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 }; 106 107 static DEFINE_IDR(sd_index_idr); 108 static DEFINE_SPINLOCK(sd_index_lock); 109 110 /* This semaphore is used to mediate the 0->1 reference get in the 111 * face of object destruction (i.e. we can't allow a get on an 112 * object after last put) */ 113 static DECLARE_MUTEX(sd_ref_sem); 114 115 static int sd_revalidate_disk(struct gendisk *disk); 116 static void sd_rw_intr(struct scsi_cmnd * SCpnt); 117 118 static int sd_probe(struct device *); 119 static int sd_remove(struct device *); 120 static void sd_shutdown(struct device *dev); 121 static void sd_rescan(struct device *); 122 static int sd_init_command(struct scsi_cmnd *); 123 static int sd_issue_flush(struct device *, sector_t *); 124 static void sd_end_flush(request_queue_t *, struct request *); 125 static int 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 .prepare_flush = sd_prepare_flush, 141 .end_flush = sd_end_flush, 142 }; 143 144 /* 145 * Device no to disk mapping: 146 * 147 * major disc2 disc p1 148 * |............|.............|....|....| <- dev_t 149 * 31 20 19 8 7 4 3 0 150 * 151 * Inside a major, we have 16k disks, however mapped non- 152 * contiguously. The first 16 disks are for major0, the next 153 * ones with major1, ... Disk 256 is for major0 again, disk 272 154 * for major1, ... 155 * As we stay compatible with our numbering scheme, we can reuse 156 * the well-know SCSI majors 8, 65--71, 136--143. 157 */ 158 static int sd_major(int major_idx) 159 { 160 switch (major_idx) { 161 case 0: 162 return SCSI_DISK0_MAJOR; 163 case 1 ... 7: 164 return SCSI_DISK1_MAJOR + major_idx - 1; 165 case 8 ... 15: 166 return SCSI_DISK8_MAJOR + major_idx - 8; 167 default: 168 BUG(); 169 return 0; /* shut up gcc */ 170 } 171 } 172 173 #define to_scsi_disk(obj) container_of(obj,struct scsi_disk,kref) 174 175 static inline struct scsi_disk *scsi_disk(struct gendisk *disk) 176 { 177 return container_of(disk->private_data, struct scsi_disk, driver); 178 } 179 180 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk) 181 { 182 struct scsi_disk *sdkp = NULL; 183 184 if (disk->private_data) { 185 sdkp = scsi_disk(disk); 186 if (scsi_device_get(sdkp->device) == 0) 187 kref_get(&sdkp->kref); 188 else 189 sdkp = NULL; 190 } 191 return sdkp; 192 } 193 194 static struct scsi_disk *scsi_disk_get(struct gendisk *disk) 195 { 196 struct scsi_disk *sdkp; 197 198 down(&sd_ref_sem); 199 sdkp = __scsi_disk_get(disk); 200 up(&sd_ref_sem); 201 return sdkp; 202 } 203 204 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev) 205 { 206 struct scsi_disk *sdkp; 207 208 down(&sd_ref_sem); 209 sdkp = dev_get_drvdata(dev); 210 if (sdkp) 211 sdkp = __scsi_disk_get(sdkp->disk); 212 up(&sd_ref_sem); 213 return sdkp; 214 } 215 216 static void scsi_disk_put(struct scsi_disk *sdkp) 217 { 218 struct scsi_device *sdev = sdkp->device; 219 220 down(&sd_ref_sem); 221 kref_put(&sdkp->kref, scsi_disk_release); 222 scsi_device_put(sdev); 223 up(&sd_ref_sem); 224 } 225 226 /** 227 * sd_init_command - build a scsi (read or write) command from 228 * information in the request structure. 229 * @SCpnt: pointer to mid-level's per scsi command structure that 230 * contains request and into which the scsi command is written 231 * 232 * Returns 1 if successful and 0 if error (or cannot be done now). 233 **/ 234 static int sd_init_command(struct scsi_cmnd * SCpnt) 235 { 236 unsigned int this_count, timeout; 237 struct gendisk *disk; 238 sector_t block; 239 struct scsi_device *sdp = SCpnt->device; 240 struct request *rq = SCpnt->request; 241 242 timeout = sdp->timeout; 243 244 /* 245 * SG_IO from block layer already setup, just copy cdb basically 246 */ 247 if (blk_pc_request(rq)) { 248 if (sizeof(rq->cmd) > sizeof(SCpnt->cmnd)) 249 return 0; 250 251 memcpy(SCpnt->cmnd, rq->cmd, sizeof(SCpnt->cmnd)); 252 SCpnt->cmd_len = rq->cmd_len; 253 if (rq_data_dir(rq) == WRITE) 254 SCpnt->sc_data_direction = DMA_TO_DEVICE; 255 else if (rq->data_len) 256 SCpnt->sc_data_direction = DMA_FROM_DEVICE; 257 else 258 SCpnt->sc_data_direction = DMA_NONE; 259 260 this_count = rq->data_len; 261 if (rq->timeout) 262 timeout = rq->timeout; 263 264 SCpnt->transfersize = rq->data_len; 265 SCpnt->allowed = SD_PASSTHROUGH_RETRIES; 266 goto queue; 267 } 268 269 /* 270 * we only do REQ_CMD and REQ_BLOCK_PC 271 */ 272 if (!blk_fs_request(rq)) 273 return 0; 274 275 disk = rq->rq_disk; 276 block = rq->sector; 277 this_count = SCpnt->request_bufflen >> 9; 278 279 SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, " 280 "count=%d\n", disk->disk_name, 281 (unsigned long long)block, this_count)); 282 283 if (!sdp || !scsi_device_online(sdp) || 284 block + rq->nr_sectors > get_capacity(disk)) { 285 SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n", 286 rq->nr_sectors)); 287 SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt)); 288 return 0; 289 } 290 291 if (sdp->changed) { 292 /* 293 * quietly refuse to do anything to a changed disc until 294 * the changed bit has been reset 295 */ 296 /* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */ 297 return 0; 298 } 299 SCSI_LOG_HLQUEUE(2, printk("%s : block=%llu\n", 300 disk->disk_name, (unsigned long long)block)); 301 302 /* 303 * If we have a 1K hardware sectorsize, prevent access to single 304 * 512 byte sectors. In theory we could handle this - in fact 305 * the scsi cdrom driver must be able to handle this because 306 * we typically use 1K blocksizes, and cdroms typically have 307 * 2K hardware sectorsizes. Of course, things are simpler 308 * with the cdrom, since it is read-only. For performance 309 * reasons, the filesystems should be able to handle this 310 * and not force the scsi disk driver to use bounce buffers 311 * for this. 312 */ 313 if (sdp->sector_size == 1024) { 314 if ((block & 1) || (rq->nr_sectors & 1)) { 315 printk(KERN_ERR "sd: Bad block number requested"); 316 return 0; 317 } else { 318 block = block >> 1; 319 this_count = this_count >> 1; 320 } 321 } 322 if (sdp->sector_size == 2048) { 323 if ((block & 3) || (rq->nr_sectors & 3)) { 324 printk(KERN_ERR "sd: Bad block number requested"); 325 return 0; 326 } else { 327 block = block >> 2; 328 this_count = this_count >> 2; 329 } 330 } 331 if (sdp->sector_size == 4096) { 332 if ((block & 7) || (rq->nr_sectors & 7)) { 333 printk(KERN_ERR "sd: Bad block number requested"); 334 return 0; 335 } else { 336 block = block >> 3; 337 this_count = this_count >> 3; 338 } 339 } 340 if (rq_data_dir(rq) == WRITE) { 341 if (!sdp->writeable) { 342 return 0; 343 } 344 SCpnt->cmnd[0] = WRITE_6; 345 SCpnt->sc_data_direction = DMA_TO_DEVICE; 346 } else if (rq_data_dir(rq) == READ) { 347 SCpnt->cmnd[0] = READ_6; 348 SCpnt->sc_data_direction = DMA_FROM_DEVICE; 349 } else { 350 printk(KERN_ERR "sd: Unknown command %lx\n", rq->flags); 351 /* overkill panic("Unknown sd command %lx\n", rq->flags); */ 352 return 0; 353 } 354 355 SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n", 356 disk->disk_name, (rq_data_dir(rq) == WRITE) ? 357 "writing" : "reading", this_count, rq->nr_sectors)); 358 359 SCpnt->cmnd[1] = 0; 360 361 if (block > 0xffffffff) { 362 SCpnt->cmnd[0] += READ_16 - READ_6; 363 SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0; 364 SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0; 365 SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0; 366 SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0; 367 SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff; 368 SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff; 369 SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff; 370 SCpnt->cmnd[9] = (unsigned char) block & 0xff; 371 SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff; 372 SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff; 373 SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff; 374 SCpnt->cmnd[13] = (unsigned char) this_count & 0xff; 375 SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0; 376 } else if ((this_count > 0xff) || (block > 0x1fffff) || 377 SCpnt->device->use_10_for_rw) { 378 if (this_count > 0xffff) 379 this_count = 0xffff; 380 381 SCpnt->cmnd[0] += READ_10 - READ_6; 382 SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff; 383 SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff; 384 SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff; 385 SCpnt->cmnd[5] = (unsigned char) block & 0xff; 386 SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0; 387 SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff; 388 SCpnt->cmnd[8] = (unsigned char) this_count & 0xff; 389 } else { 390 SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f); 391 SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff); 392 SCpnt->cmnd[3] = (unsigned char) block & 0xff; 393 SCpnt->cmnd[4] = (unsigned char) this_count; 394 SCpnt->cmnd[5] = 0; 395 } 396 SCpnt->request_bufflen = SCpnt->bufflen = 397 this_count * sdp->sector_size; 398 399 /* 400 * We shouldn't disconnect in the middle of a sector, so with a dumb 401 * host adapter, it's safe to assume that we can at least transfer 402 * this many bytes between each connect / disconnect. 403 */ 404 SCpnt->transfersize = sdp->sector_size; 405 SCpnt->underflow = this_count << 9; 406 SCpnt->allowed = SD_MAX_RETRIES; 407 408 queue: 409 SCpnt->timeout_per_command = timeout; 410 411 /* 412 * This is the completion routine we use. This is matched in terms 413 * of capability to this function. 414 */ 415 SCpnt->done = sd_rw_intr; 416 417 /* 418 * This indicates that the command is ready from our end to be 419 * queued. 420 */ 421 return 1; 422 } 423 424 /** 425 * sd_open - open a scsi disk device 426 * @inode: only i_rdev member may be used 427 * @filp: only f_mode and f_flags may be used 428 * 429 * Returns 0 if successful. Returns a negated errno value in case 430 * of error. 431 * 432 * Note: This can be called from a user context (e.g. fsck(1) ) 433 * or from within the kernel (e.g. as a result of a mount(1) ). 434 * In the latter case @inode and @filp carry an abridged amount 435 * of information as noted above. 436 **/ 437 static int sd_open(struct inode *inode, struct file *filp) 438 { 439 struct gendisk *disk = inode->i_bdev->bd_disk; 440 struct scsi_disk *sdkp; 441 struct scsi_device *sdev; 442 int retval; 443 444 if (!(sdkp = scsi_disk_get(disk))) 445 return -ENXIO; 446 447 448 SCSI_LOG_HLQUEUE(3, printk("sd_open: disk=%s\n", disk->disk_name)); 449 450 sdev = sdkp->device; 451 452 /* 453 * If the device is in error recovery, wait until it is done. 454 * If the device is offline, then disallow any access to it. 455 */ 456 retval = -ENXIO; 457 if (!scsi_block_when_processing_errors(sdev)) 458 goto error_out; 459 460 if (sdev->removable || sdkp->write_prot) 461 check_disk_change(inode->i_bdev); 462 463 /* 464 * If the drive is empty, just let the open fail. 465 */ 466 retval = -ENOMEDIUM; 467 if (sdev->removable && !sdkp->media_present && 468 !(filp->f_flags & O_NDELAY)) 469 goto error_out; 470 471 /* 472 * If the device has the write protect tab set, have the open fail 473 * if the user expects to be able to write to the thing. 474 */ 475 retval = -EROFS; 476 if (sdkp->write_prot && (filp->f_mode & FMODE_WRITE)) 477 goto error_out; 478 479 /* 480 * It is possible that the disk changing stuff resulted in 481 * the device being taken offline. If this is the case, 482 * report this to the user, and don't pretend that the 483 * open actually succeeded. 484 */ 485 retval = -ENXIO; 486 if (!scsi_device_online(sdev)) 487 goto error_out; 488 489 if (!sdkp->openers++ && sdev->removable) { 490 if (scsi_block_when_processing_errors(sdev)) 491 scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT); 492 } 493 494 return 0; 495 496 error_out: 497 scsi_disk_put(sdkp); 498 return retval; 499 } 500 501 /** 502 * sd_release - invoked when the (last) close(2) is called on this 503 * scsi disk. 504 * @inode: only i_rdev member may be used 505 * @filp: only f_mode and f_flags may be used 506 * 507 * Returns 0. 508 * 509 * Note: may block (uninterruptible) if error recovery is underway 510 * on this disk. 511 **/ 512 static int sd_release(struct inode *inode, struct file *filp) 513 { 514 struct gendisk *disk = inode->i_bdev->bd_disk; 515 struct scsi_disk *sdkp = scsi_disk(disk); 516 struct scsi_device *sdev = sdkp->device; 517 518 SCSI_LOG_HLQUEUE(3, printk("sd_release: disk=%s\n", disk->disk_name)); 519 520 if (!--sdkp->openers && sdev->removable) { 521 if (scsi_block_when_processing_errors(sdev)) 522 scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW); 523 } 524 525 /* 526 * XXX and what if there are packets in flight and this close() 527 * XXX is followed by a "rmmod sd_mod"? 528 */ 529 scsi_disk_put(sdkp); 530 return 0; 531 } 532 533 static int sd_hdio_getgeo(struct block_device *bdev, struct hd_geometry __user *loc) 534 { 535 struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk); 536 struct scsi_device *sdp = sdkp->device; 537 struct Scsi_Host *host = sdp->host; 538 int diskinfo[4]; 539 540 /* default to most commonly used values */ 541 diskinfo[0] = 0x40; /* 1 << 6 */ 542 diskinfo[1] = 0x20; /* 1 << 5 */ 543 diskinfo[2] = sdkp->capacity >> 11; 544 545 /* override with calculated, extended default, or driver values */ 546 if (host->hostt->bios_param) 547 host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo); 548 else 549 scsicam_bios_param(bdev, sdkp->capacity, diskinfo); 550 551 if (put_user(diskinfo[0], &loc->heads)) 552 return -EFAULT; 553 if (put_user(diskinfo[1], &loc->sectors)) 554 return -EFAULT; 555 if (put_user(diskinfo[2], &loc->cylinders)) 556 return -EFAULT; 557 if (put_user((unsigned)get_start_sect(bdev), 558 (unsigned long __user *)&loc->start)) 559 return -EFAULT; 560 return 0; 561 } 562 563 /** 564 * sd_ioctl - process an ioctl 565 * @inode: only i_rdev/i_bdev members may be used 566 * @filp: only f_mode and f_flags may be used 567 * @cmd: ioctl command number 568 * @arg: this is third argument given to ioctl(2) system call. 569 * Often contains a pointer. 570 * 571 * Returns 0 if successful (some ioctls return postive numbers on 572 * success as well). Returns a negated errno value in case of error. 573 * 574 * Note: most ioctls are forward onto the block subsystem or further 575 * down in the scsi subsytem. 576 **/ 577 static int sd_ioctl(struct inode * inode, struct file * filp, 578 unsigned int cmd, unsigned long arg) 579 { 580 struct block_device *bdev = inode->i_bdev; 581 struct gendisk *disk = bdev->bd_disk; 582 struct scsi_device *sdp = scsi_disk(disk)->device; 583 void __user *p = (void __user *)arg; 584 int error; 585 586 SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n", 587 disk->disk_name, cmd)); 588 589 /* 590 * If we are in the middle of error recovery, don't let anyone 591 * else try and use this device. Also, if error recovery fails, it 592 * may try and take the device offline, in which case all further 593 * access to the device is prohibited. 594 */ 595 error = scsi_nonblockable_ioctl(sdp, cmd, p, filp); 596 if (!scsi_block_when_processing_errors(sdp) || !error) 597 return error; 598 599 if (cmd == HDIO_GETGEO) { 600 if (!arg) 601 return -EINVAL; 602 return sd_hdio_getgeo(bdev, p); 603 } 604 605 /* 606 * Send SCSI addressing ioctls directly to mid level, send other 607 * ioctls to block level and then onto mid level if they can't be 608 * resolved. 609 */ 610 switch (cmd) { 611 case SCSI_IOCTL_GET_IDLUN: 612 case SCSI_IOCTL_GET_BUS_NUMBER: 613 return scsi_ioctl(sdp, cmd, p); 614 default: 615 error = scsi_cmd_ioctl(filp, disk, cmd, p); 616 if (error != -ENOTTY) 617 return error; 618 } 619 return scsi_ioctl(sdp, cmd, p); 620 } 621 622 static void set_media_not_present(struct scsi_disk *sdkp) 623 { 624 sdkp->media_present = 0; 625 sdkp->capacity = 0; 626 sdkp->device->changed = 1; 627 } 628 629 /** 630 * sd_media_changed - check if our medium changed 631 * @disk: kernel device descriptor 632 * 633 * Returns 0 if not applicable or no change; 1 if change 634 * 635 * Note: this function is invoked from the block subsystem. 636 **/ 637 static int sd_media_changed(struct gendisk *disk) 638 { 639 struct scsi_disk *sdkp = scsi_disk(disk); 640 struct scsi_device *sdp = sdkp->device; 641 int retval; 642 643 SCSI_LOG_HLQUEUE(3, printk("sd_media_changed: disk=%s\n", 644 disk->disk_name)); 645 646 if (!sdp->removable) 647 return 0; 648 649 /* 650 * If the device is offline, don't send any commands - just pretend as 651 * if the command failed. If the device ever comes back online, we 652 * can deal with it then. It is only because of unrecoverable errors 653 * that we would ever take a device offline in the first place. 654 */ 655 if (!scsi_device_online(sdp)) 656 goto not_present; 657 658 /* 659 * Using TEST_UNIT_READY enables differentiation between drive with 660 * no cartridge loaded - NOT READY, drive with changed cartridge - 661 * UNIT ATTENTION, or with same cartridge - GOOD STATUS. 662 * 663 * Drives that auto spin down. eg iomega jaz 1G, will be started 664 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever 665 * sd_revalidate() is called. 666 */ 667 retval = -ENODEV; 668 if (scsi_block_when_processing_errors(sdp)) 669 retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES); 670 671 /* 672 * Unable to test, unit probably not ready. This usually 673 * means there is no disc in the drive. Mark as changed, 674 * and we will figure it out later once the drive is 675 * available again. 676 */ 677 if (retval) 678 goto not_present; 679 680 /* 681 * For removable scsi disk we have to recognise the presence 682 * of a disk in the drive. This is kept in the struct scsi_disk 683 * struct and tested at open ! Daniel Roche (dan@lectra.fr) 684 */ 685 sdkp->media_present = 1; 686 687 retval = sdp->changed; 688 sdp->changed = 0; 689 690 return retval; 691 692 not_present: 693 set_media_not_present(sdkp); 694 return 1; 695 } 696 697 static int sd_sync_cache(struct scsi_device *sdp) 698 { 699 int retries, res; 700 struct scsi_sense_hdr sshdr; 701 702 if (!scsi_device_online(sdp)) 703 return -ENODEV; 704 705 706 for (retries = 3; retries > 0; --retries) { 707 unsigned char cmd[10] = { 0 }; 708 709 cmd[0] = SYNCHRONIZE_CACHE; 710 /* 711 * Leave the rest of the command zero to indicate 712 * flush everything. 713 */ 714 res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr, 715 SD_TIMEOUT, SD_MAX_RETRIES); 716 if (res == 0) 717 break; 718 } 719 720 if (res) { printk(KERN_WARNING "FAILED\n status = %x, message = %02x, " 721 "host = %d, driver = %02x\n ", 722 status_byte(res), msg_byte(res), 723 host_byte(res), driver_byte(res)); 724 if (driver_byte(res) & DRIVER_SENSE) 725 scsi_print_sense_hdr("sd", &sshdr); 726 } 727 728 return res; 729 } 730 731 static int sd_issue_flush(struct device *dev, sector_t *error_sector) 732 { 733 int ret = 0; 734 struct scsi_device *sdp = to_scsi_device(dev); 735 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 736 737 if (!sdkp) 738 return -ENODEV; 739 740 if (sdkp->WCE) 741 ret = sd_sync_cache(sdp); 742 scsi_disk_put(sdkp); 743 return ret; 744 } 745 746 static void sd_end_flush(request_queue_t *q, struct request *flush_rq) 747 { 748 struct request *rq = flush_rq->end_io_data; 749 struct scsi_cmnd *cmd = rq->special; 750 unsigned int bytes = rq->hard_nr_sectors << 9; 751 752 if (!flush_rq->errors) { 753 spin_unlock(q->queue_lock); 754 scsi_io_completion(cmd, bytes, 0); 755 spin_lock(q->queue_lock); 756 } else if (blk_barrier_postflush(rq)) { 757 spin_unlock(q->queue_lock); 758 scsi_io_completion(cmd, 0, bytes); 759 spin_lock(q->queue_lock); 760 } else { 761 /* 762 * force journal abort of barriers 763 */ 764 end_that_request_first(rq, -EOPNOTSUPP, rq->hard_nr_sectors); 765 end_that_request_last(rq); 766 } 767 } 768 769 static int sd_prepare_flush(request_queue_t *q, struct request *rq) 770 { 771 struct scsi_device *sdev = q->queuedata; 772 struct scsi_disk *sdkp = scsi_disk_get_from_dev(&sdev->sdev_gendev); 773 int ret = 0; 774 775 if (sdkp) { 776 if (sdkp->WCE) { 777 memset(rq->cmd, 0, sizeof(rq->cmd)); 778 rq->flags |= REQ_BLOCK_PC | REQ_SOFTBARRIER; 779 rq->timeout = SD_TIMEOUT; 780 rq->cmd[0] = SYNCHRONIZE_CACHE; 781 ret = 1; 782 } 783 scsi_disk_put(sdkp); 784 } 785 return ret; 786 } 787 788 static void sd_rescan(struct device *dev) 789 { 790 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 791 792 if (sdkp) { 793 sd_revalidate_disk(sdkp->disk); 794 scsi_disk_put(sdkp); 795 } 796 } 797 798 799 #ifdef CONFIG_COMPAT 800 /* 801 * This gets directly called from VFS. When the ioctl 802 * is not recognized we go back to the other translation paths. 803 */ 804 static long sd_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 805 { 806 struct block_device *bdev = file->f_dentry->d_inode->i_bdev; 807 struct gendisk *disk = bdev->bd_disk; 808 struct scsi_device *sdev = scsi_disk(disk)->device; 809 810 /* 811 * If we are in the middle of error recovery, don't let anyone 812 * else try and use this device. Also, if error recovery fails, it 813 * may try and take the device offline, in which case all further 814 * access to the device is prohibited. 815 */ 816 if (!scsi_block_when_processing_errors(sdev)) 817 return -ENODEV; 818 819 if (sdev->host->hostt->compat_ioctl) { 820 int ret; 821 822 ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg); 823 824 return ret; 825 } 826 827 /* 828 * Let the static ioctl translation table take care of it. 829 */ 830 return -ENOIOCTLCMD; 831 } 832 #endif 833 834 static struct block_device_operations sd_fops = { 835 .owner = THIS_MODULE, 836 .open = sd_open, 837 .release = sd_release, 838 .ioctl = sd_ioctl, 839 #ifdef CONFIG_COMPAT 840 .compat_ioctl = sd_compat_ioctl, 841 #endif 842 .media_changed = sd_media_changed, 843 .revalidate_disk = sd_revalidate_disk, 844 }; 845 846 /** 847 * sd_rw_intr - bottom half handler: called when the lower level 848 * driver has completed (successfully or otherwise) a scsi command. 849 * @SCpnt: mid-level's per command structure. 850 * 851 * Note: potentially run from within an ISR. Must not block. 852 **/ 853 static void sd_rw_intr(struct scsi_cmnd * SCpnt) 854 { 855 int result = SCpnt->result; 856 int this_count = SCpnt->bufflen; 857 int good_bytes = (result == 0 ? this_count : 0); 858 sector_t block_sectors = 1; 859 u64 first_err_block; 860 sector_t error_sector; 861 struct scsi_sense_hdr sshdr; 862 int sense_valid = 0; 863 int sense_deferred = 0; 864 int info_valid; 865 866 if (result) { 867 sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr); 868 if (sense_valid) 869 sense_deferred = scsi_sense_is_deferred(&sshdr); 870 } 871 872 #ifdef CONFIG_SCSI_LOGGING 873 SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n", 874 SCpnt->request->rq_disk->disk_name, result)); 875 if (sense_valid) { 876 SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: sb[respc,sk,asc," 877 "ascq]=%x,%x,%x,%x\n", sshdr.response_code, 878 sshdr.sense_key, sshdr.asc, sshdr.ascq)); 879 } 880 #endif 881 /* 882 Handle MEDIUM ERRORs that indicate partial success. Since this is a 883 relatively rare error condition, no care is taken to avoid 884 unnecessary additional work such as memcpy's that could be avoided. 885 */ 886 887 /* 888 * If SG_IO from block layer then set good_bytes to stop retries; 889 * else if errors, check them, and if necessary prepare for 890 * (partial) retries. 891 */ 892 if (blk_pc_request(SCpnt->request)) 893 good_bytes = this_count; 894 else if (driver_byte(result) != 0 && 895 sense_valid && !sense_deferred) { 896 switch (sshdr.sense_key) { 897 case MEDIUM_ERROR: 898 if (!blk_fs_request(SCpnt->request)) 899 break; 900 info_valid = scsi_get_sense_info_fld( 901 SCpnt->sense_buffer, SCSI_SENSE_BUFFERSIZE, 902 &first_err_block); 903 /* 904 * May want to warn and skip if following cast results 905 * in actual truncation (if sector_t < 64 bits) 906 */ 907 error_sector = (sector_t)first_err_block; 908 if (SCpnt->request->bio != NULL) 909 block_sectors = bio_sectors(SCpnt->request->bio); 910 switch (SCpnt->device->sector_size) { 911 case 1024: 912 error_sector <<= 1; 913 if (block_sectors < 2) 914 block_sectors = 2; 915 break; 916 case 2048: 917 error_sector <<= 2; 918 if (block_sectors < 4) 919 block_sectors = 4; 920 break; 921 case 4096: 922 error_sector <<=3; 923 if (block_sectors < 8) 924 block_sectors = 8; 925 break; 926 case 256: 927 error_sector >>= 1; 928 break; 929 default: 930 break; 931 } 932 933 error_sector &= ~(block_sectors - 1); 934 good_bytes = (error_sector - SCpnt->request->sector) << 9; 935 if (good_bytes < 0 || good_bytes >= this_count) 936 good_bytes = 0; 937 break; 938 939 case RECOVERED_ERROR: /* an error occurred, but it recovered */ 940 case NO_SENSE: /* LLDD got sense data */ 941 /* 942 * Inform the user, but make sure that it's not treated 943 * as a hard error. 944 */ 945 scsi_print_sense("sd", SCpnt); 946 SCpnt->result = 0; 947 memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); 948 good_bytes = this_count; 949 break; 950 951 case ILLEGAL_REQUEST: 952 if (SCpnt->device->use_10_for_rw && 953 (SCpnt->cmnd[0] == READ_10 || 954 SCpnt->cmnd[0] == WRITE_10)) 955 SCpnt->device->use_10_for_rw = 0; 956 if (SCpnt->device->use_10_for_ms && 957 (SCpnt->cmnd[0] == MODE_SENSE_10 || 958 SCpnt->cmnd[0] == MODE_SELECT_10)) 959 SCpnt->device->use_10_for_ms = 0; 960 break; 961 962 default: 963 break; 964 } 965 } 966 /* 967 * This calls the generic completion function, now that we know 968 * how many actual sectors finished, and how many sectors we need 969 * to say have failed. 970 */ 971 scsi_io_completion(SCpnt, good_bytes, block_sectors << 9); 972 } 973 974 static int media_not_present(struct scsi_disk *sdkp, 975 struct scsi_sense_hdr *sshdr) 976 { 977 978 if (!scsi_sense_valid(sshdr)) 979 return 0; 980 /* not invoked for commands that could return deferred errors */ 981 if (sshdr->sense_key != NOT_READY && 982 sshdr->sense_key != UNIT_ATTENTION) 983 return 0; 984 if (sshdr->asc != 0x3A) /* medium not present */ 985 return 0; 986 987 set_media_not_present(sdkp); 988 return 1; 989 } 990 991 /* 992 * spinup disk - called only in sd_revalidate_disk() 993 */ 994 static void 995 sd_spinup_disk(struct scsi_disk *sdkp, char *diskname) 996 { 997 unsigned char cmd[10]; 998 unsigned long spintime_expire = 0; 999 int retries, spintime; 1000 unsigned int the_result; 1001 struct scsi_sense_hdr sshdr; 1002 int sense_valid = 0; 1003 1004 spintime = 0; 1005 1006 /* Spin up drives, as required. Only do this at boot time */ 1007 /* Spinup needs to be done for module loads too. */ 1008 do { 1009 retries = 0; 1010 1011 do { 1012 cmd[0] = TEST_UNIT_READY; 1013 memset((void *) &cmd[1], 0, 9); 1014 1015 the_result = scsi_execute_req(sdkp->device, cmd, 1016 DMA_NONE, NULL, 0, 1017 &sshdr, SD_TIMEOUT, 1018 SD_MAX_RETRIES); 1019 1020 if (the_result) 1021 sense_valid = scsi_sense_valid(&sshdr); 1022 retries++; 1023 } while (retries < 3 && 1024 (!scsi_status_is_good(the_result) || 1025 ((driver_byte(the_result) & DRIVER_SENSE) && 1026 sense_valid && sshdr.sense_key == UNIT_ATTENTION))); 1027 1028 /* 1029 * If the drive has indicated to us that it doesn't have 1030 * any media in it, don't bother with any of the rest of 1031 * this crap. 1032 */ 1033 if (media_not_present(sdkp, &sshdr)) 1034 return; 1035 1036 if ((driver_byte(the_result) & DRIVER_SENSE) == 0) { 1037 /* no sense, TUR either succeeded or failed 1038 * with a status error */ 1039 if(!spintime && !scsi_status_is_good(the_result)) 1040 printk(KERN_NOTICE "%s: Unit Not Ready, " 1041 "error = 0x%x\n", diskname, the_result); 1042 break; 1043 } 1044 1045 /* 1046 * The device does not want the automatic start to be issued. 1047 */ 1048 if (sdkp->device->no_start_on_add) { 1049 break; 1050 } 1051 1052 /* 1053 * If manual intervention is required, or this is an 1054 * absent USB storage device, a spinup is meaningless. 1055 */ 1056 if (sense_valid && 1057 sshdr.sense_key == NOT_READY && 1058 sshdr.asc == 4 && sshdr.ascq == 3) { 1059 break; /* manual intervention required */ 1060 1061 /* 1062 * Issue command to spin up drive when not ready 1063 */ 1064 } else if (sense_valid && sshdr.sense_key == NOT_READY) { 1065 if (!spintime) { 1066 printk(KERN_NOTICE "%s: Spinning up disk...", 1067 diskname); 1068 cmd[0] = START_STOP; 1069 cmd[1] = 1; /* Return immediately */ 1070 memset((void *) &cmd[2], 0, 8); 1071 cmd[4] = 1; /* Start spin cycle */ 1072 scsi_execute_req(sdkp->device, cmd, DMA_NONE, 1073 NULL, 0, &sshdr, 1074 SD_TIMEOUT, SD_MAX_RETRIES); 1075 spintime_expire = jiffies + 100 * HZ; 1076 spintime = 1; 1077 } 1078 /* Wait 1 second for next try */ 1079 msleep(1000); 1080 printk("."); 1081 1082 /* 1083 * Wait for USB flash devices with slow firmware. 1084 * Yes, this sense key/ASC combination shouldn't 1085 * occur here. It's characteristic of these devices. 1086 */ 1087 } else if (sense_valid && 1088 sshdr.sense_key == UNIT_ATTENTION && 1089 sshdr.asc == 0x28) { 1090 if (!spintime) { 1091 spintime_expire = jiffies + 5 * HZ; 1092 spintime = 1; 1093 } 1094 /* Wait 1 second for next try */ 1095 msleep(1000); 1096 } else { 1097 /* we don't understand the sense code, so it's 1098 * probably pointless to loop */ 1099 if(!spintime) { 1100 printk(KERN_NOTICE "%s: Unit Not Ready, " 1101 "sense:\n", diskname); 1102 scsi_print_sense_hdr("", &sshdr); 1103 } 1104 break; 1105 } 1106 1107 } while (spintime && time_before_eq(jiffies, spintime_expire)); 1108 1109 if (spintime) { 1110 if (scsi_status_is_good(the_result)) 1111 printk("ready\n"); 1112 else 1113 printk("not responding...\n"); 1114 } 1115 } 1116 1117 /* 1118 * read disk capacity 1119 */ 1120 static void 1121 sd_read_capacity(struct scsi_disk *sdkp, char *diskname, 1122 unsigned char *buffer) 1123 { 1124 unsigned char cmd[16]; 1125 int the_result, retries; 1126 int sector_size = 0; 1127 int longrc = 0; 1128 struct scsi_sense_hdr sshdr; 1129 int sense_valid = 0; 1130 struct scsi_device *sdp = sdkp->device; 1131 1132 repeat: 1133 retries = 3; 1134 do { 1135 if (longrc) { 1136 memset((void *) cmd, 0, 16); 1137 cmd[0] = SERVICE_ACTION_IN; 1138 cmd[1] = SAI_READ_CAPACITY_16; 1139 cmd[13] = 12; 1140 memset((void *) buffer, 0, 12); 1141 } else { 1142 cmd[0] = READ_CAPACITY; 1143 memset((void *) &cmd[1], 0, 9); 1144 memset((void *) buffer, 0, 8); 1145 } 1146 1147 the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE, 1148 buffer, longrc ? 12 : 8, &sshdr, 1149 SD_TIMEOUT, SD_MAX_RETRIES); 1150 1151 if (media_not_present(sdkp, &sshdr)) 1152 return; 1153 1154 if (the_result) 1155 sense_valid = scsi_sense_valid(&sshdr); 1156 retries--; 1157 1158 } while (the_result && retries); 1159 1160 if (the_result && !longrc) { 1161 printk(KERN_NOTICE "%s : READ CAPACITY failed.\n" 1162 "%s : status=%x, message=%02x, host=%d, driver=%02x \n", 1163 diskname, diskname, 1164 status_byte(the_result), 1165 msg_byte(the_result), 1166 host_byte(the_result), 1167 driver_byte(the_result)); 1168 1169 if (driver_byte(the_result) & DRIVER_SENSE) 1170 scsi_print_sense_hdr("sd", &sshdr); 1171 else 1172 printk("%s : sense not available. \n", diskname); 1173 1174 /* Set dirty bit for removable devices if not ready - 1175 * sometimes drives will not report this properly. */ 1176 if (sdp->removable && 1177 sense_valid && sshdr.sense_key == NOT_READY) 1178 sdp->changed = 1; 1179 1180 /* Either no media are present but the drive didn't tell us, 1181 or they are present but the read capacity command fails */ 1182 /* sdkp->media_present = 0; -- not always correct */ 1183 sdkp->capacity = 0x200000; /* 1 GB - random */ 1184 1185 return; 1186 } else if (the_result && longrc) { 1187 /* READ CAPACITY(16) has been failed */ 1188 printk(KERN_NOTICE "%s : READ CAPACITY(16) failed.\n" 1189 "%s : status=%x, message=%02x, host=%d, driver=%02x \n", 1190 diskname, diskname, 1191 status_byte(the_result), 1192 msg_byte(the_result), 1193 host_byte(the_result), 1194 driver_byte(the_result)); 1195 printk(KERN_NOTICE "%s : use 0xffffffff as device size\n", 1196 diskname); 1197 1198 sdkp->capacity = 1 + (sector_t) 0xffffffff; 1199 goto got_data; 1200 } 1201 1202 if (!longrc) { 1203 sector_size = (buffer[4] << 24) | 1204 (buffer[5] << 16) | (buffer[6] << 8) | buffer[7]; 1205 if (buffer[0] == 0xff && buffer[1] == 0xff && 1206 buffer[2] == 0xff && buffer[3] == 0xff) { 1207 if(sizeof(sdkp->capacity) > 4) { 1208 printk(KERN_NOTICE "%s : very big device. try to use" 1209 " READ CAPACITY(16).\n", diskname); 1210 longrc = 1; 1211 goto repeat; 1212 } 1213 printk(KERN_ERR "%s: too big for this kernel. Use a " 1214 "kernel compiled with support for large block " 1215 "devices.\n", diskname); 1216 sdkp->capacity = 0; 1217 goto got_data; 1218 } 1219 sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) | 1220 (buffer[1] << 16) | 1221 (buffer[2] << 8) | 1222 buffer[3]); 1223 } else { 1224 sdkp->capacity = 1 + (((u64)buffer[0] << 56) | 1225 ((u64)buffer[1] << 48) | 1226 ((u64)buffer[2] << 40) | 1227 ((u64)buffer[3] << 32) | 1228 ((sector_t)buffer[4] << 24) | 1229 ((sector_t)buffer[5] << 16) | 1230 ((sector_t)buffer[6] << 8) | 1231 (sector_t)buffer[7]); 1232 1233 sector_size = (buffer[8] << 24) | 1234 (buffer[9] << 16) | (buffer[10] << 8) | buffer[11]; 1235 } 1236 1237 /* Some devices return the total number of sectors, not the 1238 * highest sector number. Make the necessary adjustment. */ 1239 if (sdp->fix_capacity) 1240 --sdkp->capacity; 1241 1242 got_data: 1243 if (sector_size == 0) { 1244 sector_size = 512; 1245 printk(KERN_NOTICE "%s : sector size 0 reported, " 1246 "assuming 512.\n", diskname); 1247 } 1248 1249 if (sector_size != 512 && 1250 sector_size != 1024 && 1251 sector_size != 2048 && 1252 sector_size != 4096 && 1253 sector_size != 256) { 1254 printk(KERN_NOTICE "%s : unsupported sector size " 1255 "%d.\n", diskname, sector_size); 1256 /* 1257 * The user might want to re-format the drive with 1258 * a supported sectorsize. Once this happens, it 1259 * would be relatively trivial to set the thing up. 1260 * For this reason, we leave the thing in the table. 1261 */ 1262 sdkp->capacity = 0; 1263 /* 1264 * set a bogus sector size so the normal read/write 1265 * logic in the block layer will eventually refuse any 1266 * request on this device without tripping over power 1267 * of two sector size assumptions 1268 */ 1269 sector_size = 512; 1270 } 1271 { 1272 /* 1273 * The msdos fs needs to know the hardware sector size 1274 * So I have created this table. See ll_rw_blk.c 1275 * Jacques Gelinas (Jacques@solucorp.qc.ca) 1276 */ 1277 int hard_sector = sector_size; 1278 sector_t sz = (sdkp->capacity/2) * (hard_sector/256); 1279 request_queue_t *queue = sdp->request_queue; 1280 sector_t mb = sz; 1281 1282 blk_queue_hardsect_size(queue, hard_sector); 1283 /* avoid 64-bit division on 32-bit platforms */ 1284 sector_div(sz, 625); 1285 mb -= sz - 974; 1286 sector_div(mb, 1950); 1287 1288 printk(KERN_NOTICE "SCSI device %s: " 1289 "%llu %d-byte hdwr sectors (%llu MB)\n", 1290 diskname, (unsigned long long)sdkp->capacity, 1291 hard_sector, (unsigned long long)mb); 1292 } 1293 1294 /* Rescale capacity to 512-byte units */ 1295 if (sector_size == 4096) 1296 sdkp->capacity <<= 3; 1297 else if (sector_size == 2048) 1298 sdkp->capacity <<= 2; 1299 else if (sector_size == 1024) 1300 sdkp->capacity <<= 1; 1301 else if (sector_size == 256) 1302 sdkp->capacity >>= 1; 1303 1304 sdkp->device->sector_size = sector_size; 1305 } 1306 1307 /* called with buffer of length 512 */ 1308 static inline int 1309 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage, 1310 unsigned char *buffer, int len, struct scsi_mode_data *data, 1311 struct scsi_sense_hdr *sshdr) 1312 { 1313 return scsi_mode_sense(sdp, dbd, modepage, buffer, len, 1314 SD_TIMEOUT, SD_MAX_RETRIES, data, 1315 sshdr); 1316 } 1317 1318 /* 1319 * read write protect setting, if possible - called only in sd_revalidate_disk() 1320 * called with buffer of length 512 1321 */ 1322 static void 1323 sd_read_write_protect_flag(struct scsi_disk *sdkp, char *diskname, 1324 unsigned char *buffer) 1325 { 1326 int res; 1327 struct scsi_device *sdp = sdkp->device; 1328 struct scsi_mode_data data; 1329 1330 set_disk_ro(sdkp->disk, 0); 1331 if (sdp->skip_ms_page_3f) { 1332 printk(KERN_NOTICE "%s: assuming Write Enabled\n", diskname); 1333 return; 1334 } 1335 1336 if (sdp->use_192_bytes_for_3f) { 1337 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL); 1338 } else { 1339 /* 1340 * First attempt: ask for all pages (0x3F), but only 4 bytes. 1341 * We have to start carefully: some devices hang if we ask 1342 * for more than is available. 1343 */ 1344 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL); 1345 1346 /* 1347 * Second attempt: ask for page 0 When only page 0 is 1348 * implemented, a request for page 3F may return Sense Key 1349 * 5: Illegal Request, Sense Code 24: Invalid field in 1350 * CDB. 1351 */ 1352 if (!scsi_status_is_good(res)) 1353 res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL); 1354 1355 /* 1356 * Third attempt: ask 255 bytes, as we did earlier. 1357 */ 1358 if (!scsi_status_is_good(res)) 1359 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255, 1360 &data, NULL); 1361 } 1362 1363 if (!scsi_status_is_good(res)) { 1364 printk(KERN_WARNING 1365 "%s: test WP failed, assume Write Enabled\n", diskname); 1366 } else { 1367 sdkp->write_prot = ((data.device_specific & 0x80) != 0); 1368 set_disk_ro(sdkp->disk, sdkp->write_prot); 1369 printk(KERN_NOTICE "%s: Write Protect is %s\n", diskname, 1370 sdkp->write_prot ? "on" : "off"); 1371 printk(KERN_DEBUG "%s: Mode Sense: %02x %02x %02x %02x\n", 1372 diskname, buffer[0], buffer[1], buffer[2], buffer[3]); 1373 } 1374 } 1375 1376 /* 1377 * sd_read_cache_type - called only from sd_revalidate_disk() 1378 * called with buffer of length 512 1379 */ 1380 static void 1381 sd_read_cache_type(struct scsi_disk *sdkp, char *diskname, 1382 unsigned char *buffer) 1383 { 1384 int len = 0, res; 1385 struct scsi_device *sdp = sdkp->device; 1386 1387 int dbd; 1388 int modepage; 1389 struct scsi_mode_data data; 1390 struct scsi_sense_hdr sshdr; 1391 1392 if (sdp->skip_ms_page_8) 1393 goto defaults; 1394 1395 if (sdp->type == TYPE_RBC) { 1396 modepage = 6; 1397 dbd = 8; 1398 } else { 1399 modepage = 8; 1400 dbd = 0; 1401 } 1402 1403 /* cautiously ask */ 1404 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr); 1405 1406 if (!scsi_status_is_good(res)) 1407 goto bad_sense; 1408 1409 /* that went OK, now ask for the proper length */ 1410 len = data.length; 1411 1412 /* 1413 * We're only interested in the first three bytes, actually. 1414 * But the data cache page is defined for the first 20. 1415 */ 1416 if (len < 3) 1417 goto bad_sense; 1418 if (len > 20) 1419 len = 20; 1420 1421 /* Take headers and block descriptors into account */ 1422 len += data.header_length + data.block_descriptor_length; 1423 1424 /* Get the data */ 1425 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr); 1426 1427 if (scsi_status_is_good(res)) { 1428 const char *types[] = { 1429 "write through", "none", "write back", 1430 "write back, no read (daft)" 1431 }; 1432 int ct = 0; 1433 int offset = data.header_length + data.block_descriptor_length; 1434 1435 if ((buffer[offset] & 0x3f) != modepage) { 1436 printk(KERN_ERR "%s: got wrong page\n", diskname); 1437 goto defaults; 1438 } 1439 1440 if (modepage == 8) { 1441 sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0); 1442 sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0); 1443 } else { 1444 sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0); 1445 sdkp->RCD = 0; 1446 } 1447 1448 ct = sdkp->RCD + 2*sdkp->WCE; 1449 1450 printk(KERN_NOTICE "SCSI device %s: drive cache: %s\n", 1451 diskname, types[ct]); 1452 1453 return; 1454 } 1455 1456 bad_sense: 1457 if (scsi_sense_valid(&sshdr) && 1458 sshdr.sense_key == ILLEGAL_REQUEST && 1459 sshdr.asc == 0x24 && sshdr.ascq == 0x0) 1460 printk(KERN_NOTICE "%s: cache data unavailable\n", 1461 diskname); /* Invalid field in CDB */ 1462 else 1463 printk(KERN_ERR "%s: asking for cache data failed\n", 1464 diskname); 1465 1466 defaults: 1467 printk(KERN_ERR "%s: assuming drive cache: write through\n", 1468 diskname); 1469 sdkp->WCE = 0; 1470 sdkp->RCD = 0; 1471 } 1472 1473 /** 1474 * sd_revalidate_disk - called the first time a new disk is seen, 1475 * performs disk spin up, read_capacity, etc. 1476 * @disk: struct gendisk we care about 1477 **/ 1478 static int sd_revalidate_disk(struct gendisk *disk) 1479 { 1480 struct scsi_disk *sdkp = scsi_disk(disk); 1481 struct scsi_device *sdp = sdkp->device; 1482 unsigned char *buffer; 1483 1484 SCSI_LOG_HLQUEUE(3, printk("sd_revalidate_disk: disk=%s\n", disk->disk_name)); 1485 1486 /* 1487 * If the device is offline, don't try and read capacity or any 1488 * of the other niceties. 1489 */ 1490 if (!scsi_device_online(sdp)) 1491 goto out; 1492 1493 buffer = kmalloc(512, GFP_KERNEL | __GFP_DMA); 1494 if (!buffer) { 1495 printk(KERN_WARNING "(sd_revalidate_disk:) Memory allocation " 1496 "failure.\n"); 1497 goto out; 1498 } 1499 1500 /* defaults, until the device tells us otherwise */ 1501 sdp->sector_size = 512; 1502 sdkp->capacity = 0; 1503 sdkp->media_present = 1; 1504 sdkp->write_prot = 0; 1505 sdkp->WCE = 0; 1506 sdkp->RCD = 0; 1507 1508 sd_spinup_disk(sdkp, disk->disk_name); 1509 1510 /* 1511 * Without media there is no reason to ask; moreover, some devices 1512 * react badly if we do. 1513 */ 1514 if (sdkp->media_present) { 1515 sd_read_capacity(sdkp, disk->disk_name, buffer); 1516 if (sdp->removable) 1517 sd_read_write_protect_flag(sdkp, disk->disk_name, 1518 buffer); 1519 sd_read_cache_type(sdkp, disk->disk_name, buffer); 1520 } 1521 1522 set_capacity(disk, sdkp->capacity); 1523 kfree(buffer); 1524 1525 out: 1526 return 0; 1527 } 1528 1529 /** 1530 * sd_probe - called during driver initialization and whenever a 1531 * new scsi device is attached to the system. It is called once 1532 * for each scsi device (not just disks) present. 1533 * @dev: pointer to device object 1534 * 1535 * Returns 0 if successful (or not interested in this scsi device 1536 * (e.g. scanner)); 1 when there is an error. 1537 * 1538 * Note: this function is invoked from the scsi mid-level. 1539 * This function sets up the mapping between a given 1540 * <host,channel,id,lun> (found in sdp) and new device name 1541 * (e.g. /dev/sda). More precisely it is the block device major 1542 * and minor number that is chosen here. 1543 * 1544 * Assume sd_attach is not re-entrant (for time being) 1545 * Also think about sd_attach() and sd_remove() running coincidentally. 1546 **/ 1547 static int sd_probe(struct device *dev) 1548 { 1549 struct scsi_device *sdp = to_scsi_device(dev); 1550 struct scsi_disk *sdkp; 1551 struct gendisk *gd; 1552 u32 index; 1553 int error; 1554 1555 error = -ENODEV; 1556 if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC) 1557 goto out; 1558 1559 SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp, 1560 "sd_attach\n")); 1561 1562 error = -ENOMEM; 1563 sdkp = kmalloc(sizeof(*sdkp), GFP_KERNEL); 1564 if (!sdkp) 1565 goto out; 1566 1567 memset (sdkp, 0, sizeof(*sdkp)); 1568 kref_init(&sdkp->kref); 1569 1570 gd = alloc_disk(16); 1571 if (!gd) 1572 goto out_free; 1573 1574 if (!idr_pre_get(&sd_index_idr, GFP_KERNEL)) 1575 goto out_put; 1576 1577 spin_lock(&sd_index_lock); 1578 error = idr_get_new(&sd_index_idr, NULL, &index); 1579 spin_unlock(&sd_index_lock); 1580 1581 if (index >= SD_MAX_DISKS) 1582 error = -EBUSY; 1583 if (error) 1584 goto out_put; 1585 1586 get_device(&sdp->sdev_gendev); 1587 sdkp->device = sdp; 1588 sdkp->driver = &sd_template; 1589 sdkp->disk = gd; 1590 sdkp->index = index; 1591 sdkp->openers = 0; 1592 1593 if (!sdp->timeout) { 1594 if (sdp->type != TYPE_MOD) 1595 sdp->timeout = SD_TIMEOUT; 1596 else 1597 sdp->timeout = SD_MOD_TIMEOUT; 1598 } 1599 1600 gd->major = sd_major((index & 0xf0) >> 4); 1601 gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00); 1602 gd->minors = 16; 1603 gd->fops = &sd_fops; 1604 1605 if (index < 26) { 1606 sprintf(gd->disk_name, "sd%c", 'a' + index % 26); 1607 } else if (index < (26 + 1) * 26) { 1608 sprintf(gd->disk_name, "sd%c%c", 1609 'a' + index / 26 - 1,'a' + index % 26); 1610 } else { 1611 const unsigned int m1 = (index / 26 - 1) / 26 - 1; 1612 const unsigned int m2 = (index / 26 - 1) % 26; 1613 const unsigned int m3 = index % 26; 1614 sprintf(gd->disk_name, "sd%c%c%c", 1615 'a' + m1, 'a' + m2, 'a' + m3); 1616 } 1617 1618 strcpy(gd->devfs_name, sdp->devfs_name); 1619 1620 gd->private_data = &sdkp->driver; 1621 1622 sd_revalidate_disk(gd); 1623 1624 gd->driverfs_dev = &sdp->sdev_gendev; 1625 gd->flags = GENHD_FL_DRIVERFS; 1626 if (sdp->removable) 1627 gd->flags |= GENHD_FL_REMOVABLE; 1628 gd->queue = sdkp->device->request_queue; 1629 1630 dev_set_drvdata(dev, sdkp); 1631 add_disk(gd); 1632 1633 sdev_printk(KERN_NOTICE, sdp, "Attached scsi %sdisk %s\n", 1634 sdp->removable ? "removable " : "", gd->disk_name); 1635 1636 return 0; 1637 1638 out_put: 1639 put_disk(gd); 1640 out_free: 1641 kfree(sdkp); 1642 out: 1643 return error; 1644 } 1645 1646 /** 1647 * sd_remove - called whenever a scsi disk (previously recognized by 1648 * sd_probe) is detached from the system. It is called (potentially 1649 * multiple times) during sd module unload. 1650 * @sdp: pointer to mid level scsi device object 1651 * 1652 * Note: this function is invoked from the scsi mid-level. 1653 * This function potentially frees up a device name (e.g. /dev/sdc) 1654 * that could be re-used by a subsequent sd_probe(). 1655 * This function is not called when the built-in sd driver is "exit-ed". 1656 **/ 1657 static int sd_remove(struct device *dev) 1658 { 1659 struct scsi_disk *sdkp = dev_get_drvdata(dev); 1660 1661 del_gendisk(sdkp->disk); 1662 sd_shutdown(dev); 1663 1664 down(&sd_ref_sem); 1665 dev_set_drvdata(dev, NULL); 1666 kref_put(&sdkp->kref, scsi_disk_release); 1667 up(&sd_ref_sem); 1668 1669 return 0; 1670 } 1671 1672 /** 1673 * scsi_disk_release - Called to free the scsi_disk structure 1674 * @kref: pointer to embedded kref 1675 * 1676 * sd_ref_sem must be held entering this routine. Because it is 1677 * called on last put, you should always use the scsi_disk_get() 1678 * scsi_disk_put() helpers which manipulate the semaphore directly 1679 * and never do a direct kref_put(). 1680 **/ 1681 static void scsi_disk_release(struct kref *kref) 1682 { 1683 struct scsi_disk *sdkp = to_scsi_disk(kref); 1684 struct gendisk *disk = sdkp->disk; 1685 1686 spin_lock(&sd_index_lock); 1687 idr_remove(&sd_index_idr, sdkp->index); 1688 spin_unlock(&sd_index_lock); 1689 1690 disk->private_data = NULL; 1691 put_disk(disk); 1692 put_device(&sdkp->device->sdev_gendev); 1693 1694 kfree(sdkp); 1695 } 1696 1697 /* 1698 * Send a SYNCHRONIZE CACHE instruction down to the device through 1699 * the normal SCSI command structure. Wait for the command to 1700 * complete. 1701 */ 1702 static void sd_shutdown(struct device *dev) 1703 { 1704 struct scsi_device *sdp = to_scsi_device(dev); 1705 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev); 1706 1707 if (!sdkp) 1708 return; /* this can happen */ 1709 1710 if (sdkp->WCE) { 1711 printk(KERN_NOTICE "Synchronizing SCSI cache for disk %s: \n", 1712 sdkp->disk->disk_name); 1713 sd_sync_cache(sdp); 1714 } 1715 scsi_disk_put(sdkp); 1716 } 1717 1718 /** 1719 * init_sd - entry point for this driver (both when built in or when 1720 * a module). 1721 * 1722 * Note: this function registers this driver with the scsi mid-level. 1723 **/ 1724 static int __init init_sd(void) 1725 { 1726 int majors = 0, i; 1727 1728 SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n")); 1729 1730 for (i = 0; i < SD_MAJORS; i++) 1731 if (register_blkdev(sd_major(i), "sd") == 0) 1732 majors++; 1733 1734 if (!majors) 1735 return -ENODEV; 1736 1737 return scsi_register_driver(&sd_template.gendrv); 1738 } 1739 1740 /** 1741 * exit_sd - exit point for this driver (when it is a module). 1742 * 1743 * Note: this function unregisters this driver from the scsi mid-level. 1744 **/ 1745 static void __exit exit_sd(void) 1746 { 1747 int i; 1748 1749 SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n")); 1750 1751 scsi_unregister_driver(&sd_template.gendrv); 1752 for (i = 0; i < SD_MAJORS; i++) 1753 unregister_blkdev(sd_major(i), "sd"); 1754 } 1755 1756 MODULE_LICENSE("GPL"); 1757 MODULE_AUTHOR("Eric Youngdale"); 1758 MODULE_DESCRIPTION("SCSI disk (sd) driver"); 1759 1760 module_init(init_sd); 1761 module_exit(exit_sd); 1762