2 * Network block device - make block devices work over TCP
4 * Note that you can not swap over this thing, yet. Seems to work but
5 * deadlocks sometimes - you can not swap over TCP in general.
7 * Copyright 1997-2000, 2008 Pavel Machek <pavel@ucw.cz>
8 * Parts copyright 2001 Steven Whitehouse <steve@chygwyn.com>
10 * This file is released under GPLv2 or later.
12 * (part of code stolen from loop.c)
15 #include <linux/major.h>
17 #include <linux/blkdev.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/sched.h>
22 #include <linux/bio.h>
23 #include <linux/stat.h>
24 #include <linux/errno.h>
25 #include <linux/file.h>
26 #include <linux/ioctl.h>
27 #include <linux/mutex.h>
28 #include <linux/compiler.h>
29 #include <linux/err.h>
30 #include <linux/kernel.h>
31 #include <linux/slab.h>
33 #include <linux/net.h>
34 #include <linux/kthread.h>
35 #include <linux/types.h>
36 #include <linux/debugfs.h>
37 #include <linux/blk-mq.h>
39 #include <asm/uaccess.h>
40 #include <asm/types.h>
42 #include <linux/nbd.h>
44 #define NBD_TIMEDOUT 0
45 #define NBD_DISCONNECT_REQUESTED 1
49 unsigned long runtime_flags;
50 struct socket * sock; /* If == NULL, device is not ready, yet */
53 atomic_t outstanding_cmds;
54 struct blk_mq_tag_set tag_set;
62 struct timer_list timeout_timer;
63 /* protects initialization and shutdown of the socket */
65 struct task_struct *task_recv;
66 struct task_struct *task_send;
68 #if IS_ENABLED(CONFIG_DEBUG_FS)
69 struct dentry *dbg_dir;
74 struct nbd_device *nbd;
75 struct list_head list;
78 #if IS_ENABLED(CONFIG_DEBUG_FS)
79 static struct dentry *nbd_dbg_dir;
82 #define nbd_name(nbd) ((nbd)->disk->disk_name)
84 #define NBD_MAGIC 0x68797548
86 static unsigned int nbds_max = 16;
87 static struct nbd_device *nbd_dev;
90 static inline struct device *nbd_to_dev(struct nbd_device *nbd)
92 return disk_to_dev(nbd->disk);
95 static bool nbd_is_connected(struct nbd_device *nbd)
97 return !!nbd->task_recv;
100 static const char *nbdcmd_to_ascii(int cmd)
103 case NBD_CMD_READ: return "read";
104 case NBD_CMD_WRITE: return "write";
105 case NBD_CMD_DISC: return "disconnect";
106 case NBD_CMD_FLUSH: return "flush";
107 case NBD_CMD_TRIM: return "trim/discard";
112 static int nbd_size_clear(struct nbd_device *nbd, struct block_device *bdev)
114 bdev->bd_inode->i_size = 0;
115 set_capacity(nbd->disk, 0);
116 kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
121 static void nbd_size_update(struct nbd_device *nbd, struct block_device *bdev)
123 if (!nbd_is_connected(nbd))
126 bdev->bd_inode->i_size = nbd->bytesize;
127 set_capacity(nbd->disk, nbd->bytesize >> 9);
128 kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
131 static int nbd_size_set(struct nbd_device *nbd, struct block_device *bdev,
132 int blocksize, int nr_blocks)
136 ret = set_blocksize(bdev, blocksize);
140 nbd->blksize = blocksize;
141 nbd->bytesize = (loff_t)blocksize * (loff_t)nr_blocks;
143 nbd_size_update(nbd, bdev);
148 static void nbd_end_request(struct nbd_cmd *cmd)
150 struct nbd_device *nbd = cmd->nbd;
151 struct request *req = blk_mq_rq_from_pdu(cmd);
152 int error = req->errors ? -EIO : 0;
154 dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", cmd,
155 error ? "failed" : "done");
157 atomic_dec(&nbd->outstanding_cmds);
158 blk_mq_complete_request(req, error);
162 * Forcibly shutdown the socket causing all listeners to error
164 static void sock_shutdown(struct nbd_device *nbd)
168 spin_lock_irq(&nbd->sock_lock);
171 spin_unlock_irq(&nbd->sock_lock);
176 dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n");
178 spin_unlock_irq(&nbd->sock_lock);
180 kernel_sock_shutdown(sock, SHUT_RDWR);
183 del_timer(&nbd->timeout_timer);
186 static void nbd_xmit_timeout(unsigned long arg)
188 struct nbd_device *nbd = (struct nbd_device *)arg;
189 struct socket *sock = NULL;
192 if (!atomic_read(&nbd->outstanding_cmds))
195 spin_lock_irqsave(&nbd->sock_lock, flags);
197 set_bit(NBD_TIMEDOUT, &nbd->runtime_flags);
201 get_file(sock->file);
204 spin_unlock_irqrestore(&nbd->sock_lock, flags);
206 kernel_sock_shutdown(sock, SHUT_RDWR);
210 dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n");
214 * Send or receive packet.
216 static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size,
219 struct socket *sock = nbd->sock;
223 unsigned long pflags = current->flags;
225 if (unlikely(!sock)) {
226 dev_err(disk_to_dev(nbd->disk),
227 "Attempted %s on closed socket in sock_xmit\n",
228 (send ? "send" : "recv"));
232 current->flags |= PF_MEMALLOC;
234 sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC;
239 msg.msg_control = NULL;
240 msg.msg_controllen = 0;
241 msg.msg_flags = msg_flags | MSG_NOSIGNAL;
244 result = kernel_sendmsg(sock, &msg, &iov, 1, size);
246 result = kernel_recvmsg(sock, &msg, &iov, 1, size,
251 result = -EPIPE; /* short read */
258 tsk_restore_flags(current, pflags, PF_MEMALLOC);
260 if (!send && nbd->xmit_timeout)
261 mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout);
266 static inline int sock_send_bvec(struct nbd_device *nbd, struct bio_vec *bvec,
270 void *kaddr = kmap(bvec->bv_page);
271 result = sock_xmit(nbd, 1, kaddr + bvec->bv_offset,
272 bvec->bv_len, flags);
273 kunmap(bvec->bv_page);
277 /* always call with the tx_lock held */
278 static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd)
280 struct request *req = blk_mq_rq_from_pdu(cmd);
282 struct nbd_request request;
283 unsigned long size = blk_rq_bytes(req);
286 if (req->cmd_type == REQ_TYPE_DRV_PRIV)
288 else if (req_op(req) == REQ_OP_DISCARD)
290 else if (req_op(req) == REQ_OP_FLUSH)
291 type = NBD_CMD_FLUSH;
292 else if (rq_data_dir(req) == WRITE)
293 type = NBD_CMD_WRITE;
297 memset(&request, 0, sizeof(request));
298 request.magic = htonl(NBD_REQUEST_MAGIC);
299 request.type = htonl(type);
300 if (type != NBD_CMD_FLUSH && type != NBD_CMD_DISC) {
301 request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);
302 request.len = htonl(size);
304 memcpy(request.handle, &req->tag, sizeof(req->tag));
306 dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n",
307 cmd, nbdcmd_to_ascii(type),
308 (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req));
309 result = sock_xmit(nbd, 1, &request, sizeof(request),
310 (type == NBD_CMD_WRITE) ? MSG_MORE : 0);
312 dev_err(disk_to_dev(nbd->disk),
313 "Send control failed (result %d)\n", result);
317 if (type == NBD_CMD_WRITE) {
318 struct req_iterator iter;
321 * we are really probing at internals to determine
322 * whether to set MSG_MORE or not...
324 rq_for_each_segment(bvec, req, iter) {
326 if (!rq_iter_last(bvec, iter))
328 dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",
330 result = sock_send_bvec(nbd, &bvec, flags);
332 dev_err(disk_to_dev(nbd->disk),
333 "Send data failed (result %d)\n",
342 static inline int sock_recv_bvec(struct nbd_device *nbd, struct bio_vec *bvec)
345 void *kaddr = kmap(bvec->bv_page);
346 result = sock_xmit(nbd, 0, kaddr + bvec->bv_offset, bvec->bv_len,
348 kunmap(bvec->bv_page);
352 /* NULL returned = something went wrong, inform userspace */
353 static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd)
356 struct nbd_reply reply;
358 struct request *req = NULL;
363 result = sock_xmit(nbd, 0, &reply, sizeof(reply), MSG_WAITALL);
365 dev_err(disk_to_dev(nbd->disk),
366 "Receive control failed (result %d)\n", result);
367 return ERR_PTR(result);
370 if (ntohl(reply.magic) != NBD_REPLY_MAGIC) {
371 dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n",
372 (unsigned long)ntohl(reply.magic));
373 return ERR_PTR(-EPROTO);
376 memcpy(&tag, reply.handle, sizeof(int));
378 hwq = blk_mq_unique_tag_to_hwq(tag);
379 if (hwq < nbd->tag_set.nr_hw_queues)
380 req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq],
381 blk_mq_unique_tag_to_tag(tag));
382 if (!req || !blk_mq_request_started(req)) {
383 dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n",
385 return ERR_PTR(-ENOENT);
387 cmd = blk_mq_rq_to_pdu(req);
389 if (ntohl(reply.error)) {
390 dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n",
396 dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", cmd);
397 if (rq_data_dir(req) != WRITE) {
398 struct req_iterator iter;
401 rq_for_each_segment(bvec, req, iter) {
402 result = sock_recv_bvec(nbd, &bvec);
404 dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n",
409 dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n",
416 static ssize_t pid_show(struct device *dev,
417 struct device_attribute *attr, char *buf)
419 struct gendisk *disk = dev_to_disk(dev);
420 struct nbd_device *nbd = (struct nbd_device *)disk->private_data;
422 return sprintf(buf, "%d\n", task_pid_nr(nbd->task_recv));
425 static struct device_attribute pid_attr = {
426 .attr = { .name = "pid", .mode = S_IRUGO},
430 static int nbd_thread_recv(struct nbd_device *nbd, struct block_device *bdev)
435 BUG_ON(nbd->magic != NBD_MAGIC);
437 sk_set_memalloc(nbd->sock->sk);
439 ret = device_create_file(disk_to_dev(nbd->disk), &pid_attr);
441 dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n");
445 nbd_size_update(nbd, bdev);
448 cmd = nbd_read_stat(nbd);
454 nbd_end_request(cmd);
457 nbd_size_clear(nbd, bdev);
459 device_remove_file(disk_to_dev(nbd->disk), &pid_attr);
463 static void nbd_clear_req(struct request *req, void *data, bool reserved)
467 if (!blk_mq_request_started(req))
469 cmd = blk_mq_rq_to_pdu(req);
471 nbd_end_request(cmd);
474 static void nbd_clear_que(struct nbd_device *nbd)
476 BUG_ON(nbd->magic != NBD_MAGIC);
479 * Because we have set nbd->sock to NULL under the tx_lock, all
480 * modifications to the list must have completed by now.
484 blk_mq_tagset_busy_iter(&nbd->tag_set, nbd_clear_req, NULL);
485 dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n");
489 static void nbd_handle_cmd(struct nbd_cmd *cmd)
491 struct request *req = blk_mq_rq_from_pdu(cmd);
492 struct nbd_device *nbd = cmd->nbd;
494 if (req->cmd_type != REQ_TYPE_FS)
497 if (rq_data_dir(req) == WRITE &&
498 (nbd->flags & NBD_FLAG_READ_ONLY)) {
499 dev_err(disk_to_dev(nbd->disk),
500 "Write on read-only\n");
506 mutex_lock(&nbd->tx_lock);
507 nbd->task_send = current;
508 if (unlikely(!nbd->sock)) {
509 mutex_unlock(&nbd->tx_lock);
510 dev_err(disk_to_dev(nbd->disk),
511 "Attempted send on closed socket\n");
515 if (nbd->xmit_timeout && !atomic_read(&nbd->outstanding_cmds))
516 mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout);
518 atomic_inc(&nbd->outstanding_cmds);
519 if (nbd_send_cmd(nbd, cmd) != 0) {
520 dev_err(disk_to_dev(nbd->disk), "Request send failed\n");
522 nbd_end_request(cmd);
525 nbd->task_send = NULL;
526 mutex_unlock(&nbd->tx_lock);
532 nbd_end_request(cmd);
535 static int nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
536 const struct blk_mq_queue_data *bd)
538 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
540 blk_mq_start_request(bd->rq);
542 return BLK_MQ_RQ_QUEUE_OK;
545 static int nbd_set_socket(struct nbd_device *nbd, struct socket *sock)
549 spin_lock_irq(&nbd->sock_lock);
559 spin_unlock_irq(&nbd->sock_lock);
564 /* Reset all properties of an NBD device */
565 static void nbd_reset(struct nbd_device *nbd)
567 nbd->runtime_flags = 0;
570 set_capacity(nbd->disk, 0);
572 nbd->xmit_timeout = 0;
573 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);
574 del_timer_sync(&nbd->timeout_timer);
577 static void nbd_bdev_reset(struct block_device *bdev)
579 set_device_ro(bdev, false);
580 bdev->bd_inode->i_size = 0;
582 blkdev_reread_part(bdev);
583 bdev->bd_invalidated = 1;
587 static void nbd_parse_flags(struct nbd_device *nbd, struct block_device *bdev)
589 if (nbd->flags & NBD_FLAG_READ_ONLY)
590 set_device_ro(bdev, true);
591 if (nbd->flags & NBD_FLAG_SEND_TRIM)
592 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);
593 if (nbd->flags & NBD_FLAG_SEND_FLUSH)
594 blk_queue_write_cache(nbd->disk->queue, true, false);
596 blk_queue_write_cache(nbd->disk->queue, false, false);
599 static int nbd_dev_dbg_init(struct nbd_device *nbd);
600 static void nbd_dev_dbg_close(struct nbd_device *nbd);
602 /* Must be called with tx_lock held */
604 static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
605 unsigned int cmd, unsigned long arg)
608 case NBD_DISCONNECT: {
609 struct request *sreq;
611 dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n");
615 sreq = blk_mq_alloc_request(bdev_get_queue(bdev), WRITE, 0);
619 mutex_unlock(&nbd->tx_lock);
621 mutex_lock(&nbd->tx_lock);
622 sreq->cmd_type = REQ_TYPE_DRV_PRIV;
624 /* Check again after getting mutex back. */
626 blk_mq_free_request(sreq);
630 set_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags);
632 nbd_send_cmd(nbd, blk_mq_rq_to_pdu(sreq));
633 blk_mq_free_request(sreq);
645 struct socket *sock = sockfd_lookup(arg, &err);
650 err = nbd_set_socket(nbd, sock);
651 if (!err && max_part)
652 bdev->bd_invalidated = 1;
657 case NBD_SET_BLKSIZE: {
658 loff_t bsize = div_s64(nbd->bytesize, arg);
660 return nbd_size_set(nbd, bdev, arg, bsize);
664 return nbd_size_set(nbd, bdev, nbd->blksize,
667 case NBD_SET_SIZE_BLOCKS:
668 return nbd_size_set(nbd, bdev, nbd->blksize, arg);
670 case NBD_SET_TIMEOUT:
671 nbd->xmit_timeout = arg * HZ;
673 mod_timer(&nbd->timeout_timer,
674 jiffies + nbd->xmit_timeout);
676 del_timer_sync(&nbd->timeout_timer);
692 /* We have to claim the device under the lock */
693 nbd->task_recv = current;
694 mutex_unlock(&nbd->tx_lock);
696 nbd_parse_flags(nbd, bdev);
698 nbd_dev_dbg_init(nbd);
699 error = nbd_thread_recv(nbd, bdev);
700 nbd_dev_dbg_close(nbd);
702 mutex_lock(&nbd->tx_lock);
703 nbd->task_recv = NULL;
708 nbd_bdev_reset(bdev);
710 /* user requested, ignore socket errors */
711 if (test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags))
713 if (test_bit(NBD_TIMEDOUT, &nbd->runtime_flags))
723 * This is for compatibility only. The queue is always cleared
724 * by NBD_DO_IT or NBD_CLEAR_SOCK.
728 case NBD_PRINT_DEBUG:
730 * For compatibility only, we no longer keep a list of
731 * outstanding requests.
738 static int nbd_ioctl(struct block_device *bdev, fmode_t mode,
739 unsigned int cmd, unsigned long arg)
741 struct nbd_device *nbd = bdev->bd_disk->private_data;
744 if (!capable(CAP_SYS_ADMIN))
747 BUG_ON(nbd->magic != NBD_MAGIC);
749 mutex_lock(&nbd->tx_lock);
750 error = __nbd_ioctl(bdev, nbd, cmd, arg);
751 mutex_unlock(&nbd->tx_lock);
756 static const struct block_device_operations nbd_fops =
758 .owner = THIS_MODULE,
760 .compat_ioctl = nbd_ioctl,
763 #if IS_ENABLED(CONFIG_DEBUG_FS)
765 static int nbd_dbg_tasks_show(struct seq_file *s, void *unused)
767 struct nbd_device *nbd = s->private;
770 seq_printf(s, "recv: %d\n", task_pid_nr(nbd->task_recv));
772 seq_printf(s, "send: %d\n", task_pid_nr(nbd->task_send));
777 static int nbd_dbg_tasks_open(struct inode *inode, struct file *file)
779 return single_open(file, nbd_dbg_tasks_show, inode->i_private);
782 static const struct file_operations nbd_dbg_tasks_ops = {
783 .open = nbd_dbg_tasks_open,
786 .release = single_release,
789 static int nbd_dbg_flags_show(struct seq_file *s, void *unused)
791 struct nbd_device *nbd = s->private;
792 u32 flags = nbd->flags;
794 seq_printf(s, "Hex: 0x%08x\n\n", flags);
796 seq_puts(s, "Known flags:\n");
798 if (flags & NBD_FLAG_HAS_FLAGS)
799 seq_puts(s, "NBD_FLAG_HAS_FLAGS\n");
800 if (flags & NBD_FLAG_READ_ONLY)
801 seq_puts(s, "NBD_FLAG_READ_ONLY\n");
802 if (flags & NBD_FLAG_SEND_FLUSH)
803 seq_puts(s, "NBD_FLAG_SEND_FLUSH\n");
804 if (flags & NBD_FLAG_SEND_TRIM)
805 seq_puts(s, "NBD_FLAG_SEND_TRIM\n");
810 static int nbd_dbg_flags_open(struct inode *inode, struct file *file)
812 return single_open(file, nbd_dbg_flags_show, inode->i_private);
815 static const struct file_operations nbd_dbg_flags_ops = {
816 .open = nbd_dbg_flags_open,
819 .release = single_release,
822 static int nbd_dev_dbg_init(struct nbd_device *nbd)
829 dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir);
831 dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n",
837 debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops);
838 debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize);
839 debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout);
840 debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize);
841 debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops);
846 static void nbd_dev_dbg_close(struct nbd_device *nbd)
848 debugfs_remove_recursive(nbd->dbg_dir);
851 static int nbd_dbg_init(void)
853 struct dentry *dbg_dir;
855 dbg_dir = debugfs_create_dir("nbd", NULL);
859 nbd_dbg_dir = dbg_dir;
864 static void nbd_dbg_close(void)
866 debugfs_remove_recursive(nbd_dbg_dir);
869 #else /* IS_ENABLED(CONFIG_DEBUG_FS) */
871 static int nbd_dev_dbg_init(struct nbd_device *nbd)
876 static void nbd_dev_dbg_close(struct nbd_device *nbd)
880 static int nbd_dbg_init(void)
885 static void nbd_dbg_close(void)
891 static int nbd_init_request(void *data, struct request *rq,
892 unsigned int hctx_idx, unsigned int request_idx,
893 unsigned int numa_node)
895 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq);
898 INIT_LIST_HEAD(&cmd->list);
902 static struct blk_mq_ops nbd_mq_ops = {
903 .queue_rq = nbd_queue_rq,
904 .map_queue = blk_mq_map_queue,
905 .init_request = nbd_init_request,
909 * And here should be modules and kernel interface
910 * (Just smiley confuses emacs :-)
913 static int __init nbd_init(void)
919 BUILD_BUG_ON(sizeof(struct nbd_request) != 28);
922 printk(KERN_ERR "nbd: max_part must be >= 0\n");
928 part_shift = fls(max_part);
931 * Adjust max_part according to part_shift as it is exported
932 * to user space so that user can know the max number of
933 * partition kernel should be able to manage.
935 * Note that -1 is required because partition 0 is reserved
936 * for the whole disk.
938 max_part = (1UL << part_shift) - 1;
941 if ((1UL << part_shift) > DISK_MAX_PARTS)
944 if (nbds_max > 1UL << (MINORBITS - part_shift))
947 nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL);
951 for (i = 0; i < nbds_max; i++) {
952 struct gendisk *disk = alloc_disk(1 << part_shift);
955 nbd_dev[i].disk = disk;
957 nbd_dev[i].tag_set.ops = &nbd_mq_ops;
958 nbd_dev[i].tag_set.nr_hw_queues = 1;
959 nbd_dev[i].tag_set.queue_depth = 128;
960 nbd_dev[i].tag_set.numa_node = NUMA_NO_NODE;
961 nbd_dev[i].tag_set.cmd_size = sizeof(struct nbd_cmd);
962 nbd_dev[i].tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
964 nbd_dev[i].tag_set.driver_data = &nbd_dev[i];
966 err = blk_mq_alloc_tag_set(&nbd_dev[i].tag_set);
973 * The new linux 2.5 block layer implementation requires
974 * every gendisk to have its very own request_queue struct.
975 * These structs are big so we dynamically allocate them.
977 disk->queue = blk_mq_init_queue(&nbd_dev[i].tag_set);
979 blk_mq_free_tag_set(&nbd_dev[i].tag_set);
985 * Tell the block layer that we are not a rotational device
987 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue);
988 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, disk->queue);
989 disk->queue->limits.discard_granularity = 512;
990 blk_queue_max_discard_sectors(disk->queue, UINT_MAX);
991 disk->queue->limits.discard_zeroes_data = 0;
992 blk_queue_max_hw_sectors(disk->queue, 65536);
993 disk->queue->limits.max_sectors = 256;
996 if (register_blkdev(NBD_MAJOR, "nbd")) {
1001 printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR);
1005 for (i = 0; i < nbds_max; i++) {
1006 struct gendisk *disk = nbd_dev[i].disk;
1007 nbd_dev[i].magic = NBD_MAGIC;
1008 spin_lock_init(&nbd_dev[i].sock_lock);
1009 mutex_init(&nbd_dev[i].tx_lock);
1010 init_timer(&nbd_dev[i].timeout_timer);
1011 nbd_dev[i].timeout_timer.function = nbd_xmit_timeout;
1012 nbd_dev[i].timeout_timer.data = (unsigned long)&nbd_dev[i];
1013 atomic_set(&nbd_dev[i].outstanding_cmds, 0);
1014 disk->major = NBD_MAJOR;
1015 disk->first_minor = i << part_shift;
1016 disk->fops = &nbd_fops;
1017 disk->private_data = &nbd_dev[i];
1018 sprintf(disk->disk_name, "nbd%d", i);
1019 nbd_reset(&nbd_dev[i]);
1026 blk_mq_free_tag_set(&nbd_dev[i].tag_set);
1027 blk_cleanup_queue(nbd_dev[i].disk->queue);
1028 put_disk(nbd_dev[i].disk);
1034 static void __exit nbd_cleanup(void)
1040 for (i = 0; i < nbds_max; i++) {
1041 struct gendisk *disk = nbd_dev[i].disk;
1042 nbd_dev[i].magic = 0;
1045 blk_cleanup_queue(disk->queue);
1046 blk_mq_free_tag_set(&nbd_dev[i].tag_set);
1050 unregister_blkdev(NBD_MAJOR, "nbd");
1052 printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR);
1055 module_init(nbd_init);
1056 module_exit(nbd_cleanup);
1058 MODULE_DESCRIPTION("Network Block Device");
1059 MODULE_LICENSE("GPL");
1061 module_param(nbds_max, int, 0444);
1062 MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)");
1063 module_param(max_part, int, 0444);
1064 MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)");