334         return count;
 335 }
 336 static DEVICE_ATTR_RW(protection_type);
 337
 338 static ssize_t
 339 protection_mode_show(struct device *dev, struct device_attribute *attr,
 340                      char *buf)
 341 {
 342         struct scsi_disk *sdkp = to_scsi_disk(dev);
 343         struct scsi_device *sdp = sdkp->device;
 344         unsigned int dif, dix;
 345
 346         dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
 347         dix = scsi_host_dix_capable(sdp->host, sdkp->protection_type);
 348
 349         if (!dix && scsi_host_dix_capable(sdp->host, SD_DIF_TYPE0_PROTECTION)) {
 350                 dif = 0;
 351                 dix = 1;
 352         }
 353
 354         if (!dif && !dix)
 355                 return snprintf(buf, 20, "none\n");
 356
 357         return snprintf(buf, 20, "%s%u\n", dix ? "dix" : "dif", dif);
 358 }
 359 static DEVICE_ATTR_RO(protection_mode);
 360
 361 static ssize_t
 362 app_tag_own_show(struct device *dev, struct device_attribute *attr, char *buf)
 363 {
 364         struct scsi_disk *sdkp = to_scsi_disk(dev);
 365
 366         return snprintf(buf, 20, "%u\n", sdkp->ATO);
 367 }
 368 static DEVICE_ATTR_RO(app_tag_own);
 369
 370 static ssize_t
 371 thin_provisioning_show(struct device *dev, struct device_attribute *attr,
 372                        char *buf)
 373 {
 374         struct scsi_disk *sdkp = to_scsi_disk(dev);
 375
 376         return snprintf(buf, 20, "%u\n", sdkp->lbpme);
 377 }
 378 static DEVICE_ATTR_RO(thin_provisioning);
 379
 380 static const char *lbp_mode[] = {
 381         [SD_LBP_FULL]           = "full",
 382         [SD_LBP_UNMAP]          = "unmap",
 383         [SD_LBP_WS16]           = "writesame_16",
 384         [SD_LBP_WS10]           = "writesame_10",
 385         [SD_LBP_ZERO]           = "writesame_zero",
 386         [SD_LBP_DISABLE]        = "disabled",
 387 };
 388
 389 static ssize_t
 390 provisioning_mode_show(struct device *dev, struct device_attribute *attr,
 391                        char *buf)
 392 {
 393         struct scsi_disk *sdkp = to_scsi_disk(dev);
 394
 395         return snprintf(buf, 20, "%s\n", lbp_mode[sdkp->provisioning_mode]);
 396 }
 397
 398 static ssize_t
 399 provisioning_mode_store(struct device *dev, struct device_attribute *attr,
 400                         const char *buf, size_t count)
 401 {
 402         struct scsi_disk *sdkp = to_scsi_disk(dev);
 403         struct scsi_device *sdp = sdkp->device;
 404
 405         if (!capable(CAP_SYS_ADMIN))
 406                 return -EACCES;
 407
 408         if (sdp->type != TYPE_DISK)
 409                 return -EINVAL;
 410
 411         if (!strncmp(buf, lbp_mode[SD_LBP_UNMAP], 20))
 412                 sd_config_discard(sdkp, SD_LBP_UNMAP);
 413         else if (!strncmp(buf, lbp_mode[SD_LBP_WS16], 20))
 414                 sd_config_discard(sdkp, SD_LBP_WS16);
 415         else if (!strncmp(buf, lbp_mode[SD_LBP_WS10], 20))
 416                 sd_config_discard(sdkp, SD_LBP_WS10);
 417         else if (!strncmp(buf, lbp_mode[SD_LBP_ZERO], 20))
 418                 sd_config_discard(sdkp, SD_LBP_ZERO);
 419         else if (!strncmp(buf, lbp_mode[SD_LBP_DISABLE], 20))
 420                 sd_config_discard(sdkp, SD_LBP_DISABLE);
 421         else
 422                 return -EINVAL;
 423
 424         return count;
 425 }
 426 static DEVICE_ATTR_RW(provisioning_mode);
 427
 428 static ssize_t
 429 max_medium_access_timeouts_show(struct device *dev,
 430                                 struct device_attribute *attr, char *buf)
 431 {
 432         struct scsi_disk *sdkp = to_scsi_disk(dev);
 433
 434         return snprintf(buf, 20, "%u\n", sdkp->max_medium_access_timeouts);
 435 }
 436
 437 static ssize_t
 438 max_medium_access_timeouts_store(struct device *dev,
 439                                  struct device_attribute *attr, const char *buf,
 440                                  size_t count)
 441 {
 442         struct scsi_disk *sdkp = to_scsi_disk(dev);
 443         int err;
 444
 445         if (!capable(CAP_SYS_ADMIN))
 446                 return -EACCES;
 447
 448         err = kstrtouint(buf, 10, &sdkp->max_medium_access_timeouts);
 449
 450         return err ? err : count;
 451 }
 452 static DEVICE_ATTR_RW(max_medium_access_timeouts);
 453
 454 static ssize_t
 455 max_write_same_blocks_show(struct device *dev, struct device_attribute *attr,
 456                            char *buf)
 457 {
 458         struct scsi_disk *sdkp = to_scsi_disk(dev);
 459
 460         return snprintf(buf, 20, "%u\n", sdkp->max_ws_blocks);
 461 }
 462
 463 static ssize_t
 464 max_write_same_blocks_store(struct device *dev, struct device_attribute *attr,
 465                             const char *buf, size_t count)
 466 {
 467         struct scsi_disk *sdkp = to_scsi_disk(dev);
 468         struct scsi_device *sdp = sdkp->device;
 469         unsigned long max;
 470         int err;
 471
 472         if (!capable(CAP_SYS_ADMIN))
 473                 return -EACCES;
 474
 475         if (sdp->type != TYPE_DISK)
 476                 return -EINVAL;
 477
 478         err = kstrtoul(buf, 10, &max);
 479
 480         if (err)
 481                 return err;
 482
 483         if (max == 0)
 484                 sdp->no_write_same = 1;
 485         else if (max <= SD_MAX_WS16_BLOCKS) {
 486                 sdp->no_write_same = 0;
 487                 sdkp->max_ws_blocks = max;
 488         }
 489
 490         sd_config_write_same(sdkp);
 491
 492         return count;
 493 }
 494 static DEVICE_ATTR_RW(max_write_same_blocks);
 495
 496 static struct attribute *sd_disk_attrs[] = {
 497         &dev_attr_cache_type.attr,
 498         &dev_attr_FUA.attr,
 499         &dev_attr_allow_restart.attr,
 500         &dev_attr_manage_start_stop.attr,
 501         &dev_attr_protection_type.attr,
 502         &dev_attr_protection_mode.attr,
 503         &dev_attr_app_tag_own.attr,
 504         &dev_attr_thin_provisioning.attr,
 505         &dev_attr_provisioning_mode.attr,
 506         &dev_attr_max_write_same_blocks.attr,
 507         &dev_attr_max_medium_access_timeouts.attr,
 508         NULL,
 509 };
 510 ATTRIBUTE_GROUPS(sd_disk);
 511
 512 static struct class sd_disk_class = {
 513         .name           = "scsi_disk",
 514         .owner          = THIS_MODULE,
 515         .dev_release    = scsi_disk_release,
 516         .dev_groups     = sd_disk_groups,
 517 };
 518
 519 static const struct dev_pm_ops sd_pm_ops = {
 520         .suspend                = sd_suspend_system,
 521         .resume                 = sd_resume,
 522         .poweroff               = sd_suspend_system,
 523         .restore                = sd_resume,
 524         .runtime_suspend        = sd_suspend_runtime,
 525         .runtime_resume         = sd_resume,
 526 };
 527
 528 static struct scsi_driver sd_template = {
 529         .gendrv = {
 530                 .name           = "sd",
 531                 .owner          = THIS_MODULE,
 532                 .probe          = sd_probe,
 533                 .remove         = sd_remove,
 534                 .shutdown       = sd_shutdown,
 535                 .pm             = &sd_pm_ops,
 536         },
 537         .rescan                 = sd_rescan,
 538         .init_command           = sd_init_command,
 539         .uninit_command         = sd_uninit_command,
 540         .done                   = sd_done,
 541         .eh_action              = sd_eh_action,
 542 };
 543
 544 /*
 545  * Dummy kobj_map->probe function.
 546  * The default ->probe function will call modprobe, which is
 547  * pointless as this module is already loaded.
 548  */
 549 static struct kobject *sd_default_probe(dev_t devt, int *partno, void *data)
 550 {
 551         return NULL;
 552 }
 553
 554 /*
 555  * Device no to disk mapping:
 556  *
 557  *       major         disc2     disc  p1
 558  *   |............|.............|....|....| <- dev_t
 559  *    31        20 19          8 7  4 3  0
 560  *
 561  * Inside a major, we have 16k disks, however mapped non-
 562  * contiguously. The first 16 disks are for major0, the next
 563  * ones with major1, ... Disk 256 is for major0 again, disk 272
 564  * for major1, ...
 565  * As we stay compatible with our numbering scheme, we can reuse
 566  * the well-know SCSI majors 8, 65--71, 136--143.
 567  */
 568 static int sd_major(int major_idx)
 569 {
 570         switch (major_idx) {
 571         case 0:
 572                 return SCSI_DISK0_MAJOR;
 573         case 1 ... 7:
 574                 return SCSI_DISK1_MAJOR + major_idx - 1;
 575         case 8 ... 15:
 576                 return SCSI_DISK8_MAJOR + major_idx - 8;
 577         default:
 578                 BUG();
 579                 return 0;       /* shut up gcc */
 580         }
 581 }
 582
 583 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
 584 {
 585         struct scsi_disk *sdkp = NULL;
 586
 587         mutex_lock(&sd_ref_mutex);
 588
 589         if (disk->private_data) {
 590                 sdkp = scsi_disk(disk);
 591                 if (scsi_device_get(sdkp->device) == 0)
 592                         get_device(&sdkp->dev);
 593                 else
 594                         sdkp = NULL;
 595         }
 596         mutex_unlock(&sd_ref_mutex);
 597         return sdkp;
 598 }
 599
 600 static void scsi_disk_put(struct scsi_disk *sdkp)
 601 {
 602         struct scsi_device *sdev = sdkp->device;
 603
 604         mutex_lock(&sd_ref_mutex);
 605         put_device(&sdkp->dev);
 606         scsi_device_put(sdev);
 607         mutex_unlock(&sd_ref_mutex);
 608 }
 609
 610 static unsigned char sd_setup_protect_cmnd(struct scsi_cmnd *scmd,
 611                                            unsigned int dix, unsigned int dif)
 612 {
 613         struct bio *bio = scmd->request->bio;
 614         unsigned int prot_op = sd_prot_op(rq_data_dir(scmd->request), dix, dif);
 615         unsigned int protect = 0;
 616
 617         if (dix) {                              /* DIX Type 0, 1, 2, 3 */
 618                 if (bio_integrity_flagged(bio, BIP_IP_CHECKSUM))
 619                         scmd->prot_flags |= SCSI_PROT_IP_CHECKSUM;
 620
 621                 if (bio_integrity_flagged(bio, BIP_CTRL_NOCHECK) == false)
 622                         scmd->prot_flags |= SCSI_PROT_GUARD_CHECK;
 623         }
 624
 625         if (dif != SD_DIF_TYPE3_PROTECTION) {   /* DIX/DIF Type 0, 1, 2 */
 626                 scmd->prot_flags |= SCSI_PROT_REF_INCREMENT;
 627
 628                 if (bio_integrity_flagged(bio, BIP_CTRL_NOCHECK) == false)
 629                         scmd->prot_flags |= SCSI_PROT_REF_CHECK;
 630         }
 631
 632         if (dif) {                              /* DIX/DIF Type 1, 2, 3 */
 633                 scmd->prot_flags |= SCSI_PROT_TRANSFER_PI;
 634
 635                 if (bio_integrity_flagged(bio, BIP_DISK_NOCHECK))
 636                         protect = 3 << 5;       /* Disable target PI checking */
 637                 else
 638                         protect = 1 << 5;       /* Enable target PI checking */
 639         }
 640
 641         scsi_set_prot_op(scmd, prot_op);
 642         scsi_set_prot_type(scmd, dif);
 643         scmd->prot_flags &= sd_prot_flag_mask(prot_op);
 644
 645         return protect;
 646 }
 647
 648 static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
 649 {
 650         struct request_queue *q = sdkp->disk->queue;
 651         unsigned int logical_block_size = sdkp->device->sector_size;
 652         unsigned int max_blocks = 0;
 653
 654         q->limits.discard_zeroes_data = 0;
 655
 656         /*
 657          * When LBPRZ is reported, discard alignment and granularity
 658          * must be fixed to the logical block size. Otherwise the block
 659          * layer will drop misaligned portions of the request which can
 660          * lead to data corruption. If LBPRZ is not set, we honor the
 661          * device preference.
 662          */
 663         if (sdkp->lbprz) {
 664                 q->limits.discard_alignment = 0;
 665                 q->limits.discard_granularity = logical_block_size;
 666         } else {
 667                 q->limits.discard_alignment = sdkp->unmap_alignment *
 668                         logical_block_size;
 669                 q->limits.discard_granularity =
 670                         max(sdkp->physical_block_size,
 671                             sdkp->unmap_granularity * logical_block_size);
 672         }
 673
 674         sdkp->provisioning_mode = mode;
 675
 676         switch (mode) {
 677
 678         case SD_LBP_DISABLE:
 679                 blk_queue_max_discard_sectors(q, 0);
 680                 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
 681                 return;
 682
 683         case SD_LBP_UNMAP:
 684                 max_blocks = min_not_zero(sdkp->max_unmap_blocks,
 685                                           (u32)SD_MAX_WS16_BLOCKS);
 686                 break;
 687
 688         case SD_LBP_WS16:
 689                 max_blocks = min_not_zero(sdkp->max_ws_blocks,
 690                                           (u32)SD_MAX_WS16_BLOCKS);
 691                 q->limits.discard_zeroes_data = sdkp->lbprz;
 692                 break;
 693
 694         case SD_LBP_WS10:
 695                 max_blocks = min_not_zero(sdkp->max_ws_blocks,
 696                                           (u32)SD_MAX_WS10_BLOCKS);
 697                 q->limits.discard_zeroes_data = sdkp->lbprz;
 698                 break;
 699
 700         case SD_LBP_ZERO:
 701                 max_blocks = min_not_zero(sdkp->max_ws_blocks,
 702                                           (u32)SD_MAX_WS10_BLOCKS);
 703                 q->limits.discard_zeroes_data = 1;
 704                 break;
 705         }
 706
 707         blk_queue_max_discard_sectors(q, max_blocks * (logical_block_size >> 9));
 708         queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
 709 }
 710
 711 /**
 712  * sd_setup_discard_cmnd - unmap blocks on thinly provisioned device
 713  * @sdp: scsi device to operate one
 714  * @rq: Request to prepare
 715  *
 716  * Will issue either UNMAP or WRITE SAME(16) depending on preference
 717  * indicated by target device.
 718  **/
 719 static int sd_setup_discard_cmnd(struct scsi_cmnd *cmd)
 720 {
 721         struct request *rq = cmd->request;
 722         struct scsi_device *sdp = cmd->device;
 723         struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
 724         sector_t sector = blk_rq_pos(rq);
 725         unsigned int nr_sectors = blk_rq_sectors(rq);
 726         unsigned int nr_bytes = blk_rq_bytes(rq);
 727         unsigned int len;
 728         int ret;
 729         char *buf;
 730         struct page *page;
 731
 732         sector >>= ilog2(sdp->sector_size) - 9;
 733         nr_sectors >>= ilog2(sdp->sector_size) - 9;
 734
 735         page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
 736         if (!page)
 737                 return BLKPREP_DEFER;
 738
 739         switch (sdkp->provisioning_mode) {
 740         case SD_LBP_UNMAP:
 741                 buf = page_address(page);
 742
 743                 cmd->cmd_len = 10;
 744                 cmd->cmnd[0] = UNMAP;
 745                 cmd->cmnd[8] = 24;
 746
 747                 put_unaligned_be16(6 + 16, &buf[0]);
 748                 put_unaligned_be16(16, &buf[2]);
 749                 put_unaligned_be64(sector, &buf[8]);
 750                 put_unaligned_be32(nr_sectors, &buf[16]);
 751
 752                 len = 24;
 753                 break;
 754
 755         case SD_LBP_WS16:
 756                 cmd->cmd_len = 16;
 757                 cmd->cmnd[0] = WRITE_SAME_16;
 758                 cmd->cmnd[1] = 0x8; /* UNMAP */
 759                 put_unaligned_be64(sector, &cmd->cmnd[2]);
 760                 put_unaligned_be32(nr_sectors, &cmd->cmnd[10]);
 761
 762                 len = sdkp->device->sector_size;
 763                 break;
 764
 765         case SD_LBP_WS10:
 766         case SD_LBP_ZERO:
 767                 cmd->cmd_len = 10;
 768                 cmd->cmnd[0] = WRITE_SAME;
 769                 if (sdkp->provisioning_mode == SD_LBP_WS10)
 770                         cmd->cmnd[1] = 0x8; /* UNMAP */
 771                 put_unaligned_be32(sector, &cmd->cmnd[2]);
 772                 put_unaligned_be16(nr_sectors, &cmd->cmnd[7]);
 773
 774                 len = sdkp->device->sector_size;
 775                 break;
 776
 777         default:
 778                 ret = BLKPREP_KILL;
 779                 goto out;
 780         }
 781
 782         rq->completion_data = page;
 783         rq->timeout = SD_TIMEOUT;
 784
 785         cmd->transfersize = len;
 786         cmd->allowed = SD_MAX_RETRIES;
 787
 788         /*
 789          * Initially __data_len is set to the amount of data that needs to be
 790          * transferred to the target. This amount depends on whether WRITE SAME
 791          * or UNMAP is being used. After the scatterlist has been mapped by
 792          * scsi_init_io() we set __data_len to the size of the area to be
 793          * discarded on disk. This allows us to report completion on the full
 794          * amount of blocks described by the request.
 795          */
 796         blk_add_request_payload(rq, page, len);
 797         ret = scsi_init_io(cmd);
 798         rq->__data_len = nr_bytes;
 799
 800 out:
 801         if (ret != BLKPREP_OK)
 802                 __free_page(page);
 803         return ret;
 804 }
 805
 806 static void sd_config_write_same(struct scsi_disk *sdkp)
 807 {
 808         struct request_queue *q = sdkp->disk->queue;
 809         unsigned int logical_block_size = sdkp->device->sector_size;
 810
 811         if (sdkp->device->no_write_same) {
 812                 sdkp->max_ws_blocks = 0;
 813                 goto out;
 814         }
 815
 816         /* Some devices can not handle block counts above 0xffff despite
 817          * supporting WRITE SAME(16). Consequently we default to 64k
 818          * blocks per I/O unless the device explicitly advertises a
 819          * bigger limit.
 820          */
 821         if (sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS)
 822                 sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks,
 823                                                    (u32)SD_MAX_WS16_BLOCKS);
 824         else if (sdkp->ws16 || sdkp->ws10 || sdkp->device->no_report_opcodes)
 825                 sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks,
 826                                                    (u32)SD_MAX_WS10_BLOCKS);
 827         else {
 828                 sdkp->device->no_write_same = 1;
 829                 sdkp->max_ws_blocks = 0;
 830         }
 831
 832 out:
 833         blk_queue_max_write_same_sectors(q, sdkp->max_ws_blocks *
 834                                          (logical_block_size >> 9));
 835 }
 836
 837 /**
 838  * sd_setup_write_same_cmnd - write the same data to multiple blocks
 839  * @cmd: command to prepare
 840  *
 841  * Will issue either WRITE SAME(10) or WRITE SAME(16) depending on
 842  * preference indicated by target device.
 843  **/
 844 static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
 845 {
 846         struct request *rq = cmd->request;
 847         struct scsi_device *sdp = cmd->device;
 848         struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
 849         struct bio *bio = rq->bio;
 850         sector_t sector = blk_rq_pos(rq);
 851         unsigned int nr_sectors = blk_rq_sectors(rq);
 852         unsigned int nr_bytes = blk_rq_bytes(rq);
 853         int ret;
 854
 855         if (sdkp->device->no_write_same)
 856                 return BLKPREP_KILL;
 857
 858         BUG_ON(bio_offset(bio) || bio_iovec(bio).bv_len != sdp->sector_size);
 859
 860         sector >>= ilog2(sdp->sector_size) - 9;
 861         nr_sectors >>= ilog2(sdp->sector_size) - 9;
 862
 863         rq->timeout = SD_WRITE_SAME_TIMEOUT;
 864
 865         if (sdkp->ws16 || sector > 0xffffffff || nr_sectors > 0xffff) {
 866                 cmd->cmd_len = 16;
 867                 cmd->cmnd[0] = WRITE_SAME_16;
 868                 put_unaligned_be64(sector, &cmd->cmnd[2]);
 869                 put_unaligned_be32(nr_sectors, &cmd->cmnd[10]);
 870         } else {
 871                 cmd->cmd_len = 10;
 872                 cmd->cmnd[0] = WRITE_SAME;
 873                 put_unaligned_be32(sector, &cmd->cmnd[2]);
 874                 put_unaligned_be16(nr_sectors, &cmd->cmnd[7]);
 875         }
 876
 877         cmd->transfersize = sdp->sector_size;
 878         cmd->allowed = SD_MAX_RETRIES;
 879
 880         /*
 881          * For WRITE_SAME the data transferred in the DATA IN buffer is
 882          * different from the amount of data actually written to the target.
 883          *
 884          * We set up __data_len to the amount of data transferred from the
 885          * DATA IN buffer so that blk_rq_map_sg set up the proper S/G list
 886          * to transfer a single sector of data first, but then reset it to
 887          * the amount of data to be written right after so that the I/O path
 888          * knows how much to actually write.
 889          */
 890         rq->__data_len = sdp->sector_size;
 891         ret = scsi_init_io(cmd);
 892         rq->__data_len = nr_bytes;
 893         return ret;
 894 }
 895
 896 static int sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
 897 {
 898         struct request *rq = cmd->request;
 899
 900         /* flush requests don't perform I/O, zero the S/G table */
 901         memset(&cmd->sdb, 0, sizeof(cmd->sdb));
 902
 903         cmd->cmnd[0] = SYNCHRONIZE_CACHE;
 904         cmd->cmd_len = 10;
 905         cmd->transfersize = 0;
 906         cmd->allowed = SD_MAX_RETRIES;
 907
 908         rq->timeout = rq->q->rq_timeout * SD_FLUSH_TIMEOUT_MULTIPLIER;
 909         return BLKPREP_OK;
 910 }
 911
 912 static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 913 {
 914         struct request *rq = SCpnt->request;
 915         struct scsi_device *sdp = SCpnt->device;
 916         struct gendisk *disk = rq->rq_disk;
 917         struct scsi_disk *sdkp;
 918         sector_t block = blk_rq_pos(rq);
 919         sector_t threshold;
 920         unsigned int this_count = blk_rq_sectors(rq);
 921         unsigned int dif, dix;
 922         int ret;
 923         unsigned char protect;
 924
 925         ret = scsi_init_io(SCpnt);
 926         if (ret != BLKPREP_OK)
 927                 goto out;
 928         SCpnt = rq->special;
 929         sdkp = scsi_disk(disk);
 930
 931         /* from here on until we're complete, any goto out
 932          * is used for a killable error condition */
 933         ret = BLKPREP_KILL;
 934
 935         SCSI_LOG_HLQUEUE(1,
 936                 scmd_printk(KERN_INFO, SCpnt,
 937                         "%s: block=%llu, count=%d\n",
 938                         __func__, (unsigned long long)block, this_count));
 939
 940         if (!sdp || !scsi_device_online(sdp) ||
 941             block + blk_rq_sectors(rq) > get_capacity(disk)) {
 942                 SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 943                                                 "Finishing %u sectors\n",
 944                                                 blk_rq_sectors(rq)));
 945                 SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 946                                                 "Retry with 0x%p\n", SCpnt));
 947                 goto out;
 948         }
 949
 950         if (sdp->changed) {
 951                 /*
 952                  * quietly refuse to do anything to a changed disc until
 953                  * the changed bit has been reset
 954                  */
 955                 /* printk("SCSI disk has been changed or is not present. Prohibiting further I/O.\n"); */
 956                 goto out;
 957         }
 958
 959         /*
 960          * Some SD card readers can't handle multi-sector accesses which touch
 961          * the last one or two hardware sectors.  Split accesses as needed.
 962          */
 963         threshold = get_capacity(disk) - SD_LAST_BUGGY_SECTORS *
 964                 (sdp->sector_size / 512);
 965
 966         if (unlikely(sdp->last_sector_bug && block + this_count > threshold)) {
 967                 if (block < threshold) {
 968                         /* Access up to the threshold but not beyond */
 969                         this_count = threshold - block;
 970                 } else {
 971                         /* Access only a single hardware sector */
 972                         this_count = sdp->sector_size / 512;
 973                 }
 974         }
 975
 976         SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
 977                                         (unsigned long long)block));
 978
 979         /*
 980          * If we have a 1K hardware sectorsize, prevent access to single
 981          * 512 byte sectors.  In theory we could handle this - in fact
 982          * the scsi cdrom driver must be able to handle this because
 983          * we typically use 1K blocksizes, and cdroms typically have
 984          * 2K hardware sectorsizes.  Of course, things are simpler
 985          * with the cdrom, since it is read-only.  For performance
 986          * reasons, the filesystems should be able to handle this
 987          * and not force the scsi disk driver to use bounce buffers
 988          * for this.
 989          */
 990         if (sdp->sector_size == 1024) {
 991                 if ((block & 1) || (blk_rq_sectors(rq) & 1)) {
 992                         scmd_printk(KERN_ERR, SCpnt,
 993                                     "Bad block number requested\n");
 994                         goto out;
 995                 } else {
 996                         block = block >> 1;
 997                         this_count = this_count >> 1;
 998                 }
 999         }
1000         if (sdp->sector_size == 2048) {
1001                 if ((block & 3) || (blk_rq_sectors(rq) & 3)) {
1002                         scmd_printk(KERN_ERR, SCpnt,
1003                                     "Bad block number requested\n");
1004                         goto out;
1005                 } else {
1006                         block = block >> 2;
1007                         this_count = this_count >> 2;
1008                 }
1009         }
1010         if (sdp->sector_size == 4096) {
1011                 if ((block & 7) || (blk_rq_sectors(rq) & 7)) {
1012                         scmd_printk(KERN_ERR, SCpnt,
1013                                     "Bad block number requested\n");
1014                         goto out;
1015                 } else {
1016                         block = block >> 3;
1017                         this_count = this_count >> 3;
1018                 }
1019         }
1020         if (rq_data_dir(rq) == WRITE) {
1021                 SCpnt->cmnd[0] = WRITE_6;
1022
1023                 if (blk_integrity_rq(rq))
1024                         sd_dif_prepare(SCpnt);
1025
1026         } else if (rq_data_dir(rq) == READ) {
1027                 SCpnt->cmnd[0] = READ_6;
1028         } else {
1029                 scmd_printk(KERN_ERR, SCpnt, "Unknown command %llx\n", (unsigned long long) rq->cmd_flags);
1030                 goto out;
1031         }
1032
1033         SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
1034                                         "%s %d/%u 512 byte blocks.\n",
1035                                         (rq_data_dir(rq) == WRITE) ?
1036                                         "writing" : "reading", this_count,
1037                                         blk_rq_sectors(rq)));
1038
1039         dix = scsi_prot_sg_count(SCpnt);
1040         dif = scsi_host_dif_capable(SCpnt->device->host, sdkp->protection_type);
1041
1042         if (dif || dix)
1043                 protect = sd_setup_protect_cmnd(SCpnt, dix, dif);
1044         else
1045                 protect = 0;
1046
1047         if (protect && sdkp->protection_type == SD_DIF_TYPE2_PROTECTION) {
1048                 SCpnt->cmnd = mempool_alloc(sd_cdb_pool, GFP_ATOMIC);
1049
1050                 if (unlikely(SCpnt->cmnd == NULL)) {
1051                         ret = BLKPREP_DEFER;
1052                         goto out;
1053                 }
1054
1055                 SCpnt->cmd_len = SD_EXT_CDB_SIZE;
1056                 memset(SCpnt->cmnd, 0, SCpnt->cmd_len);
1057                 SCpnt->cmnd[0] = VARIABLE_LENGTH_CMD;
1058                 SCpnt->cmnd[7] = 0x18;
1059                 SCpnt->cmnd[9] = (rq_data_dir(rq) == READ) ? READ_32 : WRITE_32;
1060                 SCpnt->cmnd[10] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
1061
1062                 /* LBA */
1063                 SCpnt->cmnd[12] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
1064                 SCpnt->cmnd[13] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
1065                 SCpnt->cmnd[14] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
1066                 SCpnt->cmnd[15] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
1067                 SCpnt->cmnd[16] = (unsigned char) (block >> 24) & 0xff;
1068                 SCpnt->cmnd[17] = (unsigned char) (block >> 16) & 0xff;
1069                 SCpnt->cmnd[18] = (unsigned char) (block >> 8) & 0xff;
1070                 SCpnt->cmnd[19] = (unsigned char) block & 0xff;
1071
1072                 /* Expected Indirect LBA */
1073                 SCpnt->cmnd[20] = (unsigned char) (block >> 24) & 0xff;
1074                 SCpnt->cmnd[21] = (unsigned char) (block >> 16) & 0xff;
1075                 SCpnt->cmnd[22] = (unsigned char) (block >> 8) & 0xff;
1076                 SCpnt->cmnd[23] = (unsigned char) block & 0xff;
1077
1078                 /* Transfer length */
1079                 SCpnt->cmnd[28] = (unsigned char) (this_count >> 24) & 0xff;
1080                 SCpnt->cmnd[29] = (unsigned char) (this_count >> 16) & 0xff;
1081                 SCpnt->cmnd[30] = (unsigned char) (this_count >> 8) & 0xff;
1082                 SCpnt->cmnd[31] = (unsigned char) this_count & 0xff;
1083         } else if (sdp->use_16_for_rw || (this_count > 0xffff)) {
1084                 SCpnt->cmnd[0] += READ_16 - READ_6;
1085                 SCpnt->cmnd[1] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
1086                 SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
1087                 SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
1088                 SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
1089                 SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
1090                 SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
1091                 SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
1092                 SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
1093                 SCpnt->cmnd[9] = (unsigned char) block & 0xff;
1094                 SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
1095                 SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
1096                 SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
1097                 SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
1098                 SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
1099         } else if ((this_count > 0xff) || (block > 0x1fffff) ||
1100                    scsi_device_protection(SCpnt->device) ||
1101                    SCpnt->device->use_10_for_rw) {
1102                 SCpnt->cmnd[0] += READ_10 - READ_6;
1103                 SCpnt->cmnd[1] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
1104                 SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
1105                 SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
1106                 SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
1107                 SCpnt->cmnd[5] = (unsigned char) block & 0xff;
1108                 SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
1109                 SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
1110                 SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
1111         } else {
1112                 if (unlikely(rq->cmd_flags & REQ_FUA)) {
1113                         /*
1114                          * This happens only if this drive failed
1115                          * 10byte rw command with ILLEGAL_REQUEST
1116                          * during operation and thus turned off
1117                          * use_10_for_rw.
1118                          */
1119                         scmd_printk(KERN_ERR, SCpnt,
1120                                     "FUA write on READ/WRITE(6) drive\n");
1121                         goto out;
1122                 }
1123
1124                 SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
1125                 SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
1126                 SCpnt->cmnd[3] = (unsigned char) block & 0xff;
1127                 SCpnt->cmnd[4] = (unsigned char) this_count;
1128                 SCpnt->cmnd[5] = 0;
1129         }
1130         SCpnt->sdb.length = this_count * sdp->sector_size;
1131
1132         /*
1133          * We shouldn't disconnect in the middle of a sector, so with a dumb
1134          * host adapter, it's safe to assume that we can at least transfer
1135          * this many bytes between each connect / disconnect.
1136          */
1137         SCpnt->transfersize = sdp->sector_size;
1138         SCpnt->underflow = this_count << 9;
1139         SCpnt->allowed = SD_MAX_RETRIES;
1140
1141         /*
1142          * This indicates that the command is ready from our end to be
1143          * queued.
1144          */
1145         ret = BLKPREP_OK;
1146  out:
1147         return ret;
1148 }
1149
1150 static int sd_init_command(struct scsi_cmnd *cmd)
1151 {
1152         struct request *rq = cmd->request;
1153
1154         if (rq->cmd_flags & REQ_DISCARD)
1155                 return sd_setup_discard_cmnd(cmd);
1156         else if (rq->cmd_flags & REQ_WRITE_SAME)
1157                 return sd_setup_write_same_cmnd(cmd);
1158         else if (rq->cmd_flags & REQ_FLUSH)
1159                 return sd_setup_flush_cmnd(cmd);
1160         else
1161                 return sd_setup_read_write_cmnd(cmd);
1162 }
1163
1164 static void sd_uninit_command(struct scsi_cmnd *SCpnt)
1165 {
1166         struct request *rq = SCpnt->request;
1167
1168         if (rq->cmd_flags & REQ_DISCARD)
1169                 __free_page(rq->completion_data);
1170
1171         if (SCpnt->cmnd != rq->cmd) {
1172                 mempool_free(SCpnt->cmnd, sd_cdb_pool);
1173                 SCpnt->cmnd = NULL;
1174                 SCpnt->cmd_len = 0;
1175         }
1176 }
1177
1178 /**
1179  *      sd_open - open a scsi disk device
1180  *      @inode: only i_rdev member may be used
1181  *      @filp: only f_mode and f_flags may be used
1182  *
1183  *      Returns 0 if successful. Returns a negated errno value in case
1184  *      of error.
1185  *
1186  *      Note: This can be called from a user context (e.g. fsck(1) )
1187  *      or from within the kernel (e.g. as a result of a mount(1) ).
1188  *      In the latter case @inode and @filp carry an abridged amount
1189  *      of information as noted above.
1190  *
1191  *      Locking: called with bdev->bd_mutex held.
1192  **/
1193 static int sd_open(struct block_device *bdev, fmode_t mode)
1194 {
1195         struct scsi_disk *sdkp = scsi_disk_get(bdev->bd_disk);
1196         struct scsi_device *sdev;
1197         int retval;
1198
1199         if (!sdkp)
1200                 return -ENXIO;
1201
1202         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
1203
1204         sdev = sdkp->device;
1205
1206         /*
1207          * If the device is in error recovery, wait until it is done.
1208          * If the device is offline, then disallow any access to it.
1209          */
1210         retval = -ENXIO;
1211         if (!scsi_block_when_processing_errors(sdev))
1212                 goto error_out;
1213
1214         if (sdev->removable || sdkp->write_prot)
1215                 check_disk_change(bdev);
1216
1217         /*
1218          * If the drive is empty, just let the open fail.
1219          */
1220         retval = -ENOMEDIUM;
1221         if (sdev->removable && !sdkp->media_present && !(mode & FMODE_NDELAY))
1222                 goto error_out;
1223
1224         /*
1225          * If the device has the write protect tab set, have the open fail
1226          * if the user expects to be able to write to the thing.
1227          */
1228         retval = -EROFS;
1229         if (sdkp->write_prot && (mode & FMODE_WRITE))
1230                 goto error_out;
1231
1232         /*
1233          * It is possible that the disk changing stuff resulted in
1234          * the device being taken offline.  If this is the case,
1235          * report this to the user, and don't pretend that the
1236          * open actually succeeded.
1237          */
1238         retval = -ENXIO;
1239         if (!scsi_device_online(sdev))
1240                 goto error_out;
1241
1242         if ((atomic_inc_return(&sdkp->openers) == 1) && sdev->removable) {
1243                 if (scsi_block_when_processing_errors(sdev))
1244                         scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
1245         }
1246
1247         return 0;
1248
1249 error_out:
1250         scsi_disk_put(sdkp);
1251         return retval;
1252 }
1253
1254 /**
1255  *      sd_release - invoked when the (last) close(2) is called on this
1256  *      scsi disk.
1257  *      @inode: only i_rdev member may be used
1258  *      @filp: only f_mode and f_flags may be used
1259  *
1260  *      Returns 0.
1261  *
1262  *      Note: may block (uninterruptible) if error recovery is underway
1263  *      on this disk.
1264  *
1265  *      Locking: called with bdev->bd_mutex held.
1266  **/
1267 static void sd_release(struct gendisk *disk, fmode_t mode)
1268 {
1269         struct scsi_disk *sdkp = scsi_disk(disk);
1270         struct scsi_device *sdev = sdkp->device;
1271
1272         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_release\n"));
1273
1274         if (atomic_dec_return(&sdkp->openers) == 0 && sdev->removable) {
1275                 if (scsi_block_when_processing_errors(sdev))
1276                         scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
1277         }
1278
1279         scsi_disk_put(sdkp);
1280 }
1281
1282 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1283 {
1284         struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
1285         struct scsi_device *sdp = sdkp->device;
1286         struct Scsi_Host *host = sdp->host;
1287         sector_t capacity = logical_to_sectors(sdp, sdkp->capacity);
1288         int diskinfo[4];
1289
1290         /* default to most commonly used values */
1291         diskinfo[0] = 0x40;     /* 1 << 6 */
1292         diskinfo[1] = 0x20;     /* 1 << 5 */
1293         diskinfo[2] = capacity >> 11;
1294
1295         /* override with calculated, extended default, or driver values */
1296         if (host->hostt->bios_param)
1297                 host->hostt->bios_param(sdp, bdev, capacity, diskinfo);
1298         else
1299                 scsicam_bios_param(bdev, capacity, diskinfo);
1300
1301         geo->heads = diskinfo[0];
1302         geo->sectors = diskinfo[1];
1303         geo->cylinders = diskinfo[2];
1304         return 0;
1305 }
1306
1307 /**
1308  *      sd_ioctl - process an ioctl
1309  *      @inode: only i_rdev/i_bdev members may be used
1310  *      @filp: only f_mode and f_flags may be used
1311  *      @cmd: ioctl command number
1312  *      @arg: this is third argument given to ioctl(2) system call.
1313  *      Often contains a pointer.
1314  *
1315  *      Returns 0 if successful (some ioctls return positive numbers on
1316  *      success as well). Returns a negated errno value in case of error.
1317  *
1318  *      Note: most ioctls are forward onto the block subsystem or further
1319  *      down in the scsi subsystem.
1320  **/
1321 static int sd_ioctl(struct block_device *bdev, fmode_t mode,
1322                     unsigned int cmd, unsigned long arg)
1323 {
1324         struct gendisk *disk = bdev->bd_disk;
1325         struct scsi_disk *sdkp = scsi_disk(disk);
1326         struct scsi_device *sdp = sdkp->device;
1327         void __user *p = (void __user *)arg;
1328         int error;
1329
1330         SCSI_LOG_IOCTL(1, sd_printk(KERN_INFO, sdkp, "sd_ioctl: disk=%s, "
1331                                     "cmd=0x%x\n", disk->disk_name, cmd));
1332
1333         error = scsi_verify_blk_ioctl(bdev, cmd);
1334         if (error < 0)
1335                 return error;
1336
1337         /*
1338          * If we are in the middle of error recovery, don't let anyone
1339          * else try and use this device.  Also, if error recovery fails, it
1340          * may try and take the device offline, in which case all further
1341          * access to the device is prohibited.
1342          */
1343         error = scsi_ioctl_block_when_processing_errors(sdp, cmd,
1344                         (mode & FMODE_NDELAY) != 0);
1345         if (error)
1346                 goto out;
1347
1348         /*
1349          * Send SCSI addressing ioctls directly to mid level, send other
1350          * ioctls to block level and then onto mid level if they can't be
1351          * resolved.
1352          */
1353         switch (cmd) {
1354                 case SCSI_IOCTL_GET_IDLUN:
1355                 case SCSI_IOCTL_GET_BUS_NUMBER:
1356                         error = scsi_ioctl(sdp, cmd, p);
1357                         break;
1358                 default:
1359                         error = scsi_cmd_blk_ioctl(bdev, mode, cmd, p);
1360                         if (error != -ENOTTY)
1361                                 break;
1362                         error = scsi_ioctl(sdp, cmd, p);
1363                         break;
1364         }
1365 out:
1366         return error;
1367 }
1368
1369 static void set_media_not_present(struct scsi_disk *sdkp)
1370 {
1371         if (sdkp->media_present)
1372                 sdkp->device->changed = 1;
1373
1374         if (sdkp->device->removable) {
1375                 sdkp->media_present = 0;
1376                 sdkp->capacity = 0;
1377         }
1378 }
1379
1380 static int media_not_present(struct scsi_disk *sdkp,
1381                              struct scsi_sense_hdr *sshdr)
1382 {
1383         if (!scsi_sense_valid(sshdr))
1384                 return 0;
1385
1386         /* not invoked for commands that could return deferred errors */
1387         switch (sshdr->sense_key) {
1388         case UNIT_ATTENTION:
1389         case NOT_READY:
1390                 /* medium not present */
1391                 if (sshdr->asc == 0x3A) {
1392                         set_media_not_present(sdkp);
1393                         return 1;
1394                 }
1395         }
1396         return 0;
1397 }
1398
1399 /**
1400  *      sd_check_events - check media events
1401  *      @disk: kernel device descriptor
1402  *      @clearing: disk events currently being cleared
1403  *
1404  *      Returns mask of DISK_EVENT_*.
1405  *
1406  *      Note: this function is invoked from the block subsystem.
1407  **/
1408 static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
1409 {
1410         struct scsi_disk *sdkp = scsi_disk_get(disk);
1411         struct scsi_device *sdp;
1412         struct scsi_sense_hdr *sshdr = NULL;
1413         int retval;
1414
1415         if (!sdkp)
1416                 return 0;
1417
1418         sdp = sdkp->device;
1419         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_check_events\n"));
1420
1421         /*
1422          * If the device is offline, don't send any commands - just pretend as
1423          * if the command failed.  If the device ever comes back online, we
1424          * can deal with it then.  It is only because of unrecoverable errors
1425          * that we would ever take a device offline in the first place.
1426          */
1427         if (!scsi_device_online(sdp)) {
1428                 set_media_not_present(sdkp);
1429                 goto out;
1430         }
1431
1432         /*
1433          * Using TEST_UNIT_READY enables differentiation between drive with
1434          * no cartridge loaded - NOT READY, drive with changed cartridge -
1435          * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
1436          *
1437          * Drives that auto spin down. eg iomega jaz 1G, will be started
1438          * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
1439          * sd_revalidate() is called.
1440          */
1441         retval = -ENODEV;
1442
1443         if (scsi_block_when_processing_errors(sdp)) {
1444                 sshdr  = kzalloc(sizeof(*sshdr), GFP_KERNEL);
1445                 retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
1446                                               sshdr);
1447         }
1448
1449         /* failed to execute TUR, assume media not present */
1450         if (host_byte(retval)) {
1451                 set_media_not_present(sdkp);
1452                 goto out;
1453         }
1454
1455         if (media_not_present(sdkp, sshdr))
1456                 goto out;
1457
1458         /*
1459          * For removable scsi disk we have to recognise the presence
1460          * of a disk in the drive.
1461          */
1462         if (!sdkp->media_present)
1463                 sdp->changed = 1;
1464         sdkp->media_present = 1;
1465 out:
1466         /*
1467          * sdp->changed is set under the following conditions:
1468          *
1469          *      Medium present state has changed in either direction.
1470          *      Device has indicated UNIT_ATTENTION.
1471          */
1472         kfree(sshdr);
1473         retval = sdp->changed ? DISK_EVENT_MEDIA_CHANGE : 0;
1474         sdp->changed = 0;
1475         scsi_disk_put(sdkp);
1476         return retval;
1477 }
1478
1479 static int sd_sync_cache(struct scsi_disk *sdkp)
1480 {
1481         int retries, res;
1482         struct scsi_device *sdp = sdkp->device;
1483         const int timeout = sdp->request_queue->rq_timeout
1484                 * SD_FLUSH_TIMEOUT_MULTIPLIER;
1485         struct scsi_sense_hdr sshdr;
1486
1487         if (!scsi_device_online(sdp))
1488                 return -ENODEV;
1489
1490         for (retries = 3; retries > 0; --retries) {
1491                 unsigned char cmd[10] = { 0 };
1492
1493                 cmd[0] = SYNCHRONIZE_CACHE;
1494                 /*
1495                  * Leave the rest of the command zero to indicate
1496                  * flush everything.
1497                  */
1498                 res = scsi_execute_req_flags(sdp, cmd, DMA_NONE, NULL, 0,
1499                                              &sshdr, timeout, SD_MAX_RETRIES,
1500                                              NULL, REQ_PM);
1501                 if (res == 0)
1502                         break;
1503         }
1504
1505         if (res) {
1506                 sd_print_result(sdkp, "Synchronize Cache(10) failed", res);
1507
1508                 if (driver_byte(res) & DRIVER_SENSE)
1509                         sd_print_sense_hdr(sdkp, &sshdr);
1510                 /* we need to evaluate the error return  */
1511                 if (scsi_sense_valid(&sshdr) &&
1512                         (sshdr.asc == 0x3a ||   /* medium not present */
1513                          sshdr.asc == 0x20))    /* invalid command */
1514                                 /* this is no error here */
1515                                 return 0;
1516
1517                 switch (host_byte(res)) {
1518                 /* ignore errors due to racing a disconnection */
1519                 case DID_BAD_TARGET:
1520                 case DID_NO_CONNECT:
1521                         return 0;
1522                 /* signal the upper layer it might try again */
1523                 case DID_BUS_BUSY:
1524                 case DID_IMM_RETRY:
1525                 case DID_REQUEUE:
1526                 case DID_SOFT_ERROR:
1527                         return -EBUSY;
1528                 default:
1529                         return -EIO;
1530                 }
1531         }
1532         return 0;
1533 }
1534
1535 static void sd_rescan(struct device *dev)
1536 {
1537         struct scsi_disk *sdkp = dev_get_drvdata(dev);
1538
1539         revalidate_disk(sdkp->disk);
1540 }
1541
1542
1543 #ifdef CONFIG_COMPAT
1544 /*
1545  * This gets directly called from VFS. When the ioctl
1546  * is not recognized we go back to the other translation paths.
1547  */
1548 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
1549                            unsigned int cmd, unsigned long arg)
1550 {
1551         struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
1552         int error;
1553
1554         error = scsi_ioctl_block_when_processing_errors(sdev, cmd,
1555                         (mode & FMODE_NDELAY) != 0);
1556         if (error)
1557                 return error;
1558
1559         /*
1560          * Let the static ioctl translation table take care of it.
1561          */
1562         if (!sdev->host->hostt->compat_ioctl)
1563                 return -ENOIOCTLCMD;
1564         return sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
1565 }
1566 #endif
1567
1568 static char sd_pr_type(enum pr_type type)
1569 {
1570         switch (type) {
1571         case PR_WRITE_EXCLUSIVE:
1572                 return 0x01;
1573         case PR_EXCLUSIVE_ACCESS:
1574                 return 0x03;
1575         case PR_WRITE_EXCLUSIVE_REG_ONLY:
1576                 return 0x05;
1577         case PR_EXCLUSIVE_ACCESS_REG_ONLY:
1578                 return 0x06;
1579         case PR_WRITE_EXCLUSIVE_ALL_REGS:
1580                 return 0x07;
1581         case PR_EXCLUSIVE_ACCESS_ALL_REGS:
1582                 return 0x08;
1583         default:
1584                 return 0;
1585         }
1586 };
1587
1588 static int sd_pr_command(struct block_device *bdev, u8 sa,
1589                 u64 key, u64 sa_key, u8 type, u8 flags)
1590 {
1591         struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
1592         struct scsi_sense_hdr sshdr;
1593         int result;
1594         u8 cmd[16] = { 0, };
1595         u8 data[24] = { 0, };
1596
1597         cmd[0] = PERSISTENT_RESERVE_OUT;
1598         cmd[1] = sa;
1599         cmd[2] = type;
1600         put_unaligned_be32(sizeof(data), &cmd[5]);
1601
1602         put_unaligned_be64(key, &data[0]);
1603         put_unaligned_be64(sa_key, &data[8]);
1604         data[20] = flags;
1605
1606         result = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, &data, sizeof(data),
1607                         &sshdr, SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1608
1609         if ((driver_byte(result) & DRIVER_SENSE) &&
1610             (scsi_sense_valid(&sshdr))) {
1611                 sdev_printk(KERN_INFO, sdev, "PR command failed: %d\n", result);
1612                 scsi_print_sense_hdr(sdev, NULL, &sshdr);
1613         }
1614
1615         return result;
1616 }
1617
1618 static int sd_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
1619                 u32 flags)
1620 {
1621         if (flags & ~PR_FL_IGNORE_KEY)
1622                 return -EOPNOTSUPP;
1623         return sd_pr_command(bdev, (flags & PR_FL_IGNORE_KEY) ? 0x06 : 0x00,
1624                         old_key, new_key, 0,
1625                         (1 << 0) /* APTPL */ |
1626                         (1 << 2) /* ALL_TG_PT */);
1627 }
1628
1629 static int sd_pr_reserve(struct block_device *bdev, u64 key, enum pr_type type,
1630                 u32 flags)
1631 {
1632         if (flags)
1633                 return -EOPNOTSUPP;
1634         return sd_pr_command(bdev, 0x01, key, 0, sd_pr_type(type), 0);
1635 }
1636
1637 static int sd_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
1638 {
1639         return sd_pr_command(bdev, 0x02, key, 0, sd_pr_type(type), 0);
1640 }
1641
1642 static int sd_pr_preempt(struct block_device *bdev, u64 old_key, u64 new_key,
1643                 enum pr_type type, bool abort)
1644 {
1645         return sd_pr_command(bdev, abort ? 0x05 : 0x04, old_key, new_key,
1646                              sd_pr_type(type), 0);
1647 }
1648
1649 static int sd_pr_clear(struct block_device *bdev, u64 key)
1650 {
1651         return sd_pr_command(bdev, 0x03, key, 0, 0, 0);
1652 }
1653
1654 static const struct pr_ops sd_pr_ops = {
1655         .pr_register    = sd_pr_register,
1656         .pr_reserve     = sd_pr_reserve,
1657         .pr_release     = sd_pr_release,
1658         .pr_preempt     = sd_pr_preempt,
1659         .pr_clear       = sd_pr_clear,
1660 };
1661
1662 static const struct block_device_operations sd_fops = {
1663         .owner                  = THIS_MODULE,
1664         .open                   = sd_open,
1665         .release                = sd_release,
1666         .ioctl                  = sd_ioctl,
1667         .getgeo                 = sd_getgeo,
1668 #ifdef CONFIG_COMPAT
1669         .compat_ioctl           = sd_compat_ioctl,
1670 #endif
1671         .check_events           = sd_check_events,
1672         .revalidate_disk        = sd_revalidate_disk,
1673         .unlock_native_capacity = sd_unlock_native_capacity,
1674         .pr_ops                 = &sd_pr_ops,
1675 };
1676
1677 /**
1678  *      sd_eh_action - error handling callback
1679  *      @scmd:          sd-issued command that has failed
1680  *      @eh_disp:       The recovery disposition suggested by the midlayer
1681  *
1682  *      This function is called by the SCSI midlayer upon completion of an
1683  *      error test command (currently TEST UNIT READY). The result of sending
1684  *      the eh command is passed in eh_disp.  We're looking for devices that
1685  *      fail medium access commands but are OK with non access commands like
1686  *      test unit ready (so wrongly see the device as having a successful
1687  *      recovery)
1688  **/
1689 static int sd_eh_action(struct scsi_cmnd *scmd, int eh_disp)
1690 {
1691         struct scsi_disk *sdkp = scsi_disk(scmd->request->rq_disk);
1692
1693         if (!scsi_device_online(scmd->device) ||
1694             !scsi_medium_access_command(scmd) ||
1695             host_byte(scmd->result) != DID_TIME_OUT ||
1696             eh_disp != SUCCESS)
1697                 return eh_disp;
1698
1699         /*
1700          * The device has timed out executing a medium access command.
1701          * However, the TEST UNIT READY command sent during error
1702          * handling completed successfully. Either the device is in the
1703          * process of recovering or has it suffered an internal failure
1704          * that prevents access to the storage medium.
1705          */
1706         sdkp->medium_access_timed_out++;
1707
1708         /*
1709          * If the device keeps failing read/write commands but TEST UNIT
1710          * READY always completes successfully we assume that medium
1711          * access is no longer possible and take the device offline.
1712          */
1713         if (sdkp->medium_access_timed_out >= sdkp->max_medium_access_timeouts) {
1714                 scmd_printk(KERN_ERR, scmd,
1715                             "Medium access timeout failure. Offlining disk!\n");
1716                 scsi_device_set_state(scmd->device, SDEV_OFFLINE);
1717
1718                 return FAILED;
1719         }
1720
1721         return eh_disp;
1722 }
1723
1724 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
1725 {
1726         u64 start_lba = blk_rq_pos(scmd->request);
1727         u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
1728         u64 factor = scmd->device->sector_size / 512;
1729         u64 bad_lba;
1730         int info_valid;
1731         /*
1732          * resid is optional but mostly filled in.  When it's unused,
1733          * its value is zero, so we assume the whole buffer transferred
1734          */
1735         unsigned int transferred = scsi_bufflen(scmd) - scsi_get_resid(scmd);
1736         unsigned int good_bytes;
1737
1738         if (scmd->request->cmd_type != REQ_TYPE_FS)
1739                 return 0;
1740
1741         info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
1742                                              SCSI_SENSE_BUFFERSIZE,
1743                                              &bad_lba);
1744         if (!info_valid)
1745                 return 0;
1746
1747         if (scsi_bufflen(scmd) <= scmd->device->sector_size)
1748                 return 0;
1749
1750         /* be careful ... don't want any overflows */
1751         do_div(start_lba, factor);
1752         do_div(end_lba, factor);
1753
1754         /* The bad lba was reported incorrectly, we have no idea where
1755          * the error is.
1756          */
1757         if (bad_lba < start_lba  || bad_lba >= end_lba)
1758                 return 0;
1759
1760         /* This computation should always be done in terms of
1761          * the resolution of the device's medium.
1762          */
1763         good_bytes = (bad_lba - start_lba) * scmd->device->sector_size;
1764         return min(good_bytes, transferred);
1765 }
1766
1767 /**
1768  *      sd_done - bottom half handler: called when the lower level
1769  *      driver has completed (successfully or otherwise) a scsi command.
1770  *      @SCpnt: mid-level's per command structure.
1771  *
1772  *      Note: potentially run from within an ISR. Must not block.
1773  **/
1774 static int sd_done(struct scsi_cmnd *SCpnt)
1775 {
1776         int result = SCpnt->result;
1777         unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
1778         struct scsi_sense_hdr sshdr;
1779         struct scsi_disk *sdkp = scsi_disk(SCpnt->request->rq_disk);
1780         struct request *req = SCpnt->request;
1781         int sense_valid = 0;
1782         int sense_deferred = 0;
1783         unsigned char op = SCpnt->cmnd[0];
1784         unsigned char unmap = SCpnt->cmnd[1] & 8;
1785
1786         if (req->cmd_flags & REQ_DISCARD || req->cmd_flags & REQ_WRITE_SAME) {
1787                 if (!result) {
1788                         good_bytes = blk_rq_bytes(req);
1789                         scsi_set_resid(SCpnt, 0);
1790                 } else {
1791                         good_bytes = 0;
1792                         scsi_set_resid(SCpnt, blk_rq_bytes(req));
1793                 }
1794         }
1795
1796         if (result) {
1797                 sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
1798                 if (sense_valid)
1799                         sense_deferred = scsi_sense_is_deferred(&sshdr);
1800         }
1801         sdkp->medium_access_timed_out = 0;
1802
1803         if (driver_byte(result) != DRIVER_SENSE &&
1804             (!sense_valid || sense_deferred))
1805                 goto out;
1806
1807         switch (sshdr.sense_key) {
1808         case HARDWARE_ERROR:
1809         case MEDIUM_ERROR:
1810                 good_bytes = sd_completed_bytes(SCpnt);
1811                 break;
1812         case RECOVERED_ERROR:
1813                 good_bytes = scsi_bufflen(SCpnt);
1814                 break;
1815         case NO_SENSE:
1816                 /* This indicates a false check condition, so ignore it.  An
1817                  * unknown amount of data was transferred so treat it as an
1818                  * error.
1819                  */
1820                 SCpnt->result = 0;
1821                 memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1822                 break;
1823         case ABORTED_COMMAND:
1824                 if (sshdr.asc == 0x10)  /* DIF: Target detected corruption */
1825                         good_bytes = sd_completed_bytes(SCpnt);
1826                 break;
1827         case ILLEGAL_REQUEST:
1828                 if (sshdr.asc == 0x10)  /* DIX: Host detected corruption */
1829                         good_bytes = sd_completed_bytes(SCpnt);
1830                 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
1831                 if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
1832                         switch (op) {
1833                         case UNMAP:
1834                                 sd_config_discard(sdkp, SD_LBP_DISABLE);
1835                                 break;
1836                         case WRITE_SAME_16:
1837                         case WRITE_SAME:
1838                                 if (unmap)
1839                                         sd_config_discard(sdkp, SD_LBP_DISABLE);
1840                                 else {
1841                                         sdkp->device->no_write_same = 1;
1842                                         sd_config_write_same(sdkp);
1843
1844                                         good_bytes = 0;
1845                                         req->__data_len = blk_rq_bytes(req);
1846                                         req->cmd_flags |= REQ_QUIET;
1847                                 }
1848                         }
1849                 }
1850                 break;
1851         default:
1852                 break;
1853         }
1854  out:
1855         SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
1856                                            "sd_done: completed %d of %d bytes\n",
1857                                            good_bytes, scsi_bufflen(SCpnt)));
1858
1859         if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
1860                 sd_dif_complete(SCpnt, good_bytes);
1861
1862         return good_bytes;
1863 }
1864
1865 /*
1866  * spinup disk - called only in sd_revalidate_disk()
1867  */
1868 static void
1869 sd_spinup_disk(struct scsi_disk *sdkp)
1870 {
1871         unsigned char cmd[10];
1872         unsigned long spintime_expire = 0;
1873         int retries, spintime;
1874         unsigned int the_result;
1875         struct scsi_sense_hdr sshdr;
1876         int sense_valid = 0;
1877
1878         spintime = 0;
1879
1880         /* Spin up drives, as required.  Only do this at boot time */
1881         /* Spinup needs to be done for module loads too. */
1882         do {
1883                 retries = 0;
1884
1885                 do {
1886                         cmd[0] = TEST_UNIT_READY;
1887                         memset((void *) &cmd[1], 0, 9);
1888
1889                         the_result = scsi_execute_req(sdkp->device, cmd,
1890                                                       DMA_NONE, NULL, 0,
1891                                                       &sshdr, SD_TIMEOUT,
1892                                                       SD_MAX_RETRIES, NULL);
1893
1894                         /*
1895                          * If the drive has indicated to us that it
1896                          * doesn't have any media in it, don't bother
1897                          * with any more polling.
1898                          */
1899                         if (media_not_present(sdkp, &sshdr))
1900                                 return;
1901
1902                         if (the_result)
1903                                 sense_valid = scsi_sense_valid(&sshdr);
1904                         retries++;
1905                 } while (retries < 3 &&
1906                          (!scsi_status_is_good(the_result) ||
1907                           ((driver_byte(the_result) & DRIVER_SENSE) &&
1908                           sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1909
1910                 if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1911                         /* no sense, TUR either succeeded or failed
1912                          * with a status error */
1913                         if(!spintime && !scsi_status_is_good(the_result)) {
1914                                 sd_print_result(sdkp, "Test Unit Ready failed",
1915                                                 the_result);
1916                         }
1917                         break;
1918                 }
1919
1920                 /*
1921                  * The device does not want the automatic start to be issued.
1922                  */
1923                 if (sdkp->device->no_start_on_add)
1924                         break;
1925
1926                 if (sense_valid && sshdr.sense_key == NOT_READY) {
1927                         if (sshdr.asc == 4 && sshdr.ascq == 3)
1928                                 break;  /* manual intervention required */
1929                         if (sshdr.asc == 4 && sshdr.ascq == 0xb)
1930                                 break;  /* standby */
1931                         if (sshdr.asc == 4 && sshdr.ascq == 0xc)
1932                                 break;  /* unavailable */
1933                         if (sshdr.asc == 4 && sshdr.ascq == 0x1b)
1934                                 break;  /* sanitize in progress */
1935                         /*
1936                          * Issue command to spin up drive when not ready
1937                          */
1938                         if (!spintime) {
1939                                 sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
1940                                 cmd[0] = START_STOP;
1941                                 cmd[1] = 1;     /* Return immediately */
1942                                 memset((void *) &cmd[2], 0, 8);
1943                                 cmd[4] = 1;     /* Start spin cycle */
1944                                 if (sdkp->device->start_stop_pwr_cond)
1945                                         cmd[4] |= 1 << 4;
1946                                 scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1947                                                  NULL, 0, &sshdr,
1948                                                  SD_TIMEOUT, SD_MAX_RETRIES,
1949                                                  NULL);
1950                                 spintime_expire = jiffies + 100 * HZ;
1951                                 spintime = 1;
1952                         }
1953                         /* Wait 1 second for next try */
1954                         msleep(1000);
1955                         printk(".");
1956
1957                 /*
1958                  * Wait for USB flash devices with slow firmware.
1959                  * Yes, this sense key/ASC combination shouldn't
1960                  * occur here.  It's characteristic of these devices.
1961                  */
1962                 } else if (sense_valid &&
1963                                 sshdr.sense_key == UNIT_ATTENTION &&
1964                                 sshdr.asc == 0x28) {
1965                         if (!spintime) {
1966                                 spintime_expire = jiffies + 5 * HZ;
1967                                 spintime = 1;
1968                         }
1969                         /* Wait 1 second for next try */
1970                         msleep(1000);
1971                 } else {
1972                         /* we don't understand the sense code, so it's
1973                          * probably pointless to loop */
1974                         if(!spintime) {
1975                                 sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1976                                 sd_print_sense_hdr(sdkp, &sshdr);
1977                         }
1978                         break;
1979                 }
1980
1981         } while (spintime && time_before_eq(jiffies, spintime_expire));
1982
1983         if (spintime) {
1984                 if (scsi_status_is_good(the_result))
1985                         printk("ready\n");
1986                 else
1987                         printk("not responding...\n");
1988         }
1989 }
1990
1991
1992 /*
1993  * Determine whether disk supports Data Integrity Field.
1994  */
1995 static int sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
1996 {
1997         struct scsi_device *sdp = sdkp->device;
1998         u8 type;
1999         int ret = 0;
2000
2001         if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0) {
2002                 sdkp->protection_type = 0;
2003                 return ret;
2004         }
2005
2006         type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
2007
2008         if (type > SD_DIF_TYPE3_PROTECTION)
2009                 ret = -ENODEV;
2010         else if (scsi_host_dif_capable(sdp->host, type))
2011                 ret = 1;
2012
2013         if (sdkp->first_scan || type != sdkp->protection_type)
2014                 switch (ret) {
2015                 case -ENODEV:
2016                         sd_printk(KERN_ERR, sdkp, "formatted with unsupported" \
2017                                   " protection type %u. Disabling disk!\n",
2018                                   type);
2019                         break;
2020                 case 1:
2021                         sd_printk(KERN_NOTICE, sdkp,
2022                                   "Enabling DIF Type %u protection\n", type);
2023                         break;
2024                 case 0:
2025                         sd_printk(KERN_NOTICE, sdkp,
2026                                   "Disabling DIF Type %u protection\n", type);
2027                         break;
2028                 }
2029
2030         sdkp->protection_type = type;
2031
2032         return ret;
2033 }
2034
2035 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
2036                         struct scsi_sense_hdr *sshdr, int sense_valid,
2037                         int the_result)
2038 {
2039         if (driver_byte(the_result) & DRIVER_SENSE)
2040                 sd_print_sense_hdr(sdkp, sshdr);
2041         else
2042                 sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
2043
2044         /*
2045          * Set dirty bit for removable devices if not ready -
2046          * sometimes drives will not report this properly.
2047          */
2048         if (sdp->removable &&
2049             sense_valid && sshdr->sense_key == NOT_READY)
2050                 set_media_not_present(sdkp);
2051
2052         /*
2053          * We used to set media_present to 0 here to indicate no media
2054          * in the drive, but some drives fail read capacity even with
2055          * media present, so we can't do that.
2056          */
2057         sdkp->capacity = 0; /* unknown mapped to zero - as usual */
2058 }
2059
2060 #define RC16_LEN 32
2061 #if RC16_LEN > SD_BUF_SIZE
2062 #error RC16_LEN must not be more than SD_BUF_SIZE
2063 #endif
2064
2065 #define READ_CAPACITY_RETRIES_ON_RESET  10
2066
2067 /*
2068  * Ensure that we don't overflow sector_t when CONFIG_LBDAF is not set
2069  * and the reported logical block size is bigger than 512 bytes. Note
2070  * that last_sector is a u64 and therefore logical_to_sectors() is not
2071  * applicable.
2072  */
2073 static bool sd_addressable_capacity(u64 lba, unsigned int sector_size)
2074 {
2075         u64 last_sector = (lba + 1ULL) << (ilog2(sector_size) - 9);
2076
2077         if (sizeof(sector_t) == 4 && last_sector > U32_MAX)
2078                 return false;
2079
2080         return true;
2081 }
2082
2083 static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
2084                                                 unsigned char *buffer)
2085 {
2086         unsigned char cmd[16];
2087         struct scsi_sense_hdr sshdr;
2088         int sense_valid = 0;
2089         int the_result;
2090         int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
2091         unsigned int alignment;
2092         unsigned long long lba;
2093         unsigned sector_size;
2094
2095         if (sdp->no_read_capacity_16)
2096                 return -EINVAL;
2097
2098         do {
2099                 memset(cmd, 0, 16);
2100                 cmd[0] = SERVICE_ACTION_IN_16;
2101                 cmd[1] = SAI_READ_CAPACITY_16;
2102                 cmd[13] = RC16_LEN;
2103                 memset(buffer, 0, RC16_LEN);
2104
2105                 the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
2106                                         buffer, RC16_LEN, &sshdr,
2107                                         SD_TIMEOUT, SD_MAX_RETRIES, NULL);
2108
2109                 if (media_not_present(sdkp, &sshdr))
2110                         return -ENODEV;
2111
2112                 if (the_result) {
2113                         sense_valid = scsi_sense_valid(&sshdr);
2114                         if (sense_valid &&
2115                             sshdr.sense_key == ILLEGAL_REQUEST &&
2116                             (sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
2117                             sshdr.ascq == 0x00)
2118                                 /* Invalid Command Operation Code or
2119                                  * Invalid Field in CDB, just retry
2120                                  * silently with RC10 */
2121                                 return -EINVAL;
2122                         if (sense_valid &&
2123                             sshdr.sense_key == UNIT_ATTENTION &&
2124                             sshdr.asc == 0x29 && sshdr.ascq == 0x00)
2125                                 /* Device reset might occur several times,
2126                                  * give it one more chance */
2127                                 if (--reset_retries > 0)
2128                                         continue;
2129                 }
2130                 retries--;
2131
2132         } while (the_result && retries);
2133
2134         if (the_result) {
2135                 sd_print_result(sdkp, "Read Capacity(16) failed", the_result);
2136                 read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
2137                 return -EINVAL;
2138         }
2139
2140         sector_size = get_unaligned_be32(&buffer[8]);
2141         lba = get_unaligned_be64(&buffer[0]);
2142
2143         if (sd_read_protection_type(sdkp, buffer) < 0) {
2144                 sdkp->capacity = 0;
2145                 return -ENODEV;
2146         }
2147
2148         if (!sd_addressable_capacity(lba, sector_size)) {
2149                 sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
2150                         "kernel compiled with support for large block "
2151                         "devices.\n");
2152                 sdkp->capacity = 0;
2153                 return -EOVERFLOW;
2154         }
2155
2156         /* Logical blocks per physical block exponent */
2157         sdkp->physical_block_size = (1 << (buffer[13] & 0xf)) * sector_size;
2158
2159         /* Lowest aligned logical block */
2160         alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) * sector_size;
2161         blk_queue_alignment_offset(sdp->request_queue, alignment);
2162         if (alignment && sdkp->first_scan)
2163                 sd_printk(KERN_NOTICE, sdkp,
2164                           "physical block alignment offset: %u\n", alignment);
2165
2166         if (buffer[14] & 0x80) { /* LBPME */
2167                 sdkp->lbpme = 1;
2168
2169                 if (buffer[14] & 0x40) /* LBPRZ */
2170                         sdkp->lbprz = 1;
2171
2172                 sd_config_discard(sdkp, SD_LBP_WS16);
2173         }
2174
2175         sdkp->capacity = lba + 1;
2176         return sector_size;
2177 }
2178
2179 static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
2180                                                 unsigned char *buffer)
2181 {
2182         unsigned char cmd[16];
2183         struct scsi_sense_hdr sshdr;
2184         int sense_valid = 0;
2185         int the_result;
2186         int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
2187         sector_t lba;
2188         unsigned sector_size;
2189
2190         do {
2191                 cmd[0] = READ_CAPACITY;
2192                 memset(&cmd[1], 0, 9);
2193                 memset(buffer, 0, 8);
2194
2195                 the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
2196                                         buffer, 8, &sshdr,
2197                                         SD_TIMEOUT, SD_MAX_RETRIES, NULL);
2198
2199                 if (media_not_present(sdkp, &sshdr))
2200                         return -ENODEV;
2201
2202                 if (the_result) {
2203                         sense_valid = scsi_sense_valid(&sshdr);
2204                         if (sense_valid &&
2205                             sshdr.sense_key == UNIT_ATTENTION &&
2206                             sshdr.asc == 0x29 && sshdr.ascq == 0x00)
2207                                 /* Device reset might occur several times,
2208                                  * give it one more chance */
2209                                 if (--reset_retries > 0)
2210                                         continue;
2211                 }
2212                 retries--;
2213
2214         } while (the_result && retries);
2215
2216         if (the_result) {
2217                 sd_print_result(sdkp, "Read Capacity(10) failed", the_result);
2218                 read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
2219                 return -EINVAL;
2220         }
2221
2222         sector_size = get_unaligned_be32(&buffer[4]);
2223         lba = get_unaligned_be32(&buffer[0]);
2224
2225         if (sdp->no_read_capacity_16 && (lba == 0xffffffff)) {
2226                 /* Some buggy (usb cardreader) devices return an lba of
2227                    0xffffffff when the want to report a size of 0 (with
2228                    which they really mean no media is present) */
2229                 sdkp->capacity = 0;
2230                 sdkp->physical_block_size = sector_size;
2231                 return sector_size;
2232         }
2233
2234         if (!sd_addressable_capacity(lba, sector_size)) {
2235                 sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
2236                         "kernel compiled with support for large block "
2237                         "devices.\n");
2238                 sdkp->capacity = 0;
2239                 return -EOVERFLOW;
2240         }
2241
2242         sdkp->capacity = lba + 1;
2243         sdkp->physical_block_size = sector_size;
2244         return sector_size;
2245 }
2246
2247 static int sd_try_rc16_first(struct scsi_device *sdp)
2248 {
2249         if (sdp->host->max_cmd_len < 16)
2250                 return 0;
2251         if (sdp->try_rc_10_first)
2252                 return 0;
2253         if (sdp->scsi_level > SCSI_SPC_2)
2254                 return 1;
2255         if (scsi_device_protection(sdp))
2256                 return 1;
2257         return 0;
2258 }
2259
2260 /*
2261  * read disk capacity
2262  */
2263 static void
2264 sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
2265 {
2266         int sector_size;
2267         struct scsi_device *sdp = sdkp->device;
2268         sector_t old_capacity = sdkp->capacity;
2269
2270         if (sd_try_rc16_first(sdp)) {
2271                 sector_size = read_capacity_16(sdkp, sdp, buffer);
2272                 if (sector_size == -EOVERFLOW)
2273                         goto got_data;
2274                 if (sector_size == -ENODEV)
2275                         return;
2276                 if (sector_size < 0)
2277                         sector_size = read_capacity_10(sdkp, sdp, buffer);
2278                 if (sector_size < 0)
2279                         return;
2280         } else {
2281                 sector_size = read_capacity_10(sdkp, sdp, buffer);
2282                 if (sector_size == -EOVERFLOW)
2283                         goto got_data;
2284                 if (sector_size < 0)
2285                         return;
2286                 if ((sizeof(sdkp->capacity) > 4) &&
2287                     (sdkp->capacity > 0xffffffffULL)) {
2288                         int old_sector_size = sector_size;
2289                         sd_printk(KERN_NOTICE, sdkp, "Very big device. "
2290                                         "Trying to use READ CAPACITY(16).\n");
2291                         sector_size = read_capacity_16(sdkp, sdp, buffer);
2292                         if (sector_size < 0) {
2293                                 sd_printk(KERN_NOTICE, sdkp,
2294                                         "Using 0xffffffff as device size\n");
2295                                 sdkp->capacity = 1 + (sector_t) 0xffffffff;
2296                                 sector_size = old_sector_size;
2297                                 goto got_data;
2298                         }
2299                 }
2300         }
2301
2302         /* Some devices are known to return the total number of blocks,
2303          * not the highest block number.  Some devices have versions
2304          * which do this and others which do not.  Some devices we might
2305          * suspect of doing this but we don't know for certain.
2306          *
2307          * If we know the reported capacity is wrong, decrement it.  If
2308          * we can only guess, then assume the number of blocks is even
2309          * (usually true but not always) and err on the side of lowering
2310          * the capacity.
2311          */
2312         if (sdp->fix_capacity ||
2313             (sdp->guess_capacity && (sdkp->capacity & 0x01))) {
2314                 sd_printk(KERN_INFO, sdkp, "Adjusting the sector count "
2315                                 "from its reported value: %llu\n",
2316                                 (unsigned long long) sdkp->capacity);
2317                 --sdkp->capacity;
2318         }
2319
2320 got_data:
2321         if (sector_size == 0) {
2322                 sector_size = 512;
2323                 sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
2324                           "assuming 512.\n");
2325         }
2326
2327         if (sector_size != 512 &&
2328             sector_size != 1024 &&
2329             sector_size != 2048 &&
2330             sector_size != 4096) {
2331                 sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
2332                           sector_size);
2333                 /*
2334                  * The user might want to re-format the drive with
2335                  * a supported sectorsize.  Once this happens, it
2336                  * would be relatively trivial to set the thing up.
2337                  * For this reason, we leave the thing in the table.
2338                  */
2339                 sdkp->capacity = 0;
2340                 /*
2341                  * set a bogus sector size so the normal read/write
2342                  * logic in the block layer will eventually refuse any
2343                  * request on this device without tripping over power
2344                  * of two sector size assumptions
2345                  */
2346                 sector_size = 512;
2347         }
2348         blk_queue_logical_block_size(sdp->request_queue, sector_size);
2349
2350         {
2351                 char cap_str_2[10], cap_str_10[10];
2352
2353                 string_get_size(sdkp->capacity, sector_size,
2354                                 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
2355                 string_get_size(sdkp->capacity, sector_size,
2356                                 STRING_UNITS_10, cap_str_10,
2357                                 sizeof(cap_str_10));
2358
2359                 if (sdkp->first_scan || old_capacity != sdkp->capacity) {
2360                         sd_printk(KERN_NOTICE, sdkp,
2361                                   "%llu %d-byte logical blocks: (%s/%s)\n",
2362                                   (unsigned long long)sdkp->capacity,
2363                                   sector_size, cap_str_10, cap_str_2);
2364
2365                         if (sdkp->physical_block_size != sector_size)
2366                                 sd_printk(KERN_NOTICE, sdkp,
2367                                           "%u-byte physical blocks\n",
2368                                           sdkp->physical_block_size);
2369                 }
2370         }
2371
2372         if (sdkp->capacity > 0xffffffff)
2373                 sdp->use_16_for_rw = 1;
2374
2375         blk_queue_physical_block_size(sdp->request_queue,
2376                                       sdkp->physical_block_size);
2377         sdkp->device->sector_size = sector_size;
2378 }
2379
2380 /* called with buffer of length 512 */
2381 static inline int
2382 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
2383                  unsigned char *buffer, int len, struct scsi_mode_data *data,
2384                  struct scsi_sense_hdr *sshdr)
2385 {
2386         return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
2387                                SD_TIMEOUT, SD_MAX_RETRIES, data,
2388                                sshdr);
2389 }
2390
2391 /*
2392  * read write protect setting, if possible - called only in sd_revalidate_disk()
2393  * called with buffer of length SD_BUF_SIZE
2394  */
2395 static void
2396 sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
2397 {
2398         int res;
2399         struct scsi_device *sdp = sdkp->device;
2400         struct scsi_mode_data data;
2401         int old_wp = sdkp->write_prot;
2402
2403         set_disk_ro(sdkp->disk, 0);
2404         if (sdp->skip_ms_page_3f) {
2405                 sd_first_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
2406                 return;
2407         }
2408
2409         if (sdp->use_192_bytes_for_3f) {
2410                 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
2411         } else {
2412                 /*
2413                  * First attempt: ask for all pages (0x3F), but only 4 bytes.
2414                  * We have to start carefully: some devices hang if we ask
2415                  * for more than is available.
2416                  */
2417                 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
2418
2419                 /*
2420                  * Second attempt: ask for page 0 When only page 0 is
2421                  * implemented, a request for page 3F may return Sense Key
2422                  * 5: Illegal Request, Sense Code 24: Invalid field in
2423                  * CDB.
2424                  */
2425                 if (!scsi_status_is_good(res))
2426                         res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
2427
2428                 /*
2429                  * Third attempt: ask 255 bytes, as we did earlier.
2430                  */
2431                 if (!scsi_status_is_good(res))
2432                         res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
2433                                                &data, NULL);
2434         }
2435
2436         if (!scsi_status_is_good(res)) {
2437                 sd_first_printk(KERN_WARNING, sdkp,
2438                           "Test WP failed, assume Write Enabled\n");
2439         } else {
2440                 sdkp->write_prot = ((data.device_specific & 0x80) != 0);
2441                 set_disk_ro(sdkp->disk, sdkp->write_prot);
2442                 if (sdkp->first_scan || old_wp != sdkp->write_prot) {
2443                         sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
2444                                   sdkp->write_prot ? "on" : "off");
2445                         sd_printk(KERN_DEBUG, sdkp,
2446                                   "Mode Sense: %02x %02x %02x %02x\n",
2447                                   buffer[0], buffer[1], buffer[2], buffer[3]);
2448                 }
2449         }
2450 }
2451
2452 /*
2453  * sd_read_cache_type - called only from sd_revalidate_disk()
2454  * called with buffer of length SD_BUF_SIZE
2455  */
2456 static void
2457 sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
2458 {
2459         int len = 0, res;
2460         struct scsi_device *sdp = sdkp->device;
2461
2462         int dbd;
2463         int modepage;
2464         int first_len;
2465         struct scsi_mode_data data;
2466         struct scsi_sense_hdr sshdr;
2467         int old_wce = sdkp->WCE;
2468         int old_rcd = sdkp->RCD;
2469         int old_dpofua = sdkp->DPOFUA;
2470
2471
2472         if (sdkp->cache_override)
2473                 return;
2474
2475         first_len = 4;
2476         if (sdp->skip_ms_page_8) {
2477                 if (sdp->type == TYPE_RBC)
2478                         goto defaults;
2479                 else {
2480                         if (sdp->skip_ms_page_3f)
2481                                 goto defaults;
2482                         modepage = 0x3F;
2483                         if (sdp->use_192_bytes_for_3f)
2484                                 first_len = 192;
2485                         dbd = 0;
2486                 }
2487         } else if (sdp->type == TYPE_RBC) {
2488                 modepage = 6;
2489                 dbd = 8;
2490         } else {
2491                 modepage = 8;
2492                 dbd = 0;
2493         }
2494
2495         /* cautiously ask */
2496         res = sd_do_mode_sense(sdp, dbd, modepage, buffer, first_len,
2497                         &data, &sshdr);
2498
2499         if (!scsi_status_is_good(res))
2500                 goto bad_sense;
2501
2502         if (!data.header_length) {
2503                 modepage = 6;
2504                 first_len = 0;
2505                 sd_first_printk(KERN_ERR, sdkp,
2506                                 "Missing header in MODE_SENSE response\n");
2507         }
2508
2509         /* that went OK, now ask for the proper length */
2510         len = data.length;
2511
2512         /*
2513          * We're only interested in the first three bytes, actually.
2514          * But the data cache page is defined for the first 20.
2515          */
2516         if (len < 3)
2517                 goto bad_sense;
2518         else if (len > SD_BUF_SIZE) {
2519                 sd_first_printk(KERN_NOTICE, sdkp, "Truncating mode parameter "
2520                           "data from %d to %d bytes\n", len, SD_BUF_SIZE);
2521                 len = SD_BUF_SIZE;
2522         }
2523         if (modepage == 0x3F && sdp->use_192_bytes_for_3f)
2524                 len = 192;
2525
2526         /* Get the data */
2527         if (len > first_len)
2528                 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len,
2529                                 &data, &sshdr);
2530
2531         if (scsi_status_is_good(res)) {
2532                 int offset = data.header_length + data.block_descriptor_length;
2533
2534                 while (offset < len) {
2535                         u8 page_code = buffer[offset] & 0x3F;
2536                         u8 spf       = buffer[offset] & 0x40;
2537
2538                         if (page_code == 8 || page_code == 6) {
2539                                 /* We're interested only in the first 3 bytes.
2540                                  */
2541                                 if (len - offset <= 2) {
2542                                         sd_first_printk(KERN_ERR, sdkp,
2543                                                 "Incomplete mode parameter "
2544                                                         "data\n");
2545                                         goto defaults;
2546                                 } else {
2547                                         modepage = page_code;
2548                                         goto Page_found;
2549                                 }
2550                         } else {
2551                                 /* Go to the next page */
2552                                 if (spf && len - offset > 3)
2553                                         offset += 4 + (buffer[offset+2] << 8) +
2554                                                 buffer[offset+3];
2555                                 else if (!spf && len - offset > 1)
2556                                         offset += 2 + buffer[offset+1];
2557                                 else {
2558                                         sd_first_printk(KERN_ERR, sdkp,
2559                                                         "Incomplete mode "
2560                                                         "parameter data\n");
2561                                         goto defaults;
2562                                 }
2563                         }
2564                 }
2565
2566                 sd_first_printk(KERN_ERR, sdkp, "No Caching mode page found\n");
2567                 goto defaults;
2568
2569         Page_found:
2570                 if (modepage == 8) {
2571                         sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
2572                         sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
2573                 } else {
2574                         sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
2575                         sdkp->RCD = 0;
2576                 }
2577
2578                 sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
2579                 if (sdp->broken_fua) {
2580                         sd_first_printk(KERN_NOTICE, sdkp, "Disabling FUA\n");
2581                         sdkp->DPOFUA = 0;
2582                 } else if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw &&
2583                            !sdkp->device->use_16_for_rw) {
2584                         sd_first_printk(KERN_NOTICE, sdkp,
2585                                   "Uses READ/WRITE(6), disabling FUA\n");
2586                         sdkp->DPOFUA = 0;
2587                 }
2588
2589                 /* No cache flush allowed for write protected devices */
2590                 if (sdkp->WCE && sdkp->write_prot)
2591                         sdkp->WCE = 0;
2592
2593                 if (sdkp->first_scan || old_wce != sdkp->WCE ||
2594                     old_rcd != sdkp->RCD || old_dpofua != sdkp->DPOFUA)
2595                         sd_printk(KERN_NOTICE, sdkp,
2596                                   "Write cache: %s, read cache: %s, %s\n",
2597                                   sdkp->WCE ? "enabled" : "disabled",
2598                                   sdkp->RCD ? "disabled" : "enabled",
2599                                   sdkp->DPOFUA ? "supports DPO and FUA"
2600                                   : "doesn't support DPO or FUA");
2601
2602                 return;
2603         }
2604
2605 bad_sense:
2606         if (scsi_sense_valid(&sshdr) &&
2607             sshdr.sense_key == ILLEGAL_REQUEST &&
2608             sshdr.asc == 0x24 && sshdr.ascq == 0x0)
2609                 /* Invalid field in CDB */
2610                 sd_first_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
2611         else
2612                 sd_first_printk(KERN_ERR, sdkp,
2613                                 "Asking for cache data failed\n");
2614
2615 defaults:
2616         if (sdp->wce_default_on) {
2617                 sd_first_printk(KERN_NOTICE, sdkp,
2618                                 "Assuming drive cache: write back\n");
2619                 sdkp->WCE = 1;
2620         } else {
2621                 sd_first_printk(KERN_ERR, sdkp,
2622                                 "Assuming drive cache: write through\n");
2623                 sdkp->WCE = 0;
2624         }
2625         sdkp->RCD = 0;
2626         sdkp->DPOFUA = 0;
2627 }
2628
2629 /*
2630  * The ATO bit indicates whether the DIF application tag is available
2631  * for use by the operating system.
2632  */
2633 static void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
2634 {
2635         int res, offset;
2636         struct scsi_device *sdp = sdkp->device;
2637         struct scsi_mode_data data;
2638         struct scsi_sense_hdr sshdr;
2639
2640         if (sdp->type != TYPE_DISK)
2641                 return;
2642
2643         if (sdkp->protection_type == 0)
2644                 return;
2645
2646         res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
2647                               SD_MAX_RETRIES, &data, &sshdr);
2648
2649         if (!scsi_status_is_good(res) || !data.header_length ||
2650             data.length < 6) {
2651                 sd_first_printk(KERN_WARNING, sdkp,
2652                           "getting Control mode page failed, assume no ATO\n");
2653
2654                 if (scsi_sense_valid(&sshdr))
2655                         sd_print_sense_hdr(sdkp, &sshdr);
2656
2657                 return;
2658         }
2659
2660         offset = data.header_length + data.block_descriptor_length;
2661
2662         if ((buffer[offset] & 0x3f) != 0x0a) {
2663                 sd_first_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
2664                 return;
2665         }
2666
2667         if ((buffer[offset + 5] & 0x80) == 0)
2668                 return;
2669
2670         sdkp->ATO = 1;
2671
2672         return;
2673 }
2674
2675 /**
2676  * sd_read_block_limits - Query disk device for preferred I/O sizes.
2677  * @disk: disk to query
2678  */
2679 static void sd_read_block_limits(struct scsi_disk *sdkp)
2680 {
2681         unsigned int sector_sz = sdkp->device->sector_size;
2682         const int vpd_len = 64;
2683         unsigned char *buffer = kmalloc(vpd_len, GFP_KERNEL);
2684
2685         if (!buffer ||
2686             /* Block Limits VPD */
2687             scsi_get_vpd_page(sdkp->device, 0xb0, buffer, vpd_len))
2688                 goto out;
2689
2690         blk_queue_io_min(sdkp->disk->queue,
2691                          get_unaligned_be16(&buffer[6]) * sector_sz);
2692
2693         sdkp->max_xfer_blocks = get_unaligned_be32(&buffer[8]);
2694         sdkp->opt_xfer_blocks = get_unaligned_be32(&buffer[12]);
2695
2696         if (buffer[3] == 0x3c) {
2697                 unsigned int lba_count, desc_count;
2698
2699                 sdkp->max_ws_blocks = (u32)get_unaligned_be64(&buffer[36]);
2700
2701                 if (!sdkp->lbpme)
2702                         goto out;
2703
2704                 lba_count = get_unaligned_be32(&buffer[20]);
2705                 desc_count = get_unaligned_be32(&buffer[24]);
2706
2707                 if (lba_count && desc_count)
2708                         sdkp->max_unmap_blocks = lba_count;
2709
2710                 sdkp->unmap_granularity = get_unaligned_be32(&buffer[28]);
2711
2712                 if (buffer[32] & 0x80)
2713                         sdkp->unmap_alignment =
2714                                 get_unaligned_be32(&buffer[32]) & ~(1 << 31);
2715
2716                 if (!sdkp->lbpvpd) { /* LBP VPD page not provided */
2717
2718                         if (sdkp->max_unmap_blocks)
2719                                 sd_config_discard(sdkp, SD_LBP_UNMAP);
2720                         else
2721                                 sd_config_discard(sdkp, SD_LBP_WS16);
2722
2723                 } else {        /* LBP VPD page tells us what to use */
2724                         if (sdkp->lbpu && sdkp->max_unmap_blocks && !sdkp->lbprz)
2725                                 sd_config_discard(sdkp, SD_LBP_UNMAP);
2726                         else if (sdkp->lbpws)
2727                                 sd_config_discard(sdkp, SD_LBP_WS16);
2728                         else if (sdkp->lbpws10)
2729                                 sd_config_discard(sdkp, SD_LBP_WS10);
2730                         else if (sdkp->lbpu && sdkp->max_unmap_blocks)
2731                                 sd_config_discard(sdkp, SD_LBP_UNMAP);
2732                         else
2733                                 sd_config_discard(sdkp, SD_LBP_DISABLE);
2734                 }
2735         }
2736
2737  out:
2738         kfree(buffer);
2739 }
2740
2741 /**
2742  * sd_read_block_characteristics - Query block dev. characteristics
2743  * @disk: disk to query
2744  */
2745 static void sd_read_block_characteristics(struct scsi_disk *sdkp)
2746 {
2747         unsigned char *buffer;
2748         u16 rot;
2749         const int vpd_len = 64;
2750
2751         buffer = kmalloc(vpd_len, GFP_KERNEL);
2752
2753         if (!buffer ||
2754             /* Block Device Characteristics VPD */
2755             scsi_get_vpd_page(sdkp->device, 0xb1, buffer, vpd_len))
2756                 goto out;
2757
2758         rot = get_unaligned_be16(&buffer[4]);
2759
2760         if (rot == 1) {
2761                 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, sdkp->disk->queue);
2762                 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, sdkp->disk->queue);
2763         }
2764
2765  out:
2766         kfree(buffer);
2767 }
2768
2769 /**
2770  * sd_read_block_provisioning - Query provisioning VPD page
2771  * @disk: disk to query
2772  */
2773 static void sd_read_block_provisioning(struct scsi_disk *sdkp)
2774 {
2775         unsigned char *buffer;
2776         const int vpd_len = 8;
2777
2778         if (sdkp->lbpme == 0)
2779                 return;
2780
2781         buffer = kmalloc(vpd_len, GFP_KERNEL);
2782
2783         if (!buffer || scsi_get_vpd_page(sdkp->device, 0xb2, buffer, vpd_len))
2784                 goto out;
2785
2786         sdkp->lbpvpd    = 1;
2787         sdkp->lbpu      = (buffer[5] >> 7) & 1; /* UNMAP */
2788         sdkp->lbpws     = (buffer[5] >> 6) & 1; /* WRITE SAME(16) with UNMAP */
2789         sdkp->lbpws10   = (buffer[5] >> 5) & 1; /* WRITE SAME(10) with UNMAP */
2790
2791  out:
2792         kfree(buffer);
2793 }
2794
2795 static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
2796 {
2797         struct scsi_device *sdev = sdkp->device;
2798
2799         if (sdev->host->no_write_same) {
2800                 sdev->no_write_same = 1;
2801
2802                 return;
2803         }
2804
2805         if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY) < 0) {
2806                 /* too large values might cause issues with arcmsr */
2807                 int vpd_buf_len = 64;
2808
2809                 sdev->no_report_opcodes = 1;
2810
2811                 /* Disable WRITE SAME if REPORT SUPPORTED OPERATION
2812                  * CODES is unsupported and the device has an ATA
2813                  * Information VPD page (SAT).
2814                  */
2815                 if (!scsi_get_vpd_page(sdev, 0x89, buffer, vpd_buf_len))
2816                         sdev->no_write_same = 1;
2817         }
2818
2819         if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME_16) == 1)
2820                 sdkp->ws16 = 1;
2821
2822         if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME) == 1)
2823                 sdkp->ws10 = 1;
2824 }
2825
2826 static int sd_try_extended_inquiry(struct scsi_device *sdp)
2827 {
2828         /* Attempt VPD inquiry if the device blacklist explicitly calls
2829          * for it.
2830          */
2831         if (sdp->try_vpd_pages)
2832                 return 1;
2833         /*
2834          * Although VPD inquiries can go to SCSI-2 type devices,
2835          * some USB ones crash on receiving them, and the pages
2836          * we currently ask for are for SPC-3 and beyond
2837          */
2838         if (sdp->scsi_level > SCSI_SPC_2 && !sdp->skip_vpd_pages)
2839                 return 1;
2840         return 0;
2841 }
2842
2843 /**
2844  *      sd_revalidate_disk - called the first time a new disk is seen,
2845  *      performs disk spin up, read_capacity, etc.
2846  *      @disk: struct gendisk we care about
2847  **/
2848 static int sd_revalidate_disk(struct gendisk *disk)
2849 {
2850         struct scsi_disk *sdkp = scsi_disk(disk);
2851         struct scsi_device *sdp = sdkp->device;
2852         struct request_queue *q = sdkp->disk->queue;
2853         unsigned char *buffer;
2854         unsigned int dev_max, rw_max;
2855
2856         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
2857                                       "sd_revalidate_disk\n"));
2858
2859         /*
2860          * If the device is offline, don't try and read capacity or any
2861          * of the other niceties.
2862          */
2863         if (!scsi_device_online(sdp))
2864                 goto out;
2865
2866         buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
2867         if (!buffer) {
2868                 sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
2869                           "allocation failure.\n");
2870                 goto out;
2871         }
2872
2873         sd_spinup_disk(sdkp);
2874
2875         /*
2876          * Without media there is no reason to ask; moreover, some devices
2877          * react badly if we do.
2878          */
2879         if (sdkp->media_present) {
2880                 sd_read_capacity(sdkp, buffer);
2881
2882                 if (sd_try_extended_inquiry(sdp)) {
2883                         sd_read_block_provisioning(sdkp);
2884                         sd_read_block_limits(sdkp);
2885                         sd_read_block_characteristics(sdkp);
2886                 }
2887
2888                 sd_read_write_protect_flag(sdkp, buffer);
2889                 sd_read_cache_type(sdkp, buffer);
2890                 sd_read_app_tag_own(sdkp, buffer);
2891                 sd_read_write_same(sdkp, buffer);
2892         }
2893
2894         /*
2895          * We now have all cache related info, determine how we deal
2896          * with flush requests.
2897          */
2898         sd_set_flush_flag(sdkp);
2899
2900         /* Initial block count limit based on CDB TRANSFER LENGTH field size. */
2901         dev_max = sdp->use_16_for_rw ? SD_MAX_XFER_BLOCKS : SD_DEF_XFER_BLOCKS;
2902
2903         /* Some devices report a maximum block count for READ/WRITE requests. */
2904         dev_max = min_not_zero(dev_max, sdkp->max_xfer_blocks);
2905         q->limits.max_dev_sectors = logical_to_sectors(sdp, dev_max);
2906
2907         /*
2908          * Determine the device's preferred I/O size for reads and writes
2909          * unless the reported value is unreasonably small, large, or
2910          * garbage.
2911          */
2912         if (sdkp->opt_xfer_blocks &&
2913             sdkp->opt_xfer_blocks <= dev_max &&
2914             sdkp->opt_xfer_blocks <= SD_DEF_XFER_BLOCKS &&
2915             logical_to_bytes(sdp, sdkp->opt_xfer_blocks) >= PAGE_CACHE_SIZE) {
2916                 q->limits.io_opt = logical_to_bytes(sdp, sdkp->opt_xfer_blocks);
2917                 rw_max = logical_to_sectors(sdp, sdkp->opt_xfer_blocks);
2918         } else
2919                 rw_max = min_not_zero(logical_to_sectors(sdp, dev_max),
2920                                       (sector_t)BLK_DEF_MAX_SECTORS);
2921
2922         /* Do not exceed controller limit */
2923         rw_max = min(rw_max, queue_max_hw_sectors(q));
2924
2925         /*
2926          * Only update max_sectors if previously unset or if the current value
2927          * exceeds the capabilities of the hardware.
2928          */
2929         if (sdkp->first_scan ||
2930             q->limits.max_sectors > q->limits.max_dev_sectors ||
2931             q->limits.max_sectors > q->limits.max_hw_sectors)
2932                 q->limits.max_sectors = rw_max;
2933
2934         sdkp->first_scan = 0;
2935
2936         set_capacity(disk, logical_to_sectors(sdp, sdkp->capacity));
2937         sd_config_write_same(sdkp);
2938         kfree(buffer);
2939
2940  out:
2941         return 0;
2942 }
2943
2944 /**
2945  *      sd_unlock_native_capacity - unlock native capacity
2946  *      @disk: struct gendisk to set capacity for
2947  *
2948  *      Block layer calls this function if it detects that partitions
2949  *      on @disk reach beyond the end of the device.  If the SCSI host
2950  *      implements ->unlock_native_capacity() method, it's invoked to
2951  *      give it a chance to adjust the device capacity.
2952  *
2953  *      CONTEXT:
2954  *      Defined by block layer.  Might sleep.
2955  */
2956 static void sd_unlock_native_capacity(struct gendisk *disk)
2957 {
2958         struct scsi_device *sdev = scsi_disk(disk)->device;
2959
2960         if (sdev->host->hostt->unlock_native_capacity)
2961                 sdev->host->hostt->unlock_native_capacity(sdev);
2962 }
2963
2964 /**
2965  *      sd_format_disk_name - format disk name
2966  *      @prefix: name prefix - ie. "sd" for SCSI disks
2967  *      @index: index of the disk to format name for
2968  *      @buf: output buffer
2969  *      @buflen: length of the output buffer
2970  *
2971  *      SCSI disk names starts at sda.  The 26th device is sdz and the
2972  *      27th is sdaa.  The last one for two lettered suffix is sdzz
2973  *      which is followed by sdaaa.
2974  *
2975  *      This is basically 26 base counting with one extra 'nil' entry
2976  *      at the beginning from the second digit on and can be
2977  *      determined using similar method as 26 base conversion with the
2978  *      index shifted -1 after each digit is computed.
2979  *
2980  *      CONTEXT:
2981  *      Don't care.
2982  *
2983  *      RETURNS:
2984  *      0 on success, -errno on failure.
2985  */
2986 static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
2987 {
2988         const int base = 'z' - 'a' + 1;
2989         char *begin = buf + strlen(prefix);
2990         char *end = buf + buflen;
2991         char *p;
2992         int unit;
2993
2994         p = end - 1;
2995         *p = '\0';
2996         unit = base;
2997         do {
2998                 if (p == begin)
2999                         return -EINVAL;
3000                 *--p = 'a' + (index % unit);
3001                 index = (index / unit) - 1;
3002         } while (index >= 0);
3003
3004         memmove(begin, p, end - p);
3005         memcpy(buf, prefix, strlen(prefix));
3006
3007         return 0;
3008 }
3009
3010 /*
3011  * The asynchronous part of sd_probe
3012  */
3013 static void sd_probe_async(void *data, async_cookie_t cookie)
3014 {
3015         struct scsi_disk *sdkp = data;
3016         struct scsi_device *sdp;
3017         struct gendisk *gd;
3018         u32 index;
3019         struct device *dev;
3020
3021         sdp = sdkp->device;
3022         gd = sdkp->disk;
3023         index = sdkp->index;
3024         dev = &sdp->sdev_gendev;
3025
3026         gd->major = sd_major((index & 0xf0) >> 4);
3027         gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
3028         gd->minors = SD_MINORS;
3029
3030         gd->fops = &sd_fops;
3031         gd->private_data = &sdkp->driver;
3032         gd->queue = sdkp->device->request_queue;
3033
3034         /* defaults, until the device tells us otherwise */
3035         sdp->sector_size = 512;
3036         sdkp->capacity = 0;
3037         sdkp->media_present = 1;
3038         sdkp->write_prot = 0;
3039         sdkp->cache_override = 0;
3040         sdkp->WCE = 0;
3041         sdkp->RCD = 0;
3042         sdkp->ATO = 0;
3043         sdkp->first_scan = 1;
3044         sdkp->max_medium_access_timeouts = SD_MAX_MEDIUM_TIMEOUTS;
3045
3046         sd_revalidate_disk(gd);
3047
3048         gd->driverfs_dev = &sdp->sdev_gendev;
3049         gd->flags = GENHD_FL_EXT_DEVT;
3050         if (sdp->removable) {
3051                 gd->flags |= GENHD_FL_REMOVABLE;
3052                 gd->events |= DISK_EVENT_MEDIA_CHANGE;
3053         }
3054
3055         blk_pm_runtime_init(sdp->request_queue, dev);
3056         add_disk(gd);
3057         if (sdkp->capacity)
3058                 sd_dif_config_host(sdkp);
3059
3060         sd_revalidate_disk(gd);
3061
3062         sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
3063                   sdp->removable ? "removable " : "");
3064         scsi_autopm_put_device(sdp);
3065         put_device(&sdkp->dev);
3066 }
3067
3068 /**
3069  *      sd_probe - called during driver initialization and whenever a
3070  *      new scsi device is attached to the system. It is called once
3071  *      for each scsi device (not just disks) present.
3072  *      @dev: pointer to device object
3073  *
3074  *      Returns 0 if successful (or not interested in this scsi device
3075  *      (e.g. scanner)); 1 when there is an error.
3076  *
3077  *      Note: this function is invoked from the scsi mid-level.
3078  *      This function sets up the mapping between a given
3079  *      <host,channel,id,lun> (found in sdp) and new device name
3080  *      (e.g. /dev/sda). More precisely it is the block device major
3081  *      and minor number that is chosen here.
3082  *
3083  *      Assume sd_probe is not re-entrant (for time being)
3084  *      Also think about sd_probe() and sd_remove() running coincidentally.
3085  **/
3086 static int sd_probe(struct device *dev)
3087 {
3088         struct scsi_device *sdp = to_scsi_device(dev);
3089         struct scsi_disk *sdkp;
3090         struct gendisk *gd;
3091         int index;
3092         int error;
3093
3094         scsi_autopm_get_device(sdp);
3095         error = -ENODEV;
3096         if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
3097                 goto out;
3098
3099         SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
3100                                         "sd_probe\n"));
3101
3102         error = -ENOMEM;
3103         sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
3104         if (!sdkp)
3105                 goto out;
3106
3107         gd = alloc_disk(SD_MINORS);
3108         if (!gd)
3109                 goto out_free;
3110
3111         do {
3112                 if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
3113                         goto out_put;
3114
3115                 spin_lock(&sd_index_lock);
3116                 error = ida_get_new(&sd_index_ida, &index);
3117                 spin_unlock(&sd_index_lock);
3118         } while (error == -EAGAIN);
3119
3120         if (error) {
3121                 sdev_printk(KERN_WARNING, sdp, "sd_probe: memory exhausted.\n");
3122                 goto out_put;
3123         }
3124
3125         error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
3126         if (error) {
3127                 sdev_printk(KERN_WARNING, sdp, "SCSI disk (sd) name length exceeded.\n");
3128                 goto out_free_index;
3129         }
3130
3131         sdkp->device = sdp;
3132         sdkp->driver = &sd_template;
3133         sdkp->disk = gd;
3134         sdkp->index = index;
3135         atomic_set(&sdkp->openers, 0);
3136         atomic_set(&sdkp->device->ioerr_cnt, 0);
3137
3138         if (!sdp->request_queue->rq_timeout) {
3139                 if (sdp->type != TYPE_MOD)
3140                         blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
3141                 else
3142                         blk_queue_rq_timeout(sdp->request_queue,
3143                                              SD_MOD_TIMEOUT);
3144         }
3145
3146         device_initialize(&sdkp->dev);
3147         sdkp->dev.parent = dev;
3148         sdkp->dev.class = &sd_disk_class;
3149         dev_set_name(&sdkp->dev, "%s", dev_name(dev));
3150
3151         error = device_add(&sdkp->dev);
3152         if (error)
3153                 goto out_free_index;
3154
3155         get_device(dev);
3156         dev_set_drvdata(dev, sdkp);
3157
3158         get_device(&sdkp->dev); /* prevent release before async_schedule */
3159         async_schedule_domain(sd_probe_async, sdkp, &scsi_sd_probe_domain);
3160
3161         return 0;
3162
3163  out_free_index:
3164         spin_lock(&sd_index_lock);
3165         ida_remove(&sd_index_ida, index);
3166         spin_unlock(&sd_index_lock);
3167  out_put:
3168         put_disk(gd);
3169  out_free:
3170         kfree(sdkp);
3171  out:
3172         scsi_autopm_put_device(sdp);
3173         return error;
3174 }
3175
3176 /**
3177  *      sd_remove - called whenever a scsi disk (previously recognized by
3178  *      sd_probe) is detached from the system. It is called (potentially
3179  *      multiple times) during sd module unload.
3180  *      @sdp: pointer to mid level scsi device object
3181  *
3182  *      Note: this function is invoked from the scsi mid-level.
3183  *      This function potentially frees up a device name (e.g. /dev/sdc)
3184  *      that could be re-used by a subsequent sd_probe().
3185  *      This function is not called when the built-in sd driver is "exit-ed".
3186  **/
3187 static int sd_remove(struct device *dev)
3188 {
3189         struct scsi_disk *sdkp;
3190         dev_t devt;
3191
3192         sdkp = dev_get_drvdata(dev);
3193         devt = disk_devt(sdkp->disk);
3194         scsi_autopm_get_device(sdkp->device);
3195
3196         async_synchronize_full_domain(&scsi_sd_pm_domain);
3197         async_synchronize_full_domain(&scsi_sd_probe_domain);
3198         device_del(&sdkp->dev);
3199         del_gendisk(sdkp->disk);
3200         sd_shutdown(dev);
3201
3202         blk_register_region(devt, SD_MINORS, NULL,
3203                             sd_default_probe, NULL, NULL);
3204
3205         mutex_lock(&sd_ref_mutex);
3206         dev_set_drvdata(dev, NULL);
3207         put_device(&sdkp->dev);
3208         mutex_unlock(&sd_ref_mutex);
3209
3210         return 0;
3211 }
3212
3213 /**
3214  *      scsi_disk_release - Called to free the scsi_disk structure
3215  *      @dev: pointer to embedded class device
3216  *
3217  *      sd_ref_mutex must be held entering this routine.  Because it is
3218  *      called on last put, you should always use the scsi_disk_get()
3219  *      scsi_disk_put() helpers which manipulate the semaphore directly
3220  *      and never do a direct put_device.
3221  **/
3222 static void scsi_disk_release(struct device *dev)
3223 {
3224         struct scsi_disk *sdkp = to_scsi_disk(dev);
3225         struct gendisk *disk = sdkp->disk;
3226         struct request_queue *q = disk->queue;
3227
3228         spin_lock(&sd_index_lock);
3229         ida_remove(&sd_index_ida, sdkp->index);
3230         spin_unlock(&sd_index_lock);
3231
3232         /*
3233          * Wait until all requests that are in progress have completed.
3234          * This is necessary to avoid that e.g. scsi_end_request() crashes
3235          * due to clearing the disk->private_data pointer. Wait from inside
3236          * scsi_disk_release() instead of from sd_release() to avoid that
3237          * freezing and unfreezing the request queue affects user space I/O
3238          * in case multiple processes open a /dev/sd... node concurrently.
3239          */
3240         blk_mq_freeze_queue(q);
3241         blk_mq_unfreeze_queue(q);
3242
3243         disk->private_data = NULL;
3244         put_disk(disk);
3245         put_device(&sdkp->device->sdev_gendev);
3246
3247         kfree(sdkp);
3248 }
3249
3250 static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
3251 {
3252         unsigned char cmd[6] = { START_STOP };  /* START_VALID */
3253         struct scsi_sense_hdr sshdr;
3254         struct scsi_device *sdp = sdkp->device;
3255         int res;
3256
3257         if (start)
3258                 cmd[4] |= 1;    /* START */
3259
3260         if (sdp->start_stop_pwr_cond)
3261                 cmd[4] |= start ? 1 << 4 : 3 << 4;      /* Active or Standby */
3262
3263         if (!scsi_device_online(sdp))
3264                 return -ENODEV;
3265
3266         res = scsi_execute_req_flags(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
3267                                SD_TIMEOUT, SD_MAX_RETRIES, NULL, REQ_PM);
3268         if (res) {
3269                 sd_print_result(sdkp, "Start/Stop Unit failed", res);
3270                 if (driver_byte(res) & DRIVER_SENSE)
3271                         sd_print_sense_hdr(sdkp, &sshdr);
3272                 if (scsi_sense_valid(&sshdr) &&
3273                         /* 0x3a is medium not present */
3274                         sshdr.asc == 0x3a)
3275                         res = 0;
3276         }
3277
3278         /* SCSI error codes must not go to the generic layer */
3279         if (res)
3280                 return -EIO;
3281
3282         return 0;
3283 }
3284
3285 /*
3286  * Send a SYNCHRONIZE CACHE instruction down to the device through
3287  * the normal SCSI command structure.  Wait for the command to
3288  * complete.
3289  */
3290 static void sd_shutdown(struct device *dev)
3291 {
3292         struct scsi_disk *sdkp = dev_get_drvdata(dev);
3293
3294         if (!sdkp)
3295                 return;         /* this can happen */
3296
3297         if (pm_runtime_suspended(dev))
3298                 return;
3299
3300         if (sdkp->WCE && sdkp->media_present) {
3301                 sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
3302                 sd_sync_cache(sdkp);
3303         }
3304
3305         if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
3306                 sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
3307                 sd_start_stop_device(sdkp, 0);
3308         }
3309 }
3310
3311 static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)
3312 {
3313         struct scsi_disk *sdkp = dev_get_drvdata(dev);
3314         int ret = 0;
3315
3316         if (!sdkp)      /* E.g.: runtime suspend following sd_remove() */
3317                 return 0;
3318
3319         if (sdkp->WCE && sdkp->media_present) {
3320                 sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
3321                 ret = sd_sync_cache(sdkp);
3322                 if (ret) {
3323                         /* ignore OFFLINE device */
3324                         if (ret == -ENODEV)
3325                                 ret = 0;
3326                         goto done;
3327                 }
3328         }
3329
3330         if (sdkp->device->manage_start_stop) {
3331                 sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
3332                 /* an error is not worth aborting a system sleep */
3333                 ret = sd_start_stop_device(sdkp, 0);
3334                 if (ignore_stop_errors)
3335                         ret = 0;
3336         }
3337
3338 done:
3339         return ret;
3340 }
3341
3342 static int sd_suspend_system(struct device *dev)
3343 {
3344         return sd_suspend_common(dev, true);
3345 }
3346
3347 static int sd_suspend_runtime(struct device *dev)
3348 {
3349         return sd_suspend_common(dev, false);
3350 }
3351
3352 static int sd_resume(struct device *dev)
3353 {
3354         struct scsi_disk *sdkp = dev_get_drvdata(dev);
3355
3356         if (!sdkp)      /* E.g.: runtime resume at the start of sd_probe() */
3357                 return 0;
3358
3359         if (!sdkp->device->manage_start_stop)
3360                 return 0;
3361
3362         sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
3363         return sd_start_stop_device(sdkp, 1);
3364 }
3365
3366 /**
3367  *      init_sd - entry point for this driver (both when built in or when
3368  *      a module).
3369  *
3370  *      Note: this function registers this driver with the scsi mid-level.
3371  **/
3372 static int __init init_sd(void)
3373 {
3374         int majors = 0, i, err;
3375
3376         SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
3377
3378         for (i = 0; i < SD_MAJORS; i++) {
3379                 if (register_blkdev(sd_major(i), "sd") != 0)
3380                         continue;
3381                 majors++;
3382                 blk_register_region(sd_major(i), SD_MINORS, NULL,
3383                                     sd_default_probe, NULL, NULL);
3384         }
3385
3386         if (!majors)
3387                 return -ENODEV;
3388
3389         err = class_register(&sd_disk_class);
3390         if (err)
3391                 goto err_out;
3392
3393         sd_cdb_cache = kmem_cache_create("sd_ext_cdb", SD_EXT_CDB_SIZE,
3394                                          0, 0, NULL);
3395         if (!sd_cdb_cache) {
3396                 printk(KERN_ERR "sd: can't init extended cdb cache\n");
3397                 err = -ENOMEM;
3398                 goto err_out_class;
3399         }
3400
3401         sd_cdb_pool = mempool_create_slab_pool(SD_MEMPOOL_SIZE, sd_cdb_cache);
3402         if (!sd_cdb_pool) {
3403                 printk(KERN_ERR "sd: can't init extended cdb pool\n");
3404                 err = -ENOMEM;
3405                 goto err_out_cache;
3406         }
3407
3408         err = scsi_register_driver(&sd_template.gendrv);
3409         if (err)
3410                 goto err_out_driver;
3411
3412         return 0;
3413
3414 err_out_driver:
3415         mempool_destroy(sd_cdb_pool);
3416
3417 err_out_cache:
3418         kmem_cache_destroy(sd_cdb_cache);
3419
3420 err_out_class:
3421         class_unregister(&sd_disk_class);
3422 err_out:
3423         for (i = 0; i < SD_MAJORS; i++)
3424                 unregister_blkdev(sd_major(i), "sd");
3425         return err;
3426 }
3427
3428 /**
3429  *      exit_sd - exit point for this driver (when it is a module).
3430  *
3431  *      Note: this function unregisters this driver from the scsi mid-level.
3432  **/
3433 static void __exit exit_sd(void)
3434 {
3435         int i;
3436
3437         SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
3438
3439         scsi_unregister_driver(&sd_template.gendrv);
3440         mempool_destroy(sd_cdb_pool);
3441         kmem_cache_destroy(sd_cdb_cache);
3442
3443         class_unregister(&sd_disk_class);
3444
3445         for (i = 0; i < SD_MAJORS; i++) {
3446                 blk_unregister_region(sd_major(i), SD_MINORS);
3447                 unregister_blkdev(sd_major(i), "sd");
3448         }
3449 }
3450
3451 module_init(init_sd);
3452 module_exit(exit_sd);
3453
3454 static void sd_print_sense_hdr(struct scsi_disk *sdkp,
3455                                struct scsi_sense_hdr *sshdr)
3456 {
3457         scsi_print_sense_hdr(sdkp->device,
3458                              sdkp->disk ? sdkp->disk->disk_name : NULL, sshdr);
3459 }
3460
3461 static void sd_print_result(const struct scsi_disk *sdkp, const char *msg,
3462                             int result)
3463 {
3464         const char *hb_string = scsi_hostbyte_string(result);
3465         const char *db_string = scsi_driverbyte_string(result);
3466
3467         if (hb_string || db_string)
3468                 sd_printk(KERN_INFO, sdkp,
3469                           "%s: Result: hostbyte=%s driverbyte=%s\n", msg,
3470                           hb_string ? hb_string : "invalid",
3471                           db_string ? db_string : "invalid");
3472         else
3473                 sd_printk(KERN_INFO, sdkp,
3474                           "%s: Result: hostbyte=0x%02x driverbyte=0x%02x\n",
3475                           msg, host_byte(result), driver_byte(result));
3476 }
3477