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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 | { | |
e544541b | 127 | bd_set_size(bdev, 0); |
37091fdd MP |
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 | { | |
e544541b JB |
136 | blk_queue_logical_block_size(nbd->disk->queue, nbd->blksize); |
137 | blk_queue_physical_block_size(nbd->disk->queue, nbd->blksize); | |
138 | bd_set_size(bdev, nbd->bytesize); | |
37091fdd MP |
139 | set_capacity(nbd->disk, nbd->bytesize >> 9); |
140 | kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); | |
141 | } | |
142 | ||
e544541b | 143 | static void nbd_size_set(struct nbd_device *nbd, struct block_device *bdev, |
ef77b515 | 144 | loff_t blocksize, loff_t nr_blocks) |
37091fdd | 145 | { |
37091fdd | 146 | nbd->blksize = blocksize; |
ef77b515 | 147 | nbd->bytesize = blocksize * nr_blocks; |
e544541b JB |
148 | if (nbd_is_connected(nbd)) |
149 | nbd_size_update(nbd, bdev); | |
37091fdd MP |
150 | } |
151 | ||
fd8383fd | 152 | static void nbd_end_request(struct nbd_cmd *cmd) |
1da177e4 | 153 | { |
fd8383fd JB |
154 | struct nbd_device *nbd = cmd->nbd; |
155 | struct request *req = blk_mq_rq_from_pdu(cmd); | |
097c94a4 | 156 | int error = req->errors ? -EIO : 0; |
1da177e4 | 157 | |
fd8383fd | 158 | dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", cmd, |
d18509f5 | 159 | error ? "failed" : "done"); |
1da177e4 | 160 | |
fd8383fd | 161 | blk_mq_complete_request(req, error); |
1da177e4 LT |
162 | } |
163 | ||
e018e757 MP |
164 | /* |
165 | * Forcibly shutdown the socket causing all listeners to error | |
166 | */ | |
36e47bee | 167 | static void sock_shutdown(struct nbd_device *nbd) |
7fdfd406 | 168 | { |
9561a7ad | 169 | int i; |
23272a67 | 170 | |
9561a7ad JB |
171 | if (nbd->num_connections == 0) |
172 | return; | |
173 | if (test_and_set_bit(NBD_DISCONNECTED, &nbd->runtime_flags)) | |
260bbce4 | 174 | return; |
23272a67 | 175 | |
9561a7ad JB |
176 | for (i = 0; i < nbd->num_connections; i++) { |
177 | struct nbd_sock *nsock = nbd->socks[i]; | |
178 | mutex_lock(&nsock->tx_lock); | |
179 | kernel_sock_shutdown(nsock->sock, SHUT_RDWR); | |
180 | mutex_unlock(&nsock->tx_lock); | |
181 | } | |
182 | dev_warn(disk_to_dev(nbd->disk), "shutting down sockets\n"); | |
7fdfd406 PC |
183 | } |
184 | ||
0eadf37a JB |
185 | static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, |
186 | bool reserved) | |
7fdfd406 | 187 | { |
0eadf37a JB |
188 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req); |
189 | struct nbd_device *nbd = cmd->nbd; | |
dcc909d9 | 190 | |
9561a7ad | 191 | dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n"); |
9b4a6ba9 | 192 | set_bit(NBD_TIMEDOUT, &nbd->runtime_flags); |
0eadf37a | 193 | req->errors++; |
9561a7ad | 194 | |
9561a7ad JB |
195 | mutex_lock(&nbd->config_lock); |
196 | sock_shutdown(nbd); | |
197 | mutex_unlock(&nbd->config_lock); | |
0eadf37a | 198 | return BLK_EH_HANDLED; |
7fdfd406 PC |
199 | } |
200 | ||
1da177e4 LT |
201 | /* |
202 | * Send or receive packet. | |
203 | */ | |
c9f2b6ae AV |
204 | static int sock_xmit(struct nbd_device *nbd, int index, int send, |
205 | struct iov_iter *iter, int msg_flags) | |
1da177e4 | 206 | { |
9561a7ad | 207 | struct socket *sock = nbd->socks[index]->sock; |
1da177e4 LT |
208 | int result; |
209 | struct msghdr msg; | |
7f338fe4 | 210 | unsigned long pflags = current->flags; |
1da177e4 | 211 | |
ffc41cf8 | 212 | if (unlikely(!sock)) { |
a897b666 | 213 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
214 | "Attempted %s on closed socket in sock_xmit\n", |
215 | (send ? "send" : "recv")); | |
ffc41cf8 MS |
216 | return -EINVAL; |
217 | } | |
218 | ||
c9f2b6ae | 219 | msg.msg_iter = *iter; |
c1696cab | 220 | |
7f338fe4 | 221 | current->flags |= PF_MEMALLOC; |
1da177e4 | 222 | do { |
7f338fe4 | 223 | sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC; |
1da177e4 LT |
224 | msg.msg_name = NULL; |
225 | msg.msg_namelen = 0; | |
226 | msg.msg_control = NULL; | |
227 | msg.msg_controllen = 0; | |
1da177e4 LT |
228 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
229 | ||
7e2893a1 | 230 | if (send) |
c1696cab | 231 | result = sock_sendmsg(sock, &msg); |
7e2893a1 | 232 | else |
c1696cab | 233 | result = sock_recvmsg(sock, &msg, msg.msg_flags); |
1da177e4 | 234 | |
1da177e4 LT |
235 | if (result <= 0) { |
236 | if (result == 0) | |
237 | result = -EPIPE; /* short read */ | |
238 | break; | |
239 | } | |
c1696cab | 240 | } while (msg_data_left(&msg)); |
1da177e4 | 241 | |
7f338fe4 | 242 | tsk_restore_flags(current, pflags, PF_MEMALLOC); |
1da177e4 LT |
243 | |
244 | return result; | |
245 | } | |
246 | ||
7fdfd406 | 247 | /* always call with the tx_lock held */ |
9561a7ad | 248 | static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) |
1da177e4 | 249 | { |
fd8383fd | 250 | struct request *req = blk_mq_rq_from_pdu(cmd); |
d61b7f97 | 251 | int result; |
c9f2b6ae AV |
252 | struct nbd_request request = {.magic = htonl(NBD_REQUEST_MAGIC)}; |
253 | struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)}; | |
254 | struct iov_iter from; | |
1011c1b9 | 255 | unsigned long size = blk_rq_bytes(req); |
429a787b | 256 | struct bio *bio; |
9dc6c806 | 257 | u32 type; |
9561a7ad | 258 | u32 tag = blk_mq_unique_tag(req); |
9dc6c806 | 259 | |
c9f2b6ae AV |
260 | iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request)); |
261 | ||
aebf526b CH |
262 | switch (req_op(req)) { |
263 | case REQ_OP_DISCARD: | |
9dc6c806 | 264 | type = NBD_CMD_TRIM; |
aebf526b CH |
265 | break; |
266 | case REQ_OP_FLUSH: | |
9dc6c806 | 267 | type = NBD_CMD_FLUSH; |
aebf526b CH |
268 | break; |
269 | case REQ_OP_WRITE: | |
9dc6c806 | 270 | type = NBD_CMD_WRITE; |
aebf526b CH |
271 | break; |
272 | case REQ_OP_READ: | |
9dc6c806 | 273 | type = NBD_CMD_READ; |
aebf526b CH |
274 | break; |
275 | default: | |
276 | return -EIO; | |
277 | } | |
1da177e4 | 278 | |
09fc54cc CH |
279 | if (rq_data_dir(req) == WRITE && |
280 | (nbd->flags & NBD_FLAG_READ_ONLY)) { | |
281 | dev_err_ratelimited(disk_to_dev(nbd->disk), | |
282 | "Write on read-only\n"); | |
283 | return -EIO; | |
284 | } | |
285 | ||
9dc6c806 | 286 | request.type = htonl(type); |
9561a7ad | 287 | if (type != NBD_CMD_FLUSH) { |
75f187ab AB |
288 | request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); |
289 | request.len = htonl(size); | |
290 | } | |
9561a7ad | 291 | memcpy(request.handle, &tag, sizeof(tag)); |
1da177e4 | 292 | |
d18509f5 | 293 | dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n", |
fd8383fd | 294 | cmd, nbdcmd_to_ascii(type), |
d18509f5 | 295 | (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req)); |
c9f2b6ae | 296 | result = sock_xmit(nbd, index, 1, &from, |
9dc6c806 | 297 | (type == NBD_CMD_WRITE) ? MSG_MORE : 0); |
1da177e4 | 298 | if (result <= 0) { |
a897b666 | 299 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
7f1b90f9 | 300 | "Send control failed (result %d)\n", result); |
dab5313a | 301 | return -EIO; |
1da177e4 LT |
302 | } |
303 | ||
429a787b JA |
304 | if (type != NBD_CMD_WRITE) |
305 | return 0; | |
306 | ||
429a787b JA |
307 | bio = req->bio; |
308 | while (bio) { | |
309 | struct bio *next = bio->bi_next; | |
310 | struct bvec_iter iter; | |
7988613b | 311 | struct bio_vec bvec; |
429a787b JA |
312 | |
313 | bio_for_each_segment(bvec, bio, iter) { | |
314 | bool is_last = !next && bio_iter_last(bvec, iter); | |
d61b7f97 | 315 | int flags = is_last ? 0 : MSG_MORE; |
429a787b | 316 | |
d18509f5 | 317 | dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n", |
fd8383fd | 318 | cmd, bvec.bv_len); |
c9f2b6ae AV |
319 | iov_iter_bvec(&from, ITER_BVEC | WRITE, |
320 | &bvec, 1, bvec.bv_len); | |
321 | result = sock_xmit(nbd, index, 1, &from, flags); | |
6c92e699 | 322 | if (result <= 0) { |
f4507164 | 323 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
324 | "Send data failed (result %d)\n", |
325 | result); | |
dab5313a | 326 | return -EIO; |
6c92e699 | 327 | } |
429a787b JA |
328 | /* |
329 | * The completion might already have come in, | |
330 | * so break for the last one instead of letting | |
331 | * the iterator do it. This prevents use-after-free | |
332 | * of the bio. | |
333 | */ | |
334 | if (is_last) | |
335 | break; | |
1da177e4 | 336 | } |
429a787b | 337 | bio = next; |
1da177e4 | 338 | } |
1da177e4 | 339 | return 0; |
1da177e4 LT |
340 | } |
341 | ||
1da177e4 | 342 | /* NULL returned = something went wrong, inform userspace */ |
9561a7ad | 343 | static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) |
1da177e4 LT |
344 | { |
345 | int result; | |
346 | struct nbd_reply reply; | |
fd8383fd JB |
347 | struct nbd_cmd *cmd; |
348 | struct request *req = NULL; | |
349 | u16 hwq; | |
9561a7ad | 350 | u32 tag; |
c9f2b6ae AV |
351 | struct kvec iov = {.iov_base = &reply, .iov_len = sizeof(reply)}; |
352 | struct iov_iter to; | |
1da177e4 LT |
353 | |
354 | reply.magic = 0; | |
c9f2b6ae AV |
355 | iov_iter_kvec(&to, READ | ITER_KVEC, &iov, 1, sizeof(reply)); |
356 | result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL); | |
1da177e4 | 357 | if (result <= 0) { |
9561a7ad JB |
358 | if (!test_bit(NBD_DISCONNECTED, &nbd->runtime_flags) && |
359 | !test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
360 | dev_err(disk_to_dev(nbd->disk), | |
361 | "Receive control failed (result %d)\n", result); | |
19391830 | 362 | return ERR_PTR(result); |
1da177e4 | 363 | } |
e4b57e08 MF |
364 | |
365 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
f4507164 | 366 | dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n", |
e4b57e08 | 367 | (unsigned long)ntohl(reply.magic)); |
19391830 | 368 | return ERR_PTR(-EPROTO); |
e4b57e08 MF |
369 | } |
370 | ||
9561a7ad | 371 | memcpy(&tag, reply.handle, sizeof(u32)); |
4b2f0260 | 372 | |
fd8383fd JB |
373 | hwq = blk_mq_unique_tag_to_hwq(tag); |
374 | if (hwq < nbd->tag_set.nr_hw_queues) | |
375 | req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq], | |
376 | blk_mq_unique_tag_to_tag(tag)); | |
377 | if (!req || !blk_mq_request_started(req)) { | |
378 | dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n", | |
379 | tag, req); | |
380 | return ERR_PTR(-ENOENT); | |
1da177e4 | 381 | } |
fd8383fd | 382 | cmd = blk_mq_rq_to_pdu(req); |
1da177e4 | 383 | if (ntohl(reply.error)) { |
f4507164 | 384 | dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n", |
7f1b90f9 | 385 | ntohl(reply.error)); |
1da177e4 | 386 | req->errors++; |
fd8383fd | 387 | return cmd; |
1da177e4 LT |
388 | } |
389 | ||
fd8383fd | 390 | dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", cmd); |
9dc6c806 | 391 | if (rq_data_dir(req) != WRITE) { |
5705f702 | 392 | struct req_iterator iter; |
7988613b | 393 | struct bio_vec bvec; |
5705f702 N |
394 | |
395 | rq_for_each_segment(bvec, req, iter) { | |
c9f2b6ae AV |
396 | iov_iter_bvec(&to, ITER_BVEC | READ, |
397 | &bvec, 1, bvec.bv_len); | |
398 | result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL); | |
6c92e699 | 399 | if (result <= 0) { |
f4507164 | 400 | dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", |
7f1b90f9 | 401 | result); |
6c92e699 | 402 | req->errors++; |
fd8383fd | 403 | return cmd; |
6c92e699 | 404 | } |
d18509f5 | 405 | dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n", |
fd8383fd | 406 | cmd, bvec.bv_len); |
1da177e4 | 407 | } |
9561a7ad JB |
408 | } else { |
409 | /* See the comment in nbd_queue_rq. */ | |
410 | wait_for_completion(&cmd->send_complete); | |
1da177e4 | 411 | } |
fd8383fd | 412 | return cmd; |
1da177e4 LT |
413 | } |
414 | ||
edfaa7c3 KS |
415 | static ssize_t pid_show(struct device *dev, |
416 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 417 | { |
edfaa7c3 | 418 | struct gendisk *disk = dev_to_disk(dev); |
6521d39a | 419 | struct nbd_device *nbd = (struct nbd_device *)disk->private_data; |
edfaa7c3 | 420 | |
6521d39a | 421 | return sprintf(buf, "%d\n", task_pid_nr(nbd->task_recv)); |
6b39bb65 PC |
422 | } |
423 | ||
edfaa7c3 | 424 | static struct device_attribute pid_attr = { |
01e8ef11 | 425 | .attr = { .name = "pid", .mode = S_IRUGO}, |
6b39bb65 PC |
426 | .show = pid_show, |
427 | }; | |
428 | ||
9561a7ad JB |
429 | struct recv_thread_args { |
430 | struct work_struct work; | |
431 | struct nbd_device *nbd; | |
432 | int index; | |
433 | }; | |
434 | ||
435 | static void recv_work(struct work_struct *work) | |
1da177e4 | 436 | { |
9561a7ad JB |
437 | struct recv_thread_args *args = container_of(work, |
438 | struct recv_thread_args, | |
439 | work); | |
440 | struct nbd_device *nbd = args->nbd; | |
fd8383fd | 441 | struct nbd_cmd *cmd; |
9561a7ad | 442 | int ret = 0; |
1da177e4 | 443 | |
f4507164 | 444 | BUG_ON(nbd->magic != NBD_MAGIC); |
19391830 | 445 | while (1) { |
9561a7ad | 446 | cmd = nbd_read_stat(nbd, args->index); |
fd8383fd JB |
447 | if (IS_ERR(cmd)) { |
448 | ret = PTR_ERR(cmd); | |
19391830 MP |
449 | break; |
450 | } | |
451 | ||
fd8383fd | 452 | nbd_end_request(cmd); |
19391830 | 453 | } |
6b39bb65 | 454 | |
9561a7ad JB |
455 | /* |
456 | * We got an error, shut everybody down if this wasn't the result of a | |
457 | * disconnect request. | |
458 | */ | |
459 | if (ret && !test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
460 | sock_shutdown(nbd); | |
461 | atomic_dec(&nbd->recv_threads); | |
462 | wake_up(&nbd->recv_wq); | |
1da177e4 LT |
463 | } |
464 | ||
fd8383fd | 465 | static void nbd_clear_req(struct request *req, void *data, bool reserved) |
1da177e4 | 466 | { |
fd8383fd | 467 | struct nbd_cmd *cmd; |
1da177e4 | 468 | |
fd8383fd JB |
469 | if (!blk_mq_request_started(req)) |
470 | return; | |
471 | cmd = blk_mq_rq_to_pdu(req); | |
472 | req->errors++; | |
473 | nbd_end_request(cmd); | |
474 | } | |
475 | ||
476 | static void nbd_clear_que(struct nbd_device *nbd) | |
477 | { | |
f4507164 | 478 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 479 | |
fd8383fd | 480 | blk_mq_tagset_busy_iter(&nbd->tag_set, nbd_clear_req, NULL); |
e78273c8 | 481 | dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n"); |
1da177e4 LT |
482 | } |
483 | ||
7fdfd406 | 484 | |
9561a7ad | 485 | static void nbd_handle_cmd(struct nbd_cmd *cmd, int index) |
48cf6061 | 486 | { |
fd8383fd JB |
487 | struct request *req = blk_mq_rq_from_pdu(cmd); |
488 | struct nbd_device *nbd = cmd->nbd; | |
9561a7ad | 489 | struct nbd_sock *nsock; |
fd8383fd | 490 | |
9561a7ad | 491 | if (index >= nbd->num_connections) { |
a897b666 JB |
492 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
493 | "Attempted send on invalid socket\n"); | |
48cf6061 | 494 | goto error_out; |
9561a7ad | 495 | } |
48cf6061 | 496 | |
9561a7ad | 497 | if (test_bit(NBD_DISCONNECTED, &nbd->runtime_flags)) { |
a897b666 JB |
498 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
499 | "Attempted send on closed socket\n"); | |
9561a7ad JB |
500 | goto error_out; |
501 | } | |
502 | ||
48cf6061 LV |
503 | req->errors = 0; |
504 | ||
9561a7ad JB |
505 | nsock = nbd->socks[index]; |
506 | mutex_lock(&nsock->tx_lock); | |
507 | if (unlikely(!nsock->sock)) { | |
508 | mutex_unlock(&nsock->tx_lock); | |
a897b666 JB |
509 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
510 | "Attempted send on closed socket\n"); | |
15746fca | 511 | goto error_out; |
48cf6061 LV |
512 | } |
513 | ||
9561a7ad | 514 | if (nbd_send_cmd(nbd, cmd, index) != 0) { |
a897b666 JB |
515 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
516 | "Request send failed\n"); | |
48cf6061 | 517 | req->errors++; |
fd8383fd | 518 | nbd_end_request(cmd); |
48cf6061 LV |
519 | } |
520 | ||
9561a7ad | 521 | mutex_unlock(&nsock->tx_lock); |
48cf6061 LV |
522 | |
523 | return; | |
524 | ||
525 | error_out: | |
526 | req->errors++; | |
fd8383fd | 527 | nbd_end_request(cmd); |
48cf6061 LV |
528 | } |
529 | ||
fd8383fd JB |
530 | static int nbd_queue_rq(struct blk_mq_hw_ctx *hctx, |
531 | const struct blk_mq_queue_data *bd) | |
1da177e4 | 532 | { |
fd8383fd | 533 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); |
1da177e4 | 534 | |
9561a7ad JB |
535 | /* |
536 | * Since we look at the bio's to send the request over the network we | |
537 | * need to make sure the completion work doesn't mark this request done | |
538 | * before we are done doing our send. This keeps us from dereferencing | |
539 | * freed data if we have particularly fast completions (ie we get the | |
540 | * completion before we exit sock_xmit on the last bvec) or in the case | |
541 | * that the server is misbehaving (or there was an error) before we're | |
542 | * done sending everything over the wire. | |
543 | */ | |
544 | init_completion(&cmd->send_complete); | |
fd8383fd | 545 | blk_mq_start_request(bd->rq); |
9561a7ad JB |
546 | nbd_handle_cmd(cmd, hctx->queue_num); |
547 | complete(&cmd->send_complete); | |
548 | ||
fd8383fd | 549 | return BLK_MQ_RQ_QUEUE_OK; |
1da177e4 LT |
550 | } |
551 | ||
9442b739 JB |
552 | static int nbd_add_socket(struct nbd_device *nbd, struct block_device *bdev, |
553 | unsigned long arg) | |
23272a67 | 554 | { |
9442b739 | 555 | struct socket *sock; |
9561a7ad JB |
556 | struct nbd_sock **socks; |
557 | struct nbd_sock *nsock; | |
9442b739 JB |
558 | int err; |
559 | ||
560 | sock = sockfd_lookup(arg, &err); | |
561 | if (!sock) | |
562 | return err; | |
23272a67 | 563 | |
9561a7ad JB |
564 | if (!nbd->task_setup) |
565 | nbd->task_setup = current; | |
566 | if (nbd->task_setup != current) { | |
567 | dev_err(disk_to_dev(nbd->disk), | |
568 | "Device being setup by another task"); | |
569 | return -EINVAL; | |
23272a67 MP |
570 | } |
571 | ||
9561a7ad JB |
572 | socks = krealloc(nbd->socks, (nbd->num_connections + 1) * |
573 | sizeof(struct nbd_sock *), GFP_KERNEL); | |
574 | if (!socks) | |
575 | return -ENOMEM; | |
576 | nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL); | |
577 | if (!nsock) | |
578 | return -ENOMEM; | |
579 | ||
580 | nbd->socks = socks; | |
23272a67 | 581 | |
9561a7ad JB |
582 | mutex_init(&nsock->tx_lock); |
583 | nsock->sock = sock; | |
584 | socks[nbd->num_connections++] = nsock; | |
23272a67 | 585 | |
9442b739 JB |
586 | if (max_part) |
587 | bdev->bd_invalidated = 1; | |
9561a7ad | 588 | return 0; |
23272a67 MP |
589 | } |
590 | ||
0e4f0f6f MP |
591 | /* Reset all properties of an NBD device */ |
592 | static void nbd_reset(struct nbd_device *nbd) | |
593 | { | |
9b4a6ba9 | 594 | nbd->runtime_flags = 0; |
0e4f0f6f MP |
595 | nbd->blksize = 1024; |
596 | nbd->bytesize = 0; | |
597 | set_capacity(nbd->disk, 0); | |
598 | nbd->flags = 0; | |
0eadf37a | 599 | nbd->tag_set.timeout = 0; |
0e4f0f6f | 600 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); |
0e4f0f6f MP |
601 | } |
602 | ||
603 | static void nbd_bdev_reset(struct block_device *bdev) | |
604 | { | |
605 | set_device_ro(bdev, false); | |
606 | bdev->bd_inode->i_size = 0; | |
607 | if (max_part > 0) { | |
608 | blkdev_reread_part(bdev); | |
609 | bdev->bd_invalidated = 1; | |
610 | } | |
611 | } | |
612 | ||
d02cf531 MP |
613 | static void nbd_parse_flags(struct nbd_device *nbd, struct block_device *bdev) |
614 | { | |
615 | if (nbd->flags & NBD_FLAG_READ_ONLY) | |
616 | set_device_ro(bdev, true); | |
617 | if (nbd->flags & NBD_FLAG_SEND_TRIM) | |
618 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); | |
619 | if (nbd->flags & NBD_FLAG_SEND_FLUSH) | |
aafb1eec | 620 | blk_queue_write_cache(nbd->disk->queue, true, false); |
d02cf531 | 621 | else |
aafb1eec | 622 | blk_queue_write_cache(nbd->disk->queue, false, false); |
d02cf531 MP |
623 | } |
624 | ||
9561a7ad JB |
625 | static void send_disconnects(struct nbd_device *nbd) |
626 | { | |
c9f2b6ae AV |
627 | struct nbd_request request = { |
628 | .magic = htonl(NBD_REQUEST_MAGIC), | |
629 | .type = htonl(NBD_CMD_DISC), | |
630 | }; | |
631 | struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)}; | |
632 | struct iov_iter from; | |
9561a7ad JB |
633 | int i, ret; |
634 | ||
9561a7ad | 635 | for (i = 0; i < nbd->num_connections; i++) { |
c9f2b6ae AV |
636 | iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request)); |
637 | ret = sock_xmit(nbd, i, 1, &from, 0); | |
9561a7ad JB |
638 | if (ret <= 0) |
639 | dev_err(disk_to_dev(nbd->disk), | |
640 | "Send disconnect failed %d\n", ret); | |
641 | } | |
642 | } | |
643 | ||
9442b739 JB |
644 | static int nbd_disconnect(struct nbd_device *nbd, struct block_device *bdev) |
645 | { | |
646 | dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n"); | |
647 | if (!nbd->socks) | |
648 | return -EINVAL; | |
30d53d9c | 649 | |
9442b739 JB |
650 | mutex_unlock(&nbd->config_lock); |
651 | fsync_bdev(bdev); | |
652 | mutex_lock(&nbd->config_lock); | |
653 | ||
654 | /* Check again after getting mutex back. */ | |
655 | if (!nbd->socks) | |
656 | return -EINVAL; | |
657 | ||
658 | if (!test_and_set_bit(NBD_DISCONNECT_REQUESTED, | |
659 | &nbd->runtime_flags)) | |
660 | send_disconnects(nbd); | |
661 | return 0; | |
662 | } | |
663 | ||
664 | static int nbd_clear_sock(struct nbd_device *nbd, struct block_device *bdev) | |
1a2ad211 | 665 | { |
9442b739 JB |
666 | sock_shutdown(nbd); |
667 | nbd_clear_que(nbd); | |
668 | kill_bdev(bdev); | |
669 | nbd_bdev_reset(bdev); | |
670 | /* | |
671 | * We want to give the run thread a chance to wait for everybody | |
672 | * to clean up and then do it's own cleanup. | |
673 | */ | |
674 | if (!test_bit(NBD_RUNNING, &nbd->runtime_flags) && | |
675 | nbd->num_connections) { | |
676 | int i; | |
677 | ||
6a8a2154 JB |
678 | for (i = 0; i < nbd->num_connections; i++) { |
679 | sockfd_put(nbd->socks[i]->sock); | |
9442b739 | 680 | kfree(nbd->socks[i]); |
6a8a2154 | 681 | } |
9442b739 JB |
682 | kfree(nbd->socks); |
683 | nbd->socks = NULL; | |
684 | nbd->num_connections = 0; | |
1a2ad211 | 685 | } |
9442b739 | 686 | nbd->task_setup = NULL; |
9561a7ad | 687 | |
9442b739 JB |
688 | return 0; |
689 | } | |
690 | ||
691 | static int nbd_start_device(struct nbd_device *nbd, struct block_device *bdev) | |
692 | { | |
693 | struct recv_thread_args *args; | |
694 | int num_connections = nbd->num_connections; | |
695 | int error = 0, i; | |
1a2ad211 | 696 | |
9442b739 JB |
697 | if (nbd->task_recv) |
698 | return -EBUSY; | |
699 | if (!nbd->socks) | |
700 | return -EINVAL; | |
701 | if (num_connections > 1 && | |
702 | !(nbd->flags & NBD_FLAG_CAN_MULTI_CONN)) { | |
703 | dev_err(disk_to_dev(nbd->disk), "server does not support multiple connections per device.\n"); | |
704 | error = -EINVAL; | |
705 | goto out_err; | |
706 | } | |
23272a67 | 707 | |
9442b739 JB |
708 | set_bit(NBD_RUNNING, &nbd->runtime_flags); |
709 | blk_mq_update_nr_hw_queues(&nbd->tag_set, nbd->num_connections); | |
710 | args = kcalloc(num_connections, sizeof(*args), GFP_KERNEL); | |
711 | if (!args) { | |
712 | error = -ENOMEM; | |
713 | goto out_err; | |
714 | } | |
715 | nbd->task_recv = current; | |
716 | mutex_unlock(&nbd->config_lock); | |
23272a67 | 717 | |
9442b739 | 718 | nbd_parse_flags(nbd, bdev); |
23272a67 | 719 | |
9442b739 JB |
720 | error = device_create_file(disk_to_dev(nbd->disk), &pid_attr); |
721 | if (error) { | |
722 | dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); | |
723 | goto out_recv; | |
1a2ad211 PM |
724 | } |
725 | ||
9442b739 | 726 | nbd_size_update(nbd, bdev); |
37091fdd | 727 | |
9442b739 JB |
728 | nbd_dev_dbg_init(nbd); |
729 | for (i = 0; i < num_connections; i++) { | |
730 | sk_set_memalloc(nbd->socks[i]->sock->sk); | |
731 | atomic_inc(&nbd->recv_threads); | |
732 | INIT_WORK(&args[i].work, recv_work); | |
733 | args[i].nbd = nbd; | |
734 | args[i].index = i; | |
735 | queue_work(recv_workqueue, &args[i].work); | |
37091fdd | 736 | } |
9442b739 JB |
737 | wait_event_interruptible(nbd->recv_wq, |
738 | atomic_read(&nbd->recv_threads) == 0); | |
739 | for (i = 0; i < num_connections; i++) | |
740 | flush_work(&args[i].work); | |
741 | nbd_dev_dbg_close(nbd); | |
742 | nbd_size_clear(nbd, bdev); | |
743 | device_remove_file(disk_to_dev(nbd->disk), &pid_attr); | |
744 | out_recv: | |
745 | mutex_lock(&nbd->config_lock); | |
746 | nbd->task_recv = NULL; | |
747 | out_err: | |
748 | clear_bit(NBD_RUNNING, &nbd->runtime_flags); | |
749 | nbd_clear_sock(nbd, bdev); | |
750 | ||
751 | /* user requested, ignore socket errors */ | |
752 | if (test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
753 | error = 0; | |
754 | if (test_bit(NBD_TIMEDOUT, &nbd->runtime_flags)) | |
755 | error = -ETIMEDOUT; | |
1a2ad211 | 756 | |
9442b739 JB |
757 | nbd_reset(nbd); |
758 | return error; | |
759 | } | |
760 | ||
761 | /* Must be called with config_lock held */ | |
762 | static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, | |
763 | unsigned int cmd, unsigned long arg) | |
764 | { | |
765 | switch (cmd) { | |
766 | case NBD_DISCONNECT: | |
767 | return nbd_disconnect(nbd, bdev); | |
768 | case NBD_CLEAR_SOCK: | |
769 | return nbd_clear_sock(nbd, bdev); | |
770 | case NBD_SET_SOCK: | |
771 | return nbd_add_socket(nbd, bdev, arg); | |
772 | case NBD_SET_BLKSIZE: | |
e544541b JB |
773 | nbd_size_set(nbd, bdev, arg, |
774 | div_s64(nbd->bytesize, arg)); | |
775 | return 0; | |
1da177e4 | 776 | case NBD_SET_SIZE: |
e544541b JB |
777 | nbd_size_set(nbd, bdev, nbd->blksize, |
778 | div_s64(arg, nbd->blksize)); | |
779 | return 0; | |
37091fdd | 780 | case NBD_SET_SIZE_BLOCKS: |
e544541b JB |
781 | nbd_size_set(nbd, bdev, nbd->blksize, arg); |
782 | return 0; | |
7fdfd406 | 783 | case NBD_SET_TIMEOUT: |
0eadf37a | 784 | nbd->tag_set.timeout = arg * HZ; |
7fdfd406 | 785 | return 0; |
1a2ad211 | 786 | |
2f012508 PC |
787 | case NBD_SET_FLAGS: |
788 | nbd->flags = arg; | |
789 | return 0; | |
9442b739 JB |
790 | case NBD_DO_IT: |
791 | return nbd_start_device(nbd, bdev); | |
1da177e4 | 792 | case NBD_CLEAR_QUE: |
4b2f0260 HX |
793 | /* |
794 | * This is for compatibility only. The queue is always cleared | |
795 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
796 | */ | |
1da177e4 LT |
797 | return 0; |
798 | case NBD_PRINT_DEBUG: | |
fd8383fd JB |
799 | /* |
800 | * For compatibility only, we no longer keep a list of | |
801 | * outstanding requests. | |
802 | */ | |
1da177e4 LT |
803 | return 0; |
804 | } | |
1a2ad211 PM |
805 | return -ENOTTY; |
806 | } | |
807 | ||
808 | static int nbd_ioctl(struct block_device *bdev, fmode_t mode, | |
809 | unsigned int cmd, unsigned long arg) | |
810 | { | |
f4507164 | 811 | struct nbd_device *nbd = bdev->bd_disk->private_data; |
1a2ad211 PM |
812 | int error; |
813 | ||
814 | if (!capable(CAP_SYS_ADMIN)) | |
815 | return -EPERM; | |
816 | ||
f4507164 | 817 | BUG_ON(nbd->magic != NBD_MAGIC); |
1a2ad211 | 818 | |
9561a7ad | 819 | mutex_lock(&nbd->config_lock); |
f4507164 | 820 | error = __nbd_ioctl(bdev, nbd, cmd, arg); |
9561a7ad | 821 | mutex_unlock(&nbd->config_lock); |
1a2ad211 PM |
822 | |
823 | return error; | |
1da177e4 LT |
824 | } |
825 | ||
83d5cde4 | 826 | static const struct block_device_operations nbd_fops = |
1da177e4 LT |
827 | { |
828 | .owner = THIS_MODULE, | |
8a6cfeb6 | 829 | .ioctl = nbd_ioctl, |
263a3df1 | 830 | .compat_ioctl = nbd_ioctl, |
1da177e4 LT |
831 | }; |
832 | ||
30d53d9c MP |
833 | #if IS_ENABLED(CONFIG_DEBUG_FS) |
834 | ||
835 | static int nbd_dbg_tasks_show(struct seq_file *s, void *unused) | |
836 | { | |
837 | struct nbd_device *nbd = s->private; | |
838 | ||
839 | if (nbd->task_recv) | |
840 | seq_printf(s, "recv: %d\n", task_pid_nr(nbd->task_recv)); | |
30d53d9c MP |
841 | |
842 | return 0; | |
843 | } | |
844 | ||
845 | static int nbd_dbg_tasks_open(struct inode *inode, struct file *file) | |
846 | { | |
847 | return single_open(file, nbd_dbg_tasks_show, inode->i_private); | |
848 | } | |
849 | ||
850 | static const struct file_operations nbd_dbg_tasks_ops = { | |
851 | .open = nbd_dbg_tasks_open, | |
852 | .read = seq_read, | |
853 | .llseek = seq_lseek, | |
854 | .release = single_release, | |
855 | }; | |
856 | ||
857 | static int nbd_dbg_flags_show(struct seq_file *s, void *unused) | |
858 | { | |
859 | struct nbd_device *nbd = s->private; | |
860 | u32 flags = nbd->flags; | |
861 | ||
862 | seq_printf(s, "Hex: 0x%08x\n\n", flags); | |
863 | ||
864 | seq_puts(s, "Known flags:\n"); | |
865 | ||
866 | if (flags & NBD_FLAG_HAS_FLAGS) | |
867 | seq_puts(s, "NBD_FLAG_HAS_FLAGS\n"); | |
868 | if (flags & NBD_FLAG_READ_ONLY) | |
869 | seq_puts(s, "NBD_FLAG_READ_ONLY\n"); | |
870 | if (flags & NBD_FLAG_SEND_FLUSH) | |
871 | seq_puts(s, "NBD_FLAG_SEND_FLUSH\n"); | |
872 | if (flags & NBD_FLAG_SEND_TRIM) | |
873 | seq_puts(s, "NBD_FLAG_SEND_TRIM\n"); | |
874 | ||
875 | return 0; | |
876 | } | |
877 | ||
878 | static int nbd_dbg_flags_open(struct inode *inode, struct file *file) | |
879 | { | |
880 | return single_open(file, nbd_dbg_flags_show, inode->i_private); | |
881 | } | |
882 | ||
883 | static const struct file_operations nbd_dbg_flags_ops = { | |
884 | .open = nbd_dbg_flags_open, | |
885 | .read = seq_read, | |
886 | .llseek = seq_lseek, | |
887 | .release = single_release, | |
888 | }; | |
889 | ||
890 | static int nbd_dev_dbg_init(struct nbd_device *nbd) | |
891 | { | |
892 | struct dentry *dir; | |
27ea43fe MP |
893 | |
894 | if (!nbd_dbg_dir) | |
895 | return -EIO; | |
30d53d9c MP |
896 | |
897 | dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir); | |
27ea43fe MP |
898 | if (!dir) { |
899 | dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n", | |
900 | nbd_name(nbd)); | |
901 | return -EIO; | |
30d53d9c MP |
902 | } |
903 | nbd->dbg_dir = dir; | |
904 | ||
27ea43fe MP |
905 | debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops); |
906 | debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize); | |
0eadf37a | 907 | debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout); |
ef77b515 | 908 | debugfs_create_u64("blocksize", 0444, dir, &nbd->blksize); |
d366a0ff | 909 | debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops); |
30d53d9c MP |
910 | |
911 | return 0; | |
912 | } | |
913 | ||
914 | static void nbd_dev_dbg_close(struct nbd_device *nbd) | |
915 | { | |
916 | debugfs_remove_recursive(nbd->dbg_dir); | |
917 | } | |
918 | ||
919 | static int nbd_dbg_init(void) | |
920 | { | |
921 | struct dentry *dbg_dir; | |
922 | ||
923 | dbg_dir = debugfs_create_dir("nbd", NULL); | |
27ea43fe MP |
924 | if (!dbg_dir) |
925 | return -EIO; | |
30d53d9c MP |
926 | |
927 | nbd_dbg_dir = dbg_dir; | |
928 | ||
929 | return 0; | |
930 | } | |
931 | ||
932 | static void nbd_dbg_close(void) | |
933 | { | |
934 | debugfs_remove_recursive(nbd_dbg_dir); | |
935 | } | |
936 | ||
937 | #else /* IS_ENABLED(CONFIG_DEBUG_FS) */ | |
938 | ||
939 | static int nbd_dev_dbg_init(struct nbd_device *nbd) | |
940 | { | |
941 | return 0; | |
942 | } | |
943 | ||
944 | static void nbd_dev_dbg_close(struct nbd_device *nbd) | |
945 | { | |
946 | } | |
947 | ||
948 | static int nbd_dbg_init(void) | |
949 | { | |
950 | return 0; | |
951 | } | |
952 | ||
953 | static void nbd_dbg_close(void) | |
954 | { | |
955 | } | |
956 | ||
957 | #endif | |
958 | ||
fd8383fd JB |
959 | static int nbd_init_request(void *data, struct request *rq, |
960 | unsigned int hctx_idx, unsigned int request_idx, | |
961 | unsigned int numa_node) | |
962 | { | |
963 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq); | |
fd8383fd | 964 | cmd->nbd = data; |
fd8383fd JB |
965 | return 0; |
966 | } | |
967 | ||
f363b089 | 968 | static const struct blk_mq_ops nbd_mq_ops = { |
fd8383fd | 969 | .queue_rq = nbd_queue_rq, |
fd8383fd | 970 | .init_request = nbd_init_request, |
0eadf37a | 971 | .timeout = nbd_xmit_timeout, |
fd8383fd JB |
972 | }; |
973 | ||
b0d9111a JB |
974 | static void nbd_dev_remove(struct nbd_device *nbd) |
975 | { | |
976 | struct gendisk *disk = nbd->disk; | |
977 | nbd->magic = 0; | |
978 | if (disk) { | |
979 | del_gendisk(disk); | |
980 | blk_cleanup_queue(disk->queue); | |
981 | blk_mq_free_tag_set(&nbd->tag_set); | |
982 | put_disk(disk); | |
983 | } | |
984 | kfree(nbd); | |
985 | } | |
986 | ||
987 | static int nbd_dev_add(int index) | |
988 | { | |
989 | struct nbd_device *nbd; | |
990 | struct gendisk *disk; | |
991 | struct request_queue *q; | |
992 | int err = -ENOMEM; | |
993 | ||
994 | nbd = kzalloc(sizeof(struct nbd_device), GFP_KERNEL); | |
995 | if (!nbd) | |
996 | goto out; | |
997 | ||
998 | disk = alloc_disk(1 << part_shift); | |
999 | if (!disk) | |
1000 | goto out_free_nbd; | |
1001 | ||
1002 | if (index >= 0) { | |
1003 | err = idr_alloc(&nbd_index_idr, nbd, index, index + 1, | |
1004 | GFP_KERNEL); | |
1005 | if (err == -ENOSPC) | |
1006 | err = -EEXIST; | |
1007 | } else { | |
1008 | err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL); | |
1009 | if (err >= 0) | |
1010 | index = err; | |
1011 | } | |
1012 | if (err < 0) | |
1013 | goto out_free_disk; | |
1014 | ||
1015 | nbd->disk = disk; | |
1016 | nbd->tag_set.ops = &nbd_mq_ops; | |
1017 | nbd->tag_set.nr_hw_queues = 1; | |
1018 | nbd->tag_set.queue_depth = 128; | |
1019 | nbd->tag_set.numa_node = NUMA_NO_NODE; | |
1020 | nbd->tag_set.cmd_size = sizeof(struct nbd_cmd); | |
1021 | nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | | |
1022 | BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING; | |
1023 | nbd->tag_set.driver_data = nbd; | |
1024 | ||
1025 | err = blk_mq_alloc_tag_set(&nbd->tag_set); | |
1026 | if (err) | |
1027 | goto out_free_idr; | |
1028 | ||
1029 | q = blk_mq_init_queue(&nbd->tag_set); | |
1030 | if (IS_ERR(q)) { | |
1031 | err = PTR_ERR(q); | |
1032 | goto out_free_tags; | |
1033 | } | |
1034 | disk->queue = q; | |
1035 | ||
1036 | /* | |
1037 | * Tell the block layer that we are not a rotational device | |
1038 | */ | |
1039 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue); | |
1040 | queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, disk->queue); | |
1041 | disk->queue->limits.discard_granularity = 512; | |
1042 | blk_queue_max_discard_sectors(disk->queue, UINT_MAX); | |
1043 | disk->queue->limits.discard_zeroes_data = 0; | |
1044 | blk_queue_max_hw_sectors(disk->queue, 65536); | |
1045 | disk->queue->limits.max_sectors = 256; | |
1046 | ||
1047 | nbd->magic = NBD_MAGIC; | |
1048 | mutex_init(&nbd->config_lock); | |
1049 | disk->major = NBD_MAJOR; | |
1050 | disk->first_minor = index << part_shift; | |
1051 | disk->fops = &nbd_fops; | |
1052 | disk->private_data = nbd; | |
1053 | sprintf(disk->disk_name, "nbd%d", index); | |
1054 | init_waitqueue_head(&nbd->recv_wq); | |
1055 | nbd_reset(nbd); | |
1056 | add_disk(disk); | |
1057 | return index; | |
1058 | ||
1059 | out_free_tags: | |
1060 | blk_mq_free_tag_set(&nbd->tag_set); | |
1061 | out_free_idr: | |
1062 | idr_remove(&nbd_index_idr, index); | |
1063 | out_free_disk: | |
1064 | put_disk(disk); | |
1065 | out_free_nbd: | |
1066 | kfree(nbd); | |
1067 | out: | |
1068 | return err; | |
1069 | } | |
1070 | ||
1da177e4 LT |
1071 | /* |
1072 | * And here should be modules and kernel interface | |
1073 | * (Just smiley confuses emacs :-) | |
1074 | */ | |
1075 | ||
1076 | static int __init nbd_init(void) | |
1077 | { | |
1da177e4 LT |
1078 | int i; |
1079 | ||
5b7b18cc | 1080 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 1081 | |
d71a6d73 | 1082 | if (max_part < 0) { |
7742ce4a | 1083 | printk(KERN_ERR "nbd: max_part must be >= 0\n"); |
d71a6d73 LV |
1084 | return -EINVAL; |
1085 | } | |
1086 | ||
1087 | part_shift = 0; | |
5988ce23 | 1088 | if (max_part > 0) { |
d71a6d73 LV |
1089 | part_shift = fls(max_part); |
1090 | ||
5988ce23 NK |
1091 | /* |
1092 | * Adjust max_part according to part_shift as it is exported | |
1093 | * to user space so that user can know the max number of | |
1094 | * partition kernel should be able to manage. | |
1095 | * | |
1096 | * Note that -1 is required because partition 0 is reserved | |
1097 | * for the whole disk. | |
1098 | */ | |
1099 | max_part = (1UL << part_shift) - 1; | |
1100 | } | |
1101 | ||
3b271082 NK |
1102 | if ((1UL << part_shift) > DISK_MAX_PARTS) |
1103 | return -EINVAL; | |
1104 | ||
1105 | if (nbds_max > 1UL << (MINORBITS - part_shift)) | |
1106 | return -EINVAL; | |
124d6db0 JB |
1107 | recv_workqueue = alloc_workqueue("knbd-recv", |
1108 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 0); | |
1109 | if (!recv_workqueue) | |
1110 | return -ENOMEM; | |
3b271082 | 1111 | |
6330a2d0 JB |
1112 | if (register_blkdev(NBD_MAJOR, "nbd")) { |
1113 | destroy_workqueue(recv_workqueue); | |
b0d9111a | 1114 | return -EIO; |
6330a2d0 | 1115 | } |
1da177e4 | 1116 | |
30d53d9c MP |
1117 | nbd_dbg_init(); |
1118 | ||
b0d9111a JB |
1119 | mutex_lock(&nbd_index_mutex); |
1120 | for (i = 0; i < nbds_max; i++) | |
1121 | nbd_dev_add(i); | |
1122 | mutex_unlock(&nbd_index_mutex); | |
1123 | return 0; | |
1124 | } | |
1da177e4 | 1125 | |
b0d9111a JB |
1126 | static int nbd_exit_cb(int id, void *ptr, void *data) |
1127 | { | |
1128 | struct nbd_device *nbd = ptr; | |
1129 | nbd_dev_remove(nbd); | |
1da177e4 | 1130 | return 0; |
1da177e4 LT |
1131 | } |
1132 | ||
1133 | static void __exit nbd_cleanup(void) | |
1134 | { | |
30d53d9c MP |
1135 | nbd_dbg_close(); |
1136 | ||
b0d9111a JB |
1137 | idr_for_each(&nbd_index_idr, &nbd_exit_cb, NULL); |
1138 | idr_destroy(&nbd_index_idr); | |
124d6db0 | 1139 | destroy_workqueue(recv_workqueue); |
1da177e4 | 1140 | unregister_blkdev(NBD_MAJOR, "nbd"); |
1da177e4 LT |
1141 | } |
1142 | ||
1143 | module_init(nbd_init); | |
1144 | module_exit(nbd_cleanup); | |
1145 | ||
1146 | MODULE_DESCRIPTION("Network Block Device"); | |
1147 | MODULE_LICENSE("GPL"); | |
1148 | ||
40be0c28 | 1149 | module_param(nbds_max, int, 0444); |
d71a6d73 LV |
1150 | MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); |
1151 | module_param(max_part, int, 0444); | |
1152 | MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)"); |