xref: /openbmc/linux/drivers/scsi/sd.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 <asm/uaccess.h>
51 
52 #include <scsi/scsi.h>
53 #include <scsi/scsi_cmnd.h>
54 #include <scsi/scsi_dbg.h>
55 #include <scsi/scsi_device.h>
56 #include <scsi/scsi_driver.h>
57 #include <scsi/scsi_eh.h>
58 #include <scsi/scsi_host.h>
59 #include <scsi/scsi_ioctl.h>
60 #include <scsi/scsicam.h>
61 #include <scsi/sd.h>
62 
63 #include "scsi_logging.h"
64 
65 MODULE_AUTHOR("Eric Youngdale");
66 MODULE_DESCRIPTION("SCSI disk (sd) driver");
67 MODULE_LICENSE("GPL");
68 
69 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK0_MAJOR);
70 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK1_MAJOR);
71 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK2_MAJOR);
72 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK3_MAJOR);
73 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK4_MAJOR);
74 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK5_MAJOR);
75 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK6_MAJOR);
76 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK7_MAJOR);
77 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK8_MAJOR);
78 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK9_MAJOR);
79 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK10_MAJOR);
80 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK11_MAJOR);
81 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK12_MAJOR);
82 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK13_MAJOR);
83 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK14_MAJOR);
84 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
85 MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
86 MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
87 MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
88 
89 static DEFINE_IDR(sd_index_idr);
90 static DEFINE_SPINLOCK(sd_index_lock);
91 
92 /* This semaphore is used to mediate the 0->1 reference get in the
93  * face of object destruction (i.e. we can't allow a get on an
94  * object after last put) */
95 static DEFINE_MUTEX(sd_ref_mutex);
96 
97 static const char *sd_cache_types[] = {
98 	"write through", "none", "write back",
99 	"write back, no read (daft)"
100 };
101 
102 static ssize_t sd_store_cache_type(struct class_device *cdev, const char *buf,
103 				   size_t count)
104 {
105 	int i, ct = -1, rcd, wce, sp;
106 	struct scsi_disk *sdkp = to_scsi_disk(cdev);
107 	struct scsi_device *sdp = sdkp->device;
108 	char buffer[64];
109 	char *buffer_data;
110 	struct scsi_mode_data data;
111 	struct scsi_sense_hdr sshdr;
112 	int len;
113 
114 	if (sdp->type != TYPE_DISK)
115 		/* no cache control on RBC devices; theoretically they
116 		 * can do it, but there's probably so many exceptions
117 		 * it's not worth the risk */
118 		return -EINVAL;
119 
120 	for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {
121 		const int len = strlen(sd_cache_types[i]);
122 		if (strncmp(sd_cache_types[i], buf, len) == 0 &&
123 		    buf[len] == '\n') {
124 			ct = i;
125 			break;
126 		}
127 	}
128 	if (ct < 0)
129 		return -EINVAL;
130 	rcd = ct & 0x01 ? 1 : 0;
131 	wce = ct & 0x02 ? 1 : 0;
132 	if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
133 			    SD_MAX_RETRIES, &data, NULL))
134 		return -EINVAL;
135 	len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
136 		  data.block_descriptor_length);
137 	buffer_data = buffer + data.header_length +
138 		data.block_descriptor_length;
139 	buffer_data[2] &= ~0x05;
140 	buffer_data[2] |= wce << 2 | rcd;
141 	sp = buffer_data[0] & 0x80 ? 1 : 0;
142 
143 	if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
144 			     SD_MAX_RETRIES, &data, &sshdr)) {
145 		if (scsi_sense_valid(&sshdr))
146 			sd_print_sense_hdr(sdkp, &sshdr);
147 		return -EINVAL;
148 	}
149 	sd_revalidate_disk(sdkp->disk);
150 	return count;
151 }
152 
153 static ssize_t sd_store_manage_start_stop(struct class_device *cdev,
154 					  const char *buf, size_t count)
155 {
156 	struct scsi_disk *sdkp = to_scsi_disk(cdev);
157 	struct scsi_device *sdp = sdkp->device;
158 
159 	if (!capable(CAP_SYS_ADMIN))
160 		return -EACCES;
161 
162 	sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
163 
164 	return count;
165 }
166 
167 static ssize_t sd_store_allow_restart(struct class_device *cdev, const char *buf,
168 				      size_t count)
169 {
170 	struct scsi_disk *sdkp = to_scsi_disk(cdev);
171 	struct scsi_device *sdp = sdkp->device;
172 
173 	if (!capable(CAP_SYS_ADMIN))
174 		return -EACCES;
175 
176 	if (sdp->type != TYPE_DISK)
177 		return -EINVAL;
178 
179 	sdp->allow_restart = simple_strtoul(buf, NULL, 10);
180 
181 	return count;
182 }
183 
184 static ssize_t sd_show_cache_type(struct class_device *cdev, char *buf)
185 {
186 	struct scsi_disk *sdkp = to_scsi_disk(cdev);
187 	int ct = sdkp->RCD + 2*sdkp->WCE;
188 
189 	return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
190 }
191 
192 static ssize_t sd_show_fua(struct class_device *cdev, char *buf)
193 {
194 	struct scsi_disk *sdkp = to_scsi_disk(cdev);
195 
196 	return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
197 }
198 
199 static ssize_t sd_show_manage_start_stop(struct class_device *cdev, char *buf)
200 {
201 	struct scsi_disk *sdkp = to_scsi_disk(cdev);
202 	struct scsi_device *sdp = sdkp->device;
203 
204 	return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
205 }
206 
207 static ssize_t sd_show_allow_restart(struct class_device *cdev, char *buf)
208 {
209 	struct scsi_disk *sdkp = to_scsi_disk(cdev);
210 
211 	return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
212 }
213 
214 static struct class_device_attribute sd_disk_attrs[] = {
215 	__ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
216 	       sd_store_cache_type),
217 	__ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
218 	__ATTR(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
219 	       sd_store_allow_restart),
220 	__ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
221 	       sd_store_manage_start_stop),
222 	__ATTR_NULL,
223 };
224 
225 static struct class sd_disk_class = {
226 	.name		= "scsi_disk",
227 	.owner		= THIS_MODULE,
228 	.release	= scsi_disk_release,
229 	.class_dev_attrs = sd_disk_attrs,
230 };
231 
232 static struct scsi_driver sd_template = {
233 	.owner			= THIS_MODULE,
234 	.gendrv = {
235 		.name		= "sd",
236 		.probe		= sd_probe,
237 		.remove		= sd_remove,
238 		.suspend	= sd_suspend,
239 		.resume		= sd_resume,
240 		.shutdown	= sd_shutdown,
241 	},
242 	.rescan			= sd_rescan,
243 	.init_command		= sd_init_command,
244 	.issue_flush		= sd_issue_flush,
245 };
246 
247 /*
248  * Device no to disk mapping:
249  *
250  *       major         disc2     disc  p1
251  *   |............|.............|....|....| <- dev_t
252  *    31        20 19          8 7  4 3  0
253  *
254  * Inside a major, we have 16k disks, however mapped non-
255  * contiguously. The first 16 disks are for major0, the next
256  * ones with major1, ... Disk 256 is for major0 again, disk 272
257  * for major1, ...
258  * As we stay compatible with our numbering scheme, we can reuse
259  * the well-know SCSI majors 8, 65--71, 136--143.
260  */
261 static int sd_major(int major_idx)
262 {
263 	switch (major_idx) {
264 	case 0:
265 		return SCSI_DISK0_MAJOR;
266 	case 1 ... 7:
267 		return SCSI_DISK1_MAJOR + major_idx - 1;
268 	case 8 ... 15:
269 		return SCSI_DISK8_MAJOR + major_idx - 8;
270 	default:
271 		BUG();
272 		return 0;	/* shut up gcc */
273 	}
274 }
275 
276 static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
277 {
278 	return container_of(disk->private_data, struct scsi_disk, driver);
279 }
280 
281 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
282 {
283 	struct scsi_disk *sdkp = NULL;
284 
285 	if (disk->private_data) {
286 		sdkp = scsi_disk(disk);
287 		if (scsi_device_get(sdkp->device) == 0)
288 			class_device_get(&sdkp->cdev);
289 		else
290 			sdkp = NULL;
291 	}
292 	return sdkp;
293 }
294 
295 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
296 {
297 	struct scsi_disk *sdkp;
298 
299 	mutex_lock(&sd_ref_mutex);
300 	sdkp = __scsi_disk_get(disk);
301 	mutex_unlock(&sd_ref_mutex);
302 	return sdkp;
303 }
304 
305 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
306 {
307 	struct scsi_disk *sdkp;
308 
309 	mutex_lock(&sd_ref_mutex);
310 	sdkp = dev_get_drvdata(dev);
311 	if (sdkp)
312 		sdkp = __scsi_disk_get(sdkp->disk);
313 	mutex_unlock(&sd_ref_mutex);
314 	return sdkp;
315 }
316 
317 static void scsi_disk_put(struct scsi_disk *sdkp)
318 {
319 	struct scsi_device *sdev = sdkp->device;
320 
321 	mutex_lock(&sd_ref_mutex);
322 	class_device_put(&sdkp->cdev);
323 	scsi_device_put(sdev);
324 	mutex_unlock(&sd_ref_mutex);
325 }
326 
327 /**
328  *	sd_init_command - build a scsi (read or write) command from
329  *	information in the request structure.
330  *	@SCpnt: pointer to mid-level's per scsi command structure that
331  *	contains request and into which the scsi command is written
332  *
333  *	Returns 1 if successful and 0 if error (or cannot be done now).
334  **/
335 static int sd_init_command(struct scsi_cmnd * SCpnt)
336 {
337 	struct scsi_device *sdp = SCpnt->device;
338 	struct request *rq = SCpnt->request;
339 	struct gendisk *disk = rq->rq_disk;
340 	sector_t block = rq->sector;
341 	unsigned int this_count = SCpnt->request_bufflen >> 9;
342 	unsigned int timeout = sdp->timeout;
343 
344 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
345 					"sd_init_command: block=%llu, "
346 					"count=%d\n",
347 					(unsigned long long)block,
348 					this_count));
349 
350 	if (!sdp || !scsi_device_online(sdp) ||
351  	    block + rq->nr_sectors > get_capacity(disk)) {
352 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
353 						"Finishing %ld sectors\n",
354 						rq->nr_sectors));
355 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
356 						"Retry with 0x%p\n", SCpnt));
357 		return 0;
358 	}
359 
360 	if (sdp->changed) {
361 		/*
362 		 * quietly refuse to do anything to a changed disc until
363 		 * the changed bit has been reset
364 		 */
365 		/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
366 		return 0;
367 	}
368 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
369 					(unsigned long long)block));
370 
371 	/*
372 	 * If we have a 1K hardware sectorsize, prevent access to single
373 	 * 512 byte sectors.  In theory we could handle this - in fact
374 	 * the scsi cdrom driver must be able to handle this because
375 	 * we typically use 1K blocksizes, and cdroms typically have
376 	 * 2K hardware sectorsizes.  Of course, things are simpler
377 	 * with the cdrom, since it is read-only.  For performance
378 	 * reasons, the filesystems should be able to handle this
379 	 * and not force the scsi disk driver to use bounce buffers
380 	 * for this.
381 	 */
382 	if (sdp->sector_size == 1024) {
383 		if ((block & 1) || (rq->nr_sectors & 1)) {
384 			scmd_printk(KERN_ERR, SCpnt,
385 				    "Bad block number requested\n");
386 			return 0;
387 		} else {
388 			block = block >> 1;
389 			this_count = this_count >> 1;
390 		}
391 	}
392 	if (sdp->sector_size == 2048) {
393 		if ((block & 3) || (rq->nr_sectors & 3)) {
394 			scmd_printk(KERN_ERR, SCpnt,
395 				    "Bad block number requested\n");
396 			return 0;
397 		} else {
398 			block = block >> 2;
399 			this_count = this_count >> 2;
400 		}
401 	}
402 	if (sdp->sector_size == 4096) {
403 		if ((block & 7) || (rq->nr_sectors & 7)) {
404 			scmd_printk(KERN_ERR, SCpnt,
405 				    "Bad block number requested\n");
406 			return 0;
407 		} else {
408 			block = block >> 3;
409 			this_count = this_count >> 3;
410 		}
411 	}
412 	if (rq_data_dir(rq) == WRITE) {
413 		if (!sdp->writeable) {
414 			return 0;
415 		}
416 		SCpnt->cmnd[0] = WRITE_6;
417 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
418 	} else if (rq_data_dir(rq) == READ) {
419 		SCpnt->cmnd[0] = READ_6;
420 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
421 	} else {
422 		scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
423 		return 0;
424 	}
425 
426 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
427 					"%s %d/%ld 512 byte blocks.\n",
428 					(rq_data_dir(rq) == WRITE) ?
429 					"writing" : "reading", this_count,
430 					rq->nr_sectors));
431 
432 	SCpnt->cmnd[1] = 0;
433 
434 	if (block > 0xffffffff) {
435 		SCpnt->cmnd[0] += READ_16 - READ_6;
436 		SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
437 		SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
438 		SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
439 		SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
440 		SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
441 		SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
442 		SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
443 		SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
444 		SCpnt->cmnd[9] = (unsigned char) block & 0xff;
445 		SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
446 		SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
447 		SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
448 		SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
449 		SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
450 	} else if ((this_count > 0xff) || (block > 0x1fffff) ||
451 		   SCpnt->device->use_10_for_rw) {
452 		if (this_count > 0xffff)
453 			this_count = 0xffff;
454 
455 		SCpnt->cmnd[0] += READ_10 - READ_6;
456 		SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
457 		SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
458 		SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
459 		SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
460 		SCpnt->cmnd[5] = (unsigned char) block & 0xff;
461 		SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
462 		SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
463 		SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
464 	} else {
465 		if (unlikely(blk_fua_rq(rq))) {
466 			/*
467 			 * This happens only if this drive failed
468 			 * 10byte rw command with ILLEGAL_REQUEST
469 			 * during operation and thus turned off
470 			 * use_10_for_rw.
471 			 */
472 			scmd_printk(KERN_ERR, SCpnt,
473 				    "FUA write on READ/WRITE(6) drive\n");
474 			return 0;
475 		}
476 
477 		SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
478 		SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
479 		SCpnt->cmnd[3] = (unsigned char) block & 0xff;
480 		SCpnt->cmnd[4] = (unsigned char) this_count;
481 		SCpnt->cmnd[5] = 0;
482 	}
483 	SCpnt->request_bufflen = this_count * sdp->sector_size;
484 
485 	/*
486 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
487 	 * host adapter, it's safe to assume that we can at least transfer
488 	 * this many bytes between each connect / disconnect.
489 	 */
490 	SCpnt->transfersize = sdp->sector_size;
491 	SCpnt->underflow = this_count << 9;
492 	SCpnt->allowed = SD_MAX_RETRIES;
493 	SCpnt->timeout_per_command = timeout;
494 
495 	/*
496 	 * This is the completion routine we use.  This is matched in terms
497 	 * of capability to this function.
498 	 */
499 	SCpnt->done = sd_rw_intr;
500 
501 	/*
502 	 * This indicates that the command is ready from our end to be
503 	 * queued.
504 	 */
505 	return 1;
506 }
507 
508 /**
509  *	sd_open - open a scsi disk device
510  *	@inode: only i_rdev member may be used
511  *	@filp: only f_mode and f_flags may be used
512  *
513  *	Returns 0 if successful. Returns a negated errno value in case
514  *	of error.
515  *
516  *	Note: This can be called from a user context (e.g. fsck(1) )
517  *	or from within the kernel (e.g. as a result of a mount(1) ).
518  *	In the latter case @inode and @filp carry an abridged amount
519  *	of information as noted above.
520  **/
521 static int sd_open(struct inode *inode, struct file *filp)
522 {
523 	struct gendisk *disk = inode->i_bdev->bd_disk;
524 	struct scsi_disk *sdkp;
525 	struct scsi_device *sdev;
526 	int retval;
527 
528 	if (!(sdkp = scsi_disk_get(disk)))
529 		return -ENXIO;
530 
531 
532 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
533 
534 	sdev = sdkp->device;
535 
536 	/*
537 	 * If the device is in error recovery, wait until it is done.
538 	 * If the device is offline, then disallow any access to it.
539 	 */
540 	retval = -ENXIO;
541 	if (!scsi_block_when_processing_errors(sdev))
542 		goto error_out;
543 
544 	if (sdev->removable || sdkp->write_prot)
545 		check_disk_change(inode->i_bdev);
546 
547 	/*
548 	 * If the drive is empty, just let the open fail.
549 	 */
550 	retval = -ENOMEDIUM;
551 	if (sdev->removable && !sdkp->media_present &&
552 	    !(filp->f_flags & O_NDELAY))
553 		goto error_out;
554 
555 	/*
556 	 * If the device has the write protect tab set, have the open fail
557 	 * if the user expects to be able to write to the thing.
558 	 */
559 	retval = -EROFS;
560 	if (sdkp->write_prot && (filp->f_mode & FMODE_WRITE))
561 		goto error_out;
562 
563 	/*
564 	 * It is possible that the disk changing stuff resulted in
565 	 * the device being taken offline.  If this is the case,
566 	 * report this to the user, and don't pretend that the
567 	 * open actually succeeded.
568 	 */
569 	retval = -ENXIO;
570 	if (!scsi_device_online(sdev))
571 		goto error_out;
572 
573 	if (!sdkp->openers++ && sdev->removable) {
574 		if (scsi_block_when_processing_errors(sdev))
575 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
576 	}
577 
578 	return 0;
579 
580 error_out:
581 	scsi_disk_put(sdkp);
582 	return retval;
583 }
584 
585 /**
586  *	sd_release - invoked when the (last) close(2) is called on this
587  *	scsi disk.
588  *	@inode: only i_rdev member may be used
589  *	@filp: only f_mode and f_flags may be used
590  *
591  *	Returns 0.
592  *
593  *	Note: may block (uninterruptible) if error recovery is underway
594  *	on this disk.
595  **/
596 static int sd_release(struct inode *inode, struct file *filp)
597 {
598 	struct gendisk *disk = inode->i_bdev->bd_disk;
599 	struct scsi_disk *sdkp = scsi_disk(disk);
600 	struct scsi_device *sdev = sdkp->device;
601 
602 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_release\n"));
603 
604 	if (!--sdkp->openers && sdev->removable) {
605 		if (scsi_block_when_processing_errors(sdev))
606 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
607 	}
608 
609 	/*
610 	 * XXX and what if there are packets in flight and this close()
611 	 * XXX is followed by a "rmmod sd_mod"?
612 	 */
613 	scsi_disk_put(sdkp);
614 	return 0;
615 }
616 
617 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
618 {
619 	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
620 	struct scsi_device *sdp = sdkp->device;
621 	struct Scsi_Host *host = sdp->host;
622 	int diskinfo[4];
623 
624 	/* default to most commonly used values */
625         diskinfo[0] = 0x40;	/* 1 << 6 */
626        	diskinfo[1] = 0x20;	/* 1 << 5 */
627        	diskinfo[2] = sdkp->capacity >> 11;
628 
629 	/* override with calculated, extended default, or driver values */
630 	if (host->hostt->bios_param)
631 		host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
632 	else
633 		scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
634 
635 	geo->heads = diskinfo[0];
636 	geo->sectors = diskinfo[1];
637 	geo->cylinders = diskinfo[2];
638 	return 0;
639 }
640 
641 /**
642  *	sd_ioctl - process an ioctl
643  *	@inode: only i_rdev/i_bdev members may be used
644  *	@filp: only f_mode and f_flags may be used
645  *	@cmd: ioctl command number
646  *	@arg: this is third argument given to ioctl(2) system call.
647  *	Often contains a pointer.
648  *
649  *	Returns 0 if successful (some ioctls return postive numbers on
650  *	success as well). Returns a negated errno value in case of error.
651  *
652  *	Note: most ioctls are forward onto the block subsystem or further
653  *	down in the scsi subsytem.
654  **/
655 static int sd_ioctl(struct inode * inode, struct file * filp,
656 		    unsigned int cmd, unsigned long arg)
657 {
658 	struct block_device *bdev = inode->i_bdev;
659 	struct gendisk *disk = bdev->bd_disk;
660 	struct scsi_device *sdp = scsi_disk(disk)->device;
661 	void __user *p = (void __user *)arg;
662 	int error;
663 
664 	SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
665 						disk->disk_name, cmd));
666 
667 	/*
668 	 * If we are in the middle of error recovery, don't let anyone
669 	 * else try and use this device.  Also, if error recovery fails, it
670 	 * may try and take the device offline, in which case all further
671 	 * access to the device is prohibited.
672 	 */
673 	error = scsi_nonblockable_ioctl(sdp, cmd, p, filp);
674 	if (!scsi_block_when_processing_errors(sdp) || !error)
675 		return error;
676 
677 	/*
678 	 * Send SCSI addressing ioctls directly to mid level, send other
679 	 * ioctls to block level and then onto mid level if they can't be
680 	 * resolved.
681 	 */
682 	switch (cmd) {
683 		case SCSI_IOCTL_GET_IDLUN:
684 		case SCSI_IOCTL_GET_BUS_NUMBER:
685 			return scsi_ioctl(sdp, cmd, p);
686 		default:
687 			error = scsi_cmd_ioctl(filp, disk, cmd, p);
688 			if (error != -ENOTTY)
689 				return error;
690 	}
691 	return scsi_ioctl(sdp, cmd, p);
692 }
693 
694 static void set_media_not_present(struct scsi_disk *sdkp)
695 {
696 	sdkp->media_present = 0;
697 	sdkp->capacity = 0;
698 	sdkp->device->changed = 1;
699 }
700 
701 /**
702  *	sd_media_changed - check if our medium changed
703  *	@disk: kernel device descriptor
704  *
705  *	Returns 0 if not applicable or no change; 1 if change
706  *
707  *	Note: this function is invoked from the block subsystem.
708  **/
709 static int sd_media_changed(struct gendisk *disk)
710 {
711 	struct scsi_disk *sdkp = scsi_disk(disk);
712 	struct scsi_device *sdp = sdkp->device;
713 	int retval;
714 
715 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_media_changed\n"));
716 
717 	if (!sdp->removable)
718 		return 0;
719 
720 	/*
721 	 * If the device is offline, don't send any commands - just pretend as
722 	 * if the command failed.  If the device ever comes back online, we
723 	 * can deal with it then.  It is only because of unrecoverable errors
724 	 * that we would ever take a device offline in the first place.
725 	 */
726 	if (!scsi_device_online(sdp))
727 		goto not_present;
728 
729 	/*
730 	 * Using TEST_UNIT_READY enables differentiation between drive with
731 	 * no cartridge loaded - NOT READY, drive with changed cartridge -
732 	 * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
733 	 *
734 	 * Drives that auto spin down. eg iomega jaz 1G, will be started
735 	 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
736 	 * sd_revalidate() is called.
737 	 */
738 	retval = -ENODEV;
739 	if (scsi_block_when_processing_errors(sdp))
740 		retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES);
741 
742 	/*
743 	 * Unable to test, unit probably not ready.   This usually
744 	 * means there is no disc in the drive.  Mark as changed,
745 	 * and we will figure it out later once the drive is
746 	 * available again.
747 	 */
748 	if (retval)
749 		 goto not_present;
750 
751 	/*
752 	 * For removable scsi disk we have to recognise the presence
753 	 * of a disk in the drive. This is kept in the struct scsi_disk
754 	 * struct and tested at open !  Daniel Roche (dan@lectra.fr)
755 	 */
756 	sdkp->media_present = 1;
757 
758 	retval = sdp->changed;
759 	sdp->changed = 0;
760 
761 	return retval;
762 
763 not_present:
764 	set_media_not_present(sdkp);
765 	return 1;
766 }
767 
768 static int sd_sync_cache(struct scsi_disk *sdkp)
769 {
770 	int retries, res;
771 	struct scsi_device *sdp = sdkp->device;
772 	struct scsi_sense_hdr sshdr;
773 
774 	if (!scsi_device_online(sdp))
775 		return -ENODEV;
776 
777 
778 	for (retries = 3; retries > 0; --retries) {
779 		unsigned char cmd[10] = { 0 };
780 
781 		cmd[0] = SYNCHRONIZE_CACHE;
782 		/*
783 		 * Leave the rest of the command zero to indicate
784 		 * flush everything.
785 		 */
786 		res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
787 				       SD_TIMEOUT, SD_MAX_RETRIES);
788 		if (res == 0)
789 			break;
790 	}
791 
792 	if (res) {
793 		sd_print_result(sdkp, res);
794 		if (driver_byte(res) & DRIVER_SENSE)
795 			sd_print_sense_hdr(sdkp, &sshdr);
796 	}
797 
798 	if (res)
799 		return -EIO;
800 	return 0;
801 }
802 
803 static int sd_issue_flush(struct device *dev, sector_t *error_sector)
804 {
805 	int ret = 0;
806 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
807 
808 	if (!sdkp)
809                return -ENODEV;
810 
811 	if (sdkp->WCE)
812 		ret = sd_sync_cache(sdkp);
813 	scsi_disk_put(sdkp);
814 	return ret;
815 }
816 
817 static void sd_prepare_flush(request_queue_t *q, struct request *rq)
818 {
819 	memset(rq->cmd, 0, sizeof(rq->cmd));
820 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
821 	rq->timeout = SD_TIMEOUT;
822 	rq->cmd[0] = SYNCHRONIZE_CACHE;
823 	rq->cmd_len = 10;
824 }
825 
826 static void sd_rescan(struct device *dev)
827 {
828 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
829 
830 	if (sdkp) {
831 		sd_revalidate_disk(sdkp->disk);
832 		scsi_disk_put(sdkp);
833 	}
834 }
835 
836 
837 #ifdef CONFIG_COMPAT
838 /*
839  * This gets directly called from VFS. When the ioctl
840  * is not recognized we go back to the other translation paths.
841  */
842 static long sd_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
843 {
844 	struct block_device *bdev = file->f_path.dentry->d_inode->i_bdev;
845 	struct gendisk *disk = bdev->bd_disk;
846 	struct scsi_device *sdev = scsi_disk(disk)->device;
847 
848 	/*
849 	 * If we are in the middle of error recovery, don't let anyone
850 	 * else try and use this device.  Also, if error recovery fails, it
851 	 * may try and take the device offline, in which case all further
852 	 * access to the device is prohibited.
853 	 */
854 	if (!scsi_block_when_processing_errors(sdev))
855 		return -ENODEV;
856 
857 	if (sdev->host->hostt->compat_ioctl) {
858 		int ret;
859 
860 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
861 
862 		return ret;
863 	}
864 
865 	/*
866 	 * Let the static ioctl translation table take care of it.
867 	 */
868 	return -ENOIOCTLCMD;
869 }
870 #endif
871 
872 static struct block_device_operations sd_fops = {
873 	.owner			= THIS_MODULE,
874 	.open			= sd_open,
875 	.release		= sd_release,
876 	.ioctl			= sd_ioctl,
877 	.getgeo			= sd_getgeo,
878 #ifdef CONFIG_COMPAT
879 	.compat_ioctl		= sd_compat_ioctl,
880 #endif
881 	.media_changed		= sd_media_changed,
882 	.revalidate_disk	= sd_revalidate_disk,
883 };
884 
885 /**
886  *	sd_rw_intr - bottom half handler: called when the lower level
887  *	driver has completed (successfully or otherwise) a scsi command.
888  *	@SCpnt: mid-level's per command structure.
889  *
890  *	Note: potentially run from within an ISR. Must not block.
891  **/
892 static void sd_rw_intr(struct scsi_cmnd * SCpnt)
893 {
894 	int result = SCpnt->result;
895  	unsigned int xfer_size = SCpnt->request_bufflen;
896  	unsigned int good_bytes = result ? 0 : xfer_size;
897  	u64 start_lba = SCpnt->request->sector;
898  	u64 bad_lba;
899 	struct scsi_sense_hdr sshdr;
900 	int sense_valid = 0;
901 	int sense_deferred = 0;
902 	int info_valid;
903 
904 	if (result) {
905 		sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
906 		if (sense_valid)
907 			sense_deferred = scsi_sense_is_deferred(&sshdr);
908 	}
909 #ifdef CONFIG_SCSI_LOGGING
910 	SCSI_LOG_HLCOMPLETE(1, scsi_print_result(SCpnt));
911 	if (sense_valid) {
912 		SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
913 						   "sd_rw_intr: sb[respc,sk,asc,"
914 						   "ascq]=%x,%x,%x,%x\n",
915 						   sshdr.response_code,
916 						   sshdr.sense_key, sshdr.asc,
917 						   sshdr.ascq));
918 	}
919 #endif
920 	if (driver_byte(result) != DRIVER_SENSE &&
921 	    (!sense_valid || sense_deferred))
922 		goto out;
923 
924 	switch (sshdr.sense_key) {
925 	case HARDWARE_ERROR:
926 	case MEDIUM_ERROR:
927 		if (!blk_fs_request(SCpnt->request))
928 			goto out;
929 		info_valid = scsi_get_sense_info_fld(SCpnt->sense_buffer,
930 						     SCSI_SENSE_BUFFERSIZE,
931 						     &bad_lba);
932 		if (!info_valid)
933 			goto out;
934 		if (xfer_size <= SCpnt->device->sector_size)
935 			goto out;
936 		switch (SCpnt->device->sector_size) {
937 		case 256:
938 			start_lba <<= 1;
939 			break;
940 		case 512:
941 			break;
942 		case 1024:
943 			start_lba >>= 1;
944 			break;
945 		case 2048:
946 			start_lba >>= 2;
947 			break;
948 		case 4096:
949 			start_lba >>= 3;
950 			break;
951 		default:
952 			/* Print something here with limiting frequency. */
953 			goto out;
954 			break;
955 		}
956 		/* This computation should always be done in terms of
957 		 * the resolution of the device's medium.
958 		 */
959 		good_bytes = (bad_lba - start_lba)*SCpnt->device->sector_size;
960 		break;
961 	case RECOVERED_ERROR:
962 	case NO_SENSE:
963 		/* Inform the user, but make sure that it's not treated
964 		 * as a hard error.
965 		 */
966 		scsi_print_sense("sd", SCpnt);
967 		SCpnt->result = 0;
968 		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
969 		good_bytes = xfer_size;
970 		break;
971 	case ILLEGAL_REQUEST:
972 		if (SCpnt->device->use_10_for_rw &&
973 		    (SCpnt->cmnd[0] == READ_10 ||
974 		     SCpnt->cmnd[0] == WRITE_10))
975 			SCpnt->device->use_10_for_rw = 0;
976 		if (SCpnt->device->use_10_for_ms &&
977 		    (SCpnt->cmnd[0] == MODE_SENSE_10 ||
978 		     SCpnt->cmnd[0] == MODE_SELECT_10))
979 			SCpnt->device->use_10_for_ms = 0;
980 		break;
981 	default:
982 		break;
983 	}
984  out:
985 	scsi_io_completion(SCpnt, good_bytes);
986 }
987 
988 static int media_not_present(struct scsi_disk *sdkp,
989 			     struct scsi_sense_hdr *sshdr)
990 {
991 
992 	if (!scsi_sense_valid(sshdr))
993 		return 0;
994 	/* not invoked for commands that could return deferred errors */
995 	if (sshdr->sense_key != NOT_READY &&
996 	    sshdr->sense_key != UNIT_ATTENTION)
997 		return 0;
998 	if (sshdr->asc != 0x3A) /* medium not present */
999 		return 0;
1000 
1001 	set_media_not_present(sdkp);
1002 	return 1;
1003 }
1004 
1005 /*
1006  * spinup disk - called only in sd_revalidate_disk()
1007  */
1008 static void
1009 sd_spinup_disk(struct scsi_disk *sdkp)
1010 {
1011 	unsigned char cmd[10];
1012 	unsigned long spintime_expire = 0;
1013 	int retries, spintime;
1014 	unsigned int the_result;
1015 	struct scsi_sense_hdr sshdr;
1016 	int sense_valid = 0;
1017 
1018 	spintime = 0;
1019 
1020 	/* Spin up drives, as required.  Only do this at boot time */
1021 	/* Spinup needs to be done for module loads too. */
1022 	do {
1023 		retries = 0;
1024 
1025 		do {
1026 			cmd[0] = TEST_UNIT_READY;
1027 			memset((void *) &cmd[1], 0, 9);
1028 
1029 			the_result = scsi_execute_req(sdkp->device, cmd,
1030 						      DMA_NONE, NULL, 0,
1031 						      &sshdr, SD_TIMEOUT,
1032 						      SD_MAX_RETRIES);
1033 
1034 			/*
1035 			 * If the drive has indicated to us that it
1036 			 * doesn't have any media in it, don't bother
1037 			 * with any more polling.
1038 			 */
1039 			if (media_not_present(sdkp, &sshdr))
1040 				return;
1041 
1042 			if (the_result)
1043 				sense_valid = scsi_sense_valid(&sshdr);
1044 			retries++;
1045 		} while (retries < 3 &&
1046 			 (!scsi_status_is_good(the_result) ||
1047 			  ((driver_byte(the_result) & DRIVER_SENSE) &&
1048 			  sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1049 
1050 		if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1051 			/* no sense, TUR either succeeded or failed
1052 			 * with a status error */
1053 			if(!spintime && !scsi_status_is_good(the_result)) {
1054 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1055 				sd_print_result(sdkp, the_result);
1056 			}
1057 			break;
1058 		}
1059 
1060 		/*
1061 		 * The device does not want the automatic start to be issued.
1062 		 */
1063 		if (sdkp->device->no_start_on_add) {
1064 			break;
1065 		}
1066 
1067 		/*
1068 		 * If manual intervention is required, or this is an
1069 		 * absent USB storage device, a spinup is meaningless.
1070 		 */
1071 		if (sense_valid &&
1072 		    sshdr.sense_key == NOT_READY &&
1073 		    sshdr.asc == 4 && sshdr.ascq == 3) {
1074 			break;		/* manual intervention required */
1075 
1076 		/*
1077 		 * Issue command to spin up drive when not ready
1078 		 */
1079 		} else if (sense_valid && sshdr.sense_key == NOT_READY) {
1080 			if (!spintime) {
1081 				sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
1082 				cmd[0] = START_STOP;
1083 				cmd[1] = 1;	/* Return immediately */
1084 				memset((void *) &cmd[2], 0, 8);
1085 				cmd[4] = 1;	/* Start spin cycle */
1086 				scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1087 						 NULL, 0, &sshdr,
1088 						 SD_TIMEOUT, SD_MAX_RETRIES);
1089 				spintime_expire = jiffies + 100 * HZ;
1090 				spintime = 1;
1091 			}
1092 			/* Wait 1 second for next try */
1093 			msleep(1000);
1094 			printk(".");
1095 
1096 		/*
1097 		 * Wait for USB flash devices with slow firmware.
1098 		 * Yes, this sense key/ASC combination shouldn't
1099 		 * occur here.  It's characteristic of these devices.
1100 		 */
1101 		} else if (sense_valid &&
1102 				sshdr.sense_key == UNIT_ATTENTION &&
1103 				sshdr.asc == 0x28) {
1104 			if (!spintime) {
1105 				spintime_expire = jiffies + 5 * HZ;
1106 				spintime = 1;
1107 			}
1108 			/* Wait 1 second for next try */
1109 			msleep(1000);
1110 		} else {
1111 			/* we don't understand the sense code, so it's
1112 			 * probably pointless to loop */
1113 			if(!spintime) {
1114 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1115 				sd_print_sense_hdr(sdkp, &sshdr);
1116 			}
1117 			break;
1118 		}
1119 
1120 	} while (spintime && time_before_eq(jiffies, spintime_expire));
1121 
1122 	if (spintime) {
1123 		if (scsi_status_is_good(the_result))
1124 			printk("ready\n");
1125 		else
1126 			printk("not responding...\n");
1127 	}
1128 }
1129 
1130 /*
1131  * read disk capacity
1132  */
1133 static void
1134 sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
1135 {
1136 	unsigned char cmd[16];
1137 	int the_result, retries;
1138 	int sector_size = 0;
1139 	int longrc = 0;
1140 	struct scsi_sense_hdr sshdr;
1141 	int sense_valid = 0;
1142 	struct scsi_device *sdp = sdkp->device;
1143 
1144 repeat:
1145 	retries = 3;
1146 	do {
1147 		if (longrc) {
1148 			memset((void *) cmd, 0, 16);
1149 			cmd[0] = SERVICE_ACTION_IN;
1150 			cmd[1] = SAI_READ_CAPACITY_16;
1151 			cmd[13] = 12;
1152 			memset((void *) buffer, 0, 12);
1153 		} else {
1154 			cmd[0] = READ_CAPACITY;
1155 			memset((void *) &cmd[1], 0, 9);
1156 			memset((void *) buffer, 0, 8);
1157 		}
1158 
1159 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1160 					      buffer, longrc ? 12 : 8, &sshdr,
1161 					      SD_TIMEOUT, SD_MAX_RETRIES);
1162 
1163 		if (media_not_present(sdkp, &sshdr))
1164 			return;
1165 
1166 		if (the_result)
1167 			sense_valid = scsi_sense_valid(&sshdr);
1168 		retries--;
1169 
1170 	} while (the_result && retries);
1171 
1172 	if (the_result && !longrc) {
1173 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
1174 		sd_print_result(sdkp, the_result);
1175 		if (driver_byte(the_result) & DRIVER_SENSE)
1176 			sd_print_sense_hdr(sdkp, &sshdr);
1177 		else
1178 			sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
1179 
1180 		/* Set dirty bit for removable devices if not ready -
1181 		 * sometimes drives will not report this properly. */
1182 		if (sdp->removable &&
1183 		    sense_valid && sshdr.sense_key == NOT_READY)
1184 			sdp->changed = 1;
1185 
1186 		/* Either no media are present but the drive didn't tell us,
1187 		   or they are present but the read capacity command fails */
1188 		/* sdkp->media_present = 0; -- not always correct */
1189 		sdkp->capacity = 0; /* unknown mapped to zero - as usual */
1190 
1191 		return;
1192 	} else if (the_result && longrc) {
1193 		/* READ CAPACITY(16) has been failed */
1194 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY(16) failed\n");
1195 		sd_print_result(sdkp, the_result);
1196 		sd_printk(KERN_NOTICE, sdkp, "Use 0xffffffff as device size\n");
1197 
1198 		sdkp->capacity = 1 + (sector_t) 0xffffffff;
1199 		goto got_data;
1200 	}
1201 
1202 	if (!longrc) {
1203 		sector_size = (buffer[4] << 24) |
1204 			(buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
1205 		if (buffer[0] == 0xff && buffer[1] == 0xff &&
1206 		    buffer[2] == 0xff && buffer[3] == 0xff) {
1207 			if(sizeof(sdkp->capacity) > 4) {
1208 				sd_printk(KERN_NOTICE, sdkp, "Very big device. "
1209 					  "Trying to use READ CAPACITY(16).\n");
1210 				longrc = 1;
1211 				goto repeat;
1212 			}
1213 			sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use "
1214 				  "a kernel compiled with support for large "
1215 				  "block devices.\n");
1216 			sdkp->capacity = 0;
1217 			goto got_data;
1218 		}
1219 		sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) |
1220 			(buffer[1] << 16) |
1221 			(buffer[2] << 8) |
1222 			buffer[3]);
1223 	} else {
1224 		sdkp->capacity = 1 + (((u64)buffer[0] << 56) |
1225 			((u64)buffer[1] << 48) |
1226 			((u64)buffer[2] << 40) |
1227 			((u64)buffer[3] << 32) |
1228 			((sector_t)buffer[4] << 24) |
1229 			((sector_t)buffer[5] << 16) |
1230 			((sector_t)buffer[6] << 8)  |
1231 			(sector_t)buffer[7]);
1232 
1233 		sector_size = (buffer[8] << 24) |
1234 			(buffer[9] << 16) | (buffer[10] << 8) | buffer[11];
1235 	}
1236 
1237 	/* Some devices return the total number of sectors, not the
1238 	 * highest sector number.  Make the necessary adjustment. */
1239 	if (sdp->fix_capacity) {
1240 		--sdkp->capacity;
1241 
1242 	/* Some devices have version which report the correct sizes
1243 	 * and others which do not. We guess size according to a heuristic
1244 	 * and err on the side of lowering the capacity. */
1245 	} else {
1246 		if (sdp->guess_capacity)
1247 			if (sdkp->capacity & 0x01) /* odd sizes are odd */
1248 				--sdkp->capacity;
1249 	}
1250 
1251 got_data:
1252 	if (sector_size == 0) {
1253 		sector_size = 512;
1254 		sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
1255 			  "assuming 512.\n");
1256 	}
1257 
1258 	if (sector_size != 512 &&
1259 	    sector_size != 1024 &&
1260 	    sector_size != 2048 &&
1261 	    sector_size != 4096 &&
1262 	    sector_size != 256) {
1263 		sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
1264 			  sector_size);
1265 		/*
1266 		 * The user might want to re-format the drive with
1267 		 * a supported sectorsize.  Once this happens, it
1268 		 * would be relatively trivial to set the thing up.
1269 		 * For this reason, we leave the thing in the table.
1270 		 */
1271 		sdkp->capacity = 0;
1272 		/*
1273 		 * set a bogus sector size so the normal read/write
1274 		 * logic in the block layer will eventually refuse any
1275 		 * request on this device without tripping over power
1276 		 * of two sector size assumptions
1277 		 */
1278 		sector_size = 512;
1279 	}
1280 	{
1281 		/*
1282 		 * The msdos fs needs to know the hardware sector size
1283 		 * So I have created this table. See ll_rw_blk.c
1284 		 * Jacques Gelinas (Jacques@solucorp.qc.ca)
1285 		 */
1286 		int hard_sector = sector_size;
1287 		sector_t sz = (sdkp->capacity/2) * (hard_sector/256);
1288 		request_queue_t *queue = sdp->request_queue;
1289 		sector_t mb = sz;
1290 
1291 		blk_queue_hardsect_size(queue, hard_sector);
1292 		/* avoid 64-bit division on 32-bit platforms */
1293 		sector_div(sz, 625);
1294 		mb -= sz - 974;
1295 		sector_div(mb, 1950);
1296 
1297 		sd_printk(KERN_NOTICE, sdkp,
1298 			  "%llu %d-byte hardware sectors (%llu MB)\n",
1299 			  (unsigned long long)sdkp->capacity,
1300 			  hard_sector, (unsigned long long)mb);
1301 	}
1302 
1303 	/* Rescale capacity to 512-byte units */
1304 	if (sector_size == 4096)
1305 		sdkp->capacity <<= 3;
1306 	else if (sector_size == 2048)
1307 		sdkp->capacity <<= 2;
1308 	else if (sector_size == 1024)
1309 		sdkp->capacity <<= 1;
1310 	else if (sector_size == 256)
1311 		sdkp->capacity >>= 1;
1312 
1313 	sdkp->device->sector_size = sector_size;
1314 }
1315 
1316 /* called with buffer of length 512 */
1317 static inline int
1318 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
1319 		 unsigned char *buffer, int len, struct scsi_mode_data *data,
1320 		 struct scsi_sense_hdr *sshdr)
1321 {
1322 	return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
1323 			       SD_TIMEOUT, SD_MAX_RETRIES, data,
1324 			       sshdr);
1325 }
1326 
1327 /*
1328  * read write protect setting, if possible - called only in sd_revalidate_disk()
1329  * called with buffer of length SD_BUF_SIZE
1330  */
1331 static void
1332 sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
1333 {
1334 	int res;
1335 	struct scsi_device *sdp = sdkp->device;
1336 	struct scsi_mode_data data;
1337 
1338 	set_disk_ro(sdkp->disk, 0);
1339 	if (sdp->skip_ms_page_3f) {
1340 		sd_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
1341 		return;
1342 	}
1343 
1344 	if (sdp->use_192_bytes_for_3f) {
1345 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
1346 	} else {
1347 		/*
1348 		 * First attempt: ask for all pages (0x3F), but only 4 bytes.
1349 		 * We have to start carefully: some devices hang if we ask
1350 		 * for more than is available.
1351 		 */
1352 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
1353 
1354 		/*
1355 		 * Second attempt: ask for page 0 When only page 0 is
1356 		 * implemented, a request for page 3F may return Sense Key
1357 		 * 5: Illegal Request, Sense Code 24: Invalid field in
1358 		 * CDB.
1359 		 */
1360 		if (!scsi_status_is_good(res))
1361 			res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
1362 
1363 		/*
1364 		 * Third attempt: ask 255 bytes, as we did earlier.
1365 		 */
1366 		if (!scsi_status_is_good(res))
1367 			res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
1368 					       &data, NULL);
1369 	}
1370 
1371 	if (!scsi_status_is_good(res)) {
1372 		sd_printk(KERN_WARNING, sdkp,
1373 			  "Test WP failed, assume Write Enabled\n");
1374 	} else {
1375 		sdkp->write_prot = ((data.device_specific & 0x80) != 0);
1376 		set_disk_ro(sdkp->disk, sdkp->write_prot);
1377 		sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
1378 			  sdkp->write_prot ? "on" : "off");
1379 		sd_printk(KERN_DEBUG, sdkp,
1380 			  "Mode Sense: %02x %02x %02x %02x\n",
1381 			  buffer[0], buffer[1], buffer[2], buffer[3]);
1382 	}
1383 }
1384 
1385 /*
1386  * sd_read_cache_type - called only from sd_revalidate_disk()
1387  * called with buffer of length SD_BUF_SIZE
1388  */
1389 static void
1390 sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
1391 {
1392 	int len = 0, res;
1393 	struct scsi_device *sdp = sdkp->device;
1394 
1395 	int dbd;
1396 	int modepage;
1397 	struct scsi_mode_data data;
1398 	struct scsi_sense_hdr sshdr;
1399 
1400 	if (sdp->skip_ms_page_8)
1401 		goto defaults;
1402 
1403 	if (sdp->type == TYPE_RBC) {
1404 		modepage = 6;
1405 		dbd = 8;
1406 	} else {
1407 		modepage = 8;
1408 		dbd = 0;
1409 	}
1410 
1411 	/* cautiously ask */
1412 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);
1413 
1414 	if (!scsi_status_is_good(res))
1415 		goto bad_sense;
1416 
1417 	if (!data.header_length) {
1418 		modepage = 6;
1419 		sd_printk(KERN_ERR, sdkp, "Missing header in MODE_SENSE response\n");
1420 	}
1421 
1422 	/* that went OK, now ask for the proper length */
1423 	len = data.length;
1424 
1425 	/*
1426 	 * We're only interested in the first three bytes, actually.
1427 	 * But the data cache page is defined for the first 20.
1428 	 */
1429 	if (len < 3)
1430 		goto bad_sense;
1431 	if (len > 20)
1432 		len = 20;
1433 
1434 	/* Take headers and block descriptors into account */
1435 	len += data.header_length + data.block_descriptor_length;
1436 	if (len > SD_BUF_SIZE)
1437 		goto bad_sense;
1438 
1439 	/* Get the data */
1440 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
1441 
1442 	if (scsi_status_is_good(res)) {
1443 		int offset = data.header_length + data.block_descriptor_length;
1444 
1445 		if (offset >= SD_BUF_SIZE - 2) {
1446 			sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
1447 			goto defaults;
1448 		}
1449 
1450 		if ((buffer[offset] & 0x3f) != modepage) {
1451 			sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
1452 			goto defaults;
1453 		}
1454 
1455 		if (modepage == 8) {
1456 			sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
1457 			sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
1458 		} else {
1459 			sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
1460 			sdkp->RCD = 0;
1461 		}
1462 
1463 		sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
1464 		if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
1465 			sd_printk(KERN_NOTICE, sdkp,
1466 				  "Uses READ/WRITE(6), disabling FUA\n");
1467 			sdkp->DPOFUA = 0;
1468 		}
1469 
1470 		sd_printk(KERN_NOTICE, sdkp,
1471 		       "Write cache: %s, read cache: %s, %s\n",
1472 		       sdkp->WCE ? "enabled" : "disabled",
1473 		       sdkp->RCD ? "disabled" : "enabled",
1474 		       sdkp->DPOFUA ? "supports DPO and FUA"
1475 		       : "doesn't support DPO or FUA");
1476 
1477 		return;
1478 	}
1479 
1480 bad_sense:
1481 	if (scsi_sense_valid(&sshdr) &&
1482 	    sshdr.sense_key == ILLEGAL_REQUEST &&
1483 	    sshdr.asc == 0x24 && sshdr.ascq == 0x0)
1484 		/* Invalid field in CDB */
1485 		sd_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
1486 	else
1487 		sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n");
1488 
1489 defaults:
1490 	sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
1491 	sdkp->WCE = 0;
1492 	sdkp->RCD = 0;
1493 	sdkp->DPOFUA = 0;
1494 }
1495 
1496 /**
1497  *	sd_revalidate_disk - called the first time a new disk is seen,
1498  *	performs disk spin up, read_capacity, etc.
1499  *	@disk: struct gendisk we care about
1500  **/
1501 static int sd_revalidate_disk(struct gendisk *disk)
1502 {
1503 	struct scsi_disk *sdkp = scsi_disk(disk);
1504 	struct scsi_device *sdp = sdkp->device;
1505 	unsigned char *buffer;
1506 	unsigned ordered;
1507 
1508 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
1509 				      "sd_revalidate_disk\n"));
1510 
1511 	/*
1512 	 * If the device is offline, don't try and read capacity or any
1513 	 * of the other niceties.
1514 	 */
1515 	if (!scsi_device_online(sdp))
1516 		goto out;
1517 
1518 	buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL | __GFP_DMA);
1519 	if (!buffer) {
1520 		sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
1521 			  "allocation failure.\n");
1522 		goto out;
1523 	}
1524 
1525 	/* defaults, until the device tells us otherwise */
1526 	sdp->sector_size = 512;
1527 	sdkp->capacity = 0;
1528 	sdkp->media_present = 1;
1529 	sdkp->write_prot = 0;
1530 	sdkp->WCE = 0;
1531 	sdkp->RCD = 0;
1532 
1533 	sd_spinup_disk(sdkp);
1534 
1535 	/*
1536 	 * Without media there is no reason to ask; moreover, some devices
1537 	 * react badly if we do.
1538 	 */
1539 	if (sdkp->media_present) {
1540 		sd_read_capacity(sdkp, buffer);
1541 		sd_read_write_protect_flag(sdkp, buffer);
1542 		sd_read_cache_type(sdkp, buffer);
1543 	}
1544 
1545 	/*
1546 	 * We now have all cache related info, determine how we deal
1547 	 * with ordered requests.  Note that as the current SCSI
1548 	 * dispatch function can alter request order, we cannot use
1549 	 * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
1550 	 */
1551 	if (sdkp->WCE)
1552 		ordered = sdkp->DPOFUA
1553 			? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
1554 	else
1555 		ordered = QUEUE_ORDERED_DRAIN;
1556 
1557 	blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush);
1558 
1559 	set_capacity(disk, sdkp->capacity);
1560 	kfree(buffer);
1561 
1562  out:
1563 	return 0;
1564 }
1565 
1566 /**
1567  *	sd_probe - called during driver initialization and whenever a
1568  *	new scsi device is attached to the system. It is called once
1569  *	for each scsi device (not just disks) present.
1570  *	@dev: pointer to device object
1571  *
1572  *	Returns 0 if successful (or not interested in this scsi device
1573  *	(e.g. scanner)); 1 when there is an error.
1574  *
1575  *	Note: this function is invoked from the scsi mid-level.
1576  *	This function sets up the mapping between a given
1577  *	<host,channel,id,lun> (found in sdp) and new device name
1578  *	(e.g. /dev/sda). More precisely it is the block device major
1579  *	and minor number that is chosen here.
1580  *
1581  *	Assume sd_attach is not re-entrant (for time being)
1582  *	Also think about sd_attach() and sd_remove() running coincidentally.
1583  **/
1584 static int sd_probe(struct device *dev)
1585 {
1586 	struct scsi_device *sdp = to_scsi_device(dev);
1587 	struct scsi_disk *sdkp;
1588 	struct gendisk *gd;
1589 	u32 index;
1590 	int error;
1591 
1592 	error = -ENODEV;
1593 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
1594 		goto out;
1595 
1596 	SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
1597 					"sd_attach\n"));
1598 
1599 	error = -ENOMEM;
1600 	sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
1601 	if (!sdkp)
1602 		goto out;
1603 
1604 	gd = alloc_disk(16);
1605 	if (!gd)
1606 		goto out_free;
1607 
1608 	if (!idr_pre_get(&sd_index_idr, GFP_KERNEL))
1609 		goto out_put;
1610 
1611 	spin_lock(&sd_index_lock);
1612 	error = idr_get_new(&sd_index_idr, NULL, &index);
1613 	spin_unlock(&sd_index_lock);
1614 
1615 	if (index >= SD_MAX_DISKS)
1616 		error = -EBUSY;
1617 	if (error)
1618 		goto out_put;
1619 
1620 	sdkp->device = sdp;
1621 	sdkp->driver = &sd_template;
1622 	sdkp->disk = gd;
1623 	sdkp->index = index;
1624 	sdkp->openers = 0;
1625 
1626 	if (!sdp->timeout) {
1627 		if (sdp->type != TYPE_MOD)
1628 			sdp->timeout = SD_TIMEOUT;
1629 		else
1630 			sdp->timeout = SD_MOD_TIMEOUT;
1631 	}
1632 
1633 	class_device_initialize(&sdkp->cdev);
1634 	sdkp->cdev.dev = &sdp->sdev_gendev;
1635 	sdkp->cdev.class = &sd_disk_class;
1636 	strncpy(sdkp->cdev.class_id, sdp->sdev_gendev.bus_id, BUS_ID_SIZE);
1637 
1638 	if (class_device_add(&sdkp->cdev))
1639 		goto out_put;
1640 
1641 	get_device(&sdp->sdev_gendev);
1642 
1643 	gd->major = sd_major((index & 0xf0) >> 4);
1644 	gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
1645 	gd->minors = 16;
1646 	gd->fops = &sd_fops;
1647 
1648 	if (index < 26) {
1649 		sprintf(gd->disk_name, "sd%c", 'a' + index % 26);
1650 	} else if (index < (26 + 1) * 26) {
1651 		sprintf(gd->disk_name, "sd%c%c",
1652 			'a' + index / 26 - 1,'a' + index % 26);
1653 	} else {
1654 		const unsigned int m1 = (index / 26 - 1) / 26 - 1;
1655 		const unsigned int m2 = (index / 26 - 1) % 26;
1656 		const unsigned int m3 =  index % 26;
1657 		sprintf(gd->disk_name, "sd%c%c%c",
1658 			'a' + m1, 'a' + m2, 'a' + m3);
1659 	}
1660 
1661 	gd->private_data = &sdkp->driver;
1662 	gd->queue = sdkp->device->request_queue;
1663 
1664 	sd_revalidate_disk(gd);
1665 
1666 	gd->driverfs_dev = &sdp->sdev_gendev;
1667 	gd->flags = GENHD_FL_DRIVERFS;
1668 	if (sdp->removable)
1669 		gd->flags |= GENHD_FL_REMOVABLE;
1670 
1671 	dev_set_drvdata(dev, sdkp);
1672 	add_disk(gd);
1673 
1674 	sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
1675 		  sdp->removable ? "removable " : "");
1676 
1677 	return 0;
1678 
1679  out_put:
1680 	put_disk(gd);
1681  out_free:
1682 	kfree(sdkp);
1683  out:
1684 	return error;
1685 }
1686 
1687 /**
1688  *	sd_remove - called whenever a scsi disk (previously recognized by
1689  *	sd_probe) is detached from the system. It is called (potentially
1690  *	multiple times) during sd module unload.
1691  *	@sdp: pointer to mid level scsi device object
1692  *
1693  *	Note: this function is invoked from the scsi mid-level.
1694  *	This function potentially frees up a device name (e.g. /dev/sdc)
1695  *	that could be re-used by a subsequent sd_probe().
1696  *	This function is not called when the built-in sd driver is "exit-ed".
1697  **/
1698 static int sd_remove(struct device *dev)
1699 {
1700 	struct scsi_disk *sdkp = dev_get_drvdata(dev);
1701 
1702 	class_device_del(&sdkp->cdev);
1703 	del_gendisk(sdkp->disk);
1704 	sd_shutdown(dev);
1705 
1706 	mutex_lock(&sd_ref_mutex);
1707 	dev_set_drvdata(dev, NULL);
1708 	class_device_put(&sdkp->cdev);
1709 	mutex_unlock(&sd_ref_mutex);
1710 
1711 	return 0;
1712 }
1713 
1714 /**
1715  *	scsi_disk_release - Called to free the scsi_disk structure
1716  *	@cdev: pointer to embedded class device
1717  *
1718  *	sd_ref_mutex must be held entering this routine.  Because it is
1719  *	called on last put, you should always use the scsi_disk_get()
1720  *	scsi_disk_put() helpers which manipulate the semaphore directly
1721  *	and never do a direct class_device_put().
1722  **/
1723 static void scsi_disk_release(struct class_device *cdev)
1724 {
1725 	struct scsi_disk *sdkp = to_scsi_disk(cdev);
1726 	struct gendisk *disk = sdkp->disk;
1727 
1728 	spin_lock(&sd_index_lock);
1729 	idr_remove(&sd_index_idr, sdkp->index);
1730 	spin_unlock(&sd_index_lock);
1731 
1732 	disk->private_data = NULL;
1733 	put_disk(disk);
1734 	put_device(&sdkp->device->sdev_gendev);
1735 
1736 	kfree(sdkp);
1737 }
1738 
1739 static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
1740 {
1741 	unsigned char cmd[6] = { START_STOP };	/* START_VALID */
1742 	struct scsi_sense_hdr sshdr;
1743 	struct scsi_device *sdp = sdkp->device;
1744 	int res;
1745 
1746 	if (start)
1747 		cmd[4] |= 1;	/* START */
1748 
1749 	if (!scsi_device_online(sdp))
1750 		return -ENODEV;
1751 
1752 	res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
1753 			       SD_TIMEOUT, SD_MAX_RETRIES);
1754 	if (res) {
1755 		sd_printk(KERN_WARNING, sdkp, "START_STOP FAILED\n");
1756 		sd_print_result(sdkp, res);
1757 		if (driver_byte(res) & DRIVER_SENSE)
1758 			sd_print_sense_hdr(sdkp, &sshdr);
1759 	}
1760 
1761 	return res;
1762 }
1763 
1764 /*
1765  * Send a SYNCHRONIZE CACHE instruction down to the device through
1766  * the normal SCSI command structure.  Wait for the command to
1767  * complete.
1768  */
1769 static void sd_shutdown(struct device *dev)
1770 {
1771 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
1772 
1773 	if (!sdkp)
1774 		return;         /* this can happen */
1775 
1776 	if (sdkp->WCE) {
1777 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
1778 		sd_sync_cache(sdkp);
1779 	}
1780 
1781 	if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
1782 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
1783 		sd_start_stop_device(sdkp, 0);
1784 	}
1785 
1786 	scsi_disk_put(sdkp);
1787 }
1788 
1789 static int sd_suspend(struct device *dev, pm_message_t mesg)
1790 {
1791 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
1792 	int ret;
1793 
1794 	if (!sdkp)
1795 		return 0;	/* this can happen */
1796 
1797 	if (sdkp->WCE) {
1798 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
1799 		ret = sd_sync_cache(sdkp);
1800 		if (ret)
1801 			return ret;
1802 	}
1803 
1804 	if (mesg.event == PM_EVENT_SUSPEND &&
1805 	    sdkp->device->manage_start_stop) {
1806 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
1807 		ret = sd_start_stop_device(sdkp, 0);
1808 		if (ret)
1809 			return ret;
1810 	}
1811 
1812 	return 0;
1813 }
1814 
1815 static int sd_resume(struct device *dev)
1816 {
1817 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
1818 
1819 	if (!sdkp->device->manage_start_stop)
1820 		return 0;
1821 
1822 	sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
1823 
1824 	return sd_start_stop_device(sdkp, 1);
1825 }
1826 
1827 /**
1828  *	init_sd - entry point for this driver (both when built in or when
1829  *	a module).
1830  *
1831  *	Note: this function registers this driver with the scsi mid-level.
1832  **/
1833 static int __init init_sd(void)
1834 {
1835 	int majors = 0, i, err;
1836 
1837 	SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
1838 
1839 	for (i = 0; i < SD_MAJORS; i++)
1840 		if (register_blkdev(sd_major(i), "sd") == 0)
1841 			majors++;
1842 
1843 	if (!majors)
1844 		return -ENODEV;
1845 
1846 	err = class_register(&sd_disk_class);
1847 	if (err)
1848 		goto err_out;
1849 
1850 	err = scsi_register_driver(&sd_template.gendrv);
1851 	if (err)
1852 		goto err_out_class;
1853 
1854 	return 0;
1855 
1856 err_out_class:
1857 	class_unregister(&sd_disk_class);
1858 err_out:
1859 	for (i = 0; i < SD_MAJORS; i++)
1860 		unregister_blkdev(sd_major(i), "sd");
1861 	return err;
1862 }
1863 
1864 /**
1865  *	exit_sd - exit point for this driver (when it is a module).
1866  *
1867  *	Note: this function unregisters this driver from the scsi mid-level.
1868  **/
1869 static void __exit exit_sd(void)
1870 {
1871 	int i;
1872 
1873 	SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
1874 
1875 	scsi_unregister_driver(&sd_template.gendrv);
1876 	class_unregister(&sd_disk_class);
1877 
1878 	for (i = 0; i < SD_MAJORS; i++)
1879 		unregister_blkdev(sd_major(i), "sd");
1880 }
1881 
1882 module_init(init_sd);
1883 module_exit(exit_sd);
1884 
1885 static void sd_print_sense_hdr(struct scsi_disk *sdkp,
1886 			       struct scsi_sense_hdr *sshdr)
1887 {
1888 	sd_printk(KERN_INFO, sdkp, "");
1889 	scsi_show_sense_hdr(sshdr);
1890 	sd_printk(KERN_INFO, sdkp, "");
1891 	scsi_show_extd_sense(sshdr->asc, sshdr->ascq);
1892 }
1893 
1894 static void sd_print_result(struct scsi_disk *sdkp, int result)
1895 {
1896 	sd_printk(KERN_INFO, sdkp, "");
1897 	scsi_show_result(result);
1898 }
1899 
1900