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 | * | |
7 | * Copyright 1997-2000 Pavel Machek <pavel@ucw.cz> | |
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> | |
4b2f0260 HX |
27 | #include <linux/compiler.h> |
28 | #include <linux/err.h> | |
29 | #include <linux/kernel.h> | |
1da177e4 LT |
30 | #include <net/sock.h> |
31 | ||
1da177e4 | 32 | #include <asm/uaccess.h> |
4b2f0260 | 33 | #include <asm/system.h> |
1da177e4 LT |
34 | #include <asm/types.h> |
35 | ||
36 | #include <linux/nbd.h> | |
37 | ||
38 | #define LO_MAGIC 0x68797548 | |
39 | ||
40 | #ifdef NDEBUG | |
41 | #define dprintk(flags, fmt...) | |
42 | #else /* NDEBUG */ | |
43 | #define dprintk(flags, fmt...) do { \ | |
44 | if (debugflags & (flags)) printk(KERN_DEBUG fmt); \ | |
45 | } while (0) | |
46 | #define DBG_IOCTL 0x0004 | |
47 | #define DBG_INIT 0x0010 | |
48 | #define DBG_EXIT 0x0020 | |
49 | #define DBG_BLKDEV 0x0100 | |
50 | #define DBG_RX 0x0200 | |
51 | #define DBG_TX 0x0400 | |
52 | static unsigned int debugflags; | |
53 | #endif /* NDEBUG */ | |
54 | ||
9c7a4169 | 55 | static unsigned int nbds_max = 16; |
1da177e4 LT |
56 | static struct nbd_device nbd_dev[MAX_NBD]; |
57 | ||
58 | /* | |
59 | * Use just one lock (or at most 1 per NIC). Two arguments for this: | |
60 | * 1. Each NIC is essentially a synchronization point for all servers | |
61 | * accessed through that NIC so there's no need to have more locks | |
62 | * than NICs anyway. | |
63 | * 2. More locks lead to more "Dirty cache line bouncing" which will slow | |
64 | * down each lock to the point where they're actually slower than just | |
65 | * a single lock. | |
66 | * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! | |
67 | */ | |
68 | static DEFINE_SPINLOCK(nbd_lock); | |
69 | ||
70 | #ifndef NDEBUG | |
71 | static const char *ioctl_cmd_to_ascii(int cmd) | |
72 | { | |
73 | switch (cmd) { | |
74 | case NBD_SET_SOCK: return "set-sock"; | |
75 | case NBD_SET_BLKSIZE: return "set-blksize"; | |
76 | case NBD_SET_SIZE: return "set-size"; | |
77 | case NBD_DO_IT: return "do-it"; | |
78 | case NBD_CLEAR_SOCK: return "clear-sock"; | |
79 | case NBD_CLEAR_QUE: return "clear-que"; | |
80 | case NBD_PRINT_DEBUG: return "print-debug"; | |
81 | case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; | |
82 | case NBD_DISCONNECT: return "disconnect"; | |
83 | case BLKROSET: return "set-read-only"; | |
84 | case BLKFLSBUF: return "flush-buffer-cache"; | |
85 | } | |
86 | return "unknown"; | |
87 | } | |
88 | ||
89 | static const char *nbdcmd_to_ascii(int cmd) | |
90 | { | |
91 | switch (cmd) { | |
92 | case NBD_CMD_READ: return "read"; | |
93 | case NBD_CMD_WRITE: return "write"; | |
94 | case NBD_CMD_DISC: return "disconnect"; | |
95 | } | |
96 | return "invalid"; | |
97 | } | |
98 | #endif /* NDEBUG */ | |
99 | ||
100 | static void nbd_end_request(struct request *req) | |
101 | { | |
102 | int uptodate = (req->errors == 0) ? 1 : 0; | |
165125e1 | 103 | struct request_queue *q = req->q; |
1da177e4 LT |
104 | unsigned long flags; |
105 | ||
106 | dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, | |
107 | req, uptodate? "done": "failed"); | |
108 | ||
109 | spin_lock_irqsave(q->queue_lock, flags); | |
110 | if (!end_that_request_first(req, uptodate, req->nr_sectors)) { | |
8ffdc655 | 111 | end_that_request_last(req, uptodate); |
1da177e4 LT |
112 | } |
113 | spin_unlock_irqrestore(q->queue_lock, flags); | |
114 | } | |
115 | ||
7fdfd406 PC |
116 | static void sock_shutdown(struct nbd_device *lo, int lock) |
117 | { | |
118 | /* Forcibly shutdown the socket causing all listeners | |
119 | * to error | |
120 | * | |
121 | * FIXME: This code is duplicated from sys_shutdown, but | |
122 | * there should be a more generic interface rather than | |
123 | * calling socket ops directly here */ | |
124 | if (lock) | |
125 | mutex_lock(&lo->tx_lock); | |
126 | if (lo->sock) { | |
127 | printk(KERN_WARNING "%s: shutting down socket\n", | |
128 | lo->disk->disk_name); | |
129 | lo->sock->ops->shutdown(lo->sock, SEND_SHUTDOWN|RCV_SHUTDOWN); | |
130 | lo->sock = NULL; | |
131 | } | |
132 | if (lock) | |
133 | mutex_unlock(&lo->tx_lock); | |
134 | } | |
135 | ||
136 | static void nbd_xmit_timeout(unsigned long arg) | |
137 | { | |
138 | struct task_struct *task = (struct task_struct *)arg; | |
139 | ||
140 | printk(KERN_WARNING "nbd: killing hung xmit (%s, pid: %d)\n", | |
141 | task->comm, task->pid); | |
142 | force_sig(SIGKILL, task); | |
143 | } | |
144 | ||
1da177e4 LT |
145 | /* |
146 | * Send or receive packet. | |
147 | */ | |
7fdfd406 | 148 | static int sock_xmit(struct nbd_device *lo, int send, void *buf, int size, |
1da177e4 LT |
149 | int msg_flags) |
150 | { | |
7fdfd406 | 151 | struct socket *sock = lo->sock; |
1da177e4 LT |
152 | int result; |
153 | struct msghdr msg; | |
154 | struct kvec iov; | |
be0ef957 | 155 | sigset_t blocked, oldset; |
1da177e4 LT |
156 | |
157 | /* Allow interception of SIGKILL only | |
158 | * Don't allow other signals to interrupt the transmission */ | |
be0ef957 ON |
159 | siginitsetinv(&blocked, sigmask(SIGKILL)); |
160 | sigprocmask(SIG_SETMASK, &blocked, &oldset); | |
1da177e4 LT |
161 | |
162 | do { | |
163 | sock->sk->sk_allocation = GFP_NOIO; | |
164 | iov.iov_base = buf; | |
165 | iov.iov_len = size; | |
166 | msg.msg_name = NULL; | |
167 | msg.msg_namelen = 0; | |
168 | msg.msg_control = NULL; | |
169 | msg.msg_controllen = 0; | |
1da177e4 LT |
170 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
171 | ||
7fdfd406 PC |
172 | if (send) { |
173 | struct timer_list ti; | |
174 | ||
175 | if (lo->xmit_timeout) { | |
176 | init_timer(&ti); | |
177 | ti.function = nbd_xmit_timeout; | |
178 | ti.data = (unsigned long)current; | |
179 | ti.expires = jiffies + lo->xmit_timeout; | |
180 | add_timer(&ti); | |
181 | } | |
1da177e4 | 182 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
7fdfd406 PC |
183 | if (lo->xmit_timeout) |
184 | del_timer_sync(&ti); | |
185 | } else | |
1da177e4 LT |
186 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); |
187 | ||
188 | if (signal_pending(current)) { | |
189 | siginfo_t info; | |
1da177e4 | 190 | printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", |
ba25f9dc | 191 | task_pid_nr(current), current->comm, |
be0ef957 | 192 | dequeue_signal_lock(current, ¤t->blocked, &info)); |
1da177e4 | 193 | result = -EINTR; |
7fdfd406 | 194 | sock_shutdown(lo, !send); |
1da177e4 LT |
195 | break; |
196 | } | |
197 | ||
198 | if (result <= 0) { | |
199 | if (result == 0) | |
200 | result = -EPIPE; /* short read */ | |
201 | break; | |
202 | } | |
203 | size -= result; | |
204 | buf += result; | |
205 | } while (size > 0); | |
206 | ||
be0ef957 | 207 | sigprocmask(SIG_SETMASK, &oldset, NULL); |
1da177e4 LT |
208 | |
209 | return result; | |
210 | } | |
211 | ||
7fdfd406 | 212 | static inline int sock_send_bvec(struct nbd_device *lo, struct bio_vec *bvec, |
1da177e4 LT |
213 | int flags) |
214 | { | |
215 | int result; | |
216 | void *kaddr = kmap(bvec->bv_page); | |
7fdfd406 | 217 | result = sock_xmit(lo, 1, kaddr + bvec->bv_offset, bvec->bv_len, flags); |
1da177e4 LT |
218 | kunmap(bvec->bv_page); |
219 | return result; | |
220 | } | |
221 | ||
7fdfd406 | 222 | /* always call with the tx_lock held */ |
1da177e4 LT |
223 | static int nbd_send_req(struct nbd_device *lo, struct request *req) |
224 | { | |
5705f702 | 225 | int result, flags; |
1da177e4 LT |
226 | struct nbd_request request; |
227 | unsigned long size = req->nr_sectors << 9; | |
1da177e4 LT |
228 | |
229 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
230 | request.type = htonl(nbd_cmd(req)); | |
231 | request.from = cpu_to_be64((u64) req->sector << 9); | |
232 | request.len = htonl(size); | |
233 | memcpy(request.handle, &req, sizeof(req)); | |
234 | ||
1da177e4 LT |
235 | dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", |
236 | lo->disk->disk_name, req, | |
237 | nbdcmd_to_ascii(nbd_cmd(req)), | |
238 | (unsigned long long)req->sector << 9, | |
239 | req->nr_sectors << 9); | |
7fdfd406 PC |
240 | result = sock_xmit(lo, 1, &request, sizeof(request), |
241 | (nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0); | |
1da177e4 LT |
242 | if (result <= 0) { |
243 | printk(KERN_ERR "%s: Send control failed (result %d)\n", | |
244 | lo->disk->disk_name, result); | |
245 | goto error_out; | |
246 | } | |
247 | ||
248 | if (nbd_cmd(req) == NBD_CMD_WRITE) { | |
5705f702 N |
249 | struct req_iterator iter; |
250 | struct bio_vec *bvec; | |
1da177e4 LT |
251 | /* |
252 | * we are really probing at internals to determine | |
253 | * whether to set MSG_MORE or not... | |
254 | */ | |
5705f702 | 255 | rq_for_each_segment(bvec, req, iter) { |
6c92e699 JA |
256 | flags = 0; |
257 | if (!rq_iter_last(req, iter)) | |
258 | flags = MSG_MORE; | |
259 | dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", | |
260 | lo->disk->disk_name, req, bvec->bv_len); | |
7fdfd406 | 261 | result = sock_send_bvec(lo, bvec, flags); |
6c92e699 JA |
262 | if (result <= 0) { |
263 | printk(KERN_ERR "%s: Send data failed (result %d)\n", | |
264 | lo->disk->disk_name, result); | |
265 | goto error_out; | |
266 | } | |
1da177e4 LT |
267 | } |
268 | } | |
1da177e4 LT |
269 | return 0; |
270 | ||
271 | error_out: | |
1da177e4 LT |
272 | return 1; |
273 | } | |
274 | ||
0cbc591b DC |
275 | static struct request *nbd_find_request(struct nbd_device *lo, |
276 | struct request *xreq) | |
1da177e4 | 277 | { |
d2c9740b | 278 | struct request *req, *tmp; |
4b2f0260 | 279 | int err; |
1da177e4 | 280 | |
4b2f0260 HX |
281 | err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); |
282 | if (unlikely(err)) | |
283 | goto out; | |
284 | ||
1da177e4 | 285 | spin_lock(&lo->queue_lock); |
d2c9740b | 286 | list_for_each_entry_safe(req, tmp, &lo->queue_head, queuelist) { |
1da177e4 LT |
287 | if (req != xreq) |
288 | continue; | |
289 | list_del_init(&req->queuelist); | |
290 | spin_unlock(&lo->queue_lock); | |
291 | return req; | |
292 | } | |
293 | spin_unlock(&lo->queue_lock); | |
4b2f0260 HX |
294 | |
295 | err = -ENOENT; | |
296 | ||
297 | out: | |
298 | return ERR_PTR(err); | |
1da177e4 LT |
299 | } |
300 | ||
7fdfd406 | 301 | static inline int sock_recv_bvec(struct nbd_device *lo, struct bio_vec *bvec) |
1da177e4 LT |
302 | { |
303 | int result; | |
304 | void *kaddr = kmap(bvec->bv_page); | |
7fdfd406 | 305 | result = sock_xmit(lo, 0, kaddr + bvec->bv_offset, bvec->bv_len, |
1da177e4 LT |
306 | MSG_WAITALL); |
307 | kunmap(bvec->bv_page); | |
308 | return result; | |
309 | } | |
310 | ||
311 | /* NULL returned = something went wrong, inform userspace */ | |
312 | static struct request *nbd_read_stat(struct nbd_device *lo) | |
313 | { | |
314 | int result; | |
315 | struct nbd_reply reply; | |
316 | struct request *req; | |
1da177e4 LT |
317 | |
318 | reply.magic = 0; | |
7fdfd406 | 319 | result = sock_xmit(lo, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 LT |
320 | if (result <= 0) { |
321 | printk(KERN_ERR "%s: Receive control failed (result %d)\n", | |
322 | lo->disk->disk_name, result); | |
323 | goto harderror; | |
324 | } | |
e4b57e08 MF |
325 | |
326 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
327 | printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", | |
328 | lo->disk->disk_name, | |
329 | (unsigned long)ntohl(reply.magic)); | |
330 | result = -EPROTO; | |
331 | goto harderror; | |
332 | } | |
333 | ||
0cbc591b | 334 | req = nbd_find_request(lo, *(struct request **)reply.handle); |
4b2f0260 HX |
335 | if (unlikely(IS_ERR(req))) { |
336 | result = PTR_ERR(req); | |
337 | if (result != -ENOENT) | |
338 | goto harderror; | |
339 | ||
1da177e4 LT |
340 | printk(KERN_ERR "%s: Unexpected reply (%p)\n", |
341 | lo->disk->disk_name, reply.handle); | |
342 | result = -EBADR; | |
343 | goto harderror; | |
344 | } | |
345 | ||
1da177e4 LT |
346 | if (ntohl(reply.error)) { |
347 | printk(KERN_ERR "%s: Other side returned error (%d)\n", | |
348 | lo->disk->disk_name, ntohl(reply.error)); | |
349 | req->errors++; | |
350 | return req; | |
351 | } | |
352 | ||
353 | dprintk(DBG_RX, "%s: request %p: got reply\n", | |
354 | lo->disk->disk_name, req); | |
355 | if (nbd_cmd(req) == NBD_CMD_READ) { | |
5705f702 N |
356 | struct req_iterator iter; |
357 | struct bio_vec *bvec; | |
358 | ||
359 | rq_for_each_segment(bvec, req, iter) { | |
7fdfd406 | 360 | result = sock_recv_bvec(lo, bvec); |
6c92e699 JA |
361 | if (result <= 0) { |
362 | printk(KERN_ERR "%s: Receive data failed (result %d)\n", | |
363 | lo->disk->disk_name, result); | |
364 | req->errors++; | |
365 | return req; | |
366 | } | |
367 | dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", | |
368 | lo->disk->disk_name, req, bvec->bv_len); | |
1da177e4 LT |
369 | } |
370 | } | |
371 | return req; | |
372 | harderror: | |
373 | lo->harderror = result; | |
374 | return NULL; | |
375 | } | |
376 | ||
6b39bb65 PC |
377 | static ssize_t pid_show(struct gendisk *disk, char *page) |
378 | { | |
379 | return sprintf(page, "%ld\n", | |
380 | (long) ((struct nbd_device *)disk->private_data)->pid); | |
381 | } | |
382 | ||
383 | static struct disk_attribute pid_attr = { | |
384 | .attr = { .name = "pid", .mode = S_IRUGO }, | |
385 | .show = pid_show, | |
386 | }; | |
387 | ||
84963048 | 388 | static int nbd_do_it(struct nbd_device *lo) |
1da177e4 LT |
389 | { |
390 | struct request *req; | |
84963048 | 391 | int ret; |
1da177e4 LT |
392 | |
393 | BUG_ON(lo->magic != LO_MAGIC); | |
394 | ||
6b39bb65 | 395 | lo->pid = current->pid; |
84963048 WC |
396 | ret = sysfs_create_file(&lo->disk->kobj, &pid_attr.attr); |
397 | if (ret) { | |
398 | printk(KERN_ERR "nbd: sysfs_create_file failed!"); | |
399 | return ret; | |
400 | } | |
6b39bb65 | 401 | |
1da177e4 LT |
402 | while ((req = nbd_read_stat(lo)) != NULL) |
403 | nbd_end_request(req); | |
6b39bb65 PC |
404 | |
405 | sysfs_remove_file(&lo->disk->kobj, &pid_attr.attr); | |
84963048 | 406 | return 0; |
1da177e4 LT |
407 | } |
408 | ||
409 | static void nbd_clear_que(struct nbd_device *lo) | |
410 | { | |
411 | struct request *req; | |
412 | ||
413 | BUG_ON(lo->magic != LO_MAGIC); | |
414 | ||
4b2f0260 HX |
415 | /* |
416 | * Because we have set lo->sock to NULL under the tx_lock, all | |
417 | * modifications to the list must have completed by now. For | |
418 | * the same reason, the active_req must be NULL. | |
419 | * | |
420 | * As a consequence, we don't need to take the spin lock while | |
421 | * purging the list here. | |
422 | */ | |
423 | BUG_ON(lo->sock); | |
424 | BUG_ON(lo->active_req); | |
425 | ||
426 | while (!list_empty(&lo->queue_head)) { | |
427 | req = list_entry(lo->queue_head.next, struct request, | |
428 | queuelist); | |
429 | list_del_init(&req->queuelist); | |
430 | req->errors++; | |
431 | nbd_end_request(req); | |
432 | } | |
1da177e4 LT |
433 | } |
434 | ||
7fdfd406 | 435 | |
1da177e4 LT |
436 | /* |
437 | * We always wait for result of write, for now. It would be nice to make it optional | |
438 | * in future | |
e654bc43 | 439 | * if ((rq_data_dir(req) == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) |
1da177e4 LT |
440 | * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } |
441 | */ | |
442 | ||
165125e1 | 443 | static void do_nbd_request(struct request_queue * q) |
1da177e4 LT |
444 | { |
445 | struct request *req; | |
446 | ||
447 | while ((req = elv_next_request(q)) != NULL) { | |
448 | struct nbd_device *lo; | |
449 | ||
450 | blkdev_dequeue_request(req); | |
4aff5e23 JA |
451 | dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n", |
452 | req->rq_disk->disk_name, req, req->cmd_type); | |
1da177e4 | 453 | |
4aff5e23 | 454 | if (!blk_fs_request(req)) |
1da177e4 LT |
455 | goto error_out; |
456 | ||
457 | lo = req->rq_disk->private_data; | |
458 | ||
459 | BUG_ON(lo->magic != LO_MAGIC); | |
460 | ||
1da177e4 LT |
461 | nbd_cmd(req) = NBD_CMD_READ; |
462 | if (rq_data_dir(req) == WRITE) { | |
463 | nbd_cmd(req) = NBD_CMD_WRITE; | |
464 | if (lo->flags & NBD_READ_ONLY) { | |
465 | printk(KERN_ERR "%s: Write on read-only\n", | |
466 | lo->disk->disk_name); | |
467 | goto error_out; | |
468 | } | |
469 | } | |
470 | ||
471 | req->errors = 0; | |
472 | spin_unlock_irq(q->queue_lock); | |
473 | ||
82d4dc5a | 474 | mutex_lock(&lo->tx_lock); |
4b2f0260 | 475 | if (unlikely(!lo->sock)) { |
82d4dc5a | 476 | mutex_unlock(&lo->tx_lock); |
4b2f0260 HX |
477 | printk(KERN_ERR "%s: Attempted send on closed socket\n", |
478 | lo->disk->disk_name); | |
1da177e4 LT |
479 | req->errors++; |
480 | nbd_end_request(req); | |
481 | spin_lock_irq(q->queue_lock); | |
482 | continue; | |
483 | } | |
484 | ||
4b2f0260 | 485 | lo->active_req = req; |
1da177e4 LT |
486 | |
487 | if (nbd_send_req(lo, req) != 0) { | |
488 | printk(KERN_ERR "%s: Request send failed\n", | |
489 | lo->disk->disk_name); | |
4b2f0260 HX |
490 | req->errors++; |
491 | nbd_end_request(req); | |
492 | } else { | |
493 | spin_lock(&lo->queue_lock); | |
494 | list_add(&req->queuelist, &lo->queue_head); | |
495 | spin_unlock(&lo->queue_lock); | |
1da177e4 LT |
496 | } |
497 | ||
4b2f0260 | 498 | lo->active_req = NULL; |
82d4dc5a | 499 | mutex_unlock(&lo->tx_lock); |
4b2f0260 HX |
500 | wake_up_all(&lo->active_wq); |
501 | ||
1da177e4 LT |
502 | spin_lock_irq(q->queue_lock); |
503 | continue; | |
504 | ||
505 | error_out: | |
506 | req->errors++; | |
507 | spin_unlock(q->queue_lock); | |
508 | nbd_end_request(req); | |
509 | spin_lock(q->queue_lock); | |
510 | } | |
511 | return; | |
512 | } | |
513 | ||
514 | static int nbd_ioctl(struct inode *inode, struct file *file, | |
515 | unsigned int cmd, unsigned long arg) | |
516 | { | |
517 | struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; | |
518 | int error; | |
519 | struct request sreq ; | |
520 | ||
521 | if (!capable(CAP_SYS_ADMIN)) | |
522 | return -EPERM; | |
523 | ||
524 | BUG_ON(lo->magic != LO_MAGIC); | |
525 | ||
526 | /* Anyone capable of this syscall can do *real bad* things */ | |
527 | dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", | |
528 | lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); | |
529 | ||
530 | switch (cmd) { | |
531 | case NBD_DISCONNECT: | |
532 | printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name); | |
4aff5e23 | 533 | sreq.cmd_type = REQ_TYPE_SPECIAL; |
1da177e4 LT |
534 | nbd_cmd(&sreq) = NBD_CMD_DISC; |
535 | /* | |
536 | * Set these to sane values in case server implementation | |
537 | * fails to check the request type first and also to keep | |
538 | * debugging output cleaner. | |
539 | */ | |
540 | sreq.sector = 0; | |
541 | sreq.nr_sectors = 0; | |
542 | if (!lo->sock) | |
543 | return -EINVAL; | |
7fdfd406 | 544 | mutex_lock(&lo->tx_lock); |
1da177e4 | 545 | nbd_send_req(lo, &sreq); |
7fdfd406 | 546 | mutex_unlock(&lo->tx_lock); |
1da177e4 LT |
547 | return 0; |
548 | ||
549 | case NBD_CLEAR_SOCK: | |
550 | error = 0; | |
82d4dc5a | 551 | mutex_lock(&lo->tx_lock); |
1da177e4 | 552 | lo->sock = NULL; |
82d4dc5a | 553 | mutex_unlock(&lo->tx_lock); |
1da177e4 LT |
554 | file = lo->file; |
555 | lo->file = NULL; | |
1da177e4 | 556 | nbd_clear_que(lo); |
4b2f0260 | 557 | BUG_ON(!list_empty(&lo->queue_head)); |
1da177e4 LT |
558 | if (file) |
559 | fput(file); | |
560 | return error; | |
561 | case NBD_SET_SOCK: | |
562 | if (lo->file) | |
563 | return -EBUSY; | |
564 | error = -EINVAL; | |
565 | file = fget(arg); | |
566 | if (file) { | |
17506041 | 567 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
568 | if (S_ISSOCK(inode->i_mode)) { |
569 | lo->file = file; | |
570 | lo->sock = SOCKET_I(inode); | |
571 | error = 0; | |
572 | } else { | |
573 | fput(file); | |
574 | } | |
575 | } | |
576 | return error; | |
577 | case NBD_SET_BLKSIZE: | |
578 | lo->blksize = arg; | |
579 | lo->bytesize &= ~(lo->blksize-1); | |
580 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
581 | set_blocksize(inode->i_bdev, lo->blksize); | |
582 | set_capacity(lo->disk, lo->bytesize >> 9); | |
583 | return 0; | |
584 | case NBD_SET_SIZE: | |
585 | lo->bytesize = arg & ~(lo->blksize-1); | |
586 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
587 | set_blocksize(inode->i_bdev, lo->blksize); | |
588 | set_capacity(lo->disk, lo->bytesize >> 9); | |
589 | return 0; | |
7fdfd406 PC |
590 | case NBD_SET_TIMEOUT: |
591 | lo->xmit_timeout = arg * HZ; | |
592 | return 0; | |
1da177e4 LT |
593 | case NBD_SET_SIZE_BLOCKS: |
594 | lo->bytesize = ((u64) arg) * lo->blksize; | |
595 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
596 | set_blocksize(inode->i_bdev, lo->blksize); | |
597 | set_capacity(lo->disk, lo->bytesize >> 9); | |
598 | return 0; | |
599 | case NBD_DO_IT: | |
600 | if (!lo->file) | |
601 | return -EINVAL; | |
84963048 WC |
602 | error = nbd_do_it(lo); |
603 | if (error) | |
604 | return error; | |
7fdfd406 | 605 | sock_shutdown(lo, 1); |
1da177e4 LT |
606 | file = lo->file; |
607 | lo->file = NULL; | |
1da177e4 LT |
608 | nbd_clear_que(lo); |
609 | printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); | |
610 | if (file) | |
611 | fput(file); | |
4b86a872 PC |
612 | lo->bytesize = 0; |
613 | inode->i_bdev->bd_inode->i_size = 0; | |
614 | set_capacity(lo->disk, 0); | |
1da177e4 LT |
615 | return lo->harderror; |
616 | case NBD_CLEAR_QUE: | |
4b2f0260 HX |
617 | /* |
618 | * This is for compatibility only. The queue is always cleared | |
619 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
620 | */ | |
621 | BUG_ON(!lo->sock && !list_empty(&lo->queue_head)); | |
1da177e4 LT |
622 | return 0; |
623 | case NBD_PRINT_DEBUG: | |
624 | printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n", | |
625 | inode->i_bdev->bd_disk->disk_name, | |
626 | lo->queue_head.next, lo->queue_head.prev, | |
627 | &lo->queue_head); | |
628 | return 0; | |
629 | } | |
630 | return -EINVAL; | |
631 | } | |
632 | ||
633 | static struct block_device_operations nbd_fops = | |
634 | { | |
635 | .owner = THIS_MODULE, | |
636 | .ioctl = nbd_ioctl, | |
637 | }; | |
638 | ||
639 | /* | |
640 | * And here should be modules and kernel interface | |
641 | * (Just smiley confuses emacs :-) | |
642 | */ | |
643 | ||
644 | static int __init nbd_init(void) | |
645 | { | |
646 | int err = -ENOMEM; | |
647 | int i; | |
648 | ||
5b7b18cc | 649 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 650 | |
40be0c28 LMB |
651 | if (nbds_max > MAX_NBD) { |
652 | printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD, | |
653 | nbds_max); | |
654 | return -EINVAL; | |
655 | } | |
656 | ||
657 | for (i = 0; i < nbds_max; i++) { | |
1da177e4 LT |
658 | struct gendisk *disk = alloc_disk(1); |
659 | if (!disk) | |
660 | goto out; | |
661 | nbd_dev[i].disk = disk; | |
662 | /* | |
663 | * The new linux 2.5 block layer implementation requires | |
664 | * every gendisk to have its very own request_queue struct. | |
665 | * These structs are big so we dynamically allocate them. | |
666 | */ | |
667 | disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); | |
668 | if (!disk->queue) { | |
669 | put_disk(disk); | |
670 | goto out; | |
671 | } | |
672 | } | |
673 | ||
674 | if (register_blkdev(NBD_MAJOR, "nbd")) { | |
675 | err = -EIO; | |
676 | goto out; | |
677 | } | |
678 | ||
679 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); | |
680 | dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); | |
681 | ||
40be0c28 | 682 | for (i = 0; i < nbds_max; i++) { |
1da177e4 LT |
683 | struct gendisk *disk = nbd_dev[i].disk; |
684 | nbd_dev[i].file = NULL; | |
685 | nbd_dev[i].magic = LO_MAGIC; | |
686 | nbd_dev[i].flags = 0; | |
687 | spin_lock_init(&nbd_dev[i].queue_lock); | |
688 | INIT_LIST_HEAD(&nbd_dev[i].queue_head); | |
82d4dc5a | 689 | mutex_init(&nbd_dev[i].tx_lock); |
4b2f0260 | 690 | init_waitqueue_head(&nbd_dev[i].active_wq); |
1da177e4 | 691 | nbd_dev[i].blksize = 1024; |
4b86a872 | 692 | nbd_dev[i].bytesize = 0; |
1da177e4 LT |
693 | disk->major = NBD_MAJOR; |
694 | disk->first_minor = i; | |
695 | disk->fops = &nbd_fops; | |
696 | disk->private_data = &nbd_dev[i]; | |
697 | disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO; | |
698 | sprintf(disk->disk_name, "nbd%d", i); | |
4b86a872 | 699 | set_capacity(disk, 0); |
1da177e4 LT |
700 | add_disk(disk); |
701 | } | |
702 | ||
703 | return 0; | |
704 | out: | |
705 | while (i--) { | |
706 | blk_cleanup_queue(nbd_dev[i].disk->queue); | |
707 | put_disk(nbd_dev[i].disk); | |
708 | } | |
709 | return err; | |
710 | } | |
711 | ||
712 | static void __exit nbd_cleanup(void) | |
713 | { | |
714 | int i; | |
40be0c28 | 715 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 716 | struct gendisk *disk = nbd_dev[i].disk; |
40be0c28 | 717 | nbd_dev[i].magic = 0; |
1da177e4 LT |
718 | if (disk) { |
719 | del_gendisk(disk); | |
720 | blk_cleanup_queue(disk->queue); | |
721 | put_disk(disk); | |
722 | } | |
723 | } | |
1da177e4 LT |
724 | unregister_blkdev(NBD_MAJOR, "nbd"); |
725 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); | |
726 | } | |
727 | ||
728 | module_init(nbd_init); | |
729 | module_exit(nbd_cleanup); | |
730 | ||
731 | MODULE_DESCRIPTION("Network Block Device"); | |
732 | MODULE_LICENSE("GPL"); | |
733 | ||
40be0c28 LMB |
734 | module_param(nbds_max, int, 0444); |
735 | MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize."); | |
1da177e4 LT |
736 | #ifndef NDEBUG |
737 | module_param(debugflags, int, 0644); | |
738 | MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); | |
739 | #endif |