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