xref: /linux/drivers/scsi/sd.c (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
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 int  sd_probe(struct device *);
101 static int  sd_remove(struct device *);
102 static void sd_shutdown(struct device *);
103 static int sd_suspend(struct device *, pm_message_t state);
104 static int sd_resume(struct device *);
105 static void sd_rescan(struct device *);
106 static int sd_done(struct scsi_cmnd *);
107 static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
108 static void scsi_disk_release(struct device *cdev);
109 static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
110 static void sd_print_result(struct scsi_disk *, int);
111 
112 static DEFINE_SPINLOCK(sd_index_lock);
113 static DEFINE_IDA(sd_index_ida);
114 
115 /* This semaphore is used to mediate the 0->1 reference get in the
116  * face of object destruction (i.e. we can't allow a get on an
117  * object after last put) */
118 static DEFINE_MUTEX(sd_ref_mutex);
119 
120 struct kmem_cache *sd_cdb_cache;
121 mempool_t *sd_cdb_pool;
122 
123 static const char *sd_cache_types[] = {
124 	"write through", "none", "write back",
125 	"write back, no read (daft)"
126 };
127 
128 static ssize_t
129 sd_store_cache_type(struct device *dev, struct device_attribute *attr,
130 		    const char *buf, size_t count)
131 {
132 	int i, ct = -1, rcd, wce, sp;
133 	struct scsi_disk *sdkp = to_scsi_disk(dev);
134 	struct scsi_device *sdp = sdkp->device;
135 	char buffer[64];
136 	char *buffer_data;
137 	struct scsi_mode_data data;
138 	struct scsi_sense_hdr sshdr;
139 	int len;
140 
141 	if (sdp->type != TYPE_DISK)
142 		/* no cache control on RBC devices; theoretically they
143 		 * can do it, but there's probably so many exceptions
144 		 * it's not worth the risk */
145 		return -EINVAL;
146 
147 	for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {
148 		const int len = strlen(sd_cache_types[i]);
149 		if (strncmp(sd_cache_types[i], buf, len) == 0 &&
150 		    buf[len] == '\n') {
151 			ct = i;
152 			break;
153 		}
154 	}
155 	if (ct < 0)
156 		return -EINVAL;
157 	rcd = ct & 0x01 ? 1 : 0;
158 	wce = ct & 0x02 ? 1 : 0;
159 	if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
160 			    SD_MAX_RETRIES, &data, NULL))
161 		return -EINVAL;
162 	len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
163 		  data.block_descriptor_length);
164 	buffer_data = buffer + data.header_length +
165 		data.block_descriptor_length;
166 	buffer_data[2] &= ~0x05;
167 	buffer_data[2] |= wce << 2 | rcd;
168 	sp = buffer_data[0] & 0x80 ? 1 : 0;
169 
170 	if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
171 			     SD_MAX_RETRIES, &data, &sshdr)) {
172 		if (scsi_sense_valid(&sshdr))
173 			sd_print_sense_hdr(sdkp, &sshdr);
174 		return -EINVAL;
175 	}
176 	revalidate_disk(sdkp->disk);
177 	return count;
178 }
179 
180 static ssize_t
181 sd_store_manage_start_stop(struct device *dev, struct device_attribute *attr,
182 			   const char *buf, size_t count)
183 {
184 	struct scsi_disk *sdkp = to_scsi_disk(dev);
185 	struct scsi_device *sdp = sdkp->device;
186 
187 	if (!capable(CAP_SYS_ADMIN))
188 		return -EACCES;
189 
190 	sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
191 
192 	return count;
193 }
194 
195 static ssize_t
196 sd_store_allow_restart(struct device *dev, struct device_attribute *attr,
197 		       const char *buf, size_t count)
198 {
199 	struct scsi_disk *sdkp = to_scsi_disk(dev);
200 	struct scsi_device *sdp = sdkp->device;
201 
202 	if (!capable(CAP_SYS_ADMIN))
203 		return -EACCES;
204 
205 	if (sdp->type != TYPE_DISK)
206 		return -EINVAL;
207 
208 	sdp->allow_restart = simple_strtoul(buf, NULL, 10);
209 
210 	return count;
211 }
212 
213 static ssize_t
214 sd_show_cache_type(struct device *dev, struct device_attribute *attr,
215 		   char *buf)
216 {
217 	struct scsi_disk *sdkp = to_scsi_disk(dev);
218 	int ct = sdkp->RCD + 2*sdkp->WCE;
219 
220 	return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
221 }
222 
223 static ssize_t
224 sd_show_fua(struct device *dev, struct device_attribute *attr, char *buf)
225 {
226 	struct scsi_disk *sdkp = to_scsi_disk(dev);
227 
228 	return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
229 }
230 
231 static ssize_t
232 sd_show_manage_start_stop(struct device *dev, struct device_attribute *attr,
233 			  char *buf)
234 {
235 	struct scsi_disk *sdkp = to_scsi_disk(dev);
236 	struct scsi_device *sdp = sdkp->device;
237 
238 	return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
239 }
240 
241 static ssize_t
242 sd_show_allow_restart(struct device *dev, struct device_attribute *attr,
243 		      char *buf)
244 {
245 	struct scsi_disk *sdkp = to_scsi_disk(dev);
246 
247 	return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
248 }
249 
250 static ssize_t
251 sd_show_protection_type(struct device *dev, struct device_attribute *attr,
252 			char *buf)
253 {
254 	struct scsi_disk *sdkp = to_scsi_disk(dev);
255 
256 	return snprintf(buf, 20, "%u\n", sdkp->protection_type);
257 }
258 
259 static ssize_t
260 sd_show_app_tag_own(struct device *dev, struct device_attribute *attr,
261 		    char *buf)
262 {
263 	struct scsi_disk *sdkp = to_scsi_disk(dev);
264 
265 	return snprintf(buf, 20, "%u\n", sdkp->ATO);
266 }
267 
268 static ssize_t
269 sd_show_thin_provisioning(struct device *dev, struct device_attribute *attr,
270 			  char *buf)
271 {
272 	struct scsi_disk *sdkp = to_scsi_disk(dev);
273 
274 	return snprintf(buf, 20, "%u\n", sdkp->thin_provisioning);
275 }
276 
277 static struct device_attribute sd_disk_attrs[] = {
278 	__ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
279 	       sd_store_cache_type),
280 	__ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
281 	__ATTR(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
282 	       sd_store_allow_restart),
283 	__ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
284 	       sd_store_manage_start_stop),
285 	__ATTR(protection_type, S_IRUGO, sd_show_protection_type, NULL),
286 	__ATTR(app_tag_own, S_IRUGO, sd_show_app_tag_own, NULL),
287 	__ATTR(thin_provisioning, S_IRUGO, sd_show_thin_provisioning, NULL),
288 	__ATTR_NULL,
289 };
290 
291 static struct class sd_disk_class = {
292 	.name		= "scsi_disk",
293 	.owner		= THIS_MODULE,
294 	.dev_release	= scsi_disk_release,
295 	.dev_attrs	= sd_disk_attrs,
296 };
297 
298 static struct scsi_driver sd_template = {
299 	.owner			= THIS_MODULE,
300 	.gendrv = {
301 		.name		= "sd",
302 		.probe		= sd_probe,
303 		.remove		= sd_remove,
304 		.suspend	= sd_suspend,
305 		.resume		= sd_resume,
306 		.shutdown	= sd_shutdown,
307 	},
308 	.rescan			= sd_rescan,
309 	.done			= sd_done,
310 };
311 
312 /*
313  * Device no to disk mapping:
314  *
315  *       major         disc2     disc  p1
316  *   |............|.............|....|....| <- dev_t
317  *    31        20 19          8 7  4 3  0
318  *
319  * Inside a major, we have 16k disks, however mapped non-
320  * contiguously. The first 16 disks are for major0, the next
321  * ones with major1, ... Disk 256 is for major0 again, disk 272
322  * for major1, ...
323  * As we stay compatible with our numbering scheme, we can reuse
324  * the well-know SCSI majors 8, 65--71, 136--143.
325  */
326 static int sd_major(int major_idx)
327 {
328 	switch (major_idx) {
329 	case 0:
330 		return SCSI_DISK0_MAJOR;
331 	case 1 ... 7:
332 		return SCSI_DISK1_MAJOR + major_idx - 1;
333 	case 8 ... 15:
334 		return SCSI_DISK8_MAJOR + major_idx - 8;
335 	default:
336 		BUG();
337 		return 0;	/* shut up gcc */
338 	}
339 }
340 
341 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
342 {
343 	struct scsi_disk *sdkp = NULL;
344 
345 	if (disk->private_data) {
346 		sdkp = scsi_disk(disk);
347 		if (scsi_device_get(sdkp->device) == 0)
348 			get_device(&sdkp->dev);
349 		else
350 			sdkp = NULL;
351 	}
352 	return sdkp;
353 }
354 
355 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
356 {
357 	struct scsi_disk *sdkp;
358 
359 	mutex_lock(&sd_ref_mutex);
360 	sdkp = __scsi_disk_get(disk);
361 	mutex_unlock(&sd_ref_mutex);
362 	return sdkp;
363 }
364 
365 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
366 {
367 	struct scsi_disk *sdkp;
368 
369 	mutex_lock(&sd_ref_mutex);
370 	sdkp = dev_get_drvdata(dev);
371 	if (sdkp)
372 		sdkp = __scsi_disk_get(sdkp->disk);
373 	mutex_unlock(&sd_ref_mutex);
374 	return sdkp;
375 }
376 
377 static void scsi_disk_put(struct scsi_disk *sdkp)
378 {
379 	struct scsi_device *sdev = sdkp->device;
380 
381 	mutex_lock(&sd_ref_mutex);
382 	put_device(&sdkp->dev);
383 	scsi_device_put(sdev);
384 	mutex_unlock(&sd_ref_mutex);
385 }
386 
387 static void sd_prot_op(struct scsi_cmnd *scmd, unsigned int dif)
388 {
389 	unsigned int prot_op = SCSI_PROT_NORMAL;
390 	unsigned int dix = scsi_prot_sg_count(scmd);
391 
392 	if (scmd->sc_data_direction == DMA_FROM_DEVICE) {
393 		if (dif && dix)
394 			prot_op = SCSI_PROT_READ_PASS;
395 		else if (dif && !dix)
396 			prot_op = SCSI_PROT_READ_STRIP;
397 		else if (!dif && dix)
398 			prot_op = SCSI_PROT_READ_INSERT;
399 	} else {
400 		if (dif && dix)
401 			prot_op = SCSI_PROT_WRITE_PASS;
402 		else if (dif && !dix)
403 			prot_op = SCSI_PROT_WRITE_INSERT;
404 		else if (!dif && dix)
405 			prot_op = SCSI_PROT_WRITE_STRIP;
406 	}
407 
408 	scsi_set_prot_op(scmd, prot_op);
409 	scsi_set_prot_type(scmd, dif);
410 }
411 
412 /**
413  * sd_prepare_discard - unmap blocks on thinly provisioned device
414  * @rq: Request to prepare
415  *
416  * Will issue either UNMAP or WRITE SAME(16) depending on preference
417  * indicated by target device.
418  **/
419 static int sd_prepare_discard(struct request *rq)
420 {
421 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
422 	struct bio *bio = rq->bio;
423 	sector_t sector = bio->bi_sector;
424 	unsigned int num = bio_sectors(bio);
425 
426 	if (sdkp->device->sector_size == 4096) {
427 		sector >>= 3;
428 		num >>= 3;
429 	}
430 
431 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
432 	rq->timeout = SD_TIMEOUT;
433 
434 	memset(rq->cmd, 0, rq->cmd_len);
435 
436 	if (sdkp->unmap) {
437 		char *buf = kmap_atomic(bio_page(bio), KM_USER0);
438 
439 		rq->cmd[0] = UNMAP;
440 		rq->cmd[8] = 24;
441 		rq->cmd_len = 10;
442 
443 		/* Ensure that data length matches payload */
444 		rq->__data_len = bio->bi_size = bio->bi_io_vec->bv_len = 24;
445 
446 		put_unaligned_be16(6 + 16, &buf[0]);
447 		put_unaligned_be16(16, &buf[2]);
448 		put_unaligned_be64(sector, &buf[8]);
449 		put_unaligned_be32(num, &buf[16]);
450 
451 		kunmap_atomic(buf, KM_USER0);
452 	} else {
453 		rq->cmd[0] = WRITE_SAME_16;
454 		rq->cmd[1] = 0x8; /* UNMAP */
455 		put_unaligned_be64(sector, &rq->cmd[2]);
456 		put_unaligned_be32(num, &rq->cmd[10]);
457 		rq->cmd_len = 16;
458 	}
459 
460 	return BLKPREP_OK;
461 }
462 
463 /**
464  *	sd_init_command - build a scsi (read or write) command from
465  *	information in the request structure.
466  *	@SCpnt: pointer to mid-level's per scsi command structure that
467  *	contains request and into which the scsi command is written
468  *
469  *	Returns 1 if successful and 0 if error (or cannot be done now).
470  **/
471 static int sd_prep_fn(struct request_queue *q, struct request *rq)
472 {
473 	struct scsi_cmnd *SCpnt;
474 	struct scsi_device *sdp = q->queuedata;
475 	struct gendisk *disk = rq->rq_disk;
476 	struct scsi_disk *sdkp;
477 	sector_t block = blk_rq_pos(rq);
478 	sector_t threshold;
479 	unsigned int this_count = blk_rq_sectors(rq);
480 	int ret, host_dif;
481 	unsigned char protect;
482 
483 	/*
484 	 * Discard request come in as REQ_TYPE_FS but we turn them into
485 	 * block PC requests to make life easier.
486 	 */
487 	if (blk_discard_rq(rq))
488 		ret = sd_prepare_discard(rq);
489 
490 	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
491 		ret = scsi_setup_blk_pc_cmnd(sdp, rq);
492 		goto out;
493 	} else if (rq->cmd_type != REQ_TYPE_FS) {
494 		ret = BLKPREP_KILL;
495 		goto out;
496 	}
497 	ret = scsi_setup_fs_cmnd(sdp, rq);
498 	if (ret != BLKPREP_OK)
499 		goto out;
500 	SCpnt = rq->special;
501 	sdkp = scsi_disk(disk);
502 
503 	/* from here on until we're complete, any goto out
504 	 * is used for a killable error condition */
505 	ret = BLKPREP_KILL;
506 
507 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
508 					"sd_init_command: block=%llu, "
509 					"count=%d\n",
510 					(unsigned long long)block,
511 					this_count));
512 
513 	if (!sdp || !scsi_device_online(sdp) ||
514 	    block + blk_rq_sectors(rq) > get_capacity(disk)) {
515 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
516 						"Finishing %u sectors\n",
517 						blk_rq_sectors(rq)));
518 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
519 						"Retry with 0x%p\n", SCpnt));
520 		goto out;
521 	}
522 
523 	if (sdp->changed) {
524 		/*
525 		 * quietly refuse to do anything to a changed disc until
526 		 * the changed bit has been reset
527 		 */
528 		/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
529 		goto out;
530 	}
531 
532 	/*
533 	 * Some SD card readers can't handle multi-sector accesses which touch
534 	 * the last one or two hardware sectors.  Split accesses as needed.
535 	 */
536 	threshold = get_capacity(disk) - SD_LAST_BUGGY_SECTORS *
537 		(sdp->sector_size / 512);
538 
539 	if (unlikely(sdp->last_sector_bug && block + this_count > threshold)) {
540 		if (block < threshold) {
541 			/* Access up to the threshold but not beyond */
542 			this_count = threshold - block;
543 		} else {
544 			/* Access only a single hardware sector */
545 			this_count = sdp->sector_size / 512;
546 		}
547 	}
548 
549 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
550 					(unsigned long long)block));
551 
552 	/*
553 	 * If we have a 1K hardware sectorsize, prevent access to single
554 	 * 512 byte sectors.  In theory we could handle this - in fact
555 	 * the scsi cdrom driver must be able to handle this because
556 	 * we typically use 1K blocksizes, and cdroms typically have
557 	 * 2K hardware sectorsizes.  Of course, things are simpler
558 	 * with the cdrom, since it is read-only.  For performance
559 	 * reasons, the filesystems should be able to handle this
560 	 * and not force the scsi disk driver to use bounce buffers
561 	 * for this.
562 	 */
563 	if (sdp->sector_size == 1024) {
564 		if ((block & 1) || (blk_rq_sectors(rq) & 1)) {
565 			scmd_printk(KERN_ERR, SCpnt,
566 				    "Bad block number requested\n");
567 			goto out;
568 		} else {
569 			block = block >> 1;
570 			this_count = this_count >> 1;
571 		}
572 	}
573 	if (sdp->sector_size == 2048) {
574 		if ((block & 3) || (blk_rq_sectors(rq) & 3)) {
575 			scmd_printk(KERN_ERR, SCpnt,
576 				    "Bad block number requested\n");
577 			goto out;
578 		} else {
579 			block = block >> 2;
580 			this_count = this_count >> 2;
581 		}
582 	}
583 	if (sdp->sector_size == 4096) {
584 		if ((block & 7) || (blk_rq_sectors(rq) & 7)) {
585 			scmd_printk(KERN_ERR, SCpnt,
586 				    "Bad block number requested\n");
587 			goto out;
588 		} else {
589 			block = block >> 3;
590 			this_count = this_count >> 3;
591 		}
592 	}
593 	if (rq_data_dir(rq) == WRITE) {
594 		if (!sdp->writeable) {
595 			goto out;
596 		}
597 		SCpnt->cmnd[0] = WRITE_6;
598 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
599 
600 		if (blk_integrity_rq(rq) &&
601 		    sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
602 			goto out;
603 
604 	} else if (rq_data_dir(rq) == READ) {
605 		SCpnt->cmnd[0] = READ_6;
606 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
607 	} else {
608 		scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
609 		goto out;
610 	}
611 
612 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
613 					"%s %d/%u 512 byte blocks.\n",
614 					(rq_data_dir(rq) == WRITE) ?
615 					"writing" : "reading", this_count,
616 					blk_rq_sectors(rq)));
617 
618 	/* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
619 	host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
620 	if (host_dif)
621 		protect = 1 << 5;
622 	else
623 		protect = 0;
624 
625 	if (host_dif == SD_DIF_TYPE2_PROTECTION) {
626 		SCpnt->cmnd = mempool_alloc(sd_cdb_pool, GFP_ATOMIC);
627 
628 		if (unlikely(SCpnt->cmnd == NULL)) {
629 			ret = BLKPREP_DEFER;
630 			goto out;
631 		}
632 
633 		SCpnt->cmd_len = SD_EXT_CDB_SIZE;
634 		memset(SCpnt->cmnd, 0, SCpnt->cmd_len);
635 		SCpnt->cmnd[0] = VARIABLE_LENGTH_CMD;
636 		SCpnt->cmnd[7] = 0x18;
637 		SCpnt->cmnd[9] = (rq_data_dir(rq) == READ) ? READ_32 : WRITE_32;
638 		SCpnt->cmnd[10] = protect | (blk_fua_rq(rq) ? 0x8 : 0);
639 
640 		/* LBA */
641 		SCpnt->cmnd[12] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
642 		SCpnt->cmnd[13] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
643 		SCpnt->cmnd[14] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
644 		SCpnt->cmnd[15] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
645 		SCpnt->cmnd[16] = (unsigned char) (block >> 24) & 0xff;
646 		SCpnt->cmnd[17] = (unsigned char) (block >> 16) & 0xff;
647 		SCpnt->cmnd[18] = (unsigned char) (block >> 8) & 0xff;
648 		SCpnt->cmnd[19] = (unsigned char) block & 0xff;
649 
650 		/* Expected Indirect LBA */
651 		SCpnt->cmnd[20] = (unsigned char) (block >> 24) & 0xff;
652 		SCpnt->cmnd[21] = (unsigned char) (block >> 16) & 0xff;
653 		SCpnt->cmnd[22] = (unsigned char) (block >> 8) & 0xff;
654 		SCpnt->cmnd[23] = (unsigned char) block & 0xff;
655 
656 		/* Transfer length */
657 		SCpnt->cmnd[28] = (unsigned char) (this_count >> 24) & 0xff;
658 		SCpnt->cmnd[29] = (unsigned char) (this_count >> 16) & 0xff;
659 		SCpnt->cmnd[30] = (unsigned char) (this_count >> 8) & 0xff;
660 		SCpnt->cmnd[31] = (unsigned char) this_count & 0xff;
661 	} else if (block > 0xffffffff) {
662 		SCpnt->cmnd[0] += READ_16 - READ_6;
663 		SCpnt->cmnd[1] = protect | (blk_fua_rq(rq) ? 0x8 : 0);
664 		SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
665 		SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
666 		SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
667 		SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
668 		SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
669 		SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
670 		SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
671 		SCpnt->cmnd[9] = (unsigned char) block & 0xff;
672 		SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
673 		SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
674 		SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
675 		SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
676 		SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
677 	} else if ((this_count > 0xff) || (block > 0x1fffff) ||
678 		   scsi_device_protection(SCpnt->device) ||
679 		   SCpnt->device->use_10_for_rw) {
680 		if (this_count > 0xffff)
681 			this_count = 0xffff;
682 
683 		SCpnt->cmnd[0] += READ_10 - READ_6;
684 		SCpnt->cmnd[1] = protect | (blk_fua_rq(rq) ? 0x8 : 0);
685 		SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
686 		SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
687 		SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
688 		SCpnt->cmnd[5] = (unsigned char) block & 0xff;
689 		SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
690 		SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
691 		SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
692 	} else {
693 		if (unlikely(blk_fua_rq(rq))) {
694 			/*
695 			 * This happens only if this drive failed
696 			 * 10byte rw command with ILLEGAL_REQUEST
697 			 * during operation and thus turned off
698 			 * use_10_for_rw.
699 			 */
700 			scmd_printk(KERN_ERR, SCpnt,
701 				    "FUA write on READ/WRITE(6) drive\n");
702 			goto out;
703 		}
704 
705 		SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
706 		SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
707 		SCpnt->cmnd[3] = (unsigned char) block & 0xff;
708 		SCpnt->cmnd[4] = (unsigned char) this_count;
709 		SCpnt->cmnd[5] = 0;
710 	}
711 	SCpnt->sdb.length = this_count * sdp->sector_size;
712 
713 	/* If DIF or DIX is enabled, tell HBA how to handle request */
714 	if (host_dif || scsi_prot_sg_count(SCpnt))
715 		sd_prot_op(SCpnt, host_dif);
716 
717 	/*
718 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
719 	 * host adapter, it's safe to assume that we can at least transfer
720 	 * this many bytes between each connect / disconnect.
721 	 */
722 	SCpnt->transfersize = sdp->sector_size;
723 	SCpnt->underflow = this_count << 9;
724 	SCpnt->allowed = SD_MAX_RETRIES;
725 
726 	/*
727 	 * This indicates that the command is ready from our end to be
728 	 * queued.
729 	 */
730 	ret = BLKPREP_OK;
731  out:
732 	return scsi_prep_return(q, rq, ret);
733 }
734 
735 /**
736  *	sd_open - open a scsi disk device
737  *	@inode: only i_rdev member may be used
738  *	@filp: only f_mode and f_flags may be used
739  *
740  *	Returns 0 if successful. Returns a negated errno value in case
741  *	of error.
742  *
743  *	Note: This can be called from a user context (e.g. fsck(1) )
744  *	or from within the kernel (e.g. as a result of a mount(1) ).
745  *	In the latter case @inode and @filp carry an abridged amount
746  *	of information as noted above.
747  **/
748 static int sd_open(struct block_device *bdev, fmode_t mode)
749 {
750 	struct scsi_disk *sdkp = scsi_disk_get(bdev->bd_disk);
751 	struct scsi_device *sdev;
752 	int retval;
753 
754 	if (!sdkp)
755 		return -ENXIO;
756 
757 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
758 
759 	sdev = sdkp->device;
760 
761 	/*
762 	 * If the device is in error recovery, wait until it is done.
763 	 * If the device is offline, then disallow any access to it.
764 	 */
765 	retval = -ENXIO;
766 	if (!scsi_block_when_processing_errors(sdev))
767 		goto error_out;
768 
769 	if (sdev->removable || sdkp->write_prot)
770 		check_disk_change(bdev);
771 
772 	/*
773 	 * If the drive is empty, just let the open fail.
774 	 */
775 	retval = -ENOMEDIUM;
776 	if (sdev->removable && !sdkp->media_present && !(mode & FMODE_NDELAY))
777 		goto error_out;
778 
779 	/*
780 	 * If the device has the write protect tab set, have the open fail
781 	 * if the user expects to be able to write to the thing.
782 	 */
783 	retval = -EROFS;
784 	if (sdkp->write_prot && (mode & FMODE_WRITE))
785 		goto error_out;
786 
787 	/*
788 	 * It is possible that the disk changing stuff resulted in
789 	 * the device being taken offline.  If this is the case,
790 	 * report this to the user, and don't pretend that the
791 	 * open actually succeeded.
792 	 */
793 	retval = -ENXIO;
794 	if (!scsi_device_online(sdev))
795 		goto error_out;
796 
797 	if (!sdkp->openers++ && sdev->removable) {
798 		if (scsi_block_when_processing_errors(sdev))
799 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
800 	}
801 
802 	return 0;
803 
804 error_out:
805 	scsi_disk_put(sdkp);
806 	return retval;
807 }
808 
809 /**
810  *	sd_release - invoked when the (last) close(2) is called on this
811  *	scsi disk.
812  *	@inode: only i_rdev member may be used
813  *	@filp: only f_mode and f_flags may be used
814  *
815  *	Returns 0.
816  *
817  *	Note: may block (uninterruptible) if error recovery is underway
818  *	on this disk.
819  **/
820 static int sd_release(struct gendisk *disk, fmode_t mode)
821 {
822 	struct scsi_disk *sdkp = scsi_disk(disk);
823 	struct scsi_device *sdev = sdkp->device;
824 
825 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_release\n"));
826 
827 	if (!--sdkp->openers && sdev->removable) {
828 		if (scsi_block_when_processing_errors(sdev))
829 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
830 	}
831 
832 	/*
833 	 * XXX and what if there are packets in flight and this close()
834 	 * XXX is followed by a "rmmod sd_mod"?
835 	 */
836 	scsi_disk_put(sdkp);
837 	return 0;
838 }
839 
840 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
841 {
842 	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
843 	struct scsi_device *sdp = sdkp->device;
844 	struct Scsi_Host *host = sdp->host;
845 	int diskinfo[4];
846 
847 	/* default to most commonly used values */
848         diskinfo[0] = 0x40;	/* 1 << 6 */
849        	diskinfo[1] = 0x20;	/* 1 << 5 */
850        	diskinfo[2] = sdkp->capacity >> 11;
851 
852 	/* override with calculated, extended default, or driver values */
853 	if (host->hostt->bios_param)
854 		host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
855 	else
856 		scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
857 
858 	geo->heads = diskinfo[0];
859 	geo->sectors = diskinfo[1];
860 	geo->cylinders = diskinfo[2];
861 	return 0;
862 }
863 
864 /**
865  *	sd_ioctl - process an ioctl
866  *	@inode: only i_rdev/i_bdev members may be used
867  *	@filp: only f_mode and f_flags may be used
868  *	@cmd: ioctl command number
869  *	@arg: this is third argument given to ioctl(2) system call.
870  *	Often contains a pointer.
871  *
872  *	Returns 0 if successful (some ioctls return postive numbers on
873  *	success as well). Returns a negated errno value in case of error.
874  *
875  *	Note: most ioctls are forward onto the block subsystem or further
876  *	down in the scsi subsystem.
877  **/
878 static int sd_ioctl(struct block_device *bdev, fmode_t mode,
879 		    unsigned int cmd, unsigned long arg)
880 {
881 	struct gendisk *disk = bdev->bd_disk;
882 	struct scsi_device *sdp = scsi_disk(disk)->device;
883 	void __user *p = (void __user *)arg;
884 	int error;
885 
886 	SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
887 						disk->disk_name, cmd));
888 
889 	/*
890 	 * If we are in the middle of error recovery, don't let anyone
891 	 * else try and use this device.  Also, if error recovery fails, it
892 	 * may try and take the device offline, in which case all further
893 	 * access to the device is prohibited.
894 	 */
895 	error = scsi_nonblockable_ioctl(sdp, cmd, p,
896 					(mode & FMODE_NDELAY) != 0);
897 	if (!scsi_block_when_processing_errors(sdp) || !error)
898 		return error;
899 
900 	/*
901 	 * Send SCSI addressing ioctls directly to mid level, send other
902 	 * ioctls to block level and then onto mid level if they can't be
903 	 * resolved.
904 	 */
905 	switch (cmd) {
906 		case SCSI_IOCTL_GET_IDLUN:
907 		case SCSI_IOCTL_GET_BUS_NUMBER:
908 			return scsi_ioctl(sdp, cmd, p);
909 		default:
910 			error = scsi_cmd_ioctl(disk->queue, disk, mode, cmd, p);
911 			if (error != -ENOTTY)
912 				return error;
913 	}
914 	return scsi_ioctl(sdp, cmd, p);
915 }
916 
917 static void set_media_not_present(struct scsi_disk *sdkp)
918 {
919 	sdkp->media_present = 0;
920 	sdkp->capacity = 0;
921 	sdkp->device->changed = 1;
922 }
923 
924 /**
925  *	sd_media_changed - check if our medium changed
926  *	@disk: kernel device descriptor
927  *
928  *	Returns 0 if not applicable or no change; 1 if change
929  *
930  *	Note: this function is invoked from the block subsystem.
931  **/
932 static int sd_media_changed(struct gendisk *disk)
933 {
934 	struct scsi_disk *sdkp = scsi_disk(disk);
935 	struct scsi_device *sdp = sdkp->device;
936 	struct scsi_sense_hdr *sshdr = NULL;
937 	int retval;
938 
939 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_media_changed\n"));
940 
941 	if (!sdp->removable)
942 		return 0;
943 
944 	/*
945 	 * If the device is offline, don't send any commands - just pretend as
946 	 * if the command failed.  If the device ever comes back online, we
947 	 * can deal with it then.  It is only because of unrecoverable errors
948 	 * that we would ever take a device offline in the first place.
949 	 */
950 	if (!scsi_device_online(sdp)) {
951 		set_media_not_present(sdkp);
952 		retval = 1;
953 		goto out;
954 	}
955 
956 	/*
957 	 * Using TEST_UNIT_READY enables differentiation between drive with
958 	 * no cartridge loaded - NOT READY, drive with changed cartridge -
959 	 * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
960 	 *
961 	 * Drives that auto spin down. eg iomega jaz 1G, will be started
962 	 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
963 	 * sd_revalidate() is called.
964 	 */
965 	retval = -ENODEV;
966 
967 	if (scsi_block_when_processing_errors(sdp)) {
968 		sshdr  = kzalloc(sizeof(*sshdr), GFP_KERNEL);
969 		retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
970 					      sshdr);
971 	}
972 
973 	/*
974 	 * Unable to test, unit probably not ready.   This usually
975 	 * means there is no disc in the drive.  Mark as changed,
976 	 * and we will figure it out later once the drive is
977 	 * available again.
978 	 */
979 	if (retval || (scsi_sense_valid(sshdr) &&
980 		       /* 0x3a is medium not present */
981 		       sshdr->asc == 0x3a)) {
982 		set_media_not_present(sdkp);
983 		retval = 1;
984 		goto out;
985 	}
986 
987 	/*
988 	 * For removable scsi disk we have to recognise the presence
989 	 * of a disk in the drive. This is kept in the struct scsi_disk
990 	 * struct and tested at open !  Daniel Roche (dan@lectra.fr)
991 	 */
992 	sdkp->media_present = 1;
993 
994 	retval = sdp->changed;
995 	sdp->changed = 0;
996 out:
997 	if (retval != sdkp->previous_state)
998 		sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL);
999 	sdkp->previous_state = retval;
1000 	kfree(sshdr);
1001 	return retval;
1002 }
1003 
1004 static int sd_sync_cache(struct scsi_disk *sdkp)
1005 {
1006 	int retries, res;
1007 	struct scsi_device *sdp = sdkp->device;
1008 	struct scsi_sense_hdr sshdr;
1009 
1010 	if (!scsi_device_online(sdp))
1011 		return -ENODEV;
1012 
1013 
1014 	for (retries = 3; retries > 0; --retries) {
1015 		unsigned char cmd[10] = { 0 };
1016 
1017 		cmd[0] = SYNCHRONIZE_CACHE;
1018 		/*
1019 		 * Leave the rest of the command zero to indicate
1020 		 * flush everything.
1021 		 */
1022 		res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
1023 				       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1024 		if (res == 0)
1025 			break;
1026 	}
1027 
1028 	if (res) {
1029 		sd_print_result(sdkp, res);
1030 		if (driver_byte(res) & DRIVER_SENSE)
1031 			sd_print_sense_hdr(sdkp, &sshdr);
1032 	}
1033 
1034 	if (res)
1035 		return -EIO;
1036 	return 0;
1037 }
1038 
1039 static void sd_prepare_flush(struct request_queue *q, struct request *rq)
1040 {
1041 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
1042 	rq->timeout = SD_TIMEOUT;
1043 	rq->cmd[0] = SYNCHRONIZE_CACHE;
1044 	rq->cmd_len = 10;
1045 }
1046 
1047 static void sd_rescan(struct device *dev)
1048 {
1049 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
1050 
1051 	if (sdkp) {
1052 		revalidate_disk(sdkp->disk);
1053 		scsi_disk_put(sdkp);
1054 	}
1055 }
1056 
1057 
1058 #ifdef CONFIG_COMPAT
1059 /*
1060  * This gets directly called from VFS. When the ioctl
1061  * is not recognized we go back to the other translation paths.
1062  */
1063 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
1064 			   unsigned int cmd, unsigned long arg)
1065 {
1066 	struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
1067 
1068 	/*
1069 	 * If we are in the middle of error recovery, don't let anyone
1070 	 * else try and use this device.  Also, if error recovery fails, it
1071 	 * may try and take the device offline, in which case all further
1072 	 * access to the device is prohibited.
1073 	 */
1074 	if (!scsi_block_when_processing_errors(sdev))
1075 		return -ENODEV;
1076 
1077 	if (sdev->host->hostt->compat_ioctl) {
1078 		int ret;
1079 
1080 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
1081 
1082 		return ret;
1083 	}
1084 
1085 	/*
1086 	 * Let the static ioctl translation table take care of it.
1087 	 */
1088 	return -ENOIOCTLCMD;
1089 }
1090 #endif
1091 
1092 static const struct block_device_operations sd_fops = {
1093 	.owner			= THIS_MODULE,
1094 	.open			= sd_open,
1095 	.release		= sd_release,
1096 	.locked_ioctl		= sd_ioctl,
1097 	.getgeo			= sd_getgeo,
1098 #ifdef CONFIG_COMPAT
1099 	.compat_ioctl		= sd_compat_ioctl,
1100 #endif
1101 	.media_changed		= sd_media_changed,
1102 	.revalidate_disk	= sd_revalidate_disk,
1103 };
1104 
1105 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
1106 {
1107 	u64 start_lba = blk_rq_pos(scmd->request);
1108 	u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
1109 	u64 bad_lba;
1110 	int info_valid;
1111 
1112 	if (!blk_fs_request(scmd->request))
1113 		return 0;
1114 
1115 	info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
1116 					     SCSI_SENSE_BUFFERSIZE,
1117 					     &bad_lba);
1118 	if (!info_valid)
1119 		return 0;
1120 
1121 	if (scsi_bufflen(scmd) <= scmd->device->sector_size)
1122 		return 0;
1123 
1124 	if (scmd->device->sector_size < 512) {
1125 		/* only legitimate sector_size here is 256 */
1126 		start_lba <<= 1;
1127 		end_lba <<= 1;
1128 	} else {
1129 		/* be careful ... don't want any overflows */
1130 		u64 factor = scmd->device->sector_size / 512;
1131 		do_div(start_lba, factor);
1132 		do_div(end_lba, factor);
1133 	}
1134 
1135 	/* The bad lba was reported incorrectly, we have no idea where
1136 	 * the error is.
1137 	 */
1138 	if (bad_lba < start_lba  || bad_lba >= end_lba)
1139 		return 0;
1140 
1141 	/* This computation should always be done in terms of
1142 	 * the resolution of the device's medium.
1143 	 */
1144 	return (bad_lba - start_lba) * scmd->device->sector_size;
1145 }
1146 
1147 /**
1148  *	sd_done - bottom half handler: called when the lower level
1149  *	driver has completed (successfully or otherwise) a scsi command.
1150  *	@SCpnt: mid-level's per command structure.
1151  *
1152  *	Note: potentially run from within an ISR. Must not block.
1153  **/
1154 static int sd_done(struct scsi_cmnd *SCpnt)
1155 {
1156 	int result = SCpnt->result;
1157 	unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
1158 	struct scsi_sense_hdr sshdr;
1159 	struct scsi_disk *sdkp = scsi_disk(SCpnt->request->rq_disk);
1160 	int sense_valid = 0;
1161 	int sense_deferred = 0;
1162 
1163 	if (result) {
1164 		sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
1165 		if (sense_valid)
1166 			sense_deferred = scsi_sense_is_deferred(&sshdr);
1167 	}
1168 #ifdef CONFIG_SCSI_LOGGING
1169 	SCSI_LOG_HLCOMPLETE(1, scsi_print_result(SCpnt));
1170 	if (sense_valid) {
1171 		SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
1172 						   "sd_done: sb[respc,sk,asc,"
1173 						   "ascq]=%x,%x,%x,%x\n",
1174 						   sshdr.response_code,
1175 						   sshdr.sense_key, sshdr.asc,
1176 						   sshdr.ascq));
1177 	}
1178 #endif
1179 	if (driver_byte(result) != DRIVER_SENSE &&
1180 	    (!sense_valid || sense_deferred))
1181 		goto out;
1182 
1183 	switch (sshdr.sense_key) {
1184 	case HARDWARE_ERROR:
1185 	case MEDIUM_ERROR:
1186 		good_bytes = sd_completed_bytes(SCpnt);
1187 		break;
1188 	case RECOVERED_ERROR:
1189 		good_bytes = scsi_bufflen(SCpnt);
1190 		break;
1191 	case NO_SENSE:
1192 		/* This indicates a false check condition, so ignore it.  An
1193 		 * unknown amount of data was transferred so treat it as an
1194 		 * error.
1195 		 */
1196 		scsi_print_sense("sd", SCpnt);
1197 		SCpnt->result = 0;
1198 		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1199 		break;
1200 	case ABORTED_COMMAND: /* DIF: Target detected corruption */
1201 	case ILLEGAL_REQUEST: /* DIX: Host detected corruption */
1202 		if (sshdr.asc == 0x10)
1203 			good_bytes = sd_completed_bytes(SCpnt);
1204 		break;
1205 	default:
1206 		break;
1207 	}
1208  out:
1209 	if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
1210 		sd_dif_complete(SCpnt, good_bytes);
1211 
1212 	if (scsi_host_dif_capable(sdkp->device->host, sdkp->protection_type)
1213 	    == SD_DIF_TYPE2_PROTECTION && SCpnt->cmnd != SCpnt->request->cmd) {
1214 
1215 		/* We have to print a failed command here as the
1216 		 * extended CDB gets freed before scsi_io_completion()
1217 		 * is called.
1218 		 */
1219 		if (result)
1220 			scsi_print_command(SCpnt);
1221 
1222 		mempool_free(SCpnt->cmnd, sd_cdb_pool);
1223 		SCpnt->cmnd = NULL;
1224 		SCpnt->cmd_len = 0;
1225 	}
1226 
1227 	return good_bytes;
1228 }
1229 
1230 static int media_not_present(struct scsi_disk *sdkp,
1231 			     struct scsi_sense_hdr *sshdr)
1232 {
1233 
1234 	if (!scsi_sense_valid(sshdr))
1235 		return 0;
1236 	/* not invoked for commands that could return deferred errors */
1237 	if (sshdr->sense_key != NOT_READY &&
1238 	    sshdr->sense_key != UNIT_ATTENTION)
1239 		return 0;
1240 	if (sshdr->asc != 0x3A) /* medium not present */
1241 		return 0;
1242 
1243 	set_media_not_present(sdkp);
1244 	return 1;
1245 }
1246 
1247 /*
1248  * spinup disk - called only in sd_revalidate_disk()
1249  */
1250 static void
1251 sd_spinup_disk(struct scsi_disk *sdkp)
1252 {
1253 	unsigned char cmd[10];
1254 	unsigned long spintime_expire = 0;
1255 	int retries, spintime;
1256 	unsigned int the_result;
1257 	struct scsi_sense_hdr sshdr;
1258 	int sense_valid = 0;
1259 
1260 	spintime = 0;
1261 
1262 	/* Spin up drives, as required.  Only do this at boot time */
1263 	/* Spinup needs to be done for module loads too. */
1264 	do {
1265 		retries = 0;
1266 
1267 		do {
1268 			cmd[0] = TEST_UNIT_READY;
1269 			memset((void *) &cmd[1], 0, 9);
1270 
1271 			the_result = scsi_execute_req(sdkp->device, cmd,
1272 						      DMA_NONE, NULL, 0,
1273 						      &sshdr, SD_TIMEOUT,
1274 						      SD_MAX_RETRIES, NULL);
1275 
1276 			/*
1277 			 * If the drive has indicated to us that it
1278 			 * doesn't have any media in it, don't bother
1279 			 * with any more polling.
1280 			 */
1281 			if (media_not_present(sdkp, &sshdr))
1282 				return;
1283 
1284 			if (the_result)
1285 				sense_valid = scsi_sense_valid(&sshdr);
1286 			retries++;
1287 		} while (retries < 3 &&
1288 			 (!scsi_status_is_good(the_result) ||
1289 			  ((driver_byte(the_result) & DRIVER_SENSE) &&
1290 			  sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1291 
1292 		if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1293 			/* no sense, TUR either succeeded or failed
1294 			 * with a status error */
1295 			if(!spintime && !scsi_status_is_good(the_result)) {
1296 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1297 				sd_print_result(sdkp, the_result);
1298 			}
1299 			break;
1300 		}
1301 
1302 		/*
1303 		 * The device does not want the automatic start to be issued.
1304 		 */
1305 		if (sdkp->device->no_start_on_add)
1306 			break;
1307 
1308 		if (sense_valid && sshdr.sense_key == NOT_READY) {
1309 			if (sshdr.asc == 4 && sshdr.ascq == 3)
1310 				break;	/* manual intervention required */
1311 			if (sshdr.asc == 4 && sshdr.ascq == 0xb)
1312 				break;	/* standby */
1313 			if (sshdr.asc == 4 && sshdr.ascq == 0xc)
1314 				break;	/* unavailable */
1315 			/*
1316 			 * Issue command to spin up drive when not ready
1317 			 */
1318 			if (!spintime) {
1319 				sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
1320 				cmd[0] = START_STOP;
1321 				cmd[1] = 1;	/* Return immediately */
1322 				memset((void *) &cmd[2], 0, 8);
1323 				cmd[4] = 1;	/* Start spin cycle */
1324 				if (sdkp->device->start_stop_pwr_cond)
1325 					cmd[4] |= 1 << 4;
1326 				scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1327 						 NULL, 0, &sshdr,
1328 						 SD_TIMEOUT, SD_MAX_RETRIES,
1329 						 NULL);
1330 				spintime_expire = jiffies + 100 * HZ;
1331 				spintime = 1;
1332 			}
1333 			/* Wait 1 second for next try */
1334 			msleep(1000);
1335 			printk(".");
1336 
1337 		/*
1338 		 * Wait for USB flash devices with slow firmware.
1339 		 * Yes, this sense key/ASC combination shouldn't
1340 		 * occur here.  It's characteristic of these devices.
1341 		 */
1342 		} else if (sense_valid &&
1343 				sshdr.sense_key == UNIT_ATTENTION &&
1344 				sshdr.asc == 0x28) {
1345 			if (!spintime) {
1346 				spintime_expire = jiffies + 5 * HZ;
1347 				spintime = 1;
1348 			}
1349 			/* Wait 1 second for next try */
1350 			msleep(1000);
1351 		} else {
1352 			/* we don't understand the sense code, so it's
1353 			 * probably pointless to loop */
1354 			if(!spintime) {
1355 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1356 				sd_print_sense_hdr(sdkp, &sshdr);
1357 			}
1358 			break;
1359 		}
1360 
1361 	} while (spintime && time_before_eq(jiffies, spintime_expire));
1362 
1363 	if (spintime) {
1364 		if (scsi_status_is_good(the_result))
1365 			printk("ready\n");
1366 		else
1367 			printk("not responding...\n");
1368 	}
1369 }
1370 
1371 
1372 /*
1373  * Determine whether disk supports Data Integrity Field.
1374  */
1375 void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
1376 {
1377 	struct scsi_device *sdp = sdkp->device;
1378 	u8 type;
1379 
1380 	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
1381 		return;
1382 
1383 	type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
1384 
1385 	if (type == sdkp->protection_type || !sdkp->first_scan)
1386 		return;
1387 
1388 	sdkp->protection_type = type;
1389 
1390 	if (type > SD_DIF_TYPE3_PROTECTION) {
1391 		sd_printk(KERN_ERR, sdkp, "formatted with unsupported "	\
1392 			  "protection type %u. Disabling disk!\n", type);
1393 		sdkp->capacity = 0;
1394 		return;
1395 	}
1396 
1397 	if (scsi_host_dif_capable(sdp->host, type))
1398 		sd_printk(KERN_NOTICE, sdkp,
1399 			  "Enabling DIF Type %u protection\n", type);
1400 	else
1401 		sd_printk(KERN_NOTICE, sdkp,
1402 			  "Disabling DIF Type %u protection\n", type);
1403 }
1404 
1405 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
1406 			struct scsi_sense_hdr *sshdr, int sense_valid,
1407 			int the_result)
1408 {
1409 	sd_print_result(sdkp, the_result);
1410 	if (driver_byte(the_result) & DRIVER_SENSE)
1411 		sd_print_sense_hdr(sdkp, sshdr);
1412 	else
1413 		sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
1414 
1415 	/*
1416 	 * Set dirty bit for removable devices if not ready -
1417 	 * sometimes drives will not report this properly.
1418 	 */
1419 	if (sdp->removable &&
1420 	    sense_valid && sshdr->sense_key == NOT_READY)
1421 		sdp->changed = 1;
1422 
1423 	/*
1424 	 * We used to set media_present to 0 here to indicate no media
1425 	 * in the drive, but some drives fail read capacity even with
1426 	 * media present, so we can't do that.
1427 	 */
1428 	sdkp->capacity = 0; /* unknown mapped to zero - as usual */
1429 }
1430 
1431 #define RC16_LEN 32
1432 #if RC16_LEN > SD_BUF_SIZE
1433 #error RC16_LEN must not be more than SD_BUF_SIZE
1434 #endif
1435 
1436 static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
1437 						unsigned char *buffer)
1438 {
1439 	unsigned char cmd[16];
1440 	struct scsi_sense_hdr sshdr;
1441 	int sense_valid = 0;
1442 	int the_result;
1443 	int retries = 3;
1444 	unsigned int alignment;
1445 	unsigned long long lba;
1446 	unsigned sector_size;
1447 
1448 	do {
1449 		memset(cmd, 0, 16);
1450 		cmd[0] = SERVICE_ACTION_IN;
1451 		cmd[1] = SAI_READ_CAPACITY_16;
1452 		cmd[13] = RC16_LEN;
1453 		memset(buffer, 0, RC16_LEN);
1454 
1455 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1456 					buffer, RC16_LEN, &sshdr,
1457 					SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1458 
1459 		if (media_not_present(sdkp, &sshdr))
1460 			return -ENODEV;
1461 
1462 		if (the_result) {
1463 			sense_valid = scsi_sense_valid(&sshdr);
1464 			if (sense_valid &&
1465 			    sshdr.sense_key == ILLEGAL_REQUEST &&
1466 			    (sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
1467 			    sshdr.ascq == 0x00)
1468 				/* Invalid Command Operation Code or
1469 				 * Invalid Field in CDB, just retry
1470 				 * silently with RC10 */
1471 				return -EINVAL;
1472 		}
1473 		retries--;
1474 
1475 	} while (the_result && retries);
1476 
1477 	if (the_result) {
1478 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY(16) failed\n");
1479 		read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
1480 		return -EINVAL;
1481 	}
1482 
1483 	sector_size = get_unaligned_be32(&buffer[8]);
1484 	lba = get_unaligned_be64(&buffer[0]);
1485 
1486 	sd_read_protection_type(sdkp, buffer);
1487 
1488 	if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) {
1489 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
1490 			"kernel compiled with support for large block "
1491 			"devices.\n");
1492 		sdkp->capacity = 0;
1493 		return -EOVERFLOW;
1494 	}
1495 
1496 	/* Logical blocks per physical block exponent */
1497 	sdkp->hw_sector_size = (1 << (buffer[13] & 0xf)) * sector_size;
1498 
1499 	/* Lowest aligned logical block */
1500 	alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) * sector_size;
1501 	blk_queue_alignment_offset(sdp->request_queue, alignment);
1502 	if (alignment && sdkp->first_scan)
1503 		sd_printk(KERN_NOTICE, sdkp,
1504 			  "physical block alignment offset: %u\n", alignment);
1505 
1506 	if (buffer[14] & 0x80) { /* TPE */
1507 		struct request_queue *q = sdp->request_queue;
1508 
1509 		sdkp->thin_provisioning = 1;
1510 		q->limits.discard_granularity = sdkp->hw_sector_size;
1511 		q->limits.max_discard_sectors = 0xffffffff;
1512 
1513 		if (buffer[14] & 0x40) /* TPRZ */
1514 			q->limits.discard_zeroes_data = 1;
1515 
1516 		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1517 	}
1518 
1519 	sdkp->capacity = lba + 1;
1520 	return sector_size;
1521 }
1522 
1523 static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
1524 						unsigned char *buffer)
1525 {
1526 	unsigned char cmd[16];
1527 	struct scsi_sense_hdr sshdr;
1528 	int sense_valid = 0;
1529 	int the_result;
1530 	int retries = 3;
1531 	sector_t lba;
1532 	unsigned sector_size;
1533 
1534 	do {
1535 		cmd[0] = READ_CAPACITY;
1536 		memset(&cmd[1], 0, 9);
1537 		memset(buffer, 0, 8);
1538 
1539 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1540 					buffer, 8, &sshdr,
1541 					SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1542 
1543 		if (media_not_present(sdkp, &sshdr))
1544 			return -ENODEV;
1545 
1546 		if (the_result)
1547 			sense_valid = scsi_sense_valid(&sshdr);
1548 		retries--;
1549 
1550 	} while (the_result && retries);
1551 
1552 	if (the_result) {
1553 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
1554 		read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
1555 		return -EINVAL;
1556 	}
1557 
1558 	sector_size = get_unaligned_be32(&buffer[4]);
1559 	lba = get_unaligned_be32(&buffer[0]);
1560 
1561 	if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) {
1562 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
1563 			"kernel compiled with support for large block "
1564 			"devices.\n");
1565 		sdkp->capacity = 0;
1566 		return -EOVERFLOW;
1567 	}
1568 
1569 	sdkp->capacity = lba + 1;
1570 	sdkp->hw_sector_size = sector_size;
1571 	return sector_size;
1572 }
1573 
1574 static int sd_try_rc16_first(struct scsi_device *sdp)
1575 {
1576 	if (sdp->scsi_level > SCSI_SPC_2)
1577 		return 1;
1578 	if (scsi_device_protection(sdp))
1579 		return 1;
1580 	return 0;
1581 }
1582 
1583 /*
1584  * read disk capacity
1585  */
1586 static void
1587 sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
1588 {
1589 	int sector_size;
1590 	struct scsi_device *sdp = sdkp->device;
1591 	sector_t old_capacity = sdkp->capacity;
1592 
1593 	if (sd_try_rc16_first(sdp)) {
1594 		sector_size = read_capacity_16(sdkp, sdp, buffer);
1595 		if (sector_size == -EOVERFLOW)
1596 			goto got_data;
1597 		if (sector_size == -ENODEV)
1598 			return;
1599 		if (sector_size < 0)
1600 			sector_size = read_capacity_10(sdkp, sdp, buffer);
1601 		if (sector_size < 0)
1602 			return;
1603 	} else {
1604 		sector_size = read_capacity_10(sdkp, sdp, buffer);
1605 		if (sector_size == -EOVERFLOW)
1606 			goto got_data;
1607 		if (sector_size < 0)
1608 			return;
1609 		if ((sizeof(sdkp->capacity) > 4) &&
1610 		    (sdkp->capacity > 0xffffffffULL)) {
1611 			int old_sector_size = sector_size;
1612 			sd_printk(KERN_NOTICE, sdkp, "Very big device. "
1613 					"Trying to use READ CAPACITY(16).\n");
1614 			sector_size = read_capacity_16(sdkp, sdp, buffer);
1615 			if (sector_size < 0) {
1616 				sd_printk(KERN_NOTICE, sdkp,
1617 					"Using 0xffffffff as device size\n");
1618 				sdkp->capacity = 1 + (sector_t) 0xffffffff;
1619 				sector_size = old_sector_size;
1620 				goto got_data;
1621 			}
1622 		}
1623 	}
1624 
1625 	/* Some devices are known to return the total number of blocks,
1626 	 * not the highest block number.  Some devices have versions
1627 	 * which do this and others which do not.  Some devices we might
1628 	 * suspect of doing this but we don't know for certain.
1629 	 *
1630 	 * If we know the reported capacity is wrong, decrement it.  If
1631 	 * we can only guess, then assume the number of blocks is even
1632 	 * (usually true but not always) and err on the side of lowering
1633 	 * the capacity.
1634 	 */
1635 	if (sdp->fix_capacity ||
1636 	    (sdp->guess_capacity && (sdkp->capacity & 0x01))) {
1637 		sd_printk(KERN_INFO, sdkp, "Adjusting the sector count "
1638 				"from its reported value: %llu\n",
1639 				(unsigned long long) sdkp->capacity);
1640 		--sdkp->capacity;
1641 	}
1642 
1643 got_data:
1644 	if (sector_size == 0) {
1645 		sector_size = 512;
1646 		sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
1647 			  "assuming 512.\n");
1648 	}
1649 
1650 	if (sector_size != 512 &&
1651 	    sector_size != 1024 &&
1652 	    sector_size != 2048 &&
1653 	    sector_size != 4096 &&
1654 	    sector_size != 256) {
1655 		sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
1656 			  sector_size);
1657 		/*
1658 		 * The user might want to re-format the drive with
1659 		 * a supported sectorsize.  Once this happens, it
1660 		 * would be relatively trivial to set the thing up.
1661 		 * For this reason, we leave the thing in the table.
1662 		 */
1663 		sdkp->capacity = 0;
1664 		/*
1665 		 * set a bogus sector size so the normal read/write
1666 		 * logic in the block layer will eventually refuse any
1667 		 * request on this device without tripping over power
1668 		 * of two sector size assumptions
1669 		 */
1670 		sector_size = 512;
1671 	}
1672 	blk_queue_logical_block_size(sdp->request_queue, sector_size);
1673 
1674 	{
1675 		char cap_str_2[10], cap_str_10[10];
1676 		u64 sz = (u64)sdkp->capacity << ilog2(sector_size);
1677 
1678 		string_get_size(sz, STRING_UNITS_2, cap_str_2,
1679 				sizeof(cap_str_2));
1680 		string_get_size(sz, STRING_UNITS_10, cap_str_10,
1681 				sizeof(cap_str_10));
1682 
1683 		if (sdkp->first_scan || old_capacity != sdkp->capacity) {
1684 			sd_printk(KERN_NOTICE, sdkp,
1685 				  "%llu %d-byte logical blocks: (%s/%s)\n",
1686 				  (unsigned long long)sdkp->capacity,
1687 				  sector_size, cap_str_10, cap_str_2);
1688 
1689 			if (sdkp->hw_sector_size != sector_size)
1690 				sd_printk(KERN_NOTICE, sdkp,
1691 					  "%u-byte physical blocks\n",
1692 					  sdkp->hw_sector_size);
1693 		}
1694 	}
1695 
1696 	/* Rescale capacity to 512-byte units */
1697 	if (sector_size == 4096)
1698 		sdkp->capacity <<= 3;
1699 	else if (sector_size == 2048)
1700 		sdkp->capacity <<= 2;
1701 	else if (sector_size == 1024)
1702 		sdkp->capacity <<= 1;
1703 	else if (sector_size == 256)
1704 		sdkp->capacity >>= 1;
1705 
1706 	blk_queue_physical_block_size(sdp->request_queue, sdkp->hw_sector_size);
1707 	sdkp->device->sector_size = sector_size;
1708 }
1709 
1710 /* called with buffer of length 512 */
1711 static inline int
1712 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
1713 		 unsigned char *buffer, int len, struct scsi_mode_data *data,
1714 		 struct scsi_sense_hdr *sshdr)
1715 {
1716 	return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
1717 			       SD_TIMEOUT, SD_MAX_RETRIES, data,
1718 			       sshdr);
1719 }
1720 
1721 /*
1722  * read write protect setting, if possible - called only in sd_revalidate_disk()
1723  * called with buffer of length SD_BUF_SIZE
1724  */
1725 static void
1726 sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
1727 {
1728 	int res;
1729 	struct scsi_device *sdp = sdkp->device;
1730 	struct scsi_mode_data data;
1731 	int old_wp = sdkp->write_prot;
1732 
1733 	set_disk_ro(sdkp->disk, 0);
1734 	if (sdp->skip_ms_page_3f) {
1735 		sd_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
1736 		return;
1737 	}
1738 
1739 	if (sdp->use_192_bytes_for_3f) {
1740 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
1741 	} else {
1742 		/*
1743 		 * First attempt: ask for all pages (0x3F), but only 4 bytes.
1744 		 * We have to start carefully: some devices hang if we ask
1745 		 * for more than is available.
1746 		 */
1747 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
1748 
1749 		/*
1750 		 * Second attempt: ask for page 0 When only page 0 is
1751 		 * implemented, a request for page 3F may return Sense Key
1752 		 * 5: Illegal Request, Sense Code 24: Invalid field in
1753 		 * CDB.
1754 		 */
1755 		if (!scsi_status_is_good(res))
1756 			res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
1757 
1758 		/*
1759 		 * Third attempt: ask 255 bytes, as we did earlier.
1760 		 */
1761 		if (!scsi_status_is_good(res))
1762 			res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
1763 					       &data, NULL);
1764 	}
1765 
1766 	if (!scsi_status_is_good(res)) {
1767 		sd_printk(KERN_WARNING, sdkp,
1768 			  "Test WP failed, assume Write Enabled\n");
1769 	} else {
1770 		sdkp->write_prot = ((data.device_specific & 0x80) != 0);
1771 		set_disk_ro(sdkp->disk, sdkp->write_prot);
1772 		if (sdkp->first_scan || old_wp != sdkp->write_prot) {
1773 			sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
1774 				  sdkp->write_prot ? "on" : "off");
1775 			sd_printk(KERN_DEBUG, sdkp,
1776 				  "Mode Sense: %02x %02x %02x %02x\n",
1777 				  buffer[0], buffer[1], buffer[2], buffer[3]);
1778 		}
1779 	}
1780 }
1781 
1782 /*
1783  * sd_read_cache_type - called only from sd_revalidate_disk()
1784  * called with buffer of length SD_BUF_SIZE
1785  */
1786 static void
1787 sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
1788 {
1789 	int len = 0, res;
1790 	struct scsi_device *sdp = sdkp->device;
1791 
1792 	int dbd;
1793 	int modepage;
1794 	struct scsi_mode_data data;
1795 	struct scsi_sense_hdr sshdr;
1796 	int old_wce = sdkp->WCE;
1797 	int old_rcd = sdkp->RCD;
1798 	int old_dpofua = sdkp->DPOFUA;
1799 
1800 	if (sdp->skip_ms_page_8)
1801 		goto defaults;
1802 
1803 	if (sdp->type == TYPE_RBC) {
1804 		modepage = 6;
1805 		dbd = 8;
1806 	} else {
1807 		modepage = 8;
1808 		dbd = 0;
1809 	}
1810 
1811 	/* cautiously ask */
1812 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);
1813 
1814 	if (!scsi_status_is_good(res))
1815 		goto bad_sense;
1816 
1817 	if (!data.header_length) {
1818 		modepage = 6;
1819 		sd_printk(KERN_ERR, sdkp, "Missing header in MODE_SENSE response\n");
1820 	}
1821 
1822 	/* that went OK, now ask for the proper length */
1823 	len = data.length;
1824 
1825 	/*
1826 	 * We're only interested in the first three bytes, actually.
1827 	 * But the data cache page is defined for the first 20.
1828 	 */
1829 	if (len < 3)
1830 		goto bad_sense;
1831 	if (len > 20)
1832 		len = 20;
1833 
1834 	/* Take headers and block descriptors into account */
1835 	len += data.header_length + data.block_descriptor_length;
1836 	if (len > SD_BUF_SIZE)
1837 		goto bad_sense;
1838 
1839 	/* Get the data */
1840 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
1841 
1842 	if (scsi_status_is_good(res)) {
1843 		int offset = data.header_length + data.block_descriptor_length;
1844 
1845 		if (offset >= SD_BUF_SIZE - 2) {
1846 			sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
1847 			goto defaults;
1848 		}
1849 
1850 		if ((buffer[offset] & 0x3f) != modepage) {
1851 			sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
1852 			goto defaults;
1853 		}
1854 
1855 		if (modepage == 8) {
1856 			sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
1857 			sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
1858 		} else {
1859 			sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
1860 			sdkp->RCD = 0;
1861 		}
1862 
1863 		sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
1864 		if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
1865 			sd_printk(KERN_NOTICE, sdkp,
1866 				  "Uses READ/WRITE(6), disabling FUA\n");
1867 			sdkp->DPOFUA = 0;
1868 		}
1869 
1870 		if (sdkp->first_scan || old_wce != sdkp->WCE ||
1871 		    old_rcd != sdkp->RCD || old_dpofua != sdkp->DPOFUA)
1872 			sd_printk(KERN_NOTICE, sdkp,
1873 				  "Write cache: %s, read cache: %s, %s\n",
1874 				  sdkp->WCE ? "enabled" : "disabled",
1875 				  sdkp->RCD ? "disabled" : "enabled",
1876 				  sdkp->DPOFUA ? "supports DPO and FUA"
1877 				  : "doesn't support DPO or FUA");
1878 
1879 		return;
1880 	}
1881 
1882 bad_sense:
1883 	if (scsi_sense_valid(&sshdr) &&
1884 	    sshdr.sense_key == ILLEGAL_REQUEST &&
1885 	    sshdr.asc == 0x24 && sshdr.ascq == 0x0)
1886 		/* Invalid field in CDB */
1887 		sd_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
1888 	else
1889 		sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n");
1890 
1891 defaults:
1892 	sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
1893 	sdkp->WCE = 0;
1894 	sdkp->RCD = 0;
1895 	sdkp->DPOFUA = 0;
1896 }
1897 
1898 /*
1899  * The ATO bit indicates whether the DIF application tag is available
1900  * for use by the operating system.
1901  */
1902 void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
1903 {
1904 	int res, offset;
1905 	struct scsi_device *sdp = sdkp->device;
1906 	struct scsi_mode_data data;
1907 	struct scsi_sense_hdr sshdr;
1908 
1909 	if (sdp->type != TYPE_DISK)
1910 		return;
1911 
1912 	if (sdkp->protection_type == 0)
1913 		return;
1914 
1915 	res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
1916 			      SD_MAX_RETRIES, &data, &sshdr);
1917 
1918 	if (!scsi_status_is_good(res) || !data.header_length ||
1919 	    data.length < 6) {
1920 		sd_printk(KERN_WARNING, sdkp,
1921 			  "getting Control mode page failed, assume no ATO\n");
1922 
1923 		if (scsi_sense_valid(&sshdr))
1924 			sd_print_sense_hdr(sdkp, &sshdr);
1925 
1926 		return;
1927 	}
1928 
1929 	offset = data.header_length + data.block_descriptor_length;
1930 
1931 	if ((buffer[offset] & 0x3f) != 0x0a) {
1932 		sd_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
1933 		return;
1934 	}
1935 
1936 	if ((buffer[offset + 5] & 0x80) == 0)
1937 		return;
1938 
1939 	sdkp->ATO = 1;
1940 
1941 	return;
1942 }
1943 
1944 /**
1945  * sd_read_block_limits - Query disk device for preferred I/O sizes.
1946  * @disk: disk to query
1947  */
1948 static void sd_read_block_limits(struct scsi_disk *sdkp)
1949 {
1950 	struct request_queue *q = sdkp->disk->queue;
1951 	unsigned int sector_sz = sdkp->device->sector_size;
1952 	const int vpd_len = 64;
1953 	unsigned char *buffer = kmalloc(vpd_len, GFP_KERNEL);
1954 
1955 	if (!buffer ||
1956 	    /* Block Limits VPD */
1957 	    scsi_get_vpd_page(sdkp->device, 0xb0, buffer, vpd_len))
1958 		goto out;
1959 
1960 	blk_queue_io_min(sdkp->disk->queue,
1961 			 get_unaligned_be16(&buffer[6]) * sector_sz);
1962 	blk_queue_io_opt(sdkp->disk->queue,
1963 			 get_unaligned_be32(&buffer[12]) * sector_sz);
1964 
1965 	/* Thin provisioning enabled and page length indicates TP support */
1966 	if (sdkp->thin_provisioning && buffer[3] == 0x3c) {
1967 		unsigned int lba_count, desc_count, granularity;
1968 
1969 		lba_count = get_unaligned_be32(&buffer[20]);
1970 		desc_count = get_unaligned_be32(&buffer[24]);
1971 
1972 		if (lba_count) {
1973 			q->limits.max_discard_sectors =
1974 				lba_count * sector_sz >> 9;
1975 
1976 			if (desc_count)
1977 				sdkp->unmap = 1;
1978 		}
1979 
1980 		granularity = get_unaligned_be32(&buffer[28]);
1981 
1982 		if (granularity)
1983 			q->limits.discard_granularity = granularity * sector_sz;
1984 
1985 		if (buffer[32] & 0x80)
1986 			q->limits.discard_alignment =
1987 				get_unaligned_be32(&buffer[32]) & ~(1 << 31);
1988 	}
1989 
1990  out:
1991 	kfree(buffer);
1992 }
1993 
1994 /**
1995  * sd_read_block_characteristics - Query block dev. characteristics
1996  * @disk: disk to query
1997  */
1998 static void sd_read_block_characteristics(struct scsi_disk *sdkp)
1999 {
2000 	unsigned char *buffer;
2001 	u16 rot;
2002 	const int vpd_len = 64;
2003 
2004 	buffer = kmalloc(vpd_len, GFP_KERNEL);
2005 
2006 	if (!buffer ||
2007 	    /* Block Device Characteristics VPD */
2008 	    scsi_get_vpd_page(sdkp->device, 0xb1, buffer, vpd_len))
2009 		goto out;
2010 
2011 	rot = get_unaligned_be16(&buffer[4]);
2012 
2013 	if (rot == 1)
2014 		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, sdkp->disk->queue);
2015 
2016  out:
2017 	kfree(buffer);
2018 }
2019 
2020 static int sd_try_extended_inquiry(struct scsi_device *sdp)
2021 {
2022 	/*
2023 	 * Although VPD inquiries can go to SCSI-2 type devices,
2024 	 * some USB ones crash on receiving them, and the pages
2025 	 * we currently ask for are for SPC-3 and beyond
2026 	 */
2027 	if (sdp->scsi_level > SCSI_SPC_2)
2028 		return 1;
2029 	return 0;
2030 }
2031 
2032 /**
2033  *	sd_revalidate_disk - called the first time a new disk is seen,
2034  *	performs disk spin up, read_capacity, etc.
2035  *	@disk: struct gendisk we care about
2036  **/
2037 static int sd_revalidate_disk(struct gendisk *disk)
2038 {
2039 	struct scsi_disk *sdkp = scsi_disk(disk);
2040 	struct scsi_device *sdp = sdkp->device;
2041 	unsigned char *buffer;
2042 	unsigned ordered;
2043 
2044 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
2045 				      "sd_revalidate_disk\n"));
2046 
2047 	/*
2048 	 * If the device is offline, don't try and read capacity or any
2049 	 * of the other niceties.
2050 	 */
2051 	if (!scsi_device_online(sdp))
2052 		goto out;
2053 
2054 	buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
2055 	if (!buffer) {
2056 		sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
2057 			  "allocation failure.\n");
2058 		goto out;
2059 	}
2060 
2061 	sd_spinup_disk(sdkp);
2062 
2063 	/*
2064 	 * Without media there is no reason to ask; moreover, some devices
2065 	 * react badly if we do.
2066 	 */
2067 	if (sdkp->media_present) {
2068 		sd_read_capacity(sdkp, buffer);
2069 
2070 		if (sd_try_extended_inquiry(sdp)) {
2071 			sd_read_block_limits(sdkp);
2072 			sd_read_block_characteristics(sdkp);
2073 		}
2074 
2075 		sd_read_write_protect_flag(sdkp, buffer);
2076 		sd_read_cache_type(sdkp, buffer);
2077 		sd_read_app_tag_own(sdkp, buffer);
2078 	}
2079 
2080 	sdkp->first_scan = 0;
2081 
2082 	/*
2083 	 * We now have all cache related info, determine how we deal
2084 	 * with ordered requests.  Note that as the current SCSI
2085 	 * dispatch function can alter request order, we cannot use
2086 	 * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
2087 	 */
2088 	if (sdkp->WCE)
2089 		ordered = sdkp->DPOFUA
2090 			? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
2091 	else
2092 		ordered = QUEUE_ORDERED_DRAIN;
2093 
2094 	blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush);
2095 
2096 	set_capacity(disk, sdkp->capacity);
2097 	kfree(buffer);
2098 
2099  out:
2100 	return 0;
2101 }
2102 
2103 /**
2104  *	sd_format_disk_name - format disk name
2105  *	@prefix: name prefix - ie. "sd" for SCSI disks
2106  *	@index: index of the disk to format name for
2107  *	@buf: output buffer
2108  *	@buflen: length of the output buffer
2109  *
2110  *	SCSI disk names starts at sda.  The 26th device is sdz and the
2111  *	27th is sdaa.  The last one for two lettered suffix is sdzz
2112  *	which is followed by sdaaa.
2113  *
2114  *	This is basically 26 base counting with one extra 'nil' entry
2115  *	at the beginning from the second digit on and can be
2116  *	determined using similar method as 26 base conversion with the
2117  *	index shifted -1 after each digit is computed.
2118  *
2119  *	CONTEXT:
2120  *	Don't care.
2121  *
2122  *	RETURNS:
2123  *	0 on success, -errno on failure.
2124  */
2125 static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
2126 {
2127 	const int base = 'z' - 'a' + 1;
2128 	char *begin = buf + strlen(prefix);
2129 	char *end = buf + buflen;
2130 	char *p;
2131 	int unit;
2132 
2133 	p = end - 1;
2134 	*p = '\0';
2135 	unit = base;
2136 	do {
2137 		if (p == begin)
2138 			return -EINVAL;
2139 		*--p = 'a' + (index % unit);
2140 		index = (index / unit) - 1;
2141 	} while (index >= 0);
2142 
2143 	memmove(begin, p, end - p);
2144 	memcpy(buf, prefix, strlen(prefix));
2145 
2146 	return 0;
2147 }
2148 
2149 /*
2150  * The asynchronous part of sd_probe
2151  */
2152 static void sd_probe_async(void *data, async_cookie_t cookie)
2153 {
2154 	struct scsi_disk *sdkp = data;
2155 	struct scsi_device *sdp;
2156 	struct gendisk *gd;
2157 	u32 index;
2158 	struct device *dev;
2159 
2160 	sdp = sdkp->device;
2161 	gd = sdkp->disk;
2162 	index = sdkp->index;
2163 	dev = &sdp->sdev_gendev;
2164 
2165 	if (index < SD_MAX_DISKS) {
2166 		gd->major = sd_major((index & 0xf0) >> 4);
2167 		gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
2168 		gd->minors = SD_MINORS;
2169 	}
2170 	gd->fops = &sd_fops;
2171 	gd->private_data = &sdkp->driver;
2172 	gd->queue = sdkp->device->request_queue;
2173 
2174 	/* defaults, until the device tells us otherwise */
2175 	sdp->sector_size = 512;
2176 	sdkp->capacity = 0;
2177 	sdkp->media_present = 1;
2178 	sdkp->write_prot = 0;
2179 	sdkp->WCE = 0;
2180 	sdkp->RCD = 0;
2181 	sdkp->ATO = 0;
2182 	sdkp->first_scan = 1;
2183 
2184 	sd_revalidate_disk(gd);
2185 
2186 	blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);
2187 
2188 	gd->driverfs_dev = &sdp->sdev_gendev;
2189 	gd->flags = GENHD_FL_EXT_DEVT;
2190 	if (sdp->removable)
2191 		gd->flags |= GENHD_FL_REMOVABLE;
2192 
2193 	dev_set_drvdata(dev, sdkp);
2194 	add_disk(gd);
2195 	sd_dif_config_host(sdkp);
2196 
2197 	sd_revalidate_disk(gd);
2198 
2199 	sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
2200 		  sdp->removable ? "removable " : "");
2201 	put_device(&sdkp->dev);
2202 }
2203 
2204 /**
2205  *	sd_probe - called during driver initialization and whenever a
2206  *	new scsi device is attached to the system. It is called once
2207  *	for each scsi device (not just disks) present.
2208  *	@dev: pointer to device object
2209  *
2210  *	Returns 0 if successful (or not interested in this scsi device
2211  *	(e.g. scanner)); 1 when there is an error.
2212  *
2213  *	Note: this function is invoked from the scsi mid-level.
2214  *	This function sets up the mapping between a given
2215  *	<host,channel,id,lun> (found in sdp) and new device name
2216  *	(e.g. /dev/sda). More precisely it is the block device major
2217  *	and minor number that is chosen here.
2218  *
2219  *	Assume sd_attach is not re-entrant (for time being)
2220  *	Also think about sd_attach() and sd_remove() running coincidentally.
2221  **/
2222 static int sd_probe(struct device *dev)
2223 {
2224 	struct scsi_device *sdp = to_scsi_device(dev);
2225 	struct scsi_disk *sdkp;
2226 	struct gendisk *gd;
2227 	u32 index;
2228 	int error;
2229 
2230 	error = -ENODEV;
2231 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
2232 		goto out;
2233 
2234 	SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
2235 					"sd_attach\n"));
2236 
2237 	error = -ENOMEM;
2238 	sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
2239 	if (!sdkp)
2240 		goto out;
2241 
2242 	gd = alloc_disk(SD_MINORS);
2243 	if (!gd)
2244 		goto out_free;
2245 
2246 	do {
2247 		if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
2248 			goto out_put;
2249 
2250 		spin_lock(&sd_index_lock);
2251 		error = ida_get_new(&sd_index_ida, &index);
2252 		spin_unlock(&sd_index_lock);
2253 	} while (error == -EAGAIN);
2254 
2255 	if (error)
2256 		goto out_put;
2257 
2258 	error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
2259 	if (error)
2260 		goto out_free_index;
2261 
2262 	sdkp->device = sdp;
2263 	sdkp->driver = &sd_template;
2264 	sdkp->disk = gd;
2265 	sdkp->index = index;
2266 	sdkp->openers = 0;
2267 	sdkp->previous_state = 1;
2268 
2269 	if (!sdp->request_queue->rq_timeout) {
2270 		if (sdp->type != TYPE_MOD)
2271 			blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
2272 		else
2273 			blk_queue_rq_timeout(sdp->request_queue,
2274 					     SD_MOD_TIMEOUT);
2275 	}
2276 
2277 	device_initialize(&sdkp->dev);
2278 	sdkp->dev.parent = &sdp->sdev_gendev;
2279 	sdkp->dev.class = &sd_disk_class;
2280 	dev_set_name(&sdkp->dev, dev_name(&sdp->sdev_gendev));
2281 
2282 	if (device_add(&sdkp->dev))
2283 		goto out_free_index;
2284 
2285 	get_device(&sdp->sdev_gendev);
2286 
2287 	get_device(&sdkp->dev);	/* prevent release before async_schedule */
2288 	async_schedule(sd_probe_async, sdkp);
2289 
2290 	return 0;
2291 
2292  out_free_index:
2293 	spin_lock(&sd_index_lock);
2294 	ida_remove(&sd_index_ida, index);
2295 	spin_unlock(&sd_index_lock);
2296  out_put:
2297 	put_disk(gd);
2298  out_free:
2299 	kfree(sdkp);
2300  out:
2301 	return error;
2302 }
2303 
2304 /**
2305  *	sd_remove - called whenever a scsi disk (previously recognized by
2306  *	sd_probe) is detached from the system. It is called (potentially
2307  *	multiple times) during sd module unload.
2308  *	@sdp: pointer to mid level scsi device object
2309  *
2310  *	Note: this function is invoked from the scsi mid-level.
2311  *	This function potentially frees up a device name (e.g. /dev/sdc)
2312  *	that could be re-used by a subsequent sd_probe().
2313  *	This function is not called when the built-in sd driver is "exit-ed".
2314  **/
2315 static int sd_remove(struct device *dev)
2316 {
2317 	struct scsi_disk *sdkp;
2318 
2319 	async_synchronize_full();
2320 	sdkp = dev_get_drvdata(dev);
2321 	blk_queue_prep_rq(sdkp->device->request_queue, scsi_prep_fn);
2322 	device_del(&sdkp->dev);
2323 	del_gendisk(sdkp->disk);
2324 	sd_shutdown(dev);
2325 
2326 	mutex_lock(&sd_ref_mutex);
2327 	dev_set_drvdata(dev, NULL);
2328 	put_device(&sdkp->dev);
2329 	mutex_unlock(&sd_ref_mutex);
2330 
2331 	return 0;
2332 }
2333 
2334 /**
2335  *	scsi_disk_release - Called to free the scsi_disk structure
2336  *	@dev: pointer to embedded class device
2337  *
2338  *	sd_ref_mutex must be held entering this routine.  Because it is
2339  *	called on last put, you should always use the scsi_disk_get()
2340  *	scsi_disk_put() helpers which manipulate the semaphore directly
2341  *	and never do a direct put_device.
2342  **/
2343 static void scsi_disk_release(struct device *dev)
2344 {
2345 	struct scsi_disk *sdkp = to_scsi_disk(dev);
2346 	struct gendisk *disk = sdkp->disk;
2347 
2348 	spin_lock(&sd_index_lock);
2349 	ida_remove(&sd_index_ida, sdkp->index);
2350 	spin_unlock(&sd_index_lock);
2351 
2352 	disk->private_data = NULL;
2353 	put_disk(disk);
2354 	put_device(&sdkp->device->sdev_gendev);
2355 
2356 	kfree(sdkp);
2357 }
2358 
2359 static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
2360 {
2361 	unsigned char cmd[6] = { START_STOP };	/* START_VALID */
2362 	struct scsi_sense_hdr sshdr;
2363 	struct scsi_device *sdp = sdkp->device;
2364 	int res;
2365 
2366 	if (start)
2367 		cmd[4] |= 1;	/* START */
2368 
2369 	if (sdp->start_stop_pwr_cond)
2370 		cmd[4] |= start ? 1 << 4 : 3 << 4;	/* Active or Standby */
2371 
2372 	if (!scsi_device_online(sdp))
2373 		return -ENODEV;
2374 
2375 	res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
2376 			       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
2377 	if (res) {
2378 		sd_printk(KERN_WARNING, sdkp, "START_STOP FAILED\n");
2379 		sd_print_result(sdkp, res);
2380 		if (driver_byte(res) & DRIVER_SENSE)
2381 			sd_print_sense_hdr(sdkp, &sshdr);
2382 	}
2383 
2384 	return res;
2385 }
2386 
2387 /*
2388  * Send a SYNCHRONIZE CACHE instruction down to the device through
2389  * the normal SCSI command structure.  Wait for the command to
2390  * complete.
2391  */
2392 static void sd_shutdown(struct device *dev)
2393 {
2394 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2395 
2396 	if (!sdkp)
2397 		return;         /* this can happen */
2398 
2399 	if (sdkp->WCE) {
2400 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2401 		sd_sync_cache(sdkp);
2402 	}
2403 
2404 	if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
2405 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2406 		sd_start_stop_device(sdkp, 0);
2407 	}
2408 
2409 	scsi_disk_put(sdkp);
2410 }
2411 
2412 static int sd_suspend(struct device *dev, pm_message_t mesg)
2413 {
2414 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2415 	int ret = 0;
2416 
2417 	if (!sdkp)
2418 		return 0;	/* this can happen */
2419 
2420 	if (sdkp->WCE) {
2421 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2422 		ret = sd_sync_cache(sdkp);
2423 		if (ret)
2424 			goto done;
2425 	}
2426 
2427 	if ((mesg.event & PM_EVENT_SLEEP) && sdkp->device->manage_start_stop) {
2428 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2429 		ret = sd_start_stop_device(sdkp, 0);
2430 	}
2431 
2432 done:
2433 	scsi_disk_put(sdkp);
2434 	return ret;
2435 }
2436 
2437 static int sd_resume(struct device *dev)
2438 {
2439 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2440 	int ret = 0;
2441 
2442 	if (!sdkp->device->manage_start_stop)
2443 		goto done;
2444 
2445 	sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
2446 	ret = sd_start_stop_device(sdkp, 1);
2447 
2448 done:
2449 	scsi_disk_put(sdkp);
2450 	return ret;
2451 }
2452 
2453 /**
2454  *	init_sd - entry point for this driver (both when built in or when
2455  *	a module).
2456  *
2457  *	Note: this function registers this driver with the scsi mid-level.
2458  **/
2459 static int __init init_sd(void)
2460 {
2461 	int majors = 0, i, err;
2462 
2463 	SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
2464 
2465 	for (i = 0; i < SD_MAJORS; i++)
2466 		if (register_blkdev(sd_major(i), "sd") == 0)
2467 			majors++;
2468 
2469 	if (!majors)
2470 		return -ENODEV;
2471 
2472 	err = class_register(&sd_disk_class);
2473 	if (err)
2474 		goto err_out;
2475 
2476 	err = scsi_register_driver(&sd_template.gendrv);
2477 	if (err)
2478 		goto err_out_class;
2479 
2480 	sd_cdb_cache = kmem_cache_create("sd_ext_cdb", SD_EXT_CDB_SIZE,
2481 					 0, 0, NULL);
2482 	if (!sd_cdb_cache) {
2483 		printk(KERN_ERR "sd: can't init extended cdb cache\n");
2484 		goto err_out_class;
2485 	}
2486 
2487 	sd_cdb_pool = mempool_create_slab_pool(SD_MEMPOOL_SIZE, sd_cdb_cache);
2488 	if (!sd_cdb_pool) {
2489 		printk(KERN_ERR "sd: can't init extended cdb pool\n");
2490 		goto err_out_cache;
2491 	}
2492 
2493 	return 0;
2494 
2495 err_out_cache:
2496 	kmem_cache_destroy(sd_cdb_cache);
2497 
2498 err_out_class:
2499 	class_unregister(&sd_disk_class);
2500 err_out:
2501 	for (i = 0; i < SD_MAJORS; i++)
2502 		unregister_blkdev(sd_major(i), "sd");
2503 	return err;
2504 }
2505 
2506 /**
2507  *	exit_sd - exit point for this driver (when it is a module).
2508  *
2509  *	Note: this function unregisters this driver from the scsi mid-level.
2510  **/
2511 static void __exit exit_sd(void)
2512 {
2513 	int i;
2514 
2515 	SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
2516 
2517 	mempool_destroy(sd_cdb_pool);
2518 	kmem_cache_destroy(sd_cdb_cache);
2519 
2520 	scsi_unregister_driver(&sd_template.gendrv);
2521 	class_unregister(&sd_disk_class);
2522 
2523 	for (i = 0; i < SD_MAJORS; i++)
2524 		unregister_blkdev(sd_major(i), "sd");
2525 }
2526 
2527 module_init(init_sd);
2528 module_exit(exit_sd);
2529 
2530 static void sd_print_sense_hdr(struct scsi_disk *sdkp,
2531 			       struct scsi_sense_hdr *sshdr)
2532 {
2533 	sd_printk(KERN_INFO, sdkp, "");
2534 	scsi_show_sense_hdr(sshdr);
2535 	sd_printk(KERN_INFO, sdkp, "");
2536 	scsi_show_extd_sense(sshdr->asc, sshdr->ascq);
2537 }
2538 
2539 static void sd_print_result(struct scsi_disk *sdkp, int result)
2540 {
2541 	sd_printk(KERN_INFO, sdkp, "");
2542 	scsi_show_result(result);
2543 }
2544 
2545