Commit | Line | Data |
---|---|---|
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 | |
d18509f5 | 99 | static inline struct device *nbd_to_dev(struct nbd_device *nbd) |
1da177e4 | 100 | { |
d18509f5 | 101 | return disk_to_dev(nbd->disk); |
1da177e4 LT |
102 | } |
103 | ||
37091fdd MP |
104 | static bool nbd_is_connected(struct nbd_device *nbd) |
105 | { | |
106 | return !!nbd->task_recv; | |
107 | } | |
108 | ||
1da177e4 LT |
109 | static const char *nbdcmd_to_ascii(int cmd) |
110 | { | |
111 | switch (cmd) { | |
112 | case NBD_CMD_READ: return "read"; | |
113 | case NBD_CMD_WRITE: return "write"; | |
114 | case NBD_CMD_DISC: return "disconnect"; | |
75f187ab | 115 | case NBD_CMD_FLUSH: return "flush"; |
a336d298 | 116 | case NBD_CMD_TRIM: return "trim/discard"; |
1da177e4 LT |
117 | } |
118 | return "invalid"; | |
119 | } | |
1da177e4 | 120 | |
37091fdd MP |
121 | static int nbd_size_clear(struct nbd_device *nbd, struct block_device *bdev) |
122 | { | |
123 | bdev->bd_inode->i_size = 0; | |
124 | set_capacity(nbd->disk, 0); | |
125 | kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); | |
126 | ||
127 | return 0; | |
128 | } | |
129 | ||
130 | static void nbd_size_update(struct nbd_device *nbd, struct block_device *bdev) | |
131 | { | |
132 | if (!nbd_is_connected(nbd)) | |
133 | return; | |
134 | ||
135 | bdev->bd_inode->i_size = nbd->bytesize; | |
136 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
137 | kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); | |
138 | } | |
139 | ||
140 | static int nbd_size_set(struct nbd_device *nbd, struct block_device *bdev, | |
ef77b515 | 141 | loff_t blocksize, loff_t nr_blocks) |
37091fdd MP |
142 | { |
143 | int ret; | |
144 | ||
145 | ret = set_blocksize(bdev, blocksize); | |
146 | if (ret) | |
147 | return ret; | |
148 | ||
149 | nbd->blksize = blocksize; | |
ef77b515 | 150 | nbd->bytesize = blocksize * nr_blocks; |
37091fdd MP |
151 | |
152 | nbd_size_update(nbd, bdev); | |
153 | ||
154 | return 0; | |
155 | } | |
156 | ||
fd8383fd | 157 | static void nbd_end_request(struct nbd_cmd *cmd) |
1da177e4 | 158 | { |
fd8383fd JB |
159 | struct nbd_device *nbd = cmd->nbd; |
160 | struct request *req = blk_mq_rq_from_pdu(cmd); | |
097c94a4 | 161 | int error = req->errors ? -EIO : 0; |
1da177e4 | 162 | |
fd8383fd | 163 | dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", cmd, |
d18509f5 | 164 | error ? "failed" : "done"); |
1da177e4 | 165 | |
fd8383fd | 166 | blk_mq_complete_request(req, error); |
1da177e4 LT |
167 | } |
168 | ||
e018e757 MP |
169 | /* |
170 | * Forcibly shutdown the socket causing all listeners to error | |
171 | */ | |
36e47bee | 172 | static void sock_shutdown(struct nbd_device *nbd) |
7fdfd406 | 173 | { |
9561a7ad | 174 | int i; |
23272a67 | 175 | |
9561a7ad JB |
176 | if (nbd->num_connections == 0) |
177 | return; | |
178 | if (test_and_set_bit(NBD_DISCONNECTED, &nbd->runtime_flags)) | |
260bbce4 | 179 | return; |
23272a67 | 180 | |
9561a7ad JB |
181 | for (i = 0; i < nbd->num_connections; i++) { |
182 | struct nbd_sock *nsock = nbd->socks[i]; | |
183 | mutex_lock(&nsock->tx_lock); | |
184 | kernel_sock_shutdown(nsock->sock, SHUT_RDWR); | |
185 | mutex_unlock(&nsock->tx_lock); | |
186 | } | |
187 | dev_warn(disk_to_dev(nbd->disk), "shutting down sockets\n"); | |
7fdfd406 PC |
188 | } |
189 | ||
0eadf37a JB |
190 | static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, |
191 | bool reserved) | |
7fdfd406 | 192 | { |
0eadf37a JB |
193 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req); |
194 | struct nbd_device *nbd = cmd->nbd; | |
dcc909d9 | 195 | |
9561a7ad | 196 | dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n"); |
9b4a6ba9 | 197 | set_bit(NBD_TIMEDOUT, &nbd->runtime_flags); |
0eadf37a | 198 | req->errors++; |
9561a7ad | 199 | |
9561a7ad JB |
200 | mutex_lock(&nbd->config_lock); |
201 | sock_shutdown(nbd); | |
202 | mutex_unlock(&nbd->config_lock); | |
0eadf37a | 203 | return BLK_EH_HANDLED; |
7fdfd406 PC |
204 | } |
205 | ||
1da177e4 LT |
206 | /* |
207 | * Send or receive packet. | |
208 | */ | |
9561a7ad JB |
209 | static int sock_xmit(struct nbd_device *nbd, int index, int send, void *buf, |
210 | int size, int msg_flags) | |
1da177e4 | 211 | { |
9561a7ad | 212 | struct socket *sock = nbd->socks[index]->sock; |
1da177e4 LT |
213 | int result; |
214 | struct msghdr msg; | |
215 | struct kvec iov; | |
7f338fe4 | 216 | unsigned long pflags = current->flags; |
1da177e4 | 217 | |
ffc41cf8 | 218 | if (unlikely(!sock)) { |
a897b666 | 219 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
220 | "Attempted %s on closed socket in sock_xmit\n", |
221 | (send ? "send" : "recv")); | |
ffc41cf8 MS |
222 | return -EINVAL; |
223 | } | |
224 | ||
7f338fe4 | 225 | current->flags |= PF_MEMALLOC; |
1da177e4 | 226 | do { |
7f338fe4 | 227 | sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC; |
1da177e4 LT |
228 | iov.iov_base = buf; |
229 | iov.iov_len = size; | |
230 | msg.msg_name = NULL; | |
231 | msg.msg_namelen = 0; | |
232 | msg.msg_control = NULL; | |
233 | msg.msg_controllen = 0; | |
1da177e4 LT |
234 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
235 | ||
7e2893a1 | 236 | if (send) |
1da177e4 | 237 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
7e2893a1 | 238 | else |
35fbf5bc NK |
239 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, |
240 | msg.msg_flags); | |
1da177e4 | 241 | |
1da177e4 LT |
242 | if (result <= 0) { |
243 | if (result == 0) | |
244 | result = -EPIPE; /* short read */ | |
245 | break; | |
246 | } | |
247 | size -= result; | |
248 | buf += result; | |
249 | } while (size > 0); | |
250 | ||
7f338fe4 | 251 | tsk_restore_flags(current, pflags, PF_MEMALLOC); |
1da177e4 LT |
252 | |
253 | return result; | |
254 | } | |
255 | ||
9561a7ad JB |
256 | static inline int sock_send_bvec(struct nbd_device *nbd, int index, |
257 | struct bio_vec *bvec, int flags) | |
1da177e4 LT |
258 | { |
259 | int result; | |
260 | void *kaddr = kmap(bvec->bv_page); | |
9561a7ad | 261 | result = sock_xmit(nbd, index, 1, kaddr + bvec->bv_offset, |
f4507164 | 262 | bvec->bv_len, flags); |
1da177e4 LT |
263 | kunmap(bvec->bv_page); |
264 | return result; | |
265 | } | |
266 | ||
7fdfd406 | 267 | /* always call with the tx_lock held */ |
9561a7ad | 268 | static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) |
1da177e4 | 269 | { |
fd8383fd | 270 | struct request *req = blk_mq_rq_from_pdu(cmd); |
d61b7f97 | 271 | int result; |
1da177e4 | 272 | struct nbd_request request; |
1011c1b9 | 273 | unsigned long size = blk_rq_bytes(req); |
429a787b | 274 | struct bio *bio; |
9dc6c806 | 275 | u32 type; |
9561a7ad | 276 | u32 tag = blk_mq_unique_tag(req); |
9dc6c806 | 277 | |
aebf526b CH |
278 | switch (req_op(req)) { |
279 | case REQ_OP_DISCARD: | |
9dc6c806 | 280 | type = NBD_CMD_TRIM; |
aebf526b CH |
281 | break; |
282 | case REQ_OP_FLUSH: | |
9dc6c806 | 283 | type = NBD_CMD_FLUSH; |
aebf526b CH |
284 | break; |
285 | case REQ_OP_WRITE: | |
9dc6c806 | 286 | type = NBD_CMD_WRITE; |
aebf526b CH |
287 | break; |
288 | case REQ_OP_READ: | |
9dc6c806 | 289 | type = NBD_CMD_READ; |
aebf526b CH |
290 | break; |
291 | default: | |
292 | return -EIO; | |
293 | } | |
1da177e4 | 294 | |
09fc54cc CH |
295 | if (rq_data_dir(req) == WRITE && |
296 | (nbd->flags & NBD_FLAG_READ_ONLY)) { | |
297 | dev_err_ratelimited(disk_to_dev(nbd->disk), | |
298 | "Write on read-only\n"); | |
299 | return -EIO; | |
300 | } | |
301 | ||
04cfac4e | 302 | memset(&request, 0, sizeof(request)); |
1da177e4 | 303 | request.magic = htonl(NBD_REQUEST_MAGIC); |
9dc6c806 | 304 | request.type = htonl(type); |
9561a7ad | 305 | if (type != NBD_CMD_FLUSH) { |
75f187ab AB |
306 | request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); |
307 | request.len = htonl(size); | |
308 | } | |
9561a7ad | 309 | memcpy(request.handle, &tag, sizeof(tag)); |
1da177e4 | 310 | |
d18509f5 | 311 | dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n", |
fd8383fd | 312 | cmd, nbdcmd_to_ascii(type), |
d18509f5 | 313 | (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req)); |
9561a7ad | 314 | result = sock_xmit(nbd, index, 1, &request, sizeof(request), |
9dc6c806 | 315 | (type == NBD_CMD_WRITE) ? MSG_MORE : 0); |
1da177e4 | 316 | if (result <= 0) { |
a897b666 | 317 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
7f1b90f9 | 318 | "Send control failed (result %d)\n", result); |
dab5313a | 319 | return -EIO; |
1da177e4 LT |
320 | } |
321 | ||
429a787b JA |
322 | if (type != NBD_CMD_WRITE) |
323 | return 0; | |
324 | ||
429a787b JA |
325 | bio = req->bio; |
326 | while (bio) { | |
327 | struct bio *next = bio->bi_next; | |
328 | struct bvec_iter iter; | |
7988613b | 329 | struct bio_vec bvec; |
429a787b JA |
330 | |
331 | bio_for_each_segment(bvec, bio, iter) { | |
332 | bool is_last = !next && bio_iter_last(bvec, iter); | |
d61b7f97 | 333 | int flags = is_last ? 0 : MSG_MORE; |
429a787b | 334 | |
d18509f5 | 335 | dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n", |
fd8383fd | 336 | cmd, bvec.bv_len); |
9561a7ad | 337 | result = sock_send_bvec(nbd, index, &bvec, flags); |
6c92e699 | 338 | if (result <= 0) { |
f4507164 | 339 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
340 | "Send data failed (result %d)\n", |
341 | result); | |
dab5313a | 342 | return -EIO; |
6c92e699 | 343 | } |
429a787b JA |
344 | /* |
345 | * The completion might already have come in, | |
346 | * so break for the last one instead of letting | |
347 | * the iterator do it. This prevents use-after-free | |
348 | * of the bio. | |
349 | */ | |
350 | if (is_last) | |
351 | break; | |
1da177e4 | 352 | } |
429a787b | 353 | bio = next; |
1da177e4 | 354 | } |
1da177e4 | 355 | return 0; |
1da177e4 LT |
356 | } |
357 | ||
9561a7ad JB |
358 | static inline int sock_recv_bvec(struct nbd_device *nbd, int index, |
359 | struct bio_vec *bvec) | |
1da177e4 LT |
360 | { |
361 | int result; | |
362 | void *kaddr = kmap(bvec->bv_page); | |
9561a7ad JB |
363 | result = sock_xmit(nbd, index, 0, kaddr + bvec->bv_offset, |
364 | bvec->bv_len, MSG_WAITALL); | |
1da177e4 LT |
365 | kunmap(bvec->bv_page); |
366 | return result; | |
367 | } | |
368 | ||
369 | /* NULL returned = something went wrong, inform userspace */ | |
9561a7ad | 370 | static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) |
1da177e4 LT |
371 | { |
372 | int result; | |
373 | struct nbd_reply reply; | |
fd8383fd JB |
374 | struct nbd_cmd *cmd; |
375 | struct request *req = NULL; | |
376 | u16 hwq; | |
9561a7ad | 377 | u32 tag; |
1da177e4 LT |
378 | |
379 | reply.magic = 0; | |
9561a7ad | 380 | result = sock_xmit(nbd, index, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 | 381 | if (result <= 0) { |
9561a7ad JB |
382 | if (!test_bit(NBD_DISCONNECTED, &nbd->runtime_flags) && |
383 | !test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
384 | dev_err(disk_to_dev(nbd->disk), | |
385 | "Receive control failed (result %d)\n", result); | |
19391830 | 386 | return ERR_PTR(result); |
1da177e4 | 387 | } |
e4b57e08 MF |
388 | |
389 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
f4507164 | 390 | dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n", |
e4b57e08 | 391 | (unsigned long)ntohl(reply.magic)); |
19391830 | 392 | return ERR_PTR(-EPROTO); |
e4b57e08 MF |
393 | } |
394 | ||
9561a7ad | 395 | memcpy(&tag, reply.handle, sizeof(u32)); |
4b2f0260 | 396 | |
fd8383fd JB |
397 | hwq = blk_mq_unique_tag_to_hwq(tag); |
398 | if (hwq < nbd->tag_set.nr_hw_queues) | |
399 | req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq], | |
400 | blk_mq_unique_tag_to_tag(tag)); | |
401 | if (!req || !blk_mq_request_started(req)) { | |
402 | dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n", | |
403 | tag, req); | |
404 | return ERR_PTR(-ENOENT); | |
1da177e4 | 405 | } |
fd8383fd | 406 | cmd = blk_mq_rq_to_pdu(req); |
1da177e4 | 407 | if (ntohl(reply.error)) { |
f4507164 | 408 | dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n", |
7f1b90f9 | 409 | ntohl(reply.error)); |
1da177e4 | 410 | req->errors++; |
fd8383fd | 411 | return cmd; |
1da177e4 LT |
412 | } |
413 | ||
fd8383fd | 414 | dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", cmd); |
9dc6c806 | 415 | if (rq_data_dir(req) != WRITE) { |
5705f702 | 416 | struct req_iterator iter; |
7988613b | 417 | struct bio_vec bvec; |
5705f702 N |
418 | |
419 | rq_for_each_segment(bvec, req, iter) { | |
9561a7ad | 420 | result = sock_recv_bvec(nbd, index, &bvec); |
6c92e699 | 421 | if (result <= 0) { |
f4507164 | 422 | dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", |
7f1b90f9 | 423 | result); |
6c92e699 | 424 | req->errors++; |
fd8383fd | 425 | return cmd; |
6c92e699 | 426 | } |
d18509f5 | 427 | dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n", |
fd8383fd | 428 | cmd, bvec.bv_len); |
1da177e4 | 429 | } |
9561a7ad JB |
430 | } else { |
431 | /* See the comment in nbd_queue_rq. */ | |
432 | wait_for_completion(&cmd->send_complete); | |
1da177e4 | 433 | } |
fd8383fd | 434 | return cmd; |
1da177e4 LT |
435 | } |
436 | ||
edfaa7c3 KS |
437 | static ssize_t pid_show(struct device *dev, |
438 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 439 | { |
edfaa7c3 | 440 | struct gendisk *disk = dev_to_disk(dev); |
6521d39a | 441 | struct nbd_device *nbd = (struct nbd_device *)disk->private_data; |
edfaa7c3 | 442 | |
6521d39a | 443 | return sprintf(buf, "%d\n", task_pid_nr(nbd->task_recv)); |
6b39bb65 PC |
444 | } |
445 | ||
edfaa7c3 | 446 | static struct device_attribute pid_attr = { |
01e8ef11 | 447 | .attr = { .name = "pid", .mode = S_IRUGO}, |
6b39bb65 PC |
448 | .show = pid_show, |
449 | }; | |
450 | ||
9561a7ad JB |
451 | struct recv_thread_args { |
452 | struct work_struct work; | |
453 | struct nbd_device *nbd; | |
454 | int index; | |
455 | }; | |
456 | ||
457 | static void recv_work(struct work_struct *work) | |
1da177e4 | 458 | { |
9561a7ad JB |
459 | struct recv_thread_args *args = container_of(work, |
460 | struct recv_thread_args, | |
461 | work); | |
462 | struct nbd_device *nbd = args->nbd; | |
fd8383fd | 463 | struct nbd_cmd *cmd; |
9561a7ad | 464 | int ret = 0; |
1da177e4 | 465 | |
f4507164 | 466 | BUG_ON(nbd->magic != NBD_MAGIC); |
19391830 | 467 | while (1) { |
9561a7ad | 468 | cmd = nbd_read_stat(nbd, args->index); |
fd8383fd JB |
469 | if (IS_ERR(cmd)) { |
470 | ret = PTR_ERR(cmd); | |
19391830 MP |
471 | break; |
472 | } | |
473 | ||
fd8383fd | 474 | nbd_end_request(cmd); |
19391830 | 475 | } |
6b39bb65 | 476 | |
9561a7ad JB |
477 | /* |
478 | * We got an error, shut everybody down if this wasn't the result of a | |
479 | * disconnect request. | |
480 | */ | |
481 | if (ret && !test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
482 | sock_shutdown(nbd); | |
483 | atomic_dec(&nbd->recv_threads); | |
484 | wake_up(&nbd->recv_wq); | |
1da177e4 LT |
485 | } |
486 | ||
fd8383fd | 487 | static void nbd_clear_req(struct request *req, void *data, bool reserved) |
1da177e4 | 488 | { |
fd8383fd | 489 | struct nbd_cmd *cmd; |
1da177e4 | 490 | |
fd8383fd JB |
491 | if (!blk_mq_request_started(req)) |
492 | return; | |
493 | cmd = blk_mq_rq_to_pdu(req); | |
494 | req->errors++; | |
495 | nbd_end_request(cmd); | |
496 | } | |
497 | ||
498 | static void nbd_clear_que(struct nbd_device *nbd) | |
499 | { | |
f4507164 | 500 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 501 | |
fd8383fd | 502 | blk_mq_tagset_busy_iter(&nbd->tag_set, nbd_clear_req, NULL); |
e78273c8 | 503 | dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n"); |
1da177e4 LT |
504 | } |
505 | ||
7fdfd406 | 506 | |
9561a7ad | 507 | static void nbd_handle_cmd(struct nbd_cmd *cmd, int index) |
48cf6061 | 508 | { |
fd8383fd JB |
509 | struct request *req = blk_mq_rq_from_pdu(cmd); |
510 | struct nbd_device *nbd = cmd->nbd; | |
9561a7ad | 511 | struct nbd_sock *nsock; |
fd8383fd | 512 | |
9561a7ad | 513 | if (index >= nbd->num_connections) { |
a897b666 JB |
514 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
515 | "Attempted send on invalid socket\n"); | |
48cf6061 | 516 | goto error_out; |
9561a7ad | 517 | } |
48cf6061 | 518 | |
9561a7ad | 519 | if (test_bit(NBD_DISCONNECTED, &nbd->runtime_flags)) { |
a897b666 JB |
520 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
521 | "Attempted send on closed socket\n"); | |
9561a7ad JB |
522 | goto error_out; |
523 | } | |
524 | ||
48cf6061 LV |
525 | req->errors = 0; |
526 | ||
9561a7ad JB |
527 | nsock = nbd->socks[index]; |
528 | mutex_lock(&nsock->tx_lock); | |
529 | if (unlikely(!nsock->sock)) { | |
530 | mutex_unlock(&nsock->tx_lock); | |
a897b666 JB |
531 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
532 | "Attempted send on closed socket\n"); | |
15746fca | 533 | goto error_out; |
48cf6061 LV |
534 | } |
535 | ||
9561a7ad | 536 | if (nbd_send_cmd(nbd, cmd, index) != 0) { |
a897b666 JB |
537 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
538 | "Request send failed\n"); | |
48cf6061 | 539 | req->errors++; |
fd8383fd | 540 | nbd_end_request(cmd); |
48cf6061 LV |
541 | } |
542 | ||
9561a7ad | 543 | mutex_unlock(&nsock->tx_lock); |
48cf6061 LV |
544 | |
545 | return; | |
546 | ||
547 | error_out: | |
548 | req->errors++; | |
fd8383fd | 549 | nbd_end_request(cmd); |
48cf6061 LV |
550 | } |
551 | ||
fd8383fd JB |
552 | static int nbd_queue_rq(struct blk_mq_hw_ctx *hctx, |
553 | const struct blk_mq_queue_data *bd) | |
1da177e4 | 554 | { |
fd8383fd | 555 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); |
1da177e4 | 556 | |
9561a7ad JB |
557 | /* |
558 | * Since we look at the bio's to send the request over the network we | |
559 | * need to make sure the completion work doesn't mark this request done | |
560 | * before we are done doing our send. This keeps us from dereferencing | |
561 | * freed data if we have particularly fast completions (ie we get the | |
562 | * completion before we exit sock_xmit on the last bvec) or in the case | |
563 | * that the server is misbehaving (or there was an error) before we're | |
564 | * done sending everything over the wire. | |
565 | */ | |
566 | init_completion(&cmd->send_complete); | |
fd8383fd | 567 | blk_mq_start_request(bd->rq); |
9561a7ad JB |
568 | nbd_handle_cmd(cmd, hctx->queue_num); |
569 | complete(&cmd->send_complete); | |
570 | ||
fd8383fd | 571 | return BLK_MQ_RQ_QUEUE_OK; |
1da177e4 LT |
572 | } |
573 | ||
9561a7ad | 574 | static int nbd_add_socket(struct nbd_device *nbd, struct socket *sock) |
23272a67 | 575 | { |
9561a7ad JB |
576 | struct nbd_sock **socks; |
577 | struct nbd_sock *nsock; | |
23272a67 | 578 | |
9561a7ad JB |
579 | if (!nbd->task_setup) |
580 | nbd->task_setup = current; | |
581 | if (nbd->task_setup != current) { | |
582 | dev_err(disk_to_dev(nbd->disk), | |
583 | "Device being setup by another task"); | |
584 | return -EINVAL; | |
23272a67 MP |
585 | } |
586 | ||
9561a7ad JB |
587 | socks = krealloc(nbd->socks, (nbd->num_connections + 1) * |
588 | sizeof(struct nbd_sock *), GFP_KERNEL); | |
589 | if (!socks) | |
590 | return -ENOMEM; | |
591 | nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL); | |
592 | if (!nsock) | |
593 | return -ENOMEM; | |
594 | ||
595 | nbd->socks = socks; | |
23272a67 | 596 | |
9561a7ad JB |
597 | mutex_init(&nsock->tx_lock); |
598 | nsock->sock = sock; | |
599 | socks[nbd->num_connections++] = nsock; | |
23272a67 | 600 | |
9561a7ad | 601 | return 0; |
23272a67 MP |
602 | } |
603 | ||
0e4f0f6f MP |
604 | /* Reset all properties of an NBD device */ |
605 | static void nbd_reset(struct nbd_device *nbd) | |
606 | { | |
9561a7ad JB |
607 | int i; |
608 | ||
609 | for (i = 0; i < nbd->num_connections; i++) | |
610 | kfree(nbd->socks[i]); | |
611 | kfree(nbd->socks); | |
612 | nbd->socks = NULL; | |
9b4a6ba9 | 613 | nbd->runtime_flags = 0; |
0e4f0f6f MP |
614 | nbd->blksize = 1024; |
615 | nbd->bytesize = 0; | |
616 | set_capacity(nbd->disk, 0); | |
617 | nbd->flags = 0; | |
0eadf37a | 618 | nbd->tag_set.timeout = 0; |
9561a7ad JB |
619 | nbd->num_connections = 0; |
620 | nbd->task_setup = NULL; | |
0e4f0f6f | 621 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); |
0e4f0f6f MP |
622 | } |
623 | ||
624 | static void nbd_bdev_reset(struct block_device *bdev) | |
625 | { | |
626 | set_device_ro(bdev, false); | |
627 | bdev->bd_inode->i_size = 0; | |
628 | if (max_part > 0) { | |
629 | blkdev_reread_part(bdev); | |
630 | bdev->bd_invalidated = 1; | |
631 | } | |
632 | } | |
633 | ||
d02cf531 MP |
634 | static void nbd_parse_flags(struct nbd_device *nbd, struct block_device *bdev) |
635 | { | |
636 | if (nbd->flags & NBD_FLAG_READ_ONLY) | |
637 | set_device_ro(bdev, true); | |
638 | if (nbd->flags & NBD_FLAG_SEND_TRIM) | |
639 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); | |
640 | if (nbd->flags & NBD_FLAG_SEND_FLUSH) | |
aafb1eec | 641 | blk_queue_write_cache(nbd->disk->queue, true, false); |
d02cf531 | 642 | else |
aafb1eec | 643 | blk_queue_write_cache(nbd->disk->queue, false, false); |
d02cf531 MP |
644 | } |
645 | ||
9561a7ad JB |
646 | static void send_disconnects(struct nbd_device *nbd) |
647 | { | |
648 | struct nbd_request request = {}; | |
649 | int i, ret; | |
650 | ||
651 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
652 | request.type = htonl(NBD_CMD_DISC); | |
653 | ||
654 | for (i = 0; i < nbd->num_connections; i++) { | |
655 | ret = sock_xmit(nbd, i, 1, &request, sizeof(request), 0); | |
656 | if (ret <= 0) | |
657 | dev_err(disk_to_dev(nbd->disk), | |
658 | "Send disconnect failed %d\n", ret); | |
659 | } | |
660 | } | |
661 | ||
30d53d9c MP |
662 | static int nbd_dev_dbg_init(struct nbd_device *nbd); |
663 | static void nbd_dev_dbg_close(struct nbd_device *nbd); | |
664 | ||
9561a7ad | 665 | /* Must be called with config_lock held */ |
f4507164 | 666 | static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, |
1a2ad211 PM |
667 | unsigned int cmd, unsigned long arg) |
668 | { | |
1da177e4 | 669 | switch (cmd) { |
1a2ad211 | 670 | case NBD_DISCONNECT: { |
f4507164 | 671 | dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n"); |
9561a7ad | 672 | if (!nbd->socks) |
3a2d63f8 | 673 | return -EINVAL; |
1a2ad211 | 674 | |
9561a7ad | 675 | mutex_unlock(&nbd->config_lock); |
3a2d63f8 | 676 | fsync_bdev(bdev); |
9561a7ad | 677 | mutex_lock(&nbd->config_lock); |
3a2d63f8 PB |
678 | |
679 | /* Check again after getting mutex back. */ | |
9561a7ad | 680 | if (!nbd->socks) |
1da177e4 | 681 | return -EINVAL; |
c378f70a | 682 | |
9561a7ad JB |
683 | if (!test_and_set_bit(NBD_DISCONNECT_REQUESTED, |
684 | &nbd->runtime_flags)) | |
685 | send_disconnects(nbd); | |
c378f70a | 686 | return 0; |
1a2ad211 | 687 | } |
9561a7ad | 688 | |
23272a67 MP |
689 | case NBD_CLEAR_SOCK: |
690 | sock_shutdown(nbd); | |
f4507164 | 691 | nbd_clear_que(nbd); |
3a2d63f8 | 692 | kill_bdev(bdev); |
9561a7ad JB |
693 | nbd_bdev_reset(bdev); |
694 | /* | |
695 | * We want to give the run thread a chance to wait for everybody | |
696 | * to clean up and then do it's own cleanup. | |
697 | */ | |
698 | if (!test_bit(NBD_RUNNING, &nbd->runtime_flags)) { | |
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; | |
20032ec3 | 706 | nbd->task_setup = NULL; |
9561a7ad | 707 | } |
1a2ad211 | 708 | return 0; |
1a2ad211 PM |
709 | |
710 | case NBD_SET_SOCK: { | |
e2511578 | 711 | int err; |
23272a67 MP |
712 | struct socket *sock = sockfd_lookup(arg, &err); |
713 | ||
714 | if (!sock) | |
715 | return err; | |
716 | ||
9561a7ad | 717 | err = nbd_add_socket(nbd, sock); |
23272a67 MP |
718 | if (!err && max_part) |
719 | bdev->bd_invalidated = 1; | |
720 | ||
721 | return err; | |
1a2ad211 PM |
722 | } |
723 | ||
37091fdd | 724 | case NBD_SET_BLKSIZE: { |
5e454c67 | 725 | loff_t bsize = div_s64(nbd->bytesize, arg); |
37091fdd MP |
726 | |
727 | return nbd_size_set(nbd, bdev, arg, bsize); | |
728 | } | |
1a2ad211 | 729 | |
1da177e4 | 730 | case NBD_SET_SIZE: |
37091fdd | 731 | return nbd_size_set(nbd, bdev, nbd->blksize, |
e88f72cb | 732 | div_s64(arg, nbd->blksize)); |
37091fdd MP |
733 | |
734 | case NBD_SET_SIZE_BLOCKS: | |
735 | return nbd_size_set(nbd, bdev, nbd->blksize, arg); | |
1a2ad211 | 736 | |
7fdfd406 | 737 | case NBD_SET_TIMEOUT: |
0eadf37a | 738 | nbd->tag_set.timeout = arg * HZ; |
7fdfd406 | 739 | return 0; |
1a2ad211 | 740 | |
2f012508 PC |
741 | case NBD_SET_FLAGS: |
742 | nbd->flags = arg; | |
743 | return 0; | |
744 | ||
1a2ad211 | 745 | case NBD_DO_IT: { |
9561a7ad JB |
746 | struct recv_thread_args *args; |
747 | int num_connections = nbd->num_connections; | |
feffa5cc | 748 | int error = 0, i; |
1a2ad211 | 749 | |
6521d39a | 750 | if (nbd->task_recv) |
c91192d6 | 751 | return -EBUSY; |
9561a7ad | 752 | if (!nbd->socks) |
1da177e4 | 753 | return -EINVAL; |
9561a7ad JB |
754 | if (num_connections > 1 && |
755 | !(nbd->flags & NBD_FLAG_CAN_MULTI_CONN)) { | |
756 | dev_err(disk_to_dev(nbd->disk), "server does not support multiple connections per device.\n"); | |
feffa5cc | 757 | error = -EINVAL; |
9561a7ad JB |
758 | goto out_err; |
759 | } | |
1a2ad211 | 760 | |
9561a7ad JB |
761 | set_bit(NBD_RUNNING, &nbd->runtime_flags); |
762 | blk_mq_update_nr_hw_queues(&nbd->tag_set, nbd->num_connections); | |
763 | args = kcalloc(num_connections, sizeof(*args), GFP_KERNEL); | |
feffa5cc JA |
764 | if (!args) { |
765 | error = -ENOMEM; | |
9561a7ad | 766 | goto out_err; |
feffa5cc | 767 | } |
97240963 | 768 | nbd->task_recv = current; |
9561a7ad | 769 | mutex_unlock(&nbd->config_lock); |
1a2ad211 | 770 | |
d02cf531 | 771 | nbd_parse_flags(nbd, bdev); |
a336d298 | 772 | |
9561a7ad JB |
773 | error = device_create_file(disk_to_dev(nbd->disk), &pid_attr); |
774 | if (error) { | |
775 | dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); | |
776 | goto out_recv; | |
777 | } | |
778 | ||
779 | nbd_size_update(nbd, bdev); | |
780 | ||
30d53d9c | 781 | nbd_dev_dbg_init(nbd); |
9561a7ad JB |
782 | for (i = 0; i < num_connections; i++) { |
783 | sk_set_memalloc(nbd->socks[i]->sock->sk); | |
784 | atomic_inc(&nbd->recv_threads); | |
785 | INIT_WORK(&args[i].work, recv_work); | |
786 | args[i].nbd = nbd; | |
787 | args[i].index = i; | |
124d6db0 | 788 | queue_work(recv_workqueue, &args[i].work); |
9561a7ad JB |
789 | } |
790 | wait_event_interruptible(nbd->recv_wq, | |
791 | atomic_read(&nbd->recv_threads) == 0); | |
792 | for (i = 0; i < num_connections; i++) | |
793 | flush_work(&args[i].work); | |
30d53d9c | 794 | nbd_dev_dbg_close(nbd); |
9561a7ad JB |
795 | nbd_size_clear(nbd, bdev); |
796 | device_remove_file(disk_to_dev(nbd->disk), &pid_attr); | |
797 | out_recv: | |
798 | mutex_lock(&nbd->config_lock); | |
97240963 | 799 | nbd->task_recv = NULL; |
9561a7ad | 800 | out_err: |
36e47bee | 801 | sock_shutdown(nbd); |
f4507164 | 802 | nbd_clear_que(nbd); |
3a2d63f8 | 803 | kill_bdev(bdev); |
0e4f0f6f MP |
804 | nbd_bdev_reset(bdev); |
805 | ||
9b4a6ba9 JB |
806 | /* user requested, ignore socket errors */ |
807 | if (test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
1f7b5cf1 | 808 | error = 0; |
9b4a6ba9 | 809 | if (test_bit(NBD_TIMEDOUT, &nbd->runtime_flags)) |
1f7b5cf1 MP |
810 | error = -ETIMEDOUT; |
811 | ||
0e4f0f6f | 812 | nbd_reset(nbd); |
19391830 | 813 | return error; |
1a2ad211 PM |
814 | } |
815 | ||
1da177e4 | 816 | case NBD_CLEAR_QUE: |
4b2f0260 HX |
817 | /* |
818 | * This is for compatibility only. The queue is always cleared | |
819 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
820 | */ | |
1da177e4 | 821 | return 0; |
1a2ad211 | 822 | |
1da177e4 | 823 | case NBD_PRINT_DEBUG: |
fd8383fd JB |
824 | /* |
825 | * For compatibility only, we no longer keep a list of | |
826 | * outstanding requests. | |
827 | */ | |
1da177e4 LT |
828 | return 0; |
829 | } | |
1a2ad211 PM |
830 | return -ENOTTY; |
831 | } | |
832 | ||
833 | static int nbd_ioctl(struct block_device *bdev, fmode_t mode, | |
834 | unsigned int cmd, unsigned long arg) | |
835 | { | |
f4507164 | 836 | struct nbd_device *nbd = bdev->bd_disk->private_data; |
1a2ad211 PM |
837 | int error; |
838 | ||
839 | if (!capable(CAP_SYS_ADMIN)) | |
840 | return -EPERM; | |
841 | ||
f4507164 | 842 | BUG_ON(nbd->magic != NBD_MAGIC); |
1a2ad211 | 843 | |
9561a7ad | 844 | mutex_lock(&nbd->config_lock); |
f4507164 | 845 | error = __nbd_ioctl(bdev, nbd, cmd, arg); |
9561a7ad | 846 | mutex_unlock(&nbd->config_lock); |
1a2ad211 PM |
847 | |
848 | return error; | |
1da177e4 LT |
849 | } |
850 | ||
83d5cde4 | 851 | static const struct block_device_operations nbd_fops = |
1da177e4 LT |
852 | { |
853 | .owner = THIS_MODULE, | |
8a6cfeb6 | 854 | .ioctl = nbd_ioctl, |
263a3df1 | 855 | .compat_ioctl = nbd_ioctl, |
1da177e4 LT |
856 | }; |
857 | ||
30d53d9c MP |
858 | #if IS_ENABLED(CONFIG_DEBUG_FS) |
859 | ||
860 | static int nbd_dbg_tasks_show(struct seq_file *s, void *unused) | |
861 | { | |
862 | struct nbd_device *nbd = s->private; | |
863 | ||
864 | if (nbd->task_recv) | |
865 | seq_printf(s, "recv: %d\n", task_pid_nr(nbd->task_recv)); | |
30d53d9c MP |
866 | |
867 | return 0; | |
868 | } | |
869 | ||
870 | static int nbd_dbg_tasks_open(struct inode *inode, struct file *file) | |
871 | { | |
872 | return single_open(file, nbd_dbg_tasks_show, inode->i_private); | |
873 | } | |
874 | ||
875 | static const struct file_operations nbd_dbg_tasks_ops = { | |
876 | .open = nbd_dbg_tasks_open, | |
877 | .read = seq_read, | |
878 | .llseek = seq_lseek, | |
879 | .release = single_release, | |
880 | }; | |
881 | ||
882 | static int nbd_dbg_flags_show(struct seq_file *s, void *unused) | |
883 | { | |
884 | struct nbd_device *nbd = s->private; | |
885 | u32 flags = nbd->flags; | |
886 | ||
887 | seq_printf(s, "Hex: 0x%08x\n\n", flags); | |
888 | ||
889 | seq_puts(s, "Known flags:\n"); | |
890 | ||
891 | if (flags & NBD_FLAG_HAS_FLAGS) | |
892 | seq_puts(s, "NBD_FLAG_HAS_FLAGS\n"); | |
893 | if (flags & NBD_FLAG_READ_ONLY) | |
894 | seq_puts(s, "NBD_FLAG_READ_ONLY\n"); | |
895 | if (flags & NBD_FLAG_SEND_FLUSH) | |
896 | seq_puts(s, "NBD_FLAG_SEND_FLUSH\n"); | |
897 | if (flags & NBD_FLAG_SEND_TRIM) | |
898 | seq_puts(s, "NBD_FLAG_SEND_TRIM\n"); | |
899 | ||
900 | return 0; | |
901 | } | |
902 | ||
903 | static int nbd_dbg_flags_open(struct inode *inode, struct file *file) | |
904 | { | |
905 | return single_open(file, nbd_dbg_flags_show, inode->i_private); | |
906 | } | |
907 | ||
908 | static const struct file_operations nbd_dbg_flags_ops = { | |
909 | .open = nbd_dbg_flags_open, | |
910 | .read = seq_read, | |
911 | .llseek = seq_lseek, | |
912 | .release = single_release, | |
913 | }; | |
914 | ||
915 | static int nbd_dev_dbg_init(struct nbd_device *nbd) | |
916 | { | |
917 | struct dentry *dir; | |
27ea43fe MP |
918 | |
919 | if (!nbd_dbg_dir) | |
920 | return -EIO; | |
30d53d9c MP |
921 | |
922 | dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir); | |
27ea43fe MP |
923 | if (!dir) { |
924 | dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n", | |
925 | nbd_name(nbd)); | |
926 | return -EIO; | |
30d53d9c MP |
927 | } |
928 | nbd->dbg_dir = dir; | |
929 | ||
27ea43fe MP |
930 | debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops); |
931 | debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize); | |
0eadf37a | 932 | debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout); |
ef77b515 | 933 | debugfs_create_u64("blocksize", 0444, dir, &nbd->blksize); |
d366a0ff | 934 | debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops); |
30d53d9c MP |
935 | |
936 | return 0; | |
937 | } | |
938 | ||
939 | static void nbd_dev_dbg_close(struct nbd_device *nbd) | |
940 | { | |
941 | debugfs_remove_recursive(nbd->dbg_dir); | |
942 | } | |
943 | ||
944 | static int nbd_dbg_init(void) | |
945 | { | |
946 | struct dentry *dbg_dir; | |
947 | ||
948 | dbg_dir = debugfs_create_dir("nbd", NULL); | |
27ea43fe MP |
949 | if (!dbg_dir) |
950 | return -EIO; | |
30d53d9c MP |
951 | |
952 | nbd_dbg_dir = dbg_dir; | |
953 | ||
954 | return 0; | |
955 | } | |
956 | ||
957 | static void nbd_dbg_close(void) | |
958 | { | |
959 | debugfs_remove_recursive(nbd_dbg_dir); | |
960 | } | |
961 | ||
962 | #else /* IS_ENABLED(CONFIG_DEBUG_FS) */ | |
963 | ||
964 | static int nbd_dev_dbg_init(struct nbd_device *nbd) | |
965 | { | |
966 | return 0; | |
967 | } | |
968 | ||
969 | static void nbd_dev_dbg_close(struct nbd_device *nbd) | |
970 | { | |
971 | } | |
972 | ||
973 | static int nbd_dbg_init(void) | |
974 | { | |
975 | return 0; | |
976 | } | |
977 | ||
978 | static void nbd_dbg_close(void) | |
979 | { | |
980 | } | |
981 | ||
982 | #endif | |
983 | ||
fd8383fd JB |
984 | static int nbd_init_request(void *data, struct request *rq, |
985 | unsigned int hctx_idx, unsigned int request_idx, | |
986 | unsigned int numa_node) | |
987 | { | |
988 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq); | |
fd8383fd | 989 | cmd->nbd = data; |
fd8383fd JB |
990 | return 0; |
991 | } | |
992 | ||
993 | static struct blk_mq_ops nbd_mq_ops = { | |
994 | .queue_rq = nbd_queue_rq, | |
fd8383fd | 995 | .init_request = nbd_init_request, |
0eadf37a | 996 | .timeout = nbd_xmit_timeout, |
fd8383fd JB |
997 | }; |
998 | ||
b0d9111a JB |
999 | static void nbd_dev_remove(struct nbd_device *nbd) |
1000 | { | |
1001 | struct gendisk *disk = nbd->disk; | |
1002 | nbd->magic = 0; | |
1003 | if (disk) { | |
1004 | del_gendisk(disk); | |
1005 | blk_cleanup_queue(disk->queue); | |
1006 | blk_mq_free_tag_set(&nbd->tag_set); | |
1007 | put_disk(disk); | |
1008 | } | |
1009 | kfree(nbd); | |
1010 | } | |
1011 | ||
1012 | static int nbd_dev_add(int index) | |
1013 | { | |
1014 | struct nbd_device *nbd; | |
1015 | struct gendisk *disk; | |
1016 | struct request_queue *q; | |
1017 | int err = -ENOMEM; | |
1018 | ||
1019 | nbd = kzalloc(sizeof(struct nbd_device), GFP_KERNEL); | |
1020 | if (!nbd) | |
1021 | goto out; | |
1022 | ||
1023 | disk = alloc_disk(1 << part_shift); | |
1024 | if (!disk) | |
1025 | goto out_free_nbd; | |
1026 | ||
1027 | if (index >= 0) { | |
1028 | err = idr_alloc(&nbd_index_idr, nbd, index, index + 1, | |
1029 | GFP_KERNEL); | |
1030 | if (err == -ENOSPC) | |
1031 | err = -EEXIST; | |
1032 | } else { | |
1033 | err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL); | |
1034 | if (err >= 0) | |
1035 | index = err; | |
1036 | } | |
1037 | if (err < 0) | |
1038 | goto out_free_disk; | |
1039 | ||
1040 | nbd->disk = disk; | |
1041 | nbd->tag_set.ops = &nbd_mq_ops; | |
1042 | nbd->tag_set.nr_hw_queues = 1; | |
1043 | nbd->tag_set.queue_depth = 128; | |
1044 | nbd->tag_set.numa_node = NUMA_NO_NODE; | |
1045 | nbd->tag_set.cmd_size = sizeof(struct nbd_cmd); | |
1046 | nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | | |
1047 | BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING; | |
1048 | nbd->tag_set.driver_data = nbd; | |
1049 | ||
1050 | err = blk_mq_alloc_tag_set(&nbd->tag_set); | |
1051 | if (err) | |
1052 | goto out_free_idr; | |
1053 | ||
1054 | q = blk_mq_init_queue(&nbd->tag_set); | |
1055 | if (IS_ERR(q)) { | |
1056 | err = PTR_ERR(q); | |
1057 | goto out_free_tags; | |
1058 | } | |
1059 | disk->queue = q; | |
1060 | ||
1061 | /* | |
1062 | * Tell the block layer that we are not a rotational device | |
1063 | */ | |
1064 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue); | |
1065 | queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, disk->queue); | |
1066 | disk->queue->limits.discard_granularity = 512; | |
1067 | blk_queue_max_discard_sectors(disk->queue, UINT_MAX); | |
1068 | disk->queue->limits.discard_zeroes_data = 0; | |
1069 | blk_queue_max_hw_sectors(disk->queue, 65536); | |
1070 | disk->queue->limits.max_sectors = 256; | |
1071 | ||
1072 | nbd->magic = NBD_MAGIC; | |
1073 | mutex_init(&nbd->config_lock); | |
1074 | disk->major = NBD_MAJOR; | |
1075 | disk->first_minor = index << part_shift; | |
1076 | disk->fops = &nbd_fops; | |
1077 | disk->private_data = nbd; | |
1078 | sprintf(disk->disk_name, "nbd%d", index); | |
1079 | init_waitqueue_head(&nbd->recv_wq); | |
1080 | nbd_reset(nbd); | |
1081 | add_disk(disk); | |
1082 | return index; | |
1083 | ||
1084 | out_free_tags: | |
1085 | blk_mq_free_tag_set(&nbd->tag_set); | |
1086 | out_free_idr: | |
1087 | idr_remove(&nbd_index_idr, index); | |
1088 | out_free_disk: | |
1089 | put_disk(disk); | |
1090 | out_free_nbd: | |
1091 | kfree(nbd); | |
1092 | out: | |
1093 | return err; | |
1094 | } | |
1095 | ||
1da177e4 LT |
1096 | /* |
1097 | * And here should be modules and kernel interface | |
1098 | * (Just smiley confuses emacs :-) | |
1099 | */ | |
1100 | ||
1101 | static int __init nbd_init(void) | |
1102 | { | |
1da177e4 LT |
1103 | int i; |
1104 | ||
5b7b18cc | 1105 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 1106 | |
d71a6d73 | 1107 | if (max_part < 0) { |
7742ce4a | 1108 | printk(KERN_ERR "nbd: max_part must be >= 0\n"); |
d71a6d73 LV |
1109 | return -EINVAL; |
1110 | } | |
1111 | ||
1112 | part_shift = 0; | |
5988ce23 | 1113 | if (max_part > 0) { |
d71a6d73 LV |
1114 | part_shift = fls(max_part); |
1115 | ||
5988ce23 NK |
1116 | /* |
1117 | * Adjust max_part according to part_shift as it is exported | |
1118 | * to user space so that user can know the max number of | |
1119 | * partition kernel should be able to manage. | |
1120 | * | |
1121 | * Note that -1 is required because partition 0 is reserved | |
1122 | * for the whole disk. | |
1123 | */ | |
1124 | max_part = (1UL << part_shift) - 1; | |
1125 | } | |
1126 | ||
3b271082 NK |
1127 | if ((1UL << part_shift) > DISK_MAX_PARTS) |
1128 | return -EINVAL; | |
1129 | ||
1130 | if (nbds_max > 1UL << (MINORBITS - part_shift)) | |
1131 | return -EINVAL; | |
124d6db0 JB |
1132 | recv_workqueue = alloc_workqueue("knbd-recv", |
1133 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 0); | |
1134 | if (!recv_workqueue) | |
1135 | return -ENOMEM; | |
3b271082 | 1136 | |
b0d9111a JB |
1137 | if (register_blkdev(NBD_MAJOR, "nbd")) |
1138 | return -EIO; | |
1da177e4 | 1139 | |
30d53d9c MP |
1140 | nbd_dbg_init(); |
1141 | ||
b0d9111a JB |
1142 | mutex_lock(&nbd_index_mutex); |
1143 | for (i = 0; i < nbds_max; i++) | |
1144 | nbd_dev_add(i); | |
1145 | mutex_unlock(&nbd_index_mutex); | |
1146 | return 0; | |
1147 | } | |
1da177e4 | 1148 | |
b0d9111a JB |
1149 | static int nbd_exit_cb(int id, void *ptr, void *data) |
1150 | { | |
1151 | struct nbd_device *nbd = ptr; | |
1152 | nbd_dev_remove(nbd); | |
1da177e4 | 1153 | return 0; |
1da177e4 LT |
1154 | } |
1155 | ||
1156 | static void __exit nbd_cleanup(void) | |
1157 | { | |
30d53d9c MP |
1158 | nbd_dbg_close(); |
1159 | ||
b0d9111a JB |
1160 | idr_for_each(&nbd_index_idr, &nbd_exit_cb, NULL); |
1161 | idr_destroy(&nbd_index_idr); | |
124d6db0 | 1162 | destroy_workqueue(recv_workqueue); |
1da177e4 | 1163 | unregister_blkdev(NBD_MAJOR, "nbd"); |
1da177e4 LT |
1164 | } |
1165 | ||
1166 | module_init(nbd_init); | |
1167 | module_exit(nbd_cleanup); | |
1168 | ||
1169 | MODULE_DESCRIPTION("Network Block Device"); | |
1170 | MODULE_LICENSE("GPL"); | |
1171 | ||
40be0c28 | 1172 | module_param(nbds_max, int, 0444); |
d71a6d73 LV |
1173 | MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); |
1174 | module_param(max_part, int, 0444); | |
1175 | MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)"); |