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> |
1da177e4 | 36 | |
1da177e4 LT |
37 | #include <asm/uaccess.h> |
38 | #include <asm/types.h> | |
39 | ||
40 | #include <linux/nbd.h> | |
41 | ||
13e71d69 MP |
42 | struct nbd_device { |
43 | int flags; | |
44 | int harderror; /* Code of hard error */ | |
45 | struct socket * sock; /* If == NULL, device is not ready, yet */ | |
46 | int magic; | |
47 | ||
48 | spinlock_t queue_lock; | |
49 | struct list_head queue_head; /* Requests waiting result */ | |
50 | struct request *active_req; | |
51 | wait_queue_head_t active_wq; | |
52 | struct list_head waiting_queue; /* Requests to be sent */ | |
53 | wait_queue_head_t waiting_wq; | |
54 | ||
55 | struct mutex tx_lock; | |
56 | struct gendisk *disk; | |
57 | int blksize; | |
b9c495bb | 58 | loff_t bytesize; |
13e71d69 MP |
59 | pid_t pid; /* pid of nbd-client, if attached */ |
60 | int xmit_timeout; | |
61 | int disconnect; /* a disconnect has been requested by user */ | |
62 | }; | |
63 | ||
f4507164 | 64 | #define NBD_MAGIC 0x68797548 |
1da177e4 | 65 | |
9c7a4169 | 66 | static unsigned int nbds_max = 16; |
20a8143e | 67 | static struct nbd_device *nbd_dev; |
d71a6d73 | 68 | static int max_part; |
1da177e4 LT |
69 | |
70 | /* | |
71 | * Use just one lock (or at most 1 per NIC). Two arguments for this: | |
72 | * 1. Each NIC is essentially a synchronization point for all servers | |
73 | * accessed through that NIC so there's no need to have more locks | |
74 | * than NICs anyway. | |
75 | * 2. More locks lead to more "Dirty cache line bouncing" which will slow | |
76 | * down each lock to the point where they're actually slower than just | |
77 | * a single lock. | |
78 | * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! | |
79 | */ | |
80 | static DEFINE_SPINLOCK(nbd_lock); | |
81 | ||
d18509f5 | 82 | static inline struct device *nbd_to_dev(struct nbd_device *nbd) |
1da177e4 | 83 | { |
d18509f5 | 84 | return disk_to_dev(nbd->disk); |
1da177e4 LT |
85 | } |
86 | ||
87 | static const char *nbdcmd_to_ascii(int cmd) | |
88 | { | |
89 | switch (cmd) { | |
90 | case NBD_CMD_READ: return "read"; | |
91 | case NBD_CMD_WRITE: return "write"; | |
92 | case NBD_CMD_DISC: return "disconnect"; | |
75f187ab | 93 | case NBD_CMD_FLUSH: return "flush"; |
a336d298 | 94 | case NBD_CMD_TRIM: return "trim/discard"; |
1da177e4 LT |
95 | } |
96 | return "invalid"; | |
97 | } | |
1da177e4 | 98 | |
d18509f5 | 99 | static void nbd_end_request(struct nbd_device *nbd, struct request *req) |
1da177e4 | 100 | { |
097c94a4 | 101 | int error = req->errors ? -EIO : 0; |
165125e1 | 102 | struct request_queue *q = req->q; |
1da177e4 LT |
103 | unsigned long flags; |
104 | ||
d18509f5 MP |
105 | dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", req, |
106 | error ? "failed" : "done"); | |
1da177e4 LT |
107 | |
108 | spin_lock_irqsave(q->queue_lock, flags); | |
1011c1b9 | 109 | __blk_end_request_all(req, error); |
1da177e4 LT |
110 | spin_unlock_irqrestore(q->queue_lock, flags); |
111 | } | |
112 | ||
e018e757 MP |
113 | /* |
114 | * Forcibly shutdown the socket causing all listeners to error | |
115 | */ | |
f4507164 | 116 | static void sock_shutdown(struct nbd_device *nbd, int lock) |
7fdfd406 | 117 | { |
7fdfd406 | 118 | if (lock) |
f4507164 WG |
119 | mutex_lock(&nbd->tx_lock); |
120 | if (nbd->sock) { | |
121 | dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n"); | |
122 | kernel_sock_shutdown(nbd->sock, SHUT_RDWR); | |
123 | nbd->sock = NULL; | |
7fdfd406 PC |
124 | } |
125 | if (lock) | |
f4507164 | 126 | mutex_unlock(&nbd->tx_lock); |
7fdfd406 PC |
127 | } |
128 | ||
129 | static void nbd_xmit_timeout(unsigned long arg) | |
130 | { | |
131 | struct task_struct *task = (struct task_struct *)arg; | |
132 | ||
133 | printk(KERN_WARNING "nbd: killing hung xmit (%s, pid: %d)\n", | |
134 | task->comm, task->pid); | |
135 | force_sig(SIGKILL, task); | |
136 | } | |
137 | ||
1da177e4 LT |
138 | /* |
139 | * Send or receive packet. | |
140 | */ | |
f4507164 | 141 | static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size, |
1da177e4 LT |
142 | int msg_flags) |
143 | { | |
f4507164 | 144 | struct socket *sock = nbd->sock; |
1da177e4 LT |
145 | int result; |
146 | struct msghdr msg; | |
147 | struct kvec iov; | |
be0ef957 | 148 | sigset_t blocked, oldset; |
7f338fe4 | 149 | unsigned long pflags = current->flags; |
1da177e4 | 150 | |
ffc41cf8 | 151 | if (unlikely(!sock)) { |
f4507164 | 152 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
153 | "Attempted %s on closed socket in sock_xmit\n", |
154 | (send ? "send" : "recv")); | |
ffc41cf8 MS |
155 | return -EINVAL; |
156 | } | |
157 | ||
1da177e4 LT |
158 | /* Allow interception of SIGKILL only |
159 | * Don't allow other signals to interrupt the transmission */ | |
be0ef957 ON |
160 | siginitsetinv(&blocked, sigmask(SIGKILL)); |
161 | sigprocmask(SIG_SETMASK, &blocked, &oldset); | |
1da177e4 | 162 | |
7f338fe4 | 163 | current->flags |= PF_MEMALLOC; |
1da177e4 | 164 | do { |
7f338fe4 | 165 | sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC; |
1da177e4 LT |
166 | iov.iov_base = buf; |
167 | iov.iov_len = size; | |
168 | msg.msg_name = NULL; | |
169 | msg.msg_namelen = 0; | |
170 | msg.msg_control = NULL; | |
171 | msg.msg_controllen = 0; | |
1da177e4 LT |
172 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
173 | ||
7fdfd406 PC |
174 | if (send) { |
175 | struct timer_list ti; | |
176 | ||
f4507164 | 177 | if (nbd->xmit_timeout) { |
7fdfd406 PC |
178 | init_timer(&ti); |
179 | ti.function = nbd_xmit_timeout; | |
180 | ti.data = (unsigned long)current; | |
f4507164 | 181 | ti.expires = jiffies + nbd->xmit_timeout; |
7fdfd406 PC |
182 | add_timer(&ti); |
183 | } | |
1da177e4 | 184 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
f4507164 | 185 | if (nbd->xmit_timeout) |
7fdfd406 PC |
186 | del_timer_sync(&ti); |
187 | } else | |
35fbf5bc NK |
188 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, |
189 | msg.msg_flags); | |
1da177e4 LT |
190 | |
191 | if (signal_pending(current)) { | |
192 | siginfo_t info; | |
1da177e4 | 193 | printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", |
ba25f9dc | 194 | task_pid_nr(current), current->comm, |
be0ef957 | 195 | dequeue_signal_lock(current, ¤t->blocked, &info)); |
1da177e4 | 196 | result = -EINTR; |
f4507164 | 197 | sock_shutdown(nbd, !send); |
1da177e4 LT |
198 | break; |
199 | } | |
200 | ||
201 | if (result <= 0) { | |
202 | if (result == 0) | |
203 | result = -EPIPE; /* short read */ | |
204 | break; | |
205 | } | |
206 | size -= result; | |
207 | buf += result; | |
208 | } while (size > 0); | |
209 | ||
be0ef957 | 210 | sigprocmask(SIG_SETMASK, &oldset, NULL); |
7f338fe4 | 211 | tsk_restore_flags(current, pflags, PF_MEMALLOC); |
1da177e4 LT |
212 | |
213 | return result; | |
214 | } | |
215 | ||
f4507164 | 216 | static inline int sock_send_bvec(struct nbd_device *nbd, struct bio_vec *bvec, |
1da177e4 LT |
217 | int flags) |
218 | { | |
219 | int result; | |
220 | void *kaddr = kmap(bvec->bv_page); | |
f4507164 WG |
221 | result = sock_xmit(nbd, 1, kaddr + bvec->bv_offset, |
222 | bvec->bv_len, flags); | |
1da177e4 LT |
223 | kunmap(bvec->bv_page); |
224 | return result; | |
225 | } | |
226 | ||
7fdfd406 | 227 | /* always call with the tx_lock held */ |
f4507164 | 228 | static int nbd_send_req(struct nbd_device *nbd, struct request *req) |
1da177e4 | 229 | { |
5705f702 | 230 | int result, flags; |
1da177e4 | 231 | struct nbd_request request; |
1011c1b9 | 232 | unsigned long size = blk_rq_bytes(req); |
1da177e4 | 233 | |
04cfac4e | 234 | memset(&request, 0, sizeof(request)); |
1da177e4 LT |
235 | request.magic = htonl(NBD_REQUEST_MAGIC); |
236 | request.type = htonl(nbd_cmd(req)); | |
75f187ab | 237 | |
04cfac4e | 238 | if (nbd_cmd(req) != NBD_CMD_FLUSH && nbd_cmd(req) != NBD_CMD_DISC) { |
75f187ab AB |
239 | request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); |
240 | request.len = htonl(size); | |
241 | } | |
1da177e4 LT |
242 | memcpy(request.handle, &req, sizeof(req)); |
243 | ||
d18509f5 MP |
244 | dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n", |
245 | req, nbdcmd_to_ascii(nbd_cmd(req)), | |
246 | (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req)); | |
f4507164 | 247 | result = sock_xmit(nbd, 1, &request, sizeof(request), |
7fdfd406 | 248 | (nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0); |
1da177e4 | 249 | if (result <= 0) { |
f4507164 | 250 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 | 251 | "Send control failed (result %d)\n", result); |
dab5313a | 252 | return -EIO; |
1da177e4 LT |
253 | } |
254 | ||
255 | if (nbd_cmd(req) == NBD_CMD_WRITE) { | |
5705f702 | 256 | struct req_iterator iter; |
7988613b | 257 | struct bio_vec bvec; |
1da177e4 LT |
258 | /* |
259 | * we are really probing at internals to determine | |
260 | * whether to set MSG_MORE or not... | |
261 | */ | |
5705f702 | 262 | rq_for_each_segment(bvec, req, iter) { |
6c92e699 | 263 | flags = 0; |
4550dd6c | 264 | if (!rq_iter_last(bvec, iter)) |
6c92e699 | 265 | flags = MSG_MORE; |
d18509f5 MP |
266 | dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n", |
267 | req, bvec.bv_len); | |
7988613b | 268 | result = sock_send_bvec(nbd, &bvec, flags); |
6c92e699 | 269 | if (result <= 0) { |
f4507164 | 270 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
271 | "Send data failed (result %d)\n", |
272 | result); | |
dab5313a | 273 | return -EIO; |
6c92e699 | 274 | } |
1da177e4 LT |
275 | } |
276 | } | |
1da177e4 | 277 | return 0; |
1da177e4 LT |
278 | } |
279 | ||
f4507164 | 280 | static struct request *nbd_find_request(struct nbd_device *nbd, |
0cbc591b | 281 | struct request *xreq) |
1da177e4 | 282 | { |
d2c9740b | 283 | struct request *req, *tmp; |
4b2f0260 | 284 | int err; |
1da177e4 | 285 | |
f4507164 | 286 | err = wait_event_interruptible(nbd->active_wq, nbd->active_req != xreq); |
4b2f0260 HX |
287 | if (unlikely(err)) |
288 | goto out; | |
289 | ||
f4507164 WG |
290 | spin_lock(&nbd->queue_lock); |
291 | list_for_each_entry_safe(req, tmp, &nbd->queue_head, queuelist) { | |
1da177e4 LT |
292 | if (req != xreq) |
293 | continue; | |
294 | list_del_init(&req->queuelist); | |
f4507164 | 295 | spin_unlock(&nbd->queue_lock); |
1da177e4 LT |
296 | return req; |
297 | } | |
f4507164 | 298 | spin_unlock(&nbd->queue_lock); |
4b2f0260 HX |
299 | |
300 | err = -ENOENT; | |
301 | ||
302 | out: | |
303 | return ERR_PTR(err); | |
1da177e4 LT |
304 | } |
305 | ||
f4507164 | 306 | static inline int sock_recv_bvec(struct nbd_device *nbd, struct bio_vec *bvec) |
1da177e4 LT |
307 | { |
308 | int result; | |
309 | void *kaddr = kmap(bvec->bv_page); | |
f4507164 | 310 | result = sock_xmit(nbd, 0, kaddr + bvec->bv_offset, bvec->bv_len, |
1da177e4 LT |
311 | MSG_WAITALL); |
312 | kunmap(bvec->bv_page); | |
313 | return result; | |
314 | } | |
315 | ||
316 | /* NULL returned = something went wrong, inform userspace */ | |
f4507164 | 317 | static struct request *nbd_read_stat(struct nbd_device *nbd) |
1da177e4 LT |
318 | { |
319 | int result; | |
320 | struct nbd_reply reply; | |
321 | struct request *req; | |
1da177e4 LT |
322 | |
323 | reply.magic = 0; | |
f4507164 | 324 | result = sock_xmit(nbd, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 | 325 | if (result <= 0) { |
f4507164 | 326 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 | 327 | "Receive control failed (result %d)\n", result); |
1da177e4 LT |
328 | goto harderror; |
329 | } | |
e4b57e08 MF |
330 | |
331 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
f4507164 | 332 | dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n", |
e4b57e08 MF |
333 | (unsigned long)ntohl(reply.magic)); |
334 | result = -EPROTO; | |
335 | goto harderror; | |
336 | } | |
337 | ||
f4507164 | 338 | req = nbd_find_request(nbd, *(struct request **)reply.handle); |
801678c5 | 339 | if (IS_ERR(req)) { |
4b2f0260 HX |
340 | result = PTR_ERR(req); |
341 | if (result != -ENOENT) | |
342 | goto harderror; | |
343 | ||
f4507164 | 344 | dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%p)\n", |
7f1b90f9 | 345 | reply.handle); |
1da177e4 LT |
346 | result = -EBADR; |
347 | goto harderror; | |
348 | } | |
349 | ||
1da177e4 | 350 | if (ntohl(reply.error)) { |
f4507164 | 351 | dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n", |
7f1b90f9 | 352 | ntohl(reply.error)); |
1da177e4 LT |
353 | req->errors++; |
354 | return req; | |
355 | } | |
356 | ||
d18509f5 | 357 | dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", req); |
1da177e4 | 358 | if (nbd_cmd(req) == NBD_CMD_READ) { |
5705f702 | 359 | struct req_iterator iter; |
7988613b | 360 | struct bio_vec bvec; |
5705f702 N |
361 | |
362 | rq_for_each_segment(bvec, req, iter) { | |
7988613b | 363 | result = sock_recv_bvec(nbd, &bvec); |
6c92e699 | 364 | if (result <= 0) { |
f4507164 | 365 | dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", |
7f1b90f9 | 366 | result); |
6c92e699 JA |
367 | req->errors++; |
368 | return req; | |
369 | } | |
d18509f5 MP |
370 | dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n", |
371 | req, bvec.bv_len); | |
1da177e4 LT |
372 | } |
373 | } | |
374 | return req; | |
375 | harderror: | |
f4507164 | 376 | nbd->harderror = result; |
1da177e4 LT |
377 | return NULL; |
378 | } | |
379 | ||
edfaa7c3 KS |
380 | static ssize_t pid_show(struct device *dev, |
381 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 382 | { |
edfaa7c3 KS |
383 | struct gendisk *disk = dev_to_disk(dev); |
384 | ||
385 | return sprintf(buf, "%ld\n", | |
6b39bb65 PC |
386 | (long) ((struct nbd_device *)disk->private_data)->pid); |
387 | } | |
388 | ||
edfaa7c3 | 389 | static struct device_attribute pid_attr = { |
01e8ef11 | 390 | .attr = { .name = "pid", .mode = S_IRUGO}, |
6b39bb65 PC |
391 | .show = pid_show, |
392 | }; | |
393 | ||
f4507164 | 394 | static int nbd_do_it(struct nbd_device *nbd) |
1da177e4 LT |
395 | { |
396 | struct request *req; | |
84963048 | 397 | int ret; |
1da177e4 | 398 | |
f4507164 | 399 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 400 | |
7f338fe4 | 401 | sk_set_memalloc(nbd->sock->sk); |
f4507164 WG |
402 | nbd->pid = task_pid_nr(current); |
403 | ret = device_create_file(disk_to_dev(nbd->disk), &pid_attr); | |
84963048 | 404 | if (ret) { |
f4507164 WG |
405 | dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); |
406 | nbd->pid = 0; | |
84963048 WC |
407 | return ret; |
408 | } | |
6b39bb65 | 409 | |
f4507164 | 410 | while ((req = nbd_read_stat(nbd)) != NULL) |
d18509f5 | 411 | nbd_end_request(nbd, req); |
6b39bb65 | 412 | |
f4507164 WG |
413 | device_remove_file(disk_to_dev(nbd->disk), &pid_attr); |
414 | nbd->pid = 0; | |
84963048 | 415 | return 0; |
1da177e4 LT |
416 | } |
417 | ||
f4507164 | 418 | static void nbd_clear_que(struct nbd_device *nbd) |
1da177e4 LT |
419 | { |
420 | struct request *req; | |
421 | ||
f4507164 | 422 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 423 | |
4b2f0260 | 424 | /* |
f4507164 | 425 | * Because we have set nbd->sock to NULL under the tx_lock, all |
4b2f0260 HX |
426 | * modifications to the list must have completed by now. For |
427 | * the same reason, the active_req must be NULL. | |
428 | * | |
429 | * As a consequence, we don't need to take the spin lock while | |
430 | * purging the list here. | |
431 | */ | |
f4507164 WG |
432 | BUG_ON(nbd->sock); |
433 | BUG_ON(nbd->active_req); | |
4b2f0260 | 434 | |
f4507164 WG |
435 | while (!list_empty(&nbd->queue_head)) { |
436 | req = list_entry(nbd->queue_head.next, struct request, | |
4b2f0260 HX |
437 | queuelist); |
438 | list_del_init(&req->queuelist); | |
439 | req->errors++; | |
d18509f5 | 440 | nbd_end_request(nbd, req); |
4b2f0260 | 441 | } |
fded4e09 PC |
442 | |
443 | while (!list_empty(&nbd->waiting_queue)) { | |
444 | req = list_entry(nbd->waiting_queue.next, struct request, | |
445 | queuelist); | |
446 | list_del_init(&req->queuelist); | |
447 | req->errors++; | |
d18509f5 | 448 | nbd_end_request(nbd, req); |
fded4e09 | 449 | } |
1da177e4 LT |
450 | } |
451 | ||
7fdfd406 | 452 | |
f4507164 | 453 | static void nbd_handle_req(struct nbd_device *nbd, struct request *req) |
48cf6061 | 454 | { |
33659ebb | 455 | if (req->cmd_type != REQ_TYPE_FS) |
48cf6061 LV |
456 | goto error_out; |
457 | ||
458 | nbd_cmd(req) = NBD_CMD_READ; | |
459 | if (rq_data_dir(req) == WRITE) { | |
a336d298 PC |
460 | if ((req->cmd_flags & REQ_DISCARD)) { |
461 | WARN_ON(!(nbd->flags & NBD_FLAG_SEND_TRIM)); | |
462 | nbd_cmd(req) = NBD_CMD_TRIM; | |
463 | } else | |
464 | nbd_cmd(req) = NBD_CMD_WRITE; | |
2f012508 | 465 | if (nbd->flags & NBD_FLAG_READ_ONLY) { |
f4507164 | 466 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 | 467 | "Write on read-only\n"); |
48cf6061 LV |
468 | goto error_out; |
469 | } | |
470 | } | |
471 | ||
75f187ab AB |
472 | if (req->cmd_flags & REQ_FLUSH) { |
473 | BUG_ON(unlikely(blk_rq_sectors(req))); | |
474 | nbd_cmd(req) = NBD_CMD_FLUSH; | |
475 | } | |
476 | ||
48cf6061 LV |
477 | req->errors = 0; |
478 | ||
f4507164 WG |
479 | mutex_lock(&nbd->tx_lock); |
480 | if (unlikely(!nbd->sock)) { | |
481 | mutex_unlock(&nbd->tx_lock); | |
482 | dev_err(disk_to_dev(nbd->disk), | |
7f1b90f9 | 483 | "Attempted send on closed socket\n"); |
15746fca | 484 | goto error_out; |
48cf6061 LV |
485 | } |
486 | ||
f4507164 | 487 | nbd->active_req = req; |
48cf6061 | 488 | |
f4507164 WG |
489 | if (nbd_send_req(nbd, req) != 0) { |
490 | dev_err(disk_to_dev(nbd->disk), "Request send failed\n"); | |
48cf6061 | 491 | req->errors++; |
d18509f5 | 492 | nbd_end_request(nbd, req); |
48cf6061 | 493 | } else { |
f4507164 | 494 | spin_lock(&nbd->queue_lock); |
01ff5dbc | 495 | list_add_tail(&req->queuelist, &nbd->queue_head); |
f4507164 | 496 | spin_unlock(&nbd->queue_lock); |
48cf6061 LV |
497 | } |
498 | ||
f4507164 WG |
499 | nbd->active_req = NULL; |
500 | mutex_unlock(&nbd->tx_lock); | |
501 | wake_up_all(&nbd->active_wq); | |
48cf6061 LV |
502 | |
503 | return; | |
504 | ||
505 | error_out: | |
506 | req->errors++; | |
d18509f5 | 507 | nbd_end_request(nbd, req); |
48cf6061 LV |
508 | } |
509 | ||
510 | static int nbd_thread(void *data) | |
511 | { | |
f4507164 | 512 | struct nbd_device *nbd = data; |
48cf6061 LV |
513 | struct request *req; |
514 | ||
8698a745 | 515 | set_user_nice(current, MIN_NICE); |
f4507164 | 516 | while (!kthread_should_stop() || !list_empty(&nbd->waiting_queue)) { |
48cf6061 | 517 | /* wait for something to do */ |
f4507164 | 518 | wait_event_interruptible(nbd->waiting_wq, |
48cf6061 | 519 | kthread_should_stop() || |
f4507164 | 520 | !list_empty(&nbd->waiting_queue)); |
48cf6061 LV |
521 | |
522 | /* extract request */ | |
f4507164 | 523 | if (list_empty(&nbd->waiting_queue)) |
48cf6061 LV |
524 | continue; |
525 | ||
f4507164 WG |
526 | spin_lock_irq(&nbd->queue_lock); |
527 | req = list_entry(nbd->waiting_queue.next, struct request, | |
48cf6061 LV |
528 | queuelist); |
529 | list_del_init(&req->queuelist); | |
f4507164 | 530 | spin_unlock_irq(&nbd->queue_lock); |
48cf6061 LV |
531 | |
532 | /* handle request */ | |
f4507164 | 533 | nbd_handle_req(nbd, req); |
48cf6061 LV |
534 | } |
535 | return 0; | |
536 | } | |
537 | ||
1da177e4 LT |
538 | /* |
539 | * We always wait for result of write, for now. It would be nice to make it optional | |
540 | * in future | |
f4507164 | 541 | * if ((rq_data_dir(req) == WRITE) && (nbd->flags & NBD_WRITE_NOCHK)) |
1da177e4 LT |
542 | * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } |
543 | */ | |
544 | ||
15746fca | 545 | static void do_nbd_request(struct request_queue *q) |
398eb085 | 546 | __releases(q->queue_lock) __acquires(q->queue_lock) |
1da177e4 LT |
547 | { |
548 | struct request *req; | |
549 | ||
9934c8c0 | 550 | while ((req = blk_fetch_request(q)) != NULL) { |
f4507164 | 551 | struct nbd_device *nbd; |
1da177e4 | 552 | |
48cf6061 LV |
553 | spin_unlock_irq(q->queue_lock); |
554 | ||
f4507164 | 555 | nbd = req->rq_disk->private_data; |
1da177e4 | 556 | |
f4507164 | 557 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 558 | |
d18509f5 MP |
559 | dev_dbg(nbd_to_dev(nbd), "request %p: dequeued (flags=%x)\n", |
560 | req, req->cmd_type); | |
561 | ||
f4507164 WG |
562 | if (unlikely(!nbd->sock)) { |
563 | dev_err(disk_to_dev(nbd->disk), | |
7f1b90f9 | 564 | "Attempted send on closed socket\n"); |
4d48a542 | 565 | req->errors++; |
d18509f5 | 566 | nbd_end_request(nbd, req); |
4d48a542 PC |
567 | spin_lock_irq(q->queue_lock); |
568 | continue; | |
569 | } | |
570 | ||
f4507164 WG |
571 | spin_lock_irq(&nbd->queue_lock); |
572 | list_add_tail(&req->queuelist, &nbd->waiting_queue); | |
573 | spin_unlock_irq(&nbd->queue_lock); | |
1da177e4 | 574 | |
f4507164 | 575 | wake_up(&nbd->waiting_wq); |
4b2f0260 | 576 | |
1da177e4 | 577 | spin_lock_irq(q->queue_lock); |
1da177e4 | 578 | } |
1da177e4 LT |
579 | } |
580 | ||
1a2ad211 | 581 | /* Must be called with tx_lock held */ |
1da177e4 | 582 | |
f4507164 | 583 | static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, |
1a2ad211 PM |
584 | unsigned int cmd, unsigned long arg) |
585 | { | |
1da177e4 | 586 | switch (cmd) { |
1a2ad211 PM |
587 | case NBD_DISCONNECT: { |
588 | struct request sreq; | |
589 | ||
f4507164 | 590 | dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n"); |
3a2d63f8 PB |
591 | if (!nbd->sock) |
592 | return -EINVAL; | |
1a2ad211 | 593 | |
3a2d63f8 PB |
594 | mutex_unlock(&nbd->tx_lock); |
595 | fsync_bdev(bdev); | |
596 | mutex_lock(&nbd->tx_lock); | |
4f54eec8 | 597 | blk_rq_init(NULL, &sreq); |
4aff5e23 | 598 | sreq.cmd_type = REQ_TYPE_SPECIAL; |
1da177e4 | 599 | nbd_cmd(&sreq) = NBD_CMD_DISC; |
3a2d63f8 PB |
600 | |
601 | /* Check again after getting mutex back. */ | |
f4507164 | 602 | if (!nbd->sock) |
1da177e4 | 603 | return -EINVAL; |
3a2d63f8 | 604 | |
c378f70a PC |
605 | nbd->disconnect = 1; |
606 | ||
f4507164 | 607 | nbd_send_req(nbd, &sreq); |
c378f70a | 608 | return 0; |
1a2ad211 | 609 | } |
1da177e4 | 610 | |
1a2ad211 | 611 | case NBD_CLEAR_SOCK: { |
e2511578 | 612 | struct socket *sock = nbd->sock; |
f4507164 | 613 | nbd->sock = NULL; |
f4507164 WG |
614 | nbd_clear_que(nbd); |
615 | BUG_ON(!list_empty(&nbd->queue_head)); | |
fded4e09 | 616 | BUG_ON(!list_empty(&nbd->waiting_queue)); |
3a2d63f8 | 617 | kill_bdev(bdev); |
e2511578 AV |
618 | if (sock) |
619 | sockfd_put(sock); | |
1a2ad211 PM |
620 | return 0; |
621 | } | |
622 | ||
623 | case NBD_SET_SOCK: { | |
e2511578 AV |
624 | struct socket *sock; |
625 | int err; | |
626 | if (nbd->sock) | |
1da177e4 | 627 | return -EBUSY; |
e2511578 AV |
628 | sock = sockfd_lookup(arg, &err); |
629 | if (sock) { | |
630 | nbd->sock = sock; | |
631 | if (max_part > 0) | |
632 | bdev->bd_invalidated = 1; | |
633 | nbd->disconnect = 0; /* we're connected now */ | |
634 | return 0; | |
1da177e4 | 635 | } |
1a2ad211 PM |
636 | return -EINVAL; |
637 | } | |
638 | ||
1da177e4 | 639 | case NBD_SET_BLKSIZE: |
f4507164 WG |
640 | nbd->blksize = arg; |
641 | nbd->bytesize &= ~(nbd->blksize-1); | |
642 | bdev->bd_inode->i_size = nbd->bytesize; | |
643 | set_blocksize(bdev, nbd->blksize); | |
644 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
1da177e4 | 645 | return 0; |
1a2ad211 | 646 | |
1da177e4 | 647 | case NBD_SET_SIZE: |
f4507164 WG |
648 | nbd->bytesize = arg & ~(nbd->blksize-1); |
649 | bdev->bd_inode->i_size = nbd->bytesize; | |
650 | set_blocksize(bdev, nbd->blksize); | |
651 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
1da177e4 | 652 | return 0; |
1a2ad211 | 653 | |
7fdfd406 | 654 | case NBD_SET_TIMEOUT: |
f4507164 | 655 | nbd->xmit_timeout = arg * HZ; |
7fdfd406 | 656 | return 0; |
1a2ad211 | 657 | |
2f012508 PC |
658 | case NBD_SET_FLAGS: |
659 | nbd->flags = arg; | |
660 | return 0; | |
661 | ||
1da177e4 | 662 | case NBD_SET_SIZE_BLOCKS: |
f4507164 WG |
663 | nbd->bytesize = ((u64) arg) * nbd->blksize; |
664 | bdev->bd_inode->i_size = nbd->bytesize; | |
665 | set_blocksize(bdev, nbd->blksize); | |
666 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
1da177e4 | 667 | return 0; |
1a2ad211 PM |
668 | |
669 | case NBD_DO_IT: { | |
670 | struct task_struct *thread; | |
e2511578 | 671 | struct socket *sock; |
1a2ad211 PM |
672 | int error; |
673 | ||
f4507164 | 674 | if (nbd->pid) |
c91192d6 | 675 | return -EBUSY; |
e2511578 | 676 | if (!nbd->sock) |
1da177e4 | 677 | return -EINVAL; |
1a2ad211 | 678 | |
f4507164 | 679 | mutex_unlock(&nbd->tx_lock); |
1a2ad211 | 680 | |
a83e814b PB |
681 | if (nbd->flags & NBD_FLAG_READ_ONLY) |
682 | set_device_ro(bdev, true); | |
a336d298 PC |
683 | if (nbd->flags & NBD_FLAG_SEND_TRIM) |
684 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, | |
685 | nbd->disk->queue); | |
75f187ab AB |
686 | if (nbd->flags & NBD_FLAG_SEND_FLUSH) |
687 | blk_queue_flush(nbd->disk->queue, REQ_FLUSH); | |
688 | else | |
689 | blk_queue_flush(nbd->disk->queue, 0); | |
a336d298 | 690 | |
d06df60b MP |
691 | thread = kthread_run(nbd_thread, nbd, "%s", |
692 | nbd->disk->disk_name); | |
1a2ad211 | 693 | if (IS_ERR(thread)) { |
f4507164 | 694 | mutex_lock(&nbd->tx_lock); |
48cf6061 | 695 | return PTR_ERR(thread); |
1a2ad211 | 696 | } |
d06df60b | 697 | |
f4507164 | 698 | error = nbd_do_it(nbd); |
48cf6061 | 699 | kthread_stop(thread); |
1a2ad211 | 700 | |
f4507164 | 701 | mutex_lock(&nbd->tx_lock); |
84963048 WC |
702 | if (error) |
703 | return error; | |
f4507164 | 704 | sock_shutdown(nbd, 0); |
e2511578 AV |
705 | sock = nbd->sock; |
706 | nbd->sock = NULL; | |
f4507164 WG |
707 | nbd_clear_que(nbd); |
708 | dev_warn(disk_to_dev(nbd->disk), "queue cleared\n"); | |
3a2d63f8 | 709 | kill_bdev(bdev); |
a336d298 | 710 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); |
a83e814b | 711 | set_device_ro(bdev, false); |
e2511578 AV |
712 | if (sock) |
713 | sockfd_put(sock); | |
75f187ab | 714 | nbd->flags = 0; |
f4507164 | 715 | nbd->bytesize = 0; |
a8cdc308 | 716 | bdev->bd_inode->i_size = 0; |
f4507164 | 717 | set_capacity(nbd->disk, 0); |
d71a6d73 | 718 | if (max_part > 0) |
a8cdc308 | 719 | ioctl_by_bdev(bdev, BLKRRPART, 0); |
c378f70a PC |
720 | if (nbd->disconnect) /* user requested, ignore socket errors */ |
721 | return 0; | |
f4507164 | 722 | return nbd->harderror; |
1a2ad211 PM |
723 | } |
724 | ||
1da177e4 | 725 | case NBD_CLEAR_QUE: |
4b2f0260 HX |
726 | /* |
727 | * This is for compatibility only. The queue is always cleared | |
728 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
729 | */ | |
1da177e4 | 730 | return 0; |
1a2ad211 | 731 | |
1da177e4 | 732 | case NBD_PRINT_DEBUG: |
f4507164 | 733 | dev_info(disk_to_dev(nbd->disk), |
5eedf541 | 734 | "next = %p, prev = %p, head = %p\n", |
f4507164 WG |
735 | nbd->queue_head.next, nbd->queue_head.prev, |
736 | &nbd->queue_head); | |
1da177e4 LT |
737 | return 0; |
738 | } | |
1a2ad211 PM |
739 | return -ENOTTY; |
740 | } | |
741 | ||
742 | static int nbd_ioctl(struct block_device *bdev, fmode_t mode, | |
743 | unsigned int cmd, unsigned long arg) | |
744 | { | |
f4507164 | 745 | struct nbd_device *nbd = bdev->bd_disk->private_data; |
1a2ad211 PM |
746 | int error; |
747 | ||
748 | if (!capable(CAP_SYS_ADMIN)) | |
749 | return -EPERM; | |
750 | ||
f4507164 | 751 | BUG_ON(nbd->magic != NBD_MAGIC); |
1a2ad211 | 752 | |
f4507164 WG |
753 | mutex_lock(&nbd->tx_lock); |
754 | error = __nbd_ioctl(bdev, nbd, cmd, arg); | |
755 | mutex_unlock(&nbd->tx_lock); | |
1a2ad211 PM |
756 | |
757 | return error; | |
1da177e4 LT |
758 | } |
759 | ||
83d5cde4 | 760 | static const struct block_device_operations nbd_fops = |
1da177e4 LT |
761 | { |
762 | .owner = THIS_MODULE, | |
8a6cfeb6 | 763 | .ioctl = nbd_ioctl, |
1da177e4 LT |
764 | }; |
765 | ||
766 | /* | |
767 | * And here should be modules and kernel interface | |
768 | * (Just smiley confuses emacs :-) | |
769 | */ | |
770 | ||
771 | static int __init nbd_init(void) | |
772 | { | |
773 | int err = -ENOMEM; | |
774 | int i; | |
d71a6d73 | 775 | int part_shift; |
1da177e4 | 776 | |
5b7b18cc | 777 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 778 | |
d71a6d73 | 779 | if (max_part < 0) { |
7742ce4a | 780 | printk(KERN_ERR "nbd: max_part must be >= 0\n"); |
d71a6d73 LV |
781 | return -EINVAL; |
782 | } | |
783 | ||
784 | part_shift = 0; | |
5988ce23 | 785 | if (max_part > 0) { |
d71a6d73 LV |
786 | part_shift = fls(max_part); |
787 | ||
5988ce23 NK |
788 | /* |
789 | * Adjust max_part according to part_shift as it is exported | |
790 | * to user space so that user can know the max number of | |
791 | * partition kernel should be able to manage. | |
792 | * | |
793 | * Note that -1 is required because partition 0 is reserved | |
794 | * for the whole disk. | |
795 | */ | |
796 | max_part = (1UL << part_shift) - 1; | |
797 | } | |
798 | ||
3b271082 NK |
799 | if ((1UL << part_shift) > DISK_MAX_PARTS) |
800 | return -EINVAL; | |
801 | ||
802 | if (nbds_max > 1UL << (MINORBITS - part_shift)) | |
803 | return -EINVAL; | |
804 | ||
ff6b8090 SM |
805 | nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL); |
806 | if (!nbd_dev) | |
807 | return -ENOMEM; | |
808 | ||
40be0c28 | 809 | for (i = 0; i < nbds_max; i++) { |
d71a6d73 | 810 | struct gendisk *disk = alloc_disk(1 << part_shift); |
1da177e4 LT |
811 | if (!disk) |
812 | goto out; | |
813 | nbd_dev[i].disk = disk; | |
814 | /* | |
815 | * The new linux 2.5 block layer implementation requires | |
816 | * every gendisk to have its very own request_queue struct. | |
817 | * These structs are big so we dynamically allocate them. | |
818 | */ | |
819 | disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); | |
820 | if (!disk->queue) { | |
821 | put_disk(disk); | |
822 | goto out; | |
823 | } | |
31dcfab0 JA |
824 | /* |
825 | * Tell the block layer that we are not a rotational device | |
826 | */ | |
827 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue); | |
b277da0a | 828 | queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, disk->queue); |
a336d298 PC |
829 | disk->queue->limits.discard_granularity = 512; |
830 | disk->queue->limits.max_discard_sectors = UINT_MAX; | |
831 | disk->queue->limits.discard_zeroes_data = 0; | |
078be02b MB |
832 | blk_queue_max_hw_sectors(disk->queue, 65536); |
833 | disk->queue->limits.max_sectors = 256; | |
1da177e4 LT |
834 | } |
835 | ||
836 | if (register_blkdev(NBD_MAJOR, "nbd")) { | |
837 | err = -EIO; | |
838 | goto out; | |
839 | } | |
840 | ||
841 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); | |
1da177e4 | 842 | |
40be0c28 | 843 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 844 | struct gendisk *disk = nbd_dev[i].disk; |
f4507164 | 845 | nbd_dev[i].magic = NBD_MAGIC; |
48cf6061 | 846 | INIT_LIST_HEAD(&nbd_dev[i].waiting_queue); |
1da177e4 LT |
847 | spin_lock_init(&nbd_dev[i].queue_lock); |
848 | INIT_LIST_HEAD(&nbd_dev[i].queue_head); | |
82d4dc5a | 849 | mutex_init(&nbd_dev[i].tx_lock); |
4b2f0260 | 850 | init_waitqueue_head(&nbd_dev[i].active_wq); |
48cf6061 | 851 | init_waitqueue_head(&nbd_dev[i].waiting_wq); |
1da177e4 | 852 | nbd_dev[i].blksize = 1024; |
4b86a872 | 853 | nbd_dev[i].bytesize = 0; |
1da177e4 | 854 | disk->major = NBD_MAJOR; |
d71a6d73 | 855 | disk->first_minor = i << part_shift; |
1da177e4 LT |
856 | disk->fops = &nbd_fops; |
857 | disk->private_data = &nbd_dev[i]; | |
1da177e4 | 858 | sprintf(disk->disk_name, "nbd%d", i); |
4b86a872 | 859 | set_capacity(disk, 0); |
1da177e4 LT |
860 | add_disk(disk); |
861 | } | |
862 | ||
863 | return 0; | |
864 | out: | |
865 | while (i--) { | |
866 | blk_cleanup_queue(nbd_dev[i].disk->queue); | |
867 | put_disk(nbd_dev[i].disk); | |
868 | } | |
f3944d61 | 869 | kfree(nbd_dev); |
1da177e4 LT |
870 | return err; |
871 | } | |
872 | ||
873 | static void __exit nbd_cleanup(void) | |
874 | { | |
875 | int i; | |
40be0c28 | 876 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 877 | struct gendisk *disk = nbd_dev[i].disk; |
40be0c28 | 878 | nbd_dev[i].magic = 0; |
1da177e4 LT |
879 | if (disk) { |
880 | del_gendisk(disk); | |
881 | blk_cleanup_queue(disk->queue); | |
882 | put_disk(disk); | |
883 | } | |
884 | } | |
1da177e4 | 885 | unregister_blkdev(NBD_MAJOR, "nbd"); |
f3944d61 | 886 | kfree(nbd_dev); |
1da177e4 LT |
887 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); |
888 | } | |
889 | ||
890 | module_init(nbd_init); | |
891 | module_exit(nbd_cleanup); | |
892 | ||
893 | MODULE_DESCRIPTION("Network Block Device"); | |
894 | MODULE_LICENSE("GPL"); | |
895 | ||
40be0c28 | 896 | module_param(nbds_max, int, 0444); |
d71a6d73 LV |
897 | MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); |
898 | module_param(max_part, int, 0444); | |
899 | MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)"); |