xref: /linux/drivers/scsi/sd.c (revision f8324e20f8289dffc646d64366332e05eaacab25)
1 /*
2  *      sd.c Copyright (C) 1992 Drew Eckhardt
3  *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4  *
5  *      Linux scsi disk driver
6  *              Initial versions: Drew Eckhardt
7  *              Subsequent revisions: Eric Youngdale
8  *	Modification history:
9  *       - Drew Eckhardt <drew@colorado.edu> original
10  *       - Eric Youngdale <eric@andante.org> add scatter-gather, multiple
11  *         outstanding request, and other enhancements.
12  *         Support loadable low-level scsi drivers.
13  *       - Jirka Hanika <geo@ff.cuni.cz> support more scsi disks using
14  *         eight major numbers.
15  *       - Richard Gooch <rgooch@atnf.csiro.au> support devfs.
16  *	 - Torben Mathiasen <tmm@image.dk> Resource allocation fixes in
17  *	   sd_init and cleanups.
18  *	 - Alex Davis <letmein@erols.com> Fix problem where partition info
19  *	   not being read in sd_open. Fix problem where removable media
20  *	   could be ejected after sd_open.
21  *	 - Douglas Gilbert <dgilbert@interlog.com> cleanup for lk 2.5.x
22  *	 - Badari Pulavarty <pbadari@us.ibm.com>, Matthew Wilcox
23  *	   <willy@debian.org>, Kurt Garloff <garloff@suse.de>:
24  *	   Support 32k/1M disks.
25  *
26  *	Logging policy (needs CONFIG_SCSI_LOGGING defined):
27  *	 - setting up transfer: SCSI_LOG_HLQUEUE levels 1 and 2
28  *	 - end of transfer (bh + scsi_lib): SCSI_LOG_HLCOMPLETE level 1
29  *	 - entering sd_ioctl: SCSI_LOG_IOCTL level 1
30  *	 - entering other commands: SCSI_LOG_HLQUEUE level 3
31  *	Note: when the logging level is set by the user, it must be greater
32  *	than the level indicated above to trigger output.
33  */
34 
35 #include <linux/module.h>
36 #include <linux/fs.h>
37 #include <linux/kernel.h>
38 #include <linux/mm.h>
39 #include <linux/bio.h>
40 #include <linux/genhd.h>
41 #include <linux/hdreg.h>
42 #include <linux/errno.h>
43 #include <linux/idr.h>
44 #include <linux/interrupt.h>
45 #include <linux/init.h>
46 #include <linux/blkdev.h>
47 #include <linux/blkpg.h>
48 #include <linux/delay.h>
49 #include <linux/mutex.h>
50 #include <linux/string_helpers.h>
51 #include <linux/async.h>
52 #include <linux/slab.h>
53 #include <asm/uaccess.h>
54 #include <asm/unaligned.h>
55 
56 #include <scsi/scsi.h>
57 #include <scsi/scsi_cmnd.h>
58 #include <scsi/scsi_dbg.h>
59 #include <scsi/scsi_device.h>
60 #include <scsi/scsi_driver.h>
61 #include <scsi/scsi_eh.h>
62 #include <scsi/scsi_host.h>
63 #include <scsi/scsi_ioctl.h>
64 #include <scsi/scsicam.h>
65 
66 #include "sd.h"
67 #include "scsi_logging.h"
68 
69 MODULE_AUTHOR("Eric Youngdale");
70 MODULE_DESCRIPTION("SCSI disk (sd) driver");
71 MODULE_LICENSE("GPL");
72 
73 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK0_MAJOR);
74 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK1_MAJOR);
75 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK2_MAJOR);
76 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK3_MAJOR);
77 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK4_MAJOR);
78 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK5_MAJOR);
79 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK6_MAJOR);
80 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK7_MAJOR);
81 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK8_MAJOR);
82 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK9_MAJOR);
83 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK10_MAJOR);
84 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK11_MAJOR);
85 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK12_MAJOR);
86 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK13_MAJOR);
87 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK14_MAJOR);
88 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
89 MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
90 MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
91 MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
92 
93 #if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
94 #define SD_MINORS	16
95 #else
96 #define SD_MINORS	0
97 #endif
98 
99 static int  sd_revalidate_disk(struct gendisk *);
100 static void sd_unlock_native_capacity(struct gendisk *disk);
101 static int  sd_probe(struct device *);
102 static int  sd_remove(struct device *);
103 static void sd_shutdown(struct device *);
104 static int sd_suspend(struct device *, pm_message_t state);
105 static int sd_resume(struct device *);
106 static void sd_rescan(struct device *);
107 static int sd_done(struct scsi_cmnd *);
108 static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
109 static void scsi_disk_release(struct device *cdev);
110 static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
111 static void sd_print_result(struct scsi_disk *, int);
112 
113 static DEFINE_SPINLOCK(sd_index_lock);
114 static DEFINE_IDA(sd_index_ida);
115 
116 /* This semaphore is used to mediate the 0->1 reference get in the
117  * face of object destruction (i.e. we can't allow a get on an
118  * object after last put) */
119 static DEFINE_MUTEX(sd_ref_mutex);
120 
121 struct kmem_cache *sd_cdb_cache;
122 mempool_t *sd_cdb_pool;
123 
124 static const char *sd_cache_types[] = {
125 	"write through", "none", "write back",
126 	"write back, no read (daft)"
127 };
128 
129 static ssize_t
130 sd_store_cache_type(struct device *dev, struct device_attribute *attr,
131 		    const char *buf, size_t count)
132 {
133 	int i, ct = -1, rcd, wce, sp;
134 	struct scsi_disk *sdkp = to_scsi_disk(dev);
135 	struct scsi_device *sdp = sdkp->device;
136 	char buffer[64];
137 	char *buffer_data;
138 	struct scsi_mode_data data;
139 	struct scsi_sense_hdr sshdr;
140 	int len;
141 
142 	if (sdp->type != TYPE_DISK)
143 		/* no cache control on RBC devices; theoretically they
144 		 * can do it, but there's probably so many exceptions
145 		 * it's not worth the risk */
146 		return -EINVAL;
147 
148 	for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {
149 		const int len = strlen(sd_cache_types[i]);
150 		if (strncmp(sd_cache_types[i], buf, len) == 0 &&
151 		    buf[len] == '\n') {
152 			ct = i;
153 			break;
154 		}
155 	}
156 	if (ct < 0)
157 		return -EINVAL;
158 	rcd = ct & 0x01 ? 1 : 0;
159 	wce = ct & 0x02 ? 1 : 0;
160 	if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
161 			    SD_MAX_RETRIES, &data, NULL))
162 		return -EINVAL;
163 	len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
164 		  data.block_descriptor_length);
165 	buffer_data = buffer + data.header_length +
166 		data.block_descriptor_length;
167 	buffer_data[2] &= ~0x05;
168 	buffer_data[2] |= wce << 2 | rcd;
169 	sp = buffer_data[0] & 0x80 ? 1 : 0;
170 
171 	if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
172 			     SD_MAX_RETRIES, &data, &sshdr)) {
173 		if (scsi_sense_valid(&sshdr))
174 			sd_print_sense_hdr(sdkp, &sshdr);
175 		return -EINVAL;
176 	}
177 	revalidate_disk(sdkp->disk);
178 	return count;
179 }
180 
181 static ssize_t
182 sd_store_manage_start_stop(struct device *dev, struct device_attribute *attr,
183 			   const char *buf, size_t count)
184 {
185 	struct scsi_disk *sdkp = to_scsi_disk(dev);
186 	struct scsi_device *sdp = sdkp->device;
187 
188 	if (!capable(CAP_SYS_ADMIN))
189 		return -EACCES;
190 
191 	sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
192 
193 	return count;
194 }
195 
196 static ssize_t
197 sd_store_allow_restart(struct device *dev, struct device_attribute *attr,
198 		       const char *buf, size_t count)
199 {
200 	struct scsi_disk *sdkp = to_scsi_disk(dev);
201 	struct scsi_device *sdp = sdkp->device;
202 
203 	if (!capable(CAP_SYS_ADMIN))
204 		return -EACCES;
205 
206 	if (sdp->type != TYPE_DISK)
207 		return -EINVAL;
208 
209 	sdp->allow_restart = simple_strtoul(buf, NULL, 10);
210 
211 	return count;
212 }
213 
214 static ssize_t
215 sd_show_cache_type(struct device *dev, struct device_attribute *attr,
216 		   char *buf)
217 {
218 	struct scsi_disk *sdkp = to_scsi_disk(dev);
219 	int ct = sdkp->RCD + 2*sdkp->WCE;
220 
221 	return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
222 }
223 
224 static ssize_t
225 sd_show_fua(struct device *dev, struct device_attribute *attr, char *buf)
226 {
227 	struct scsi_disk *sdkp = to_scsi_disk(dev);
228 
229 	return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
230 }
231 
232 static ssize_t
233 sd_show_manage_start_stop(struct device *dev, struct device_attribute *attr,
234 			  char *buf)
235 {
236 	struct scsi_disk *sdkp = to_scsi_disk(dev);
237 	struct scsi_device *sdp = sdkp->device;
238 
239 	return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
240 }
241 
242 static ssize_t
243 sd_show_allow_restart(struct device *dev, struct device_attribute *attr,
244 		      char *buf)
245 {
246 	struct scsi_disk *sdkp = to_scsi_disk(dev);
247 
248 	return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
249 }
250 
251 static ssize_t
252 sd_show_protection_type(struct device *dev, struct device_attribute *attr,
253 			char *buf)
254 {
255 	struct scsi_disk *sdkp = to_scsi_disk(dev);
256 
257 	return snprintf(buf, 20, "%u\n", sdkp->protection_type);
258 }
259 
260 static ssize_t
261 sd_show_app_tag_own(struct device *dev, struct device_attribute *attr,
262 		    char *buf)
263 {
264 	struct scsi_disk *sdkp = to_scsi_disk(dev);
265 
266 	return snprintf(buf, 20, "%u\n", sdkp->ATO);
267 }
268 
269 static ssize_t
270 sd_show_thin_provisioning(struct device *dev, struct device_attribute *attr,
271 			  char *buf)
272 {
273 	struct scsi_disk *sdkp = to_scsi_disk(dev);
274 
275 	return snprintf(buf, 20, "%u\n", sdkp->thin_provisioning);
276 }
277 
278 static struct device_attribute sd_disk_attrs[] = {
279 	__ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
280 	       sd_store_cache_type),
281 	__ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
282 	__ATTR(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
283 	       sd_store_allow_restart),
284 	__ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
285 	       sd_store_manage_start_stop),
286 	__ATTR(protection_type, S_IRUGO, sd_show_protection_type, NULL),
287 	__ATTR(app_tag_own, S_IRUGO, sd_show_app_tag_own, NULL),
288 	__ATTR(thin_provisioning, S_IRUGO, sd_show_thin_provisioning, NULL),
289 	__ATTR_NULL,
290 };
291 
292 static struct class sd_disk_class = {
293 	.name		= "scsi_disk",
294 	.owner		= THIS_MODULE,
295 	.dev_release	= scsi_disk_release,
296 	.dev_attrs	= sd_disk_attrs,
297 };
298 
299 static struct scsi_driver sd_template = {
300 	.owner			= THIS_MODULE,
301 	.gendrv = {
302 		.name		= "sd",
303 		.probe		= sd_probe,
304 		.remove		= sd_remove,
305 		.suspend	= sd_suspend,
306 		.resume		= sd_resume,
307 		.shutdown	= sd_shutdown,
308 	},
309 	.rescan			= sd_rescan,
310 	.done			= sd_done,
311 };
312 
313 /*
314  * Device no to disk mapping:
315  *
316  *       major         disc2     disc  p1
317  *   |............|.............|....|....| <- dev_t
318  *    31        20 19          8 7  4 3  0
319  *
320  * Inside a major, we have 16k disks, however mapped non-
321  * contiguously. The first 16 disks are for major0, the next
322  * ones with major1, ... Disk 256 is for major0 again, disk 272
323  * for major1, ...
324  * As we stay compatible with our numbering scheme, we can reuse
325  * the well-know SCSI majors 8, 65--71, 136--143.
326  */
327 static int sd_major(int major_idx)
328 {
329 	switch (major_idx) {
330 	case 0:
331 		return SCSI_DISK0_MAJOR;
332 	case 1 ... 7:
333 		return SCSI_DISK1_MAJOR + major_idx - 1;
334 	case 8 ... 15:
335 		return SCSI_DISK8_MAJOR + major_idx - 8;
336 	default:
337 		BUG();
338 		return 0;	/* shut up gcc */
339 	}
340 }
341 
342 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
343 {
344 	struct scsi_disk *sdkp = NULL;
345 
346 	if (disk->private_data) {
347 		sdkp = scsi_disk(disk);
348 		if (scsi_device_get(sdkp->device) == 0)
349 			get_device(&sdkp->dev);
350 		else
351 			sdkp = NULL;
352 	}
353 	return sdkp;
354 }
355 
356 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
357 {
358 	struct scsi_disk *sdkp;
359 
360 	mutex_lock(&sd_ref_mutex);
361 	sdkp = __scsi_disk_get(disk);
362 	mutex_unlock(&sd_ref_mutex);
363 	return sdkp;
364 }
365 
366 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
367 {
368 	struct scsi_disk *sdkp;
369 
370 	mutex_lock(&sd_ref_mutex);
371 	sdkp = dev_get_drvdata(dev);
372 	if (sdkp)
373 		sdkp = __scsi_disk_get(sdkp->disk);
374 	mutex_unlock(&sd_ref_mutex);
375 	return sdkp;
376 }
377 
378 static void scsi_disk_put(struct scsi_disk *sdkp)
379 {
380 	struct scsi_device *sdev = sdkp->device;
381 
382 	mutex_lock(&sd_ref_mutex);
383 	put_device(&sdkp->dev);
384 	scsi_device_put(sdev);
385 	mutex_unlock(&sd_ref_mutex);
386 }
387 
388 static void sd_prot_op(struct scsi_cmnd *scmd, unsigned int dif)
389 {
390 	unsigned int prot_op = SCSI_PROT_NORMAL;
391 	unsigned int dix = scsi_prot_sg_count(scmd);
392 
393 	if (scmd->sc_data_direction == DMA_FROM_DEVICE) {
394 		if (dif && dix)
395 			prot_op = SCSI_PROT_READ_PASS;
396 		else if (dif && !dix)
397 			prot_op = SCSI_PROT_READ_STRIP;
398 		else if (!dif && dix)
399 			prot_op = SCSI_PROT_READ_INSERT;
400 	} else {
401 		if (dif && dix)
402 			prot_op = SCSI_PROT_WRITE_PASS;
403 		else if (dif && !dix)
404 			prot_op = SCSI_PROT_WRITE_INSERT;
405 		else if (!dif && dix)
406 			prot_op = SCSI_PROT_WRITE_STRIP;
407 	}
408 
409 	scsi_set_prot_op(scmd, prot_op);
410 	scsi_set_prot_type(scmd, dif);
411 }
412 
413 /**
414  * sd_prepare_discard - unmap blocks on thinly provisioned device
415  * @rq: Request to prepare
416  *
417  * Will issue either UNMAP or WRITE SAME(16) depending on preference
418  * indicated by target device.
419  **/
420 static int sd_prepare_discard(struct request *rq)
421 {
422 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
423 	struct bio *bio = rq->bio;
424 	sector_t sector = bio->bi_sector;
425 	unsigned int num = bio_sectors(bio);
426 
427 	if (sdkp->device->sector_size == 4096) {
428 		sector >>= 3;
429 		num >>= 3;
430 	}
431 
432 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
433 	rq->timeout = SD_TIMEOUT;
434 
435 	memset(rq->cmd, 0, rq->cmd_len);
436 
437 	if (sdkp->unmap) {
438 		char *buf = kmap_atomic(bio_page(bio), KM_USER0);
439 
440 		rq->cmd[0] = UNMAP;
441 		rq->cmd[8] = 24;
442 		rq->cmd_len = 10;
443 
444 		/* Ensure that data length matches payload */
445 		rq->__data_len = bio->bi_size = bio->bi_io_vec->bv_len = 24;
446 
447 		put_unaligned_be16(6 + 16, &buf[0]);
448 		put_unaligned_be16(16, &buf[2]);
449 		put_unaligned_be64(sector, &buf[8]);
450 		put_unaligned_be32(num, &buf[16]);
451 
452 		kunmap_atomic(buf, KM_USER0);
453 	} else {
454 		rq->cmd[0] = WRITE_SAME_16;
455 		rq->cmd[1] = 0x8; /* UNMAP */
456 		put_unaligned_be64(sector, &rq->cmd[2]);
457 		put_unaligned_be32(num, &rq->cmd[10]);
458 		rq->cmd_len = 16;
459 	}
460 
461 	return BLKPREP_OK;
462 }
463 
464 /**
465  *	sd_init_command - build a scsi (read or write) command from
466  *	information in the request structure.
467  *	@SCpnt: pointer to mid-level's per scsi command structure that
468  *	contains request and into which the scsi command is written
469  *
470  *	Returns 1 if successful and 0 if error (or cannot be done now).
471  **/
472 static int sd_prep_fn(struct request_queue *q, struct request *rq)
473 {
474 	struct scsi_cmnd *SCpnt;
475 	struct scsi_device *sdp = q->queuedata;
476 	struct gendisk *disk = rq->rq_disk;
477 	struct scsi_disk *sdkp;
478 	sector_t block = blk_rq_pos(rq);
479 	sector_t threshold;
480 	unsigned int this_count = blk_rq_sectors(rq);
481 	int ret, host_dif;
482 	unsigned char protect;
483 
484 	/*
485 	 * Discard request come in as REQ_TYPE_FS but we turn them into
486 	 * block PC requests to make life easier.
487 	 */
488 	if (blk_discard_rq(rq))
489 		ret = sd_prepare_discard(rq);
490 
491 	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
492 		ret = scsi_setup_blk_pc_cmnd(sdp, rq);
493 		goto out;
494 	} else if (rq->cmd_type != REQ_TYPE_FS) {
495 		ret = BLKPREP_KILL;
496 		goto out;
497 	}
498 	ret = scsi_setup_fs_cmnd(sdp, rq);
499 	if (ret != BLKPREP_OK)
500 		goto out;
501 	SCpnt = rq->special;
502 	sdkp = scsi_disk(disk);
503 
504 	/* from here on until we're complete, any goto out
505 	 * is used for a killable error condition */
506 	ret = BLKPREP_KILL;
507 
508 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
509 					"sd_init_command: block=%llu, "
510 					"count=%d\n",
511 					(unsigned long long)block,
512 					this_count));
513 
514 	if (!sdp || !scsi_device_online(sdp) ||
515 	    block + blk_rq_sectors(rq) > get_capacity(disk)) {
516 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
517 						"Finishing %u sectors\n",
518 						blk_rq_sectors(rq)));
519 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
520 						"Retry with 0x%p\n", SCpnt));
521 		goto out;
522 	}
523 
524 	if (sdp->changed) {
525 		/*
526 		 * quietly refuse to do anything to a changed disc until
527 		 * the changed bit has been reset
528 		 */
529 		/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
530 		goto out;
531 	}
532 
533 	/*
534 	 * Some SD card readers can't handle multi-sector accesses which touch
535 	 * the last one or two hardware sectors.  Split accesses as needed.
536 	 */
537 	threshold = get_capacity(disk) - SD_LAST_BUGGY_SECTORS *
538 		(sdp->sector_size / 512);
539 
540 	if (unlikely(sdp->last_sector_bug && block + this_count > threshold)) {
541 		if (block < threshold) {
542 			/* Access up to the threshold but not beyond */
543 			this_count = threshold - block;
544 		} else {
545 			/* Access only a single hardware sector */
546 			this_count = sdp->sector_size / 512;
547 		}
548 	}
549 
550 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
551 					(unsigned long long)block));
552 
553 	/*
554 	 * If we have a 1K hardware sectorsize, prevent access to single
555 	 * 512 byte sectors.  In theory we could handle this - in fact
556 	 * the scsi cdrom driver must be able to handle this because
557 	 * we typically use 1K blocksizes, and cdroms typically have
558 	 * 2K hardware sectorsizes.  Of course, things are simpler
559 	 * with the cdrom, since it is read-only.  For performance
560 	 * reasons, the filesystems should be able to handle this
561 	 * and not force the scsi disk driver to use bounce buffers
562 	 * for this.
563 	 */
564 	if (sdp->sector_size == 1024) {
565 		if ((block & 1) || (blk_rq_sectors(rq) & 1)) {
566 			scmd_printk(KERN_ERR, SCpnt,
567 				    "Bad block number requested\n");
568 			goto out;
569 		} else {
570 			block = block >> 1;
571 			this_count = this_count >> 1;
572 		}
573 	}
574 	if (sdp->sector_size == 2048) {
575 		if ((block & 3) || (blk_rq_sectors(rq) & 3)) {
576 			scmd_printk(KERN_ERR, SCpnt,
577 				    "Bad block number requested\n");
578 			goto out;
579 		} else {
580 			block = block >> 2;
581 			this_count = this_count >> 2;
582 		}
583 	}
584 	if (sdp->sector_size == 4096) {
585 		if ((block & 7) || (blk_rq_sectors(rq) & 7)) {
586 			scmd_printk(KERN_ERR, SCpnt,
587 				    "Bad block number requested\n");
588 			goto out;
589 		} else {
590 			block = block >> 3;
591 			this_count = this_count >> 3;
592 		}
593 	}
594 	if (rq_data_dir(rq) == WRITE) {
595 		if (!sdp->writeable) {
596 			goto out;
597 		}
598 		SCpnt->cmnd[0] = WRITE_6;
599 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
600 
601 		if (blk_integrity_rq(rq) &&
602 		    sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
603 			goto out;
604 
605 	} else if (rq_data_dir(rq) == READ) {
606 		SCpnt->cmnd[0] = READ_6;
607 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
608 	} else {
609 		scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
610 		goto out;
611 	}
612 
613 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
614 					"%s %d/%u 512 byte blocks.\n",
615 					(rq_data_dir(rq) == WRITE) ?
616 					"writing" : "reading", this_count,
617 					blk_rq_sectors(rq)));
618 
619 	/* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
620 	host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
621 	if (host_dif)
622 		protect = 1 << 5;
623 	else
624 		protect = 0;
625 
626 	if (host_dif == SD_DIF_TYPE2_PROTECTION) {
627 		SCpnt->cmnd = mempool_alloc(sd_cdb_pool, GFP_ATOMIC);
628 
629 		if (unlikely(SCpnt->cmnd == NULL)) {
630 			ret = BLKPREP_DEFER;
631 			goto out;
632 		}
633 
634 		SCpnt->cmd_len = SD_EXT_CDB_SIZE;
635 		memset(SCpnt->cmnd, 0, SCpnt->cmd_len);
636 		SCpnt->cmnd[0] = VARIABLE_LENGTH_CMD;
637 		SCpnt->cmnd[7] = 0x18;
638 		SCpnt->cmnd[9] = (rq_data_dir(rq) == READ) ? READ_32 : WRITE_32;
639 		SCpnt->cmnd[10] = protect | (blk_fua_rq(rq) ? 0x8 : 0);
640 
641 		/* LBA */
642 		SCpnt->cmnd[12] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
643 		SCpnt->cmnd[13] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
644 		SCpnt->cmnd[14] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
645 		SCpnt->cmnd[15] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
646 		SCpnt->cmnd[16] = (unsigned char) (block >> 24) & 0xff;
647 		SCpnt->cmnd[17] = (unsigned char) (block >> 16) & 0xff;
648 		SCpnt->cmnd[18] = (unsigned char) (block >> 8) & 0xff;
649 		SCpnt->cmnd[19] = (unsigned char) block & 0xff;
650 
651 		/* Expected Indirect LBA */
652 		SCpnt->cmnd[20] = (unsigned char) (block >> 24) & 0xff;
653 		SCpnt->cmnd[21] = (unsigned char) (block >> 16) & 0xff;
654 		SCpnt->cmnd[22] = (unsigned char) (block >> 8) & 0xff;
655 		SCpnt->cmnd[23] = (unsigned char) block & 0xff;
656 
657 		/* Transfer length */
658 		SCpnt->cmnd[28] = (unsigned char) (this_count >> 24) & 0xff;
659 		SCpnt->cmnd[29] = (unsigned char) (this_count >> 16) & 0xff;
660 		SCpnt->cmnd[30] = (unsigned char) (this_count >> 8) & 0xff;
661 		SCpnt->cmnd[31] = (unsigned char) this_count & 0xff;
662 	} else if (block > 0xffffffff) {
663 		SCpnt->cmnd[0] += READ_16 - READ_6;
664 		SCpnt->cmnd[1] = protect | (blk_fua_rq(rq) ? 0x8 : 0);
665 		SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
666 		SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
667 		SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
668 		SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
669 		SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
670 		SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
671 		SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
672 		SCpnt->cmnd[9] = (unsigned char) block & 0xff;
673 		SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
674 		SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
675 		SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
676 		SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
677 		SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
678 	} else if ((this_count > 0xff) || (block > 0x1fffff) ||
679 		   scsi_device_protection(SCpnt->device) ||
680 		   SCpnt->device->use_10_for_rw) {
681 		if (this_count > 0xffff)
682 			this_count = 0xffff;
683 
684 		SCpnt->cmnd[0] += READ_10 - READ_6;
685 		SCpnt->cmnd[1] = protect | (blk_fua_rq(rq) ? 0x8 : 0);
686 		SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
687 		SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
688 		SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
689 		SCpnt->cmnd[5] = (unsigned char) block & 0xff;
690 		SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
691 		SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
692 		SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
693 	} else {
694 		if (unlikely(blk_fua_rq(rq))) {
695 			/*
696 			 * This happens only if this drive failed
697 			 * 10byte rw command with ILLEGAL_REQUEST
698 			 * during operation and thus turned off
699 			 * use_10_for_rw.
700 			 */
701 			scmd_printk(KERN_ERR, SCpnt,
702 				    "FUA write on READ/WRITE(6) drive\n");
703 			goto out;
704 		}
705 
706 		SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
707 		SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
708 		SCpnt->cmnd[3] = (unsigned char) block & 0xff;
709 		SCpnt->cmnd[4] = (unsigned char) this_count;
710 		SCpnt->cmnd[5] = 0;
711 	}
712 	SCpnt->sdb.length = this_count * sdp->sector_size;
713 
714 	/* If DIF or DIX is enabled, tell HBA how to handle request */
715 	if (host_dif || scsi_prot_sg_count(SCpnt))
716 		sd_prot_op(SCpnt, host_dif);
717 
718 	/*
719 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
720 	 * host adapter, it's safe to assume that we can at least transfer
721 	 * this many bytes between each connect / disconnect.
722 	 */
723 	SCpnt->transfersize = sdp->sector_size;
724 	SCpnt->underflow = this_count << 9;
725 	SCpnt->allowed = SD_MAX_RETRIES;
726 
727 	/*
728 	 * This indicates that the command is ready from our end to be
729 	 * queued.
730 	 */
731 	ret = BLKPREP_OK;
732  out:
733 	return scsi_prep_return(q, rq, ret);
734 }
735 
736 /**
737  *	sd_open - open a scsi disk device
738  *	@inode: only i_rdev member may be used
739  *	@filp: only f_mode and f_flags may be used
740  *
741  *	Returns 0 if successful. Returns a negated errno value in case
742  *	of error.
743  *
744  *	Note: This can be called from a user context (e.g. fsck(1) )
745  *	or from within the kernel (e.g. as a result of a mount(1) ).
746  *	In the latter case @inode and @filp carry an abridged amount
747  *	of information as noted above.
748  **/
749 static int sd_open(struct block_device *bdev, fmode_t mode)
750 {
751 	struct scsi_disk *sdkp = scsi_disk_get(bdev->bd_disk);
752 	struct scsi_device *sdev;
753 	int retval;
754 
755 	if (!sdkp)
756 		return -ENXIO;
757 
758 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
759 
760 	sdev = sdkp->device;
761 
762 	/*
763 	 * If the device is in error recovery, wait until it is done.
764 	 * If the device is offline, then disallow any access to it.
765 	 */
766 	retval = -ENXIO;
767 	if (!scsi_block_when_processing_errors(sdev))
768 		goto error_out;
769 
770 	if (sdev->removable || sdkp->write_prot)
771 		check_disk_change(bdev);
772 
773 	/*
774 	 * If the drive is empty, just let the open fail.
775 	 */
776 	retval = -ENOMEDIUM;
777 	if (sdev->removable && !sdkp->media_present && !(mode & FMODE_NDELAY))
778 		goto error_out;
779 
780 	/*
781 	 * If the device has the write protect tab set, have the open fail
782 	 * if the user expects to be able to write to the thing.
783 	 */
784 	retval = -EROFS;
785 	if (sdkp->write_prot && (mode & FMODE_WRITE))
786 		goto error_out;
787 
788 	/*
789 	 * It is possible that the disk changing stuff resulted in
790 	 * the device being taken offline.  If this is the case,
791 	 * report this to the user, and don't pretend that the
792 	 * open actually succeeded.
793 	 */
794 	retval = -ENXIO;
795 	if (!scsi_device_online(sdev))
796 		goto error_out;
797 
798 	if (!sdkp->openers++ && sdev->removable) {
799 		if (scsi_block_when_processing_errors(sdev))
800 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
801 	}
802 
803 	return 0;
804 
805 error_out:
806 	scsi_disk_put(sdkp);
807 	return retval;
808 }
809 
810 /**
811  *	sd_release - invoked when the (last) close(2) is called on this
812  *	scsi disk.
813  *	@inode: only i_rdev member may be used
814  *	@filp: only f_mode and f_flags may be used
815  *
816  *	Returns 0.
817  *
818  *	Note: may block (uninterruptible) if error recovery is underway
819  *	on this disk.
820  **/
821 static int sd_release(struct gendisk *disk, fmode_t mode)
822 {
823 	struct scsi_disk *sdkp = scsi_disk(disk);
824 	struct scsi_device *sdev = sdkp->device;
825 
826 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_release\n"));
827 
828 	if (!--sdkp->openers && sdev->removable) {
829 		if (scsi_block_when_processing_errors(sdev))
830 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
831 	}
832 
833 	/*
834 	 * XXX and what if there are packets in flight and this close()
835 	 * XXX is followed by a "rmmod sd_mod"?
836 	 */
837 	scsi_disk_put(sdkp);
838 	return 0;
839 }
840 
841 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
842 {
843 	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
844 	struct scsi_device *sdp = sdkp->device;
845 	struct Scsi_Host *host = sdp->host;
846 	int diskinfo[4];
847 
848 	/* default to most commonly used values */
849         diskinfo[0] = 0x40;	/* 1 << 6 */
850        	diskinfo[1] = 0x20;	/* 1 << 5 */
851        	diskinfo[2] = sdkp->capacity >> 11;
852 
853 	/* override with calculated, extended default, or driver values */
854 	if (host->hostt->bios_param)
855 		host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
856 	else
857 		scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
858 
859 	geo->heads = diskinfo[0];
860 	geo->sectors = diskinfo[1];
861 	geo->cylinders = diskinfo[2];
862 	return 0;
863 }
864 
865 /**
866  *	sd_ioctl - process an ioctl
867  *	@inode: only i_rdev/i_bdev members may be used
868  *	@filp: only f_mode and f_flags may be used
869  *	@cmd: ioctl command number
870  *	@arg: this is third argument given to ioctl(2) system call.
871  *	Often contains a pointer.
872  *
873  *	Returns 0 if successful (some ioctls return postive numbers on
874  *	success as well). Returns a negated errno value in case of error.
875  *
876  *	Note: most ioctls are forward onto the block subsystem or further
877  *	down in the scsi subsystem.
878  **/
879 static int sd_ioctl(struct block_device *bdev, fmode_t mode,
880 		    unsigned int cmd, unsigned long arg)
881 {
882 	struct gendisk *disk = bdev->bd_disk;
883 	struct scsi_device *sdp = scsi_disk(disk)->device;
884 	void __user *p = (void __user *)arg;
885 	int error;
886 
887 	SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
888 						disk->disk_name, cmd));
889 
890 	/*
891 	 * If we are in the middle of error recovery, don't let anyone
892 	 * else try and use this device.  Also, if error recovery fails, it
893 	 * may try and take the device offline, in which case all further
894 	 * access to the device is prohibited.
895 	 */
896 	error = scsi_nonblockable_ioctl(sdp, cmd, p,
897 					(mode & FMODE_NDELAY) != 0);
898 	if (!scsi_block_when_processing_errors(sdp) || !error)
899 		return error;
900 
901 	/*
902 	 * Send SCSI addressing ioctls directly to mid level, send other
903 	 * ioctls to block level and then onto mid level if they can't be
904 	 * resolved.
905 	 */
906 	switch (cmd) {
907 		case SCSI_IOCTL_GET_IDLUN:
908 		case SCSI_IOCTL_GET_BUS_NUMBER:
909 			return scsi_ioctl(sdp, cmd, p);
910 		default:
911 			error = scsi_cmd_ioctl(disk->queue, disk, mode, cmd, p);
912 			if (error != -ENOTTY)
913 				return error;
914 	}
915 	return scsi_ioctl(sdp, cmd, p);
916 }
917 
918 static void set_media_not_present(struct scsi_disk *sdkp)
919 {
920 	sdkp->media_present = 0;
921 	sdkp->capacity = 0;
922 	sdkp->device->changed = 1;
923 }
924 
925 /**
926  *	sd_media_changed - check if our medium changed
927  *	@disk: kernel device descriptor
928  *
929  *	Returns 0 if not applicable or no change; 1 if change
930  *
931  *	Note: this function is invoked from the block subsystem.
932  **/
933 static int sd_media_changed(struct gendisk *disk)
934 {
935 	struct scsi_disk *sdkp = scsi_disk(disk);
936 	struct scsi_device *sdp = sdkp->device;
937 	struct scsi_sense_hdr *sshdr = NULL;
938 	int retval;
939 
940 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_media_changed\n"));
941 
942 	if (!sdp->removable)
943 		return 0;
944 
945 	/*
946 	 * If the device is offline, don't send any commands - just pretend as
947 	 * if the command failed.  If the device ever comes back online, we
948 	 * can deal with it then.  It is only because of unrecoverable errors
949 	 * that we would ever take a device offline in the first place.
950 	 */
951 	if (!scsi_device_online(sdp)) {
952 		set_media_not_present(sdkp);
953 		retval = 1;
954 		goto out;
955 	}
956 
957 	/*
958 	 * Using TEST_UNIT_READY enables differentiation between drive with
959 	 * no cartridge loaded - NOT READY, drive with changed cartridge -
960 	 * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
961 	 *
962 	 * Drives that auto spin down. eg iomega jaz 1G, will be started
963 	 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
964 	 * sd_revalidate() is called.
965 	 */
966 	retval = -ENODEV;
967 
968 	if (scsi_block_when_processing_errors(sdp)) {
969 		sshdr  = kzalloc(sizeof(*sshdr), GFP_KERNEL);
970 		retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
971 					      sshdr);
972 	}
973 
974 	/*
975 	 * Unable to test, unit probably not ready.   This usually
976 	 * means there is no disc in the drive.  Mark as changed,
977 	 * and we will figure it out later once the drive is
978 	 * available again.
979 	 */
980 	if (retval || (scsi_sense_valid(sshdr) &&
981 		       /* 0x3a is medium not present */
982 		       sshdr->asc == 0x3a)) {
983 		set_media_not_present(sdkp);
984 		retval = 1;
985 		goto out;
986 	}
987 
988 	/*
989 	 * For removable scsi disk we have to recognise the presence
990 	 * of a disk in the drive. This is kept in the struct scsi_disk
991 	 * struct and tested at open !  Daniel Roche (dan@lectra.fr)
992 	 */
993 	sdkp->media_present = 1;
994 
995 	retval = sdp->changed;
996 	sdp->changed = 0;
997 out:
998 	if (retval != sdkp->previous_state)
999 		sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL);
1000 	sdkp->previous_state = retval;
1001 	kfree(sshdr);
1002 	return retval;
1003 }
1004 
1005 static int sd_sync_cache(struct scsi_disk *sdkp)
1006 {
1007 	int retries, res;
1008 	struct scsi_device *sdp = sdkp->device;
1009 	struct scsi_sense_hdr sshdr;
1010 
1011 	if (!scsi_device_online(sdp))
1012 		return -ENODEV;
1013 
1014 
1015 	for (retries = 3; retries > 0; --retries) {
1016 		unsigned char cmd[10] = { 0 };
1017 
1018 		cmd[0] = SYNCHRONIZE_CACHE;
1019 		/*
1020 		 * Leave the rest of the command zero to indicate
1021 		 * flush everything.
1022 		 */
1023 		res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
1024 				       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1025 		if (res == 0)
1026 			break;
1027 	}
1028 
1029 	if (res) {
1030 		sd_print_result(sdkp, res);
1031 		if (driver_byte(res) & DRIVER_SENSE)
1032 			sd_print_sense_hdr(sdkp, &sshdr);
1033 	}
1034 
1035 	if (res)
1036 		return -EIO;
1037 	return 0;
1038 }
1039 
1040 static void sd_prepare_flush(struct request_queue *q, struct request *rq)
1041 {
1042 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
1043 	rq->timeout = SD_TIMEOUT;
1044 	rq->retries = SD_MAX_RETRIES;
1045 	rq->cmd[0] = SYNCHRONIZE_CACHE;
1046 	rq->cmd_len = 10;
1047 }
1048 
1049 static void sd_rescan(struct device *dev)
1050 {
1051 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
1052 
1053 	if (sdkp) {
1054 		revalidate_disk(sdkp->disk);
1055 		scsi_disk_put(sdkp);
1056 	}
1057 }
1058 
1059 
1060 #ifdef CONFIG_COMPAT
1061 /*
1062  * This gets directly called from VFS. When the ioctl
1063  * is not recognized we go back to the other translation paths.
1064  */
1065 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
1066 			   unsigned int cmd, unsigned long arg)
1067 {
1068 	struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
1069 
1070 	/*
1071 	 * If we are in the middle of error recovery, don't let anyone
1072 	 * else try and use this device.  Also, if error recovery fails, it
1073 	 * may try and take the device offline, in which case all further
1074 	 * access to the device is prohibited.
1075 	 */
1076 	if (!scsi_block_when_processing_errors(sdev))
1077 		return -ENODEV;
1078 
1079 	if (sdev->host->hostt->compat_ioctl) {
1080 		int ret;
1081 
1082 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
1083 
1084 		return ret;
1085 	}
1086 
1087 	/*
1088 	 * Let the static ioctl translation table take care of it.
1089 	 */
1090 	return -ENOIOCTLCMD;
1091 }
1092 #endif
1093 
1094 static const struct block_device_operations sd_fops = {
1095 	.owner			= THIS_MODULE,
1096 	.open			= sd_open,
1097 	.release		= sd_release,
1098 	.locked_ioctl		= sd_ioctl,
1099 	.getgeo			= sd_getgeo,
1100 #ifdef CONFIG_COMPAT
1101 	.compat_ioctl		= sd_compat_ioctl,
1102 #endif
1103 	.media_changed		= sd_media_changed,
1104 	.revalidate_disk	= sd_revalidate_disk,
1105 	.unlock_native_capacity	= sd_unlock_native_capacity,
1106 };
1107 
1108 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
1109 {
1110 	u64 start_lba = blk_rq_pos(scmd->request);
1111 	u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
1112 	u64 bad_lba;
1113 	int info_valid;
1114 
1115 	if (!blk_fs_request(scmd->request))
1116 		return 0;
1117 
1118 	info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
1119 					     SCSI_SENSE_BUFFERSIZE,
1120 					     &bad_lba);
1121 	if (!info_valid)
1122 		return 0;
1123 
1124 	if (scsi_bufflen(scmd) <= scmd->device->sector_size)
1125 		return 0;
1126 
1127 	if (scmd->device->sector_size < 512) {
1128 		/* only legitimate sector_size here is 256 */
1129 		start_lba <<= 1;
1130 		end_lba <<= 1;
1131 	} else {
1132 		/* be careful ... don't want any overflows */
1133 		u64 factor = scmd->device->sector_size / 512;
1134 		do_div(start_lba, factor);
1135 		do_div(end_lba, factor);
1136 	}
1137 
1138 	/* The bad lba was reported incorrectly, we have no idea where
1139 	 * the error is.
1140 	 */
1141 	if (bad_lba < start_lba  || bad_lba >= end_lba)
1142 		return 0;
1143 
1144 	/* This computation should always be done in terms of
1145 	 * the resolution of the device's medium.
1146 	 */
1147 	return (bad_lba - start_lba) * scmd->device->sector_size;
1148 }
1149 
1150 /**
1151  *	sd_done - bottom half handler: called when the lower level
1152  *	driver has completed (successfully or otherwise) a scsi command.
1153  *	@SCpnt: mid-level's per command structure.
1154  *
1155  *	Note: potentially run from within an ISR. Must not block.
1156  **/
1157 static int sd_done(struct scsi_cmnd *SCpnt)
1158 {
1159 	int result = SCpnt->result;
1160 	unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
1161 	struct scsi_sense_hdr sshdr;
1162 	struct scsi_disk *sdkp = scsi_disk(SCpnt->request->rq_disk);
1163 	int sense_valid = 0;
1164 	int sense_deferred = 0;
1165 
1166 	if (result) {
1167 		sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
1168 		if (sense_valid)
1169 			sense_deferred = scsi_sense_is_deferred(&sshdr);
1170 	}
1171 #ifdef CONFIG_SCSI_LOGGING
1172 	SCSI_LOG_HLCOMPLETE(1, scsi_print_result(SCpnt));
1173 	if (sense_valid) {
1174 		SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
1175 						   "sd_done: sb[respc,sk,asc,"
1176 						   "ascq]=%x,%x,%x,%x\n",
1177 						   sshdr.response_code,
1178 						   sshdr.sense_key, sshdr.asc,
1179 						   sshdr.ascq));
1180 	}
1181 #endif
1182 	if (driver_byte(result) != DRIVER_SENSE &&
1183 	    (!sense_valid || sense_deferred))
1184 		goto out;
1185 
1186 	switch (sshdr.sense_key) {
1187 	case HARDWARE_ERROR:
1188 	case MEDIUM_ERROR:
1189 		good_bytes = sd_completed_bytes(SCpnt);
1190 		break;
1191 	case RECOVERED_ERROR:
1192 		good_bytes = scsi_bufflen(SCpnt);
1193 		break;
1194 	case NO_SENSE:
1195 		/* This indicates a false check condition, so ignore it.  An
1196 		 * unknown amount of data was transferred so treat it as an
1197 		 * error.
1198 		 */
1199 		scsi_print_sense("sd", SCpnt);
1200 		SCpnt->result = 0;
1201 		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1202 		break;
1203 	case ABORTED_COMMAND: /* DIF: Target detected corruption */
1204 	case ILLEGAL_REQUEST: /* DIX: Host detected corruption */
1205 		if (sshdr.asc == 0x10)
1206 			good_bytes = sd_completed_bytes(SCpnt);
1207 		break;
1208 	default:
1209 		break;
1210 	}
1211  out:
1212 	if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
1213 		sd_dif_complete(SCpnt, good_bytes);
1214 
1215 	if (scsi_host_dif_capable(sdkp->device->host, sdkp->protection_type)
1216 	    == SD_DIF_TYPE2_PROTECTION && SCpnt->cmnd != SCpnt->request->cmd) {
1217 
1218 		/* We have to print a failed command here as the
1219 		 * extended CDB gets freed before scsi_io_completion()
1220 		 * is called.
1221 		 */
1222 		if (result)
1223 			scsi_print_command(SCpnt);
1224 
1225 		mempool_free(SCpnt->cmnd, sd_cdb_pool);
1226 		SCpnt->cmnd = NULL;
1227 		SCpnt->cmd_len = 0;
1228 	}
1229 
1230 	return good_bytes;
1231 }
1232 
1233 static int media_not_present(struct scsi_disk *sdkp,
1234 			     struct scsi_sense_hdr *sshdr)
1235 {
1236 
1237 	if (!scsi_sense_valid(sshdr))
1238 		return 0;
1239 	/* not invoked for commands that could return deferred errors */
1240 	if (sshdr->sense_key != NOT_READY &&
1241 	    sshdr->sense_key != UNIT_ATTENTION)
1242 		return 0;
1243 	if (sshdr->asc != 0x3A) /* medium not present */
1244 		return 0;
1245 
1246 	set_media_not_present(sdkp);
1247 	return 1;
1248 }
1249 
1250 /*
1251  * spinup disk - called only in sd_revalidate_disk()
1252  */
1253 static void
1254 sd_spinup_disk(struct scsi_disk *sdkp)
1255 {
1256 	unsigned char cmd[10];
1257 	unsigned long spintime_expire = 0;
1258 	int retries, spintime;
1259 	unsigned int the_result;
1260 	struct scsi_sense_hdr sshdr;
1261 	int sense_valid = 0;
1262 
1263 	spintime = 0;
1264 
1265 	/* Spin up drives, as required.  Only do this at boot time */
1266 	/* Spinup needs to be done for module loads too. */
1267 	do {
1268 		retries = 0;
1269 
1270 		do {
1271 			cmd[0] = TEST_UNIT_READY;
1272 			memset((void *) &cmd[1], 0, 9);
1273 
1274 			the_result = scsi_execute_req(sdkp->device, cmd,
1275 						      DMA_NONE, NULL, 0,
1276 						      &sshdr, SD_TIMEOUT,
1277 						      SD_MAX_RETRIES, NULL);
1278 
1279 			/*
1280 			 * If the drive has indicated to us that it
1281 			 * doesn't have any media in it, don't bother
1282 			 * with any more polling.
1283 			 */
1284 			if (media_not_present(sdkp, &sshdr))
1285 				return;
1286 
1287 			if (the_result)
1288 				sense_valid = scsi_sense_valid(&sshdr);
1289 			retries++;
1290 		} while (retries < 3 &&
1291 			 (!scsi_status_is_good(the_result) ||
1292 			  ((driver_byte(the_result) & DRIVER_SENSE) &&
1293 			  sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1294 
1295 		if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1296 			/* no sense, TUR either succeeded or failed
1297 			 * with a status error */
1298 			if(!spintime && !scsi_status_is_good(the_result)) {
1299 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1300 				sd_print_result(sdkp, the_result);
1301 			}
1302 			break;
1303 		}
1304 
1305 		/*
1306 		 * The device does not want the automatic start to be issued.
1307 		 */
1308 		if (sdkp->device->no_start_on_add)
1309 			break;
1310 
1311 		if (sense_valid && sshdr.sense_key == NOT_READY) {
1312 			if (sshdr.asc == 4 && sshdr.ascq == 3)
1313 				break;	/* manual intervention required */
1314 			if (sshdr.asc == 4 && sshdr.ascq == 0xb)
1315 				break;	/* standby */
1316 			if (sshdr.asc == 4 && sshdr.ascq == 0xc)
1317 				break;	/* unavailable */
1318 			/*
1319 			 * Issue command to spin up drive when not ready
1320 			 */
1321 			if (!spintime) {
1322 				sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
1323 				cmd[0] = START_STOP;
1324 				cmd[1] = 1;	/* Return immediately */
1325 				memset((void *) &cmd[2], 0, 8);
1326 				cmd[4] = 1;	/* Start spin cycle */
1327 				if (sdkp->device->start_stop_pwr_cond)
1328 					cmd[4] |= 1 << 4;
1329 				scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1330 						 NULL, 0, &sshdr,
1331 						 SD_TIMEOUT, SD_MAX_RETRIES,
1332 						 NULL);
1333 				spintime_expire = jiffies + 100 * HZ;
1334 				spintime = 1;
1335 			}
1336 			/* Wait 1 second for next try */
1337 			msleep(1000);
1338 			printk(".");
1339 
1340 		/*
1341 		 * Wait for USB flash devices with slow firmware.
1342 		 * Yes, this sense key/ASC combination shouldn't
1343 		 * occur here.  It's characteristic of these devices.
1344 		 */
1345 		} else if (sense_valid &&
1346 				sshdr.sense_key == UNIT_ATTENTION &&
1347 				sshdr.asc == 0x28) {
1348 			if (!spintime) {
1349 				spintime_expire = jiffies + 5 * HZ;
1350 				spintime = 1;
1351 			}
1352 			/* Wait 1 second for next try */
1353 			msleep(1000);
1354 		} else {
1355 			/* we don't understand the sense code, so it's
1356 			 * probably pointless to loop */
1357 			if(!spintime) {
1358 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1359 				sd_print_sense_hdr(sdkp, &sshdr);
1360 			}
1361 			break;
1362 		}
1363 
1364 	} while (spintime && time_before_eq(jiffies, spintime_expire));
1365 
1366 	if (spintime) {
1367 		if (scsi_status_is_good(the_result))
1368 			printk("ready\n");
1369 		else
1370 			printk("not responding...\n");
1371 	}
1372 }
1373 
1374 
1375 /*
1376  * Determine whether disk supports Data Integrity Field.
1377  */
1378 void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
1379 {
1380 	struct scsi_device *sdp = sdkp->device;
1381 	u8 type;
1382 
1383 	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
1384 		return;
1385 
1386 	type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
1387 
1388 	if (type == sdkp->protection_type || !sdkp->first_scan)
1389 		return;
1390 
1391 	sdkp->protection_type = type;
1392 
1393 	if (type > SD_DIF_TYPE3_PROTECTION) {
1394 		sd_printk(KERN_ERR, sdkp, "formatted with unsupported "	\
1395 			  "protection type %u. Disabling disk!\n", type);
1396 		sdkp->capacity = 0;
1397 		return;
1398 	}
1399 
1400 	if (scsi_host_dif_capable(sdp->host, type))
1401 		sd_printk(KERN_NOTICE, sdkp,
1402 			  "Enabling DIF Type %u protection\n", type);
1403 	else
1404 		sd_printk(KERN_NOTICE, sdkp,
1405 			  "Disabling DIF Type %u protection\n", type);
1406 }
1407 
1408 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
1409 			struct scsi_sense_hdr *sshdr, int sense_valid,
1410 			int the_result)
1411 {
1412 	sd_print_result(sdkp, the_result);
1413 	if (driver_byte(the_result) & DRIVER_SENSE)
1414 		sd_print_sense_hdr(sdkp, sshdr);
1415 	else
1416 		sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
1417 
1418 	/*
1419 	 * Set dirty bit for removable devices if not ready -
1420 	 * sometimes drives will not report this properly.
1421 	 */
1422 	if (sdp->removable &&
1423 	    sense_valid && sshdr->sense_key == NOT_READY)
1424 		sdp->changed = 1;
1425 
1426 	/*
1427 	 * We used to set media_present to 0 here to indicate no media
1428 	 * in the drive, but some drives fail read capacity even with
1429 	 * media present, so we can't do that.
1430 	 */
1431 	sdkp->capacity = 0; /* unknown mapped to zero - as usual */
1432 }
1433 
1434 #define RC16_LEN 32
1435 #if RC16_LEN > SD_BUF_SIZE
1436 #error RC16_LEN must not be more than SD_BUF_SIZE
1437 #endif
1438 
1439 #define READ_CAPACITY_RETRIES_ON_RESET	10
1440 
1441 static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
1442 						unsigned char *buffer)
1443 {
1444 	unsigned char cmd[16];
1445 	struct scsi_sense_hdr sshdr;
1446 	int sense_valid = 0;
1447 	int the_result;
1448 	int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
1449 	unsigned int alignment;
1450 	unsigned long long lba;
1451 	unsigned sector_size;
1452 
1453 	do {
1454 		memset(cmd, 0, 16);
1455 		cmd[0] = SERVICE_ACTION_IN;
1456 		cmd[1] = SAI_READ_CAPACITY_16;
1457 		cmd[13] = RC16_LEN;
1458 		memset(buffer, 0, RC16_LEN);
1459 
1460 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1461 					buffer, RC16_LEN, &sshdr,
1462 					SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1463 
1464 		if (media_not_present(sdkp, &sshdr))
1465 			return -ENODEV;
1466 
1467 		if (the_result) {
1468 			sense_valid = scsi_sense_valid(&sshdr);
1469 			if (sense_valid &&
1470 			    sshdr.sense_key == ILLEGAL_REQUEST &&
1471 			    (sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
1472 			    sshdr.ascq == 0x00)
1473 				/* Invalid Command Operation Code or
1474 				 * Invalid Field in CDB, just retry
1475 				 * silently with RC10 */
1476 				return -EINVAL;
1477 			if (sense_valid &&
1478 			    sshdr.sense_key == UNIT_ATTENTION &&
1479 			    sshdr.asc == 0x29 && sshdr.ascq == 0x00)
1480 				/* Device reset might occur several times,
1481 				 * give it one more chance */
1482 				if (--reset_retries > 0)
1483 					continue;
1484 		}
1485 		retries--;
1486 
1487 	} while (the_result && retries);
1488 
1489 	if (the_result) {
1490 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY(16) failed\n");
1491 		read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
1492 		return -EINVAL;
1493 	}
1494 
1495 	sector_size = get_unaligned_be32(&buffer[8]);
1496 	lba = get_unaligned_be64(&buffer[0]);
1497 
1498 	sd_read_protection_type(sdkp, buffer);
1499 
1500 	if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) {
1501 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
1502 			"kernel compiled with support for large block "
1503 			"devices.\n");
1504 		sdkp->capacity = 0;
1505 		return -EOVERFLOW;
1506 	}
1507 
1508 	/* Logical blocks per physical block exponent */
1509 	sdkp->hw_sector_size = (1 << (buffer[13] & 0xf)) * sector_size;
1510 
1511 	/* Lowest aligned logical block */
1512 	alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) * sector_size;
1513 	blk_queue_alignment_offset(sdp->request_queue, alignment);
1514 	if (alignment && sdkp->first_scan)
1515 		sd_printk(KERN_NOTICE, sdkp,
1516 			  "physical block alignment offset: %u\n", alignment);
1517 
1518 	if (buffer[14] & 0x80) { /* TPE */
1519 		struct request_queue *q = sdp->request_queue;
1520 
1521 		sdkp->thin_provisioning = 1;
1522 		q->limits.discard_granularity = sdkp->hw_sector_size;
1523 		q->limits.max_discard_sectors = 0xffffffff;
1524 
1525 		if (buffer[14] & 0x40) /* TPRZ */
1526 			q->limits.discard_zeroes_data = 1;
1527 
1528 		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1529 	}
1530 
1531 	sdkp->capacity = lba + 1;
1532 	return sector_size;
1533 }
1534 
1535 static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
1536 						unsigned char *buffer)
1537 {
1538 	unsigned char cmd[16];
1539 	struct scsi_sense_hdr sshdr;
1540 	int sense_valid = 0;
1541 	int the_result;
1542 	int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
1543 	sector_t lba;
1544 	unsigned sector_size;
1545 
1546 	do {
1547 		cmd[0] = READ_CAPACITY;
1548 		memset(&cmd[1], 0, 9);
1549 		memset(buffer, 0, 8);
1550 
1551 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1552 					buffer, 8, &sshdr,
1553 					SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1554 
1555 		if (media_not_present(sdkp, &sshdr))
1556 			return -ENODEV;
1557 
1558 		if (the_result) {
1559 			sense_valid = scsi_sense_valid(&sshdr);
1560 			if (sense_valid &&
1561 			    sshdr.sense_key == UNIT_ATTENTION &&
1562 			    sshdr.asc == 0x29 && sshdr.ascq == 0x00)
1563 				/* Device reset might occur several times,
1564 				 * give it one more chance */
1565 				if (--reset_retries > 0)
1566 					continue;
1567 		}
1568 		retries--;
1569 
1570 	} while (the_result && retries);
1571 
1572 	if (the_result) {
1573 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
1574 		read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
1575 		return -EINVAL;
1576 	}
1577 
1578 	sector_size = get_unaligned_be32(&buffer[4]);
1579 	lba = get_unaligned_be32(&buffer[0]);
1580 
1581 	if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) {
1582 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
1583 			"kernel compiled with support for large block "
1584 			"devices.\n");
1585 		sdkp->capacity = 0;
1586 		return -EOVERFLOW;
1587 	}
1588 
1589 	sdkp->capacity = lba + 1;
1590 	sdkp->hw_sector_size = sector_size;
1591 	return sector_size;
1592 }
1593 
1594 static int sd_try_rc16_first(struct scsi_device *sdp)
1595 {
1596 	if (sdp->host->max_cmd_len < 16)
1597 		return 0;
1598 	if (sdp->scsi_level > SCSI_SPC_2)
1599 		return 1;
1600 	if (scsi_device_protection(sdp))
1601 		return 1;
1602 	return 0;
1603 }
1604 
1605 /*
1606  * read disk capacity
1607  */
1608 static void
1609 sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
1610 {
1611 	int sector_size;
1612 	struct scsi_device *sdp = sdkp->device;
1613 	sector_t old_capacity = sdkp->capacity;
1614 
1615 	if (sd_try_rc16_first(sdp)) {
1616 		sector_size = read_capacity_16(sdkp, sdp, buffer);
1617 		if (sector_size == -EOVERFLOW)
1618 			goto got_data;
1619 		if (sector_size == -ENODEV)
1620 			return;
1621 		if (sector_size < 0)
1622 			sector_size = read_capacity_10(sdkp, sdp, buffer);
1623 		if (sector_size < 0)
1624 			return;
1625 	} else {
1626 		sector_size = read_capacity_10(sdkp, sdp, buffer);
1627 		if (sector_size == -EOVERFLOW)
1628 			goto got_data;
1629 		if (sector_size < 0)
1630 			return;
1631 		if ((sizeof(sdkp->capacity) > 4) &&
1632 		    (sdkp->capacity > 0xffffffffULL)) {
1633 			int old_sector_size = sector_size;
1634 			sd_printk(KERN_NOTICE, sdkp, "Very big device. "
1635 					"Trying to use READ CAPACITY(16).\n");
1636 			sector_size = read_capacity_16(sdkp, sdp, buffer);
1637 			if (sector_size < 0) {
1638 				sd_printk(KERN_NOTICE, sdkp,
1639 					"Using 0xffffffff as device size\n");
1640 				sdkp->capacity = 1 + (sector_t) 0xffffffff;
1641 				sector_size = old_sector_size;
1642 				goto got_data;
1643 			}
1644 		}
1645 	}
1646 
1647 	/* Some devices are known to return the total number of blocks,
1648 	 * not the highest block number.  Some devices have versions
1649 	 * which do this and others which do not.  Some devices we might
1650 	 * suspect of doing this but we don't know for certain.
1651 	 *
1652 	 * If we know the reported capacity is wrong, decrement it.  If
1653 	 * we can only guess, then assume the number of blocks is even
1654 	 * (usually true but not always) and err on the side of lowering
1655 	 * the capacity.
1656 	 */
1657 	if (sdp->fix_capacity ||
1658 	    (sdp->guess_capacity && (sdkp->capacity & 0x01))) {
1659 		sd_printk(KERN_INFO, sdkp, "Adjusting the sector count "
1660 				"from its reported value: %llu\n",
1661 				(unsigned long long) sdkp->capacity);
1662 		--sdkp->capacity;
1663 	}
1664 
1665 got_data:
1666 	if (sector_size == 0) {
1667 		sector_size = 512;
1668 		sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
1669 			  "assuming 512.\n");
1670 	}
1671 
1672 	if (sector_size != 512 &&
1673 	    sector_size != 1024 &&
1674 	    sector_size != 2048 &&
1675 	    sector_size != 4096 &&
1676 	    sector_size != 256) {
1677 		sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
1678 			  sector_size);
1679 		/*
1680 		 * The user might want to re-format the drive with
1681 		 * a supported sectorsize.  Once this happens, it
1682 		 * would be relatively trivial to set the thing up.
1683 		 * For this reason, we leave the thing in the table.
1684 		 */
1685 		sdkp->capacity = 0;
1686 		/*
1687 		 * set a bogus sector size so the normal read/write
1688 		 * logic in the block layer will eventually refuse any
1689 		 * request on this device without tripping over power
1690 		 * of two sector size assumptions
1691 		 */
1692 		sector_size = 512;
1693 	}
1694 	blk_queue_logical_block_size(sdp->request_queue, sector_size);
1695 
1696 	{
1697 		char cap_str_2[10], cap_str_10[10];
1698 		u64 sz = (u64)sdkp->capacity << ilog2(sector_size);
1699 
1700 		string_get_size(sz, STRING_UNITS_2, cap_str_2,
1701 				sizeof(cap_str_2));
1702 		string_get_size(sz, STRING_UNITS_10, cap_str_10,
1703 				sizeof(cap_str_10));
1704 
1705 		if (sdkp->first_scan || old_capacity != sdkp->capacity) {
1706 			sd_printk(KERN_NOTICE, sdkp,
1707 				  "%llu %d-byte logical blocks: (%s/%s)\n",
1708 				  (unsigned long long)sdkp->capacity,
1709 				  sector_size, cap_str_10, cap_str_2);
1710 
1711 			if (sdkp->hw_sector_size != sector_size)
1712 				sd_printk(KERN_NOTICE, sdkp,
1713 					  "%u-byte physical blocks\n",
1714 					  sdkp->hw_sector_size);
1715 		}
1716 	}
1717 
1718 	/* Rescale capacity to 512-byte units */
1719 	if (sector_size == 4096)
1720 		sdkp->capacity <<= 3;
1721 	else if (sector_size == 2048)
1722 		sdkp->capacity <<= 2;
1723 	else if (sector_size == 1024)
1724 		sdkp->capacity <<= 1;
1725 	else if (sector_size == 256)
1726 		sdkp->capacity >>= 1;
1727 
1728 	blk_queue_physical_block_size(sdp->request_queue, sdkp->hw_sector_size);
1729 	sdkp->device->sector_size = sector_size;
1730 }
1731 
1732 /* called with buffer of length 512 */
1733 static inline int
1734 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
1735 		 unsigned char *buffer, int len, struct scsi_mode_data *data,
1736 		 struct scsi_sense_hdr *sshdr)
1737 {
1738 	return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
1739 			       SD_TIMEOUT, SD_MAX_RETRIES, data,
1740 			       sshdr);
1741 }
1742 
1743 /*
1744  * read write protect setting, if possible - called only in sd_revalidate_disk()
1745  * called with buffer of length SD_BUF_SIZE
1746  */
1747 static void
1748 sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
1749 {
1750 	int res;
1751 	struct scsi_device *sdp = sdkp->device;
1752 	struct scsi_mode_data data;
1753 	int old_wp = sdkp->write_prot;
1754 
1755 	set_disk_ro(sdkp->disk, 0);
1756 	if (sdp->skip_ms_page_3f) {
1757 		sd_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
1758 		return;
1759 	}
1760 
1761 	if (sdp->use_192_bytes_for_3f) {
1762 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
1763 	} else {
1764 		/*
1765 		 * First attempt: ask for all pages (0x3F), but only 4 bytes.
1766 		 * We have to start carefully: some devices hang if we ask
1767 		 * for more than is available.
1768 		 */
1769 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
1770 
1771 		/*
1772 		 * Second attempt: ask for page 0 When only page 0 is
1773 		 * implemented, a request for page 3F may return Sense Key
1774 		 * 5: Illegal Request, Sense Code 24: Invalid field in
1775 		 * CDB.
1776 		 */
1777 		if (!scsi_status_is_good(res))
1778 			res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
1779 
1780 		/*
1781 		 * Third attempt: ask 255 bytes, as we did earlier.
1782 		 */
1783 		if (!scsi_status_is_good(res))
1784 			res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
1785 					       &data, NULL);
1786 	}
1787 
1788 	if (!scsi_status_is_good(res)) {
1789 		sd_printk(KERN_WARNING, sdkp,
1790 			  "Test WP failed, assume Write Enabled\n");
1791 	} else {
1792 		sdkp->write_prot = ((data.device_specific & 0x80) != 0);
1793 		set_disk_ro(sdkp->disk, sdkp->write_prot);
1794 		if (sdkp->first_scan || old_wp != sdkp->write_prot) {
1795 			sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
1796 				  sdkp->write_prot ? "on" : "off");
1797 			sd_printk(KERN_DEBUG, sdkp,
1798 				  "Mode Sense: %02x %02x %02x %02x\n",
1799 				  buffer[0], buffer[1], buffer[2], buffer[3]);
1800 		}
1801 	}
1802 }
1803 
1804 /*
1805  * sd_read_cache_type - called only from sd_revalidate_disk()
1806  * called with buffer of length SD_BUF_SIZE
1807  */
1808 static void
1809 sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
1810 {
1811 	int len = 0, res;
1812 	struct scsi_device *sdp = sdkp->device;
1813 
1814 	int dbd;
1815 	int modepage;
1816 	struct scsi_mode_data data;
1817 	struct scsi_sense_hdr sshdr;
1818 	int old_wce = sdkp->WCE;
1819 	int old_rcd = sdkp->RCD;
1820 	int old_dpofua = sdkp->DPOFUA;
1821 
1822 	if (sdp->skip_ms_page_8)
1823 		goto defaults;
1824 
1825 	if (sdp->type == TYPE_RBC) {
1826 		modepage = 6;
1827 		dbd = 8;
1828 	} else {
1829 		modepage = 8;
1830 		dbd = 0;
1831 	}
1832 
1833 	/* cautiously ask */
1834 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);
1835 
1836 	if (!scsi_status_is_good(res))
1837 		goto bad_sense;
1838 
1839 	if (!data.header_length) {
1840 		modepage = 6;
1841 		sd_printk(KERN_ERR, sdkp, "Missing header in MODE_SENSE response\n");
1842 	}
1843 
1844 	/* that went OK, now ask for the proper length */
1845 	len = data.length;
1846 
1847 	/*
1848 	 * We're only interested in the first three bytes, actually.
1849 	 * But the data cache page is defined for the first 20.
1850 	 */
1851 	if (len < 3)
1852 		goto bad_sense;
1853 	if (len > 20)
1854 		len = 20;
1855 
1856 	/* Take headers and block descriptors into account */
1857 	len += data.header_length + data.block_descriptor_length;
1858 	if (len > SD_BUF_SIZE)
1859 		goto bad_sense;
1860 
1861 	/* Get the data */
1862 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
1863 
1864 	if (scsi_status_is_good(res)) {
1865 		int offset = data.header_length + data.block_descriptor_length;
1866 
1867 		if (offset >= SD_BUF_SIZE - 2) {
1868 			sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
1869 			goto defaults;
1870 		}
1871 
1872 		if ((buffer[offset] & 0x3f) != modepage) {
1873 			sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
1874 			goto defaults;
1875 		}
1876 
1877 		if (modepage == 8) {
1878 			sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
1879 			sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
1880 		} else {
1881 			sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
1882 			sdkp->RCD = 0;
1883 		}
1884 
1885 		sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
1886 		if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
1887 			sd_printk(KERN_NOTICE, sdkp,
1888 				  "Uses READ/WRITE(6), disabling FUA\n");
1889 			sdkp->DPOFUA = 0;
1890 		}
1891 
1892 		if (sdkp->first_scan || old_wce != sdkp->WCE ||
1893 		    old_rcd != sdkp->RCD || old_dpofua != sdkp->DPOFUA)
1894 			sd_printk(KERN_NOTICE, sdkp,
1895 				  "Write cache: %s, read cache: %s, %s\n",
1896 				  sdkp->WCE ? "enabled" : "disabled",
1897 				  sdkp->RCD ? "disabled" : "enabled",
1898 				  sdkp->DPOFUA ? "supports DPO and FUA"
1899 				  : "doesn't support DPO or FUA");
1900 
1901 		return;
1902 	}
1903 
1904 bad_sense:
1905 	if (scsi_sense_valid(&sshdr) &&
1906 	    sshdr.sense_key == ILLEGAL_REQUEST &&
1907 	    sshdr.asc == 0x24 && sshdr.ascq == 0x0)
1908 		/* Invalid field in CDB */
1909 		sd_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
1910 	else
1911 		sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n");
1912 
1913 defaults:
1914 	sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
1915 	sdkp->WCE = 0;
1916 	sdkp->RCD = 0;
1917 	sdkp->DPOFUA = 0;
1918 }
1919 
1920 /*
1921  * The ATO bit indicates whether the DIF application tag is available
1922  * for use by the operating system.
1923  */
1924 void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
1925 {
1926 	int res, offset;
1927 	struct scsi_device *sdp = sdkp->device;
1928 	struct scsi_mode_data data;
1929 	struct scsi_sense_hdr sshdr;
1930 
1931 	if (sdp->type != TYPE_DISK)
1932 		return;
1933 
1934 	if (sdkp->protection_type == 0)
1935 		return;
1936 
1937 	res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
1938 			      SD_MAX_RETRIES, &data, &sshdr);
1939 
1940 	if (!scsi_status_is_good(res) || !data.header_length ||
1941 	    data.length < 6) {
1942 		sd_printk(KERN_WARNING, sdkp,
1943 			  "getting Control mode page failed, assume no ATO\n");
1944 
1945 		if (scsi_sense_valid(&sshdr))
1946 			sd_print_sense_hdr(sdkp, &sshdr);
1947 
1948 		return;
1949 	}
1950 
1951 	offset = data.header_length + data.block_descriptor_length;
1952 
1953 	if ((buffer[offset] & 0x3f) != 0x0a) {
1954 		sd_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
1955 		return;
1956 	}
1957 
1958 	if ((buffer[offset + 5] & 0x80) == 0)
1959 		return;
1960 
1961 	sdkp->ATO = 1;
1962 
1963 	return;
1964 }
1965 
1966 /**
1967  * sd_read_block_limits - Query disk device for preferred I/O sizes.
1968  * @disk: disk to query
1969  */
1970 static void sd_read_block_limits(struct scsi_disk *sdkp)
1971 {
1972 	struct request_queue *q = sdkp->disk->queue;
1973 	unsigned int sector_sz = sdkp->device->sector_size;
1974 	const int vpd_len = 64;
1975 	unsigned char *buffer = kmalloc(vpd_len, GFP_KERNEL);
1976 
1977 	if (!buffer ||
1978 	    /* Block Limits VPD */
1979 	    scsi_get_vpd_page(sdkp->device, 0xb0, buffer, vpd_len))
1980 		goto out;
1981 
1982 	blk_queue_io_min(sdkp->disk->queue,
1983 			 get_unaligned_be16(&buffer[6]) * sector_sz);
1984 	blk_queue_io_opt(sdkp->disk->queue,
1985 			 get_unaligned_be32(&buffer[12]) * sector_sz);
1986 
1987 	/* Thin provisioning enabled and page length indicates TP support */
1988 	if (sdkp->thin_provisioning && buffer[3] == 0x3c) {
1989 		unsigned int lba_count, desc_count, granularity;
1990 
1991 		lba_count = get_unaligned_be32(&buffer[20]);
1992 		desc_count = get_unaligned_be32(&buffer[24]);
1993 
1994 		if (lba_count) {
1995 			q->limits.max_discard_sectors =
1996 				lba_count * sector_sz >> 9;
1997 
1998 			if (desc_count)
1999 				sdkp->unmap = 1;
2000 		}
2001 
2002 		granularity = get_unaligned_be32(&buffer[28]);
2003 
2004 		if (granularity)
2005 			q->limits.discard_granularity = granularity * sector_sz;
2006 
2007 		if (buffer[32] & 0x80)
2008 			q->limits.discard_alignment =
2009 				get_unaligned_be32(&buffer[32]) & ~(1 << 31);
2010 	}
2011 
2012  out:
2013 	kfree(buffer);
2014 }
2015 
2016 /**
2017  * sd_read_block_characteristics - Query block dev. characteristics
2018  * @disk: disk to query
2019  */
2020 static void sd_read_block_characteristics(struct scsi_disk *sdkp)
2021 {
2022 	unsigned char *buffer;
2023 	u16 rot;
2024 	const int vpd_len = 64;
2025 
2026 	buffer = kmalloc(vpd_len, GFP_KERNEL);
2027 
2028 	if (!buffer ||
2029 	    /* Block Device Characteristics VPD */
2030 	    scsi_get_vpd_page(sdkp->device, 0xb1, buffer, vpd_len))
2031 		goto out;
2032 
2033 	rot = get_unaligned_be16(&buffer[4]);
2034 
2035 	if (rot == 1)
2036 		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, sdkp->disk->queue);
2037 
2038  out:
2039 	kfree(buffer);
2040 }
2041 
2042 static int sd_try_extended_inquiry(struct scsi_device *sdp)
2043 {
2044 	/*
2045 	 * Although VPD inquiries can go to SCSI-2 type devices,
2046 	 * some USB ones crash on receiving them, and the pages
2047 	 * we currently ask for are for SPC-3 and beyond
2048 	 */
2049 	if (sdp->scsi_level > SCSI_SPC_2)
2050 		return 1;
2051 	return 0;
2052 }
2053 
2054 /**
2055  *	sd_revalidate_disk - called the first time a new disk is seen,
2056  *	performs disk spin up, read_capacity, etc.
2057  *	@disk: struct gendisk we care about
2058  **/
2059 static int sd_revalidate_disk(struct gendisk *disk)
2060 {
2061 	struct scsi_disk *sdkp = scsi_disk(disk);
2062 	struct scsi_device *sdp = sdkp->device;
2063 	unsigned char *buffer;
2064 	unsigned ordered;
2065 
2066 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
2067 				      "sd_revalidate_disk\n"));
2068 
2069 	/*
2070 	 * If the device is offline, don't try and read capacity or any
2071 	 * of the other niceties.
2072 	 */
2073 	if (!scsi_device_online(sdp))
2074 		goto out;
2075 
2076 	buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
2077 	if (!buffer) {
2078 		sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
2079 			  "allocation failure.\n");
2080 		goto out;
2081 	}
2082 
2083 	sd_spinup_disk(sdkp);
2084 
2085 	/*
2086 	 * Without media there is no reason to ask; moreover, some devices
2087 	 * react badly if we do.
2088 	 */
2089 	if (sdkp->media_present) {
2090 		sd_read_capacity(sdkp, buffer);
2091 
2092 		if (sd_try_extended_inquiry(sdp)) {
2093 			sd_read_block_limits(sdkp);
2094 			sd_read_block_characteristics(sdkp);
2095 		}
2096 
2097 		sd_read_write_protect_flag(sdkp, buffer);
2098 		sd_read_cache_type(sdkp, buffer);
2099 		sd_read_app_tag_own(sdkp, buffer);
2100 	}
2101 
2102 	sdkp->first_scan = 0;
2103 
2104 	/*
2105 	 * We now have all cache related info, determine how we deal
2106 	 * with ordered requests.  Note that as the current SCSI
2107 	 * dispatch function can alter request order, we cannot use
2108 	 * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
2109 	 */
2110 	if (sdkp->WCE)
2111 		ordered = sdkp->DPOFUA
2112 			? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
2113 	else
2114 		ordered = QUEUE_ORDERED_DRAIN;
2115 
2116 	blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush);
2117 
2118 	set_capacity(disk, sdkp->capacity);
2119 	kfree(buffer);
2120 
2121  out:
2122 	return 0;
2123 }
2124 
2125 /**
2126  *	sd_unlock_native_capacity - unlock native capacity
2127  *	@disk: struct gendisk to set capacity for
2128  *
2129  *	Block layer calls this function if it detects that partitions
2130  *	on @disk reach beyond the end of the device.  If the SCSI host
2131  *	implements ->unlock_native_capacity() method, it's invoked to
2132  *	give it a chance to adjust the device capacity.
2133  *
2134  *	CONTEXT:
2135  *	Defined by block layer.  Might sleep.
2136  */
2137 static void sd_unlock_native_capacity(struct gendisk *disk)
2138 {
2139 	struct scsi_device *sdev = scsi_disk(disk)->device;
2140 
2141 	if (sdev->host->hostt->unlock_native_capacity)
2142 		sdev->host->hostt->unlock_native_capacity(sdev);
2143 }
2144 
2145 /**
2146  *	sd_format_disk_name - format disk name
2147  *	@prefix: name prefix - ie. "sd" for SCSI disks
2148  *	@index: index of the disk to format name for
2149  *	@buf: output buffer
2150  *	@buflen: length of the output buffer
2151  *
2152  *	SCSI disk names starts at sda.  The 26th device is sdz and the
2153  *	27th is sdaa.  The last one for two lettered suffix is sdzz
2154  *	which is followed by sdaaa.
2155  *
2156  *	This is basically 26 base counting with one extra 'nil' entry
2157  *	at the beginning from the second digit on and can be
2158  *	determined using similar method as 26 base conversion with the
2159  *	index shifted -1 after each digit is computed.
2160  *
2161  *	CONTEXT:
2162  *	Don't care.
2163  *
2164  *	RETURNS:
2165  *	0 on success, -errno on failure.
2166  */
2167 static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
2168 {
2169 	const int base = 'z' - 'a' + 1;
2170 	char *begin = buf + strlen(prefix);
2171 	char *end = buf + buflen;
2172 	char *p;
2173 	int unit;
2174 
2175 	p = end - 1;
2176 	*p = '\0';
2177 	unit = base;
2178 	do {
2179 		if (p == begin)
2180 			return -EINVAL;
2181 		*--p = 'a' + (index % unit);
2182 		index = (index / unit) - 1;
2183 	} while (index >= 0);
2184 
2185 	memmove(begin, p, end - p);
2186 	memcpy(buf, prefix, strlen(prefix));
2187 
2188 	return 0;
2189 }
2190 
2191 /*
2192  * The asynchronous part of sd_probe
2193  */
2194 static void sd_probe_async(void *data, async_cookie_t cookie)
2195 {
2196 	struct scsi_disk *sdkp = data;
2197 	struct scsi_device *sdp;
2198 	struct gendisk *gd;
2199 	u32 index;
2200 	struct device *dev;
2201 
2202 	sdp = sdkp->device;
2203 	gd = sdkp->disk;
2204 	index = sdkp->index;
2205 	dev = &sdp->sdev_gendev;
2206 
2207 	if (index < SD_MAX_DISKS) {
2208 		gd->major = sd_major((index & 0xf0) >> 4);
2209 		gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
2210 		gd->minors = SD_MINORS;
2211 	}
2212 	gd->fops = &sd_fops;
2213 	gd->private_data = &sdkp->driver;
2214 	gd->queue = sdkp->device->request_queue;
2215 
2216 	/* defaults, until the device tells us otherwise */
2217 	sdp->sector_size = 512;
2218 	sdkp->capacity = 0;
2219 	sdkp->media_present = 1;
2220 	sdkp->write_prot = 0;
2221 	sdkp->WCE = 0;
2222 	sdkp->RCD = 0;
2223 	sdkp->ATO = 0;
2224 	sdkp->first_scan = 1;
2225 
2226 	sd_revalidate_disk(gd);
2227 
2228 	blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);
2229 
2230 	gd->driverfs_dev = &sdp->sdev_gendev;
2231 	gd->flags = GENHD_FL_EXT_DEVT;
2232 	if (sdp->removable)
2233 		gd->flags |= GENHD_FL_REMOVABLE;
2234 
2235 	dev_set_drvdata(dev, sdkp);
2236 	add_disk(gd);
2237 	sd_dif_config_host(sdkp);
2238 
2239 	sd_revalidate_disk(gd);
2240 
2241 	sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
2242 		  sdp->removable ? "removable " : "");
2243 	put_device(&sdkp->dev);
2244 }
2245 
2246 /**
2247  *	sd_probe - called during driver initialization and whenever a
2248  *	new scsi device is attached to the system. It is called once
2249  *	for each scsi device (not just disks) present.
2250  *	@dev: pointer to device object
2251  *
2252  *	Returns 0 if successful (or not interested in this scsi device
2253  *	(e.g. scanner)); 1 when there is an error.
2254  *
2255  *	Note: this function is invoked from the scsi mid-level.
2256  *	This function sets up the mapping between a given
2257  *	<host,channel,id,lun> (found in sdp) and new device name
2258  *	(e.g. /dev/sda). More precisely it is the block device major
2259  *	and minor number that is chosen here.
2260  *
2261  *	Assume sd_attach is not re-entrant (for time being)
2262  *	Also think about sd_attach() and sd_remove() running coincidentally.
2263  **/
2264 static int sd_probe(struct device *dev)
2265 {
2266 	struct scsi_device *sdp = to_scsi_device(dev);
2267 	struct scsi_disk *sdkp;
2268 	struct gendisk *gd;
2269 	u32 index;
2270 	int error;
2271 
2272 	error = -ENODEV;
2273 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
2274 		goto out;
2275 
2276 	SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
2277 					"sd_attach\n"));
2278 
2279 	error = -ENOMEM;
2280 	sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
2281 	if (!sdkp)
2282 		goto out;
2283 
2284 	gd = alloc_disk(SD_MINORS);
2285 	if (!gd)
2286 		goto out_free;
2287 
2288 	do {
2289 		if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
2290 			goto out_put;
2291 
2292 		spin_lock(&sd_index_lock);
2293 		error = ida_get_new(&sd_index_ida, &index);
2294 		spin_unlock(&sd_index_lock);
2295 	} while (error == -EAGAIN);
2296 
2297 	if (error)
2298 		goto out_put;
2299 
2300 	error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
2301 	if (error)
2302 		goto out_free_index;
2303 
2304 	sdkp->device = sdp;
2305 	sdkp->driver = &sd_template;
2306 	sdkp->disk = gd;
2307 	sdkp->index = index;
2308 	sdkp->openers = 0;
2309 	sdkp->previous_state = 1;
2310 
2311 	if (!sdp->request_queue->rq_timeout) {
2312 		if (sdp->type != TYPE_MOD)
2313 			blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
2314 		else
2315 			blk_queue_rq_timeout(sdp->request_queue,
2316 					     SD_MOD_TIMEOUT);
2317 	}
2318 
2319 	device_initialize(&sdkp->dev);
2320 	sdkp->dev.parent = &sdp->sdev_gendev;
2321 	sdkp->dev.class = &sd_disk_class;
2322 	dev_set_name(&sdkp->dev, dev_name(&sdp->sdev_gendev));
2323 
2324 	if (device_add(&sdkp->dev))
2325 		goto out_free_index;
2326 
2327 	get_device(&sdp->sdev_gendev);
2328 
2329 	get_device(&sdkp->dev);	/* prevent release before async_schedule */
2330 	async_schedule(sd_probe_async, sdkp);
2331 
2332 	return 0;
2333 
2334  out_free_index:
2335 	spin_lock(&sd_index_lock);
2336 	ida_remove(&sd_index_ida, index);
2337 	spin_unlock(&sd_index_lock);
2338  out_put:
2339 	put_disk(gd);
2340  out_free:
2341 	kfree(sdkp);
2342  out:
2343 	return error;
2344 }
2345 
2346 /**
2347  *	sd_remove - called whenever a scsi disk (previously recognized by
2348  *	sd_probe) is detached from the system. It is called (potentially
2349  *	multiple times) during sd module unload.
2350  *	@sdp: pointer to mid level scsi device object
2351  *
2352  *	Note: this function is invoked from the scsi mid-level.
2353  *	This function potentially frees up a device name (e.g. /dev/sdc)
2354  *	that could be re-used by a subsequent sd_probe().
2355  *	This function is not called when the built-in sd driver is "exit-ed".
2356  **/
2357 static int sd_remove(struct device *dev)
2358 {
2359 	struct scsi_disk *sdkp;
2360 
2361 	async_synchronize_full();
2362 	sdkp = dev_get_drvdata(dev);
2363 	blk_queue_prep_rq(sdkp->device->request_queue, scsi_prep_fn);
2364 	device_del(&sdkp->dev);
2365 	del_gendisk(sdkp->disk);
2366 	sd_shutdown(dev);
2367 
2368 	mutex_lock(&sd_ref_mutex);
2369 	dev_set_drvdata(dev, NULL);
2370 	put_device(&sdkp->dev);
2371 	mutex_unlock(&sd_ref_mutex);
2372 
2373 	return 0;
2374 }
2375 
2376 /**
2377  *	scsi_disk_release - Called to free the scsi_disk structure
2378  *	@dev: pointer to embedded class device
2379  *
2380  *	sd_ref_mutex must be held entering this routine.  Because it is
2381  *	called on last put, you should always use the scsi_disk_get()
2382  *	scsi_disk_put() helpers which manipulate the semaphore directly
2383  *	and never do a direct put_device.
2384  **/
2385 static void scsi_disk_release(struct device *dev)
2386 {
2387 	struct scsi_disk *sdkp = to_scsi_disk(dev);
2388 	struct gendisk *disk = sdkp->disk;
2389 
2390 	spin_lock(&sd_index_lock);
2391 	ida_remove(&sd_index_ida, sdkp->index);
2392 	spin_unlock(&sd_index_lock);
2393 
2394 	disk->private_data = NULL;
2395 	put_disk(disk);
2396 	put_device(&sdkp->device->sdev_gendev);
2397 
2398 	kfree(sdkp);
2399 }
2400 
2401 static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
2402 {
2403 	unsigned char cmd[6] = { START_STOP };	/* START_VALID */
2404 	struct scsi_sense_hdr sshdr;
2405 	struct scsi_device *sdp = sdkp->device;
2406 	int res;
2407 
2408 	if (start)
2409 		cmd[4] |= 1;	/* START */
2410 
2411 	if (sdp->start_stop_pwr_cond)
2412 		cmd[4] |= start ? 1 << 4 : 3 << 4;	/* Active or Standby */
2413 
2414 	if (!scsi_device_online(sdp))
2415 		return -ENODEV;
2416 
2417 	res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
2418 			       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
2419 	if (res) {
2420 		sd_printk(KERN_WARNING, sdkp, "START_STOP FAILED\n");
2421 		sd_print_result(sdkp, res);
2422 		if (driver_byte(res) & DRIVER_SENSE)
2423 			sd_print_sense_hdr(sdkp, &sshdr);
2424 	}
2425 
2426 	return res;
2427 }
2428 
2429 /*
2430  * Send a SYNCHRONIZE CACHE instruction down to the device through
2431  * the normal SCSI command structure.  Wait for the command to
2432  * complete.
2433  */
2434 static void sd_shutdown(struct device *dev)
2435 {
2436 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2437 
2438 	if (!sdkp)
2439 		return;         /* this can happen */
2440 
2441 	if (sdkp->WCE) {
2442 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2443 		sd_sync_cache(sdkp);
2444 	}
2445 
2446 	if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
2447 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2448 		sd_start_stop_device(sdkp, 0);
2449 	}
2450 
2451 	scsi_disk_put(sdkp);
2452 }
2453 
2454 static int sd_suspend(struct device *dev, pm_message_t mesg)
2455 {
2456 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2457 	int ret = 0;
2458 
2459 	if (!sdkp)
2460 		return 0;	/* this can happen */
2461 
2462 	if (sdkp->WCE) {
2463 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2464 		ret = sd_sync_cache(sdkp);
2465 		if (ret)
2466 			goto done;
2467 	}
2468 
2469 	if ((mesg.event & PM_EVENT_SLEEP) && sdkp->device->manage_start_stop) {
2470 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2471 		ret = sd_start_stop_device(sdkp, 0);
2472 	}
2473 
2474 done:
2475 	scsi_disk_put(sdkp);
2476 	return ret;
2477 }
2478 
2479 static int sd_resume(struct device *dev)
2480 {
2481 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2482 	int ret = 0;
2483 
2484 	if (!sdkp->device->manage_start_stop)
2485 		goto done;
2486 
2487 	sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
2488 	ret = sd_start_stop_device(sdkp, 1);
2489 
2490 done:
2491 	scsi_disk_put(sdkp);
2492 	return ret;
2493 }
2494 
2495 /**
2496  *	init_sd - entry point for this driver (both when built in or when
2497  *	a module).
2498  *
2499  *	Note: this function registers this driver with the scsi mid-level.
2500  **/
2501 static int __init init_sd(void)
2502 {
2503 	int majors = 0, i, err;
2504 
2505 	SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
2506 
2507 	for (i = 0; i < SD_MAJORS; i++)
2508 		if (register_blkdev(sd_major(i), "sd") == 0)
2509 			majors++;
2510 
2511 	if (!majors)
2512 		return -ENODEV;
2513 
2514 	err = class_register(&sd_disk_class);
2515 	if (err)
2516 		goto err_out;
2517 
2518 	err = scsi_register_driver(&sd_template.gendrv);
2519 	if (err)
2520 		goto err_out_class;
2521 
2522 	sd_cdb_cache = kmem_cache_create("sd_ext_cdb", SD_EXT_CDB_SIZE,
2523 					 0, 0, NULL);
2524 	if (!sd_cdb_cache) {
2525 		printk(KERN_ERR "sd: can't init extended cdb cache\n");
2526 		goto err_out_class;
2527 	}
2528 
2529 	sd_cdb_pool = mempool_create_slab_pool(SD_MEMPOOL_SIZE, sd_cdb_cache);
2530 	if (!sd_cdb_pool) {
2531 		printk(KERN_ERR "sd: can't init extended cdb pool\n");
2532 		goto err_out_cache;
2533 	}
2534 
2535 	return 0;
2536 
2537 err_out_cache:
2538 	kmem_cache_destroy(sd_cdb_cache);
2539 
2540 err_out_class:
2541 	class_unregister(&sd_disk_class);
2542 err_out:
2543 	for (i = 0; i < SD_MAJORS; i++)
2544 		unregister_blkdev(sd_major(i), "sd");
2545 	return err;
2546 }
2547 
2548 /**
2549  *	exit_sd - exit point for this driver (when it is a module).
2550  *
2551  *	Note: this function unregisters this driver from the scsi mid-level.
2552  **/
2553 static void __exit exit_sd(void)
2554 {
2555 	int i;
2556 
2557 	SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
2558 
2559 	mempool_destroy(sd_cdb_pool);
2560 	kmem_cache_destroy(sd_cdb_cache);
2561 
2562 	scsi_unregister_driver(&sd_template.gendrv);
2563 	class_unregister(&sd_disk_class);
2564 
2565 	for (i = 0; i < SD_MAJORS; i++)
2566 		unregister_blkdev(sd_major(i), "sd");
2567 }
2568 
2569 module_init(init_sd);
2570 module_exit(exit_sd);
2571 
2572 static void sd_print_sense_hdr(struct scsi_disk *sdkp,
2573 			       struct scsi_sense_hdr *sshdr)
2574 {
2575 	sd_printk(KERN_INFO, sdkp, "");
2576 	scsi_show_sense_hdr(sshdr);
2577 	sd_printk(KERN_INFO, sdkp, "");
2578 	scsi_show_extd_sense(sshdr->asc, sshdr->ascq);
2579 }
2580 
2581 static void sd_print_result(struct scsi_disk *sdkp, int result)
2582 {
2583 	sd_printk(KERN_INFO, sdkp, "");
2584 	scsi_show_result(result);
2585 }
2586 
2587