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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"; | |
81 | case NBD_DO_IT: return "do-it"; | |
82 | case NBD_CLEAR_SOCK: return "clear-sock"; | |
83 | case NBD_CLEAR_QUE: return "clear-que"; | |
84 | case NBD_PRINT_DEBUG: return "print-debug"; | |
85 | case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; | |
86 | case NBD_DISCONNECT: return "disconnect"; | |
87 | case BLKROSET: return "set-read-only"; | |
88 | case BLKFLSBUF: return "flush-buffer-cache"; | |
89 | } | |
90 | return "unknown"; | |
91 | } | |
92 | ||
93 | static const char *nbdcmd_to_ascii(int cmd) | |
94 | { | |
95 | switch (cmd) { | |
96 | case NBD_CMD_READ: return "read"; | |
97 | case NBD_CMD_WRITE: return "write"; | |
98 | case NBD_CMD_DISC: return "disconnect"; | |
99 | } | |
100 | return "invalid"; | |
101 | } | |
102 | #endif /* NDEBUG */ | |
103 | ||
104 | static void nbd_end_request(struct request *req) | |
105 | { | |
097c94a4 | 106 | int error = req->errors ? -EIO : 0; |
165125e1 | 107 | struct request_queue *q = req->q; |
1da177e4 LT |
108 | unsigned long flags; |
109 | ||
110 | dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, | |
097c94a4 | 111 | req, error ? "failed" : "done"); |
1da177e4 LT |
112 | |
113 | spin_lock_irqsave(q->queue_lock, flags); | |
1011c1b9 | 114 | __blk_end_request_all(req, error); |
1da177e4 LT |
115 | spin_unlock_irqrestore(q->queue_lock, flags); |
116 | } | |
117 | ||
f4507164 | 118 | static void sock_shutdown(struct nbd_device *nbd, int lock) |
7fdfd406 PC |
119 | { |
120 | /* Forcibly shutdown the socket causing all listeners | |
121 | * to error | |
122 | * | |
123 | * FIXME: This code is duplicated from sys_shutdown, but | |
124 | * there should be a more generic interface rather than | |
125 | * calling socket ops directly here */ | |
126 | if (lock) | |
f4507164 WG |
127 | mutex_lock(&nbd->tx_lock); |
128 | if (nbd->sock) { | |
129 | dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n"); | |
130 | kernel_sock_shutdown(nbd->sock, SHUT_RDWR); | |
131 | nbd->sock = NULL; | |
7fdfd406 PC |
132 | } |
133 | if (lock) | |
f4507164 | 134 | mutex_unlock(&nbd->tx_lock); |
7fdfd406 PC |
135 | } |
136 | ||
137 | static void nbd_xmit_timeout(unsigned long arg) | |
138 | { | |
139 | struct task_struct *task = (struct task_struct *)arg; | |
140 | ||
141 | printk(KERN_WARNING "nbd: killing hung xmit (%s, pid: %d)\n", | |
142 | task->comm, task->pid); | |
143 | force_sig(SIGKILL, task); | |
144 | } | |
145 | ||
1da177e4 LT |
146 | /* |
147 | * Send or receive packet. | |
148 | */ | |
f4507164 | 149 | static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size, |
1da177e4 LT |
150 | int msg_flags) |
151 | { | |
f4507164 | 152 | struct socket *sock = nbd->sock; |
1da177e4 LT |
153 | int result; |
154 | struct msghdr msg; | |
155 | struct kvec iov; | |
be0ef957 | 156 | sigset_t blocked, oldset; |
7f338fe4 | 157 | unsigned long pflags = current->flags; |
1da177e4 | 158 | |
ffc41cf8 | 159 | if (unlikely(!sock)) { |
f4507164 | 160 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
161 | "Attempted %s on closed socket in sock_xmit\n", |
162 | (send ? "send" : "recv")); | |
ffc41cf8 MS |
163 | return -EINVAL; |
164 | } | |
165 | ||
1da177e4 LT |
166 | /* Allow interception of SIGKILL only |
167 | * Don't allow other signals to interrupt the transmission */ | |
be0ef957 ON |
168 | siginitsetinv(&blocked, sigmask(SIGKILL)); |
169 | sigprocmask(SIG_SETMASK, &blocked, &oldset); | |
1da177e4 | 170 | |
7f338fe4 | 171 | current->flags |= PF_MEMALLOC; |
1da177e4 | 172 | do { |
7f338fe4 | 173 | sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC; |
1da177e4 LT |
174 | iov.iov_base = buf; |
175 | iov.iov_len = size; | |
176 | msg.msg_name = NULL; | |
177 | msg.msg_namelen = 0; | |
178 | msg.msg_control = NULL; | |
179 | msg.msg_controllen = 0; | |
1da177e4 LT |
180 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
181 | ||
7fdfd406 PC |
182 | if (send) { |
183 | struct timer_list ti; | |
184 | ||
f4507164 | 185 | if (nbd->xmit_timeout) { |
7fdfd406 PC |
186 | init_timer(&ti); |
187 | ti.function = nbd_xmit_timeout; | |
188 | ti.data = (unsigned long)current; | |
f4507164 | 189 | ti.expires = jiffies + nbd->xmit_timeout; |
7fdfd406 PC |
190 | add_timer(&ti); |
191 | } | |
1da177e4 | 192 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
f4507164 | 193 | if (nbd->xmit_timeout) |
7fdfd406 PC |
194 | del_timer_sync(&ti); |
195 | } else | |
35fbf5bc NK |
196 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, |
197 | msg.msg_flags); | |
1da177e4 LT |
198 | |
199 | if (signal_pending(current)) { | |
200 | siginfo_t info; | |
1da177e4 | 201 | printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", |
ba25f9dc | 202 | task_pid_nr(current), current->comm, |
be0ef957 | 203 | dequeue_signal_lock(current, ¤t->blocked, &info)); |
1da177e4 | 204 | result = -EINTR; |
f4507164 | 205 | sock_shutdown(nbd, !send); |
1da177e4 LT |
206 | break; |
207 | } | |
208 | ||
209 | if (result <= 0) { | |
210 | if (result == 0) | |
211 | result = -EPIPE; /* short read */ | |
212 | break; | |
213 | } | |
214 | size -= result; | |
215 | buf += result; | |
216 | } while (size > 0); | |
217 | ||
be0ef957 | 218 | sigprocmask(SIG_SETMASK, &oldset, NULL); |
7f338fe4 | 219 | tsk_restore_flags(current, pflags, PF_MEMALLOC); |
1da177e4 LT |
220 | |
221 | return result; | |
222 | } | |
223 | ||
f4507164 | 224 | static inline int sock_send_bvec(struct nbd_device *nbd, struct bio_vec *bvec, |
1da177e4 LT |
225 | int flags) |
226 | { | |
227 | int result; | |
228 | void *kaddr = kmap(bvec->bv_page); | |
f4507164 WG |
229 | result = sock_xmit(nbd, 1, kaddr + bvec->bv_offset, |
230 | bvec->bv_len, flags); | |
1da177e4 LT |
231 | kunmap(bvec->bv_page); |
232 | return result; | |
233 | } | |
234 | ||
7fdfd406 | 235 | /* always call with the tx_lock held */ |
f4507164 | 236 | static int nbd_send_req(struct nbd_device *nbd, struct request *req) |
1da177e4 | 237 | { |
5705f702 | 238 | int result, flags; |
1da177e4 | 239 | struct nbd_request request; |
1011c1b9 | 240 | unsigned long size = blk_rq_bytes(req); |
1da177e4 LT |
241 | |
242 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
243 | request.type = htonl(nbd_cmd(req)); | |
83096ebf | 244 | request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); |
1da177e4 LT |
245 | request.len = htonl(size); |
246 | memcpy(request.handle, &req, sizeof(req)); | |
247 | ||
83096ebf | 248 | dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%uB)\n", |
f4507164 | 249 | nbd->disk->disk_name, req, |
1da177e4 | 250 | nbdcmd_to_ascii(nbd_cmd(req)), |
83096ebf | 251 | (unsigned long long)blk_rq_pos(req) << 9, |
1011c1b9 | 252 | blk_rq_bytes(req)); |
f4507164 | 253 | result = sock_xmit(nbd, 1, &request, sizeof(request), |
7fdfd406 | 254 | (nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0); |
1da177e4 | 255 | if (result <= 0) { |
f4507164 | 256 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 | 257 | "Send control failed (result %d)\n", result); |
1da177e4 LT |
258 | goto error_out; |
259 | } | |
260 | ||
261 | if (nbd_cmd(req) == NBD_CMD_WRITE) { | |
5705f702 N |
262 | struct req_iterator iter; |
263 | struct bio_vec *bvec; | |
1da177e4 LT |
264 | /* |
265 | * we are really probing at internals to determine | |
266 | * whether to set MSG_MORE or not... | |
267 | */ | |
5705f702 | 268 | rq_for_each_segment(bvec, req, iter) { |
6c92e699 JA |
269 | flags = 0; |
270 | if (!rq_iter_last(req, iter)) | |
271 | flags = MSG_MORE; | |
272 | dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", | |
f4507164 WG |
273 | nbd->disk->disk_name, req, bvec->bv_len); |
274 | result = sock_send_bvec(nbd, bvec, flags); | |
6c92e699 | 275 | if (result <= 0) { |
f4507164 | 276 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 WC |
277 | "Send data failed (result %d)\n", |
278 | result); | |
6c92e699 JA |
279 | goto error_out; |
280 | } | |
1da177e4 LT |
281 | } |
282 | } | |
1da177e4 LT |
283 | return 0; |
284 | ||
285 | error_out: | |
15746fca | 286 | return -EIO; |
1da177e4 LT |
287 | } |
288 | ||
f4507164 | 289 | static struct request *nbd_find_request(struct nbd_device *nbd, |
0cbc591b | 290 | struct request *xreq) |
1da177e4 | 291 | { |
d2c9740b | 292 | struct request *req, *tmp; |
4b2f0260 | 293 | int err; |
1da177e4 | 294 | |
f4507164 | 295 | err = wait_event_interruptible(nbd->active_wq, nbd->active_req != xreq); |
4b2f0260 HX |
296 | if (unlikely(err)) |
297 | goto out; | |
298 | ||
f4507164 WG |
299 | spin_lock(&nbd->queue_lock); |
300 | list_for_each_entry_safe(req, tmp, &nbd->queue_head, queuelist) { | |
1da177e4 LT |
301 | if (req != xreq) |
302 | continue; | |
303 | list_del_init(&req->queuelist); | |
f4507164 | 304 | spin_unlock(&nbd->queue_lock); |
1da177e4 LT |
305 | return req; |
306 | } | |
f4507164 | 307 | spin_unlock(&nbd->queue_lock); |
4b2f0260 HX |
308 | |
309 | err = -ENOENT; | |
310 | ||
311 | out: | |
312 | return ERR_PTR(err); | |
1da177e4 LT |
313 | } |
314 | ||
f4507164 | 315 | static inline int sock_recv_bvec(struct nbd_device *nbd, struct bio_vec *bvec) |
1da177e4 LT |
316 | { |
317 | int result; | |
318 | void *kaddr = kmap(bvec->bv_page); | |
f4507164 | 319 | result = sock_xmit(nbd, 0, kaddr + bvec->bv_offset, bvec->bv_len, |
1da177e4 LT |
320 | MSG_WAITALL); |
321 | kunmap(bvec->bv_page); | |
322 | return result; | |
323 | } | |
324 | ||
325 | /* NULL returned = something went wrong, inform userspace */ | |
f4507164 | 326 | static struct request *nbd_read_stat(struct nbd_device *nbd) |
1da177e4 LT |
327 | { |
328 | int result; | |
329 | struct nbd_reply reply; | |
330 | struct request *req; | |
1da177e4 LT |
331 | |
332 | reply.magic = 0; | |
f4507164 | 333 | result = sock_xmit(nbd, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 | 334 | if (result <= 0) { |
f4507164 | 335 | dev_err(disk_to_dev(nbd->disk), |
7f1b90f9 | 336 | "Receive control failed (result %d)\n", result); |
1da177e4 LT |
337 | goto harderror; |
338 | } | |
e4b57e08 MF |
339 | |
340 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
f4507164 | 341 | dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n", |
e4b57e08 MF |
342 | (unsigned long)ntohl(reply.magic)); |
343 | result = -EPROTO; | |
344 | goto harderror; | |
345 | } | |
346 | ||
f4507164 | 347 | req = nbd_find_request(nbd, *(struct request **)reply.handle); |
801678c5 | 348 | if (IS_ERR(req)) { |
4b2f0260 HX |
349 | result = PTR_ERR(req); |
350 | if (result != -ENOENT) | |
351 | goto harderror; | |
352 | ||
f4507164 | 353 | dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%p)\n", |
7f1b90f9 | 354 | reply.handle); |
1da177e4 LT |
355 | result = -EBADR; |
356 | goto harderror; | |
357 | } | |
358 | ||
1da177e4 | 359 | if (ntohl(reply.error)) { |
f4507164 | 360 | dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n", |
7f1b90f9 | 361 | ntohl(reply.error)); |
1da177e4 LT |
362 | req->errors++; |
363 | return req; | |
364 | } | |
365 | ||
366 | dprintk(DBG_RX, "%s: request %p: got reply\n", | |
f4507164 | 367 | nbd->disk->disk_name, req); |
1da177e4 | 368 | if (nbd_cmd(req) == NBD_CMD_READ) { |
5705f702 N |
369 | struct req_iterator iter; |
370 | struct bio_vec *bvec; | |
371 | ||
372 | rq_for_each_segment(bvec, req, iter) { | |
f4507164 | 373 | result = sock_recv_bvec(nbd, bvec); |
6c92e699 | 374 | if (result <= 0) { |
f4507164 | 375 | dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", |
7f1b90f9 | 376 | result); |
6c92e699 JA |
377 | req->errors++; |
378 | return req; | |
379 | } | |
380 | dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", | |
f4507164 | 381 | nbd->disk->disk_name, req, bvec->bv_len); |
1da177e4 LT |
382 | } |
383 | } | |
384 | return req; | |
385 | harderror: | |
f4507164 | 386 | nbd->harderror = result; |
1da177e4 LT |
387 | return NULL; |
388 | } | |
389 | ||
edfaa7c3 KS |
390 | static ssize_t pid_show(struct device *dev, |
391 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 392 | { |
edfaa7c3 KS |
393 | struct gendisk *disk = dev_to_disk(dev); |
394 | ||
395 | return sprintf(buf, "%ld\n", | |
6b39bb65 PC |
396 | (long) ((struct nbd_device *)disk->private_data)->pid); |
397 | } | |
398 | ||
edfaa7c3 | 399 | static struct device_attribute pid_attr = { |
01e8ef11 | 400 | .attr = { .name = "pid", .mode = S_IRUGO}, |
6b39bb65 PC |
401 | .show = pid_show, |
402 | }; | |
403 | ||
f4507164 | 404 | static int nbd_do_it(struct nbd_device *nbd) |
1da177e4 LT |
405 | { |
406 | struct request *req; | |
84963048 | 407 | int ret; |
1da177e4 | 408 | |
f4507164 | 409 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 410 | |
7f338fe4 | 411 | sk_set_memalloc(nbd->sock->sk); |
f4507164 WG |
412 | nbd->pid = task_pid_nr(current); |
413 | ret = device_create_file(disk_to_dev(nbd->disk), &pid_attr); | |
84963048 | 414 | if (ret) { |
f4507164 WG |
415 | dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); |
416 | nbd->pid = 0; | |
84963048 WC |
417 | return ret; |
418 | } | |
6b39bb65 | 419 | |
f4507164 | 420 | while ((req = nbd_read_stat(nbd)) != NULL) |
1da177e4 | 421 | nbd_end_request(req); |
6b39bb65 | 422 | |
f4507164 WG |
423 | device_remove_file(disk_to_dev(nbd->disk), &pid_attr); |
424 | nbd->pid = 0; | |
84963048 | 425 | return 0; |
1da177e4 LT |
426 | } |
427 | ||
f4507164 | 428 | static void nbd_clear_que(struct nbd_device *nbd) |
1da177e4 LT |
429 | { |
430 | struct request *req; | |
431 | ||
f4507164 | 432 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 433 | |
4b2f0260 | 434 | /* |
f4507164 | 435 | * Because we have set nbd->sock to NULL under the tx_lock, all |
4b2f0260 HX |
436 | * modifications to the list must have completed by now. For |
437 | * the same reason, the active_req must be NULL. | |
438 | * | |
439 | * As a consequence, we don't need to take the spin lock while | |
440 | * purging the list here. | |
441 | */ | |
f4507164 WG |
442 | BUG_ON(nbd->sock); |
443 | BUG_ON(nbd->active_req); | |
4b2f0260 | 444 | |
f4507164 WG |
445 | while (!list_empty(&nbd->queue_head)) { |
446 | req = list_entry(nbd->queue_head.next, struct request, | |
4b2f0260 HX |
447 | queuelist); |
448 | list_del_init(&req->queuelist); | |
449 | req->errors++; | |
450 | nbd_end_request(req); | |
451 | } | |
1da177e4 LT |
452 | } |
453 | ||
7fdfd406 | 454 | |
f4507164 | 455 | static void nbd_handle_req(struct nbd_device *nbd, struct request *req) |
48cf6061 | 456 | { |
33659ebb | 457 | if (req->cmd_type != REQ_TYPE_FS) |
48cf6061 LV |
458 | goto error_out; |
459 | ||
460 | nbd_cmd(req) = NBD_CMD_READ; | |
461 | if (rq_data_dir(req) == WRITE) { | |
462 | nbd_cmd(req) = NBD_CMD_WRITE; | |
f4507164 WG |
463 | if (nbd->flags & NBD_READ_ONLY) { |
464 | dev_err(disk_to_dev(nbd->disk), | |
7f1b90f9 | 465 | "Write on read-only\n"); |
48cf6061 LV |
466 | goto error_out; |
467 | } | |
468 | } | |
469 | ||
470 | req->errors = 0; | |
471 | ||
f4507164 WG |
472 | mutex_lock(&nbd->tx_lock); |
473 | if (unlikely(!nbd->sock)) { | |
474 | mutex_unlock(&nbd->tx_lock); | |
475 | dev_err(disk_to_dev(nbd->disk), | |
7f1b90f9 | 476 | "Attempted send on closed socket\n"); |
15746fca | 477 | goto error_out; |
48cf6061 LV |
478 | } |
479 | ||
f4507164 | 480 | nbd->active_req = req; |
48cf6061 | 481 | |
f4507164 WG |
482 | if (nbd_send_req(nbd, req) != 0) { |
483 | dev_err(disk_to_dev(nbd->disk), "Request send failed\n"); | |
48cf6061 LV |
484 | req->errors++; |
485 | nbd_end_request(req); | |
486 | } else { | |
f4507164 WG |
487 | spin_lock(&nbd->queue_lock); |
488 | list_add(&req->queuelist, &nbd->queue_head); | |
489 | spin_unlock(&nbd->queue_lock); | |
48cf6061 LV |
490 | } |
491 | ||
f4507164 WG |
492 | nbd->active_req = NULL; |
493 | mutex_unlock(&nbd->tx_lock); | |
494 | wake_up_all(&nbd->active_wq); | |
48cf6061 LV |
495 | |
496 | return; | |
497 | ||
498 | error_out: | |
499 | req->errors++; | |
500 | nbd_end_request(req); | |
501 | } | |
502 | ||
503 | static int nbd_thread(void *data) | |
504 | { | |
f4507164 | 505 | struct nbd_device *nbd = data; |
48cf6061 LV |
506 | struct request *req; |
507 | ||
508 | set_user_nice(current, -20); | |
f4507164 | 509 | while (!kthread_should_stop() || !list_empty(&nbd->waiting_queue)) { |
48cf6061 | 510 | /* wait for something to do */ |
f4507164 | 511 | wait_event_interruptible(nbd->waiting_wq, |
48cf6061 | 512 | kthread_should_stop() || |
f4507164 | 513 | !list_empty(&nbd->waiting_queue)); |
48cf6061 LV |
514 | |
515 | /* extract request */ | |
f4507164 | 516 | if (list_empty(&nbd->waiting_queue)) |
48cf6061 LV |
517 | continue; |
518 | ||
f4507164 WG |
519 | spin_lock_irq(&nbd->queue_lock); |
520 | req = list_entry(nbd->waiting_queue.next, struct request, | |
48cf6061 LV |
521 | queuelist); |
522 | list_del_init(&req->queuelist); | |
f4507164 | 523 | spin_unlock_irq(&nbd->queue_lock); |
48cf6061 LV |
524 | |
525 | /* handle request */ | |
f4507164 | 526 | nbd_handle_req(nbd, req); |
48cf6061 LV |
527 | } |
528 | return 0; | |
529 | } | |
530 | ||
1da177e4 LT |
531 | /* |
532 | * We always wait for result of write, for now. It would be nice to make it optional | |
533 | * in future | |
f4507164 | 534 | * if ((rq_data_dir(req) == WRITE) && (nbd->flags & NBD_WRITE_NOCHK)) |
1da177e4 LT |
535 | * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } |
536 | */ | |
537 | ||
15746fca | 538 | static void do_nbd_request(struct request_queue *q) |
1da177e4 LT |
539 | { |
540 | struct request *req; | |
541 | ||
9934c8c0 | 542 | while ((req = blk_fetch_request(q)) != NULL) { |
f4507164 | 543 | struct nbd_device *nbd; |
1da177e4 | 544 | |
48cf6061 LV |
545 | spin_unlock_irq(q->queue_lock); |
546 | ||
4aff5e23 JA |
547 | dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n", |
548 | req->rq_disk->disk_name, req, req->cmd_type); | |
1da177e4 | 549 | |
f4507164 | 550 | nbd = req->rq_disk->private_data; |
1da177e4 | 551 | |
f4507164 | 552 | BUG_ON(nbd->magic != NBD_MAGIC); |
1da177e4 | 553 | |
f4507164 WG |
554 | if (unlikely(!nbd->sock)) { |
555 | dev_err(disk_to_dev(nbd->disk), | |
7f1b90f9 | 556 | "Attempted send on closed socket\n"); |
4d48a542 PC |
557 | req->errors++; |
558 | nbd_end_request(req); | |
559 | spin_lock_irq(q->queue_lock); | |
560 | continue; | |
561 | } | |
562 | ||
f4507164 WG |
563 | spin_lock_irq(&nbd->queue_lock); |
564 | list_add_tail(&req->queuelist, &nbd->waiting_queue); | |
565 | spin_unlock_irq(&nbd->queue_lock); | |
1da177e4 | 566 | |
f4507164 | 567 | wake_up(&nbd->waiting_wq); |
4b2f0260 | 568 | |
1da177e4 | 569 | spin_lock_irq(q->queue_lock); |
1da177e4 | 570 | } |
1da177e4 LT |
571 | } |
572 | ||
1a2ad211 | 573 | /* Must be called with tx_lock held */ |
1da177e4 | 574 | |
f4507164 | 575 | static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, |
1a2ad211 PM |
576 | unsigned int cmd, unsigned long arg) |
577 | { | |
1da177e4 | 578 | switch (cmd) { |
1a2ad211 PM |
579 | case NBD_DISCONNECT: { |
580 | struct request sreq; | |
581 | ||
f4507164 | 582 | dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n"); |
1a2ad211 | 583 | |
4f54eec8 | 584 | blk_rq_init(NULL, &sreq); |
4aff5e23 | 585 | sreq.cmd_type = REQ_TYPE_SPECIAL; |
1da177e4 | 586 | nbd_cmd(&sreq) = NBD_CMD_DISC; |
f4507164 | 587 | if (!nbd->sock) |
1da177e4 | 588 | return -EINVAL; |
f4507164 | 589 | nbd_send_req(nbd, &sreq); |
1da177e4 | 590 | return 0; |
1a2ad211 | 591 | } |
1da177e4 | 592 | |
1a2ad211 PM |
593 | case NBD_CLEAR_SOCK: { |
594 | struct file *file; | |
595 | ||
f4507164 WG |
596 | nbd->sock = NULL; |
597 | file = nbd->file; | |
598 | nbd->file = NULL; | |
599 | nbd_clear_que(nbd); | |
600 | BUG_ON(!list_empty(&nbd->queue_head)); | |
1da177e4 LT |
601 | if (file) |
602 | fput(file); | |
1a2ad211 PM |
603 | return 0; |
604 | } | |
605 | ||
606 | case NBD_SET_SOCK: { | |
607 | struct file *file; | |
f4507164 | 608 | if (nbd->file) |
1da177e4 | 609 | return -EBUSY; |
1da177e4 LT |
610 | file = fget(arg); |
611 | if (file) { | |
a8cdc308 | 612 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 | 613 | if (S_ISSOCK(inode->i_mode)) { |
f4507164 WG |
614 | nbd->file = file; |
615 | nbd->sock = SOCKET_I(inode); | |
d71a6d73 LV |
616 | if (max_part > 0) |
617 | bdev->bd_invalidated = 1; | |
1a2ad211 | 618 | return 0; |
1da177e4 LT |
619 | } else { |
620 | fput(file); | |
621 | } | |
622 | } | |
1a2ad211 PM |
623 | return -EINVAL; |
624 | } | |
625 | ||
1da177e4 | 626 | case NBD_SET_BLKSIZE: |
f4507164 WG |
627 | nbd->blksize = arg; |
628 | nbd->bytesize &= ~(nbd->blksize-1); | |
629 | bdev->bd_inode->i_size = nbd->bytesize; | |
630 | set_blocksize(bdev, nbd->blksize); | |
631 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
1da177e4 | 632 | return 0; |
1a2ad211 | 633 | |
1da177e4 | 634 | case NBD_SET_SIZE: |
f4507164 WG |
635 | nbd->bytesize = arg & ~(nbd->blksize-1); |
636 | bdev->bd_inode->i_size = nbd->bytesize; | |
637 | set_blocksize(bdev, nbd->blksize); | |
638 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
1da177e4 | 639 | return 0; |
1a2ad211 | 640 | |
7fdfd406 | 641 | case NBD_SET_TIMEOUT: |
f4507164 | 642 | nbd->xmit_timeout = arg * HZ; |
7fdfd406 | 643 | return 0; |
1a2ad211 | 644 | |
1da177e4 | 645 | case NBD_SET_SIZE_BLOCKS: |
f4507164 WG |
646 | nbd->bytesize = ((u64) arg) * nbd->blksize; |
647 | bdev->bd_inode->i_size = nbd->bytesize; | |
648 | set_blocksize(bdev, nbd->blksize); | |
649 | set_capacity(nbd->disk, nbd->bytesize >> 9); | |
1da177e4 | 650 | return 0; |
1a2ad211 PM |
651 | |
652 | case NBD_DO_IT: { | |
653 | struct task_struct *thread; | |
654 | struct file *file; | |
655 | int error; | |
656 | ||
f4507164 | 657 | if (nbd->pid) |
c91192d6 | 658 | return -EBUSY; |
f4507164 | 659 | if (!nbd->file) |
1da177e4 | 660 | return -EINVAL; |
1a2ad211 | 661 | |
f4507164 | 662 | mutex_unlock(&nbd->tx_lock); |
1a2ad211 | 663 | |
f4507164 | 664 | thread = kthread_create(nbd_thread, nbd, nbd->disk->disk_name); |
1a2ad211 | 665 | if (IS_ERR(thread)) { |
f4507164 | 666 | mutex_lock(&nbd->tx_lock); |
48cf6061 | 667 | return PTR_ERR(thread); |
1a2ad211 | 668 | } |
48cf6061 | 669 | wake_up_process(thread); |
f4507164 | 670 | error = nbd_do_it(nbd); |
48cf6061 | 671 | kthread_stop(thread); |
1a2ad211 | 672 | |
f4507164 | 673 | mutex_lock(&nbd->tx_lock); |
84963048 WC |
674 | if (error) |
675 | return error; | |
f4507164 WG |
676 | sock_shutdown(nbd, 0); |
677 | file = nbd->file; | |
678 | nbd->file = NULL; | |
679 | nbd_clear_que(nbd); | |
680 | dev_warn(disk_to_dev(nbd->disk), "queue cleared\n"); | |
1da177e4 LT |
681 | if (file) |
682 | fput(file); | |
f4507164 | 683 | nbd->bytesize = 0; |
a8cdc308 | 684 | bdev->bd_inode->i_size = 0; |
f4507164 | 685 | set_capacity(nbd->disk, 0); |
d71a6d73 | 686 | if (max_part > 0) |
a8cdc308 | 687 | ioctl_by_bdev(bdev, BLKRRPART, 0); |
f4507164 | 688 | return nbd->harderror; |
1a2ad211 PM |
689 | } |
690 | ||
1da177e4 | 691 | case NBD_CLEAR_QUE: |
4b2f0260 HX |
692 | /* |
693 | * This is for compatibility only. The queue is always cleared | |
694 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
695 | */ | |
f4507164 | 696 | BUG_ON(!nbd->sock && !list_empty(&nbd->queue_head)); |
1da177e4 | 697 | return 0; |
1a2ad211 | 698 | |
1da177e4 | 699 | case NBD_PRINT_DEBUG: |
f4507164 | 700 | dev_info(disk_to_dev(nbd->disk), |
5eedf541 | 701 | "next = %p, prev = %p, head = %p\n", |
f4507164 WG |
702 | nbd->queue_head.next, nbd->queue_head.prev, |
703 | &nbd->queue_head); | |
1da177e4 LT |
704 | return 0; |
705 | } | |
1a2ad211 PM |
706 | return -ENOTTY; |
707 | } | |
708 | ||
709 | static int nbd_ioctl(struct block_device *bdev, fmode_t mode, | |
710 | unsigned int cmd, unsigned long arg) | |
711 | { | |
f4507164 | 712 | struct nbd_device *nbd = bdev->bd_disk->private_data; |
1a2ad211 PM |
713 | int error; |
714 | ||
715 | if (!capable(CAP_SYS_ADMIN)) | |
716 | return -EPERM; | |
717 | ||
f4507164 | 718 | BUG_ON(nbd->magic != NBD_MAGIC); |
1a2ad211 PM |
719 | |
720 | /* Anyone capable of this syscall can do *real bad* things */ | |
721 | dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", | |
f4507164 | 722 | nbd->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); |
1a2ad211 | 723 | |
f4507164 WG |
724 | mutex_lock(&nbd->tx_lock); |
725 | error = __nbd_ioctl(bdev, nbd, cmd, arg); | |
726 | mutex_unlock(&nbd->tx_lock); | |
1a2ad211 PM |
727 | |
728 | return error; | |
1da177e4 LT |
729 | } |
730 | ||
83d5cde4 | 731 | static const struct block_device_operations nbd_fops = |
1da177e4 LT |
732 | { |
733 | .owner = THIS_MODULE, | |
8a6cfeb6 | 734 | .ioctl = nbd_ioctl, |
1da177e4 LT |
735 | }; |
736 | ||
737 | /* | |
738 | * And here should be modules and kernel interface | |
739 | * (Just smiley confuses emacs :-) | |
740 | */ | |
741 | ||
742 | static int __init nbd_init(void) | |
743 | { | |
744 | int err = -ENOMEM; | |
745 | int i; | |
d71a6d73 | 746 | int part_shift; |
1da177e4 | 747 | |
5b7b18cc | 748 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 749 | |
d71a6d73 | 750 | if (max_part < 0) { |
7742ce4a | 751 | printk(KERN_ERR "nbd: max_part must be >= 0\n"); |
d71a6d73 LV |
752 | return -EINVAL; |
753 | } | |
754 | ||
f3944d61 SW |
755 | nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL); |
756 | if (!nbd_dev) | |
757 | return -ENOMEM; | |
758 | ||
d71a6d73 | 759 | part_shift = 0; |
5988ce23 | 760 | if (max_part > 0) { |
d71a6d73 LV |
761 | part_shift = fls(max_part); |
762 | ||
5988ce23 NK |
763 | /* |
764 | * Adjust max_part according to part_shift as it is exported | |
765 | * to user space so that user can know the max number of | |
766 | * partition kernel should be able to manage. | |
767 | * | |
768 | * Note that -1 is required because partition 0 is reserved | |
769 | * for the whole disk. | |
770 | */ | |
771 | max_part = (1UL << part_shift) - 1; | |
772 | } | |
773 | ||
3b271082 NK |
774 | if ((1UL << part_shift) > DISK_MAX_PARTS) |
775 | return -EINVAL; | |
776 | ||
777 | if (nbds_max > 1UL << (MINORBITS - part_shift)) | |
778 | return -EINVAL; | |
779 | ||
40be0c28 | 780 | for (i = 0; i < nbds_max; i++) { |
d71a6d73 | 781 | struct gendisk *disk = alloc_disk(1 << part_shift); |
1da177e4 LT |
782 | if (!disk) |
783 | goto out; | |
784 | nbd_dev[i].disk = disk; | |
785 | /* | |
786 | * The new linux 2.5 block layer implementation requires | |
787 | * every gendisk to have its very own request_queue struct. | |
788 | * These structs are big so we dynamically allocate them. | |
789 | */ | |
790 | disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); | |
791 | if (!disk->queue) { | |
792 | put_disk(disk); | |
793 | goto out; | |
794 | } | |
31dcfab0 JA |
795 | /* |
796 | * Tell the block layer that we are not a rotational device | |
797 | */ | |
798 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue); | |
1da177e4 LT |
799 | } |
800 | ||
801 | if (register_blkdev(NBD_MAJOR, "nbd")) { | |
802 | err = -EIO; | |
803 | goto out; | |
804 | } | |
805 | ||
806 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); | |
807 | dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); | |
808 | ||
40be0c28 | 809 | for (i = 0; i < nbds_max; i++) { |
1da177e4 LT |
810 | struct gendisk *disk = nbd_dev[i].disk; |
811 | nbd_dev[i].file = NULL; | |
f4507164 | 812 | nbd_dev[i].magic = NBD_MAGIC; |
1da177e4 | 813 | nbd_dev[i].flags = 0; |
48cf6061 | 814 | INIT_LIST_HEAD(&nbd_dev[i].waiting_queue); |
1da177e4 LT |
815 | spin_lock_init(&nbd_dev[i].queue_lock); |
816 | INIT_LIST_HEAD(&nbd_dev[i].queue_head); | |
82d4dc5a | 817 | mutex_init(&nbd_dev[i].tx_lock); |
4b2f0260 | 818 | init_waitqueue_head(&nbd_dev[i].active_wq); |
48cf6061 | 819 | init_waitqueue_head(&nbd_dev[i].waiting_wq); |
1da177e4 | 820 | nbd_dev[i].blksize = 1024; |
4b86a872 | 821 | nbd_dev[i].bytesize = 0; |
1da177e4 | 822 | disk->major = NBD_MAJOR; |
d71a6d73 | 823 | disk->first_minor = i << part_shift; |
1da177e4 LT |
824 | disk->fops = &nbd_fops; |
825 | disk->private_data = &nbd_dev[i]; | |
1da177e4 | 826 | sprintf(disk->disk_name, "nbd%d", i); |
4b86a872 | 827 | set_capacity(disk, 0); |
1da177e4 LT |
828 | add_disk(disk); |
829 | } | |
830 | ||
831 | return 0; | |
832 | out: | |
833 | while (i--) { | |
834 | blk_cleanup_queue(nbd_dev[i].disk->queue); | |
835 | put_disk(nbd_dev[i].disk); | |
836 | } | |
f3944d61 | 837 | kfree(nbd_dev); |
1da177e4 LT |
838 | return err; |
839 | } | |
840 | ||
841 | static void __exit nbd_cleanup(void) | |
842 | { | |
843 | int i; | |
40be0c28 | 844 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 845 | struct gendisk *disk = nbd_dev[i].disk; |
40be0c28 | 846 | nbd_dev[i].magic = 0; |
1da177e4 LT |
847 | if (disk) { |
848 | del_gendisk(disk); | |
849 | blk_cleanup_queue(disk->queue); | |
850 | put_disk(disk); | |
851 | } | |
852 | } | |
1da177e4 | 853 | unregister_blkdev(NBD_MAJOR, "nbd"); |
f3944d61 | 854 | kfree(nbd_dev); |
1da177e4 LT |
855 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); |
856 | } | |
857 | ||
858 | module_init(nbd_init); | |
859 | module_exit(nbd_cleanup); | |
860 | ||
861 | MODULE_DESCRIPTION("Network Block Device"); | |
862 | MODULE_LICENSE("GPL"); | |
863 | ||
40be0c28 | 864 | module_param(nbds_max, int, 0444); |
d71a6d73 LV |
865 | MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); |
866 | module_param(max_part, int, 0444); | |
867 | MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)"); | |
1da177e4 LT |
868 | #ifndef NDEBUG |
869 | module_param(debugflags, int, 0644); | |
870 | MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); | |
871 | #endif |