[SCSI] ses: add subenclosure support
[linux-2.6.git] / drivers / scsi / sd.c
1 /*
2  *      sd.c Copyright (C) 1992 Drew Eckhardt
3  *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4  *
5  *      Linux scsi disk driver
6  *              Initial versions: Drew Eckhardt
7  *              Subsequent revisions: Eric Youngdale
8  *      Modification history:
9  *       - Drew Eckhardt <drew@colorado.edu> original
10  *       - Eric Youngdale <eric@andante.org> add scatter-gather, multiple 
11  *         outstanding request, and other enhancements.
12  *         Support loadable low-level scsi drivers.
13  *       - Jirka Hanika <geo@ff.cuni.cz> support more scsi disks using 
14  *         eight major numbers.
15  *       - Richard Gooch <rgooch@atnf.csiro.au> support devfs.
16  *       - Torben Mathiasen <tmm@image.dk> Resource allocation fixes in 
17  *         sd_init and cleanups.
18  *       - Alex Davis <letmein@erols.com> Fix problem where partition info
19  *         not being read in sd_open. Fix problem where removable media 
20  *         could be ejected after sd_open.
21  *       - Douglas Gilbert <dgilbert@interlog.com> cleanup for lk 2.5.x
22  *       - Badari Pulavarty <pbadari@us.ibm.com>, Matthew Wilcox 
23  *         <willy@debian.org>, Kurt Garloff <garloff@suse.de>: 
24  *         Support 32k/1M disks.
25  *
26  *      Logging policy (needs CONFIG_SCSI_LOGGING defined):
27  *       - setting up transfer: SCSI_LOG_HLQUEUE levels 1 and 2
28  *       - end of transfer (bh + scsi_lib): SCSI_LOG_HLCOMPLETE level 1
29  *       - entering sd_ioctl: SCSI_LOG_IOCTL level 1
30  *       - entering other commands: SCSI_LOG_HLQUEUE level 3
31  *      Note: when the logging level is set by the user, it must be greater
32  *      than the level indicated above to trigger output.       
33  */
34
35 #include <linux/module.h>
36 #include <linux/fs.h>
37 #include <linux/kernel.h>
38 #include <linux/mm.h>
39 #include <linux/bio.h>
40 #include <linux/genhd.h>
41 #include <linux/hdreg.h>
42 #include <linux/errno.h>
43 #include <linux/idr.h>
44 #include <linux/interrupt.h>
45 #include <linux/init.h>
46 #include <linux/blkdev.h>
47 #include <linux/blkpg.h>
48 #include <linux/delay.h>
49 #include <linux/mutex.h>
50 #include <linux/string_helpers.h>
51 #include <linux/async.h>
52 #include <linux/slab.h>
53 #include <asm/uaccess.h>
54 #include <asm/unaligned.h>
55
56 #include <scsi/scsi.h>
57 #include <scsi/scsi_cmnd.h>
58 #include <scsi/scsi_dbg.h>
59 #include <scsi/scsi_device.h>
60 #include <scsi/scsi_driver.h>
61 #include <scsi/scsi_eh.h>
62 #include <scsi/scsi_host.h>
63 #include <scsi/scsi_ioctl.h>
64 #include <scsi/scsicam.h>
65
66 #include "sd.h"
67 #include "scsi_logging.h"
68
69 MODULE_AUTHOR("Eric Youngdale");
70 MODULE_DESCRIPTION("SCSI disk (sd) driver");
71 MODULE_LICENSE("GPL");
72
73 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK0_MAJOR);
74 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK1_MAJOR);
75 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK2_MAJOR);
76 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK3_MAJOR);
77 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK4_MAJOR);
78 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK5_MAJOR);
79 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK6_MAJOR);
80 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK7_MAJOR);
81 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK8_MAJOR);
82 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK9_MAJOR);
83 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK10_MAJOR);
84 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK11_MAJOR);
85 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK12_MAJOR);
86 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK13_MAJOR);
87 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK14_MAJOR);
88 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
89 MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
90 MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
91 MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
92
93 #if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
94 #define SD_MINORS       16
95 #else
96 #define SD_MINORS       0
97 #endif
98
99 static void sd_config_discard(struct scsi_disk *, unsigned int);
100 static int  sd_revalidate_disk(struct gendisk *);
101 static void sd_unlock_native_capacity(struct gendisk *disk);
102 static int  sd_probe(struct device *);
103 static int  sd_remove(struct device *);
104 static void sd_shutdown(struct device *);
105 static int sd_suspend(struct device *, pm_message_t state);
106 static int sd_resume(struct device *);
107 static void sd_rescan(struct device *);
108 static int sd_done(struct scsi_cmnd *);
109 static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
110 static void scsi_disk_release(struct device *cdev);
111 static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
112 static void sd_print_result(struct scsi_disk *, int);
113
114 static DEFINE_SPINLOCK(sd_index_lock);
115 static DEFINE_IDA(sd_index_ida);
116
117 /* This semaphore is used to mediate the 0->1 reference get in the
118  * face of object destruction (i.e. we can't allow a get on an
119  * object after last put) */
120 static DEFINE_MUTEX(sd_ref_mutex);
121
122 static struct kmem_cache *sd_cdb_cache;
123 static mempool_t *sd_cdb_pool;
124
125 static const char *sd_cache_types[] = {
126         "write through", "none", "write back",
127         "write back, no read (daft)"
128 };
129
130 static ssize_t
131 sd_store_cache_type(struct device *dev, struct device_attribute *attr,
132                     const char *buf, size_t count)
133 {
134         int i, ct = -1, rcd, wce, sp;
135         struct scsi_disk *sdkp = to_scsi_disk(dev);
136         struct scsi_device *sdp = sdkp->device;
137         char buffer[64];
138         char *buffer_data;
139         struct scsi_mode_data data;
140         struct scsi_sense_hdr sshdr;
141         int len;
142
143         if (sdp->type != TYPE_DISK)
144                 /* no cache control on RBC devices; theoretically they
145                  * can do it, but there's probably so many exceptions
146                  * it's not worth the risk */
147                 return -EINVAL;
148
149         for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {
150                 len = strlen(sd_cache_types[i]);
151                 if (strncmp(sd_cache_types[i], buf, len) == 0 &&
152                     buf[len] == '\n') {
153                         ct = i;
154                         break;
155                 }
156         }
157         if (ct < 0)
158                 return -EINVAL;
159         rcd = ct & 0x01 ? 1 : 0;
160         wce = ct & 0x02 ? 1 : 0;
161         if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
162                             SD_MAX_RETRIES, &data, NULL))
163                 return -EINVAL;
164         len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
165                   data.block_descriptor_length);
166         buffer_data = buffer + data.header_length +
167                 data.block_descriptor_length;
168         buffer_data[2] &= ~0x05;
169         buffer_data[2] |= wce << 2 | rcd;
170         sp = buffer_data[0] & 0x80 ? 1 : 0;
171
172         if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
173                              SD_MAX_RETRIES, &data, &sshdr)) {
174                 if (scsi_sense_valid(&sshdr))
175                         sd_print_sense_hdr(sdkp, &sshdr);
176                 return -EINVAL;
177         }
178         revalidate_disk(sdkp->disk);
179         return count;
180 }
181
182 static ssize_t
183 sd_store_manage_start_stop(struct device *dev, struct device_attribute *attr,
184                            const char *buf, size_t count)
185 {
186         struct scsi_disk *sdkp = to_scsi_disk(dev);
187         struct scsi_device *sdp = sdkp->device;
188
189         if (!capable(CAP_SYS_ADMIN))
190                 return -EACCES;
191
192         sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
193
194         return count;
195 }
196
197 static ssize_t
198 sd_store_allow_restart(struct device *dev, struct device_attribute *attr,
199                        const char *buf, size_t count)
200 {
201         struct scsi_disk *sdkp = to_scsi_disk(dev);
202         struct scsi_device *sdp = sdkp->device;
203
204         if (!capable(CAP_SYS_ADMIN))
205                 return -EACCES;
206
207         if (sdp->type != TYPE_DISK)
208                 return -EINVAL;
209
210         sdp->allow_restart = simple_strtoul(buf, NULL, 10);
211
212         return count;
213 }
214
215 static ssize_t
216 sd_show_cache_type(struct device *dev, struct device_attribute *attr,
217                    char *buf)
218 {
219         struct scsi_disk *sdkp = to_scsi_disk(dev);
220         int ct = sdkp->RCD + 2*sdkp->WCE;
221
222         return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
223 }
224
225 static ssize_t
226 sd_show_fua(struct device *dev, struct device_attribute *attr, char *buf)
227 {
228         struct scsi_disk *sdkp = to_scsi_disk(dev);
229
230         return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
231 }
232
233 static ssize_t
234 sd_show_manage_start_stop(struct device *dev, struct device_attribute *attr,
235                           char *buf)
236 {
237         struct scsi_disk *sdkp = to_scsi_disk(dev);
238         struct scsi_device *sdp = sdkp->device;
239
240         return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
241 }
242
243 static ssize_t
244 sd_show_allow_restart(struct device *dev, struct device_attribute *attr,
245                       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 sd_show_protection_type(struct device *dev, struct device_attribute *attr,
254                         char *buf)
255 {
256         struct scsi_disk *sdkp = to_scsi_disk(dev);
257
258         return snprintf(buf, 20, "%u\n", sdkp->protection_type);
259 }
260
261 static ssize_t
262 sd_show_protection_mode(struct device *dev, struct device_attribute *attr,
263                         char *buf)
264 {
265         struct scsi_disk *sdkp = to_scsi_disk(dev);
266         struct scsi_device *sdp = sdkp->device;
267         unsigned int dif, dix;
268
269         dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
270         dix = scsi_host_dix_capable(sdp->host, sdkp->protection_type);
271
272         if (!dix && scsi_host_dix_capable(sdp->host, SD_DIF_TYPE0_PROTECTION)) {
273                 dif = 0;
274                 dix = 1;
275         }
276
277         if (!dif && !dix)
278                 return snprintf(buf, 20, "none\n");
279
280         return snprintf(buf, 20, "%s%u\n", dix ? "dix" : "dif", dif);
281 }
282
283 static ssize_t
284 sd_show_app_tag_own(struct device *dev, struct device_attribute *attr,
285                     char *buf)
286 {
287         struct scsi_disk *sdkp = to_scsi_disk(dev);
288
289         return snprintf(buf, 20, "%u\n", sdkp->ATO);
290 }
291
292 static ssize_t
293 sd_show_thin_provisioning(struct device *dev, struct device_attribute *attr,
294                           char *buf)
295 {
296         struct scsi_disk *sdkp = to_scsi_disk(dev);
297
298         return snprintf(buf, 20, "%u\n", sdkp->lbpme);
299 }
300
301 static const char *lbp_mode[] = {
302         [SD_LBP_FULL]           = "full",
303         [SD_LBP_UNMAP]          = "unmap",
304         [SD_LBP_WS16]           = "writesame_16",
305         [SD_LBP_WS10]           = "writesame_10",
306         [SD_LBP_ZERO]           = "writesame_zero",
307         [SD_LBP_DISABLE]        = "disabled",
308 };
309
310 static ssize_t
311 sd_show_provisioning_mode(struct device *dev, struct device_attribute *attr,
312                           char *buf)
313 {
314         struct scsi_disk *sdkp = to_scsi_disk(dev);
315
316         return snprintf(buf, 20, "%s\n", lbp_mode[sdkp->provisioning_mode]);
317 }
318
319 static ssize_t
320 sd_store_provisioning_mode(struct device *dev, struct device_attribute *attr,
321                            const char *buf, size_t count)
322 {
323         struct scsi_disk *sdkp = to_scsi_disk(dev);
324         struct scsi_device *sdp = sdkp->device;
325
326         if (!capable(CAP_SYS_ADMIN))
327                 return -EACCES;
328
329         if (sdp->type != TYPE_DISK)
330                 return -EINVAL;
331
332         if (!strncmp(buf, lbp_mode[SD_LBP_UNMAP], 20))
333                 sd_config_discard(sdkp, SD_LBP_UNMAP);
334         else if (!strncmp(buf, lbp_mode[SD_LBP_WS16], 20))
335                 sd_config_discard(sdkp, SD_LBP_WS16);
336         else if (!strncmp(buf, lbp_mode[SD_LBP_WS10], 20))
337                 sd_config_discard(sdkp, SD_LBP_WS10);
338         else if (!strncmp(buf, lbp_mode[SD_LBP_ZERO], 20))
339                 sd_config_discard(sdkp, SD_LBP_ZERO);
340         else if (!strncmp(buf, lbp_mode[SD_LBP_DISABLE], 20))
341                 sd_config_discard(sdkp, SD_LBP_DISABLE);
342         else
343                 return -EINVAL;
344
345         return count;
346 }
347
348 static struct device_attribute sd_disk_attrs[] = {
349         __ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
350                sd_store_cache_type),
351         __ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
352         __ATTR(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
353                sd_store_allow_restart),
354         __ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
355                sd_store_manage_start_stop),
356         __ATTR(protection_type, S_IRUGO, sd_show_protection_type, NULL),
357         __ATTR(protection_mode, S_IRUGO, sd_show_protection_mode, NULL),
358         __ATTR(app_tag_own, S_IRUGO, sd_show_app_tag_own, NULL),
359         __ATTR(thin_provisioning, S_IRUGO, sd_show_thin_provisioning, NULL),
360         __ATTR(provisioning_mode, S_IRUGO|S_IWUSR, sd_show_provisioning_mode,
361                sd_store_provisioning_mode),
362         __ATTR_NULL,
363 };
364
365 static struct class sd_disk_class = {
366         .name           = "scsi_disk",
367         .owner          = THIS_MODULE,
368         .dev_release    = scsi_disk_release,
369         .dev_attrs      = sd_disk_attrs,
370 };
371
372 static struct scsi_driver sd_template = {
373         .owner                  = THIS_MODULE,
374         .gendrv = {
375                 .name           = "sd",
376                 .probe          = sd_probe,
377                 .remove         = sd_remove,
378                 .suspend        = sd_suspend,
379                 .resume         = sd_resume,
380                 .shutdown       = sd_shutdown,
381         },
382         .rescan                 = sd_rescan,
383         .done                   = sd_done,
384 };
385
386 /*
387  * Device no to disk mapping:
388  * 
389  *       major         disc2     disc  p1
390  *   |............|.............|....|....| <- dev_t
391  *    31        20 19          8 7  4 3  0
392  * 
393  * Inside a major, we have 16k disks, however mapped non-
394  * contiguously. The first 16 disks are for major0, the next
395  * ones with major1, ... Disk 256 is for major0 again, disk 272 
396  * for major1, ... 
397  * As we stay compatible with our numbering scheme, we can reuse 
398  * the well-know SCSI majors 8, 65--71, 136--143.
399  */
400 static int sd_major(int major_idx)
401 {
402         switch (major_idx) {
403         case 0:
404                 return SCSI_DISK0_MAJOR;
405         case 1 ... 7:
406                 return SCSI_DISK1_MAJOR + major_idx - 1;
407         case 8 ... 15:
408                 return SCSI_DISK8_MAJOR + major_idx - 8;
409         default:
410                 BUG();
411                 return 0;       /* shut up gcc */
412         }
413 }
414
415 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
416 {
417         struct scsi_disk *sdkp = NULL;
418
419         if (disk->private_data) {
420                 sdkp = scsi_disk(disk);
421                 if (scsi_device_get(sdkp->device) == 0)
422                         get_device(&sdkp->dev);
423                 else
424                         sdkp = NULL;
425         }
426         return sdkp;
427 }
428
429 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
430 {
431         struct scsi_disk *sdkp;
432
433         mutex_lock(&sd_ref_mutex);
434         sdkp = __scsi_disk_get(disk);
435         mutex_unlock(&sd_ref_mutex);
436         return sdkp;
437 }
438
439 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
440 {
441         struct scsi_disk *sdkp;
442
443         mutex_lock(&sd_ref_mutex);
444         sdkp = dev_get_drvdata(dev);
445         if (sdkp)
446                 sdkp = __scsi_disk_get(sdkp->disk);
447         mutex_unlock(&sd_ref_mutex);
448         return sdkp;
449 }
450
451 static void scsi_disk_put(struct scsi_disk *sdkp)
452 {
453         struct scsi_device *sdev = sdkp->device;
454
455         mutex_lock(&sd_ref_mutex);
456         put_device(&sdkp->dev);
457         scsi_device_put(sdev);
458         mutex_unlock(&sd_ref_mutex);
459 }
460
461 static void sd_prot_op(struct scsi_cmnd *scmd, unsigned int dif)
462 {
463         unsigned int prot_op = SCSI_PROT_NORMAL;
464         unsigned int dix = scsi_prot_sg_count(scmd);
465
466         if (scmd->sc_data_direction == DMA_FROM_DEVICE) {
467                 if (dif && dix)
468                         prot_op = SCSI_PROT_READ_PASS;
469                 else if (dif && !dix)
470                         prot_op = SCSI_PROT_READ_STRIP;
471                 else if (!dif && dix)
472                         prot_op = SCSI_PROT_READ_INSERT;
473         } else {
474                 if (dif && dix)
475                         prot_op = SCSI_PROT_WRITE_PASS;
476                 else if (dif && !dix)
477                         prot_op = SCSI_PROT_WRITE_INSERT;
478                 else if (!dif && dix)
479                         prot_op = SCSI_PROT_WRITE_STRIP;
480         }
481
482         scsi_set_prot_op(scmd, prot_op);
483         scsi_set_prot_type(scmd, dif);
484 }
485
486 static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
487 {
488         struct request_queue *q = sdkp->disk->queue;
489         unsigned int logical_block_size = sdkp->device->sector_size;
490         unsigned int max_blocks = 0;
491
492         q->limits.discard_zeroes_data = sdkp->lbprz;
493         q->limits.discard_alignment = sdkp->unmap_alignment;
494         q->limits.discard_granularity =
495                 max(sdkp->physical_block_size,
496                     sdkp->unmap_granularity * logical_block_size);
497
498         switch (mode) {
499
500         case SD_LBP_DISABLE:
501                 q->limits.max_discard_sectors = 0;
502                 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
503                 return;
504
505         case SD_LBP_UNMAP:
506                 max_blocks = min_not_zero(sdkp->max_unmap_blocks, 0xffffffff);
507                 break;
508
509         case SD_LBP_WS16:
510                 max_blocks = min_not_zero(sdkp->max_ws_blocks, 0xffffffff);
511                 break;
512
513         case SD_LBP_WS10:
514                 max_blocks = min_not_zero(sdkp->max_ws_blocks, (u32)0xffff);
515                 break;
516
517         case SD_LBP_ZERO:
518                 max_blocks = min_not_zero(sdkp->max_ws_blocks, (u32)0xffff);
519                 q->limits.discard_zeroes_data = 1;
520                 break;
521         }
522
523         q->limits.max_discard_sectors = max_blocks * (logical_block_size >> 9);
524         queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
525
526         sdkp->provisioning_mode = mode;
527 }
528
529 /**
530  * scsi_setup_discard_cmnd - unmap blocks on thinly provisioned device
531  * @sdp: scsi device to operate one
532  * @rq: Request to prepare
533  *
534  * Will issue either UNMAP or WRITE SAME(16) depending on preference
535  * indicated by target device.
536  **/
537 static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq)
538 {
539         struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
540         struct bio *bio = rq->bio;
541         sector_t sector = bio->bi_sector;
542         unsigned int nr_sectors = bio_sectors(bio);
543         unsigned int len;
544         int ret;
545         char *buf;
546         struct page *page;
547
548         if (sdkp->device->sector_size == 4096) {
549                 sector >>= 3;
550                 nr_sectors >>= 3;
551         }
552
553         rq->timeout = SD_TIMEOUT;
554
555         memset(rq->cmd, 0, rq->cmd_len);
556
557         page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
558         if (!page)
559                 return BLKPREP_DEFER;
560
561         switch (sdkp->provisioning_mode) {
562         case SD_LBP_UNMAP:
563                 buf = page_address(page);
564
565                 rq->cmd_len = 10;
566                 rq->cmd[0] = UNMAP;
567                 rq->cmd[8] = 24;
568
569                 put_unaligned_be16(6 + 16, &buf[0]);
570                 put_unaligned_be16(16, &buf[2]);
571                 put_unaligned_be64(sector, &buf[8]);
572                 put_unaligned_be32(nr_sectors, &buf[16]);
573
574                 len = 24;
575                 break;
576
577         case SD_LBP_WS16:
578                 rq->cmd_len = 16;
579                 rq->cmd[0] = WRITE_SAME_16;
580                 rq->cmd[1] = 0x8; /* UNMAP */
581                 put_unaligned_be64(sector, &rq->cmd[2]);
582                 put_unaligned_be32(nr_sectors, &rq->cmd[10]);
583
584                 len = sdkp->device->sector_size;
585                 break;
586
587         case SD_LBP_WS10:
588         case SD_LBP_ZERO:
589                 rq->cmd_len = 10;
590                 rq->cmd[0] = WRITE_SAME;
591                 if (sdkp->provisioning_mode == SD_LBP_WS10)
592                         rq->cmd[1] = 0x8; /* UNMAP */
593                 put_unaligned_be32(sector, &rq->cmd[2]);
594                 put_unaligned_be16(nr_sectors, &rq->cmd[7]);
595
596                 len = sdkp->device->sector_size;
597                 break;
598
599         default:
600                 ret = BLKPREP_KILL;
601                 goto out;
602         }
603
604         blk_add_request_payload(rq, page, len);
605         ret = scsi_setup_blk_pc_cmnd(sdp, rq);
606         rq->buffer = page_address(page);
607
608 out:
609         if (ret != BLKPREP_OK) {
610                 __free_page(page);
611                 rq->buffer = NULL;
612         }
613         return ret;
614 }
615
616 static int scsi_setup_flush_cmnd(struct scsi_device *sdp, struct request *rq)
617 {
618         rq->timeout = SD_FLUSH_TIMEOUT;
619         rq->retries = SD_MAX_RETRIES;
620         rq->cmd[0] = SYNCHRONIZE_CACHE;
621         rq->cmd_len = 10;
622
623         return scsi_setup_blk_pc_cmnd(sdp, rq);
624 }
625
626 static void sd_unprep_fn(struct request_queue *q, struct request *rq)
627 {
628         if (rq->cmd_flags & REQ_DISCARD) {
629                 free_page((unsigned long)rq->buffer);
630                 rq->buffer = NULL;
631         }
632 }
633
634 /**
635  *      sd_init_command - build a scsi (read or write) command from
636  *      information in the request structure.
637  *      @SCpnt: pointer to mid-level's per scsi command structure that
638  *      contains request and into which the scsi command is written
639  *
640  *      Returns 1 if successful and 0 if error (or cannot be done now).
641  **/
642 static int sd_prep_fn(struct request_queue *q, struct request *rq)
643 {
644         struct scsi_cmnd *SCpnt;
645         struct scsi_device *sdp = q->queuedata;
646         struct gendisk *disk = rq->rq_disk;
647         struct scsi_disk *sdkp;
648         sector_t block = blk_rq_pos(rq);
649         sector_t threshold;
650         unsigned int this_count = blk_rq_sectors(rq);
651         int ret, host_dif;
652         unsigned char protect;
653
654         /*
655          * Discard request come in as REQ_TYPE_FS but we turn them into
656          * block PC requests to make life easier.
657          */
658         if (rq->cmd_flags & REQ_DISCARD) {
659                 ret = scsi_setup_discard_cmnd(sdp, rq);
660                 goto out;
661         } else if (rq->cmd_flags & REQ_FLUSH) {
662                 ret = scsi_setup_flush_cmnd(sdp, rq);
663                 goto out;
664         } else if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
665                 ret = scsi_setup_blk_pc_cmnd(sdp, rq);
666                 goto out;
667         } else if (rq->cmd_type != REQ_TYPE_FS) {
668                 ret = BLKPREP_KILL;
669                 goto out;
670         }
671         ret = scsi_setup_fs_cmnd(sdp, rq);
672         if (ret != BLKPREP_OK)
673                 goto out;
674         SCpnt = rq->special;
675         sdkp = scsi_disk(disk);
676
677         /* from here on until we're complete, any goto out
678          * is used for a killable error condition */
679         ret = BLKPREP_KILL;
680
681         SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
682                                         "sd_init_command: block=%llu, "
683                                         "count=%d\n",
684                                         (unsigned long long)block,
685                                         this_count));
686
687         if (!sdp || !scsi_device_online(sdp) ||
688             block + blk_rq_sectors(rq) > get_capacity(disk)) {
689                 SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
690                                                 "Finishing %u sectors\n",
691                                                 blk_rq_sectors(rq)));
692                 SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
693                                                 "Retry with 0x%p\n", SCpnt));
694                 goto out;
695         }
696
697         if (sdp->changed) {
698                 /*
699                  * quietly refuse to do anything to a changed disc until 
700                  * the changed bit has been reset
701                  */
702                 /* printk("SCSI disk has been changed or is not present. Prohibiting further I/O.\n"); */
703                 goto out;
704         }
705
706         /*
707          * Some SD card readers can't handle multi-sector accesses which touch
708          * the last one or two hardware sectors.  Split accesses as needed.
709          */
710         threshold = get_capacity(disk) - SD_LAST_BUGGY_SECTORS *
711                 (sdp->sector_size / 512);
712
713         if (unlikely(sdp->last_sector_bug && block + this_count > threshold)) {
714                 if (block < threshold) {
715                         /* Access up to the threshold but not beyond */
716                         this_count = threshold - block;
717                 } else {
718                         /* Access only a single hardware sector */
719                         this_count = sdp->sector_size / 512;
720                 }
721         }
722
723         SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
724                                         (unsigned long long)block));
725
726         /*
727          * If we have a 1K hardware sectorsize, prevent access to single
728          * 512 byte sectors.  In theory we could handle this - in fact
729          * the scsi cdrom driver must be able to handle this because
730          * we typically use 1K blocksizes, and cdroms typically have
731          * 2K hardware sectorsizes.  Of course, things are simpler
732          * with the cdrom, since it is read-only.  For performance
733          * reasons, the filesystems should be able to handle this
734          * and not force the scsi disk driver to use bounce buffers
735          * for this.
736          */
737         if (sdp->sector_size == 1024) {
738                 if ((block & 1) || (blk_rq_sectors(rq) & 1)) {
739                         scmd_printk(KERN_ERR, SCpnt,
740                                     "Bad block number requested\n");
741                         goto out;
742                 } else {
743                         block = block >> 1;
744                         this_count = this_count >> 1;
745                 }
746         }
747         if (sdp->sector_size == 2048) {
748                 if ((block & 3) || (blk_rq_sectors(rq) & 3)) {
749                         scmd_printk(KERN_ERR, SCpnt,
750                                     "Bad block number requested\n");
751                         goto out;
752                 } else {
753                         block = block >> 2;
754                         this_count = this_count >> 2;
755                 }
756         }
757         if (sdp->sector_size == 4096) {
758                 if ((block & 7) || (blk_rq_sectors(rq) & 7)) {
759                         scmd_printk(KERN_ERR, SCpnt,
760                                     "Bad block number requested\n");
761                         goto out;
762                 } else {
763                         block = block >> 3;
764                         this_count = this_count >> 3;
765                 }
766         }
767         if (rq_data_dir(rq) == WRITE) {
768                 if (!sdp->writeable) {
769                         goto out;
770                 }
771                 SCpnt->cmnd[0] = WRITE_6;
772                 SCpnt->sc_data_direction = DMA_TO_DEVICE;
773
774                 if (blk_integrity_rq(rq) &&
775                     sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
776                         goto out;
777
778         } else if (rq_data_dir(rq) == READ) {
779                 SCpnt->cmnd[0] = READ_6;
780                 SCpnt->sc_data_direction = DMA_FROM_DEVICE;
781         } else {
782                 scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
783                 goto out;
784         }
785
786         SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
787                                         "%s %d/%u 512 byte blocks.\n",
788                                         (rq_data_dir(rq) == WRITE) ?
789                                         "writing" : "reading", this_count,
790                                         blk_rq_sectors(rq)));
791
792         /* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
793         host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
794         if (host_dif)
795                 protect = 1 << 5;
796         else
797                 protect = 0;
798
799         if (host_dif == SD_DIF_TYPE2_PROTECTION) {
800                 SCpnt->cmnd = mempool_alloc(sd_cdb_pool, GFP_ATOMIC);
801
802                 if (unlikely(SCpnt->cmnd == NULL)) {
803                         ret = BLKPREP_DEFER;
804                         goto out;
805                 }
806
807                 SCpnt->cmd_len = SD_EXT_CDB_SIZE;
808                 memset(SCpnt->cmnd, 0, SCpnt->cmd_len);
809                 SCpnt->cmnd[0] = VARIABLE_LENGTH_CMD;
810                 SCpnt->cmnd[7] = 0x18;
811                 SCpnt->cmnd[9] = (rq_data_dir(rq) == READ) ? READ_32 : WRITE_32;
812                 SCpnt->cmnd[10] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
813
814                 /* LBA */
815                 SCpnt->cmnd[12] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
816                 SCpnt->cmnd[13] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
817                 SCpnt->cmnd[14] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
818                 SCpnt->cmnd[15] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
819                 SCpnt->cmnd[16] = (unsigned char) (block >> 24) & 0xff;
820                 SCpnt->cmnd[17] = (unsigned char) (block >> 16) & 0xff;
821                 SCpnt->cmnd[18] = (unsigned char) (block >> 8) & 0xff;
822                 SCpnt->cmnd[19] = (unsigned char) block & 0xff;
823
824                 /* Expected Indirect LBA */
825                 SCpnt->cmnd[20] = (unsigned char) (block >> 24) & 0xff;
826                 SCpnt->cmnd[21] = (unsigned char) (block >> 16) & 0xff;
827                 SCpnt->cmnd[22] = (unsigned char) (block >> 8) & 0xff;
828                 SCpnt->cmnd[23] = (unsigned char) block & 0xff;
829
830                 /* Transfer length */
831                 SCpnt->cmnd[28] = (unsigned char) (this_count >> 24) & 0xff;
832                 SCpnt->cmnd[29] = (unsigned char) (this_count >> 16) & 0xff;
833                 SCpnt->cmnd[30] = (unsigned char) (this_count >> 8) & 0xff;
834                 SCpnt->cmnd[31] = (unsigned char) this_count & 0xff;
835         } else if (block > 0xffffffff) {
836                 SCpnt->cmnd[0] += READ_16 - READ_6;
837                 SCpnt->cmnd[1] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
838                 SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
839                 SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
840                 SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
841                 SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
842                 SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
843                 SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
844                 SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
845                 SCpnt->cmnd[9] = (unsigned char) block & 0xff;
846                 SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
847                 SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
848                 SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
849                 SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
850                 SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
851         } else if ((this_count > 0xff) || (block > 0x1fffff) ||
852                    scsi_device_protection(SCpnt->device) ||
853                    SCpnt->device->use_10_for_rw) {
854                 if (this_count > 0xffff)
855                         this_count = 0xffff;
856
857                 SCpnt->cmnd[0] += READ_10 - READ_6;
858                 SCpnt->cmnd[1] = protect | ((rq->cmd_flags & REQ_FUA) ? 0x8 : 0);
859                 SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
860                 SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
861                 SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
862                 SCpnt->cmnd[5] = (unsigned char) block & 0xff;
863                 SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
864                 SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
865                 SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
866         } else {
867                 if (unlikely(rq->cmd_flags & REQ_FUA)) {
868                         /*
869                          * This happens only if this drive failed
870                          * 10byte rw command with ILLEGAL_REQUEST
871                          * during operation and thus turned off
872                          * use_10_for_rw.
873                          */
874                         scmd_printk(KERN_ERR, SCpnt,
875                                     "FUA write on READ/WRITE(6) drive\n");
876                         goto out;
877                 }
878
879                 SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
880                 SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
881                 SCpnt->cmnd[3] = (unsigned char) block & 0xff;
882                 SCpnt->cmnd[4] = (unsigned char) this_count;
883                 SCpnt->cmnd[5] = 0;
884         }
885         SCpnt->sdb.length = this_count * sdp->sector_size;
886
887         /* If DIF or DIX is enabled, tell HBA how to handle request */
888         if (host_dif || scsi_prot_sg_count(SCpnt))
889                 sd_prot_op(SCpnt, host_dif);
890
891         /*
892          * We shouldn't disconnect in the middle of a sector, so with a dumb
893          * host adapter, it's safe to assume that we can at least transfer
894          * this many bytes between each connect / disconnect.
895          */
896         SCpnt->transfersize = sdp->sector_size;
897         SCpnt->underflow = this_count << 9;
898         SCpnt->allowed = SD_MAX_RETRIES;
899
900         /*
901          * This indicates that the command is ready from our end to be
902          * queued.
903          */
904         ret = BLKPREP_OK;
905  out:
906         return scsi_prep_return(q, rq, ret);
907 }
908
909 /**
910  *      sd_open - open a scsi disk device
911  *      @inode: only i_rdev member may be used
912  *      @filp: only f_mode and f_flags may be used
913  *
914  *      Returns 0 if successful. Returns a negated errno value in case 
915  *      of error.
916  *
917  *      Note: This can be called from a user context (e.g. fsck(1) )
918  *      or from within the kernel (e.g. as a result of a mount(1) ).
919  *      In the latter case @inode and @filp carry an abridged amount
920  *      of information as noted above.
921  *
922  *      Locking: called with bdev->bd_mutex held.
923  **/
924 static int sd_open(struct block_device *bdev, fmode_t mode)
925 {
926         struct scsi_disk *sdkp = scsi_disk_get(bdev->bd_disk);
927         struct scsi_device *sdev;
928         int retval;
929
930         if (!sdkp)
931                 return -ENXIO;
932
933         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
934
935         sdev = sdkp->device;
936
937         retval = scsi_autopm_get_device(sdev);
938         if (retval)
939                 goto error_autopm;
940
941         /*
942          * If the device is in error recovery, wait until it is done.
943          * If the device is offline, then disallow any access to it.
944          */
945         retval = -ENXIO;
946         if (!scsi_block_when_processing_errors(sdev))
947                 goto error_out;
948
949         if (sdev->removable || sdkp->write_prot)
950                 check_disk_change(bdev);
951
952         /*
953          * If the drive is empty, just let the open fail.
954          */
955         retval = -ENOMEDIUM;
956         if (sdev->removable && !sdkp->media_present && !(mode & FMODE_NDELAY))
957                 goto error_out;
958
959         /*
960          * If the device has the write protect tab set, have the open fail
961          * if the user expects to be able to write to the thing.
962          */
963         retval = -EROFS;
964         if (sdkp->write_prot && (mode & FMODE_WRITE))
965                 goto error_out;
966
967         /*
968          * It is possible that the disk changing stuff resulted in
969          * the device being taken offline.  If this is the case,
970          * report this to the user, and don't pretend that the
971          * open actually succeeded.
972          */
973         retval = -ENXIO;
974         if (!scsi_device_online(sdev))
975                 goto error_out;
976
977         if ((atomic_inc_return(&sdkp->openers) == 1) && sdev->removable) {
978                 if (scsi_block_when_processing_errors(sdev))
979                         scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
980         }
981
982         return 0;
983
984 error_out:
985         scsi_autopm_put_device(sdev);
986 error_autopm:
987         scsi_disk_put(sdkp);
988         return retval;  
989 }
990
991 /**
992  *      sd_release - invoked when the (last) close(2) is called on this
993  *      scsi disk.
994  *      @inode: only i_rdev member may be used
995  *      @filp: only f_mode and f_flags may be used
996  *
997  *      Returns 0. 
998  *
999  *      Note: may block (uninterruptible) if error recovery is underway
1000  *      on this disk.
1001  *
1002  *      Locking: called with bdev->bd_mutex held.
1003  **/
1004 static int sd_release(struct gendisk *disk, fmode_t mode)
1005 {
1006         struct scsi_disk *sdkp = scsi_disk(disk);
1007         struct scsi_device *sdev = sdkp->device;
1008
1009         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_release\n"));
1010
1011         if (atomic_dec_return(&sdkp->openers) == 0 && sdev->removable) {
1012                 if (scsi_block_when_processing_errors(sdev))
1013                         scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
1014         }
1015
1016         /*
1017          * XXX and what if there are packets in flight and this close()
1018          * XXX is followed by a "rmmod sd_mod"?
1019          */
1020
1021         scsi_autopm_put_device(sdev);
1022         scsi_disk_put(sdkp);
1023         return 0;
1024 }
1025
1026 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
1027 {
1028         struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
1029         struct scsi_device *sdp = sdkp->device;
1030         struct Scsi_Host *host = sdp->host;
1031         int diskinfo[4];
1032
1033         /* default to most commonly used values */
1034         diskinfo[0] = 0x40;     /* 1 << 6 */
1035         diskinfo[1] = 0x20;     /* 1 << 5 */
1036         diskinfo[2] = sdkp->capacity >> 11;
1037         
1038         /* override with calculated, extended default, or driver values */
1039         if (host->hostt->bios_param)
1040                 host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
1041         else
1042                 scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
1043
1044         geo->heads = diskinfo[0];
1045         geo->sectors = diskinfo[1];
1046         geo->cylinders = diskinfo[2];
1047         return 0;
1048 }
1049
1050 /**
1051  *      sd_ioctl - process an ioctl
1052  *      @inode: only i_rdev/i_bdev members may be used
1053  *      @filp: only f_mode and f_flags may be used
1054  *      @cmd: ioctl command number
1055  *      @arg: this is third argument given to ioctl(2) system call.
1056  *      Often contains a pointer.
1057  *
1058  *      Returns 0 if successful (some ioctls return postive numbers on
1059  *      success as well). Returns a negated errno value in case of error.
1060  *
1061  *      Note: most ioctls are forward onto the block subsystem or further
1062  *      down in the scsi subsystem.
1063  **/
1064 static int sd_ioctl(struct block_device *bdev, fmode_t mode,
1065                     unsigned int cmd, unsigned long arg)
1066 {
1067         struct gendisk *disk = bdev->bd_disk;
1068         struct scsi_device *sdp = scsi_disk(disk)->device;
1069         void __user *p = (void __user *)arg;
1070         int error;
1071     
1072         SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
1073                                                 disk->disk_name, cmd));
1074
1075         /*
1076          * If we are in the middle of error recovery, don't let anyone
1077          * else try and use this device.  Also, if error recovery fails, it
1078          * may try and take the device offline, in which case all further
1079          * access to the device is prohibited.
1080          */
1081         error = scsi_nonblockable_ioctl(sdp, cmd, p,
1082                                         (mode & FMODE_NDELAY) != 0);
1083         if (!scsi_block_when_processing_errors(sdp) || !error)
1084                 goto out;
1085
1086         /*
1087          * Send SCSI addressing ioctls directly to mid level, send other
1088          * ioctls to block level and then onto mid level if they can't be
1089          * resolved.
1090          */
1091         switch (cmd) {
1092                 case SCSI_IOCTL_GET_IDLUN:
1093                 case SCSI_IOCTL_GET_BUS_NUMBER:
1094                         error = scsi_ioctl(sdp, cmd, p);
1095                         break;
1096                 default:
1097                         error = scsi_cmd_ioctl(disk->queue, disk, mode, cmd, p);
1098                         if (error != -ENOTTY)
1099                                 break;
1100                         error = scsi_ioctl(sdp, cmd, p);
1101                         break;
1102         }
1103 out:
1104         return error;
1105 }
1106
1107 static void set_media_not_present(struct scsi_disk *sdkp)
1108 {
1109         if (sdkp->media_present)
1110                 sdkp->device->changed = 1;
1111
1112         if (sdkp->device->removable) {
1113                 sdkp->media_present = 0;
1114                 sdkp->capacity = 0;
1115         }
1116 }
1117
1118 static int media_not_present(struct scsi_disk *sdkp,
1119                              struct scsi_sense_hdr *sshdr)
1120 {
1121         if (!scsi_sense_valid(sshdr))
1122                 return 0;
1123
1124         /* not invoked for commands that could return deferred errors */
1125         switch (sshdr->sense_key) {
1126         case UNIT_ATTENTION:
1127         case NOT_READY:
1128                 /* medium not present */
1129                 if (sshdr->asc == 0x3A) {
1130                         set_media_not_present(sdkp);
1131                         return 1;
1132                 }
1133         }
1134         return 0;
1135 }
1136
1137 /**
1138  *      sd_check_events - check media events
1139  *      @disk: kernel device descriptor
1140  *      @clearing: disk events currently being cleared
1141  *
1142  *      Returns mask of DISK_EVENT_*.
1143  *
1144  *      Note: this function is invoked from the block subsystem.
1145  **/
1146 static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
1147 {
1148         struct scsi_disk *sdkp = scsi_disk(disk);
1149         struct scsi_device *sdp = sdkp->device;
1150         struct scsi_sense_hdr *sshdr = NULL;
1151         int retval;
1152
1153         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_check_events\n"));
1154
1155         /*
1156          * If the device is offline, don't send any commands - just pretend as
1157          * if the command failed.  If the device ever comes back online, we
1158          * can deal with it then.  It is only because of unrecoverable errors
1159          * that we would ever take a device offline in the first place.
1160          */
1161         if (!scsi_device_online(sdp)) {
1162                 set_media_not_present(sdkp);
1163                 goto out;
1164         }
1165
1166         /*
1167          * Using TEST_UNIT_READY enables differentiation between drive with
1168          * no cartridge loaded - NOT READY, drive with changed cartridge -
1169          * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
1170          *
1171          * Drives that auto spin down. eg iomega jaz 1G, will be started
1172          * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
1173          * sd_revalidate() is called.
1174          */
1175         retval = -ENODEV;
1176
1177         if (scsi_block_when_processing_errors(sdp)) {
1178                 sshdr  = kzalloc(sizeof(*sshdr), GFP_KERNEL);
1179                 retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
1180                                               sshdr);
1181         }
1182
1183         /* failed to execute TUR, assume media not present */
1184         if (host_byte(retval)) {
1185                 set_media_not_present(sdkp);
1186                 goto out;
1187         }
1188
1189         if (media_not_present(sdkp, sshdr))
1190                 goto out;
1191
1192         /*
1193          * For removable scsi disk we have to recognise the presence
1194          * of a disk in the drive.
1195          */
1196         if (!sdkp->media_present)
1197                 sdp->changed = 1;
1198         sdkp->media_present = 1;
1199 out:
1200         /*
1201          * sdp->changed is set under the following conditions:
1202          *
1203          *      Medium present state has changed in either direction.
1204          *      Device has indicated UNIT_ATTENTION.
1205          */
1206         kfree(sshdr);
1207         retval = sdp->changed ? DISK_EVENT_MEDIA_CHANGE : 0;
1208         sdp->changed = 0;
1209         return retval;
1210 }
1211
1212 static int sd_sync_cache(struct scsi_disk *sdkp)
1213 {
1214         int retries, res;
1215         struct scsi_device *sdp = sdkp->device;
1216         struct scsi_sense_hdr sshdr;
1217
1218         if (!scsi_device_online(sdp))
1219                 return -ENODEV;
1220
1221
1222         for (retries = 3; retries > 0; --retries) {
1223                 unsigned char cmd[10] = { 0 };
1224
1225                 cmd[0] = SYNCHRONIZE_CACHE;
1226                 /*
1227                  * Leave the rest of the command zero to indicate
1228                  * flush everything.
1229                  */
1230                 res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
1231                                        SD_FLUSH_TIMEOUT, SD_MAX_RETRIES, NULL);
1232                 if (res == 0)
1233                         break;
1234         }
1235
1236         if (res) {
1237                 sd_print_result(sdkp, res);
1238                 if (driver_byte(res) & DRIVER_SENSE)
1239                         sd_print_sense_hdr(sdkp, &sshdr);
1240         }
1241
1242         if (res)
1243                 return -EIO;
1244         return 0;
1245 }
1246
1247 static void sd_rescan(struct device *dev)
1248 {
1249         struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
1250
1251         if (sdkp) {
1252                 revalidate_disk(sdkp->disk);
1253                 scsi_disk_put(sdkp);
1254         }
1255 }
1256
1257
1258 #ifdef CONFIG_COMPAT
1259 /* 
1260  * This gets directly called from VFS. When the ioctl 
1261  * is not recognized we go back to the other translation paths. 
1262  */
1263 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
1264                            unsigned int cmd, unsigned long arg)
1265 {
1266         struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
1267
1268         /*
1269          * If we are in the middle of error recovery, don't let anyone
1270          * else try and use this device.  Also, if error recovery fails, it
1271          * may try and take the device offline, in which case all further
1272          * access to the device is prohibited.
1273          */
1274         if (!scsi_block_when_processing_errors(sdev))
1275                 return -ENODEV;
1276                
1277         if (sdev->host->hostt->compat_ioctl) {
1278                 int ret;
1279
1280                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
1281
1282                 return ret;
1283         }
1284
1285         /* 
1286          * Let the static ioctl translation table take care of it.
1287          */
1288         return -ENOIOCTLCMD; 
1289 }
1290 #endif
1291
1292 static const struct block_device_operations sd_fops = {
1293         .owner                  = THIS_MODULE,
1294         .open                   = sd_open,
1295         .release                = sd_release,
1296         .ioctl                  = sd_ioctl,
1297         .getgeo                 = sd_getgeo,
1298 #ifdef CONFIG_COMPAT
1299         .compat_ioctl           = sd_compat_ioctl,
1300 #endif
1301         .check_events           = sd_check_events,
1302         .revalidate_disk        = sd_revalidate_disk,
1303         .unlock_native_capacity = sd_unlock_native_capacity,
1304 };
1305
1306 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
1307 {
1308         u64 start_lba = blk_rq_pos(scmd->request);
1309         u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
1310         u64 bad_lba;
1311         int info_valid;
1312         /*
1313          * resid is optional but mostly filled in.  When it's unused,
1314          * its value is zero, so we assume the whole buffer transferred
1315          */
1316         unsigned int transferred = scsi_bufflen(scmd) - scsi_get_resid(scmd);
1317         unsigned int good_bytes;
1318
1319         if (scmd->request->cmd_type != REQ_TYPE_FS)
1320                 return 0;
1321
1322         info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
1323                                              SCSI_SENSE_BUFFERSIZE,
1324                                              &bad_lba);
1325         if (!info_valid)
1326                 return 0;
1327
1328         if (scsi_bufflen(scmd) <= scmd->device->sector_size)
1329                 return 0;
1330
1331         if (scmd->device->sector_size < 512) {
1332                 /* only legitimate sector_size here is 256 */
1333                 start_lba <<= 1;
1334                 end_lba <<= 1;
1335         } else {
1336                 /* be careful ... don't want any overflows */
1337                 u64 factor = scmd->device->sector_size / 512;
1338                 do_div(start_lba, factor);
1339                 do_div(end_lba, factor);
1340         }
1341
1342         /* The bad lba was reported incorrectly, we have no idea where
1343          * the error is.
1344          */
1345         if (bad_lba < start_lba  || bad_lba >= end_lba)
1346                 return 0;
1347
1348         /* This computation should always be done in terms of
1349          * the resolution of the device's medium.
1350          */
1351         good_bytes = (bad_lba - start_lba) * scmd->device->sector_size;
1352         return min(good_bytes, transferred);
1353 }
1354
1355 /**
1356  *      sd_done - bottom half handler: called when the lower level
1357  *      driver has completed (successfully or otherwise) a scsi command.
1358  *      @SCpnt: mid-level's per command structure.
1359  *
1360  *      Note: potentially run from within an ISR. Must not block.
1361  **/
1362 static int sd_done(struct scsi_cmnd *SCpnt)
1363 {
1364         int result = SCpnt->result;
1365         unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
1366         struct scsi_sense_hdr sshdr;
1367         struct scsi_disk *sdkp = scsi_disk(SCpnt->request->rq_disk);
1368         int sense_valid = 0;
1369         int sense_deferred = 0;
1370         unsigned char op = SCpnt->cmnd[0];
1371
1372         if ((SCpnt->request->cmd_flags & REQ_DISCARD) && !result)
1373                 scsi_set_resid(SCpnt, 0);
1374
1375         if (result) {
1376                 sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
1377                 if (sense_valid)
1378                         sense_deferred = scsi_sense_is_deferred(&sshdr);
1379         }
1380 #ifdef CONFIG_SCSI_LOGGING
1381         SCSI_LOG_HLCOMPLETE(1, scsi_print_result(SCpnt));
1382         if (sense_valid) {
1383                 SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
1384                                                    "sd_done: sb[respc,sk,asc,"
1385                                                    "ascq]=%x,%x,%x,%x\n",
1386                                                    sshdr.response_code,
1387                                                    sshdr.sense_key, sshdr.asc,
1388                                                    sshdr.ascq));
1389         }
1390 #endif
1391         if (driver_byte(result) != DRIVER_SENSE &&
1392             (!sense_valid || sense_deferred))
1393                 goto out;
1394
1395         switch (sshdr.sense_key) {
1396         case HARDWARE_ERROR:
1397         case MEDIUM_ERROR:
1398                 good_bytes = sd_completed_bytes(SCpnt);
1399                 break;
1400         case RECOVERED_ERROR:
1401                 good_bytes = scsi_bufflen(SCpnt);
1402                 break;
1403         case NO_SENSE:
1404                 /* This indicates a false check condition, so ignore it.  An
1405                  * unknown amount of data was transferred so treat it as an
1406                  * error.
1407                  */
1408                 scsi_print_sense("sd", SCpnt);
1409                 SCpnt->result = 0;
1410                 memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1411                 break;
1412         case ABORTED_COMMAND:
1413                 if (sshdr.asc == 0x10)  /* DIF: Target detected corruption */
1414                         good_bytes = sd_completed_bytes(SCpnt);
1415                 break;
1416         case ILLEGAL_REQUEST:
1417                 if (sshdr.asc == 0x10)  /* DIX: Host detected corruption */
1418                         good_bytes = sd_completed_bytes(SCpnt);
1419                 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
1420                 if ((sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
1421                     (op == UNMAP || op == WRITE_SAME_16 || op == WRITE_SAME))
1422                         sd_config_discard(sdkp, SD_LBP_DISABLE);
1423                 break;
1424         default:
1425                 break;
1426         }
1427  out:
1428         if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
1429                 sd_dif_complete(SCpnt, good_bytes);
1430
1431         if (scsi_host_dif_capable(sdkp->device->host, sdkp->protection_type)
1432             == SD_DIF_TYPE2_PROTECTION && SCpnt->cmnd != SCpnt->request->cmd) {
1433
1434                 /* We have to print a failed command here as the
1435                  * extended CDB gets freed before scsi_io_completion()
1436                  * is called.
1437                  */
1438                 if (result)
1439                         scsi_print_command(SCpnt);
1440
1441                 mempool_free(SCpnt->cmnd, sd_cdb_pool);
1442                 SCpnt->cmnd = NULL;
1443                 SCpnt->cmd_len = 0;
1444         }
1445
1446         return good_bytes;
1447 }
1448
1449 /*
1450  * spinup disk - called only in sd_revalidate_disk()
1451  */
1452 static void
1453 sd_spinup_disk(struct scsi_disk *sdkp)
1454 {
1455         unsigned char cmd[10];
1456         unsigned long spintime_expire = 0;
1457         int retries, spintime;
1458         unsigned int the_result;
1459         struct scsi_sense_hdr sshdr;
1460         int sense_valid = 0;
1461
1462         spintime = 0;
1463
1464         /* Spin up drives, as required.  Only do this at boot time */
1465         /* Spinup needs to be done for module loads too. */
1466         do {
1467                 retries = 0;
1468
1469                 do {
1470                         cmd[0] = TEST_UNIT_READY;
1471                         memset((void *) &cmd[1], 0, 9);
1472
1473                         the_result = scsi_execute_req(sdkp->device, cmd,
1474                                                       DMA_NONE, NULL, 0,
1475                                                       &sshdr, SD_TIMEOUT,
1476                                                       SD_MAX_RETRIES, NULL);
1477
1478                         /*
1479                          * If the drive has indicated to us that it
1480                          * doesn't have any media in it, don't bother
1481                          * with any more polling.
1482                          */
1483                         if (media_not_present(sdkp, &sshdr))
1484                                 return;
1485
1486                         if (the_result)
1487                                 sense_valid = scsi_sense_valid(&sshdr);
1488                         retries++;
1489                 } while (retries < 3 && 
1490                          (!scsi_status_is_good(the_result) ||
1491                           ((driver_byte(the_result) & DRIVER_SENSE) &&
1492                           sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1493
1494                 if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1495                         /* no sense, TUR either succeeded or failed
1496                          * with a status error */
1497                         if(!spintime && !scsi_status_is_good(the_result)) {
1498                                 sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1499                                 sd_print_result(sdkp, the_result);
1500                         }
1501                         break;
1502                 }
1503                                         
1504                 /*
1505                  * The device does not want the automatic start to be issued.
1506                  */
1507                 if (sdkp->device->no_start_on_add)
1508                         break;
1509
1510                 if (sense_valid && sshdr.sense_key == NOT_READY) {
1511                         if (sshdr.asc == 4 && sshdr.ascq == 3)
1512                                 break;  /* manual intervention required */
1513                         if (sshdr.asc == 4 && sshdr.ascq == 0xb)
1514                                 break;  /* standby */
1515                         if (sshdr.asc == 4 && sshdr.ascq == 0xc)
1516                                 break;  /* unavailable */
1517                         /*
1518                          * Issue command to spin up drive when not ready
1519                          */
1520                         if (!spintime) {
1521                                 sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
1522                                 cmd[0] = START_STOP;
1523                                 cmd[1] = 1;     /* Return immediately */
1524                                 memset((void *) &cmd[2], 0, 8);
1525                                 cmd[4] = 1;     /* Start spin cycle */
1526                                 if (sdkp->device->start_stop_pwr_cond)
1527                                         cmd[4] |= 1 << 4;
1528                                 scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1529                                                  NULL, 0, &sshdr,
1530                                                  SD_TIMEOUT, SD_MAX_RETRIES,
1531                                                  NULL);
1532                                 spintime_expire = jiffies + 100 * HZ;
1533                                 spintime = 1;
1534                         }
1535                         /* Wait 1 second for next try */
1536                         msleep(1000);
1537                         printk(".");
1538
1539                 /*
1540                  * Wait for USB flash devices with slow firmware.
1541                  * Yes, this sense key/ASC combination shouldn't
1542                  * occur here.  It's characteristic of these devices.
1543                  */
1544                 } else if (sense_valid &&
1545                                 sshdr.sense_key == UNIT_ATTENTION &&
1546                                 sshdr.asc == 0x28) {
1547                         if (!spintime) {
1548                                 spintime_expire = jiffies + 5 * HZ;
1549                                 spintime = 1;
1550                         }
1551                         /* Wait 1 second for next try */
1552                         msleep(1000);
1553                 } else {
1554                         /* we don't understand the sense code, so it's
1555                          * probably pointless to loop */
1556                         if(!spintime) {
1557                                 sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1558                                 sd_print_sense_hdr(sdkp, &sshdr);
1559                         }
1560                         break;
1561                 }
1562                                 
1563         } while (spintime && time_before_eq(jiffies, spintime_expire));
1564
1565         if (spintime) {
1566                 if (scsi_status_is_good(the_result))
1567                         printk("ready\n");
1568                 else
1569                         printk("not responding...\n");
1570         }
1571 }
1572
1573
1574 /*
1575  * Determine whether disk supports Data Integrity Field.
1576  */
1577 static void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
1578 {
1579         struct scsi_device *sdp = sdkp->device;
1580         u8 type;
1581
1582         if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
1583                 return;
1584
1585         type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
1586
1587         if (type == sdkp->protection_type || !sdkp->first_scan)
1588                 return;
1589
1590         sdkp->protection_type = type;
1591
1592         if (type > SD_DIF_TYPE3_PROTECTION) {
1593                 sd_printk(KERN_ERR, sdkp, "formatted with unsupported " \
1594                           "protection type %u. Disabling disk!\n", type);
1595                 sdkp->capacity = 0;
1596                 return;
1597         }
1598
1599         if (scsi_host_dif_capable(sdp->host, type))
1600                 sd_printk(KERN_NOTICE, sdkp,
1601                           "Enabling DIF Type %u protection\n", type);
1602         else
1603                 sd_printk(KERN_NOTICE, sdkp,
1604                           "Disabling DIF Type %u protection\n", type);
1605 }
1606
1607 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
1608                         struct scsi_sense_hdr *sshdr, int sense_valid,
1609                         int the_result)
1610 {
1611         sd_print_result(sdkp, the_result);
1612         if (driver_byte(the_result) & DRIVER_SENSE)
1613                 sd_print_sense_hdr(sdkp, sshdr);
1614         else
1615                 sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
1616
1617         /*
1618          * Set dirty bit for removable devices if not ready -
1619          * sometimes drives will not report this properly.
1620          */
1621         if (sdp->removable &&
1622             sense_valid && sshdr->sense_key == NOT_READY)
1623                 set_media_not_present(sdkp);
1624
1625         /*
1626          * We used to set media_present to 0 here to indicate no media
1627          * in the drive, but some drives fail read capacity even with
1628          * media present, so we can't do that.
1629          */
1630         sdkp->capacity = 0; /* unknown mapped to zero - as usual */
1631 }
1632
1633 #define RC16_LEN 32
1634 #if RC16_LEN > SD_BUF_SIZE
1635 #error RC16_LEN must not be more than SD_BUF_SIZE
1636 #endif
1637
1638 #define READ_CAPACITY_RETRIES_ON_RESET  10
1639
1640 static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
1641                                                 unsigned char *buffer)
1642 {
1643         unsigned char cmd[16];
1644         struct scsi_sense_hdr sshdr;
1645         int sense_valid = 0;
1646         int the_result;
1647         int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
1648         unsigned int alignment;
1649         unsigned long long lba;
1650         unsigned sector_size;
1651
1652         if (sdp->no_read_capacity_16)
1653                 return -EINVAL;
1654
1655         do {
1656                 memset(cmd, 0, 16);
1657                 cmd[0] = SERVICE_ACTION_IN;
1658                 cmd[1] = SAI_READ_CAPACITY_16;
1659                 cmd[13] = RC16_LEN;
1660                 memset(buffer, 0, RC16_LEN);
1661
1662                 the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1663                                         buffer, RC16_LEN, &sshdr,
1664                                         SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1665
1666                 if (media_not_present(sdkp, &sshdr))
1667                         return -ENODEV;
1668
1669                 if (the_result) {
1670                         sense_valid = scsi_sense_valid(&sshdr);
1671                         if (sense_valid &&
1672                             sshdr.sense_key == ILLEGAL_REQUEST &&
1673                             (sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
1674                             sshdr.ascq == 0x00)
1675                                 /* Invalid Command Operation Code or
1676                                  * Invalid Field in CDB, just retry
1677                                  * silently with RC10 */
1678                                 return -EINVAL;
1679                         if (sense_valid &&
1680                             sshdr.sense_key == UNIT_ATTENTION &&
1681                             sshdr.asc == 0x29 && sshdr.ascq == 0x00)
1682                                 /* Device reset might occur several times,
1683                                  * give it one more chance */
1684                                 if (--reset_retries > 0)
1685                                         continue;
1686                 }
1687                 retries--;
1688
1689         } while (the_result && retries);
1690
1691         if (the_result) {
1692                 sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY(16) failed\n");
1693                 read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
1694                 return -EINVAL;
1695         }
1696
1697         sector_size = get_unaligned_be32(&buffer[8]);
1698         lba = get_unaligned_be64(&buffer[0]);
1699
1700         sd_read_protection_type(sdkp, buffer);
1701
1702         if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) {
1703                 sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
1704                         "kernel compiled with support for large block "
1705                         "devices.\n");
1706                 sdkp->capacity = 0;
1707                 return -EOVERFLOW;
1708         }
1709
1710         /* Logical blocks per physical block exponent */
1711         sdkp->physical_block_size = (1 << (buffer[13] & 0xf)) * sector_size;
1712
1713         /* Lowest aligned logical block */
1714         alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) * sector_size;
1715         blk_queue_alignment_offset(sdp->request_queue, alignment);
1716         if (alignment && sdkp->first_scan)
1717                 sd_printk(KERN_NOTICE, sdkp,
1718                           "physical block alignment offset: %u\n", alignment);
1719
1720         if (buffer[14] & 0x80) { /* LBPME */
1721                 sdkp->lbpme = 1;
1722
1723                 if (buffer[14] & 0x40) /* LBPRZ */
1724                         sdkp->lbprz = 1;
1725
1726                 sd_config_discard(sdkp, SD_LBP_WS16);
1727         }
1728
1729         sdkp->capacity = lba + 1;
1730         return sector_size;
1731 }
1732
1733 static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
1734                                                 unsigned char *buffer)
1735 {
1736         unsigned char cmd[16];
1737         struct scsi_sense_hdr sshdr;
1738         int sense_valid = 0;
1739         int the_result;
1740         int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
1741         sector_t lba;
1742         unsigned sector_size;
1743
1744         do {
1745                 cmd[0] = READ_CAPACITY;
1746                 memset(&cmd[1], 0, 9);
1747                 memset(buffer, 0, 8);
1748
1749                 the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1750                                         buffer, 8, &sshdr,
1751                                         SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1752
1753                 if (media_not_present(sdkp, &sshdr))
1754                         return -ENODEV;
1755
1756                 if (the_result) {
1757                         sense_valid = scsi_sense_valid(&sshdr);
1758                         if (sense_valid &&
1759                             sshdr.sense_key == UNIT_ATTENTION &&
1760                             sshdr.asc == 0x29 && sshdr.ascq == 0x00)
1761                                 /* Device reset might occur several times,
1762                                  * give it one more chance */
1763                                 if (--reset_retries > 0)
1764                                         continue;
1765                 }
1766                 retries--;
1767
1768         } while (the_result && retries);
1769
1770         if (the_result) {
1771                 sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
1772                 read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
1773                 return -EINVAL;
1774         }
1775
1776         sector_size = get_unaligned_be32(&buffer[4]);
1777         lba = get_unaligned_be32(&buffer[0]);
1778
1779         if (sdp->no_read_capacity_16 && (lba == 0xffffffff)) {
1780                 /* Some buggy (usb cardreader) devices return an lba of
1781                    0xffffffff when the want to report a size of 0 (with
1782                    which they really mean no media is present) */
1783                 sdkp->capacity = 0;
1784                 sdkp->physical_block_size = sector_size;
1785                 return sector_size;
1786         }
1787
1788         if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) {
1789                 sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
1790                         "kernel compiled with support for large block "
1791                         "devices.\n");
1792                 sdkp->capacity = 0;
1793                 return -EOVERFLOW;
1794         }
1795
1796         sdkp->capacity = lba + 1;
1797         sdkp->physical_block_size = sector_size;
1798         return sector_size;
1799 }
1800
1801 static int sd_try_rc16_first(struct scsi_device *sdp)
1802 {
1803         if (sdp->host->max_cmd_len < 16)
1804                 return 0;
1805         if (sdp->scsi_level > SCSI_SPC_2)
1806                 return 1;
1807         if (scsi_device_protection(sdp))
1808                 return 1;
1809         return 0;
1810 }
1811
1812 /*
1813  * read disk capacity
1814  */
1815 static void
1816 sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
1817 {
1818         int sector_size;
1819         struct scsi_device *sdp = sdkp->device;
1820         sector_t old_capacity = sdkp->capacity;
1821
1822         if (sd_try_rc16_first(sdp)) {
1823                 sector_size = read_capacity_16(sdkp, sdp, buffer);
1824                 if (sector_size == -EOVERFLOW)
1825                         goto got_data;
1826                 if (sector_size == -ENODEV)
1827                         return;
1828                 if (sector_size < 0)
1829                         sector_size = read_capacity_10(sdkp, sdp, buffer);
1830                 if (sector_size < 0)
1831                         return;
1832         } else {
1833                 sector_size = read_capacity_10(sdkp, sdp, buffer);
1834                 if (sector_size == -EOVERFLOW)
1835                         goto got_data;
1836                 if (sector_size < 0)
1837                         return;
1838                 if ((sizeof(sdkp->capacity) > 4) &&
1839                     (sdkp->capacity > 0xffffffffULL)) {
1840                         int old_sector_size = sector_size;
1841                         sd_printk(KERN_NOTICE, sdkp, "Very big device. "
1842                                         "Trying to use READ CAPACITY(16).\n");
1843                         sector_size = read_capacity_16(sdkp, sdp, buffer);
1844                         if (sector_size < 0) {
1845                                 sd_printk(KERN_NOTICE, sdkp,
1846                                         "Using 0xffffffff as device size\n");
1847                                 sdkp->capacity = 1 + (sector_t) 0xffffffff;
1848                                 sector_size = old_sector_size;
1849                                 goto got_data;
1850                         }
1851                 }
1852         }
1853
1854         /* Some devices are known to return the total number of blocks,
1855          * not the highest block number.  Some devices have versions
1856          * which do this and others which do not.  Some devices we might
1857          * suspect of doing this but we don't know for certain.
1858          *
1859          * If we know the reported capacity is wrong, decrement it.  If
1860          * we can only guess, then assume the number of blocks is even
1861          * (usually true but not always) and err on the side of lowering
1862          * the capacity.
1863          */
1864         if (sdp->fix_capacity ||
1865             (sdp->guess_capacity && (sdkp->capacity & 0x01))) {
1866                 sd_printk(KERN_INFO, sdkp, "Adjusting the sector count "
1867                                 "from its reported value: %llu\n",
1868                                 (unsigned long long) sdkp->capacity);
1869                 --sdkp->capacity;
1870         }
1871
1872 got_data:
1873         if (sector_size == 0) {
1874                 sector_size = 512;
1875                 sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
1876                           "assuming 512.\n");
1877         }
1878
1879         if (sector_size != 512 &&
1880             sector_size != 1024 &&
1881             sector_size != 2048 &&
1882             sector_size != 4096 &&
1883             sector_size != 256) {
1884                 sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
1885                           sector_size);
1886                 /*
1887                  * The user might want to re-format the drive with
1888                  * a supported sectorsize.  Once this happens, it
1889                  * would be relatively trivial to set the thing up.
1890                  * For this reason, we leave the thing in the table.
1891                  */
1892                 sdkp->capacity = 0;
1893                 /*
1894                  * set a bogus sector size so the normal read/write
1895                  * logic in the block layer will eventually refuse any
1896                  * request on this device without tripping over power
1897                  * of two sector size assumptions
1898                  */
1899                 sector_size = 512;
1900         }
1901         blk_queue_logical_block_size(sdp->request_queue, sector_size);
1902
1903         {
1904                 char cap_str_2[10], cap_str_10[10];
1905                 u64 sz = (u64)sdkp->capacity << ilog2(sector_size);
1906
1907                 string_get_size(sz, STRING_UNITS_2, cap_str_2,
1908                                 sizeof(cap_str_2));
1909                 string_get_size(sz, STRING_UNITS_10, cap_str_10,
1910                                 sizeof(cap_str_10));
1911
1912                 if (sdkp->first_scan || old_capacity != sdkp->capacity) {
1913                         sd_printk(KERN_NOTICE, sdkp,
1914                                   "%llu %d-byte logical blocks: (%s/%s)\n",
1915                                   (unsigned long long)sdkp->capacity,
1916                                   sector_size, cap_str_10, cap_str_2);
1917
1918                         if (sdkp->physical_block_size != sector_size)
1919                                 sd_printk(KERN_NOTICE, sdkp,
1920                                           "%u-byte physical blocks\n",
1921                                           sdkp->physical_block_size);
1922                 }
1923         }
1924
1925         /* Rescale capacity to 512-byte units */
1926         if (sector_size == 4096)
1927                 sdkp->capacity <<= 3;
1928         else if (sector_size == 2048)
1929                 sdkp->capacity <<= 2;
1930         else if (sector_size == 1024)
1931                 sdkp->capacity <<= 1;
1932         else if (sector_size == 256)
1933                 sdkp->capacity >>= 1;
1934
1935         blk_queue_physical_block_size(sdp->request_queue,
1936                                       sdkp->physical_block_size);
1937         sdkp->device->sector_size = sector_size;
1938 }
1939
1940 /* called with buffer of length 512 */
1941 static inline int
1942 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
1943                  unsigned char *buffer, int len, struct scsi_mode_data *data,
1944                  struct scsi_sense_hdr *sshdr)
1945 {
1946         return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
1947                                SD_TIMEOUT, SD_MAX_RETRIES, data,
1948                                sshdr);
1949 }
1950
1951 /*
1952  * read write protect setting, if possible - called only in sd_revalidate_disk()
1953  * called with buffer of length SD_BUF_SIZE
1954  */
1955 static void
1956 sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
1957 {
1958         int res;
1959         struct scsi_device *sdp = sdkp->device;
1960         struct scsi_mode_data data;
1961         int old_wp = sdkp->write_prot;
1962
1963         set_disk_ro(sdkp->disk, 0);
1964         if (sdp->skip_ms_page_3f) {
1965                 sd_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
1966                 return;
1967         }
1968
1969         if (sdp->use_192_bytes_for_3f) {
1970                 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
1971         } else {
1972                 /*
1973                  * First attempt: ask for all pages (0x3F), but only 4 bytes.
1974                  * We have to start carefully: some devices hang if we ask
1975                  * for more than is available.
1976                  */
1977                 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
1978
1979                 /*
1980                  * Second attempt: ask for page 0 When only page 0 is
1981                  * implemented, a request for page 3F may return Sense Key
1982                  * 5: Illegal Request, Sense Code 24: Invalid field in
1983                  * CDB.
1984                  */
1985                 if (!scsi_status_is_good(res))
1986                         res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
1987
1988                 /*
1989                  * Third attempt: ask 255 bytes, as we did earlier.
1990                  */
1991                 if (!scsi_status_is_good(res))
1992                         res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
1993                                                &data, NULL);
1994         }
1995
1996         if (!scsi_status_is_good(res)) {
1997                 sd_printk(KERN_WARNING, sdkp,
1998                           "Test WP failed, assume Write Enabled\n");
1999         } else {
2000                 sdkp->write_prot = ((data.device_specific & 0x80) != 0);
2001                 set_disk_ro(sdkp->disk, sdkp->write_prot);
2002                 if (sdkp->first_scan || old_wp != sdkp->write_prot) {
2003                         sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
2004                                   sdkp->write_prot ? "on" : "off");
2005                         sd_printk(KERN_DEBUG, sdkp,
2006                                   "Mode Sense: %02x %02x %02x %02x\n",
2007                                   buffer[0], buffer[1], buffer[2], buffer[3]);
2008                 }
2009         }
2010 }
2011
2012 /*
2013  * sd_read_cache_type - called only from sd_revalidate_disk()
2014  * called with buffer of length SD_BUF_SIZE
2015  */
2016 static void
2017 sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
2018 {
2019         int len = 0, res;
2020         struct scsi_device *sdp = sdkp->device;
2021
2022         int dbd;
2023         int modepage;
2024         struct scsi_mode_data data;
2025         struct scsi_sense_hdr sshdr;
2026         int old_wce = sdkp->WCE;
2027         int old_rcd = sdkp->RCD;
2028         int old_dpofua = sdkp->DPOFUA;
2029
2030         if (sdp->skip_ms_page_8) {
2031                 if (sdp->type == TYPE_RBC)
2032                         goto defaults;
2033                 else {
2034                         modepage = 0x3F;
2035                         dbd = 0;
2036                 }
2037         } else if (sdp->type == TYPE_RBC) {
2038                 modepage = 6;
2039                 dbd = 8;
2040         } else {
2041                 modepage = 8;
2042                 dbd = 0;
2043         }
2044
2045         /* cautiously ask */
2046         res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);
2047
2048         if (!scsi_status_is_good(res))
2049                 goto bad_sense;
2050
2051         if (!data.header_length) {
2052                 modepage = 6;
2053                 sd_printk(KERN_ERR, sdkp, "Missing header in MODE_SENSE response\n");
2054         }
2055
2056         /* that went OK, now ask for the proper length */
2057         len = data.length;
2058
2059         /*
2060          * We're only interested in the first three bytes, actually.
2061          * But the data cache page is defined for the first 20.
2062          */
2063         if (len < 3)
2064                 goto bad_sense;
2065         else if (len > SD_BUF_SIZE) {
2066                 sd_printk(KERN_NOTICE, sdkp, "Truncating mode parameter "
2067                           "data from %d to %d bytes\n", len, SD_BUF_SIZE);
2068                 len = SD_BUF_SIZE;
2069         }
2070
2071         /* Get the data */
2072         res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
2073
2074         if (scsi_status_is_good(res)) {
2075                 int offset = data.header_length + data.block_descriptor_length;
2076
2077                 while (offset < len) {
2078                         u8 page_code = buffer[offset] & 0x3F;
2079                         u8 spf       = buffer[offset] & 0x40;
2080
2081                         if (page_code == 8 || page_code == 6) {
2082                                 /* We're interested only in the first 3 bytes.
2083                                  */
2084                                 if (len - offset <= 2) {
2085                                         sd_printk(KERN_ERR, sdkp, "Incomplete "
2086                                                   "mode parameter data\n");
2087                                         goto defaults;
2088                                 } else {
2089                                         modepage = page_code;
2090                                         goto Page_found;
2091                                 }
2092                         } else {
2093                                 /* Go to the next page */
2094                                 if (spf && len - offset > 3)
2095                                         offset += 4 + (buffer[offset+2] << 8) +
2096                                                 buffer[offset+3];
2097                                 else if (!spf && len - offset > 1)
2098                                         offset += 2 + buffer[offset+1];
2099                                 else {
2100                                         sd_printk(KERN_ERR, sdkp, "Incomplete "
2101                                                   "mode parameter data\n");
2102                                         goto defaults;
2103                                 }
2104                         }
2105                 }
2106
2107                 if (modepage == 0x3F) {
2108                         sd_printk(KERN_ERR, sdkp, "No Caching mode page "
2109                                   "present\n");
2110                         goto defaults;
2111                 } else if ((buffer[offset] & 0x3f) != modepage) {
2112                         sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
2113                         goto defaults;
2114                 }
2115         Page_found:
2116                 if (modepage == 8) {
2117                         sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
2118                         sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
2119                 } else {
2120                         sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
2121                         sdkp->RCD = 0;
2122                 }
2123
2124                 sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
2125                 if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
2126                         sd_printk(KERN_NOTICE, sdkp,
2127                                   "Uses READ/WRITE(6), disabling FUA\n");
2128                         sdkp->DPOFUA = 0;
2129                 }
2130
2131                 if (sdkp->first_scan || old_wce != sdkp->WCE ||
2132                     old_rcd != sdkp->RCD || old_dpofua != sdkp->DPOFUA)
2133                         sd_printk(KERN_NOTICE, sdkp,
2134                                   "Write cache: %s, read cache: %s, %s\n",
2135                                   sdkp->WCE ? "enabled" : "disabled",
2136                                   sdkp->RCD ? "disabled" : "enabled",
2137                                   sdkp->DPOFUA ? "supports DPO and FUA"
2138                                   : "doesn't support DPO or FUA");
2139
2140                 return;
2141         }
2142
2143 bad_sense:
2144         if (scsi_sense_valid(&sshdr) &&
2145             sshdr.sense_key == ILLEGAL_REQUEST &&
2146             sshdr.asc == 0x24 && sshdr.ascq == 0x0)
2147                 /* Invalid field in CDB */
2148                 sd_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
2149         else
2150                 sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n");
2151
2152 defaults:
2153         sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
2154         sdkp->WCE = 0;
2155         sdkp->RCD = 0;
2156         sdkp->DPOFUA = 0;
2157 }
2158
2159 /*
2160  * The ATO bit indicates whether the DIF application tag is available
2161  * for use by the operating system.
2162  */
2163 static void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
2164 {
2165         int res, offset;
2166         struct scsi_device *sdp = sdkp->device;
2167         struct scsi_mode_data data;
2168         struct scsi_sense_hdr sshdr;
2169
2170         if (sdp->type != TYPE_DISK)
2171                 return;
2172
2173         if (sdkp->protection_type == 0)
2174                 return;
2175
2176         res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
2177                               SD_MAX_RETRIES, &data, &sshdr);
2178
2179         if (!scsi_status_is_good(res) || !data.header_length ||
2180             data.length < 6) {
2181                 sd_printk(KERN_WARNING, sdkp,
2182                           "getting Control mode page failed, assume no ATO\n");
2183
2184                 if (scsi_sense_valid(&sshdr))
2185                         sd_print_sense_hdr(sdkp, &sshdr);
2186
2187                 return;
2188         }
2189
2190         offset = data.header_length + data.block_descriptor_length;
2191
2192         if ((buffer[offset] & 0x3f) != 0x0a) {
2193                 sd_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
2194                 return;
2195         }
2196
2197         if ((buffer[offset + 5] & 0x80) == 0)
2198                 return;
2199
2200         sdkp->ATO = 1;
2201
2202         return;
2203 }
2204
2205 /**
2206  * sd_read_block_limits - Query disk device for preferred I/O sizes.
2207  * @disk: disk to query
2208  */
2209 static void sd_read_block_limits(struct scsi_disk *sdkp)
2210 {
2211         unsigned int sector_sz = sdkp->device->sector_size;
2212         const int vpd_len = 64;
2213         unsigned char *buffer = kmalloc(vpd_len, GFP_KERNEL);
2214
2215         if (!buffer ||
2216             /* Block Limits VPD */
2217             scsi_get_vpd_page(sdkp->device, 0xb0, buffer, vpd_len))
2218                 goto out;
2219
2220         blk_queue_io_min(sdkp->disk->queue,
2221                          get_unaligned_be16(&buffer[6]) * sector_sz);
2222         blk_queue_io_opt(sdkp->disk->queue,
2223                          get_unaligned_be32(&buffer[12]) * sector_sz);
2224
2225         if (buffer[3] == 0x3c) {
2226                 unsigned int lba_count, desc_count;
2227
2228                 sdkp->max_ws_blocks =
2229                         (u32) min_not_zero(get_unaligned_be64(&buffer[36]),
2230                                            (u64)0xffffffff);
2231
2232                 if (!sdkp->lbpme)
2233                         goto out;
2234
2235                 lba_count = get_unaligned_be32(&buffer[20]);
2236                 desc_count = get_unaligned_be32(&buffer[24]);
2237
2238                 if (lba_count && desc_count)
2239                         sdkp->max_unmap_blocks = lba_count;
2240
2241                 sdkp->unmap_granularity = get_unaligned_be32(&buffer[28]);
2242
2243                 if (buffer[32] & 0x80)
2244                         sdkp->unmap_alignment =
2245                                 get_unaligned_be32(&buffer[32]) & ~(1 << 31);
2246
2247                 if (!sdkp->lbpvpd) { /* LBP VPD page not provided */
2248
2249                         if (sdkp->max_unmap_blocks)
2250                                 sd_config_discard(sdkp, SD_LBP_UNMAP);
2251                         else
2252                                 sd_config_discard(sdkp, SD_LBP_WS16);
2253
2254                 } else {        /* LBP VPD page tells us what to use */
2255
2256                         if (sdkp->lbpu && sdkp->max_unmap_blocks)
2257                                 sd_config_discard(sdkp, SD_LBP_UNMAP);
2258                         else if (sdkp->lbpws)
2259                                 sd_config_discard(sdkp, SD_LBP_WS16);
2260                         else if (sdkp->lbpws10)
2261                                 sd_config_discard(sdkp, SD_LBP_WS10);
2262                         else
2263                                 sd_config_discard(sdkp, SD_LBP_DISABLE);
2264                 }
2265         }
2266
2267  out:
2268         kfree(buffer);
2269 }
2270
2271 /**
2272  * sd_read_block_characteristics - Query block dev. characteristics
2273  * @disk: disk to query
2274  */
2275 static void sd_read_block_characteristics(struct scsi_disk *sdkp)
2276 {
2277         unsigned char *buffer;
2278         u16 rot;
2279         const int vpd_len = 64;
2280
2281         buffer = kmalloc(vpd_len, GFP_KERNEL);
2282
2283         if (!buffer ||
2284             /* Block Device Characteristics VPD */
2285             scsi_get_vpd_page(sdkp->device, 0xb1, buffer, vpd_len))
2286                 goto out;
2287
2288         rot = get_unaligned_be16(&buffer[4]);
2289
2290         if (rot == 1)
2291                 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, sdkp->disk->queue);
2292
2293  out:
2294         kfree(buffer);
2295 }
2296
2297 /**
2298  * sd_read_block_provisioning - Query provisioning VPD page
2299  * @disk: disk to query
2300  */
2301 static void sd_read_block_provisioning(struct scsi_disk *sdkp)
2302 {
2303         unsigned char *buffer;
2304         const int vpd_len = 8;
2305
2306         if (sdkp->lbpme == 0)
2307                 return;
2308
2309         buffer = kmalloc(vpd_len, GFP_KERNEL);
2310
2311         if (!buffer || scsi_get_vpd_page(sdkp->device, 0xb2, buffer, vpd_len))
2312                 goto out;
2313
2314         sdkp->lbpvpd    = 1;
2315         sdkp->lbpu      = (buffer[5] >> 7) & 1; /* UNMAP */
2316         sdkp->lbpws     = (buffer[5] >> 6) & 1; /* WRITE SAME(16) with UNMAP */
2317         sdkp->lbpws10   = (buffer[5] >> 5) & 1; /* WRITE SAME(10) with UNMAP */
2318
2319  out:
2320         kfree(buffer);
2321 }
2322
2323 static int sd_try_extended_inquiry(struct scsi_device *sdp)
2324 {
2325         /*
2326          * Although VPD inquiries can go to SCSI-2 type devices,
2327          * some USB ones crash on receiving them, and the pages
2328          * we currently ask for are for SPC-3 and beyond
2329          */
2330         if (sdp->scsi_level > SCSI_SPC_2)
2331                 return 1;
2332         return 0;
2333 }
2334
2335 /**
2336  *      sd_revalidate_disk - called the first time a new disk is seen,
2337  *      performs disk spin up, read_capacity, etc.
2338  *      @disk: struct gendisk we care about
2339  **/
2340 static int sd_revalidate_disk(struct gendisk *disk)
2341 {
2342         struct scsi_disk *sdkp = scsi_disk(disk);
2343         struct scsi_device *sdp = sdkp->device;
2344         unsigned char *buffer;
2345         unsigned flush = 0;
2346
2347         SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
2348                                       "sd_revalidate_disk\n"));
2349
2350         /*
2351          * If the device is offline, don't try and read capacity or any
2352          * of the other niceties.
2353          */
2354         if (!scsi_device_online(sdp))
2355                 goto out;
2356
2357         buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
2358         if (!buffer) {
2359                 sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
2360                           "allocation failure.\n");
2361                 goto out;
2362         }
2363
2364         sd_spinup_disk(sdkp);
2365
2366         /*
2367          * Without media there is no reason to ask; moreover, some devices
2368          * react badly if we do.
2369          */
2370         if (sdkp->media_present) {
2371                 sd_read_capacity(sdkp, buffer);
2372
2373                 if (sd_try_extended_inquiry(sdp)) {
2374                         sd_read_block_provisioning(sdkp);
2375                         sd_read_block_limits(sdkp);
2376                         sd_read_block_characteristics(sdkp);
2377                 }
2378
2379                 sd_read_write_protect_flag(sdkp, buffer);
2380                 sd_read_cache_type(sdkp, buffer);
2381                 sd_read_app_tag_own(sdkp, buffer);
2382         }
2383
2384         sdkp->first_scan = 0;
2385
2386         /*
2387          * We now have all cache related info, determine how we deal
2388          * with flush requests.
2389          */
2390         if (sdkp->WCE) {
2391                 flush |= REQ_FLUSH;
2392                 if (sdkp->DPOFUA)
2393                         flush |= REQ_FUA;
2394         }
2395
2396         blk_queue_flush(sdkp->disk->queue, flush);
2397
2398         set_capacity(disk, sdkp->capacity);
2399         kfree(buffer);
2400
2401  out:
2402         return 0;
2403 }
2404
2405 /**
2406  *      sd_unlock_native_capacity - unlock native capacity
2407  *      @disk: struct gendisk to set capacity for
2408  *
2409  *      Block layer calls this function if it detects that partitions
2410  *      on @disk reach beyond the end of the device.  If the SCSI host
2411  *      implements ->unlock_native_capacity() method, it's invoked to
2412  *      give it a chance to adjust the device capacity.
2413  *
2414  *      CONTEXT:
2415  *      Defined by block layer.  Might sleep.
2416  */
2417 static void sd_unlock_native_capacity(struct gendisk *disk)
2418 {
2419         struct scsi_device *sdev = scsi_disk(disk)->device;
2420
2421         if (sdev->host->hostt->unlock_native_capacity)
2422                 sdev->host->hostt->unlock_native_capacity(sdev);
2423 }
2424
2425 /**
2426  *      sd_format_disk_name - format disk name
2427  *      @prefix: name prefix - ie. "sd" for SCSI disks
2428  *      @index: index of the disk to format name for
2429  *      @buf: output buffer
2430  *      @buflen: length of the output buffer
2431  *
2432  *      SCSI disk names starts at sda.  The 26th device is sdz and the
2433  *      27th is sdaa.  The last one for two lettered suffix is sdzz
2434  *      which is followed by sdaaa.
2435  *
2436  *      This is basically 26 base counting with one extra 'nil' entry
2437  *      at the beginning from the second digit on and can be
2438  *      determined using similar method as 26 base conversion with the
2439  *      index shifted -1 after each digit is computed.
2440  *
2441  *      CONTEXT:
2442  *      Don't care.
2443  *
2444  *      RETURNS:
2445  *      0 on success, -errno on failure.
2446  */
2447 static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
2448 {
2449         const int base = 'z' - 'a' + 1;
2450         char *begin = buf + strlen(prefix);
2451         char *end = buf + buflen;
2452         char *p;
2453         int unit;
2454
2455         p = end - 1;
2456         *p = '\0';
2457         unit = base;
2458         do {
2459                 if (p == begin)
2460                         return -EINVAL;
2461                 *--p = 'a' + (index % unit);
2462                 index = (index / unit) - 1;
2463         } while (index >= 0);
2464
2465         memmove(begin, p, end - p);
2466         memcpy(buf, prefix, strlen(prefix));
2467
2468         return 0;
2469 }
2470
2471 /*
2472  * The asynchronous part of sd_probe
2473  */
2474 static void sd_probe_async(void *data, async_cookie_t cookie)
2475 {
2476         struct scsi_disk *sdkp = data;
2477         struct scsi_device *sdp;
2478         struct gendisk *gd;
2479         u32 index;
2480         struct device *dev;
2481
2482         sdp = sdkp->device;
2483         gd = sdkp->disk;
2484         index = sdkp->index;
2485         dev = &sdp->sdev_gendev;
2486
2487         gd->major = sd_major((index & 0xf0) >> 4);
2488         gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
2489         gd->minors = SD_MINORS;
2490
2491         gd->fops = &sd_fops;
2492         gd->private_data = &sdkp->driver;
2493         gd->queue = sdkp->device->request_queue;
2494
2495         /* defaults, until the device tells us otherwise */
2496         sdp->sector_size = 512;
2497         sdkp->capacity = 0;
2498         sdkp->media_present = 1;
2499         sdkp->write_prot = 0;
2500         sdkp->WCE = 0;
2501         sdkp->RCD = 0;
2502         sdkp->ATO = 0;
2503         sdkp->first_scan = 1;
2504
2505         sd_revalidate_disk(gd);
2506
2507         blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);
2508         blk_queue_unprep_rq(sdp->request_queue, sd_unprep_fn);
2509
2510         gd->driverfs_dev = &sdp->sdev_gendev;
2511         gd->flags = GENHD_FL_EXT_DEVT;
2512         if (sdp->removable) {
2513                 gd->flags |= GENHD_FL_REMOVABLE;
2514                 gd->events |= DISK_EVENT_MEDIA_CHANGE;
2515         }
2516
2517         add_disk(gd);
2518         sd_dif_config_host(sdkp);
2519
2520         sd_revalidate_disk(gd);
2521
2522         sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
2523                   sdp->removable ? "removable " : "");
2524         scsi_autopm_put_device(sdp);
2525         put_device(&sdkp->dev);
2526 }
2527
2528 /**
2529  *      sd_probe - called during driver initialization and whenever a
2530  *      new scsi device is attached to the system. It is called once
2531  *      for each scsi device (not just disks) present.
2532  *      @dev: pointer to device object
2533  *
2534  *      Returns 0 if successful (or not interested in this scsi device 
2535  *      (e.g. scanner)); 1 when there is an error.
2536  *
2537  *      Note: this function is invoked from the scsi mid-level.
2538  *      This function sets up the mapping between a given 
2539  *      <host,channel,id,lun> (found in sdp) and new device name 
2540  *      (e.g. /dev/sda). More precisely it is the block device major 
2541  *      and minor number that is chosen here.
2542  *
2543  *      Assume sd_attach is not re-entrant (for time being)
2544  *      Also think about sd_attach() and sd_remove() running coincidentally.
2545  **/
2546 static int sd_probe(struct device *dev)
2547 {
2548         struct scsi_device *sdp = to_scsi_device(dev);
2549         struct scsi_disk *sdkp;
2550         struct gendisk *gd;
2551         int index;
2552         int error;
2553
2554         error = -ENODEV;
2555         if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
2556                 goto out;
2557
2558         SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
2559                                         "sd_attach\n"));
2560
2561         error = -ENOMEM;
2562         sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
2563         if (!sdkp)
2564                 goto out;
2565
2566         gd = alloc_disk(SD_MINORS);
2567         if (!gd)
2568                 goto out_free;
2569
2570         do {
2571                 if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
2572                         goto out_put;
2573
2574                 spin_lock(&sd_index_lock);
2575                 error = ida_get_new(&sd_index_ida, &index);
2576                 spin_unlock(&sd_index_lock);
2577         } while (error == -EAGAIN);
2578
2579         if (error)
2580                 goto out_put;
2581
2582         if (index >= SD_MAX_DISKS) {
2583                 error = -ENODEV;
2584                 sdev_printk(KERN_WARNING, sdp, "SCSI disk (sd) name space exhausted.\n");
2585                 goto out_free_index;
2586         }
2587
2588         error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
2589         if (error)
2590                 goto out_free_index;
2591
2592         sdkp->device = sdp;
2593         sdkp->driver = &sd_template;
2594         sdkp->disk = gd;
2595         sdkp->index = index;
2596         atomic_set(&sdkp->openers, 0);
2597
2598         if (!sdp->request_queue->rq_timeout) {
2599                 if (sdp->type != TYPE_MOD)
2600                         blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
2601                 else
2602                         blk_queue_rq_timeout(sdp->request_queue,
2603                                              SD_MOD_TIMEOUT);
2604         }
2605
2606         device_initialize(&sdkp->dev);
2607         sdkp->dev.parent = dev;
2608         sdkp->dev.class = &sd_disk_class;
2609         dev_set_name(&sdkp->dev, dev_name(dev));
2610
2611         if (device_add(&sdkp->dev))
2612                 goto out_free_index;
2613
2614         get_device(dev);
2615         dev_set_drvdata(dev, sdkp);
2616
2617         get_device(&sdkp->dev); /* prevent release before async_schedule */
2618         async_schedule(sd_probe_async, sdkp);
2619
2620         return 0;
2621
2622  out_free_index:
2623         spin_lock(&sd_index_lock);
2624         ida_remove(&sd_index_ida, index);
2625         spin_unlock(&sd_index_lock);
2626  out_put:
2627         put_disk(gd);
2628  out_free:
2629         kfree(sdkp);
2630  out:
2631         return error;
2632 }
2633
2634 /**
2635  *      sd_remove - called whenever a scsi disk (previously recognized by
2636  *      sd_probe) is detached from the system. It is called (potentially
2637  *      multiple times) during sd module unload.
2638  *      @sdp: pointer to mid level scsi device object
2639  *
2640  *      Note: this function is invoked from the scsi mid-level.
2641  *      This function potentially frees up a device name (e.g. /dev/sdc)
2642  *      that could be re-used by a subsequent sd_probe().
2643  *      This function is not called when the built-in sd driver is "exit-ed".
2644  **/
2645 static int sd_remove(struct device *dev)
2646 {
2647         struct scsi_disk *sdkp;
2648
2649         sdkp = dev_get_drvdata(dev);
2650         scsi_autopm_get_device(sdkp->device);
2651
2652         async_synchronize_full();
2653         blk_queue_prep_rq(sdkp->device->request_queue, scsi_prep_fn);
2654         blk_queue_unprep_rq(sdkp->device->request_queue, NULL);
2655         device_del(&sdkp->dev);
2656         del_gendisk(sdkp->disk);
2657         sd_shutdown(dev);
2658
2659         mutex_lock(&sd_ref_mutex);
2660         dev_set_drvdata(dev, NULL);
2661         put_device(&sdkp->dev);
2662         mutex_unlock(&sd_ref_mutex);
2663
2664         return 0;
2665 }
2666
2667 /**
2668  *      scsi_disk_release - Called to free the scsi_disk structure
2669  *      @dev: pointer to embedded class device
2670  *
2671  *      sd_ref_mutex must be held entering this routine.  Because it is
2672  *      called on last put, you should always use the scsi_disk_get()
2673  *      scsi_disk_put() helpers which manipulate the semaphore directly
2674  *      and never do a direct put_device.
2675  **/
2676 static void scsi_disk_release(struct device *dev)
2677 {
2678         struct scsi_disk *sdkp = to_scsi_disk(dev);
2679         struct gendisk *disk = sdkp->disk;
2680         
2681         spin_lock(&sd_index_lock);
2682         ida_remove(&sd_index_ida, sdkp->index);
2683         spin_unlock(&sd_index_lock);
2684
2685         disk->private_data = NULL;
2686         put_disk(disk);
2687         put_device(&sdkp->device->sdev_gendev);
2688
2689         kfree(sdkp);
2690 }
2691
2692 static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
2693 {
2694         unsigned char cmd[6] = { START_STOP };  /* START_VALID */
2695         struct scsi_sense_hdr sshdr;
2696         struct scsi_device *sdp = sdkp->device;
2697         int res;
2698
2699         if (start)
2700                 cmd[4] |= 1;    /* START */
2701
2702         if (sdp->start_stop_pwr_cond)
2703                 cmd[4] |= start ? 1 << 4 : 3 << 4;      /* Active or Standby */
2704
2705         if (!scsi_device_online(sdp))
2706                 return -ENODEV;
2707
2708         res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
2709                                SD_TIMEOUT, SD_MAX_RETRIES, NULL);
2710         if (res) {
2711                 sd_printk(KERN_WARNING, sdkp, "START_STOP FAILED\n");
2712                 sd_print_result(sdkp, res);
2713                 if (driver_byte(res) & DRIVER_SENSE)
2714                         sd_print_sense_hdr(sdkp, &sshdr);
2715         }
2716
2717         return res;
2718 }
2719
2720 /*
2721  * Send a SYNCHRONIZE CACHE instruction down to the device through
2722  * the normal SCSI command structure.  Wait for the command to
2723  * complete.
2724  */
2725 static void sd_shutdown(struct device *dev)
2726 {
2727         struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2728
2729         if (!sdkp)
2730                 return;         /* this can happen */
2731
2732         if (sdkp->WCE) {
2733                 sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2734                 sd_sync_cache(sdkp);
2735         }
2736
2737         if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
2738                 sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2739                 sd_start_stop_device(sdkp, 0);
2740         }
2741
2742         scsi_disk_put(sdkp);
2743 }
2744
2745 static int sd_suspend(struct device *dev, pm_message_t mesg)
2746 {
2747         struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2748         int ret = 0;
2749
2750         if (!sdkp)
2751                 return 0;       /* this can happen */
2752
2753         if (sdkp->WCE) {
2754                 sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2755                 ret = sd_sync_cache(sdkp);
2756                 if (ret)
2757                         goto done;
2758         }
2759
2760         if ((mesg.event & PM_EVENT_SLEEP) && sdkp->device->manage_start_stop) {
2761                 sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2762                 ret = sd_start_stop_device(sdkp, 0);
2763         }
2764
2765 done:
2766         scsi_disk_put(sdkp);
2767         return ret;
2768 }
2769
2770 static int sd_resume(struct device *dev)
2771 {
2772         struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2773         int ret = 0;
2774
2775         if (!sdkp->device->manage_start_stop)
2776                 goto done;
2777
2778         sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
2779         ret = sd_start_stop_device(sdkp, 1);
2780
2781 done:
2782         scsi_disk_put(sdkp);
2783         return ret;
2784 }
2785
2786 /**
2787  *      init_sd - entry point for this driver (both when built in or when
2788  *      a module).
2789  *
2790  *      Note: this function registers this driver with the scsi mid-level.
2791  **/
2792 static int __init init_sd(void)
2793 {
2794         int majors = 0, i, err;
2795
2796         SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
2797
2798         for (i = 0; i < SD_MAJORS; i++)
2799                 if (register_blkdev(sd_major(i), "sd") == 0)
2800                         majors++;
2801
2802         if (!majors)
2803                 return -ENODEV;
2804
2805         err = class_register(&sd_disk_class);
2806         if (err)
2807                 goto err_out;
2808
2809         err = scsi_register_driver(&sd_template.gendrv);
2810         if (err)
2811                 goto err_out_class;
2812
2813         sd_cdb_cache = kmem_cache_create("sd_ext_cdb", SD_EXT_CDB_SIZE,
2814                                          0, 0, NULL);
2815         if (!sd_cdb_cache) {
2816                 printk(KERN_ERR "sd: can't init extended cdb cache\n");
2817                 goto err_out_class;
2818         }
2819
2820         sd_cdb_pool = mempool_create_slab_pool(SD_MEMPOOL_SIZE, sd_cdb_cache);
2821         if (!sd_cdb_pool) {
2822                 printk(KERN_ERR "sd: can't init extended cdb pool\n");
2823                 goto err_out_cache;
2824         }
2825
2826         return 0;
2827
2828 err_out_cache:
2829         kmem_cache_destroy(sd_cdb_cache);
2830
2831 err_out_class:
2832         class_unregister(&sd_disk_class);
2833 err_out:
2834         for (i = 0; i < SD_MAJORS; i++)
2835                 unregister_blkdev(sd_major(i), "sd");
2836         return err;
2837 }
2838
2839 /**
2840  *      exit_sd - exit point for this driver (when it is a module).
2841  *
2842  *      Note: this function unregisters this driver from the scsi mid-level.
2843  **/
2844 static void __exit exit_sd(void)
2845 {
2846         int i;
2847
2848         SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
2849
2850         mempool_destroy(sd_cdb_pool);
2851         kmem_cache_destroy(sd_cdb_cache);
2852
2853         scsi_unregister_driver(&sd_template.gendrv);
2854         class_unregister(&sd_disk_class);
2855
2856         for (i = 0; i < SD_MAJORS; i++)
2857                 unregister_blkdev(sd_major(i), "sd");
2858 }
2859
2860 module_init(init_sd);
2861 module_exit(exit_sd);
2862
2863 static void sd_print_sense_hdr(struct scsi_disk *sdkp,
2864                                struct scsi_sense_hdr *sshdr)
2865 {
2866         sd_printk(KERN_INFO, sdkp, " ");
2867         scsi_show_sense_hdr(sshdr);
2868         sd_printk(KERN_INFO, sdkp, " ");
2869         scsi_show_extd_sense(sshdr->asc, sshdr->ascq);
2870 }
2871
2872 static void sd_print_result(struct scsi_disk *sdkp, int result)
2873 {
2874         sd_printk(KERN_INFO, sdkp, " ");
2875         scsi_show_result(result);
2876 }
2877