xref: /linux/drivers/scsi/sd.c (revision b233b28eac0cc37d07c2d007ea08c86c778c5af4)
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_IDA(sd_index_ida);
111 
112 /* This semaphore is used to mediate the 0->1 reference get in the
113  * face of object destruction (i.e. we can't allow a get on an
114  * object after last put) */
115 static DEFINE_MUTEX(sd_ref_mutex);
116 
117 static const char *sd_cache_types[] = {
118 	"write through", "none", "write back",
119 	"write back, no read (daft)"
120 };
121 
122 static ssize_t
123 sd_store_cache_type(struct device *dev, struct device_attribute *attr,
124 		    const char *buf, size_t count)
125 {
126 	int i, ct = -1, rcd, wce, sp;
127 	struct scsi_disk *sdkp = to_scsi_disk(dev);
128 	struct scsi_device *sdp = sdkp->device;
129 	char buffer[64];
130 	char *buffer_data;
131 	struct scsi_mode_data data;
132 	struct scsi_sense_hdr sshdr;
133 	int len;
134 
135 	if (sdp->type != TYPE_DISK)
136 		/* no cache control on RBC devices; theoretically they
137 		 * can do it, but there's probably so many exceptions
138 		 * it's not worth the risk */
139 		return -EINVAL;
140 
141 	for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {
142 		const int len = strlen(sd_cache_types[i]);
143 		if (strncmp(sd_cache_types[i], buf, len) == 0 &&
144 		    buf[len] == '\n') {
145 			ct = i;
146 			break;
147 		}
148 	}
149 	if (ct < 0)
150 		return -EINVAL;
151 	rcd = ct & 0x01 ? 1 : 0;
152 	wce = ct & 0x02 ? 1 : 0;
153 	if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
154 			    SD_MAX_RETRIES, &data, NULL))
155 		return -EINVAL;
156 	len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
157 		  data.block_descriptor_length);
158 	buffer_data = buffer + data.header_length +
159 		data.block_descriptor_length;
160 	buffer_data[2] &= ~0x05;
161 	buffer_data[2] |= wce << 2 | rcd;
162 	sp = buffer_data[0] & 0x80 ? 1 : 0;
163 
164 	if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
165 			     SD_MAX_RETRIES, &data, &sshdr)) {
166 		if (scsi_sense_valid(&sshdr))
167 			sd_print_sense_hdr(sdkp, &sshdr);
168 		return -EINVAL;
169 	}
170 	revalidate_disk(sdkp->disk);
171 	return count;
172 }
173 
174 static ssize_t
175 sd_store_manage_start_stop(struct device *dev, struct device_attribute *attr,
176 			   const char *buf, size_t count)
177 {
178 	struct scsi_disk *sdkp = to_scsi_disk(dev);
179 	struct scsi_device *sdp = sdkp->device;
180 
181 	if (!capable(CAP_SYS_ADMIN))
182 		return -EACCES;
183 
184 	sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
185 
186 	return count;
187 }
188 
189 static ssize_t
190 sd_store_allow_restart(struct device *dev, struct device_attribute *attr,
191 		       const char *buf, size_t count)
192 {
193 	struct scsi_disk *sdkp = to_scsi_disk(dev);
194 	struct scsi_device *sdp = sdkp->device;
195 
196 	if (!capable(CAP_SYS_ADMIN))
197 		return -EACCES;
198 
199 	if (sdp->type != TYPE_DISK)
200 		return -EINVAL;
201 
202 	sdp->allow_restart = simple_strtoul(buf, NULL, 10);
203 
204 	return count;
205 }
206 
207 static ssize_t
208 sd_show_cache_type(struct device *dev, struct device_attribute *attr,
209 		   char *buf)
210 {
211 	struct scsi_disk *sdkp = to_scsi_disk(dev);
212 	int ct = sdkp->RCD + 2*sdkp->WCE;
213 
214 	return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
215 }
216 
217 static ssize_t
218 sd_show_fua(struct device *dev, struct device_attribute *attr, char *buf)
219 {
220 	struct scsi_disk *sdkp = to_scsi_disk(dev);
221 
222 	return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
223 }
224 
225 static ssize_t
226 sd_show_manage_start_stop(struct device *dev, struct device_attribute *attr,
227 			  char *buf)
228 {
229 	struct scsi_disk *sdkp = to_scsi_disk(dev);
230 	struct scsi_device *sdp = sdkp->device;
231 
232 	return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
233 }
234 
235 static ssize_t
236 sd_show_allow_restart(struct device *dev, struct device_attribute *attr,
237 		      char *buf)
238 {
239 	struct scsi_disk *sdkp = to_scsi_disk(dev);
240 
241 	return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
242 }
243 
244 static ssize_t
245 sd_show_protection_type(struct device *dev, struct device_attribute *attr,
246 			char *buf)
247 {
248 	struct scsi_disk *sdkp = to_scsi_disk(dev);
249 
250 	return snprintf(buf, 20, "%u\n", sdkp->protection_type);
251 }
252 
253 static ssize_t
254 sd_show_app_tag_own(struct device *dev, struct device_attribute *attr,
255 		    char *buf)
256 {
257 	struct scsi_disk *sdkp = to_scsi_disk(dev);
258 
259 	return snprintf(buf, 20, "%u\n", sdkp->ATO);
260 }
261 
262 static struct device_attribute sd_disk_attrs[] = {
263 	__ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
264 	       sd_store_cache_type),
265 	__ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
266 	__ATTR(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
267 	       sd_store_allow_restart),
268 	__ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
269 	       sd_store_manage_start_stop),
270 	__ATTR(protection_type, S_IRUGO, sd_show_protection_type, NULL),
271 	__ATTR(app_tag_own, S_IRUGO, sd_show_app_tag_own, NULL),
272 	__ATTR_NULL,
273 };
274 
275 static struct class sd_disk_class = {
276 	.name		= "scsi_disk",
277 	.owner		= THIS_MODULE,
278 	.dev_release	= scsi_disk_release,
279 	.dev_attrs	= sd_disk_attrs,
280 };
281 
282 static struct scsi_driver sd_template = {
283 	.owner			= THIS_MODULE,
284 	.gendrv = {
285 		.name		= "sd",
286 		.probe		= sd_probe,
287 		.remove		= sd_remove,
288 		.suspend	= sd_suspend,
289 		.resume		= sd_resume,
290 		.shutdown	= sd_shutdown,
291 	},
292 	.rescan			= sd_rescan,
293 	.done			= sd_done,
294 };
295 
296 /*
297  * Device no to disk mapping:
298  *
299  *       major         disc2     disc  p1
300  *   |............|.............|....|....| <- dev_t
301  *    31        20 19          8 7  4 3  0
302  *
303  * Inside a major, we have 16k disks, however mapped non-
304  * contiguously. The first 16 disks are for major0, the next
305  * ones with major1, ... Disk 256 is for major0 again, disk 272
306  * for major1, ...
307  * As we stay compatible with our numbering scheme, we can reuse
308  * the well-know SCSI majors 8, 65--71, 136--143.
309  */
310 static int sd_major(int major_idx)
311 {
312 	switch (major_idx) {
313 	case 0:
314 		return SCSI_DISK0_MAJOR;
315 	case 1 ... 7:
316 		return SCSI_DISK1_MAJOR + major_idx - 1;
317 	case 8 ... 15:
318 		return SCSI_DISK8_MAJOR + major_idx - 8;
319 	default:
320 		BUG();
321 		return 0;	/* shut up gcc */
322 	}
323 }
324 
325 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
326 {
327 	struct scsi_disk *sdkp = NULL;
328 
329 	if (disk->private_data) {
330 		sdkp = scsi_disk(disk);
331 		if (scsi_device_get(sdkp->device) == 0)
332 			get_device(&sdkp->dev);
333 		else
334 			sdkp = NULL;
335 	}
336 	return sdkp;
337 }
338 
339 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
340 {
341 	struct scsi_disk *sdkp;
342 
343 	mutex_lock(&sd_ref_mutex);
344 	sdkp = __scsi_disk_get(disk);
345 	mutex_unlock(&sd_ref_mutex);
346 	return sdkp;
347 }
348 
349 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
350 {
351 	struct scsi_disk *sdkp;
352 
353 	mutex_lock(&sd_ref_mutex);
354 	sdkp = dev_get_drvdata(dev);
355 	if (sdkp)
356 		sdkp = __scsi_disk_get(sdkp->disk);
357 	mutex_unlock(&sd_ref_mutex);
358 	return sdkp;
359 }
360 
361 static void scsi_disk_put(struct scsi_disk *sdkp)
362 {
363 	struct scsi_device *sdev = sdkp->device;
364 
365 	mutex_lock(&sd_ref_mutex);
366 	put_device(&sdkp->dev);
367 	scsi_device_put(sdev);
368 	mutex_unlock(&sd_ref_mutex);
369 }
370 
371 /**
372  *	sd_init_command - build a scsi (read or write) command from
373  *	information in the request structure.
374  *	@SCpnt: pointer to mid-level's per scsi command structure that
375  *	contains request and into which the scsi command is written
376  *
377  *	Returns 1 if successful and 0 if error (or cannot be done now).
378  **/
379 static int sd_prep_fn(struct request_queue *q, struct request *rq)
380 {
381 	struct scsi_cmnd *SCpnt;
382 	struct scsi_device *sdp = q->queuedata;
383 	struct gendisk *disk = rq->rq_disk;
384 	struct scsi_disk *sdkp;
385 	sector_t block = rq->sector;
386 	sector_t threshold;
387 	unsigned int this_count = rq->nr_sectors;
388 	int ret, host_dif;
389 
390 	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
391 		ret = scsi_setup_blk_pc_cmnd(sdp, rq);
392 		goto out;
393 	} else if (rq->cmd_type != REQ_TYPE_FS) {
394 		ret = BLKPREP_KILL;
395 		goto out;
396 	}
397 	ret = scsi_setup_fs_cmnd(sdp, rq);
398 	if (ret != BLKPREP_OK)
399 		goto out;
400 	SCpnt = rq->special;
401 	sdkp = scsi_disk(disk);
402 
403 	/* from here on until we're complete, any goto out
404 	 * is used for a killable error condition */
405 	ret = BLKPREP_KILL;
406 
407 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
408 					"sd_init_command: block=%llu, "
409 					"count=%d\n",
410 					(unsigned long long)block,
411 					this_count));
412 
413 	if (!sdp || !scsi_device_online(sdp) ||
414  	    block + rq->nr_sectors > get_capacity(disk)) {
415 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
416 						"Finishing %ld sectors\n",
417 						rq->nr_sectors));
418 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
419 						"Retry with 0x%p\n", SCpnt));
420 		goto out;
421 	}
422 
423 	if (sdp->changed) {
424 		/*
425 		 * quietly refuse to do anything to a changed disc until
426 		 * the changed bit has been reset
427 		 */
428 		/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
429 		goto out;
430 	}
431 
432 	/*
433 	 * Some SD card readers can't handle multi-sector accesses which touch
434 	 * the last one or two hardware sectors.  Split accesses as needed.
435 	 */
436 	threshold = get_capacity(disk) - SD_LAST_BUGGY_SECTORS *
437 		(sdp->sector_size / 512);
438 
439 	if (unlikely(sdp->last_sector_bug && block + this_count > threshold)) {
440 		if (block < threshold) {
441 			/* Access up to the threshold but not beyond */
442 			this_count = threshold - block;
443 		} else {
444 			/* Access only a single hardware sector */
445 			this_count = sdp->sector_size / 512;
446 		}
447 	}
448 
449 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
450 					(unsigned long long)block));
451 
452 	/*
453 	 * If we have a 1K hardware sectorsize, prevent access to single
454 	 * 512 byte sectors.  In theory we could handle this - in fact
455 	 * the scsi cdrom driver must be able to handle this because
456 	 * we typically use 1K blocksizes, and cdroms typically have
457 	 * 2K hardware sectorsizes.  Of course, things are simpler
458 	 * with the cdrom, since it is read-only.  For performance
459 	 * reasons, the filesystems should be able to handle this
460 	 * and not force the scsi disk driver to use bounce buffers
461 	 * for this.
462 	 */
463 	if (sdp->sector_size == 1024) {
464 		if ((block & 1) || (rq->nr_sectors & 1)) {
465 			scmd_printk(KERN_ERR, SCpnt,
466 				    "Bad block number requested\n");
467 			goto out;
468 		} else {
469 			block = block >> 1;
470 			this_count = this_count >> 1;
471 		}
472 	}
473 	if (sdp->sector_size == 2048) {
474 		if ((block & 3) || (rq->nr_sectors & 3)) {
475 			scmd_printk(KERN_ERR, SCpnt,
476 				    "Bad block number requested\n");
477 			goto out;
478 		} else {
479 			block = block >> 2;
480 			this_count = this_count >> 2;
481 		}
482 	}
483 	if (sdp->sector_size == 4096) {
484 		if ((block & 7) || (rq->nr_sectors & 7)) {
485 			scmd_printk(KERN_ERR, SCpnt,
486 				    "Bad block number requested\n");
487 			goto out;
488 		} else {
489 			block = block >> 3;
490 			this_count = this_count >> 3;
491 		}
492 	}
493 	if (rq_data_dir(rq) == WRITE) {
494 		if (!sdp->writeable) {
495 			goto out;
496 		}
497 		SCpnt->cmnd[0] = WRITE_6;
498 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
499 
500 		if (blk_integrity_rq(rq) &&
501 		    sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
502 			goto out;
503 
504 	} else if (rq_data_dir(rq) == READ) {
505 		SCpnt->cmnd[0] = READ_6;
506 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
507 	} else {
508 		scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
509 		goto out;
510 	}
511 
512 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
513 					"%s %d/%ld 512 byte blocks.\n",
514 					(rq_data_dir(rq) == WRITE) ?
515 					"writing" : "reading", this_count,
516 					rq->nr_sectors));
517 
518 	/* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
519 	host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
520 	if (host_dif)
521 		SCpnt->cmnd[1] = 1 << 5;
522 	else
523 		SCpnt->cmnd[1] = 0;
524 
525 	if (block > 0xffffffff) {
526 		SCpnt->cmnd[0] += READ_16 - READ_6;
527 		SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
528 		SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
529 		SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
530 		SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
531 		SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
532 		SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
533 		SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
534 		SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
535 		SCpnt->cmnd[9] = (unsigned char) block & 0xff;
536 		SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
537 		SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
538 		SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
539 		SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
540 		SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
541 	} else if ((this_count > 0xff) || (block > 0x1fffff) ||
542 		   scsi_device_protection(SCpnt->device) ||
543 		   SCpnt->device->use_10_for_rw) {
544 		if (this_count > 0xffff)
545 			this_count = 0xffff;
546 
547 		SCpnt->cmnd[0] += READ_10 - READ_6;
548 		SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
549 		SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
550 		SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
551 		SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
552 		SCpnt->cmnd[5] = (unsigned char) block & 0xff;
553 		SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
554 		SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
555 		SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
556 	} else {
557 		if (unlikely(blk_fua_rq(rq))) {
558 			/*
559 			 * This happens only if this drive failed
560 			 * 10byte rw command with ILLEGAL_REQUEST
561 			 * during operation and thus turned off
562 			 * use_10_for_rw.
563 			 */
564 			scmd_printk(KERN_ERR, SCpnt,
565 				    "FUA write on READ/WRITE(6) drive\n");
566 			goto out;
567 		}
568 
569 		SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
570 		SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
571 		SCpnt->cmnd[3] = (unsigned char) block & 0xff;
572 		SCpnt->cmnd[4] = (unsigned char) this_count;
573 		SCpnt->cmnd[5] = 0;
574 	}
575 	SCpnt->sdb.length = this_count * sdp->sector_size;
576 
577 	/* If DIF or DIX is enabled, tell HBA how to handle request */
578 	if (host_dif || scsi_prot_sg_count(SCpnt))
579 		sd_dif_op(SCpnt, host_dif, scsi_prot_sg_count(SCpnt),
580 			  sdkp->protection_type);
581 
582 	/*
583 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
584 	 * host adapter, it's safe to assume that we can at least transfer
585 	 * this many bytes between each connect / disconnect.
586 	 */
587 	SCpnt->transfersize = sdp->sector_size;
588 	SCpnt->underflow = this_count << 9;
589 	SCpnt->allowed = SD_MAX_RETRIES;
590 
591 	/*
592 	 * This indicates that the command is ready from our end to be
593 	 * queued.
594 	 */
595 	ret = BLKPREP_OK;
596  out:
597 	return scsi_prep_return(q, rq, ret);
598 }
599 
600 /**
601  *	sd_open - open a scsi disk device
602  *	@inode: only i_rdev member may be used
603  *	@filp: only f_mode and f_flags may be used
604  *
605  *	Returns 0 if successful. Returns a negated errno value in case
606  *	of error.
607  *
608  *	Note: This can be called from a user context (e.g. fsck(1) )
609  *	or from within the kernel (e.g. as a result of a mount(1) ).
610  *	In the latter case @inode and @filp carry an abridged amount
611  *	of information as noted above.
612  **/
613 static int sd_open(struct block_device *bdev, fmode_t mode)
614 {
615 	struct scsi_disk *sdkp = scsi_disk_get(bdev->bd_disk);
616 	struct scsi_device *sdev;
617 	int retval;
618 
619 	if (!sdkp)
620 		return -ENXIO;
621 
622 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
623 
624 	sdev = sdkp->device;
625 
626 	/*
627 	 * If the device is in error recovery, wait until it is done.
628 	 * If the device is offline, then disallow any access to it.
629 	 */
630 	retval = -ENXIO;
631 	if (!scsi_block_when_processing_errors(sdev))
632 		goto error_out;
633 
634 	if (sdev->removable || sdkp->write_prot)
635 		check_disk_change(bdev);
636 
637 	/*
638 	 * If the drive is empty, just let the open fail.
639 	 */
640 	retval = -ENOMEDIUM;
641 	if (sdev->removable && !sdkp->media_present && !(mode & FMODE_NDELAY))
642 		goto error_out;
643 
644 	/*
645 	 * If the device has the write protect tab set, have the open fail
646 	 * if the user expects to be able to write to the thing.
647 	 */
648 	retval = -EROFS;
649 	if (sdkp->write_prot && (mode & FMODE_WRITE))
650 		goto error_out;
651 
652 	/*
653 	 * It is possible that the disk changing stuff resulted in
654 	 * the device being taken offline.  If this is the case,
655 	 * report this to the user, and don't pretend that the
656 	 * open actually succeeded.
657 	 */
658 	retval = -ENXIO;
659 	if (!scsi_device_online(sdev))
660 		goto error_out;
661 
662 	if (!sdkp->openers++ && sdev->removable) {
663 		if (scsi_block_when_processing_errors(sdev))
664 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
665 	}
666 
667 	return 0;
668 
669 error_out:
670 	scsi_disk_put(sdkp);
671 	return retval;
672 }
673 
674 /**
675  *	sd_release - invoked when the (last) close(2) is called on this
676  *	scsi disk.
677  *	@inode: only i_rdev member may be used
678  *	@filp: only f_mode and f_flags may be used
679  *
680  *	Returns 0.
681  *
682  *	Note: may block (uninterruptible) if error recovery is underway
683  *	on this disk.
684  **/
685 static int sd_release(struct gendisk *disk, fmode_t mode)
686 {
687 	struct scsi_disk *sdkp = scsi_disk(disk);
688 	struct scsi_device *sdev = sdkp->device;
689 
690 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_release\n"));
691 
692 	if (!--sdkp->openers && sdev->removable) {
693 		if (scsi_block_when_processing_errors(sdev))
694 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
695 	}
696 
697 	/*
698 	 * XXX and what if there are packets in flight and this close()
699 	 * XXX is followed by a "rmmod sd_mod"?
700 	 */
701 	scsi_disk_put(sdkp);
702 	return 0;
703 }
704 
705 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
706 {
707 	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
708 	struct scsi_device *sdp = sdkp->device;
709 	struct Scsi_Host *host = sdp->host;
710 	int diskinfo[4];
711 
712 	/* default to most commonly used values */
713         diskinfo[0] = 0x40;	/* 1 << 6 */
714        	diskinfo[1] = 0x20;	/* 1 << 5 */
715        	diskinfo[2] = sdkp->capacity >> 11;
716 
717 	/* override with calculated, extended default, or driver values */
718 	if (host->hostt->bios_param)
719 		host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
720 	else
721 		scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
722 
723 	geo->heads = diskinfo[0];
724 	geo->sectors = diskinfo[1];
725 	geo->cylinders = diskinfo[2];
726 	return 0;
727 }
728 
729 /**
730  *	sd_ioctl - process an ioctl
731  *	@inode: only i_rdev/i_bdev members may be used
732  *	@filp: only f_mode and f_flags may be used
733  *	@cmd: ioctl command number
734  *	@arg: this is third argument given to ioctl(2) system call.
735  *	Often contains a pointer.
736  *
737  *	Returns 0 if successful (some ioctls return postive numbers on
738  *	success as well). Returns a negated errno value in case of error.
739  *
740  *	Note: most ioctls are forward onto the block subsystem or further
741  *	down in the scsi subsystem.
742  **/
743 static int sd_ioctl(struct block_device *bdev, fmode_t mode,
744 		    unsigned int cmd, unsigned long arg)
745 {
746 	struct gendisk *disk = bdev->bd_disk;
747 	struct scsi_device *sdp = scsi_disk(disk)->device;
748 	void __user *p = (void __user *)arg;
749 	int error;
750 
751 	SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
752 						disk->disk_name, cmd));
753 
754 	/*
755 	 * If we are in the middle of error recovery, don't let anyone
756 	 * else try and use this device.  Also, if error recovery fails, it
757 	 * may try and take the device offline, in which case all further
758 	 * access to the device is prohibited.
759 	 */
760 	error = scsi_nonblockable_ioctl(sdp, cmd, p,
761 					(mode & FMODE_NDELAY) != 0);
762 	if (!scsi_block_when_processing_errors(sdp) || !error)
763 		return error;
764 
765 	/*
766 	 * Send SCSI addressing ioctls directly to mid level, send other
767 	 * ioctls to block level and then onto mid level if they can't be
768 	 * resolved.
769 	 */
770 	switch (cmd) {
771 		case SCSI_IOCTL_GET_IDLUN:
772 		case SCSI_IOCTL_GET_BUS_NUMBER:
773 			return scsi_ioctl(sdp, cmd, p);
774 		default:
775 			error = scsi_cmd_ioctl(disk->queue, disk, mode, cmd, p);
776 			if (error != -ENOTTY)
777 				return error;
778 	}
779 	return scsi_ioctl(sdp, cmd, p);
780 }
781 
782 static void set_media_not_present(struct scsi_disk *sdkp)
783 {
784 	sdkp->media_present = 0;
785 	sdkp->capacity = 0;
786 	sdkp->device->changed = 1;
787 }
788 
789 /**
790  *	sd_media_changed - check if our medium changed
791  *	@disk: kernel device descriptor
792  *
793  *	Returns 0 if not applicable or no change; 1 if change
794  *
795  *	Note: this function is invoked from the block subsystem.
796  **/
797 static int sd_media_changed(struct gendisk *disk)
798 {
799 	struct scsi_disk *sdkp = scsi_disk(disk);
800 	struct scsi_device *sdp = sdkp->device;
801 	struct scsi_sense_hdr *sshdr = NULL;
802 	int retval;
803 
804 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_media_changed\n"));
805 
806 	if (!sdp->removable)
807 		return 0;
808 
809 	/*
810 	 * If the device is offline, don't send any commands - just pretend as
811 	 * if the command failed.  If the device ever comes back online, we
812 	 * can deal with it then.  It is only because of unrecoverable errors
813 	 * that we would ever take a device offline in the first place.
814 	 */
815 	if (!scsi_device_online(sdp)) {
816 		set_media_not_present(sdkp);
817 		retval = 1;
818 		goto out;
819 	}
820 
821 	/*
822 	 * Using TEST_UNIT_READY enables differentiation between drive with
823 	 * no cartridge loaded - NOT READY, drive with changed cartridge -
824 	 * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
825 	 *
826 	 * Drives that auto spin down. eg iomega jaz 1G, will be started
827 	 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
828 	 * sd_revalidate() is called.
829 	 */
830 	retval = -ENODEV;
831 
832 	if (scsi_block_when_processing_errors(sdp)) {
833 		sshdr  = kzalloc(sizeof(*sshdr), GFP_KERNEL);
834 		retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
835 					      sshdr);
836 	}
837 
838 	/*
839 	 * Unable to test, unit probably not ready.   This usually
840 	 * means there is no disc in the drive.  Mark as changed,
841 	 * and we will figure it out later once the drive is
842 	 * available again.
843 	 */
844 	if (retval || (scsi_sense_valid(sshdr) &&
845 		       /* 0x3a is medium not present */
846 		       sshdr->asc == 0x3a)) {
847 		set_media_not_present(sdkp);
848 		retval = 1;
849 		goto out;
850 	}
851 
852 	/*
853 	 * For removable scsi disk we have to recognise the presence
854 	 * of a disk in the drive. This is kept in the struct scsi_disk
855 	 * struct and tested at open !  Daniel Roche (dan@lectra.fr)
856 	 */
857 	sdkp->media_present = 1;
858 
859 	retval = sdp->changed;
860 	sdp->changed = 0;
861 out:
862 	if (retval != sdkp->previous_state)
863 		sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL);
864 	sdkp->previous_state = retval;
865 	kfree(sshdr);
866 	return retval;
867 }
868 
869 static int sd_sync_cache(struct scsi_disk *sdkp)
870 {
871 	int retries, res;
872 	struct scsi_device *sdp = sdkp->device;
873 	struct scsi_sense_hdr sshdr;
874 
875 	if (!scsi_device_online(sdp))
876 		return -ENODEV;
877 
878 
879 	for (retries = 3; retries > 0; --retries) {
880 		unsigned char cmd[10] = { 0 };
881 
882 		cmd[0] = SYNCHRONIZE_CACHE;
883 		/*
884 		 * Leave the rest of the command zero to indicate
885 		 * flush everything.
886 		 */
887 		res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
888 				       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
889 		if (res == 0)
890 			break;
891 	}
892 
893 	if (res) {
894 		sd_print_result(sdkp, res);
895 		if (driver_byte(res) & DRIVER_SENSE)
896 			sd_print_sense_hdr(sdkp, &sshdr);
897 	}
898 
899 	if (res)
900 		return -EIO;
901 	return 0;
902 }
903 
904 static void sd_prepare_flush(struct request_queue *q, struct request *rq)
905 {
906 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
907 	rq->timeout = SD_TIMEOUT;
908 	rq->cmd[0] = SYNCHRONIZE_CACHE;
909 	rq->cmd_len = 10;
910 }
911 
912 static void sd_rescan(struct device *dev)
913 {
914 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
915 
916 	if (sdkp) {
917 		revalidate_disk(sdkp->disk);
918 		scsi_disk_put(sdkp);
919 	}
920 }
921 
922 
923 #ifdef CONFIG_COMPAT
924 /*
925  * This gets directly called from VFS. When the ioctl
926  * is not recognized we go back to the other translation paths.
927  */
928 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
929 			   unsigned int cmd, unsigned long arg)
930 {
931 	struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
932 
933 	/*
934 	 * If we are in the middle of error recovery, don't let anyone
935 	 * else try and use this device.  Also, if error recovery fails, it
936 	 * may try and take the device offline, in which case all further
937 	 * access to the device is prohibited.
938 	 */
939 	if (!scsi_block_when_processing_errors(sdev))
940 		return -ENODEV;
941 
942 	if (sdev->host->hostt->compat_ioctl) {
943 		int ret;
944 
945 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
946 
947 		return ret;
948 	}
949 
950 	/*
951 	 * Let the static ioctl translation table take care of it.
952 	 */
953 	return -ENOIOCTLCMD;
954 }
955 #endif
956 
957 static struct block_device_operations sd_fops = {
958 	.owner			= THIS_MODULE,
959 	.open			= sd_open,
960 	.release		= sd_release,
961 	.locked_ioctl		= sd_ioctl,
962 	.getgeo			= sd_getgeo,
963 #ifdef CONFIG_COMPAT
964 	.compat_ioctl		= sd_compat_ioctl,
965 #endif
966 	.media_changed		= sd_media_changed,
967 	.revalidate_disk	= sd_revalidate_disk,
968 };
969 
970 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
971 {
972 	u64 start_lba = scmd->request->sector;
973 	u64 end_lba = scmd->request->sector + (scsi_bufflen(scmd) / 512);
974 	u64 bad_lba;
975 	int info_valid;
976 
977 	if (!blk_fs_request(scmd->request))
978 		return 0;
979 
980 	info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
981 					     SCSI_SENSE_BUFFERSIZE,
982 					     &bad_lba);
983 	if (!info_valid)
984 		return 0;
985 
986 	if (scsi_bufflen(scmd) <= scmd->device->sector_size)
987 		return 0;
988 
989 	if (scmd->device->sector_size < 512) {
990 		/* only legitimate sector_size here is 256 */
991 		start_lba <<= 1;
992 		end_lba <<= 1;
993 	} else {
994 		/* be careful ... don't want any overflows */
995 		u64 factor = scmd->device->sector_size / 512;
996 		do_div(start_lba, factor);
997 		do_div(end_lba, factor);
998 	}
999 
1000 	/* The bad lba was reported incorrectly, we have no idea where
1001 	 * the error is.
1002 	 */
1003 	if (bad_lba < start_lba  || bad_lba >= end_lba)
1004 		return 0;
1005 
1006 	/* This computation should always be done in terms of
1007 	 * the resolution of the device's medium.
1008 	 */
1009 	return (bad_lba - start_lba) * scmd->device->sector_size;
1010 }
1011 
1012 /**
1013  *	sd_done - bottom half handler: called when the lower level
1014  *	driver has completed (successfully or otherwise) a scsi command.
1015  *	@SCpnt: mid-level's per command structure.
1016  *
1017  *	Note: potentially run from within an ISR. Must not block.
1018  **/
1019 static int sd_done(struct scsi_cmnd *SCpnt)
1020 {
1021 	int result = SCpnt->result;
1022 	unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
1023 	struct scsi_sense_hdr sshdr;
1024 	int sense_valid = 0;
1025 	int sense_deferred = 0;
1026 
1027 	if (result) {
1028 		sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
1029 		if (sense_valid)
1030 			sense_deferred = scsi_sense_is_deferred(&sshdr);
1031 	}
1032 #ifdef CONFIG_SCSI_LOGGING
1033 	SCSI_LOG_HLCOMPLETE(1, scsi_print_result(SCpnt));
1034 	if (sense_valid) {
1035 		SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
1036 						   "sd_done: sb[respc,sk,asc,"
1037 						   "ascq]=%x,%x,%x,%x\n",
1038 						   sshdr.response_code,
1039 						   sshdr.sense_key, sshdr.asc,
1040 						   sshdr.ascq));
1041 	}
1042 #endif
1043 	if (driver_byte(result) != DRIVER_SENSE &&
1044 	    (!sense_valid || sense_deferred))
1045 		goto out;
1046 
1047 	switch (sshdr.sense_key) {
1048 	case HARDWARE_ERROR:
1049 	case MEDIUM_ERROR:
1050 		good_bytes = sd_completed_bytes(SCpnt);
1051 		break;
1052 	case RECOVERED_ERROR:
1053 		/* Inform the user, but make sure that it's not treated
1054 		 * as a hard error.
1055 		 */
1056 		scsi_print_sense("sd", SCpnt);
1057 		SCpnt->result = 0;
1058 		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1059 		good_bytes = scsi_bufflen(SCpnt);
1060 		break;
1061 	case NO_SENSE:
1062 		/* This indicates a false check condition, so ignore it.  An
1063 		 * unknown amount of data was transferred so treat it as an
1064 		 * error.
1065 		 */
1066 		scsi_print_sense("sd", SCpnt);
1067 		SCpnt->result = 0;
1068 		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1069 		break;
1070 	case ABORTED_COMMAND:
1071 		if (sshdr.asc == 0x10) { /* DIF: Disk detected corruption */
1072 			scsi_print_result(SCpnt);
1073 			scsi_print_sense("sd", SCpnt);
1074 			good_bytes = sd_completed_bytes(SCpnt);
1075 		}
1076 		break;
1077 	case ILLEGAL_REQUEST:
1078 		if (sshdr.asc == 0x10) { /* DIX: HBA detected corruption */
1079 			scsi_print_result(SCpnt);
1080 			scsi_print_sense("sd", SCpnt);
1081 			good_bytes = sd_completed_bytes(SCpnt);
1082 		}
1083 		break;
1084 	default:
1085 		break;
1086 	}
1087  out:
1088 	if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
1089 		sd_dif_complete(SCpnt, good_bytes);
1090 
1091 	return good_bytes;
1092 }
1093 
1094 static int media_not_present(struct scsi_disk *sdkp,
1095 			     struct scsi_sense_hdr *sshdr)
1096 {
1097 
1098 	if (!scsi_sense_valid(sshdr))
1099 		return 0;
1100 	/* not invoked for commands that could return deferred errors */
1101 	if (sshdr->sense_key != NOT_READY &&
1102 	    sshdr->sense_key != UNIT_ATTENTION)
1103 		return 0;
1104 	if (sshdr->asc != 0x3A) /* medium not present */
1105 		return 0;
1106 
1107 	set_media_not_present(sdkp);
1108 	return 1;
1109 }
1110 
1111 /*
1112  * spinup disk - called only in sd_revalidate_disk()
1113  */
1114 static void
1115 sd_spinup_disk(struct scsi_disk *sdkp)
1116 {
1117 	unsigned char cmd[10];
1118 	unsigned long spintime_expire = 0;
1119 	int retries, spintime;
1120 	unsigned int the_result;
1121 	struct scsi_sense_hdr sshdr;
1122 	int sense_valid = 0;
1123 
1124 	spintime = 0;
1125 
1126 	/* Spin up drives, as required.  Only do this at boot time */
1127 	/* Spinup needs to be done for module loads too. */
1128 	do {
1129 		retries = 0;
1130 
1131 		do {
1132 			cmd[0] = TEST_UNIT_READY;
1133 			memset((void *) &cmd[1], 0, 9);
1134 
1135 			the_result = scsi_execute_req(sdkp->device, cmd,
1136 						      DMA_NONE, NULL, 0,
1137 						      &sshdr, SD_TIMEOUT,
1138 						      SD_MAX_RETRIES, NULL);
1139 
1140 			/*
1141 			 * If the drive has indicated to us that it
1142 			 * doesn't have any media in it, don't bother
1143 			 * with any more polling.
1144 			 */
1145 			if (media_not_present(sdkp, &sshdr))
1146 				return;
1147 
1148 			if (the_result)
1149 				sense_valid = scsi_sense_valid(&sshdr);
1150 			retries++;
1151 		} while (retries < 3 &&
1152 			 (!scsi_status_is_good(the_result) ||
1153 			  ((driver_byte(the_result) & DRIVER_SENSE) &&
1154 			  sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1155 
1156 		if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1157 			/* no sense, TUR either succeeded or failed
1158 			 * with a status error */
1159 			if(!spintime && !scsi_status_is_good(the_result)) {
1160 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1161 				sd_print_result(sdkp, the_result);
1162 			}
1163 			break;
1164 		}
1165 
1166 		/*
1167 		 * The device does not want the automatic start to be issued.
1168 		 */
1169 		if (sdkp->device->no_start_on_add) {
1170 			break;
1171 		}
1172 
1173 		/*
1174 		 * If manual intervention is required, or this is an
1175 		 * absent USB storage device, a spinup is meaningless.
1176 		 */
1177 		if (sense_valid &&
1178 		    sshdr.sense_key == NOT_READY &&
1179 		    sshdr.asc == 4 && sshdr.ascq == 3) {
1180 			break;		/* manual intervention required */
1181 
1182 		/*
1183 		 * Issue command to spin up drive when not ready
1184 		 */
1185 		} else if (sense_valid && sshdr.sense_key == NOT_READY) {
1186 			if (!spintime) {
1187 				sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
1188 				cmd[0] = START_STOP;
1189 				cmd[1] = 1;	/* Return immediately */
1190 				memset((void *) &cmd[2], 0, 8);
1191 				cmd[4] = 1;	/* Start spin cycle */
1192 				if (sdkp->device->start_stop_pwr_cond)
1193 					cmd[4] |= 1 << 4;
1194 				scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1195 						 NULL, 0, &sshdr,
1196 						 SD_TIMEOUT, SD_MAX_RETRIES,
1197 						 NULL);
1198 				spintime_expire = jiffies + 100 * HZ;
1199 				spintime = 1;
1200 			}
1201 			/* Wait 1 second for next try */
1202 			msleep(1000);
1203 			printk(".");
1204 
1205 		/*
1206 		 * Wait for USB flash devices with slow firmware.
1207 		 * Yes, this sense key/ASC combination shouldn't
1208 		 * occur here.  It's characteristic of these devices.
1209 		 */
1210 		} else if (sense_valid &&
1211 				sshdr.sense_key == UNIT_ATTENTION &&
1212 				sshdr.asc == 0x28) {
1213 			if (!spintime) {
1214 				spintime_expire = jiffies + 5 * HZ;
1215 				spintime = 1;
1216 			}
1217 			/* Wait 1 second for next try */
1218 			msleep(1000);
1219 		} else {
1220 			/* we don't understand the sense code, so it's
1221 			 * probably pointless to loop */
1222 			if(!spintime) {
1223 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1224 				sd_print_sense_hdr(sdkp, &sshdr);
1225 			}
1226 			break;
1227 		}
1228 
1229 	} while (spintime && time_before_eq(jiffies, spintime_expire));
1230 
1231 	if (spintime) {
1232 		if (scsi_status_is_good(the_result))
1233 			printk("ready\n");
1234 		else
1235 			printk("not responding...\n");
1236 	}
1237 }
1238 
1239 
1240 /*
1241  * Determine whether disk supports Data Integrity Field.
1242  */
1243 void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
1244 {
1245 	struct scsi_device *sdp = sdkp->device;
1246 	u8 type;
1247 
1248 	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
1249 		type = 0;
1250 	else
1251 		type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
1252 
1253 	sdkp->protection_type = type;
1254 
1255 	switch (type) {
1256 	case SD_DIF_TYPE0_PROTECTION:
1257 	case SD_DIF_TYPE1_PROTECTION:
1258 	case SD_DIF_TYPE3_PROTECTION:
1259 		break;
1260 
1261 	case SD_DIF_TYPE2_PROTECTION:
1262 		sd_printk(KERN_ERR, sdkp, "formatted with DIF Type 2 "	\
1263 			  "protection which is currently unsupported. "	\
1264 			  "Disabling disk!\n");
1265 		goto disable;
1266 
1267 	default:
1268 		sd_printk(KERN_ERR, sdkp, "formatted with unknown "	\
1269 			  "protection type %d. Disabling disk!\n", type);
1270 		goto disable;
1271 	}
1272 
1273 	return;
1274 
1275 disable:
1276 	sdkp->capacity = 0;
1277 }
1278 
1279 /*
1280  * read disk capacity
1281  */
1282 static void
1283 sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
1284 {
1285 	unsigned char cmd[16];
1286 	int the_result, retries;
1287 	int sector_size = 0;
1288 	/* Force READ CAPACITY(16) when PROTECT=1 */
1289 	int longrc = scsi_device_protection(sdkp->device) ? 1 : 0;
1290 	struct scsi_sense_hdr sshdr;
1291 	int sense_valid = 0;
1292 	struct scsi_device *sdp = sdkp->device;
1293 
1294 repeat:
1295 	retries = 3;
1296 	do {
1297 		if (longrc) {
1298 			memset((void *) cmd, 0, 16);
1299 			cmd[0] = SERVICE_ACTION_IN;
1300 			cmd[1] = SAI_READ_CAPACITY_16;
1301 			cmd[13] = 13;
1302 			memset((void *) buffer, 0, 13);
1303 		} else {
1304 			cmd[0] = READ_CAPACITY;
1305 			memset((void *) &cmd[1], 0, 9);
1306 			memset((void *) buffer, 0, 8);
1307 		}
1308 
1309 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1310 					      buffer, longrc ? 13 : 8, &sshdr,
1311 					      SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1312 
1313 		if (media_not_present(sdkp, &sshdr))
1314 			return;
1315 
1316 		if (the_result)
1317 			sense_valid = scsi_sense_valid(&sshdr);
1318 		retries--;
1319 
1320 	} while (the_result && retries);
1321 
1322 	if (the_result && !longrc) {
1323 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
1324 		sd_print_result(sdkp, the_result);
1325 		if (driver_byte(the_result) & DRIVER_SENSE)
1326 			sd_print_sense_hdr(sdkp, &sshdr);
1327 		else
1328 			sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
1329 
1330 		/* Set dirty bit for removable devices if not ready -
1331 		 * sometimes drives will not report this properly. */
1332 		if (sdp->removable &&
1333 		    sense_valid && sshdr.sense_key == NOT_READY)
1334 			sdp->changed = 1;
1335 
1336 		/* Either no media are present but the drive didn't tell us,
1337 		   or they are present but the read capacity command fails */
1338 		/* sdkp->media_present = 0; -- not always correct */
1339 		sdkp->capacity = 0; /* unknown mapped to zero - as usual */
1340 
1341 		return;
1342 	} else if (the_result && longrc) {
1343 		/* READ CAPACITY(16) has been failed */
1344 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY(16) failed\n");
1345 		sd_print_result(sdkp, the_result);
1346 		sd_printk(KERN_NOTICE, sdkp, "Use 0xffffffff as device size\n");
1347 
1348 		sdkp->capacity = 1 + (sector_t) 0xffffffff;
1349 		goto got_data;
1350 	}
1351 
1352 	if (!longrc) {
1353 		sector_size = (buffer[4] << 24) |
1354 			(buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
1355 		if (buffer[0] == 0xff && buffer[1] == 0xff &&
1356 		    buffer[2] == 0xff && buffer[3] == 0xff) {
1357 			if(sizeof(sdkp->capacity) > 4) {
1358 				sd_printk(KERN_NOTICE, sdkp, "Very big device. "
1359 					  "Trying to use READ CAPACITY(16).\n");
1360 				longrc = 1;
1361 				goto repeat;
1362 			}
1363 			sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use "
1364 				  "a kernel compiled with support for large "
1365 				  "block devices.\n");
1366 			sdkp->capacity = 0;
1367 			goto got_data;
1368 		}
1369 		sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) |
1370 			(buffer[1] << 16) |
1371 			(buffer[2] << 8) |
1372 			buffer[3]);
1373 	} else {
1374 		sdkp->capacity = 1 + (((u64)buffer[0] << 56) |
1375 			((u64)buffer[1] << 48) |
1376 			((u64)buffer[2] << 40) |
1377 			((u64)buffer[3] << 32) |
1378 			((sector_t)buffer[4] << 24) |
1379 			((sector_t)buffer[5] << 16) |
1380 			((sector_t)buffer[6] << 8)  |
1381 			(sector_t)buffer[7]);
1382 
1383 		sector_size = (buffer[8] << 24) |
1384 			(buffer[9] << 16) | (buffer[10] << 8) | buffer[11];
1385 
1386 		sd_read_protection_type(sdkp, buffer);
1387 	}
1388 
1389 	/* Some devices return the total number of sectors, not the
1390 	 * highest sector number.  Make the necessary adjustment. */
1391 	if (sdp->fix_capacity) {
1392 		--sdkp->capacity;
1393 
1394 	/* Some devices have version which report the correct sizes
1395 	 * and others which do not. We guess size according to a heuristic
1396 	 * and err on the side of lowering the capacity. */
1397 	} else {
1398 		if (sdp->guess_capacity)
1399 			if (sdkp->capacity & 0x01) /* odd sizes are odd */
1400 				--sdkp->capacity;
1401 	}
1402 
1403 got_data:
1404 	if (sector_size == 0) {
1405 		sector_size = 512;
1406 		sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
1407 			  "assuming 512.\n");
1408 	}
1409 
1410 	if (sector_size != 512 &&
1411 	    sector_size != 1024 &&
1412 	    sector_size != 2048 &&
1413 	    sector_size != 4096 &&
1414 	    sector_size != 256) {
1415 		sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
1416 			  sector_size);
1417 		/*
1418 		 * The user might want to re-format the drive with
1419 		 * a supported sectorsize.  Once this happens, it
1420 		 * would be relatively trivial to set the thing up.
1421 		 * For this reason, we leave the thing in the table.
1422 		 */
1423 		sdkp->capacity = 0;
1424 		/*
1425 		 * set a bogus sector size so the normal read/write
1426 		 * logic in the block layer will eventually refuse any
1427 		 * request on this device without tripping over power
1428 		 * of two sector size assumptions
1429 		 */
1430 		sector_size = 512;
1431 	}
1432 	blk_queue_hardsect_size(sdp->request_queue, sector_size);
1433 
1434 	{
1435 		char cap_str_2[10], cap_str_10[10];
1436 		u64 sz = (u64)sdkp->capacity << ilog2(sector_size);
1437 
1438 		string_get_size(sz, STRING_UNITS_2, cap_str_2,
1439 				sizeof(cap_str_2));
1440 		string_get_size(sz, STRING_UNITS_10, cap_str_10,
1441 				sizeof(cap_str_10));
1442 
1443 		sd_printk(KERN_NOTICE, sdkp,
1444 			  "%llu %d-byte hardware sectors: (%s/%s)\n",
1445 			  (unsigned long long)sdkp->capacity,
1446 			  sector_size, cap_str_10, cap_str_2);
1447 	}
1448 
1449 	/* Rescale capacity to 512-byte units */
1450 	if (sector_size == 4096)
1451 		sdkp->capacity <<= 3;
1452 	else if (sector_size == 2048)
1453 		sdkp->capacity <<= 2;
1454 	else if (sector_size == 1024)
1455 		sdkp->capacity <<= 1;
1456 	else if (sector_size == 256)
1457 		sdkp->capacity >>= 1;
1458 
1459 	sdkp->device->sector_size = sector_size;
1460 }
1461 
1462 /* called with buffer of length 512 */
1463 static inline int
1464 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
1465 		 unsigned char *buffer, int len, struct scsi_mode_data *data,
1466 		 struct scsi_sense_hdr *sshdr)
1467 {
1468 	return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
1469 			       SD_TIMEOUT, SD_MAX_RETRIES, data,
1470 			       sshdr);
1471 }
1472 
1473 /*
1474  * read write protect setting, if possible - called only in sd_revalidate_disk()
1475  * called with buffer of length SD_BUF_SIZE
1476  */
1477 static void
1478 sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
1479 {
1480 	int res;
1481 	struct scsi_device *sdp = sdkp->device;
1482 	struct scsi_mode_data data;
1483 
1484 	set_disk_ro(sdkp->disk, 0);
1485 	if (sdp->skip_ms_page_3f) {
1486 		sd_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
1487 		return;
1488 	}
1489 
1490 	if (sdp->use_192_bytes_for_3f) {
1491 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
1492 	} else {
1493 		/*
1494 		 * First attempt: ask for all pages (0x3F), but only 4 bytes.
1495 		 * We have to start carefully: some devices hang if we ask
1496 		 * for more than is available.
1497 		 */
1498 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
1499 
1500 		/*
1501 		 * Second attempt: ask for page 0 When only page 0 is
1502 		 * implemented, a request for page 3F may return Sense Key
1503 		 * 5: Illegal Request, Sense Code 24: Invalid field in
1504 		 * CDB.
1505 		 */
1506 		if (!scsi_status_is_good(res))
1507 			res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
1508 
1509 		/*
1510 		 * Third attempt: ask 255 bytes, as we did earlier.
1511 		 */
1512 		if (!scsi_status_is_good(res))
1513 			res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
1514 					       &data, NULL);
1515 	}
1516 
1517 	if (!scsi_status_is_good(res)) {
1518 		sd_printk(KERN_WARNING, sdkp,
1519 			  "Test WP failed, assume Write Enabled\n");
1520 	} else {
1521 		sdkp->write_prot = ((data.device_specific & 0x80) != 0);
1522 		set_disk_ro(sdkp->disk, sdkp->write_prot);
1523 		sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
1524 			  sdkp->write_prot ? "on" : "off");
1525 		sd_printk(KERN_DEBUG, sdkp,
1526 			  "Mode Sense: %02x %02x %02x %02x\n",
1527 			  buffer[0], buffer[1], buffer[2], buffer[3]);
1528 	}
1529 }
1530 
1531 /*
1532  * sd_read_cache_type - called only from sd_revalidate_disk()
1533  * called with buffer of length SD_BUF_SIZE
1534  */
1535 static void
1536 sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
1537 {
1538 	int len = 0, res;
1539 	struct scsi_device *sdp = sdkp->device;
1540 
1541 	int dbd;
1542 	int modepage;
1543 	struct scsi_mode_data data;
1544 	struct scsi_sense_hdr sshdr;
1545 
1546 	if (sdp->skip_ms_page_8)
1547 		goto defaults;
1548 
1549 	if (sdp->type == TYPE_RBC) {
1550 		modepage = 6;
1551 		dbd = 8;
1552 	} else {
1553 		modepage = 8;
1554 		dbd = 0;
1555 	}
1556 
1557 	/* cautiously ask */
1558 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);
1559 
1560 	if (!scsi_status_is_good(res))
1561 		goto bad_sense;
1562 
1563 	if (!data.header_length) {
1564 		modepage = 6;
1565 		sd_printk(KERN_ERR, sdkp, "Missing header in MODE_SENSE response\n");
1566 	}
1567 
1568 	/* that went OK, now ask for the proper length */
1569 	len = data.length;
1570 
1571 	/*
1572 	 * We're only interested in the first three bytes, actually.
1573 	 * But the data cache page is defined for the first 20.
1574 	 */
1575 	if (len < 3)
1576 		goto bad_sense;
1577 	if (len > 20)
1578 		len = 20;
1579 
1580 	/* Take headers and block descriptors into account */
1581 	len += data.header_length + data.block_descriptor_length;
1582 	if (len > SD_BUF_SIZE)
1583 		goto bad_sense;
1584 
1585 	/* Get the data */
1586 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
1587 
1588 	if (scsi_status_is_good(res)) {
1589 		int offset = data.header_length + data.block_descriptor_length;
1590 
1591 		if (offset >= SD_BUF_SIZE - 2) {
1592 			sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
1593 			goto defaults;
1594 		}
1595 
1596 		if ((buffer[offset] & 0x3f) != modepage) {
1597 			sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
1598 			goto defaults;
1599 		}
1600 
1601 		if (modepage == 8) {
1602 			sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
1603 			sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
1604 		} else {
1605 			sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
1606 			sdkp->RCD = 0;
1607 		}
1608 
1609 		sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
1610 		if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
1611 			sd_printk(KERN_NOTICE, sdkp,
1612 				  "Uses READ/WRITE(6), disabling FUA\n");
1613 			sdkp->DPOFUA = 0;
1614 		}
1615 
1616 		sd_printk(KERN_NOTICE, sdkp,
1617 		       "Write cache: %s, read cache: %s, %s\n",
1618 		       sdkp->WCE ? "enabled" : "disabled",
1619 		       sdkp->RCD ? "disabled" : "enabled",
1620 		       sdkp->DPOFUA ? "supports DPO and FUA"
1621 		       : "doesn't support DPO or FUA");
1622 
1623 		return;
1624 	}
1625 
1626 bad_sense:
1627 	if (scsi_sense_valid(&sshdr) &&
1628 	    sshdr.sense_key == ILLEGAL_REQUEST &&
1629 	    sshdr.asc == 0x24 && sshdr.ascq == 0x0)
1630 		/* Invalid field in CDB */
1631 		sd_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
1632 	else
1633 		sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n");
1634 
1635 defaults:
1636 	sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
1637 	sdkp->WCE = 0;
1638 	sdkp->RCD = 0;
1639 	sdkp->DPOFUA = 0;
1640 }
1641 
1642 /*
1643  * The ATO bit indicates whether the DIF application tag is available
1644  * for use by the operating system.
1645  */
1646 void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
1647 {
1648 	int res, offset;
1649 	struct scsi_device *sdp = sdkp->device;
1650 	struct scsi_mode_data data;
1651 	struct scsi_sense_hdr sshdr;
1652 
1653 	if (sdp->type != TYPE_DISK)
1654 		return;
1655 
1656 	if (sdkp->protection_type == 0)
1657 		return;
1658 
1659 	res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
1660 			      SD_MAX_RETRIES, &data, &sshdr);
1661 
1662 	if (!scsi_status_is_good(res) || !data.header_length ||
1663 	    data.length < 6) {
1664 		sd_printk(KERN_WARNING, sdkp,
1665 			  "getting Control mode page failed, assume no ATO\n");
1666 
1667 		if (scsi_sense_valid(&sshdr))
1668 			sd_print_sense_hdr(sdkp, &sshdr);
1669 
1670 		return;
1671 	}
1672 
1673 	offset = data.header_length + data.block_descriptor_length;
1674 
1675 	if ((buffer[offset] & 0x3f) != 0x0a) {
1676 		sd_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
1677 		return;
1678 	}
1679 
1680 	if ((buffer[offset + 5] & 0x80) == 0)
1681 		return;
1682 
1683 	sdkp->ATO = 1;
1684 
1685 	return;
1686 }
1687 
1688 /**
1689  *	sd_revalidate_disk - called the first time a new disk is seen,
1690  *	performs disk spin up, read_capacity, etc.
1691  *	@disk: struct gendisk we care about
1692  **/
1693 static int sd_revalidate_disk(struct gendisk *disk)
1694 {
1695 	struct scsi_disk *sdkp = scsi_disk(disk);
1696 	struct scsi_device *sdp = sdkp->device;
1697 	unsigned char *buffer;
1698 	unsigned ordered;
1699 
1700 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
1701 				      "sd_revalidate_disk\n"));
1702 
1703 	/*
1704 	 * If the device is offline, don't try and read capacity or any
1705 	 * of the other niceties.
1706 	 */
1707 	if (!scsi_device_online(sdp))
1708 		goto out;
1709 
1710 	buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
1711 	if (!buffer) {
1712 		sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
1713 			  "allocation failure.\n");
1714 		goto out;
1715 	}
1716 
1717 	/* defaults, until the device tells us otherwise */
1718 	sdp->sector_size = 512;
1719 	sdkp->capacity = 0;
1720 	sdkp->media_present = 1;
1721 	sdkp->write_prot = 0;
1722 	sdkp->WCE = 0;
1723 	sdkp->RCD = 0;
1724 	sdkp->ATO = 0;
1725 
1726 	sd_spinup_disk(sdkp);
1727 
1728 	/*
1729 	 * Without media there is no reason to ask; moreover, some devices
1730 	 * react badly if we do.
1731 	 */
1732 	if (sdkp->media_present) {
1733 		sd_read_capacity(sdkp, buffer);
1734 		sd_read_write_protect_flag(sdkp, buffer);
1735 		sd_read_cache_type(sdkp, buffer);
1736 		sd_read_app_tag_own(sdkp, buffer);
1737 	}
1738 
1739 	/*
1740 	 * We now have all cache related info, determine how we deal
1741 	 * with ordered requests.  Note that as the current SCSI
1742 	 * dispatch function can alter request order, we cannot use
1743 	 * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
1744 	 */
1745 	if (sdkp->WCE)
1746 		ordered = sdkp->DPOFUA
1747 			? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
1748 	else
1749 		ordered = QUEUE_ORDERED_DRAIN;
1750 
1751 	blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush);
1752 
1753 	set_capacity(disk, sdkp->capacity);
1754 	kfree(buffer);
1755 
1756  out:
1757 	return 0;
1758 }
1759 
1760 /**
1761  *	sd_format_disk_name - format disk name
1762  *	@prefix: name prefix - ie. "sd" for SCSI disks
1763  *	@index: index of the disk to format name for
1764  *	@buf: output buffer
1765  *	@buflen: length of the output buffer
1766  *
1767  *	SCSI disk names starts at sda.  The 26th device is sdz and the
1768  *	27th is sdaa.  The last one for two lettered suffix is sdzz
1769  *	which is followed by sdaaa.
1770  *
1771  *	This is basically 26 base counting with one extra 'nil' entry
1772  *	at the beggining from the second digit on and can be
1773  *	determined using similar method as 26 base conversion with the
1774  *	index shifted -1 after each digit is computed.
1775  *
1776  *	CONTEXT:
1777  *	Don't care.
1778  *
1779  *	RETURNS:
1780  *	0 on success, -errno on failure.
1781  */
1782 static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
1783 {
1784 	const int base = 'z' - 'a' + 1;
1785 	char *begin = buf + strlen(prefix);
1786 	char *end = buf + buflen;
1787 	char *p;
1788 	int unit;
1789 
1790 	p = end - 1;
1791 	*p = '\0';
1792 	unit = base;
1793 	do {
1794 		if (p == begin)
1795 			return -EINVAL;
1796 		*--p = 'a' + (index % unit);
1797 		index = (index / unit) - 1;
1798 	} while (index >= 0);
1799 
1800 	memmove(begin, p, end - p);
1801 	memcpy(buf, prefix, strlen(prefix));
1802 
1803 	return 0;
1804 }
1805 
1806 /*
1807  * The asynchronous part of sd_probe
1808  */
1809 static void sd_probe_async(void *data, async_cookie_t cookie)
1810 {
1811 	struct scsi_disk *sdkp = data;
1812 	struct scsi_device *sdp;
1813 	struct gendisk *gd;
1814 	u32 index;
1815 	struct device *dev;
1816 
1817 	sdp = sdkp->device;
1818 	gd = sdkp->disk;
1819 	index = sdkp->index;
1820 	dev = &sdp->sdev_gendev;
1821 
1822 	if (!sdp->request_queue->rq_timeout) {
1823 		if (sdp->type != TYPE_MOD)
1824 			blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
1825 		else
1826 			blk_queue_rq_timeout(sdp->request_queue,
1827 					     SD_MOD_TIMEOUT);
1828 	}
1829 
1830 	device_initialize(&sdkp->dev);
1831 	sdkp->dev.parent = &sdp->sdev_gendev;
1832 	sdkp->dev.class = &sd_disk_class;
1833 	dev_set_name(&sdkp->dev, dev_name(&sdp->sdev_gendev));
1834 
1835 	if (device_add(&sdkp->dev))
1836 		goto out_free_index;
1837 
1838 	get_device(&sdp->sdev_gendev);
1839 
1840 	if (index < SD_MAX_DISKS) {
1841 		gd->major = sd_major((index & 0xf0) >> 4);
1842 		gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
1843 		gd->minors = SD_MINORS;
1844 	}
1845 	gd->fops = &sd_fops;
1846 	gd->private_data = &sdkp->driver;
1847 	gd->queue = sdkp->device->request_queue;
1848 
1849 	sd_revalidate_disk(gd);
1850 
1851 	blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);
1852 
1853 	gd->driverfs_dev = &sdp->sdev_gendev;
1854 	gd->flags = GENHD_FL_EXT_DEVT | GENHD_FL_DRIVERFS;
1855 	if (sdp->removable)
1856 		gd->flags |= GENHD_FL_REMOVABLE;
1857 
1858 	dev_set_drvdata(dev, sdkp);
1859 	add_disk(gd);
1860 	sd_dif_config_host(sdkp);
1861 
1862 	sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
1863 		  sdp->removable ? "removable " : "");
1864 
1865 	return;
1866 
1867  out_free_index:
1868 	ida_remove(&sd_index_ida, index);
1869 }
1870 
1871 /**
1872  *	sd_probe - called during driver initialization and whenever a
1873  *	new scsi device is attached to the system. It is called once
1874  *	for each scsi device (not just disks) present.
1875  *	@dev: pointer to device object
1876  *
1877  *	Returns 0 if successful (or not interested in this scsi device
1878  *	(e.g. scanner)); 1 when there is an error.
1879  *
1880  *	Note: this function is invoked from the scsi mid-level.
1881  *	This function sets up the mapping between a given
1882  *	<host,channel,id,lun> (found in sdp) and new device name
1883  *	(e.g. /dev/sda). More precisely it is the block device major
1884  *	and minor number that is chosen here.
1885  *
1886  *	Assume sd_attach is not re-entrant (for time being)
1887  *	Also think about sd_attach() and sd_remove() running coincidentally.
1888  **/
1889 static int sd_probe(struct device *dev)
1890 {
1891 	struct scsi_device *sdp = to_scsi_device(dev);
1892 	struct scsi_disk *sdkp;
1893 	struct gendisk *gd;
1894 	u32 index;
1895 	int error;
1896 
1897 	error = -ENODEV;
1898 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
1899 		goto out;
1900 
1901 	SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
1902 					"sd_attach\n"));
1903 
1904 	error = -ENOMEM;
1905 	sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
1906 	if (!sdkp)
1907 		goto out;
1908 
1909 	gd = alloc_disk(SD_MINORS);
1910 	if (!gd)
1911 		goto out_free;
1912 
1913 	do {
1914 		if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
1915 			goto out_put;
1916 
1917 		error = ida_get_new(&sd_index_ida, &index);
1918 	} while (error == -EAGAIN);
1919 
1920 	if (error)
1921 		goto out_put;
1922 
1923 	error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
1924 	if (error)
1925 		goto out_free_index;
1926 
1927 	sdkp->device = sdp;
1928 	sdkp->driver = &sd_template;
1929 	sdkp->disk = gd;
1930 	sdkp->index = index;
1931 	sdkp->openers = 0;
1932 	sdkp->previous_state = 1;
1933 
1934 	async_schedule(sd_probe_async, sdkp);
1935 
1936 	return 0;
1937 
1938  out_free_index:
1939 	ida_remove(&sd_index_ida, index);
1940  out_put:
1941 	put_disk(gd);
1942  out_free:
1943 	kfree(sdkp);
1944  out:
1945 	return error;
1946 }
1947 
1948 /**
1949  *	sd_remove - called whenever a scsi disk (previously recognized by
1950  *	sd_probe) is detached from the system. It is called (potentially
1951  *	multiple times) during sd module unload.
1952  *	@sdp: pointer to mid level scsi device object
1953  *
1954  *	Note: this function is invoked from the scsi mid-level.
1955  *	This function potentially frees up a device name (e.g. /dev/sdc)
1956  *	that could be re-used by a subsequent sd_probe().
1957  *	This function is not called when the built-in sd driver is "exit-ed".
1958  **/
1959 static int sd_remove(struct device *dev)
1960 {
1961 	struct scsi_disk *sdkp = dev_get_drvdata(dev);
1962 
1963 	device_del(&sdkp->dev);
1964 	del_gendisk(sdkp->disk);
1965 	sd_shutdown(dev);
1966 
1967 	mutex_lock(&sd_ref_mutex);
1968 	dev_set_drvdata(dev, NULL);
1969 	put_device(&sdkp->dev);
1970 	mutex_unlock(&sd_ref_mutex);
1971 
1972 	return 0;
1973 }
1974 
1975 /**
1976  *	scsi_disk_release - Called to free the scsi_disk structure
1977  *	@dev: pointer to embedded class device
1978  *
1979  *	sd_ref_mutex must be held entering this routine.  Because it is
1980  *	called on last put, you should always use the scsi_disk_get()
1981  *	scsi_disk_put() helpers which manipulate the semaphore directly
1982  *	and never do a direct put_device.
1983  **/
1984 static void scsi_disk_release(struct device *dev)
1985 {
1986 	struct scsi_disk *sdkp = to_scsi_disk(dev);
1987 	struct gendisk *disk = sdkp->disk;
1988 
1989 	ida_remove(&sd_index_ida, sdkp->index);
1990 
1991 	disk->private_data = NULL;
1992 	put_disk(disk);
1993 	put_device(&sdkp->device->sdev_gendev);
1994 
1995 	kfree(sdkp);
1996 }
1997 
1998 static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
1999 {
2000 	unsigned char cmd[6] = { START_STOP };	/* START_VALID */
2001 	struct scsi_sense_hdr sshdr;
2002 	struct scsi_device *sdp = sdkp->device;
2003 	int res;
2004 
2005 	if (start)
2006 		cmd[4] |= 1;	/* START */
2007 
2008 	if (sdp->start_stop_pwr_cond)
2009 		cmd[4] |= start ? 1 << 4 : 3 << 4;	/* Active or Standby */
2010 
2011 	if (!scsi_device_online(sdp))
2012 		return -ENODEV;
2013 
2014 	res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
2015 			       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
2016 	if (res) {
2017 		sd_printk(KERN_WARNING, sdkp, "START_STOP FAILED\n");
2018 		sd_print_result(sdkp, res);
2019 		if (driver_byte(res) & DRIVER_SENSE)
2020 			sd_print_sense_hdr(sdkp, &sshdr);
2021 	}
2022 
2023 	return res;
2024 }
2025 
2026 /*
2027  * Send a SYNCHRONIZE CACHE instruction down to the device through
2028  * the normal SCSI command structure.  Wait for the command to
2029  * complete.
2030  */
2031 static void sd_shutdown(struct device *dev)
2032 {
2033 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2034 
2035 	if (!sdkp)
2036 		return;         /* this can happen */
2037 
2038 	if (sdkp->WCE) {
2039 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2040 		sd_sync_cache(sdkp);
2041 	}
2042 
2043 	if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
2044 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2045 		sd_start_stop_device(sdkp, 0);
2046 	}
2047 
2048 	scsi_disk_put(sdkp);
2049 }
2050 
2051 static int sd_suspend(struct device *dev, pm_message_t mesg)
2052 {
2053 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2054 	int ret = 0;
2055 
2056 	if (!sdkp)
2057 		return 0;	/* this can happen */
2058 
2059 	if (sdkp->WCE) {
2060 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2061 		ret = sd_sync_cache(sdkp);
2062 		if (ret)
2063 			goto done;
2064 	}
2065 
2066 	if ((mesg.event & PM_EVENT_SLEEP) && sdkp->device->manage_start_stop) {
2067 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2068 		ret = sd_start_stop_device(sdkp, 0);
2069 	}
2070 
2071 done:
2072 	scsi_disk_put(sdkp);
2073 	return ret;
2074 }
2075 
2076 static int sd_resume(struct device *dev)
2077 {
2078 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2079 	int ret = 0;
2080 
2081 	if (!sdkp->device->manage_start_stop)
2082 		goto done;
2083 
2084 	sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
2085 	ret = sd_start_stop_device(sdkp, 1);
2086 
2087 done:
2088 	scsi_disk_put(sdkp);
2089 	return ret;
2090 }
2091 
2092 /**
2093  *	init_sd - entry point for this driver (both when built in or when
2094  *	a module).
2095  *
2096  *	Note: this function registers this driver with the scsi mid-level.
2097  **/
2098 static int __init init_sd(void)
2099 {
2100 	int majors = 0, i, err;
2101 
2102 	SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
2103 
2104 	for (i = 0; i < SD_MAJORS; i++)
2105 		if (register_blkdev(sd_major(i), "sd") == 0)
2106 			majors++;
2107 
2108 	if (!majors)
2109 		return -ENODEV;
2110 
2111 	err = class_register(&sd_disk_class);
2112 	if (err)
2113 		goto err_out;
2114 
2115 	err = scsi_register_driver(&sd_template.gendrv);
2116 	if (err)
2117 		goto err_out_class;
2118 
2119 	return 0;
2120 
2121 err_out_class:
2122 	class_unregister(&sd_disk_class);
2123 err_out:
2124 	for (i = 0; i < SD_MAJORS; i++)
2125 		unregister_blkdev(sd_major(i), "sd");
2126 	return err;
2127 }
2128 
2129 /**
2130  *	exit_sd - exit point for this driver (when it is a module).
2131  *
2132  *	Note: this function unregisters this driver from the scsi mid-level.
2133  **/
2134 static void __exit exit_sd(void)
2135 {
2136 	int i;
2137 
2138 	SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
2139 
2140 	scsi_unregister_driver(&sd_template.gendrv);
2141 	class_unregister(&sd_disk_class);
2142 
2143 	for (i = 0; i < SD_MAJORS; i++)
2144 		unregister_blkdev(sd_major(i), "sd");
2145 }
2146 
2147 module_init(init_sd);
2148 module_exit(exit_sd);
2149 
2150 static void sd_print_sense_hdr(struct scsi_disk *sdkp,
2151 			       struct scsi_sense_hdr *sshdr)
2152 {
2153 	sd_printk(KERN_INFO, sdkp, "");
2154 	scsi_show_sense_hdr(sshdr);
2155 	sd_printk(KERN_INFO, sdkp, "");
2156 	scsi_show_extd_sense(sshdr->asc, sshdr->ascq);
2157 }
2158 
2159 static void sd_print_result(struct scsi_disk *sdkp, int result)
2160 {
2161 	sd_printk(KERN_INFO, sdkp, "");
2162 	scsi_show_result(result);
2163 }
2164 
2165