xref: /linux/drivers/scsi/sd.c (revision 3bf509230a626d11cba0e0145f552918092f586d)
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 <asm/uaccess.h>
53 
54 #include <scsi/scsi.h>
55 #include <scsi/scsi_cmnd.h>
56 #include <scsi/scsi_dbg.h>
57 #include <scsi/scsi_device.h>
58 #include <scsi/scsi_driver.h>
59 #include <scsi/scsi_eh.h>
60 #include <scsi/scsi_host.h>
61 #include <scsi/scsi_ioctl.h>
62 #include <scsi/scsicam.h>
63 
64 #include "sd.h"
65 #include "scsi_logging.h"
66 
67 MODULE_AUTHOR("Eric Youngdale");
68 MODULE_DESCRIPTION("SCSI disk (sd) driver");
69 MODULE_LICENSE("GPL");
70 
71 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK0_MAJOR);
72 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK1_MAJOR);
73 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK2_MAJOR);
74 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK3_MAJOR);
75 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK4_MAJOR);
76 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK5_MAJOR);
77 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK6_MAJOR);
78 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK7_MAJOR);
79 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK8_MAJOR);
80 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK9_MAJOR);
81 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK10_MAJOR);
82 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK11_MAJOR);
83 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK12_MAJOR);
84 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK13_MAJOR);
85 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK14_MAJOR);
86 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
87 MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
88 MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
89 MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
90 
91 #if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
92 #define SD_MINORS	16
93 #else
94 #define SD_MINORS	0
95 #endif
96 
97 static int  sd_revalidate_disk(struct gendisk *);
98 static int  sd_probe(struct device *);
99 static int  sd_remove(struct device *);
100 static void sd_shutdown(struct device *);
101 static int sd_suspend(struct device *, pm_message_t state);
102 static int sd_resume(struct device *);
103 static void sd_rescan(struct device *);
104 static int sd_done(struct scsi_cmnd *);
105 static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
106 static void scsi_disk_release(struct device *cdev);
107 static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
108 static void sd_print_result(struct scsi_disk *, int);
109 
110 static DEFINE_SPINLOCK(sd_index_lock);
111 static DEFINE_IDA(sd_index_ida);
112 
113 /* This semaphore is used to mediate the 0->1 reference get in the
114  * face of object destruction (i.e. we can't allow a get on an
115  * object after last put) */
116 static DEFINE_MUTEX(sd_ref_mutex);
117 
118 static const char *sd_cache_types[] = {
119 	"write through", "none", "write back",
120 	"write back, no read (daft)"
121 };
122 
123 static ssize_t
124 sd_store_cache_type(struct device *dev, struct device_attribute *attr,
125 		    const char *buf, size_t count)
126 {
127 	int i, ct = -1, rcd, wce, sp;
128 	struct scsi_disk *sdkp = to_scsi_disk(dev);
129 	struct scsi_device *sdp = sdkp->device;
130 	char buffer[64];
131 	char *buffer_data;
132 	struct scsi_mode_data data;
133 	struct scsi_sense_hdr sshdr;
134 	int len;
135 
136 	if (sdp->type != TYPE_DISK)
137 		/* no cache control on RBC devices; theoretically they
138 		 * can do it, but there's probably so many exceptions
139 		 * it's not worth the risk */
140 		return -EINVAL;
141 
142 	for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {
143 		const int len = strlen(sd_cache_types[i]);
144 		if (strncmp(sd_cache_types[i], buf, len) == 0 &&
145 		    buf[len] == '\n') {
146 			ct = i;
147 			break;
148 		}
149 	}
150 	if (ct < 0)
151 		return -EINVAL;
152 	rcd = ct & 0x01 ? 1 : 0;
153 	wce = ct & 0x02 ? 1 : 0;
154 	if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
155 			    SD_MAX_RETRIES, &data, NULL))
156 		return -EINVAL;
157 	len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
158 		  data.block_descriptor_length);
159 	buffer_data = buffer + data.header_length +
160 		data.block_descriptor_length;
161 	buffer_data[2] &= ~0x05;
162 	buffer_data[2] |= wce << 2 | rcd;
163 	sp = buffer_data[0] & 0x80 ? 1 : 0;
164 
165 	if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
166 			     SD_MAX_RETRIES, &data, &sshdr)) {
167 		if (scsi_sense_valid(&sshdr))
168 			sd_print_sense_hdr(sdkp, &sshdr);
169 		return -EINVAL;
170 	}
171 	revalidate_disk(sdkp->disk);
172 	return count;
173 }
174 
175 static ssize_t
176 sd_store_manage_start_stop(struct device *dev, struct device_attribute *attr,
177 			   const char *buf, size_t count)
178 {
179 	struct scsi_disk *sdkp = to_scsi_disk(dev);
180 	struct scsi_device *sdp = sdkp->device;
181 
182 	if (!capable(CAP_SYS_ADMIN))
183 		return -EACCES;
184 
185 	sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
186 
187 	return count;
188 }
189 
190 static ssize_t
191 sd_store_allow_restart(struct device *dev, struct device_attribute *attr,
192 		       const char *buf, size_t count)
193 {
194 	struct scsi_disk *sdkp = to_scsi_disk(dev);
195 	struct scsi_device *sdp = sdkp->device;
196 
197 	if (!capable(CAP_SYS_ADMIN))
198 		return -EACCES;
199 
200 	if (sdp->type != TYPE_DISK)
201 		return -EINVAL;
202 
203 	sdp->allow_restart = simple_strtoul(buf, NULL, 10);
204 
205 	return count;
206 }
207 
208 static ssize_t
209 sd_show_cache_type(struct device *dev, struct device_attribute *attr,
210 		   char *buf)
211 {
212 	struct scsi_disk *sdkp = to_scsi_disk(dev);
213 	int ct = sdkp->RCD + 2*sdkp->WCE;
214 
215 	return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
216 }
217 
218 static ssize_t
219 sd_show_fua(struct device *dev, struct device_attribute *attr, char *buf)
220 {
221 	struct scsi_disk *sdkp = to_scsi_disk(dev);
222 
223 	return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
224 }
225 
226 static ssize_t
227 sd_show_manage_start_stop(struct device *dev, struct device_attribute *attr,
228 			  char *buf)
229 {
230 	struct scsi_disk *sdkp = to_scsi_disk(dev);
231 	struct scsi_device *sdp = sdkp->device;
232 
233 	return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
234 }
235 
236 static ssize_t
237 sd_show_allow_restart(struct device *dev, struct device_attribute *attr,
238 		      char *buf)
239 {
240 	struct scsi_disk *sdkp = to_scsi_disk(dev);
241 
242 	return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
243 }
244 
245 static ssize_t
246 sd_show_protection_type(struct device *dev, struct device_attribute *attr,
247 			char *buf)
248 {
249 	struct scsi_disk *sdkp = to_scsi_disk(dev);
250 
251 	return snprintf(buf, 20, "%u\n", sdkp->protection_type);
252 }
253 
254 static ssize_t
255 sd_show_app_tag_own(struct device *dev, struct device_attribute *attr,
256 		    char *buf)
257 {
258 	struct scsi_disk *sdkp = to_scsi_disk(dev);
259 
260 	return snprintf(buf, 20, "%u\n", sdkp->ATO);
261 }
262 
263 static struct device_attribute sd_disk_attrs[] = {
264 	__ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
265 	       sd_store_cache_type),
266 	__ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
267 	__ATTR(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
268 	       sd_store_allow_restart),
269 	__ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
270 	       sd_store_manage_start_stop),
271 	__ATTR(protection_type, S_IRUGO, sd_show_protection_type, NULL),
272 	__ATTR(app_tag_own, S_IRUGO, sd_show_app_tag_own, NULL),
273 	__ATTR_NULL,
274 };
275 
276 static struct class sd_disk_class = {
277 	.name		= "scsi_disk",
278 	.owner		= THIS_MODULE,
279 	.dev_release	= scsi_disk_release,
280 	.dev_attrs	= sd_disk_attrs,
281 };
282 
283 static struct scsi_driver sd_template = {
284 	.owner			= THIS_MODULE,
285 	.gendrv = {
286 		.name		= "sd",
287 		.probe		= sd_probe,
288 		.remove		= sd_remove,
289 		.suspend	= sd_suspend,
290 		.resume		= sd_resume,
291 		.shutdown	= sd_shutdown,
292 	},
293 	.rescan			= sd_rescan,
294 	.done			= sd_done,
295 };
296 
297 /*
298  * Device no to disk mapping:
299  *
300  *       major         disc2     disc  p1
301  *   |............|.............|....|....| <- dev_t
302  *    31        20 19          8 7  4 3  0
303  *
304  * Inside a major, we have 16k disks, however mapped non-
305  * contiguously. The first 16 disks are for major0, the next
306  * ones with major1, ... Disk 256 is for major0 again, disk 272
307  * for major1, ...
308  * As we stay compatible with our numbering scheme, we can reuse
309  * the well-know SCSI majors 8, 65--71, 136--143.
310  */
311 static int sd_major(int major_idx)
312 {
313 	switch (major_idx) {
314 	case 0:
315 		return SCSI_DISK0_MAJOR;
316 	case 1 ... 7:
317 		return SCSI_DISK1_MAJOR + major_idx - 1;
318 	case 8 ... 15:
319 		return SCSI_DISK8_MAJOR + major_idx - 8;
320 	default:
321 		BUG();
322 		return 0;	/* shut up gcc */
323 	}
324 }
325 
326 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
327 {
328 	struct scsi_disk *sdkp = NULL;
329 
330 	if (disk->private_data) {
331 		sdkp = scsi_disk(disk);
332 		if (scsi_device_get(sdkp->device) == 0)
333 			get_device(&sdkp->dev);
334 		else
335 			sdkp = NULL;
336 	}
337 	return sdkp;
338 }
339 
340 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
341 {
342 	struct scsi_disk *sdkp;
343 
344 	mutex_lock(&sd_ref_mutex);
345 	sdkp = __scsi_disk_get(disk);
346 	mutex_unlock(&sd_ref_mutex);
347 	return sdkp;
348 }
349 
350 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
351 {
352 	struct scsi_disk *sdkp;
353 
354 	mutex_lock(&sd_ref_mutex);
355 	sdkp = dev_get_drvdata(dev);
356 	if (sdkp)
357 		sdkp = __scsi_disk_get(sdkp->disk);
358 	mutex_unlock(&sd_ref_mutex);
359 	return sdkp;
360 }
361 
362 static void scsi_disk_put(struct scsi_disk *sdkp)
363 {
364 	struct scsi_device *sdev = sdkp->device;
365 
366 	mutex_lock(&sd_ref_mutex);
367 	put_device(&sdkp->dev);
368 	scsi_device_put(sdev);
369 	mutex_unlock(&sd_ref_mutex);
370 }
371 
372 /**
373  *	sd_init_command - build a scsi (read or write) command from
374  *	information in the request structure.
375  *	@SCpnt: pointer to mid-level's per scsi command structure that
376  *	contains request and into which the scsi command is written
377  *
378  *	Returns 1 if successful and 0 if error (or cannot be done now).
379  **/
380 static int sd_prep_fn(struct request_queue *q, struct request *rq)
381 {
382 	struct scsi_cmnd *SCpnt;
383 	struct scsi_device *sdp = q->queuedata;
384 	struct gendisk *disk = rq->rq_disk;
385 	struct scsi_disk *sdkp;
386 	sector_t block = rq->sector;
387 	sector_t threshold;
388 	unsigned int this_count = rq->nr_sectors;
389 	int ret, host_dif;
390 
391 	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
392 		ret = scsi_setup_blk_pc_cmnd(sdp, rq);
393 		goto out;
394 	} else if (rq->cmd_type != REQ_TYPE_FS) {
395 		ret = BLKPREP_KILL;
396 		goto out;
397 	}
398 	ret = scsi_setup_fs_cmnd(sdp, rq);
399 	if (ret != BLKPREP_OK)
400 		goto out;
401 	SCpnt = rq->special;
402 	sdkp = scsi_disk(disk);
403 
404 	/* from here on until we're complete, any goto out
405 	 * is used for a killable error condition */
406 	ret = BLKPREP_KILL;
407 
408 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
409 					"sd_init_command: block=%llu, "
410 					"count=%d\n",
411 					(unsigned long long)block,
412 					this_count));
413 
414 	if (!sdp || !scsi_device_online(sdp) ||
415  	    block + rq->nr_sectors > get_capacity(disk)) {
416 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
417 						"Finishing %ld sectors\n",
418 						rq->nr_sectors));
419 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
420 						"Retry with 0x%p\n", SCpnt));
421 		goto out;
422 	}
423 
424 	if (sdp->changed) {
425 		/*
426 		 * quietly refuse to do anything to a changed disc until
427 		 * the changed bit has been reset
428 		 */
429 		/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
430 		goto out;
431 	}
432 
433 	/*
434 	 * Some SD card readers can't handle multi-sector accesses which touch
435 	 * the last one or two hardware sectors.  Split accesses as needed.
436 	 */
437 	threshold = get_capacity(disk) - SD_LAST_BUGGY_SECTORS *
438 		(sdp->sector_size / 512);
439 
440 	if (unlikely(sdp->last_sector_bug && block + this_count > threshold)) {
441 		if (block < threshold) {
442 			/* Access up to the threshold but not beyond */
443 			this_count = threshold - block;
444 		} else {
445 			/* Access only a single hardware sector */
446 			this_count = sdp->sector_size / 512;
447 		}
448 	}
449 
450 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
451 					(unsigned long long)block));
452 
453 	/*
454 	 * If we have a 1K hardware sectorsize, prevent access to single
455 	 * 512 byte sectors.  In theory we could handle this - in fact
456 	 * the scsi cdrom driver must be able to handle this because
457 	 * we typically use 1K blocksizes, and cdroms typically have
458 	 * 2K hardware sectorsizes.  Of course, things are simpler
459 	 * with the cdrom, since it is read-only.  For performance
460 	 * reasons, the filesystems should be able to handle this
461 	 * and not force the scsi disk driver to use bounce buffers
462 	 * for this.
463 	 */
464 	if (sdp->sector_size == 1024) {
465 		if ((block & 1) || (rq->nr_sectors & 1)) {
466 			scmd_printk(KERN_ERR, SCpnt,
467 				    "Bad block number requested\n");
468 			goto out;
469 		} else {
470 			block = block >> 1;
471 			this_count = this_count >> 1;
472 		}
473 	}
474 	if (sdp->sector_size == 2048) {
475 		if ((block & 3) || (rq->nr_sectors & 3)) {
476 			scmd_printk(KERN_ERR, SCpnt,
477 				    "Bad block number requested\n");
478 			goto out;
479 		} else {
480 			block = block >> 2;
481 			this_count = this_count >> 2;
482 		}
483 	}
484 	if (sdp->sector_size == 4096) {
485 		if ((block & 7) || (rq->nr_sectors & 7)) {
486 			scmd_printk(KERN_ERR, SCpnt,
487 				    "Bad block number requested\n");
488 			goto out;
489 		} else {
490 			block = block >> 3;
491 			this_count = this_count >> 3;
492 		}
493 	}
494 	if (rq_data_dir(rq) == WRITE) {
495 		if (!sdp->writeable) {
496 			goto out;
497 		}
498 		SCpnt->cmnd[0] = WRITE_6;
499 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
500 
501 		if (blk_integrity_rq(rq) &&
502 		    sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
503 			goto out;
504 
505 	} else if (rq_data_dir(rq) == READ) {
506 		SCpnt->cmnd[0] = READ_6;
507 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
508 	} else {
509 		scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
510 		goto out;
511 	}
512 
513 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
514 					"%s %d/%ld 512 byte blocks.\n",
515 					(rq_data_dir(rq) == WRITE) ?
516 					"writing" : "reading", this_count,
517 					rq->nr_sectors));
518 
519 	/* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
520 	host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
521 	if (host_dif)
522 		SCpnt->cmnd[1] = 1 << 5;
523 	else
524 		SCpnt->cmnd[1] = 0;
525 
526 	if (block > 0xffffffff) {
527 		SCpnt->cmnd[0] += READ_16 - READ_6;
528 		SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
529 		SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
530 		SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
531 		SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
532 		SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
533 		SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
534 		SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
535 		SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
536 		SCpnt->cmnd[9] = (unsigned char) block & 0xff;
537 		SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
538 		SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
539 		SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
540 		SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
541 		SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
542 	} else if ((this_count > 0xff) || (block > 0x1fffff) ||
543 		   scsi_device_protection(SCpnt->device) ||
544 		   SCpnt->device->use_10_for_rw) {
545 		if (this_count > 0xffff)
546 			this_count = 0xffff;
547 
548 		SCpnt->cmnd[0] += READ_10 - READ_6;
549 		SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
550 		SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
551 		SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
552 		SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
553 		SCpnt->cmnd[5] = (unsigned char) block & 0xff;
554 		SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
555 		SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
556 		SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
557 	} else {
558 		if (unlikely(blk_fua_rq(rq))) {
559 			/*
560 			 * This happens only if this drive failed
561 			 * 10byte rw command with ILLEGAL_REQUEST
562 			 * during operation and thus turned off
563 			 * use_10_for_rw.
564 			 */
565 			scmd_printk(KERN_ERR, SCpnt,
566 				    "FUA write on READ/WRITE(6) drive\n");
567 			goto out;
568 		}
569 
570 		SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
571 		SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
572 		SCpnt->cmnd[3] = (unsigned char) block & 0xff;
573 		SCpnt->cmnd[4] = (unsigned char) this_count;
574 		SCpnt->cmnd[5] = 0;
575 	}
576 	SCpnt->sdb.length = this_count * sdp->sector_size;
577 
578 	/* If DIF or DIX is enabled, tell HBA how to handle request */
579 	if (host_dif || scsi_prot_sg_count(SCpnt))
580 		sd_dif_op(SCpnt, host_dif, scsi_prot_sg_count(SCpnt),
581 			  sdkp->protection_type);
582 
583 	/*
584 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
585 	 * host adapter, it's safe to assume that we can at least transfer
586 	 * this many bytes between each connect / disconnect.
587 	 */
588 	SCpnt->transfersize = sdp->sector_size;
589 	SCpnt->underflow = this_count << 9;
590 	SCpnt->allowed = SD_MAX_RETRIES;
591 
592 	/*
593 	 * This indicates that the command is ready from our end to be
594 	 * queued.
595 	 */
596 	ret = BLKPREP_OK;
597  out:
598 	return scsi_prep_return(q, rq, ret);
599 }
600 
601 /**
602  *	sd_open - open a scsi disk device
603  *	@inode: only i_rdev member may be used
604  *	@filp: only f_mode and f_flags may be used
605  *
606  *	Returns 0 if successful. Returns a negated errno value in case
607  *	of error.
608  *
609  *	Note: This can be called from a user context (e.g. fsck(1) )
610  *	or from within the kernel (e.g. as a result of a mount(1) ).
611  *	In the latter case @inode and @filp carry an abridged amount
612  *	of information as noted above.
613  **/
614 static int sd_open(struct block_device *bdev, fmode_t mode)
615 {
616 	struct scsi_disk *sdkp = scsi_disk_get(bdev->bd_disk);
617 	struct scsi_device *sdev;
618 	int retval;
619 
620 	if (!sdkp)
621 		return -ENXIO;
622 
623 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
624 
625 	sdev = sdkp->device;
626 
627 	/*
628 	 * If the device is in error recovery, wait until it is done.
629 	 * If the device is offline, then disallow any access to it.
630 	 */
631 	retval = -ENXIO;
632 	if (!scsi_block_when_processing_errors(sdev))
633 		goto error_out;
634 
635 	if (sdev->removable || sdkp->write_prot)
636 		check_disk_change(bdev);
637 
638 	/*
639 	 * If the drive is empty, just let the open fail.
640 	 */
641 	retval = -ENOMEDIUM;
642 	if (sdev->removable && !sdkp->media_present && !(mode & FMODE_NDELAY))
643 		goto error_out;
644 
645 	/*
646 	 * If the device has the write protect tab set, have the open fail
647 	 * if the user expects to be able to write to the thing.
648 	 */
649 	retval = -EROFS;
650 	if (sdkp->write_prot && (mode & FMODE_WRITE))
651 		goto error_out;
652 
653 	/*
654 	 * It is possible that the disk changing stuff resulted in
655 	 * the device being taken offline.  If this is the case,
656 	 * report this to the user, and don't pretend that the
657 	 * open actually succeeded.
658 	 */
659 	retval = -ENXIO;
660 	if (!scsi_device_online(sdev))
661 		goto error_out;
662 
663 	if (!sdkp->openers++ && sdev->removable) {
664 		if (scsi_block_when_processing_errors(sdev))
665 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
666 	}
667 
668 	return 0;
669 
670 error_out:
671 	scsi_disk_put(sdkp);
672 	return retval;
673 }
674 
675 /**
676  *	sd_release - invoked when the (last) close(2) is called on this
677  *	scsi disk.
678  *	@inode: only i_rdev member may be used
679  *	@filp: only f_mode and f_flags may be used
680  *
681  *	Returns 0.
682  *
683  *	Note: may block (uninterruptible) if error recovery is underway
684  *	on this disk.
685  **/
686 static int sd_release(struct gendisk *disk, fmode_t mode)
687 {
688 	struct scsi_disk *sdkp = scsi_disk(disk);
689 	struct scsi_device *sdev = sdkp->device;
690 
691 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_release\n"));
692 
693 	if (!--sdkp->openers && sdev->removable) {
694 		if (scsi_block_when_processing_errors(sdev))
695 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
696 	}
697 
698 	/*
699 	 * XXX and what if there are packets in flight and this close()
700 	 * XXX is followed by a "rmmod sd_mod"?
701 	 */
702 	scsi_disk_put(sdkp);
703 	return 0;
704 }
705 
706 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
707 {
708 	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
709 	struct scsi_device *sdp = sdkp->device;
710 	struct Scsi_Host *host = sdp->host;
711 	int diskinfo[4];
712 
713 	/* default to most commonly used values */
714         diskinfo[0] = 0x40;	/* 1 << 6 */
715        	diskinfo[1] = 0x20;	/* 1 << 5 */
716        	diskinfo[2] = sdkp->capacity >> 11;
717 
718 	/* override with calculated, extended default, or driver values */
719 	if (host->hostt->bios_param)
720 		host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
721 	else
722 		scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
723 
724 	geo->heads = diskinfo[0];
725 	geo->sectors = diskinfo[1];
726 	geo->cylinders = diskinfo[2];
727 	return 0;
728 }
729 
730 /**
731  *	sd_ioctl - process an ioctl
732  *	@inode: only i_rdev/i_bdev members may be used
733  *	@filp: only f_mode and f_flags may be used
734  *	@cmd: ioctl command number
735  *	@arg: this is third argument given to ioctl(2) system call.
736  *	Often contains a pointer.
737  *
738  *	Returns 0 if successful (some ioctls return postive numbers on
739  *	success as well). Returns a negated errno value in case of error.
740  *
741  *	Note: most ioctls are forward onto the block subsystem or further
742  *	down in the scsi subsystem.
743  **/
744 static int sd_ioctl(struct block_device *bdev, fmode_t mode,
745 		    unsigned int cmd, unsigned long arg)
746 {
747 	struct gendisk *disk = bdev->bd_disk;
748 	struct scsi_device *sdp = scsi_disk(disk)->device;
749 	void __user *p = (void __user *)arg;
750 	int error;
751 
752 	SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
753 						disk->disk_name, cmd));
754 
755 	/*
756 	 * If we are in the middle of error recovery, don't let anyone
757 	 * else try and use this device.  Also, if error recovery fails, it
758 	 * may try and take the device offline, in which case all further
759 	 * access to the device is prohibited.
760 	 */
761 	error = scsi_nonblockable_ioctl(sdp, cmd, p,
762 					(mode & FMODE_NDELAY) != 0);
763 	if (!scsi_block_when_processing_errors(sdp) || !error)
764 		return error;
765 
766 	/*
767 	 * Send SCSI addressing ioctls directly to mid level, send other
768 	 * ioctls to block level and then onto mid level if they can't be
769 	 * resolved.
770 	 */
771 	switch (cmd) {
772 		case SCSI_IOCTL_GET_IDLUN:
773 		case SCSI_IOCTL_GET_BUS_NUMBER:
774 			return scsi_ioctl(sdp, cmd, p);
775 		default:
776 			error = scsi_cmd_ioctl(disk->queue, disk, mode, cmd, p);
777 			if (error != -ENOTTY)
778 				return error;
779 	}
780 	return scsi_ioctl(sdp, cmd, p);
781 }
782 
783 static void set_media_not_present(struct scsi_disk *sdkp)
784 {
785 	sdkp->media_present = 0;
786 	sdkp->capacity = 0;
787 	sdkp->device->changed = 1;
788 }
789 
790 /**
791  *	sd_media_changed - check if our medium changed
792  *	@disk: kernel device descriptor
793  *
794  *	Returns 0 if not applicable or no change; 1 if change
795  *
796  *	Note: this function is invoked from the block subsystem.
797  **/
798 static int sd_media_changed(struct gendisk *disk)
799 {
800 	struct scsi_disk *sdkp = scsi_disk(disk);
801 	struct scsi_device *sdp = sdkp->device;
802 	struct scsi_sense_hdr *sshdr = NULL;
803 	int retval;
804 
805 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_media_changed\n"));
806 
807 	if (!sdp->removable)
808 		return 0;
809 
810 	/*
811 	 * If the device is offline, don't send any commands - just pretend as
812 	 * if the command failed.  If the device ever comes back online, we
813 	 * can deal with it then.  It is only because of unrecoverable errors
814 	 * that we would ever take a device offline in the first place.
815 	 */
816 	if (!scsi_device_online(sdp)) {
817 		set_media_not_present(sdkp);
818 		retval = 1;
819 		goto out;
820 	}
821 
822 	/*
823 	 * Using TEST_UNIT_READY enables differentiation between drive with
824 	 * no cartridge loaded - NOT READY, drive with changed cartridge -
825 	 * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
826 	 *
827 	 * Drives that auto spin down. eg iomega jaz 1G, will be started
828 	 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
829 	 * sd_revalidate() is called.
830 	 */
831 	retval = -ENODEV;
832 
833 	if (scsi_block_when_processing_errors(sdp)) {
834 		sshdr  = kzalloc(sizeof(*sshdr), GFP_KERNEL);
835 		retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
836 					      sshdr);
837 	}
838 
839 	/*
840 	 * Unable to test, unit probably not ready.   This usually
841 	 * means there is no disc in the drive.  Mark as changed,
842 	 * and we will figure it out later once the drive is
843 	 * available again.
844 	 */
845 	if (retval || (scsi_sense_valid(sshdr) &&
846 		       /* 0x3a is medium not present */
847 		       sshdr->asc == 0x3a)) {
848 		set_media_not_present(sdkp);
849 		retval = 1;
850 		goto out;
851 	}
852 
853 	/*
854 	 * For removable scsi disk we have to recognise the presence
855 	 * of a disk in the drive. This is kept in the struct scsi_disk
856 	 * struct and tested at open !  Daniel Roche (dan@lectra.fr)
857 	 */
858 	sdkp->media_present = 1;
859 
860 	retval = sdp->changed;
861 	sdp->changed = 0;
862 out:
863 	if (retval != sdkp->previous_state)
864 		sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL);
865 	sdkp->previous_state = retval;
866 	kfree(sshdr);
867 	return retval;
868 }
869 
870 static int sd_sync_cache(struct scsi_disk *sdkp)
871 {
872 	int retries, res;
873 	struct scsi_device *sdp = sdkp->device;
874 	struct scsi_sense_hdr sshdr;
875 
876 	if (!scsi_device_online(sdp))
877 		return -ENODEV;
878 
879 
880 	for (retries = 3; retries > 0; --retries) {
881 		unsigned char cmd[10] = { 0 };
882 
883 		cmd[0] = SYNCHRONIZE_CACHE;
884 		/*
885 		 * Leave the rest of the command zero to indicate
886 		 * flush everything.
887 		 */
888 		res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
889 				       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
890 		if (res == 0)
891 			break;
892 	}
893 
894 	if (res) {
895 		sd_print_result(sdkp, res);
896 		if (driver_byte(res) & DRIVER_SENSE)
897 			sd_print_sense_hdr(sdkp, &sshdr);
898 	}
899 
900 	if (res)
901 		return -EIO;
902 	return 0;
903 }
904 
905 static void sd_prepare_flush(struct request_queue *q, struct request *rq)
906 {
907 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
908 	rq->timeout = SD_TIMEOUT;
909 	rq->cmd[0] = SYNCHRONIZE_CACHE;
910 	rq->cmd_len = 10;
911 }
912 
913 static void sd_rescan(struct device *dev)
914 {
915 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
916 
917 	if (sdkp) {
918 		revalidate_disk(sdkp->disk);
919 		scsi_disk_put(sdkp);
920 	}
921 }
922 
923 
924 #ifdef CONFIG_COMPAT
925 /*
926  * This gets directly called from VFS. When the ioctl
927  * is not recognized we go back to the other translation paths.
928  */
929 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
930 			   unsigned int cmd, unsigned long arg)
931 {
932 	struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
933 
934 	/*
935 	 * If we are in the middle of error recovery, don't let anyone
936 	 * else try and use this device.  Also, if error recovery fails, it
937 	 * may try and take the device offline, in which case all further
938 	 * access to the device is prohibited.
939 	 */
940 	if (!scsi_block_when_processing_errors(sdev))
941 		return -ENODEV;
942 
943 	if (sdev->host->hostt->compat_ioctl) {
944 		int ret;
945 
946 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
947 
948 		return ret;
949 	}
950 
951 	/*
952 	 * Let the static ioctl translation table take care of it.
953 	 */
954 	return -ENOIOCTLCMD;
955 }
956 #endif
957 
958 static struct block_device_operations sd_fops = {
959 	.owner			= THIS_MODULE,
960 	.open			= sd_open,
961 	.release		= sd_release,
962 	.locked_ioctl		= sd_ioctl,
963 	.getgeo			= sd_getgeo,
964 #ifdef CONFIG_COMPAT
965 	.compat_ioctl		= sd_compat_ioctl,
966 #endif
967 	.media_changed		= sd_media_changed,
968 	.revalidate_disk	= sd_revalidate_disk,
969 };
970 
971 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
972 {
973 	u64 start_lba = scmd->request->sector;
974 	u64 end_lba = scmd->request->sector + (scsi_bufflen(scmd) / 512);
975 	u64 bad_lba;
976 	int info_valid;
977 
978 	if (!blk_fs_request(scmd->request))
979 		return 0;
980 
981 	info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
982 					     SCSI_SENSE_BUFFERSIZE,
983 					     &bad_lba);
984 	if (!info_valid)
985 		return 0;
986 
987 	if (scsi_bufflen(scmd) <= scmd->device->sector_size)
988 		return 0;
989 
990 	if (scmd->device->sector_size < 512) {
991 		/* only legitimate sector_size here is 256 */
992 		start_lba <<= 1;
993 		end_lba <<= 1;
994 	} else {
995 		/* be careful ... don't want any overflows */
996 		u64 factor = scmd->device->sector_size / 512;
997 		do_div(start_lba, factor);
998 		do_div(end_lba, factor);
999 	}
1000 
1001 	/* The bad lba was reported incorrectly, we have no idea where
1002 	 * the error is.
1003 	 */
1004 	if (bad_lba < start_lba  || bad_lba >= end_lba)
1005 		return 0;
1006 
1007 	/* This computation should always be done in terms of
1008 	 * the resolution of the device's medium.
1009 	 */
1010 	return (bad_lba - start_lba) * scmd->device->sector_size;
1011 }
1012 
1013 /**
1014  *	sd_done - bottom half handler: called when the lower level
1015  *	driver has completed (successfully or otherwise) a scsi command.
1016  *	@SCpnt: mid-level's per command structure.
1017  *
1018  *	Note: potentially run from within an ISR. Must not block.
1019  **/
1020 static int sd_done(struct scsi_cmnd *SCpnt)
1021 {
1022 	int result = SCpnt->result;
1023 	unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
1024 	struct scsi_sense_hdr sshdr;
1025 	int sense_valid = 0;
1026 	int sense_deferred = 0;
1027 
1028 	if (result) {
1029 		sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
1030 		if (sense_valid)
1031 			sense_deferred = scsi_sense_is_deferred(&sshdr);
1032 	}
1033 #ifdef CONFIG_SCSI_LOGGING
1034 	SCSI_LOG_HLCOMPLETE(1, scsi_print_result(SCpnt));
1035 	if (sense_valid) {
1036 		SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
1037 						   "sd_done: sb[respc,sk,asc,"
1038 						   "ascq]=%x,%x,%x,%x\n",
1039 						   sshdr.response_code,
1040 						   sshdr.sense_key, sshdr.asc,
1041 						   sshdr.ascq));
1042 	}
1043 #endif
1044 	if (driver_byte(result) != DRIVER_SENSE &&
1045 	    (!sense_valid || sense_deferred))
1046 		goto out;
1047 
1048 	switch (sshdr.sense_key) {
1049 	case HARDWARE_ERROR:
1050 	case MEDIUM_ERROR:
1051 		good_bytes = sd_completed_bytes(SCpnt);
1052 		break;
1053 	case RECOVERED_ERROR:
1054 		/* Inform the user, but make sure that it's not treated
1055 		 * as a hard error.
1056 		 */
1057 		scsi_print_sense("sd", SCpnt);
1058 		SCpnt->result = 0;
1059 		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1060 		good_bytes = scsi_bufflen(SCpnt);
1061 		break;
1062 	case NO_SENSE:
1063 		/* This indicates a false check condition, so ignore it.  An
1064 		 * unknown amount of data was transferred so treat it as an
1065 		 * error.
1066 		 */
1067 		scsi_print_sense("sd", SCpnt);
1068 		SCpnt->result = 0;
1069 		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1070 		break;
1071 	case ABORTED_COMMAND:
1072 		if (sshdr.asc == 0x10) { /* DIF: Disk detected corruption */
1073 			scsi_print_result(SCpnt);
1074 			scsi_print_sense("sd", SCpnt);
1075 			good_bytes = sd_completed_bytes(SCpnt);
1076 		}
1077 		break;
1078 	case ILLEGAL_REQUEST:
1079 		if (sshdr.asc == 0x10) { /* DIX: HBA detected corruption */
1080 			scsi_print_result(SCpnt);
1081 			scsi_print_sense("sd", SCpnt);
1082 			good_bytes = sd_completed_bytes(SCpnt);
1083 		}
1084 		break;
1085 	default:
1086 		break;
1087 	}
1088  out:
1089 	if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
1090 		sd_dif_complete(SCpnt, good_bytes);
1091 
1092 	return good_bytes;
1093 }
1094 
1095 static int media_not_present(struct scsi_disk *sdkp,
1096 			     struct scsi_sense_hdr *sshdr)
1097 {
1098 
1099 	if (!scsi_sense_valid(sshdr))
1100 		return 0;
1101 	/* not invoked for commands that could return deferred errors */
1102 	if (sshdr->sense_key != NOT_READY &&
1103 	    sshdr->sense_key != UNIT_ATTENTION)
1104 		return 0;
1105 	if (sshdr->asc != 0x3A) /* medium not present */
1106 		return 0;
1107 
1108 	set_media_not_present(sdkp);
1109 	return 1;
1110 }
1111 
1112 /*
1113  * spinup disk - called only in sd_revalidate_disk()
1114  */
1115 static void
1116 sd_spinup_disk(struct scsi_disk *sdkp)
1117 {
1118 	unsigned char cmd[10];
1119 	unsigned long spintime_expire = 0;
1120 	int retries, spintime;
1121 	unsigned int the_result;
1122 	struct scsi_sense_hdr sshdr;
1123 	int sense_valid = 0;
1124 
1125 	spintime = 0;
1126 
1127 	/* Spin up drives, as required.  Only do this at boot time */
1128 	/* Spinup needs to be done for module loads too. */
1129 	do {
1130 		retries = 0;
1131 
1132 		do {
1133 			cmd[0] = TEST_UNIT_READY;
1134 			memset((void *) &cmd[1], 0, 9);
1135 
1136 			the_result = scsi_execute_req(sdkp->device, cmd,
1137 						      DMA_NONE, NULL, 0,
1138 						      &sshdr, SD_TIMEOUT,
1139 						      SD_MAX_RETRIES, NULL);
1140 
1141 			/*
1142 			 * If the drive has indicated to us that it
1143 			 * doesn't have any media in it, don't bother
1144 			 * with any more polling.
1145 			 */
1146 			if (media_not_present(sdkp, &sshdr))
1147 				return;
1148 
1149 			if (the_result)
1150 				sense_valid = scsi_sense_valid(&sshdr);
1151 			retries++;
1152 		} while (retries < 3 &&
1153 			 (!scsi_status_is_good(the_result) ||
1154 			  ((driver_byte(the_result) & DRIVER_SENSE) &&
1155 			  sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1156 
1157 		if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1158 			/* no sense, TUR either succeeded or failed
1159 			 * with a status error */
1160 			if(!spintime && !scsi_status_is_good(the_result)) {
1161 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1162 				sd_print_result(sdkp, the_result);
1163 			}
1164 			break;
1165 		}
1166 
1167 		/*
1168 		 * The device does not want the automatic start to be issued.
1169 		 */
1170 		if (sdkp->device->no_start_on_add) {
1171 			break;
1172 		}
1173 
1174 		/*
1175 		 * If manual intervention is required, or this is an
1176 		 * absent USB storage device, a spinup is meaningless.
1177 		 */
1178 		if (sense_valid &&
1179 		    sshdr.sense_key == NOT_READY &&
1180 		    sshdr.asc == 4 && sshdr.ascq == 3) {
1181 			break;		/* manual intervention required */
1182 
1183 		/*
1184 		 * Issue command to spin up drive when not ready
1185 		 */
1186 		} else if (sense_valid && sshdr.sense_key == NOT_READY) {
1187 			if (!spintime) {
1188 				sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
1189 				cmd[0] = START_STOP;
1190 				cmd[1] = 1;	/* Return immediately */
1191 				memset((void *) &cmd[2], 0, 8);
1192 				cmd[4] = 1;	/* Start spin cycle */
1193 				if (sdkp->device->start_stop_pwr_cond)
1194 					cmd[4] |= 1 << 4;
1195 				scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1196 						 NULL, 0, &sshdr,
1197 						 SD_TIMEOUT, SD_MAX_RETRIES,
1198 						 NULL);
1199 				spintime_expire = jiffies + 100 * HZ;
1200 				spintime = 1;
1201 			}
1202 			/* Wait 1 second for next try */
1203 			msleep(1000);
1204 			printk(".");
1205 
1206 		/*
1207 		 * Wait for USB flash devices with slow firmware.
1208 		 * Yes, this sense key/ASC combination shouldn't
1209 		 * occur here.  It's characteristic of these devices.
1210 		 */
1211 		} else if (sense_valid &&
1212 				sshdr.sense_key == UNIT_ATTENTION &&
1213 				sshdr.asc == 0x28) {
1214 			if (!spintime) {
1215 				spintime_expire = jiffies + 5 * HZ;
1216 				spintime = 1;
1217 			}
1218 			/* Wait 1 second for next try */
1219 			msleep(1000);
1220 		} else {
1221 			/* we don't understand the sense code, so it's
1222 			 * probably pointless to loop */
1223 			if(!spintime) {
1224 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1225 				sd_print_sense_hdr(sdkp, &sshdr);
1226 			}
1227 			break;
1228 		}
1229 
1230 	} while (spintime && time_before_eq(jiffies, spintime_expire));
1231 
1232 	if (spintime) {
1233 		if (scsi_status_is_good(the_result))
1234 			printk("ready\n");
1235 		else
1236 			printk("not responding...\n");
1237 	}
1238 }
1239 
1240 
1241 /*
1242  * Determine whether disk supports Data Integrity Field.
1243  */
1244 void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
1245 {
1246 	struct scsi_device *sdp = sdkp->device;
1247 	u8 type;
1248 
1249 	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
1250 		type = 0;
1251 	else
1252 		type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
1253 
1254 	sdkp->protection_type = type;
1255 
1256 	switch (type) {
1257 	case SD_DIF_TYPE0_PROTECTION:
1258 	case SD_DIF_TYPE1_PROTECTION:
1259 	case SD_DIF_TYPE3_PROTECTION:
1260 		break;
1261 
1262 	case SD_DIF_TYPE2_PROTECTION:
1263 		sd_printk(KERN_ERR, sdkp, "formatted with DIF Type 2 "	\
1264 			  "protection which is currently unsupported. "	\
1265 			  "Disabling disk!\n");
1266 		goto disable;
1267 
1268 	default:
1269 		sd_printk(KERN_ERR, sdkp, "formatted with unknown "	\
1270 			  "protection type %d. Disabling disk!\n", type);
1271 		goto disable;
1272 	}
1273 
1274 	return;
1275 
1276 disable:
1277 	sdkp->capacity = 0;
1278 }
1279 
1280 /*
1281  * read disk capacity
1282  */
1283 static void
1284 sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
1285 {
1286 	unsigned char cmd[16];
1287 	int the_result, retries;
1288 	int sector_size = 0;
1289 	/* Force READ CAPACITY(16) when PROTECT=1 */
1290 	int longrc = scsi_device_protection(sdkp->device) ? 1 : 0;
1291 	struct scsi_sense_hdr sshdr;
1292 	int sense_valid = 0;
1293 	struct scsi_device *sdp = sdkp->device;
1294 
1295 repeat:
1296 	retries = 3;
1297 	do {
1298 		if (longrc) {
1299 			memset((void *) cmd, 0, 16);
1300 			cmd[0] = SERVICE_ACTION_IN;
1301 			cmd[1] = SAI_READ_CAPACITY_16;
1302 			cmd[13] = 13;
1303 			memset((void *) buffer, 0, 13);
1304 		} else {
1305 			cmd[0] = READ_CAPACITY;
1306 			memset((void *) &cmd[1], 0, 9);
1307 			memset((void *) buffer, 0, 8);
1308 		}
1309 
1310 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1311 					      buffer, longrc ? 13 : 8, &sshdr,
1312 					      SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1313 
1314 		if (media_not_present(sdkp, &sshdr))
1315 			return;
1316 
1317 		if (the_result)
1318 			sense_valid = scsi_sense_valid(&sshdr);
1319 		retries--;
1320 
1321 	} while (the_result && retries);
1322 
1323 	if (the_result && !longrc) {
1324 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
1325 		sd_print_result(sdkp, the_result);
1326 		if (driver_byte(the_result) & DRIVER_SENSE)
1327 			sd_print_sense_hdr(sdkp, &sshdr);
1328 		else
1329 			sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
1330 
1331 		/* Set dirty bit for removable devices if not ready -
1332 		 * sometimes drives will not report this properly. */
1333 		if (sdp->removable &&
1334 		    sense_valid && sshdr.sense_key == NOT_READY)
1335 			sdp->changed = 1;
1336 
1337 		/* Either no media are present but the drive didn't tell us,
1338 		   or they are present but the read capacity command fails */
1339 		/* sdkp->media_present = 0; -- not always correct */
1340 		sdkp->capacity = 0; /* unknown mapped to zero - as usual */
1341 
1342 		return;
1343 	} else if (the_result && longrc) {
1344 		/* READ CAPACITY(16) has been failed */
1345 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY(16) failed\n");
1346 		sd_print_result(sdkp, the_result);
1347 		sd_printk(KERN_NOTICE, sdkp, "Use 0xffffffff as device size\n");
1348 
1349 		sdkp->capacity = 1 + (sector_t) 0xffffffff;
1350 		goto got_data;
1351 	}
1352 
1353 	if (!longrc) {
1354 		sector_size = (buffer[4] << 24) |
1355 			(buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
1356 		if (buffer[0] == 0xff && buffer[1] == 0xff &&
1357 		    buffer[2] == 0xff && buffer[3] == 0xff) {
1358 			if(sizeof(sdkp->capacity) > 4) {
1359 				sd_printk(KERN_NOTICE, sdkp, "Very big device. "
1360 					  "Trying to use READ CAPACITY(16).\n");
1361 				longrc = 1;
1362 				goto repeat;
1363 			}
1364 			sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use "
1365 				  "a kernel compiled with support for large "
1366 				  "block devices.\n");
1367 			sdkp->capacity = 0;
1368 			goto got_data;
1369 		}
1370 		sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) |
1371 			(buffer[1] << 16) |
1372 			(buffer[2] << 8) |
1373 			buffer[3]);
1374 	} else {
1375 		sdkp->capacity = 1 + (((u64)buffer[0] << 56) |
1376 			((u64)buffer[1] << 48) |
1377 			((u64)buffer[2] << 40) |
1378 			((u64)buffer[3] << 32) |
1379 			((sector_t)buffer[4] << 24) |
1380 			((sector_t)buffer[5] << 16) |
1381 			((sector_t)buffer[6] << 8)  |
1382 			(sector_t)buffer[7]);
1383 
1384 		sector_size = (buffer[8] << 24) |
1385 			(buffer[9] << 16) | (buffer[10] << 8) | buffer[11];
1386 
1387 		sd_read_protection_type(sdkp, buffer);
1388 	}
1389 
1390 	/* Some devices return the total number of sectors, not the
1391 	 * highest sector number.  Make the necessary adjustment. */
1392 	if (sdp->fix_capacity) {
1393 		--sdkp->capacity;
1394 
1395 	/* Some devices have version which report the correct sizes
1396 	 * and others which do not. We guess size according to a heuristic
1397 	 * and err on the side of lowering the capacity. */
1398 	} else {
1399 		if (sdp->guess_capacity)
1400 			if (sdkp->capacity & 0x01) /* odd sizes are odd */
1401 				--sdkp->capacity;
1402 	}
1403 
1404 got_data:
1405 	if (sector_size == 0) {
1406 		sector_size = 512;
1407 		sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
1408 			  "assuming 512.\n");
1409 	}
1410 
1411 	if (sector_size != 512 &&
1412 	    sector_size != 1024 &&
1413 	    sector_size != 2048 &&
1414 	    sector_size != 4096 &&
1415 	    sector_size != 256) {
1416 		sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
1417 			  sector_size);
1418 		/*
1419 		 * The user might want to re-format the drive with
1420 		 * a supported sectorsize.  Once this happens, it
1421 		 * would be relatively trivial to set the thing up.
1422 		 * For this reason, we leave the thing in the table.
1423 		 */
1424 		sdkp->capacity = 0;
1425 		/*
1426 		 * set a bogus sector size so the normal read/write
1427 		 * logic in the block layer will eventually refuse any
1428 		 * request on this device without tripping over power
1429 		 * of two sector size assumptions
1430 		 */
1431 		sector_size = 512;
1432 	}
1433 	blk_queue_hardsect_size(sdp->request_queue, sector_size);
1434 
1435 	{
1436 		char cap_str_2[10], cap_str_10[10];
1437 		u64 sz = (u64)sdkp->capacity << ilog2(sector_size);
1438 
1439 		string_get_size(sz, STRING_UNITS_2, cap_str_2,
1440 				sizeof(cap_str_2));
1441 		string_get_size(sz, STRING_UNITS_10, cap_str_10,
1442 				sizeof(cap_str_10));
1443 
1444 		sd_printk(KERN_NOTICE, sdkp,
1445 			  "%llu %d-byte hardware sectors: (%s/%s)\n",
1446 			  (unsigned long long)sdkp->capacity,
1447 			  sector_size, cap_str_10, cap_str_2);
1448 	}
1449 
1450 	/* Rescale capacity to 512-byte units */
1451 	if (sector_size == 4096)
1452 		sdkp->capacity <<= 3;
1453 	else if (sector_size == 2048)
1454 		sdkp->capacity <<= 2;
1455 	else if (sector_size == 1024)
1456 		sdkp->capacity <<= 1;
1457 	else if (sector_size == 256)
1458 		sdkp->capacity >>= 1;
1459 
1460 	sdkp->device->sector_size = sector_size;
1461 }
1462 
1463 /* called with buffer of length 512 */
1464 static inline int
1465 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
1466 		 unsigned char *buffer, int len, struct scsi_mode_data *data,
1467 		 struct scsi_sense_hdr *sshdr)
1468 {
1469 	return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
1470 			       SD_TIMEOUT, SD_MAX_RETRIES, data,
1471 			       sshdr);
1472 }
1473 
1474 /*
1475  * read write protect setting, if possible - called only in sd_revalidate_disk()
1476  * called with buffer of length SD_BUF_SIZE
1477  */
1478 static void
1479 sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
1480 {
1481 	int res;
1482 	struct scsi_device *sdp = sdkp->device;
1483 	struct scsi_mode_data data;
1484 
1485 	set_disk_ro(sdkp->disk, 0);
1486 	if (sdp->skip_ms_page_3f) {
1487 		sd_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
1488 		return;
1489 	}
1490 
1491 	if (sdp->use_192_bytes_for_3f) {
1492 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
1493 	} else {
1494 		/*
1495 		 * First attempt: ask for all pages (0x3F), but only 4 bytes.
1496 		 * We have to start carefully: some devices hang if we ask
1497 		 * for more than is available.
1498 		 */
1499 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
1500 
1501 		/*
1502 		 * Second attempt: ask for page 0 When only page 0 is
1503 		 * implemented, a request for page 3F may return Sense Key
1504 		 * 5: Illegal Request, Sense Code 24: Invalid field in
1505 		 * CDB.
1506 		 */
1507 		if (!scsi_status_is_good(res))
1508 			res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
1509 
1510 		/*
1511 		 * Third attempt: ask 255 bytes, as we did earlier.
1512 		 */
1513 		if (!scsi_status_is_good(res))
1514 			res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
1515 					       &data, NULL);
1516 	}
1517 
1518 	if (!scsi_status_is_good(res)) {
1519 		sd_printk(KERN_WARNING, sdkp,
1520 			  "Test WP failed, assume Write Enabled\n");
1521 	} else {
1522 		sdkp->write_prot = ((data.device_specific & 0x80) != 0);
1523 		set_disk_ro(sdkp->disk, sdkp->write_prot);
1524 		sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
1525 			  sdkp->write_prot ? "on" : "off");
1526 		sd_printk(KERN_DEBUG, sdkp,
1527 			  "Mode Sense: %02x %02x %02x %02x\n",
1528 			  buffer[0], buffer[1], buffer[2], buffer[3]);
1529 	}
1530 }
1531 
1532 /*
1533  * sd_read_cache_type - called only from sd_revalidate_disk()
1534  * called with buffer of length SD_BUF_SIZE
1535  */
1536 static void
1537 sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
1538 {
1539 	int len = 0, res;
1540 	struct scsi_device *sdp = sdkp->device;
1541 
1542 	int dbd;
1543 	int modepage;
1544 	struct scsi_mode_data data;
1545 	struct scsi_sense_hdr sshdr;
1546 
1547 	if (sdp->skip_ms_page_8)
1548 		goto defaults;
1549 
1550 	if (sdp->type == TYPE_RBC) {
1551 		modepage = 6;
1552 		dbd = 8;
1553 	} else {
1554 		modepage = 8;
1555 		dbd = 0;
1556 	}
1557 
1558 	/* cautiously ask */
1559 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);
1560 
1561 	if (!scsi_status_is_good(res))
1562 		goto bad_sense;
1563 
1564 	if (!data.header_length) {
1565 		modepage = 6;
1566 		sd_printk(KERN_ERR, sdkp, "Missing header in MODE_SENSE response\n");
1567 	}
1568 
1569 	/* that went OK, now ask for the proper length */
1570 	len = data.length;
1571 
1572 	/*
1573 	 * We're only interested in the first three bytes, actually.
1574 	 * But the data cache page is defined for the first 20.
1575 	 */
1576 	if (len < 3)
1577 		goto bad_sense;
1578 	if (len > 20)
1579 		len = 20;
1580 
1581 	/* Take headers and block descriptors into account */
1582 	len += data.header_length + data.block_descriptor_length;
1583 	if (len > SD_BUF_SIZE)
1584 		goto bad_sense;
1585 
1586 	/* Get the data */
1587 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
1588 
1589 	if (scsi_status_is_good(res)) {
1590 		int offset = data.header_length + data.block_descriptor_length;
1591 
1592 		if (offset >= SD_BUF_SIZE - 2) {
1593 			sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
1594 			goto defaults;
1595 		}
1596 
1597 		if ((buffer[offset] & 0x3f) != modepage) {
1598 			sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
1599 			goto defaults;
1600 		}
1601 
1602 		if (modepage == 8) {
1603 			sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
1604 			sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
1605 		} else {
1606 			sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
1607 			sdkp->RCD = 0;
1608 		}
1609 
1610 		sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
1611 		if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
1612 			sd_printk(KERN_NOTICE, sdkp,
1613 				  "Uses READ/WRITE(6), disabling FUA\n");
1614 			sdkp->DPOFUA = 0;
1615 		}
1616 
1617 		sd_printk(KERN_NOTICE, sdkp,
1618 		       "Write cache: %s, read cache: %s, %s\n",
1619 		       sdkp->WCE ? "enabled" : "disabled",
1620 		       sdkp->RCD ? "disabled" : "enabled",
1621 		       sdkp->DPOFUA ? "supports DPO and FUA"
1622 		       : "doesn't support DPO or FUA");
1623 
1624 		return;
1625 	}
1626 
1627 bad_sense:
1628 	if (scsi_sense_valid(&sshdr) &&
1629 	    sshdr.sense_key == ILLEGAL_REQUEST &&
1630 	    sshdr.asc == 0x24 && sshdr.ascq == 0x0)
1631 		/* Invalid field in CDB */
1632 		sd_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
1633 	else
1634 		sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n");
1635 
1636 defaults:
1637 	sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
1638 	sdkp->WCE = 0;
1639 	sdkp->RCD = 0;
1640 	sdkp->DPOFUA = 0;
1641 }
1642 
1643 /*
1644  * The ATO bit indicates whether the DIF application tag is available
1645  * for use by the operating system.
1646  */
1647 void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
1648 {
1649 	int res, offset;
1650 	struct scsi_device *sdp = sdkp->device;
1651 	struct scsi_mode_data data;
1652 	struct scsi_sense_hdr sshdr;
1653 
1654 	if (sdp->type != TYPE_DISK)
1655 		return;
1656 
1657 	if (sdkp->protection_type == 0)
1658 		return;
1659 
1660 	res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
1661 			      SD_MAX_RETRIES, &data, &sshdr);
1662 
1663 	if (!scsi_status_is_good(res) || !data.header_length ||
1664 	    data.length < 6) {
1665 		sd_printk(KERN_WARNING, sdkp,
1666 			  "getting Control mode page failed, assume no ATO\n");
1667 
1668 		if (scsi_sense_valid(&sshdr))
1669 			sd_print_sense_hdr(sdkp, &sshdr);
1670 
1671 		return;
1672 	}
1673 
1674 	offset = data.header_length + data.block_descriptor_length;
1675 
1676 	if ((buffer[offset] & 0x3f) != 0x0a) {
1677 		sd_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
1678 		return;
1679 	}
1680 
1681 	if ((buffer[offset + 5] & 0x80) == 0)
1682 		return;
1683 
1684 	sdkp->ATO = 1;
1685 
1686 	return;
1687 }
1688 
1689 /**
1690  *	sd_revalidate_disk - called the first time a new disk is seen,
1691  *	performs disk spin up, read_capacity, etc.
1692  *	@disk: struct gendisk we care about
1693  **/
1694 static int sd_revalidate_disk(struct gendisk *disk)
1695 {
1696 	struct scsi_disk *sdkp = scsi_disk(disk);
1697 	struct scsi_device *sdp = sdkp->device;
1698 	unsigned char *buffer;
1699 	unsigned ordered;
1700 
1701 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
1702 				      "sd_revalidate_disk\n"));
1703 
1704 	/*
1705 	 * If the device is offline, don't try and read capacity or any
1706 	 * of the other niceties.
1707 	 */
1708 	if (!scsi_device_online(sdp))
1709 		goto out;
1710 
1711 	buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
1712 	if (!buffer) {
1713 		sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
1714 			  "allocation failure.\n");
1715 		goto out;
1716 	}
1717 
1718 	/* defaults, until the device tells us otherwise */
1719 	sdp->sector_size = 512;
1720 	sdkp->capacity = 0;
1721 	sdkp->media_present = 1;
1722 	sdkp->write_prot = 0;
1723 	sdkp->WCE = 0;
1724 	sdkp->RCD = 0;
1725 	sdkp->ATO = 0;
1726 
1727 	sd_spinup_disk(sdkp);
1728 
1729 	/*
1730 	 * Without media there is no reason to ask; moreover, some devices
1731 	 * react badly if we do.
1732 	 */
1733 	if (sdkp->media_present) {
1734 		sd_read_capacity(sdkp, buffer);
1735 		sd_read_write_protect_flag(sdkp, buffer);
1736 		sd_read_cache_type(sdkp, buffer);
1737 		sd_read_app_tag_own(sdkp, buffer);
1738 	}
1739 
1740 	/*
1741 	 * We now have all cache related info, determine how we deal
1742 	 * with ordered requests.  Note that as the current SCSI
1743 	 * dispatch function can alter request order, we cannot use
1744 	 * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
1745 	 */
1746 	if (sdkp->WCE)
1747 		ordered = sdkp->DPOFUA
1748 			? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
1749 	else
1750 		ordered = QUEUE_ORDERED_DRAIN;
1751 
1752 	blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush);
1753 
1754 	set_capacity(disk, sdkp->capacity);
1755 	kfree(buffer);
1756 
1757  out:
1758 	return 0;
1759 }
1760 
1761 /**
1762  *	sd_format_disk_name - format disk name
1763  *	@prefix: name prefix - ie. "sd" for SCSI disks
1764  *	@index: index of the disk to format name for
1765  *	@buf: output buffer
1766  *	@buflen: length of the output buffer
1767  *
1768  *	SCSI disk names starts at sda.  The 26th device is sdz and the
1769  *	27th is sdaa.  The last one for two lettered suffix is sdzz
1770  *	which is followed by sdaaa.
1771  *
1772  *	This is basically 26 base counting with one extra 'nil' entry
1773  *	at the beggining from the second digit on and can be
1774  *	determined using similar method as 26 base conversion with the
1775  *	index shifted -1 after each digit is computed.
1776  *
1777  *	CONTEXT:
1778  *	Don't care.
1779  *
1780  *	RETURNS:
1781  *	0 on success, -errno on failure.
1782  */
1783 static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
1784 {
1785 	const int base = 'z' - 'a' + 1;
1786 	char *begin = buf + strlen(prefix);
1787 	char *end = buf + buflen;
1788 	char *p;
1789 	int unit;
1790 
1791 	p = end - 1;
1792 	*p = '\0';
1793 	unit = base;
1794 	do {
1795 		if (p == begin)
1796 			return -EINVAL;
1797 		*--p = 'a' + (index % unit);
1798 		index = (index / unit) - 1;
1799 	} while (index >= 0);
1800 
1801 	memmove(begin, p, end - p);
1802 	memcpy(buf, prefix, strlen(prefix));
1803 
1804 	return 0;
1805 }
1806 
1807 /*
1808  * The asynchronous part of sd_probe
1809  */
1810 static void sd_probe_async(void *data, async_cookie_t cookie)
1811 {
1812 	struct scsi_disk *sdkp = data;
1813 	struct scsi_device *sdp;
1814 	struct gendisk *gd;
1815 	u32 index;
1816 	struct device *dev;
1817 
1818 	sdp = sdkp->device;
1819 	gd = sdkp->disk;
1820 	index = sdkp->index;
1821 	dev = &sdp->sdev_gendev;
1822 
1823 	if (!sdp->request_queue->rq_timeout) {
1824 		if (sdp->type != TYPE_MOD)
1825 			blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
1826 		else
1827 			blk_queue_rq_timeout(sdp->request_queue,
1828 					     SD_MOD_TIMEOUT);
1829 	}
1830 
1831 	device_initialize(&sdkp->dev);
1832 	sdkp->dev.parent = &sdp->sdev_gendev;
1833 	sdkp->dev.class = &sd_disk_class;
1834 	dev_set_name(&sdkp->dev, dev_name(&sdp->sdev_gendev));
1835 
1836 	if (device_add(&sdkp->dev))
1837 		goto out_free_index;
1838 
1839 	get_device(&sdp->sdev_gendev);
1840 
1841 	if (index < SD_MAX_DISKS) {
1842 		gd->major = sd_major((index & 0xf0) >> 4);
1843 		gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
1844 		gd->minors = SD_MINORS;
1845 	}
1846 	gd->fops = &sd_fops;
1847 	gd->private_data = &sdkp->driver;
1848 	gd->queue = sdkp->device->request_queue;
1849 
1850 	sd_revalidate_disk(gd);
1851 
1852 	blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);
1853 
1854 	gd->driverfs_dev = &sdp->sdev_gendev;
1855 	gd->flags = GENHD_FL_EXT_DEVT | GENHD_FL_DRIVERFS;
1856 	if (sdp->removable)
1857 		gd->flags |= GENHD_FL_REMOVABLE;
1858 
1859 	dev_set_drvdata(dev, sdkp);
1860 	add_disk(gd);
1861 	sd_dif_config_host(sdkp);
1862 
1863 	sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
1864 		  sdp->removable ? "removable " : "");
1865 
1866 	return;
1867 
1868  out_free_index:
1869 	ida_remove(&sd_index_ida, index);
1870 }
1871 
1872 /**
1873  *	sd_probe - called during driver initialization and whenever a
1874  *	new scsi device is attached to the system. It is called once
1875  *	for each scsi device (not just disks) present.
1876  *	@dev: pointer to device object
1877  *
1878  *	Returns 0 if successful (or not interested in this scsi device
1879  *	(e.g. scanner)); 1 when there is an error.
1880  *
1881  *	Note: this function is invoked from the scsi mid-level.
1882  *	This function sets up the mapping between a given
1883  *	<host,channel,id,lun> (found in sdp) and new device name
1884  *	(e.g. /dev/sda). More precisely it is the block device major
1885  *	and minor number that is chosen here.
1886  *
1887  *	Assume sd_attach is not re-entrant (for time being)
1888  *	Also think about sd_attach() and sd_remove() running coincidentally.
1889  **/
1890 static int sd_probe(struct device *dev)
1891 {
1892 	struct scsi_device *sdp = to_scsi_device(dev);
1893 	struct scsi_disk *sdkp;
1894 	struct gendisk *gd;
1895 	u32 index;
1896 	int error;
1897 
1898 	error = -ENODEV;
1899 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
1900 		goto out;
1901 
1902 	SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
1903 					"sd_attach\n"));
1904 
1905 	error = -ENOMEM;
1906 	sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
1907 	if (!sdkp)
1908 		goto out;
1909 
1910 	gd = alloc_disk(SD_MINORS);
1911 	if (!gd)
1912 		goto out_free;
1913 
1914 	do {
1915 		if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
1916 			goto out_put;
1917 
1918 		spin_lock(&sd_index_lock);
1919 		error = ida_get_new(&sd_index_ida, &index);
1920 		spin_unlock(&sd_index_lock);
1921 	} while (error == -EAGAIN);
1922 
1923 	if (error)
1924 		goto out_put;
1925 
1926 	error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
1927 	if (error)
1928 		goto out_free_index;
1929 
1930 	sdkp->device = sdp;
1931 	sdkp->driver = &sd_template;
1932 	sdkp->disk = gd;
1933 	sdkp->index = index;
1934 	sdkp->openers = 0;
1935 	sdkp->previous_state = 1;
1936 
1937 	async_schedule(sd_probe_async, sdkp);
1938 
1939 	return 0;
1940 
1941  out_free_index:
1942 	spin_lock(&sd_index_lock);
1943 	ida_remove(&sd_index_ida, index);
1944 	spin_unlock(&sd_index_lock);
1945  out_put:
1946 	put_disk(gd);
1947  out_free:
1948 	kfree(sdkp);
1949  out:
1950 	return error;
1951 }
1952 
1953 /**
1954  *	sd_remove - called whenever a scsi disk (previously recognized by
1955  *	sd_probe) is detached from the system. It is called (potentially
1956  *	multiple times) during sd module unload.
1957  *	@sdp: pointer to mid level scsi device object
1958  *
1959  *	Note: this function is invoked from the scsi mid-level.
1960  *	This function potentially frees up a device name (e.g. /dev/sdc)
1961  *	that could be re-used by a subsequent sd_probe().
1962  *	This function is not called when the built-in sd driver is "exit-ed".
1963  **/
1964 static int sd_remove(struct device *dev)
1965 {
1966 	struct scsi_disk *sdkp = dev_get_drvdata(dev);
1967 
1968 	device_del(&sdkp->dev);
1969 	del_gendisk(sdkp->disk);
1970 	sd_shutdown(dev);
1971 
1972 	mutex_lock(&sd_ref_mutex);
1973 	dev_set_drvdata(dev, NULL);
1974 	put_device(&sdkp->dev);
1975 	mutex_unlock(&sd_ref_mutex);
1976 
1977 	return 0;
1978 }
1979 
1980 /**
1981  *	scsi_disk_release - Called to free the scsi_disk structure
1982  *	@dev: pointer to embedded class device
1983  *
1984  *	sd_ref_mutex must be held entering this routine.  Because it is
1985  *	called on last put, you should always use the scsi_disk_get()
1986  *	scsi_disk_put() helpers which manipulate the semaphore directly
1987  *	and never do a direct put_device.
1988  **/
1989 static void scsi_disk_release(struct device *dev)
1990 {
1991 	struct scsi_disk *sdkp = to_scsi_disk(dev);
1992 	struct gendisk *disk = sdkp->disk;
1993 
1994 	spin_lock(&sd_index_lock);
1995 	ida_remove(&sd_index_ida, sdkp->index);
1996 	spin_unlock(&sd_index_lock);
1997 
1998 	disk->private_data = NULL;
1999 	put_disk(disk);
2000 	put_device(&sdkp->device->sdev_gendev);
2001 
2002 	kfree(sdkp);
2003 }
2004 
2005 static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
2006 {
2007 	unsigned char cmd[6] = { START_STOP };	/* START_VALID */
2008 	struct scsi_sense_hdr sshdr;
2009 	struct scsi_device *sdp = sdkp->device;
2010 	int res;
2011 
2012 	if (start)
2013 		cmd[4] |= 1;	/* START */
2014 
2015 	if (sdp->start_stop_pwr_cond)
2016 		cmd[4] |= start ? 1 << 4 : 3 << 4;	/* Active or Standby */
2017 
2018 	if (!scsi_device_online(sdp))
2019 		return -ENODEV;
2020 
2021 	res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
2022 			       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
2023 	if (res) {
2024 		sd_printk(KERN_WARNING, sdkp, "START_STOP FAILED\n");
2025 		sd_print_result(sdkp, res);
2026 		if (driver_byte(res) & DRIVER_SENSE)
2027 			sd_print_sense_hdr(sdkp, &sshdr);
2028 	}
2029 
2030 	return res;
2031 }
2032 
2033 /*
2034  * Send a SYNCHRONIZE CACHE instruction down to the device through
2035  * the normal SCSI command structure.  Wait for the command to
2036  * complete.
2037  */
2038 static void sd_shutdown(struct device *dev)
2039 {
2040 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2041 
2042 	if (!sdkp)
2043 		return;         /* this can happen */
2044 
2045 	if (sdkp->WCE) {
2046 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2047 		sd_sync_cache(sdkp);
2048 	}
2049 
2050 	if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
2051 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2052 		sd_start_stop_device(sdkp, 0);
2053 	}
2054 
2055 	scsi_disk_put(sdkp);
2056 }
2057 
2058 static int sd_suspend(struct device *dev, pm_message_t mesg)
2059 {
2060 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2061 	int ret = 0;
2062 
2063 	if (!sdkp)
2064 		return 0;	/* this can happen */
2065 
2066 	if (sdkp->WCE) {
2067 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2068 		ret = sd_sync_cache(sdkp);
2069 		if (ret)
2070 			goto done;
2071 	}
2072 
2073 	if ((mesg.event & PM_EVENT_SLEEP) && sdkp->device->manage_start_stop) {
2074 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2075 		ret = sd_start_stop_device(sdkp, 0);
2076 	}
2077 
2078 done:
2079 	scsi_disk_put(sdkp);
2080 	return ret;
2081 }
2082 
2083 static int sd_resume(struct device *dev)
2084 {
2085 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2086 	int ret = 0;
2087 
2088 	if (!sdkp->device->manage_start_stop)
2089 		goto done;
2090 
2091 	sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
2092 	ret = sd_start_stop_device(sdkp, 1);
2093 
2094 done:
2095 	scsi_disk_put(sdkp);
2096 	return ret;
2097 }
2098 
2099 /**
2100  *	init_sd - entry point for this driver (both when built in or when
2101  *	a module).
2102  *
2103  *	Note: this function registers this driver with the scsi mid-level.
2104  **/
2105 static int __init init_sd(void)
2106 {
2107 	int majors = 0, i, err;
2108 
2109 	SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
2110 
2111 	for (i = 0; i < SD_MAJORS; i++)
2112 		if (register_blkdev(sd_major(i), "sd") == 0)
2113 			majors++;
2114 
2115 	if (!majors)
2116 		return -ENODEV;
2117 
2118 	err = class_register(&sd_disk_class);
2119 	if (err)
2120 		goto err_out;
2121 
2122 	err = scsi_register_driver(&sd_template.gendrv);
2123 	if (err)
2124 		goto err_out_class;
2125 
2126 	return 0;
2127 
2128 err_out_class:
2129 	class_unregister(&sd_disk_class);
2130 err_out:
2131 	for (i = 0; i < SD_MAJORS; i++)
2132 		unregister_blkdev(sd_major(i), "sd");
2133 	return err;
2134 }
2135 
2136 /**
2137  *	exit_sd - exit point for this driver (when it is a module).
2138  *
2139  *	Note: this function unregisters this driver from the scsi mid-level.
2140  **/
2141 static void __exit exit_sd(void)
2142 {
2143 	int i;
2144 
2145 	SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
2146 
2147 	scsi_unregister_driver(&sd_template.gendrv);
2148 	class_unregister(&sd_disk_class);
2149 
2150 	for (i = 0; i < SD_MAJORS; i++)
2151 		unregister_blkdev(sd_major(i), "sd");
2152 }
2153 
2154 module_init(init_sd);
2155 module_exit(exit_sd);
2156 
2157 static void sd_print_sense_hdr(struct scsi_disk *sdkp,
2158 			       struct scsi_sense_hdr *sshdr)
2159 {
2160 	sd_printk(KERN_INFO, sdkp, "");
2161 	scsi_show_sense_hdr(sshdr);
2162 	sd_printk(KERN_INFO, sdkp, "");
2163 	scsi_show_extd_sense(sshdr->asc, sshdr->ascq);
2164 }
2165 
2166 static void sd_print_result(struct scsi_disk *sdkp, int result)
2167 {
2168 	sd_printk(KERN_INFO, sdkp, "");
2169 	scsi_show_result(result);
2170 }
2171 
2172