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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Network block device - make block devices work over TCP | |
3 | * | |
4 | * Note that you can not swap over this thing, yet. Seems to work but | |
5 | * deadlocks sometimes - you can not swap over TCP in general. | |
6 | * | |
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; | |
103 | request_queue_t *q = req->q; | |
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 | ||
116 | /* | |
117 | * Send or receive packet. | |
118 | */ | |
119 | static int sock_xmit(struct socket *sock, int send, void *buf, int size, | |
120 | int msg_flags) | |
121 | { | |
122 | int result; | |
123 | struct msghdr msg; | |
124 | struct kvec iov; | |
125 | unsigned long flags; | |
126 | sigset_t oldset; | |
127 | ||
128 | /* Allow interception of SIGKILL only | |
129 | * Don't allow other signals to interrupt the transmission */ | |
130 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
131 | oldset = current->blocked; | |
132 | sigfillset(¤t->blocked); | |
133 | sigdelsetmask(¤t->blocked, sigmask(SIGKILL)); | |
134 | recalc_sigpending(); | |
135 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
136 | ||
137 | do { | |
138 | sock->sk->sk_allocation = GFP_NOIO; | |
139 | iov.iov_base = buf; | |
140 | iov.iov_len = size; | |
141 | msg.msg_name = NULL; | |
142 | msg.msg_namelen = 0; | |
143 | msg.msg_control = NULL; | |
144 | msg.msg_controllen = 0; | |
1da177e4 LT |
145 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
146 | ||
147 | if (send) | |
148 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); | |
149 | else | |
150 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); | |
151 | ||
152 | if (signal_pending(current)) { | |
153 | siginfo_t info; | |
154 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
155 | printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", | |
156 | current->pid, current->comm, | |
157 | dequeue_signal(current, ¤t->blocked, &info)); | |
158 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
159 | result = -EINTR; | |
160 | break; | |
161 | } | |
162 | ||
163 | if (result <= 0) { | |
164 | if (result == 0) | |
165 | result = -EPIPE; /* short read */ | |
166 | break; | |
167 | } | |
168 | size -= result; | |
169 | buf += result; | |
170 | } while (size > 0); | |
171 | ||
172 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
173 | current->blocked = oldset; | |
174 | recalc_sigpending(); | |
175 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
176 | ||
177 | return result; | |
178 | } | |
179 | ||
180 | static inline int sock_send_bvec(struct socket *sock, struct bio_vec *bvec, | |
181 | int flags) | |
182 | { | |
183 | int result; | |
184 | void *kaddr = kmap(bvec->bv_page); | |
185 | result = sock_xmit(sock, 1, kaddr + bvec->bv_offset, bvec->bv_len, | |
186 | flags); | |
187 | kunmap(bvec->bv_page); | |
188 | return result; | |
189 | } | |
190 | ||
191 | static int nbd_send_req(struct nbd_device *lo, struct request *req) | |
192 | { | |
193 | int result, i, flags; | |
194 | struct nbd_request request; | |
195 | unsigned long size = req->nr_sectors << 9; | |
196 | struct socket *sock = lo->sock; | |
197 | ||
198 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
199 | request.type = htonl(nbd_cmd(req)); | |
200 | request.from = cpu_to_be64((u64) req->sector << 9); | |
201 | request.len = htonl(size); | |
202 | memcpy(request.handle, &req, sizeof(req)); | |
203 | ||
1da177e4 LT |
204 | dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", |
205 | lo->disk->disk_name, req, | |
206 | nbdcmd_to_ascii(nbd_cmd(req)), | |
207 | (unsigned long long)req->sector << 9, | |
208 | req->nr_sectors << 9); | |
209 | result = sock_xmit(sock, 1, &request, sizeof(request), | |
210 | (nbd_cmd(req) == NBD_CMD_WRITE)? MSG_MORE: 0); | |
211 | if (result <= 0) { | |
212 | printk(KERN_ERR "%s: Send control failed (result %d)\n", | |
213 | lo->disk->disk_name, result); | |
214 | goto error_out; | |
215 | } | |
216 | ||
217 | if (nbd_cmd(req) == NBD_CMD_WRITE) { | |
218 | struct bio *bio; | |
219 | /* | |
220 | * we are really probing at internals to determine | |
221 | * whether to set MSG_MORE or not... | |
222 | */ | |
223 | rq_for_each_bio(bio, req) { | |
224 | struct bio_vec *bvec; | |
225 | bio_for_each_segment(bvec, bio, i) { | |
226 | flags = 0; | |
227 | if ((i < (bio->bi_vcnt - 1)) || bio->bi_next) | |
228 | flags = MSG_MORE; | |
229 | dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", | |
230 | lo->disk->disk_name, req, | |
231 | bvec->bv_len); | |
232 | result = sock_send_bvec(sock, bvec, flags); | |
233 | if (result <= 0) { | |
234 | printk(KERN_ERR "%s: Send data failed (result %d)\n", | |
235 | lo->disk->disk_name, | |
236 | result); | |
237 | goto error_out; | |
238 | } | |
239 | } | |
240 | } | |
241 | } | |
1da177e4 LT |
242 | return 0; |
243 | ||
244 | error_out: | |
1da177e4 LT |
245 | return 1; |
246 | } | |
247 | ||
248 | static struct request *nbd_find_request(struct nbd_device *lo, char *handle) | |
249 | { | |
250 | struct request *req; | |
251 | struct list_head *tmp; | |
252 | struct request *xreq; | |
4b2f0260 | 253 | int err; |
1da177e4 LT |
254 | |
255 | memcpy(&xreq, handle, sizeof(xreq)); | |
256 | ||
4b2f0260 HX |
257 | err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); |
258 | if (unlikely(err)) | |
259 | goto out; | |
260 | ||
1da177e4 LT |
261 | spin_lock(&lo->queue_lock); |
262 | list_for_each(tmp, &lo->queue_head) { | |
263 | req = list_entry(tmp, struct request, queuelist); | |
264 | if (req != xreq) | |
265 | continue; | |
266 | list_del_init(&req->queuelist); | |
267 | spin_unlock(&lo->queue_lock); | |
268 | return req; | |
269 | } | |
270 | spin_unlock(&lo->queue_lock); | |
4b2f0260 HX |
271 | |
272 | err = -ENOENT; | |
273 | ||
274 | out: | |
275 | return ERR_PTR(err); | |
1da177e4 LT |
276 | } |
277 | ||
278 | static inline int sock_recv_bvec(struct socket *sock, struct bio_vec *bvec) | |
279 | { | |
280 | int result; | |
281 | void *kaddr = kmap(bvec->bv_page); | |
282 | result = sock_xmit(sock, 0, kaddr + bvec->bv_offset, bvec->bv_len, | |
283 | MSG_WAITALL); | |
284 | kunmap(bvec->bv_page); | |
285 | return result; | |
286 | } | |
287 | ||
288 | /* NULL returned = something went wrong, inform userspace */ | |
289 | static struct request *nbd_read_stat(struct nbd_device *lo) | |
290 | { | |
291 | int result; | |
292 | struct nbd_reply reply; | |
293 | struct request *req; | |
294 | struct socket *sock = lo->sock; | |
295 | ||
296 | reply.magic = 0; | |
297 | result = sock_xmit(sock, 0, &reply, sizeof(reply), MSG_WAITALL); | |
298 | if (result <= 0) { | |
299 | printk(KERN_ERR "%s: Receive control failed (result %d)\n", | |
300 | lo->disk->disk_name, result); | |
301 | goto harderror; | |
302 | } | |
303 | req = nbd_find_request(lo, reply.handle); | |
4b2f0260 HX |
304 | if (unlikely(IS_ERR(req))) { |
305 | result = PTR_ERR(req); | |
306 | if (result != -ENOENT) | |
307 | goto harderror; | |
308 | ||
1da177e4 LT |
309 | printk(KERN_ERR "%s: Unexpected reply (%p)\n", |
310 | lo->disk->disk_name, reply.handle); | |
311 | result = -EBADR; | |
312 | goto harderror; | |
313 | } | |
314 | ||
315 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
316 | printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", | |
317 | lo->disk->disk_name, | |
318 | (unsigned long)ntohl(reply.magic)); | |
319 | result = -EPROTO; | |
320 | goto harderror; | |
321 | } | |
322 | if (ntohl(reply.error)) { | |
323 | printk(KERN_ERR "%s: Other side returned error (%d)\n", | |
324 | lo->disk->disk_name, ntohl(reply.error)); | |
325 | req->errors++; | |
326 | return req; | |
327 | } | |
328 | ||
329 | dprintk(DBG_RX, "%s: request %p: got reply\n", | |
330 | lo->disk->disk_name, req); | |
331 | if (nbd_cmd(req) == NBD_CMD_READ) { | |
332 | int i; | |
333 | struct bio *bio; | |
334 | rq_for_each_bio(bio, req) { | |
335 | struct bio_vec *bvec; | |
336 | bio_for_each_segment(bvec, bio, i) { | |
337 | result = sock_recv_bvec(sock, bvec); | |
338 | if (result <= 0) { | |
339 | printk(KERN_ERR "%s: Receive data failed (result %d)\n", | |
340 | lo->disk->disk_name, | |
341 | result); | |
342 | goto harderror; | |
343 | } | |
344 | dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", | |
345 | lo->disk->disk_name, req, bvec->bv_len); | |
346 | } | |
347 | } | |
348 | } | |
349 | return req; | |
350 | harderror: | |
351 | lo->harderror = result; | |
352 | return NULL; | |
353 | } | |
354 | ||
355 | static void nbd_do_it(struct nbd_device *lo) | |
356 | { | |
357 | struct request *req; | |
358 | ||
359 | BUG_ON(lo->magic != LO_MAGIC); | |
360 | ||
361 | while ((req = nbd_read_stat(lo)) != NULL) | |
362 | nbd_end_request(req); | |
363 | return; | |
364 | } | |
365 | ||
366 | static void nbd_clear_que(struct nbd_device *lo) | |
367 | { | |
368 | struct request *req; | |
369 | ||
370 | BUG_ON(lo->magic != LO_MAGIC); | |
371 | ||
4b2f0260 HX |
372 | /* |
373 | * Because we have set lo->sock to NULL under the tx_lock, all | |
374 | * modifications to the list must have completed by now. For | |
375 | * the same reason, the active_req must be NULL. | |
376 | * | |
377 | * As a consequence, we don't need to take the spin lock while | |
378 | * purging the list here. | |
379 | */ | |
380 | BUG_ON(lo->sock); | |
381 | BUG_ON(lo->active_req); | |
382 | ||
383 | while (!list_empty(&lo->queue_head)) { | |
384 | req = list_entry(lo->queue_head.next, struct request, | |
385 | queuelist); | |
386 | list_del_init(&req->queuelist); | |
387 | req->errors++; | |
388 | nbd_end_request(req); | |
389 | } | |
1da177e4 LT |
390 | } |
391 | ||
392 | /* | |
393 | * We always wait for result of write, for now. It would be nice to make it optional | |
394 | * in future | |
395 | * if ((req->cmd == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) | |
396 | * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } | |
397 | */ | |
398 | ||
399 | static void do_nbd_request(request_queue_t * q) | |
400 | { | |
401 | struct request *req; | |
402 | ||
403 | while ((req = elv_next_request(q)) != NULL) { | |
404 | struct nbd_device *lo; | |
405 | ||
406 | blkdev_dequeue_request(req); | |
407 | dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%lx)\n", | |
408 | req->rq_disk->disk_name, req, req->flags); | |
409 | ||
410 | if (!(req->flags & REQ_CMD)) | |
411 | goto error_out; | |
412 | ||
413 | lo = req->rq_disk->private_data; | |
414 | ||
415 | BUG_ON(lo->magic != LO_MAGIC); | |
416 | ||
1da177e4 LT |
417 | nbd_cmd(req) = NBD_CMD_READ; |
418 | if (rq_data_dir(req) == WRITE) { | |
419 | nbd_cmd(req) = NBD_CMD_WRITE; | |
420 | if (lo->flags & NBD_READ_ONLY) { | |
421 | printk(KERN_ERR "%s: Write on read-only\n", | |
422 | lo->disk->disk_name); | |
423 | goto error_out; | |
424 | } | |
425 | } | |
426 | ||
427 | req->errors = 0; | |
428 | spin_unlock_irq(q->queue_lock); | |
429 | ||
82d4dc5a | 430 | mutex_lock(&lo->tx_lock); |
4b2f0260 | 431 | if (unlikely(!lo->sock)) { |
82d4dc5a | 432 | mutex_unlock(&lo->tx_lock); |
4b2f0260 HX |
433 | printk(KERN_ERR "%s: Attempted send on closed socket\n", |
434 | lo->disk->disk_name); | |
1da177e4 LT |
435 | req->errors++; |
436 | nbd_end_request(req); | |
437 | spin_lock_irq(q->queue_lock); | |
438 | continue; | |
439 | } | |
440 | ||
4b2f0260 | 441 | lo->active_req = req; |
1da177e4 LT |
442 | |
443 | if (nbd_send_req(lo, req) != 0) { | |
444 | printk(KERN_ERR "%s: Request send failed\n", | |
445 | lo->disk->disk_name); | |
4b2f0260 HX |
446 | req->errors++; |
447 | nbd_end_request(req); | |
448 | } else { | |
449 | spin_lock(&lo->queue_lock); | |
450 | list_add(&req->queuelist, &lo->queue_head); | |
451 | spin_unlock(&lo->queue_lock); | |
1da177e4 LT |
452 | } |
453 | ||
4b2f0260 | 454 | lo->active_req = NULL; |
82d4dc5a | 455 | mutex_unlock(&lo->tx_lock); |
4b2f0260 HX |
456 | wake_up_all(&lo->active_wq); |
457 | ||
1da177e4 LT |
458 | spin_lock_irq(q->queue_lock); |
459 | continue; | |
460 | ||
461 | error_out: | |
462 | req->errors++; | |
463 | spin_unlock(q->queue_lock); | |
464 | nbd_end_request(req); | |
465 | spin_lock(q->queue_lock); | |
466 | } | |
467 | return; | |
468 | } | |
469 | ||
470 | static int nbd_ioctl(struct inode *inode, struct file *file, | |
471 | unsigned int cmd, unsigned long arg) | |
472 | { | |
473 | struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; | |
474 | int error; | |
475 | struct request sreq ; | |
476 | ||
477 | if (!capable(CAP_SYS_ADMIN)) | |
478 | return -EPERM; | |
479 | ||
480 | BUG_ON(lo->magic != LO_MAGIC); | |
481 | ||
482 | /* Anyone capable of this syscall can do *real bad* things */ | |
483 | dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", | |
484 | lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); | |
485 | ||
486 | switch (cmd) { | |
487 | case NBD_DISCONNECT: | |
488 | printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name); | |
489 | sreq.flags = REQ_SPECIAL; | |
490 | nbd_cmd(&sreq) = NBD_CMD_DISC; | |
491 | /* | |
492 | * Set these to sane values in case server implementation | |
493 | * fails to check the request type first and also to keep | |
494 | * debugging output cleaner. | |
495 | */ | |
496 | sreq.sector = 0; | |
497 | sreq.nr_sectors = 0; | |
498 | if (!lo->sock) | |
499 | return -EINVAL; | |
500 | nbd_send_req(lo, &sreq); | |
501 | return 0; | |
502 | ||
503 | case NBD_CLEAR_SOCK: | |
504 | error = 0; | |
82d4dc5a | 505 | mutex_lock(&lo->tx_lock); |
1da177e4 | 506 | lo->sock = NULL; |
82d4dc5a | 507 | mutex_unlock(&lo->tx_lock); |
1da177e4 LT |
508 | file = lo->file; |
509 | lo->file = NULL; | |
1da177e4 | 510 | nbd_clear_que(lo); |
4b2f0260 | 511 | BUG_ON(!list_empty(&lo->queue_head)); |
1da177e4 LT |
512 | if (file) |
513 | fput(file); | |
514 | return error; | |
515 | case NBD_SET_SOCK: | |
516 | if (lo->file) | |
517 | return -EBUSY; | |
518 | error = -EINVAL; | |
519 | file = fget(arg); | |
520 | if (file) { | |
521 | inode = file->f_dentry->d_inode; | |
522 | if (S_ISSOCK(inode->i_mode)) { | |
523 | lo->file = file; | |
524 | lo->sock = SOCKET_I(inode); | |
525 | error = 0; | |
526 | } else { | |
527 | fput(file); | |
528 | } | |
529 | } | |
530 | return error; | |
531 | case NBD_SET_BLKSIZE: | |
532 | lo->blksize = arg; | |
533 | lo->bytesize &= ~(lo->blksize-1); | |
534 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
535 | set_blocksize(inode->i_bdev, lo->blksize); | |
536 | set_capacity(lo->disk, lo->bytesize >> 9); | |
537 | return 0; | |
538 | case NBD_SET_SIZE: | |
539 | lo->bytesize = arg & ~(lo->blksize-1); | |
540 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
541 | set_blocksize(inode->i_bdev, lo->blksize); | |
542 | set_capacity(lo->disk, lo->bytesize >> 9); | |
543 | return 0; | |
544 | case NBD_SET_SIZE_BLOCKS: | |
545 | lo->bytesize = ((u64) arg) * lo->blksize; | |
546 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
547 | set_blocksize(inode->i_bdev, lo->blksize); | |
548 | set_capacity(lo->disk, lo->bytesize >> 9); | |
549 | return 0; | |
550 | case NBD_DO_IT: | |
551 | if (!lo->file) | |
552 | return -EINVAL; | |
553 | nbd_do_it(lo); | |
554 | /* on return tidy up in case we have a signal */ | |
555 | /* Forcibly shutdown the socket causing all listeners | |
556 | * to error | |
557 | * | |
558 | * FIXME: This code is duplicated from sys_shutdown, but | |
559 | * there should be a more generic interface rather than | |
560 | * calling socket ops directly here */ | |
82d4dc5a | 561 | mutex_lock(&lo->tx_lock); |
1da177e4 LT |
562 | if (lo->sock) { |
563 | printk(KERN_WARNING "%s: shutting down socket\n", | |
564 | lo->disk->disk_name); | |
565 | lo->sock->ops->shutdown(lo->sock, | |
566 | SEND_SHUTDOWN|RCV_SHUTDOWN); | |
567 | lo->sock = NULL; | |
568 | } | |
82d4dc5a | 569 | mutex_unlock(&lo->tx_lock); |
1da177e4 LT |
570 | file = lo->file; |
571 | lo->file = NULL; | |
1da177e4 LT |
572 | nbd_clear_que(lo); |
573 | printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); | |
574 | if (file) | |
575 | fput(file); | |
576 | return lo->harderror; | |
577 | case NBD_CLEAR_QUE: | |
4b2f0260 HX |
578 | /* |
579 | * This is for compatibility only. The queue is always cleared | |
580 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
581 | */ | |
582 | BUG_ON(!lo->sock && !list_empty(&lo->queue_head)); | |
1da177e4 LT |
583 | return 0; |
584 | case NBD_PRINT_DEBUG: | |
585 | printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n", | |
586 | inode->i_bdev->bd_disk->disk_name, | |
587 | lo->queue_head.next, lo->queue_head.prev, | |
588 | &lo->queue_head); | |
589 | return 0; | |
590 | } | |
591 | return -EINVAL; | |
592 | } | |
593 | ||
594 | static struct block_device_operations nbd_fops = | |
595 | { | |
596 | .owner = THIS_MODULE, | |
597 | .ioctl = nbd_ioctl, | |
598 | }; | |
599 | ||
600 | /* | |
601 | * And here should be modules and kernel interface | |
602 | * (Just smiley confuses emacs :-) | |
603 | */ | |
604 | ||
605 | static int __init nbd_init(void) | |
606 | { | |
607 | int err = -ENOMEM; | |
608 | int i; | |
609 | ||
5b7b18cc | 610 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 611 | |
40be0c28 LMB |
612 | if (nbds_max > MAX_NBD) { |
613 | printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD, | |
614 | nbds_max); | |
615 | return -EINVAL; | |
616 | } | |
617 | ||
618 | for (i = 0; i < nbds_max; i++) { | |
1da177e4 LT |
619 | struct gendisk *disk = alloc_disk(1); |
620 | if (!disk) | |
621 | goto out; | |
622 | nbd_dev[i].disk = disk; | |
623 | /* | |
624 | * The new linux 2.5 block layer implementation requires | |
625 | * every gendisk to have its very own request_queue struct. | |
626 | * These structs are big so we dynamically allocate them. | |
627 | */ | |
628 | disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); | |
629 | if (!disk->queue) { | |
630 | put_disk(disk); | |
631 | goto out; | |
632 | } | |
633 | } | |
634 | ||
635 | if (register_blkdev(NBD_MAJOR, "nbd")) { | |
636 | err = -EIO; | |
637 | goto out; | |
638 | } | |
639 | ||
640 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); | |
641 | dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); | |
642 | ||
40be0c28 | 643 | for (i = 0; i < nbds_max; i++) { |
1da177e4 LT |
644 | struct gendisk *disk = nbd_dev[i].disk; |
645 | nbd_dev[i].file = NULL; | |
646 | nbd_dev[i].magic = LO_MAGIC; | |
647 | nbd_dev[i].flags = 0; | |
648 | spin_lock_init(&nbd_dev[i].queue_lock); | |
649 | INIT_LIST_HEAD(&nbd_dev[i].queue_head); | |
82d4dc5a | 650 | mutex_init(&nbd_dev[i].tx_lock); |
4b2f0260 | 651 | init_waitqueue_head(&nbd_dev[i].active_wq); |
1da177e4 LT |
652 | nbd_dev[i].blksize = 1024; |
653 | nbd_dev[i].bytesize = 0x7ffffc00ULL << 10; /* 2TB */ | |
654 | disk->major = NBD_MAJOR; | |
655 | disk->first_minor = i; | |
656 | disk->fops = &nbd_fops; | |
657 | disk->private_data = &nbd_dev[i]; | |
658 | disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO; | |
659 | sprintf(disk->disk_name, "nbd%d", i); | |
1da177e4 LT |
660 | set_capacity(disk, 0x7ffffc00ULL << 1); /* 2 TB */ |
661 | add_disk(disk); | |
662 | } | |
663 | ||
664 | return 0; | |
665 | out: | |
666 | while (i--) { | |
667 | blk_cleanup_queue(nbd_dev[i].disk->queue); | |
668 | put_disk(nbd_dev[i].disk); | |
669 | } | |
670 | return err; | |
671 | } | |
672 | ||
673 | static void __exit nbd_cleanup(void) | |
674 | { | |
675 | int i; | |
40be0c28 | 676 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 677 | struct gendisk *disk = nbd_dev[i].disk; |
40be0c28 | 678 | nbd_dev[i].magic = 0; |
1da177e4 LT |
679 | if (disk) { |
680 | del_gendisk(disk); | |
681 | blk_cleanup_queue(disk->queue); | |
682 | put_disk(disk); | |
683 | } | |
684 | } | |
1da177e4 LT |
685 | unregister_blkdev(NBD_MAJOR, "nbd"); |
686 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); | |
687 | } | |
688 | ||
689 | module_init(nbd_init); | |
690 | module_exit(nbd_cleanup); | |
691 | ||
692 | MODULE_DESCRIPTION("Network Block Device"); | |
693 | MODULE_LICENSE("GPL"); | |
694 | ||
40be0c28 LMB |
695 | module_param(nbds_max, int, 0444); |
696 | MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize."); | |
1da177e4 LT |
697 | #ifndef NDEBUG |
698 | module_param(debugflags, int, 0644); | |
699 | MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); | |
700 | #endif |