xref: /linux/drivers/scsi/sd.c (revision b3b77c8caef1750ebeea1054e39e358550ea9f55)
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->retries = SD_MAX_RETRIES;
1044 	rq->cmd[0] = SYNCHRONIZE_CACHE;
1045 	rq->cmd_len = 10;
1046 }
1047 
1048 static void sd_rescan(struct device *dev)
1049 {
1050 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
1051 
1052 	if (sdkp) {
1053 		revalidate_disk(sdkp->disk);
1054 		scsi_disk_put(sdkp);
1055 	}
1056 }
1057 
1058 
1059 #ifdef CONFIG_COMPAT
1060 /*
1061  * This gets directly called from VFS. When the ioctl
1062  * is not recognized we go back to the other translation paths.
1063  */
1064 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
1065 			   unsigned int cmd, unsigned long arg)
1066 {
1067 	struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
1068 
1069 	/*
1070 	 * If we are in the middle of error recovery, don't let anyone
1071 	 * else try and use this device.  Also, if error recovery fails, it
1072 	 * may try and take the device offline, in which case all further
1073 	 * access to the device is prohibited.
1074 	 */
1075 	if (!scsi_block_when_processing_errors(sdev))
1076 		return -ENODEV;
1077 
1078 	if (sdev->host->hostt->compat_ioctl) {
1079 		int ret;
1080 
1081 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
1082 
1083 		return ret;
1084 	}
1085 
1086 	/*
1087 	 * Let the static ioctl translation table take care of it.
1088 	 */
1089 	return -ENOIOCTLCMD;
1090 }
1091 #endif
1092 
1093 static const struct block_device_operations sd_fops = {
1094 	.owner			= THIS_MODULE,
1095 	.open			= sd_open,
1096 	.release		= sd_release,
1097 	.locked_ioctl		= sd_ioctl,
1098 	.getgeo			= sd_getgeo,
1099 #ifdef CONFIG_COMPAT
1100 	.compat_ioctl		= sd_compat_ioctl,
1101 #endif
1102 	.media_changed		= sd_media_changed,
1103 	.revalidate_disk	= sd_revalidate_disk,
1104 };
1105 
1106 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
1107 {
1108 	u64 start_lba = blk_rq_pos(scmd->request);
1109 	u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
1110 	u64 bad_lba;
1111 	int info_valid;
1112 
1113 	if (!blk_fs_request(scmd->request))
1114 		return 0;
1115 
1116 	info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
1117 					     SCSI_SENSE_BUFFERSIZE,
1118 					     &bad_lba);
1119 	if (!info_valid)
1120 		return 0;
1121 
1122 	if (scsi_bufflen(scmd) <= scmd->device->sector_size)
1123 		return 0;
1124 
1125 	if (scmd->device->sector_size < 512) {
1126 		/* only legitimate sector_size here is 256 */
1127 		start_lba <<= 1;
1128 		end_lba <<= 1;
1129 	} else {
1130 		/* be careful ... don't want any overflows */
1131 		u64 factor = scmd->device->sector_size / 512;
1132 		do_div(start_lba, factor);
1133 		do_div(end_lba, factor);
1134 	}
1135 
1136 	/* The bad lba was reported incorrectly, we have no idea where
1137 	 * the error is.
1138 	 */
1139 	if (bad_lba < start_lba  || bad_lba >= end_lba)
1140 		return 0;
1141 
1142 	/* This computation should always be done in terms of
1143 	 * the resolution of the device's medium.
1144 	 */
1145 	return (bad_lba - start_lba) * scmd->device->sector_size;
1146 }
1147 
1148 /**
1149  *	sd_done - bottom half handler: called when the lower level
1150  *	driver has completed (successfully or otherwise) a scsi command.
1151  *	@SCpnt: mid-level's per command structure.
1152  *
1153  *	Note: potentially run from within an ISR. Must not block.
1154  **/
1155 static int sd_done(struct scsi_cmnd *SCpnt)
1156 {
1157 	int result = SCpnt->result;
1158 	unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
1159 	struct scsi_sense_hdr sshdr;
1160 	struct scsi_disk *sdkp = scsi_disk(SCpnt->request->rq_disk);
1161 	int sense_valid = 0;
1162 	int sense_deferred = 0;
1163 
1164 	if (result) {
1165 		sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
1166 		if (sense_valid)
1167 			sense_deferred = scsi_sense_is_deferred(&sshdr);
1168 	}
1169 #ifdef CONFIG_SCSI_LOGGING
1170 	SCSI_LOG_HLCOMPLETE(1, scsi_print_result(SCpnt));
1171 	if (sense_valid) {
1172 		SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
1173 						   "sd_done: sb[respc,sk,asc,"
1174 						   "ascq]=%x,%x,%x,%x\n",
1175 						   sshdr.response_code,
1176 						   sshdr.sense_key, sshdr.asc,
1177 						   sshdr.ascq));
1178 	}
1179 #endif
1180 	if (driver_byte(result) != DRIVER_SENSE &&
1181 	    (!sense_valid || sense_deferred))
1182 		goto out;
1183 
1184 	switch (sshdr.sense_key) {
1185 	case HARDWARE_ERROR:
1186 	case MEDIUM_ERROR:
1187 		good_bytes = sd_completed_bytes(SCpnt);
1188 		break;
1189 	case RECOVERED_ERROR:
1190 		good_bytes = scsi_bufflen(SCpnt);
1191 		break;
1192 	case NO_SENSE:
1193 		/* This indicates a false check condition, so ignore it.  An
1194 		 * unknown amount of data was transferred so treat it as an
1195 		 * error.
1196 		 */
1197 		scsi_print_sense("sd", SCpnt);
1198 		SCpnt->result = 0;
1199 		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1200 		break;
1201 	case ABORTED_COMMAND: /* DIF: Target detected corruption */
1202 	case ILLEGAL_REQUEST: /* DIX: Host detected corruption */
1203 		if (sshdr.asc == 0x10)
1204 			good_bytes = sd_completed_bytes(SCpnt);
1205 		break;
1206 	default:
1207 		break;
1208 	}
1209  out:
1210 	if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
1211 		sd_dif_complete(SCpnt, good_bytes);
1212 
1213 	if (scsi_host_dif_capable(sdkp->device->host, sdkp->protection_type)
1214 	    == SD_DIF_TYPE2_PROTECTION && SCpnt->cmnd != SCpnt->request->cmd) {
1215 
1216 		/* We have to print a failed command here as the
1217 		 * extended CDB gets freed before scsi_io_completion()
1218 		 * is called.
1219 		 */
1220 		if (result)
1221 			scsi_print_command(SCpnt);
1222 
1223 		mempool_free(SCpnt->cmnd, sd_cdb_pool);
1224 		SCpnt->cmnd = NULL;
1225 		SCpnt->cmd_len = 0;
1226 	}
1227 
1228 	return good_bytes;
1229 }
1230 
1231 static int media_not_present(struct scsi_disk *sdkp,
1232 			     struct scsi_sense_hdr *sshdr)
1233 {
1234 
1235 	if (!scsi_sense_valid(sshdr))
1236 		return 0;
1237 	/* not invoked for commands that could return deferred errors */
1238 	if (sshdr->sense_key != NOT_READY &&
1239 	    sshdr->sense_key != UNIT_ATTENTION)
1240 		return 0;
1241 	if (sshdr->asc != 0x3A) /* medium not present */
1242 		return 0;
1243 
1244 	set_media_not_present(sdkp);
1245 	return 1;
1246 }
1247 
1248 /*
1249  * spinup disk - called only in sd_revalidate_disk()
1250  */
1251 static void
1252 sd_spinup_disk(struct scsi_disk *sdkp)
1253 {
1254 	unsigned char cmd[10];
1255 	unsigned long spintime_expire = 0;
1256 	int retries, spintime;
1257 	unsigned int the_result;
1258 	struct scsi_sense_hdr sshdr;
1259 	int sense_valid = 0;
1260 
1261 	spintime = 0;
1262 
1263 	/* Spin up drives, as required.  Only do this at boot time */
1264 	/* Spinup needs to be done for module loads too. */
1265 	do {
1266 		retries = 0;
1267 
1268 		do {
1269 			cmd[0] = TEST_UNIT_READY;
1270 			memset((void *) &cmd[1], 0, 9);
1271 
1272 			the_result = scsi_execute_req(sdkp->device, cmd,
1273 						      DMA_NONE, NULL, 0,
1274 						      &sshdr, SD_TIMEOUT,
1275 						      SD_MAX_RETRIES, NULL);
1276 
1277 			/*
1278 			 * If the drive has indicated to us that it
1279 			 * doesn't have any media in it, don't bother
1280 			 * with any more polling.
1281 			 */
1282 			if (media_not_present(sdkp, &sshdr))
1283 				return;
1284 
1285 			if (the_result)
1286 				sense_valid = scsi_sense_valid(&sshdr);
1287 			retries++;
1288 		} while (retries < 3 &&
1289 			 (!scsi_status_is_good(the_result) ||
1290 			  ((driver_byte(the_result) & DRIVER_SENSE) &&
1291 			  sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1292 
1293 		if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1294 			/* no sense, TUR either succeeded or failed
1295 			 * with a status error */
1296 			if(!spintime && !scsi_status_is_good(the_result)) {
1297 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1298 				sd_print_result(sdkp, the_result);
1299 			}
1300 			break;
1301 		}
1302 
1303 		/*
1304 		 * The device does not want the automatic start to be issued.
1305 		 */
1306 		if (sdkp->device->no_start_on_add)
1307 			break;
1308 
1309 		if (sense_valid && sshdr.sense_key == NOT_READY) {
1310 			if (sshdr.asc == 4 && sshdr.ascq == 3)
1311 				break;	/* manual intervention required */
1312 			if (sshdr.asc == 4 && sshdr.ascq == 0xb)
1313 				break;	/* standby */
1314 			if (sshdr.asc == 4 && sshdr.ascq == 0xc)
1315 				break;	/* unavailable */
1316 			/*
1317 			 * Issue command to spin up drive when not ready
1318 			 */
1319 			if (!spintime) {
1320 				sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
1321 				cmd[0] = START_STOP;
1322 				cmd[1] = 1;	/* Return immediately */
1323 				memset((void *) &cmd[2], 0, 8);
1324 				cmd[4] = 1;	/* Start spin cycle */
1325 				if (sdkp->device->start_stop_pwr_cond)
1326 					cmd[4] |= 1 << 4;
1327 				scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1328 						 NULL, 0, &sshdr,
1329 						 SD_TIMEOUT, SD_MAX_RETRIES,
1330 						 NULL);
1331 				spintime_expire = jiffies + 100 * HZ;
1332 				spintime = 1;
1333 			}
1334 			/* Wait 1 second for next try */
1335 			msleep(1000);
1336 			printk(".");
1337 
1338 		/*
1339 		 * Wait for USB flash devices with slow firmware.
1340 		 * Yes, this sense key/ASC combination shouldn't
1341 		 * occur here.  It's characteristic of these devices.
1342 		 */
1343 		} else if (sense_valid &&
1344 				sshdr.sense_key == UNIT_ATTENTION &&
1345 				sshdr.asc == 0x28) {
1346 			if (!spintime) {
1347 				spintime_expire = jiffies + 5 * HZ;
1348 				spintime = 1;
1349 			}
1350 			/* Wait 1 second for next try */
1351 			msleep(1000);
1352 		} else {
1353 			/* we don't understand the sense code, so it's
1354 			 * probably pointless to loop */
1355 			if(!spintime) {
1356 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1357 				sd_print_sense_hdr(sdkp, &sshdr);
1358 			}
1359 			break;
1360 		}
1361 
1362 	} while (spintime && time_before_eq(jiffies, spintime_expire));
1363 
1364 	if (spintime) {
1365 		if (scsi_status_is_good(the_result))
1366 			printk("ready\n");
1367 		else
1368 			printk("not responding...\n");
1369 	}
1370 }
1371 
1372 
1373 /*
1374  * Determine whether disk supports Data Integrity Field.
1375  */
1376 void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
1377 {
1378 	struct scsi_device *sdp = sdkp->device;
1379 	u8 type;
1380 
1381 	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
1382 		return;
1383 
1384 	type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
1385 
1386 	if (type == sdkp->protection_type || !sdkp->first_scan)
1387 		return;
1388 
1389 	sdkp->protection_type = type;
1390 
1391 	if (type > SD_DIF_TYPE3_PROTECTION) {
1392 		sd_printk(KERN_ERR, sdkp, "formatted with unsupported "	\
1393 			  "protection type %u. Disabling disk!\n", type);
1394 		sdkp->capacity = 0;
1395 		return;
1396 	}
1397 
1398 	if (scsi_host_dif_capable(sdp->host, type))
1399 		sd_printk(KERN_NOTICE, sdkp,
1400 			  "Enabling DIF Type %u protection\n", type);
1401 	else
1402 		sd_printk(KERN_NOTICE, sdkp,
1403 			  "Disabling DIF Type %u protection\n", type);
1404 }
1405 
1406 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
1407 			struct scsi_sense_hdr *sshdr, int sense_valid,
1408 			int the_result)
1409 {
1410 	sd_print_result(sdkp, the_result);
1411 	if (driver_byte(the_result) & DRIVER_SENSE)
1412 		sd_print_sense_hdr(sdkp, sshdr);
1413 	else
1414 		sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
1415 
1416 	/*
1417 	 * Set dirty bit for removable devices if not ready -
1418 	 * sometimes drives will not report this properly.
1419 	 */
1420 	if (sdp->removable &&
1421 	    sense_valid && sshdr->sense_key == NOT_READY)
1422 		sdp->changed = 1;
1423 
1424 	/*
1425 	 * We used to set media_present to 0 here to indicate no media
1426 	 * in the drive, but some drives fail read capacity even with
1427 	 * media present, so we can't do that.
1428 	 */
1429 	sdkp->capacity = 0; /* unknown mapped to zero - as usual */
1430 }
1431 
1432 #define RC16_LEN 32
1433 #if RC16_LEN > SD_BUF_SIZE
1434 #error RC16_LEN must not be more than SD_BUF_SIZE
1435 #endif
1436 
1437 #define READ_CAPACITY_RETRIES_ON_RESET	10
1438 
1439 static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
1440 						unsigned char *buffer)
1441 {
1442 	unsigned char cmd[16];
1443 	struct scsi_sense_hdr sshdr;
1444 	int sense_valid = 0;
1445 	int the_result;
1446 	int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
1447 	unsigned int alignment;
1448 	unsigned long long lba;
1449 	unsigned sector_size;
1450 
1451 	do {
1452 		memset(cmd, 0, 16);
1453 		cmd[0] = SERVICE_ACTION_IN;
1454 		cmd[1] = SAI_READ_CAPACITY_16;
1455 		cmd[13] = RC16_LEN;
1456 		memset(buffer, 0, RC16_LEN);
1457 
1458 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1459 					buffer, RC16_LEN, &sshdr,
1460 					SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1461 
1462 		if (media_not_present(sdkp, &sshdr))
1463 			return -ENODEV;
1464 
1465 		if (the_result) {
1466 			sense_valid = scsi_sense_valid(&sshdr);
1467 			if (sense_valid &&
1468 			    sshdr.sense_key == ILLEGAL_REQUEST &&
1469 			    (sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
1470 			    sshdr.ascq == 0x00)
1471 				/* Invalid Command Operation Code or
1472 				 * Invalid Field in CDB, just retry
1473 				 * silently with RC10 */
1474 				return -EINVAL;
1475 			if (sense_valid &&
1476 			    sshdr.sense_key == UNIT_ATTENTION &&
1477 			    sshdr.asc == 0x29 && sshdr.ascq == 0x00)
1478 				/* Device reset might occur several times,
1479 				 * give it one more chance */
1480 				if (--reset_retries > 0)
1481 					continue;
1482 		}
1483 		retries--;
1484 
1485 	} while (the_result && retries);
1486 
1487 	if (the_result) {
1488 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY(16) failed\n");
1489 		read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
1490 		return -EINVAL;
1491 	}
1492 
1493 	sector_size = get_unaligned_be32(&buffer[8]);
1494 	lba = get_unaligned_be64(&buffer[0]);
1495 
1496 	sd_read_protection_type(sdkp, buffer);
1497 
1498 	if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) {
1499 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
1500 			"kernel compiled with support for large block "
1501 			"devices.\n");
1502 		sdkp->capacity = 0;
1503 		return -EOVERFLOW;
1504 	}
1505 
1506 	/* Logical blocks per physical block exponent */
1507 	sdkp->hw_sector_size = (1 << (buffer[13] & 0xf)) * sector_size;
1508 
1509 	/* Lowest aligned logical block */
1510 	alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) * sector_size;
1511 	blk_queue_alignment_offset(sdp->request_queue, alignment);
1512 	if (alignment && sdkp->first_scan)
1513 		sd_printk(KERN_NOTICE, sdkp,
1514 			  "physical block alignment offset: %u\n", alignment);
1515 
1516 	if (buffer[14] & 0x80) { /* TPE */
1517 		struct request_queue *q = sdp->request_queue;
1518 
1519 		sdkp->thin_provisioning = 1;
1520 		q->limits.discard_granularity = sdkp->hw_sector_size;
1521 		q->limits.max_discard_sectors = 0xffffffff;
1522 
1523 		if (buffer[14] & 0x40) /* TPRZ */
1524 			q->limits.discard_zeroes_data = 1;
1525 
1526 		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1527 	}
1528 
1529 	sdkp->capacity = lba + 1;
1530 	return sector_size;
1531 }
1532 
1533 static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
1534 						unsigned char *buffer)
1535 {
1536 	unsigned char cmd[16];
1537 	struct scsi_sense_hdr sshdr;
1538 	int sense_valid = 0;
1539 	int the_result;
1540 	int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
1541 	sector_t lba;
1542 	unsigned sector_size;
1543 
1544 	do {
1545 		cmd[0] = READ_CAPACITY;
1546 		memset(&cmd[1], 0, 9);
1547 		memset(buffer, 0, 8);
1548 
1549 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1550 					buffer, 8, &sshdr,
1551 					SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1552 
1553 		if (media_not_present(sdkp, &sshdr))
1554 			return -ENODEV;
1555 
1556 		if (the_result) {
1557 			sense_valid = scsi_sense_valid(&sshdr);
1558 			if (sense_valid &&
1559 			    sshdr.sense_key == UNIT_ATTENTION &&
1560 			    sshdr.asc == 0x29 && sshdr.ascq == 0x00)
1561 				/* Device reset might occur several times,
1562 				 * give it one more chance */
1563 				if (--reset_retries > 0)
1564 					continue;
1565 		}
1566 		retries--;
1567 
1568 	} while (the_result && retries);
1569 
1570 	if (the_result) {
1571 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
1572 		read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
1573 		return -EINVAL;
1574 	}
1575 
1576 	sector_size = get_unaligned_be32(&buffer[4]);
1577 	lba = get_unaligned_be32(&buffer[0]);
1578 
1579 	if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) {
1580 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
1581 			"kernel compiled with support for large block "
1582 			"devices.\n");
1583 		sdkp->capacity = 0;
1584 		return -EOVERFLOW;
1585 	}
1586 
1587 	sdkp->capacity = lba + 1;
1588 	sdkp->hw_sector_size = sector_size;
1589 	return sector_size;
1590 }
1591 
1592 static int sd_try_rc16_first(struct scsi_device *sdp)
1593 {
1594 	if (sdp->host->max_cmd_len < 16)
1595 		return 0;
1596 	if (sdp->scsi_level > SCSI_SPC_2)
1597 		return 1;
1598 	if (scsi_device_protection(sdp))
1599 		return 1;
1600 	return 0;
1601 }
1602 
1603 /*
1604  * read disk capacity
1605  */
1606 static void
1607 sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
1608 {
1609 	int sector_size;
1610 	struct scsi_device *sdp = sdkp->device;
1611 	sector_t old_capacity = sdkp->capacity;
1612 
1613 	if (sd_try_rc16_first(sdp)) {
1614 		sector_size = read_capacity_16(sdkp, sdp, buffer);
1615 		if (sector_size == -EOVERFLOW)
1616 			goto got_data;
1617 		if (sector_size == -ENODEV)
1618 			return;
1619 		if (sector_size < 0)
1620 			sector_size = read_capacity_10(sdkp, sdp, buffer);
1621 		if (sector_size < 0)
1622 			return;
1623 	} else {
1624 		sector_size = read_capacity_10(sdkp, sdp, buffer);
1625 		if (sector_size == -EOVERFLOW)
1626 			goto got_data;
1627 		if (sector_size < 0)
1628 			return;
1629 		if ((sizeof(sdkp->capacity) > 4) &&
1630 		    (sdkp->capacity > 0xffffffffULL)) {
1631 			int old_sector_size = sector_size;
1632 			sd_printk(KERN_NOTICE, sdkp, "Very big device. "
1633 					"Trying to use READ CAPACITY(16).\n");
1634 			sector_size = read_capacity_16(sdkp, sdp, buffer);
1635 			if (sector_size < 0) {
1636 				sd_printk(KERN_NOTICE, sdkp,
1637 					"Using 0xffffffff as device size\n");
1638 				sdkp->capacity = 1 + (sector_t) 0xffffffff;
1639 				sector_size = old_sector_size;
1640 				goto got_data;
1641 			}
1642 		}
1643 	}
1644 
1645 	/* Some devices are known to return the total number of blocks,
1646 	 * not the highest block number.  Some devices have versions
1647 	 * which do this and others which do not.  Some devices we might
1648 	 * suspect of doing this but we don't know for certain.
1649 	 *
1650 	 * If we know the reported capacity is wrong, decrement it.  If
1651 	 * we can only guess, then assume the number of blocks is even
1652 	 * (usually true but not always) and err on the side of lowering
1653 	 * the capacity.
1654 	 */
1655 	if (sdp->fix_capacity ||
1656 	    (sdp->guess_capacity && (sdkp->capacity & 0x01))) {
1657 		sd_printk(KERN_INFO, sdkp, "Adjusting the sector count "
1658 				"from its reported value: %llu\n",
1659 				(unsigned long long) sdkp->capacity);
1660 		--sdkp->capacity;
1661 	}
1662 
1663 got_data:
1664 	if (sector_size == 0) {
1665 		sector_size = 512;
1666 		sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
1667 			  "assuming 512.\n");
1668 	}
1669 
1670 	if (sector_size != 512 &&
1671 	    sector_size != 1024 &&
1672 	    sector_size != 2048 &&
1673 	    sector_size != 4096 &&
1674 	    sector_size != 256) {
1675 		sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
1676 			  sector_size);
1677 		/*
1678 		 * The user might want to re-format the drive with
1679 		 * a supported sectorsize.  Once this happens, it
1680 		 * would be relatively trivial to set the thing up.
1681 		 * For this reason, we leave the thing in the table.
1682 		 */
1683 		sdkp->capacity = 0;
1684 		/*
1685 		 * set a bogus sector size so the normal read/write
1686 		 * logic in the block layer will eventually refuse any
1687 		 * request on this device without tripping over power
1688 		 * of two sector size assumptions
1689 		 */
1690 		sector_size = 512;
1691 	}
1692 	blk_queue_logical_block_size(sdp->request_queue, sector_size);
1693 
1694 	{
1695 		char cap_str_2[10], cap_str_10[10];
1696 		u64 sz = (u64)sdkp->capacity << ilog2(sector_size);
1697 
1698 		string_get_size(sz, STRING_UNITS_2, cap_str_2,
1699 				sizeof(cap_str_2));
1700 		string_get_size(sz, STRING_UNITS_10, cap_str_10,
1701 				sizeof(cap_str_10));
1702 
1703 		if (sdkp->first_scan || old_capacity != sdkp->capacity) {
1704 			sd_printk(KERN_NOTICE, sdkp,
1705 				  "%llu %d-byte logical blocks: (%s/%s)\n",
1706 				  (unsigned long long)sdkp->capacity,
1707 				  sector_size, cap_str_10, cap_str_2);
1708 
1709 			if (sdkp->hw_sector_size != sector_size)
1710 				sd_printk(KERN_NOTICE, sdkp,
1711 					  "%u-byte physical blocks\n",
1712 					  sdkp->hw_sector_size);
1713 		}
1714 	}
1715 
1716 	/* Rescale capacity to 512-byte units */
1717 	if (sector_size == 4096)
1718 		sdkp->capacity <<= 3;
1719 	else if (sector_size == 2048)
1720 		sdkp->capacity <<= 2;
1721 	else if (sector_size == 1024)
1722 		sdkp->capacity <<= 1;
1723 	else if (sector_size == 256)
1724 		sdkp->capacity >>= 1;
1725 
1726 	blk_queue_physical_block_size(sdp->request_queue, sdkp->hw_sector_size);
1727 	sdkp->device->sector_size = sector_size;
1728 }
1729 
1730 /* called with buffer of length 512 */
1731 static inline int
1732 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
1733 		 unsigned char *buffer, int len, struct scsi_mode_data *data,
1734 		 struct scsi_sense_hdr *sshdr)
1735 {
1736 	return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
1737 			       SD_TIMEOUT, SD_MAX_RETRIES, data,
1738 			       sshdr);
1739 }
1740 
1741 /*
1742  * read write protect setting, if possible - called only in sd_revalidate_disk()
1743  * called with buffer of length SD_BUF_SIZE
1744  */
1745 static void
1746 sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
1747 {
1748 	int res;
1749 	struct scsi_device *sdp = sdkp->device;
1750 	struct scsi_mode_data data;
1751 	int old_wp = sdkp->write_prot;
1752 
1753 	set_disk_ro(sdkp->disk, 0);
1754 	if (sdp->skip_ms_page_3f) {
1755 		sd_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
1756 		return;
1757 	}
1758 
1759 	if (sdp->use_192_bytes_for_3f) {
1760 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
1761 	} else {
1762 		/*
1763 		 * First attempt: ask for all pages (0x3F), but only 4 bytes.
1764 		 * We have to start carefully: some devices hang if we ask
1765 		 * for more than is available.
1766 		 */
1767 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
1768 
1769 		/*
1770 		 * Second attempt: ask for page 0 When only page 0 is
1771 		 * implemented, a request for page 3F may return Sense Key
1772 		 * 5: Illegal Request, Sense Code 24: Invalid field in
1773 		 * CDB.
1774 		 */
1775 		if (!scsi_status_is_good(res))
1776 			res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
1777 
1778 		/*
1779 		 * Third attempt: ask 255 bytes, as we did earlier.
1780 		 */
1781 		if (!scsi_status_is_good(res))
1782 			res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
1783 					       &data, NULL);
1784 	}
1785 
1786 	if (!scsi_status_is_good(res)) {
1787 		sd_printk(KERN_WARNING, sdkp,
1788 			  "Test WP failed, assume Write Enabled\n");
1789 	} else {
1790 		sdkp->write_prot = ((data.device_specific & 0x80) != 0);
1791 		set_disk_ro(sdkp->disk, sdkp->write_prot);
1792 		if (sdkp->first_scan || old_wp != sdkp->write_prot) {
1793 			sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
1794 				  sdkp->write_prot ? "on" : "off");
1795 			sd_printk(KERN_DEBUG, sdkp,
1796 				  "Mode Sense: %02x %02x %02x %02x\n",
1797 				  buffer[0], buffer[1], buffer[2], buffer[3]);
1798 		}
1799 	}
1800 }
1801 
1802 /*
1803  * sd_read_cache_type - called only from sd_revalidate_disk()
1804  * called with buffer of length SD_BUF_SIZE
1805  */
1806 static void
1807 sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
1808 {
1809 	int len = 0, res;
1810 	struct scsi_device *sdp = sdkp->device;
1811 
1812 	int dbd;
1813 	int modepage;
1814 	struct scsi_mode_data data;
1815 	struct scsi_sense_hdr sshdr;
1816 	int old_wce = sdkp->WCE;
1817 	int old_rcd = sdkp->RCD;
1818 	int old_dpofua = sdkp->DPOFUA;
1819 
1820 	if (sdp->skip_ms_page_8)
1821 		goto defaults;
1822 
1823 	if (sdp->type == TYPE_RBC) {
1824 		modepage = 6;
1825 		dbd = 8;
1826 	} else {
1827 		modepage = 8;
1828 		dbd = 0;
1829 	}
1830 
1831 	/* cautiously ask */
1832 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);
1833 
1834 	if (!scsi_status_is_good(res))
1835 		goto bad_sense;
1836 
1837 	if (!data.header_length) {
1838 		modepage = 6;
1839 		sd_printk(KERN_ERR, sdkp, "Missing header in MODE_SENSE response\n");
1840 	}
1841 
1842 	/* that went OK, now ask for the proper length */
1843 	len = data.length;
1844 
1845 	/*
1846 	 * We're only interested in the first three bytes, actually.
1847 	 * But the data cache page is defined for the first 20.
1848 	 */
1849 	if (len < 3)
1850 		goto bad_sense;
1851 	if (len > 20)
1852 		len = 20;
1853 
1854 	/* Take headers and block descriptors into account */
1855 	len += data.header_length + data.block_descriptor_length;
1856 	if (len > SD_BUF_SIZE)
1857 		goto bad_sense;
1858 
1859 	/* Get the data */
1860 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
1861 
1862 	if (scsi_status_is_good(res)) {
1863 		int offset = data.header_length + data.block_descriptor_length;
1864 
1865 		if (offset >= SD_BUF_SIZE - 2) {
1866 			sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
1867 			goto defaults;
1868 		}
1869 
1870 		if ((buffer[offset] & 0x3f) != modepage) {
1871 			sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
1872 			goto defaults;
1873 		}
1874 
1875 		if (modepage == 8) {
1876 			sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
1877 			sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
1878 		} else {
1879 			sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
1880 			sdkp->RCD = 0;
1881 		}
1882 
1883 		sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
1884 		if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
1885 			sd_printk(KERN_NOTICE, sdkp,
1886 				  "Uses READ/WRITE(6), disabling FUA\n");
1887 			sdkp->DPOFUA = 0;
1888 		}
1889 
1890 		if (sdkp->first_scan || old_wce != sdkp->WCE ||
1891 		    old_rcd != sdkp->RCD || old_dpofua != sdkp->DPOFUA)
1892 			sd_printk(KERN_NOTICE, sdkp,
1893 				  "Write cache: %s, read cache: %s, %s\n",
1894 				  sdkp->WCE ? "enabled" : "disabled",
1895 				  sdkp->RCD ? "disabled" : "enabled",
1896 				  sdkp->DPOFUA ? "supports DPO and FUA"
1897 				  : "doesn't support DPO or FUA");
1898 
1899 		return;
1900 	}
1901 
1902 bad_sense:
1903 	if (scsi_sense_valid(&sshdr) &&
1904 	    sshdr.sense_key == ILLEGAL_REQUEST &&
1905 	    sshdr.asc == 0x24 && sshdr.ascq == 0x0)
1906 		/* Invalid field in CDB */
1907 		sd_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
1908 	else
1909 		sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n");
1910 
1911 defaults:
1912 	sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
1913 	sdkp->WCE = 0;
1914 	sdkp->RCD = 0;
1915 	sdkp->DPOFUA = 0;
1916 }
1917 
1918 /*
1919  * The ATO bit indicates whether the DIF application tag is available
1920  * for use by the operating system.
1921  */
1922 void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
1923 {
1924 	int res, offset;
1925 	struct scsi_device *sdp = sdkp->device;
1926 	struct scsi_mode_data data;
1927 	struct scsi_sense_hdr sshdr;
1928 
1929 	if (sdp->type != TYPE_DISK)
1930 		return;
1931 
1932 	if (sdkp->protection_type == 0)
1933 		return;
1934 
1935 	res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
1936 			      SD_MAX_RETRIES, &data, &sshdr);
1937 
1938 	if (!scsi_status_is_good(res) || !data.header_length ||
1939 	    data.length < 6) {
1940 		sd_printk(KERN_WARNING, sdkp,
1941 			  "getting Control mode page failed, assume no ATO\n");
1942 
1943 		if (scsi_sense_valid(&sshdr))
1944 			sd_print_sense_hdr(sdkp, &sshdr);
1945 
1946 		return;
1947 	}
1948 
1949 	offset = data.header_length + data.block_descriptor_length;
1950 
1951 	if ((buffer[offset] & 0x3f) != 0x0a) {
1952 		sd_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
1953 		return;
1954 	}
1955 
1956 	if ((buffer[offset + 5] & 0x80) == 0)
1957 		return;
1958 
1959 	sdkp->ATO = 1;
1960 
1961 	return;
1962 }
1963 
1964 /**
1965  * sd_read_block_limits - Query disk device for preferred I/O sizes.
1966  * @disk: disk to query
1967  */
1968 static void sd_read_block_limits(struct scsi_disk *sdkp)
1969 {
1970 	struct request_queue *q = sdkp->disk->queue;
1971 	unsigned int sector_sz = sdkp->device->sector_size;
1972 	const int vpd_len = 64;
1973 	unsigned char *buffer = kmalloc(vpd_len, GFP_KERNEL);
1974 
1975 	if (!buffer ||
1976 	    /* Block Limits VPD */
1977 	    scsi_get_vpd_page(sdkp->device, 0xb0, buffer, vpd_len))
1978 		goto out;
1979 
1980 	blk_queue_io_min(sdkp->disk->queue,
1981 			 get_unaligned_be16(&buffer[6]) * sector_sz);
1982 	blk_queue_io_opt(sdkp->disk->queue,
1983 			 get_unaligned_be32(&buffer[12]) * sector_sz);
1984 
1985 	/* Thin provisioning enabled and page length indicates TP support */
1986 	if (sdkp->thin_provisioning && buffer[3] == 0x3c) {
1987 		unsigned int lba_count, desc_count, granularity;
1988 
1989 		lba_count = get_unaligned_be32(&buffer[20]);
1990 		desc_count = get_unaligned_be32(&buffer[24]);
1991 
1992 		if (lba_count) {
1993 			q->limits.max_discard_sectors =
1994 				lba_count * sector_sz >> 9;
1995 
1996 			if (desc_count)
1997 				sdkp->unmap = 1;
1998 		}
1999 
2000 		granularity = get_unaligned_be32(&buffer[28]);
2001 
2002 		if (granularity)
2003 			q->limits.discard_granularity = granularity * sector_sz;
2004 
2005 		if (buffer[32] & 0x80)
2006 			q->limits.discard_alignment =
2007 				get_unaligned_be32(&buffer[32]) & ~(1 << 31);
2008 	}
2009 
2010  out:
2011 	kfree(buffer);
2012 }
2013 
2014 /**
2015  * sd_read_block_characteristics - Query block dev. characteristics
2016  * @disk: disk to query
2017  */
2018 static void sd_read_block_characteristics(struct scsi_disk *sdkp)
2019 {
2020 	unsigned char *buffer;
2021 	u16 rot;
2022 	const int vpd_len = 64;
2023 
2024 	buffer = kmalloc(vpd_len, GFP_KERNEL);
2025 
2026 	if (!buffer ||
2027 	    /* Block Device Characteristics VPD */
2028 	    scsi_get_vpd_page(sdkp->device, 0xb1, buffer, vpd_len))
2029 		goto out;
2030 
2031 	rot = get_unaligned_be16(&buffer[4]);
2032 
2033 	if (rot == 1)
2034 		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, sdkp->disk->queue);
2035 
2036  out:
2037 	kfree(buffer);
2038 }
2039 
2040 static int sd_try_extended_inquiry(struct scsi_device *sdp)
2041 {
2042 	/*
2043 	 * Although VPD inquiries can go to SCSI-2 type devices,
2044 	 * some USB ones crash on receiving them, and the pages
2045 	 * we currently ask for are for SPC-3 and beyond
2046 	 */
2047 	if (sdp->scsi_level > SCSI_SPC_2)
2048 		return 1;
2049 	return 0;
2050 }
2051 
2052 /**
2053  *	sd_revalidate_disk - called the first time a new disk is seen,
2054  *	performs disk spin up, read_capacity, etc.
2055  *	@disk: struct gendisk we care about
2056  **/
2057 static int sd_revalidate_disk(struct gendisk *disk)
2058 {
2059 	struct scsi_disk *sdkp = scsi_disk(disk);
2060 	struct scsi_device *sdp = sdkp->device;
2061 	unsigned char *buffer;
2062 	unsigned ordered;
2063 
2064 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
2065 				      "sd_revalidate_disk\n"));
2066 
2067 	/*
2068 	 * If the device is offline, don't try and read capacity or any
2069 	 * of the other niceties.
2070 	 */
2071 	if (!scsi_device_online(sdp))
2072 		goto out;
2073 
2074 	buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
2075 	if (!buffer) {
2076 		sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
2077 			  "allocation failure.\n");
2078 		goto out;
2079 	}
2080 
2081 	sd_spinup_disk(sdkp);
2082 
2083 	/*
2084 	 * Without media there is no reason to ask; moreover, some devices
2085 	 * react badly if we do.
2086 	 */
2087 	if (sdkp->media_present) {
2088 		sd_read_capacity(sdkp, buffer);
2089 
2090 		if (sd_try_extended_inquiry(sdp)) {
2091 			sd_read_block_limits(sdkp);
2092 			sd_read_block_characteristics(sdkp);
2093 		}
2094 
2095 		sd_read_write_protect_flag(sdkp, buffer);
2096 		sd_read_cache_type(sdkp, buffer);
2097 		sd_read_app_tag_own(sdkp, buffer);
2098 	}
2099 
2100 	sdkp->first_scan = 0;
2101 
2102 	/*
2103 	 * We now have all cache related info, determine how we deal
2104 	 * with ordered requests.  Note that as the current SCSI
2105 	 * dispatch function can alter request order, we cannot use
2106 	 * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
2107 	 */
2108 	if (sdkp->WCE)
2109 		ordered = sdkp->DPOFUA
2110 			? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
2111 	else
2112 		ordered = QUEUE_ORDERED_DRAIN;
2113 
2114 	blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush);
2115 
2116 	set_capacity(disk, sdkp->capacity);
2117 	kfree(buffer);
2118 
2119  out:
2120 	return 0;
2121 }
2122 
2123 /**
2124  *	sd_format_disk_name - format disk name
2125  *	@prefix: name prefix - ie. "sd" for SCSI disks
2126  *	@index: index of the disk to format name for
2127  *	@buf: output buffer
2128  *	@buflen: length of the output buffer
2129  *
2130  *	SCSI disk names starts at sda.  The 26th device is sdz and the
2131  *	27th is sdaa.  The last one for two lettered suffix is sdzz
2132  *	which is followed by sdaaa.
2133  *
2134  *	This is basically 26 base counting with one extra 'nil' entry
2135  *	at the beginning from the second digit on and can be
2136  *	determined using similar method as 26 base conversion with the
2137  *	index shifted -1 after each digit is computed.
2138  *
2139  *	CONTEXT:
2140  *	Don't care.
2141  *
2142  *	RETURNS:
2143  *	0 on success, -errno on failure.
2144  */
2145 static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
2146 {
2147 	const int base = 'z' - 'a' + 1;
2148 	char *begin = buf + strlen(prefix);
2149 	char *end = buf + buflen;
2150 	char *p;
2151 	int unit;
2152 
2153 	p = end - 1;
2154 	*p = '\0';
2155 	unit = base;
2156 	do {
2157 		if (p == begin)
2158 			return -EINVAL;
2159 		*--p = 'a' + (index % unit);
2160 		index = (index / unit) - 1;
2161 	} while (index >= 0);
2162 
2163 	memmove(begin, p, end - p);
2164 	memcpy(buf, prefix, strlen(prefix));
2165 
2166 	return 0;
2167 }
2168 
2169 /*
2170  * The asynchronous part of sd_probe
2171  */
2172 static void sd_probe_async(void *data, async_cookie_t cookie)
2173 {
2174 	struct scsi_disk *sdkp = data;
2175 	struct scsi_device *sdp;
2176 	struct gendisk *gd;
2177 	u32 index;
2178 	struct device *dev;
2179 
2180 	sdp = sdkp->device;
2181 	gd = sdkp->disk;
2182 	index = sdkp->index;
2183 	dev = &sdp->sdev_gendev;
2184 
2185 	if (index < SD_MAX_DISKS) {
2186 		gd->major = sd_major((index & 0xf0) >> 4);
2187 		gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
2188 		gd->minors = SD_MINORS;
2189 	}
2190 	gd->fops = &sd_fops;
2191 	gd->private_data = &sdkp->driver;
2192 	gd->queue = sdkp->device->request_queue;
2193 
2194 	/* defaults, until the device tells us otherwise */
2195 	sdp->sector_size = 512;
2196 	sdkp->capacity = 0;
2197 	sdkp->media_present = 1;
2198 	sdkp->write_prot = 0;
2199 	sdkp->WCE = 0;
2200 	sdkp->RCD = 0;
2201 	sdkp->ATO = 0;
2202 	sdkp->first_scan = 1;
2203 
2204 	sd_revalidate_disk(gd);
2205 
2206 	blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);
2207 
2208 	gd->driverfs_dev = &sdp->sdev_gendev;
2209 	gd->flags = GENHD_FL_EXT_DEVT;
2210 	if (sdp->removable)
2211 		gd->flags |= GENHD_FL_REMOVABLE;
2212 
2213 	dev_set_drvdata(dev, sdkp);
2214 	add_disk(gd);
2215 	sd_dif_config_host(sdkp);
2216 
2217 	sd_revalidate_disk(gd);
2218 
2219 	sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
2220 		  sdp->removable ? "removable " : "");
2221 	put_device(&sdkp->dev);
2222 }
2223 
2224 /**
2225  *	sd_probe - called during driver initialization and whenever a
2226  *	new scsi device is attached to the system. It is called once
2227  *	for each scsi device (not just disks) present.
2228  *	@dev: pointer to device object
2229  *
2230  *	Returns 0 if successful (or not interested in this scsi device
2231  *	(e.g. scanner)); 1 when there is an error.
2232  *
2233  *	Note: this function is invoked from the scsi mid-level.
2234  *	This function sets up the mapping between a given
2235  *	<host,channel,id,lun> (found in sdp) and new device name
2236  *	(e.g. /dev/sda). More precisely it is the block device major
2237  *	and minor number that is chosen here.
2238  *
2239  *	Assume sd_attach is not re-entrant (for time being)
2240  *	Also think about sd_attach() and sd_remove() running coincidentally.
2241  **/
2242 static int sd_probe(struct device *dev)
2243 {
2244 	struct scsi_device *sdp = to_scsi_device(dev);
2245 	struct scsi_disk *sdkp;
2246 	struct gendisk *gd;
2247 	u32 index;
2248 	int error;
2249 
2250 	error = -ENODEV;
2251 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
2252 		goto out;
2253 
2254 	SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
2255 					"sd_attach\n"));
2256 
2257 	error = -ENOMEM;
2258 	sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
2259 	if (!sdkp)
2260 		goto out;
2261 
2262 	gd = alloc_disk(SD_MINORS);
2263 	if (!gd)
2264 		goto out_free;
2265 
2266 	do {
2267 		if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
2268 			goto out_put;
2269 
2270 		spin_lock(&sd_index_lock);
2271 		error = ida_get_new(&sd_index_ida, &index);
2272 		spin_unlock(&sd_index_lock);
2273 	} while (error == -EAGAIN);
2274 
2275 	if (error)
2276 		goto out_put;
2277 
2278 	error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
2279 	if (error)
2280 		goto out_free_index;
2281 
2282 	sdkp->device = sdp;
2283 	sdkp->driver = &sd_template;
2284 	sdkp->disk = gd;
2285 	sdkp->index = index;
2286 	sdkp->openers = 0;
2287 	sdkp->previous_state = 1;
2288 
2289 	if (!sdp->request_queue->rq_timeout) {
2290 		if (sdp->type != TYPE_MOD)
2291 			blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
2292 		else
2293 			blk_queue_rq_timeout(sdp->request_queue,
2294 					     SD_MOD_TIMEOUT);
2295 	}
2296 
2297 	device_initialize(&sdkp->dev);
2298 	sdkp->dev.parent = &sdp->sdev_gendev;
2299 	sdkp->dev.class = &sd_disk_class;
2300 	dev_set_name(&sdkp->dev, dev_name(&sdp->sdev_gendev));
2301 
2302 	if (device_add(&sdkp->dev))
2303 		goto out_free_index;
2304 
2305 	get_device(&sdp->sdev_gendev);
2306 
2307 	get_device(&sdkp->dev);	/* prevent release before async_schedule */
2308 	async_schedule(sd_probe_async, sdkp);
2309 
2310 	return 0;
2311 
2312  out_free_index:
2313 	spin_lock(&sd_index_lock);
2314 	ida_remove(&sd_index_ida, index);
2315 	spin_unlock(&sd_index_lock);
2316  out_put:
2317 	put_disk(gd);
2318  out_free:
2319 	kfree(sdkp);
2320  out:
2321 	return error;
2322 }
2323 
2324 /**
2325  *	sd_remove - called whenever a scsi disk (previously recognized by
2326  *	sd_probe) is detached from the system. It is called (potentially
2327  *	multiple times) during sd module unload.
2328  *	@sdp: pointer to mid level scsi device object
2329  *
2330  *	Note: this function is invoked from the scsi mid-level.
2331  *	This function potentially frees up a device name (e.g. /dev/sdc)
2332  *	that could be re-used by a subsequent sd_probe().
2333  *	This function is not called when the built-in sd driver is "exit-ed".
2334  **/
2335 static int sd_remove(struct device *dev)
2336 {
2337 	struct scsi_disk *sdkp;
2338 
2339 	async_synchronize_full();
2340 	sdkp = dev_get_drvdata(dev);
2341 	blk_queue_prep_rq(sdkp->device->request_queue, scsi_prep_fn);
2342 	device_del(&sdkp->dev);
2343 	del_gendisk(sdkp->disk);
2344 	sd_shutdown(dev);
2345 
2346 	mutex_lock(&sd_ref_mutex);
2347 	dev_set_drvdata(dev, NULL);
2348 	put_device(&sdkp->dev);
2349 	mutex_unlock(&sd_ref_mutex);
2350 
2351 	return 0;
2352 }
2353 
2354 /**
2355  *	scsi_disk_release - Called to free the scsi_disk structure
2356  *	@dev: pointer to embedded class device
2357  *
2358  *	sd_ref_mutex must be held entering this routine.  Because it is
2359  *	called on last put, you should always use the scsi_disk_get()
2360  *	scsi_disk_put() helpers which manipulate the semaphore directly
2361  *	and never do a direct put_device.
2362  **/
2363 static void scsi_disk_release(struct device *dev)
2364 {
2365 	struct scsi_disk *sdkp = to_scsi_disk(dev);
2366 	struct gendisk *disk = sdkp->disk;
2367 
2368 	spin_lock(&sd_index_lock);
2369 	ida_remove(&sd_index_ida, sdkp->index);
2370 	spin_unlock(&sd_index_lock);
2371 
2372 	disk->private_data = NULL;
2373 	put_disk(disk);
2374 	put_device(&sdkp->device->sdev_gendev);
2375 
2376 	kfree(sdkp);
2377 }
2378 
2379 static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
2380 {
2381 	unsigned char cmd[6] = { START_STOP };	/* START_VALID */
2382 	struct scsi_sense_hdr sshdr;
2383 	struct scsi_device *sdp = sdkp->device;
2384 	int res;
2385 
2386 	if (start)
2387 		cmd[4] |= 1;	/* START */
2388 
2389 	if (sdp->start_stop_pwr_cond)
2390 		cmd[4] |= start ? 1 << 4 : 3 << 4;	/* Active or Standby */
2391 
2392 	if (!scsi_device_online(sdp))
2393 		return -ENODEV;
2394 
2395 	res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
2396 			       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
2397 	if (res) {
2398 		sd_printk(KERN_WARNING, sdkp, "START_STOP FAILED\n");
2399 		sd_print_result(sdkp, res);
2400 		if (driver_byte(res) & DRIVER_SENSE)
2401 			sd_print_sense_hdr(sdkp, &sshdr);
2402 	}
2403 
2404 	return res;
2405 }
2406 
2407 /*
2408  * Send a SYNCHRONIZE CACHE instruction down to the device through
2409  * the normal SCSI command structure.  Wait for the command to
2410  * complete.
2411  */
2412 static void sd_shutdown(struct device *dev)
2413 {
2414 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2415 
2416 	if (!sdkp)
2417 		return;         /* this can happen */
2418 
2419 	if (sdkp->WCE) {
2420 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2421 		sd_sync_cache(sdkp);
2422 	}
2423 
2424 	if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
2425 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2426 		sd_start_stop_device(sdkp, 0);
2427 	}
2428 
2429 	scsi_disk_put(sdkp);
2430 }
2431 
2432 static int sd_suspend(struct device *dev, pm_message_t mesg)
2433 {
2434 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2435 	int ret = 0;
2436 
2437 	if (!sdkp)
2438 		return 0;	/* this can happen */
2439 
2440 	if (sdkp->WCE) {
2441 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2442 		ret = sd_sync_cache(sdkp);
2443 		if (ret)
2444 			goto done;
2445 	}
2446 
2447 	if ((mesg.event & PM_EVENT_SLEEP) && sdkp->device->manage_start_stop) {
2448 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2449 		ret = sd_start_stop_device(sdkp, 0);
2450 	}
2451 
2452 done:
2453 	scsi_disk_put(sdkp);
2454 	return ret;
2455 }
2456 
2457 static int sd_resume(struct device *dev)
2458 {
2459 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2460 	int ret = 0;
2461 
2462 	if (!sdkp->device->manage_start_stop)
2463 		goto done;
2464 
2465 	sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
2466 	ret = sd_start_stop_device(sdkp, 1);
2467 
2468 done:
2469 	scsi_disk_put(sdkp);
2470 	return ret;
2471 }
2472 
2473 /**
2474  *	init_sd - entry point for this driver (both when built in or when
2475  *	a module).
2476  *
2477  *	Note: this function registers this driver with the scsi mid-level.
2478  **/
2479 static int __init init_sd(void)
2480 {
2481 	int majors = 0, i, err;
2482 
2483 	SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
2484 
2485 	for (i = 0; i < SD_MAJORS; i++)
2486 		if (register_blkdev(sd_major(i), "sd") == 0)
2487 			majors++;
2488 
2489 	if (!majors)
2490 		return -ENODEV;
2491 
2492 	err = class_register(&sd_disk_class);
2493 	if (err)
2494 		goto err_out;
2495 
2496 	err = scsi_register_driver(&sd_template.gendrv);
2497 	if (err)
2498 		goto err_out_class;
2499 
2500 	sd_cdb_cache = kmem_cache_create("sd_ext_cdb", SD_EXT_CDB_SIZE,
2501 					 0, 0, NULL);
2502 	if (!sd_cdb_cache) {
2503 		printk(KERN_ERR "sd: can't init extended cdb cache\n");
2504 		goto err_out_class;
2505 	}
2506 
2507 	sd_cdb_pool = mempool_create_slab_pool(SD_MEMPOOL_SIZE, sd_cdb_cache);
2508 	if (!sd_cdb_pool) {
2509 		printk(KERN_ERR "sd: can't init extended cdb pool\n");
2510 		goto err_out_cache;
2511 	}
2512 
2513 	return 0;
2514 
2515 err_out_cache:
2516 	kmem_cache_destroy(sd_cdb_cache);
2517 
2518 err_out_class:
2519 	class_unregister(&sd_disk_class);
2520 err_out:
2521 	for (i = 0; i < SD_MAJORS; i++)
2522 		unregister_blkdev(sd_major(i), "sd");
2523 	return err;
2524 }
2525 
2526 /**
2527  *	exit_sd - exit point for this driver (when it is a module).
2528  *
2529  *	Note: this function unregisters this driver from the scsi mid-level.
2530  **/
2531 static void __exit exit_sd(void)
2532 {
2533 	int i;
2534 
2535 	SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
2536 
2537 	mempool_destroy(sd_cdb_pool);
2538 	kmem_cache_destroy(sd_cdb_cache);
2539 
2540 	scsi_unregister_driver(&sd_template.gendrv);
2541 	class_unregister(&sd_disk_class);
2542 
2543 	for (i = 0; i < SD_MAJORS; i++)
2544 		unregister_blkdev(sd_major(i), "sd");
2545 }
2546 
2547 module_init(init_sd);
2548 module_exit(exit_sd);
2549 
2550 static void sd_print_sense_hdr(struct scsi_disk *sdkp,
2551 			       struct scsi_sense_hdr *sshdr)
2552 {
2553 	sd_printk(KERN_INFO, sdkp, "");
2554 	scsi_show_sense_hdr(sshdr);
2555 	sd_printk(KERN_INFO, sdkp, "");
2556 	scsi_show_extd_sense(sshdr->asc, sshdr->ascq);
2557 }
2558 
2559 static void sd_print_result(struct scsi_disk *sdkp, int result)
2560 {
2561 	sd_printk(KERN_INFO, sdkp, "");
2562 	scsi_show_result(result);
2563 }
2564 
2565