xref: /linux/drivers/scsi/sd.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /*
2  *      sd.c Copyright (C) 1992 Drew Eckhardt
3  *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4  *
5  *      Linux scsi disk driver
6  *              Initial versions: Drew Eckhardt
7  *              Subsequent revisions: Eric Youngdale
8  *	Modification history:
9  *       - Drew Eckhardt <drew@colorado.edu> original
10  *       - Eric Youngdale <eric@andante.org> add scatter-gather, multiple
11  *         outstanding request, and other enhancements.
12  *         Support loadable low-level scsi drivers.
13  *       - Jirka Hanika <geo@ff.cuni.cz> support more scsi disks using
14  *         eight major numbers.
15  *       - Richard Gooch <rgooch@atnf.csiro.au> support devfs.
16  *	 - Torben Mathiasen <tmm@image.dk> Resource allocation fixes in
17  *	   sd_init and cleanups.
18  *	 - Alex Davis <letmein@erols.com> Fix problem where partition info
19  *	   not being read in sd_open. Fix problem where removable media
20  *	   could be ejected after sd_open.
21  *	 - Douglas Gilbert <dgilbert@interlog.com> cleanup for lk 2.5.x
22  *	 - Badari Pulavarty <pbadari@us.ibm.com>, Matthew Wilcox
23  *	   <willy@debian.org>, Kurt Garloff <garloff@suse.de>:
24  *	   Support 32k/1M disks.
25  *
26  *	Logging policy (needs CONFIG_SCSI_LOGGING defined):
27  *	 - setting up transfer: SCSI_LOG_HLQUEUE levels 1 and 2
28  *	 - end of transfer (bh + scsi_lib): SCSI_LOG_HLCOMPLETE level 1
29  *	 - entering sd_ioctl: SCSI_LOG_IOCTL level 1
30  *	 - entering other commands: SCSI_LOG_HLQUEUE level 3
31  *	Note: when the logging level is set by the user, it must be greater
32  *	than the level indicated above to trigger output.
33  */
34 
35 #include <linux/module.h>
36 #include <linux/fs.h>
37 #include <linux/kernel.h>
38 #include <linux/mm.h>
39 #include <linux/bio.h>
40 #include <linux/genhd.h>
41 #include <linux/hdreg.h>
42 #include <linux/errno.h>
43 #include <linux/idr.h>
44 #include <linux/interrupt.h>
45 #include <linux/init.h>
46 #include <linux/blkdev.h>
47 #include <linux/blkpg.h>
48 #include <linux/delay.h>
49 #include <linux/mutex.h>
50 #include <linux/string_helpers.h>
51 #include <linux/async.h>
52 #include <linux/slab.h>
53 #include <linux/pm_runtime.h>
54 #include <asm/uaccess.h>
55 #include <asm/unaligned.h>
56 
57 #include <scsi/scsi.h>
58 #include <scsi/scsi_cmnd.h>
59 #include <scsi/scsi_dbg.h>
60 #include <scsi/scsi_device.h>
61 #include <scsi/scsi_driver.h>
62 #include <scsi/scsi_eh.h>
63 #include <scsi/scsi_host.h>
64 #include <scsi/scsi_ioctl.h>
65 #include <scsi/scsicam.h>
66 
67 #include "sd.h"
68 #include "scsi_priv.h"
69 #include "scsi_logging.h"
70 
71 MODULE_AUTHOR("Eric Youngdale");
72 MODULE_DESCRIPTION("SCSI disk (sd) driver");
73 MODULE_LICENSE("GPL");
74 
75 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK0_MAJOR);
76 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK1_MAJOR);
77 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK2_MAJOR);
78 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK3_MAJOR);
79 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK4_MAJOR);
80 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK5_MAJOR);
81 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK6_MAJOR);
82 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK7_MAJOR);
83 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK8_MAJOR);
84 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK9_MAJOR);
85 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK10_MAJOR);
86 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK11_MAJOR);
87 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK12_MAJOR);
88 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK13_MAJOR);
89 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK14_MAJOR);
90 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
91 MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
92 MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
93 MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
94 
95 #if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
96 #define SD_MINORS	16
97 #else
98 #define SD_MINORS	0
99 #endif
100 
101 static void sd_config_discard(struct scsi_disk *, unsigned int);
102 static void sd_config_write_same(struct scsi_disk *);
103 static int  sd_revalidate_disk(struct gendisk *);
104 static void sd_unlock_native_capacity(struct gendisk *disk);
105 static int  sd_probe(struct device *);
106 static int  sd_remove(struct device *);
107 static void sd_shutdown(struct device *);
108 static int sd_suspend_system(struct device *);
109 static int sd_suspend_runtime(struct device *);
110 static int sd_resume(struct device *);
111 static void sd_rescan(struct device *);
112 static int sd_init_command(struct scsi_cmnd *SCpnt);
113 static void sd_uninit_command(struct scsi_cmnd *SCpnt);
114 static int sd_done(struct scsi_cmnd *);
115 static int sd_eh_action(struct scsi_cmnd *, int);
116 static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
117 static void scsi_disk_release(struct device *cdev);
118 static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
119 static void sd_print_result(const struct scsi_disk *, const char *, int);
120 
121 static DEFINE_SPINLOCK(sd_index_lock);
122 static DEFINE_IDA(sd_index_ida);
123 
124 /* This semaphore is used to mediate the 0->1 reference get in the
125  * face of object destruction (i.e. we can't allow a get on an
126  * object after last put) */
127 static DEFINE_MUTEX(sd_ref_mutex);
128 
129 static struct kmem_cache *sd_cdb_cache;
130 static mempool_t *sd_cdb_pool;
131 
132 static const char *sd_cache_types[] = {
133 	"write through", "none", "write back",
134 	"write back, no read (daft)"
135 };
136 
137 static void sd_set_flush_flag(struct scsi_disk *sdkp)
138 {
139 	unsigned flush = 0;
140 
141 	if (sdkp->WCE) {
142 		flush |= REQ_FLUSH;
143 		if (sdkp->DPOFUA)
144 			flush |= REQ_FUA;
145 	}
146 
147 	blk_queue_flush(sdkp->disk->queue, flush);
148 }
149 
150 static ssize_t
151 cache_type_store(struct device *dev, struct device_attribute *attr,
152 		 const char *buf, size_t count)
153 {
154 	int i, ct = -1, rcd, wce, sp;
155 	struct scsi_disk *sdkp = to_scsi_disk(dev);
156 	struct scsi_device *sdp = sdkp->device;
157 	char buffer[64];
158 	char *buffer_data;
159 	struct scsi_mode_data data;
160 	struct scsi_sense_hdr sshdr;
161 	static const char temp[] = "temporary ";
162 	int len;
163 
164 	if (sdp->type != TYPE_DISK)
165 		/* no cache control on RBC devices; theoretically they
166 		 * can do it, but there's probably so many exceptions
167 		 * it's not worth the risk */
168 		return -EINVAL;
169 
170 	if (strncmp(buf, temp, sizeof(temp) - 1) == 0) {
171 		buf += sizeof(temp) - 1;
172 		sdkp->cache_override = 1;
173 	} else {
174 		sdkp->cache_override = 0;
175 	}
176 
177 	for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {
178 		len = strlen(sd_cache_types[i]);
179 		if (strncmp(sd_cache_types[i], buf, len) == 0 &&
180 		    buf[len] == '\n') {
181 			ct = i;
182 			break;
183 		}
184 	}
185 	if (ct < 0)
186 		return -EINVAL;
187 	rcd = ct & 0x01 ? 1 : 0;
188 	wce = (ct & 0x02) && !sdkp->write_prot ? 1 : 0;
189 
190 	if (sdkp->cache_override) {
191 		sdkp->WCE = wce;
192 		sdkp->RCD = rcd;
193 		sd_set_flush_flag(sdkp);
194 		return count;
195 	}
196 
197 	if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
198 			    SD_MAX_RETRIES, &data, NULL))
199 		return -EINVAL;
200 	len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
201 		  data.block_descriptor_length);
202 	buffer_data = buffer + data.header_length +
203 		data.block_descriptor_length;
204 	buffer_data[2] &= ~0x05;
205 	buffer_data[2] |= wce << 2 | rcd;
206 	sp = buffer_data[0] & 0x80 ? 1 : 0;
207 
208 	if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
209 			     SD_MAX_RETRIES, &data, &sshdr)) {
210 		if (scsi_sense_valid(&sshdr))
211 			sd_print_sense_hdr(sdkp, &sshdr);
212 		return -EINVAL;
213 	}
214 	revalidate_disk(sdkp->disk);
215 	return count;
216 }
217 
218 static ssize_t
219 manage_start_stop_show(struct device *dev, struct device_attribute *attr,
220 		       char *buf)
221 {
222 	struct scsi_disk *sdkp = to_scsi_disk(dev);
223 	struct scsi_device *sdp = sdkp->device;
224 
225 	return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
226 }
227 
228 static ssize_t
229 manage_start_stop_store(struct device *dev, struct device_attribute *attr,
230 			const char *buf, size_t count)
231 {
232 	struct scsi_disk *sdkp = to_scsi_disk(dev);
233 	struct scsi_device *sdp = sdkp->device;
234 
235 	if (!capable(CAP_SYS_ADMIN))
236 		return -EACCES;
237 
238 	sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
239 
240 	return count;
241 }
242 static DEVICE_ATTR_RW(manage_start_stop);
243 
244 static ssize_t
245 allow_restart_show(struct device *dev, struct device_attribute *attr, char *buf)
246 {
247 	struct scsi_disk *sdkp = to_scsi_disk(dev);
248 
249 	return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
250 }
251 
252 static ssize_t
253 allow_restart_store(struct device *dev, struct device_attribute *attr,
254 		    const char *buf, size_t count)
255 {
256 	struct scsi_disk *sdkp = to_scsi_disk(dev);
257 	struct scsi_device *sdp = sdkp->device;
258 
259 	if (!capable(CAP_SYS_ADMIN))
260 		return -EACCES;
261 
262 	if (sdp->type != TYPE_DISK)
263 		return -EINVAL;
264 
265 	sdp->allow_restart = simple_strtoul(buf, NULL, 10);
266 
267 	return count;
268 }
269 static DEVICE_ATTR_RW(allow_restart);
270 
271 static ssize_t
272 cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
273 {
274 	struct scsi_disk *sdkp = to_scsi_disk(dev);
275 	int ct = sdkp->RCD + 2*sdkp->WCE;
276 
277 	return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
278 }
279 static DEVICE_ATTR_RW(cache_type);
280 
281 static ssize_t
282 FUA_show(struct device *dev, struct device_attribute *attr, char *buf)
283 {
284 	struct scsi_disk *sdkp = to_scsi_disk(dev);
285 
286 	return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
287 }
288 static DEVICE_ATTR_RO(FUA);
289 
290 static ssize_t
291 protection_type_show(struct device *dev, struct device_attribute *attr,
292 		     char *buf)
293 {
294 	struct scsi_disk *sdkp = to_scsi_disk(dev);
295 
296 	return snprintf(buf, 20, "%u\n", sdkp->protection_type);
297 }
298 
299 static ssize_t
300 protection_type_store(struct device *dev, struct device_attribute *attr,
301 		      const char *buf, size_t count)
302 {
303 	struct scsi_disk *sdkp = to_scsi_disk(dev);
304 	unsigned int val;
305 	int err;
306 
307 	if (!capable(CAP_SYS_ADMIN))
308 		return -EACCES;
309 
310 	err = kstrtouint(buf, 10, &val);
311 
312 	if (err)
313 		return err;
314 
315 	if (val >= 0 && val <= SD_DIF_TYPE3_PROTECTION)
316 		sdkp->protection_type = val;
317 
318 	return count;
319 }
320 static DEVICE_ATTR_RW(protection_type);
321 
322 static ssize_t
323 protection_mode_show(struct device *dev, struct device_attribute *attr,
324 		     char *buf)
325 {
326 	struct scsi_disk *sdkp = to_scsi_disk(dev);
327 	struct scsi_device *sdp = sdkp->device;
328 	unsigned int dif, dix;
329 
330 	dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
331 	dix = scsi_host_dix_capable(sdp->host, sdkp->protection_type);
332 
333 	if (!dix && scsi_host_dix_capable(sdp->host, SD_DIF_TYPE0_PROTECTION)) {
334 		dif = 0;
335 		dix = 1;
336 	}
337 
338 	if (!dif && !dix)
339 		return snprintf(buf, 20, "none\n");
340 
341 	return snprintf(buf, 20, "%s%u\n", dix ? "dix" : "dif", dif);
342 }
343 static DEVICE_ATTR_RO(protection_mode);
344 
345 static ssize_t
346 app_tag_own_show(struct device *dev, struct device_attribute *attr, char *buf)
347 {
348 	struct scsi_disk *sdkp = to_scsi_disk(dev);
349 
350 	return snprintf(buf, 20, "%u\n", sdkp->ATO);
351 }
352 static DEVICE_ATTR_RO(app_tag_own);
353 
354 static ssize_t
355 thin_provisioning_show(struct device *dev, struct device_attribute *attr,
356 		       char *buf)
357 {
358 	struct scsi_disk *sdkp = to_scsi_disk(dev);
359 
360 	return snprintf(buf, 20, "%u\n", sdkp->lbpme);
361 }
362 static DEVICE_ATTR_RO(thin_provisioning);
363 
364 static const char *lbp_mode[] = {
365 	[SD_LBP_FULL]		= "full",
366 	[SD_LBP_UNMAP]		= "unmap",
367 	[SD_LBP_WS16]		= "writesame_16",
368 	[SD_LBP_WS10]		= "writesame_10",
369 	[SD_LBP_ZERO]		= "writesame_zero",
370 	[SD_LBP_DISABLE]	= "disabled",
371 };
372 
373 static ssize_t
374 provisioning_mode_show(struct device *dev, struct device_attribute *attr,
375 		       char *buf)
376 {
377 	struct scsi_disk *sdkp = to_scsi_disk(dev);
378 
379 	return snprintf(buf, 20, "%s\n", lbp_mode[sdkp->provisioning_mode]);
380 }
381 
382 static ssize_t
383 provisioning_mode_store(struct device *dev, struct device_attribute *attr,
384 			const char *buf, size_t count)
385 {
386 	struct scsi_disk *sdkp = to_scsi_disk(dev);
387 	struct scsi_device *sdp = sdkp->device;
388 
389 	if (!capable(CAP_SYS_ADMIN))
390 		return -EACCES;
391 
392 	if (sdp->type != TYPE_DISK)
393 		return -EINVAL;
394 
395 	if (!strncmp(buf, lbp_mode[SD_LBP_UNMAP], 20))
396 		sd_config_discard(sdkp, SD_LBP_UNMAP);
397 	else if (!strncmp(buf, lbp_mode[SD_LBP_WS16], 20))
398 		sd_config_discard(sdkp, SD_LBP_WS16);
399 	else if (!strncmp(buf, lbp_mode[SD_LBP_WS10], 20))
400 		sd_config_discard(sdkp, SD_LBP_WS10);
401 	else if (!strncmp(buf, lbp_mode[SD_LBP_ZERO], 20))
402 		sd_config_discard(sdkp, SD_LBP_ZERO);
403 	else if (!strncmp(buf, lbp_mode[SD_LBP_DISABLE], 20))
404 		sd_config_discard(sdkp, SD_LBP_DISABLE);
405 	else
406 		return -EINVAL;
407 
408 	return count;
409 }
410 static DEVICE_ATTR_RW(provisioning_mode);
411 
412 static ssize_t
413 max_medium_access_timeouts_show(struct device *dev,
414 				struct device_attribute *attr, char *buf)
415 {
416 	struct scsi_disk *sdkp = to_scsi_disk(dev);
417 
418 	return snprintf(buf, 20, "%u\n", sdkp->max_medium_access_timeouts);
419 }
420 
421 static ssize_t
422 max_medium_access_timeouts_store(struct device *dev,
423 				 struct device_attribute *attr, const char *buf,
424 				 size_t count)
425 {
426 	struct scsi_disk *sdkp = to_scsi_disk(dev);
427 	int err;
428 
429 	if (!capable(CAP_SYS_ADMIN))
430 		return -EACCES;
431 
432 	err = kstrtouint(buf, 10, &sdkp->max_medium_access_timeouts);
433 
434 	return err ? err : count;
435 }
436 static DEVICE_ATTR_RW(max_medium_access_timeouts);
437 
438 static ssize_t
439 max_write_same_blocks_show(struct device *dev, struct device_attribute *attr,
440 			   char *buf)
441 {
442 	struct scsi_disk *sdkp = to_scsi_disk(dev);
443 
444 	return snprintf(buf, 20, "%u\n", sdkp->max_ws_blocks);
445 }
446 
447 static ssize_t
448 max_write_same_blocks_store(struct device *dev, struct device_attribute *attr,
449 			    const char *buf, size_t count)
450 {
451 	struct scsi_disk *sdkp = to_scsi_disk(dev);
452 	struct scsi_device *sdp = sdkp->device;
453 	unsigned long max;
454 	int err;
455 
456 	if (!capable(CAP_SYS_ADMIN))
457 		return -EACCES;
458 
459 	if (sdp->type != TYPE_DISK)
460 		return -EINVAL;
461 
462 	err = kstrtoul(buf, 10, &max);
463 
464 	if (err)
465 		return err;
466 
467 	if (max == 0)
468 		sdp->no_write_same = 1;
469 	else if (max <= SD_MAX_WS16_BLOCKS) {
470 		sdp->no_write_same = 0;
471 		sdkp->max_ws_blocks = max;
472 	}
473 
474 	sd_config_write_same(sdkp);
475 
476 	return count;
477 }
478 static DEVICE_ATTR_RW(max_write_same_blocks);
479 
480 static struct attribute *sd_disk_attrs[] = {
481 	&dev_attr_cache_type.attr,
482 	&dev_attr_FUA.attr,
483 	&dev_attr_allow_restart.attr,
484 	&dev_attr_manage_start_stop.attr,
485 	&dev_attr_protection_type.attr,
486 	&dev_attr_protection_mode.attr,
487 	&dev_attr_app_tag_own.attr,
488 	&dev_attr_thin_provisioning.attr,
489 	&dev_attr_provisioning_mode.attr,
490 	&dev_attr_max_write_same_blocks.attr,
491 	&dev_attr_max_medium_access_timeouts.attr,
492 	NULL,
493 };
494 ATTRIBUTE_GROUPS(sd_disk);
495 
496 static struct class sd_disk_class = {
497 	.name		= "scsi_disk",
498 	.owner		= THIS_MODULE,
499 	.dev_release	= scsi_disk_release,
500 	.dev_groups	= sd_disk_groups,
501 };
502 
503 static const struct dev_pm_ops sd_pm_ops = {
504 	.suspend		= sd_suspend_system,
505 	.resume			= sd_resume,
506 	.poweroff		= sd_suspend_system,
507 	.restore		= sd_resume,
508 	.runtime_suspend	= sd_suspend_runtime,
509 	.runtime_resume		= sd_resume,
510 };
511 
512 static struct scsi_driver sd_template = {
513 	.gendrv = {
514 		.name		= "sd",
515 		.owner		= THIS_MODULE,
516 		.probe		= sd_probe,
517 		.remove		= sd_remove,
518 		.shutdown	= sd_shutdown,
519 		.pm		= &sd_pm_ops,
520 	},
521 	.rescan			= sd_rescan,
522 	.init_command		= sd_init_command,
523 	.uninit_command		= sd_uninit_command,
524 	.done			= sd_done,
525 	.eh_action		= sd_eh_action,
526 };
527 
528 /*
529  * Dummy kobj_map->probe function.
530  * The default ->probe function will call modprobe, which is
531  * pointless as this module is already loaded.
532  */
533 static struct kobject *sd_default_probe(dev_t devt, int *partno, void *data)
534 {
535 	return NULL;
536 }
537 
538 /*
539  * Device no to disk mapping:
540  *
541  *       major         disc2     disc  p1
542  *   |............|.............|....|....| <- dev_t
543  *    31        20 19          8 7  4 3  0
544  *
545  * Inside a major, we have 16k disks, however mapped non-
546  * contiguously. The first 16 disks are for major0, the next
547  * ones with major1, ... Disk 256 is for major0 again, disk 272
548  * for major1, ...
549  * As we stay compatible with our numbering scheme, we can reuse
550  * the well-know SCSI majors 8, 65--71, 136--143.
551  */
552 static int sd_major(int major_idx)
553 {
554 	switch (major_idx) {
555 	case 0:
556 		return SCSI_DISK0_MAJOR;
557 	case 1 ... 7:
558 		return SCSI_DISK1_MAJOR + major_idx - 1;
559 	case 8 ... 15:
560 		return SCSI_DISK8_MAJOR + major_idx - 8;
561 	default:
562 		BUG();
563 		return 0;	/* shut up gcc */
564 	}
565 }
566 
567 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
568 {
569 	struct scsi_disk *sdkp = NULL;
570 
571 	if (disk->private_data) {
572 		sdkp = scsi_disk(disk);
573 		if (scsi_device_get(sdkp->device) == 0)
574 			get_device(&sdkp->dev);
575 		else
576 			sdkp = NULL;
577 	}
578 	return sdkp;
579 }
580 
581 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
582 {
583 	struct scsi_disk *sdkp;
584 
585 	mutex_lock(&sd_ref_mutex);
586 	sdkp = __scsi_disk_get(disk);
587 	mutex_unlock(&sd_ref_mutex);
588 	return sdkp;
589 }
590 
591 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
592 {
593 	struct scsi_disk *sdkp;
594 
595 	mutex_lock(&sd_ref_mutex);
596 	sdkp = dev_get_drvdata(dev);
597 	if (sdkp)
598 		sdkp = __scsi_disk_get(sdkp->disk);
599 	mutex_unlock(&sd_ref_mutex);
600 	return sdkp;
601 }
602 
603 static void scsi_disk_put(struct scsi_disk *sdkp)
604 {
605 	struct scsi_device *sdev = sdkp->device;
606 
607 	mutex_lock(&sd_ref_mutex);
608 	put_device(&sdkp->dev);
609 	scsi_device_put(sdev);
610 	mutex_unlock(&sd_ref_mutex);
611 }
612 
613 
614 
615 static unsigned char sd_setup_protect_cmnd(struct scsi_cmnd *scmd,
616 					   unsigned int dix, unsigned int dif)
617 {
618 	struct bio *bio = scmd->request->bio;
619 	unsigned int prot_op = sd_prot_op(rq_data_dir(scmd->request), dix, dif);
620 	unsigned int protect = 0;
621 
622 	if (dix) {				/* DIX Type 0, 1, 2, 3 */
623 		if (bio_integrity_flagged(bio, BIP_IP_CHECKSUM))
624 			scmd->prot_flags |= SCSI_PROT_IP_CHECKSUM;
625 
626 		if (bio_integrity_flagged(bio, BIP_CTRL_NOCHECK) == false)
627 			scmd->prot_flags |= SCSI_PROT_GUARD_CHECK;
628 	}
629 
630 	if (dif != SD_DIF_TYPE3_PROTECTION) {	/* DIX/DIF Type 0, 1, 2 */
631 		scmd->prot_flags |= SCSI_PROT_REF_INCREMENT;
632 
633 		if (bio_integrity_flagged(bio, BIP_CTRL_NOCHECK) == false)
634 			scmd->prot_flags |= SCSI_PROT_REF_CHECK;
635 	}
636 
637 	if (dif) {				/* DIX/DIF Type 1, 2, 3 */
638 		scmd->prot_flags |= SCSI_PROT_TRANSFER_PI;
639 
640 		if (bio_integrity_flagged(bio, BIP_DISK_NOCHECK))
641 			protect = 3 << 5;	/* Disable target PI checking */
642 		else
643 			protect = 1 << 5;	/* Enable target PI checking */
644 	}
645 
646 	scsi_set_prot_op(scmd, prot_op);
647 	scsi_set_prot_type(scmd, dif);
648 	scmd->prot_flags &= sd_prot_flag_mask(prot_op);
649 
650 	return protect;
651 }
652 
653 static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
654 {
655 	struct request_queue *q = sdkp->disk->queue;
656 	unsigned int logical_block_size = sdkp->device->sector_size;
657 	unsigned int max_blocks = 0;
658 
659 	q->limits.discard_zeroes_data = 0;
660 	q->limits.discard_alignment = sdkp->unmap_alignment *
661 		logical_block_size;
662 	q->limits.discard_granularity =
663 		max(sdkp->physical_block_size,
664 		    sdkp->unmap_granularity * logical_block_size);
665 
666 	sdkp->provisioning_mode = mode;
667 
668 	switch (mode) {
669 
670 	case SD_LBP_DISABLE:
671 		q->limits.max_discard_sectors = 0;
672 		queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
673 		return;
674 
675 	case SD_LBP_UNMAP:
676 		max_blocks = min_not_zero(sdkp->max_unmap_blocks,
677 					  (u32)SD_MAX_WS16_BLOCKS);
678 		break;
679 
680 	case SD_LBP_WS16:
681 		max_blocks = min_not_zero(sdkp->max_ws_blocks,
682 					  (u32)SD_MAX_WS16_BLOCKS);
683 		q->limits.discard_zeroes_data = sdkp->lbprz;
684 		break;
685 
686 	case SD_LBP_WS10:
687 		max_blocks = min_not_zero(sdkp->max_ws_blocks,
688 					  (u32)SD_MAX_WS10_BLOCKS);
689 		q->limits.discard_zeroes_data = sdkp->lbprz;
690 		break;
691 
692 	case SD_LBP_ZERO:
693 		max_blocks = min_not_zero(sdkp->max_ws_blocks,
694 					  (u32)SD_MAX_WS10_BLOCKS);
695 		q->limits.discard_zeroes_data = 1;
696 		break;
697 	}
698 
699 	q->limits.max_discard_sectors = max_blocks * (logical_block_size >> 9);
700 	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
701 }
702 
703 /**
704  * sd_setup_discard_cmnd - unmap blocks on thinly provisioned device
705  * @sdp: scsi device to operate one
706  * @rq: Request to prepare
707  *
708  * Will issue either UNMAP or WRITE SAME(16) depending on preference
709  * indicated by target device.
710  **/
711 static int sd_setup_discard_cmnd(struct scsi_cmnd *cmd)
712 {
713 	struct request *rq = cmd->request;
714 	struct scsi_device *sdp = cmd->device;
715 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
716 	sector_t sector = blk_rq_pos(rq);
717 	unsigned int nr_sectors = blk_rq_sectors(rq);
718 	unsigned int nr_bytes = blk_rq_bytes(rq);
719 	unsigned int len;
720 	int ret;
721 	char *buf;
722 	struct page *page;
723 
724 	sector >>= ilog2(sdp->sector_size) - 9;
725 	nr_sectors >>= ilog2(sdp->sector_size) - 9;
726 
727 	page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
728 	if (!page)
729 		return BLKPREP_DEFER;
730 
731 	switch (sdkp->provisioning_mode) {
732 	case SD_LBP_UNMAP:
733 		buf = page_address(page);
734 
735 		cmd->cmd_len = 10;
736 		cmd->cmnd[0] = UNMAP;
737 		cmd->cmnd[8] = 24;
738 
739 		put_unaligned_be16(6 + 16, &buf[0]);
740 		put_unaligned_be16(16, &buf[2]);
741 		put_unaligned_be64(sector, &buf[8]);
742 		put_unaligned_be32(nr_sectors, &buf[16]);
743 
744 		len = 24;
745 		break;
746 
747 	case SD_LBP_WS16:
748 		cmd->cmd_len = 16;
749 		cmd->cmnd[0] = WRITE_SAME_16;
750 		cmd->cmnd[1] = 0x8; /* UNMAP */
751 		put_unaligned_be64(sector, &cmd->cmnd[2]);
752 		put_unaligned_be32(nr_sectors, &cmd->cmnd[10]);
753 
754 		len = sdkp->device->sector_size;
755 		break;
756 
757 	case SD_LBP_WS10:
758 	case SD_LBP_ZERO:
759 		cmd->cmd_len = 10;
760 		cmd->cmnd[0] = WRITE_SAME;
761 		if (sdkp->provisioning_mode == SD_LBP_WS10)
762 			cmd->cmnd[1] = 0x8; /* UNMAP */
763 		put_unaligned_be32(sector, &cmd->cmnd[2]);
764 		put_unaligned_be16(nr_sectors, &cmd->cmnd[7]);
765 
766 		len = sdkp->device->sector_size;
767 		break;
768 
769 	default:
770 		ret = BLKPREP_KILL;
771 		goto out;
772 	}
773 
774 	rq->completion_data = page;
775 	rq->timeout = SD_TIMEOUT;
776 
777 	cmd->transfersize = len;
778 	cmd->allowed = SD_MAX_RETRIES;
779 
780 	/*
781 	 * Initially __data_len is set to the amount of data that needs to be
782 	 * transferred to the target. This amount depends on whether WRITE SAME
783 	 * or UNMAP is being used. After the scatterlist has been mapped by
784 	 * scsi_init_io() we set __data_len to the size of the area to be
785 	 * discarded on disk. This allows us to report completion on the full
786 	 * amount of blocks described by the request.
787 	 */
788 	blk_add_request_payload(rq, page, len);
789 	ret = scsi_init_io(cmd);
790 	rq->__data_len = nr_bytes;
791 
792 out:
793 	if (ret != BLKPREP_OK)
794 		__free_page(page);
795 	return ret;
796 }
797 
798 static void sd_config_write_same(struct scsi_disk *sdkp)
799 {
800 	struct request_queue *q = sdkp->disk->queue;
801 	unsigned int logical_block_size = sdkp->device->sector_size;
802 
803 	if (sdkp->device->no_write_same) {
804 		sdkp->max_ws_blocks = 0;
805 		goto out;
806 	}
807 
808 	/* Some devices can not handle block counts above 0xffff despite
809 	 * supporting WRITE SAME(16). Consequently we default to 64k
810 	 * blocks per I/O unless the device explicitly advertises a
811 	 * bigger limit.
812 	 */
813 	if (sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS)
814 		sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks,
815 						   (u32)SD_MAX_WS16_BLOCKS);
816 	else if (sdkp->ws16 || sdkp->ws10 || sdkp->device->no_report_opcodes)
817 		sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks,
818 						   (u32)SD_MAX_WS10_BLOCKS);
819 	else {
820 		sdkp->device->no_write_same = 1;
821 		sdkp->max_ws_blocks = 0;
822 	}
823 
824 out:
825 	blk_queue_max_write_same_sectors(q, sdkp->max_ws_blocks *
826 					 (logical_block_size >> 9));
827 }
828 
829 /**
830  * sd_setup_write_same_cmnd - write the same data to multiple blocks
831  * @cmd: command to prepare
832  *
833  * Will issue either WRITE SAME(10) or WRITE SAME(16) depending on
834  * preference indicated by target device.
835  **/
836 static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
837 {
838 	struct request *rq = cmd->request;
839 	struct scsi_device *sdp = cmd->device;
840 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
841 	struct bio *bio = rq->bio;
842 	sector_t sector = blk_rq_pos(rq);
843 	unsigned int nr_sectors = blk_rq_sectors(rq);
844 	unsigned int nr_bytes = blk_rq_bytes(rq);
845 	int ret;
846 
847 	if (sdkp->device->no_write_same)
848 		return BLKPREP_KILL;
849 
850 	BUG_ON(bio_offset(bio) || bio_iovec(bio).bv_len != sdp->sector_size);
851 
852 	sector >>= ilog2(sdp->sector_size) - 9;
853 	nr_sectors >>= ilog2(sdp->sector_size) - 9;
854 
855 	rq->timeout = SD_WRITE_SAME_TIMEOUT;
856 
857 	if (sdkp->ws16 || sector > 0xffffffff || nr_sectors > 0xffff) {
858 		cmd->cmd_len = 16;
859 		cmd->cmnd[0] = WRITE_SAME_16;
860 		put_unaligned_be64(sector, &cmd->cmnd[2]);
861 		put_unaligned_be32(nr_sectors, &cmd->cmnd[10]);
862 	} else {
863 		cmd->cmd_len = 10;
864 		cmd->cmnd[0] = WRITE_SAME;
865 		put_unaligned_be32(sector, &cmd->cmnd[2]);
866 		put_unaligned_be16(nr_sectors, &cmd->cmnd[7]);
867 	}
868 
869 	cmd->transfersize = sdp->sector_size;
870 	cmd->allowed = SD_MAX_RETRIES;
871 
872 	/*
873 	 * For WRITE_SAME the data transferred in the DATA IN buffer is
874 	 * different from the amount of data actually written to the target.
875 	 *
876 	 * We set up __data_len to the amount of data transferred from the
877 	 * DATA IN buffer so that blk_rq_map_sg set up the proper S/G list
878 	 * to transfer a single sector of data first, but then reset it to
879 	 * the amount of data to be written right after so that the I/O path
880 	 * knows how much to actually write.
881 	 */
882 	rq->__data_len = sdp->sector_size;
883 	ret = scsi_init_io(cmd);
884 	rq->__data_len = nr_bytes;
885 	return ret;
886 }
887 
888 static int sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
889 {
890 	struct request *rq = cmd->request;
891 
892 	/* flush requests don't perform I/O, zero the S/G table */
893 	memset(&cmd->sdb, 0, sizeof(cmd->sdb));
894 
895 	cmd->cmnd[0] = SYNCHRONIZE_CACHE;
896 	cmd->cmd_len = 10;
897 	cmd->transfersize = 0;
898 	cmd->allowed = SD_MAX_RETRIES;
899 
900 	rq->timeout = rq->q->rq_timeout * SD_FLUSH_TIMEOUT_MULTIPLIER;
901 	return BLKPREP_OK;
902 }
903 
904 static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
905 {
906 	struct request *rq = SCpnt->request;
907 	struct scsi_device *sdp = SCpnt->device;
908 	struct gendisk *disk = rq->rq_disk;
909 	struct scsi_disk *sdkp;
910 	sector_t block = blk_rq_pos(rq);
911 	sector_t threshold;
912 	unsigned int this_count = blk_rq_sectors(rq);
913 	unsigned int dif, dix;
914 	int ret;
915 	unsigned char protect;
916 
917 	ret = scsi_init_io(SCpnt);
918 	if (ret != BLKPREP_OK)
919 		goto out;
920 	SCpnt = rq->special;
921 	sdkp = scsi_disk(disk);
922 
923 	/* from here on until we're complete, any goto out
924 	 * is used for a killable error condition */
925 	ret = BLKPREP_KILL;
926 
927 	SCSI_LOG_HLQUEUE(1,
928 		scmd_printk(KERN_INFO, SCpnt,
929 			"%s: block=%llu, count=%d\n",
930 			__func__, (unsigned long long)block, this_count));
931 
932 	if (!sdp || !scsi_device_online(sdp) ||
933 	    block + blk_rq_sectors(rq) > get_capacity(disk)) {
934 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
935 						"Finishing %u sectors\n",
936 						blk_rq_sectors(rq)));
937 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
938 						"Retry with 0x%p\n", SCpnt));
939 		goto out;
940 	}
941 
942 	if (sdp->changed) {
943 		/*
944 		 * quietly refuse to do anything to a changed disc until
945 		 * the changed bit has been reset
946 		 */
947 		/* printk("SCSI disk has been changed or is not present. Prohibiting further I/O.\n"); */
948 		goto out;
949 	}
950 
951 	/*
952 	 * Some SD card readers can't handle multi-sector accesses which touch
953 	 * the last one or two hardware sectors.  Split accesses as needed.
954 	 */
955 	threshold = get_capacity(disk) - SD_LAST_BUGGY_SECTORS *
956 		(sdp->sector_size / 512);
957 
958 	if (unlikely(sdp->last_sector_bug && block + this_count > threshold)) {
959 		if (block < threshold) {
960 			/* Access up to the threshold but not beyond */
961 			this_count = threshold - block;
962 		} else {
963 			/* Access only a single hardware sector */
964 			this_count = sdp->sector_size / 512;
965 		}
966 	}
967 
968 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
969 					(unsigned long long)block));
970 
971 	/*
972 	 * If we have a 1K hardware sectorsize, prevent access to single
973 	 * 512 byte sectors.  In theory we could handle this - in fact
974 	 * the scsi cdrom driver must be able to handle this because
975 	 * we typically use 1K blocksizes, and cdroms typically have
976 	 * 2K hardware sectorsizes.  Of course, things are simpler
977 	 * with the cdrom, since it is read-only.  For performance
978 	 * reasons, the filesystems should be able to handle this
979 	 * and not force the scsi disk driver to use bounce buffers
980 	 * for this.
981 	 */
982 	if (sdp->sector_size == 1024) {
983 		if ((block & 1) || (blk_rq_sectors(rq) & 1)) {
984 			scmd_printk(KERN_ERR, SCpnt,
985 				    "Bad block number requested\n");
986 			goto out;
987 		} else {
988 			block = block >> 1;
989 			this_count = this_count >> 1;
990 		}
991 	}
992 	if (sdp->sector_size == 2048) {
993 		if ((block & 3) || (blk_rq_sectors(rq) & 3)) {
994 			scmd_printk(KERN_ERR, SCpnt,
995 				    "Bad block number requested\n");
996 			goto out;
997 		} else {
998 			block = block >> 2;
999 			this_count = this_count >> 2;
1000 		}
1001 	}
1002 	if (sdp->sector_size == 4096) {
1003 		if ((block & 7) || (blk_rq_sectors(rq) & 7)) {
1004 			scmd_printk(KERN_ERR, SCpnt,
1005 				    "Bad block number requested\n");
1006 			goto out;
1007 		} else {
1008 			block = block >> 3;
1009 			this_count = this_count >> 3;
1010 		}
1011 	}
1012 	if (rq_data_dir(rq) == WRITE) {
1013 		SCpnt->cmnd[0] = WRITE_6;
1014 
1015 		if (blk_integrity_rq(rq))
1016 			sd_dif_prepare(SCpnt);
1017 
1018 	} else if (rq_data_dir(rq) == READ) {
1019 		SCpnt->cmnd[0] = READ_6;
1020 	} else {
1021 		scmd_printk(KERN_ERR, SCpnt, "Unknown command %llx\n", (unsigned long long) rq->cmd_flags);
1022 		goto out;
1023 	}
1024 
1025 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
1026 					"%s %d/%u 512 byte blocks.\n",
1027 					(rq_data_dir(rq) == WRITE) ?
1028 					"writing" : "reading", this_count,
1029 					blk_rq_sectors(rq)));
1030 
1031 	dix = scsi_prot_sg_count(SCpnt);
1032 	dif = scsi_host_dif_capable(SCpnt->device->host, sdkp->protection_type);
1033 
1034 	if (dif || dix)
1035 		protect = sd_setup_protect_cmnd(SCpnt, dix, dif);
1036 	else
1037 		protect = 0;
1038 
1039 	if (protect && sdkp->protection_type == SD_DIF_TYPE2_PROTECTION) {
1040 		SCpnt->cmnd = mempool_alloc(sd_cdb_pool, GFP_ATOMIC);
1041 
1042 		if (unlikely(SCpnt->cmnd == NULL)) {
1043 			ret = BLKPREP_DEFER;
1044 			goto out;
1045 		}
1046 
1047 		SCpnt->cmd_len = SD_EXT_CDB_SIZE;
1048 		memset(SCpnt->cmnd, 0, SCpnt->cmd_len);
1049 		SCpnt->cmnd[0] = VARIABLE_LENGTH_CMD;
1050 		SCpnt->cmnd[7] = 0x18;
1051 		SCpnt->cmnd[9] = (rq_data_dir(rq) == READ) ? READ_32 : WRITE_32;
1052 		SCpnt->cmnd[10] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
1053 
1054 		/* LBA */
1055 		SCpnt->cmnd[12] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
1056 		SCpnt->cmnd[13] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
1057 		SCpnt->cmnd[14] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
1058 		SCpnt->cmnd[15] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
1059 		SCpnt->cmnd[16] = (unsigned char) (block >> 24) & 0xff;
1060 		SCpnt->cmnd[17] = (unsigned char) (block >> 16) & 0xff;
1061 		SCpnt->cmnd[18] = (unsigned char) (block >> 8) & 0xff;
1062 		SCpnt->cmnd[19] = (unsigned char) block & 0xff;
1063 
1064 		/* Expected Indirect LBA */
1065 		SCpnt->cmnd[20] = (unsigned char) (block >> 24) & 0xff;
1066 		SCpnt->cmnd[21] = (unsigned char) (block >> 16) & 0xff;
1067 		SCpnt->cmnd[22] = (unsigned char) (block >> 8) & 0xff;
1068 		SCpnt->cmnd[23] = (unsigned char) block & 0xff;
1069 
1070 		/* Transfer length */
1071 		SCpnt->cmnd[28] = (unsigned char) (this_count >> 24) & 0xff;
1072 		SCpnt->cmnd[29] = (unsigned char) (this_count >> 16) & 0xff;
1073 		SCpnt->cmnd[30] = (unsigned char) (this_count >> 8) & 0xff;
1074 		SCpnt->cmnd[31] = (unsigned char) this_count & 0xff;
1075 	} else if (sdp->use_16_for_rw || (this_count > 0xffff)) {
1076 		SCpnt->cmnd[0] += READ_16 - READ_6;
1077 		SCpnt->cmnd[1] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
1078 		SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
1079 		SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
1080 		SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
1081 		SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
1082 		SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
1083 		SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
1084 		SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
1085 		SCpnt->cmnd[9] = (unsigned char) block & 0xff;
1086 		SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
1087 		SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
1088 		SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
1089 		SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
1090 		SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
1091 	} else if ((this_count > 0xff) || (block > 0x1fffff) ||
1092 		   scsi_device_protection(SCpnt->device) ||
1093 		   SCpnt->device->use_10_for_rw) {
1094 		SCpnt->cmnd[0] += READ_10 - READ_6;
1095 		SCpnt->cmnd[1] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
1096 		SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
1097 		SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
1098 		SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
1099 		SCpnt->cmnd[5] = (unsigned char) block & 0xff;
1100 		SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
1101 		SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
1102 		SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
1103 	} else {
1104 		if (unlikely(rq->cmd_flags & REQ_FUA)) {
1105 			/*
1106 			 * This happens only if this drive failed
1107 			 * 10byte rw command with ILLEGAL_REQUEST
1108 			 * during operation and thus turned off
1109 			 * use_10_for_rw.
1110 			 */
1111 			scmd_printk(KERN_ERR, SCpnt,
1112 				    "FUA write on READ/WRITE(6) drive\n");
1113 			goto out;
1114 		}
1115 
1116 		SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
1117 		SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
1118 		SCpnt->cmnd[3] = (unsigned char) block & 0xff;
1119 		SCpnt->cmnd[4] = (unsigned char) this_count;
1120 		SCpnt->cmnd[5] = 0;
1121 	}
1122 	SCpnt->sdb.length = this_count * sdp->sector_size;
1123 
1124 	/*
1125 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
1126 	 * host adapter, it's safe to assume that we can at least transfer
1127 	 * this many bytes between each connect / disconnect.
1128 	 */
1129 	SCpnt->transfersize = sdp->sector_size;
1130 	SCpnt->underflow = this_count << 9;
1131 	SCpnt->allowed = SD_MAX_RETRIES;
1132 
1133 	/*
1134 	 * This indicates that the command is ready from our end to be
1135 	 * queued.
1136 	 */
1137 	ret = BLKPREP_OK;
1138  out:
1139 	return ret;
1140 }
1141 
1142 static int sd_init_command(struct scsi_cmnd *cmd)
1143 {
1144 	struct request *rq = cmd->request;
1145 
1146 	if (rq->cmd_flags & REQ_DISCARD)
1147 		return sd_setup_discard_cmnd(cmd);
1148 	else if (rq->cmd_flags & REQ_WRITE_SAME)
1149 		return sd_setup_write_same_cmnd(cmd);
1150 	else if (rq->cmd_flags & REQ_FLUSH)
1151 		return sd_setup_flush_cmnd(cmd);
1152 	else
1153 		return sd_setup_read_write_cmnd(cmd);
1154 }
1155 
1156 static void sd_uninit_command(struct scsi_cmnd *SCpnt)
1157 {
1158 	struct request *rq = SCpnt->request;
1159 
1160 	if (rq->cmd_flags & REQ_DISCARD)
1161 		__free_page(rq->completion_data);
1162 
1163 	if (SCpnt->cmnd != rq->cmd) {
1164 		mempool_free(SCpnt->cmnd, sd_cdb_pool);
1165 		SCpnt->cmnd = NULL;
1166 		SCpnt->cmd_len = 0;
1167 	}
1168 }
1169 
1170 /**
1171  *	sd_open - open a scsi disk device
1172  *	@inode: only i_rdev member may be used
1173  *	@filp: only f_mode and f_flags may be used
1174  *
1175  *	Returns 0 if successful. Returns a negated errno value in case
1176  *	of error.
1177  *
1178  *	Note: This can be called from a user context (e.g. fsck(1) )
1179  *	or from within the kernel (e.g. as a result of a mount(1) ).
1180  *	In the latter case @inode and @filp carry an abridged amount
1181  *	of information as noted above.
1182  *
1183  *	Locking: called with bdev->bd_mutex held.
1184  **/
1185 static int sd_open(struct block_device *bdev, fmode_t mode)
1186 {
1187 	struct scsi_disk *sdkp = scsi_disk_get(bdev->bd_disk);
1188 	struct scsi_device *sdev;
1189 	int retval;
1190 
1191 	if (!sdkp)
1192 		return -ENXIO;
1193 
1194 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
1195 
1196 	sdev = sdkp->device;
1197 
1198 	/*
1199 	 * If the device is in error recovery, wait until it is done.
1200 	 * If the device is offline, then disallow any access to it.
1201 	 */
1202 	retval = -ENXIO;
1203 	if (!scsi_block_when_processing_errors(sdev))
1204 		goto error_out;
1205 
1206 	if (sdev->removable || sdkp->write_prot)
1207 		check_disk_change(bdev);
1208 
1209 	/*
1210 	 * If the drive is empty, just let the open fail.
1211 	 */
1212 	retval = -ENOMEDIUM;
1213 	if (sdev->removable && !sdkp->media_present && !(mode & FMODE_NDELAY))
1214 		goto error_out;
1215 
1216 	/*
1217 	 * If the device has the write protect tab set, have the open fail
1218 	 * if the user expects to be able to write to the thing.
1219 	 */
1220 	retval = -EROFS;
1221 	if (sdkp->write_prot && (mode & FMODE_WRITE))
1222 		goto error_out;
1223 
1224 	/*
1225 	 * It is possible that the disk changing stuff resulted in
1226 	 * the device being taken offline.  If this is the case,
1227 	 * report this to the user, and don't pretend that the
1228 	 * open actually succeeded.
1229 	 */
1230 	retval = -ENXIO;
1231 	if (!scsi_device_online(sdev))
1232 		goto error_out;
1233 
1234 	if ((atomic_inc_return(&sdkp->openers) == 1) && sdev->removable) {
1235 		if (scsi_block_when_processing_errors(sdev))
1236 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
1237 	}
1238 
1239 	return 0;
1240 
1241 error_out:
1242 	scsi_disk_put(sdkp);
1243 	return retval;
1244 }
1245 
1246 /**
1247  *	sd_release - invoked when the (last) close(2) is called on this
1248  *	scsi disk.
1249  *	@inode: only i_rdev member may be used
1250  *	@filp: only f_mode and f_flags may be used
1251  *
1252  *	Returns 0.
1253  *
1254  *	Note: may block (uninterruptible) if error recovery is underway
1255  *	on this disk.
1256  *
1257  *	Locking: called with bdev->bd_mutex held.
1258  **/
1259 static void sd_release(struct gendisk *disk, fmode_t mode)
1260 {
1261 	struct scsi_disk *sdkp = scsi_disk(disk);
1262 	struct scsi_device *sdev = sdkp->device;
1263 
1264 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_release\n"));
1265 
1266 	if (atomic_dec_return(&sdkp->openers) == 0 && sdev->removable) {
1267 		if (scsi_block_when_processing_errors(sdev))
1268 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
1269 	}
1270 
1271 	/*
1272 	 * XXX and what if there are packets in flight and this close()
1273 	 * XXX is followed by a "rmmod sd_mod"?
1274 	 */
1275 
1276 	scsi_disk_put(sdkp);
1277 }
1278 
1279 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1280 {
1281 	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
1282 	struct scsi_device *sdp = sdkp->device;
1283 	struct Scsi_Host *host = sdp->host;
1284 	int diskinfo[4];
1285 
1286 	/* default to most commonly used values */
1287         diskinfo[0] = 0x40;	/* 1 << 6 */
1288        	diskinfo[1] = 0x20;	/* 1 << 5 */
1289        	diskinfo[2] = sdkp->capacity >> 11;
1290 
1291 	/* override with calculated, extended default, or driver values */
1292 	if (host->hostt->bios_param)
1293 		host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
1294 	else
1295 		scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
1296 
1297 	geo->heads = diskinfo[0];
1298 	geo->sectors = diskinfo[1];
1299 	geo->cylinders = diskinfo[2];
1300 	return 0;
1301 }
1302 
1303 /**
1304  *	sd_ioctl - process an ioctl
1305  *	@inode: only i_rdev/i_bdev members may be used
1306  *	@filp: only f_mode and f_flags may be used
1307  *	@cmd: ioctl command number
1308  *	@arg: this is third argument given to ioctl(2) system call.
1309  *	Often contains a pointer.
1310  *
1311  *	Returns 0 if successful (some ioctls return positive numbers on
1312  *	success as well). Returns a negated errno value in case of error.
1313  *
1314  *	Note: most ioctls are forward onto the block subsystem or further
1315  *	down in the scsi subsystem.
1316  **/
1317 static int sd_ioctl(struct block_device *bdev, fmode_t mode,
1318 		    unsigned int cmd, unsigned long arg)
1319 {
1320 	struct gendisk *disk = bdev->bd_disk;
1321 	struct scsi_disk *sdkp = scsi_disk(disk);
1322 	struct scsi_device *sdp = sdkp->device;
1323 	void __user *p = (void __user *)arg;
1324 	int error;
1325 
1326 	SCSI_LOG_IOCTL(1, sd_printk(KERN_INFO, sdkp, "sd_ioctl: disk=%s, "
1327 				    "cmd=0x%x\n", disk->disk_name, cmd));
1328 
1329 	error = scsi_verify_blk_ioctl(bdev, cmd);
1330 	if (error < 0)
1331 		return error;
1332 
1333 	/*
1334 	 * If we are in the middle of error recovery, don't let anyone
1335 	 * else try and use this device.  Also, if error recovery fails, it
1336 	 * may try and take the device offline, in which case all further
1337 	 * access to the device is prohibited.
1338 	 */
1339 	error = scsi_ioctl_block_when_processing_errors(sdp, cmd,
1340 			(mode & FMODE_NDELAY) != 0);
1341 	if (error)
1342 		goto out;
1343 
1344 	/*
1345 	 * Send SCSI addressing ioctls directly to mid level, send other
1346 	 * ioctls to block level and then onto mid level if they can't be
1347 	 * resolved.
1348 	 */
1349 	switch (cmd) {
1350 		case SCSI_IOCTL_GET_IDLUN:
1351 		case SCSI_IOCTL_GET_BUS_NUMBER:
1352 			error = scsi_ioctl(sdp, cmd, p);
1353 			break;
1354 		default:
1355 			error = scsi_cmd_blk_ioctl(bdev, mode, cmd, p);
1356 			if (error != -ENOTTY)
1357 				break;
1358 			error = scsi_ioctl(sdp, cmd, p);
1359 			break;
1360 	}
1361 out:
1362 	return error;
1363 }
1364 
1365 static void set_media_not_present(struct scsi_disk *sdkp)
1366 {
1367 	if (sdkp->media_present)
1368 		sdkp->device->changed = 1;
1369 
1370 	if (sdkp->device->removable) {
1371 		sdkp->media_present = 0;
1372 		sdkp->capacity = 0;
1373 	}
1374 }
1375 
1376 static int media_not_present(struct scsi_disk *sdkp,
1377 			     struct scsi_sense_hdr *sshdr)
1378 {
1379 	if (!scsi_sense_valid(sshdr))
1380 		return 0;
1381 
1382 	/* not invoked for commands that could return deferred errors */
1383 	switch (sshdr->sense_key) {
1384 	case UNIT_ATTENTION:
1385 	case NOT_READY:
1386 		/* medium not present */
1387 		if (sshdr->asc == 0x3A) {
1388 			set_media_not_present(sdkp);
1389 			return 1;
1390 		}
1391 	}
1392 	return 0;
1393 }
1394 
1395 /**
1396  *	sd_check_events - check media events
1397  *	@disk: kernel device descriptor
1398  *	@clearing: disk events currently being cleared
1399  *
1400  *	Returns mask of DISK_EVENT_*.
1401  *
1402  *	Note: this function is invoked from the block subsystem.
1403  **/
1404 static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
1405 {
1406 	struct scsi_disk *sdkp = scsi_disk(disk);
1407 	struct scsi_device *sdp = sdkp->device;
1408 	struct scsi_sense_hdr *sshdr = NULL;
1409 	int retval;
1410 
1411 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_check_events\n"));
1412 
1413 	/*
1414 	 * If the device is offline, don't send any commands - just pretend as
1415 	 * if the command failed.  If the device ever comes back online, we
1416 	 * can deal with it then.  It is only because of unrecoverable errors
1417 	 * that we would ever take a device offline in the first place.
1418 	 */
1419 	if (!scsi_device_online(sdp)) {
1420 		set_media_not_present(sdkp);
1421 		goto out;
1422 	}
1423 
1424 	/*
1425 	 * Using TEST_UNIT_READY enables differentiation between drive with
1426 	 * no cartridge loaded - NOT READY, drive with changed cartridge -
1427 	 * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
1428 	 *
1429 	 * Drives that auto spin down. eg iomega jaz 1G, will be started
1430 	 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
1431 	 * sd_revalidate() is called.
1432 	 */
1433 	retval = -ENODEV;
1434 
1435 	if (scsi_block_when_processing_errors(sdp)) {
1436 		sshdr  = kzalloc(sizeof(*sshdr), GFP_KERNEL);
1437 		retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
1438 					      sshdr);
1439 	}
1440 
1441 	/* failed to execute TUR, assume media not present */
1442 	if (host_byte(retval)) {
1443 		set_media_not_present(sdkp);
1444 		goto out;
1445 	}
1446 
1447 	if (media_not_present(sdkp, sshdr))
1448 		goto out;
1449 
1450 	/*
1451 	 * For removable scsi disk we have to recognise the presence
1452 	 * of a disk in the drive.
1453 	 */
1454 	if (!sdkp->media_present)
1455 		sdp->changed = 1;
1456 	sdkp->media_present = 1;
1457 out:
1458 	/*
1459 	 * sdp->changed is set under the following conditions:
1460 	 *
1461 	 *	Medium present state has changed in either direction.
1462 	 *	Device has indicated UNIT_ATTENTION.
1463 	 */
1464 	kfree(sshdr);
1465 	retval = sdp->changed ? DISK_EVENT_MEDIA_CHANGE : 0;
1466 	sdp->changed = 0;
1467 	return retval;
1468 }
1469 
1470 static int sd_sync_cache(struct scsi_disk *sdkp)
1471 {
1472 	int retries, res;
1473 	struct scsi_device *sdp = sdkp->device;
1474 	const int timeout = sdp->request_queue->rq_timeout
1475 		* SD_FLUSH_TIMEOUT_MULTIPLIER;
1476 	struct scsi_sense_hdr sshdr;
1477 
1478 	if (!scsi_device_online(sdp))
1479 		return -ENODEV;
1480 
1481 	for (retries = 3; retries > 0; --retries) {
1482 		unsigned char cmd[10] = { 0 };
1483 
1484 		cmd[0] = SYNCHRONIZE_CACHE;
1485 		/*
1486 		 * Leave the rest of the command zero to indicate
1487 		 * flush everything.
1488 		 */
1489 		res = scsi_execute_req_flags(sdp, cmd, DMA_NONE, NULL, 0,
1490 					     &sshdr, timeout, SD_MAX_RETRIES,
1491 					     NULL, REQ_PM);
1492 		if (res == 0)
1493 			break;
1494 	}
1495 
1496 	if (res) {
1497 		sd_print_result(sdkp, "Synchronize Cache(10) failed", res);
1498 
1499 		if (driver_byte(res) & DRIVER_SENSE)
1500 			sd_print_sense_hdr(sdkp, &sshdr);
1501 		/* we need to evaluate the error return  */
1502 		if (scsi_sense_valid(&sshdr) &&
1503 			(sshdr.asc == 0x3a ||	/* medium not present */
1504 			 sshdr.asc == 0x20))	/* invalid command */
1505 				/* this is no error here */
1506 				return 0;
1507 
1508 		switch (host_byte(res)) {
1509 		/* ignore errors due to racing a disconnection */
1510 		case DID_BAD_TARGET:
1511 		case DID_NO_CONNECT:
1512 			return 0;
1513 		/* signal the upper layer it might try again */
1514 		case DID_BUS_BUSY:
1515 		case DID_IMM_RETRY:
1516 		case DID_REQUEUE:
1517 		case DID_SOFT_ERROR:
1518 			return -EBUSY;
1519 		default:
1520 			return -EIO;
1521 		}
1522 	}
1523 	return 0;
1524 }
1525 
1526 static void sd_rescan(struct device *dev)
1527 {
1528 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
1529 
1530 	if (sdkp) {
1531 		revalidate_disk(sdkp->disk);
1532 		scsi_disk_put(sdkp);
1533 	}
1534 }
1535 
1536 
1537 #ifdef CONFIG_COMPAT
1538 /*
1539  * This gets directly called from VFS. When the ioctl
1540  * is not recognized we go back to the other translation paths.
1541  */
1542 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
1543 			   unsigned int cmd, unsigned long arg)
1544 {
1545 	struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
1546 	int error;
1547 
1548 	error = scsi_ioctl_block_when_processing_errors(sdev, cmd,
1549 			(mode & FMODE_NDELAY) != 0);
1550 	if (error)
1551 		return error;
1552 
1553 	/*
1554 	 * Let the static ioctl translation table take care of it.
1555 	 */
1556 	if (!sdev->host->hostt->compat_ioctl)
1557 		return -ENOIOCTLCMD;
1558 	return sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
1559 }
1560 #endif
1561 
1562 static const struct block_device_operations sd_fops = {
1563 	.owner			= THIS_MODULE,
1564 	.open			= sd_open,
1565 	.release		= sd_release,
1566 	.ioctl			= sd_ioctl,
1567 	.getgeo			= sd_getgeo,
1568 #ifdef CONFIG_COMPAT
1569 	.compat_ioctl		= sd_compat_ioctl,
1570 #endif
1571 	.check_events		= sd_check_events,
1572 	.revalidate_disk	= sd_revalidate_disk,
1573 	.unlock_native_capacity	= sd_unlock_native_capacity,
1574 };
1575 
1576 /**
1577  *	sd_eh_action - error handling callback
1578  *	@scmd:		sd-issued command that has failed
1579  *	@eh_disp:	The recovery disposition suggested by the midlayer
1580  *
1581  *	This function is called by the SCSI midlayer upon completion of an
1582  *	error test command (currently TEST UNIT READY). The result of sending
1583  *	the eh command is passed in eh_disp.  We're looking for devices that
1584  *	fail medium access commands but are OK with non access commands like
1585  *	test unit ready (so wrongly see the device as having a successful
1586  *	recovery)
1587  **/
1588 static int sd_eh_action(struct scsi_cmnd *scmd, int eh_disp)
1589 {
1590 	struct scsi_disk *sdkp = scsi_disk(scmd->request->rq_disk);
1591 
1592 	if (!scsi_device_online(scmd->device) ||
1593 	    !scsi_medium_access_command(scmd) ||
1594 	    host_byte(scmd->result) != DID_TIME_OUT ||
1595 	    eh_disp != SUCCESS)
1596 		return eh_disp;
1597 
1598 	/*
1599 	 * The device has timed out executing a medium access command.
1600 	 * However, the TEST UNIT READY command sent during error
1601 	 * handling completed successfully. Either the device is in the
1602 	 * process of recovering or has it suffered an internal failure
1603 	 * that prevents access to the storage medium.
1604 	 */
1605 	sdkp->medium_access_timed_out++;
1606 
1607 	/*
1608 	 * If the device keeps failing read/write commands but TEST UNIT
1609 	 * READY always completes successfully we assume that medium
1610 	 * access is no longer possible and take the device offline.
1611 	 */
1612 	if (sdkp->medium_access_timed_out >= sdkp->max_medium_access_timeouts) {
1613 		scmd_printk(KERN_ERR, scmd,
1614 			    "Medium access timeout failure. Offlining disk!\n");
1615 		scsi_device_set_state(scmd->device, SDEV_OFFLINE);
1616 
1617 		return FAILED;
1618 	}
1619 
1620 	return eh_disp;
1621 }
1622 
1623 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
1624 {
1625 	u64 start_lba = blk_rq_pos(scmd->request);
1626 	u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
1627 	u64 bad_lba;
1628 	int info_valid;
1629 	/*
1630 	 * resid is optional but mostly filled in.  When it's unused,
1631 	 * its value is zero, so we assume the whole buffer transferred
1632 	 */
1633 	unsigned int transferred = scsi_bufflen(scmd) - scsi_get_resid(scmd);
1634 	unsigned int good_bytes;
1635 
1636 	if (scmd->request->cmd_type != REQ_TYPE_FS)
1637 		return 0;
1638 
1639 	info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
1640 					     SCSI_SENSE_BUFFERSIZE,
1641 					     &bad_lba);
1642 	if (!info_valid)
1643 		return 0;
1644 
1645 	if (scsi_bufflen(scmd) <= scmd->device->sector_size)
1646 		return 0;
1647 
1648 	if (scmd->device->sector_size < 512) {
1649 		/* only legitimate sector_size here is 256 */
1650 		start_lba <<= 1;
1651 		end_lba <<= 1;
1652 	} else {
1653 		/* be careful ... don't want any overflows */
1654 		unsigned int factor = scmd->device->sector_size / 512;
1655 		do_div(start_lba, factor);
1656 		do_div(end_lba, factor);
1657 	}
1658 
1659 	/* The bad lba was reported incorrectly, we have no idea where
1660 	 * the error is.
1661 	 */
1662 	if (bad_lba < start_lba  || bad_lba >= end_lba)
1663 		return 0;
1664 
1665 	/* This computation should always be done in terms of
1666 	 * the resolution of the device's medium.
1667 	 */
1668 	good_bytes = (bad_lba - start_lba) * scmd->device->sector_size;
1669 	return min(good_bytes, transferred);
1670 }
1671 
1672 /**
1673  *	sd_done - bottom half handler: called when the lower level
1674  *	driver has completed (successfully or otherwise) a scsi command.
1675  *	@SCpnt: mid-level's per command structure.
1676  *
1677  *	Note: potentially run from within an ISR. Must not block.
1678  **/
1679 static int sd_done(struct scsi_cmnd *SCpnt)
1680 {
1681 	int result = SCpnt->result;
1682 	unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
1683 	struct scsi_sense_hdr sshdr;
1684 	struct scsi_disk *sdkp = scsi_disk(SCpnt->request->rq_disk);
1685 	struct request *req = SCpnt->request;
1686 	int sense_valid = 0;
1687 	int sense_deferred = 0;
1688 	unsigned char op = SCpnt->cmnd[0];
1689 	unsigned char unmap = SCpnt->cmnd[1] & 8;
1690 
1691 	if (req->cmd_flags & REQ_DISCARD || req->cmd_flags & REQ_WRITE_SAME) {
1692 		if (!result) {
1693 			good_bytes = blk_rq_bytes(req);
1694 			scsi_set_resid(SCpnt, 0);
1695 		} else {
1696 			good_bytes = 0;
1697 			scsi_set_resid(SCpnt, blk_rq_bytes(req));
1698 		}
1699 	}
1700 
1701 	if (result) {
1702 		sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
1703 		if (sense_valid)
1704 			sense_deferred = scsi_sense_is_deferred(&sshdr);
1705 	}
1706 	sdkp->medium_access_timed_out = 0;
1707 
1708 	if (driver_byte(result) != DRIVER_SENSE &&
1709 	    (!sense_valid || sense_deferred))
1710 		goto out;
1711 
1712 	switch (sshdr.sense_key) {
1713 	case HARDWARE_ERROR:
1714 	case MEDIUM_ERROR:
1715 		good_bytes = sd_completed_bytes(SCpnt);
1716 		break;
1717 	case RECOVERED_ERROR:
1718 		good_bytes = scsi_bufflen(SCpnt);
1719 		break;
1720 	case NO_SENSE:
1721 		/* This indicates a false check condition, so ignore it.  An
1722 		 * unknown amount of data was transferred so treat it as an
1723 		 * error.
1724 		 */
1725 		SCpnt->result = 0;
1726 		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1727 		break;
1728 	case ABORTED_COMMAND:
1729 		if (sshdr.asc == 0x10)  /* DIF: Target detected corruption */
1730 			good_bytes = sd_completed_bytes(SCpnt);
1731 		break;
1732 	case ILLEGAL_REQUEST:
1733 		if (sshdr.asc == 0x10)  /* DIX: Host detected corruption */
1734 			good_bytes = sd_completed_bytes(SCpnt);
1735 		/* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
1736 		if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
1737 			switch (op) {
1738 			case UNMAP:
1739 				sd_config_discard(sdkp, SD_LBP_DISABLE);
1740 				break;
1741 			case WRITE_SAME_16:
1742 			case WRITE_SAME:
1743 				if (unmap)
1744 					sd_config_discard(sdkp, SD_LBP_DISABLE);
1745 				else {
1746 					sdkp->device->no_write_same = 1;
1747 					sd_config_write_same(sdkp);
1748 
1749 					good_bytes = 0;
1750 					req->__data_len = blk_rq_bytes(req);
1751 					req->cmd_flags |= REQ_QUIET;
1752 				}
1753 			}
1754 		}
1755 		break;
1756 	default:
1757 		break;
1758 	}
1759  out:
1760 	SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
1761 					   "sd_done: completed %d of %d bytes\n",
1762 					   good_bytes, scsi_bufflen(SCpnt)));
1763 
1764 	if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
1765 		sd_dif_complete(SCpnt, good_bytes);
1766 
1767 	return good_bytes;
1768 }
1769 
1770 /*
1771  * spinup disk - called only in sd_revalidate_disk()
1772  */
1773 static void
1774 sd_spinup_disk(struct scsi_disk *sdkp)
1775 {
1776 	unsigned char cmd[10];
1777 	unsigned long spintime_expire = 0;
1778 	int retries, spintime;
1779 	unsigned int the_result;
1780 	struct scsi_sense_hdr sshdr;
1781 	int sense_valid = 0;
1782 
1783 	spintime = 0;
1784 
1785 	/* Spin up drives, as required.  Only do this at boot time */
1786 	/* Spinup needs to be done for module loads too. */
1787 	do {
1788 		retries = 0;
1789 
1790 		do {
1791 			cmd[0] = TEST_UNIT_READY;
1792 			memset((void *) &cmd[1], 0, 9);
1793 
1794 			the_result = scsi_execute_req(sdkp->device, cmd,
1795 						      DMA_NONE, NULL, 0,
1796 						      &sshdr, SD_TIMEOUT,
1797 						      SD_MAX_RETRIES, NULL);
1798 
1799 			/*
1800 			 * If the drive has indicated to us that it
1801 			 * doesn't have any media in it, don't bother
1802 			 * with any more polling.
1803 			 */
1804 			if (media_not_present(sdkp, &sshdr))
1805 				return;
1806 
1807 			if (the_result)
1808 				sense_valid = scsi_sense_valid(&sshdr);
1809 			retries++;
1810 		} while (retries < 3 &&
1811 			 (!scsi_status_is_good(the_result) ||
1812 			  ((driver_byte(the_result) & DRIVER_SENSE) &&
1813 			  sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1814 
1815 		if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1816 			/* no sense, TUR either succeeded or failed
1817 			 * with a status error */
1818 			if(!spintime && !scsi_status_is_good(the_result)) {
1819 				sd_print_result(sdkp, "Test Unit Ready failed",
1820 						the_result);
1821 			}
1822 			break;
1823 		}
1824 
1825 		/*
1826 		 * The device does not want the automatic start to be issued.
1827 		 */
1828 		if (sdkp->device->no_start_on_add)
1829 			break;
1830 
1831 		if (sense_valid && sshdr.sense_key == NOT_READY) {
1832 			if (sshdr.asc == 4 && sshdr.ascq == 3)
1833 				break;	/* manual intervention required */
1834 			if (sshdr.asc == 4 && sshdr.ascq == 0xb)
1835 				break;	/* standby */
1836 			if (sshdr.asc == 4 && sshdr.ascq == 0xc)
1837 				break;	/* unavailable */
1838 			/*
1839 			 * Issue command to spin up drive when not ready
1840 			 */
1841 			if (!spintime) {
1842 				sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
1843 				cmd[0] = START_STOP;
1844 				cmd[1] = 1;	/* Return immediately */
1845 				memset((void *) &cmd[2], 0, 8);
1846 				cmd[4] = 1;	/* Start spin cycle */
1847 				if (sdkp->device->start_stop_pwr_cond)
1848 					cmd[4] |= 1 << 4;
1849 				scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1850 						 NULL, 0, &sshdr,
1851 						 SD_TIMEOUT, SD_MAX_RETRIES,
1852 						 NULL);
1853 				spintime_expire = jiffies + 100 * HZ;
1854 				spintime = 1;
1855 			}
1856 			/* Wait 1 second for next try */
1857 			msleep(1000);
1858 			printk(".");
1859 
1860 		/*
1861 		 * Wait for USB flash devices with slow firmware.
1862 		 * Yes, this sense key/ASC combination shouldn't
1863 		 * occur here.  It's characteristic of these devices.
1864 		 */
1865 		} else if (sense_valid &&
1866 				sshdr.sense_key == UNIT_ATTENTION &&
1867 				sshdr.asc == 0x28) {
1868 			if (!spintime) {
1869 				spintime_expire = jiffies + 5 * HZ;
1870 				spintime = 1;
1871 			}
1872 			/* Wait 1 second for next try */
1873 			msleep(1000);
1874 		} else {
1875 			/* we don't understand the sense code, so it's
1876 			 * probably pointless to loop */
1877 			if(!spintime) {
1878 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1879 				sd_print_sense_hdr(sdkp, &sshdr);
1880 			}
1881 			break;
1882 		}
1883 
1884 	} while (spintime && time_before_eq(jiffies, spintime_expire));
1885 
1886 	if (spintime) {
1887 		if (scsi_status_is_good(the_result))
1888 			printk("ready\n");
1889 		else
1890 			printk("not responding...\n");
1891 	}
1892 }
1893 
1894 
1895 /*
1896  * Determine whether disk supports Data Integrity Field.
1897  */
1898 static int sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
1899 {
1900 	struct scsi_device *sdp = sdkp->device;
1901 	u8 type;
1902 	int ret = 0;
1903 
1904 	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
1905 		return ret;
1906 
1907 	type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
1908 
1909 	if (type > SD_DIF_TYPE3_PROTECTION)
1910 		ret = -ENODEV;
1911 	else if (scsi_host_dif_capable(sdp->host, type))
1912 		ret = 1;
1913 
1914 	if (sdkp->first_scan || type != sdkp->protection_type)
1915 		switch (ret) {
1916 		case -ENODEV:
1917 			sd_printk(KERN_ERR, sdkp, "formatted with unsupported" \
1918 				  " protection type %u. Disabling disk!\n",
1919 				  type);
1920 			break;
1921 		case 1:
1922 			sd_printk(KERN_NOTICE, sdkp,
1923 				  "Enabling DIF Type %u protection\n", type);
1924 			break;
1925 		case 0:
1926 			sd_printk(KERN_NOTICE, sdkp,
1927 				  "Disabling DIF Type %u protection\n", type);
1928 			break;
1929 		}
1930 
1931 	sdkp->protection_type = type;
1932 
1933 	return ret;
1934 }
1935 
1936 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
1937 			struct scsi_sense_hdr *sshdr, int sense_valid,
1938 			int the_result)
1939 {
1940 	if (driver_byte(the_result) & DRIVER_SENSE)
1941 		sd_print_sense_hdr(sdkp, sshdr);
1942 	else
1943 		sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
1944 
1945 	/*
1946 	 * Set dirty bit for removable devices if not ready -
1947 	 * sometimes drives will not report this properly.
1948 	 */
1949 	if (sdp->removable &&
1950 	    sense_valid && sshdr->sense_key == NOT_READY)
1951 		set_media_not_present(sdkp);
1952 
1953 	/*
1954 	 * We used to set media_present to 0 here to indicate no media
1955 	 * in the drive, but some drives fail read capacity even with
1956 	 * media present, so we can't do that.
1957 	 */
1958 	sdkp->capacity = 0; /* unknown mapped to zero - as usual */
1959 }
1960 
1961 #define RC16_LEN 32
1962 #if RC16_LEN > SD_BUF_SIZE
1963 #error RC16_LEN must not be more than SD_BUF_SIZE
1964 #endif
1965 
1966 #define READ_CAPACITY_RETRIES_ON_RESET	10
1967 
1968 static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
1969 						unsigned char *buffer)
1970 {
1971 	unsigned char cmd[16];
1972 	struct scsi_sense_hdr sshdr;
1973 	int sense_valid = 0;
1974 	int the_result;
1975 	int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
1976 	unsigned int alignment;
1977 	unsigned long long lba;
1978 	unsigned sector_size;
1979 
1980 	if (sdp->no_read_capacity_16)
1981 		return -EINVAL;
1982 
1983 	do {
1984 		memset(cmd, 0, 16);
1985 		cmd[0] = SERVICE_ACTION_IN_16;
1986 		cmd[1] = SAI_READ_CAPACITY_16;
1987 		cmd[13] = RC16_LEN;
1988 		memset(buffer, 0, RC16_LEN);
1989 
1990 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1991 					buffer, RC16_LEN, &sshdr,
1992 					SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1993 
1994 		if (media_not_present(sdkp, &sshdr))
1995 			return -ENODEV;
1996 
1997 		if (the_result) {
1998 			sense_valid = scsi_sense_valid(&sshdr);
1999 			if (sense_valid &&
2000 			    sshdr.sense_key == ILLEGAL_REQUEST &&
2001 			    (sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
2002 			    sshdr.ascq == 0x00)
2003 				/* Invalid Command Operation Code or
2004 				 * Invalid Field in CDB, just retry
2005 				 * silently with RC10 */
2006 				return -EINVAL;
2007 			if (sense_valid &&
2008 			    sshdr.sense_key == UNIT_ATTENTION &&
2009 			    sshdr.asc == 0x29 && sshdr.ascq == 0x00)
2010 				/* Device reset might occur several times,
2011 				 * give it one more chance */
2012 				if (--reset_retries > 0)
2013 					continue;
2014 		}
2015 		retries--;
2016 
2017 	} while (the_result && retries);
2018 
2019 	if (the_result) {
2020 		sd_print_result(sdkp, "Read Capacity(16) failed", the_result);
2021 		read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
2022 		return -EINVAL;
2023 	}
2024 
2025 	sector_size = get_unaligned_be32(&buffer[8]);
2026 	lba = get_unaligned_be64(&buffer[0]);
2027 
2028 	if (sd_read_protection_type(sdkp, buffer) < 0) {
2029 		sdkp->capacity = 0;
2030 		return -ENODEV;
2031 	}
2032 
2033 	if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) {
2034 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
2035 			"kernel compiled with support for large block "
2036 			"devices.\n");
2037 		sdkp->capacity = 0;
2038 		return -EOVERFLOW;
2039 	}
2040 
2041 	/* Logical blocks per physical block exponent */
2042 	sdkp->physical_block_size = (1 << (buffer[13] & 0xf)) * sector_size;
2043 
2044 	/* Lowest aligned logical block */
2045 	alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) * sector_size;
2046 	blk_queue_alignment_offset(sdp->request_queue, alignment);
2047 	if (alignment && sdkp->first_scan)
2048 		sd_printk(KERN_NOTICE, sdkp,
2049 			  "physical block alignment offset: %u\n", alignment);
2050 
2051 	if (buffer[14] & 0x80) { /* LBPME */
2052 		sdkp->lbpme = 1;
2053 
2054 		if (buffer[14] & 0x40) /* LBPRZ */
2055 			sdkp->lbprz = 1;
2056 
2057 		sd_config_discard(sdkp, SD_LBP_WS16);
2058 	}
2059 
2060 	sdkp->capacity = lba + 1;
2061 	return sector_size;
2062 }
2063 
2064 static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
2065 						unsigned char *buffer)
2066 {
2067 	unsigned char cmd[16];
2068 	struct scsi_sense_hdr sshdr;
2069 	int sense_valid = 0;
2070 	int the_result;
2071 	int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
2072 	sector_t lba;
2073 	unsigned sector_size;
2074 
2075 	do {
2076 		cmd[0] = READ_CAPACITY;
2077 		memset(&cmd[1], 0, 9);
2078 		memset(buffer, 0, 8);
2079 
2080 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
2081 					buffer, 8, &sshdr,
2082 					SD_TIMEOUT, SD_MAX_RETRIES, NULL);
2083 
2084 		if (media_not_present(sdkp, &sshdr))
2085 			return -ENODEV;
2086 
2087 		if (the_result) {
2088 			sense_valid = scsi_sense_valid(&sshdr);
2089 			if (sense_valid &&
2090 			    sshdr.sense_key == UNIT_ATTENTION &&
2091 			    sshdr.asc == 0x29 && sshdr.ascq == 0x00)
2092 				/* Device reset might occur several times,
2093 				 * give it one more chance */
2094 				if (--reset_retries > 0)
2095 					continue;
2096 		}
2097 		retries--;
2098 
2099 	} while (the_result && retries);
2100 
2101 	if (the_result) {
2102 		sd_print_result(sdkp, "Read Capacity(10) failed", the_result);
2103 		read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
2104 		return -EINVAL;
2105 	}
2106 
2107 	sector_size = get_unaligned_be32(&buffer[4]);
2108 	lba = get_unaligned_be32(&buffer[0]);
2109 
2110 	if (sdp->no_read_capacity_16 && (lba == 0xffffffff)) {
2111 		/* Some buggy (usb cardreader) devices return an lba of
2112 		   0xffffffff when the want to report a size of 0 (with
2113 		   which they really mean no media is present) */
2114 		sdkp->capacity = 0;
2115 		sdkp->physical_block_size = sector_size;
2116 		return sector_size;
2117 	}
2118 
2119 	if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) {
2120 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
2121 			"kernel compiled with support for large block "
2122 			"devices.\n");
2123 		sdkp->capacity = 0;
2124 		return -EOVERFLOW;
2125 	}
2126 
2127 	sdkp->capacity = lba + 1;
2128 	sdkp->physical_block_size = sector_size;
2129 	return sector_size;
2130 }
2131 
2132 static int sd_try_rc16_first(struct scsi_device *sdp)
2133 {
2134 	if (sdp->host->max_cmd_len < 16)
2135 		return 0;
2136 	if (sdp->try_rc_10_first)
2137 		return 0;
2138 	if (sdp->scsi_level > SCSI_SPC_2)
2139 		return 1;
2140 	if (scsi_device_protection(sdp))
2141 		return 1;
2142 	return 0;
2143 }
2144 
2145 /*
2146  * read disk capacity
2147  */
2148 static void
2149 sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
2150 {
2151 	int sector_size;
2152 	struct scsi_device *sdp = sdkp->device;
2153 	sector_t old_capacity = sdkp->capacity;
2154 
2155 	if (sd_try_rc16_first(sdp)) {
2156 		sector_size = read_capacity_16(sdkp, sdp, buffer);
2157 		if (sector_size == -EOVERFLOW)
2158 			goto got_data;
2159 		if (sector_size == -ENODEV)
2160 			return;
2161 		if (sector_size < 0)
2162 			sector_size = read_capacity_10(sdkp, sdp, buffer);
2163 		if (sector_size < 0)
2164 			return;
2165 	} else {
2166 		sector_size = read_capacity_10(sdkp, sdp, buffer);
2167 		if (sector_size == -EOVERFLOW)
2168 			goto got_data;
2169 		if (sector_size < 0)
2170 			return;
2171 		if ((sizeof(sdkp->capacity) > 4) &&
2172 		    (sdkp->capacity > 0xffffffffULL)) {
2173 			int old_sector_size = sector_size;
2174 			sd_printk(KERN_NOTICE, sdkp, "Very big device. "
2175 					"Trying to use READ CAPACITY(16).\n");
2176 			sector_size = read_capacity_16(sdkp, sdp, buffer);
2177 			if (sector_size < 0) {
2178 				sd_printk(KERN_NOTICE, sdkp,
2179 					"Using 0xffffffff as device size\n");
2180 				sdkp->capacity = 1 + (sector_t) 0xffffffff;
2181 				sector_size = old_sector_size;
2182 				goto got_data;
2183 			}
2184 		}
2185 	}
2186 
2187 	/* Some devices are known to return the total number of blocks,
2188 	 * not the highest block number.  Some devices have versions
2189 	 * which do this and others which do not.  Some devices we might
2190 	 * suspect of doing this but we don't know for certain.
2191 	 *
2192 	 * If we know the reported capacity is wrong, decrement it.  If
2193 	 * we can only guess, then assume the number of blocks is even
2194 	 * (usually true but not always) and err on the side of lowering
2195 	 * the capacity.
2196 	 */
2197 	if (sdp->fix_capacity ||
2198 	    (sdp->guess_capacity && (sdkp->capacity & 0x01))) {
2199 		sd_printk(KERN_INFO, sdkp, "Adjusting the sector count "
2200 				"from its reported value: %llu\n",
2201 				(unsigned long long) sdkp->capacity);
2202 		--sdkp->capacity;
2203 	}
2204 
2205 got_data:
2206 	if (sector_size == 0) {
2207 		sector_size = 512;
2208 		sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
2209 			  "assuming 512.\n");
2210 	}
2211 
2212 	if (sector_size != 512 &&
2213 	    sector_size != 1024 &&
2214 	    sector_size != 2048 &&
2215 	    sector_size != 4096 &&
2216 	    sector_size != 256) {
2217 		sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
2218 			  sector_size);
2219 		/*
2220 		 * The user might want to re-format the drive with
2221 		 * a supported sectorsize.  Once this happens, it
2222 		 * would be relatively trivial to set the thing up.
2223 		 * For this reason, we leave the thing in the table.
2224 		 */
2225 		sdkp->capacity = 0;
2226 		/*
2227 		 * set a bogus sector size so the normal read/write
2228 		 * logic in the block layer will eventually refuse any
2229 		 * request on this device without tripping over power
2230 		 * of two sector size assumptions
2231 		 */
2232 		sector_size = 512;
2233 	}
2234 	blk_queue_logical_block_size(sdp->request_queue, sector_size);
2235 
2236 	{
2237 		char cap_str_2[10], cap_str_10[10];
2238 		u64 sz = (u64)sdkp->capacity << ilog2(sector_size);
2239 
2240 		string_get_size(sz, STRING_UNITS_2, cap_str_2,
2241 				sizeof(cap_str_2));
2242 		string_get_size(sz, STRING_UNITS_10, cap_str_10,
2243 				sizeof(cap_str_10));
2244 
2245 		if (sdkp->first_scan || old_capacity != sdkp->capacity) {
2246 			sd_printk(KERN_NOTICE, sdkp,
2247 				  "%llu %d-byte logical blocks: (%s/%s)\n",
2248 				  (unsigned long long)sdkp->capacity,
2249 				  sector_size, cap_str_10, cap_str_2);
2250 
2251 			if (sdkp->physical_block_size != sector_size)
2252 				sd_printk(KERN_NOTICE, sdkp,
2253 					  "%u-byte physical blocks\n",
2254 					  sdkp->physical_block_size);
2255 		}
2256 	}
2257 
2258 	if (sdkp->capacity > 0xffffffff) {
2259 		sdp->use_16_for_rw = 1;
2260 		sdkp->max_xfer_blocks = SD_MAX_XFER_BLOCKS;
2261 	} else
2262 		sdkp->max_xfer_blocks = SD_DEF_XFER_BLOCKS;
2263 
2264 	/* Rescale capacity to 512-byte units */
2265 	if (sector_size == 4096)
2266 		sdkp->capacity <<= 3;
2267 	else if (sector_size == 2048)
2268 		sdkp->capacity <<= 2;
2269 	else if (sector_size == 1024)
2270 		sdkp->capacity <<= 1;
2271 	else if (sector_size == 256)
2272 		sdkp->capacity >>= 1;
2273 
2274 	blk_queue_physical_block_size(sdp->request_queue,
2275 				      sdkp->physical_block_size);
2276 	sdkp->device->sector_size = sector_size;
2277 }
2278 
2279 /* called with buffer of length 512 */
2280 static inline int
2281 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
2282 		 unsigned char *buffer, int len, struct scsi_mode_data *data,
2283 		 struct scsi_sense_hdr *sshdr)
2284 {
2285 	return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
2286 			       SD_TIMEOUT, SD_MAX_RETRIES, data,
2287 			       sshdr);
2288 }
2289 
2290 /*
2291  * read write protect setting, if possible - called only in sd_revalidate_disk()
2292  * called with buffer of length SD_BUF_SIZE
2293  */
2294 static void
2295 sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
2296 {
2297 	int res;
2298 	struct scsi_device *sdp = sdkp->device;
2299 	struct scsi_mode_data data;
2300 	int old_wp = sdkp->write_prot;
2301 
2302 	set_disk_ro(sdkp->disk, 0);
2303 	if (sdp->skip_ms_page_3f) {
2304 		sd_first_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
2305 		return;
2306 	}
2307 
2308 	if (sdp->use_192_bytes_for_3f) {
2309 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
2310 	} else {
2311 		/*
2312 		 * First attempt: ask for all pages (0x3F), but only 4 bytes.
2313 		 * We have to start carefully: some devices hang if we ask
2314 		 * for more than is available.
2315 		 */
2316 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
2317 
2318 		/*
2319 		 * Second attempt: ask for page 0 When only page 0 is
2320 		 * implemented, a request for page 3F may return Sense Key
2321 		 * 5: Illegal Request, Sense Code 24: Invalid field in
2322 		 * CDB.
2323 		 */
2324 		if (!scsi_status_is_good(res))
2325 			res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
2326 
2327 		/*
2328 		 * Third attempt: ask 255 bytes, as we did earlier.
2329 		 */
2330 		if (!scsi_status_is_good(res))
2331 			res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
2332 					       &data, NULL);
2333 	}
2334 
2335 	if (!scsi_status_is_good(res)) {
2336 		sd_first_printk(KERN_WARNING, sdkp,
2337 			  "Test WP failed, assume Write Enabled\n");
2338 	} else {
2339 		sdkp->write_prot = ((data.device_specific & 0x80) != 0);
2340 		set_disk_ro(sdkp->disk, sdkp->write_prot);
2341 		if (sdkp->first_scan || old_wp != sdkp->write_prot) {
2342 			sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
2343 				  sdkp->write_prot ? "on" : "off");
2344 			sd_printk(KERN_DEBUG, sdkp,
2345 				  "Mode Sense: %02x %02x %02x %02x\n",
2346 				  buffer[0], buffer[1], buffer[2], buffer[3]);
2347 		}
2348 	}
2349 }
2350 
2351 /*
2352  * sd_read_cache_type - called only from sd_revalidate_disk()
2353  * called with buffer of length SD_BUF_SIZE
2354  */
2355 static void
2356 sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
2357 {
2358 	int len = 0, res;
2359 	struct scsi_device *sdp = sdkp->device;
2360 
2361 	int dbd;
2362 	int modepage;
2363 	int first_len;
2364 	struct scsi_mode_data data;
2365 	struct scsi_sense_hdr sshdr;
2366 	int old_wce = sdkp->WCE;
2367 	int old_rcd = sdkp->RCD;
2368 	int old_dpofua = sdkp->DPOFUA;
2369 
2370 
2371 	if (sdkp->cache_override)
2372 		return;
2373 
2374 	first_len = 4;
2375 	if (sdp->skip_ms_page_8) {
2376 		if (sdp->type == TYPE_RBC)
2377 			goto defaults;
2378 		else {
2379 			if (sdp->skip_ms_page_3f)
2380 				goto defaults;
2381 			modepage = 0x3F;
2382 			if (sdp->use_192_bytes_for_3f)
2383 				first_len = 192;
2384 			dbd = 0;
2385 		}
2386 	} else if (sdp->type == TYPE_RBC) {
2387 		modepage = 6;
2388 		dbd = 8;
2389 	} else {
2390 		modepage = 8;
2391 		dbd = 0;
2392 	}
2393 
2394 	/* cautiously ask */
2395 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, first_len,
2396 			&data, &sshdr);
2397 
2398 	if (!scsi_status_is_good(res))
2399 		goto bad_sense;
2400 
2401 	if (!data.header_length) {
2402 		modepage = 6;
2403 		first_len = 0;
2404 		sd_first_printk(KERN_ERR, sdkp,
2405 				"Missing header in MODE_SENSE response\n");
2406 	}
2407 
2408 	/* that went OK, now ask for the proper length */
2409 	len = data.length;
2410 
2411 	/*
2412 	 * We're only interested in the first three bytes, actually.
2413 	 * But the data cache page is defined for the first 20.
2414 	 */
2415 	if (len < 3)
2416 		goto bad_sense;
2417 	else if (len > SD_BUF_SIZE) {
2418 		sd_first_printk(KERN_NOTICE, sdkp, "Truncating mode parameter "
2419 			  "data from %d to %d bytes\n", len, SD_BUF_SIZE);
2420 		len = SD_BUF_SIZE;
2421 	}
2422 	if (modepage == 0x3F && sdp->use_192_bytes_for_3f)
2423 		len = 192;
2424 
2425 	/* Get the data */
2426 	if (len > first_len)
2427 		res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len,
2428 				&data, &sshdr);
2429 
2430 	if (scsi_status_is_good(res)) {
2431 		int offset = data.header_length + data.block_descriptor_length;
2432 
2433 		while (offset < len) {
2434 			u8 page_code = buffer[offset] & 0x3F;
2435 			u8 spf       = buffer[offset] & 0x40;
2436 
2437 			if (page_code == 8 || page_code == 6) {
2438 				/* We're interested only in the first 3 bytes.
2439 				 */
2440 				if (len - offset <= 2) {
2441 					sd_first_printk(KERN_ERR, sdkp,
2442 						"Incomplete mode parameter "
2443 							"data\n");
2444 					goto defaults;
2445 				} else {
2446 					modepage = page_code;
2447 					goto Page_found;
2448 				}
2449 			} else {
2450 				/* Go to the next page */
2451 				if (spf && len - offset > 3)
2452 					offset += 4 + (buffer[offset+2] << 8) +
2453 						buffer[offset+3];
2454 				else if (!spf && len - offset > 1)
2455 					offset += 2 + buffer[offset+1];
2456 				else {
2457 					sd_first_printk(KERN_ERR, sdkp,
2458 							"Incomplete mode "
2459 							"parameter data\n");
2460 					goto defaults;
2461 				}
2462 			}
2463 		}
2464 
2465 		sd_first_printk(KERN_ERR, sdkp, "No Caching mode page found\n");
2466 		goto defaults;
2467 
2468 	Page_found:
2469 		if (modepage == 8) {
2470 			sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
2471 			sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
2472 		} else {
2473 			sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
2474 			sdkp->RCD = 0;
2475 		}
2476 
2477 		sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
2478 		if (sdp->broken_fua) {
2479 			sd_first_printk(KERN_NOTICE, sdkp, "Disabling FUA\n");
2480 			sdkp->DPOFUA = 0;
2481 		} else if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
2482 			sd_first_printk(KERN_NOTICE, sdkp,
2483 				  "Uses READ/WRITE(6), disabling FUA\n");
2484 			sdkp->DPOFUA = 0;
2485 		}
2486 
2487 		/* No cache flush allowed for write protected devices */
2488 		if (sdkp->WCE && sdkp->write_prot)
2489 			sdkp->WCE = 0;
2490 
2491 		if (sdkp->first_scan || old_wce != sdkp->WCE ||
2492 		    old_rcd != sdkp->RCD || old_dpofua != sdkp->DPOFUA)
2493 			sd_printk(KERN_NOTICE, sdkp,
2494 				  "Write cache: %s, read cache: %s, %s\n",
2495 				  sdkp->WCE ? "enabled" : "disabled",
2496 				  sdkp->RCD ? "disabled" : "enabled",
2497 				  sdkp->DPOFUA ? "supports DPO and FUA"
2498 				  : "doesn't support DPO or FUA");
2499 
2500 		return;
2501 	}
2502 
2503 bad_sense:
2504 	if (scsi_sense_valid(&sshdr) &&
2505 	    sshdr.sense_key == ILLEGAL_REQUEST &&
2506 	    sshdr.asc == 0x24 && sshdr.ascq == 0x0)
2507 		/* Invalid field in CDB */
2508 		sd_first_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
2509 	else
2510 		sd_first_printk(KERN_ERR, sdkp,
2511 				"Asking for cache data failed\n");
2512 
2513 defaults:
2514 	if (sdp->wce_default_on) {
2515 		sd_first_printk(KERN_NOTICE, sdkp,
2516 				"Assuming drive cache: write back\n");
2517 		sdkp->WCE = 1;
2518 	} else {
2519 		sd_first_printk(KERN_ERR, sdkp,
2520 				"Assuming drive cache: write through\n");
2521 		sdkp->WCE = 0;
2522 	}
2523 	sdkp->RCD = 0;
2524 	sdkp->DPOFUA = 0;
2525 }
2526 
2527 /*
2528  * The ATO bit indicates whether the DIF application tag is available
2529  * for use by the operating system.
2530  */
2531 static void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
2532 {
2533 	int res, offset;
2534 	struct scsi_device *sdp = sdkp->device;
2535 	struct scsi_mode_data data;
2536 	struct scsi_sense_hdr sshdr;
2537 
2538 	if (sdp->type != TYPE_DISK)
2539 		return;
2540 
2541 	if (sdkp->protection_type == 0)
2542 		return;
2543 
2544 	res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
2545 			      SD_MAX_RETRIES, &data, &sshdr);
2546 
2547 	if (!scsi_status_is_good(res) || !data.header_length ||
2548 	    data.length < 6) {
2549 		sd_first_printk(KERN_WARNING, sdkp,
2550 			  "getting Control mode page failed, assume no ATO\n");
2551 
2552 		if (scsi_sense_valid(&sshdr))
2553 			sd_print_sense_hdr(sdkp, &sshdr);
2554 
2555 		return;
2556 	}
2557 
2558 	offset = data.header_length + data.block_descriptor_length;
2559 
2560 	if ((buffer[offset] & 0x3f) != 0x0a) {
2561 		sd_first_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
2562 		return;
2563 	}
2564 
2565 	if ((buffer[offset + 5] & 0x80) == 0)
2566 		return;
2567 
2568 	sdkp->ATO = 1;
2569 
2570 	return;
2571 }
2572 
2573 /**
2574  * sd_read_block_limits - Query disk device for preferred I/O sizes.
2575  * @disk: disk to query
2576  */
2577 static void sd_read_block_limits(struct scsi_disk *sdkp)
2578 {
2579 	unsigned int sector_sz = sdkp->device->sector_size;
2580 	const int vpd_len = 64;
2581 	u32 max_xfer_length;
2582 	unsigned char *buffer = kmalloc(vpd_len, GFP_KERNEL);
2583 
2584 	if (!buffer ||
2585 	    /* Block Limits VPD */
2586 	    scsi_get_vpd_page(sdkp->device, 0xb0, buffer, vpd_len))
2587 		goto out;
2588 
2589 	max_xfer_length = get_unaligned_be32(&buffer[8]);
2590 	if (max_xfer_length)
2591 		sdkp->max_xfer_blocks = max_xfer_length;
2592 
2593 	blk_queue_io_min(sdkp->disk->queue,
2594 			 get_unaligned_be16(&buffer[6]) * sector_sz);
2595 	blk_queue_io_opt(sdkp->disk->queue,
2596 			 get_unaligned_be32(&buffer[12]) * sector_sz);
2597 
2598 	if (buffer[3] == 0x3c) {
2599 		unsigned int lba_count, desc_count;
2600 
2601 		sdkp->max_ws_blocks = (u32)get_unaligned_be64(&buffer[36]);
2602 
2603 		if (!sdkp->lbpme)
2604 			goto out;
2605 
2606 		lba_count = get_unaligned_be32(&buffer[20]);
2607 		desc_count = get_unaligned_be32(&buffer[24]);
2608 
2609 		if (lba_count && desc_count)
2610 			sdkp->max_unmap_blocks = lba_count;
2611 
2612 		sdkp->unmap_granularity = get_unaligned_be32(&buffer[28]);
2613 
2614 		if (buffer[32] & 0x80)
2615 			sdkp->unmap_alignment =
2616 				get_unaligned_be32(&buffer[32]) & ~(1 << 31);
2617 
2618 		if (!sdkp->lbpvpd) { /* LBP VPD page not provided */
2619 
2620 			if (sdkp->max_unmap_blocks)
2621 				sd_config_discard(sdkp, SD_LBP_UNMAP);
2622 			else
2623 				sd_config_discard(sdkp, SD_LBP_WS16);
2624 
2625 		} else {	/* LBP VPD page tells us what to use */
2626 			if (sdkp->lbpu && sdkp->max_unmap_blocks && !sdkp->lbprz)
2627 				sd_config_discard(sdkp, SD_LBP_UNMAP);
2628 			else if (sdkp->lbpws)
2629 				sd_config_discard(sdkp, SD_LBP_WS16);
2630 			else if (sdkp->lbpws10)
2631 				sd_config_discard(sdkp, SD_LBP_WS10);
2632 			else if (sdkp->lbpu && sdkp->max_unmap_blocks)
2633 				sd_config_discard(sdkp, SD_LBP_UNMAP);
2634 			else
2635 				sd_config_discard(sdkp, SD_LBP_DISABLE);
2636 		}
2637 	}
2638 
2639  out:
2640 	kfree(buffer);
2641 }
2642 
2643 /**
2644  * sd_read_block_characteristics - Query block dev. characteristics
2645  * @disk: disk to query
2646  */
2647 static void sd_read_block_characteristics(struct scsi_disk *sdkp)
2648 {
2649 	unsigned char *buffer;
2650 	u16 rot;
2651 	const int vpd_len = 64;
2652 
2653 	buffer = kmalloc(vpd_len, GFP_KERNEL);
2654 
2655 	if (!buffer ||
2656 	    /* Block Device Characteristics VPD */
2657 	    scsi_get_vpd_page(sdkp->device, 0xb1, buffer, vpd_len))
2658 		goto out;
2659 
2660 	rot = get_unaligned_be16(&buffer[4]);
2661 
2662 	if (rot == 1) {
2663 		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, sdkp->disk->queue);
2664 		queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, sdkp->disk->queue);
2665 	}
2666 
2667  out:
2668 	kfree(buffer);
2669 }
2670 
2671 /**
2672  * sd_read_block_provisioning - Query provisioning VPD page
2673  * @disk: disk to query
2674  */
2675 static void sd_read_block_provisioning(struct scsi_disk *sdkp)
2676 {
2677 	unsigned char *buffer;
2678 	const int vpd_len = 8;
2679 
2680 	if (sdkp->lbpme == 0)
2681 		return;
2682 
2683 	buffer = kmalloc(vpd_len, GFP_KERNEL);
2684 
2685 	if (!buffer || scsi_get_vpd_page(sdkp->device, 0xb2, buffer, vpd_len))
2686 		goto out;
2687 
2688 	sdkp->lbpvpd	= 1;
2689 	sdkp->lbpu	= (buffer[5] >> 7) & 1;	/* UNMAP */
2690 	sdkp->lbpws	= (buffer[5] >> 6) & 1;	/* WRITE SAME(16) with UNMAP */
2691 	sdkp->lbpws10	= (buffer[5] >> 5) & 1;	/* WRITE SAME(10) with UNMAP */
2692 
2693  out:
2694 	kfree(buffer);
2695 }
2696 
2697 static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
2698 {
2699 	struct scsi_device *sdev = sdkp->device;
2700 
2701 	if (sdev->host->no_write_same) {
2702 		sdev->no_write_same = 1;
2703 
2704 		return;
2705 	}
2706 
2707 	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY) < 0) {
2708 		/* too large values might cause issues with arcmsr */
2709 		int vpd_buf_len = 64;
2710 
2711 		sdev->no_report_opcodes = 1;
2712 
2713 		/* Disable WRITE SAME if REPORT SUPPORTED OPERATION
2714 		 * CODES is unsupported and the device has an ATA
2715 		 * Information VPD page (SAT).
2716 		 */
2717 		if (!scsi_get_vpd_page(sdev, 0x89, buffer, vpd_buf_len))
2718 			sdev->no_write_same = 1;
2719 	}
2720 
2721 	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME_16) == 1)
2722 		sdkp->ws16 = 1;
2723 
2724 	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME) == 1)
2725 		sdkp->ws10 = 1;
2726 }
2727 
2728 static int sd_try_extended_inquiry(struct scsi_device *sdp)
2729 {
2730 	/* Attempt VPD inquiry if the device blacklist explicitly calls
2731 	 * for it.
2732 	 */
2733 	if (sdp->try_vpd_pages)
2734 		return 1;
2735 	/*
2736 	 * Although VPD inquiries can go to SCSI-2 type devices,
2737 	 * some USB ones crash on receiving them, and the pages
2738 	 * we currently ask for are for SPC-3 and beyond
2739 	 */
2740 	if (sdp->scsi_level > SCSI_SPC_2 && !sdp->skip_vpd_pages)
2741 		return 1;
2742 	return 0;
2743 }
2744 
2745 /**
2746  *	sd_revalidate_disk - called the first time a new disk is seen,
2747  *	performs disk spin up, read_capacity, etc.
2748  *	@disk: struct gendisk we care about
2749  **/
2750 static int sd_revalidate_disk(struct gendisk *disk)
2751 {
2752 	struct scsi_disk *sdkp = scsi_disk(disk);
2753 	struct scsi_device *sdp = sdkp->device;
2754 	unsigned char *buffer;
2755 	unsigned int max_xfer;
2756 
2757 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
2758 				      "sd_revalidate_disk\n"));
2759 
2760 	/*
2761 	 * If the device is offline, don't try and read capacity or any
2762 	 * of the other niceties.
2763 	 */
2764 	if (!scsi_device_online(sdp))
2765 		goto out;
2766 
2767 	buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
2768 	if (!buffer) {
2769 		sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
2770 			  "allocation failure.\n");
2771 		goto out;
2772 	}
2773 
2774 	sd_spinup_disk(sdkp);
2775 
2776 	/*
2777 	 * Without media there is no reason to ask; moreover, some devices
2778 	 * react badly if we do.
2779 	 */
2780 	if (sdkp->media_present) {
2781 		sd_read_capacity(sdkp, buffer);
2782 
2783 		if (sd_try_extended_inquiry(sdp)) {
2784 			sd_read_block_provisioning(sdkp);
2785 			sd_read_block_limits(sdkp);
2786 			sd_read_block_characteristics(sdkp);
2787 		}
2788 
2789 		sd_read_write_protect_flag(sdkp, buffer);
2790 		sd_read_cache_type(sdkp, buffer);
2791 		sd_read_app_tag_own(sdkp, buffer);
2792 		sd_read_write_same(sdkp, buffer);
2793 	}
2794 
2795 	sdkp->first_scan = 0;
2796 
2797 	/*
2798 	 * We now have all cache related info, determine how we deal
2799 	 * with flush requests.
2800 	 */
2801 	sd_set_flush_flag(sdkp);
2802 
2803 	max_xfer = sdkp->max_xfer_blocks;
2804 	max_xfer <<= ilog2(sdp->sector_size) - 9;
2805 
2806 	max_xfer = min_not_zero(queue_max_hw_sectors(sdkp->disk->queue),
2807 				max_xfer);
2808 	blk_queue_max_hw_sectors(sdkp->disk->queue, max_xfer);
2809 	set_capacity(disk, sdkp->capacity);
2810 	sd_config_write_same(sdkp);
2811 	kfree(buffer);
2812 
2813  out:
2814 	return 0;
2815 }
2816 
2817 /**
2818  *	sd_unlock_native_capacity - unlock native capacity
2819  *	@disk: struct gendisk to set capacity for
2820  *
2821  *	Block layer calls this function if it detects that partitions
2822  *	on @disk reach beyond the end of the device.  If the SCSI host
2823  *	implements ->unlock_native_capacity() method, it's invoked to
2824  *	give it a chance to adjust the device capacity.
2825  *
2826  *	CONTEXT:
2827  *	Defined by block layer.  Might sleep.
2828  */
2829 static void sd_unlock_native_capacity(struct gendisk *disk)
2830 {
2831 	struct scsi_device *sdev = scsi_disk(disk)->device;
2832 
2833 	if (sdev->host->hostt->unlock_native_capacity)
2834 		sdev->host->hostt->unlock_native_capacity(sdev);
2835 }
2836 
2837 /**
2838  *	sd_format_disk_name - format disk name
2839  *	@prefix: name prefix - ie. "sd" for SCSI disks
2840  *	@index: index of the disk to format name for
2841  *	@buf: output buffer
2842  *	@buflen: length of the output buffer
2843  *
2844  *	SCSI disk names starts at sda.  The 26th device is sdz and the
2845  *	27th is sdaa.  The last one for two lettered suffix is sdzz
2846  *	which is followed by sdaaa.
2847  *
2848  *	This is basically 26 base counting with one extra 'nil' entry
2849  *	at the beginning from the second digit on and can be
2850  *	determined using similar method as 26 base conversion with the
2851  *	index shifted -1 after each digit is computed.
2852  *
2853  *	CONTEXT:
2854  *	Don't care.
2855  *
2856  *	RETURNS:
2857  *	0 on success, -errno on failure.
2858  */
2859 static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
2860 {
2861 	const int base = 'z' - 'a' + 1;
2862 	char *begin = buf + strlen(prefix);
2863 	char *end = buf + buflen;
2864 	char *p;
2865 	int unit;
2866 
2867 	p = end - 1;
2868 	*p = '\0';
2869 	unit = base;
2870 	do {
2871 		if (p == begin)
2872 			return -EINVAL;
2873 		*--p = 'a' + (index % unit);
2874 		index = (index / unit) - 1;
2875 	} while (index >= 0);
2876 
2877 	memmove(begin, p, end - p);
2878 	memcpy(buf, prefix, strlen(prefix));
2879 
2880 	return 0;
2881 }
2882 
2883 /*
2884  * The asynchronous part of sd_probe
2885  */
2886 static void sd_probe_async(void *data, async_cookie_t cookie)
2887 {
2888 	struct scsi_disk *sdkp = data;
2889 	struct scsi_device *sdp;
2890 	struct gendisk *gd;
2891 	u32 index;
2892 	struct device *dev;
2893 
2894 	sdp = sdkp->device;
2895 	gd = sdkp->disk;
2896 	index = sdkp->index;
2897 	dev = &sdp->sdev_gendev;
2898 
2899 	gd->major = sd_major((index & 0xf0) >> 4);
2900 	gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
2901 	gd->minors = SD_MINORS;
2902 
2903 	gd->fops = &sd_fops;
2904 	gd->private_data = &sdkp->driver;
2905 	gd->queue = sdkp->device->request_queue;
2906 
2907 	/* defaults, until the device tells us otherwise */
2908 	sdp->sector_size = 512;
2909 	sdkp->capacity = 0;
2910 	sdkp->media_present = 1;
2911 	sdkp->write_prot = 0;
2912 	sdkp->cache_override = 0;
2913 	sdkp->WCE = 0;
2914 	sdkp->RCD = 0;
2915 	sdkp->ATO = 0;
2916 	sdkp->first_scan = 1;
2917 	sdkp->max_medium_access_timeouts = SD_MAX_MEDIUM_TIMEOUTS;
2918 
2919 	sd_revalidate_disk(gd);
2920 
2921 	gd->driverfs_dev = &sdp->sdev_gendev;
2922 	gd->flags = GENHD_FL_EXT_DEVT;
2923 	if (sdp->removable) {
2924 		gd->flags |= GENHD_FL_REMOVABLE;
2925 		gd->events |= DISK_EVENT_MEDIA_CHANGE;
2926 	}
2927 
2928 	blk_pm_runtime_init(sdp->request_queue, dev);
2929 	add_disk(gd);
2930 	if (sdkp->capacity)
2931 		sd_dif_config_host(sdkp);
2932 
2933 	sd_revalidate_disk(gd);
2934 
2935 	sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
2936 		  sdp->removable ? "removable " : "");
2937 	scsi_autopm_put_device(sdp);
2938 	put_device(&sdkp->dev);
2939 }
2940 
2941 /**
2942  *	sd_probe - called during driver initialization and whenever a
2943  *	new scsi device is attached to the system. It is called once
2944  *	for each scsi device (not just disks) present.
2945  *	@dev: pointer to device object
2946  *
2947  *	Returns 0 if successful (or not interested in this scsi device
2948  *	(e.g. scanner)); 1 when there is an error.
2949  *
2950  *	Note: this function is invoked from the scsi mid-level.
2951  *	This function sets up the mapping between a given
2952  *	<host,channel,id,lun> (found in sdp) and new device name
2953  *	(e.g. /dev/sda). More precisely it is the block device major
2954  *	and minor number that is chosen here.
2955  *
2956  *	Assume sd_probe is not re-entrant (for time being)
2957  *	Also think about sd_probe() and sd_remove() running coincidentally.
2958  **/
2959 static int sd_probe(struct device *dev)
2960 {
2961 	struct scsi_device *sdp = to_scsi_device(dev);
2962 	struct scsi_disk *sdkp;
2963 	struct gendisk *gd;
2964 	int index;
2965 	int error;
2966 
2967 	scsi_autopm_get_device(sdp);
2968 	error = -ENODEV;
2969 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
2970 		goto out;
2971 
2972 	SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
2973 					"sd_probe\n"));
2974 
2975 	error = -ENOMEM;
2976 	sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
2977 	if (!sdkp)
2978 		goto out;
2979 
2980 	gd = alloc_disk(SD_MINORS);
2981 	if (!gd)
2982 		goto out_free;
2983 
2984 	do {
2985 		if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
2986 			goto out_put;
2987 
2988 		spin_lock(&sd_index_lock);
2989 		error = ida_get_new(&sd_index_ida, &index);
2990 		spin_unlock(&sd_index_lock);
2991 	} while (error == -EAGAIN);
2992 
2993 	if (error) {
2994 		sdev_printk(KERN_WARNING, sdp, "sd_probe: memory exhausted.\n");
2995 		goto out_put;
2996 	}
2997 
2998 	error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
2999 	if (error) {
3000 		sdev_printk(KERN_WARNING, sdp, "SCSI disk (sd) name length exceeded.\n");
3001 		goto out_free_index;
3002 	}
3003 
3004 	sdkp->device = sdp;
3005 	sdkp->driver = &sd_template;
3006 	sdkp->disk = gd;
3007 	sdkp->index = index;
3008 	atomic_set(&sdkp->openers, 0);
3009 	atomic_set(&sdkp->device->ioerr_cnt, 0);
3010 
3011 	if (!sdp->request_queue->rq_timeout) {
3012 		if (sdp->type != TYPE_MOD)
3013 			blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
3014 		else
3015 			blk_queue_rq_timeout(sdp->request_queue,
3016 					     SD_MOD_TIMEOUT);
3017 	}
3018 
3019 	device_initialize(&sdkp->dev);
3020 	sdkp->dev.parent = dev;
3021 	sdkp->dev.class = &sd_disk_class;
3022 	dev_set_name(&sdkp->dev, "%s", dev_name(dev));
3023 
3024 	if (device_add(&sdkp->dev))
3025 		goto out_free_index;
3026 
3027 	get_device(dev);
3028 	dev_set_drvdata(dev, sdkp);
3029 
3030 	get_device(&sdkp->dev);	/* prevent release before async_schedule */
3031 	async_schedule_domain(sd_probe_async, sdkp, &scsi_sd_probe_domain);
3032 
3033 	return 0;
3034 
3035  out_free_index:
3036 	spin_lock(&sd_index_lock);
3037 	ida_remove(&sd_index_ida, index);
3038 	spin_unlock(&sd_index_lock);
3039  out_put:
3040 	put_disk(gd);
3041  out_free:
3042 	kfree(sdkp);
3043  out:
3044 	scsi_autopm_put_device(sdp);
3045 	return error;
3046 }
3047 
3048 /**
3049  *	sd_remove - called whenever a scsi disk (previously recognized by
3050  *	sd_probe) is detached from the system. It is called (potentially
3051  *	multiple times) during sd module unload.
3052  *	@sdp: pointer to mid level scsi device object
3053  *
3054  *	Note: this function is invoked from the scsi mid-level.
3055  *	This function potentially frees up a device name (e.g. /dev/sdc)
3056  *	that could be re-used by a subsequent sd_probe().
3057  *	This function is not called when the built-in sd driver is "exit-ed".
3058  **/
3059 static int sd_remove(struct device *dev)
3060 {
3061 	struct scsi_disk *sdkp;
3062 	dev_t devt;
3063 
3064 	sdkp = dev_get_drvdata(dev);
3065 	devt = disk_devt(sdkp->disk);
3066 	scsi_autopm_get_device(sdkp->device);
3067 
3068 	async_synchronize_full_domain(&scsi_sd_pm_domain);
3069 	async_synchronize_full_domain(&scsi_sd_probe_domain);
3070 	device_del(&sdkp->dev);
3071 	del_gendisk(sdkp->disk);
3072 	sd_shutdown(dev);
3073 
3074 	blk_register_region(devt, SD_MINORS, NULL,
3075 			    sd_default_probe, NULL, NULL);
3076 
3077 	mutex_lock(&sd_ref_mutex);
3078 	dev_set_drvdata(dev, NULL);
3079 	put_device(&sdkp->dev);
3080 	mutex_unlock(&sd_ref_mutex);
3081 
3082 	return 0;
3083 }
3084 
3085 /**
3086  *	scsi_disk_release - Called to free the scsi_disk structure
3087  *	@dev: pointer to embedded class device
3088  *
3089  *	sd_ref_mutex must be held entering this routine.  Because it is
3090  *	called on last put, you should always use the scsi_disk_get()
3091  *	scsi_disk_put() helpers which manipulate the semaphore directly
3092  *	and never do a direct put_device.
3093  **/
3094 static void scsi_disk_release(struct device *dev)
3095 {
3096 	struct scsi_disk *sdkp = to_scsi_disk(dev);
3097 	struct gendisk *disk = sdkp->disk;
3098 
3099 	spin_lock(&sd_index_lock);
3100 	ida_remove(&sd_index_ida, sdkp->index);
3101 	spin_unlock(&sd_index_lock);
3102 
3103 	disk->private_data = NULL;
3104 	put_disk(disk);
3105 	put_device(&sdkp->device->sdev_gendev);
3106 
3107 	kfree(sdkp);
3108 }
3109 
3110 static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
3111 {
3112 	unsigned char cmd[6] = { START_STOP };	/* START_VALID */
3113 	struct scsi_sense_hdr sshdr;
3114 	struct scsi_device *sdp = sdkp->device;
3115 	int res;
3116 
3117 	if (start)
3118 		cmd[4] |= 1;	/* START */
3119 
3120 	if (sdp->start_stop_pwr_cond)
3121 		cmd[4] |= start ? 1 << 4 : 3 << 4;	/* Active or Standby */
3122 
3123 	if (!scsi_device_online(sdp))
3124 		return -ENODEV;
3125 
3126 	res = scsi_execute_req_flags(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
3127 			       SD_TIMEOUT, SD_MAX_RETRIES, NULL, REQ_PM);
3128 	if (res) {
3129 		sd_print_result(sdkp, "Start/Stop Unit failed", res);
3130 		if (driver_byte(res) & DRIVER_SENSE)
3131 			sd_print_sense_hdr(sdkp, &sshdr);
3132 		if (scsi_sense_valid(&sshdr) &&
3133 			/* 0x3a is medium not present */
3134 			sshdr.asc == 0x3a)
3135 			res = 0;
3136 	}
3137 
3138 	/* SCSI error codes must not go to the generic layer */
3139 	if (res)
3140 		return -EIO;
3141 
3142 	return 0;
3143 }
3144 
3145 /*
3146  * Send a SYNCHRONIZE CACHE instruction down to the device through
3147  * the normal SCSI command structure.  Wait for the command to
3148  * complete.
3149  */
3150 static void sd_shutdown(struct device *dev)
3151 {
3152 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
3153 
3154 	if (!sdkp)
3155 		return;         /* this can happen */
3156 
3157 	if (pm_runtime_suspended(dev))
3158 		goto exit;
3159 
3160 	if (sdkp->WCE && sdkp->media_present) {
3161 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
3162 		sd_sync_cache(sdkp);
3163 	}
3164 
3165 	if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
3166 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
3167 		sd_start_stop_device(sdkp, 0);
3168 	}
3169 
3170 exit:
3171 	scsi_disk_put(sdkp);
3172 }
3173 
3174 static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)
3175 {
3176 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
3177 	int ret = 0;
3178 
3179 	if (!sdkp)
3180 		return 0;	/* this can happen */
3181 
3182 	if (sdkp->WCE && sdkp->media_present) {
3183 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
3184 		ret = sd_sync_cache(sdkp);
3185 		if (ret) {
3186 			/* ignore OFFLINE device */
3187 			if (ret == -ENODEV)
3188 				ret = 0;
3189 			goto done;
3190 		}
3191 	}
3192 
3193 	if (sdkp->device->manage_start_stop) {
3194 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
3195 		/* an error is not worth aborting a system sleep */
3196 		ret = sd_start_stop_device(sdkp, 0);
3197 		if (ignore_stop_errors)
3198 			ret = 0;
3199 	}
3200 
3201 done:
3202 	scsi_disk_put(sdkp);
3203 	return ret;
3204 }
3205 
3206 static int sd_suspend_system(struct device *dev)
3207 {
3208 	return sd_suspend_common(dev, true);
3209 }
3210 
3211 static int sd_suspend_runtime(struct device *dev)
3212 {
3213 	return sd_suspend_common(dev, false);
3214 }
3215 
3216 static int sd_resume(struct device *dev)
3217 {
3218 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
3219 	int ret = 0;
3220 
3221 	if (!sdkp->device->manage_start_stop)
3222 		goto done;
3223 
3224 	sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
3225 	ret = sd_start_stop_device(sdkp, 1);
3226 
3227 done:
3228 	scsi_disk_put(sdkp);
3229 	return ret;
3230 }
3231 
3232 /**
3233  *	init_sd - entry point for this driver (both when built in or when
3234  *	a module).
3235  *
3236  *	Note: this function registers this driver with the scsi mid-level.
3237  **/
3238 static int __init init_sd(void)
3239 {
3240 	int majors = 0, i, err;
3241 
3242 	SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
3243 
3244 	for (i = 0; i < SD_MAJORS; i++) {
3245 		if (register_blkdev(sd_major(i), "sd") != 0)
3246 			continue;
3247 		majors++;
3248 		blk_register_region(sd_major(i), SD_MINORS, NULL,
3249 				    sd_default_probe, NULL, NULL);
3250 	}
3251 
3252 	if (!majors)
3253 		return -ENODEV;
3254 
3255 	err = class_register(&sd_disk_class);
3256 	if (err)
3257 		goto err_out;
3258 
3259 	sd_cdb_cache = kmem_cache_create("sd_ext_cdb", SD_EXT_CDB_SIZE,
3260 					 0, 0, NULL);
3261 	if (!sd_cdb_cache) {
3262 		printk(KERN_ERR "sd: can't init extended cdb cache\n");
3263 		err = -ENOMEM;
3264 		goto err_out_class;
3265 	}
3266 
3267 	sd_cdb_pool = mempool_create_slab_pool(SD_MEMPOOL_SIZE, sd_cdb_cache);
3268 	if (!sd_cdb_pool) {
3269 		printk(KERN_ERR "sd: can't init extended cdb pool\n");
3270 		err = -ENOMEM;
3271 		goto err_out_cache;
3272 	}
3273 
3274 	err = scsi_register_driver(&sd_template.gendrv);
3275 	if (err)
3276 		goto err_out_driver;
3277 
3278 	return 0;
3279 
3280 err_out_driver:
3281 	mempool_destroy(sd_cdb_pool);
3282 
3283 err_out_cache:
3284 	kmem_cache_destroy(sd_cdb_cache);
3285 
3286 err_out_class:
3287 	class_unregister(&sd_disk_class);
3288 err_out:
3289 	for (i = 0; i < SD_MAJORS; i++)
3290 		unregister_blkdev(sd_major(i), "sd");
3291 	return err;
3292 }
3293 
3294 /**
3295  *	exit_sd - exit point for this driver (when it is a module).
3296  *
3297  *	Note: this function unregisters this driver from the scsi mid-level.
3298  **/
3299 static void __exit exit_sd(void)
3300 {
3301 	int i;
3302 
3303 	SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
3304 
3305 	scsi_unregister_driver(&sd_template.gendrv);
3306 	mempool_destroy(sd_cdb_pool);
3307 	kmem_cache_destroy(sd_cdb_cache);
3308 
3309 	class_unregister(&sd_disk_class);
3310 
3311 	for (i = 0; i < SD_MAJORS; i++) {
3312 		blk_unregister_region(sd_major(i), SD_MINORS);
3313 		unregister_blkdev(sd_major(i), "sd");
3314 	}
3315 }
3316 
3317 module_init(init_sd);
3318 module_exit(exit_sd);
3319 
3320 static void sd_print_sense_hdr(struct scsi_disk *sdkp,
3321 			       struct scsi_sense_hdr *sshdr)
3322 {
3323 	scsi_print_sense_hdr(sdkp->device,
3324 			     sdkp->disk ? sdkp->disk->disk_name : NULL, sshdr);
3325 }
3326 
3327 static void sd_print_result(const struct scsi_disk *sdkp, const char *msg,
3328 			    int result)
3329 {
3330 	const char *hb_string = scsi_hostbyte_string(result);
3331 	const char *db_string = scsi_driverbyte_string(result);
3332 
3333 	if (hb_string || db_string)
3334 		sd_printk(KERN_INFO, sdkp,
3335 			  "%s: Result: hostbyte=%s driverbyte=%s\n", msg,
3336 			  hb_string ? hb_string : "invalid",
3337 			  db_string ? db_string : "invalid");
3338 	else
3339 		sd_printk(KERN_INFO, sdkp,
3340 			  "%s: Result: hostbyte=0x%02x driverbyte=0x%02x\n",
3341 			  msg, host_byte(result), driver_byte(result));
3342 }
3343 
3344