2 * bsg.c - block layer implementation of the sg v4 interface
4 * Copyright (C) 2004 Jens Axboe <axboe@suse.de> SUSE Labs
5 * Copyright (C) 2004 Peter M. Jones <pjones@redhat.com>
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License version 2. See the file "COPYING" in the main directory of this
9 * archive for more details.
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/file.h>
15 #include <linux/blkdev.h>
16 #include <linux/poll.h>
17 #include <linux/cdev.h>
18 #include <linux/jiffies.h>
19 #include <linux/percpu.h>
20 #include <linux/uio.h>
21 #include <linux/idr.h>
22 #include <linux/bsg.h>
23 #include <linux/slab.h>
25 #include <scsi/scsi.h>
26 #include <scsi/scsi_ioctl.h>
27 #include <scsi/scsi_cmnd.h>
28 #include <scsi/scsi_device.h>
29 #include <scsi/scsi_driver.h>
32 #define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
33 #define BSG_VERSION "0.4"
36 struct request_queue *queue;
38 struct list_head busy_list;
39 struct list_head done_list;
40 struct hlist_node dev_list;
44 wait_queue_head_t wq_done;
45 wait_queue_head_t wq_free;
55 #define BSG_DEFAULT_CMDS 64
56 #define BSG_MAX_DEVS 32768
61 #define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args)
63 #define dprintk(fmt, args...)
66 static DEFINE_MUTEX(bsg_mutex);
67 static DEFINE_IDR(bsg_minor_idr);
69 #define BSG_LIST_ARRAY_SIZE 8
70 static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
72 static struct class *bsg_class;
75 static struct kmem_cache *bsg_cmd_cachep;
78 * our internal command type
81 struct bsg_device *bd;
82 struct list_head list;
90 static void bsg_free_command(struct bsg_command *bc)
92 struct bsg_device *bd = bc->bd;
95 kmem_cache_free(bsg_cmd_cachep, bc);
97 spin_lock_irqsave(&bd->lock, flags);
99 spin_unlock_irqrestore(&bd->lock, flags);
101 wake_up(&bd->wq_free);
104 static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
106 struct bsg_command *bc = ERR_PTR(-EINVAL);
108 spin_lock_irq(&bd->lock);
110 if (bd->queued_cmds >= bd->max_queue)
114 spin_unlock_irq(&bd->lock);
116 bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
118 spin_lock_irq(&bd->lock);
120 bc = ERR_PTR(-ENOMEM);
125 INIT_LIST_HEAD(&bc->list);
126 dprintk("%s: returning free cmd %p\n", bd->name, bc);
129 spin_unlock_irq(&bd->lock);
133 static inline struct hlist_head *bsg_dev_idx_hash(int index)
135 return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
138 static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
139 struct sg_io_v4 *hdr, struct bsg_device *bd,
140 fmode_t has_write_perm)
142 struct scsi_request *req = scsi_req(rq);
144 if (hdr->request_len > BLK_MAX_CDB) {
145 req->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
150 if (copy_from_user(req->cmd, (void __user *)(unsigned long)hdr->request,
154 if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
155 if (blk_verify_command(req->cmd, has_write_perm))
157 } else if (!capable(CAP_SYS_RAWIO))
161 * fill in request structure
163 req->cmd_len = hdr->request_len;
165 rq->timeout = msecs_to_jiffies(hdr->timeout);
167 rq->timeout = q->sg_timeout;
169 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
170 if (rq->timeout < BLK_MIN_SG_TIMEOUT)
171 rq->timeout = BLK_MIN_SG_TIMEOUT;
177 * Check if sg_io_v4 from user is allowed and valid
180 bsg_validate_sgv4_hdr(struct sg_io_v4 *hdr, int *op)
184 if (hdr->guard != 'Q')
187 switch (hdr->protocol) {
188 case BSG_PROTOCOL_SCSI:
189 switch (hdr->subprotocol) {
190 case BSG_SUB_PROTOCOL_SCSI_CMD:
191 case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
201 *op = hdr->dout_xfer_len ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN;
206 * map sg_io_v4 to a request.
208 static struct request *
209 bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm)
211 struct request_queue *q = bd->queue;
212 struct request *rq, *next_rq = NULL;
214 unsigned int op, dxfer_len;
215 void __user *dxferp = NULL;
216 struct bsg_class_device *bcd = &q->bsg_dev;
218 /* if the LLD has been removed then the bsg_unregister_queue will
219 * eventually be called and the class_dev was freed, so we can no
220 * longer use this request_queue. Return no such address.
223 return ERR_PTR(-ENXIO);
225 dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
226 hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
229 ret = bsg_validate_sgv4_hdr(hdr, &op);
234 * map scatter-gather elements separately and string them to request
236 rq = blk_get_request(q, op, GFP_KERNEL);
241 ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
245 if (op == REQ_OP_SCSI_OUT && hdr->din_xfer_len) {
246 if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
251 next_rq = blk_get_request(q, REQ_OP_SCSI_IN, GFP_KERNEL);
252 if (IS_ERR(next_rq)) {
253 ret = PTR_ERR(next_rq);
257 rq->next_rq = next_rq;
259 dxferp = (void __user *)(unsigned long)hdr->din_xferp;
260 ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
261 hdr->din_xfer_len, GFP_KERNEL);
266 if (hdr->dout_xfer_len) {
267 dxfer_len = hdr->dout_xfer_len;
268 dxferp = (void __user *)(unsigned long)hdr->dout_xferp;
269 } else if (hdr->din_xfer_len) {
270 dxfer_len = hdr->din_xfer_len;
271 dxferp = (void __user *)(unsigned long)hdr->din_xferp;
276 ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
284 scsi_req_free_cmd(scsi_req(rq));
287 blk_rq_unmap_user(next_rq->bio);
288 blk_put_request(next_rq);
294 * async completion call-back from the block layer, when scsi/ide/whatever
295 * calls end_that_request_last() on a request
297 static void bsg_rq_end_io(struct request *rq, blk_status_t status)
299 struct bsg_command *bc = rq->end_io_data;
300 struct bsg_device *bd = bc->bd;
303 dprintk("%s: finished rq %p bc %p, bio %p\n",
304 bd->name, rq, bc, bc->bio);
306 bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
308 spin_lock_irqsave(&bd->lock, flags);
309 list_move_tail(&bc->list, &bd->done_list);
311 spin_unlock_irqrestore(&bd->lock, flags);
313 wake_up(&bd->wq_done);
317 * do final setup of a 'bc' and submit the matching 'rq' to the block
320 static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
321 struct bsg_command *bc, struct request *rq)
323 int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
326 * add bc command to busy queue and submit rq for io
331 bc->bidi_bio = rq->next_rq->bio;
332 bc->hdr.duration = jiffies;
333 spin_lock_irq(&bd->lock);
334 list_add_tail(&bc->list, &bd->busy_list);
335 spin_unlock_irq(&bd->lock);
337 dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
339 rq->end_io_data = bc;
340 blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
343 static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
345 struct bsg_command *bc = NULL;
347 spin_lock_irq(&bd->lock);
349 bc = list_first_entry(&bd->done_list, struct bsg_command, list);
353 spin_unlock_irq(&bd->lock);
359 * Get a finished command from the done list
361 static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
363 struct bsg_command *bc;
367 bc = bsg_next_done_cmd(bd);
371 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
372 bc = ERR_PTR(-EAGAIN);
376 ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
378 bc = ERR_PTR(-ERESTARTSYS);
383 dprintk("%s: returning done %p\n", bd->name, bc);
388 static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
389 struct bio *bio, struct bio *bidi_bio)
391 struct scsi_request *req = scsi_req(rq);
394 dprintk("rq %p bio %p 0x%x\n", rq, bio, req->result);
396 * fill in all the output members
398 hdr->device_status = req->result & 0xff;
399 hdr->transport_status = host_byte(req->result);
400 hdr->driver_status = driver_byte(req->result);
402 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
403 hdr->info |= SG_INFO_CHECK;
404 hdr->response_len = 0;
406 if (req->sense_len && hdr->response) {
407 int len = min_t(unsigned int, hdr->max_response_len,
410 ret = copy_to_user((void __user *)(unsigned long)hdr->response,
413 hdr->response_len = len;
419 hdr->dout_resid = req->resid_len;
420 hdr->din_resid = scsi_req(rq->next_rq)->resid_len;
421 blk_rq_unmap_user(bidi_bio);
422 blk_put_request(rq->next_rq);
423 } else if (rq_data_dir(rq) == READ)
424 hdr->din_resid = req->resid_len;
426 hdr->dout_resid = req->resid_len;
429 * If the request generated a negative error number, return it
430 * (providing we aren't already returning an error); if it's
431 * just a protocol response (i.e. non negative), that gets
434 if (!ret && req->result < 0)
437 blk_rq_unmap_user(bio);
438 scsi_req_free_cmd(req);
444 static bool bsg_complete(struct bsg_device *bd)
450 spin_lock_irq(&bd->lock);
452 BUG_ON(bd->done_cmds > bd->queued_cmds);
455 * All commands consumed.
457 if (bd->done_cmds == bd->queued_cmds)
460 spin = !test_bit(BSG_F_BLOCK, &bd->flags);
462 spin_unlock_irq(&bd->lock);
463 } while (!ret && spin);
468 static int bsg_complete_all_commands(struct bsg_device *bd)
470 struct bsg_command *bc;
473 dprintk("%s: entered\n", bd->name);
476 * wait for all commands to complete
478 io_wait_event(bd->wq_done, bsg_complete(bd));
481 * discard done commands
485 spin_lock_irq(&bd->lock);
486 if (!bd->queued_cmds) {
487 spin_unlock_irq(&bd->lock);
490 spin_unlock_irq(&bd->lock);
492 bc = bsg_get_done_cmd(bd);
496 tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
501 bsg_free_command(bc);
508 __bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
509 const struct iovec *iov, ssize_t *bytes_read)
511 struct bsg_command *bc;
512 int nr_commands, ret;
514 if (count % sizeof(struct sg_io_v4))
518 nr_commands = count / sizeof(struct sg_io_v4);
519 while (nr_commands) {
520 bc = bsg_get_done_cmd(bd);
527 * this is the only case where we need to copy data back
528 * after completing the request. so do that here,
529 * bsg_complete_work() cannot do that for us
531 ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
534 if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
537 bsg_free_command(bc);
542 buf += sizeof(struct sg_io_v4);
543 *bytes_read += sizeof(struct sg_io_v4);
550 static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
552 if (file->f_flags & O_NONBLOCK)
553 clear_bit(BSG_F_BLOCK, &bd->flags);
555 set_bit(BSG_F_BLOCK, &bd->flags);
559 * Check if the error is a "real" error that we should return.
561 static inline int err_block_err(int ret)
563 if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
570 bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
572 struct bsg_device *bd = file->private_data;
576 dprintk("%s: read %zd bytes\n", bd->name, count);
578 bsg_set_block(bd, file);
581 ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
584 if (!bytes_read || err_block_err(ret))
590 static int __bsg_write(struct bsg_device *bd, const char __user *buf,
591 size_t count, ssize_t *bytes_written,
592 fmode_t has_write_perm)
594 struct bsg_command *bc;
596 int ret, nr_commands;
598 if (count % sizeof(struct sg_io_v4))
601 nr_commands = count / sizeof(struct sg_io_v4);
605 while (nr_commands) {
606 struct request_queue *q = bd->queue;
608 bc = bsg_alloc_command(bd);
615 if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
621 * get a request, fill in the blanks, and add to request queue
623 rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm);
630 bsg_add_command(bd, q, bc, rq);
634 buf += sizeof(struct sg_io_v4);
635 *bytes_written += sizeof(struct sg_io_v4);
639 bsg_free_command(bc);
645 bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
647 struct bsg_device *bd = file->private_data;
648 ssize_t bytes_written;
651 dprintk("%s: write %zd bytes\n", bd->name, count);
653 if (unlikely(uaccess_kernel()))
656 bsg_set_block(bd, file);
659 ret = __bsg_write(bd, buf, count, &bytes_written,
660 file->f_mode & FMODE_WRITE);
662 *ppos = bytes_written;
665 * return bytes written on non-fatal errors
667 if (!bytes_written || err_block_err(ret))
670 dprintk("%s: returning %zd\n", bd->name, bytes_written);
671 return bytes_written;
674 static struct bsg_device *bsg_alloc_device(void)
676 struct bsg_device *bd;
678 bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
682 spin_lock_init(&bd->lock);
684 bd->max_queue = BSG_DEFAULT_CMDS;
686 INIT_LIST_HEAD(&bd->busy_list);
687 INIT_LIST_HEAD(&bd->done_list);
688 INIT_HLIST_NODE(&bd->dev_list);
690 init_waitqueue_head(&bd->wq_free);
691 init_waitqueue_head(&bd->wq_done);
695 static void bsg_kref_release_function(struct kref *kref)
697 struct bsg_class_device *bcd =
698 container_of(kref, struct bsg_class_device, ref);
699 struct device *parent = bcd->parent;
702 bcd->release(bcd->parent);
707 static int bsg_put_device(struct bsg_device *bd)
709 int ret = 0, do_free;
710 struct request_queue *q = bd->queue;
712 mutex_lock(&bsg_mutex);
714 do_free = atomic_dec_and_test(&bd->ref_count);
716 mutex_unlock(&bsg_mutex);
720 hlist_del(&bd->dev_list);
721 mutex_unlock(&bsg_mutex);
723 dprintk("%s: tearing down\n", bd->name);
726 * close can always block
728 set_bit(BSG_F_BLOCK, &bd->flags);
731 * correct error detection baddies here again. it's the responsibility
732 * of the app to properly reap commands before close() if it wants
733 * fool-proof error detection
735 ret = bsg_complete_all_commands(bd);
739 kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
745 static struct bsg_device *bsg_add_device(struct inode *inode,
746 struct request_queue *rq,
749 struct bsg_device *bd;
751 unsigned char buf[32];
754 if (!blk_queue_scsi_passthrough(rq)) {
755 WARN_ONCE(true, "Attempt to register a non-SCSI queue\n");
756 return ERR_PTR(-EINVAL);
759 if (!blk_get_queue(rq))
760 return ERR_PTR(-ENXIO);
762 bd = bsg_alloc_device();
765 return ERR_PTR(-ENOMEM);
770 bsg_set_block(bd, file);
772 atomic_set(&bd->ref_count, 1);
773 mutex_lock(&bsg_mutex);
774 hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
776 strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
777 dprintk("bound to <%s>, max queue %d\n",
778 format_dev_t(buf, inode->i_rdev), bd->max_queue);
780 mutex_unlock(&bsg_mutex);
784 static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
786 struct bsg_device *bd;
788 mutex_lock(&bsg_mutex);
790 hlist_for_each_entry(bd, bsg_dev_idx_hash(minor), dev_list) {
791 if (bd->queue == q) {
792 atomic_inc(&bd->ref_count);
798 mutex_unlock(&bsg_mutex);
802 static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
804 struct bsg_device *bd;
805 struct bsg_class_device *bcd;
808 * find the class device
810 mutex_lock(&bsg_mutex);
811 bcd = idr_find(&bsg_minor_idr, iminor(inode));
814 mutex_unlock(&bsg_mutex);
817 return ERR_PTR(-ENODEV);
819 bd = __bsg_get_device(iminor(inode), bcd->queue);
823 bd = bsg_add_device(inode, bcd->queue, file);
825 kref_put(&bcd->ref, bsg_kref_release_function);
830 static int bsg_open(struct inode *inode, struct file *file)
832 struct bsg_device *bd;
834 bd = bsg_get_device(inode, file);
839 file->private_data = bd;
843 static int bsg_release(struct inode *inode, struct file *file)
845 struct bsg_device *bd = file->private_data;
847 file->private_data = NULL;
848 return bsg_put_device(bd);
851 static unsigned int bsg_poll(struct file *file, poll_table *wait)
853 struct bsg_device *bd = file->private_data;
854 unsigned int mask = 0;
856 poll_wait(file, &bd->wq_done, wait);
857 poll_wait(file, &bd->wq_free, wait);
859 spin_lock_irq(&bd->lock);
860 if (!list_empty(&bd->done_list))
861 mask |= POLLIN | POLLRDNORM;
862 if (bd->queued_cmds < bd->max_queue)
864 spin_unlock_irq(&bd->lock);
869 static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
871 struct bsg_device *bd = file->private_data;
872 int __user *uarg = (int __user *) arg;
879 case SG_GET_COMMAND_Q:
880 return put_user(bd->max_queue, uarg);
881 case SG_SET_COMMAND_Q: {
884 if (get_user(queue, uarg))
889 spin_lock_irq(&bd->lock);
890 bd->max_queue = queue;
891 spin_unlock_irq(&bd->lock);
898 case SG_GET_VERSION_NUM:
899 case SCSI_IOCTL_GET_IDLUN:
900 case SCSI_IOCTL_GET_BUS_NUMBER:
903 case SG_GET_RESERVED_SIZE:
904 case SG_SET_RESERVED_SIZE:
905 case SG_EMULATED_HOST:
906 case SCSI_IOCTL_SEND_COMMAND: {
907 void __user *uarg = (void __user *) arg;
908 return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
912 struct bio *bio, *bidi_bio = NULL;
916 if (copy_from_user(&hdr, uarg, sizeof(hdr)))
919 rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE);
925 bidi_bio = rq->next_rq->bio;
927 at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
928 blk_execute_rq(bd->queue, NULL, rq, at_head);
929 ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
931 if (copy_to_user(uarg, &hdr, sizeof(hdr)))
937 * block device ioctls
941 return ioctl_by_bdev(bd->bdev, cmd, arg);
948 static const struct file_operations bsg_fops = {
953 .release = bsg_release,
954 .unlocked_ioctl = bsg_ioctl,
955 .owner = THIS_MODULE,
956 .llseek = default_llseek,
959 void bsg_unregister_queue(struct request_queue *q)
961 struct bsg_class_device *bcd = &q->bsg_dev;
966 mutex_lock(&bsg_mutex);
967 idr_remove(&bsg_minor_idr, bcd->minor);
969 sysfs_remove_link(&q->kobj, "bsg");
970 device_unregister(bcd->class_dev);
971 bcd->class_dev = NULL;
972 kref_put(&bcd->ref, bsg_kref_release_function);
973 mutex_unlock(&bsg_mutex);
975 EXPORT_SYMBOL_GPL(bsg_unregister_queue);
977 int bsg_register_queue(struct request_queue *q, struct device *parent,
978 const char *name, void (*release)(struct device *))
980 struct bsg_class_device *bcd;
983 struct device *class_dev = NULL;
989 devname = dev_name(parent);
992 * we need a proper transport to send commands, not a stacked device
994 if (!queue_is_rq_based(q))
998 memset(bcd, 0, sizeof(*bcd));
1000 mutex_lock(&bsg_mutex);
1002 ret = idr_alloc(&bsg_minor_idr, bcd, 0, BSG_MAX_DEVS, GFP_KERNEL);
1004 if (ret == -ENOSPC) {
1005 printk(KERN_ERR "bsg: too many bsg devices\n");
1013 bcd->parent = get_device(parent);
1014 bcd->release = release;
1015 kref_init(&bcd->ref);
1016 dev = MKDEV(bsg_major, bcd->minor);
1017 class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
1018 if (IS_ERR(class_dev)) {
1019 ret = PTR_ERR(class_dev);
1022 bcd->class_dev = class_dev;
1025 ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
1027 goto unregister_class_dev;
1030 mutex_unlock(&bsg_mutex);
1033 unregister_class_dev:
1034 device_unregister(class_dev);
1037 idr_remove(&bsg_minor_idr, bcd->minor);
1039 mutex_unlock(&bsg_mutex);
1042 EXPORT_SYMBOL_GPL(bsg_register_queue);
1044 static struct cdev bsg_cdev;
1046 static char *bsg_devnode(struct device *dev, umode_t *mode)
1048 return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
1051 static int __init bsg_init(void)
1056 bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
1057 sizeof(struct bsg_command), 0, 0, NULL);
1058 if (!bsg_cmd_cachep) {
1059 printk(KERN_ERR "bsg: failed creating slab cache\n");
1063 for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
1064 INIT_HLIST_HEAD(&bsg_device_list[i]);
1066 bsg_class = class_create(THIS_MODULE, "bsg");
1067 if (IS_ERR(bsg_class)) {
1068 ret = PTR_ERR(bsg_class);
1069 goto destroy_kmemcache;
1071 bsg_class->devnode = bsg_devnode;
1073 ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
1075 goto destroy_bsg_class;
1077 bsg_major = MAJOR(devid);
1079 cdev_init(&bsg_cdev, &bsg_fops);
1080 ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1082 goto unregister_chrdev;
1084 printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
1085 " loaded (major %d)\n", bsg_major);
1088 unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1090 class_destroy(bsg_class);
1092 kmem_cache_destroy(bsg_cmd_cachep);
1096 MODULE_AUTHOR("Jens Axboe");
1097 MODULE_DESCRIPTION(BSG_DESCRIPTION);
1098 MODULE_LICENSE("GPL");
1100 device_initcall(bsg_init);