This source file includes following definitions.
- nbd_to_dev
- nbd_requeue_cmd
- nbd_cmd_handle
- nbd_handle_to_tag
- nbd_handle_to_cookie
- nbdcmd_to_ascii
- pid_show
- nbd_dev_remove
- nbd_put
- nbd_disconnected
- nbd_mark_nsock_dead
- nbd_size_clear
- nbd_size_update
- nbd_size_set
- nbd_complete_rq
- sock_shutdown
- req_to_nbd_cmd_type
- nbd_xmit_timeout
- sock_xmit
- was_interrupted
- nbd_send_cmd
- nbd_read_stat
- recv_work
- nbd_clear_req
- nbd_clear_que
- find_fallback
- wait_for_reconnect
- nbd_handle_cmd
- nbd_queue_rq
- nbd_get_socket
- nbd_add_socket
- nbd_reconnect_socket
- nbd_bdev_reset
- nbd_parse_flags
- send_disconnects
- nbd_disconnect
- nbd_clear_sock
- nbd_config_put
- nbd_start_device
- nbd_start_device_ioctl
- nbd_clear_sock_ioctl
- nbd_is_valid_blksize
- nbd_set_cmd_timeout
- __nbd_ioctl
- nbd_ioctl
- nbd_alloc_config
- nbd_open
- nbd_release
- nbd_dbg_tasks_show
- nbd_dbg_tasks_open
- nbd_dbg_flags_show
- nbd_dbg_flags_open
- nbd_dev_dbg_init
- nbd_dev_dbg_close
- nbd_dbg_init
- nbd_dbg_close
- nbd_dev_dbg_init
- nbd_dev_dbg_close
- nbd_dbg_init
- nbd_dbg_close
- nbd_init_request
- nbd_dev_add
- find_free_cb
- nbd_genl_size_set
- nbd_genl_connect
- nbd_disconnect_and_put
- nbd_genl_disconnect
- nbd_genl_reconfigure
- populate_nbd_status
- status_cb
- nbd_genl_status
- nbd_connect_reply
- nbd_mcast_index
- nbd_dead_link_work
- nbd_init
- nbd_exit_cb
- nbd_cleanup
1
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13
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/completion.h>
30 #include <linux/err.h>
31 #include <linux/kernel.h>
32 #include <linux/slab.h>
33 #include <net/sock.h>
34 #include <linux/net.h>
35 #include <linux/kthread.h>
36 #include <linux/types.h>
37 #include <linux/debugfs.h>
38 #include <linux/blk-mq.h>
39
40 #include <linux/uaccess.h>
41 #include <asm/types.h>
42
43 #include <linux/nbd.h>
44 #include <linux/nbd-netlink.h>
45 #include <net/genetlink.h>
46
47 #define CREATE_TRACE_POINTS
48 #include <trace/events/nbd.h>
49
50 static DEFINE_IDR(nbd_index_idr);
51 static DEFINE_MUTEX(nbd_index_mutex);
52 static int nbd_total_devices = 0;
53
54 struct nbd_sock {
55 struct socket *sock;
56 struct mutex tx_lock;
57 struct request *pending;
58 int sent;
59 bool dead;
60 int fallback_index;
61 int cookie;
62 };
63
64 struct recv_thread_args {
65 struct work_struct work;
66 struct nbd_device *nbd;
67 int index;
68 };
69
70 struct link_dead_args {
71 struct work_struct work;
72 int index;
73 };
74
75 #define NBD_RT_TIMEDOUT 0
76 #define NBD_RT_DISCONNECT_REQUESTED 1
77 #define NBD_RT_DISCONNECTED 2
78 #define NBD_RT_HAS_PID_FILE 3
79 #define NBD_RT_HAS_CONFIG_REF 4
80 #define NBD_RT_BOUND 5
81 #define NBD_RT_DESTROY_ON_DISCONNECT 6
82 #define NBD_RT_DISCONNECT_ON_CLOSE 7
83
84 #define NBD_DESTROY_ON_DISCONNECT 0
85 #define NBD_DISCONNECT_REQUESTED 1
86
87 struct nbd_config {
88 u32 flags;
89 unsigned long runtime_flags;
90 u64 dead_conn_timeout;
91
92 struct nbd_sock **socks;
93 int num_connections;
94 atomic_t live_connections;
95 wait_queue_head_t conn_wait;
96
97 atomic_t recv_threads;
98 wait_queue_head_t recv_wq;
99 loff_t blksize;
100 loff_t bytesize;
101 #if IS_ENABLED(CONFIG_DEBUG_FS)
102 struct dentry *dbg_dir;
103 #endif
104 };
105
106 struct nbd_device {
107 struct blk_mq_tag_set tag_set;
108
109 int index;
110 refcount_t config_refs;
111 refcount_t refs;
112 struct nbd_config *config;
113 struct mutex config_lock;
114 struct gendisk *disk;
115 struct workqueue_struct *recv_workq;
116
117 struct list_head list;
118 struct task_struct *task_recv;
119 struct task_struct *task_setup;
120
121 struct completion *destroy_complete;
122 unsigned long flags;
123 };
124
125 #define NBD_CMD_REQUEUED 1
126
127 struct nbd_cmd {
128 struct nbd_device *nbd;
129 struct mutex lock;
130 int index;
131 int cookie;
132 int retries;
133 blk_status_t status;
134 unsigned long flags;
135 u32 cmd_cookie;
136 };
137
138 #if IS_ENABLED(CONFIG_DEBUG_FS)
139 static struct dentry *nbd_dbg_dir;
140 #endif
141
142 #define nbd_name(nbd) ((nbd)->disk->disk_name)
143
144 #define NBD_MAGIC 0x68797548
145
146 #define NBD_DEF_BLKSIZE 1024
147
148 static unsigned int nbds_max = 16;
149 static int max_part = 16;
150 static int part_shift;
151
152 static int nbd_dev_dbg_init(struct nbd_device *nbd);
153 static void nbd_dev_dbg_close(struct nbd_device *nbd);
154 static void nbd_config_put(struct nbd_device *nbd);
155 static void nbd_connect_reply(struct genl_info *info, int index);
156 static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info);
157 static void nbd_dead_link_work(struct work_struct *work);
158 static void nbd_disconnect_and_put(struct nbd_device *nbd);
159
160 static inline struct device *nbd_to_dev(struct nbd_device *nbd)
161 {
162 return disk_to_dev(nbd->disk);
163 }
164
165 static void nbd_requeue_cmd(struct nbd_cmd *cmd)
166 {
167 struct request *req = blk_mq_rq_from_pdu(cmd);
168
169 if (!test_and_set_bit(NBD_CMD_REQUEUED, &cmd->flags))
170 blk_mq_requeue_request(req, true);
171 }
172
173 #define NBD_COOKIE_BITS 32
174
175 static u64 nbd_cmd_handle(struct nbd_cmd *cmd)
176 {
177 struct request *req = blk_mq_rq_from_pdu(cmd);
178 u32 tag = blk_mq_unique_tag(req);
179 u64 cookie = cmd->cmd_cookie;
180
181 return (cookie << NBD_COOKIE_BITS) | tag;
182 }
183
184 static u32 nbd_handle_to_tag(u64 handle)
185 {
186 return (u32)handle;
187 }
188
189 static u32 nbd_handle_to_cookie(u64 handle)
190 {
191 return (u32)(handle >> NBD_COOKIE_BITS);
192 }
193
194 static const char *nbdcmd_to_ascii(int cmd)
195 {
196 switch (cmd) {
197 case NBD_CMD_READ: return "read";
198 case NBD_CMD_WRITE: return "write";
199 case NBD_CMD_DISC: return "disconnect";
200 case NBD_CMD_FLUSH: return "flush";
201 case NBD_CMD_TRIM: return "trim/discard";
202 }
203 return "invalid";
204 }
205
206 static ssize_t pid_show(struct device *dev,
207 struct device_attribute *attr, char *buf)
208 {
209 struct gendisk *disk = dev_to_disk(dev);
210 struct nbd_device *nbd = (struct nbd_device *)disk->private_data;
211
212 return sprintf(buf, "%d\n", task_pid_nr(nbd->task_recv));
213 }
214
215 static const struct device_attribute pid_attr = {
216 .attr = { .name = "pid", .mode = 0444},
217 .show = pid_show,
218 };
219
220 static void nbd_dev_remove(struct nbd_device *nbd)
221 {
222 struct gendisk *disk = nbd->disk;
223 struct request_queue *q;
224
225 if (disk) {
226 q = disk->queue;
227 del_gendisk(disk);
228 blk_cleanup_queue(q);
229 blk_mq_free_tag_set(&nbd->tag_set);
230 disk->private_data = NULL;
231 put_disk(disk);
232 }
233
234
235
236
237
238
239
240 if (test_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags) && nbd->destroy_complete)
241 complete(nbd->destroy_complete);
242
243 kfree(nbd);
244 }
245
246 static void nbd_put(struct nbd_device *nbd)
247 {
248 if (refcount_dec_and_mutex_lock(&nbd->refs,
249 &nbd_index_mutex)) {
250 idr_remove(&nbd_index_idr, nbd->index);
251 nbd_dev_remove(nbd);
252 mutex_unlock(&nbd_index_mutex);
253 }
254 }
255
256 static int nbd_disconnected(struct nbd_config *config)
257 {
258 return test_bit(NBD_RT_DISCONNECTED, &config->runtime_flags) ||
259 test_bit(NBD_RT_DISCONNECT_REQUESTED, &config->runtime_flags);
260 }
261
262 static void nbd_mark_nsock_dead(struct nbd_device *nbd, struct nbd_sock *nsock,
263 int notify)
264 {
265 if (!nsock->dead && notify && !nbd_disconnected(nbd->config)) {
266 struct link_dead_args *args;
267 args = kmalloc(sizeof(struct link_dead_args), GFP_NOIO);
268 if (args) {
269 INIT_WORK(&args->work, nbd_dead_link_work);
270 args->index = nbd->index;
271 queue_work(system_wq, &args->work);
272 }
273 }
274 if (!nsock->dead) {
275 kernel_sock_shutdown(nsock->sock, SHUT_RDWR);
276 if (atomic_dec_return(&nbd->config->live_connections) == 0) {
277 if (test_and_clear_bit(NBD_RT_DISCONNECT_REQUESTED,
278 &nbd->config->runtime_flags)) {
279 set_bit(NBD_RT_DISCONNECTED,
280 &nbd->config->runtime_flags);
281 dev_info(nbd_to_dev(nbd),
282 "Disconnected due to user request.\n");
283 }
284 }
285 }
286 nsock->dead = true;
287 nsock->pending = NULL;
288 nsock->sent = 0;
289 }
290
291 static void nbd_size_clear(struct nbd_device *nbd)
292 {
293 if (nbd->config->bytesize) {
294 set_capacity(nbd->disk, 0);
295 kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
296 }
297 }
298
299 static void nbd_size_update(struct nbd_device *nbd)
300 {
301 struct nbd_config *config = nbd->config;
302 struct block_device *bdev = bdget_disk(nbd->disk, 0);
303
304 if (config->flags & NBD_FLAG_SEND_TRIM) {
305 nbd->disk->queue->limits.discard_granularity = config->blksize;
306 nbd->disk->queue->limits.discard_alignment = config->blksize;
307 blk_queue_max_discard_sectors(nbd->disk->queue, UINT_MAX);
308 }
309 blk_queue_logical_block_size(nbd->disk->queue, config->blksize);
310 blk_queue_physical_block_size(nbd->disk->queue, config->blksize);
311 set_capacity(nbd->disk, config->bytesize >> 9);
312 if (bdev) {
313 if (bdev->bd_disk) {
314 bd_set_size(bdev, config->bytesize);
315 set_blocksize(bdev, config->blksize);
316 } else
317 bdev->bd_invalidated = 1;
318 bdput(bdev);
319 }
320 kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE);
321 }
322
323 static void nbd_size_set(struct nbd_device *nbd, loff_t blocksize,
324 loff_t nr_blocks)
325 {
326 struct nbd_config *config = nbd->config;
327 config->blksize = blocksize;
328 config->bytesize = blocksize * nr_blocks;
329 if (nbd->task_recv != NULL)
330 nbd_size_update(nbd);
331 }
332
333 static void nbd_complete_rq(struct request *req)
334 {
335 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
336
337 dev_dbg(nbd_to_dev(cmd->nbd), "request %p: %s\n", req,
338 cmd->status ? "failed" : "done");
339
340 blk_mq_end_request(req, cmd->status);
341 }
342
343
344
345
346 static void sock_shutdown(struct nbd_device *nbd)
347 {
348 struct nbd_config *config = nbd->config;
349 int i;
350
351 if (config->num_connections == 0)
352 return;
353 if (test_and_set_bit(NBD_RT_DISCONNECTED, &config->runtime_flags))
354 return;
355
356 for (i = 0; i < config->num_connections; i++) {
357 struct nbd_sock *nsock = config->socks[i];
358 mutex_lock(&nsock->tx_lock);
359 nbd_mark_nsock_dead(nbd, nsock, 0);
360 mutex_unlock(&nsock->tx_lock);
361 }
362 dev_warn(disk_to_dev(nbd->disk), "shutting down sockets\n");
363 }
364
365 static u32 req_to_nbd_cmd_type(struct request *req)
366 {
367 switch (req_op(req)) {
368 case REQ_OP_DISCARD:
369 return NBD_CMD_TRIM;
370 case REQ_OP_FLUSH:
371 return NBD_CMD_FLUSH;
372 case REQ_OP_WRITE:
373 return NBD_CMD_WRITE;
374 case REQ_OP_READ:
375 return NBD_CMD_READ;
376 default:
377 return U32_MAX;
378 }
379 }
380
381 static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
382 bool reserved)
383 {
384 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
385 struct nbd_device *nbd = cmd->nbd;
386 struct nbd_config *config;
387
388 if (!mutex_trylock(&cmd->lock))
389 return BLK_EH_RESET_TIMER;
390
391 if (!refcount_inc_not_zero(&nbd->config_refs)) {
392 cmd->status = BLK_STS_TIMEOUT;
393 mutex_unlock(&cmd->lock);
394 goto done;
395 }
396 config = nbd->config;
397
398 if (config->num_connections > 1) {
399 dev_err_ratelimited(nbd_to_dev(nbd),
400 "Connection timed out, retrying (%d/%d alive)\n",
401 atomic_read(&config->live_connections),
402 config->num_connections);
403
404
405
406
407 if (config->socks && config->num_connections > 1) {
408 if (cmd->index < config->num_connections) {
409 struct nbd_sock *nsock =
410 config->socks[cmd->index];
411 mutex_lock(&nsock->tx_lock);
412
413
414
415
416
417
418 if (cmd->cookie == nsock->cookie)
419 nbd_mark_nsock_dead(nbd, nsock, 1);
420 mutex_unlock(&nsock->tx_lock);
421 }
422 mutex_unlock(&cmd->lock);
423 nbd_requeue_cmd(cmd);
424 nbd_config_put(nbd);
425 return BLK_EH_DONE;
426 }
427 }
428
429 if (!nbd->tag_set.timeout) {
430
431
432
433
434 cmd->retries++;
435 dev_info(nbd_to_dev(nbd), "Possible stuck request %p: control (%s@%llu,%uB). Runtime %u seconds\n",
436 req, nbdcmd_to_ascii(req_to_nbd_cmd_type(req)),
437 (unsigned long long)blk_rq_pos(req) << 9,
438 blk_rq_bytes(req), (req->timeout / HZ) * cmd->retries);
439
440 mutex_unlock(&cmd->lock);
441 nbd_config_put(nbd);
442 return BLK_EH_RESET_TIMER;
443 }
444
445 dev_err_ratelimited(nbd_to_dev(nbd), "Connection timed out\n");
446 set_bit(NBD_RT_TIMEDOUT, &config->runtime_flags);
447 cmd->status = BLK_STS_IOERR;
448 mutex_unlock(&cmd->lock);
449 sock_shutdown(nbd);
450 nbd_config_put(nbd);
451 done:
452 blk_mq_complete_request(req);
453 return BLK_EH_DONE;
454 }
455
456
457
458
459 static int sock_xmit(struct nbd_device *nbd, int index, int send,
460 struct iov_iter *iter, int msg_flags, int *sent)
461 {
462 struct nbd_config *config = nbd->config;
463 struct socket *sock = config->socks[index]->sock;
464 int result;
465 struct msghdr msg;
466 unsigned int noreclaim_flag;
467
468 if (unlikely(!sock)) {
469 dev_err_ratelimited(disk_to_dev(nbd->disk),
470 "Attempted %s on closed socket in sock_xmit\n",
471 (send ? "send" : "recv"));
472 return -EINVAL;
473 }
474
475 msg.msg_iter = *iter;
476
477 noreclaim_flag = memalloc_noreclaim_save();
478 do {
479 sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC;
480 msg.msg_name = NULL;
481 msg.msg_namelen = 0;
482 msg.msg_control = NULL;
483 msg.msg_controllen = 0;
484 msg.msg_flags = msg_flags | MSG_NOSIGNAL;
485
486 if (send)
487 result = sock_sendmsg(sock, &msg);
488 else
489 result = sock_recvmsg(sock, &msg, msg.msg_flags);
490
491 if (result <= 0) {
492 if (result == 0)
493 result = -EPIPE;
494 break;
495 }
496 if (sent)
497 *sent += result;
498 } while (msg_data_left(&msg));
499
500 memalloc_noreclaim_restore(noreclaim_flag);
501
502 return result;
503 }
504
505
506
507
508
509 static inline int was_interrupted(int result)
510 {
511 return result == -ERESTARTSYS || result == -EINTR;
512 }
513
514
515 static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
516 {
517 struct request *req = blk_mq_rq_from_pdu(cmd);
518 struct nbd_config *config = nbd->config;
519 struct nbd_sock *nsock = config->socks[index];
520 int result;
521 struct nbd_request request = {.magic = htonl(NBD_REQUEST_MAGIC)};
522 struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)};
523 struct iov_iter from;
524 unsigned long size = blk_rq_bytes(req);
525 struct bio *bio;
526 u64 handle;
527 u32 type;
528 u32 nbd_cmd_flags = 0;
529 int sent = nsock->sent, skip = 0;
530
531 iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
532
533 type = req_to_nbd_cmd_type(req);
534 if (type == U32_MAX)
535 return -EIO;
536
537 if (rq_data_dir(req) == WRITE &&
538 (config->flags & NBD_FLAG_READ_ONLY)) {
539 dev_err_ratelimited(disk_to_dev(nbd->disk),
540 "Write on read-only\n");
541 return -EIO;
542 }
543
544 if (req->cmd_flags & REQ_FUA)
545 nbd_cmd_flags |= NBD_CMD_FLAG_FUA;
546
547
548
549
550
551 if (sent) {
552 if (sent >= sizeof(request)) {
553 skip = sent - sizeof(request);
554
555
556 handle = nbd_cmd_handle(cmd);
557
558 goto send_pages;
559 }
560 iov_iter_advance(&from, sent);
561 } else {
562 cmd->cmd_cookie++;
563 }
564 cmd->index = index;
565 cmd->cookie = nsock->cookie;
566 cmd->retries = 0;
567 request.type = htonl(type | nbd_cmd_flags);
568 if (type != NBD_CMD_FLUSH) {
569 request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);
570 request.len = htonl(size);
571 }
572 handle = nbd_cmd_handle(cmd);
573 memcpy(request.handle, &handle, sizeof(handle));
574
575 trace_nbd_send_request(&request, nbd->index, blk_mq_rq_from_pdu(cmd));
576
577 dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n",
578 req, nbdcmd_to_ascii(type),
579 (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req));
580 result = sock_xmit(nbd, index, 1, &from,
581 (type == NBD_CMD_WRITE) ? MSG_MORE : 0, &sent);
582 trace_nbd_header_sent(req, handle);
583 if (result <= 0) {
584 if (was_interrupted(result)) {
585
586
587
588
589
590 if (sent) {
591 nsock->pending = req;
592 nsock->sent = sent;
593 }
594 set_bit(NBD_CMD_REQUEUED, &cmd->flags);
595 return BLK_STS_RESOURCE;
596 }
597 dev_err_ratelimited(disk_to_dev(nbd->disk),
598 "Send control failed (result %d)\n", result);
599 return -EAGAIN;
600 }
601 send_pages:
602 if (type != NBD_CMD_WRITE)
603 goto out;
604
605 bio = req->bio;
606 while (bio) {
607 struct bio *next = bio->bi_next;
608 struct bvec_iter iter;
609 struct bio_vec bvec;
610
611 bio_for_each_segment(bvec, bio, iter) {
612 bool is_last = !next && bio_iter_last(bvec, iter);
613 int flags = is_last ? 0 : MSG_MORE;
614
615 dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n",
616 req, bvec.bv_len);
617 iov_iter_bvec(&from, WRITE, &bvec, 1, bvec.bv_len);
618 if (skip) {
619 if (skip >= iov_iter_count(&from)) {
620 skip -= iov_iter_count(&from);
621 continue;
622 }
623 iov_iter_advance(&from, skip);
624 skip = 0;
625 }
626 result = sock_xmit(nbd, index, 1, &from, flags, &sent);
627 if (result <= 0) {
628 if (was_interrupted(result)) {
629
630
631
632
633 nsock->pending = req;
634 nsock->sent = sent;
635 set_bit(NBD_CMD_REQUEUED, &cmd->flags);
636 return BLK_STS_RESOURCE;
637 }
638 dev_err(disk_to_dev(nbd->disk),
639 "Send data failed (result %d)\n",
640 result);
641 return -EAGAIN;
642 }
643
644
645
646
647
648
649 if (is_last)
650 break;
651 }
652 bio = next;
653 }
654 out:
655 trace_nbd_payload_sent(req, handle);
656 nsock->pending = NULL;
657 nsock->sent = 0;
658 return 0;
659 }
660
661
662 static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
663 {
664 struct nbd_config *config = nbd->config;
665 int result;
666 struct nbd_reply reply;
667 struct nbd_cmd *cmd;
668 struct request *req = NULL;
669 u64 handle;
670 u16 hwq;
671 u32 tag;
672 struct kvec iov = {.iov_base = &reply, .iov_len = sizeof(reply)};
673 struct iov_iter to;
674 int ret = 0;
675
676 reply.magic = 0;
677 iov_iter_kvec(&to, READ, &iov, 1, sizeof(reply));
678 result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
679 if (result <= 0) {
680 if (!nbd_disconnected(config))
681 dev_err(disk_to_dev(nbd->disk),
682 "Receive control failed (result %d)\n", result);
683 return ERR_PTR(result);
684 }
685
686 if (ntohl(reply.magic) != NBD_REPLY_MAGIC) {
687 dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n",
688 (unsigned long)ntohl(reply.magic));
689 return ERR_PTR(-EPROTO);
690 }
691
692 memcpy(&handle, reply.handle, sizeof(handle));
693 tag = nbd_handle_to_tag(handle);
694 hwq = blk_mq_unique_tag_to_hwq(tag);
695 if (hwq < nbd->tag_set.nr_hw_queues)
696 req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq],
697 blk_mq_unique_tag_to_tag(tag));
698 if (!req || !blk_mq_request_started(req)) {
699 dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n",
700 tag, req);
701 return ERR_PTR(-ENOENT);
702 }
703 trace_nbd_header_received(req, handle);
704 cmd = blk_mq_rq_to_pdu(req);
705
706 mutex_lock(&cmd->lock);
707 if (cmd->cmd_cookie != nbd_handle_to_cookie(handle)) {
708 dev_err(disk_to_dev(nbd->disk), "Double reply on req %p, cmd_cookie %u, handle cookie %u\n",
709 req, cmd->cmd_cookie, nbd_handle_to_cookie(handle));
710 ret = -ENOENT;
711 goto out;
712 }
713 if (cmd->status != BLK_STS_OK) {
714 dev_err(disk_to_dev(nbd->disk), "Command already handled %p\n",
715 req);
716 ret = -ENOENT;
717 goto out;
718 }
719 if (test_bit(NBD_CMD_REQUEUED, &cmd->flags)) {
720 dev_err(disk_to_dev(nbd->disk), "Raced with timeout on req %p\n",
721 req);
722 ret = -ENOENT;
723 goto out;
724 }
725 if (ntohl(reply.error)) {
726 dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n",
727 ntohl(reply.error));
728 cmd->status = BLK_STS_IOERR;
729 goto out;
730 }
731
732 dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", req);
733 if (rq_data_dir(req) != WRITE) {
734 struct req_iterator iter;
735 struct bio_vec bvec;
736
737 rq_for_each_segment(bvec, req, iter) {
738 iov_iter_bvec(&to, READ, &bvec, 1, bvec.bv_len);
739 result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
740 if (result <= 0) {
741 dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n",
742 result);
743
744
745
746
747
748
749
750 if (nbd_disconnected(config) ||
751 config->num_connections <= 1) {
752 cmd->status = BLK_STS_IOERR;
753 goto out;
754 }
755 ret = -EIO;
756 goto out;
757 }
758 dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n",
759 req, bvec.bv_len);
760 }
761 }
762 out:
763 trace_nbd_payload_received(req, handle);
764 mutex_unlock(&cmd->lock);
765 return ret ? ERR_PTR(ret) : cmd;
766 }
767
768 static void recv_work(struct work_struct *work)
769 {
770 struct recv_thread_args *args = container_of(work,
771 struct recv_thread_args,
772 work);
773 struct nbd_device *nbd = args->nbd;
774 struct nbd_config *config = nbd->config;
775 struct nbd_cmd *cmd;
776
777 while (1) {
778 cmd = nbd_read_stat(nbd, args->index);
779 if (IS_ERR(cmd)) {
780 struct nbd_sock *nsock = config->socks[args->index];
781
782 mutex_lock(&nsock->tx_lock);
783 nbd_mark_nsock_dead(nbd, nsock, 1);
784 mutex_unlock(&nsock->tx_lock);
785 break;
786 }
787
788 blk_mq_complete_request(blk_mq_rq_from_pdu(cmd));
789 }
790 atomic_dec(&config->recv_threads);
791 wake_up(&config->recv_wq);
792 nbd_config_put(nbd);
793 kfree(args);
794 }
795
796 static bool nbd_clear_req(struct request *req, void *data, bool reserved)
797 {
798 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
799
800 mutex_lock(&cmd->lock);
801 cmd->status = BLK_STS_IOERR;
802 mutex_unlock(&cmd->lock);
803
804 blk_mq_complete_request(req);
805 return true;
806 }
807
808 static void nbd_clear_que(struct nbd_device *nbd)
809 {
810 blk_mq_quiesce_queue(nbd->disk->queue);
811 blk_mq_tagset_busy_iter(&nbd->tag_set, nbd_clear_req, NULL);
812 blk_mq_unquiesce_queue(nbd->disk->queue);
813 dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n");
814 }
815
816 static int find_fallback(struct nbd_device *nbd, int index)
817 {
818 struct nbd_config *config = nbd->config;
819 int new_index = -1;
820 struct nbd_sock *nsock = config->socks[index];
821 int fallback = nsock->fallback_index;
822
823 if (test_bit(NBD_RT_DISCONNECTED, &config->runtime_flags))
824 return new_index;
825
826 if (config->num_connections <= 1) {
827 dev_err_ratelimited(disk_to_dev(nbd->disk),
828 "Attempted send on invalid socket\n");
829 return new_index;
830 }
831
832 if (fallback >= 0 && fallback < config->num_connections &&
833 !config->socks[fallback]->dead)
834 return fallback;
835
836 if (nsock->fallback_index < 0 ||
837 nsock->fallback_index >= config->num_connections ||
838 config->socks[nsock->fallback_index]->dead) {
839 int i;
840 for (i = 0; i < config->num_connections; i++) {
841 if (i == index)
842 continue;
843 if (!config->socks[i]->dead) {
844 new_index = i;
845 break;
846 }
847 }
848 nsock->fallback_index = new_index;
849 if (new_index < 0) {
850 dev_err_ratelimited(disk_to_dev(nbd->disk),
851 "Dead connection, failed to find a fallback\n");
852 return new_index;
853 }
854 }
855 new_index = nsock->fallback_index;
856 return new_index;
857 }
858
859 static int wait_for_reconnect(struct nbd_device *nbd)
860 {
861 struct nbd_config *config = nbd->config;
862 if (!config->dead_conn_timeout)
863 return 0;
864 if (test_bit(NBD_RT_DISCONNECTED, &config->runtime_flags))
865 return 0;
866 return wait_event_timeout(config->conn_wait,
867 atomic_read(&config->live_connections) > 0,
868 config->dead_conn_timeout) > 0;
869 }
870
871 static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
872 {
873 struct request *req = blk_mq_rq_from_pdu(cmd);
874 struct nbd_device *nbd = cmd->nbd;
875 struct nbd_config *config;
876 struct nbd_sock *nsock;
877 int ret;
878
879 if (!refcount_inc_not_zero(&nbd->config_refs)) {
880 dev_err_ratelimited(disk_to_dev(nbd->disk),
881 "Socks array is empty\n");
882 blk_mq_start_request(req);
883 return -EINVAL;
884 }
885 config = nbd->config;
886
887 if (index >= config->num_connections) {
888 dev_err_ratelimited(disk_to_dev(nbd->disk),
889 "Attempted send on invalid socket\n");
890 nbd_config_put(nbd);
891 blk_mq_start_request(req);
892 return -EINVAL;
893 }
894 cmd->status = BLK_STS_OK;
895 again:
896 nsock = config->socks[index];
897 mutex_lock(&nsock->tx_lock);
898 if (nsock->dead) {
899 int old_index = index;
900 index = find_fallback(nbd, index);
901 mutex_unlock(&nsock->tx_lock);
902 if (index < 0) {
903 if (wait_for_reconnect(nbd)) {
904 index = old_index;
905 goto again;
906 }
907
908
909
910
911
912
913 sock_shutdown(nbd);
914 nbd_config_put(nbd);
915 blk_mq_start_request(req);
916 return -EIO;
917 }
918 goto again;
919 }
920
921
922
923
924
925
926 blk_mq_start_request(req);
927 if (unlikely(nsock->pending && nsock->pending != req)) {
928 nbd_requeue_cmd(cmd);
929 ret = 0;
930 goto out;
931 }
932
933
934
935
936 ret = nbd_send_cmd(nbd, cmd, index);
937 if (ret == -EAGAIN) {
938 dev_err_ratelimited(disk_to_dev(nbd->disk),
939 "Request send failed, requeueing\n");
940 nbd_mark_nsock_dead(nbd, nsock, 1);
941 nbd_requeue_cmd(cmd);
942 ret = 0;
943 }
944 out:
945 mutex_unlock(&nsock->tx_lock);
946 nbd_config_put(nbd);
947 return ret;
948 }
949
950 static blk_status_t nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
951 const struct blk_mq_queue_data *bd)
952 {
953 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
954 int ret;
955
956
957
958
959
960
961
962
963
964
965 mutex_lock(&cmd->lock);
966 clear_bit(NBD_CMD_REQUEUED, &cmd->flags);
967
968
969
970
971
972
973 ret = nbd_handle_cmd(cmd, hctx->queue_num);
974 if (ret < 0)
975 ret = BLK_STS_IOERR;
976 else if (!ret)
977 ret = BLK_STS_OK;
978 mutex_unlock(&cmd->lock);
979
980 return ret;
981 }
982
983 static struct socket *nbd_get_socket(struct nbd_device *nbd, unsigned long fd,
984 int *err)
985 {
986 struct socket *sock;
987
988 *err = 0;
989 sock = sockfd_lookup(fd, err);
990 if (!sock)
991 return NULL;
992
993 if (sock->ops->shutdown == sock_no_shutdown) {
994 dev_err(disk_to_dev(nbd->disk), "Unsupported socket: shutdown callout must be supported.\n");
995 *err = -EINVAL;
996 sockfd_put(sock);
997 return NULL;
998 }
999
1000 return sock;
1001 }
1002
1003 static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
1004 bool netlink)
1005 {
1006 struct nbd_config *config = nbd->config;
1007 struct socket *sock;
1008 struct nbd_sock **socks;
1009 struct nbd_sock *nsock;
1010 int err;
1011
1012 sock = nbd_get_socket(nbd, arg, &err);
1013 if (!sock)
1014 return err;
1015
1016 if (!netlink && !nbd->task_setup &&
1017 !test_bit(NBD_RT_BOUND, &config->runtime_flags))
1018 nbd->task_setup = current;
1019
1020 if (!netlink &&
1021 (nbd->task_setup != current ||
1022 test_bit(NBD_RT_BOUND, &config->runtime_flags))) {
1023 dev_err(disk_to_dev(nbd->disk),
1024 "Device being setup by another task");
1025 sockfd_put(sock);
1026 return -EBUSY;
1027 }
1028
1029 socks = krealloc(config->socks, (config->num_connections + 1) *
1030 sizeof(struct nbd_sock *), GFP_KERNEL);
1031 if (!socks) {
1032 sockfd_put(sock);
1033 return -ENOMEM;
1034 }
1035
1036 config->socks = socks;
1037
1038 nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL);
1039 if (!nsock) {
1040 sockfd_put(sock);
1041 return -ENOMEM;
1042 }
1043
1044 nsock->fallback_index = -1;
1045 nsock->dead = false;
1046 mutex_init(&nsock->tx_lock);
1047 nsock->sock = sock;
1048 nsock->pending = NULL;
1049 nsock->sent = 0;
1050 nsock->cookie = 0;
1051 socks[config->num_connections++] = nsock;
1052 atomic_inc(&config->live_connections);
1053
1054 return 0;
1055 }
1056
1057 static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg)
1058 {
1059 struct nbd_config *config = nbd->config;
1060 struct socket *sock, *old;
1061 struct recv_thread_args *args;
1062 int i;
1063 int err;
1064
1065 sock = nbd_get_socket(nbd, arg, &err);
1066 if (!sock)
1067 return err;
1068
1069 args = kzalloc(sizeof(*args), GFP_KERNEL);
1070 if (!args) {
1071 sockfd_put(sock);
1072 return -ENOMEM;
1073 }
1074
1075 for (i = 0; i < config->num_connections; i++) {
1076 struct nbd_sock *nsock = config->socks[i];
1077
1078 if (!nsock->dead)
1079 continue;
1080
1081 mutex_lock(&nsock->tx_lock);
1082 if (!nsock->dead) {
1083 mutex_unlock(&nsock->tx_lock);
1084 continue;
1085 }
1086 sk_set_memalloc(sock->sk);
1087 if (nbd->tag_set.timeout)
1088 sock->sk->sk_sndtimeo = nbd->tag_set.timeout;
1089 atomic_inc(&config->recv_threads);
1090 refcount_inc(&nbd->config_refs);
1091 old = nsock->sock;
1092 nsock->fallback_index = -1;
1093 nsock->sock = sock;
1094 nsock->dead = false;
1095 INIT_WORK(&args->work, recv_work);
1096 args->index = i;
1097 args->nbd = nbd;
1098 nsock->cookie++;
1099 mutex_unlock(&nsock->tx_lock);
1100 sockfd_put(old);
1101
1102 clear_bit(NBD_RT_DISCONNECTED, &config->runtime_flags);
1103
1104
1105
1106
1107 queue_work(nbd->recv_workq, &args->work);
1108
1109 atomic_inc(&config->live_connections);
1110 wake_up(&config->conn_wait);
1111 return 0;
1112 }
1113 sockfd_put(sock);
1114 kfree(args);
1115 return -ENOSPC;
1116 }
1117
1118 static void nbd_bdev_reset(struct block_device *bdev)
1119 {
1120 if (bdev->bd_openers > 1)
1121 return;
1122 bd_set_size(bdev, 0);
1123 }
1124
1125 static void nbd_parse_flags(struct nbd_device *nbd)
1126 {
1127 struct nbd_config *config = nbd->config;
1128 if (config->flags & NBD_FLAG_READ_ONLY)
1129 set_disk_ro(nbd->disk, true);
1130 else
1131 set_disk_ro(nbd->disk, false);
1132 if (config->flags & NBD_FLAG_SEND_TRIM)
1133 blk_queue_flag_set(QUEUE_FLAG_DISCARD, nbd->disk->queue);
1134 if (config->flags & NBD_FLAG_SEND_FLUSH) {
1135 if (config->flags & NBD_FLAG_SEND_FUA)
1136 blk_queue_write_cache(nbd->disk->queue, true, true);
1137 else
1138 blk_queue_write_cache(nbd->disk->queue, true, false);
1139 }
1140 else
1141 blk_queue_write_cache(nbd->disk->queue, false, false);
1142 }
1143
1144 static void send_disconnects(struct nbd_device *nbd)
1145 {
1146 struct nbd_config *config = nbd->config;
1147 struct nbd_request request = {
1148 .magic = htonl(NBD_REQUEST_MAGIC),
1149 .type = htonl(NBD_CMD_DISC),
1150 };
1151 struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)};
1152 struct iov_iter from;
1153 int i, ret;
1154
1155 for (i = 0; i < config->num_connections; i++) {
1156 struct nbd_sock *nsock = config->socks[i];
1157
1158 iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
1159 mutex_lock(&nsock->tx_lock);
1160 ret = sock_xmit(nbd, i, 1, &from, 0, NULL);
1161 if (ret <= 0)
1162 dev_err(disk_to_dev(nbd->disk),
1163 "Send disconnect failed %d\n", ret);
1164 mutex_unlock(&nsock->tx_lock);
1165 }
1166 }
1167
1168 static int nbd_disconnect(struct nbd_device *nbd)
1169 {
1170 struct nbd_config *config = nbd->config;
1171
1172 dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n");
1173 set_bit(NBD_RT_DISCONNECT_REQUESTED, &config->runtime_flags);
1174 set_bit(NBD_DISCONNECT_REQUESTED, &nbd->flags);
1175 send_disconnects(nbd);
1176 return 0;
1177 }
1178
1179 static void nbd_clear_sock(struct nbd_device *nbd)
1180 {
1181 sock_shutdown(nbd);
1182 nbd_clear_que(nbd);
1183 nbd->task_setup = NULL;
1184 }
1185
1186 static void nbd_config_put(struct nbd_device *nbd)
1187 {
1188 if (refcount_dec_and_mutex_lock(&nbd->config_refs,
1189 &nbd->config_lock)) {
1190 struct nbd_config *config = nbd->config;
1191 nbd_dev_dbg_close(nbd);
1192 nbd_size_clear(nbd);
1193 if (test_and_clear_bit(NBD_RT_HAS_PID_FILE,
1194 &config->runtime_flags))
1195 device_remove_file(disk_to_dev(nbd->disk), &pid_attr);
1196 nbd->task_recv = NULL;
1197 nbd_clear_sock(nbd);
1198 if (config->num_connections) {
1199 int i;
1200 for (i = 0; i < config->num_connections; i++) {
1201 sockfd_put(config->socks[i]->sock);
1202 kfree(config->socks[i]);
1203 }
1204 kfree(config->socks);
1205 }
1206 kfree(nbd->config);
1207 nbd->config = NULL;
1208
1209 if (nbd->recv_workq)
1210 destroy_workqueue(nbd->recv_workq);
1211 nbd->recv_workq = NULL;
1212
1213 nbd->tag_set.timeout = 0;
1214 nbd->disk->queue->limits.discard_granularity = 0;
1215 nbd->disk->queue->limits.discard_alignment = 0;
1216 blk_queue_max_discard_sectors(nbd->disk->queue, UINT_MAX);
1217 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, nbd->disk->queue);
1218
1219 mutex_unlock(&nbd->config_lock);
1220 nbd_put(nbd);
1221 module_put(THIS_MODULE);
1222 }
1223 }
1224
1225 static int nbd_start_device(struct nbd_device *nbd)
1226 {
1227 struct nbd_config *config = nbd->config;
1228 int num_connections = config->num_connections;
1229 int error = 0, i;
1230
1231 if (nbd->task_recv)
1232 return -EBUSY;
1233 if (!config->socks)
1234 return -EINVAL;
1235 if (num_connections > 1 &&
1236 !(config->flags & NBD_FLAG_CAN_MULTI_CONN)) {
1237 dev_err(disk_to_dev(nbd->disk), "server does not support multiple connections per device.\n");
1238 return -EINVAL;
1239 }
1240
1241 nbd->recv_workq = alloc_workqueue("knbd%d-recv",
1242 WQ_MEM_RECLAIM | WQ_HIGHPRI |
1243 WQ_UNBOUND, 0, nbd->index);
1244 if (!nbd->recv_workq) {
1245 dev_err(disk_to_dev(nbd->disk), "Could not allocate knbd recv work queue.\n");
1246 return -ENOMEM;
1247 }
1248
1249 blk_mq_update_nr_hw_queues(&nbd->tag_set, config->num_connections);
1250 nbd->task_recv = current;
1251
1252 nbd_parse_flags(nbd);
1253
1254 error = device_create_file(disk_to_dev(nbd->disk), &pid_attr);
1255 if (error) {
1256 dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n");
1257 return error;
1258 }
1259 set_bit(NBD_RT_HAS_PID_FILE, &config->runtime_flags);
1260
1261 nbd_dev_dbg_init(nbd);
1262 for (i = 0; i < num_connections; i++) {
1263 struct recv_thread_args *args;
1264
1265 args = kzalloc(sizeof(*args), GFP_KERNEL);
1266 if (!args) {
1267 sock_shutdown(nbd);
1268
1269
1270
1271
1272
1273
1274
1275
1276 if (i)
1277 flush_workqueue(nbd->recv_workq);
1278 return -ENOMEM;
1279 }
1280 sk_set_memalloc(config->socks[i]->sock->sk);
1281 if (nbd->tag_set.timeout)
1282 config->socks[i]->sock->sk->sk_sndtimeo =
1283 nbd->tag_set.timeout;
1284 atomic_inc(&config->recv_threads);
1285 refcount_inc(&nbd->config_refs);
1286 INIT_WORK(&args->work, recv_work);
1287 args->nbd = nbd;
1288 args->index = i;
1289 queue_work(nbd->recv_workq, &args->work);
1290 }
1291 nbd_size_update(nbd);
1292 return error;
1293 }
1294
1295 static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *bdev)
1296 {
1297 struct nbd_config *config = nbd->config;
1298 int ret;
1299
1300 ret = nbd_start_device(nbd);
1301 if (ret)
1302 return ret;
1303
1304 if (max_part)
1305 bdev->bd_invalidated = 1;
1306 mutex_unlock(&nbd->config_lock);
1307 ret = wait_event_interruptible(config->recv_wq,
1308 atomic_read(&config->recv_threads) == 0);
1309 if (ret)
1310 sock_shutdown(nbd);
1311 flush_workqueue(nbd->recv_workq);
1312
1313 mutex_lock(&nbd->config_lock);
1314 nbd_bdev_reset(bdev);
1315
1316 if (test_bit(NBD_RT_DISCONNECT_REQUESTED, &config->runtime_flags))
1317 ret = 0;
1318 if (test_bit(NBD_RT_TIMEDOUT, &config->runtime_flags))
1319 ret = -ETIMEDOUT;
1320 return ret;
1321 }
1322
1323 static void nbd_clear_sock_ioctl(struct nbd_device *nbd,
1324 struct block_device *bdev)
1325 {
1326 sock_shutdown(nbd);
1327 __invalidate_device(bdev, true);
1328 nbd_bdev_reset(bdev);
1329 if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF,
1330 &nbd->config->runtime_flags))
1331 nbd_config_put(nbd);
1332 }
1333
1334 static bool nbd_is_valid_blksize(unsigned long blksize)
1335 {
1336 if (!blksize || !is_power_of_2(blksize) || blksize < 512 ||
1337 blksize > PAGE_SIZE)
1338 return false;
1339 return true;
1340 }
1341
1342 static void nbd_set_cmd_timeout(struct nbd_device *nbd, u64 timeout)
1343 {
1344 nbd->tag_set.timeout = timeout * HZ;
1345 if (timeout)
1346 blk_queue_rq_timeout(nbd->disk->queue, timeout * HZ);
1347 }
1348
1349
1350 static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
1351 unsigned int cmd, unsigned long arg)
1352 {
1353 struct nbd_config *config = nbd->config;
1354
1355 switch (cmd) {
1356 case NBD_DISCONNECT:
1357 return nbd_disconnect(nbd);
1358 case NBD_CLEAR_SOCK:
1359 nbd_clear_sock_ioctl(nbd, bdev);
1360 return 0;
1361 case NBD_SET_SOCK:
1362 return nbd_add_socket(nbd, arg, false);
1363 case NBD_SET_BLKSIZE:
1364 if (!arg)
1365 arg = NBD_DEF_BLKSIZE;
1366 if (!nbd_is_valid_blksize(arg))
1367 return -EINVAL;
1368 nbd_size_set(nbd, arg,
1369 div_s64(config->bytesize, arg));
1370 return 0;
1371 case NBD_SET_SIZE:
1372 nbd_size_set(nbd, config->blksize,
1373 div_s64(arg, config->blksize));
1374 return 0;
1375 case NBD_SET_SIZE_BLOCKS:
1376 nbd_size_set(nbd, config->blksize, arg);
1377 return 0;
1378 case NBD_SET_TIMEOUT:
1379 nbd_set_cmd_timeout(nbd, arg);
1380 return 0;
1381
1382 case NBD_SET_FLAGS:
1383 config->flags = arg;
1384 return 0;
1385 case NBD_DO_IT:
1386 return nbd_start_device_ioctl(nbd, bdev);
1387 case NBD_CLEAR_QUE:
1388
1389
1390
1391
1392 return 0;
1393 case NBD_PRINT_DEBUG:
1394
1395
1396
1397
1398 return 0;
1399 }
1400 return -ENOTTY;
1401 }
1402
1403 static int nbd_ioctl(struct block_device *bdev, fmode_t mode,
1404 unsigned int cmd, unsigned long arg)
1405 {
1406 struct nbd_device *nbd = bdev->bd_disk->private_data;
1407 struct nbd_config *config = nbd->config;
1408 int error = -EINVAL;
1409
1410 if (!capable(CAP_SYS_ADMIN))
1411 return -EPERM;
1412
1413
1414
1415
1416 if (_IOC_TYPE(cmd) != 0xab)
1417 return -EINVAL;
1418
1419 mutex_lock(&nbd->config_lock);
1420
1421
1422
1423
1424 if (!test_bit(NBD_RT_BOUND, &config->runtime_flags) ||
1425 (cmd == NBD_DISCONNECT || cmd == NBD_CLEAR_SOCK))
1426 error = __nbd_ioctl(bdev, nbd, cmd, arg);
1427 else
1428 dev_err(nbd_to_dev(nbd), "Cannot use ioctl interface on a netlink controlled device.\n");
1429 mutex_unlock(&nbd->config_lock);
1430 return error;
1431 }
1432
1433 static struct nbd_config *nbd_alloc_config(void)
1434 {
1435 struct nbd_config *config;
1436
1437 config = kzalloc(sizeof(struct nbd_config), GFP_NOFS);
1438 if (!config)
1439 return NULL;
1440 atomic_set(&config->recv_threads, 0);
1441 init_waitqueue_head(&config->recv_wq);
1442 init_waitqueue_head(&config->conn_wait);
1443 config->blksize = NBD_DEF_BLKSIZE;
1444 atomic_set(&config->live_connections, 0);
1445 try_module_get(THIS_MODULE);
1446 return config;
1447 }
1448
1449 static int nbd_open(struct block_device *bdev, fmode_t mode)
1450 {
1451 struct nbd_device *nbd;
1452 int ret = 0;
1453
1454 mutex_lock(&nbd_index_mutex);
1455 nbd = bdev->bd_disk->private_data;
1456 if (!nbd) {
1457 ret = -ENXIO;
1458 goto out;
1459 }
1460 if (!refcount_inc_not_zero(&nbd->refs)) {
1461 ret = -ENXIO;
1462 goto out;
1463 }
1464 if (!refcount_inc_not_zero(&nbd->config_refs)) {
1465 struct nbd_config *config;
1466
1467 mutex_lock(&nbd->config_lock);
1468 if (refcount_inc_not_zero(&nbd->config_refs)) {
1469 mutex_unlock(&nbd->config_lock);
1470 goto out;
1471 }
1472 config = nbd->config = nbd_alloc_config();
1473 if (!config) {
1474 ret = -ENOMEM;
1475 mutex_unlock(&nbd->config_lock);
1476 goto out;
1477 }
1478 refcount_set(&nbd->config_refs, 1);
1479 refcount_inc(&nbd->refs);
1480 mutex_unlock(&nbd->config_lock);
1481 bdev->bd_invalidated = 1;
1482 } else if (nbd_disconnected(nbd->config)) {
1483 bdev->bd_invalidated = 1;
1484 }
1485 out:
1486 mutex_unlock(&nbd_index_mutex);
1487 return ret;
1488 }
1489
1490 static void nbd_release(struct gendisk *disk, fmode_t mode)
1491 {
1492 struct nbd_device *nbd = disk->private_data;
1493 struct block_device *bdev = bdget_disk(disk, 0);
1494
1495 if (test_bit(NBD_RT_DISCONNECT_ON_CLOSE, &nbd->config->runtime_flags) &&
1496 bdev->bd_openers == 0)
1497 nbd_disconnect_and_put(nbd);
1498
1499 nbd_config_put(nbd);
1500 nbd_put(nbd);
1501 }
1502
1503 static const struct block_device_operations nbd_fops =
1504 {
1505 .owner = THIS_MODULE,
1506 .open = nbd_open,
1507 .release = nbd_release,
1508 .ioctl = nbd_ioctl,
1509 .compat_ioctl = nbd_ioctl,
1510 };
1511
1512 #if IS_ENABLED(CONFIG_DEBUG_FS)
1513
1514 static int nbd_dbg_tasks_show(struct seq_file *s, void *unused)
1515 {
1516 struct nbd_device *nbd = s->private;
1517
1518 if (nbd->task_recv)
1519 seq_printf(s, "recv: %d\n", task_pid_nr(nbd->task_recv));
1520
1521 return 0;
1522 }
1523
1524 static int nbd_dbg_tasks_open(struct inode *inode, struct file *file)
1525 {
1526 return single_open(file, nbd_dbg_tasks_show, inode->i_private);
1527 }
1528
1529 static const struct file_operations nbd_dbg_tasks_ops = {
1530 .open = nbd_dbg_tasks_open,
1531 .read = seq_read,
1532 .llseek = seq_lseek,
1533 .release = single_release,
1534 };
1535
1536 static int nbd_dbg_flags_show(struct seq_file *s, void *unused)
1537 {
1538 struct nbd_device *nbd = s->private;
1539 u32 flags = nbd->config->flags;
1540
1541 seq_printf(s, "Hex: 0x%08x\n\n", flags);
1542
1543 seq_puts(s, "Known flags:\n");
1544
1545 if (flags & NBD_FLAG_HAS_FLAGS)
1546 seq_puts(s, "NBD_FLAG_HAS_FLAGS\n");
1547 if (flags & NBD_FLAG_READ_ONLY)
1548 seq_puts(s, "NBD_FLAG_READ_ONLY\n");
1549 if (flags & NBD_FLAG_SEND_FLUSH)
1550 seq_puts(s, "NBD_FLAG_SEND_FLUSH\n");
1551 if (flags & NBD_FLAG_SEND_FUA)
1552 seq_puts(s, "NBD_FLAG_SEND_FUA\n");
1553 if (flags & NBD_FLAG_SEND_TRIM)
1554 seq_puts(s, "NBD_FLAG_SEND_TRIM\n");
1555
1556 return 0;
1557 }
1558
1559 static int nbd_dbg_flags_open(struct inode *inode, struct file *file)
1560 {
1561 return single_open(file, nbd_dbg_flags_show, inode->i_private);
1562 }
1563
1564 static const struct file_operations nbd_dbg_flags_ops = {
1565 .open = nbd_dbg_flags_open,
1566 .read = seq_read,
1567 .llseek = seq_lseek,
1568 .release = single_release,
1569 };
1570
1571 static int nbd_dev_dbg_init(struct nbd_device *nbd)
1572 {
1573 struct dentry *dir;
1574 struct nbd_config *config = nbd->config;
1575
1576 if (!nbd_dbg_dir)
1577 return -EIO;
1578
1579 dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir);
1580 if (!dir) {
1581 dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n",
1582 nbd_name(nbd));
1583 return -EIO;
1584 }
1585 config->dbg_dir = dir;
1586
1587 debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops);
1588 debugfs_create_u64("size_bytes", 0444, dir, &config->bytesize);
1589 debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout);
1590 debugfs_create_u64("blocksize", 0444, dir, &config->blksize);
1591 debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops);
1592
1593 return 0;
1594 }
1595
1596 static void nbd_dev_dbg_close(struct nbd_device *nbd)
1597 {
1598 debugfs_remove_recursive(nbd->config->dbg_dir);
1599 }
1600
1601 static int nbd_dbg_init(void)
1602 {
1603 struct dentry *dbg_dir;
1604
1605 dbg_dir = debugfs_create_dir("nbd", NULL);
1606 if (!dbg_dir)
1607 return -EIO;
1608
1609 nbd_dbg_dir = dbg_dir;
1610
1611 return 0;
1612 }
1613
1614 static void nbd_dbg_close(void)
1615 {
1616 debugfs_remove_recursive(nbd_dbg_dir);
1617 }
1618
1619 #else
1620
1621 static int nbd_dev_dbg_init(struct nbd_device *nbd)
1622 {
1623 return 0;
1624 }
1625
1626 static void nbd_dev_dbg_close(struct nbd_device *nbd)
1627 {
1628 }
1629
1630 static int nbd_dbg_init(void)
1631 {
1632 return 0;
1633 }
1634
1635 static void nbd_dbg_close(void)
1636 {
1637 }
1638
1639 #endif
1640
1641 static int nbd_init_request(struct blk_mq_tag_set *set, struct request *rq,
1642 unsigned int hctx_idx, unsigned int numa_node)
1643 {
1644 struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq);
1645 cmd->nbd = set->driver_data;
1646 cmd->flags = 0;
1647 mutex_init(&cmd->lock);
1648 return 0;
1649 }
1650
1651 static const struct blk_mq_ops nbd_mq_ops = {
1652 .queue_rq = nbd_queue_rq,
1653 .complete = nbd_complete_rq,
1654 .init_request = nbd_init_request,
1655 .timeout = nbd_xmit_timeout,
1656 };
1657
1658 static int nbd_dev_add(int index)
1659 {
1660 struct nbd_device *nbd;
1661 struct gendisk *disk;
1662 struct request_queue *q;
1663 int err = -ENOMEM;
1664
1665 nbd = kzalloc(sizeof(struct nbd_device), GFP_KERNEL);
1666 if (!nbd)
1667 goto out;
1668
1669 disk = alloc_disk(1 << part_shift);
1670 if (!disk)
1671 goto out_free_nbd;
1672
1673 if (index >= 0) {
1674 err = idr_alloc(&nbd_index_idr, nbd, index, index + 1,
1675 GFP_KERNEL);
1676 if (err == -ENOSPC)
1677 err = -EEXIST;
1678 } else {
1679 err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL);
1680 if (err >= 0)
1681 index = err;
1682 }
1683 if (err < 0)
1684 goto out_free_disk;
1685
1686 nbd->index = index;
1687 nbd->disk = disk;
1688 nbd->tag_set.ops = &nbd_mq_ops;
1689 nbd->tag_set.nr_hw_queues = 1;
1690 nbd->tag_set.queue_depth = 128;
1691 nbd->tag_set.numa_node = NUMA_NO_NODE;
1692 nbd->tag_set.cmd_size = sizeof(struct nbd_cmd);
1693 nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE |
1694 BLK_MQ_F_BLOCKING;
1695 nbd->tag_set.driver_data = nbd;
1696 nbd->destroy_complete = NULL;
1697
1698 err = blk_mq_alloc_tag_set(&nbd->tag_set);
1699 if (err)
1700 goto out_free_idr;
1701
1702 q = blk_mq_init_queue(&nbd->tag_set);
1703 if (IS_ERR(q)) {
1704 err = PTR_ERR(q);
1705 goto out_free_tags;
1706 }
1707 disk->queue = q;
1708
1709
1710
1711
1712 blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);
1713 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue);
1714 disk->queue->limits.discard_granularity = 0;
1715 disk->queue->limits.discard_alignment = 0;
1716 blk_queue_max_discard_sectors(disk->queue, 0);
1717 blk_queue_max_segment_size(disk->queue, UINT_MAX);
1718 blk_queue_max_segments(disk->queue, USHRT_MAX);
1719 blk_queue_max_hw_sectors(disk->queue, 65536);
1720 disk->queue->limits.max_sectors = 256;
1721
1722 mutex_init(&nbd->config_lock);
1723 refcount_set(&nbd->config_refs, 0);
1724 refcount_set(&nbd->refs, 1);
1725 INIT_LIST_HEAD(&nbd->list);
1726 disk->major = NBD_MAJOR;
1727 disk->first_minor = index << part_shift;
1728 disk->fops = &nbd_fops;
1729 disk->private_data = nbd;
1730 sprintf(disk->disk_name, "nbd%d", index);
1731 add_disk(disk);
1732 nbd_total_devices++;
1733 return index;
1734
1735 out_free_tags:
1736 blk_mq_free_tag_set(&nbd->tag_set);
1737 out_free_idr:
1738 idr_remove(&nbd_index_idr, index);
1739 out_free_disk:
1740 put_disk(disk);
1741 out_free_nbd:
1742 kfree(nbd);
1743 out:
1744 return err;
1745 }
1746
1747 static int find_free_cb(int id, void *ptr, void *data)
1748 {
1749 struct nbd_device *nbd = ptr;
1750 struct nbd_device **found = data;
1751
1752 if (!refcount_read(&nbd->config_refs)) {
1753 *found = nbd;
1754 return 1;
1755 }
1756 return 0;
1757 }
1758
1759
1760 static const struct nla_policy nbd_attr_policy[NBD_ATTR_MAX + 1] = {
1761 [NBD_ATTR_INDEX] = { .type = NLA_U32 },
1762 [NBD_ATTR_SIZE_BYTES] = { .type = NLA_U64 },
1763 [NBD_ATTR_BLOCK_SIZE_BYTES] = { .type = NLA_U64 },
1764 [NBD_ATTR_TIMEOUT] = { .type = NLA_U64 },
1765 [NBD_ATTR_SERVER_FLAGS] = { .type = NLA_U64 },
1766 [NBD_ATTR_CLIENT_FLAGS] = { .type = NLA_U64 },
1767 [NBD_ATTR_SOCKETS] = { .type = NLA_NESTED},
1768 [NBD_ATTR_DEAD_CONN_TIMEOUT] = { .type = NLA_U64 },
1769 [NBD_ATTR_DEVICE_LIST] = { .type = NLA_NESTED},
1770 };
1771
1772 static const struct nla_policy nbd_sock_policy[NBD_SOCK_MAX + 1] = {
1773 [NBD_SOCK_FD] = { .type = NLA_U32 },
1774 };
1775
1776
1777
1778
1779 static const struct nla_policy __attribute__((unused))
1780 nbd_device_policy[NBD_DEVICE_ATTR_MAX + 1] = {
1781 [NBD_DEVICE_INDEX] = { .type = NLA_U32 },
1782 [NBD_DEVICE_CONNECTED] = { .type = NLA_U8 },
1783 };
1784
1785 static int nbd_genl_size_set(struct genl_info *info, struct nbd_device *nbd)
1786 {
1787 struct nbd_config *config = nbd->config;
1788 u64 bsize = config->blksize;
1789 u64 bytes = config->bytesize;
1790
1791 if (info->attrs[NBD_ATTR_SIZE_BYTES])
1792 bytes = nla_get_u64(info->attrs[NBD_ATTR_SIZE_BYTES]);
1793
1794 if (info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]) {
1795 bsize = nla_get_u64(info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]);
1796 if (!bsize)
1797 bsize = NBD_DEF_BLKSIZE;
1798 if (!nbd_is_valid_blksize(bsize)) {
1799 printk(KERN_ERR "Invalid block size %llu\n", bsize);
1800 return -EINVAL;
1801 }
1802 }
1803
1804 if (bytes != config->bytesize || bsize != config->blksize)
1805 nbd_size_set(nbd, bsize, div64_u64(bytes, bsize));
1806 return 0;
1807 }
1808
1809 static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info)
1810 {
1811 DECLARE_COMPLETION_ONSTACK(destroy_complete);
1812 struct nbd_device *nbd = NULL;
1813 struct nbd_config *config;
1814 int index = -1;
1815 int ret;
1816 bool put_dev = false;
1817
1818 if (!netlink_capable(skb, CAP_SYS_ADMIN))
1819 return -EPERM;
1820
1821 if (info->attrs[NBD_ATTR_INDEX])
1822 index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
1823 if (!info->attrs[NBD_ATTR_SOCKETS]) {
1824 printk(KERN_ERR "nbd: must specify at least one socket\n");
1825 return -EINVAL;
1826 }
1827 if (!info->attrs[NBD_ATTR_SIZE_BYTES]) {
1828 printk(KERN_ERR "nbd: must specify a size in bytes for the device\n");
1829 return -EINVAL;
1830 }
1831 again:
1832 mutex_lock(&nbd_index_mutex);
1833 if (index == -1) {
1834 ret = idr_for_each(&nbd_index_idr, &find_free_cb, &nbd);
1835 if (ret == 0) {
1836 int new_index;
1837 new_index = nbd_dev_add(-1);
1838 if (new_index < 0) {
1839 mutex_unlock(&nbd_index_mutex);
1840 printk(KERN_ERR "nbd: failed to add new device\n");
1841 return new_index;
1842 }
1843 nbd = idr_find(&nbd_index_idr, new_index);
1844 }
1845 } else {
1846 nbd = idr_find(&nbd_index_idr, index);
1847 if (!nbd) {
1848 ret = nbd_dev_add(index);
1849 if (ret < 0) {
1850 mutex_unlock(&nbd_index_mutex);
1851 printk(KERN_ERR "nbd: failed to add new device\n");
1852 return ret;
1853 }
1854 nbd = idr_find(&nbd_index_idr, index);
1855 }
1856 }
1857 if (!nbd) {
1858 printk(KERN_ERR "nbd: couldn't find device at index %d\n",
1859 index);
1860 mutex_unlock(&nbd_index_mutex);
1861 return -EINVAL;
1862 }
1863
1864 if (test_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags) &&
1865 test_bit(NBD_DISCONNECT_REQUESTED, &nbd->flags)) {
1866 nbd->destroy_complete = &destroy_complete;
1867 mutex_unlock(&nbd_index_mutex);
1868
1869
1870 wait_for_completion(&destroy_complete);
1871 goto again;
1872 }
1873
1874 if (!refcount_inc_not_zero(&nbd->refs)) {
1875 mutex_unlock(&nbd_index_mutex);
1876 if (index == -1)
1877 goto again;
1878 printk(KERN_ERR "nbd: device at index %d is going down\n",
1879 index);
1880 return -EINVAL;
1881 }
1882 mutex_unlock(&nbd_index_mutex);
1883
1884 mutex_lock(&nbd->config_lock);
1885 if (refcount_read(&nbd->config_refs)) {
1886 mutex_unlock(&nbd->config_lock);
1887 nbd_put(nbd);
1888 if (index == -1)
1889 goto again;
1890 printk(KERN_ERR "nbd: nbd%d already in use\n", index);
1891 return -EBUSY;
1892 }
1893 if (WARN_ON(nbd->config)) {
1894 mutex_unlock(&nbd->config_lock);
1895 nbd_put(nbd);
1896 return -EINVAL;
1897 }
1898 config = nbd->config = nbd_alloc_config();
1899 if (!nbd->config) {
1900 mutex_unlock(&nbd->config_lock);
1901 nbd_put(nbd);
1902 printk(KERN_ERR "nbd: couldn't allocate config\n");
1903 return -ENOMEM;
1904 }
1905 refcount_set(&nbd->config_refs, 1);
1906 set_bit(NBD_RT_BOUND, &config->runtime_flags);
1907
1908 ret = nbd_genl_size_set(info, nbd);
1909 if (ret)
1910 goto out;
1911
1912 if (info->attrs[NBD_ATTR_TIMEOUT])
1913 nbd_set_cmd_timeout(nbd,
1914 nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]));
1915 if (info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]) {
1916 config->dead_conn_timeout =
1917 nla_get_u64(info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]);
1918 config->dead_conn_timeout *= HZ;
1919 }
1920 if (info->attrs[NBD_ATTR_SERVER_FLAGS])
1921 config->flags =
1922 nla_get_u64(info->attrs[NBD_ATTR_SERVER_FLAGS]);
1923 if (info->attrs[NBD_ATTR_CLIENT_FLAGS]) {
1924 u64 flags = nla_get_u64(info->attrs[NBD_ATTR_CLIENT_FLAGS]);
1925 if (flags & NBD_CFLAG_DESTROY_ON_DISCONNECT) {
1926 set_bit(NBD_RT_DESTROY_ON_DISCONNECT,
1927 &config->runtime_flags);
1928 set_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags);
1929 put_dev = true;
1930 } else {
1931 clear_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags);
1932 }
1933 if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
1934 set_bit(NBD_RT_DISCONNECT_ON_CLOSE,
1935 &config->runtime_flags);
1936 }
1937 }
1938
1939 if (info->attrs[NBD_ATTR_SOCKETS]) {
1940 struct nlattr *attr;
1941 int rem, fd;
1942
1943 nla_for_each_nested(attr, info->attrs[NBD_ATTR_SOCKETS],
1944 rem) {
1945 struct nlattr *socks[NBD_SOCK_MAX+1];
1946
1947 if (nla_type(attr) != NBD_SOCK_ITEM) {
1948 printk(KERN_ERR "nbd: socks must be embedded in a SOCK_ITEM attr\n");
1949 ret = -EINVAL;
1950 goto out;
1951 }
1952 ret = nla_parse_nested_deprecated(socks, NBD_SOCK_MAX,
1953 attr,
1954 nbd_sock_policy,
1955 info->extack);
1956 if (ret != 0) {
1957 printk(KERN_ERR "nbd: error processing sock list\n");
1958 ret = -EINVAL;
1959 goto out;
1960 }
1961 if (!socks[NBD_SOCK_FD])
1962 continue;
1963 fd = (int)nla_get_u32(socks[NBD_SOCK_FD]);
1964 ret = nbd_add_socket(nbd, fd, true);
1965 if (ret)
1966 goto out;
1967 }
1968 }
1969 ret = nbd_start_device(nbd);
1970 out:
1971 mutex_unlock(&nbd->config_lock);
1972 if (!ret) {
1973 set_bit(NBD_RT_HAS_CONFIG_REF, &config->runtime_flags);
1974 refcount_inc(&nbd->config_refs);
1975 nbd_connect_reply(info, nbd->index);
1976 }
1977 nbd_config_put(nbd);
1978 if (put_dev)
1979 nbd_put(nbd);
1980 return ret;
1981 }
1982
1983 static void nbd_disconnect_and_put(struct nbd_device *nbd)
1984 {
1985 mutex_lock(&nbd->config_lock);
1986 nbd_disconnect(nbd);
1987 nbd_clear_sock(nbd);
1988 mutex_unlock(&nbd->config_lock);
1989
1990
1991
1992
1993
1994 flush_workqueue(nbd->recv_workq);
1995 if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF,
1996 &nbd->config->runtime_flags))
1997 nbd_config_put(nbd);
1998 }
1999
2000 static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info)
2001 {
2002 struct nbd_device *nbd;
2003 int index;
2004
2005 if (!netlink_capable(skb, CAP_SYS_ADMIN))
2006 return -EPERM;
2007
2008 if (!info->attrs[NBD_ATTR_INDEX]) {
2009 printk(KERN_ERR "nbd: must specify an index to disconnect\n");
2010 return -EINVAL;
2011 }
2012 index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
2013 mutex_lock(&nbd_index_mutex);
2014 nbd = idr_find(&nbd_index_idr, index);
2015 if (!nbd) {
2016 mutex_unlock(&nbd_index_mutex);
2017 printk(KERN_ERR "nbd: couldn't find device at index %d\n",
2018 index);
2019 return -EINVAL;
2020 }
2021 if (!refcount_inc_not_zero(&nbd->refs)) {
2022 mutex_unlock(&nbd_index_mutex);
2023 printk(KERN_ERR "nbd: device at index %d is going down\n",
2024 index);
2025 return -EINVAL;
2026 }
2027 mutex_unlock(&nbd_index_mutex);
2028 if (!refcount_inc_not_zero(&nbd->config_refs)) {
2029 nbd_put(nbd);
2030 return 0;
2031 }
2032 nbd_disconnect_and_put(nbd);
2033 nbd_config_put(nbd);
2034 nbd_put(nbd);
2035 return 0;
2036 }
2037
2038 static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
2039 {
2040 struct nbd_device *nbd = NULL;
2041 struct nbd_config *config;
2042 int index;
2043 int ret = 0;
2044 bool put_dev = false;
2045
2046 if (!netlink_capable(skb, CAP_SYS_ADMIN))
2047 return -EPERM;
2048
2049 if (!info->attrs[NBD_ATTR_INDEX]) {
2050 printk(KERN_ERR "nbd: must specify a device to reconfigure\n");
2051 return -EINVAL;
2052 }
2053 index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
2054 mutex_lock(&nbd_index_mutex);
2055 nbd = idr_find(&nbd_index_idr, index);
2056 if (!nbd) {
2057 mutex_unlock(&nbd_index_mutex);
2058 printk(KERN_ERR "nbd: couldn't find a device at index %d\n",
2059 index);
2060 return -EINVAL;
2061 }
2062 if (!refcount_inc_not_zero(&nbd->refs)) {
2063 mutex_unlock(&nbd_index_mutex);
2064 printk(KERN_ERR "nbd: device at index %d is going down\n",
2065 index);
2066 return -EINVAL;
2067 }
2068 mutex_unlock(&nbd_index_mutex);
2069
2070 if (!refcount_inc_not_zero(&nbd->config_refs)) {
2071 dev_err(nbd_to_dev(nbd),
2072 "not configured, cannot reconfigure\n");
2073 nbd_put(nbd);
2074 return -EINVAL;
2075 }
2076
2077 mutex_lock(&nbd->config_lock);
2078 config = nbd->config;
2079 if (!test_bit(NBD_RT_BOUND, &config->runtime_flags) ||
2080 !nbd->task_recv) {
2081 dev_err(nbd_to_dev(nbd),
2082 "not configured, cannot reconfigure\n");
2083 ret = -EINVAL;
2084 goto out;
2085 }
2086
2087 ret = nbd_genl_size_set(info, nbd);
2088 if (ret)
2089 goto out;
2090
2091 if (info->attrs[NBD_ATTR_TIMEOUT])
2092 nbd_set_cmd_timeout(nbd,
2093 nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]));
2094 if (info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]) {
2095 config->dead_conn_timeout =
2096 nla_get_u64(info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]);
2097 config->dead_conn_timeout *= HZ;
2098 }
2099 if (info->attrs[NBD_ATTR_CLIENT_FLAGS]) {
2100 u64 flags = nla_get_u64(info->attrs[NBD_ATTR_CLIENT_FLAGS]);
2101 if (flags & NBD_CFLAG_DESTROY_ON_DISCONNECT) {
2102 if (!test_and_set_bit(NBD_RT_DESTROY_ON_DISCONNECT,
2103 &config->runtime_flags))
2104 put_dev = true;
2105 set_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags);
2106 } else {
2107 if (test_and_clear_bit(NBD_RT_DESTROY_ON_DISCONNECT,
2108 &config->runtime_flags))
2109 refcount_inc(&nbd->refs);
2110 clear_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags);
2111 }
2112
2113 if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
2114 set_bit(NBD_RT_DISCONNECT_ON_CLOSE,
2115 &config->runtime_flags);
2116 } else {
2117 clear_bit(NBD_RT_DISCONNECT_ON_CLOSE,
2118 &config->runtime_flags);
2119 }
2120 }
2121
2122 if (info->attrs[NBD_ATTR_SOCKETS]) {
2123 struct nlattr *attr;
2124 int rem, fd;
2125
2126 nla_for_each_nested(attr, info->attrs[NBD_ATTR_SOCKETS],
2127 rem) {
2128 struct nlattr *socks[NBD_SOCK_MAX+1];
2129
2130 if (nla_type(attr) != NBD_SOCK_ITEM) {
2131 printk(KERN_ERR "nbd: socks must be embedded in a SOCK_ITEM attr\n");
2132 ret = -EINVAL;
2133 goto out;
2134 }
2135 ret = nla_parse_nested_deprecated(socks, NBD_SOCK_MAX,
2136 attr,
2137 nbd_sock_policy,
2138 info->extack);
2139 if (ret != 0) {
2140 printk(KERN_ERR "nbd: error processing sock list\n");
2141 ret = -EINVAL;
2142 goto out;
2143 }
2144 if (!socks[NBD_SOCK_FD])
2145 continue;
2146 fd = (int)nla_get_u32(socks[NBD_SOCK_FD]);
2147 ret = nbd_reconnect_socket(nbd, fd);
2148 if (ret) {
2149 if (ret == -ENOSPC)
2150 ret = 0;
2151 goto out;
2152 }
2153 dev_info(nbd_to_dev(nbd), "reconnected socket\n");
2154 }
2155 }
2156 out:
2157 mutex_unlock(&nbd->config_lock);
2158 nbd_config_put(nbd);
2159 nbd_put(nbd);
2160 if (put_dev)
2161 nbd_put(nbd);
2162 return ret;
2163 }
2164
2165 static const struct genl_ops nbd_connect_genl_ops[] = {
2166 {
2167 .cmd = NBD_CMD_CONNECT,
2168 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2169 .doit = nbd_genl_connect,
2170 },
2171 {
2172 .cmd = NBD_CMD_DISCONNECT,
2173 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2174 .doit = nbd_genl_disconnect,
2175 },
2176 {
2177 .cmd = NBD_CMD_RECONFIGURE,
2178 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2179 .doit = nbd_genl_reconfigure,
2180 },
2181 {
2182 .cmd = NBD_CMD_STATUS,
2183 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2184 .doit = nbd_genl_status,
2185 },
2186 };
2187
2188 static const struct genl_multicast_group nbd_mcast_grps[] = {
2189 { .name = NBD_GENL_MCAST_GROUP_NAME, },
2190 };
2191
2192 static struct genl_family nbd_genl_family __ro_after_init = {
2193 .hdrsize = 0,
2194 .name = NBD_GENL_FAMILY_NAME,
2195 .version = NBD_GENL_VERSION,
2196 .module = THIS_MODULE,
2197 .ops = nbd_connect_genl_ops,
2198 .n_ops = ARRAY_SIZE(nbd_connect_genl_ops),
2199 .maxattr = NBD_ATTR_MAX,
2200 .policy = nbd_attr_policy,
2201 .mcgrps = nbd_mcast_grps,
2202 .n_mcgrps = ARRAY_SIZE(nbd_mcast_grps),
2203 };
2204
2205 static int populate_nbd_status(struct nbd_device *nbd, struct sk_buff *reply)
2206 {
2207 struct nlattr *dev_opt;
2208 u8 connected = 0;
2209 int ret;
2210
2211
2212
2213
2214
2215
2216
2217
2218 if (refcount_read(&nbd->config_refs))
2219 connected = 1;
2220 dev_opt = nla_nest_start_noflag(reply, NBD_DEVICE_ITEM);
2221 if (!dev_opt)
2222 return -EMSGSIZE;
2223 ret = nla_put_u32(reply, NBD_DEVICE_INDEX, nbd->index);
2224 if (ret)
2225 return -EMSGSIZE;
2226 ret = nla_put_u8(reply, NBD_DEVICE_CONNECTED,
2227 connected);
2228 if (ret)
2229 return -EMSGSIZE;
2230 nla_nest_end(reply, dev_opt);
2231 return 0;
2232 }
2233
2234 static int status_cb(int id, void *ptr, void *data)
2235 {
2236 struct nbd_device *nbd = ptr;
2237 return populate_nbd_status(nbd, (struct sk_buff *)data);
2238 }
2239
2240 static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
2241 {
2242 struct nlattr *dev_list;
2243 struct sk_buff *reply;
2244 void *reply_head;
2245 size_t msg_size;
2246 int index = -1;
2247 int ret = -ENOMEM;
2248
2249 if (info->attrs[NBD_ATTR_INDEX])
2250 index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
2251
2252 mutex_lock(&nbd_index_mutex);
2253
2254 msg_size = nla_total_size(nla_attr_size(sizeof(u32)) +
2255 nla_attr_size(sizeof(u8)));
2256 msg_size *= (index == -1) ? nbd_total_devices : 1;
2257
2258 reply = genlmsg_new(msg_size, GFP_KERNEL);
2259 if (!reply)
2260 goto out;
2261 reply_head = genlmsg_put_reply(reply, info, &nbd_genl_family, 0,
2262 NBD_CMD_STATUS);
2263 if (!reply_head) {
2264 nlmsg_free(reply);
2265 goto out;
2266 }
2267
2268 dev_list = nla_nest_start_noflag(reply, NBD_ATTR_DEVICE_LIST);
2269 if (index == -1) {
2270 ret = idr_for_each(&nbd_index_idr, &status_cb, reply);
2271 if (ret) {
2272 nlmsg_free(reply);
2273 goto out;
2274 }
2275 } else {
2276 struct nbd_device *nbd;
2277 nbd = idr_find(&nbd_index_idr, index);
2278 if (nbd) {
2279 ret = populate_nbd_status(nbd, reply);
2280 if (ret) {
2281 nlmsg_free(reply);
2282 goto out;
2283 }
2284 }
2285 }
2286 nla_nest_end(reply, dev_list);
2287 genlmsg_end(reply, reply_head);
2288 ret = genlmsg_reply(reply, info);
2289 out:
2290 mutex_unlock(&nbd_index_mutex);
2291 return ret;
2292 }
2293
2294 static void nbd_connect_reply(struct genl_info *info, int index)
2295 {
2296 struct sk_buff *skb;
2297 void *msg_head;
2298 int ret;
2299
2300 skb = genlmsg_new(nla_total_size(sizeof(u32)), GFP_KERNEL);
2301 if (!skb)
2302 return;
2303 msg_head = genlmsg_put_reply(skb, info, &nbd_genl_family, 0,
2304 NBD_CMD_CONNECT);
2305 if (!msg_head) {
2306 nlmsg_free(skb);
2307 return;
2308 }
2309 ret = nla_put_u32(skb, NBD_ATTR_INDEX, index);
2310 if (ret) {
2311 nlmsg_free(skb);
2312 return;
2313 }
2314 genlmsg_end(skb, msg_head);
2315 genlmsg_reply(skb, info);
2316 }
2317
2318 static void nbd_mcast_index(int index)
2319 {
2320 struct sk_buff *skb;
2321 void *msg_head;
2322 int ret;
2323
2324 skb = genlmsg_new(nla_total_size(sizeof(u32)), GFP_KERNEL);
2325 if (!skb)
2326 return;
2327 msg_head = genlmsg_put(skb, 0, 0, &nbd_genl_family, 0,
2328 NBD_CMD_LINK_DEAD);
2329 if (!msg_head) {
2330 nlmsg_free(skb);
2331 return;
2332 }
2333 ret = nla_put_u32(skb, NBD_ATTR_INDEX, index);
2334 if (ret) {
2335 nlmsg_free(skb);
2336 return;
2337 }
2338 genlmsg_end(skb, msg_head);
2339 genlmsg_multicast(&nbd_genl_family, skb, 0, 0, GFP_KERNEL);
2340 }
2341
2342 static void nbd_dead_link_work(struct work_struct *work)
2343 {
2344 struct link_dead_args *args = container_of(work, struct link_dead_args,
2345 work);
2346 nbd_mcast_index(args->index);
2347 kfree(args);
2348 }
2349
2350 static int __init nbd_init(void)
2351 {
2352 int i;
2353
2354 BUILD_BUG_ON(sizeof(struct nbd_request) != 28);
2355
2356 if (max_part < 0) {
2357 printk(KERN_ERR "nbd: max_part must be >= 0\n");
2358 return -EINVAL;
2359 }
2360
2361 part_shift = 0;
2362 if (max_part > 0) {
2363 part_shift = fls(max_part);
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373 max_part = (1UL << part_shift) - 1;
2374 }
2375
2376 if ((1UL << part_shift) > DISK_MAX_PARTS)
2377 return -EINVAL;
2378
2379 if (nbds_max > 1UL << (MINORBITS - part_shift))
2380 return -EINVAL;
2381
2382 if (register_blkdev(NBD_MAJOR, "nbd"))
2383 return -EIO;
2384
2385 if (genl_register_family(&nbd_genl_family)) {
2386 unregister_blkdev(NBD_MAJOR, "nbd");
2387 return -EINVAL;
2388 }
2389 nbd_dbg_init();
2390
2391 mutex_lock(&nbd_index_mutex);
2392 for (i = 0; i < nbds_max; i++)
2393 nbd_dev_add(i);
2394 mutex_unlock(&nbd_index_mutex);
2395 return 0;
2396 }
2397
2398 static int nbd_exit_cb(int id, void *ptr, void *data)
2399 {
2400 struct list_head *list = (struct list_head *)data;
2401 struct nbd_device *nbd = ptr;
2402
2403 list_add_tail(&nbd->list, list);
2404 return 0;
2405 }
2406
2407 static void __exit nbd_cleanup(void)
2408 {
2409 struct nbd_device *nbd;
2410 LIST_HEAD(del_list);
2411
2412 nbd_dbg_close();
2413
2414 mutex_lock(&nbd_index_mutex);
2415 idr_for_each(&nbd_index_idr, &nbd_exit_cb, &del_list);
2416 mutex_unlock(&nbd_index_mutex);
2417
2418 while (!list_empty(&del_list)) {
2419 nbd = list_first_entry(&del_list, struct nbd_device, list);
2420 list_del_init(&nbd->list);
2421 if (refcount_read(&nbd->refs) != 1)
2422 printk(KERN_ERR "nbd: possibly leaking a device\n");
2423 nbd_put(nbd);
2424 }
2425
2426 idr_destroy(&nbd_index_idr);
2427 genl_unregister_family(&nbd_genl_family);
2428 unregister_blkdev(NBD_MAJOR, "nbd");
2429 }
2430
2431 module_init(nbd_init);
2432 module_exit(nbd_cleanup);
2433
2434 MODULE_DESCRIPTION("Network Block Device");
2435 MODULE_LICENSE("GPL");
2436
2437 module_param(nbds_max, int, 0444);
2438 MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)");
2439 module_param(max_part, int, 0444);
2440 MODULE_PARM_DESC(max_part, "number of partitions per device (default: 16)");