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Linux/drivers/scsi/sr.c

  1 /*
  2  *  sr.c Copyright (C) 1992 David Giller
  3  *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
  4  *
  5  *  adapted from:
  6  *      sd.c Copyright (C) 1992 Drew Eckhardt
  7  *      Linux scsi disk driver by
  8  *              Drew Eckhardt <drew@colorado.edu>
  9  *
 10  *      Modified by Eric Youngdale ericy@andante.org to
 11  *      add scatter-gather, multiple outstanding request, and other
 12  *      enhancements.
 13  *
 14  *      Modified by Eric Youngdale eric@andante.org to support loadable
 15  *      low-level scsi drivers.
 16  *
 17  *      Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to
 18  *      provide auto-eject.
 19  *
 20  *      Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the
 21  *      generic cdrom interface
 22  *
 23  *      Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet()
 24  *      interface, capabilities probe additions, ioctl cleanups, etc.
 25  *
 26  *      Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs
 27  *
 28  *      Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM
 29  *      transparently and lose the GHOST hack
 30  *
 31  *      Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 32  *      check resource allocation in sr_init and some cleanups
 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/string.h>
 41 #include <linux/errno.h>
 42 #include <linux/cdrom.h>
 43 #include <linux/interrupt.h>
 44 #include <linux/init.h>
 45 #include <linux/blkdev.h>
 46 #include <linux/mutex.h>
 47 #include <linux/slab.h>
 48 #include <linux/pm_runtime.h>
 49 #include <asm/uaccess.h>
 50 
 51 #include <scsi/scsi.h>
 52 #include <scsi/scsi_dbg.h>
 53 #include <scsi/scsi_device.h>
 54 #include <scsi/scsi_driver.h>
 55 #include <scsi/scsi_cmnd.h>
 56 #include <scsi/scsi_eh.h>
 57 #include <scsi/scsi_host.h>
 58 #include <scsi/scsi_ioctl.h>    /* For the door lock/unlock commands */
 59 
 60 #include "scsi_logging.h"
 61 #include "sr.h"
 62 
 63 
 64 MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
 65 MODULE_LICENSE("GPL");
 66 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
 67 MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
 68 MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
 69 
 70 #define SR_DISKS        256
 71 
 72 #define SR_CAPABILITIES \
 73         (CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
 74          CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
 75          CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
 76          CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
 77          CDC_MRW|CDC_MRW_W|CDC_RAM)
 78 
 79 static DEFINE_MUTEX(sr_mutex);
 80 static int sr_probe(struct device *);
 81 static int sr_remove(struct device *);
 82 static int sr_done(struct scsi_cmnd *);
 83 static int sr_runtime_suspend(struct device *dev);
 84 
 85 static struct dev_pm_ops sr_pm_ops = {
 86         .runtime_suspend        = sr_runtime_suspend,
 87 };
 88 
 89 static struct scsi_driver sr_template = {
 90         .owner                  = THIS_MODULE,
 91         .gendrv = {
 92                 .name           = "sr",
 93                 .probe          = sr_probe,
 94                 .remove         = sr_remove,
 95                 .pm             = &sr_pm_ops,
 96         },
 97         .done                   = sr_done,
 98 };
 99 
100 static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
101 static DEFINE_SPINLOCK(sr_index_lock);
102 
103 /* This semaphore is used to mediate the 0->1 reference get in the
104  * face of object destruction (i.e. we can't allow a get on an
105  * object after last put) */
106 static DEFINE_MUTEX(sr_ref_mutex);
107 
108 static int sr_open(struct cdrom_device_info *, int);
109 static void sr_release(struct cdrom_device_info *);
110 
111 static void get_sectorsize(struct scsi_cd *);
112 static void get_capabilities(struct scsi_cd *);
113 
114 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
115                                     unsigned int clearing, int slot);
116 static int sr_packet(struct cdrom_device_info *, struct packet_command *);
117 
118 static struct cdrom_device_ops sr_dops = {
119         .open                   = sr_open,
120         .release                = sr_release,
121         .drive_status           = sr_drive_status,
122         .check_events           = sr_check_events,
123         .tray_move              = sr_tray_move,
124         .lock_door              = sr_lock_door,
125         .select_speed           = sr_select_speed,
126         .get_last_session       = sr_get_last_session,
127         .get_mcn                = sr_get_mcn,
128         .reset                  = sr_reset,
129         .audio_ioctl            = sr_audio_ioctl,
130         .capability             = SR_CAPABILITIES,
131         .generic_packet         = sr_packet,
132 };
133 
134 static void sr_kref_release(struct kref *kref);
135 
136 static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
137 {
138         return container_of(disk->private_data, struct scsi_cd, driver);
139 }
140 
141 static int sr_runtime_suspend(struct device *dev)
142 {
143         struct scsi_cd *cd = dev_get_drvdata(dev);
144 
145         if (cd->media_present)
146                 return -EBUSY;
147         else
148                 return 0;
149 }
150 
151 /*
152  * The get and put routines for the struct scsi_cd.  Note this entity
153  * has a scsi_device pointer and owns a reference to this.
154  */
155 static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
156 {
157         struct scsi_cd *cd = NULL;
158 
159         mutex_lock(&sr_ref_mutex);
160         if (disk->private_data == NULL)
161                 goto out;
162         cd = scsi_cd(disk);
163         kref_get(&cd->kref);
164         if (scsi_device_get(cd->device)) {
165                 kref_put(&cd->kref, sr_kref_release);
166                 cd = NULL;
167         }
168  out:
169         mutex_unlock(&sr_ref_mutex);
170         return cd;
171 }
172 
173 static void scsi_cd_put(struct scsi_cd *cd)
174 {
175         struct scsi_device *sdev = cd->device;
176 
177         mutex_lock(&sr_ref_mutex);
178         kref_put(&cd->kref, sr_kref_release);
179         scsi_device_put(sdev);
180         mutex_unlock(&sr_ref_mutex);
181 }
182 
183 static unsigned int sr_get_events(struct scsi_device *sdev)
184 {
185         u8 buf[8];
186         u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
187                      1,                 /* polled */
188                      0, 0,              /* reserved */
189                      1 << 4,            /* notification class: media */
190                      0, 0,              /* reserved */
191                      0, sizeof(buf),    /* allocation length */
192                      0,                 /* control */
193         };
194         struct event_header *eh = (void *)buf;
195         struct media_event_desc *med = (void *)(buf + 4);
196         struct scsi_sense_hdr sshdr;
197         int result;
198 
199         result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
200                                   &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
201         if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
202                 return DISK_EVENT_MEDIA_CHANGE;
203 
204         if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
205                 return 0;
206 
207         if (eh->nea || eh->notification_class != 0x4)
208                 return 0;
209 
210         if (med->media_event_code == 1)
211                 return DISK_EVENT_EJECT_REQUEST;
212         else if (med->media_event_code == 2)
213                 return DISK_EVENT_MEDIA_CHANGE;
214         return 0;
215 }
216 
217 /*
218  * This function checks to see if the media has been changed or eject
219  * button has been pressed.  It is possible that we have already
220  * sensed a change, or the drive may have sensed one and not yet
221  * reported it.  The past events are accumulated in sdev->changed and
222  * returned together with the current state.
223  */
224 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
225                                     unsigned int clearing, int slot)
226 {
227         struct scsi_cd *cd = cdi->handle;
228         bool last_present;
229         struct scsi_sense_hdr sshdr;
230         unsigned int events;
231         int ret;
232 
233         /* no changer support */
234         if (CDSL_CURRENT != slot)
235                 return 0;
236 
237         events = sr_get_events(cd->device);
238         cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
239 
240         /*
241          * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
242          * for several times in a row.  We rely on TUR only for this likely
243          * broken device, to prevent generating incorrect media changed
244          * events for every open().
245          */
246         if (cd->ignore_get_event) {
247                 events &= ~DISK_EVENT_MEDIA_CHANGE;
248                 goto do_tur;
249         }
250 
251         /*
252          * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
253          * is being cleared.  Note that there are devices which hang
254          * if asked to execute TUR repeatedly.
255          */
256         if (cd->device->changed) {
257                 events |= DISK_EVENT_MEDIA_CHANGE;
258                 cd->device->changed = 0;
259                 cd->tur_changed = true;
260         }
261 
262         if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
263                 return events;
264 do_tur:
265         /* let's see whether the media is there with TUR */
266         last_present = cd->media_present;
267         ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
268 
269         /*
270          * Media is considered to be present if TUR succeeds or fails with
271          * sense data indicating something other than media-not-present
272          * (ASC 0x3a).
273          */
274         cd->media_present = scsi_status_is_good(ret) ||
275                 (scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
276 
277         if (last_present != cd->media_present)
278                 cd->device->changed = 1;
279 
280         if (cd->device->changed) {
281                 events |= DISK_EVENT_MEDIA_CHANGE;
282                 cd->device->changed = 0;
283                 cd->tur_changed = true;
284         }
285 
286         if (cd->ignore_get_event)
287                 return events;
288 
289         /* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
290         if (!cd->tur_changed) {
291                 if (cd->get_event_changed) {
292                         if (cd->tur_mismatch++ > 8) {
293                                 sdev_printk(KERN_WARNING, cd->device,
294                                             "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
295                                 cd->ignore_get_event = true;
296                         }
297                 } else {
298                         cd->tur_mismatch = 0;
299                 }
300         }
301         cd->tur_changed = false;
302         cd->get_event_changed = false;
303 
304         return events;
305 }
306 
307 /*
308  * sr_done is the interrupt routine for the device driver.
309  *
310  * It will be notified on the end of a SCSI read / write, and will take one
311  * of several actions based on success or failure.
312  */
313 static int sr_done(struct scsi_cmnd *SCpnt)
314 {
315         int result = SCpnt->result;
316         int this_count = scsi_bufflen(SCpnt);
317         int good_bytes = (result == 0 ? this_count : 0);
318         int block_sectors = 0;
319         long error_sector;
320         struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
321 
322 #ifdef DEBUG
323         printk("sr.c done: %x\n", result);
324 #endif
325 
326         /*
327          * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
328          * success.  Since this is a relatively rare error condition, no
329          * care is taken to avoid unnecessary additional work such as
330          * memcpy's that could be avoided.
331          */
332         if (driver_byte(result) != 0 &&         /* An error occurred */
333             (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
334                 switch (SCpnt->sense_buffer[2]) {
335                 case MEDIUM_ERROR:
336                 case VOLUME_OVERFLOW:
337                 case ILLEGAL_REQUEST:
338                         if (!(SCpnt->sense_buffer[0] & 0x90))
339                                 break;
340                         error_sector = (SCpnt->sense_buffer[3] << 24) |
341                                 (SCpnt->sense_buffer[4] << 16) |
342                                 (SCpnt->sense_buffer[5] << 8) |
343                                 SCpnt->sense_buffer[6];
344                         if (SCpnt->request->bio != NULL)
345                                 block_sectors =
346                                         bio_sectors(SCpnt->request->bio);
347                         if (block_sectors < 4)
348                                 block_sectors = 4;
349                         if (cd->device->sector_size == 2048)
350                                 error_sector <<= 2;
351                         error_sector &= ~(block_sectors - 1);
352                         good_bytes = (error_sector -
353                                       blk_rq_pos(SCpnt->request)) << 9;
354                         if (good_bytes < 0 || good_bytes >= this_count)
355                                 good_bytes = 0;
356                         /*
357                          * The SCSI specification allows for the value
358                          * returned by READ CAPACITY to be up to 75 2K
359                          * sectors past the last readable block.
360                          * Therefore, if we hit a medium error within the
361                          * last 75 2K sectors, we decrease the saved size
362                          * value.
363                          */
364                         if (error_sector < get_capacity(cd->disk) &&
365                             cd->capacity - error_sector < 4 * 75)
366                                 set_capacity(cd->disk, error_sector);
367                         break;
368 
369                 case RECOVERED_ERROR:
370                         good_bytes = this_count;
371                         break;
372 
373                 default:
374                         break;
375                 }
376         }
377 
378         return good_bytes;
379 }
380 
381 static int sr_prep_fn(struct request_queue *q, struct request *rq)
382 {
383         int block = 0, this_count, s_size;
384         struct scsi_cd *cd;
385         struct scsi_cmnd *SCpnt;
386         struct scsi_device *sdp = q->queuedata;
387         int ret;
388 
389         if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
390                 ret = scsi_setup_blk_pc_cmnd(sdp, rq);
391                 goto out;
392         } else if (rq->cmd_type != REQ_TYPE_FS) {
393                 ret = BLKPREP_KILL;
394                 goto out;
395         }
396         ret = scsi_setup_fs_cmnd(sdp, rq);
397         if (ret != BLKPREP_OK)
398                 goto out;
399         SCpnt = rq->special;
400         cd = scsi_cd(rq->rq_disk);
401 
402         /* from here on until we're complete, any goto out
403          * is used for a killable error condition */
404         ret = BLKPREP_KILL;
405 
406         SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %s, block = %d\n",
407                                 cd->disk->disk_name, block));
408 
409         if (!cd->device || !scsi_device_online(cd->device)) {
410                 SCSI_LOG_HLQUEUE(2, printk("Finishing %u sectors\n",
411                                            blk_rq_sectors(rq)));
412                 SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
413                 goto out;
414         }
415 
416         if (cd->device->changed) {
417                 /*
418                  * quietly refuse to do anything to a changed disc until the
419                  * changed bit has been reset
420                  */
421                 goto out;
422         }
423 
424         /*
425          * we do lazy blocksize switching (when reading XA sectors,
426          * see CDROMREADMODE2 ioctl) 
427          */
428         s_size = cd->device->sector_size;
429         if (s_size > 2048) {
430                 if (!in_interrupt())
431                         sr_set_blocklength(cd, 2048);
432                 else
433                         printk("sr: can't switch blocksize: in interrupt\n");
434         }
435 
436         if (s_size != 512 && s_size != 1024 && s_size != 2048) {
437                 scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
438                 goto out;
439         }
440 
441         if (rq_data_dir(rq) == WRITE) {
442                 if (!cd->device->writeable)
443                         goto out;
444                 SCpnt->cmnd[0] = WRITE_10;
445                 SCpnt->sc_data_direction = DMA_TO_DEVICE;
446                 cd->cdi.media_written = 1;
447         } else if (rq_data_dir(rq) == READ) {
448                 SCpnt->cmnd[0] = READ_10;
449                 SCpnt->sc_data_direction = DMA_FROM_DEVICE;
450         } else {
451                 blk_dump_rq_flags(rq, "Unknown sr command");
452                 goto out;
453         }
454 
455         {
456                 struct scatterlist *sg;
457                 int i, size = 0, sg_count = scsi_sg_count(SCpnt);
458 
459                 scsi_for_each_sg(SCpnt, sg, sg_count, i)
460                         size += sg->length;
461 
462                 if (size != scsi_bufflen(SCpnt)) {
463                         scmd_printk(KERN_ERR, SCpnt,
464                                 "mismatch count %d, bytes %d\n",
465                                 size, scsi_bufflen(SCpnt));
466                         if (scsi_bufflen(SCpnt) > size)
467                                 SCpnt->sdb.length = size;
468                 }
469         }
470 
471         /*
472          * request doesn't start on hw block boundary, add scatter pads
473          */
474         if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
475             (scsi_bufflen(SCpnt) % s_size)) {
476                 scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
477                 goto out;
478         }
479 
480         this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
481 
482 
483         SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%u 512 byte blocks.\n",
484                                 cd->cdi.name,
485                                 (rq_data_dir(rq) == WRITE) ?
486                                         "writing" : "reading",
487                                 this_count, blk_rq_sectors(rq)));
488 
489         SCpnt->cmnd[1] = 0;
490         block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
491 
492         if (this_count > 0xffff) {
493                 this_count = 0xffff;
494                 SCpnt->sdb.length = this_count * s_size;
495         }
496 
497         SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
498         SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
499         SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
500         SCpnt->cmnd[5] = (unsigned char) block & 0xff;
501         SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
502         SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
503         SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
504 
505         /*
506          * We shouldn't disconnect in the middle of a sector, so with a dumb
507          * host adapter, it's safe to assume that we can at least transfer
508          * this many bytes between each connect / disconnect.
509          */
510         SCpnt->transfersize = cd->device->sector_size;
511         SCpnt->underflow = this_count << 9;
512         SCpnt->allowed = MAX_RETRIES;
513 
514         /*
515          * This indicates that the command is ready from our end to be
516          * queued.
517          */
518         ret = BLKPREP_OK;
519  out:
520         return scsi_prep_return(q, rq, ret);
521 }
522 
523 static int sr_block_open(struct block_device *bdev, fmode_t mode)
524 {
525         struct scsi_cd *cd;
526         int ret = -ENXIO;
527 
528         mutex_lock(&sr_mutex);
529         cd = scsi_cd_get(bdev->bd_disk);
530         if (cd) {
531                 ret = cdrom_open(&cd->cdi, bdev, mode);
532                 if (ret)
533                         scsi_cd_put(cd);
534         }
535         mutex_unlock(&sr_mutex);
536         return ret;
537 }
538 
539 static void sr_block_release(struct gendisk *disk, fmode_t mode)
540 {
541         struct scsi_cd *cd = scsi_cd(disk);
542         mutex_lock(&sr_mutex);
543         cdrom_release(&cd->cdi, mode);
544         scsi_cd_put(cd);
545         mutex_unlock(&sr_mutex);
546 }
547 
548 static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
549                           unsigned long arg)
550 {
551         struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
552         struct scsi_device *sdev = cd->device;
553         void __user *argp = (void __user *)arg;
554         int ret;
555 
556         mutex_lock(&sr_mutex);
557 
558         /*
559          * Send SCSI addressing ioctls directly to mid level, send other
560          * ioctls to cdrom/block level.
561          */
562         switch (cmd) {
563         case SCSI_IOCTL_GET_IDLUN:
564         case SCSI_IOCTL_GET_BUS_NUMBER:
565                 ret = scsi_ioctl(sdev, cmd, argp);
566                 goto out;
567         }
568 
569         ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
570         if (ret != -ENOSYS)
571                 goto out;
572 
573         /*
574          * ENODEV means that we didn't recognise the ioctl, or that we
575          * cannot execute it in the current device state.  In either
576          * case fall through to scsi_ioctl, which will return ENDOEV again
577          * if it doesn't recognise the ioctl
578          */
579         ret = scsi_nonblockable_ioctl(sdev, cmd, argp,
580                                         (mode & FMODE_NDELAY) != 0);
581         if (ret != -ENODEV)
582                 goto out;
583         ret = scsi_ioctl(sdev, cmd, argp);
584 
585 out:
586         mutex_unlock(&sr_mutex);
587         return ret;
588 }
589 
590 static unsigned int sr_block_check_events(struct gendisk *disk,
591                                           unsigned int clearing)
592 {
593         struct scsi_cd *cd = scsi_cd(disk);
594 
595         if (atomic_read(&cd->device->disk_events_disable_depth))
596                 return 0;
597 
598         return cdrom_check_events(&cd->cdi, clearing);
599 }
600 
601 static int sr_block_revalidate_disk(struct gendisk *disk)
602 {
603         struct scsi_cd *cd = scsi_cd(disk);
604         struct scsi_sense_hdr sshdr;
605 
606         /* if the unit is not ready, nothing more to do */
607         if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
608                 goto out;
609 
610         sr_cd_check(&cd->cdi);
611         get_sectorsize(cd);
612 out:
613         return 0;
614 }
615 
616 static const struct block_device_operations sr_bdops =
617 {
618         .owner          = THIS_MODULE,
619         .open           = sr_block_open,
620         .release        = sr_block_release,
621         .ioctl          = sr_block_ioctl,
622         .check_events   = sr_block_check_events,
623         .revalidate_disk = sr_block_revalidate_disk,
624         /* 
625          * No compat_ioctl for now because sr_block_ioctl never
626          * seems to pass arbitrary ioctls down to host drivers.
627          */
628 };
629 
630 static int sr_open(struct cdrom_device_info *cdi, int purpose)
631 {
632         struct scsi_cd *cd = cdi->handle;
633         struct scsi_device *sdev = cd->device;
634         int retval;
635 
636         /*
637          * If the device is in error recovery, wait until it is done.
638          * If the device is offline, then disallow any access to it.
639          */
640         retval = -ENXIO;
641         if (!scsi_block_when_processing_errors(sdev))
642                 goto error_out;
643 
644         return 0;
645 
646 error_out:
647         return retval;  
648 }
649 
650 static void sr_release(struct cdrom_device_info *cdi)
651 {
652         struct scsi_cd *cd = cdi->handle;
653 
654         if (cd->device->sector_size > 2048)
655                 sr_set_blocklength(cd, 2048);
656 
657 }
658 
659 static int sr_probe(struct device *dev)
660 {
661         struct scsi_device *sdev = to_scsi_device(dev);
662         struct gendisk *disk;
663         struct scsi_cd *cd;
664         int minor, error;
665 
666         error = -ENODEV;
667         if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
668                 goto fail;
669 
670         error = -ENOMEM;
671         cd = kzalloc(sizeof(*cd), GFP_KERNEL);
672         if (!cd)
673                 goto fail;
674 
675         kref_init(&cd->kref);
676 
677         disk = alloc_disk(1);
678         if (!disk)
679                 goto fail_free;
680 
681         spin_lock(&sr_index_lock);
682         minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
683         if (minor == SR_DISKS) {
684                 spin_unlock(&sr_index_lock);
685                 error = -EBUSY;
686                 goto fail_put;
687         }
688         __set_bit(minor, sr_index_bits);
689         spin_unlock(&sr_index_lock);
690 
691         disk->major = SCSI_CDROM_MAJOR;
692         disk->first_minor = minor;
693         sprintf(disk->disk_name, "sr%d", minor);
694         disk->fops = &sr_bdops;
695         disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
696         disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
697 
698         blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
699 
700         cd->device = sdev;
701         cd->disk = disk;
702         cd->driver = &sr_template;
703         cd->disk = disk;
704         cd->capacity = 0x1fffff;
705         cd->device->changed = 1;        /* force recheck CD type */
706         cd->media_present = 1;
707         cd->use = 1;
708         cd->readcd_known = 0;
709         cd->readcd_cdda = 0;
710 
711         cd->cdi.ops = &sr_dops;
712         cd->cdi.handle = cd;
713         cd->cdi.mask = 0;
714         cd->cdi.capacity = 1;
715         sprintf(cd->cdi.name, "sr%d", minor);
716 
717         sdev->sector_size = 2048;       /* A guess, just in case */
718 
719         /* FIXME: need to handle a get_capabilities failure properly ?? */
720         get_capabilities(cd);
721         blk_queue_prep_rq(sdev->request_queue, sr_prep_fn);
722         sr_vendor_init(cd);
723 
724         disk->driverfs_dev = &sdev->sdev_gendev;
725         set_capacity(disk, cd->capacity);
726         disk->private_data = &cd->driver;
727         disk->queue = sdev->request_queue;
728         cd->cdi.disk = disk;
729 
730         if (register_cdrom(&cd->cdi))
731                 goto fail_put;
732 
733         /*
734          * Initialize block layer runtime PM stuffs before the
735          * periodic event checking request gets started in add_disk.
736          */
737         blk_pm_runtime_init(sdev->request_queue, dev);
738 
739         dev_set_drvdata(dev, cd);
740         disk->flags |= GENHD_FL_REMOVABLE;
741         add_disk(disk);
742 
743         sdev_printk(KERN_DEBUG, sdev,
744                     "Attached scsi CD-ROM %s\n", cd->cdi.name);
745         scsi_autopm_put_device(cd->device);
746 
747         return 0;
748 
749 fail_put:
750         put_disk(disk);
751 fail_free:
752         kfree(cd);
753 fail:
754         return error;
755 }
756 
757 
758 static void get_sectorsize(struct scsi_cd *cd)
759 {
760         unsigned char cmd[10];
761         unsigned char buffer[8];
762         int the_result, retries = 3;
763         int sector_size;
764         struct request_queue *queue;
765 
766         do {
767                 cmd[0] = READ_CAPACITY;
768                 memset((void *) &cmd[1], 0, 9);
769                 memset(buffer, 0, sizeof(buffer));
770 
771                 /* Do the command and wait.. */
772                 the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
773                                               buffer, sizeof(buffer), NULL,
774                                               SR_TIMEOUT, MAX_RETRIES, NULL);
775 
776                 retries--;
777 
778         } while (the_result && retries);
779 
780 
781         if (the_result) {
782                 cd->capacity = 0x1fffff;
783                 sector_size = 2048;     /* A guess, just in case */
784         } else {
785                 long last_written;
786 
787                 cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) |
788                                     (buffer[2] << 8) | buffer[3]);
789                 /*
790                  * READ_CAPACITY doesn't return the correct size on
791                  * certain UDF media.  If last_written is larger, use
792                  * it instead.
793                  *
794                  * http://bugzilla.kernel.org/show_bug.cgi?id=9668
795                  */
796                 if (!cdrom_get_last_written(&cd->cdi, &last_written))
797                         cd->capacity = max_t(long, cd->capacity, last_written);
798 
799                 sector_size = (buffer[4] << 24) |
800                     (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
801                 switch (sector_size) {
802                         /*
803                          * HP 4020i CD-Recorder reports 2340 byte sectors
804                          * Philips CD-Writers report 2352 byte sectors
805                          *
806                          * Use 2k sectors for them..
807                          */
808                 case 0:
809                 case 2340:
810                 case 2352:
811                         sector_size = 2048;
812                         /* fall through */
813                 case 2048:
814                         cd->capacity *= 4;
815                         /* fall through */
816                 case 512:
817                         break;
818                 default:
819                         printk("%s: unsupported sector size %d.\n",
820                                cd->cdi.name, sector_size);
821                         cd->capacity = 0;
822                 }
823 
824                 cd->device->sector_size = sector_size;
825 
826                 /*
827                  * Add this so that we have the ability to correctly gauge
828                  * what the device is capable of.
829                  */
830                 set_capacity(cd->disk, cd->capacity);
831         }
832 
833         queue = cd->device->request_queue;
834         blk_queue_logical_block_size(queue, sector_size);
835 
836         return;
837 }
838 
839 static void get_capabilities(struct scsi_cd *cd)
840 {
841         unsigned char *buffer;
842         struct scsi_mode_data data;
843         struct scsi_sense_hdr sshdr;
844         int rc, n;
845 
846         static const char *loadmech[] =
847         {
848                 "caddy",
849                 "tray",
850                 "pop-up",
851                 "",
852                 "changer",
853                 "cartridge changer",
854                 "",
855                 ""
856         };
857 
858 
859         /* allocate transfer buffer */
860         buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
861         if (!buffer) {
862                 printk(KERN_ERR "sr: out of memory.\n");
863                 return;
864         }
865 
866         /* eat unit attentions */
867         scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
868 
869         /* ask for mode page 0x2a */
870         rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
871                              SR_TIMEOUT, 3, &data, NULL);
872 
873         if (!scsi_status_is_good(rc)) {
874                 /* failed, drive doesn't have capabilities mode page */
875                 cd->cdi.speed = 1;
876                 cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
877                                  CDC_DVD | CDC_DVD_RAM |
878                                  CDC_SELECT_DISC | CDC_SELECT_SPEED |
879                                  CDC_MRW | CDC_MRW_W | CDC_RAM);
880                 kfree(buffer);
881                 printk("%s: scsi-1 drive\n", cd->cdi.name);
882                 return;
883         }
884 
885         n = data.header_length + data.block_descriptor_length;
886         cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
887         cd->readcd_known = 1;
888         cd->readcd_cdda = buffer[n + 5] & 0x01;
889         /* print some capability bits */
890         printk("%s: scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n", cd->cdi.name,
891                ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
892                cd->cdi.speed,
893                buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
894                buffer[n + 3] & 0x20 ? "dvd-ram " : "",
895                buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
896                buffer[n + 4] & 0x20 ? "xa/form2 " : "", /* can read xa/from2 */
897                buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
898                loadmech[buffer[n + 6] >> 5]);
899         if ((buffer[n + 6] >> 5) == 0)
900                 /* caddy drives can't close tray... */
901                 cd->cdi.mask |= CDC_CLOSE_TRAY;
902         if ((buffer[n + 2] & 0x8) == 0)
903                 /* not a DVD drive */
904                 cd->cdi.mask |= CDC_DVD;
905         if ((buffer[n + 3] & 0x20) == 0) 
906                 /* can't write DVD-RAM media */
907                 cd->cdi.mask |= CDC_DVD_RAM;
908         if ((buffer[n + 3] & 0x10) == 0)
909                 /* can't write DVD-R media */
910                 cd->cdi.mask |= CDC_DVD_R;
911         if ((buffer[n + 3] & 0x2) == 0)
912                 /* can't write CD-RW media */
913                 cd->cdi.mask |= CDC_CD_RW;
914         if ((buffer[n + 3] & 0x1) == 0)
915                 /* can't write CD-R media */
916                 cd->cdi.mask |= CDC_CD_R;
917         if ((buffer[n + 6] & 0x8) == 0)
918                 /* can't eject */
919                 cd->cdi.mask |= CDC_OPEN_TRAY;
920 
921         if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
922             (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
923                 cd->cdi.capacity =
924                     cdrom_number_of_slots(&cd->cdi);
925         if (cd->cdi.capacity <= 1)
926                 /* not a changer */
927                 cd->cdi.mask |= CDC_SELECT_DISC;
928         /*else    I don't think it can close its tray
929                 cd->cdi.mask |= CDC_CLOSE_TRAY; */
930 
931         /*
932          * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
933          */
934         if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
935                         (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
936                 cd->device->writeable = 1;
937         }
938 
939         kfree(buffer);
940 }
941 
942 /*
943  * sr_packet() is the entry point for the generic commands generated
944  * by the Uniform CD-ROM layer. 
945  */
946 static int sr_packet(struct cdrom_device_info *cdi,
947                 struct packet_command *cgc)
948 {
949         struct scsi_cd *cd = cdi->handle;
950         struct scsi_device *sdev = cd->device;
951 
952         if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
953                 return -EDRIVE_CANT_DO_THIS;
954 
955         if (cgc->timeout <= 0)
956                 cgc->timeout = IOCTL_TIMEOUT;
957 
958         sr_do_ioctl(cd, cgc);
959 
960         return cgc->stat;
961 }
962 
963 /**
964  *      sr_kref_release - Called to free the scsi_cd structure
965  *      @kref: pointer to embedded kref
966  *
967  *      sr_ref_mutex must be held entering this routine.  Because it is
968  *      called on last put, you should always use the scsi_cd_get()
969  *      scsi_cd_put() helpers which manipulate the semaphore directly
970  *      and never do a direct kref_put().
971  **/
972 static void sr_kref_release(struct kref *kref)
973 {
974         struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
975         struct gendisk *disk = cd->disk;
976 
977         spin_lock(&sr_index_lock);
978         clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
979         spin_unlock(&sr_index_lock);
980 
981         unregister_cdrom(&cd->cdi);
982 
983         disk->private_data = NULL;
984 
985         put_disk(disk);
986 
987         kfree(cd);
988 }
989 
990 static int sr_remove(struct device *dev)
991 {
992         struct scsi_cd *cd = dev_get_drvdata(dev);
993 
994         scsi_autopm_get_device(cd->device);
995 
996         blk_queue_prep_rq(cd->device->request_queue, scsi_prep_fn);
997         del_gendisk(cd->disk);
998 
999         mutex_lock(&sr_ref_mutex);
1000         kref_put(&cd->kref, sr_kref_release);
1001         mutex_unlock(&sr_ref_mutex);
1002 
1003         return 0;
1004 }
1005 
1006 static int __init init_sr(void)
1007 {
1008         int rc;
1009 
1010         rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1011         if (rc)
1012                 return rc;
1013         rc = scsi_register_driver(&sr_template.gendrv);
1014         if (rc)
1015                 unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1016 
1017         return rc;
1018 }
1019 
1020 static void __exit exit_sr(void)
1021 {
1022         scsi_unregister_driver(&sr_template.gendrv);
1023         unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1024 }
1025 
1026 module_init(init_sr);
1027 module_exit(exit_sr);
1028 MODULE_LICENSE("GPL");
1029 

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