2 * sr.c Copyright (C) 1992 David Giller
3 * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
6 * sd.c Copyright (C) 1992 Drew Eckhardt
7 * Linux scsi disk driver by
8 * Drew Eckhardt <drew@colorado.edu>
10 * Modified by Eric Youngdale ericy@andante.org to
11 * add scatter-gather, multiple outstanding request, and other
14 * Modified by Eric Youngdale eric@andante.org to support loadable
15 * low-level scsi drivers.
17 * Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to
20 * Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the
21 * generic cdrom interface
23 * Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet()
24 * interface, capabilities probe additions, ioctl cleanups, etc.
26 * Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs
28 * Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM
29 * transparently and lose the GHOST hack
31 * Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
32 * check resource allocation in sr_init and some cleanups
35 #include <linux/module.h>
37 #include <linux/kernel.h>
38 #include <linux/sched.h>
40 #include <linux/bio.h>
41 #include <linux/string.h>
42 #include <linux/errno.h>
43 #include <linux/cdrom.h>
44 #include <linux/interrupt.h>
45 #include <linux/init.h>
46 #include <linux/blkdev.h>
47 #include <linux/mutex.h>
48 #include <asm/uaccess.h>
50 #include <scsi/scsi.h>
51 #include <scsi/scsi_dbg.h>
52 #include <scsi/scsi_device.h>
53 #include <scsi/scsi_driver.h>
54 #include <scsi/scsi_cmnd.h>
55 #include <scsi/scsi_eh.h>
56 #include <scsi/scsi_host.h>
57 #include <scsi/scsi_ioctl.h> /* For the door lock/unlock commands */
59 #include "scsi_logging.h"
63 MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
64 MODULE_LICENSE("GPL");
65 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
70 #define SR_TIMEOUT (30 * HZ)
71 #define SR_CAPABILITIES \
72 (CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
73 CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
74 CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
75 CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
76 CDC_MRW|CDC_MRW_W|CDC_RAM)
78 static int sr_probe(struct device *);
79 static int sr_remove(struct device *);
80 static int sr_init_command(struct scsi_cmnd *);
82 static struct scsi_driver sr_template = {
89 .init_command = sr_init_command,
92 static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
93 static DEFINE_SPINLOCK(sr_index_lock);
95 /* This semaphore is used to mediate the 0->1 reference get in the
96 * face of object destruction (i.e. we can't allow a get on an
97 * object after last put) */
98 static DEFINE_MUTEX(sr_ref_mutex);
100 static int sr_open(struct cdrom_device_info *, int);
101 static void sr_release(struct cdrom_device_info *);
103 static void get_sectorsize(struct scsi_cd *);
104 static void get_capabilities(struct scsi_cd *);
106 static int sr_media_change(struct cdrom_device_info *, int);
107 static int sr_packet(struct cdrom_device_info *, struct packet_command *);
109 static struct cdrom_device_ops sr_dops = {
111 .release = sr_release,
112 .drive_status = sr_drive_status,
113 .media_changed = sr_media_change,
114 .tray_move = sr_tray_move,
115 .lock_door = sr_lock_door,
116 .select_speed = sr_select_speed,
117 .get_last_session = sr_get_last_session,
118 .get_mcn = sr_get_mcn,
120 .audio_ioctl = sr_audio_ioctl,
121 .capability = SR_CAPABILITIES,
122 .generic_packet = sr_packet,
125 static void sr_kref_release(struct kref *kref);
127 static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
129 return container_of(disk->private_data, struct scsi_cd, driver);
133 * The get and put routines for the struct scsi_cd. Note this entity
134 * has a scsi_device pointer and owns a reference to this.
136 static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
138 struct scsi_cd *cd = NULL;
140 mutex_lock(&sr_ref_mutex);
141 if (disk->private_data == NULL)
145 if (scsi_device_get(cd->device))
150 kref_put(&cd->kref, sr_kref_release);
153 mutex_unlock(&sr_ref_mutex);
157 static void scsi_cd_put(struct scsi_cd *cd)
159 struct scsi_device *sdev = cd->device;
161 mutex_lock(&sr_ref_mutex);
162 kref_put(&cd->kref, sr_kref_release);
163 scsi_device_put(sdev);
164 mutex_unlock(&sr_ref_mutex);
168 * This function checks to see if the media has been changed in the
169 * CDROM drive. It is possible that we have already sensed a change,
170 * or the drive may have sensed one and not yet reported it. We must
171 * be ready for either case. This function always reports the current
172 * value of the changed bit. If flag is 0, then the changed bit is reset.
173 * This function could be done as an ioctl, but we would need to have
174 * an inode for that to work, and we do not always have one.
177 int sr_media_change(struct cdrom_device_info *cdi, int slot)
179 struct scsi_cd *cd = cdi->handle;
182 if (CDSL_CURRENT != slot) {
183 /* no changer support */
187 retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES);
189 /* Unable to test, unit probably not ready. This usually
190 * means there is no disc in the drive. Mark as changed,
191 * and we will figure it out later once the drive is
192 * available again. */
193 cd->device->changed = 1;
194 return 1; /* This will force a flush, if called from
195 * check_disk_change */
198 retval = cd->device->changed;
199 cd->device->changed = 0;
200 /* If the disk changed, the capacity will now be different,
201 * so we force a re-read of this information */
203 /* check multisession offset etc */
212 * rw_intr is the interrupt routine for the device driver.
214 * It will be notified on the end of a SCSI read / write, and will take on
215 * of several actions based on success or failure.
217 static void rw_intr(struct scsi_cmnd * SCpnt)
219 int result = SCpnt->result;
220 int this_count = SCpnt->bufflen;
221 int good_bytes = (result == 0 ? this_count : 0);
222 int block_sectors = 0;
224 struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
227 printk("sr.c done: %x\n", result);
231 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
232 * success. Since this is a relatively rare error condition, no
233 * care is taken to avoid unnecessary additional work such as
234 * memcpy's that could be avoided.
236 if (driver_byte(result) != 0 && /* An error occurred */
237 (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
238 switch (SCpnt->sense_buffer[2]) {
240 case VOLUME_OVERFLOW:
241 case ILLEGAL_REQUEST:
242 if (!(SCpnt->sense_buffer[0] & 0x90))
244 error_sector = (SCpnt->sense_buffer[3] << 24) |
245 (SCpnt->sense_buffer[4] << 16) |
246 (SCpnt->sense_buffer[5] << 8) |
247 SCpnt->sense_buffer[6];
248 if (SCpnt->request->bio != NULL)
250 bio_sectors(SCpnt->request->bio);
251 if (block_sectors < 4)
253 if (cd->device->sector_size == 2048)
255 error_sector &= ~(block_sectors - 1);
256 good_bytes = (error_sector - SCpnt->request->sector) << 9;
257 if (good_bytes < 0 || good_bytes >= this_count)
260 * The SCSI specification allows for the value
261 * returned by READ CAPACITY to be up to 75 2K
262 * sectors past the last readable block.
263 * Therefore, if we hit a medium error within the
264 * last 75 2K sectors, we decrease the saved size
267 if (error_sector < get_capacity(cd->disk) &&
268 cd->capacity - error_sector < 4 * 75)
269 set_capacity(cd->disk, error_sector);
272 case RECOVERED_ERROR:
275 * An error occured, but it recovered. Inform the
276 * user, but make sure that it's not treated as a
279 scsi_print_sense("sr", SCpnt);
281 SCpnt->sense_buffer[0] = 0x0;
282 good_bytes = this_count;
291 * This calls the generic completion function, now that we know
292 * how many actual sectors finished, and how many sectors we need
293 * to say have failed.
295 scsi_io_completion(SCpnt, good_bytes, block_sectors << 9);
298 static int sr_init_command(struct scsi_cmnd * SCpnt)
300 int block=0, this_count, s_size, timeout = SR_TIMEOUT;
301 struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
303 SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %s, block = %d\n",
304 cd->disk->disk_name, block));
306 if (!cd->device || !scsi_device_online(cd->device)) {
307 SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n",
308 SCpnt->request->nr_sectors));
309 SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
313 if (cd->device->changed) {
315 * quietly refuse to do anything to a changed disc until the
316 * changed bit has been reset
322 * we do lazy blocksize switching (when reading XA sectors,
323 * see CDROMREADMODE2 ioctl)
325 s_size = cd->device->sector_size;
328 sr_set_blocklength(cd, 2048);
330 printk("sr: can't switch blocksize: in interrupt\n");
333 if (s_size != 512 && s_size != 1024 && s_size != 2048) {
334 scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
338 if (rq_data_dir(SCpnt->request) == WRITE) {
339 if (!cd->device->writeable)
341 SCpnt->cmnd[0] = WRITE_10;
342 SCpnt->sc_data_direction = DMA_TO_DEVICE;
343 cd->cdi.media_written = 1;
344 } else if (rq_data_dir(SCpnt->request) == READ) {
345 SCpnt->cmnd[0] = READ_10;
346 SCpnt->sc_data_direction = DMA_FROM_DEVICE;
348 blk_dump_rq_flags(SCpnt->request, "Unknown sr command");
353 struct scatterlist *sg = SCpnt->request_buffer;
355 for (i = 0; i < SCpnt->use_sg; i++)
356 size += sg[i].length;
358 if (size != SCpnt->request_bufflen && SCpnt->use_sg) {
359 scmd_printk(KERN_ERR, SCpnt,
360 "mismatch count %d, bytes %d\n",
361 size, SCpnt->request_bufflen);
362 if (SCpnt->request_bufflen > size)
363 SCpnt->request_bufflen = SCpnt->bufflen = size;
368 * request doesn't start on hw block boundary, add scatter pads
370 if (((unsigned int)SCpnt->request->sector % (s_size >> 9)) ||
371 (SCpnt->request_bufflen % s_size)) {
372 scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
376 this_count = (SCpnt->request_bufflen >> 9) / (s_size >> 9);
379 SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
381 (rq_data_dir(SCpnt->request) == WRITE) ?
382 "writing" : "reading",
383 this_count, SCpnt->request->nr_sectors));
386 block = (unsigned int)SCpnt->request->sector / (s_size >> 9);
388 if (this_count > 0xffff) {
390 SCpnt->request_bufflen = SCpnt->bufflen =
394 SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
395 SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
396 SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
397 SCpnt->cmnd[5] = (unsigned char) block & 0xff;
398 SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
399 SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
400 SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
403 * We shouldn't disconnect in the middle of a sector, so with a dumb
404 * host adapter, it's safe to assume that we can at least transfer
405 * this many bytes between each connect / disconnect.
407 SCpnt->transfersize = cd->device->sector_size;
408 SCpnt->underflow = this_count << 9;
409 SCpnt->allowed = MAX_RETRIES;
410 SCpnt->timeout_per_command = timeout;
413 * This is the completion routine we use. This is matched in terms
414 * of capability to this function.
416 SCpnt->done = rw_intr;
419 * This indicates that the command is ready from our end to be
425 static int sr_block_open(struct inode *inode, struct file *file)
427 struct gendisk *disk = inode->i_bdev->bd_disk;
431 if(!(cd = scsi_cd_get(disk)))
434 if((ret = cdrom_open(&cd->cdi, inode, file)) != 0)
440 static int sr_block_release(struct inode *inode, struct file *file)
443 struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
444 ret = cdrom_release(&cd->cdi, file);
453 static int sr_block_ioctl(struct inode *inode, struct file *file, unsigned cmd,
456 struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
457 struct scsi_device *sdev = cd->device;
458 void __user *argp = (void __user *)arg;
462 * Send SCSI addressing ioctls directly to mid level, send other
463 * ioctls to cdrom/block level.
466 case SCSI_IOCTL_GET_IDLUN:
467 case SCSI_IOCTL_GET_BUS_NUMBER:
468 return scsi_ioctl(sdev, cmd, argp);
471 ret = cdrom_ioctl(file, &cd->cdi, inode, cmd, arg);
476 * ENODEV means that we didn't recognise the ioctl, or that we
477 * cannot execute it in the current device state. In either
478 * case fall through to scsi_ioctl, which will return ENDOEV again
479 * if it doesn't recognise the ioctl
481 ret = scsi_nonblockable_ioctl(sdev, cmd, argp, NULL);
484 return scsi_ioctl(sdev, cmd, argp);
487 static int sr_block_media_changed(struct gendisk *disk)
489 struct scsi_cd *cd = scsi_cd(disk);
490 return cdrom_media_changed(&cd->cdi);
493 static struct block_device_operations sr_bdops =
495 .owner = THIS_MODULE,
496 .open = sr_block_open,
497 .release = sr_block_release,
498 .ioctl = sr_block_ioctl,
499 .media_changed = sr_block_media_changed,
501 * No compat_ioctl for now because sr_block_ioctl never
502 * seems to pass arbitary ioctls down to host drivers.
506 static int sr_open(struct cdrom_device_info *cdi, int purpose)
508 struct scsi_cd *cd = cdi->handle;
509 struct scsi_device *sdev = cd->device;
513 * If the device is in error recovery, wait until it is done.
514 * If the device is offline, then disallow any access to it.
517 if (!scsi_block_when_processing_errors(sdev))
526 static void sr_release(struct cdrom_device_info *cdi)
528 struct scsi_cd *cd = cdi->handle;
530 if (cd->device->sector_size > 2048)
531 sr_set_blocklength(cd, 2048);
535 static int sr_probe(struct device *dev)
537 struct scsi_device *sdev = to_scsi_device(dev);
538 struct gendisk *disk;
543 if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
547 cd = kzalloc(sizeof(*cd), GFP_KERNEL);
551 kref_init(&cd->kref);
553 disk = alloc_disk(1);
557 spin_lock(&sr_index_lock);
558 minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
559 if (minor == SR_DISKS) {
560 spin_unlock(&sr_index_lock);
564 __set_bit(minor, sr_index_bits);
565 spin_unlock(&sr_index_lock);
567 disk->major = SCSI_CDROM_MAJOR;
568 disk->first_minor = minor;
569 sprintf(disk->disk_name, "sr%d", minor);
570 disk->fops = &sr_bdops;
571 disk->flags = GENHD_FL_CD;
575 cd->driver = &sr_template;
577 cd->capacity = 0x1fffff;
578 cd->device->changed = 1; /* force recheck CD type */
580 cd->readcd_known = 0;
583 cd->cdi.ops = &sr_dops;
586 cd->cdi.capacity = 1;
587 sprintf(cd->cdi.name, "sr%d", minor);
589 sdev->sector_size = 2048; /* A guess, just in case */
591 /* FIXME: need to handle a get_capabilities failure properly ?? */
592 get_capabilities(cd);
595 disk->driverfs_dev = &sdev->sdev_gendev;
596 set_capacity(disk, cd->capacity);
597 disk->private_data = &cd->driver;
598 disk->queue = sdev->request_queue;
601 if (register_cdrom(&cd->cdi))
604 dev_set_drvdata(dev, cd);
605 disk->flags |= GENHD_FL_REMOVABLE;
608 sdev_printk(KERN_DEBUG, sdev,
609 "Attached scsi CD-ROM %s\n", cd->cdi.name);
621 static void get_sectorsize(struct scsi_cd *cd)
623 unsigned char cmd[10];
624 unsigned char *buffer;
625 int the_result, retries = 3;
627 request_queue_t *queue;
629 buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
634 cmd[0] = READ_CAPACITY;
635 memset((void *) &cmd[1], 0, 9);
636 memset(buffer, 0, 8);
638 /* Do the command and wait.. */
639 the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
640 buffer, 8, NULL, SR_TIMEOUT,
645 } while (the_result && retries);
649 cd->capacity = 0x1fffff;
650 sector_size = 2048; /* A guess, just in case */
653 if (cdrom_get_last_written(&cd->cdi,
656 cd->capacity = 1 + ((buffer[0] << 24) |
660 sector_size = (buffer[4] << 24) |
661 (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
662 switch (sector_size) {
664 * HP 4020i CD-Recorder reports 2340 byte sectors
665 * Philips CD-Writers report 2352 byte sectors
667 * Use 2k sectors for them..
680 printk("%s: unsupported sector size %d.\n",
681 cd->cdi.name, sector_size);
685 cd->device->sector_size = sector_size;
688 * Add this so that we have the ability to correctly gauge
689 * what the device is capable of.
691 set_capacity(cd->disk, cd->capacity);
694 queue = cd->device->request_queue;
695 blk_queue_hardsect_size(queue, sector_size);
701 cd->capacity = 0x1fffff;
702 cd->device->sector_size = 2048; /* A guess, just in case */
706 static void get_capabilities(struct scsi_cd *cd)
708 unsigned char *buffer;
709 struct scsi_mode_data data;
710 unsigned char cmd[MAX_COMMAND_SIZE];
711 struct scsi_sense_hdr sshdr;
712 unsigned int the_result;
715 static const char *loadmech[] =
728 /* allocate transfer buffer */
729 buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
731 printk(KERN_ERR "sr: out of memory.\n");
735 /* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION
736 * conditions are gone, or a timeout happens
740 memset((void *)cmd, 0, MAX_COMMAND_SIZE);
741 cmd[0] = TEST_UNIT_READY;
743 the_result = scsi_execute_req (cd->device, cmd, DMA_NONE, NULL,
744 0, &sshdr, SR_TIMEOUT,
748 } while (retries < 5 &&
749 (!scsi_status_is_good(the_result) ||
750 (scsi_sense_valid(&sshdr) &&
751 sshdr.sense_key == UNIT_ATTENTION)));
753 /* ask for mode page 0x2a */
754 rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
755 SR_TIMEOUT, 3, &data, NULL);
757 if (!scsi_status_is_good(rc)) {
758 /* failed, drive doesn't have capabilities mode page */
760 cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
761 CDC_DVD | CDC_DVD_RAM |
762 CDC_SELECT_DISC | CDC_SELECT_SPEED |
763 CDC_MRW | CDC_MRW_W | CDC_RAM);
765 printk("%s: scsi-1 drive\n", cd->cdi.name);
769 n = data.header_length + data.block_descriptor_length;
770 cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
771 cd->readcd_known = 1;
772 cd->readcd_cdda = buffer[n + 5] & 0x01;
773 /* print some capability bits */
774 printk("%s: scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n", cd->cdi.name,
775 ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
777 buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
778 buffer[n + 3] & 0x20 ? "dvd-ram " : "",
779 buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
780 buffer[n + 4] & 0x20 ? "xa/form2 " : "", /* can read xa/from2 */
781 buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
782 loadmech[buffer[n + 6] >> 5]);
783 if ((buffer[n + 6] >> 5) == 0)
784 /* caddy drives can't close tray... */
785 cd->cdi.mask |= CDC_CLOSE_TRAY;
786 if ((buffer[n + 2] & 0x8) == 0)
787 /* not a DVD drive */
788 cd->cdi.mask |= CDC_DVD;
789 if ((buffer[n + 3] & 0x20) == 0)
790 /* can't write DVD-RAM media */
791 cd->cdi.mask |= CDC_DVD_RAM;
792 if ((buffer[n + 3] & 0x10) == 0)
793 /* can't write DVD-R media */
794 cd->cdi.mask |= CDC_DVD_R;
795 if ((buffer[n + 3] & 0x2) == 0)
796 /* can't write CD-RW media */
797 cd->cdi.mask |= CDC_CD_RW;
798 if ((buffer[n + 3] & 0x1) == 0)
799 /* can't write CD-R media */
800 cd->cdi.mask |= CDC_CD_R;
801 if ((buffer[n + 6] & 0x8) == 0)
803 cd->cdi.mask |= CDC_OPEN_TRAY;
805 if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
806 (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
808 cdrom_number_of_slots(&cd->cdi);
809 if (cd->cdi.capacity <= 1)
811 cd->cdi.mask |= CDC_SELECT_DISC;
812 /*else I don't think it can close its tray
813 cd->cdi.mask |= CDC_CLOSE_TRAY; */
816 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
818 if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
819 (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
820 cd->device->writeable = 1;
827 * sr_packet() is the entry point for the generic commands generated
828 * by the Uniform CD-ROM layer.
830 static int sr_packet(struct cdrom_device_info *cdi,
831 struct packet_command *cgc)
833 if (cgc->timeout <= 0)
834 cgc->timeout = IOCTL_TIMEOUT;
836 sr_do_ioctl(cdi->handle, cgc);
842 * sr_kref_release - Called to free the scsi_cd structure
843 * @kref: pointer to embedded kref
845 * sr_ref_mutex must be held entering this routine. Because it is
846 * called on last put, you should always use the scsi_cd_get()
847 * scsi_cd_put() helpers which manipulate the semaphore directly
848 * and never do a direct kref_put().
850 static void sr_kref_release(struct kref *kref)
852 struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
853 struct gendisk *disk = cd->disk;
855 spin_lock(&sr_index_lock);
856 clear_bit(disk->first_minor, sr_index_bits);
857 spin_unlock(&sr_index_lock);
859 unregister_cdrom(&cd->cdi);
861 disk->private_data = NULL;
868 static int sr_remove(struct device *dev)
870 struct scsi_cd *cd = dev_get_drvdata(dev);
872 del_gendisk(cd->disk);
874 mutex_lock(&sr_ref_mutex);
875 kref_put(&cd->kref, sr_kref_release);
876 mutex_unlock(&sr_ref_mutex);
881 static int __init init_sr(void)
885 rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
888 return scsi_register_driver(&sr_template.gendrv);
891 static void __exit exit_sr(void)
893 scsi_unregister_driver(&sr_template.gendrv);
894 unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
897 module_init(init_sr);
898 module_exit(exit_sr);
899 MODULE_LICENSE("GPL");