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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 | ||
9561a7ad JB |
44 | struct nbd_sock { |
45 | struct socket *sock; | |
46 | struct mutex tx_lock; | |
47 | }; | |
48 | ||
9b4a6ba9 JB |
49 | #define NBD_TIMEDOUT 0 |
50 | #define NBD_DISCONNECT_REQUESTED 1 | |
9561a7ad JB |
51 | #define NBD_DISCONNECTED 2 |
52 | #define NBD_RUNNING 3 | |
9b4a6ba9 | 53 | |
13e71d69 | 54 | struct nbd_device { |
22d109c1 | 55 | u32 flags; |
9b4a6ba9 | 56 | unsigned long runtime_flags; |
9561a7ad | 57 | struct nbd_sock **socks; |
13e71d69 MP |
58 | int magic; |
59 | ||
fd8383fd | 60 | struct blk_mq_tag_set tag_set; |
13e71d69 | 61 | |
9561a7ad | 62 | struct mutex config_lock; |
13e71d69 | 63 | struct gendisk *disk; |
9561a7ad JB |
64 | int num_connections; |
65 | atomic_t recv_threads; | |
66 | wait_queue_head_t recv_wq; | |
ef77b515 | 67 | loff_t blksize; |
b9c495bb | 68 | loff_t bytesize; |
7e2893a1 | 69 | |
7e2893a1 | 70 | struct task_struct *task_recv; |
9561a7ad | 71 | struct task_struct *task_setup; |
30d53d9c MP |
72 | |
73 | #if IS_ENABLED(CONFIG_DEBUG_FS) | |
74 | struct dentry *dbg_dir; | |
75 | #endif | |
13e71d69 MP |
76 | }; |
77 | ||
fd8383fd JB |
78 | struct nbd_cmd { |
79 | struct nbd_device *nbd; | |
9561a7ad | 80 | struct completion send_complete; |
fd8383fd JB |
81 | }; |
82 | ||
30d53d9c MP |
83 | #if IS_ENABLED(CONFIG_DEBUG_FS) |
84 | static struct dentry *nbd_dbg_dir; | |
85 | #endif | |
86 | ||
87 | #define nbd_name(nbd) ((nbd)->disk->disk_name) | |
88 | ||
f4507164 | 89 | #define NBD_MAGIC 0x68797548 |
1da177e4 | 90 | |
9c7a4169 | 91 | static unsigned int nbds_max = 16; |
20a8143e | 92 | static struct nbd_device *nbd_dev; |
d71a6d73 | 93 | static int max_part; |
124d6db0 | 94 | static struct workqueue_struct *recv_workqueue; |
1da177e4 | 95 | |
d18509f5 | 96 | static inline struct device *nbd_to_dev(struct nbd_device *nbd) |
1da177e4 | 97 | { |
d18509f5 | 98 | return disk_to_dev(nbd->disk); |
1da177e4 LT |
99 | } |
100 | ||
37091fdd MP |
101 | static bool nbd_is_connected(struct nbd_device *nbd) |
102 | { | |
103 | return !!nbd->task_recv; | |
104 | } | |
105 | ||
1da177e4 LT |
106 | static const char *nbdcmd_to_ascii(int cmd) |
107 | { | |
108 | switch (cmd) { | |
109 | case NBD_CMD_READ: return "read"; | |
110 | case NBD_CMD_WRITE: return "write"; | |
111 | case NBD_CMD_DISC: return "disconnect"; | |
75f187ab | 112 | case NBD_CMD_FLUSH: return "flush"; |
a336d298 | 113 | case NBD_CMD_TRIM: return "trim/discard"; |
1da177e4 LT |
114 | } |
115 | return "invalid"; | |
116 | } | |
1da177e4 | 117 | |
37091fdd MP |
118 | static int nbd_size_clear(struct nbd_device *nbd, struct block_device *bdev) |
119 | { | |
120 | bdev->bd_inode->i_size = 0; | |
121 | set_capacity(nbd->disk, 0); | |
122 | kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); | |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
127 | static void nbd_size_update(struct nbd_device *nbd, struct block_device *bdev) | |
128 | { | |
129 | if (!nbd_is_connected(nbd)) | |
130 | return; | |
131 | ||
132 | bdev->bd_inode->i_size = nbd->bytesize; | |
133 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
134 | kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); | |
135 | } | |
136 | ||
137 | static int nbd_size_set(struct nbd_device *nbd, struct block_device *bdev, | |
ef77b515 | 138 | loff_t blocksize, loff_t nr_blocks) |
37091fdd MP |
139 | { |
140 | int ret; | |
141 | ||
142 | ret = set_blocksize(bdev, blocksize); | |
143 | if (ret) | |
144 | return ret; | |
145 | ||
146 | nbd->blksize = blocksize; | |
ef77b515 | 147 | nbd->bytesize = blocksize * nr_blocks; |
37091fdd MP |
148 | |
149 | nbd_size_update(nbd, bdev); | |
150 | ||
151 | return 0; | |
152 | } | |
153 | ||
fd8383fd | 154 | static void nbd_end_request(struct nbd_cmd *cmd) |
1da177e4 | 155 | { |
fd8383fd JB |
156 | struct nbd_device *nbd = cmd->nbd; |
157 | struct request *req = blk_mq_rq_from_pdu(cmd); | |
097c94a4 | 158 | int error = req->errors ? -EIO : 0; |
1da177e4 | 159 | |
fd8383fd | 160 | dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", cmd, |
d18509f5 | 161 | error ? "failed" : "done"); |
1da177e4 | 162 | |
fd8383fd | 163 | blk_mq_complete_request(req, error); |
1da177e4 LT |
164 | } |
165 | ||
e018e757 MP |
166 | /* |
167 | * Forcibly shutdown the socket causing all listeners to error | |
168 | */ | |
36e47bee | 169 | static void sock_shutdown(struct nbd_device *nbd) |
7fdfd406 | 170 | { |
9561a7ad | 171 | int i; |
23272a67 | 172 | |
9561a7ad JB |
173 | if (nbd->num_connections == 0) |
174 | return; | |
175 | if (test_and_set_bit(NBD_DISCONNECTED, &nbd->runtime_flags)) | |
260bbce4 | 176 | return; |
23272a67 | 177 | |
9561a7ad JB |
178 | for (i = 0; i < nbd->num_connections; i++) { |
179 | struct nbd_sock *nsock = nbd->socks[i]; | |
180 | mutex_lock(&nsock->tx_lock); | |
181 | kernel_sock_shutdown(nsock->sock, SHUT_RDWR); | |
182 | mutex_unlock(&nsock->tx_lock); | |
183 | } | |
184 | dev_warn(disk_to_dev(nbd->disk), "shutting down sockets\n"); | |
7fdfd406 PC |
185 | } |
186 | ||
0eadf37a JB |
187 | static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, |
188 | bool reserved) | |
7fdfd406 | 189 | { |
0eadf37a JB |
190 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req); |
191 | struct nbd_device *nbd = cmd->nbd; | |
dcc909d9 | 192 | |
9561a7ad | 193 | dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n"); |
9b4a6ba9 | 194 | set_bit(NBD_TIMEDOUT, &nbd->runtime_flags); |
0eadf37a | 195 | req->errors++; |
9561a7ad | 196 | |
9561a7ad JB |
197 | mutex_lock(&nbd->config_lock); |
198 | sock_shutdown(nbd); | |
199 | mutex_unlock(&nbd->config_lock); | |
0eadf37a | 200 | return BLK_EH_HANDLED; |
7fdfd406 PC |
201 | } |
202 | ||
1da177e4 LT |
203 | /* |
204 | * Send or receive packet. | |
205 | */ | |
9561a7ad JB |
206 | static int sock_xmit(struct nbd_device *nbd, int index, int send, void *buf, |
207 | int size, int msg_flags) | |
1da177e4 | 208 | { |
9561a7ad | 209 | struct socket *sock = nbd->socks[index]->sock; |
1da177e4 LT |
210 | int result; |
211 | struct msghdr msg; | |
212 | struct kvec iov; | |
7f338fe4 | 213 | unsigned long pflags = current->flags; |
1da177e4 | 214 | |
ffc41cf8 | 215 | if (unlikely(!sock)) { |
a897b666 | 216 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
217 | "Attempted %s on closed socket in sock_xmit\n", |
218 | (send ? "send" : "recv")); | |
ffc41cf8 MS |
219 | return -EINVAL; |
220 | } | |
221 | ||
7f338fe4 | 222 | current->flags |= PF_MEMALLOC; |
1da177e4 | 223 | do { |
7f338fe4 | 224 | sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC; |
1da177e4 LT |
225 | iov.iov_base = buf; |
226 | iov.iov_len = size; | |
227 | msg.msg_name = NULL; | |
228 | msg.msg_namelen = 0; | |
229 | msg.msg_control = NULL; | |
230 | msg.msg_controllen = 0; | |
1da177e4 LT |
231 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
232 | ||
7e2893a1 | 233 | if (send) |
1da177e4 | 234 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
7e2893a1 | 235 | else |
35fbf5bc NK |
236 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, |
237 | msg.msg_flags); | |
1da177e4 | 238 | |
1da177e4 LT |
239 | if (result <= 0) { |
240 | if (result == 0) | |
241 | result = -EPIPE; /* short read */ | |
242 | break; | |
243 | } | |
244 | size -= result; | |
245 | buf += result; | |
246 | } while (size > 0); | |
247 | ||
7f338fe4 | 248 | tsk_restore_flags(current, pflags, PF_MEMALLOC); |
1da177e4 LT |
249 | |
250 | return result; | |
251 | } | |
252 | ||
9561a7ad JB |
253 | static inline int sock_send_bvec(struct nbd_device *nbd, int index, |
254 | struct bio_vec *bvec, int flags) | |
1da177e4 LT |
255 | { |
256 | int result; | |
257 | void *kaddr = kmap(bvec->bv_page); | |
9561a7ad | 258 | result = sock_xmit(nbd, index, 1, kaddr + bvec->bv_offset, |
f4507164 | 259 | bvec->bv_len, flags); |
1da177e4 LT |
260 | kunmap(bvec->bv_page); |
261 | return result; | |
262 | } | |
263 | ||
7fdfd406 | 264 | /* always call with the tx_lock held */ |
9561a7ad | 265 | static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) |
1da177e4 | 266 | { |
fd8383fd | 267 | struct request *req = blk_mq_rq_from_pdu(cmd); |
d61b7f97 | 268 | int result; |
1da177e4 | 269 | struct nbd_request request; |
1011c1b9 | 270 | unsigned long size = blk_rq_bytes(req); |
429a787b | 271 | struct bio *bio; |
9dc6c806 | 272 | u32 type; |
9561a7ad | 273 | u32 tag = blk_mq_unique_tag(req); |
9dc6c806 | 274 | |
aebf526b CH |
275 | switch (req_op(req)) { |
276 | case REQ_OP_DISCARD: | |
9dc6c806 | 277 | type = NBD_CMD_TRIM; |
aebf526b CH |
278 | break; |
279 | case REQ_OP_FLUSH: | |
9dc6c806 | 280 | type = NBD_CMD_FLUSH; |
aebf526b CH |
281 | break; |
282 | case REQ_OP_WRITE: | |
9dc6c806 | 283 | type = NBD_CMD_WRITE; |
aebf526b CH |
284 | break; |
285 | case REQ_OP_READ: | |
9dc6c806 | 286 | type = NBD_CMD_READ; |
aebf526b CH |
287 | break; |
288 | default: | |
289 | return -EIO; | |
290 | } | |
1da177e4 | 291 | |
09fc54cc CH |
292 | if (rq_data_dir(req) == WRITE && |
293 | (nbd->flags & NBD_FLAG_READ_ONLY)) { | |
294 | dev_err_ratelimited(disk_to_dev(nbd->disk), | |
295 | "Write on read-only\n"); | |
296 | return -EIO; | |
297 | } | |
298 | ||
04cfac4e | 299 | memset(&request, 0, sizeof(request)); |
1da177e4 | 300 | request.magic = htonl(NBD_REQUEST_MAGIC); |
9dc6c806 | 301 | request.type = htonl(type); |
9561a7ad | 302 | if (type != NBD_CMD_FLUSH) { |
75f187ab AB |
303 | request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); |
304 | request.len = htonl(size); | |
305 | } | |
9561a7ad | 306 | memcpy(request.handle, &tag, sizeof(tag)); |
1da177e4 | 307 | |
d18509f5 | 308 | dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n", |
fd8383fd | 309 | cmd, nbdcmd_to_ascii(type), |
d18509f5 | 310 | (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req)); |
9561a7ad | 311 | result = sock_xmit(nbd, index, 1, &request, sizeof(request), |
9dc6c806 | 312 | (type == NBD_CMD_WRITE) ? MSG_MORE : 0); |
1da177e4 | 313 | if (result <= 0) { |
a897b666 | 314 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
7f1b90f9 | 315 | "Send control failed (result %d)\n", result); |
dab5313a | 316 | return -EIO; |
1da177e4 LT |
317 | } |
318 | ||
429a787b JA |
319 | if (type != NBD_CMD_WRITE) |
320 | return 0; | |
321 | ||
429a787b JA |
322 | bio = req->bio; |
323 | while (bio) { | |
324 | struct bio *next = bio->bi_next; | |
325 | struct bvec_iter iter; | |
7988613b | 326 | struct bio_vec bvec; |
429a787b JA |
327 | |
328 | bio_for_each_segment(bvec, bio, iter) { | |
329 | bool is_last = !next && bio_iter_last(bvec, iter); | |
d61b7f97 | 330 | int flags = is_last ? 0 : MSG_MORE; |
429a787b | 331 | |
d18509f5 | 332 | dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n", |
fd8383fd | 333 | cmd, bvec.bv_len); |
9561a7ad | 334 | result = sock_send_bvec(nbd, index, &bvec, flags); |
6c92e699 | 335 | if (result <= 0) { |
f4507164 | 336 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
337 | "Send data failed (result %d)\n", |
338 | result); | |
dab5313a | 339 | return -EIO; |
6c92e699 | 340 | } |
429a787b JA |
341 | /* |
342 | * The completion might already have come in, | |
343 | * so break for the last one instead of letting | |
344 | * the iterator do it. This prevents use-after-free | |
345 | * of the bio. | |
346 | */ | |
347 | if (is_last) | |
348 | break; | |
1da177e4 | 349 | } |
429a787b | 350 | bio = next; |
1da177e4 | 351 | } |
1da177e4 | 352 | return 0; |
1da177e4 LT |
353 | } |
354 | ||
9561a7ad JB |
355 | static inline int sock_recv_bvec(struct nbd_device *nbd, int index, |
356 | struct bio_vec *bvec) | |
1da177e4 LT |
357 | { |
358 | int result; | |
359 | void *kaddr = kmap(bvec->bv_page); | |
9561a7ad JB |
360 | result = sock_xmit(nbd, index, 0, kaddr + bvec->bv_offset, |
361 | bvec->bv_len, MSG_WAITALL); | |
1da177e4 LT |
362 | kunmap(bvec->bv_page); |
363 | return result; | |
364 | } | |
365 | ||
366 | /* NULL returned = something went wrong, inform userspace */ | |
9561a7ad | 367 | static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) |
1da177e4 LT |
368 | { |
369 | int result; | |
370 | struct nbd_reply reply; | |
fd8383fd JB |
371 | struct nbd_cmd *cmd; |
372 | struct request *req = NULL; | |
373 | u16 hwq; | |
9561a7ad | 374 | u32 tag; |
1da177e4 LT |
375 | |
376 | reply.magic = 0; | |
9561a7ad | 377 | result = sock_xmit(nbd, index, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 | 378 | if (result <= 0) { |
9561a7ad JB |
379 | if (!test_bit(NBD_DISCONNECTED, &nbd->runtime_flags) && |
380 | !test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
381 | dev_err(disk_to_dev(nbd->disk), | |
382 | "Receive control failed (result %d)\n", result); | |
19391830 | 383 | return ERR_PTR(result); |
1da177e4 | 384 | } |
e4b57e08 MF |
385 | |
386 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
f4507164 | 387 | dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n", |
e4b57e08 | 388 | (unsigned long)ntohl(reply.magic)); |
19391830 | 389 | return ERR_PTR(-EPROTO); |
e4b57e08 MF |
390 | } |
391 | ||
9561a7ad | 392 | memcpy(&tag, reply.handle, sizeof(u32)); |
4b2f0260 | 393 | |
fd8383fd JB |
394 | hwq = blk_mq_unique_tag_to_hwq(tag); |
395 | if (hwq < nbd->tag_set.nr_hw_queues) | |
396 | req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq], | |
397 | blk_mq_unique_tag_to_tag(tag)); | |
398 | if (!req || !blk_mq_request_started(req)) { | |
399 | dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n", | |
400 | tag, req); | |
401 | return ERR_PTR(-ENOENT); | |
1da177e4 | 402 | } |
fd8383fd | 403 | cmd = blk_mq_rq_to_pdu(req); |
1da177e4 | 404 | if (ntohl(reply.error)) { |
f4507164 | 405 | dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n", |
7f1b90f9 | 406 | ntohl(reply.error)); |
1da177e4 | 407 | req->errors++; |
fd8383fd | 408 | return cmd; |
1da177e4 LT |
409 | } |
410 | ||
fd8383fd | 411 | dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", cmd); |
9dc6c806 | 412 | if (rq_data_dir(req) != WRITE) { |
5705f702 | 413 | struct req_iterator iter; |
7988613b | 414 | struct bio_vec bvec; |
5705f702 N |
415 | |
416 | rq_for_each_segment(bvec, req, iter) { | |
9561a7ad | 417 | result = sock_recv_bvec(nbd, index, &bvec); |
6c92e699 | 418 | if (result <= 0) { |
f4507164 | 419 | dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", |
7f1b90f9 | 420 | result); |
6c92e699 | 421 | req->errors++; |
fd8383fd | 422 | return cmd; |
6c92e699 | 423 | } |
d18509f5 | 424 | dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n", |
fd8383fd | 425 | cmd, bvec.bv_len); |
1da177e4 | 426 | } |
9561a7ad JB |
427 | } else { |
428 | /* See the comment in nbd_queue_rq. */ | |
429 | wait_for_completion(&cmd->send_complete); | |
1da177e4 | 430 | } |
fd8383fd | 431 | return cmd; |
1da177e4 LT |
432 | } |
433 | ||
edfaa7c3 KS |
434 | static ssize_t pid_show(struct device *dev, |
435 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 436 | { |
edfaa7c3 | 437 | struct gendisk *disk = dev_to_disk(dev); |
6521d39a | 438 | struct nbd_device *nbd = (struct nbd_device *)disk->private_data; |
edfaa7c3 | 439 | |
6521d39a | 440 | return sprintf(buf, "%d\n", task_pid_nr(nbd->task_recv)); |
6b39bb65 PC |
441 | } |
442 | ||
edfaa7c3 | 443 | static struct device_attribute pid_attr = { |
01e8ef11 | 444 | .attr = { .name = "pid", .mode = S_IRUGO}, |
6b39bb65 PC |
445 | .show = pid_show, |
446 | }; | |
447 | ||
9561a7ad JB |
448 | struct recv_thread_args { |
449 | struct work_struct work; | |
450 | struct nbd_device *nbd; | |
451 | int index; | |
452 | }; | |
453 | ||
454 | static void recv_work(struct work_struct *work) | |
1da177e4 | 455 | { |
9561a7ad JB |
456 | struct recv_thread_args *args = container_of(work, |
457 | struct recv_thread_args, | |
458 | work); | |
459 | struct nbd_device *nbd = args->nbd; | |
fd8383fd | 460 | struct nbd_cmd *cmd; |
9561a7ad | 461 | int ret = 0; |
1da177e4 | 462 | |
f4507164 | 463 | BUG_ON(nbd->magic != NBD_MAGIC); |
19391830 | 464 | while (1) { |
9561a7ad | 465 | cmd = nbd_read_stat(nbd, args->index); |
fd8383fd JB |
466 | if (IS_ERR(cmd)) { |
467 | ret = PTR_ERR(cmd); | |
19391830 MP |
468 | break; |
469 | } | |
470 | ||
fd8383fd | 471 | nbd_end_request(cmd); |
19391830 | 472 | } |
6b39bb65 | 473 | |
9561a7ad JB |
474 | /* |
475 | * We got an error, shut everybody down if this wasn't the result of a | |
476 | * disconnect request. | |
477 | */ | |
478 | if (ret && !test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
479 | sock_shutdown(nbd); | |
480 | atomic_dec(&nbd->recv_threads); | |
481 | wake_up(&nbd->recv_wq); | |
1da177e4 LT |
482 | } |
483 | ||
fd8383fd | 484 | static void nbd_clear_req(struct request *req, void *data, bool reserved) |
1da177e4 | 485 | { |
fd8383fd | 486 | struct nbd_cmd *cmd; |
1da177e4 | 487 | |
fd8383fd JB |
488 | if (!blk_mq_request_started(req)) |
489 | return; | |
490 | cmd = blk_mq_rq_to_pdu(req); | |
491 | req->errors++; | |
492 | nbd_end_request(cmd); | |
493 | } | |
494 | ||
495 | static void nbd_clear_que(struct nbd_device *nbd) | |
496 | { | |
f4507164 | 497 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 498 | |
fd8383fd | 499 | blk_mq_tagset_busy_iter(&nbd->tag_set, nbd_clear_req, NULL); |
e78273c8 | 500 | dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n"); |
1da177e4 LT |
501 | } |
502 | ||
7fdfd406 | 503 | |
9561a7ad | 504 | static void nbd_handle_cmd(struct nbd_cmd *cmd, int index) |
48cf6061 | 505 | { |
fd8383fd JB |
506 | struct request *req = blk_mq_rq_from_pdu(cmd); |
507 | struct nbd_device *nbd = cmd->nbd; | |
9561a7ad | 508 | struct nbd_sock *nsock; |
fd8383fd | 509 | |
9561a7ad | 510 | if (index >= nbd->num_connections) { |
a897b666 JB |
511 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
512 | "Attempted send on invalid socket\n"); | |
48cf6061 | 513 | goto error_out; |
9561a7ad | 514 | } |
48cf6061 | 515 | |
9561a7ad | 516 | if (test_bit(NBD_DISCONNECTED, &nbd->runtime_flags)) { |
a897b666 JB |
517 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
518 | "Attempted send on closed socket\n"); | |
9561a7ad JB |
519 | goto error_out; |
520 | } | |
521 | ||
48cf6061 LV |
522 | req->errors = 0; |
523 | ||
9561a7ad JB |
524 | nsock = nbd->socks[index]; |
525 | mutex_lock(&nsock->tx_lock); | |
526 | if (unlikely(!nsock->sock)) { | |
527 | mutex_unlock(&nsock->tx_lock); | |
a897b666 JB |
528 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
529 | "Attempted send on closed socket\n"); | |
15746fca | 530 | goto error_out; |
48cf6061 LV |
531 | } |
532 | ||
9561a7ad | 533 | if (nbd_send_cmd(nbd, cmd, index) != 0) { |
a897b666 JB |
534 | dev_err_ratelimited(disk_to_dev(nbd->disk), |
535 | "Request send failed\n"); | |
48cf6061 | 536 | req->errors++; |
fd8383fd | 537 | nbd_end_request(cmd); |
48cf6061 LV |
538 | } |
539 | ||
9561a7ad | 540 | mutex_unlock(&nsock->tx_lock); |
48cf6061 LV |
541 | |
542 | return; | |
543 | ||
544 | error_out: | |
545 | req->errors++; | |
fd8383fd | 546 | nbd_end_request(cmd); |
48cf6061 LV |
547 | } |
548 | ||
fd8383fd JB |
549 | static int nbd_queue_rq(struct blk_mq_hw_ctx *hctx, |
550 | const struct blk_mq_queue_data *bd) | |
1da177e4 | 551 | { |
fd8383fd | 552 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); |
1da177e4 | 553 | |
9561a7ad JB |
554 | /* |
555 | * Since we look at the bio's to send the request over the network we | |
556 | * need to make sure the completion work doesn't mark this request done | |
557 | * before we are done doing our send. This keeps us from dereferencing | |
558 | * freed data if we have particularly fast completions (ie we get the | |
559 | * completion before we exit sock_xmit on the last bvec) or in the case | |
560 | * that the server is misbehaving (or there was an error) before we're | |
561 | * done sending everything over the wire. | |
562 | */ | |
563 | init_completion(&cmd->send_complete); | |
fd8383fd | 564 | blk_mq_start_request(bd->rq); |
9561a7ad JB |
565 | nbd_handle_cmd(cmd, hctx->queue_num); |
566 | complete(&cmd->send_complete); | |
567 | ||
fd8383fd | 568 | return BLK_MQ_RQ_QUEUE_OK; |
1da177e4 LT |
569 | } |
570 | ||
9561a7ad | 571 | static int nbd_add_socket(struct nbd_device *nbd, struct socket *sock) |
23272a67 | 572 | { |
9561a7ad JB |
573 | struct nbd_sock **socks; |
574 | struct nbd_sock *nsock; | |
23272a67 | 575 | |
9561a7ad JB |
576 | if (!nbd->task_setup) |
577 | nbd->task_setup = current; | |
578 | if (nbd->task_setup != current) { | |
579 | dev_err(disk_to_dev(nbd->disk), | |
580 | "Device being setup by another task"); | |
581 | return -EINVAL; | |
23272a67 MP |
582 | } |
583 | ||
9561a7ad JB |
584 | socks = krealloc(nbd->socks, (nbd->num_connections + 1) * |
585 | sizeof(struct nbd_sock *), GFP_KERNEL); | |
586 | if (!socks) | |
587 | return -ENOMEM; | |
588 | nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL); | |
589 | if (!nsock) | |
590 | return -ENOMEM; | |
591 | ||
592 | nbd->socks = socks; | |
23272a67 | 593 | |
9561a7ad JB |
594 | mutex_init(&nsock->tx_lock); |
595 | nsock->sock = sock; | |
596 | socks[nbd->num_connections++] = nsock; | |
23272a67 | 597 | |
9561a7ad | 598 | return 0; |
23272a67 MP |
599 | } |
600 | ||
0e4f0f6f MP |
601 | /* Reset all properties of an NBD device */ |
602 | static void nbd_reset(struct nbd_device *nbd) | |
603 | { | |
9561a7ad JB |
604 | int i; |
605 | ||
606 | for (i = 0; i < nbd->num_connections; i++) | |
607 | kfree(nbd->socks[i]); | |
608 | kfree(nbd->socks); | |
609 | nbd->socks = NULL; | |
9b4a6ba9 | 610 | nbd->runtime_flags = 0; |
0e4f0f6f MP |
611 | nbd->blksize = 1024; |
612 | nbd->bytesize = 0; | |
613 | set_capacity(nbd->disk, 0); | |
614 | nbd->flags = 0; | |
0eadf37a | 615 | nbd->tag_set.timeout = 0; |
9561a7ad JB |
616 | nbd->num_connections = 0; |
617 | nbd->task_setup = NULL; | |
0e4f0f6f | 618 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); |
0e4f0f6f MP |
619 | } |
620 | ||
621 | static void nbd_bdev_reset(struct block_device *bdev) | |
622 | { | |
623 | set_device_ro(bdev, false); | |
624 | bdev->bd_inode->i_size = 0; | |
625 | if (max_part > 0) { | |
626 | blkdev_reread_part(bdev); | |
627 | bdev->bd_invalidated = 1; | |
628 | } | |
629 | } | |
630 | ||
d02cf531 MP |
631 | static void nbd_parse_flags(struct nbd_device *nbd, struct block_device *bdev) |
632 | { | |
633 | if (nbd->flags & NBD_FLAG_READ_ONLY) | |
634 | set_device_ro(bdev, true); | |
635 | if (nbd->flags & NBD_FLAG_SEND_TRIM) | |
636 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); | |
637 | if (nbd->flags & NBD_FLAG_SEND_FLUSH) | |
aafb1eec | 638 | blk_queue_write_cache(nbd->disk->queue, true, false); |
d02cf531 | 639 | else |
aafb1eec | 640 | blk_queue_write_cache(nbd->disk->queue, false, false); |
d02cf531 MP |
641 | } |
642 | ||
9561a7ad JB |
643 | static void send_disconnects(struct nbd_device *nbd) |
644 | { | |
645 | struct nbd_request request = {}; | |
646 | int i, ret; | |
647 | ||
648 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
649 | request.type = htonl(NBD_CMD_DISC); | |
650 | ||
651 | for (i = 0; i < nbd->num_connections; i++) { | |
652 | ret = sock_xmit(nbd, i, 1, &request, sizeof(request), 0); | |
653 | if (ret <= 0) | |
654 | dev_err(disk_to_dev(nbd->disk), | |
655 | "Send disconnect failed %d\n", ret); | |
656 | } | |
657 | } | |
658 | ||
30d53d9c MP |
659 | static int nbd_dev_dbg_init(struct nbd_device *nbd); |
660 | static void nbd_dev_dbg_close(struct nbd_device *nbd); | |
661 | ||
9561a7ad | 662 | /* Must be called with config_lock held */ |
f4507164 | 663 | static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, |
1a2ad211 PM |
664 | unsigned int cmd, unsigned long arg) |
665 | { | |
1da177e4 | 666 | switch (cmd) { |
1a2ad211 | 667 | case NBD_DISCONNECT: { |
f4507164 | 668 | dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n"); |
9561a7ad | 669 | if (!nbd->socks) |
3a2d63f8 | 670 | return -EINVAL; |
1a2ad211 | 671 | |
9561a7ad | 672 | mutex_unlock(&nbd->config_lock); |
3a2d63f8 | 673 | fsync_bdev(bdev); |
9561a7ad | 674 | mutex_lock(&nbd->config_lock); |
3a2d63f8 PB |
675 | |
676 | /* Check again after getting mutex back. */ | |
9561a7ad | 677 | if (!nbd->socks) |
1da177e4 | 678 | return -EINVAL; |
c378f70a | 679 | |
9561a7ad JB |
680 | if (!test_and_set_bit(NBD_DISCONNECT_REQUESTED, |
681 | &nbd->runtime_flags)) | |
682 | send_disconnects(nbd); | |
c378f70a | 683 | return 0; |
1a2ad211 | 684 | } |
9561a7ad | 685 | |
23272a67 MP |
686 | case NBD_CLEAR_SOCK: |
687 | sock_shutdown(nbd); | |
f4507164 | 688 | nbd_clear_que(nbd); |
3a2d63f8 | 689 | kill_bdev(bdev); |
9561a7ad JB |
690 | nbd_bdev_reset(bdev); |
691 | /* | |
692 | * We want to give the run thread a chance to wait for everybody | |
693 | * to clean up and then do it's own cleanup. | |
694 | */ | |
695 | if (!test_bit(NBD_RUNNING, &nbd->runtime_flags)) { | |
696 | int i; | |
697 | ||
698 | for (i = 0; i < nbd->num_connections; i++) | |
699 | kfree(nbd->socks[i]); | |
700 | kfree(nbd->socks); | |
701 | nbd->socks = NULL; | |
702 | nbd->num_connections = 0; | |
20032ec3 | 703 | nbd->task_setup = NULL; |
9561a7ad | 704 | } |
1a2ad211 | 705 | return 0; |
1a2ad211 PM |
706 | |
707 | case NBD_SET_SOCK: { | |
e2511578 | 708 | int err; |
23272a67 MP |
709 | struct socket *sock = sockfd_lookup(arg, &err); |
710 | ||
711 | if (!sock) | |
712 | return err; | |
713 | ||
9561a7ad | 714 | err = nbd_add_socket(nbd, sock); |
23272a67 MP |
715 | if (!err && max_part) |
716 | bdev->bd_invalidated = 1; | |
717 | ||
718 | return err; | |
1a2ad211 PM |
719 | } |
720 | ||
37091fdd | 721 | case NBD_SET_BLKSIZE: { |
5e454c67 | 722 | loff_t bsize = div_s64(nbd->bytesize, arg); |
37091fdd MP |
723 | |
724 | return nbd_size_set(nbd, bdev, arg, bsize); | |
725 | } | |
1a2ad211 | 726 | |
1da177e4 | 727 | case NBD_SET_SIZE: |
37091fdd | 728 | return nbd_size_set(nbd, bdev, nbd->blksize, |
e88f72cb | 729 | div_s64(arg, nbd->blksize)); |
37091fdd MP |
730 | |
731 | case NBD_SET_SIZE_BLOCKS: | |
732 | return nbd_size_set(nbd, bdev, nbd->blksize, arg); | |
1a2ad211 | 733 | |
7fdfd406 | 734 | case NBD_SET_TIMEOUT: |
0eadf37a | 735 | nbd->tag_set.timeout = arg * HZ; |
7fdfd406 | 736 | return 0; |
1a2ad211 | 737 | |
2f012508 PC |
738 | case NBD_SET_FLAGS: |
739 | nbd->flags = arg; | |
740 | return 0; | |
741 | ||
1a2ad211 | 742 | case NBD_DO_IT: { |
9561a7ad JB |
743 | struct recv_thread_args *args; |
744 | int num_connections = nbd->num_connections; | |
feffa5cc | 745 | int error = 0, i; |
1a2ad211 | 746 | |
6521d39a | 747 | if (nbd->task_recv) |
c91192d6 | 748 | return -EBUSY; |
9561a7ad | 749 | if (!nbd->socks) |
1da177e4 | 750 | return -EINVAL; |
9561a7ad JB |
751 | if (num_connections > 1 && |
752 | !(nbd->flags & NBD_FLAG_CAN_MULTI_CONN)) { | |
753 | dev_err(disk_to_dev(nbd->disk), "server does not support multiple connections per device.\n"); | |
feffa5cc | 754 | error = -EINVAL; |
9561a7ad JB |
755 | goto out_err; |
756 | } | |
1a2ad211 | 757 | |
9561a7ad JB |
758 | set_bit(NBD_RUNNING, &nbd->runtime_flags); |
759 | blk_mq_update_nr_hw_queues(&nbd->tag_set, nbd->num_connections); | |
760 | args = kcalloc(num_connections, sizeof(*args), GFP_KERNEL); | |
feffa5cc JA |
761 | if (!args) { |
762 | error = -ENOMEM; | |
9561a7ad | 763 | goto out_err; |
feffa5cc | 764 | } |
97240963 | 765 | nbd->task_recv = current; |
9561a7ad | 766 | mutex_unlock(&nbd->config_lock); |
1a2ad211 | 767 | |
d02cf531 | 768 | nbd_parse_flags(nbd, bdev); |
a336d298 | 769 | |
9561a7ad JB |
770 | error = device_create_file(disk_to_dev(nbd->disk), &pid_attr); |
771 | if (error) { | |
772 | dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); | |
773 | goto out_recv; | |
774 | } | |
775 | ||
776 | nbd_size_update(nbd, bdev); | |
777 | ||
30d53d9c | 778 | nbd_dev_dbg_init(nbd); |
9561a7ad JB |
779 | for (i = 0; i < num_connections; i++) { |
780 | sk_set_memalloc(nbd->socks[i]->sock->sk); | |
781 | atomic_inc(&nbd->recv_threads); | |
782 | INIT_WORK(&args[i].work, recv_work); | |
783 | args[i].nbd = nbd; | |
784 | args[i].index = i; | |
124d6db0 | 785 | queue_work(recv_workqueue, &args[i].work); |
9561a7ad JB |
786 | } |
787 | wait_event_interruptible(nbd->recv_wq, | |
788 | atomic_read(&nbd->recv_threads) == 0); | |
789 | for (i = 0; i < num_connections; i++) | |
790 | flush_work(&args[i].work); | |
30d53d9c | 791 | nbd_dev_dbg_close(nbd); |
9561a7ad JB |
792 | nbd_size_clear(nbd, bdev); |
793 | device_remove_file(disk_to_dev(nbd->disk), &pid_attr); | |
794 | out_recv: | |
795 | mutex_lock(&nbd->config_lock); | |
97240963 | 796 | nbd->task_recv = NULL; |
9561a7ad | 797 | out_err: |
36e47bee | 798 | sock_shutdown(nbd); |
f4507164 | 799 | nbd_clear_que(nbd); |
3a2d63f8 | 800 | kill_bdev(bdev); |
0e4f0f6f MP |
801 | nbd_bdev_reset(bdev); |
802 | ||
9b4a6ba9 JB |
803 | /* user requested, ignore socket errors */ |
804 | if (test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags)) | |
1f7b5cf1 | 805 | error = 0; |
9b4a6ba9 | 806 | if (test_bit(NBD_TIMEDOUT, &nbd->runtime_flags)) |
1f7b5cf1 MP |
807 | error = -ETIMEDOUT; |
808 | ||
0e4f0f6f | 809 | nbd_reset(nbd); |
19391830 | 810 | return error; |
1a2ad211 PM |
811 | } |
812 | ||
1da177e4 | 813 | case NBD_CLEAR_QUE: |
4b2f0260 HX |
814 | /* |
815 | * This is for compatibility only. The queue is always cleared | |
816 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
817 | */ | |
1da177e4 | 818 | return 0; |
1a2ad211 | 819 | |
1da177e4 | 820 | case NBD_PRINT_DEBUG: |
fd8383fd JB |
821 | /* |
822 | * For compatibility only, we no longer keep a list of | |
823 | * outstanding requests. | |
824 | */ | |
1da177e4 LT |
825 | return 0; |
826 | } | |
1a2ad211 PM |
827 | return -ENOTTY; |
828 | } | |
829 | ||
830 | static int nbd_ioctl(struct block_device *bdev, fmode_t mode, | |
831 | unsigned int cmd, unsigned long arg) | |
832 | { | |
f4507164 | 833 | struct nbd_device *nbd = bdev->bd_disk->private_data; |
1a2ad211 PM |
834 | int error; |
835 | ||
836 | if (!capable(CAP_SYS_ADMIN)) | |
837 | return -EPERM; | |
838 | ||
f4507164 | 839 | BUG_ON(nbd->magic != NBD_MAGIC); |
1a2ad211 | 840 | |
9561a7ad | 841 | mutex_lock(&nbd->config_lock); |
f4507164 | 842 | error = __nbd_ioctl(bdev, nbd, cmd, arg); |
9561a7ad | 843 | mutex_unlock(&nbd->config_lock); |
1a2ad211 PM |
844 | |
845 | return error; | |
1da177e4 LT |
846 | } |
847 | ||
83d5cde4 | 848 | static const struct block_device_operations nbd_fops = |
1da177e4 LT |
849 | { |
850 | .owner = THIS_MODULE, | |
8a6cfeb6 | 851 | .ioctl = nbd_ioctl, |
263a3df1 | 852 | .compat_ioctl = nbd_ioctl, |
1da177e4 LT |
853 | }; |
854 | ||
30d53d9c MP |
855 | #if IS_ENABLED(CONFIG_DEBUG_FS) |
856 | ||
857 | static int nbd_dbg_tasks_show(struct seq_file *s, void *unused) | |
858 | { | |
859 | struct nbd_device *nbd = s->private; | |
860 | ||
861 | if (nbd->task_recv) | |
862 | seq_printf(s, "recv: %d\n", task_pid_nr(nbd->task_recv)); | |
30d53d9c MP |
863 | |
864 | return 0; | |
865 | } | |
866 | ||
867 | static int nbd_dbg_tasks_open(struct inode *inode, struct file *file) | |
868 | { | |
869 | return single_open(file, nbd_dbg_tasks_show, inode->i_private); | |
870 | } | |
871 | ||
872 | static const struct file_operations nbd_dbg_tasks_ops = { | |
873 | .open = nbd_dbg_tasks_open, | |
874 | .read = seq_read, | |
875 | .llseek = seq_lseek, | |
876 | .release = single_release, | |
877 | }; | |
878 | ||
879 | static int nbd_dbg_flags_show(struct seq_file *s, void *unused) | |
880 | { | |
881 | struct nbd_device *nbd = s->private; | |
882 | u32 flags = nbd->flags; | |
883 | ||
884 | seq_printf(s, "Hex: 0x%08x\n\n", flags); | |
885 | ||
886 | seq_puts(s, "Known flags:\n"); | |
887 | ||
888 | if (flags & NBD_FLAG_HAS_FLAGS) | |
889 | seq_puts(s, "NBD_FLAG_HAS_FLAGS\n"); | |
890 | if (flags & NBD_FLAG_READ_ONLY) | |
891 | seq_puts(s, "NBD_FLAG_READ_ONLY\n"); | |
892 | if (flags & NBD_FLAG_SEND_FLUSH) | |
893 | seq_puts(s, "NBD_FLAG_SEND_FLUSH\n"); | |
894 | if (flags & NBD_FLAG_SEND_TRIM) | |
895 | seq_puts(s, "NBD_FLAG_SEND_TRIM\n"); | |
896 | ||
897 | return 0; | |
898 | } | |
899 | ||
900 | static int nbd_dbg_flags_open(struct inode *inode, struct file *file) | |
901 | { | |
902 | return single_open(file, nbd_dbg_flags_show, inode->i_private); | |
903 | } | |
904 | ||
905 | static const struct file_operations nbd_dbg_flags_ops = { | |
906 | .open = nbd_dbg_flags_open, | |
907 | .read = seq_read, | |
908 | .llseek = seq_lseek, | |
909 | .release = single_release, | |
910 | }; | |
911 | ||
912 | static int nbd_dev_dbg_init(struct nbd_device *nbd) | |
913 | { | |
914 | struct dentry *dir; | |
27ea43fe MP |
915 | |
916 | if (!nbd_dbg_dir) | |
917 | return -EIO; | |
30d53d9c MP |
918 | |
919 | dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir); | |
27ea43fe MP |
920 | if (!dir) { |
921 | dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n", | |
922 | nbd_name(nbd)); | |
923 | return -EIO; | |
30d53d9c MP |
924 | } |
925 | nbd->dbg_dir = dir; | |
926 | ||
27ea43fe MP |
927 | debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops); |
928 | debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize); | |
0eadf37a | 929 | debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout); |
ef77b515 | 930 | debugfs_create_u64("blocksize", 0444, dir, &nbd->blksize); |
d366a0ff | 931 | debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops); |
30d53d9c MP |
932 | |
933 | return 0; | |
934 | } | |
935 | ||
936 | static void nbd_dev_dbg_close(struct nbd_device *nbd) | |
937 | { | |
938 | debugfs_remove_recursive(nbd->dbg_dir); | |
939 | } | |
940 | ||
941 | static int nbd_dbg_init(void) | |
942 | { | |
943 | struct dentry *dbg_dir; | |
944 | ||
945 | dbg_dir = debugfs_create_dir("nbd", NULL); | |
27ea43fe MP |
946 | if (!dbg_dir) |
947 | return -EIO; | |
30d53d9c MP |
948 | |
949 | nbd_dbg_dir = dbg_dir; | |
950 | ||
951 | return 0; | |
952 | } | |
953 | ||
954 | static void nbd_dbg_close(void) | |
955 | { | |
956 | debugfs_remove_recursive(nbd_dbg_dir); | |
957 | } | |
958 | ||
959 | #else /* IS_ENABLED(CONFIG_DEBUG_FS) */ | |
960 | ||
961 | static int nbd_dev_dbg_init(struct nbd_device *nbd) | |
962 | { | |
963 | return 0; | |
964 | } | |
965 | ||
966 | static void nbd_dev_dbg_close(struct nbd_device *nbd) | |
967 | { | |
968 | } | |
969 | ||
970 | static int nbd_dbg_init(void) | |
971 | { | |
972 | return 0; | |
973 | } | |
974 | ||
975 | static void nbd_dbg_close(void) | |
976 | { | |
977 | } | |
978 | ||
979 | #endif | |
980 | ||
fd8383fd JB |
981 | static int nbd_init_request(void *data, struct request *rq, |
982 | unsigned int hctx_idx, unsigned int request_idx, | |
983 | unsigned int numa_node) | |
984 | { | |
985 | struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq); | |
fd8383fd | 986 | cmd->nbd = data; |
fd8383fd JB |
987 | return 0; |
988 | } | |
989 | ||
990 | static struct blk_mq_ops nbd_mq_ops = { | |
991 | .queue_rq = nbd_queue_rq, | |
fd8383fd | 992 | .init_request = nbd_init_request, |
0eadf37a | 993 | .timeout = nbd_xmit_timeout, |
fd8383fd JB |
994 | }; |
995 | ||
1da177e4 LT |
996 | /* |
997 | * And here should be modules and kernel interface | |
998 | * (Just smiley confuses emacs :-) | |
999 | */ | |
1000 | ||
1001 | static int __init nbd_init(void) | |
1002 | { | |
1003 | int err = -ENOMEM; | |
1004 | int i; | |
d71a6d73 | 1005 | int part_shift; |
1da177e4 | 1006 | |
5b7b18cc | 1007 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 1008 | |
d71a6d73 | 1009 | if (max_part < 0) { |
7742ce4a | 1010 | printk(KERN_ERR "nbd: max_part must be >= 0\n"); |
d71a6d73 LV |
1011 | return -EINVAL; |
1012 | } | |
1013 | ||
1014 | part_shift = 0; | |
5988ce23 | 1015 | if (max_part > 0) { |
d71a6d73 LV |
1016 | part_shift = fls(max_part); |
1017 | ||
5988ce23 NK |
1018 | /* |
1019 | * Adjust max_part according to part_shift as it is exported | |
1020 | * to user space so that user can know the max number of | |
1021 | * partition kernel should be able to manage. | |
1022 | * | |
1023 | * Note that -1 is required because partition 0 is reserved | |
1024 | * for the whole disk. | |
1025 | */ | |
1026 | max_part = (1UL << part_shift) - 1; | |
1027 | } | |
1028 | ||
3b271082 NK |
1029 | if ((1UL << part_shift) > DISK_MAX_PARTS) |
1030 | return -EINVAL; | |
1031 | ||
1032 | if (nbds_max > 1UL << (MINORBITS - part_shift)) | |
1033 | return -EINVAL; | |
124d6db0 JB |
1034 | recv_workqueue = alloc_workqueue("knbd-recv", |
1035 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 0); | |
1036 | if (!recv_workqueue) | |
1037 | return -ENOMEM; | |
3b271082 | 1038 | |
ff6b8090 | 1039 | nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL); |
124d6db0 JB |
1040 | if (!nbd_dev) { |
1041 | destroy_workqueue(recv_workqueue); | |
ff6b8090 | 1042 | return -ENOMEM; |
124d6db0 | 1043 | } |
ff6b8090 | 1044 | |
40be0c28 | 1045 | for (i = 0; i < nbds_max; i++) { |
25b4acfc | 1046 | struct request_queue *q; |
d71a6d73 | 1047 | struct gendisk *disk = alloc_disk(1 << part_shift); |
1da177e4 LT |
1048 | if (!disk) |
1049 | goto out; | |
1050 | nbd_dev[i].disk = disk; | |
fd8383fd JB |
1051 | |
1052 | nbd_dev[i].tag_set.ops = &nbd_mq_ops; | |
1053 | nbd_dev[i].tag_set.nr_hw_queues = 1; | |
1054 | nbd_dev[i].tag_set.queue_depth = 128; | |
1055 | nbd_dev[i].tag_set.numa_node = NUMA_NO_NODE; | |
1056 | nbd_dev[i].tag_set.cmd_size = sizeof(struct nbd_cmd); | |
1057 | nbd_dev[i].tag_set.flags = BLK_MQ_F_SHOULD_MERGE | | |
005043ac | 1058 | BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING; |
fd8383fd JB |
1059 | nbd_dev[i].tag_set.driver_data = &nbd_dev[i]; |
1060 | ||
1061 | err = blk_mq_alloc_tag_set(&nbd_dev[i].tag_set); | |
1062 | if (err) { | |
1063 | put_disk(disk); | |
1064 | goto out; | |
1065 | } | |
1066 | ||
1da177e4 LT |
1067 | /* |
1068 | * The new linux 2.5 block layer implementation requires | |
1069 | * every gendisk to have its very own request_queue struct. | |
1070 | * These structs are big so we dynamically allocate them. | |
1071 | */ | |
25b4acfc JM |
1072 | q = blk_mq_init_queue(&nbd_dev[i].tag_set); |
1073 | if (IS_ERR(q)) { | |
fd8383fd | 1074 | blk_mq_free_tag_set(&nbd_dev[i].tag_set); |
1da177e4 LT |
1075 | put_disk(disk); |
1076 | goto out; | |
1077 | } | |
25b4acfc | 1078 | disk->queue = q; |
fd8383fd | 1079 | |
31dcfab0 JA |
1080 | /* |
1081 | * Tell the block layer that we are not a rotational device | |
1082 | */ | |
1083 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue); | |
b277da0a | 1084 | queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, disk->queue); |
a336d298 | 1085 | disk->queue->limits.discard_granularity = 512; |
2bb4cd5c | 1086 | blk_queue_max_discard_sectors(disk->queue, UINT_MAX); |
a336d298 | 1087 | disk->queue->limits.discard_zeroes_data = 0; |
078be02b MB |
1088 | blk_queue_max_hw_sectors(disk->queue, 65536); |
1089 | disk->queue->limits.max_sectors = 256; | |
1da177e4 LT |
1090 | } |
1091 | ||
1092 | if (register_blkdev(NBD_MAJOR, "nbd")) { | |
1093 | err = -EIO; | |
1094 | goto out; | |
1095 | } | |
1096 | ||
1097 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); | |
1da177e4 | 1098 | |
30d53d9c MP |
1099 | nbd_dbg_init(); |
1100 | ||
40be0c28 | 1101 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 1102 | struct gendisk *disk = nbd_dev[i].disk; |
f4507164 | 1103 | nbd_dev[i].magic = NBD_MAGIC; |
9561a7ad | 1104 | mutex_init(&nbd_dev[i].config_lock); |
1da177e4 | 1105 | disk->major = NBD_MAJOR; |
d71a6d73 | 1106 | disk->first_minor = i << part_shift; |
1da177e4 LT |
1107 | disk->fops = &nbd_fops; |
1108 | disk->private_data = &nbd_dev[i]; | |
1da177e4 | 1109 | sprintf(disk->disk_name, "nbd%d", i); |
9561a7ad | 1110 | init_waitqueue_head(&nbd_dev[i].recv_wq); |
0e4f0f6f | 1111 | nbd_reset(&nbd_dev[i]); |
1da177e4 LT |
1112 | add_disk(disk); |
1113 | } | |
1114 | ||
1115 | return 0; | |
1116 | out: | |
1117 | while (i--) { | |
fd8383fd | 1118 | blk_mq_free_tag_set(&nbd_dev[i].tag_set); |
1da177e4 LT |
1119 | blk_cleanup_queue(nbd_dev[i].disk->queue); |
1120 | put_disk(nbd_dev[i].disk); | |
1121 | } | |
f3944d61 | 1122 | kfree(nbd_dev); |
124d6db0 | 1123 | destroy_workqueue(recv_workqueue); |
1da177e4 LT |
1124 | return err; |
1125 | } | |
1126 | ||
1127 | static void __exit nbd_cleanup(void) | |
1128 | { | |
1129 | int i; | |
30d53d9c MP |
1130 | |
1131 | nbd_dbg_close(); | |
1132 | ||
40be0c28 | 1133 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 1134 | struct gendisk *disk = nbd_dev[i].disk; |
40be0c28 | 1135 | nbd_dev[i].magic = 0; |
1da177e4 LT |
1136 | if (disk) { |
1137 | del_gendisk(disk); | |
1138 | blk_cleanup_queue(disk->queue); | |
fd8383fd | 1139 | blk_mq_free_tag_set(&nbd_dev[i].tag_set); |
1da177e4 LT |
1140 | put_disk(disk); |
1141 | } | |
1142 | } | |
124d6db0 | 1143 | destroy_workqueue(recv_workqueue); |
1da177e4 | 1144 | unregister_blkdev(NBD_MAJOR, "nbd"); |
f3944d61 | 1145 | kfree(nbd_dev); |
1da177e4 LT |
1146 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); |
1147 | } | |
1148 | ||
1149 | module_init(nbd_init); | |
1150 | module_exit(nbd_cleanup); | |
1151 | ||
1152 | MODULE_DESCRIPTION("Network Block Device"); | |
1153 | MODULE_LICENSE("GPL"); | |
1154 | ||
40be0c28 | 1155 | module_param(nbds_max, int, 0444); |
d71a6d73 LV |
1156 | MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); |
1157 | module_param(max_part, int, 0444); | |
1158 | MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)"); |