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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 | 30 | #include <net/sock.h> |
91cf45f0 | 31 | #include <linux/net.h> |
1da177e4 | 32 | |
1da177e4 | 33 | #include <asm/uaccess.h> |
4b2f0260 | 34 | #include <asm/system.h> |
1da177e4 LT |
35 | #include <asm/types.h> |
36 | ||
37 | #include <linux/nbd.h> | |
38 | ||
39 | #define LO_MAGIC 0x68797548 | |
40 | ||
41 | #ifdef NDEBUG | |
42 | #define dprintk(flags, fmt...) | |
43 | #else /* NDEBUG */ | |
44 | #define dprintk(flags, fmt...) do { \ | |
45 | if (debugflags & (flags)) printk(KERN_DEBUG fmt); \ | |
46 | } while (0) | |
47 | #define DBG_IOCTL 0x0004 | |
48 | #define DBG_INIT 0x0010 | |
49 | #define DBG_EXIT 0x0020 | |
50 | #define DBG_BLKDEV 0x0100 | |
51 | #define DBG_RX 0x0200 | |
52 | #define DBG_TX 0x0400 | |
53 | static unsigned int debugflags; | |
54 | #endif /* NDEBUG */ | |
55 | ||
9c7a4169 | 56 | static unsigned int nbds_max = 16; |
20a8143e | 57 | static struct nbd_device *nbd_dev; |
1da177e4 LT |
58 | |
59 | /* | |
60 | * Use just one lock (or at most 1 per NIC). Two arguments for this: | |
61 | * 1. Each NIC is essentially a synchronization point for all servers | |
62 | * accessed through that NIC so there's no need to have more locks | |
63 | * than NICs anyway. | |
64 | * 2. More locks lead to more "Dirty cache line bouncing" which will slow | |
65 | * down each lock to the point where they're actually slower than just | |
66 | * a single lock. | |
67 | * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! | |
68 | */ | |
69 | static DEFINE_SPINLOCK(nbd_lock); | |
70 | ||
71 | #ifndef NDEBUG | |
72 | static const char *ioctl_cmd_to_ascii(int cmd) | |
73 | { | |
74 | switch (cmd) { | |
75 | case NBD_SET_SOCK: return "set-sock"; | |
76 | case NBD_SET_BLKSIZE: return "set-blksize"; | |
77 | case NBD_SET_SIZE: return "set-size"; | |
78 | case NBD_DO_IT: return "do-it"; | |
79 | case NBD_CLEAR_SOCK: return "clear-sock"; | |
80 | case NBD_CLEAR_QUE: return "clear-que"; | |
81 | case NBD_PRINT_DEBUG: return "print-debug"; | |
82 | case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; | |
83 | case NBD_DISCONNECT: return "disconnect"; | |
84 | case BLKROSET: return "set-read-only"; | |
85 | case BLKFLSBUF: return "flush-buffer-cache"; | |
86 | } | |
87 | return "unknown"; | |
88 | } | |
89 | ||
90 | static const char *nbdcmd_to_ascii(int cmd) | |
91 | { | |
92 | switch (cmd) { | |
93 | case NBD_CMD_READ: return "read"; | |
94 | case NBD_CMD_WRITE: return "write"; | |
95 | case NBD_CMD_DISC: return "disconnect"; | |
96 | } | |
97 | return "invalid"; | |
98 | } | |
99 | #endif /* NDEBUG */ | |
100 | ||
101 | static void nbd_end_request(struct request *req) | |
102 | { | |
097c94a4 | 103 | int error = req->errors ? -EIO : 0; |
165125e1 | 104 | struct request_queue *q = req->q; |
1da177e4 LT |
105 | unsigned long flags; |
106 | ||
107 | dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, | |
097c94a4 | 108 | req, error ? "failed" : "done"); |
1da177e4 LT |
109 | |
110 | spin_lock_irqsave(q->queue_lock, flags); | |
097c94a4 | 111 | __blk_end_request(req, error, req->nr_sectors << 9); |
1da177e4 LT |
112 | spin_unlock_irqrestore(q->queue_lock, flags); |
113 | } | |
114 | ||
7fdfd406 PC |
115 | static void sock_shutdown(struct nbd_device *lo, int lock) |
116 | { | |
117 | /* Forcibly shutdown the socket causing all listeners | |
118 | * to error | |
119 | * | |
120 | * FIXME: This code is duplicated from sys_shutdown, but | |
121 | * there should be a more generic interface rather than | |
122 | * calling socket ops directly here */ | |
123 | if (lock) | |
124 | mutex_lock(&lo->tx_lock); | |
125 | if (lo->sock) { | |
126 | printk(KERN_WARNING "%s: shutting down socket\n", | |
127 | lo->disk->disk_name); | |
91cf45f0 | 128 | kernel_sock_shutdown(lo->sock, SHUT_RDWR); |
7fdfd406 PC |
129 | lo->sock = NULL; |
130 | } | |
131 | if (lock) | |
132 | mutex_unlock(&lo->tx_lock); | |
133 | } | |
134 | ||
135 | static void nbd_xmit_timeout(unsigned long arg) | |
136 | { | |
137 | struct task_struct *task = (struct task_struct *)arg; | |
138 | ||
139 | printk(KERN_WARNING "nbd: killing hung xmit (%s, pid: %d)\n", | |
140 | task->comm, task->pid); | |
141 | force_sig(SIGKILL, task); | |
142 | } | |
143 | ||
1da177e4 LT |
144 | /* |
145 | * Send or receive packet. | |
146 | */ | |
7fdfd406 | 147 | static int sock_xmit(struct nbd_device *lo, int send, void *buf, int size, |
1da177e4 LT |
148 | int msg_flags) |
149 | { | |
7fdfd406 | 150 | struct socket *sock = lo->sock; |
1da177e4 LT |
151 | int result; |
152 | struct msghdr msg; | |
153 | struct kvec iov; | |
be0ef957 | 154 | sigset_t blocked, oldset; |
1da177e4 LT |
155 | |
156 | /* Allow interception of SIGKILL only | |
157 | * Don't allow other signals to interrupt the transmission */ | |
be0ef957 ON |
158 | siginitsetinv(&blocked, sigmask(SIGKILL)); |
159 | sigprocmask(SIG_SETMASK, &blocked, &oldset); | |
1da177e4 LT |
160 | |
161 | do { | |
162 | sock->sk->sk_allocation = GFP_NOIO; | |
163 | iov.iov_base = buf; | |
164 | iov.iov_len = size; | |
165 | msg.msg_name = NULL; | |
166 | msg.msg_namelen = 0; | |
167 | msg.msg_control = NULL; | |
168 | msg.msg_controllen = 0; | |
1da177e4 LT |
169 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
170 | ||
7fdfd406 PC |
171 | if (send) { |
172 | struct timer_list ti; | |
173 | ||
174 | if (lo->xmit_timeout) { | |
175 | init_timer(&ti); | |
176 | ti.function = nbd_xmit_timeout; | |
177 | ti.data = (unsigned long)current; | |
178 | ti.expires = jiffies + lo->xmit_timeout; | |
179 | add_timer(&ti); | |
180 | } | |
1da177e4 | 181 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
7fdfd406 PC |
182 | if (lo->xmit_timeout) |
183 | del_timer_sync(&ti); | |
184 | } else | |
1da177e4 LT |
185 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); |
186 | ||
187 | if (signal_pending(current)) { | |
188 | siginfo_t info; | |
1da177e4 | 189 | printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", |
ba25f9dc | 190 | task_pid_nr(current), current->comm, |
be0ef957 | 191 | dequeue_signal_lock(current, ¤t->blocked, &info)); |
1da177e4 | 192 | result = -EINTR; |
7fdfd406 | 193 | sock_shutdown(lo, !send); |
1da177e4 LT |
194 | break; |
195 | } | |
196 | ||
197 | if (result <= 0) { | |
198 | if (result == 0) | |
199 | result = -EPIPE; /* short read */ | |
200 | break; | |
201 | } | |
202 | size -= result; | |
203 | buf += result; | |
204 | } while (size > 0); | |
205 | ||
be0ef957 | 206 | sigprocmask(SIG_SETMASK, &oldset, NULL); |
1da177e4 LT |
207 | |
208 | return result; | |
209 | } | |
210 | ||
7fdfd406 | 211 | static inline int sock_send_bvec(struct nbd_device *lo, struct bio_vec *bvec, |
1da177e4 LT |
212 | int flags) |
213 | { | |
214 | int result; | |
215 | void *kaddr = kmap(bvec->bv_page); | |
7fdfd406 | 216 | result = sock_xmit(lo, 1, kaddr + bvec->bv_offset, bvec->bv_len, flags); |
1da177e4 LT |
217 | kunmap(bvec->bv_page); |
218 | return result; | |
219 | } | |
220 | ||
7fdfd406 | 221 | /* always call with the tx_lock held */ |
1da177e4 LT |
222 | static int nbd_send_req(struct nbd_device *lo, struct request *req) |
223 | { | |
5705f702 | 224 | int result, flags; |
1da177e4 LT |
225 | struct nbd_request request; |
226 | unsigned long size = req->nr_sectors << 9; | |
1da177e4 LT |
227 | |
228 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
229 | request.type = htonl(nbd_cmd(req)); | |
230 | request.from = cpu_to_be64((u64) req->sector << 9); | |
231 | request.len = htonl(size); | |
232 | memcpy(request.handle, &req, sizeof(req)); | |
233 | ||
1da177e4 LT |
234 | dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", |
235 | lo->disk->disk_name, req, | |
236 | nbdcmd_to_ascii(nbd_cmd(req)), | |
237 | (unsigned long long)req->sector << 9, | |
238 | req->nr_sectors << 9); | |
7fdfd406 PC |
239 | result = sock_xmit(lo, 1, &request, sizeof(request), |
240 | (nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0); | |
1da177e4 LT |
241 | if (result <= 0) { |
242 | printk(KERN_ERR "%s: Send control failed (result %d)\n", | |
243 | lo->disk->disk_name, result); | |
244 | goto error_out; | |
245 | } | |
246 | ||
247 | if (nbd_cmd(req) == NBD_CMD_WRITE) { | |
5705f702 N |
248 | struct req_iterator iter; |
249 | struct bio_vec *bvec; | |
1da177e4 LT |
250 | /* |
251 | * we are really probing at internals to determine | |
252 | * whether to set MSG_MORE or not... | |
253 | */ | |
5705f702 | 254 | rq_for_each_segment(bvec, req, iter) { |
6c92e699 JA |
255 | flags = 0; |
256 | if (!rq_iter_last(req, iter)) | |
257 | flags = MSG_MORE; | |
258 | dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", | |
259 | lo->disk->disk_name, req, bvec->bv_len); | |
7fdfd406 | 260 | result = sock_send_bvec(lo, bvec, flags); |
6c92e699 JA |
261 | if (result <= 0) { |
262 | printk(KERN_ERR "%s: Send data failed (result %d)\n", | |
263 | lo->disk->disk_name, result); | |
264 | goto error_out; | |
265 | } | |
1da177e4 LT |
266 | } |
267 | } | |
1da177e4 LT |
268 | return 0; |
269 | ||
270 | error_out: | |
1da177e4 LT |
271 | return 1; |
272 | } | |
273 | ||
0cbc591b DC |
274 | static struct request *nbd_find_request(struct nbd_device *lo, |
275 | struct request *xreq) | |
1da177e4 | 276 | { |
d2c9740b | 277 | struct request *req, *tmp; |
4b2f0260 | 278 | int err; |
1da177e4 | 279 | |
4b2f0260 HX |
280 | err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); |
281 | if (unlikely(err)) | |
282 | goto out; | |
283 | ||
1da177e4 | 284 | spin_lock(&lo->queue_lock); |
d2c9740b | 285 | list_for_each_entry_safe(req, tmp, &lo->queue_head, queuelist) { |
1da177e4 LT |
286 | if (req != xreq) |
287 | continue; | |
288 | list_del_init(&req->queuelist); | |
289 | spin_unlock(&lo->queue_lock); | |
290 | return req; | |
291 | } | |
292 | spin_unlock(&lo->queue_lock); | |
4b2f0260 HX |
293 | |
294 | err = -ENOENT; | |
295 | ||
296 | out: | |
297 | return ERR_PTR(err); | |
1da177e4 LT |
298 | } |
299 | ||
7fdfd406 | 300 | static inline int sock_recv_bvec(struct nbd_device *lo, struct bio_vec *bvec) |
1da177e4 LT |
301 | { |
302 | int result; | |
303 | void *kaddr = kmap(bvec->bv_page); | |
7fdfd406 | 304 | result = sock_xmit(lo, 0, kaddr + bvec->bv_offset, bvec->bv_len, |
1da177e4 LT |
305 | MSG_WAITALL); |
306 | kunmap(bvec->bv_page); | |
307 | return result; | |
308 | } | |
309 | ||
310 | /* NULL returned = something went wrong, inform userspace */ | |
311 | static struct request *nbd_read_stat(struct nbd_device *lo) | |
312 | { | |
313 | int result; | |
314 | struct nbd_reply reply; | |
315 | struct request *req; | |
1da177e4 LT |
316 | |
317 | reply.magic = 0; | |
7fdfd406 | 318 | result = sock_xmit(lo, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 LT |
319 | if (result <= 0) { |
320 | printk(KERN_ERR "%s: Receive control failed (result %d)\n", | |
321 | lo->disk->disk_name, result); | |
322 | goto harderror; | |
323 | } | |
e4b57e08 MF |
324 | |
325 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
326 | printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", | |
327 | lo->disk->disk_name, | |
328 | (unsigned long)ntohl(reply.magic)); | |
329 | result = -EPROTO; | |
330 | goto harderror; | |
331 | } | |
332 | ||
0cbc591b | 333 | req = nbd_find_request(lo, *(struct request **)reply.handle); |
4b2f0260 HX |
334 | if (unlikely(IS_ERR(req))) { |
335 | result = PTR_ERR(req); | |
336 | if (result != -ENOENT) | |
337 | goto harderror; | |
338 | ||
1da177e4 LT |
339 | printk(KERN_ERR "%s: Unexpected reply (%p)\n", |
340 | lo->disk->disk_name, reply.handle); | |
341 | result = -EBADR; | |
342 | goto harderror; | |
343 | } | |
344 | ||
1da177e4 LT |
345 | if (ntohl(reply.error)) { |
346 | printk(KERN_ERR "%s: Other side returned error (%d)\n", | |
347 | lo->disk->disk_name, ntohl(reply.error)); | |
348 | req->errors++; | |
349 | return req; | |
350 | } | |
351 | ||
352 | dprintk(DBG_RX, "%s: request %p: got reply\n", | |
353 | lo->disk->disk_name, req); | |
354 | if (nbd_cmd(req) == NBD_CMD_READ) { | |
5705f702 N |
355 | struct req_iterator iter; |
356 | struct bio_vec *bvec; | |
357 | ||
358 | rq_for_each_segment(bvec, req, iter) { | |
7fdfd406 | 359 | result = sock_recv_bvec(lo, bvec); |
6c92e699 JA |
360 | if (result <= 0) { |
361 | printk(KERN_ERR "%s: Receive data failed (result %d)\n", | |
362 | lo->disk->disk_name, result); | |
363 | req->errors++; | |
364 | return req; | |
365 | } | |
366 | dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", | |
367 | lo->disk->disk_name, req, bvec->bv_len); | |
1da177e4 LT |
368 | } |
369 | } | |
370 | return req; | |
371 | harderror: | |
372 | lo->harderror = result; | |
373 | return NULL; | |
374 | } | |
375 | ||
edfaa7c3 KS |
376 | static ssize_t pid_show(struct device *dev, |
377 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 378 | { |
edfaa7c3 KS |
379 | struct gendisk *disk = dev_to_disk(dev); |
380 | ||
381 | return sprintf(buf, "%ld\n", | |
6b39bb65 PC |
382 | (long) ((struct nbd_device *)disk->private_data)->pid); |
383 | } | |
384 | ||
edfaa7c3 KS |
385 | static struct device_attribute pid_attr = { |
386 | .attr = { .name = "pid", .mode = S_IRUGO, .owner = THIS_MODULE }, | |
6b39bb65 PC |
387 | .show = pid_show, |
388 | }; | |
389 | ||
84963048 | 390 | static int nbd_do_it(struct nbd_device *lo) |
1da177e4 LT |
391 | { |
392 | struct request *req; | |
84963048 | 393 | int ret; |
1da177e4 LT |
394 | |
395 | BUG_ON(lo->magic != LO_MAGIC); | |
396 | ||
6b39bb65 | 397 | lo->pid = current->pid; |
edfaa7c3 | 398 | ret = sysfs_create_file(&lo->disk->dev.kobj, &pid_attr.attr); |
84963048 WC |
399 | if (ret) { |
400 | printk(KERN_ERR "nbd: sysfs_create_file failed!"); | |
401 | return ret; | |
402 | } | |
6b39bb65 | 403 | |
1da177e4 LT |
404 | while ((req = nbd_read_stat(lo)) != NULL) |
405 | nbd_end_request(req); | |
6b39bb65 | 406 | |
edfaa7c3 | 407 | sysfs_remove_file(&lo->disk->dev.kobj, &pid_attr.attr); |
84963048 | 408 | return 0; |
1da177e4 LT |
409 | } |
410 | ||
411 | static void nbd_clear_que(struct nbd_device *lo) | |
412 | { | |
413 | struct request *req; | |
414 | ||
415 | BUG_ON(lo->magic != LO_MAGIC); | |
416 | ||
4b2f0260 HX |
417 | /* |
418 | * Because we have set lo->sock to NULL under the tx_lock, all | |
419 | * modifications to the list must have completed by now. For | |
420 | * the same reason, the active_req must be NULL. | |
421 | * | |
422 | * As a consequence, we don't need to take the spin lock while | |
423 | * purging the list here. | |
424 | */ | |
425 | BUG_ON(lo->sock); | |
426 | BUG_ON(lo->active_req); | |
427 | ||
428 | while (!list_empty(&lo->queue_head)) { | |
429 | req = list_entry(lo->queue_head.next, struct request, | |
430 | queuelist); | |
431 | list_del_init(&req->queuelist); | |
432 | req->errors++; | |
433 | nbd_end_request(req); | |
434 | } | |
1da177e4 LT |
435 | } |
436 | ||
7fdfd406 | 437 | |
1da177e4 LT |
438 | /* |
439 | * We always wait for result of write, for now. It would be nice to make it optional | |
440 | * in future | |
e654bc43 | 441 | * if ((rq_data_dir(req) == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) |
1da177e4 LT |
442 | * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } |
443 | */ | |
444 | ||
165125e1 | 445 | static void do_nbd_request(struct request_queue * q) |
1da177e4 LT |
446 | { |
447 | struct request *req; | |
448 | ||
449 | while ((req = elv_next_request(q)) != NULL) { | |
450 | struct nbd_device *lo; | |
451 | ||
452 | blkdev_dequeue_request(req); | |
4aff5e23 JA |
453 | dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n", |
454 | req->rq_disk->disk_name, req, req->cmd_type); | |
1da177e4 | 455 | |
4aff5e23 | 456 | if (!blk_fs_request(req)) |
1da177e4 LT |
457 | goto error_out; |
458 | ||
459 | lo = req->rq_disk->private_data; | |
460 | ||
461 | BUG_ON(lo->magic != LO_MAGIC); | |
462 | ||
1da177e4 LT |
463 | nbd_cmd(req) = NBD_CMD_READ; |
464 | if (rq_data_dir(req) == WRITE) { | |
465 | nbd_cmd(req) = NBD_CMD_WRITE; | |
466 | if (lo->flags & NBD_READ_ONLY) { | |
467 | printk(KERN_ERR "%s: Write on read-only\n", | |
468 | lo->disk->disk_name); | |
469 | goto error_out; | |
470 | } | |
471 | } | |
472 | ||
473 | req->errors = 0; | |
474 | spin_unlock_irq(q->queue_lock); | |
475 | ||
82d4dc5a | 476 | mutex_lock(&lo->tx_lock); |
4b2f0260 | 477 | if (unlikely(!lo->sock)) { |
82d4dc5a | 478 | mutex_unlock(&lo->tx_lock); |
4b2f0260 HX |
479 | printk(KERN_ERR "%s: Attempted send on closed socket\n", |
480 | lo->disk->disk_name); | |
1da177e4 LT |
481 | req->errors++; |
482 | nbd_end_request(req); | |
483 | spin_lock_irq(q->queue_lock); | |
484 | continue; | |
485 | } | |
486 | ||
4b2f0260 | 487 | lo->active_req = req; |
1da177e4 LT |
488 | |
489 | if (nbd_send_req(lo, req) != 0) { | |
490 | printk(KERN_ERR "%s: Request send failed\n", | |
491 | lo->disk->disk_name); | |
4b2f0260 HX |
492 | req->errors++; |
493 | nbd_end_request(req); | |
494 | } else { | |
495 | spin_lock(&lo->queue_lock); | |
496 | list_add(&req->queuelist, &lo->queue_head); | |
497 | spin_unlock(&lo->queue_lock); | |
1da177e4 LT |
498 | } |
499 | ||
4b2f0260 | 500 | lo->active_req = NULL; |
82d4dc5a | 501 | mutex_unlock(&lo->tx_lock); |
4b2f0260 HX |
502 | wake_up_all(&lo->active_wq); |
503 | ||
1da177e4 LT |
504 | spin_lock_irq(q->queue_lock); |
505 | continue; | |
506 | ||
507 | error_out: | |
508 | req->errors++; | |
509 | spin_unlock(q->queue_lock); | |
510 | nbd_end_request(req); | |
511 | spin_lock(q->queue_lock); | |
512 | } | |
1da177e4 LT |
513 | } |
514 | ||
515 | static int nbd_ioctl(struct inode *inode, struct file *file, | |
516 | unsigned int cmd, unsigned long arg) | |
517 | { | |
518 | struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; | |
519 | int error; | |
520 | struct request sreq ; | |
521 | ||
522 | if (!capable(CAP_SYS_ADMIN)) | |
523 | return -EPERM; | |
524 | ||
525 | BUG_ON(lo->magic != LO_MAGIC); | |
526 | ||
527 | /* Anyone capable of this syscall can do *real bad* things */ | |
528 | dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", | |
529 | lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); | |
530 | ||
531 | switch (cmd) { | |
532 | case NBD_DISCONNECT: | |
533 | printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name); | |
4aff5e23 | 534 | sreq.cmd_type = REQ_TYPE_SPECIAL; |
1da177e4 LT |
535 | nbd_cmd(&sreq) = NBD_CMD_DISC; |
536 | /* | |
537 | * Set these to sane values in case server implementation | |
538 | * fails to check the request type first and also to keep | |
539 | * debugging output cleaner. | |
540 | */ | |
541 | sreq.sector = 0; | |
542 | sreq.nr_sectors = 0; | |
543 | if (!lo->sock) | |
544 | return -EINVAL; | |
7fdfd406 | 545 | mutex_lock(&lo->tx_lock); |
1da177e4 | 546 | nbd_send_req(lo, &sreq); |
7fdfd406 | 547 | mutex_unlock(&lo->tx_lock); |
1da177e4 LT |
548 | return 0; |
549 | ||
550 | case NBD_CLEAR_SOCK: | |
551 | error = 0; | |
82d4dc5a | 552 | mutex_lock(&lo->tx_lock); |
1da177e4 | 553 | lo->sock = NULL; |
82d4dc5a | 554 | mutex_unlock(&lo->tx_lock); |
1da177e4 LT |
555 | file = lo->file; |
556 | lo->file = NULL; | |
1da177e4 | 557 | nbd_clear_que(lo); |
4b2f0260 | 558 | BUG_ON(!list_empty(&lo->queue_head)); |
1da177e4 LT |
559 | if (file) |
560 | fput(file); | |
561 | return error; | |
562 | case NBD_SET_SOCK: | |
563 | if (lo->file) | |
564 | return -EBUSY; | |
565 | error = -EINVAL; | |
566 | file = fget(arg); | |
567 | if (file) { | |
17506041 | 568 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
569 | if (S_ISSOCK(inode->i_mode)) { |
570 | lo->file = file; | |
571 | lo->sock = SOCKET_I(inode); | |
572 | error = 0; | |
573 | } else { | |
574 | fput(file); | |
575 | } | |
576 | } | |
577 | return error; | |
578 | case NBD_SET_BLKSIZE: | |
579 | lo->blksize = arg; | |
580 | lo->bytesize &= ~(lo->blksize-1); | |
581 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
582 | set_blocksize(inode->i_bdev, lo->blksize); | |
583 | set_capacity(lo->disk, lo->bytesize >> 9); | |
584 | return 0; | |
585 | case NBD_SET_SIZE: | |
586 | lo->bytesize = arg & ~(lo->blksize-1); | |
587 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
588 | set_blocksize(inode->i_bdev, lo->blksize); | |
589 | set_capacity(lo->disk, lo->bytesize >> 9); | |
590 | return 0; | |
7fdfd406 PC |
591 | case NBD_SET_TIMEOUT: |
592 | lo->xmit_timeout = arg * HZ; | |
593 | return 0; | |
1da177e4 LT |
594 | case NBD_SET_SIZE_BLOCKS: |
595 | lo->bytesize = ((u64) arg) * lo->blksize; | |
596 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
597 | set_blocksize(inode->i_bdev, lo->blksize); | |
598 | set_capacity(lo->disk, lo->bytesize >> 9); | |
599 | return 0; | |
600 | case NBD_DO_IT: | |
601 | if (!lo->file) | |
602 | return -EINVAL; | |
84963048 WC |
603 | error = nbd_do_it(lo); |
604 | if (error) | |
605 | return error; | |
7fdfd406 | 606 | sock_shutdown(lo, 1); |
1da177e4 LT |
607 | file = lo->file; |
608 | lo->file = NULL; | |
1da177e4 LT |
609 | nbd_clear_que(lo); |
610 | printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); | |
611 | if (file) | |
612 | fput(file); | |
4b86a872 PC |
613 | lo->bytesize = 0; |
614 | inode->i_bdev->bd_inode->i_size = 0; | |
615 | set_capacity(lo->disk, 0); | |
1da177e4 LT |
616 | return lo->harderror; |
617 | case NBD_CLEAR_QUE: | |
4b2f0260 HX |
618 | /* |
619 | * This is for compatibility only. The queue is always cleared | |
620 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
621 | */ | |
622 | BUG_ON(!lo->sock && !list_empty(&lo->queue_head)); | |
1da177e4 LT |
623 | return 0; |
624 | case NBD_PRINT_DEBUG: | |
625 | printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n", | |
626 | inode->i_bdev->bd_disk->disk_name, | |
627 | lo->queue_head.next, lo->queue_head.prev, | |
628 | &lo->queue_head); | |
629 | return 0; | |
630 | } | |
631 | return -EINVAL; | |
632 | } | |
633 | ||
634 | static struct block_device_operations nbd_fops = | |
635 | { | |
636 | .owner = THIS_MODULE, | |
637 | .ioctl = nbd_ioctl, | |
638 | }; | |
639 | ||
640 | /* | |
641 | * And here should be modules and kernel interface | |
642 | * (Just smiley confuses emacs :-) | |
643 | */ | |
644 | ||
645 | static int __init nbd_init(void) | |
646 | { | |
647 | int err = -ENOMEM; | |
648 | int i; | |
649 | ||
5b7b18cc | 650 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 651 | |
20a8143e PC |
652 | nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL); |
653 | if (!nbd_dev) | |
654 | return -ENOMEM; | |
40be0c28 LMB |
655 | |
656 | for (i = 0; i < nbds_max; i++) { | |
1da177e4 LT |
657 | struct gendisk *disk = alloc_disk(1); |
658 | if (!disk) | |
659 | goto out; | |
660 | nbd_dev[i].disk = disk; | |
661 | /* | |
662 | * The new linux 2.5 block layer implementation requires | |
663 | * every gendisk to have its very own request_queue struct. | |
664 | * These structs are big so we dynamically allocate them. | |
665 | */ | |
666 | disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); | |
667 | if (!disk->queue) { | |
668 | put_disk(disk); | |
669 | goto out; | |
670 | } | |
671 | } | |
672 | ||
673 | if (register_blkdev(NBD_MAJOR, "nbd")) { | |
674 | err = -EIO; | |
675 | goto out; | |
676 | } | |
677 | ||
678 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); | |
679 | dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); | |
680 | ||
40be0c28 | 681 | for (i = 0; i < nbds_max; i++) { |
1da177e4 LT |
682 | struct gendisk *disk = nbd_dev[i].disk; |
683 | nbd_dev[i].file = NULL; | |
684 | nbd_dev[i].magic = LO_MAGIC; | |
685 | nbd_dev[i].flags = 0; | |
686 | spin_lock_init(&nbd_dev[i].queue_lock); | |
687 | INIT_LIST_HEAD(&nbd_dev[i].queue_head); | |
82d4dc5a | 688 | mutex_init(&nbd_dev[i].tx_lock); |
4b2f0260 | 689 | init_waitqueue_head(&nbd_dev[i].active_wq); |
1da177e4 | 690 | nbd_dev[i].blksize = 1024; |
4b86a872 | 691 | nbd_dev[i].bytesize = 0; |
1da177e4 LT |
692 | disk->major = NBD_MAJOR; |
693 | disk->first_minor = i; | |
694 | disk->fops = &nbd_fops; | |
695 | disk->private_data = &nbd_dev[i]; | |
696 | disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO; | |
697 | sprintf(disk->disk_name, "nbd%d", i); | |
4b86a872 | 698 | set_capacity(disk, 0); |
1da177e4 LT |
699 | add_disk(disk); |
700 | } | |
701 | ||
702 | return 0; | |
703 | out: | |
704 | while (i--) { | |
705 | blk_cleanup_queue(nbd_dev[i].disk->queue); | |
706 | put_disk(nbd_dev[i].disk); | |
707 | } | |
708 | return err; | |
709 | } | |
710 | ||
711 | static void __exit nbd_cleanup(void) | |
712 | { | |
713 | int i; | |
40be0c28 | 714 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 715 | struct gendisk *disk = nbd_dev[i].disk; |
40be0c28 | 716 | nbd_dev[i].magic = 0; |
1da177e4 LT |
717 | if (disk) { |
718 | del_gendisk(disk); | |
719 | blk_cleanup_queue(disk->queue); | |
720 | put_disk(disk); | |
721 | } | |
722 | } | |
1da177e4 LT |
723 | unregister_blkdev(NBD_MAJOR, "nbd"); |
724 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); | |
725 | } | |
726 | ||
727 | module_init(nbd_init); | |
728 | module_exit(nbd_cleanup); | |
729 | ||
730 | MODULE_DESCRIPTION("Network Block Device"); | |
731 | MODULE_LICENSE("GPL"); | |
732 | ||
40be0c28 LMB |
733 | module_param(nbds_max, int, 0444); |
734 | MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize."); | |
1da177e4 LT |
735 | #ifndef NDEBUG |
736 | module_param(debugflags, int, 0644); | |
737 | MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); | |
738 | #endif |