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 <asm/uaccess.h> 53 54 #include <scsi/scsi.h> 55 #include <scsi/scsi_cmnd.h> 56 #include <scsi/scsi_dbg.h> 57 #include <scsi/scsi_device.h> 58 #include <scsi/scsi_driver.h> 59 #include <scsi/scsi_eh.h> 60 #include <scsi/scsi_host.h> 61 #include <scsi/scsi_ioctl.h> 62 #include <scsi/scsicam.h> 63 64 #include "scsi_logging.h" 65 66 /* 67 * More than enough for everybody ;) The huge number of majors 68 * is a leftover from 16bit dev_t days, we don't really need that 69 * much numberspace. 70 */ 71 #define SD_MAJORS 16 72 73 /* 74 * This is limited by the naming scheme enforced in sd_probe, 75 * add another character to it if you really need more disks. 76 */ 77 #define SD_MAX_DISKS (((26 * 26) + 26 + 1) * 26) 78 79 /* 80 * Time out in seconds for disks and Magneto-opticals (which are slower). 81 */ 82 #define SD_TIMEOUT (30 * HZ) 83 #define SD_MOD_TIMEOUT (75 * HZ) 84 85 /* 86 * Number of allowed retries 87 */ 88 #define SD_MAX_RETRIES 5 89 #define SD_PASSTHROUGH_RETRIES 1 90 91 static void scsi_disk_release(struct kref *kref); 92 93 struct scsi_disk { 94 struct scsi_driver *driver; /* always &sd_template */ 95 struct scsi_device *device; 96 struct kref kref; 97 struct gendisk *disk; 98 unsigned int openers; /* protected by BKL for now, yuck */ 99 sector_t capacity; /* size in 512-byte sectors */ 100 u32 index; 101 u8 media_present; 102 u8 write_prot; 103 unsigned WCE : 1; /* state of disk WCE bit */ 104 unsigned RCD : 1; /* state of disk RCD bit, unused */ 105 unsigned DPOFUA : 1; /* state of disk DPOFUA bit */ 106 }; 107 108 static DEFINE_IDR(sd_index_idr); 109 static DEFINE_SPINLOCK(sd_index_lock); 110 111 /* This semaphore is used to mediate the 0->1 reference get in the 112 * face of object destruction (i.e. we can't allow a get on an 113 * object after last put) */ 114 static DECLARE_MUTEX(sd_ref_sem); 115 116 static int sd_revalidate_disk(struct gendisk *disk); 117 static void sd_rw_intr(struct scsi_cmnd * SCpnt); 118 119 static int sd_probe(struct device *); 120 static int sd_remove(struct device *); 121 static void sd_shutdown(struct device *dev); 122 static void sd_rescan(struct device *); 123 static int sd_init_command(struct scsi_cmnd *); 124 static int sd_issue_flush(struct device *, sector_t *); 125 static void sd_prepare_flush(request_queue_t *, struct request *); 126 static void sd_read_capacity(struct scsi_disk *sdkp, char *diskname, 127 unsigned char *buffer); 128 129 static struct scsi_driver sd_template = { 130 .owner = THIS_MODULE, 131 .gendrv = { 132 .name = "sd", 133 .probe = sd_probe, 134 .remove = sd_remove, 135 .shutdown = sd_shutdown, 136 }, 137 .rescan = sd_rescan, 138 .init_command = sd_init_command, 139 .issue_flush = sd_issue_flush, 140 }; 141 142 /* 143 * Device no to disk mapping: 144 * 145 * major disc2 disc p1 146 * |............|.............|....|....| <- dev_t 147 * 31 20 19 8 7 4 3 0 148 * 149 * Inside a major, we have 16k disks, however mapped non- 150 * contiguously. The first 16 disks are for major0, the next 151 * ones with major1, ... Disk 256 is for major0 again, disk 272 152 * for major1, ... 153 * As we stay compatible with our numbering scheme, we can reuse 154 * the well-know SCSI majors 8, 65--71, 136--143. 155 */ 156 static int sd_major(int major_idx) 157 { 158 switch (major_idx) { 159 case 0: 160 return SCSI_DISK0_MAJOR; 161 case 1 ... 7: 162 return SCSI_DISK1_MAJOR + major_idx - 1; 163 case 8 ... 15: 164 return SCSI_DISK8_MAJOR + major_idx - 8; 165 default: 166 BUG(); 167 return 0; /* shut up gcc */ 168 } 169 } 170 171 #define to_scsi_disk(obj) container_of(obj,struct scsi_disk,kref) 172 173 static inline struct scsi_disk *scsi_disk(struct gendisk *disk) 174 { 175 return container_of(disk->private_data, struct scsi_disk, driver); 176 } 177 178 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk) 179 { 180 struct scsi_disk *sdkp = NULL; 181 182 if (disk->private_data) { 183 sdkp = scsi_disk(disk); 184 if (scsi_device_get(sdkp->device) == 0) 185 kref_get(&sdkp->kref); 186 else 187 sdkp = NULL; 188 } 189 return sdkp; 190 } 191 192 static struct scsi_disk *scsi_disk_get(struct gendisk *disk) 193 { 194 struct scsi_disk *sdkp; 195 196 down(&sd_ref_sem); 197 sdkp = __scsi_disk_get(disk); 198 up(&sd_ref_sem); 199 return sdkp; 200 } 201 202 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev) 203 { 204 struct scsi_disk *sdkp; 205 206 down(&sd_ref_sem); 207 sdkp = dev_get_drvdata(dev); 208 if (sdkp) 209 sdkp = __scsi_disk_get(sdkp->disk); 210 up(&sd_ref_sem); 211 return sdkp; 212 } 213 214 static void scsi_disk_put(struct scsi_disk *sdkp) 215 { 216 struct scsi_device *sdev = sdkp->device; 217 218 down(&sd_ref_sem); 219 kref_put(&sdkp->kref, scsi_disk_release); 220 scsi_device_put(sdev); 221 up(&sd_ref_sem); 222 } 223 224 /** 225 * sd_init_command - build a scsi (read or write) command from 226 * information in the request structure. 227 * @SCpnt: pointer to mid-level's per scsi command structure that 228 * contains request and into which the scsi command is written 229 * 230 * Returns 1 if successful and 0 if error (or cannot be done now). 231 **/ 232 static int sd_init_command(struct scsi_cmnd * SCpnt) 233 { 234 unsigned int this_count, timeout; 235 struct gendisk *disk; 236 sector_t block; 237 struct scsi_device *sdp = SCpnt->device; 238 struct request *rq = SCpnt->request; 239 240 timeout = sdp->timeout; 241 242 /* 243 * SG_IO from block layer already setup, just copy cdb basically 244 */ 245 if (blk_pc_request(rq)) { 246 scsi_setup_blk_pc_cmnd(SCpnt); 247 if (rq->timeout) 248 timeout = rq->timeout; 249 250 goto queue; 251 } 252 253 /* 254 * we only do REQ_CMD and REQ_BLOCK_PC 255 */ 256 if (!blk_fs_request(rq)) 257 return 0; 258 259 disk = rq->rq_disk; 260 block = rq->sector; 261 this_count = SCpnt->request_bufflen >> 9; 262 263 SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, " 264 "count=%d\n", disk->disk_name, 265 (unsigned long long)block, this_count)); 266 267 if (!sdp || !scsi_device_online(sdp) || 268 block + rq->nr_sectors > get_capacity(disk)) { 269 SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n", 270 rq->nr_sectors)); 271 SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt)); 272 return 0; 273 } 274 275 if (sdp->changed) { 276 /* 277 * quietly refuse to do anything to a changed disc until 278 * the changed bit has been reset 279 */ 280 /* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */ 281 return 0; 282 } 283 SCSI_LOG_HLQUEUE(2, printk("%s : block=%llu\n", 284 disk->disk_name, (unsigned long long)block)); 285 286 /* 287 * If we have a 1K hardware sectorsize, prevent access to single 288 * 512 byte sectors. In theory we could handle this - in fact 289 * the scsi cdrom driver must be able to handle this because 290 * we typically use 1K blocksizes, and cdroms typically have 291 * 2K hardware sectorsizes. Of course, things are simpler 292 * with the cdrom, since it is read-only. For performance 293 * reasons, the filesystems should be able to handle this 294 * and not force the scsi disk driver to use bounce buffers 295 * for this. 296 */ 297 if (sdp->sector_size == 1024) { 298 if ((block & 1) || (rq->nr_sectors & 1)) { 299 printk(KERN_ERR "sd: Bad block number requested"); 300 return 0; 301 } else { 302 block = block >> 1; 303 this_count = this_count >> 1; 304 } 305 } 306 if (sdp->sector_size == 2048) { 307 if ((block & 3) || (rq->nr_sectors & 3)) { 308 printk(KERN_ERR "sd: Bad block number requested"); 309 return 0; 310 } else { 311 block = block >> 2; 312 this_count = this_count >> 2; 313 } 314 } 315 if (sdp->sector_size == 4096) { 316 if ((block & 7) || (rq->nr_sectors & 7)) { 317 printk(KERN_ERR "sd: Bad block number requested"); 318 return 0; 319 } else { 320 block = block >> 3; 321 this_count = this_count >> 3; 322 } 323 } 324 if (rq_data_dir(rq) == WRITE) { 325 if (!sdp->writeable) { 326 return 0; 327 } 328 SCpnt->cmnd[0] = WRITE_6; 329 SCpnt->sc_data_direction = DMA_TO_DEVICE; 330 } else if (rq_data_dir(rq) == READ) { 331 SCpnt->cmnd[0] = READ_6; 332 SCpnt->sc_data_direction = DMA_FROM_DEVICE; 333 } else { 334 printk(KERN_ERR "sd: Unknown command %lx\n", rq->flags); 335 /* overkill panic("Unknown sd command %lx\n", rq->flags); */ 336 return 0; 337 } 338 339 SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n", 340 disk->disk_name, (rq_data_dir(rq) == WRITE) ? 341 "writing" : "reading", this_count, rq->nr_sectors)); 342 343 SCpnt->cmnd[1] = 0; 344 345 if (block > 0xffffffff) { 346 SCpnt->cmnd[0] += READ_16 - READ_6; 347 SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0; 348 SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0; 349 SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0; 350 SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0; 351 SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0; 352 SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff; 353 SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff; 354 SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff; 355 SCpnt->cmnd[9] = (unsigned char) block & 0xff; 356 SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff; 357 SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff; 358 SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff; 359 SCpnt->cmnd[13] = (unsigned char) this_count & 0xff; 360 SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0; 361 } else if ((this_count > 0xff) || (block > 0x1fffff) || 362 SCpnt->device->use_10_for_rw) { 363 if (this_count > 0xffff) 364 this_count = 0xffff; 365 366 SCpnt->cmnd[0] += READ_10 - READ_6; 367 SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0; 368 SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff; 369 SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff; 370 SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff; 371 SCpnt->cmnd[5] = (unsigned char) block & 0xff; 372 SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0; 373 SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff; 374 SCpnt->cmnd[8] = (unsigned char) this_count & 0xff; 375 } else { 376 if (unlikely(blk_fua_rq(rq))) { 377 /* 378 * This happens only if this drive failed 379 * 10byte rw command with ILLEGAL_REQUEST 380 * during operation and thus turned off 381 * use_10_for_rw. 382 */ 383 printk(KERN_ERR "sd: FUA write on READ/WRITE(6) drive\n"); 384 return 0; 385 } 386 387 SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f); 388 SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff); 389 SCpnt->cmnd[3] = (unsigned char) block & 0xff; 390 SCpnt->cmnd[4] = (unsigned char) this_count; 391 SCpnt->cmnd[5] = 0; 392 } 393 SCpnt->request_bufflen = SCpnt->bufflen = 394 this_count * sdp->sector_size; 395 396 /* 397 * We shouldn't disconnect in the middle of a sector, so with a dumb 398 * host adapter, it's safe to assume that we can at least transfer 399 * this many bytes between each connect / disconnect. 400 */ 401 SCpnt->transfersize = sdp->sector_size; 402 SCpnt->underflow = this_count << 9; 403 SCpnt->allowed = SD_MAX_RETRIES; 404 405 queue: 406 SCpnt->timeout_per_command = timeout; 407 408 /* 409 * This is the completion routine we use. This is matched in terms 410 * of capability to this function. 411 */ 412 SCpnt->done = sd_rw_intr; 413 414 /* 415 * This indicates that the command is ready from our end to be 416 * queued. 417 */ 418 return 1; 419 } 420 421 /** 422 * sd_open - open a scsi disk device 423 * @inode: only i_rdev member may be used 424 * @filp: only f_mode and f_flags may be used 425 * 426 * Returns 0 if successful. Returns a negated errno value in case 427 * of error. 428 * 429 * Note: This can be called from a user context (e.g. fsck(1) ) 430 * or from within the kernel (e.g. as a result of a mount(1) ). 431 * In the latter case @inode and @filp carry an abridged amount 432 * of information as noted above. 433 **/ 434 static int sd_open(struct inode *inode, struct file *filp) 435 { 436 struct gendisk *disk = inode->i_bdev->bd_disk; 437 struct scsi_disk *sdkp; 438 struct scsi_device *sdev; 439 int retval; 440 441 if (!(sdkp = scsi_disk_get(disk))) 442 return -ENXIO; 443 444 445 SCSI_LOG_HLQUEUE(3, printk("sd_open: disk=%s\n", disk->disk_name)); 446 447 sdev = sdkp->device; 448 449 /* 450 * If the device is in error recovery, wait until it is done. 451 * If the device is offline, then disallow any access to it. 452 */ 453 retval = -ENXIO; 454 if (!scsi_block_when_processing_errors(sdev)) 455 goto error_out; 456 457 if (sdev->removable || sdkp->write_prot) 458 check_disk_change(inode->i_bdev); 459 460 /* 461 * If the drive is empty, just let the open fail. 462 */ 463 retval = -ENOMEDIUM; 464 if (sdev->removable && !sdkp->media_present && 465 !(filp->f_flags & O_NDELAY)) 466 goto error_out; 467 468 /* 469 * If the device has the write protect tab set, have the open fail 470 * if the user expects to be able to write to the thing. 471 */ 472 retval = -EROFS; 473 if (sdkp->write_prot && (filp->f_mode & FMODE_WRITE)) 474 goto error_out; 475 476 /* 477 * It is possible that the disk changing stuff resulted in 478 * the device being taken offline. If this is the case, 479 * report this to the user, and don't pretend that the 480 * open actually succeeded. 481 */ 482 retval = -ENXIO; 483 if (!scsi_device_online(sdev)) 484 goto error_out; 485 486 if (!sdkp->openers++ && sdev->removable) { 487 if (scsi_block_when_processing_errors(sdev)) 488 scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT); 489 } 490 491 return 0; 492 493 error_out: 494 scsi_disk_put(sdkp); 495 return retval; 496 } 497 498 /** 499 * sd_release - invoked when the (last) close(2) is called on this 500 * scsi disk. 501 * @inode: only i_rdev member may be used 502 * @filp: only f_mode and f_flags may be used 503 * 504 * Returns 0. 505 * 506 * Note: may block (uninterruptible) if error recovery is underway 507 * on this disk. 508 **/ 509 static int sd_release(struct inode *inode, struct file *filp) 510 { 511 struct gendisk *disk = inode->i_bdev->bd_disk; 512 struct scsi_disk *sdkp = scsi_disk(disk); 513 struct scsi_device *sdev = sdkp->device; 514 515 SCSI_LOG_HLQUEUE(3, printk("sd_release: disk=%s\n", disk->disk_name)); 516 517 if (!--sdkp->openers && sdev->removable) { 518 if (scsi_block_when_processing_errors(sdev)) 519 scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW); 520 } 521 522 /* 523 * XXX and what if there are packets in flight and this close() 524 * XXX is followed by a "rmmod sd_mod"? 525 */ 526 scsi_disk_put(sdkp); 527 return 0; 528 } 529 530 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo) 531 { 532 struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk); 533 struct scsi_device *sdp = sdkp->device; 534 struct Scsi_Host *host = sdp->host; 535 int diskinfo[4]; 536 537 /* default to most commonly used values */ 538 diskinfo[0] = 0x40; /* 1 << 6 */ 539 diskinfo[1] = 0x20; /* 1 << 5 */ 540 diskinfo[2] = sdkp->capacity >> 11; 541 542 /* override with calculated, extended default, or driver values */ 543 if (host->hostt->bios_param) 544 host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo); 545 else 546 scsicam_bios_param(bdev, sdkp->capacity, diskinfo); 547 548 geo->heads = diskinfo[0]; 549 geo->sectors = diskinfo[1]; 550 geo->cylinders = diskinfo[2]; 551 return 0; 552 } 553 554 /** 555 * sd_ioctl - process an ioctl 556 * @inode: only i_rdev/i_bdev members may be used 557 * @filp: only f_mode and f_flags may be used 558 * @cmd: ioctl command number 559 * @arg: this is third argument given to ioctl(2) system call. 560 * Often contains a pointer. 561 * 562 * Returns 0 if successful (some ioctls return postive numbers on 563 * success as well). Returns a negated errno value in case of error. 564 * 565 * Note: most ioctls are forward onto the block subsystem or further 566 * down in the scsi subsytem. 567 **/ 568 static int sd_ioctl(struct inode * inode, struct file * filp, 569 unsigned int cmd, unsigned long arg) 570 { 571 struct block_device *bdev = inode->i_bdev; 572 struct gendisk *disk = bdev->bd_disk; 573 struct scsi_device *sdp = scsi_disk(disk)->device; 574 void __user *p = (void __user *)arg; 575 int error; 576 577 SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n", 578 disk->disk_name, cmd)); 579 580 /* 581 * If we are in the middle of error recovery, don't let anyone 582 * else try and use this device. Also, if error recovery fails, it 583 * may try and take the device offline, in which case all further 584 * access to the device is prohibited. 585 */ 586 error = scsi_nonblockable_ioctl(sdp, cmd, p, filp); 587 if (!scsi_block_when_processing_errors(sdp) || !error) 588 return error; 589 590 /* 591 * Send SCSI addressing ioctls directly to mid level, send other 592 * ioctls to block level and then onto mid level if they can't be 593 * resolved. 594 */ 595 switch (cmd) { 596 case SCSI_IOCTL_GET_IDLUN: 597 case SCSI_IOCTL_GET_BUS_NUMBER: 598 return scsi_ioctl(sdp, cmd, p); 599 default: 600 error = scsi_cmd_ioctl(filp, disk, cmd, p); 601 if (error != -ENOTTY) 602 return error; 603 } 604 return scsi_ioctl(sdp, cmd, p); 605 } 606 607 static void set_media_not_present(struct scsi_disk *sdkp) 608 { 609 sdkp->media_present = 0; 610 sdkp->capacity = 0; 611 sdkp->device->changed = 1; 612 } 613 614 /** 615 * sd_media_changed - check if our medium changed 616 * @disk: kernel device descriptor 617 * 618 * Returns 0 if not applicable or no change; 1 if change 619 * 620 * Note: this function is invoked from the block subsystem. 621 **/ 622 static int sd_media_changed(struct gendisk *disk) 623 { 624 struct scsi_disk *sdkp = scsi_disk(disk); 625 struct scsi_device *sdp = sdkp->device; 626 int retval; 627 628 SCSI_LOG_HLQUEUE(3, printk("sd_media_changed: disk=%s\n", 629 disk->disk_name)); 630 631 if (!sdp->removable) 632 return 0; 633 634 /* 635 * If the device is offline, don't send any commands - just pretend as 636 * if the command failed. If the device ever comes back online, we 637 * can deal with it then. It is only because of unrecoverable errors 638 * that we would ever take a device offline in the first place. 639 */ 640 if (!scsi_device_online(sdp)) 641 goto not_present; 642 643 /* 644 * Using TEST_UNIT_READY enables differentiation between drive with 645 * no cartridge loaded - NOT READY, drive with changed cartridge - 646 * UNIT ATTENTION, or with same cartridge - GOOD STATUS. 647 * 648 * Drives that auto spin down. eg iomega jaz 1G, will be started 649 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever 650 * sd_revalidate() is called. 651 */ 652 retval = -ENODEV; 653 if (scsi_block_when_processing_errors(sdp)) 654 retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES); 655 656 /* 657 * Unable to test, unit probably not ready. This usually 658 * means there is no disc in the drive. Mark as changed, 659 * and we will figure it out later once the drive is 660 * available again. 661 */ 662 if (retval) 663 goto not_present; 664 665 /* 666 * For removable scsi disk we have to recognise the presence 667 * of a disk in the drive. This is kept in the struct scsi_disk 668 * struct and tested at open ! Daniel Roche (dan@lectra.fr) 669 */ 670 sdkp->media_present = 1; 671 672 retval = sdp->changed; 673 sdp->changed = 0; 674 675 return retval; 676 677 not_present: 678 set_media_not_present(sdkp); 679 return 1; 680 } 681 682 static int sd_sync_cache(struct scsi_device *sdp) 683 { 684 int retries, res; 685 struct scsi_sense_hdr sshdr; 686 687 if (!scsi_device_online(sdp)) 688 return -ENODEV; 689 690 691 for (retries = 3; retries > 0; --retries) { 692 unsigned char cmd[10] = { 0 }; 693 694 cmd[0] = SYNCHRONIZE_CACHE; 695 /* 696 * Leave the rest of the command zero to indicate 697 * flush everything. 698 */ 699 res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr, 700 SD_TIMEOUT, SD_MAX_RETRIES); 701 if (res == 0) 702 break; 703 } 704 705 if (res) { printk(KERN_WARNING "FAILED\n status = %x, message = %02x, " 706 "host = %d, driver = %02x\n ", 707 status_byte(res), msg_byte(res), 708 host_byte(res), driver_byte(res)); 709 if (driver_byte(res) & DRIVER_SENSE) 710 scsi_print_sense_hdr("sd", &sshdr); 711 } 712 713 return res; 714 } 715 716 static int sd_issue_flush(struct device *dev, sector_t *error_sector) 717 { 718 int ret = 0; 719 struct scsi_device *sdp = to_scsi_device(dev); 720 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 721 722 if (!sdkp) 723 return -ENODEV; 724 725 if (sdkp->WCE) 726 ret = sd_sync_cache(sdp); 727 scsi_disk_put(sdkp); 728 return ret; 729 } 730 731 static void sd_prepare_flush(request_queue_t *q, struct request *rq) 732 { 733 memset(rq->cmd, 0, sizeof(rq->cmd)); 734 rq->flags |= REQ_BLOCK_PC; 735 rq->timeout = SD_TIMEOUT; 736 rq->cmd[0] = SYNCHRONIZE_CACHE; 737 rq->cmd_len = 10; 738 } 739 740 static void sd_rescan(struct device *dev) 741 { 742 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 743 744 if (sdkp) { 745 sd_revalidate_disk(sdkp->disk); 746 scsi_disk_put(sdkp); 747 } 748 } 749 750 751 #ifdef CONFIG_COMPAT 752 /* 753 * This gets directly called from VFS. When the ioctl 754 * is not recognized we go back to the other translation paths. 755 */ 756 static long sd_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 757 { 758 struct block_device *bdev = file->f_dentry->d_inode->i_bdev; 759 struct gendisk *disk = bdev->bd_disk; 760 struct scsi_device *sdev = scsi_disk(disk)->device; 761 762 /* 763 * If we are in the middle of error recovery, don't let anyone 764 * else try and use this device. Also, if error recovery fails, it 765 * may try and take the device offline, in which case all further 766 * access to the device is prohibited. 767 */ 768 if (!scsi_block_when_processing_errors(sdev)) 769 return -ENODEV; 770 771 if (sdev->host->hostt->compat_ioctl) { 772 int ret; 773 774 ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg); 775 776 return ret; 777 } 778 779 /* 780 * Let the static ioctl translation table take care of it. 781 */ 782 return -ENOIOCTLCMD; 783 } 784 #endif 785 786 static struct block_device_operations sd_fops = { 787 .owner = THIS_MODULE, 788 .open = sd_open, 789 .release = sd_release, 790 .ioctl = sd_ioctl, 791 .getgeo = sd_getgeo, 792 #ifdef CONFIG_COMPAT 793 .compat_ioctl = sd_compat_ioctl, 794 #endif 795 .media_changed = sd_media_changed, 796 .revalidate_disk = sd_revalidate_disk, 797 }; 798 799 /** 800 * sd_rw_intr - bottom half handler: called when the lower level 801 * driver has completed (successfully or otherwise) a scsi command. 802 * @SCpnt: mid-level's per command structure. 803 * 804 * Note: potentially run from within an ISR. Must not block. 805 **/ 806 static void sd_rw_intr(struct scsi_cmnd * SCpnt) 807 { 808 int result = SCpnt->result; 809 int this_count = SCpnt->bufflen; 810 int good_bytes = (result == 0 ? this_count : 0); 811 sector_t block_sectors = 1; 812 u64 first_err_block; 813 sector_t error_sector; 814 struct scsi_sense_hdr sshdr; 815 int sense_valid = 0; 816 int sense_deferred = 0; 817 int info_valid; 818 819 if (result) { 820 sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr); 821 if (sense_valid) 822 sense_deferred = scsi_sense_is_deferred(&sshdr); 823 } 824 825 #ifdef CONFIG_SCSI_LOGGING 826 SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n", 827 SCpnt->request->rq_disk->disk_name, result)); 828 if (sense_valid) { 829 SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: sb[respc,sk,asc," 830 "ascq]=%x,%x,%x,%x\n", sshdr.response_code, 831 sshdr.sense_key, sshdr.asc, sshdr.ascq)); 832 } 833 #endif 834 /* 835 Handle MEDIUM ERRORs that indicate partial success. Since this is a 836 relatively rare error condition, no care is taken to avoid 837 unnecessary additional work such as memcpy's that could be avoided. 838 */ 839 840 /* 841 * If SG_IO from block layer then set good_bytes to stop retries; 842 * else if errors, check them, and if necessary prepare for 843 * (partial) retries. 844 */ 845 if (blk_pc_request(SCpnt->request)) 846 good_bytes = this_count; 847 else if (driver_byte(result) != 0 && 848 sense_valid && !sense_deferred) { 849 switch (sshdr.sense_key) { 850 case MEDIUM_ERROR: 851 if (!blk_fs_request(SCpnt->request)) 852 break; 853 info_valid = scsi_get_sense_info_fld( 854 SCpnt->sense_buffer, SCSI_SENSE_BUFFERSIZE, 855 &first_err_block); 856 /* 857 * May want to warn and skip if following cast results 858 * in actual truncation (if sector_t < 64 bits) 859 */ 860 error_sector = (sector_t)first_err_block; 861 if (SCpnt->request->bio != NULL) 862 block_sectors = bio_sectors(SCpnt->request->bio); 863 switch (SCpnt->device->sector_size) { 864 case 1024: 865 error_sector <<= 1; 866 if (block_sectors < 2) 867 block_sectors = 2; 868 break; 869 case 2048: 870 error_sector <<= 2; 871 if (block_sectors < 4) 872 block_sectors = 4; 873 break; 874 case 4096: 875 error_sector <<=3; 876 if (block_sectors < 8) 877 block_sectors = 8; 878 break; 879 case 256: 880 error_sector >>= 1; 881 break; 882 default: 883 break; 884 } 885 886 error_sector &= ~(block_sectors - 1); 887 good_bytes = (error_sector - SCpnt->request->sector) << 9; 888 if (good_bytes < 0 || good_bytes >= this_count) 889 good_bytes = 0; 890 break; 891 892 case RECOVERED_ERROR: /* an error occurred, but it recovered */ 893 case NO_SENSE: /* LLDD got sense data */ 894 /* 895 * Inform the user, but make sure that it's not treated 896 * as a hard error. 897 */ 898 scsi_print_sense("sd", SCpnt); 899 SCpnt->result = 0; 900 memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); 901 good_bytes = this_count; 902 break; 903 904 case ILLEGAL_REQUEST: 905 if (SCpnt->device->use_10_for_rw && 906 (SCpnt->cmnd[0] == READ_10 || 907 SCpnt->cmnd[0] == WRITE_10)) 908 SCpnt->device->use_10_for_rw = 0; 909 if (SCpnt->device->use_10_for_ms && 910 (SCpnt->cmnd[0] == MODE_SENSE_10 || 911 SCpnt->cmnd[0] == MODE_SELECT_10)) 912 SCpnt->device->use_10_for_ms = 0; 913 break; 914 915 default: 916 break; 917 } 918 } 919 /* 920 * This calls the generic completion function, now that we know 921 * how many actual sectors finished, and how many sectors we need 922 * to say have failed. 923 */ 924 scsi_io_completion(SCpnt, good_bytes, block_sectors << 9); 925 } 926 927 static int media_not_present(struct scsi_disk *sdkp, 928 struct scsi_sense_hdr *sshdr) 929 { 930 931 if (!scsi_sense_valid(sshdr)) 932 return 0; 933 /* not invoked for commands that could return deferred errors */ 934 if (sshdr->sense_key != NOT_READY && 935 sshdr->sense_key != UNIT_ATTENTION) 936 return 0; 937 if (sshdr->asc != 0x3A) /* medium not present */ 938 return 0; 939 940 set_media_not_present(sdkp); 941 return 1; 942 } 943 944 /* 945 * spinup disk - called only in sd_revalidate_disk() 946 */ 947 static void 948 sd_spinup_disk(struct scsi_disk *sdkp, char *diskname) 949 { 950 unsigned char cmd[10]; 951 unsigned long spintime_expire = 0; 952 int retries, spintime; 953 unsigned int the_result; 954 struct scsi_sense_hdr sshdr; 955 int sense_valid = 0; 956 957 spintime = 0; 958 959 /* Spin up drives, as required. Only do this at boot time */ 960 /* Spinup needs to be done for module loads too. */ 961 do { 962 retries = 0; 963 964 do { 965 cmd[0] = TEST_UNIT_READY; 966 memset((void *) &cmd[1], 0, 9); 967 968 the_result = scsi_execute_req(sdkp->device, cmd, 969 DMA_NONE, NULL, 0, 970 &sshdr, SD_TIMEOUT, 971 SD_MAX_RETRIES); 972 973 if (the_result) 974 sense_valid = scsi_sense_valid(&sshdr); 975 retries++; 976 } while (retries < 3 && 977 (!scsi_status_is_good(the_result) || 978 ((driver_byte(the_result) & DRIVER_SENSE) && 979 sense_valid && sshdr.sense_key == UNIT_ATTENTION))); 980 981 /* 982 * If the drive has indicated to us that it doesn't have 983 * any media in it, don't bother with any of the rest of 984 * this crap. 985 */ 986 if (media_not_present(sdkp, &sshdr)) 987 return; 988 989 if ((driver_byte(the_result) & DRIVER_SENSE) == 0) { 990 /* no sense, TUR either succeeded or failed 991 * with a status error */ 992 if(!spintime && !scsi_status_is_good(the_result)) 993 printk(KERN_NOTICE "%s: Unit Not Ready, " 994 "error = 0x%x\n", diskname, the_result); 995 break; 996 } 997 998 /* 999 * The device does not want the automatic start to be issued. 1000 */ 1001 if (sdkp->device->no_start_on_add) { 1002 break; 1003 } 1004 1005 /* 1006 * If manual intervention is required, or this is an 1007 * absent USB storage device, a spinup is meaningless. 1008 */ 1009 if (sense_valid && 1010 sshdr.sense_key == NOT_READY && 1011 sshdr.asc == 4 && sshdr.ascq == 3) { 1012 break; /* manual intervention required */ 1013 1014 /* 1015 * Issue command to spin up drive when not ready 1016 */ 1017 } else if (sense_valid && sshdr.sense_key == NOT_READY) { 1018 if (!spintime) { 1019 printk(KERN_NOTICE "%s: Spinning up disk...", 1020 diskname); 1021 cmd[0] = START_STOP; 1022 cmd[1] = 1; /* Return immediately */ 1023 memset((void *) &cmd[2], 0, 8); 1024 cmd[4] = 1; /* Start spin cycle */ 1025 scsi_execute_req(sdkp->device, cmd, DMA_NONE, 1026 NULL, 0, &sshdr, 1027 SD_TIMEOUT, SD_MAX_RETRIES); 1028 spintime_expire = jiffies + 100 * HZ; 1029 spintime = 1; 1030 } 1031 /* Wait 1 second for next try */ 1032 msleep(1000); 1033 printk("."); 1034 1035 /* 1036 * Wait for USB flash devices with slow firmware. 1037 * Yes, this sense key/ASC combination shouldn't 1038 * occur here. It's characteristic of these devices. 1039 */ 1040 } else if (sense_valid && 1041 sshdr.sense_key == UNIT_ATTENTION && 1042 sshdr.asc == 0x28) { 1043 if (!spintime) { 1044 spintime_expire = jiffies + 5 * HZ; 1045 spintime = 1; 1046 } 1047 /* Wait 1 second for next try */ 1048 msleep(1000); 1049 } else { 1050 /* we don't understand the sense code, so it's 1051 * probably pointless to loop */ 1052 if(!spintime) { 1053 printk(KERN_NOTICE "%s: Unit Not Ready, " 1054 "sense:\n", diskname); 1055 scsi_print_sense_hdr("", &sshdr); 1056 } 1057 break; 1058 } 1059 1060 } while (spintime && time_before_eq(jiffies, spintime_expire)); 1061 1062 if (spintime) { 1063 if (scsi_status_is_good(the_result)) 1064 printk("ready\n"); 1065 else 1066 printk("not responding...\n"); 1067 } 1068 } 1069 1070 /* 1071 * read disk capacity 1072 */ 1073 static void 1074 sd_read_capacity(struct scsi_disk *sdkp, char *diskname, 1075 unsigned char *buffer) 1076 { 1077 unsigned char cmd[16]; 1078 int the_result, retries; 1079 int sector_size = 0; 1080 int longrc = 0; 1081 struct scsi_sense_hdr sshdr; 1082 int sense_valid = 0; 1083 struct scsi_device *sdp = sdkp->device; 1084 1085 repeat: 1086 retries = 3; 1087 do { 1088 if (longrc) { 1089 memset((void *) cmd, 0, 16); 1090 cmd[0] = SERVICE_ACTION_IN; 1091 cmd[1] = SAI_READ_CAPACITY_16; 1092 cmd[13] = 12; 1093 memset((void *) buffer, 0, 12); 1094 } else { 1095 cmd[0] = READ_CAPACITY; 1096 memset((void *) &cmd[1], 0, 9); 1097 memset((void *) buffer, 0, 8); 1098 } 1099 1100 the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE, 1101 buffer, longrc ? 12 : 8, &sshdr, 1102 SD_TIMEOUT, SD_MAX_RETRIES); 1103 1104 if (media_not_present(sdkp, &sshdr)) 1105 return; 1106 1107 if (the_result) 1108 sense_valid = scsi_sense_valid(&sshdr); 1109 retries--; 1110 1111 } while (the_result && retries); 1112 1113 if (the_result && !longrc) { 1114 printk(KERN_NOTICE "%s : READ CAPACITY failed.\n" 1115 "%s : status=%x, message=%02x, host=%d, driver=%02x \n", 1116 diskname, diskname, 1117 status_byte(the_result), 1118 msg_byte(the_result), 1119 host_byte(the_result), 1120 driver_byte(the_result)); 1121 1122 if (driver_byte(the_result) & DRIVER_SENSE) 1123 scsi_print_sense_hdr("sd", &sshdr); 1124 else 1125 printk("%s : sense not available. \n", diskname); 1126 1127 /* Set dirty bit for removable devices if not ready - 1128 * sometimes drives will not report this properly. */ 1129 if (sdp->removable && 1130 sense_valid && sshdr.sense_key == NOT_READY) 1131 sdp->changed = 1; 1132 1133 /* Either no media are present but the drive didn't tell us, 1134 or they are present but the read capacity command fails */ 1135 /* sdkp->media_present = 0; -- not always correct */ 1136 sdkp->capacity = 0x200000; /* 1 GB - random */ 1137 1138 return; 1139 } else if (the_result && longrc) { 1140 /* READ CAPACITY(16) has been failed */ 1141 printk(KERN_NOTICE "%s : READ CAPACITY(16) failed.\n" 1142 "%s : status=%x, message=%02x, host=%d, driver=%02x \n", 1143 diskname, diskname, 1144 status_byte(the_result), 1145 msg_byte(the_result), 1146 host_byte(the_result), 1147 driver_byte(the_result)); 1148 printk(KERN_NOTICE "%s : use 0xffffffff as device size\n", 1149 diskname); 1150 1151 sdkp->capacity = 1 + (sector_t) 0xffffffff; 1152 goto got_data; 1153 } 1154 1155 if (!longrc) { 1156 sector_size = (buffer[4] << 24) | 1157 (buffer[5] << 16) | (buffer[6] << 8) | buffer[7]; 1158 if (buffer[0] == 0xff && buffer[1] == 0xff && 1159 buffer[2] == 0xff && buffer[3] == 0xff) { 1160 if(sizeof(sdkp->capacity) > 4) { 1161 printk(KERN_NOTICE "%s : very big device. try to use" 1162 " READ CAPACITY(16).\n", diskname); 1163 longrc = 1; 1164 goto repeat; 1165 } 1166 printk(KERN_ERR "%s: too big for this kernel. Use a " 1167 "kernel compiled with support for large block " 1168 "devices.\n", diskname); 1169 sdkp->capacity = 0; 1170 goto got_data; 1171 } 1172 sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) | 1173 (buffer[1] << 16) | 1174 (buffer[2] << 8) | 1175 buffer[3]); 1176 } else { 1177 sdkp->capacity = 1 + (((u64)buffer[0] << 56) | 1178 ((u64)buffer[1] << 48) | 1179 ((u64)buffer[2] << 40) | 1180 ((u64)buffer[3] << 32) | 1181 ((sector_t)buffer[4] << 24) | 1182 ((sector_t)buffer[5] << 16) | 1183 ((sector_t)buffer[6] << 8) | 1184 (sector_t)buffer[7]); 1185 1186 sector_size = (buffer[8] << 24) | 1187 (buffer[9] << 16) | (buffer[10] << 8) | buffer[11]; 1188 } 1189 1190 /* Some devices return the total number of sectors, not the 1191 * highest sector number. Make the necessary adjustment. */ 1192 if (sdp->fix_capacity) 1193 --sdkp->capacity; 1194 1195 got_data: 1196 if (sector_size == 0) { 1197 sector_size = 512; 1198 printk(KERN_NOTICE "%s : sector size 0 reported, " 1199 "assuming 512.\n", diskname); 1200 } 1201 1202 if (sector_size != 512 && 1203 sector_size != 1024 && 1204 sector_size != 2048 && 1205 sector_size != 4096 && 1206 sector_size != 256) { 1207 printk(KERN_NOTICE "%s : unsupported sector size " 1208 "%d.\n", diskname, sector_size); 1209 /* 1210 * The user might want to re-format the drive with 1211 * a supported sectorsize. Once this happens, it 1212 * would be relatively trivial to set the thing up. 1213 * For this reason, we leave the thing in the table. 1214 */ 1215 sdkp->capacity = 0; 1216 /* 1217 * set a bogus sector size so the normal read/write 1218 * logic in the block layer will eventually refuse any 1219 * request on this device without tripping over power 1220 * of two sector size assumptions 1221 */ 1222 sector_size = 512; 1223 } 1224 { 1225 /* 1226 * The msdos fs needs to know the hardware sector size 1227 * So I have created this table. See ll_rw_blk.c 1228 * Jacques Gelinas (Jacques@solucorp.qc.ca) 1229 */ 1230 int hard_sector = sector_size; 1231 sector_t sz = (sdkp->capacity/2) * (hard_sector/256); 1232 request_queue_t *queue = sdp->request_queue; 1233 sector_t mb = sz; 1234 1235 blk_queue_hardsect_size(queue, hard_sector); 1236 /* avoid 64-bit division on 32-bit platforms */ 1237 sector_div(sz, 625); 1238 mb -= sz - 974; 1239 sector_div(mb, 1950); 1240 1241 printk(KERN_NOTICE "SCSI device %s: " 1242 "%llu %d-byte hdwr sectors (%llu MB)\n", 1243 diskname, (unsigned long long)sdkp->capacity, 1244 hard_sector, (unsigned long long)mb); 1245 } 1246 1247 /* Rescale capacity to 512-byte units */ 1248 if (sector_size == 4096) 1249 sdkp->capacity <<= 3; 1250 else if (sector_size == 2048) 1251 sdkp->capacity <<= 2; 1252 else if (sector_size == 1024) 1253 sdkp->capacity <<= 1; 1254 else if (sector_size == 256) 1255 sdkp->capacity >>= 1; 1256 1257 sdkp->device->sector_size = sector_size; 1258 } 1259 1260 /* called with buffer of length 512 */ 1261 static inline int 1262 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage, 1263 unsigned char *buffer, int len, struct scsi_mode_data *data, 1264 struct scsi_sense_hdr *sshdr) 1265 { 1266 return scsi_mode_sense(sdp, dbd, modepage, buffer, len, 1267 SD_TIMEOUT, SD_MAX_RETRIES, data, 1268 sshdr); 1269 } 1270 1271 /* 1272 * read write protect setting, if possible - called only in sd_revalidate_disk() 1273 * called with buffer of length 512 1274 */ 1275 static void 1276 sd_read_write_protect_flag(struct scsi_disk *sdkp, char *diskname, 1277 unsigned char *buffer) 1278 { 1279 int res; 1280 struct scsi_device *sdp = sdkp->device; 1281 struct scsi_mode_data data; 1282 1283 set_disk_ro(sdkp->disk, 0); 1284 if (sdp->skip_ms_page_3f) { 1285 printk(KERN_NOTICE "%s: assuming Write Enabled\n", diskname); 1286 return; 1287 } 1288 1289 if (sdp->use_192_bytes_for_3f) { 1290 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL); 1291 } else { 1292 /* 1293 * First attempt: ask for all pages (0x3F), but only 4 bytes. 1294 * We have to start carefully: some devices hang if we ask 1295 * for more than is available. 1296 */ 1297 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL); 1298 1299 /* 1300 * Second attempt: ask for page 0 When only page 0 is 1301 * implemented, a request for page 3F may return Sense Key 1302 * 5: Illegal Request, Sense Code 24: Invalid field in 1303 * CDB. 1304 */ 1305 if (!scsi_status_is_good(res)) 1306 res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL); 1307 1308 /* 1309 * Third attempt: ask 255 bytes, as we did earlier. 1310 */ 1311 if (!scsi_status_is_good(res)) 1312 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255, 1313 &data, NULL); 1314 } 1315 1316 if (!scsi_status_is_good(res)) { 1317 printk(KERN_WARNING 1318 "%s: test WP failed, assume Write Enabled\n", diskname); 1319 } else { 1320 sdkp->write_prot = ((data.device_specific & 0x80) != 0); 1321 set_disk_ro(sdkp->disk, sdkp->write_prot); 1322 printk(KERN_NOTICE "%s: Write Protect is %s\n", diskname, 1323 sdkp->write_prot ? "on" : "off"); 1324 printk(KERN_DEBUG "%s: Mode Sense: %02x %02x %02x %02x\n", 1325 diskname, buffer[0], buffer[1], buffer[2], buffer[3]); 1326 } 1327 } 1328 1329 /* 1330 * sd_read_cache_type - called only from sd_revalidate_disk() 1331 * called with buffer of length 512 1332 */ 1333 static void 1334 sd_read_cache_type(struct scsi_disk *sdkp, char *diskname, 1335 unsigned char *buffer) 1336 { 1337 int len = 0, res; 1338 struct scsi_device *sdp = sdkp->device; 1339 1340 int dbd; 1341 int modepage; 1342 struct scsi_mode_data data; 1343 struct scsi_sense_hdr sshdr; 1344 1345 if (sdp->skip_ms_page_8) 1346 goto defaults; 1347 1348 if (sdp->type == TYPE_RBC) { 1349 modepage = 6; 1350 dbd = 8; 1351 } else { 1352 modepage = 8; 1353 dbd = 0; 1354 } 1355 1356 /* cautiously ask */ 1357 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr); 1358 1359 if (!scsi_status_is_good(res)) 1360 goto bad_sense; 1361 1362 /* that went OK, now ask for the proper length */ 1363 len = data.length; 1364 1365 /* 1366 * We're only interested in the first three bytes, actually. 1367 * But the data cache page is defined for the first 20. 1368 */ 1369 if (len < 3) 1370 goto bad_sense; 1371 if (len > 20) 1372 len = 20; 1373 1374 /* Take headers and block descriptors into account */ 1375 len += data.header_length + data.block_descriptor_length; 1376 1377 /* Get the data */ 1378 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr); 1379 1380 if (scsi_status_is_good(res)) { 1381 const char *types[] = { 1382 "write through", "none", "write back", 1383 "write back, no read (daft)" 1384 }; 1385 int ct = 0; 1386 int offset = data.header_length + data.block_descriptor_length; 1387 1388 if ((buffer[offset] & 0x3f) != modepage) { 1389 printk(KERN_ERR "%s: got wrong page\n", diskname); 1390 goto defaults; 1391 } 1392 1393 if (modepage == 8) { 1394 sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0); 1395 sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0); 1396 } else { 1397 sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0); 1398 sdkp->RCD = 0; 1399 } 1400 1401 sdkp->DPOFUA = (data.device_specific & 0x10) != 0; 1402 if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) { 1403 printk(KERN_NOTICE "SCSI device %s: uses " 1404 "READ/WRITE(6), disabling FUA\n", diskname); 1405 sdkp->DPOFUA = 0; 1406 } 1407 1408 ct = sdkp->RCD + 2*sdkp->WCE; 1409 1410 printk(KERN_NOTICE "SCSI device %s: drive cache: %s%s\n", 1411 diskname, types[ct], 1412 sdkp->DPOFUA ? " w/ FUA" : ""); 1413 1414 return; 1415 } 1416 1417 bad_sense: 1418 if (scsi_sense_valid(&sshdr) && 1419 sshdr.sense_key == ILLEGAL_REQUEST && 1420 sshdr.asc == 0x24 && sshdr.ascq == 0x0) 1421 printk(KERN_NOTICE "%s: cache data unavailable\n", 1422 diskname); /* Invalid field in CDB */ 1423 else 1424 printk(KERN_ERR "%s: asking for cache data failed\n", 1425 diskname); 1426 1427 defaults: 1428 printk(KERN_ERR "%s: assuming drive cache: write through\n", 1429 diskname); 1430 sdkp->WCE = 0; 1431 sdkp->RCD = 0; 1432 } 1433 1434 /** 1435 * sd_revalidate_disk - called the first time a new disk is seen, 1436 * performs disk spin up, read_capacity, etc. 1437 * @disk: struct gendisk we care about 1438 **/ 1439 static int sd_revalidate_disk(struct gendisk *disk) 1440 { 1441 struct scsi_disk *sdkp = scsi_disk(disk); 1442 struct scsi_device *sdp = sdkp->device; 1443 unsigned char *buffer; 1444 unsigned ordered; 1445 1446 SCSI_LOG_HLQUEUE(3, printk("sd_revalidate_disk: disk=%s\n", disk->disk_name)); 1447 1448 /* 1449 * If the device is offline, don't try and read capacity or any 1450 * of the other niceties. 1451 */ 1452 if (!scsi_device_online(sdp)) 1453 goto out; 1454 1455 buffer = kmalloc(512, GFP_KERNEL | __GFP_DMA); 1456 if (!buffer) { 1457 printk(KERN_WARNING "(sd_revalidate_disk:) Memory allocation " 1458 "failure.\n"); 1459 goto out; 1460 } 1461 1462 /* defaults, until the device tells us otherwise */ 1463 sdp->sector_size = 512; 1464 sdkp->capacity = 0; 1465 sdkp->media_present = 1; 1466 sdkp->write_prot = 0; 1467 sdkp->WCE = 0; 1468 sdkp->RCD = 0; 1469 1470 sd_spinup_disk(sdkp, disk->disk_name); 1471 1472 /* 1473 * Without media there is no reason to ask; moreover, some devices 1474 * react badly if we do. 1475 */ 1476 if (sdkp->media_present) { 1477 sd_read_capacity(sdkp, disk->disk_name, buffer); 1478 sd_read_write_protect_flag(sdkp, disk->disk_name, buffer); 1479 sd_read_cache_type(sdkp, disk->disk_name, buffer); 1480 } 1481 1482 /* 1483 * We now have all cache related info, determine how we deal 1484 * with ordered requests. Note that as the current SCSI 1485 * dispatch function can alter request order, we cannot use 1486 * QUEUE_ORDERED_TAG_* even when ordered tag is supported. 1487 */ 1488 if (sdkp->WCE) 1489 ordered = sdkp->DPOFUA 1490 ? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH; 1491 else 1492 ordered = QUEUE_ORDERED_DRAIN; 1493 1494 blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush); 1495 1496 set_capacity(disk, sdkp->capacity); 1497 kfree(buffer); 1498 1499 out: 1500 return 0; 1501 } 1502 1503 /** 1504 * sd_probe - called during driver initialization and whenever a 1505 * new scsi device is attached to the system. It is called once 1506 * for each scsi device (not just disks) present. 1507 * @dev: pointer to device object 1508 * 1509 * Returns 0 if successful (or not interested in this scsi device 1510 * (e.g. scanner)); 1 when there is an error. 1511 * 1512 * Note: this function is invoked from the scsi mid-level. 1513 * This function sets up the mapping between a given 1514 * <host,channel,id,lun> (found in sdp) and new device name 1515 * (e.g. /dev/sda). More precisely it is the block device major 1516 * and minor number that is chosen here. 1517 * 1518 * Assume sd_attach is not re-entrant (for time being) 1519 * Also think about sd_attach() and sd_remove() running coincidentally. 1520 **/ 1521 static int sd_probe(struct device *dev) 1522 { 1523 struct scsi_device *sdp = to_scsi_device(dev); 1524 struct scsi_disk *sdkp; 1525 struct gendisk *gd; 1526 u32 index; 1527 int error; 1528 1529 error = -ENODEV; 1530 if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC) 1531 goto out; 1532 1533 SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp, 1534 "sd_attach\n")); 1535 1536 error = -ENOMEM; 1537 sdkp = kmalloc(sizeof(*sdkp), GFP_KERNEL); 1538 if (!sdkp) 1539 goto out; 1540 1541 memset (sdkp, 0, sizeof(*sdkp)); 1542 kref_init(&sdkp->kref); 1543 1544 gd = alloc_disk(16); 1545 if (!gd) 1546 goto out_free; 1547 1548 if (!idr_pre_get(&sd_index_idr, GFP_KERNEL)) 1549 goto out_put; 1550 1551 spin_lock(&sd_index_lock); 1552 error = idr_get_new(&sd_index_idr, NULL, &index); 1553 spin_unlock(&sd_index_lock); 1554 1555 if (index >= SD_MAX_DISKS) 1556 error = -EBUSY; 1557 if (error) 1558 goto out_put; 1559 1560 get_device(&sdp->sdev_gendev); 1561 sdkp->device = sdp; 1562 sdkp->driver = &sd_template; 1563 sdkp->disk = gd; 1564 sdkp->index = index; 1565 sdkp->openers = 0; 1566 1567 if (!sdp->timeout) { 1568 if (sdp->type != TYPE_MOD) 1569 sdp->timeout = SD_TIMEOUT; 1570 else 1571 sdp->timeout = SD_MOD_TIMEOUT; 1572 } 1573 1574 gd->major = sd_major((index & 0xf0) >> 4); 1575 gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00); 1576 gd->minors = 16; 1577 gd->fops = &sd_fops; 1578 1579 if (index < 26) { 1580 sprintf(gd->disk_name, "sd%c", 'a' + index % 26); 1581 } else if (index < (26 + 1) * 26) { 1582 sprintf(gd->disk_name, "sd%c%c", 1583 'a' + index / 26 - 1,'a' + index % 26); 1584 } else { 1585 const unsigned int m1 = (index / 26 - 1) / 26 - 1; 1586 const unsigned int m2 = (index / 26 - 1) % 26; 1587 const unsigned int m3 = index % 26; 1588 sprintf(gd->disk_name, "sd%c%c%c", 1589 'a' + m1, 'a' + m2, 'a' + m3); 1590 } 1591 1592 strcpy(gd->devfs_name, sdp->devfs_name); 1593 1594 gd->private_data = &sdkp->driver; 1595 gd->queue = sdkp->device->request_queue; 1596 1597 sd_revalidate_disk(gd); 1598 1599 gd->driverfs_dev = &sdp->sdev_gendev; 1600 gd->flags = GENHD_FL_DRIVERFS; 1601 if (sdp->removable) 1602 gd->flags |= GENHD_FL_REMOVABLE; 1603 1604 dev_set_drvdata(dev, sdkp); 1605 add_disk(gd); 1606 1607 sdev_printk(KERN_NOTICE, sdp, "Attached scsi %sdisk %s\n", 1608 sdp->removable ? "removable " : "", gd->disk_name); 1609 1610 return 0; 1611 1612 out_put: 1613 put_disk(gd); 1614 out_free: 1615 kfree(sdkp); 1616 out: 1617 return error; 1618 } 1619 1620 /** 1621 * sd_remove - called whenever a scsi disk (previously recognized by 1622 * sd_probe) is detached from the system. It is called (potentially 1623 * multiple times) during sd module unload. 1624 * @sdp: pointer to mid level scsi device object 1625 * 1626 * Note: this function is invoked from the scsi mid-level. 1627 * This function potentially frees up a device name (e.g. /dev/sdc) 1628 * that could be re-used by a subsequent sd_probe(). 1629 * This function is not called when the built-in sd driver is "exit-ed". 1630 **/ 1631 static int sd_remove(struct device *dev) 1632 { 1633 struct scsi_disk *sdkp = dev_get_drvdata(dev); 1634 1635 del_gendisk(sdkp->disk); 1636 sd_shutdown(dev); 1637 1638 down(&sd_ref_sem); 1639 dev_set_drvdata(dev, NULL); 1640 kref_put(&sdkp->kref, scsi_disk_release); 1641 up(&sd_ref_sem); 1642 1643 return 0; 1644 } 1645 1646 /** 1647 * scsi_disk_release - Called to free the scsi_disk structure 1648 * @kref: pointer to embedded kref 1649 * 1650 * sd_ref_sem must be held entering this routine. Because it is 1651 * called on last put, you should always use the scsi_disk_get() 1652 * scsi_disk_put() helpers which manipulate the semaphore directly 1653 * and never do a direct kref_put(). 1654 **/ 1655 static void scsi_disk_release(struct kref *kref) 1656 { 1657 struct scsi_disk *sdkp = to_scsi_disk(kref); 1658 struct gendisk *disk = sdkp->disk; 1659 1660 spin_lock(&sd_index_lock); 1661 idr_remove(&sd_index_idr, sdkp->index); 1662 spin_unlock(&sd_index_lock); 1663 1664 disk->private_data = NULL; 1665 put_disk(disk); 1666 put_device(&sdkp->device->sdev_gendev); 1667 1668 kfree(sdkp); 1669 } 1670 1671 /* 1672 * Send a SYNCHRONIZE CACHE instruction down to the device through 1673 * the normal SCSI command structure. Wait for the command to 1674 * complete. 1675 */ 1676 static void sd_shutdown(struct device *dev) 1677 { 1678 struct scsi_device *sdp = to_scsi_device(dev); 1679 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 1680 1681 if (!sdkp) 1682 return; /* this can happen */ 1683 1684 if (sdkp->WCE) { 1685 printk(KERN_NOTICE "Synchronizing SCSI cache for disk %s: \n", 1686 sdkp->disk->disk_name); 1687 sd_sync_cache(sdp); 1688 } 1689 scsi_disk_put(sdkp); 1690 } 1691 1692 /** 1693 * init_sd - entry point for this driver (both when built in or when 1694 * a module). 1695 * 1696 * Note: this function registers this driver with the scsi mid-level. 1697 **/ 1698 static int __init init_sd(void) 1699 { 1700 int majors = 0, i; 1701 1702 SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n")); 1703 1704 for (i = 0; i < SD_MAJORS; i++) 1705 if (register_blkdev(sd_major(i), "sd") == 0) 1706 majors++; 1707 1708 if (!majors) 1709 return -ENODEV; 1710 1711 return scsi_register_driver(&sd_template.gendrv); 1712 } 1713 1714 /** 1715 * exit_sd - exit point for this driver (when it is a module). 1716 * 1717 * Note: this function unregisters this driver from the scsi mid-level. 1718 **/ 1719 static void __exit exit_sd(void) 1720 { 1721 int i; 1722 1723 SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n")); 1724 1725 scsi_unregister_driver(&sd_template.gendrv); 1726 for (i = 0; i < SD_MAJORS; i++) 1727 unregister_blkdev(sd_major(i), "sd"); 1728 } 1729 1730 MODULE_LICENSE("GPL"); 1731 MODULE_AUTHOR("Eric Youngdale"); 1732 MODULE_DESCRIPTION("SCSI disk (sd) driver"); 1733 1734 module_init(init_sd); 1735 module_exit(exit_sd); 1736