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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> |
1da177e4 | 35 | |
1da177e4 LT |
36 | #include <asm/uaccess.h> |
37 | #include <asm/types.h> | |
38 | ||
39 | #include <linux/nbd.h> | |
40 | ||
f4507164 | 41 | #define NBD_MAGIC 0x68797548 |
1da177e4 LT |
42 | |
43 | #ifdef NDEBUG | |
44 | #define dprintk(flags, fmt...) | |
45 | #else /* NDEBUG */ | |
46 | #define dprintk(flags, fmt...) do { \ | |
47 | if (debugflags & (flags)) printk(KERN_DEBUG fmt); \ | |
48 | } while (0) | |
49 | #define DBG_IOCTL 0x0004 | |
50 | #define DBG_INIT 0x0010 | |
51 | #define DBG_EXIT 0x0020 | |
52 | #define DBG_BLKDEV 0x0100 | |
53 | #define DBG_RX 0x0200 | |
54 | #define DBG_TX 0x0400 | |
55 | static unsigned int debugflags; | |
56 | #endif /* NDEBUG */ | |
57 | ||
9c7a4169 | 58 | static unsigned int nbds_max = 16; |
20a8143e | 59 | static struct nbd_device *nbd_dev; |
d71a6d73 | 60 | static int max_part; |
1da177e4 LT |
61 | |
62 | /* | |
63 | * Use just one lock (or at most 1 per NIC). Two arguments for this: | |
64 | * 1. Each NIC is essentially a synchronization point for all servers | |
65 | * accessed through that NIC so there's no need to have more locks | |
66 | * than NICs anyway. | |
67 | * 2. More locks lead to more "Dirty cache line bouncing" which will slow | |
68 | * down each lock to the point where they're actually slower than just | |
69 | * a single lock. | |
70 | * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! | |
71 | */ | |
72 | static DEFINE_SPINLOCK(nbd_lock); | |
73 | ||
74 | #ifndef NDEBUG | |
75 | static const char *ioctl_cmd_to_ascii(int cmd) | |
76 | { | |
77 | switch (cmd) { | |
78 | case NBD_SET_SOCK: return "set-sock"; | |
79 | case NBD_SET_BLKSIZE: return "set-blksize"; | |
80 | case NBD_SET_SIZE: return "set-size"; | |
2f012508 PC |
81 | case NBD_SET_TIMEOUT: return "set-timeout"; |
82 | case NBD_SET_FLAGS: return "set-flags"; | |
1da177e4 LT |
83 | case NBD_DO_IT: return "do-it"; |
84 | case NBD_CLEAR_SOCK: return "clear-sock"; | |
85 | case NBD_CLEAR_QUE: return "clear-que"; | |
86 | case NBD_PRINT_DEBUG: return "print-debug"; | |
87 | case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; | |
88 | case NBD_DISCONNECT: return "disconnect"; | |
89 | case BLKROSET: return "set-read-only"; | |
90 | case BLKFLSBUF: return "flush-buffer-cache"; | |
91 | } | |
92 | return "unknown"; | |
93 | } | |
94 | ||
95 | static const char *nbdcmd_to_ascii(int cmd) | |
96 | { | |
97 | switch (cmd) { | |
98 | case NBD_CMD_READ: return "read"; | |
99 | case NBD_CMD_WRITE: return "write"; | |
100 | case NBD_CMD_DISC: return "disconnect"; | |
a336d298 | 101 | case NBD_CMD_TRIM: return "trim/discard"; |
1da177e4 LT |
102 | } |
103 | return "invalid"; | |
104 | } | |
105 | #endif /* NDEBUG */ | |
106 | ||
107 | static void nbd_end_request(struct request *req) | |
108 | { | |
097c94a4 | 109 | int error = req->errors ? -EIO : 0; |
165125e1 | 110 | struct request_queue *q = req->q; |
1da177e4 LT |
111 | unsigned long flags; |
112 | ||
113 | dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, | |
097c94a4 | 114 | req, error ? "failed" : "done"); |
1da177e4 LT |
115 | |
116 | spin_lock_irqsave(q->queue_lock, flags); | |
1011c1b9 | 117 | __blk_end_request_all(req, error); |
1da177e4 LT |
118 | spin_unlock_irqrestore(q->queue_lock, flags); |
119 | } | |
120 | ||
f4507164 | 121 | static void sock_shutdown(struct nbd_device *nbd, int lock) |
7fdfd406 PC |
122 | { |
123 | /* Forcibly shutdown the socket causing all listeners | |
124 | * to error | |
125 | * | |
126 | * FIXME: This code is duplicated from sys_shutdown, but | |
127 | * there should be a more generic interface rather than | |
128 | * calling socket ops directly here */ | |
129 | if (lock) | |
f4507164 WG |
130 | mutex_lock(&nbd->tx_lock); |
131 | if (nbd->sock) { | |
132 | dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n"); | |
133 | kernel_sock_shutdown(nbd->sock, SHUT_RDWR); | |
134 | nbd->sock = NULL; | |
7fdfd406 PC |
135 | } |
136 | if (lock) | |
f4507164 | 137 | mutex_unlock(&nbd->tx_lock); |
7fdfd406 PC |
138 | } |
139 | ||
140 | static void nbd_xmit_timeout(unsigned long arg) | |
141 | { | |
142 | struct task_struct *task = (struct task_struct *)arg; | |
143 | ||
144 | printk(KERN_WARNING "nbd: killing hung xmit (%s, pid: %d)\n", | |
145 | task->comm, task->pid); | |
146 | force_sig(SIGKILL, task); | |
147 | } | |
148 | ||
1da177e4 LT |
149 | /* |
150 | * Send or receive packet. | |
151 | */ | |
f4507164 | 152 | static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size, |
1da177e4 LT |
153 | int msg_flags) |
154 | { | |
f4507164 | 155 | struct socket *sock = nbd->sock; |
1da177e4 LT |
156 | int result; |
157 | struct msghdr msg; | |
158 | struct kvec iov; | |
be0ef957 | 159 | sigset_t blocked, oldset; |
7f338fe4 | 160 | unsigned long pflags = current->flags; |
1da177e4 | 161 | |
ffc41cf8 | 162 | if (unlikely(!sock)) { |
f4507164 | 163 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
164 | "Attempted %s on closed socket in sock_xmit\n", |
165 | (send ? "send" : "recv")); | |
ffc41cf8 MS |
166 | return -EINVAL; |
167 | } | |
168 | ||
1da177e4 LT |
169 | /* Allow interception of SIGKILL only |
170 | * Don't allow other signals to interrupt the transmission */ | |
be0ef957 ON |
171 | siginitsetinv(&blocked, sigmask(SIGKILL)); |
172 | sigprocmask(SIG_SETMASK, &blocked, &oldset); | |
1da177e4 | 173 | |
7f338fe4 | 174 | current->flags |= PF_MEMALLOC; |
1da177e4 | 175 | do { |
7f338fe4 | 176 | sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC; |
1da177e4 LT |
177 | iov.iov_base = buf; |
178 | iov.iov_len = size; | |
179 | msg.msg_name = NULL; | |
180 | msg.msg_namelen = 0; | |
181 | msg.msg_control = NULL; | |
182 | msg.msg_controllen = 0; | |
1da177e4 LT |
183 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
184 | ||
7fdfd406 PC |
185 | if (send) { |
186 | struct timer_list ti; | |
187 | ||
f4507164 | 188 | if (nbd->xmit_timeout) { |
7fdfd406 PC |
189 | init_timer(&ti); |
190 | ti.function = nbd_xmit_timeout; | |
191 | ti.data = (unsigned long)current; | |
f4507164 | 192 | ti.expires = jiffies + nbd->xmit_timeout; |
7fdfd406 PC |
193 | add_timer(&ti); |
194 | } | |
1da177e4 | 195 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
f4507164 | 196 | if (nbd->xmit_timeout) |
7fdfd406 PC |
197 | del_timer_sync(&ti); |
198 | } else | |
35fbf5bc NK |
199 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, |
200 | msg.msg_flags); | |
1da177e4 LT |
201 | |
202 | if (signal_pending(current)) { | |
203 | siginfo_t info; | |
1da177e4 | 204 | printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", |
ba25f9dc | 205 | task_pid_nr(current), current->comm, |
be0ef957 | 206 | dequeue_signal_lock(current, ¤t->blocked, &info)); |
1da177e4 | 207 | result = -EINTR; |
f4507164 | 208 | sock_shutdown(nbd, !send); |
1da177e4 LT |
209 | break; |
210 | } | |
211 | ||
212 | if (result <= 0) { | |
213 | if (result == 0) | |
214 | result = -EPIPE; /* short read */ | |
215 | break; | |
216 | } | |
217 | size -= result; | |
218 | buf += result; | |
219 | } while (size > 0); | |
220 | ||
be0ef957 | 221 | sigprocmask(SIG_SETMASK, &oldset, NULL); |
7f338fe4 | 222 | tsk_restore_flags(current, pflags, PF_MEMALLOC); |
1da177e4 LT |
223 | |
224 | return result; | |
225 | } | |
226 | ||
f4507164 | 227 | static inline int sock_send_bvec(struct nbd_device *nbd, struct bio_vec *bvec, |
1da177e4 LT |
228 | int flags) |
229 | { | |
230 | int result; | |
231 | void *kaddr = kmap(bvec->bv_page); | |
f4507164 WG |
232 | result = sock_xmit(nbd, 1, kaddr + bvec->bv_offset, |
233 | bvec->bv_len, flags); | |
1da177e4 LT |
234 | kunmap(bvec->bv_page); |
235 | return result; | |
236 | } | |
237 | ||
7fdfd406 | 238 | /* always call with the tx_lock held */ |
f4507164 | 239 | static int nbd_send_req(struct nbd_device *nbd, struct request *req) |
1da177e4 | 240 | { |
5705f702 | 241 | int result, flags; |
1da177e4 | 242 | struct nbd_request request; |
1011c1b9 | 243 | unsigned long size = blk_rq_bytes(req); |
1da177e4 LT |
244 | |
245 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
246 | request.type = htonl(nbd_cmd(req)); | |
83096ebf | 247 | request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); |
1da177e4 LT |
248 | request.len = htonl(size); |
249 | memcpy(request.handle, &req, sizeof(req)); | |
250 | ||
83096ebf | 251 | dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%uB)\n", |
f4507164 | 252 | nbd->disk->disk_name, req, |
1da177e4 | 253 | nbdcmd_to_ascii(nbd_cmd(req)), |
83096ebf | 254 | (unsigned long long)blk_rq_pos(req) << 9, |
1011c1b9 | 255 | blk_rq_bytes(req)); |
f4507164 | 256 | result = sock_xmit(nbd, 1, &request, sizeof(request), |
7fdfd406 | 257 | (nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0); |
1da177e4 | 258 | if (result <= 0) { |
f4507164 | 259 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 | 260 | "Send control failed (result %d)\n", result); |
1da177e4 LT |
261 | goto error_out; |
262 | } | |
263 | ||
264 | if (nbd_cmd(req) == NBD_CMD_WRITE) { | |
5705f702 N |
265 | struct req_iterator iter; |
266 | struct bio_vec *bvec; | |
1da177e4 LT |
267 | /* |
268 | * we are really probing at internals to determine | |
269 | * whether to set MSG_MORE or not... | |
270 | */ | |
5705f702 | 271 | rq_for_each_segment(bvec, req, iter) { |
6c92e699 JA |
272 | flags = 0; |
273 | if (!rq_iter_last(req, iter)) | |
274 | flags = MSG_MORE; | |
275 | dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", | |
f4507164 WG |
276 | nbd->disk->disk_name, req, bvec->bv_len); |
277 | result = sock_send_bvec(nbd, bvec, flags); | |
6c92e699 | 278 | if (result <= 0) { |
f4507164 | 279 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
280 | "Send data failed (result %d)\n", |
281 | result); | |
6c92e699 JA |
282 | goto error_out; |
283 | } | |
1da177e4 LT |
284 | } |
285 | } | |
1da177e4 LT |
286 | return 0; |
287 | ||
288 | error_out: | |
15746fca | 289 | return -EIO; |
1da177e4 LT |
290 | } |
291 | ||
f4507164 | 292 | static struct request *nbd_find_request(struct nbd_device *nbd, |
0cbc591b | 293 | struct request *xreq) |
1da177e4 | 294 | { |
d2c9740b | 295 | struct request *req, *tmp; |
4b2f0260 | 296 | int err; |
1da177e4 | 297 | |
f4507164 | 298 | err = wait_event_interruptible(nbd->active_wq, nbd->active_req != xreq); |
4b2f0260 HX |
299 | if (unlikely(err)) |
300 | goto out; | |
301 | ||
f4507164 WG |
302 | spin_lock(&nbd->queue_lock); |
303 | list_for_each_entry_safe(req, tmp, &nbd->queue_head, queuelist) { | |
1da177e4 LT |
304 | if (req != xreq) |
305 | continue; | |
306 | list_del_init(&req->queuelist); | |
f4507164 | 307 | spin_unlock(&nbd->queue_lock); |
1da177e4 LT |
308 | return req; |
309 | } | |
f4507164 | 310 | spin_unlock(&nbd->queue_lock); |
4b2f0260 HX |
311 | |
312 | err = -ENOENT; | |
313 | ||
314 | out: | |
315 | return ERR_PTR(err); | |
1da177e4 LT |
316 | } |
317 | ||
f4507164 | 318 | static inline int sock_recv_bvec(struct nbd_device *nbd, struct bio_vec *bvec) |
1da177e4 LT |
319 | { |
320 | int result; | |
321 | void *kaddr = kmap(bvec->bv_page); | |
f4507164 | 322 | result = sock_xmit(nbd, 0, kaddr + bvec->bv_offset, bvec->bv_len, |
1da177e4 LT |
323 | MSG_WAITALL); |
324 | kunmap(bvec->bv_page); | |
325 | return result; | |
326 | } | |
327 | ||
328 | /* NULL returned = something went wrong, inform userspace */ | |
f4507164 | 329 | static struct request *nbd_read_stat(struct nbd_device *nbd) |
1da177e4 LT |
330 | { |
331 | int result; | |
332 | struct nbd_reply reply; | |
333 | struct request *req; | |
1da177e4 LT |
334 | |
335 | reply.magic = 0; | |
f4507164 | 336 | result = sock_xmit(nbd, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 | 337 | if (result <= 0) { |
f4507164 | 338 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 | 339 | "Receive control failed (result %d)\n", result); |
1da177e4 LT |
340 | goto harderror; |
341 | } | |
e4b57e08 MF |
342 | |
343 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
f4507164 | 344 | dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n", |
e4b57e08 MF |
345 | (unsigned long)ntohl(reply.magic)); |
346 | result = -EPROTO; | |
347 | goto harderror; | |
348 | } | |
349 | ||
f4507164 | 350 | req = nbd_find_request(nbd, *(struct request **)reply.handle); |
801678c5 | 351 | if (IS_ERR(req)) { |
4b2f0260 HX |
352 | result = PTR_ERR(req); |
353 | if (result != -ENOENT) | |
354 | goto harderror; | |
355 | ||
f4507164 | 356 | dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%p)\n", |
7f1b90f9 | 357 | reply.handle); |
1da177e4 LT |
358 | result = -EBADR; |
359 | goto harderror; | |
360 | } | |
361 | ||
1da177e4 | 362 | if (ntohl(reply.error)) { |
f4507164 | 363 | dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n", |
7f1b90f9 | 364 | ntohl(reply.error)); |
1da177e4 LT |
365 | req->errors++; |
366 | return req; | |
367 | } | |
368 | ||
369 | dprintk(DBG_RX, "%s: request %p: got reply\n", | |
f4507164 | 370 | nbd->disk->disk_name, req); |
1da177e4 | 371 | if (nbd_cmd(req) == NBD_CMD_READ) { |
5705f702 N |
372 | struct req_iterator iter; |
373 | struct bio_vec *bvec; | |
374 | ||
375 | rq_for_each_segment(bvec, req, iter) { | |
f4507164 | 376 | result = sock_recv_bvec(nbd, bvec); |
6c92e699 | 377 | if (result <= 0) { |
f4507164 | 378 | dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", |
7f1b90f9 | 379 | result); |
6c92e699 JA |
380 | req->errors++; |
381 | return req; | |
382 | } | |
383 | dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", | |
f4507164 | 384 | nbd->disk->disk_name, req, bvec->bv_len); |
1da177e4 LT |
385 | } |
386 | } | |
387 | return req; | |
388 | harderror: | |
f4507164 | 389 | nbd->harderror = result; |
1da177e4 LT |
390 | return NULL; |
391 | } | |
392 | ||
edfaa7c3 KS |
393 | static ssize_t pid_show(struct device *dev, |
394 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 395 | { |
edfaa7c3 KS |
396 | struct gendisk *disk = dev_to_disk(dev); |
397 | ||
398 | return sprintf(buf, "%ld\n", | |
6b39bb65 PC |
399 | (long) ((struct nbd_device *)disk->private_data)->pid); |
400 | } | |
401 | ||
edfaa7c3 | 402 | static struct device_attribute pid_attr = { |
01e8ef11 | 403 | .attr = { .name = "pid", .mode = S_IRUGO}, |
6b39bb65 PC |
404 | .show = pid_show, |
405 | }; | |
406 | ||
f4507164 | 407 | static int nbd_do_it(struct nbd_device *nbd) |
1da177e4 LT |
408 | { |
409 | struct request *req; | |
84963048 | 410 | int ret; |
1da177e4 | 411 | |
f4507164 | 412 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 413 | |
7f338fe4 | 414 | sk_set_memalloc(nbd->sock->sk); |
f4507164 WG |
415 | nbd->pid = task_pid_nr(current); |
416 | ret = device_create_file(disk_to_dev(nbd->disk), &pid_attr); | |
84963048 | 417 | if (ret) { |
f4507164 WG |
418 | dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); |
419 | nbd->pid = 0; | |
84963048 WC |
420 | return ret; |
421 | } | |
6b39bb65 | 422 | |
f4507164 | 423 | while ((req = nbd_read_stat(nbd)) != NULL) |
1da177e4 | 424 | nbd_end_request(req); |
6b39bb65 | 425 | |
f4507164 WG |
426 | device_remove_file(disk_to_dev(nbd->disk), &pid_attr); |
427 | nbd->pid = 0; | |
84963048 | 428 | return 0; |
1da177e4 LT |
429 | } |
430 | ||
f4507164 | 431 | static void nbd_clear_que(struct nbd_device *nbd) |
1da177e4 LT |
432 | { |
433 | struct request *req; | |
434 | ||
f4507164 | 435 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 436 | |
4b2f0260 | 437 | /* |
f4507164 | 438 | * Because we have set nbd->sock to NULL under the tx_lock, all |
4b2f0260 HX |
439 | * modifications to the list must have completed by now. For |
440 | * the same reason, the active_req must be NULL. | |
441 | * | |
442 | * As a consequence, we don't need to take the spin lock while | |
443 | * purging the list here. | |
444 | */ | |
f4507164 WG |
445 | BUG_ON(nbd->sock); |
446 | BUG_ON(nbd->active_req); | |
4b2f0260 | 447 | |
f4507164 WG |
448 | while (!list_empty(&nbd->queue_head)) { |
449 | req = list_entry(nbd->queue_head.next, struct request, | |
4b2f0260 HX |
450 | queuelist); |
451 | list_del_init(&req->queuelist); | |
452 | req->errors++; | |
453 | nbd_end_request(req); | |
454 | } | |
fded4e09 PC |
455 | |
456 | while (!list_empty(&nbd->waiting_queue)) { | |
457 | req = list_entry(nbd->waiting_queue.next, struct request, | |
458 | queuelist); | |
459 | list_del_init(&req->queuelist); | |
460 | req->errors++; | |
461 | nbd_end_request(req); | |
462 | } | |
1da177e4 LT |
463 | } |
464 | ||
7fdfd406 | 465 | |
f4507164 | 466 | static void nbd_handle_req(struct nbd_device *nbd, struct request *req) |
48cf6061 | 467 | { |
33659ebb | 468 | if (req->cmd_type != REQ_TYPE_FS) |
48cf6061 LV |
469 | goto error_out; |
470 | ||
471 | nbd_cmd(req) = NBD_CMD_READ; | |
472 | if (rq_data_dir(req) == WRITE) { | |
a336d298 PC |
473 | if ((req->cmd_flags & REQ_DISCARD)) { |
474 | WARN_ON(!(nbd->flags & NBD_FLAG_SEND_TRIM)); | |
475 | nbd_cmd(req) = NBD_CMD_TRIM; | |
476 | } else | |
477 | nbd_cmd(req) = NBD_CMD_WRITE; | |
2f012508 | 478 | if (nbd->flags & NBD_FLAG_READ_ONLY) { |
f4507164 | 479 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 | 480 | "Write on read-only\n"); |
48cf6061 LV |
481 | goto error_out; |
482 | } | |
483 | } | |
484 | ||
485 | req->errors = 0; | |
486 | ||
f4507164 WG |
487 | mutex_lock(&nbd->tx_lock); |
488 | if (unlikely(!nbd->sock)) { | |
489 | mutex_unlock(&nbd->tx_lock); | |
490 | dev_err(disk_to_dev(nbd->disk), | |
7f1b90f9 | 491 | "Attempted send on closed socket\n"); |
15746fca | 492 | goto error_out; |
48cf6061 LV |
493 | } |
494 | ||
f4507164 | 495 | nbd->active_req = req; |
48cf6061 | 496 | |
f4507164 WG |
497 | if (nbd_send_req(nbd, req) != 0) { |
498 | dev_err(disk_to_dev(nbd->disk), "Request send failed\n"); | |
48cf6061 LV |
499 | req->errors++; |
500 | nbd_end_request(req); | |
501 | } else { | |
f4507164 | 502 | spin_lock(&nbd->queue_lock); |
01ff5dbc | 503 | list_add_tail(&req->queuelist, &nbd->queue_head); |
f4507164 | 504 | spin_unlock(&nbd->queue_lock); |
48cf6061 LV |
505 | } |
506 | ||
f4507164 WG |
507 | nbd->active_req = NULL; |
508 | mutex_unlock(&nbd->tx_lock); | |
509 | wake_up_all(&nbd->active_wq); | |
48cf6061 LV |
510 | |
511 | return; | |
512 | ||
513 | error_out: | |
514 | req->errors++; | |
515 | nbd_end_request(req); | |
516 | } | |
517 | ||
518 | static int nbd_thread(void *data) | |
519 | { | |
f4507164 | 520 | struct nbd_device *nbd = data; |
48cf6061 LV |
521 | struct request *req; |
522 | ||
523 | set_user_nice(current, -20); | |
f4507164 | 524 | while (!kthread_should_stop() || !list_empty(&nbd->waiting_queue)) { |
48cf6061 | 525 | /* wait for something to do */ |
f4507164 | 526 | wait_event_interruptible(nbd->waiting_wq, |
48cf6061 | 527 | kthread_should_stop() || |
f4507164 | 528 | !list_empty(&nbd->waiting_queue)); |
48cf6061 LV |
529 | |
530 | /* extract request */ | |
f4507164 | 531 | if (list_empty(&nbd->waiting_queue)) |
48cf6061 LV |
532 | continue; |
533 | ||
f4507164 WG |
534 | spin_lock_irq(&nbd->queue_lock); |
535 | req = list_entry(nbd->waiting_queue.next, struct request, | |
48cf6061 LV |
536 | queuelist); |
537 | list_del_init(&req->queuelist); | |
f4507164 | 538 | spin_unlock_irq(&nbd->queue_lock); |
48cf6061 LV |
539 | |
540 | /* handle request */ | |
f4507164 | 541 | nbd_handle_req(nbd, req); |
48cf6061 LV |
542 | } |
543 | return 0; | |
544 | } | |
545 | ||
1da177e4 LT |
546 | /* |
547 | * We always wait for result of write, for now. It would be nice to make it optional | |
548 | * in future | |
f4507164 | 549 | * if ((rq_data_dir(req) == WRITE) && (nbd->flags & NBD_WRITE_NOCHK)) |
1da177e4 LT |
550 | * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } |
551 | */ | |
552 | ||
15746fca | 553 | static void do_nbd_request(struct request_queue *q) |
1da177e4 LT |
554 | { |
555 | struct request *req; | |
556 | ||
9934c8c0 | 557 | while ((req = blk_fetch_request(q)) != NULL) { |
f4507164 | 558 | struct nbd_device *nbd; |
1da177e4 | 559 | |
48cf6061 LV |
560 | spin_unlock_irq(q->queue_lock); |
561 | ||
4aff5e23 JA |
562 | dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n", |
563 | req->rq_disk->disk_name, req, req->cmd_type); | |
1da177e4 | 564 | |
f4507164 | 565 | nbd = req->rq_disk->private_data; |
1da177e4 | 566 | |
f4507164 | 567 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 568 | |
f4507164 WG |
569 | if (unlikely(!nbd->sock)) { |
570 | dev_err(disk_to_dev(nbd->disk), | |
7f1b90f9 | 571 | "Attempted send on closed socket\n"); |
4d48a542 PC |
572 | req->errors++; |
573 | nbd_end_request(req); | |
574 | spin_lock_irq(q->queue_lock); | |
575 | continue; | |
576 | } | |
577 | ||
f4507164 WG |
578 | spin_lock_irq(&nbd->queue_lock); |
579 | list_add_tail(&req->queuelist, &nbd->waiting_queue); | |
580 | spin_unlock_irq(&nbd->queue_lock); | |
1da177e4 | 581 | |
f4507164 | 582 | wake_up(&nbd->waiting_wq); |
4b2f0260 | 583 | |
1da177e4 | 584 | spin_lock_irq(q->queue_lock); |
1da177e4 | 585 | } |
1da177e4 LT |
586 | } |
587 | ||
1a2ad211 | 588 | /* Must be called with tx_lock held */ |
1da177e4 | 589 | |
f4507164 | 590 | static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, |
1a2ad211 PM |
591 | unsigned int cmd, unsigned long arg) |
592 | { | |
1da177e4 | 593 | switch (cmd) { |
1a2ad211 PM |
594 | case NBD_DISCONNECT: { |
595 | struct request sreq; | |
596 | ||
f4507164 | 597 | dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n"); |
1a2ad211 | 598 | |
4f54eec8 | 599 | blk_rq_init(NULL, &sreq); |
4aff5e23 | 600 | sreq.cmd_type = REQ_TYPE_SPECIAL; |
1da177e4 | 601 | nbd_cmd(&sreq) = NBD_CMD_DISC; |
f4507164 | 602 | if (!nbd->sock) |
1da177e4 | 603 | return -EINVAL; |
f4507164 | 604 | nbd_send_req(nbd, &sreq); |
1da177e4 | 605 | return 0; |
1a2ad211 | 606 | } |
1da177e4 | 607 | |
1a2ad211 PM |
608 | case NBD_CLEAR_SOCK: { |
609 | struct file *file; | |
610 | ||
f4507164 WG |
611 | nbd->sock = NULL; |
612 | file = nbd->file; | |
613 | nbd->file = NULL; | |
614 | nbd_clear_que(nbd); | |
615 | BUG_ON(!list_empty(&nbd->queue_head)); | |
fded4e09 | 616 | BUG_ON(!list_empty(&nbd->waiting_queue)); |
1da177e4 LT |
617 | if (file) |
618 | fput(file); | |
1a2ad211 PM |
619 | return 0; |
620 | } | |
621 | ||
622 | case NBD_SET_SOCK: { | |
623 | struct file *file; | |
f4507164 | 624 | if (nbd->file) |
1da177e4 | 625 | return -EBUSY; |
1da177e4 LT |
626 | file = fget(arg); |
627 | if (file) { | |
496ad9aa | 628 | struct inode *inode = file_inode(file); |
1da177e4 | 629 | if (S_ISSOCK(inode->i_mode)) { |
f4507164 WG |
630 | nbd->file = file; |
631 | nbd->sock = SOCKET_I(inode); | |
d71a6d73 LV |
632 | if (max_part > 0) |
633 | bdev->bd_invalidated = 1; | |
1a2ad211 | 634 | return 0; |
1da177e4 LT |
635 | } else { |
636 | fput(file); | |
637 | } | |
638 | } | |
1a2ad211 PM |
639 | return -EINVAL; |
640 | } | |
641 | ||
1da177e4 | 642 | case NBD_SET_BLKSIZE: |
f4507164 WG |
643 | nbd->blksize = arg; |
644 | nbd->bytesize &= ~(nbd->blksize-1); | |
645 | bdev->bd_inode->i_size = nbd->bytesize; | |
646 | set_blocksize(bdev, nbd->blksize); | |
647 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
1da177e4 | 648 | return 0; |
1a2ad211 | 649 | |
1da177e4 | 650 | case NBD_SET_SIZE: |
f4507164 WG |
651 | nbd->bytesize = arg & ~(nbd->blksize-1); |
652 | bdev->bd_inode->i_size = nbd->bytesize; | |
653 | set_blocksize(bdev, nbd->blksize); | |
654 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
1da177e4 | 655 | return 0; |
1a2ad211 | 656 | |
7fdfd406 | 657 | case NBD_SET_TIMEOUT: |
f4507164 | 658 | nbd->xmit_timeout = arg * HZ; |
7fdfd406 | 659 | return 0; |
1a2ad211 | 660 | |
2f012508 PC |
661 | case NBD_SET_FLAGS: |
662 | nbd->flags = arg; | |
663 | return 0; | |
664 | ||
1da177e4 | 665 | case NBD_SET_SIZE_BLOCKS: |
f4507164 WG |
666 | nbd->bytesize = ((u64) arg) * nbd->blksize; |
667 | bdev->bd_inode->i_size = nbd->bytesize; | |
668 | set_blocksize(bdev, nbd->blksize); | |
669 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
1da177e4 | 670 | return 0; |
1a2ad211 PM |
671 | |
672 | case NBD_DO_IT: { | |
673 | struct task_struct *thread; | |
674 | struct file *file; | |
675 | int error; | |
676 | ||
f4507164 | 677 | if (nbd->pid) |
c91192d6 | 678 | return -EBUSY; |
f4507164 | 679 | if (!nbd->file) |
1da177e4 | 680 | return -EINVAL; |
1a2ad211 | 681 | |
f4507164 | 682 | mutex_unlock(&nbd->tx_lock); |
1a2ad211 | 683 | |
a336d298 PC |
684 | if (nbd->flags & NBD_FLAG_SEND_TRIM) |
685 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, | |
686 | nbd->disk->queue); | |
687 | ||
f4507164 | 688 | thread = kthread_create(nbd_thread, nbd, nbd->disk->disk_name); |
1a2ad211 | 689 | if (IS_ERR(thread)) { |
f4507164 | 690 | mutex_lock(&nbd->tx_lock); |
48cf6061 | 691 | return PTR_ERR(thread); |
1a2ad211 | 692 | } |
48cf6061 | 693 | wake_up_process(thread); |
f4507164 | 694 | error = nbd_do_it(nbd); |
48cf6061 | 695 | kthread_stop(thread); |
1a2ad211 | 696 | |
f4507164 | 697 | mutex_lock(&nbd->tx_lock); |
84963048 WC |
698 | if (error) |
699 | return error; | |
f4507164 WG |
700 | sock_shutdown(nbd, 0); |
701 | file = nbd->file; | |
702 | nbd->file = NULL; | |
703 | nbd_clear_que(nbd); | |
704 | dev_warn(disk_to_dev(nbd->disk), "queue cleared\n"); | |
a336d298 | 705 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); |
1da177e4 LT |
706 | if (file) |
707 | fput(file); | |
f4507164 | 708 | nbd->bytesize = 0; |
a8cdc308 | 709 | bdev->bd_inode->i_size = 0; |
f4507164 | 710 | set_capacity(nbd->disk, 0); |
d71a6d73 | 711 | if (max_part > 0) |
a8cdc308 | 712 | ioctl_by_bdev(bdev, BLKRRPART, 0); |
f4507164 | 713 | return nbd->harderror; |
1a2ad211 PM |
714 | } |
715 | ||
1da177e4 | 716 | case NBD_CLEAR_QUE: |
4b2f0260 HX |
717 | /* |
718 | * This is for compatibility only. The queue is always cleared | |
719 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
720 | */ | |
f4507164 | 721 | BUG_ON(!nbd->sock && !list_empty(&nbd->queue_head)); |
1da177e4 | 722 | return 0; |
1a2ad211 | 723 | |
1da177e4 | 724 | case NBD_PRINT_DEBUG: |
f4507164 | 725 | dev_info(disk_to_dev(nbd->disk), |
5eedf541 | 726 | "next = %p, prev = %p, head = %p\n", |
f4507164 WG |
727 | nbd->queue_head.next, nbd->queue_head.prev, |
728 | &nbd->queue_head); | |
1da177e4 LT |
729 | return 0; |
730 | } | |
1a2ad211 PM |
731 | return -ENOTTY; |
732 | } | |
733 | ||
734 | static int nbd_ioctl(struct block_device *bdev, fmode_t mode, | |
735 | unsigned int cmd, unsigned long arg) | |
736 | { | |
f4507164 | 737 | struct nbd_device *nbd = bdev->bd_disk->private_data; |
1a2ad211 PM |
738 | int error; |
739 | ||
740 | if (!capable(CAP_SYS_ADMIN)) | |
741 | return -EPERM; | |
742 | ||
f4507164 | 743 | BUG_ON(nbd->magic != NBD_MAGIC); |
1a2ad211 PM |
744 | |
745 | /* Anyone capable of this syscall can do *real bad* things */ | |
746 | dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", | |
f4507164 | 747 | nbd->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); |
1a2ad211 | 748 | |
f4507164 WG |
749 | mutex_lock(&nbd->tx_lock); |
750 | error = __nbd_ioctl(bdev, nbd, cmd, arg); | |
751 | mutex_unlock(&nbd->tx_lock); | |
1a2ad211 PM |
752 | |
753 | return error; | |
1da177e4 LT |
754 | } |
755 | ||
83d5cde4 | 756 | static const struct block_device_operations nbd_fops = |
1da177e4 LT |
757 | { |
758 | .owner = THIS_MODULE, | |
8a6cfeb6 | 759 | .ioctl = nbd_ioctl, |
1da177e4 LT |
760 | }; |
761 | ||
762 | /* | |
763 | * And here should be modules and kernel interface | |
764 | * (Just smiley confuses emacs :-) | |
765 | */ | |
766 | ||
767 | static int __init nbd_init(void) | |
768 | { | |
769 | int err = -ENOMEM; | |
770 | int i; | |
d71a6d73 | 771 | int part_shift; |
1da177e4 | 772 | |
5b7b18cc | 773 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 774 | |
d71a6d73 | 775 | if (max_part < 0) { |
7742ce4a | 776 | printk(KERN_ERR "nbd: max_part must be >= 0\n"); |
d71a6d73 LV |
777 | return -EINVAL; |
778 | } | |
779 | ||
f3944d61 SW |
780 | nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL); |
781 | if (!nbd_dev) | |
782 | return -ENOMEM; | |
783 | ||
d71a6d73 | 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 | ||
40be0c28 | 805 | for (i = 0; i < nbds_max; i++) { |
d71a6d73 | 806 | struct gendisk *disk = alloc_disk(1 << part_shift); |
1da177e4 LT |
807 | if (!disk) |
808 | goto out; | |
809 | nbd_dev[i].disk = disk; | |
810 | /* | |
811 | * The new linux 2.5 block layer implementation requires | |
812 | * every gendisk to have its very own request_queue struct. | |
813 | * These structs are big so we dynamically allocate them. | |
814 | */ | |
815 | disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); | |
816 | if (!disk->queue) { | |
817 | put_disk(disk); | |
818 | goto out; | |
819 | } | |
31dcfab0 JA |
820 | /* |
821 | * Tell the block layer that we are not a rotational device | |
822 | */ | |
823 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue); | |
a336d298 PC |
824 | disk->queue->limits.discard_granularity = 512; |
825 | disk->queue->limits.max_discard_sectors = UINT_MAX; | |
826 | disk->queue->limits.discard_zeroes_data = 0; | |
1da177e4 LT |
827 | } |
828 | ||
829 | if (register_blkdev(NBD_MAJOR, "nbd")) { | |
830 | err = -EIO; | |
831 | goto out; | |
832 | } | |
833 | ||
834 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); | |
835 | dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); | |
836 | ||
40be0c28 | 837 | for (i = 0; i < nbds_max; i++) { |
1da177e4 LT |
838 | struct gendisk *disk = nbd_dev[i].disk; |
839 | nbd_dev[i].file = NULL; | |
f4507164 | 840 | nbd_dev[i].magic = NBD_MAGIC; |
1da177e4 | 841 | nbd_dev[i].flags = 0; |
48cf6061 | 842 | INIT_LIST_HEAD(&nbd_dev[i].waiting_queue); |
1da177e4 LT |
843 | spin_lock_init(&nbd_dev[i].queue_lock); |
844 | INIT_LIST_HEAD(&nbd_dev[i].queue_head); | |
82d4dc5a | 845 | mutex_init(&nbd_dev[i].tx_lock); |
4b2f0260 | 846 | init_waitqueue_head(&nbd_dev[i].active_wq); |
48cf6061 | 847 | init_waitqueue_head(&nbd_dev[i].waiting_wq); |
1da177e4 | 848 | nbd_dev[i].blksize = 1024; |
4b86a872 | 849 | nbd_dev[i].bytesize = 0; |
1da177e4 | 850 | disk->major = NBD_MAJOR; |
d71a6d73 | 851 | disk->first_minor = i << part_shift; |
1da177e4 LT |
852 | disk->fops = &nbd_fops; |
853 | disk->private_data = &nbd_dev[i]; | |
1da177e4 | 854 | sprintf(disk->disk_name, "nbd%d", i); |
4b86a872 | 855 | set_capacity(disk, 0); |
1da177e4 LT |
856 | add_disk(disk); |
857 | } | |
858 | ||
859 | return 0; | |
860 | out: | |
861 | while (i--) { | |
862 | blk_cleanup_queue(nbd_dev[i].disk->queue); | |
863 | put_disk(nbd_dev[i].disk); | |
864 | } | |
f3944d61 | 865 | kfree(nbd_dev); |
1da177e4 LT |
866 | return err; |
867 | } | |
868 | ||
869 | static void __exit nbd_cleanup(void) | |
870 | { | |
871 | int i; | |
40be0c28 | 872 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 873 | struct gendisk *disk = nbd_dev[i].disk; |
40be0c28 | 874 | nbd_dev[i].magic = 0; |
1da177e4 LT |
875 | if (disk) { |
876 | del_gendisk(disk); | |
877 | blk_cleanup_queue(disk->queue); | |
878 | put_disk(disk); | |
879 | } | |
880 | } | |
1da177e4 | 881 | unregister_blkdev(NBD_MAJOR, "nbd"); |
f3944d61 | 882 | kfree(nbd_dev); |
1da177e4 LT |
883 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); |
884 | } | |
885 | ||
886 | module_init(nbd_init); | |
887 | module_exit(nbd_cleanup); | |
888 | ||
889 | MODULE_DESCRIPTION("Network Block Device"); | |
890 | MODULE_LICENSE("GPL"); | |
891 | ||
40be0c28 | 892 | module_param(nbds_max, int, 0444); |
d71a6d73 LV |
893 | MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); |
894 | module_param(max_part, int, 0444); | |
895 | MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)"); | |
1da177e4 LT |
896 | #ifndef NDEBUG |
897 | module_param(debugflags, int, 0644); | |
898 | MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); | |
899 | #endif |