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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Network block device - make block devices work over TCP | |
3 | * | |
4 | * Note that you can not swap over this thing, yet. Seems to work but | |
5 | * deadlocks sometimes - you can not swap over TCP in general. | |
6 | * | |
a2531293 | 7 | * Copyright 1997-2000, 2008 Pavel Machek <pavel@ucw.cz> |
1da177e4 LT |
8 | * Parts copyright 2001 Steven Whitehouse <steve@chygwyn.com> |
9 | * | |
dbf492d6 | 10 | * This file is released under GPLv2 or later. |
1da177e4 | 11 | * |
dbf492d6 | 12 | * (part of code stolen from loop.c) |
1da177e4 LT |
13 | */ |
14 | ||
15 | #include <linux/major.h> | |
16 | ||
17 | #include <linux/blkdev.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/sched.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> | |
2a48fc0a | 27 | #include <linux/mutex.h> |
4b2f0260 HX |
28 | #include <linux/compiler.h> |
29 | #include <linux/err.h> | |
30 | #include <linux/kernel.h> | |
5a0e3ad6 | 31 | #include <linux/slab.h> |
1da177e4 | 32 | #include <net/sock.h> |
91cf45f0 | 33 | #include <linux/net.h> |
48cf6061 | 34 | #include <linux/kthread.h> |
b9c495bb | 35 | #include <linux/types.h> |
30d53d9c | 36 | #include <linux/debugfs.h> |
fd8383fd | 37 | #include <linux/blk-mq.h> |
1da177e4 | 38 | |
7c0f6ba6 | 39 | #include <linux/uaccess.h> |
1da177e4 LT |
40 | #include <asm/types.h> |
41 | ||
42 | #include <linux/nbd.h> | |
43 | ||
b0d9111a JB |
44 | static DEFINE_IDR(nbd_index_idr); |
45 | static DEFINE_MUTEX(nbd_index_mutex); | |
46 | ||
9561a7ad JB |
47 | struct nbd_sock { |
48 | struct socket *sock; | |
49 | struct mutex tx_lock; | |
50 | }; | |
51 | ||
9b4a6ba9 JB |
52 | #define NBD_TIMEDOUT 0 |
53 | #define NBD_DISCONNECT_REQUESTED 1 | |
9561a7ad JB |
54 | #define NBD_DISCONNECTED 2 |
55 | #define NBD_RUNNING 3 | |
9b4a6ba9 | 56 | |
13e71d69 | 57 | struct nbd_device { |
22d109c1 | 58 | u32 flags; |
9b4a6ba9 | 59 | unsigned long runtime_flags; |
9561a7ad | 60 | struct nbd_sock **socks; |
13e71d69 MP |
61 | int magic; |
62 | ||
fd8383fd | 63 | struct blk_mq_tag_set tag_set; |
13e71d69 | 64 | |
9561a7ad | 65 | struct mutex config_lock; |
13e71d69 | 66 | struct gendisk *disk; |
9561a7ad JB |
67 | int num_connections; |
68 | atomic_t recv_threads; | |
69 | wait_queue_head_t recv_wq; | |
ef77b515 | 70 | loff_t blksize; |
b9c495bb | 71 | loff_t bytesize; |
7e2893a1 | 72 | |
7e2893a1 | 73 | struct task_struct *task_recv; |
9561a7ad | 74 | struct task_struct *task_setup; |
30d53d9c MP |
75 | |
76 | #if IS_ENABLED(CONFIG_DEBUG_FS) | |
77 | struct dentry *dbg_dir; | |
78 | #endif | |
13e71d69 MP |
79 | }; |
80 | ||
fd8383fd JB |
81 | struct nbd_cmd { |
82 | struct nbd_device *nbd; | |
9561a7ad | 83 | struct completion send_complete; |
fd8383fd JB |
84 | }; |
85 | ||
30d53d9c MP |
86 | #if IS_ENABLED(CONFIG_DEBUG_FS) |
87 | static struct dentry *nbd_dbg_dir; | |
88 | #endif | |
89 | ||
90 | #define nbd_name(nbd) ((nbd)->disk->disk_name) | |
91 | ||
f4507164 | 92 | #define NBD_MAGIC 0x68797548 |
1da177e4 | 93 | |
9c7a4169 | 94 | static unsigned int nbds_max = 16; |
d71a6d73 | 95 | static int max_part; |
124d6db0 | 96 | static struct workqueue_struct *recv_workqueue; |
b0d9111a | 97 | static int part_shift; |
1da177e4 | 98 | |
9442b739 JB |
99 | static int nbd_dev_dbg_init(struct nbd_device *nbd); |
100 | static void nbd_dev_dbg_close(struct nbd_device *nbd); | |
101 | ||
102 | ||
d18509f5 | 103 | static inline struct device *nbd_to_dev(struct nbd_device *nbd) |
1da177e4 | 104 | { |
d18509f5 | 105 | return disk_to_dev(nbd->disk); |
1da177e4 LT |
106 | } |
107 | ||
37091fdd MP |
108 | static bool nbd_is_connected(struct nbd_device *nbd) |
109 | { | |
110 | return !!nbd->task_recv; | |
111 | } | |
112 | ||
1da177e4 LT |
113 | static const char *nbdcmd_to_ascii(int cmd) |
114 | { | |
115 | switch (cmd) { | |
116 | case NBD_CMD_READ: return "read"; | |
117 | case NBD_CMD_WRITE: return "write"; | |
118 | case NBD_CMD_DISC: return "disconnect"; | |
75f187ab | 119 | case NBD_CMD_FLUSH: return "flush"; |
a336d298 | 120 | case NBD_CMD_TRIM: return "trim/discard"; |
1da177e4 LT |
121 | } |
122 | return "invalid"; | |
123 | } | |
1da177e4 | 124 | |
37091fdd MP |
125 | static int nbd_size_clear(struct nbd_device *nbd, struct block_device *bdev) |
126 | { | |
127 | bdev->bd_inode->i_size = 0; | |
128 | set_capacity(nbd->disk, 0); | |
129 | kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | static void nbd_size_update(struct nbd_device *nbd, struct block_device *bdev) | |
135 | { | |
136 | if (!nbd_is_connected(nbd)) | |
137 | return; | |
138 | ||
139 | bdev->bd_inode->i_size = nbd->bytesize; | |
140 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
141 | kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); | |
142 | } | |
143 | ||
144 | static int nbd_size_set(struct nbd_device *nbd, struct block_device *bdev, | |
ef77b515 | 145 | loff_t blocksize, loff_t nr_blocks) |
37091fdd MP |
146 | { |
147 | int ret; | |
148 | ||
149 | ret = set_blocksize(bdev, blocksize); | |
150 | if (ret) | |
151 | return ret; | |
152 | ||
153 | nbd->blksize = blocksize; | |
ef77b515 | 154 | nbd->bytesize = blocksize * nr_blocks; |
37091fdd MP |
155 | |
156 | nbd_size_update(nbd, bdev); | |
157 | ||
158 | return 0; | |
159 | } | |
160 | ||
fd8383fd | 161 | static void nbd_end_request(struct nbd_cmd *cmd) |
1da177e4 | 162 | { |
fd8383fd JB |
163 | struct nbd_device *nbd = cmd->nbd; |
164 | struct request *req = blk_mq_rq_from_pdu(cmd); | |
097c94a4 | 165 | int error = req->errors ? -EIO : 0; |
1da177e4 | 166 | |
fd8383fd | 167 | dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", cmd, |
d18509f5 | 168 | error ? "failed" : "done"); |
1da177e4 | 169 | |
fd8383fd | 170 | blk_mq_complete_request(req, error); |
1da177e4 LT |
171 | } |
172 | ||
e018e757 MP |
173 | /* |
174 | * Forcibly shutdown the socket causing all listeners to error | |
175 | */ | |
36e47bee | 176 | static void sock_shutdown(struct nbd_device *nbd) |
7fdfd406 | 177 | { |
9561a7ad | 178 | int i; |
23272a67 | 179 | |
9561a7ad JB |
180 | if (nbd->num_connections == 0) |
181 | return; | |
182 | if (test_and_set_bit(NBD_DISCONNECTED, &nbd->runtime_flags)) | |
260bbce4 | 183 | return; |
23272a67 | 184 | |
9561a7ad JB |
185 | for (i = 0; i < nbd->num_connections; i++) { |
186 | struct nbd_sock *nsock = nbd->socks[i]; | |
187 | mutex_lock(&nsock->tx_lock); | |
188 | kernel_sock_shutdown(nsock->sock, SHUT_RDWR); | |
189 | mutex_unlock(&nsock->tx_lock); | |
190 | } | |
191 | dev_warn(disk_to_dev(nbd->disk), "shutting down sockets\n"); | |
7fdfd406 PC |
192 | } |
193 | ||
0eadf37a JB |
194 | static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, |
195 | bool reserved) | |
7fdfd406 | 196 | { |
0eadf37a JB |
197 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req); |
198 | struct nbd_device *nbd = cmd->nbd; | |
dcc909d9 | 199 | |
9561a7ad | 200 | dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n"); |
9b4a6ba9 | 201 | set_bit(NBD_TIMEDOUT, &nbd->runtime_flags); |
0eadf37a | 202 | req->errors++; |
9561a7ad | 203 | |
9561a7ad JB |
204 | mutex_lock(&nbd->config_lock); |
205 | sock_shutdown(nbd); | |
206 | mutex_unlock(&nbd->config_lock); | |
0eadf37a | 207 | return BLK_EH_HANDLED; |
7fdfd406 PC |
208 | } |
209 | ||
1da177e4 LT |
210 | /* |
211 | * Send or receive packet. | |
212 | */ | |
9561a7ad JB |
213 | static int sock_xmit(struct nbd_device *nbd, int index, int send, void *buf, |
214 | int size, int msg_flags) | |
1da177e4 | 215 | { |
9561a7ad | 216 | struct socket *sock = nbd->socks[index]->sock; |
1da177e4 LT |
217 | int result; |
218 | struct msghdr msg; | |
219 | struct kvec iov; | |
7f338fe4 | 220 | unsigned long pflags = current->flags; |
1da177e4 | 221 | |
ffc41cf8 | 222 | if (unlikely(!sock)) { |
a897b666 | 223 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
224 | "Attempted %s on closed socket in sock_xmit\n", |
225 | (send ? "send" : "recv")); | |
ffc41cf8 MS |
226 | return -EINVAL; |
227 | } | |
228 | ||
7f338fe4 | 229 | current->flags |= PF_MEMALLOC; |
1da177e4 | 230 | do { |
7f338fe4 | 231 | sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC; |
1da177e4 LT |
232 | iov.iov_base = buf; |
233 | iov.iov_len = size; | |
234 | msg.msg_name = NULL; | |
235 | msg.msg_namelen = 0; | |
236 | msg.msg_control = NULL; | |
237 | msg.msg_controllen = 0; | |
1da177e4 LT |
238 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
239 | ||
7e2893a1 | 240 | if (send) |
1da177e4 | 241 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
7e2893a1 | 242 | else |
35fbf5bc NK |
243 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, |
244 | msg.msg_flags); | |
1da177e4 | 245 | |
1da177e4 LT |
246 | if (result <= 0) { |
247 | if (result == 0) | |
248 | result = -EPIPE; /* short read */ | |
249 | break; | |
250 | } | |
251 | size -= result; | |
252 | buf += result; | |
253 | } while (size > 0); | |
254 | ||
7f338fe4 | 255 | tsk_restore_flags(current, pflags, PF_MEMALLOC); |
1da177e4 LT |
256 | |
257 | return result; | |
258 | } | |
259 | ||
9561a7ad JB |
260 | static inline int sock_send_bvec(struct nbd_device *nbd, int index, |
261 | struct bio_vec *bvec, int flags) | |
1da177e4 LT |
262 | { |
263 | int result; | |
264 | void *kaddr = kmap(bvec->bv_page); | |
9561a7ad | 265 | result = sock_xmit(nbd, index, 1, kaddr + bvec->bv_offset, |
f4507164 | 266 | bvec->bv_len, flags); |
1da177e4 LT |
267 | kunmap(bvec->bv_page); |
268 | return result; | |
269 | } | |
270 | ||
7fdfd406 | 271 | /* always call with the tx_lock held */ |
9561a7ad | 272 | static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) |
1da177e4 | 273 | { |
fd8383fd | 274 | struct request *req = blk_mq_rq_from_pdu(cmd); |
d61b7f97 | 275 | int result; |
1da177e4 | 276 | struct nbd_request request; |
1011c1b9 | 277 | unsigned long size = blk_rq_bytes(req); |
429a787b | 278 | struct bio *bio; |
9dc6c806 | 279 | u32 type; |
9561a7ad | 280 | u32 tag = blk_mq_unique_tag(req); |
9dc6c806 | 281 | |
aebf526b CH |
282 | switch (req_op(req)) { |
283 | case REQ_OP_DISCARD: | |
9dc6c806 | 284 | type = NBD_CMD_TRIM; |
aebf526b CH |
285 | break; |
286 | case REQ_OP_FLUSH: | |
9dc6c806 | 287 | type = NBD_CMD_FLUSH; |
aebf526b CH |
288 | break; |
289 | case REQ_OP_WRITE: | |
9dc6c806 | 290 | type = NBD_CMD_WRITE; |
aebf526b CH |
291 | break; |
292 | case REQ_OP_READ: | |
9dc6c806 | 293 | type = NBD_CMD_READ; |
aebf526b CH |
294 | break; |
295 | default: | |
296 | return -EIO; | |
297 | } | |
1da177e4 | 298 | |
09fc54cc CH |
299 | if (rq_data_dir(req) == WRITE && |
300 | (nbd->flags & NBD_FLAG_READ_ONLY)) { | |
301 | dev_err_ratelimited(disk_to_dev(nbd->disk), | |
302 | "Write on read-only\n"); | |
303 | return -EIO; | |
304 | } | |
305 | ||
04cfac4e | 306 | memset(&request, 0, sizeof(request)); |
1da177e4 | 307 | request.magic = htonl(NBD_REQUEST_MAGIC); |
9dc6c806 | 308 | request.type = htonl(type); |
9561a7ad | 309 | if (type != NBD_CMD_FLUSH) { |
75f187ab AB |
310 | request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); |
311 | request.len = htonl(size); | |
312 | } | |
9561a7ad | 313 | memcpy(request.handle, &tag, sizeof(tag)); |
1da177e4 | 314 | |
d18509f5 | 315 | dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n", |
fd8383fd | 316 | cmd, nbdcmd_to_ascii(type), |
d18509f5 | 317 | (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req)); |
9561a7ad | 318 | result = sock_xmit(nbd, index, 1, &request, sizeof(request), |
9dc6c806 | 319 | (type == NBD_CMD_WRITE) ? MSG_MORE : 0); |
1da177e4 | 320 | if (result <= 0) { |
a897b666 | 321 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
7f1b90f9 | 322 | "Send control failed (result %d)\n", result); |
dab5313a | 323 | return -EIO; |
1da177e4 LT |
324 | } |
325 | ||
429a787b JA |
326 | if (type != NBD_CMD_WRITE) |
327 | return 0; | |
328 | ||
429a787b JA |
329 | bio = req->bio; |
330 | while (bio) { | |
331 | struct bio *next = bio->bi_next; | |
332 | struct bvec_iter iter; | |
7988613b | 333 | struct bio_vec bvec; |
429a787b JA |
334 | |
335 | bio_for_each_segment(bvec, bio, iter) { | |
336 | bool is_last = !next && bio_iter_last(bvec, iter); | |
d61b7f97 | 337 | int flags = is_last ? 0 : MSG_MORE; |
429a787b | 338 | |
d18509f5 | 339 | dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n", |
fd8383fd | 340 | cmd, bvec.bv_len); |
9561a7ad | 341 | result = sock_send_bvec(nbd, index, &bvec, flags); |
6c92e699 | 342 | if (result <= 0) { |
f4507164 | 343 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
344 | "Send data failed (result %d)\n", |
345 | result); | |
dab5313a | 346 | return -EIO; |
6c92e699 | 347 | } |
429a787b JA |
348 | /* |
349 | * The completion might already have come in, | |
350 | * so break for the last one instead of letting | |
351 | * the iterator do it. This prevents use-after-free | |
352 | * of the bio. | |
353 | */ | |
354 | if (is_last) | |
355 | break; | |
1da177e4 | 356 | } |
429a787b | 357 | bio = next; |
1da177e4 | 358 | } |
1da177e4 | 359 | return 0; |
1da177e4 LT |
360 | } |
361 | ||
9561a7ad JB |
362 | static inline int sock_recv_bvec(struct nbd_device *nbd, int index, |
363 | struct bio_vec *bvec) | |
1da177e4 LT |
364 | { |
365 | int result; | |
366 | void *kaddr = kmap(bvec->bv_page); | |
9561a7ad JB |
367 | result = sock_xmit(nbd, index, 0, kaddr + bvec->bv_offset, |
368 | bvec->bv_len, MSG_WAITALL); | |
1da177e4 LT |
369 | kunmap(bvec->bv_page); |
370 | return result; | |
371 | } | |
372 | ||
373 | /* NULL returned = something went wrong, inform userspace */ | |
9561a7ad | 374 | static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) |
1da177e4 LT |
375 | { |
376 | int result; | |
377 | struct nbd_reply reply; | |
fd8383fd JB |
378 | struct nbd_cmd *cmd; |
379 | struct request *req = NULL; | |
380 | u16 hwq; | |
9561a7ad | 381 | u32 tag; |
1da177e4 LT |
382 | |
383 | reply.magic = 0; | |
9561a7ad | 384 | result = sock_xmit(nbd, index, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 | 385 | if (result <= 0) { |
9561a7ad JB |
386 | if (!test_bit(NBD_DISCONNECTED, &nbd->runtime_flags) && |
387 | !test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
388 | dev_err(disk_to_dev(nbd->disk), | |
389 | "Receive control failed (result %d)\n", result); | |
19391830 | 390 | return ERR_PTR(result); |
1da177e4 | 391 | } |
e4b57e08 MF |
392 | |
393 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
f4507164 | 394 | dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n", |
e4b57e08 | 395 | (unsigned long)ntohl(reply.magic)); |
19391830 | 396 | return ERR_PTR(-EPROTO); |
e4b57e08 MF |
397 | } |
398 | ||
9561a7ad | 399 | memcpy(&tag, reply.handle, sizeof(u32)); |
4b2f0260 | 400 | |
fd8383fd JB |
401 | hwq = blk_mq_unique_tag_to_hwq(tag); |
402 | if (hwq < nbd->tag_set.nr_hw_queues) | |
403 | req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq], | |
404 | blk_mq_unique_tag_to_tag(tag)); | |
405 | if (!req || !blk_mq_request_started(req)) { | |
406 | dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n", | |
407 | tag, req); | |
408 | return ERR_PTR(-ENOENT); | |
1da177e4 | 409 | } |
fd8383fd | 410 | cmd = blk_mq_rq_to_pdu(req); |
1da177e4 | 411 | if (ntohl(reply.error)) { |
f4507164 | 412 | dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n", |
7f1b90f9 | 413 | ntohl(reply.error)); |
1da177e4 | 414 | req->errors++; |
fd8383fd | 415 | return cmd; |
1da177e4 LT |
416 | } |
417 | ||
fd8383fd | 418 | dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", cmd); |
9dc6c806 | 419 | if (rq_data_dir(req) != WRITE) { |
5705f702 | 420 | struct req_iterator iter; |
7988613b | 421 | struct bio_vec bvec; |
5705f702 N |
422 | |
423 | rq_for_each_segment(bvec, req, iter) { | |
9561a7ad | 424 | result = sock_recv_bvec(nbd, index, &bvec); |
6c92e699 | 425 | if (result <= 0) { |
f4507164 | 426 | dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", |
7f1b90f9 | 427 | result); |
6c92e699 | 428 | req->errors++; |
fd8383fd | 429 | return cmd; |
6c92e699 | 430 | } |
d18509f5 | 431 | dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n", |
fd8383fd | 432 | cmd, bvec.bv_len); |
1da177e4 | 433 | } |
9561a7ad JB |
434 | } else { |
435 | /* See the comment in nbd_queue_rq. */ | |
436 | wait_for_completion(&cmd->send_complete); | |
1da177e4 | 437 | } |
fd8383fd | 438 | return cmd; |
1da177e4 LT |
439 | } |
440 | ||
edfaa7c3 KS |
441 | static ssize_t pid_show(struct device *dev, |
442 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 443 | { |
edfaa7c3 | 444 | struct gendisk *disk = dev_to_disk(dev); |
6521d39a | 445 | struct nbd_device *nbd = (struct nbd_device *)disk->private_data; |
edfaa7c3 | 446 | |
6521d39a | 447 | return sprintf(buf, "%d\n", task_pid_nr(nbd->task_recv)); |
6b39bb65 PC |
448 | } |
449 | ||
edfaa7c3 | 450 | static struct device_attribute pid_attr = { |
01e8ef11 | 451 | .attr = { .name = "pid", .mode = S_IRUGO}, |
6b39bb65 PC |
452 | .show = pid_show, |
453 | }; | |
454 | ||
9561a7ad JB |
455 | struct recv_thread_args { |
456 | struct work_struct work; | |
457 | struct nbd_device *nbd; | |
458 | int index; | |
459 | }; | |
460 | ||
461 | static void recv_work(struct work_struct *work) | |
1da177e4 | 462 | { |
9561a7ad JB |
463 | struct recv_thread_args *args = container_of(work, |
464 | struct recv_thread_args, | |
465 | work); | |
466 | struct nbd_device *nbd = args->nbd; | |
fd8383fd | 467 | struct nbd_cmd *cmd; |
9561a7ad | 468 | int ret = 0; |
1da177e4 | 469 | |
f4507164 | 470 | BUG_ON(nbd->magic != NBD_MAGIC); |
19391830 | 471 | while (1) { |
9561a7ad | 472 | cmd = nbd_read_stat(nbd, args->index); |
fd8383fd JB |
473 | if (IS_ERR(cmd)) { |
474 | ret = PTR_ERR(cmd); | |
19391830 MP |
475 | break; |
476 | } | |
477 | ||
fd8383fd | 478 | nbd_end_request(cmd); |
19391830 | 479 | } |
6b39bb65 | 480 | |
9561a7ad JB |
481 | /* |
482 | * We got an error, shut everybody down if this wasn't the result of a | |
483 | * disconnect request. | |
484 | */ | |
485 | if (ret && !test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
486 | sock_shutdown(nbd); | |
487 | atomic_dec(&nbd->recv_threads); | |
488 | wake_up(&nbd->recv_wq); | |
1da177e4 LT |
489 | } |
490 | ||
fd8383fd | 491 | static void nbd_clear_req(struct request *req, void *data, bool reserved) |
1da177e4 | 492 | { |
fd8383fd | 493 | struct nbd_cmd *cmd; |
1da177e4 | 494 | |
fd8383fd JB |
495 | if (!blk_mq_request_started(req)) |
496 | return; | |
497 | cmd = blk_mq_rq_to_pdu(req); | |
498 | req->errors++; | |
499 | nbd_end_request(cmd); | |
500 | } | |
501 | ||
502 | static void nbd_clear_que(struct nbd_device *nbd) | |
503 | { | |
f4507164 | 504 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 505 | |
fd8383fd | 506 | blk_mq_tagset_busy_iter(&nbd->tag_set, nbd_clear_req, NULL); |
e78273c8 | 507 | dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n"); |
1da177e4 LT |
508 | } |
509 | ||
7fdfd406 | 510 | |
9561a7ad | 511 | static void nbd_handle_cmd(struct nbd_cmd *cmd, int index) |
48cf6061 | 512 | { |
fd8383fd JB |
513 | struct request *req = blk_mq_rq_from_pdu(cmd); |
514 | struct nbd_device *nbd = cmd->nbd; | |
9561a7ad | 515 | struct nbd_sock *nsock; |
fd8383fd | 516 | |
9561a7ad | 517 | if (index >= nbd->num_connections) { |
a897b666 JB |
518 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
519 | "Attempted send on invalid socket\n"); | |
48cf6061 | 520 | goto error_out; |
9561a7ad | 521 | } |
48cf6061 | 522 | |
9561a7ad | 523 | if (test_bit(NBD_DISCONNECTED, &nbd->runtime_flags)) { |
a897b666 JB |
524 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
525 | "Attempted send on closed socket\n"); | |
9561a7ad JB |
526 | goto error_out; |
527 | } | |
528 | ||
48cf6061 LV |
529 | req->errors = 0; |
530 | ||
9561a7ad JB |
531 | nsock = nbd->socks[index]; |
532 | mutex_lock(&nsock->tx_lock); | |
533 | if (unlikely(!nsock->sock)) { | |
534 | mutex_unlock(&nsock->tx_lock); | |
a897b666 JB |
535 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
536 | "Attempted send on closed socket\n"); | |
15746fca | 537 | goto error_out; |
48cf6061 LV |
538 | } |
539 | ||
9561a7ad | 540 | if (nbd_send_cmd(nbd, cmd, index) != 0) { |
a897b666 JB |
541 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
542 | "Request send failed\n"); | |
48cf6061 | 543 | req->errors++; |
fd8383fd | 544 | nbd_end_request(cmd); |
48cf6061 LV |
545 | } |
546 | ||
9561a7ad | 547 | mutex_unlock(&nsock->tx_lock); |
48cf6061 LV |
548 | |
549 | return; | |
550 | ||
551 | error_out: | |
552 | req->errors++; | |
fd8383fd | 553 | nbd_end_request(cmd); |
48cf6061 LV |
554 | } |
555 | ||
fd8383fd JB |
556 | static int nbd_queue_rq(struct blk_mq_hw_ctx *hctx, |
557 | const struct blk_mq_queue_data *bd) | |
1da177e4 | 558 | { |
fd8383fd | 559 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); |
1da177e4 | 560 | |
9561a7ad JB |
561 | /* |
562 | * Since we look at the bio's to send the request over the network we | |
563 | * need to make sure the completion work doesn't mark this request done | |
564 | * before we are done doing our send. This keeps us from dereferencing | |
565 | * freed data if we have particularly fast completions (ie we get the | |
566 | * completion before we exit sock_xmit on the last bvec) or in the case | |
567 | * that the server is misbehaving (or there was an error) before we're | |
568 | * done sending everything over the wire. | |
569 | */ | |
570 | init_completion(&cmd->send_complete); | |
fd8383fd | 571 | blk_mq_start_request(bd->rq); |
9561a7ad JB |
572 | nbd_handle_cmd(cmd, hctx->queue_num); |
573 | complete(&cmd->send_complete); | |
574 | ||
fd8383fd | 575 | return BLK_MQ_RQ_QUEUE_OK; |
1da177e4 LT |
576 | } |
577 | ||
9442b739 JB |
578 | static int nbd_add_socket(struct nbd_device *nbd, struct block_device *bdev, |
579 | unsigned long arg) | |
23272a67 | 580 | { |
9442b739 | 581 | struct socket *sock; |
9561a7ad JB |
582 | struct nbd_sock **socks; |
583 | struct nbd_sock *nsock; | |
9442b739 JB |
584 | int err; |
585 | ||
586 | sock = sockfd_lookup(arg, &err); | |
587 | if (!sock) | |
588 | return err; | |
23272a67 | 589 | |
9561a7ad JB |
590 | if (!nbd->task_setup) |
591 | nbd->task_setup = current; | |
592 | if (nbd->task_setup != current) { | |
593 | dev_err(disk_to_dev(nbd->disk), | |
594 | "Device being setup by another task"); | |
595 | return -EINVAL; | |
23272a67 MP |
596 | } |
597 | ||
9561a7ad JB |
598 | socks = krealloc(nbd->socks, (nbd->num_connections + 1) * |
599 | sizeof(struct nbd_sock *), GFP_KERNEL); | |
600 | if (!socks) | |
601 | return -ENOMEM; | |
602 | nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL); | |
603 | if (!nsock) | |
604 | return -ENOMEM; | |
605 | ||
606 | nbd->socks = socks; | |
23272a67 | 607 | |
9561a7ad JB |
608 | mutex_init(&nsock->tx_lock); |
609 | nsock->sock = sock; | |
610 | socks[nbd->num_connections++] = nsock; | |
23272a67 | 611 | |
9442b739 JB |
612 | if (max_part) |
613 | bdev->bd_invalidated = 1; | |
9561a7ad | 614 | return 0; |
23272a67 MP |
615 | } |
616 | ||
0e4f0f6f MP |
617 | /* Reset all properties of an NBD device */ |
618 | static void nbd_reset(struct nbd_device *nbd) | |
619 | { | |
9b4a6ba9 | 620 | nbd->runtime_flags = 0; |
0e4f0f6f MP |
621 | nbd->blksize = 1024; |
622 | nbd->bytesize = 0; | |
623 | set_capacity(nbd->disk, 0); | |
624 | nbd->flags = 0; | |
0eadf37a | 625 | nbd->tag_set.timeout = 0; |
0e4f0f6f | 626 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); |
0e4f0f6f MP |
627 | } |
628 | ||
629 | static void nbd_bdev_reset(struct block_device *bdev) | |
630 | { | |
631 | set_device_ro(bdev, false); | |
632 | bdev->bd_inode->i_size = 0; | |
633 | if (max_part > 0) { | |
634 | blkdev_reread_part(bdev); | |
635 | bdev->bd_invalidated = 1; | |
636 | } | |
637 | } | |
638 | ||
d02cf531 MP |
639 | static void nbd_parse_flags(struct nbd_device *nbd, struct block_device *bdev) |
640 | { | |
641 | if (nbd->flags & NBD_FLAG_READ_ONLY) | |
642 | set_device_ro(bdev, true); | |
643 | if (nbd->flags & NBD_FLAG_SEND_TRIM) | |
644 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); | |
645 | if (nbd->flags & NBD_FLAG_SEND_FLUSH) | |
aafb1eec | 646 | blk_queue_write_cache(nbd->disk->queue, true, false); |
d02cf531 | 647 | else |
aafb1eec | 648 | blk_queue_write_cache(nbd->disk->queue, false, false); |
d02cf531 MP |
649 | } |
650 | ||
9561a7ad JB |
651 | static void send_disconnects(struct nbd_device *nbd) |
652 | { | |
653 | struct nbd_request request = {}; | |
654 | int i, ret; | |
655 | ||
656 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
657 | request.type = htonl(NBD_CMD_DISC); | |
658 | ||
659 | for (i = 0; i < nbd->num_connections; i++) { | |
660 | ret = sock_xmit(nbd, i, 1, &request, sizeof(request), 0); | |
661 | if (ret <= 0) | |
662 | dev_err(disk_to_dev(nbd->disk), | |
663 | "Send disconnect failed %d\n", ret); | |
664 | } | |
665 | } | |
666 | ||
9442b739 JB |
667 | static int nbd_disconnect(struct nbd_device *nbd, struct block_device *bdev) |
668 | { | |
669 | dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n"); | |
670 | if (!nbd->socks) | |
671 | return -EINVAL; | |
30d53d9c | 672 | |
9442b739 JB |
673 | mutex_unlock(&nbd->config_lock); |
674 | fsync_bdev(bdev); | |
675 | mutex_lock(&nbd->config_lock); | |
676 | ||
677 | /* Check again after getting mutex back. */ | |
678 | if (!nbd->socks) | |
679 | return -EINVAL; | |
680 | ||
681 | if (!test_and_set_bit(NBD_DISCONNECT_REQUESTED, | |
682 | &nbd->runtime_flags)) | |
683 | send_disconnects(nbd); | |
684 | return 0; | |
685 | } | |
686 | ||
687 | static int nbd_clear_sock(struct nbd_device *nbd, struct block_device *bdev) | |
1a2ad211 | 688 | { |
9442b739 JB |
689 | sock_shutdown(nbd); |
690 | nbd_clear_que(nbd); | |
691 | kill_bdev(bdev); | |
692 | nbd_bdev_reset(bdev); | |
693 | /* | |
694 | * We want to give the run thread a chance to wait for everybody | |
695 | * to clean up and then do it's own cleanup. | |
696 | */ | |
697 | if (!test_bit(NBD_RUNNING, &nbd->runtime_flags) && | |
698 | nbd->num_connections) { | |
699 | int i; | |
700 | ||
701 | for (i = 0; i < nbd->num_connections; i++) | |
702 | kfree(nbd->socks[i]); | |
703 | kfree(nbd->socks); | |
704 | nbd->socks = NULL; | |
705 | nbd->num_connections = 0; | |
1a2ad211 | 706 | } |
9442b739 | 707 | nbd->task_setup = NULL; |
9561a7ad | 708 | |
9442b739 JB |
709 | return 0; |
710 | } | |
711 | ||
712 | static int nbd_start_device(struct nbd_device *nbd, struct block_device *bdev) | |
713 | { | |
714 | struct recv_thread_args *args; | |
715 | int num_connections = nbd->num_connections; | |
716 | int error = 0, i; | |
1a2ad211 | 717 | |
9442b739 JB |
718 | if (nbd->task_recv) |
719 | return -EBUSY; | |
720 | if (!nbd->socks) | |
721 | return -EINVAL; | |
722 | if (num_connections > 1 && | |
723 | !(nbd->flags & NBD_FLAG_CAN_MULTI_CONN)) { | |
724 | dev_err(disk_to_dev(nbd->disk), "server does not support multiple connections per device.\n"); | |
725 | error = -EINVAL; | |
726 | goto out_err; | |
727 | } | |
23272a67 | 728 | |
9442b739 JB |
729 | set_bit(NBD_RUNNING, &nbd->runtime_flags); |
730 | blk_mq_update_nr_hw_queues(&nbd->tag_set, nbd->num_connections); | |
731 | args = kcalloc(num_connections, sizeof(*args), GFP_KERNEL); | |
732 | if (!args) { | |
733 | error = -ENOMEM; | |
734 | goto out_err; | |
735 | } | |
736 | nbd->task_recv = current; | |
737 | mutex_unlock(&nbd->config_lock); | |
23272a67 | 738 | |
9442b739 | 739 | nbd_parse_flags(nbd, bdev); |
23272a67 | 740 | |
9442b739 JB |
741 | error = device_create_file(disk_to_dev(nbd->disk), &pid_attr); |
742 | if (error) { | |
743 | dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); | |
744 | goto out_recv; | |
1a2ad211 PM |
745 | } |
746 | ||
9442b739 | 747 | nbd_size_update(nbd, bdev); |
37091fdd | 748 | |
9442b739 JB |
749 | nbd_dev_dbg_init(nbd); |
750 | for (i = 0; i < num_connections; i++) { | |
751 | sk_set_memalloc(nbd->socks[i]->sock->sk); | |
752 | atomic_inc(&nbd->recv_threads); | |
753 | INIT_WORK(&args[i].work, recv_work); | |
754 | args[i].nbd = nbd; | |
755 | args[i].index = i; | |
756 | queue_work(recv_workqueue, &args[i].work); | |
37091fdd | 757 | } |
9442b739 JB |
758 | wait_event_interruptible(nbd->recv_wq, |
759 | atomic_read(&nbd->recv_threads) == 0); | |
760 | for (i = 0; i < num_connections; i++) | |
761 | flush_work(&args[i].work); | |
762 | nbd_dev_dbg_close(nbd); | |
763 | nbd_size_clear(nbd, bdev); | |
764 | device_remove_file(disk_to_dev(nbd->disk), &pid_attr); | |
765 | out_recv: | |
766 | mutex_lock(&nbd->config_lock); | |
767 | nbd->task_recv = NULL; | |
768 | out_err: | |
769 | clear_bit(NBD_RUNNING, &nbd->runtime_flags); | |
770 | nbd_clear_sock(nbd, bdev); | |
771 | ||
772 | /* user requested, ignore socket errors */ | |
773 | if (test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
774 | error = 0; | |
775 | if (test_bit(NBD_TIMEDOUT, &nbd->runtime_flags)) | |
776 | error = -ETIMEDOUT; | |
1a2ad211 | 777 | |
9442b739 JB |
778 | nbd_reset(nbd); |
779 | return error; | |
780 | } | |
781 | ||
782 | /* Must be called with config_lock held */ | |
783 | static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, | |
784 | unsigned int cmd, unsigned long arg) | |
785 | { | |
786 | switch (cmd) { | |
787 | case NBD_DISCONNECT: | |
788 | return nbd_disconnect(nbd, bdev); | |
789 | case NBD_CLEAR_SOCK: | |
790 | return nbd_clear_sock(nbd, bdev); | |
791 | case NBD_SET_SOCK: | |
792 | return nbd_add_socket(nbd, bdev, arg); | |
793 | case NBD_SET_BLKSIZE: | |
794 | return nbd_size_set(nbd, bdev, arg, | |
795 | div_s64(nbd->bytesize, arg)); | |
1da177e4 | 796 | case NBD_SET_SIZE: |
37091fdd | 797 | return nbd_size_set(nbd, bdev, nbd->blksize, |
e88f72cb | 798 | div_s64(arg, nbd->blksize)); |
37091fdd MP |
799 | |
800 | case NBD_SET_SIZE_BLOCKS: | |
801 | return nbd_size_set(nbd, bdev, nbd->blksize, arg); | |
1a2ad211 | 802 | |
7fdfd406 | 803 | case NBD_SET_TIMEOUT: |
0eadf37a | 804 | nbd->tag_set.timeout = arg * HZ; |
7fdfd406 | 805 | return 0; |
1a2ad211 | 806 | |
2f012508 PC |
807 | case NBD_SET_FLAGS: |
808 | nbd->flags = arg; | |
809 | return 0; | |
9442b739 JB |
810 | case NBD_DO_IT: |
811 | return nbd_start_device(nbd, bdev); | |
1da177e4 | 812 | case NBD_CLEAR_QUE: |
4b2f0260 HX |
813 | /* |
814 | * This is for compatibility only. The queue is always cleared | |
815 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
816 | */ | |
1da177e4 LT |
817 | return 0; |
818 | case NBD_PRINT_DEBUG: | |
fd8383fd JB |
819 | /* |
820 | * For compatibility only, we no longer keep a list of | |
821 | * outstanding requests. | |
822 | */ | |
1da177e4 LT |
823 | return 0; |
824 | } | |
1a2ad211 PM |
825 | return -ENOTTY; |
826 | } | |
827 | ||
828 | static int nbd_ioctl(struct block_device *bdev, fmode_t mode, | |
829 | unsigned int cmd, unsigned long arg) | |
830 | { | |
f4507164 | 831 | struct nbd_device *nbd = bdev->bd_disk->private_data; |
1a2ad211 PM |
832 | int error; |
833 | ||
834 | if (!capable(CAP_SYS_ADMIN)) | |
835 | return -EPERM; | |
836 | ||
f4507164 | 837 | BUG_ON(nbd->magic != NBD_MAGIC); |
1a2ad211 | 838 | |
9561a7ad | 839 | mutex_lock(&nbd->config_lock); |
f4507164 | 840 | error = __nbd_ioctl(bdev, nbd, cmd, arg); |
9561a7ad | 841 | mutex_unlock(&nbd->config_lock); |
1a2ad211 PM |
842 | |
843 | return error; | |
1da177e4 LT |
844 | } |
845 | ||
83d5cde4 | 846 | static const struct block_device_operations nbd_fops = |
1da177e4 LT |
847 | { |
848 | .owner = THIS_MODULE, | |
8a6cfeb6 | 849 | .ioctl = nbd_ioctl, |
263a3df1 | 850 | .compat_ioctl = nbd_ioctl, |
1da177e4 LT |
851 | }; |
852 | ||
30d53d9c MP |
853 | #if IS_ENABLED(CONFIG_DEBUG_FS) |
854 | ||
855 | static int nbd_dbg_tasks_show(struct seq_file *s, void *unused) | |
856 | { | |
857 | struct nbd_device *nbd = s->private; | |
858 | ||
859 | if (nbd->task_recv) | |
860 | seq_printf(s, "recv: %d\n", task_pid_nr(nbd->task_recv)); | |
30d53d9c MP |
861 | |
862 | return 0; | |
863 | } | |
864 | ||
865 | static int nbd_dbg_tasks_open(struct inode *inode, struct file *file) | |
866 | { | |
867 | return single_open(file, nbd_dbg_tasks_show, inode->i_private); | |
868 | } | |
869 | ||
870 | static const struct file_operations nbd_dbg_tasks_ops = { | |
871 | .open = nbd_dbg_tasks_open, | |
872 | .read = seq_read, | |
873 | .llseek = seq_lseek, | |
874 | .release = single_release, | |
875 | }; | |
876 | ||
877 | static int nbd_dbg_flags_show(struct seq_file *s, void *unused) | |
878 | { | |
879 | struct nbd_device *nbd = s->private; | |
880 | u32 flags = nbd->flags; | |
881 | ||
882 | seq_printf(s, "Hex: 0x%08x\n\n", flags); | |
883 | ||
884 | seq_puts(s, "Known flags:\n"); | |
885 | ||
886 | if (flags & NBD_FLAG_HAS_FLAGS) | |
887 | seq_puts(s, "NBD_FLAG_HAS_FLAGS\n"); | |
888 | if (flags & NBD_FLAG_READ_ONLY) | |
889 | seq_puts(s, "NBD_FLAG_READ_ONLY\n"); | |
890 | if (flags & NBD_FLAG_SEND_FLUSH) | |
891 | seq_puts(s, "NBD_FLAG_SEND_FLUSH\n"); | |
892 | if (flags & NBD_FLAG_SEND_TRIM) | |
893 | seq_puts(s, "NBD_FLAG_SEND_TRIM\n"); | |
894 | ||
895 | return 0; | |
896 | } | |
897 | ||
898 | static int nbd_dbg_flags_open(struct inode *inode, struct file *file) | |
899 | { | |
900 | return single_open(file, nbd_dbg_flags_show, inode->i_private); | |
901 | } | |
902 | ||
903 | static const struct file_operations nbd_dbg_flags_ops = { | |
904 | .open = nbd_dbg_flags_open, | |
905 | .read = seq_read, | |
906 | .llseek = seq_lseek, | |
907 | .release = single_release, | |
908 | }; | |
909 | ||
910 | static int nbd_dev_dbg_init(struct nbd_device *nbd) | |
911 | { | |
912 | struct dentry *dir; | |
27ea43fe MP |
913 | |
914 | if (!nbd_dbg_dir) | |
915 | return -EIO; | |
30d53d9c MP |
916 | |
917 | dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir); | |
27ea43fe MP |
918 | if (!dir) { |
919 | dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n", | |
920 | nbd_name(nbd)); | |
921 | return -EIO; | |
30d53d9c MP |
922 | } |
923 | nbd->dbg_dir = dir; | |
924 | ||
27ea43fe MP |
925 | debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops); |
926 | debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize); | |
0eadf37a | 927 | debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout); |
ef77b515 | 928 | debugfs_create_u64("blocksize", 0444, dir, &nbd->blksize); |
d366a0ff | 929 | debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops); |
30d53d9c MP |
930 | |
931 | return 0; | |
932 | } | |
933 | ||
934 | static void nbd_dev_dbg_close(struct nbd_device *nbd) | |
935 | { | |
936 | debugfs_remove_recursive(nbd->dbg_dir); | |
937 | } | |
938 | ||
939 | static int nbd_dbg_init(void) | |
940 | { | |
941 | struct dentry *dbg_dir; | |
942 | ||
943 | dbg_dir = debugfs_create_dir("nbd", NULL); | |
27ea43fe MP |
944 | if (!dbg_dir) |
945 | return -EIO; | |
30d53d9c MP |
946 | |
947 | nbd_dbg_dir = dbg_dir; | |
948 | ||
949 | return 0; | |
950 | } | |
951 | ||
952 | static void nbd_dbg_close(void) | |
953 | { | |
954 | debugfs_remove_recursive(nbd_dbg_dir); | |
955 | } | |
956 | ||
957 | #else /* IS_ENABLED(CONFIG_DEBUG_FS) */ | |
958 | ||
959 | static int nbd_dev_dbg_init(struct nbd_device *nbd) | |
960 | { | |
961 | return 0; | |
962 | } | |
963 | ||
964 | static void nbd_dev_dbg_close(struct nbd_device *nbd) | |
965 | { | |
966 | } | |
967 | ||
968 | static int nbd_dbg_init(void) | |
969 | { | |
970 | return 0; | |
971 | } | |
972 | ||
973 | static void nbd_dbg_close(void) | |
974 | { | |
975 | } | |
976 | ||
977 | #endif | |
978 | ||
fd8383fd JB |
979 | static int nbd_init_request(void *data, struct request *rq, |
980 | unsigned int hctx_idx, unsigned int request_idx, | |
981 | unsigned int numa_node) | |
982 | { | |
983 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq); | |
fd8383fd | 984 | cmd->nbd = data; |
fd8383fd JB |
985 | return 0; |
986 | } | |
987 | ||
988 | static struct blk_mq_ops nbd_mq_ops = { | |
989 | .queue_rq = nbd_queue_rq, | |
fd8383fd | 990 | .init_request = nbd_init_request, |
0eadf37a | 991 | .timeout = nbd_xmit_timeout, |
fd8383fd JB |
992 | }; |
993 | ||
b0d9111a JB |
994 | static void nbd_dev_remove(struct nbd_device *nbd) |
995 | { | |
996 | struct gendisk *disk = nbd->disk; | |
997 | nbd->magic = 0; | |
998 | if (disk) { | |
999 | del_gendisk(disk); | |
1000 | blk_cleanup_queue(disk->queue); | |
1001 | blk_mq_free_tag_set(&nbd->tag_set); | |
1002 | put_disk(disk); | |
1003 | } | |
1004 | kfree(nbd); | |
1005 | } | |
1006 | ||
1007 | static int nbd_dev_add(int index) | |
1008 | { | |
1009 | struct nbd_device *nbd; | |
1010 | struct gendisk *disk; | |
1011 | struct request_queue *q; | |
1012 | int err = -ENOMEM; | |
1013 | ||
1014 | nbd = kzalloc(sizeof(struct nbd_device), GFP_KERNEL); | |
1015 | if (!nbd) | |
1016 | goto out; | |
1017 | ||
1018 | disk = alloc_disk(1 << part_shift); | |
1019 | if (!disk) | |
1020 | goto out_free_nbd; | |
1021 | ||
1022 | if (index >= 0) { | |
1023 | err = idr_alloc(&nbd_index_idr, nbd, index, index + 1, | |
1024 | GFP_KERNEL); | |
1025 | if (err == -ENOSPC) | |
1026 | err = -EEXIST; | |
1027 | } else { | |
1028 | err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL); | |
1029 | if (err >= 0) | |
1030 | index = err; | |
1031 | } | |
1032 | if (err < 0) | |
1033 | goto out_free_disk; | |
1034 | ||
1035 | nbd->disk = disk; | |
1036 | nbd->tag_set.ops = &nbd_mq_ops; | |
1037 | nbd->tag_set.nr_hw_queues = 1; | |
1038 | nbd->tag_set.queue_depth = 128; | |
1039 | nbd->tag_set.numa_node = NUMA_NO_NODE; | |
1040 | nbd->tag_set.cmd_size = sizeof(struct nbd_cmd); | |
1041 | nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | | |
1042 | BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING; | |
1043 | nbd->tag_set.driver_data = nbd; | |
1044 | ||
1045 | err = blk_mq_alloc_tag_set(&nbd->tag_set); | |
1046 | if (err) | |
1047 | goto out_free_idr; | |
1048 | ||
1049 | q = blk_mq_init_queue(&nbd->tag_set); | |
1050 | if (IS_ERR(q)) { | |
1051 | err = PTR_ERR(q); | |
1052 | goto out_free_tags; | |
1053 | } | |
1054 | disk->queue = q; | |
1055 | ||
1056 | /* | |
1057 | * Tell the block layer that we are not a rotational device | |
1058 | */ | |
1059 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue); | |
1060 | queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, disk->queue); | |
1061 | disk->queue->limits.discard_granularity = 512; | |
1062 | blk_queue_max_discard_sectors(disk->queue, UINT_MAX); | |
1063 | disk->queue->limits.discard_zeroes_data = 0; | |
1064 | blk_queue_max_hw_sectors(disk->queue, 65536); | |
1065 | disk->queue->limits.max_sectors = 256; | |
1066 | ||
1067 | nbd->magic = NBD_MAGIC; | |
1068 | mutex_init(&nbd->config_lock); | |
1069 | disk->major = NBD_MAJOR; | |
1070 | disk->first_minor = index << part_shift; | |
1071 | disk->fops = &nbd_fops; | |
1072 | disk->private_data = nbd; | |
1073 | sprintf(disk->disk_name, "nbd%d", index); | |
1074 | init_waitqueue_head(&nbd->recv_wq); | |
1075 | nbd_reset(nbd); | |
1076 | add_disk(disk); | |
1077 | return index; | |
1078 | ||
1079 | out_free_tags: | |
1080 | blk_mq_free_tag_set(&nbd->tag_set); | |
1081 | out_free_idr: | |
1082 | idr_remove(&nbd_index_idr, index); | |
1083 | out_free_disk: | |
1084 | put_disk(disk); | |
1085 | out_free_nbd: | |
1086 | kfree(nbd); | |
1087 | out: | |
1088 | return err; | |
1089 | } | |
1090 | ||
1da177e4 LT |
1091 | /* |
1092 | * And here should be modules and kernel interface | |
1093 | * (Just smiley confuses emacs :-) | |
1094 | */ | |
1095 | ||
1096 | static int __init nbd_init(void) | |
1097 | { | |
1da177e4 LT |
1098 | int i; |
1099 | ||
5b7b18cc | 1100 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 1101 | |
d71a6d73 | 1102 | if (max_part < 0) { |
7742ce4a | 1103 | printk(KERN_ERR "nbd: max_part must be >= 0\n"); |
d71a6d73 LV |
1104 | return -EINVAL; |
1105 | } | |
1106 | ||
1107 | part_shift = 0; | |
5988ce23 | 1108 | if (max_part > 0) { |
d71a6d73 LV |
1109 | part_shift = fls(max_part); |
1110 | ||
5988ce23 NK |
1111 | /* |
1112 | * Adjust max_part according to part_shift as it is exported | |
1113 | * to user space so that user can know the max number of | |
1114 | * partition kernel should be able to manage. | |
1115 | * | |
1116 | * Note that -1 is required because partition 0 is reserved | |
1117 | * for the whole disk. | |
1118 | */ | |
1119 | max_part = (1UL << part_shift) - 1; | |
1120 | } | |
1121 | ||
3b271082 NK |
1122 | if ((1UL << part_shift) > DISK_MAX_PARTS) |
1123 | return -EINVAL; | |
1124 | ||
1125 | if (nbds_max > 1UL << (MINORBITS - part_shift)) | |
1126 | return -EINVAL; | |
124d6db0 JB |
1127 | recv_workqueue = alloc_workqueue("knbd-recv", |
1128 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 0); | |
1129 | if (!recv_workqueue) | |
1130 | return -ENOMEM; | |
3b271082 | 1131 | |
b0d9111a JB |
1132 | if (register_blkdev(NBD_MAJOR, "nbd")) |
1133 | return -EIO; | |
1da177e4 | 1134 | |
30d53d9c MP |
1135 | nbd_dbg_init(); |
1136 | ||
b0d9111a JB |
1137 | mutex_lock(&nbd_index_mutex); |
1138 | for (i = 0; i < nbds_max; i++) | |
1139 | nbd_dev_add(i); | |
1140 | mutex_unlock(&nbd_index_mutex); | |
1141 | return 0; | |
1142 | } | |
1da177e4 | 1143 | |
b0d9111a JB |
1144 | static int nbd_exit_cb(int id, void *ptr, void *data) |
1145 | { | |
1146 | struct nbd_device *nbd = ptr; | |
1147 | nbd_dev_remove(nbd); | |
1da177e4 | 1148 | return 0; |
1da177e4 LT |
1149 | } |
1150 | ||
1151 | static void __exit nbd_cleanup(void) | |
1152 | { | |
30d53d9c MP |
1153 | nbd_dbg_close(); |
1154 | ||
b0d9111a JB |
1155 | idr_for_each(&nbd_index_idr, &nbd_exit_cb, NULL); |
1156 | idr_destroy(&nbd_index_idr); | |
124d6db0 | 1157 | destroy_workqueue(recv_workqueue); |
1da177e4 | 1158 | unregister_blkdev(NBD_MAJOR, "nbd"); |
1da177e4 LT |
1159 | } |
1160 | ||
1161 | module_init(nbd_init); | |
1162 | module_exit(nbd_cleanup); | |
1163 | ||
1164 | MODULE_DESCRIPTION("Network Block Device"); | |
1165 | MODULE_LICENSE("GPL"); | |
1166 | ||
40be0c28 | 1167 | module_param(nbds_max, int, 0444); |
d71a6d73 LV |
1168 | MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); |
1169 | module_param(max_part, int, 0444); | |
1170 | MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)"); |