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/config.h> 36 #include <linux/module.h> 37 #include <linux/fs.h> 38 #include <linux/kernel.h> 39 #include <linux/sched.h> 40 #include <linux/mm.h> 41 #include <linux/bio.h> 42 #include <linux/genhd.h> 43 #include <linux/hdreg.h> 44 #include <linux/errno.h> 45 #include <linux/idr.h> 46 #include <linux/interrupt.h> 47 #include <linux/init.h> 48 #include <linux/blkdev.h> 49 #include <linux/blkpg.h> 50 #include <linux/kref.h> 51 #include <linux/delay.h> 52 #include <linux/mutex.h> 53 #include <asm/uaccess.h> 54 55 #include <scsi/scsi.h> 56 #include <scsi/scsi_cmnd.h> 57 #include <scsi/scsi_dbg.h> 58 #include <scsi/scsi_device.h> 59 #include <scsi/scsi_driver.h> 60 #include <scsi/scsi_eh.h> 61 #include <scsi/scsi_host.h> 62 #include <scsi/scsi_ioctl.h> 63 #include <scsi/scsicam.h> 64 65 #include "scsi_logging.h" 66 67 /* 68 * More than enough for everybody ;) The huge number of majors 69 * is a leftover from 16bit dev_t days, we don't really need that 70 * much numberspace. 71 */ 72 #define SD_MAJORS 16 73 74 /* 75 * This is limited by the naming scheme enforced in sd_probe, 76 * add another character to it if you really need more disks. 77 */ 78 #define SD_MAX_DISKS (((26 * 26) + 26 + 1) * 26) 79 80 /* 81 * Time out in seconds for disks and Magneto-opticals (which are slower). 82 */ 83 #define SD_TIMEOUT (30 * HZ) 84 #define SD_MOD_TIMEOUT (75 * HZ) 85 86 /* 87 * Number of allowed retries 88 */ 89 #define SD_MAX_RETRIES 5 90 #define SD_PASSTHROUGH_RETRIES 1 91 92 /* 93 * Size of the initial data buffer for mode and read capacity data 94 */ 95 #define SD_BUF_SIZE 512 96 97 static void scsi_disk_release(struct kref *kref); 98 99 struct scsi_disk { 100 struct scsi_driver *driver; /* always &sd_template */ 101 struct scsi_device *device; 102 struct kref kref; 103 struct gendisk *disk; 104 unsigned int openers; /* protected by BKL for now, yuck */ 105 sector_t capacity; /* size in 512-byte sectors */ 106 u32 index; 107 u8 media_present; 108 u8 write_prot; 109 unsigned WCE : 1; /* state of disk WCE bit */ 110 unsigned RCD : 1; /* state of disk RCD bit, unused */ 111 unsigned DPOFUA : 1; /* state of disk DPOFUA bit */ 112 }; 113 114 static DEFINE_IDR(sd_index_idr); 115 static DEFINE_SPINLOCK(sd_index_lock); 116 117 /* This semaphore is used to mediate the 0->1 reference get in the 118 * face of object destruction (i.e. we can't allow a get on an 119 * object after last put) */ 120 static DEFINE_MUTEX(sd_ref_mutex); 121 122 static int sd_revalidate_disk(struct gendisk *disk); 123 static void sd_rw_intr(struct scsi_cmnd * SCpnt); 124 125 static int sd_probe(struct device *); 126 static int sd_remove(struct device *); 127 static void sd_shutdown(struct device *dev); 128 static void sd_rescan(struct device *); 129 static int sd_init_command(struct scsi_cmnd *); 130 static int sd_issue_flush(struct device *, sector_t *); 131 static void sd_prepare_flush(request_queue_t *, struct request *); 132 static void sd_read_capacity(struct scsi_disk *sdkp, char *diskname, 133 unsigned char *buffer); 134 135 static struct scsi_driver sd_template = { 136 .owner = THIS_MODULE, 137 .gendrv = { 138 .name = "sd", 139 .probe = sd_probe, 140 .remove = sd_remove, 141 .shutdown = sd_shutdown, 142 }, 143 .rescan = sd_rescan, 144 .init_command = sd_init_command, 145 .issue_flush = sd_issue_flush, 146 }; 147 148 /* 149 * Device no to disk mapping: 150 * 151 * major disc2 disc p1 152 * |............|.............|....|....| <- dev_t 153 * 31 20 19 8 7 4 3 0 154 * 155 * Inside a major, we have 16k disks, however mapped non- 156 * contiguously. The first 16 disks are for major0, the next 157 * ones with major1, ... Disk 256 is for major0 again, disk 272 158 * for major1, ... 159 * As we stay compatible with our numbering scheme, we can reuse 160 * the well-know SCSI majors 8, 65--71, 136--143. 161 */ 162 static int sd_major(int major_idx) 163 { 164 switch (major_idx) { 165 case 0: 166 return SCSI_DISK0_MAJOR; 167 case 1 ... 7: 168 return SCSI_DISK1_MAJOR + major_idx - 1; 169 case 8 ... 15: 170 return SCSI_DISK8_MAJOR + major_idx - 8; 171 default: 172 BUG(); 173 return 0; /* shut up gcc */ 174 } 175 } 176 177 #define to_scsi_disk(obj) container_of(obj,struct scsi_disk,kref) 178 179 static inline struct scsi_disk *scsi_disk(struct gendisk *disk) 180 { 181 return container_of(disk->private_data, struct scsi_disk, driver); 182 } 183 184 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk) 185 { 186 struct scsi_disk *sdkp = NULL; 187 188 if (disk->private_data) { 189 sdkp = scsi_disk(disk); 190 if (scsi_device_get(sdkp->device) == 0) 191 kref_get(&sdkp->kref); 192 else 193 sdkp = NULL; 194 } 195 return sdkp; 196 } 197 198 static struct scsi_disk *scsi_disk_get(struct gendisk *disk) 199 { 200 struct scsi_disk *sdkp; 201 202 mutex_lock(&sd_ref_mutex); 203 sdkp = __scsi_disk_get(disk); 204 mutex_unlock(&sd_ref_mutex); 205 return sdkp; 206 } 207 208 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev) 209 { 210 struct scsi_disk *sdkp; 211 212 mutex_lock(&sd_ref_mutex); 213 sdkp = dev_get_drvdata(dev); 214 if (sdkp) 215 sdkp = __scsi_disk_get(sdkp->disk); 216 mutex_unlock(&sd_ref_mutex); 217 return sdkp; 218 } 219 220 static void scsi_disk_put(struct scsi_disk *sdkp) 221 { 222 struct scsi_device *sdev = sdkp->device; 223 224 mutex_lock(&sd_ref_mutex); 225 kref_put(&sdkp->kref, scsi_disk_release); 226 scsi_device_put(sdev); 227 mutex_unlock(&sd_ref_mutex); 228 } 229 230 /** 231 * sd_init_command - build a scsi (read or write) command from 232 * information in the request structure. 233 * @SCpnt: pointer to mid-level's per scsi command structure that 234 * contains request and into which the scsi command is written 235 * 236 * Returns 1 if successful and 0 if error (or cannot be done now). 237 **/ 238 static int sd_init_command(struct scsi_cmnd * SCpnt) 239 { 240 struct scsi_device *sdp = SCpnt->device; 241 struct request *rq = SCpnt->request; 242 struct gendisk *disk = rq->rq_disk; 243 sector_t block = rq->sector; 244 unsigned int this_count = SCpnt->request_bufflen >> 9; 245 unsigned int timeout = sdp->timeout; 246 247 SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, " 248 "count=%d\n", disk->disk_name, 249 (unsigned long long)block, this_count)); 250 251 if (!sdp || !scsi_device_online(sdp) || 252 block + rq->nr_sectors > get_capacity(disk)) { 253 SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n", 254 rq->nr_sectors)); 255 SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt)); 256 return 0; 257 } 258 259 if (sdp->changed) { 260 /* 261 * quietly refuse to do anything to a changed disc until 262 * the changed bit has been reset 263 */ 264 /* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */ 265 return 0; 266 } 267 SCSI_LOG_HLQUEUE(2, printk("%s : block=%llu\n", 268 disk->disk_name, (unsigned long long)block)); 269 270 /* 271 * If we have a 1K hardware sectorsize, prevent access to single 272 * 512 byte sectors. In theory we could handle this - in fact 273 * the scsi cdrom driver must be able to handle this because 274 * we typically use 1K blocksizes, and cdroms typically have 275 * 2K hardware sectorsizes. Of course, things are simpler 276 * with the cdrom, since it is read-only. For performance 277 * reasons, the filesystems should be able to handle this 278 * and not force the scsi disk driver to use bounce buffers 279 * for this. 280 */ 281 if (sdp->sector_size == 1024) { 282 if ((block & 1) || (rq->nr_sectors & 1)) { 283 printk(KERN_ERR "sd: Bad block number requested"); 284 return 0; 285 } else { 286 block = block >> 1; 287 this_count = this_count >> 1; 288 } 289 } 290 if (sdp->sector_size == 2048) { 291 if ((block & 3) || (rq->nr_sectors & 3)) { 292 printk(KERN_ERR "sd: Bad block number requested"); 293 return 0; 294 } else { 295 block = block >> 2; 296 this_count = this_count >> 2; 297 } 298 } 299 if (sdp->sector_size == 4096) { 300 if ((block & 7) || (rq->nr_sectors & 7)) { 301 printk(KERN_ERR "sd: Bad block number requested"); 302 return 0; 303 } else { 304 block = block >> 3; 305 this_count = this_count >> 3; 306 } 307 } 308 if (rq_data_dir(rq) == WRITE) { 309 if (!sdp->writeable) { 310 return 0; 311 } 312 SCpnt->cmnd[0] = WRITE_6; 313 SCpnt->sc_data_direction = DMA_TO_DEVICE; 314 } else if (rq_data_dir(rq) == READ) { 315 SCpnt->cmnd[0] = READ_6; 316 SCpnt->sc_data_direction = DMA_FROM_DEVICE; 317 } else { 318 printk(KERN_ERR "sd: Unknown command %lx\n", rq->flags); 319 /* overkill panic("Unknown sd command %lx\n", rq->flags); */ 320 return 0; 321 } 322 323 SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n", 324 disk->disk_name, (rq_data_dir(rq) == WRITE) ? 325 "writing" : "reading", this_count, rq->nr_sectors)); 326 327 SCpnt->cmnd[1] = 0; 328 329 if (block > 0xffffffff) { 330 SCpnt->cmnd[0] += READ_16 - READ_6; 331 SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0; 332 SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0; 333 SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0; 334 SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0; 335 SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0; 336 SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff; 337 SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff; 338 SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff; 339 SCpnt->cmnd[9] = (unsigned char) block & 0xff; 340 SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff; 341 SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff; 342 SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff; 343 SCpnt->cmnd[13] = (unsigned char) this_count & 0xff; 344 SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0; 345 } else if ((this_count > 0xff) || (block > 0x1fffff) || 346 SCpnt->device->use_10_for_rw) { 347 if (this_count > 0xffff) 348 this_count = 0xffff; 349 350 SCpnt->cmnd[0] += READ_10 - READ_6; 351 SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0; 352 SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff; 353 SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff; 354 SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff; 355 SCpnt->cmnd[5] = (unsigned char) block & 0xff; 356 SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0; 357 SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff; 358 SCpnt->cmnd[8] = (unsigned char) this_count & 0xff; 359 } else { 360 if (unlikely(blk_fua_rq(rq))) { 361 /* 362 * This happens only if this drive failed 363 * 10byte rw command with ILLEGAL_REQUEST 364 * during operation and thus turned off 365 * use_10_for_rw. 366 */ 367 printk(KERN_ERR "sd: FUA write on READ/WRITE(6) drive\n"); 368 return 0; 369 } 370 371 SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f); 372 SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff); 373 SCpnt->cmnd[3] = (unsigned char) block & 0xff; 374 SCpnt->cmnd[4] = (unsigned char) this_count; 375 SCpnt->cmnd[5] = 0; 376 } 377 SCpnt->request_bufflen = SCpnt->bufflen = 378 this_count * sdp->sector_size; 379 380 /* 381 * We shouldn't disconnect in the middle of a sector, so with a dumb 382 * host adapter, it's safe to assume that we can at least transfer 383 * this many bytes between each connect / disconnect. 384 */ 385 SCpnt->transfersize = sdp->sector_size; 386 SCpnt->underflow = this_count << 9; 387 SCpnt->allowed = SD_MAX_RETRIES; 388 SCpnt->timeout_per_command = timeout; 389 390 /* 391 * This is the completion routine we use. This is matched in terms 392 * of capability to this function. 393 */ 394 SCpnt->done = sd_rw_intr; 395 396 /* 397 * This indicates that the command is ready from our end to be 398 * queued. 399 */ 400 return 1; 401 } 402 403 /** 404 * sd_open - open a scsi disk device 405 * @inode: only i_rdev member may be used 406 * @filp: only f_mode and f_flags may be used 407 * 408 * Returns 0 if successful. Returns a negated errno value in case 409 * of error. 410 * 411 * Note: This can be called from a user context (e.g. fsck(1) ) 412 * or from within the kernel (e.g. as a result of a mount(1) ). 413 * In the latter case @inode and @filp carry an abridged amount 414 * of information as noted above. 415 **/ 416 static int sd_open(struct inode *inode, struct file *filp) 417 { 418 struct gendisk *disk = inode->i_bdev->bd_disk; 419 struct scsi_disk *sdkp; 420 struct scsi_device *sdev; 421 int retval; 422 423 if (!(sdkp = scsi_disk_get(disk))) 424 return -ENXIO; 425 426 427 SCSI_LOG_HLQUEUE(3, printk("sd_open: disk=%s\n", disk->disk_name)); 428 429 sdev = sdkp->device; 430 431 /* 432 * If the device is in error recovery, wait until it is done. 433 * If the device is offline, then disallow any access to it. 434 */ 435 retval = -ENXIO; 436 if (!scsi_block_when_processing_errors(sdev)) 437 goto error_out; 438 439 if (sdev->removable || sdkp->write_prot) 440 check_disk_change(inode->i_bdev); 441 442 /* 443 * If the drive is empty, just let the open fail. 444 */ 445 retval = -ENOMEDIUM; 446 if (sdev->removable && !sdkp->media_present && 447 !(filp->f_flags & O_NDELAY)) 448 goto error_out; 449 450 /* 451 * If the device has the write protect tab set, have the open fail 452 * if the user expects to be able to write to the thing. 453 */ 454 retval = -EROFS; 455 if (sdkp->write_prot && (filp->f_mode & FMODE_WRITE)) 456 goto error_out; 457 458 /* 459 * It is possible that the disk changing stuff resulted in 460 * the device being taken offline. If this is the case, 461 * report this to the user, and don't pretend that the 462 * open actually succeeded. 463 */ 464 retval = -ENXIO; 465 if (!scsi_device_online(sdev)) 466 goto error_out; 467 468 if (!sdkp->openers++ && sdev->removable) { 469 if (scsi_block_when_processing_errors(sdev)) 470 scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT); 471 } 472 473 return 0; 474 475 error_out: 476 scsi_disk_put(sdkp); 477 return retval; 478 } 479 480 /** 481 * sd_release - invoked when the (last) close(2) is called on this 482 * scsi disk. 483 * @inode: only i_rdev member may be used 484 * @filp: only f_mode and f_flags may be used 485 * 486 * Returns 0. 487 * 488 * Note: may block (uninterruptible) if error recovery is underway 489 * on this disk. 490 **/ 491 static int sd_release(struct inode *inode, struct file *filp) 492 { 493 struct gendisk *disk = inode->i_bdev->bd_disk; 494 struct scsi_disk *sdkp = scsi_disk(disk); 495 struct scsi_device *sdev = sdkp->device; 496 497 SCSI_LOG_HLQUEUE(3, printk("sd_release: disk=%s\n", disk->disk_name)); 498 499 if (!--sdkp->openers && sdev->removable) { 500 if (scsi_block_when_processing_errors(sdev)) 501 scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW); 502 } 503 504 /* 505 * XXX and what if there are packets in flight and this close() 506 * XXX is followed by a "rmmod sd_mod"? 507 */ 508 scsi_disk_put(sdkp); 509 return 0; 510 } 511 512 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo) 513 { 514 struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk); 515 struct scsi_device *sdp = sdkp->device; 516 struct Scsi_Host *host = sdp->host; 517 int diskinfo[4]; 518 519 /* default to most commonly used values */ 520 diskinfo[0] = 0x40; /* 1 << 6 */ 521 diskinfo[1] = 0x20; /* 1 << 5 */ 522 diskinfo[2] = sdkp->capacity >> 11; 523 524 /* override with calculated, extended default, or driver values */ 525 if (host->hostt->bios_param) 526 host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo); 527 else 528 scsicam_bios_param(bdev, sdkp->capacity, diskinfo); 529 530 geo->heads = diskinfo[0]; 531 geo->sectors = diskinfo[1]; 532 geo->cylinders = diskinfo[2]; 533 return 0; 534 } 535 536 /** 537 * sd_ioctl - process an ioctl 538 * @inode: only i_rdev/i_bdev members may be used 539 * @filp: only f_mode and f_flags may be used 540 * @cmd: ioctl command number 541 * @arg: this is third argument given to ioctl(2) system call. 542 * Often contains a pointer. 543 * 544 * Returns 0 if successful (some ioctls return postive numbers on 545 * success as well). Returns a negated errno value in case of error. 546 * 547 * Note: most ioctls are forward onto the block subsystem or further 548 * down in the scsi subsytem. 549 **/ 550 static int sd_ioctl(struct inode * inode, struct file * filp, 551 unsigned int cmd, unsigned long arg) 552 { 553 struct block_device *bdev = inode->i_bdev; 554 struct gendisk *disk = bdev->bd_disk; 555 struct scsi_device *sdp = scsi_disk(disk)->device; 556 void __user *p = (void __user *)arg; 557 int error; 558 559 SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n", 560 disk->disk_name, cmd)); 561 562 /* 563 * If we are in the middle of error recovery, don't let anyone 564 * else try and use this device. Also, if error recovery fails, it 565 * may try and take the device offline, in which case all further 566 * access to the device is prohibited. 567 */ 568 error = scsi_nonblockable_ioctl(sdp, cmd, p, filp); 569 if (!scsi_block_when_processing_errors(sdp) || !error) 570 return error; 571 572 /* 573 * Send SCSI addressing ioctls directly to mid level, send other 574 * ioctls to block level and then onto mid level if they can't be 575 * resolved. 576 */ 577 switch (cmd) { 578 case SCSI_IOCTL_GET_IDLUN: 579 case SCSI_IOCTL_GET_BUS_NUMBER: 580 return scsi_ioctl(sdp, cmd, p); 581 default: 582 error = scsi_cmd_ioctl(filp, disk, cmd, p); 583 if (error != -ENOTTY) 584 return error; 585 } 586 return scsi_ioctl(sdp, cmd, p); 587 } 588 589 static void set_media_not_present(struct scsi_disk *sdkp) 590 { 591 sdkp->media_present = 0; 592 sdkp->capacity = 0; 593 sdkp->device->changed = 1; 594 } 595 596 /** 597 * sd_media_changed - check if our medium changed 598 * @disk: kernel device descriptor 599 * 600 * Returns 0 if not applicable or no change; 1 if change 601 * 602 * Note: this function is invoked from the block subsystem. 603 **/ 604 static int sd_media_changed(struct gendisk *disk) 605 { 606 struct scsi_disk *sdkp = scsi_disk(disk); 607 struct scsi_device *sdp = sdkp->device; 608 int retval; 609 610 SCSI_LOG_HLQUEUE(3, printk("sd_media_changed: disk=%s\n", 611 disk->disk_name)); 612 613 if (!sdp->removable) 614 return 0; 615 616 /* 617 * If the device is offline, don't send any commands - just pretend as 618 * if the command failed. If the device ever comes back online, we 619 * can deal with it then. It is only because of unrecoverable errors 620 * that we would ever take a device offline in the first place. 621 */ 622 if (!scsi_device_online(sdp)) 623 goto not_present; 624 625 /* 626 * Using TEST_UNIT_READY enables differentiation between drive with 627 * no cartridge loaded - NOT READY, drive with changed cartridge - 628 * UNIT ATTENTION, or with same cartridge - GOOD STATUS. 629 * 630 * Drives that auto spin down. eg iomega jaz 1G, will be started 631 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever 632 * sd_revalidate() is called. 633 */ 634 retval = -ENODEV; 635 if (scsi_block_when_processing_errors(sdp)) 636 retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES); 637 638 /* 639 * Unable to test, unit probably not ready. This usually 640 * means there is no disc in the drive. Mark as changed, 641 * and we will figure it out later once the drive is 642 * available again. 643 */ 644 if (retval) 645 goto not_present; 646 647 /* 648 * For removable scsi disk we have to recognise the presence 649 * of a disk in the drive. This is kept in the struct scsi_disk 650 * struct and tested at open ! Daniel Roche (dan@lectra.fr) 651 */ 652 sdkp->media_present = 1; 653 654 retval = sdp->changed; 655 sdp->changed = 0; 656 657 return retval; 658 659 not_present: 660 set_media_not_present(sdkp); 661 return 1; 662 } 663 664 static int sd_sync_cache(struct scsi_device *sdp) 665 { 666 int retries, res; 667 struct scsi_sense_hdr sshdr; 668 669 if (!scsi_device_online(sdp)) 670 return -ENODEV; 671 672 673 for (retries = 3; retries > 0; --retries) { 674 unsigned char cmd[10] = { 0 }; 675 676 cmd[0] = SYNCHRONIZE_CACHE; 677 /* 678 * Leave the rest of the command zero to indicate 679 * flush everything. 680 */ 681 res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr, 682 SD_TIMEOUT, SD_MAX_RETRIES); 683 if (res == 0) 684 break; 685 } 686 687 if (res) { printk(KERN_WARNING "FAILED\n status = %x, message = %02x, " 688 "host = %d, driver = %02x\n ", 689 status_byte(res), msg_byte(res), 690 host_byte(res), driver_byte(res)); 691 if (driver_byte(res) & DRIVER_SENSE) 692 scsi_print_sense_hdr("sd", &sshdr); 693 } 694 695 return res; 696 } 697 698 static int sd_issue_flush(struct device *dev, sector_t *error_sector) 699 { 700 int ret = 0; 701 struct scsi_device *sdp = to_scsi_device(dev); 702 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 703 704 if (!sdkp) 705 return -ENODEV; 706 707 if (sdkp->WCE) 708 ret = sd_sync_cache(sdp); 709 scsi_disk_put(sdkp); 710 return ret; 711 } 712 713 static void sd_prepare_flush(request_queue_t *q, struct request *rq) 714 { 715 memset(rq->cmd, 0, sizeof(rq->cmd)); 716 rq->flags |= REQ_BLOCK_PC; 717 rq->timeout = SD_TIMEOUT; 718 rq->cmd[0] = SYNCHRONIZE_CACHE; 719 rq->cmd_len = 10; 720 } 721 722 static void sd_rescan(struct device *dev) 723 { 724 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 725 726 if (sdkp) { 727 sd_revalidate_disk(sdkp->disk); 728 scsi_disk_put(sdkp); 729 } 730 } 731 732 733 #ifdef CONFIG_COMPAT 734 /* 735 * This gets directly called from VFS. When the ioctl 736 * is not recognized we go back to the other translation paths. 737 */ 738 static long sd_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 739 { 740 struct block_device *bdev = file->f_dentry->d_inode->i_bdev; 741 struct gendisk *disk = bdev->bd_disk; 742 struct scsi_device *sdev = scsi_disk(disk)->device; 743 744 /* 745 * If we are in the middle of error recovery, don't let anyone 746 * else try and use this device. Also, if error recovery fails, it 747 * may try and take the device offline, in which case all further 748 * access to the device is prohibited. 749 */ 750 if (!scsi_block_when_processing_errors(sdev)) 751 return -ENODEV; 752 753 if (sdev->host->hostt->compat_ioctl) { 754 int ret; 755 756 ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg); 757 758 return ret; 759 } 760 761 /* 762 * Let the static ioctl translation table take care of it. 763 */ 764 return -ENOIOCTLCMD; 765 } 766 #endif 767 768 static struct block_device_operations sd_fops = { 769 .owner = THIS_MODULE, 770 .open = sd_open, 771 .release = sd_release, 772 .ioctl = sd_ioctl, 773 .getgeo = sd_getgeo, 774 #ifdef CONFIG_COMPAT 775 .compat_ioctl = sd_compat_ioctl, 776 #endif 777 .media_changed = sd_media_changed, 778 .revalidate_disk = sd_revalidate_disk, 779 }; 780 781 /** 782 * sd_rw_intr - bottom half handler: called when the lower level 783 * driver has completed (successfully or otherwise) a scsi command. 784 * @SCpnt: mid-level's per command structure. 785 * 786 * Note: potentially run from within an ISR. Must not block. 787 **/ 788 static void sd_rw_intr(struct scsi_cmnd * SCpnt) 789 { 790 int result = SCpnt->result; 791 int this_count = SCpnt->bufflen; 792 int good_bytes = (result == 0 ? this_count : 0); 793 sector_t block_sectors = 1; 794 u64 first_err_block; 795 sector_t error_sector; 796 struct scsi_sense_hdr sshdr; 797 int sense_valid = 0; 798 int sense_deferred = 0; 799 int info_valid; 800 801 if (result) { 802 sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr); 803 if (sense_valid) 804 sense_deferred = scsi_sense_is_deferred(&sshdr); 805 } 806 807 #ifdef CONFIG_SCSI_LOGGING 808 SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n", 809 SCpnt->request->rq_disk->disk_name, result)); 810 if (sense_valid) { 811 SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: sb[respc,sk,asc," 812 "ascq]=%x,%x,%x,%x\n", sshdr.response_code, 813 sshdr.sense_key, sshdr.asc, sshdr.ascq)); 814 } 815 #endif 816 /* 817 Handle MEDIUM ERRORs that indicate partial success. Since this is a 818 relatively rare error condition, no care is taken to avoid 819 unnecessary additional work such as memcpy's that could be avoided. 820 */ 821 if (driver_byte(result) != 0 && 822 sense_valid && !sense_deferred) { 823 switch (sshdr.sense_key) { 824 case MEDIUM_ERROR: 825 if (!blk_fs_request(SCpnt->request)) 826 break; 827 info_valid = scsi_get_sense_info_fld( 828 SCpnt->sense_buffer, SCSI_SENSE_BUFFERSIZE, 829 &first_err_block); 830 /* 831 * May want to warn and skip if following cast results 832 * in actual truncation (if sector_t < 64 bits) 833 */ 834 error_sector = (sector_t)first_err_block; 835 if (SCpnt->request->bio != NULL) 836 block_sectors = bio_sectors(SCpnt->request->bio); 837 switch (SCpnt->device->sector_size) { 838 case 1024: 839 error_sector <<= 1; 840 if (block_sectors < 2) 841 block_sectors = 2; 842 break; 843 case 2048: 844 error_sector <<= 2; 845 if (block_sectors < 4) 846 block_sectors = 4; 847 break; 848 case 4096: 849 error_sector <<=3; 850 if (block_sectors < 8) 851 block_sectors = 8; 852 break; 853 case 256: 854 error_sector >>= 1; 855 break; 856 default: 857 break; 858 } 859 860 error_sector &= ~(block_sectors - 1); 861 good_bytes = (error_sector - SCpnt->request->sector) << 9; 862 if (good_bytes < 0 || good_bytes >= this_count) 863 good_bytes = 0; 864 break; 865 866 case RECOVERED_ERROR: /* an error occurred, but it recovered */ 867 case NO_SENSE: /* LLDD got sense data */ 868 /* 869 * Inform the user, but make sure that it's not treated 870 * as a hard error. 871 */ 872 scsi_print_sense("sd", SCpnt); 873 SCpnt->result = 0; 874 memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); 875 good_bytes = this_count; 876 break; 877 878 case ILLEGAL_REQUEST: 879 if (SCpnt->device->use_10_for_rw && 880 (SCpnt->cmnd[0] == READ_10 || 881 SCpnt->cmnd[0] == WRITE_10)) 882 SCpnt->device->use_10_for_rw = 0; 883 if (SCpnt->device->use_10_for_ms && 884 (SCpnt->cmnd[0] == MODE_SENSE_10 || 885 SCpnt->cmnd[0] == MODE_SELECT_10)) 886 SCpnt->device->use_10_for_ms = 0; 887 break; 888 889 default: 890 break; 891 } 892 } 893 /* 894 * This calls the generic completion function, now that we know 895 * how many actual sectors finished, and how many sectors we need 896 * to say have failed. 897 */ 898 scsi_io_completion(SCpnt, good_bytes, block_sectors << 9); 899 } 900 901 static int media_not_present(struct scsi_disk *sdkp, 902 struct scsi_sense_hdr *sshdr) 903 { 904 905 if (!scsi_sense_valid(sshdr)) 906 return 0; 907 /* not invoked for commands that could return deferred errors */ 908 if (sshdr->sense_key != NOT_READY && 909 sshdr->sense_key != UNIT_ATTENTION) 910 return 0; 911 if (sshdr->asc != 0x3A) /* medium not present */ 912 return 0; 913 914 set_media_not_present(sdkp); 915 return 1; 916 } 917 918 /* 919 * spinup disk - called only in sd_revalidate_disk() 920 */ 921 static void 922 sd_spinup_disk(struct scsi_disk *sdkp, char *diskname) 923 { 924 unsigned char cmd[10]; 925 unsigned long spintime_expire = 0; 926 int retries, spintime; 927 unsigned int the_result; 928 struct scsi_sense_hdr sshdr; 929 int sense_valid = 0; 930 931 spintime = 0; 932 933 /* Spin up drives, as required. Only do this at boot time */ 934 /* Spinup needs to be done for module loads too. */ 935 do { 936 retries = 0; 937 938 do { 939 cmd[0] = TEST_UNIT_READY; 940 memset((void *) &cmd[1], 0, 9); 941 942 the_result = scsi_execute_req(sdkp->device, cmd, 943 DMA_NONE, NULL, 0, 944 &sshdr, SD_TIMEOUT, 945 SD_MAX_RETRIES); 946 947 if (the_result) 948 sense_valid = scsi_sense_valid(&sshdr); 949 retries++; 950 } while (retries < 3 && 951 (!scsi_status_is_good(the_result) || 952 ((driver_byte(the_result) & DRIVER_SENSE) && 953 sense_valid && sshdr.sense_key == UNIT_ATTENTION))); 954 955 /* 956 * If the drive has indicated to us that it doesn't have 957 * any media in it, don't bother with any of the rest of 958 * this crap. 959 */ 960 if (media_not_present(sdkp, &sshdr)) 961 return; 962 963 if ((driver_byte(the_result) & DRIVER_SENSE) == 0) { 964 /* no sense, TUR either succeeded or failed 965 * with a status error */ 966 if(!spintime && !scsi_status_is_good(the_result)) 967 printk(KERN_NOTICE "%s: Unit Not Ready, " 968 "error = 0x%x\n", diskname, the_result); 969 break; 970 } 971 972 /* 973 * The device does not want the automatic start to be issued. 974 */ 975 if (sdkp->device->no_start_on_add) { 976 break; 977 } 978 979 /* 980 * If manual intervention is required, or this is an 981 * absent USB storage device, a spinup is meaningless. 982 */ 983 if (sense_valid && 984 sshdr.sense_key == NOT_READY && 985 sshdr.asc == 4 && sshdr.ascq == 3) { 986 break; /* manual intervention required */ 987 988 /* 989 * Issue command to spin up drive when not ready 990 */ 991 } else if (sense_valid && sshdr.sense_key == NOT_READY) { 992 if (!spintime) { 993 printk(KERN_NOTICE "%s: Spinning up disk...", 994 diskname); 995 cmd[0] = START_STOP; 996 cmd[1] = 1; /* Return immediately */ 997 memset((void *) &cmd[2], 0, 8); 998 cmd[4] = 1; /* Start spin cycle */ 999 scsi_execute_req(sdkp->device, cmd, DMA_NONE, 1000 NULL, 0, &sshdr, 1001 SD_TIMEOUT, SD_MAX_RETRIES); 1002 spintime_expire = jiffies + 100 * HZ; 1003 spintime = 1; 1004 } 1005 /* Wait 1 second for next try */ 1006 msleep(1000); 1007 printk("."); 1008 1009 /* 1010 * Wait for USB flash devices with slow firmware. 1011 * Yes, this sense key/ASC combination shouldn't 1012 * occur here. It's characteristic of these devices. 1013 */ 1014 } else if (sense_valid && 1015 sshdr.sense_key == UNIT_ATTENTION && 1016 sshdr.asc == 0x28) { 1017 if (!spintime) { 1018 spintime_expire = jiffies + 5 * HZ; 1019 spintime = 1; 1020 } 1021 /* Wait 1 second for next try */ 1022 msleep(1000); 1023 } else { 1024 /* we don't understand the sense code, so it's 1025 * probably pointless to loop */ 1026 if(!spintime) { 1027 printk(KERN_NOTICE "%s: Unit Not Ready, " 1028 "sense:\n", diskname); 1029 scsi_print_sense_hdr("", &sshdr); 1030 } 1031 break; 1032 } 1033 1034 } while (spintime && time_before_eq(jiffies, spintime_expire)); 1035 1036 if (spintime) { 1037 if (scsi_status_is_good(the_result)) 1038 printk("ready\n"); 1039 else 1040 printk("not responding...\n"); 1041 } 1042 } 1043 1044 /* 1045 * read disk capacity 1046 */ 1047 static void 1048 sd_read_capacity(struct scsi_disk *sdkp, char *diskname, 1049 unsigned char *buffer) 1050 { 1051 unsigned char cmd[16]; 1052 int the_result, retries; 1053 int sector_size = 0; 1054 int longrc = 0; 1055 struct scsi_sense_hdr sshdr; 1056 int sense_valid = 0; 1057 struct scsi_device *sdp = sdkp->device; 1058 1059 repeat: 1060 retries = 3; 1061 do { 1062 if (longrc) { 1063 memset((void *) cmd, 0, 16); 1064 cmd[0] = SERVICE_ACTION_IN; 1065 cmd[1] = SAI_READ_CAPACITY_16; 1066 cmd[13] = 12; 1067 memset((void *) buffer, 0, 12); 1068 } else { 1069 cmd[0] = READ_CAPACITY; 1070 memset((void *) &cmd[1], 0, 9); 1071 memset((void *) buffer, 0, 8); 1072 } 1073 1074 the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE, 1075 buffer, longrc ? 12 : 8, &sshdr, 1076 SD_TIMEOUT, SD_MAX_RETRIES); 1077 1078 if (media_not_present(sdkp, &sshdr)) 1079 return; 1080 1081 if (the_result) 1082 sense_valid = scsi_sense_valid(&sshdr); 1083 retries--; 1084 1085 } while (the_result && retries); 1086 1087 if (the_result && !longrc) { 1088 printk(KERN_NOTICE "%s : READ CAPACITY failed.\n" 1089 "%s : status=%x, message=%02x, host=%d, driver=%02x \n", 1090 diskname, diskname, 1091 status_byte(the_result), 1092 msg_byte(the_result), 1093 host_byte(the_result), 1094 driver_byte(the_result)); 1095 1096 if (driver_byte(the_result) & DRIVER_SENSE) 1097 scsi_print_sense_hdr("sd", &sshdr); 1098 else 1099 printk("%s : sense not available. \n", diskname); 1100 1101 /* Set dirty bit for removable devices if not ready - 1102 * sometimes drives will not report this properly. */ 1103 if (sdp->removable && 1104 sense_valid && sshdr.sense_key == NOT_READY) 1105 sdp->changed = 1; 1106 1107 /* Either no media are present but the drive didn't tell us, 1108 or they are present but the read capacity command fails */ 1109 /* sdkp->media_present = 0; -- not always correct */ 1110 sdkp->capacity = 0x200000; /* 1 GB - random */ 1111 1112 return; 1113 } else if (the_result && longrc) { 1114 /* READ CAPACITY(16) has been failed */ 1115 printk(KERN_NOTICE "%s : READ CAPACITY(16) failed.\n" 1116 "%s : status=%x, message=%02x, host=%d, driver=%02x \n", 1117 diskname, diskname, 1118 status_byte(the_result), 1119 msg_byte(the_result), 1120 host_byte(the_result), 1121 driver_byte(the_result)); 1122 printk(KERN_NOTICE "%s : use 0xffffffff as device size\n", 1123 diskname); 1124 1125 sdkp->capacity = 1 + (sector_t) 0xffffffff; 1126 goto got_data; 1127 } 1128 1129 if (!longrc) { 1130 sector_size = (buffer[4] << 24) | 1131 (buffer[5] << 16) | (buffer[6] << 8) | buffer[7]; 1132 if (buffer[0] == 0xff && buffer[1] == 0xff && 1133 buffer[2] == 0xff && buffer[3] == 0xff) { 1134 if(sizeof(sdkp->capacity) > 4) { 1135 printk(KERN_NOTICE "%s : very big device. try to use" 1136 " READ CAPACITY(16).\n", diskname); 1137 longrc = 1; 1138 goto repeat; 1139 } 1140 printk(KERN_ERR "%s: too big for this kernel. Use a " 1141 "kernel compiled with support for large block " 1142 "devices.\n", diskname); 1143 sdkp->capacity = 0; 1144 goto got_data; 1145 } 1146 sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) | 1147 (buffer[1] << 16) | 1148 (buffer[2] << 8) | 1149 buffer[3]); 1150 } else { 1151 sdkp->capacity = 1 + (((u64)buffer[0] << 56) | 1152 ((u64)buffer[1] << 48) | 1153 ((u64)buffer[2] << 40) | 1154 ((u64)buffer[3] << 32) | 1155 ((sector_t)buffer[4] << 24) | 1156 ((sector_t)buffer[5] << 16) | 1157 ((sector_t)buffer[6] << 8) | 1158 (sector_t)buffer[7]); 1159 1160 sector_size = (buffer[8] << 24) | 1161 (buffer[9] << 16) | (buffer[10] << 8) | buffer[11]; 1162 } 1163 1164 /* Some devices return the total number of sectors, not the 1165 * highest sector number. Make the necessary adjustment. */ 1166 if (sdp->fix_capacity) 1167 --sdkp->capacity; 1168 1169 got_data: 1170 if (sector_size == 0) { 1171 sector_size = 512; 1172 printk(KERN_NOTICE "%s : sector size 0 reported, " 1173 "assuming 512.\n", diskname); 1174 } 1175 1176 if (sector_size != 512 && 1177 sector_size != 1024 && 1178 sector_size != 2048 && 1179 sector_size != 4096 && 1180 sector_size != 256) { 1181 printk(KERN_NOTICE "%s : unsupported sector size " 1182 "%d.\n", diskname, sector_size); 1183 /* 1184 * The user might want to re-format the drive with 1185 * a supported sectorsize. Once this happens, it 1186 * would be relatively trivial to set the thing up. 1187 * For this reason, we leave the thing in the table. 1188 */ 1189 sdkp->capacity = 0; 1190 /* 1191 * set a bogus sector size so the normal read/write 1192 * logic in the block layer will eventually refuse any 1193 * request on this device without tripping over power 1194 * of two sector size assumptions 1195 */ 1196 sector_size = 512; 1197 } 1198 { 1199 /* 1200 * The msdos fs needs to know the hardware sector size 1201 * So I have created this table. See ll_rw_blk.c 1202 * Jacques Gelinas (Jacques@solucorp.qc.ca) 1203 */ 1204 int hard_sector = sector_size; 1205 sector_t sz = (sdkp->capacity/2) * (hard_sector/256); 1206 request_queue_t *queue = sdp->request_queue; 1207 sector_t mb = sz; 1208 1209 blk_queue_hardsect_size(queue, hard_sector); 1210 /* avoid 64-bit division on 32-bit platforms */ 1211 sector_div(sz, 625); 1212 mb -= sz - 974; 1213 sector_div(mb, 1950); 1214 1215 printk(KERN_NOTICE "SCSI device %s: " 1216 "%llu %d-byte hdwr sectors (%llu MB)\n", 1217 diskname, (unsigned long long)sdkp->capacity, 1218 hard_sector, (unsigned long long)mb); 1219 } 1220 1221 /* Rescale capacity to 512-byte units */ 1222 if (sector_size == 4096) 1223 sdkp->capacity <<= 3; 1224 else if (sector_size == 2048) 1225 sdkp->capacity <<= 2; 1226 else if (sector_size == 1024) 1227 sdkp->capacity <<= 1; 1228 else if (sector_size == 256) 1229 sdkp->capacity >>= 1; 1230 1231 sdkp->device->sector_size = sector_size; 1232 } 1233 1234 /* called with buffer of length 512 */ 1235 static inline int 1236 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage, 1237 unsigned char *buffer, int len, struct scsi_mode_data *data, 1238 struct scsi_sense_hdr *sshdr) 1239 { 1240 return scsi_mode_sense(sdp, dbd, modepage, buffer, len, 1241 SD_TIMEOUT, SD_MAX_RETRIES, data, 1242 sshdr); 1243 } 1244 1245 /* 1246 * read write protect setting, if possible - called only in sd_revalidate_disk() 1247 * called with buffer of length SD_BUF_SIZE 1248 */ 1249 static void 1250 sd_read_write_protect_flag(struct scsi_disk *sdkp, char *diskname, 1251 unsigned char *buffer) 1252 { 1253 int res; 1254 struct scsi_device *sdp = sdkp->device; 1255 struct scsi_mode_data data; 1256 1257 set_disk_ro(sdkp->disk, 0); 1258 if (sdp->skip_ms_page_3f) { 1259 printk(KERN_NOTICE "%s: assuming Write Enabled\n", diskname); 1260 return; 1261 } 1262 1263 if (sdp->use_192_bytes_for_3f) { 1264 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL); 1265 } else { 1266 /* 1267 * First attempt: ask for all pages (0x3F), but only 4 bytes. 1268 * We have to start carefully: some devices hang if we ask 1269 * for more than is available. 1270 */ 1271 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL); 1272 1273 /* 1274 * Second attempt: ask for page 0 When only page 0 is 1275 * implemented, a request for page 3F may return Sense Key 1276 * 5: Illegal Request, Sense Code 24: Invalid field in 1277 * CDB. 1278 */ 1279 if (!scsi_status_is_good(res)) 1280 res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL); 1281 1282 /* 1283 * Third attempt: ask 255 bytes, as we did earlier. 1284 */ 1285 if (!scsi_status_is_good(res)) 1286 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255, 1287 &data, NULL); 1288 } 1289 1290 if (!scsi_status_is_good(res)) { 1291 printk(KERN_WARNING 1292 "%s: test WP failed, assume Write Enabled\n", diskname); 1293 } else { 1294 sdkp->write_prot = ((data.device_specific & 0x80) != 0); 1295 set_disk_ro(sdkp->disk, sdkp->write_prot); 1296 printk(KERN_NOTICE "%s: Write Protect is %s\n", diskname, 1297 sdkp->write_prot ? "on" : "off"); 1298 printk(KERN_DEBUG "%s: Mode Sense: %02x %02x %02x %02x\n", 1299 diskname, buffer[0], buffer[1], buffer[2], buffer[3]); 1300 } 1301 } 1302 1303 /* 1304 * sd_read_cache_type - called only from sd_revalidate_disk() 1305 * called with buffer of length SD_BUF_SIZE 1306 */ 1307 static void 1308 sd_read_cache_type(struct scsi_disk *sdkp, char *diskname, 1309 unsigned char *buffer) 1310 { 1311 int len = 0, res; 1312 struct scsi_device *sdp = sdkp->device; 1313 1314 int dbd; 1315 int modepage; 1316 struct scsi_mode_data data; 1317 struct scsi_sense_hdr sshdr; 1318 1319 if (sdp->skip_ms_page_8) 1320 goto defaults; 1321 1322 if (sdp->type == TYPE_RBC) { 1323 modepage = 6; 1324 dbd = 8; 1325 } else { 1326 modepage = 8; 1327 dbd = 0; 1328 } 1329 1330 /* cautiously ask */ 1331 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr); 1332 1333 if (!scsi_status_is_good(res)) 1334 goto bad_sense; 1335 1336 /* that went OK, now ask for the proper length */ 1337 len = data.length; 1338 1339 /* 1340 * We're only interested in the first three bytes, actually. 1341 * But the data cache page is defined for the first 20. 1342 */ 1343 if (len < 3) 1344 goto bad_sense; 1345 if (len > 20) 1346 len = 20; 1347 1348 /* Take headers and block descriptors into account */ 1349 len += data.header_length + data.block_descriptor_length; 1350 if (len > SD_BUF_SIZE) 1351 goto bad_sense; 1352 1353 /* Get the data */ 1354 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr); 1355 1356 if (scsi_status_is_good(res)) { 1357 const char *types[] = { 1358 "write through", "none", "write back", 1359 "write back, no read (daft)" 1360 }; 1361 int ct = 0; 1362 int offset = data.header_length + data.block_descriptor_length; 1363 1364 if (offset >= SD_BUF_SIZE - 2) { 1365 printk(KERN_ERR "%s: malformed MODE SENSE response", 1366 diskname); 1367 goto defaults; 1368 } 1369 1370 if ((buffer[offset] & 0x3f) != modepage) { 1371 printk(KERN_ERR "%s: got wrong page\n", diskname); 1372 goto defaults; 1373 } 1374 1375 if (modepage == 8) { 1376 sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0); 1377 sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0); 1378 } else { 1379 sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0); 1380 sdkp->RCD = 0; 1381 } 1382 1383 sdkp->DPOFUA = (data.device_specific & 0x10) != 0; 1384 if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) { 1385 printk(KERN_NOTICE "SCSI device %s: uses " 1386 "READ/WRITE(6), disabling FUA\n", diskname); 1387 sdkp->DPOFUA = 0; 1388 } 1389 1390 ct = sdkp->RCD + 2*sdkp->WCE; 1391 1392 printk(KERN_NOTICE "SCSI device %s: drive cache: %s%s\n", 1393 diskname, types[ct], 1394 sdkp->DPOFUA ? " w/ FUA" : ""); 1395 1396 return; 1397 } 1398 1399 bad_sense: 1400 if (scsi_sense_valid(&sshdr) && 1401 sshdr.sense_key == ILLEGAL_REQUEST && 1402 sshdr.asc == 0x24 && sshdr.ascq == 0x0) 1403 printk(KERN_NOTICE "%s: cache data unavailable\n", 1404 diskname); /* Invalid field in CDB */ 1405 else 1406 printk(KERN_ERR "%s: asking for cache data failed\n", 1407 diskname); 1408 1409 defaults: 1410 printk(KERN_ERR "%s: assuming drive cache: write through\n", 1411 diskname); 1412 sdkp->WCE = 0; 1413 sdkp->RCD = 0; 1414 sdkp->DPOFUA = 0; 1415 } 1416 1417 /** 1418 * sd_revalidate_disk - called the first time a new disk is seen, 1419 * performs disk spin up, read_capacity, etc. 1420 * @disk: struct gendisk we care about 1421 **/ 1422 static int sd_revalidate_disk(struct gendisk *disk) 1423 { 1424 struct scsi_disk *sdkp = scsi_disk(disk); 1425 struct scsi_device *sdp = sdkp->device; 1426 unsigned char *buffer; 1427 unsigned ordered; 1428 1429 SCSI_LOG_HLQUEUE(3, printk("sd_revalidate_disk: disk=%s\n", disk->disk_name)); 1430 1431 /* 1432 * If the device is offline, don't try and read capacity or any 1433 * of the other niceties. 1434 */ 1435 if (!scsi_device_online(sdp)) 1436 goto out; 1437 1438 buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL | __GFP_DMA); 1439 if (!buffer) { 1440 printk(KERN_WARNING "(sd_revalidate_disk:) Memory allocation " 1441 "failure.\n"); 1442 goto out; 1443 } 1444 1445 /* defaults, until the device tells us otherwise */ 1446 sdp->sector_size = 512; 1447 sdkp->capacity = 0; 1448 sdkp->media_present = 1; 1449 sdkp->write_prot = 0; 1450 sdkp->WCE = 0; 1451 sdkp->RCD = 0; 1452 1453 sd_spinup_disk(sdkp, disk->disk_name); 1454 1455 /* 1456 * Without media there is no reason to ask; moreover, some devices 1457 * react badly if we do. 1458 */ 1459 if (sdkp->media_present) { 1460 sd_read_capacity(sdkp, disk->disk_name, buffer); 1461 sd_read_write_protect_flag(sdkp, disk->disk_name, buffer); 1462 sd_read_cache_type(sdkp, disk->disk_name, buffer); 1463 } 1464 1465 /* 1466 * We now have all cache related info, determine how we deal 1467 * with ordered requests. Note that as the current SCSI 1468 * dispatch function can alter request order, we cannot use 1469 * QUEUE_ORDERED_TAG_* even when ordered tag is supported. 1470 */ 1471 if (sdkp->WCE) 1472 ordered = sdkp->DPOFUA 1473 ? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH; 1474 else 1475 ordered = QUEUE_ORDERED_DRAIN; 1476 1477 blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush); 1478 1479 set_capacity(disk, sdkp->capacity); 1480 kfree(buffer); 1481 1482 out: 1483 return 0; 1484 } 1485 1486 /** 1487 * sd_probe - called during driver initialization and whenever a 1488 * new scsi device is attached to the system. It is called once 1489 * for each scsi device (not just disks) present. 1490 * @dev: pointer to device object 1491 * 1492 * Returns 0 if successful (or not interested in this scsi device 1493 * (e.g. scanner)); 1 when there is an error. 1494 * 1495 * Note: this function is invoked from the scsi mid-level. 1496 * This function sets up the mapping between a given 1497 * <host,channel,id,lun> (found in sdp) and new device name 1498 * (e.g. /dev/sda). More precisely it is the block device major 1499 * and minor number that is chosen here. 1500 * 1501 * Assume sd_attach is not re-entrant (for time being) 1502 * Also think about sd_attach() and sd_remove() running coincidentally. 1503 **/ 1504 static int sd_probe(struct device *dev) 1505 { 1506 struct scsi_device *sdp = to_scsi_device(dev); 1507 struct scsi_disk *sdkp; 1508 struct gendisk *gd; 1509 u32 index; 1510 int error; 1511 1512 error = -ENODEV; 1513 if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC) 1514 goto out; 1515 1516 SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp, 1517 "sd_attach\n")); 1518 1519 error = -ENOMEM; 1520 sdkp = kmalloc(sizeof(*sdkp), GFP_KERNEL); 1521 if (!sdkp) 1522 goto out; 1523 1524 memset (sdkp, 0, sizeof(*sdkp)); 1525 kref_init(&sdkp->kref); 1526 1527 gd = alloc_disk(16); 1528 if (!gd) 1529 goto out_free; 1530 1531 if (!idr_pre_get(&sd_index_idr, GFP_KERNEL)) 1532 goto out_put; 1533 1534 spin_lock(&sd_index_lock); 1535 error = idr_get_new(&sd_index_idr, NULL, &index); 1536 spin_unlock(&sd_index_lock); 1537 1538 if (index >= SD_MAX_DISKS) 1539 error = -EBUSY; 1540 if (error) 1541 goto out_put; 1542 1543 get_device(&sdp->sdev_gendev); 1544 sdkp->device = sdp; 1545 sdkp->driver = &sd_template; 1546 sdkp->disk = gd; 1547 sdkp->index = index; 1548 sdkp->openers = 0; 1549 1550 if (!sdp->timeout) { 1551 if (sdp->type != TYPE_MOD) 1552 sdp->timeout = SD_TIMEOUT; 1553 else 1554 sdp->timeout = SD_MOD_TIMEOUT; 1555 } 1556 1557 gd->major = sd_major((index & 0xf0) >> 4); 1558 gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00); 1559 gd->minors = 16; 1560 gd->fops = &sd_fops; 1561 1562 if (index < 26) { 1563 sprintf(gd->disk_name, "sd%c", 'a' + index % 26); 1564 } else if (index < (26 + 1) * 26) { 1565 sprintf(gd->disk_name, "sd%c%c", 1566 'a' + index / 26 - 1,'a' + index % 26); 1567 } else { 1568 const unsigned int m1 = (index / 26 - 1) / 26 - 1; 1569 const unsigned int m2 = (index / 26 - 1) % 26; 1570 const unsigned int m3 = index % 26; 1571 sprintf(gd->disk_name, "sd%c%c%c", 1572 'a' + m1, 'a' + m2, 'a' + m3); 1573 } 1574 1575 strcpy(gd->devfs_name, sdp->devfs_name); 1576 1577 gd->private_data = &sdkp->driver; 1578 gd->queue = sdkp->device->request_queue; 1579 1580 sd_revalidate_disk(gd); 1581 1582 gd->driverfs_dev = &sdp->sdev_gendev; 1583 gd->flags = GENHD_FL_DRIVERFS; 1584 if (sdp->removable) 1585 gd->flags |= GENHD_FL_REMOVABLE; 1586 1587 dev_set_drvdata(dev, sdkp); 1588 add_disk(gd); 1589 1590 sdev_printk(KERN_NOTICE, sdp, "Attached scsi %sdisk %s\n", 1591 sdp->removable ? "removable " : "", gd->disk_name); 1592 1593 return 0; 1594 1595 out_put: 1596 put_disk(gd); 1597 out_free: 1598 kfree(sdkp); 1599 out: 1600 return error; 1601 } 1602 1603 /** 1604 * sd_remove - called whenever a scsi disk (previously recognized by 1605 * sd_probe) is detached from the system. It is called (potentially 1606 * multiple times) during sd module unload. 1607 * @sdp: pointer to mid level scsi device object 1608 * 1609 * Note: this function is invoked from the scsi mid-level. 1610 * This function potentially frees up a device name (e.g. /dev/sdc) 1611 * that could be re-used by a subsequent sd_probe(). 1612 * This function is not called when the built-in sd driver is "exit-ed". 1613 **/ 1614 static int sd_remove(struct device *dev) 1615 { 1616 struct scsi_disk *sdkp = dev_get_drvdata(dev); 1617 1618 del_gendisk(sdkp->disk); 1619 sd_shutdown(dev); 1620 1621 mutex_lock(&sd_ref_mutex); 1622 dev_set_drvdata(dev, NULL); 1623 kref_put(&sdkp->kref, scsi_disk_release); 1624 mutex_unlock(&sd_ref_mutex); 1625 1626 return 0; 1627 } 1628 1629 /** 1630 * scsi_disk_release - Called to free the scsi_disk structure 1631 * @kref: pointer to embedded kref 1632 * 1633 * sd_ref_mutex must be held entering this routine. Because it is 1634 * called on last put, you should always use the scsi_disk_get() 1635 * scsi_disk_put() helpers which manipulate the semaphore directly 1636 * and never do a direct kref_put(). 1637 **/ 1638 static void scsi_disk_release(struct kref *kref) 1639 { 1640 struct scsi_disk *sdkp = to_scsi_disk(kref); 1641 struct gendisk *disk = sdkp->disk; 1642 1643 spin_lock(&sd_index_lock); 1644 idr_remove(&sd_index_idr, sdkp->index); 1645 spin_unlock(&sd_index_lock); 1646 1647 disk->private_data = NULL; 1648 put_disk(disk); 1649 put_device(&sdkp->device->sdev_gendev); 1650 1651 kfree(sdkp); 1652 } 1653 1654 /* 1655 * Send a SYNCHRONIZE CACHE instruction down to the device through 1656 * the normal SCSI command structure. Wait for the command to 1657 * complete. 1658 */ 1659 static void sd_shutdown(struct device *dev) 1660 { 1661 struct scsi_device *sdp = to_scsi_device(dev); 1662 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 1663 1664 if (!sdkp) 1665 return; /* this can happen */ 1666 1667 if (sdkp->WCE) { 1668 printk(KERN_NOTICE "Synchronizing SCSI cache for disk %s: \n", 1669 sdkp->disk->disk_name); 1670 sd_sync_cache(sdp); 1671 } 1672 scsi_disk_put(sdkp); 1673 } 1674 1675 /** 1676 * init_sd - entry point for this driver (both when built in or when 1677 * a module). 1678 * 1679 * Note: this function registers this driver with the scsi mid-level. 1680 **/ 1681 static int __init init_sd(void) 1682 { 1683 int majors = 0, i; 1684 1685 SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n")); 1686 1687 for (i = 0; i < SD_MAJORS; i++) 1688 if (register_blkdev(sd_major(i), "sd") == 0) 1689 majors++; 1690 1691 if (!majors) 1692 return -ENODEV; 1693 1694 return scsi_register_driver(&sd_template.gendrv); 1695 } 1696 1697 /** 1698 * exit_sd - exit point for this driver (when it is a module). 1699 * 1700 * Note: this function unregisters this driver from the scsi mid-level. 1701 **/ 1702 static void __exit exit_sd(void) 1703 { 1704 int i; 1705 1706 SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n")); 1707 1708 scsi_unregister_driver(&sd_template.gendrv); 1709 for (i = 0; i < SD_MAJORS; i++) 1710 unregister_blkdev(sd_major(i), "sd"); 1711 } 1712 1713 MODULE_LICENSE("GPL"); 1714 MODULE_AUTHOR("Eric Youngdale"); 1715 MODULE_DESCRIPTION("SCSI disk (sd) driver"); 1716 1717 module_init(init_sd); 1718 module_exit(exit_sd); 1719