/* * sr.c Copyright (C) 1992 David Giller * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale * * adapted from: * sd.c Copyright (C) 1992 Drew Eckhardt * Linux scsi disk driver by * Drew Eckhardt <drew@colorado.edu> * * Modified by Eric Youngdale ericy@andante.org to * add scatter-gather, multiple outstanding request, and other * enhancements. * * Modified by Eric Youngdale eric@andante.org to support loadable * low-level scsi drivers. * * Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to * provide auto-eject. * * Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the * generic cdrom interface * * Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet() * interface, capabilities probe additions, ioctl cleanups, etc. * * Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs * * Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM * transparently and lose the GHOST hack * * Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br> * check resource allocation in sr_init and some cleanups */ #include <linux/module.h> #include <linux/fs.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/bio.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/cdrom.h> #include <linux/interrupt.h> #include <linux/init.h> #include <linux/blkdev.h> #include <linux/mutex.h> #include <asm/uaccess.h> #include <scsi/scsi.h> #include <scsi/scsi_dbg.h> #include <scsi/scsi_device.h> #include <scsi/scsi_driver.h> #include <scsi/scsi_cmnd.h> #include <scsi/scsi_eh.h> #include <scsi/scsi_host.h> #include <scsi/scsi_ioctl.h> /* For the door lock/unlock commands */ #include "scsi_logging.h" #include "sr.h" MODULE_DESCRIPTION("SCSI cdrom (sr) driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR); #define SR_DISKS 256 #define MAX_RETRIES 3 #define SR_TIMEOUT (30 * HZ) #define SR_CAPABILITIES \ (CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \ CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \ CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \ CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \ CDC_MRW|CDC_MRW_W|CDC_RAM) static int sr_probe(struct device *); static int sr_remove(struct device *); static int sr_init_command(struct scsi_cmnd *); static struct scsi_driver sr_template = { .owner = THIS_MODULE, .gendrv = { .name = "sr", .probe = sr_probe, .remove = sr_remove, }, .init_command = sr_init_command, }; static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG]; static DEFINE_SPINLOCK(sr_index_lock); /* This semaphore is used to mediate the 0->1 reference get in the * face of object destruction (i.e. we can't allow a get on an * object after last put) */ static DEFINE_MUTEX(sr_ref_mutex); static int sr_open(struct cdrom_device_info *, int); static void sr_release(struct cdrom_device_info *); static void get_sectorsize(struct scsi_cd *); static void get_capabilities(struct scsi_cd *); static int sr_media_change(struct cdrom_device_info *, int); static int sr_packet(struct cdrom_device_info *, struct packet_command *); static struct cdrom_device_ops sr_dops = { .open = sr_open, .release = sr_release, .drive_status = sr_drive_status, .media_changed = sr_media_change, .tray_move = sr_tray_move, .lock_door = sr_lock_door, .select_speed = sr_select_speed, .get_last_session = sr_get_last_session, .get_mcn = sr_get_mcn, .reset = sr_reset, .audio_ioctl = sr_audio_ioctl, .capability = SR_CAPABILITIES, .generic_packet = sr_packet, }; static void sr_kref_release(struct kref *kref); static inline struct scsi_cd *scsi_cd(struct gendisk *disk) { return container_of(disk->private_data, struct scsi_cd, driver); } /* * The get and put routines for the struct scsi_cd. Note this entity * has a scsi_device pointer and owns a reference to this. */ static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk) { struct scsi_cd *cd = NULL; mutex_lock(&sr_ref_mutex); if (disk->private_data == NULL) goto out; cd = scsi_cd(disk); kref_get(&cd->kref); if (scsi_device_get(cd->device)) goto out_put; goto out; out_put: kref_put(&cd->kref, sr_kref_release); cd = NULL; out: mutex_unlock(&sr_ref_mutex); return cd; } static void scsi_cd_put(struct scsi_cd *cd) { struct scsi_device *sdev = cd->device; mutex_lock(&sr_ref_mutex); kref_put(&cd->kref, sr_kref_release); scsi_device_put(sdev); mutex_unlock(&sr_ref_mutex); } /* * This function checks to see if the media has been changed in the * CDROM drive. It is possible that we have already sensed a change, * or the drive may have sensed one and not yet reported it. We must * be ready for either case. This function always reports the current * value of the changed bit. If flag is 0, then the changed bit is reset. * This function could be done as an ioctl, but we would need to have * an inode for that to work, and we do not always have one. */ int sr_media_change(struct cdrom_device_info *cdi, int slot) { struct scsi_cd *cd = cdi->handle; int retval; if (CDSL_CURRENT != slot) { /* no changer support */ return -EINVAL; } retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES); if (retval) { /* Unable to test, unit probably not ready. This usually * means there is no disc in the drive. Mark as changed, * and we will figure it out later once the drive is * available again. */ cd->device->changed = 1; return 1; /* This will force a flush, if called from * check_disk_change */ }; retval = cd->device->changed; cd->device->changed = 0; /* If the disk changed, the capacity will now be different, * so we force a re-read of this information */ if (retval) { /* check multisession offset etc */ sr_cd_check(cdi); get_sectorsize(cd); } return retval; } /* * rw_intr is the interrupt routine for the device driver. * * It will be notified on the end of a SCSI read / write, and will take on * of several actions based on success or failure. */ static void rw_intr(struct scsi_cmnd * SCpnt) { int result = SCpnt->result; int this_count = SCpnt->bufflen; int good_bytes = (result == 0 ? this_count : 0); int block_sectors = 0; long error_sector; struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk); #ifdef DEBUG printk("sr.c done: %x\n", result); #endif /* * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial * success. Since this is a relatively rare error condition, no * care is taken to avoid unnecessary additional work such as * memcpy's that could be avoided. */ if (driver_byte(result) != 0 && /* An error occurred */ (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */ switch (SCpnt->sense_buffer[2]) { case MEDIUM_ERROR: case VOLUME_OVERFLOW: case ILLEGAL_REQUEST: if (!(SCpnt->sense_buffer[0] & 0x90)) break; error_sector = (SCpnt->sense_buffer[3] << 24) | (SCpnt->sense_buffer[4] << 16) | (SCpnt->sense_buffer[5] << 8) | SCpnt->sense_buffer[6]; if (SCpnt->request->bio != NULL) block_sectors = bio_sectors(SCpnt->request->bio); if (block_sectors < 4) block_sectors = 4; if (cd->device->sector_size == 2048) error_sector <<= 2; error_sector &= ~(block_sectors - 1); good_bytes = (error_sector - SCpnt->request->sector) << 9; if (good_bytes < 0 || good_bytes >= this_count) good_bytes = 0; /* * The SCSI specification allows for the value * returned by READ CAPACITY to be up to 75 2K * sectors past the last readable block. * Therefore, if we hit a medium error within the * last 75 2K sectors, we decrease the saved size * value. */ if (error_sector < get_capacity(cd->disk) && cd->capacity - error_sector < 4 * 75) set_capacity(cd->disk, error_sector); break; case RECOVERED_ERROR: /* * An error occured, but it recovered. Inform the * user, but make sure that it's not treated as a * hard error. */ scsi_print_sense("sr", SCpnt); SCpnt->result = 0; SCpnt->sense_buffer[0] = 0x0; good_bytes = this_count; break; default: break; } } /* * This calls the generic completion function, now that we know * how many actual sectors finished, and how many sectors we need * to say have failed. */ scsi_io_completion(SCpnt, good_bytes, block_sectors << 9); } static int sr_init_command(struct scsi_cmnd * SCpnt) { int block=0, this_count, s_size, timeout = SR_TIMEOUT; struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk); SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %s, block = %d\n", cd->disk->disk_name, block)); if (!cd->device || !scsi_device_online(cd->device)) { SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n", SCpnt->request->nr_sectors)); SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt)); return 0; } if (cd->device->changed) { /* * quietly refuse to do anything to a changed disc until the * changed bit has been reset */ return 0; } /* * we do lazy blocksize switching (when reading XA sectors, * see CDROMREADMODE2 ioctl) */ s_size = cd->device->sector_size; if (s_size > 2048) { if (!in_interrupt()) sr_set_blocklength(cd, 2048); else printk("sr: can't switch blocksize: in interrupt\n"); } if (s_size != 512 && s_size != 1024 && s_size != 2048) { scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size); return 0; } if (rq_data_dir(SCpnt->request) == WRITE) { if (!cd->device->writeable) return 0; SCpnt->cmnd[0] = WRITE_10; SCpnt->sc_data_direction = DMA_TO_DEVICE; cd->cdi.media_written = 1; } else if (rq_data_dir(SCpnt->request) == READ) { SCpnt->cmnd[0] = READ_10; SCpnt->sc_data_direction = DMA_FROM_DEVICE; } else { blk_dump_rq_flags(SCpnt->request, "Unknown sr command"); return 0; } { struct scatterlist *sg = SCpnt->request_buffer; int i, size = 0; for (i = 0; i < SCpnt->use_sg; i++) size += sg[i].length; if (size != SCpnt->request_bufflen && SCpnt->use_sg) { scmd_printk(KERN_ERR, SCpnt, "mismatch count %d, bytes %d\n", size, SCpnt->request_bufflen); if (SCpnt->request_bufflen > size) SCpnt->request_bufflen = SCpnt->bufflen = size; } } /* * request doesn't start on hw block boundary, add scatter pads */ if (((unsigned int)SCpnt->request->sector % (s_size >> 9)) || (SCpnt->request_bufflen % s_size)) { scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n"); return 0; } this_count = (SCpnt->request_bufflen >> 9) / (s_size >> 9); SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n", cd->cdi.name, (rq_data_dir(SCpnt->request) == WRITE) ? "writing" : "reading", this_count, SCpnt->request->nr_sectors)); SCpnt->cmnd[1] = 0; block = (unsigned int)SCpnt->request->sector / (s_size >> 9); if (this_count > 0xffff) { this_count = 0xffff; SCpnt->request_bufflen = SCpnt->bufflen = this_count * s_size; } SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff; SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff; SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff; SCpnt->cmnd[5] = (unsigned char) block & 0xff; SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0; SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff; SCpnt->cmnd[8] = (unsigned char) this_count & 0xff; /* * We shouldn't disconnect in the middle of a sector, so with a dumb * host adapter, it's safe to assume that we can at least transfer * this many bytes between each connect / disconnect. */ SCpnt->transfersize = cd->device->sector_size; SCpnt->underflow = this_count << 9; SCpnt->allowed = MAX_RETRIES; SCpnt->timeout_per_command = timeout; /* * This is the completion routine we use. This is matched in terms * of capability to this function. */ SCpnt->done = rw_intr; /* * This indicates that the command is ready from our end to be * queued. */ return 1; } static int sr_block_open(struct inode *inode, struct file *file) { struct gendisk *disk = inode->i_bdev->bd_disk; struct scsi_cd *cd; int ret = 0; if(!(cd = scsi_cd_get(disk))) return -ENXIO; if((ret = cdrom_open(&cd->cdi, inode, file)) != 0) scsi_cd_put(cd); return ret; } static int sr_block_release(struct inode *inode, struct file *file) { int ret; struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk); ret = cdrom_release(&cd->cdi, file); if(ret) return ret; scsi_cd_put(cd); return 0; } static int sr_block_ioctl(struct inode *inode, struct file *file, unsigned cmd, unsigned long arg) { struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk); struct scsi_device *sdev = cd->device; void __user *argp = (void __user *)arg; int ret; /* * Send SCSI addressing ioctls directly to mid level, send other * ioctls to cdrom/block level. */ switch (cmd) { case SCSI_IOCTL_GET_IDLUN: case SCSI_IOCTL_GET_BUS_NUMBER: return scsi_ioctl(sdev, cmd, argp); } ret = cdrom_ioctl(file, &cd->cdi, inode, cmd, arg); if (ret != ENOSYS) return ret; /* * ENODEV means that we didn't recognise the ioctl, or that we * cannot execute it in the current device state. In either * case fall through to scsi_ioctl, which will return ENDOEV again * if it doesn't recognise the ioctl */ ret = scsi_nonblockable_ioctl(sdev, cmd, argp, NULL); if (ret != -ENODEV) return ret; return scsi_ioctl(sdev, cmd, argp); } static int sr_block_media_changed(struct gendisk *disk) { struct scsi_cd *cd = scsi_cd(disk); return cdrom_media_changed(&cd->cdi); } static struct block_device_operations sr_bdops = { .owner = THIS_MODULE, .open = sr_block_open, .release = sr_block_release, .ioctl = sr_block_ioctl, .media_changed = sr_block_media_changed, /* * No compat_ioctl for now because sr_block_ioctl never * seems to pass arbitary ioctls down to host drivers. */ }; static int sr_open(struct cdrom_device_info *cdi, int purpose) { struct scsi_cd *cd = cdi->handle; struct scsi_device *sdev = cd->device; int retval; /* * If the device is in error recovery, wait until it is done. * If the device is offline, then disallow any access to it. */ retval = -ENXIO; if (!scsi_block_when_processing_errors(sdev)) goto error_out; return 0; error_out: return retval; } static void sr_release(struct cdrom_device_info *cdi) { struct scsi_cd *cd = cdi->handle; if (cd->device->sector_size > 2048) sr_set_blocklength(cd, 2048); } static int sr_probe(struct device *dev) { struct scsi_device *sdev = to_scsi_device(dev); struct gendisk *disk; struct scsi_cd *cd; int minor, error; error = -ENODEV; if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM) goto fail; error = -ENOMEM; cd = kzalloc(sizeof(*cd), GFP_KERNEL); if (!cd) goto fail; kref_init(&cd->kref); disk = alloc_disk(1); if (!disk) goto fail_free; spin_lock(&sr_index_lock); minor = find_first_zero_bit(sr_index_bits, SR_DISKS); if (minor == SR_DISKS) { spin_unlock(&sr_index_lock); error = -EBUSY; goto fail_put; } __set_bit(minor, sr_index_bits); spin_unlock(&sr_index_lock); disk->major = SCSI_CDROM_MAJOR; disk->first_minor = minor; sprintf(disk->disk_name, "sr%d", minor); disk->fops = &sr_bdops; disk->flags = GENHD_FL_CD; cd->device = sdev; cd->disk = disk; cd->driver = &sr_template; cd->disk = disk; cd->capacity = 0x1fffff; cd->device->changed = 1; /* force recheck CD type */ cd->use = 1; cd->readcd_known = 0; cd->readcd_cdda = 0; cd->cdi.ops = &sr_dops; cd->cdi.handle = cd; cd->cdi.mask = 0; cd->cdi.capacity = 1; sprintf(cd->cdi.name, "sr%d", minor); sdev->sector_size = 2048; /* A guess, just in case */ /* FIXME: need to handle a get_capabilities failure properly ?? */ get_capabilities(cd); sr_vendor_init(cd); disk->driverfs_dev = &sdev->sdev_gendev; set_capacity(disk, cd->capacity); disk->private_data = &cd->driver; disk->queue = sdev->request_queue; cd->cdi.disk = disk; if (register_cdrom(&cd->cdi)) goto fail_put; dev_set_drvdata(dev, cd); disk->flags |= GENHD_FL_REMOVABLE; add_disk(disk); sdev_printk(KERN_DEBUG, sdev, "Attached scsi CD-ROM %s\n", cd->cdi.name); return 0; fail_put: put_disk(disk); fail_free: kfree(cd); fail: return error; } static void get_sectorsize(struct scsi_cd *cd) { unsigned char cmd[10]; unsigned char *buffer; int the_result, retries = 3; int sector_size; request_queue_t *queue; buffer = kmalloc(512, GFP_KERNEL | GFP_DMA); if (!buffer) goto Enomem; do { cmd[0] = READ_CAPACITY; memset((void *) &cmd[1], 0, 9); memset(buffer, 0, 8); /* Do the command and wait.. */ the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE, buffer, 8, NULL, SR_TIMEOUT, MAX_RETRIES); retries--; } while (the_result && retries); if (the_result) { cd->capacity = 0x1fffff; sector_size = 2048; /* A guess, just in case */ } else { #if 0 if (cdrom_get_last_written(&cd->cdi, &cd->capacity)) #endif cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]); sector_size = (buffer[4] << 24) | (buffer[5] << 16) | (buffer[6] << 8) | buffer[7]; switch (sector_size) { /* * HP 4020i CD-Recorder reports 2340 byte sectors * Philips CD-Writers report 2352 byte sectors * * Use 2k sectors for them.. */ case 0: case 2340: case 2352: sector_size = 2048; /* fall through */ case 2048: cd->capacity *= 4; /* fall through */ case 512: break; default: printk("%s: unsupported sector size %d.\n", cd->cdi.name, sector_size); cd->capacity = 0; } cd->device->sector_size = sector_size; /* * Add this so that we have the ability to correctly gauge * what the device is capable of. */ set_capacity(cd->disk, cd->capacity); } queue = cd->device->request_queue; blk_queue_hardsect_size(queue, sector_size); out: kfree(buffer); return; Enomem: cd->capacity = 0x1fffff; cd->device->sector_size = 2048; /* A guess, just in case */ goto out; } static void get_capabilities(struct scsi_cd *cd) { unsigned char *buffer; struct scsi_mode_data data; unsigned char cmd[MAX_COMMAND_SIZE]; struct scsi_sense_hdr sshdr; unsigned int the_result; int retries, rc, n; static const char *loadmech[] = { "caddy", "tray", "pop-up", "", "changer", "cartridge changer", "", "" }; /* allocate transfer buffer */ buffer = kmalloc(512, GFP_KERNEL | GFP_DMA); if (!buffer) { printk(KERN_ERR "sr: out of memory.\n"); return; } /* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION * conditions are gone, or a timeout happens */ retries = 0; do { memset((void *)cmd, 0, MAX_COMMAND_SIZE); cmd[0] = TEST_UNIT_READY; the_result = scsi_execute_req (cd->device, cmd, DMA_NONE, NULL, 0, &sshdr, SR_TIMEOUT, MAX_RETRIES); retries++; } while (retries < 5 && (!scsi_status_is_good(the_result) || (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION))); /* ask for mode page 0x2a */ rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128, SR_TIMEOUT, 3, &data, NULL); if (!scsi_status_is_good(rc)) { /* failed, drive doesn't have capabilities mode page */ cd->cdi.speed = 1; cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R | CDC_DVD | CDC_DVD_RAM | CDC_SELECT_DISC | CDC_SELECT_SPEED | CDC_MRW | CDC_MRW_W | CDC_RAM); kfree(buffer); printk("%s: scsi-1 drive\n", cd->cdi.name); return; } n = data.header_length + data.block_descriptor_length; cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176; cd->readcd_known = 1; cd->readcd_cdda = buffer[n + 5] & 0x01; /* print some capability bits */ printk("%s: scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n", cd->cdi.name, ((buffer[n + 14] << 8) + buffer[n + 15]) / 176, cd->cdi.speed, buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */ buffer[n + 3] & 0x20 ? "dvd-ram " : "", buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */ buffer[n + 4] & 0x20 ? "xa/form2 " : "", /* can read xa/from2 */ buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */ loadmech[buffer[n + 6] >> 5]); if ((buffer[n + 6] >> 5) == 0) /* caddy drives can't close tray... */ cd->cdi.mask |= CDC_CLOSE_TRAY; if ((buffer[n + 2] & 0x8) == 0) /* not a DVD drive */ cd->cdi.mask |= CDC_DVD; if ((buffer[n + 3] & 0x20) == 0) /* can't write DVD-RAM media */ cd->cdi.mask |= CDC_DVD_RAM; if ((buffer[n + 3] & 0x10) == 0) /* can't write DVD-R media */ cd->cdi.mask |= CDC_DVD_R; if ((buffer[n + 3] & 0x2) == 0) /* can't write CD-RW media */ cd->cdi.mask |= CDC_CD_RW; if ((buffer[n + 3] & 0x1) == 0) /* can't write CD-R media */ cd->cdi.mask |= CDC_CD_R; if ((buffer[n + 6] & 0x8) == 0) /* can't eject */ cd->cdi.mask |= CDC_OPEN_TRAY; if ((buffer[n + 6] >> 5) == mechtype_individual_changer || (buffer[n + 6] >> 5) == mechtype_cartridge_changer) cd->cdi.capacity = cdrom_number_of_slots(&cd->cdi); if (cd->cdi.capacity <= 1) /* not a changer */ cd->cdi.mask |= CDC_SELECT_DISC; /*else I don't think it can close its tray cd->cdi.mask |= CDC_CLOSE_TRAY; */ /* * if DVD-RAM, MRW-W or CD-RW, we are randomly writable */ if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) != (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) { cd->device->writeable = 1; } kfree(buffer); } /* * sr_packet() is the entry point for the generic commands generated * by the Uniform CD-ROM layer. */ static int sr_packet(struct cdrom_device_info *cdi, struct packet_command *cgc) { if (cgc->timeout <= 0) cgc->timeout = IOCTL_TIMEOUT; sr_do_ioctl(cdi->handle, cgc); return cgc->stat; } /** * sr_kref_release - Called to free the scsi_cd structure * @kref: pointer to embedded kref * * sr_ref_mutex must be held entering this routine. Because it is * called on last put, you should always use the scsi_cd_get() * scsi_cd_put() helpers which manipulate the semaphore directly * and never do a direct kref_put(). **/ static void sr_kref_release(struct kref *kref) { struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref); struct gendisk *disk = cd->disk; spin_lock(&sr_index_lock); clear_bit(disk->first_minor, sr_index_bits); spin_unlock(&sr_index_lock); unregister_cdrom(&cd->cdi); disk->private_data = NULL; put_disk(disk); kfree(cd); } static int sr_remove(struct device *dev) { struct scsi_cd *cd = dev_get_drvdata(dev); del_gendisk(cd->disk); mutex_lock(&sr_ref_mutex); kref_put(&cd->kref, sr_kref_release); mutex_unlock(&sr_ref_mutex); return 0; } static int __init init_sr(void) { int rc; rc = register_blkdev(SCSI_CDROM_MAJOR, "sr"); if (rc) return rc; return scsi_register_driver(&sr_template.gendrv); } static void __exit exit_sr(void) { scsi_unregister_driver(&sr_template.gendrv); unregister_blkdev(SCSI_CDROM_MAJOR, "sr"); } module_init(init_sr); module_exit(exit_sr); MODULE_LICENSE("GPL");