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14#include <linux/major.h>
15
16#include <linux/blkdev.h>
17#include <linux/module.h>
18#include <linux/init.h>
19#include <linux/sched.h>
20#include <linux/sched/mm.h>
21#include <linux/fs.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>
32#include <net/sock.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>
38
39#include <linux/uaccess.h>
40#include <asm/types.h>
41
42#include <linux/nbd.h>
43#include <linux/nbd-netlink.h>
44#include <net/genetlink.h>
45
46#define CREATE_TRACE_POINTS
47#include <trace/events/nbd.h>
48
49static DEFINE_IDR(nbd_index_idr);
50static DEFINE_MUTEX(nbd_index_mutex);
51static int nbd_total_devices = 0;
52
53struct nbd_sock {
54 struct socket *sock;
55 struct mutex tx_lock;
56 struct request *pending;
57 int sent;
58 bool dead;
59 int fallback_index;
60 int cookie;
61};
62
63struct recv_thread_args {
64 struct work_struct work;
65 struct nbd_device *nbd;
66 int index;
67};
68
69struct link_dead_args {
70 struct work_struct work;
71 int index;
72};
73
74#define NBD_TIMEDOUT 0
75#define NBD_DISCONNECT_REQUESTED 1
76#define NBD_DISCONNECTED 2
77#define NBD_HAS_PID_FILE 3
78#define NBD_HAS_CONFIG_REF 4
79#define NBD_BOUND 5
80#define NBD_DESTROY_ON_DISCONNECT 6
81#define NBD_DISCONNECT_ON_CLOSE 7
82
83struct nbd_config {
84 u32 flags;
85 unsigned long runtime_flags;
86 u64 dead_conn_timeout;
87
88 struct nbd_sock **socks;
89 int num_connections;
90 atomic_t live_connections;
91 wait_queue_head_t conn_wait;
92
93 atomic_t recv_threads;
94 wait_queue_head_t recv_wq;
95 loff_t blksize;
96 loff_t bytesize;
97#if IS_ENABLED(CONFIG_DEBUG_FS)
98 struct dentry *dbg_dir;
99#endif
100};
101
102struct nbd_device {
103 struct blk_mq_tag_set tag_set;
104
105 int index;
106 refcount_t config_refs;
107 refcount_t refs;
108 struct nbd_config *config;
109 struct mutex config_lock;
110 struct gendisk *disk;
111
112 struct list_head list;
113 struct task_struct *task_recv;
114 struct task_struct *task_setup;
115};
116
117#define NBD_CMD_REQUEUED 1
118
119struct nbd_cmd {
120 struct nbd_device *nbd;
121 struct mutex lock;
122 int index;
123 int cookie;
124 blk_status_t status;
125 unsigned long flags;
126 u32 cmd_cookie;
127};
128
129#if IS_ENABLED(CONFIG_DEBUG_FS)
130static struct dentry *nbd_dbg_dir;
131#endif
132
133#define nbd_name(nbd) ((nbd)->disk->disk_name)
134
135#define NBD_MAGIC 0x68797548
136
137#define NBD_DEF_BLKSIZE 1024
138
139static unsigned int nbds_max = 16;
140static int max_part = 16;
141static struct workqueue_struct *recv_workqueue;
142static int part_shift;
143
144static int nbd_dev_dbg_init(struct nbd_device *nbd);
145static void nbd_dev_dbg_close(struct nbd_device *nbd);
146static void nbd_config_put(struct nbd_device *nbd);
147static void nbd_connect_reply(struct genl_info *info, int index);
148static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info);
149static void nbd_dead_link_work(struct work_struct *work);
150static void nbd_disconnect_and_put(struct nbd_device *nbd);
151
152static inline struct device *nbd_to_dev(struct nbd_device *nbd)
153{
154 return disk_to_dev(nbd->disk);
155}
156
157static void nbd_requeue_cmd(struct nbd_cmd *cmd)
158{
159 struct request *req = blk_mq_rq_from_pdu(cmd);
160
161 if (!test_and_set_bit(NBD_CMD_REQUEUED, &cmd->flags))
162 blk_mq_requeue_request(req, true);
163}
164
165#define NBD_COOKIE_BITS 32
166
167static u64 nbd_cmd_handle(struct nbd_cmd *cmd)
168{
169 struct request *req = blk_mq_rq_from_pdu(cmd);
170 u32 tag = blk_mq_unique_tag(req);
171 u64 cookie = cmd->cmd_cookie;
172
173 return (cookie << NBD_COOKIE_BITS) | tag;
174}
175
176static u32 nbd_handle_to_tag(u64 handle)
177{
178 return (u32)handle;
179}
180
181static u32 nbd_handle_to_cookie(u64 handle)
182{
183 return (u32)(handle >> NBD_COOKIE_BITS);
184}
185
186static const char *nbdcmd_to_ascii(int cmd)
187{
188 switch (cmd) {
189 case NBD_CMD_READ: return "read";
190 case NBD_CMD_WRITE: return "write";
191 case NBD_CMD_DISC: return "disconnect";
192 case NBD_CMD_FLUSH: return "flush";
193 case NBD_CMD_TRIM: return "trim/discard";
194 }
195 return "invalid";
196}
197
198static ssize_t pid_show(struct device *dev,
199 struct device_attribute *attr, char *buf)
200{
201 struct gendisk *disk = dev_to_disk(dev);
202 struct nbd_device *nbd = (struct nbd_device *)disk->private_data;
203
204 return sprintf(buf, "%d\n", task_pid_nr(nbd->task_recv));
205}
206
207static const struct device_attribute pid_attr = {
208 .attr = { .name = "pid", .mode = 0444},
209 .show = pid_show,
210};
211
212static void nbd_dev_remove(struct nbd_device *nbd)
213{
214 struct gendisk *disk = nbd->disk;
215 struct request_queue *q;
216
217 if (disk) {
218 q = disk->queue;
219 del_gendisk(disk);
220 blk_cleanup_queue(q);
221 blk_mq_free_tag_set(&nbd->tag_set);
222 disk->private_data = NULL;
223 put_disk(disk);
224 }
225 kfree(nbd);
226}
227
228static void nbd_put(struct nbd_device *nbd)
229{
230 if (refcount_dec_and_mutex_lock(&nbd->refs,
231 &nbd_index_mutex)) {
232 idr_remove(&nbd_index_idr, nbd->index);
233 mutex_unlock(&nbd_index_mutex);
234 nbd_dev_remove(nbd);
235 }
236}
237
238static int nbd_disconnected(struct nbd_config *config)
239{
240 return test_bit(NBD_DISCONNECTED, &config->runtime_flags) ||
241 test_bit(NBD_DISCONNECT_REQUESTED, &config->runtime_flags);
242}
243
244static void nbd_mark_nsock_dead(struct nbd_device *nbd, struct nbd_sock *nsock,
245 int notify)
246{
247 if (!nsock->dead && notify && !nbd_disconnected(nbd->config)) {
248 struct link_dead_args *args;
249 args = kmalloc(sizeof(struct link_dead_args), GFP_NOIO);
250 if (args) {
251 INIT_WORK(&args->work, nbd_dead_link_work);
252 args->index = nbd->index;
253 queue_work(system_wq, &args->work);
254 }
255 }
256 if (!nsock->dead) {
257 kernel_sock_shutdown(nsock->sock, SHUT_RDWR);
258 if (atomic_dec_return(&nbd->config->live_connections) == 0) {
259 if (test_and_clear_bit(NBD_DISCONNECT_REQUESTED,
260 &nbd->config->runtime_flags)) {
261 set_bit(NBD_DISCONNECTED,
262 &nbd->config->runtime_flags);
263 dev_info(nbd_to_dev(nbd),
264 "Disconnected due to user request.\n");
265 }
266 }
267 }
268 nsock->dead = true;
269 nsock->pending = NULL;
270 nsock->sent = 0;
271}
272
273static void nbd_size_clear(struct nbd_device *nbd)
274{
275 if (nbd->config->bytesize) {
276 set_capacity(nbd->disk, 0);
277 kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
278 }
279}
280
281static void nbd_size_update(struct nbd_device *nbd)
282{
283 struct nbd_config *config = nbd->config;
284 struct block_device *bdev = bdget_disk(nbd->disk, 0);
285
286 if (config->flags & NBD_FLAG_SEND_TRIM) {
287 nbd->disk->queue->limits.discard_granularity = config->blksize;
288 nbd->disk->queue->limits.discard_alignment = config->blksize;
289 blk_queue_max_discard_sectors(nbd->disk->queue, UINT_MAX);
290 }
291 blk_queue_logical_block_size(nbd->disk->queue, config->blksize);
292 blk_queue_physical_block_size(nbd->disk->queue, config->blksize);
293 set_capacity(nbd->disk, config->bytesize >> 9);
294 if (bdev) {
295 if (bdev->bd_disk) {
296 bd_set_size(bdev, config->bytesize);
297 set_blocksize(bdev, config->blksize);
298 } else
299 bdev->bd_invalidated = 1;
300 bdput(bdev);
301 }
302 kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
303}
304
305static void nbd_size_set(struct nbd_device *nbd, loff_t blocksize,
306 loff_t nr_blocks)
307{
308 struct nbd_config *config = nbd->config;
309 config->blksize = blocksize;
310 config->bytesize = blocksize * nr_blocks;
311 if (nbd->task_recv != NULL)
312 nbd_size_update(nbd);
313}
314
315static void nbd_complete_rq(struct request *req)
316{
317 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
318
319 dev_dbg(nbd_to_dev(cmd->nbd), "request %p: %s\n", req,
320 cmd->status ? "failed" : "done");
321
322 blk_mq_end_request(req, cmd->status);
323}
324
325
326
327
328static void sock_shutdown(struct nbd_device *nbd)
329{
330 struct nbd_config *config = nbd->config;
331 int i;
332
333 if (config->num_connections == 0)
334 return;
335 if (test_and_set_bit(NBD_DISCONNECTED, &config->runtime_flags))
336 return;
337
338 for (i = 0; i < config->num_connections; i++) {
339 struct nbd_sock *nsock = config->socks[i];
340 mutex_lock(&nsock->tx_lock);
341 nbd_mark_nsock_dead(nbd, nsock, 0);
342 mutex_unlock(&nsock->tx_lock);
343 }
344 dev_warn(disk_to_dev(nbd->disk), "shutting down sockets\n");
345}
346
347static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
348 bool reserved)
349{
350 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
351 struct nbd_device *nbd = cmd->nbd;
352 struct nbd_config *config;
353
354 if (!refcount_inc_not_zero(&nbd->config_refs)) {
355 cmd->status = BLK_STS_TIMEOUT;
356 goto done;
357 }
358 config = nbd->config;
359
360 if (!mutex_trylock(&cmd->lock))
361 return BLK_EH_RESET_TIMER;
362
363 if (config->num_connections > 1) {
364 dev_err_ratelimited(nbd_to_dev(nbd),
365 "Connection timed out, retrying (%d/%d alive)\n",
366 atomic_read(&config->live_connections),
367 config->num_connections);
368
369
370
371
372 if (config->socks && config->num_connections > 1) {
373 if (cmd->index < config->num_connections) {
374 struct nbd_sock *nsock =
375 config->socks[cmd->index];
376 mutex_lock(&nsock->tx_lock);
377
378
379
380
381
382
383 if (cmd->cookie == nsock->cookie)
384 nbd_mark_nsock_dead(nbd, nsock, 1);
385 mutex_unlock(&nsock->tx_lock);
386 }
387 mutex_unlock(&cmd->lock);
388 nbd_requeue_cmd(cmd);
389 nbd_config_put(nbd);
390 return BLK_EH_DONE;
391 }
392 } else {
393 dev_err_ratelimited(nbd_to_dev(nbd),
394 "Connection timed out\n");
395 }
396 set_bit(NBD_TIMEDOUT, &config->runtime_flags);
397 cmd->status = BLK_STS_IOERR;
398 mutex_unlock(&cmd->lock);
399 sock_shutdown(nbd);
400 nbd_config_put(nbd);
401done:
402 blk_mq_complete_request(req);
403 return BLK_EH_DONE;
404}
405
406
407
408
409static int sock_xmit(struct nbd_device *nbd, int index, int send,
410 struct iov_iter *iter, int msg_flags, int *sent)
411{
412 struct nbd_config *config = nbd->config;
413 struct socket *sock = config->socks[index]->sock;
414 int result;
415 struct msghdr msg;
416 unsigned int noreclaim_flag;
417
418 if (unlikely(!sock)) {
419 dev_err_ratelimited(disk_to_dev(nbd->disk),
420 "Attempted %s on closed socket in sock_xmit\n",
421 (send ? "send" : "recv"));
422 return -EINVAL;
423 }
424
425 msg.msg_iter = *iter;
426
427 noreclaim_flag = memalloc_noreclaim_save();
428 do {
429 sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC;
430 msg.msg_name = NULL;
431 msg.msg_namelen = 0;
432 msg.msg_control = NULL;
433 msg.msg_controllen = 0;
434 msg.msg_flags = msg_flags | MSG_NOSIGNAL;
435
436 if (send)
437 result = sock_sendmsg(sock, &msg);
438 else
439 result = sock_recvmsg(sock, &msg, msg.msg_flags);
440
441 if (result <= 0) {
442 if (result == 0)
443 result = -EPIPE;
444 break;
445 }
446 if (sent)
447 *sent += result;
448 } while (msg_data_left(&msg));
449
450 memalloc_noreclaim_restore(noreclaim_flag);
451
452 return result;
453}
454
455
456
457
458
459static inline int was_interrupted(int result)
460{
461 return result == -ERESTARTSYS || result == -EINTR;
462}
463
464
465static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
466{
467 struct request *req = blk_mq_rq_from_pdu(cmd);
468 struct nbd_config *config = nbd->config;
469 struct nbd_sock *nsock = config->socks[index];
470 int result;
471 struct nbd_request request = {.magic = htonl(NBD_REQUEST_MAGIC)};
472 struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)};
473 struct iov_iter from;
474 unsigned long size = blk_rq_bytes(req);
475 struct bio *bio;
476 u64 handle;
477 u32 type;
478 u32 nbd_cmd_flags = 0;
479 int sent = nsock->sent, skip = 0;
480
481 iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
482
483 switch (req_op(req)) {
484 case REQ_OP_DISCARD:
485 type = NBD_CMD_TRIM;
486 break;
487 case REQ_OP_FLUSH:
488 type = NBD_CMD_FLUSH;
489 break;
490 case REQ_OP_WRITE:
491 type = NBD_CMD_WRITE;
492 break;
493 case REQ_OP_READ:
494 type = NBD_CMD_READ;
495 break;
496 default:
497 return -EIO;
498 }
499
500 if (rq_data_dir(req) == WRITE &&
501 (config->flags & NBD_FLAG_READ_ONLY)) {
502 dev_err_ratelimited(disk_to_dev(nbd->disk),
503 "Write on read-only\n");
504 return -EIO;
505 }
506
507 if (req->cmd_flags & REQ_FUA)
508 nbd_cmd_flags |= NBD_CMD_FLAG_FUA;
509
510
511
512
513
514 if (sent) {
515 if (sent >= sizeof(request)) {
516 skip = sent - sizeof(request);
517
518
519 handle = nbd_cmd_handle(cmd);
520
521 goto send_pages;
522 }
523 iov_iter_advance(&from, sent);
524 } else {
525 cmd->cmd_cookie++;
526 }
527 cmd->index = index;
528 cmd->cookie = nsock->cookie;
529 request.type = htonl(type | nbd_cmd_flags);
530 if (type != NBD_CMD_FLUSH) {
531 request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);
532 request.len = htonl(size);
533 }
534 handle = nbd_cmd_handle(cmd);
535 memcpy(request.handle, &handle, sizeof(handle));
536
537 trace_nbd_send_request(&request, nbd->index, blk_mq_rq_from_pdu(cmd));
538
539 dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n",
540 req, nbdcmd_to_ascii(type),
541 (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req));
542 result = sock_xmit(nbd, index, 1, &from,
543 (type == NBD_CMD_WRITE) ? MSG_MORE : 0, &sent);
544 trace_nbd_header_sent(req, handle);
545 if (result <= 0) {
546 if (was_interrupted(result)) {
547
548
549
550
551
552 if (sent) {
553 nsock->pending = req;
554 nsock->sent = sent;
555 }
556 set_bit(NBD_CMD_REQUEUED, &cmd->flags);
557 return BLK_STS_RESOURCE;
558 }
559 dev_err_ratelimited(disk_to_dev(nbd->disk),
560 "Send control failed (result %d)\n", result);
561 return -EAGAIN;
562 }
563send_pages:
564 if (type != NBD_CMD_WRITE)
565 goto out;
566
567 bio = req->bio;
568 while (bio) {
569 struct bio *next = bio->bi_next;
570 struct bvec_iter iter;
571 struct bio_vec bvec;
572
573 bio_for_each_segment(bvec, bio, iter) {
574 bool is_last = !next && bio_iter_last(bvec, iter);
575 int flags = is_last ? 0 : MSG_MORE;
576
577 dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",
578 req, bvec.bv_len);
579 iov_iter_bvec(&from, WRITE, &bvec, 1, bvec.bv_len);
580 if (skip) {
581 if (skip >= iov_iter_count(&from)) {
582 skip -= iov_iter_count(&from);
583 continue;
584 }
585 iov_iter_advance(&from, skip);
586 skip = 0;
587 }
588 result = sock_xmit(nbd, index, 1, &from, flags, &sent);
589 if (result <= 0) {
590 if (was_interrupted(result)) {
591
592
593
594
595 nsock->pending = req;
596 nsock->sent = sent;
597 set_bit(NBD_CMD_REQUEUED, &cmd->flags);
598 return BLK_STS_RESOURCE;
599 }
600 dev_err(disk_to_dev(nbd->disk),
601 "Send data failed (result %d)\n",
602 result);
603 return -EAGAIN;
604 }
605
606
607
608
609
610
611 if (is_last)
612 break;
613 }
614 bio = next;
615 }
616out:
617 trace_nbd_payload_sent(req, handle);
618 nsock->pending = NULL;
619 nsock->sent = 0;
620 return 0;
621}
622
623
624static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
625{
626 struct nbd_config *config = nbd->config;
627 int result;
628 struct nbd_reply reply;
629 struct nbd_cmd *cmd;
630 struct request *req = NULL;
631 u64 handle;
632 u16 hwq;
633 u32 tag;
634 struct kvec iov = {.iov_base = &reply, .iov_len = sizeof(reply)};
635 struct iov_iter to;
636 int ret = 0;
637
638 reply.magic = 0;
639 iov_iter_kvec(&to, READ, &iov, 1, sizeof(reply));
640 result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
641 if (result <= 0) {
642 if (!nbd_disconnected(config))
643 dev_err(disk_to_dev(nbd->disk),
644 "Receive control failed (result %d)\n", result);
645 return ERR_PTR(result);
646 }
647
648 if (ntohl(reply.magic) != NBD_REPLY_MAGIC) {
649 dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n",
650 (unsigned long)ntohl(reply.magic));
651 return ERR_PTR(-EPROTO);
652 }
653
654 memcpy(&handle, reply.handle, sizeof(handle));
655 tag = nbd_handle_to_tag(handle);
656 hwq = blk_mq_unique_tag_to_hwq(tag);
657 if (hwq < nbd->tag_set.nr_hw_queues)
658 req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq],
659 blk_mq_unique_tag_to_tag(tag));
660 if (!req || !blk_mq_request_started(req)) {
661 dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n",
662 tag, req);
663 return ERR_PTR(-ENOENT);
664 }
665 trace_nbd_header_received(req, handle);
666 cmd = blk_mq_rq_to_pdu(req);
667
668 mutex_lock(&cmd->lock);
669 if (cmd->cmd_cookie != nbd_handle_to_cookie(handle)) {
670 dev_err(disk_to_dev(nbd->disk), "Double reply on req %p, cmd_cookie %u, handle cookie %u\n",
671 req, cmd->cmd_cookie, nbd_handle_to_cookie(handle));
672 ret = -ENOENT;
673 goto out;
674 }
675 if (test_bit(NBD_CMD_REQUEUED, &cmd->flags)) {
676 dev_err(disk_to_dev(nbd->disk), "Raced with timeout on req %p\n",
677 req);
678 ret = -ENOENT;
679 goto out;
680 }
681 if (ntohl(reply.error)) {
682 dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n",
683 ntohl(reply.error));
684 cmd->status = BLK_STS_IOERR;
685 goto out;
686 }
687
688 dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", req);
689 if (rq_data_dir(req) != WRITE) {
690 struct req_iterator iter;
691 struct bio_vec bvec;
692
693 rq_for_each_segment(bvec, req, iter) {
694 iov_iter_bvec(&to, READ, &bvec, 1, bvec.bv_len);
695 result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
696 if (result <= 0) {
697 dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n",
698 result);
699
700
701
702
703
704
705
706 if (nbd_disconnected(config) ||
707 config->num_connections <= 1) {
708 cmd->status = BLK_STS_IOERR;
709 goto out;
710 }
711 ret = -EIO;
712 goto out;
713 }
714 dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n",
715 req, bvec.bv_len);
716 }
717 }
718out:
719 trace_nbd_payload_received(req, handle);
720 mutex_unlock(&cmd->lock);
721 return ret ? ERR_PTR(ret) : cmd;
722}
723
724static void recv_work(struct work_struct *work)
725{
726 struct recv_thread_args *args = container_of(work,
727 struct recv_thread_args,
728 work);
729 struct nbd_device *nbd = args->nbd;
730 struct nbd_config *config = nbd->config;
731 struct nbd_cmd *cmd;
732
733 while (1) {
734 cmd = nbd_read_stat(nbd, args->index);
735 if (IS_ERR(cmd)) {
736 struct nbd_sock *nsock = config->socks[args->index];
737
738 mutex_lock(&nsock->tx_lock);
739 nbd_mark_nsock_dead(nbd, nsock, 1);
740 mutex_unlock(&nsock->tx_lock);
741 break;
742 }
743
744 blk_mq_complete_request(blk_mq_rq_from_pdu(cmd));
745 }
746 atomic_dec(&config->recv_threads);
747 wake_up(&config->recv_wq);
748 nbd_config_put(nbd);
749 kfree(args);
750}
751
752static bool nbd_clear_req(struct request *req, void *data, bool reserved)
753{
754 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
755
756 cmd->status = BLK_STS_IOERR;
757 blk_mq_complete_request(req);
758 return true;
759}
760
761static void nbd_clear_que(struct nbd_device *nbd)
762{
763 blk_mq_quiesce_queue(nbd->disk->queue);
764 blk_mq_tagset_busy_iter(&nbd->tag_set, nbd_clear_req, NULL);
765 blk_mq_unquiesce_queue(nbd->disk->queue);
766 dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n");
767}
768
769static int find_fallback(struct nbd_device *nbd, int index)
770{
771 struct nbd_config *config = nbd->config;
772 int new_index = -1;
773 struct nbd_sock *nsock = config->socks[index];
774 int fallback = nsock->fallback_index;
775
776 if (test_bit(NBD_DISCONNECTED, &config->runtime_flags))
777 return new_index;
778
779 if (config->num_connections <= 1) {
780 dev_err_ratelimited(disk_to_dev(nbd->disk),
781 "Attempted send on invalid socket\n");
782 return new_index;
783 }
784
785 if (fallback >= 0 && fallback < config->num_connections &&
786 !config->socks[fallback]->dead)
787 return fallback;
788
789 if (nsock->fallback_index < 0 ||
790 nsock->fallback_index >= config->num_connections ||
791 config->socks[nsock->fallback_index]->dead) {
792 int i;
793 for (i = 0; i < config->num_connections; i++) {
794 if (i == index)
795 continue;
796 if (!config->socks[i]->dead) {
797 new_index = i;
798 break;
799 }
800 }
801 nsock->fallback_index = new_index;
802 if (new_index < 0) {
803 dev_err_ratelimited(disk_to_dev(nbd->disk),
804 "Dead connection, failed to find a fallback\n");
805 return new_index;
806 }
807 }
808 new_index = nsock->fallback_index;
809 return new_index;
810}
811
812static int wait_for_reconnect(struct nbd_device *nbd)
813{
814 struct nbd_config *config = nbd->config;
815 if (!config->dead_conn_timeout)
816 return 0;
817 if (test_bit(NBD_DISCONNECTED, &config->runtime_flags))
818 return 0;
819 return wait_event_timeout(config->conn_wait,
820 atomic_read(&config->live_connections) > 0,
821 config->dead_conn_timeout) > 0;
822}
823
824static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
825{
826 struct request *req = blk_mq_rq_from_pdu(cmd);
827 struct nbd_device *nbd = cmd->nbd;
828 struct nbd_config *config;
829 struct nbd_sock *nsock;
830 int ret;
831
832 if (!refcount_inc_not_zero(&nbd->config_refs)) {
833 dev_err_ratelimited(disk_to_dev(nbd->disk),
834 "Socks array is empty\n");
835 blk_mq_start_request(req);
836 return -EINVAL;
837 }
838 config = nbd->config;
839
840 if (index >= config->num_connections) {
841 dev_err_ratelimited(disk_to_dev(nbd->disk),
842 "Attempted send on invalid socket\n");
843 nbd_config_put(nbd);
844 blk_mq_start_request(req);
845 return -EINVAL;
846 }
847 cmd->status = BLK_STS_OK;
848again:
849 nsock = config->socks[index];
850 mutex_lock(&nsock->tx_lock);
851 if (nsock->dead) {
852 int old_index = index;
853 index = find_fallback(nbd, index);
854 mutex_unlock(&nsock->tx_lock);
855 if (index < 0) {
856 if (wait_for_reconnect(nbd)) {
857 index = old_index;
858 goto again;
859 }
860
861
862
863
864
865
866 sock_shutdown(nbd);
867 nbd_config_put(nbd);
868 blk_mq_start_request(req);
869 return -EIO;
870 }
871 goto again;
872 }
873
874
875
876
877
878
879 blk_mq_start_request(req);
880 if (unlikely(nsock->pending && nsock->pending != req)) {
881 nbd_requeue_cmd(cmd);
882 ret = 0;
883 goto out;
884 }
885
886
887
888
889 ret = nbd_send_cmd(nbd, cmd, index);
890 if (ret == -EAGAIN) {
891 dev_err_ratelimited(disk_to_dev(nbd->disk),
892 "Request send failed, requeueing\n");
893 nbd_mark_nsock_dead(nbd, nsock, 1);
894 nbd_requeue_cmd(cmd);
895 ret = 0;
896 }
897out:
898 mutex_unlock(&nsock->tx_lock);
899 nbd_config_put(nbd);
900 return ret;
901}
902
903static blk_status_t nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
904 const struct blk_mq_queue_data *bd)
905{
906 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
907 int ret;
908
909
910
911
912
913
914
915
916
917
918 mutex_lock(&cmd->lock);
919 clear_bit(NBD_CMD_REQUEUED, &cmd->flags);
920
921
922
923
924
925
926 ret = nbd_handle_cmd(cmd, hctx->queue_num);
927 if (ret < 0)
928 ret = BLK_STS_IOERR;
929 else if (!ret)
930 ret = BLK_STS_OK;
931 mutex_unlock(&cmd->lock);
932
933 return ret;
934}
935
936static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
937 bool netlink)
938{
939 struct nbd_config *config = nbd->config;
940 struct socket *sock;
941 struct nbd_sock **socks;
942 struct nbd_sock *nsock;
943 int err;
944
945 sock = sockfd_lookup(arg, &err);
946 if (!sock)
947 return err;
948
949 if (!netlink && !nbd->task_setup &&
950 !test_bit(NBD_BOUND, &config->runtime_flags))
951 nbd->task_setup = current;
952
953 if (!netlink &&
954 (nbd->task_setup != current ||
955 test_bit(NBD_BOUND, &config->runtime_flags))) {
956 dev_err(disk_to_dev(nbd->disk),
957 "Device being setup by another task");
958 sockfd_put(sock);
959 return -EBUSY;
960 }
961
962 socks = krealloc(config->socks, (config->num_connections + 1) *
963 sizeof(struct nbd_sock *), GFP_KERNEL);
964 if (!socks) {
965 sockfd_put(sock);
966 return -ENOMEM;
967 }
968 nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL);
969 if (!nsock) {
970 sockfd_put(sock);
971 return -ENOMEM;
972 }
973
974 config->socks = socks;
975
976 nsock->fallback_index = -1;
977 nsock->dead = false;
978 mutex_init(&nsock->tx_lock);
979 nsock->sock = sock;
980 nsock->pending = NULL;
981 nsock->sent = 0;
982 nsock->cookie = 0;
983 socks[config->num_connections++] = nsock;
984 atomic_inc(&config->live_connections);
985
986 return 0;
987}
988
989static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg)
990{
991 struct nbd_config *config = nbd->config;
992 struct socket *sock, *old;
993 struct recv_thread_args *args;
994 int i;
995 int err;
996
997 sock = sockfd_lookup(arg, &err);
998 if (!sock)
999 return err;
1000
1001 args = kzalloc(sizeof(*args), GFP_KERNEL);
1002 if (!args) {
1003 sockfd_put(sock);
1004 return -ENOMEM;
1005 }
1006
1007 for (i = 0; i < config->num_connections; i++) {
1008 struct nbd_sock *nsock = config->socks[i];
1009
1010 if (!nsock->dead)
1011 continue;
1012
1013 mutex_lock(&nsock->tx_lock);
1014 if (!nsock->dead) {
1015 mutex_unlock(&nsock->tx_lock);
1016 continue;
1017 }
1018 sk_set_memalloc(sock->sk);
1019 if (nbd->tag_set.timeout)
1020 sock->sk->sk_sndtimeo = nbd->tag_set.timeout;
1021 atomic_inc(&config->recv_threads);
1022 refcount_inc(&nbd->config_refs);
1023 old = nsock->sock;
1024 nsock->fallback_index = -1;
1025 nsock->sock = sock;
1026 nsock->dead = false;
1027 INIT_WORK(&args->work, recv_work);
1028 args->index = i;
1029 args->nbd = nbd;
1030 nsock->cookie++;
1031 mutex_unlock(&nsock->tx_lock);
1032 sockfd_put(old);
1033
1034 clear_bit(NBD_DISCONNECTED, &config->runtime_flags);
1035
1036
1037
1038
1039 queue_work(recv_workqueue, &args->work);
1040
1041 atomic_inc(&config->live_connections);
1042 wake_up(&config->conn_wait);
1043 return 0;
1044 }
1045 sockfd_put(sock);
1046 kfree(args);
1047 return -ENOSPC;
1048}
1049
1050static void nbd_bdev_reset(struct block_device *bdev)
1051{
1052 if (bdev->bd_openers > 1)
1053 return;
1054 bd_set_size(bdev, 0);
1055}
1056
1057static void nbd_parse_flags(struct nbd_device *nbd)
1058{
1059 struct nbd_config *config = nbd->config;
1060 if (config->flags & NBD_FLAG_READ_ONLY)
1061 set_disk_ro(nbd->disk, true);
1062 else
1063 set_disk_ro(nbd->disk, false);
1064 if (config->flags & NBD_FLAG_SEND_TRIM)
1065 blk_queue_flag_set(QUEUE_FLAG_DISCARD, nbd->disk->queue);
1066 if (config->flags & NBD_FLAG_SEND_FLUSH) {
1067 if (config->flags & NBD_FLAG_SEND_FUA)
1068 blk_queue_write_cache(nbd->disk->queue, true, true);
1069 else
1070 blk_queue_write_cache(nbd->disk->queue, true, false);
1071 }
1072 else
1073 blk_queue_write_cache(nbd->disk->queue, false, false);
1074}
1075
1076static void send_disconnects(struct nbd_device *nbd)
1077{
1078 struct nbd_config *config = nbd->config;
1079 struct nbd_request request = {
1080 .magic = htonl(NBD_REQUEST_MAGIC),
1081 .type = htonl(NBD_CMD_DISC),
1082 };
1083 struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)};
1084 struct iov_iter from;
1085 int i, ret;
1086
1087 for (i = 0; i < config->num_connections; i++) {
1088 struct nbd_sock *nsock = config->socks[i];
1089
1090 iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
1091 mutex_lock(&nsock->tx_lock);
1092 ret = sock_xmit(nbd, i, 1, &from, 0, NULL);
1093 if (ret <= 0)
1094 dev_err(disk_to_dev(nbd->disk),
1095 "Send disconnect failed %d\n", ret);
1096 mutex_unlock(&nsock->tx_lock);
1097 }
1098}
1099
1100static int nbd_disconnect(struct nbd_device *nbd)
1101{
1102 struct nbd_config *config = nbd->config;
1103
1104 dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n");
1105 set_bit(NBD_DISCONNECT_REQUESTED, &config->runtime_flags);
1106 send_disconnects(nbd);
1107 return 0;
1108}
1109
1110static void nbd_clear_sock(struct nbd_device *nbd)
1111{
1112 sock_shutdown(nbd);
1113 nbd_clear_que(nbd);
1114 nbd->task_setup = NULL;
1115}
1116
1117static void nbd_config_put(struct nbd_device *nbd)
1118{
1119 if (refcount_dec_and_mutex_lock(&nbd->config_refs,
1120 &nbd->config_lock)) {
1121 struct nbd_config *config = nbd->config;
1122 nbd_dev_dbg_close(nbd);
1123 nbd_size_clear(nbd);
1124 if (test_and_clear_bit(NBD_HAS_PID_FILE,
1125 &config->runtime_flags))
1126 device_remove_file(disk_to_dev(nbd->disk), &pid_attr);
1127 nbd->task_recv = NULL;
1128 nbd_clear_sock(nbd);
1129 if (config->num_connections) {
1130 int i;
1131 for (i = 0; i < config->num_connections; i++) {
1132 sockfd_put(config->socks[i]->sock);
1133 kfree(config->socks[i]);
1134 }
1135 kfree(config->socks);
1136 }
1137 kfree(nbd->config);
1138 nbd->config = NULL;
1139
1140 nbd->tag_set.timeout = 0;
1141 nbd->disk->queue->limits.discard_granularity = 0;
1142 nbd->disk->queue->limits.discard_alignment = 0;
1143 blk_queue_max_discard_sectors(nbd->disk->queue, UINT_MAX);
1144 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, nbd->disk->queue);
1145
1146 mutex_unlock(&nbd->config_lock);
1147 nbd_put(nbd);
1148 module_put(THIS_MODULE);
1149 }
1150}
1151
1152static int nbd_start_device(struct nbd_device *nbd)
1153{
1154 struct nbd_config *config = nbd->config;
1155 int num_connections = config->num_connections;
1156 int error = 0, i;
1157
1158 if (nbd->task_recv)
1159 return -EBUSY;
1160 if (!config->socks)
1161 return -EINVAL;
1162 if (num_connections > 1 &&
1163 !(config->flags & NBD_FLAG_CAN_MULTI_CONN)) {
1164 dev_err(disk_to_dev(nbd->disk), "server does not support multiple connections per device.\n");
1165 return -EINVAL;
1166 }
1167
1168 blk_mq_update_nr_hw_queues(&nbd->tag_set, config->num_connections);
1169 nbd->task_recv = current;
1170
1171 nbd_parse_flags(nbd);
1172
1173 error = device_create_file(disk_to_dev(nbd->disk), &pid_attr);
1174 if (error) {
1175 dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n");
1176 return error;
1177 }
1178 set_bit(NBD_HAS_PID_FILE, &config->runtime_flags);
1179
1180 nbd_dev_dbg_init(nbd);
1181 for (i = 0; i < num_connections; i++) {
1182 struct recv_thread_args *args;
1183
1184 args = kzalloc(sizeof(*args), GFP_KERNEL);
1185 if (!args) {
1186 sock_shutdown(nbd);
1187 return -ENOMEM;
1188 }
1189 sk_set_memalloc(config->socks[i]->sock->sk);
1190 if (nbd->tag_set.timeout)
1191 config->socks[i]->sock->sk->sk_sndtimeo =
1192 nbd->tag_set.timeout;
1193 atomic_inc(&config->recv_threads);
1194 refcount_inc(&nbd->config_refs);
1195 INIT_WORK(&args->work, recv_work);
1196 args->nbd = nbd;
1197 args->index = i;
1198 queue_work(recv_workqueue, &args->work);
1199 }
1200 nbd_size_update(nbd);
1201 return error;
1202}
1203
1204static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *bdev)
1205{
1206 struct nbd_config *config = nbd->config;
1207 int ret;
1208
1209 ret = nbd_start_device(nbd);
1210 if (ret)
1211 return ret;
1212
1213 if (max_part)
1214 bdev->bd_invalidated = 1;
1215 mutex_unlock(&nbd->config_lock);
1216 ret = wait_event_interruptible(config->recv_wq,
1217 atomic_read(&config->recv_threads) == 0);
1218 if (ret)
1219 sock_shutdown(nbd);
1220 mutex_lock(&nbd->config_lock);
1221 nbd_bdev_reset(bdev);
1222
1223 if (test_bit(NBD_DISCONNECT_REQUESTED, &config->runtime_flags))
1224 ret = 0;
1225 if (test_bit(NBD_TIMEDOUT, &config->runtime_flags))
1226 ret = -ETIMEDOUT;
1227 return ret;
1228}
1229
1230static void nbd_clear_sock_ioctl(struct nbd_device *nbd,
1231 struct block_device *bdev)
1232{
1233 sock_shutdown(nbd);
1234 __invalidate_device(bdev, true);
1235 nbd_bdev_reset(bdev);
1236 if (test_and_clear_bit(NBD_HAS_CONFIG_REF,
1237 &nbd->config->runtime_flags))
1238 nbd_config_put(nbd);
1239}
1240
1241static bool nbd_is_valid_blksize(unsigned long blksize)
1242{
1243 if (!blksize || !is_power_of_2(blksize) || blksize < 512 ||
1244 blksize > PAGE_SIZE)
1245 return false;
1246 return true;
1247}
1248
1249
1250static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
1251 unsigned int cmd, unsigned long arg)
1252{
1253 struct nbd_config *config = nbd->config;
1254
1255 switch (cmd) {
1256 case NBD_DISCONNECT:
1257 return nbd_disconnect(nbd);
1258 case NBD_CLEAR_SOCK:
1259 nbd_clear_sock_ioctl(nbd, bdev);
1260 return 0;
1261 case NBD_SET_SOCK:
1262 return nbd_add_socket(nbd, arg, false);
1263 case NBD_SET_BLKSIZE:
1264 if (!arg)
1265 arg = NBD_DEF_BLKSIZE;
1266 if (!nbd_is_valid_blksize(arg))
1267 return -EINVAL;
1268 nbd_size_set(nbd, arg,
1269 div_s64(config->bytesize, arg));
1270 return 0;
1271 case NBD_SET_SIZE:
1272 nbd_size_set(nbd, config->blksize,
1273 div_s64(arg, config->blksize));
1274 return 0;
1275 case NBD_SET_SIZE_BLOCKS:
1276 nbd_size_set(nbd, config->blksize, arg);
1277 return 0;
1278 case NBD_SET_TIMEOUT:
1279 if (arg) {
1280 nbd->tag_set.timeout = arg * HZ;
1281 blk_queue_rq_timeout(nbd->disk->queue, arg * HZ);
1282 }
1283 return 0;
1284
1285 case NBD_SET_FLAGS:
1286 config->flags = arg;
1287 return 0;
1288 case NBD_DO_IT:
1289 return nbd_start_device_ioctl(nbd, bdev);
1290 case NBD_CLEAR_QUE:
1291
1292
1293
1294
1295 return 0;
1296 case NBD_PRINT_DEBUG:
1297
1298
1299
1300
1301 return 0;
1302 }
1303 return -ENOTTY;
1304}
1305
1306static int nbd_ioctl(struct block_device *bdev, fmode_t mode,
1307 unsigned int cmd, unsigned long arg)
1308{
1309 struct nbd_device *nbd = bdev->bd_disk->private_data;
1310 struct nbd_config *config = nbd->config;
1311 int error = -EINVAL;
1312
1313 if (!capable(CAP_SYS_ADMIN))
1314 return -EPERM;
1315
1316
1317
1318
1319 if (_IOC_TYPE(cmd) != 0xab)
1320 return -EINVAL;
1321
1322 mutex_lock(&nbd->config_lock);
1323
1324
1325
1326
1327 if (!test_bit(NBD_BOUND, &config->runtime_flags) ||
1328 (cmd == NBD_DISCONNECT || cmd == NBD_CLEAR_SOCK))
1329 error = __nbd_ioctl(bdev, nbd, cmd, arg);
1330 else
1331 dev_err(nbd_to_dev(nbd), "Cannot use ioctl interface on a netlink controlled device.\n");
1332 mutex_unlock(&nbd->config_lock);
1333 return error;
1334}
1335
1336static struct nbd_config *nbd_alloc_config(void)
1337{
1338 struct nbd_config *config;
1339
1340 config = kzalloc(sizeof(struct nbd_config), GFP_NOFS);
1341 if (!config)
1342 return NULL;
1343 atomic_set(&config->recv_threads, 0);
1344 init_waitqueue_head(&config->recv_wq);
1345 init_waitqueue_head(&config->conn_wait);
1346 config->blksize = NBD_DEF_BLKSIZE;
1347 atomic_set(&config->live_connections, 0);
1348 try_module_get(THIS_MODULE);
1349 return config;
1350}
1351
1352static int nbd_open(struct block_device *bdev, fmode_t mode)
1353{
1354 struct nbd_device *nbd;
1355 int ret = 0;
1356
1357 mutex_lock(&nbd_index_mutex);
1358 nbd = bdev->bd_disk->private_data;
1359 if (!nbd) {
1360 ret = -ENXIO;
1361 goto out;
1362 }
1363 if (!refcount_inc_not_zero(&nbd->refs)) {
1364 ret = -ENXIO;
1365 goto out;
1366 }
1367 if (!refcount_inc_not_zero(&nbd->config_refs)) {
1368 struct nbd_config *config;
1369
1370 mutex_lock(&nbd->config_lock);
1371 if (refcount_inc_not_zero(&nbd->config_refs)) {
1372 mutex_unlock(&nbd->config_lock);
1373 goto out;
1374 }
1375 config = nbd->config = nbd_alloc_config();
1376 if (!config) {
1377 ret = -ENOMEM;
1378 mutex_unlock(&nbd->config_lock);
1379 goto out;
1380 }
1381 refcount_set(&nbd->config_refs, 1);
1382 refcount_inc(&nbd->refs);
1383 mutex_unlock(&nbd->config_lock);
1384 bdev->bd_invalidated = 1;
1385 } else if (nbd_disconnected(nbd->config)) {
1386 bdev->bd_invalidated = 1;
1387 }
1388out:
1389 mutex_unlock(&nbd_index_mutex);
1390 return ret;
1391}
1392
1393static void nbd_release(struct gendisk *disk, fmode_t mode)
1394{
1395 struct nbd_device *nbd = disk->private_data;
1396 struct block_device *bdev = bdget_disk(disk, 0);
1397
1398 if (test_bit(NBD_DISCONNECT_ON_CLOSE, &nbd->config->runtime_flags) &&
1399 bdev->bd_openers == 0)
1400 nbd_disconnect_and_put(nbd);
1401
1402 nbd_config_put(nbd);
1403 nbd_put(nbd);
1404}
1405
1406static const struct block_device_operations nbd_fops =
1407{
1408 .owner = THIS_MODULE,
1409 .open = nbd_open,
1410 .release = nbd_release,
1411 .ioctl = nbd_ioctl,
1412 .compat_ioctl = nbd_ioctl,
1413};
1414
1415#if IS_ENABLED(CONFIG_DEBUG_FS)
1416
1417static int nbd_dbg_tasks_show(struct seq_file *s, void *unused)
1418{
1419 struct nbd_device *nbd = s->private;
1420
1421 if (nbd->task_recv)
1422 seq_printf(s, "recv: %d\n", task_pid_nr(nbd->task_recv));
1423
1424 return 0;
1425}
1426
1427static int nbd_dbg_tasks_open(struct inode *inode, struct file *file)
1428{
1429 return single_open(file, nbd_dbg_tasks_show, inode->i_private);
1430}
1431
1432static const struct file_operations nbd_dbg_tasks_ops = {
1433 .open = nbd_dbg_tasks_open,
1434 .read = seq_read,
1435 .llseek = seq_lseek,
1436 .release = single_release,
1437};
1438
1439static int nbd_dbg_flags_show(struct seq_file *s, void *unused)
1440{
1441 struct nbd_device *nbd = s->private;
1442 u32 flags = nbd->config->flags;
1443
1444 seq_printf(s, "Hex: 0x%08x\n\n", flags);
1445
1446 seq_puts(s, "Known flags:\n");
1447
1448 if (flags & NBD_FLAG_HAS_FLAGS)
1449 seq_puts(s, "NBD_FLAG_HAS_FLAGS\n");
1450 if (flags & NBD_FLAG_READ_ONLY)
1451 seq_puts(s, "NBD_FLAG_READ_ONLY\n");
1452 if (flags & NBD_FLAG_SEND_FLUSH)
1453 seq_puts(s, "NBD_FLAG_SEND_FLUSH\n");
1454 if (flags & NBD_FLAG_SEND_FUA)
1455 seq_puts(s, "NBD_FLAG_SEND_FUA\n");
1456 if (flags & NBD_FLAG_SEND_TRIM)
1457 seq_puts(s, "NBD_FLAG_SEND_TRIM\n");
1458
1459 return 0;
1460}
1461
1462static int nbd_dbg_flags_open(struct inode *inode, struct file *file)
1463{
1464 return single_open(file, nbd_dbg_flags_show, inode->i_private);
1465}
1466
1467static const struct file_operations nbd_dbg_flags_ops = {
1468 .open = nbd_dbg_flags_open,
1469 .read = seq_read,
1470 .llseek = seq_lseek,
1471 .release = single_release,
1472};
1473
1474static int nbd_dev_dbg_init(struct nbd_device *nbd)
1475{
1476 struct dentry *dir;
1477 struct nbd_config *config = nbd->config;
1478
1479 if (!nbd_dbg_dir)
1480 return -EIO;
1481
1482 dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir);
1483 if (!dir) {
1484 dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n",
1485 nbd_name(nbd));
1486 return -EIO;
1487 }
1488 config->dbg_dir = dir;
1489
1490 debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops);
1491 debugfs_create_u64("size_bytes", 0444, dir, &config->bytesize);
1492 debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout);
1493 debugfs_create_u64("blocksize", 0444, dir, &config->blksize);
1494 debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops);
1495
1496 return 0;
1497}
1498
1499static void nbd_dev_dbg_close(struct nbd_device *nbd)
1500{
1501 debugfs_remove_recursive(nbd->config->dbg_dir);
1502}
1503
1504static int nbd_dbg_init(void)
1505{
1506 struct dentry *dbg_dir;
1507
1508 dbg_dir = debugfs_create_dir("nbd", NULL);
1509 if (!dbg_dir)
1510 return -EIO;
1511
1512 nbd_dbg_dir = dbg_dir;
1513
1514 return 0;
1515}
1516
1517static void nbd_dbg_close(void)
1518{
1519 debugfs_remove_recursive(nbd_dbg_dir);
1520}
1521
1522#else
1523
1524static int nbd_dev_dbg_init(struct nbd_device *nbd)
1525{
1526 return 0;
1527}
1528
1529static void nbd_dev_dbg_close(struct nbd_device *nbd)
1530{
1531}
1532
1533static int nbd_dbg_init(void)
1534{
1535 return 0;
1536}
1537
1538static void nbd_dbg_close(void)
1539{
1540}
1541
1542#endif
1543
1544static int nbd_init_request(struct blk_mq_tag_set *set, struct request *rq,
1545 unsigned int hctx_idx, unsigned int numa_node)
1546{
1547 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq);
1548 cmd->nbd = set->driver_data;
1549 cmd->flags = 0;
1550 mutex_init(&cmd->lock);
1551 return 0;
1552}
1553
1554static const struct blk_mq_ops nbd_mq_ops = {
1555 .queue_rq = nbd_queue_rq,
1556 .complete = nbd_complete_rq,
1557 .init_request = nbd_init_request,
1558 .timeout = nbd_xmit_timeout,
1559};
1560
1561static int nbd_dev_add(int index)
1562{
1563 struct nbd_device *nbd;
1564 struct gendisk *disk;
1565 struct request_queue *q;
1566 int err = -ENOMEM;
1567
1568 nbd = kzalloc(sizeof(struct nbd_device), GFP_KERNEL);
1569 if (!nbd)
1570 goto out;
1571
1572 disk = alloc_disk(1 << part_shift);
1573 if (!disk)
1574 goto out_free_nbd;
1575
1576 if (index >= 0) {
1577 err = idr_alloc(&nbd_index_idr, nbd, index, index + 1,
1578 GFP_KERNEL);
1579 if (err == -ENOSPC)
1580 err = -EEXIST;
1581 } else {
1582 err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL);
1583 if (err >= 0)
1584 index = err;
1585 }
1586 if (err < 0)
1587 goto out_free_disk;
1588
1589 nbd->index = index;
1590 nbd->disk = disk;
1591 nbd->tag_set.ops = &nbd_mq_ops;
1592 nbd->tag_set.nr_hw_queues = 1;
1593 nbd->tag_set.queue_depth = 128;
1594 nbd->tag_set.numa_node = NUMA_NO_NODE;
1595 nbd->tag_set.cmd_size = sizeof(struct nbd_cmd);
1596 nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
1597 BLK_MQ_F_BLOCKING;
1598 nbd->tag_set.driver_data = nbd;
1599
1600 err = blk_mq_alloc_tag_set(&nbd->tag_set);
1601 if (err)
1602 goto out_free_idr;
1603
1604 q = blk_mq_init_queue(&nbd->tag_set);
1605 if (IS_ERR(q)) {
1606 err = PTR_ERR(q);
1607 goto out_free_tags;
1608 }
1609 disk->queue = q;
1610
1611
1612
1613
1614 blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);
1615 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue);
1616 disk->queue->limits.discard_granularity = 0;
1617 disk->queue->limits.discard_alignment = 0;
1618 blk_queue_max_discard_sectors(disk->queue, 0);
1619 blk_queue_max_segment_size(disk->queue, UINT_MAX);
1620 blk_queue_max_segments(disk->queue, USHRT_MAX);
1621 blk_queue_max_hw_sectors(disk->queue, 65536);
1622 disk->queue->limits.max_sectors = 256;
1623
1624 mutex_init(&nbd->config_lock);
1625 refcount_set(&nbd->config_refs, 0);
1626 refcount_set(&nbd->refs, 1);
1627 INIT_LIST_HEAD(&nbd->list);
1628 disk->major = NBD_MAJOR;
1629 disk->first_minor = index << part_shift;
1630 disk->fops = &nbd_fops;
1631 disk->private_data = nbd;
1632 sprintf(disk->disk_name, "nbd%d", index);
1633 add_disk(disk);
1634 nbd_total_devices++;
1635 return index;
1636
1637out_free_tags:
1638 blk_mq_free_tag_set(&nbd->tag_set);
1639out_free_idr:
1640 idr_remove(&nbd_index_idr, index);
1641out_free_disk:
1642 put_disk(disk);
1643out_free_nbd:
1644 kfree(nbd);
1645out:
1646 return err;
1647}
1648
1649static int find_free_cb(int id, void *ptr, void *data)
1650{
1651 struct nbd_device *nbd = ptr;
1652 struct nbd_device **found = data;
1653
1654 if (!refcount_read(&nbd->config_refs)) {
1655 *found = nbd;
1656 return 1;
1657 }
1658 return 0;
1659}
1660
1661
1662static const struct nla_policy nbd_attr_policy[NBD_ATTR_MAX + 1] = {
1663 [NBD_ATTR_INDEX] = { .type = NLA_U32 },
1664 [NBD_ATTR_SIZE_BYTES] = { .type = NLA_U64 },
1665 [NBD_ATTR_BLOCK_SIZE_BYTES] = { .type = NLA_U64 },
1666 [NBD_ATTR_TIMEOUT] = { .type = NLA_U64 },
1667 [NBD_ATTR_SERVER_FLAGS] = { .type = NLA_U64 },
1668 [NBD_ATTR_CLIENT_FLAGS] = { .type = NLA_U64 },
1669 [NBD_ATTR_SOCKETS] = { .type = NLA_NESTED},
1670 [NBD_ATTR_DEAD_CONN_TIMEOUT] = { .type = NLA_U64 },
1671 [NBD_ATTR_DEVICE_LIST] = { .type = NLA_NESTED},
1672};
1673
1674static const struct nla_policy nbd_sock_policy[NBD_SOCK_MAX + 1] = {
1675 [NBD_SOCK_FD] = { .type = NLA_U32 },
1676};
1677
1678
1679
1680
1681static const struct nla_policy __attribute__((unused))
1682nbd_device_policy[NBD_DEVICE_ATTR_MAX + 1] = {
1683 [NBD_DEVICE_INDEX] = { .type = NLA_U32 },
1684 [NBD_DEVICE_CONNECTED] = { .type = NLA_U8 },
1685};
1686
1687static int nbd_genl_size_set(struct genl_info *info, struct nbd_device *nbd)
1688{
1689 struct nbd_config *config = nbd->config;
1690 u64 bsize = config->blksize;
1691 u64 bytes = config->bytesize;
1692
1693 if (info->attrs[NBD_ATTR_SIZE_BYTES])
1694 bytes = nla_get_u64(info->attrs[NBD_ATTR_SIZE_BYTES]);
1695
1696 if (info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]) {
1697 bsize = nla_get_u64(info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]);
1698 if (!bsize)
1699 bsize = NBD_DEF_BLKSIZE;
1700 if (!nbd_is_valid_blksize(bsize)) {
1701 printk(KERN_ERR "Invalid block size %llu\n", bsize);
1702 return -EINVAL;
1703 }
1704 }
1705
1706 if (bytes != config->bytesize || bsize != config->blksize)
1707 nbd_size_set(nbd, bsize, div64_u64(bytes, bsize));
1708 return 0;
1709}
1710
1711static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info)
1712{
1713 struct nbd_device *nbd = NULL;
1714 struct nbd_config *config;
1715 int index = -1;
1716 int ret;
1717 bool put_dev = false;
1718
1719 if (!netlink_capable(skb, CAP_SYS_ADMIN))
1720 return -EPERM;
1721
1722 if (info->attrs[NBD_ATTR_INDEX])
1723 index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
1724 if (!info->attrs[NBD_ATTR_SOCKETS]) {
1725 printk(KERN_ERR "nbd: must specify at least one socket\n");
1726 return -EINVAL;
1727 }
1728 if (!info->attrs[NBD_ATTR_SIZE_BYTES]) {
1729 printk(KERN_ERR "nbd: must specify a size in bytes for the device\n");
1730 return -EINVAL;
1731 }
1732again:
1733 mutex_lock(&nbd_index_mutex);
1734 if (index == -1) {
1735 ret = idr_for_each(&nbd_index_idr, &find_free_cb, &nbd);
1736 if (ret == 0) {
1737 int new_index;
1738 new_index = nbd_dev_add(-1);
1739 if (new_index < 0) {
1740 mutex_unlock(&nbd_index_mutex);
1741 printk(KERN_ERR "nbd: failed to add new device\n");
1742 return new_index;
1743 }
1744 nbd = idr_find(&nbd_index_idr, new_index);
1745 }
1746 } else {
1747 nbd = idr_find(&nbd_index_idr, index);
1748 if (!nbd) {
1749 ret = nbd_dev_add(index);
1750 if (ret < 0) {
1751 mutex_unlock(&nbd_index_mutex);
1752 printk(KERN_ERR "nbd: failed to add new device\n");
1753 return ret;
1754 }
1755 nbd = idr_find(&nbd_index_idr, index);
1756 }
1757 }
1758 if (!nbd) {
1759 printk(KERN_ERR "nbd: couldn't find device at index %d\n",
1760 index);
1761 mutex_unlock(&nbd_index_mutex);
1762 return -EINVAL;
1763 }
1764 if (!refcount_inc_not_zero(&nbd->refs)) {
1765 mutex_unlock(&nbd_index_mutex);
1766 if (index == -1)
1767 goto again;
1768 printk(KERN_ERR "nbd: device at index %d is going down\n",
1769 index);
1770 return -EINVAL;
1771 }
1772 mutex_unlock(&nbd_index_mutex);
1773
1774 mutex_lock(&nbd->config_lock);
1775 if (refcount_read(&nbd->config_refs)) {
1776 mutex_unlock(&nbd->config_lock);
1777 nbd_put(nbd);
1778 if (index == -1)
1779 goto again;
1780 printk(KERN_ERR "nbd: nbd%d already in use\n", index);
1781 return -EBUSY;
1782 }
1783 if (WARN_ON(nbd->config)) {
1784 mutex_unlock(&nbd->config_lock);
1785 nbd_put(nbd);
1786 return -EINVAL;
1787 }
1788 config = nbd->config = nbd_alloc_config();
1789 if (!nbd->config) {
1790 mutex_unlock(&nbd->config_lock);
1791 nbd_put(nbd);
1792 printk(KERN_ERR "nbd: couldn't allocate config\n");
1793 return -ENOMEM;
1794 }
1795 refcount_set(&nbd->config_refs, 1);
1796 set_bit(NBD_BOUND, &config->runtime_flags);
1797
1798 ret = nbd_genl_size_set(info, nbd);
1799 if (ret)
1800 goto out;
1801
1802 if (info->attrs[NBD_ATTR_TIMEOUT]) {
1803 u64 timeout = nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]);
1804 nbd->tag_set.timeout = timeout * HZ;
1805 blk_queue_rq_timeout(nbd->disk->queue, timeout * HZ);
1806 }
1807 if (info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]) {
1808 config->dead_conn_timeout =
1809 nla_get_u64(info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]);
1810 config->dead_conn_timeout *= HZ;
1811 }
1812 if (info->attrs[NBD_ATTR_SERVER_FLAGS])
1813 config->flags =
1814 nla_get_u64(info->attrs[NBD_ATTR_SERVER_FLAGS]);
1815 if (info->attrs[NBD_ATTR_CLIENT_FLAGS]) {
1816 u64 flags = nla_get_u64(info->attrs[NBD_ATTR_CLIENT_FLAGS]);
1817 if (flags & NBD_CFLAG_DESTROY_ON_DISCONNECT) {
1818 set_bit(NBD_DESTROY_ON_DISCONNECT,
1819 &config->runtime_flags);
1820 put_dev = true;
1821 }
1822 if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
1823 set_bit(NBD_DISCONNECT_ON_CLOSE,
1824 &config->runtime_flags);
1825 }
1826 }
1827
1828 if (info->attrs[NBD_ATTR_SOCKETS]) {
1829 struct nlattr *attr;
1830 int rem, fd;
1831
1832 nla_for_each_nested(attr, info->attrs[NBD_ATTR_SOCKETS],
1833 rem) {
1834 struct nlattr *socks[NBD_SOCK_MAX+1];
1835
1836 if (nla_type(attr) != NBD_SOCK_ITEM) {
1837 printk(KERN_ERR "nbd: socks must be embedded in a SOCK_ITEM attr\n");
1838 ret = -EINVAL;
1839 goto out;
1840 }
1841 ret = nla_parse_nested_deprecated(socks, NBD_SOCK_MAX,
1842 attr,
1843 nbd_sock_policy,
1844 info->extack);
1845 if (ret != 0) {
1846 printk(KERN_ERR "nbd: error processing sock list\n");
1847 ret = -EINVAL;
1848 goto out;
1849 }
1850 if (!socks[NBD_SOCK_FD])
1851 continue;
1852 fd = (int)nla_get_u32(socks[NBD_SOCK_FD]);
1853 ret = nbd_add_socket(nbd, fd, true);
1854 if (ret)
1855 goto out;
1856 }
1857 }
1858 ret = nbd_start_device(nbd);
1859out:
1860 mutex_unlock(&nbd->config_lock);
1861 if (!ret) {
1862 set_bit(NBD_HAS_CONFIG_REF, &config->runtime_flags);
1863 refcount_inc(&nbd->config_refs);
1864 nbd_connect_reply(info, nbd->index);
1865 }
1866 nbd_config_put(nbd);
1867 if (put_dev)
1868 nbd_put(nbd);
1869 return ret;
1870}
1871
1872static void nbd_disconnect_and_put(struct nbd_device *nbd)
1873{
1874 mutex_lock(&nbd->config_lock);
1875 nbd_disconnect(nbd);
1876 nbd_clear_sock(nbd);
1877 mutex_unlock(&nbd->config_lock);
1878 if (test_and_clear_bit(NBD_HAS_CONFIG_REF,
1879 &nbd->config->runtime_flags))
1880 nbd_config_put(nbd);
1881}
1882
1883static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info)
1884{
1885 struct nbd_device *nbd;
1886 int index;
1887
1888 if (!netlink_capable(skb, CAP_SYS_ADMIN))
1889 return -EPERM;
1890
1891 if (!info->attrs[NBD_ATTR_INDEX]) {
1892 printk(KERN_ERR "nbd: must specify an index to disconnect\n");
1893 return -EINVAL;
1894 }
1895 index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
1896 mutex_lock(&nbd_index_mutex);
1897 nbd = idr_find(&nbd_index_idr, index);
1898 if (!nbd) {
1899 mutex_unlock(&nbd_index_mutex);
1900 printk(KERN_ERR "nbd: couldn't find device at index %d\n",
1901 index);
1902 return -EINVAL;
1903 }
1904 if (!refcount_inc_not_zero(&nbd->refs)) {
1905 mutex_unlock(&nbd_index_mutex);
1906 printk(KERN_ERR "nbd: device at index %d is going down\n",
1907 index);
1908 return -EINVAL;
1909 }
1910 mutex_unlock(&nbd_index_mutex);
1911 if (!refcount_inc_not_zero(&nbd->config_refs)) {
1912 nbd_put(nbd);
1913 return 0;
1914 }
1915 nbd_disconnect_and_put(nbd);
1916 nbd_config_put(nbd);
1917 nbd_put(nbd);
1918 return 0;
1919}
1920
1921static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
1922{
1923 struct nbd_device *nbd = NULL;
1924 struct nbd_config *config;
1925 int index;
1926 int ret = 0;
1927 bool put_dev = false;
1928
1929 if (!netlink_capable(skb, CAP_SYS_ADMIN))
1930 return -EPERM;
1931
1932 if (!info->attrs[NBD_ATTR_INDEX]) {
1933 printk(KERN_ERR "nbd: must specify a device to reconfigure\n");
1934 return -EINVAL;
1935 }
1936 index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
1937 mutex_lock(&nbd_index_mutex);
1938 nbd = idr_find(&nbd_index_idr, index);
1939 if (!nbd) {
1940 mutex_unlock(&nbd_index_mutex);
1941 printk(KERN_ERR "nbd: couldn't find a device at index %d\n",
1942 index);
1943 return -EINVAL;
1944 }
1945 if (!refcount_inc_not_zero(&nbd->refs)) {
1946 mutex_unlock(&nbd_index_mutex);
1947 printk(KERN_ERR "nbd: device at index %d is going down\n",
1948 index);
1949 return -EINVAL;
1950 }
1951 mutex_unlock(&nbd_index_mutex);
1952
1953 if (!refcount_inc_not_zero(&nbd->config_refs)) {
1954 dev_err(nbd_to_dev(nbd),
1955 "not configured, cannot reconfigure\n");
1956 nbd_put(nbd);
1957 return -EINVAL;
1958 }
1959
1960 mutex_lock(&nbd->config_lock);
1961 config = nbd->config;
1962 if (!test_bit(NBD_BOUND, &config->runtime_flags) ||
1963 !nbd->task_recv) {
1964 dev_err(nbd_to_dev(nbd),
1965 "not configured, cannot reconfigure\n");
1966 ret = -EINVAL;
1967 goto out;
1968 }
1969
1970 ret = nbd_genl_size_set(info, nbd);
1971 if (ret)
1972 goto out;
1973
1974 if (info->attrs[NBD_ATTR_TIMEOUT]) {
1975 u64 timeout = nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]);
1976 nbd->tag_set.timeout = timeout * HZ;
1977 blk_queue_rq_timeout(nbd->disk->queue, timeout * HZ);
1978 }
1979 if (info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]) {
1980 config->dead_conn_timeout =
1981 nla_get_u64(info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]);
1982 config->dead_conn_timeout *= HZ;
1983 }
1984 if (info->attrs[NBD_ATTR_CLIENT_FLAGS]) {
1985 u64 flags = nla_get_u64(info->attrs[NBD_ATTR_CLIENT_FLAGS]);
1986 if (flags & NBD_CFLAG_DESTROY_ON_DISCONNECT) {
1987 if (!test_and_set_bit(NBD_DESTROY_ON_DISCONNECT,
1988 &config->runtime_flags))
1989 put_dev = true;
1990 } else {
1991 if (test_and_clear_bit(NBD_DESTROY_ON_DISCONNECT,
1992 &config->runtime_flags))
1993 refcount_inc(&nbd->refs);
1994 }
1995
1996 if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
1997 set_bit(NBD_DISCONNECT_ON_CLOSE,
1998 &config->runtime_flags);
1999 } else {
2000 clear_bit(NBD_DISCONNECT_ON_CLOSE,
2001 &config->runtime_flags);
2002 }
2003 }
2004
2005 if (info->attrs[NBD_ATTR_SOCKETS]) {
2006 struct nlattr *attr;
2007 int rem, fd;
2008
2009 nla_for_each_nested(attr, info->attrs[NBD_ATTR_SOCKETS],
2010 rem) {
2011 struct nlattr *socks[NBD_SOCK_MAX+1];
2012
2013 if (nla_type(attr) != NBD_SOCK_ITEM) {
2014 printk(KERN_ERR "nbd: socks must be embedded in a SOCK_ITEM attr\n");
2015 ret = -EINVAL;
2016 goto out;
2017 }
2018 ret = nla_parse_nested_deprecated(socks, NBD_SOCK_MAX,
2019 attr,
2020 nbd_sock_policy,
2021 info->extack);
2022 if (ret != 0) {
2023 printk(KERN_ERR "nbd: error processing sock list\n");
2024 ret = -EINVAL;
2025 goto out;
2026 }
2027 if (!socks[NBD_SOCK_FD])
2028 continue;
2029 fd = (int)nla_get_u32(socks[NBD_SOCK_FD]);
2030 ret = nbd_reconnect_socket(nbd, fd);
2031 if (ret) {
2032 if (ret == -ENOSPC)
2033 ret = 0;
2034 goto out;
2035 }
2036 dev_info(nbd_to_dev(nbd), "reconnected socket\n");
2037 }
2038 }
2039out:
2040 mutex_unlock(&nbd->config_lock);
2041 nbd_config_put(nbd);
2042 nbd_put(nbd);
2043 if (put_dev)
2044 nbd_put(nbd);
2045 return ret;
2046}
2047
2048static const struct genl_ops nbd_connect_genl_ops[] = {
2049 {
2050 .cmd = NBD_CMD_CONNECT,
2051 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2052 .doit = nbd_genl_connect,
2053 },
2054 {
2055 .cmd = NBD_CMD_DISCONNECT,
2056 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2057 .doit = nbd_genl_disconnect,
2058 },
2059 {
2060 .cmd = NBD_CMD_RECONFIGURE,
2061 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2062 .doit = nbd_genl_reconfigure,
2063 },
2064 {
2065 .cmd = NBD_CMD_STATUS,
2066 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2067 .doit = nbd_genl_status,
2068 },
2069};
2070
2071static const struct genl_multicast_group nbd_mcast_grps[] = {
2072 { .name = NBD_GENL_MCAST_GROUP_NAME, },
2073};
2074
2075static struct genl_family nbd_genl_family __ro_after_init = {
2076 .hdrsize = 0,
2077 .name = NBD_GENL_FAMILY_NAME,
2078 .version = NBD_GENL_VERSION,
2079 .module = THIS_MODULE,
2080 .ops = nbd_connect_genl_ops,
2081 .n_ops = ARRAY_SIZE(nbd_connect_genl_ops),
2082 .maxattr = NBD_ATTR_MAX,
2083 .policy = nbd_attr_policy,
2084 .mcgrps = nbd_mcast_grps,
2085 .n_mcgrps = ARRAY_SIZE(nbd_mcast_grps),
2086};
2087
2088static int populate_nbd_status(struct nbd_device *nbd, struct sk_buff *reply)
2089{
2090 struct nlattr *dev_opt;
2091 u8 connected = 0;
2092 int ret;
2093
2094
2095
2096
2097
2098
2099
2100
2101 if (refcount_read(&nbd->config_refs))
2102 connected = 1;
2103 dev_opt = nla_nest_start_noflag(reply, NBD_DEVICE_ITEM);
2104 if (!dev_opt)
2105 return -EMSGSIZE;
2106 ret = nla_put_u32(reply, NBD_DEVICE_INDEX, nbd->index);
2107 if (ret)
2108 return -EMSGSIZE;
2109 ret = nla_put_u8(reply, NBD_DEVICE_CONNECTED,
2110 connected);
2111 if (ret)
2112 return -EMSGSIZE;
2113 nla_nest_end(reply, dev_opt);
2114 return 0;
2115}
2116
2117static int status_cb(int id, void *ptr, void *data)
2118{
2119 struct nbd_device *nbd = ptr;
2120 return populate_nbd_status(nbd, (struct sk_buff *)data);
2121}
2122
2123static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
2124{
2125 struct nlattr *dev_list;
2126 struct sk_buff *reply;
2127 void *reply_head;
2128 size_t msg_size;
2129 int index = -1;
2130 int ret = -ENOMEM;
2131
2132 if (info->attrs[NBD_ATTR_INDEX])
2133 index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
2134
2135 mutex_lock(&nbd_index_mutex);
2136
2137 msg_size = nla_total_size(nla_attr_size(sizeof(u32)) +
2138 nla_attr_size(sizeof(u8)));
2139 msg_size *= (index == -1) ? nbd_total_devices : 1;
2140
2141 reply = genlmsg_new(msg_size, GFP_KERNEL);
2142 if (!reply)
2143 goto out;
2144 reply_head = genlmsg_put_reply(reply, info, &nbd_genl_family, 0,
2145 NBD_CMD_STATUS);
2146 if (!reply_head) {
2147 nlmsg_free(reply);
2148 goto out;
2149 }
2150
2151 dev_list = nla_nest_start_noflag(reply, NBD_ATTR_DEVICE_LIST);
2152 if (index == -1) {
2153 ret = idr_for_each(&nbd_index_idr, &status_cb, reply);
2154 if (ret) {
2155 nlmsg_free(reply);
2156 goto out;
2157 }
2158 } else {
2159 struct nbd_device *nbd;
2160 nbd = idr_find(&nbd_index_idr, index);
2161 if (nbd) {
2162 ret = populate_nbd_status(nbd, reply);
2163 if (ret) {
2164 nlmsg_free(reply);
2165 goto out;
2166 }
2167 }
2168 }
2169 nla_nest_end(reply, dev_list);
2170 genlmsg_end(reply, reply_head);
2171 ret = genlmsg_reply(reply, info);
2172out:
2173 mutex_unlock(&nbd_index_mutex);
2174 return ret;
2175}
2176
2177static void nbd_connect_reply(struct genl_info *info, int index)
2178{
2179 struct sk_buff *skb;
2180 void *msg_head;
2181 int ret;
2182
2183 skb = genlmsg_new(nla_total_size(sizeof(u32)), GFP_KERNEL);
2184 if (!skb)
2185 return;
2186 msg_head = genlmsg_put_reply(skb, info, &nbd_genl_family, 0,
2187 NBD_CMD_CONNECT);
2188 if (!msg_head) {
2189 nlmsg_free(skb);
2190 return;
2191 }
2192 ret = nla_put_u32(skb, NBD_ATTR_INDEX, index);
2193 if (ret) {
2194 nlmsg_free(skb);
2195 return;
2196 }
2197 genlmsg_end(skb, msg_head);
2198 genlmsg_reply(skb, info);
2199}
2200
2201static void nbd_mcast_index(int index)
2202{
2203 struct sk_buff *skb;
2204 void *msg_head;
2205 int ret;
2206
2207 skb = genlmsg_new(nla_total_size(sizeof(u32)), GFP_KERNEL);
2208 if (!skb)
2209 return;
2210 msg_head = genlmsg_put(skb, 0, 0, &nbd_genl_family, 0,
2211 NBD_CMD_LINK_DEAD);
2212 if (!msg_head) {
2213 nlmsg_free(skb);
2214 return;
2215 }
2216 ret = nla_put_u32(skb, NBD_ATTR_INDEX, index);
2217 if (ret) {
2218 nlmsg_free(skb);
2219 return;
2220 }
2221 genlmsg_end(skb, msg_head);
2222 genlmsg_multicast(&nbd_genl_family, skb, 0, 0, GFP_KERNEL);
2223}
2224
2225static void nbd_dead_link_work(struct work_struct *work)
2226{
2227 struct link_dead_args *args = container_of(work, struct link_dead_args,
2228 work);
2229 nbd_mcast_index(args->index);
2230 kfree(args);
2231}
2232
2233static int __init nbd_init(void)
2234{
2235 int i;
2236
2237 BUILD_BUG_ON(sizeof(struct nbd_request) != 28);
2238
2239 if (max_part < 0) {
2240 printk(KERN_ERR "nbd: max_part must be >= 0\n");
2241 return -EINVAL;
2242 }
2243
2244 part_shift = 0;
2245 if (max_part > 0) {
2246 part_shift = fls(max_part);
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256 max_part = (1UL << part_shift) - 1;
2257 }
2258
2259 if ((1UL << part_shift) > DISK_MAX_PARTS)
2260 return -EINVAL;
2261
2262 if (nbds_max > 1UL << (MINORBITS - part_shift))
2263 return -EINVAL;
2264 recv_workqueue = alloc_workqueue("knbd-recv",
2265 WQ_MEM_RECLAIM | WQ_HIGHPRI |
2266 WQ_UNBOUND, 0);
2267 if (!recv_workqueue)
2268 return -ENOMEM;
2269
2270 if (register_blkdev(NBD_MAJOR, "nbd")) {
2271 destroy_workqueue(recv_workqueue);
2272 return -EIO;
2273 }
2274
2275 if (genl_register_family(&nbd_genl_family)) {
2276 unregister_blkdev(NBD_MAJOR, "nbd");
2277 destroy_workqueue(recv_workqueue);
2278 return -EINVAL;
2279 }
2280 nbd_dbg_init();
2281
2282 mutex_lock(&nbd_index_mutex);
2283 for (i = 0; i < nbds_max; i++)
2284 nbd_dev_add(i);
2285 mutex_unlock(&nbd_index_mutex);
2286 return 0;
2287}
2288
2289static int nbd_exit_cb(int id, void *ptr, void *data)
2290{
2291 struct list_head *list = (struct list_head *)data;
2292 struct nbd_device *nbd = ptr;
2293
2294 list_add_tail(&nbd->list, list);
2295 return 0;
2296}
2297
2298static void __exit nbd_cleanup(void)
2299{
2300 struct nbd_device *nbd;
2301 LIST_HEAD(del_list);
2302
2303 nbd_dbg_close();
2304
2305 mutex_lock(&nbd_index_mutex);
2306 idr_for_each(&nbd_index_idr, &nbd_exit_cb, &del_list);
2307 mutex_unlock(&nbd_index_mutex);
2308
2309 while (!list_empty(&del_list)) {
2310 nbd = list_first_entry(&del_list, struct nbd_device, list);
2311 list_del_init(&nbd->list);
2312 if (refcount_read(&nbd->refs) != 1)
2313 printk(KERN_ERR "nbd: possibly leaking a device\n");
2314 nbd_put(nbd);
2315 }
2316
2317 idr_destroy(&nbd_index_idr);
2318 genl_unregister_family(&nbd_genl_family);
2319 destroy_workqueue(recv_workqueue);
2320 unregister_blkdev(NBD_MAJOR, "nbd");
2321}
2322
2323module_init(nbd_init);
2324module_exit(nbd_cleanup);
2325
2326MODULE_DESCRIPTION("Network Block Device");
2327MODULE_LICENSE("GPL");
2328
2329module_param(nbds_max, int, 0444);
2330MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)");
2331module_param(max_part, int, 0444);
2332MODULE_PARM_DESC(max_part, "number of partitions per device (default: 16)");
2333