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 | 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 | 155 | |
ffc41cf8 MS |
156 | if (unlikely(!sock)) { |
157 | printk(KERN_ERR "%s: Attempted %s on closed socket in sock_xmit\n", | |
158 | lo->disk->disk_name, (send ? "send" : "recv")); | |
159 | return -EINVAL; | |
160 | } | |
161 | ||
1da177e4 LT |
162 | /* Allow interception of SIGKILL only |
163 | * Don't allow other signals to interrupt the transmission */ | |
be0ef957 ON |
164 | siginitsetinv(&blocked, sigmask(SIGKILL)); |
165 | sigprocmask(SIG_SETMASK, &blocked, &oldset); | |
1da177e4 LT |
166 | |
167 | do { | |
168 | sock->sk->sk_allocation = GFP_NOIO; | |
169 | iov.iov_base = buf; | |
170 | iov.iov_len = size; | |
171 | msg.msg_name = NULL; | |
172 | msg.msg_namelen = 0; | |
173 | msg.msg_control = NULL; | |
174 | msg.msg_controllen = 0; | |
1da177e4 LT |
175 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
176 | ||
7fdfd406 PC |
177 | if (send) { |
178 | struct timer_list ti; | |
179 | ||
180 | if (lo->xmit_timeout) { | |
181 | init_timer(&ti); | |
182 | ti.function = nbd_xmit_timeout; | |
183 | ti.data = (unsigned long)current; | |
184 | ti.expires = jiffies + lo->xmit_timeout; | |
185 | add_timer(&ti); | |
186 | } | |
1da177e4 | 187 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
7fdfd406 PC |
188 | if (lo->xmit_timeout) |
189 | del_timer_sync(&ti); | |
190 | } else | |
1da177e4 LT |
191 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); |
192 | ||
193 | if (signal_pending(current)) { | |
194 | siginfo_t info; | |
1da177e4 | 195 | printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", |
ba25f9dc | 196 | task_pid_nr(current), current->comm, |
be0ef957 | 197 | dequeue_signal_lock(current, ¤t->blocked, &info)); |
1da177e4 | 198 | result = -EINTR; |
7fdfd406 | 199 | sock_shutdown(lo, !send); |
1da177e4 LT |
200 | break; |
201 | } | |
202 | ||
203 | if (result <= 0) { | |
204 | if (result == 0) | |
205 | result = -EPIPE; /* short read */ | |
206 | break; | |
207 | } | |
208 | size -= result; | |
209 | buf += result; | |
210 | } while (size > 0); | |
211 | ||
be0ef957 | 212 | sigprocmask(SIG_SETMASK, &oldset, NULL); |
1da177e4 LT |
213 | |
214 | return result; | |
215 | } | |
216 | ||
7fdfd406 | 217 | static inline int sock_send_bvec(struct nbd_device *lo, struct bio_vec *bvec, |
1da177e4 LT |
218 | int flags) |
219 | { | |
220 | int result; | |
221 | void *kaddr = kmap(bvec->bv_page); | |
7fdfd406 | 222 | result = sock_xmit(lo, 1, kaddr + bvec->bv_offset, bvec->bv_len, flags); |
1da177e4 LT |
223 | kunmap(bvec->bv_page); |
224 | return result; | |
225 | } | |
226 | ||
7fdfd406 | 227 | /* always call with the tx_lock held */ |
1da177e4 LT |
228 | static int nbd_send_req(struct nbd_device *lo, struct request *req) |
229 | { | |
5705f702 | 230 | int result, flags; |
1da177e4 LT |
231 | struct nbd_request request; |
232 | unsigned long size = req->nr_sectors << 9; | |
1da177e4 LT |
233 | |
234 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
235 | request.type = htonl(nbd_cmd(req)); | |
236 | request.from = cpu_to_be64((u64) req->sector << 9); | |
237 | request.len = htonl(size); | |
238 | memcpy(request.handle, &req, sizeof(req)); | |
239 | ||
1da177e4 LT |
240 | dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", |
241 | lo->disk->disk_name, req, | |
242 | nbdcmd_to_ascii(nbd_cmd(req)), | |
243 | (unsigned long long)req->sector << 9, | |
244 | req->nr_sectors << 9); | |
7fdfd406 PC |
245 | result = sock_xmit(lo, 1, &request, sizeof(request), |
246 | (nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0); | |
1da177e4 LT |
247 | if (result <= 0) { |
248 | printk(KERN_ERR "%s: Send control failed (result %d)\n", | |
249 | lo->disk->disk_name, result); | |
250 | goto error_out; | |
251 | } | |
252 | ||
253 | if (nbd_cmd(req) == NBD_CMD_WRITE) { | |
5705f702 N |
254 | struct req_iterator iter; |
255 | struct bio_vec *bvec; | |
1da177e4 LT |
256 | /* |
257 | * we are really probing at internals to determine | |
258 | * whether to set MSG_MORE or not... | |
259 | */ | |
5705f702 | 260 | rq_for_each_segment(bvec, req, iter) { |
6c92e699 JA |
261 | flags = 0; |
262 | if (!rq_iter_last(req, iter)) | |
263 | flags = MSG_MORE; | |
264 | dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", | |
265 | lo->disk->disk_name, req, bvec->bv_len); | |
7fdfd406 | 266 | result = sock_send_bvec(lo, bvec, flags); |
6c92e699 JA |
267 | if (result <= 0) { |
268 | printk(KERN_ERR "%s: Send data failed (result %d)\n", | |
269 | lo->disk->disk_name, result); | |
270 | goto error_out; | |
271 | } | |
1da177e4 LT |
272 | } |
273 | } | |
1da177e4 LT |
274 | return 0; |
275 | ||
276 | error_out: | |
1da177e4 LT |
277 | return 1; |
278 | } | |
279 | ||
0cbc591b DC |
280 | static struct request *nbd_find_request(struct nbd_device *lo, |
281 | struct request *xreq) | |
1da177e4 | 282 | { |
d2c9740b | 283 | struct request *req, *tmp; |
4b2f0260 | 284 | int err; |
1da177e4 | 285 | |
4b2f0260 HX |
286 | err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); |
287 | if (unlikely(err)) | |
288 | goto out; | |
289 | ||
1da177e4 | 290 | spin_lock(&lo->queue_lock); |
d2c9740b | 291 | list_for_each_entry_safe(req, tmp, &lo->queue_head, queuelist) { |
1da177e4 LT |
292 | if (req != xreq) |
293 | continue; | |
294 | list_del_init(&req->queuelist); | |
295 | spin_unlock(&lo->queue_lock); | |
296 | return req; | |
297 | } | |
298 | spin_unlock(&lo->queue_lock); | |
4b2f0260 HX |
299 | |
300 | err = -ENOENT; | |
301 | ||
302 | out: | |
303 | return ERR_PTR(err); | |
1da177e4 LT |
304 | } |
305 | ||
7fdfd406 | 306 | static inline int sock_recv_bvec(struct nbd_device *lo, struct bio_vec *bvec) |
1da177e4 LT |
307 | { |
308 | int result; | |
309 | void *kaddr = kmap(bvec->bv_page); | |
7fdfd406 | 310 | result = sock_xmit(lo, 0, kaddr + bvec->bv_offset, bvec->bv_len, |
1da177e4 LT |
311 | MSG_WAITALL); |
312 | kunmap(bvec->bv_page); | |
313 | return result; | |
314 | } | |
315 | ||
316 | /* NULL returned = something went wrong, inform userspace */ | |
317 | static struct request *nbd_read_stat(struct nbd_device *lo) | |
318 | { | |
319 | int result; | |
320 | struct nbd_reply reply; | |
321 | struct request *req; | |
1da177e4 LT |
322 | |
323 | reply.magic = 0; | |
7fdfd406 | 324 | result = sock_xmit(lo, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 LT |
325 | if (result <= 0) { |
326 | printk(KERN_ERR "%s: Receive control failed (result %d)\n", | |
327 | lo->disk->disk_name, result); | |
328 | goto harderror; | |
329 | } | |
e4b57e08 MF |
330 | |
331 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
332 | printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", | |
333 | lo->disk->disk_name, | |
334 | (unsigned long)ntohl(reply.magic)); | |
335 | result = -EPROTO; | |
336 | goto harderror; | |
337 | } | |
338 | ||
0cbc591b | 339 | req = nbd_find_request(lo, *(struct request **)reply.handle); |
4b2f0260 HX |
340 | if (unlikely(IS_ERR(req))) { |
341 | result = PTR_ERR(req); | |
342 | if (result != -ENOENT) | |
343 | goto harderror; | |
344 | ||
1da177e4 LT |
345 | printk(KERN_ERR "%s: Unexpected reply (%p)\n", |
346 | lo->disk->disk_name, reply.handle); | |
347 | result = -EBADR; | |
348 | goto harderror; | |
349 | } | |
350 | ||
1da177e4 LT |
351 | if (ntohl(reply.error)) { |
352 | printk(KERN_ERR "%s: Other side returned error (%d)\n", | |
353 | lo->disk->disk_name, ntohl(reply.error)); | |
354 | req->errors++; | |
355 | return req; | |
356 | } | |
357 | ||
358 | dprintk(DBG_RX, "%s: request %p: got reply\n", | |
359 | lo->disk->disk_name, req); | |
360 | if (nbd_cmd(req) == NBD_CMD_READ) { | |
5705f702 N |
361 | struct req_iterator iter; |
362 | struct bio_vec *bvec; | |
363 | ||
364 | rq_for_each_segment(bvec, req, iter) { | |
7fdfd406 | 365 | result = sock_recv_bvec(lo, bvec); |
6c92e699 JA |
366 | if (result <= 0) { |
367 | printk(KERN_ERR "%s: Receive data failed (result %d)\n", | |
368 | lo->disk->disk_name, result); | |
369 | req->errors++; | |
370 | return req; | |
371 | } | |
372 | dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", | |
373 | lo->disk->disk_name, req, bvec->bv_len); | |
1da177e4 LT |
374 | } |
375 | } | |
376 | return req; | |
377 | harderror: | |
378 | lo->harderror = result; | |
379 | return NULL; | |
380 | } | |
381 | ||
edfaa7c3 KS |
382 | static ssize_t pid_show(struct device *dev, |
383 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 384 | { |
edfaa7c3 KS |
385 | struct gendisk *disk = dev_to_disk(dev); |
386 | ||
387 | return sprintf(buf, "%ld\n", | |
6b39bb65 PC |
388 | (long) ((struct nbd_device *)disk->private_data)->pid); |
389 | } | |
390 | ||
edfaa7c3 KS |
391 | static struct device_attribute pid_attr = { |
392 | .attr = { .name = "pid", .mode = S_IRUGO, .owner = THIS_MODULE }, | |
6b39bb65 PC |
393 | .show = pid_show, |
394 | }; | |
395 | ||
84963048 | 396 | static int nbd_do_it(struct nbd_device *lo) |
1da177e4 LT |
397 | { |
398 | struct request *req; | |
84963048 | 399 | int ret; |
1da177e4 LT |
400 | |
401 | BUG_ON(lo->magic != LO_MAGIC); | |
402 | ||
6b39bb65 | 403 | lo->pid = current->pid; |
edfaa7c3 | 404 | ret = sysfs_create_file(&lo->disk->dev.kobj, &pid_attr.attr); |
84963048 WC |
405 | if (ret) { |
406 | printk(KERN_ERR "nbd: sysfs_create_file failed!"); | |
407 | return ret; | |
408 | } | |
6b39bb65 | 409 | |
1da177e4 LT |
410 | while ((req = nbd_read_stat(lo)) != NULL) |
411 | nbd_end_request(req); | |
6b39bb65 | 412 | |
edfaa7c3 | 413 | sysfs_remove_file(&lo->disk->dev.kobj, &pid_attr.attr); |
84963048 | 414 | return 0; |
1da177e4 LT |
415 | } |
416 | ||
417 | static void nbd_clear_que(struct nbd_device *lo) | |
418 | { | |
419 | struct request *req; | |
420 | ||
421 | BUG_ON(lo->magic != LO_MAGIC); | |
422 | ||
4b2f0260 HX |
423 | /* |
424 | * Because we have set lo->sock to NULL under the tx_lock, all | |
425 | * modifications to the list must have completed by now. For | |
426 | * the same reason, the active_req must be NULL. | |
427 | * | |
428 | * As a consequence, we don't need to take the spin lock while | |
429 | * purging the list here. | |
430 | */ | |
431 | BUG_ON(lo->sock); | |
432 | BUG_ON(lo->active_req); | |
433 | ||
434 | while (!list_empty(&lo->queue_head)) { | |
435 | req = list_entry(lo->queue_head.next, struct request, | |
436 | queuelist); | |
437 | list_del_init(&req->queuelist); | |
438 | req->errors++; | |
439 | nbd_end_request(req); | |
440 | } | |
1da177e4 LT |
441 | } |
442 | ||
7fdfd406 | 443 | |
1da177e4 LT |
444 | /* |
445 | * We always wait for result of write, for now. It would be nice to make it optional | |
446 | * in future | |
e654bc43 | 447 | * if ((rq_data_dir(req) == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) |
1da177e4 LT |
448 | * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } |
449 | */ | |
450 | ||
165125e1 | 451 | static void do_nbd_request(struct request_queue * q) |
1da177e4 LT |
452 | { |
453 | struct request *req; | |
454 | ||
455 | while ((req = elv_next_request(q)) != NULL) { | |
456 | struct nbd_device *lo; | |
457 | ||
458 | blkdev_dequeue_request(req); | |
4aff5e23 JA |
459 | dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n", |
460 | req->rq_disk->disk_name, req, req->cmd_type); | |
1da177e4 | 461 | |
4aff5e23 | 462 | if (!blk_fs_request(req)) |
1da177e4 LT |
463 | goto error_out; |
464 | ||
465 | lo = req->rq_disk->private_data; | |
466 | ||
467 | BUG_ON(lo->magic != LO_MAGIC); | |
468 | ||
1da177e4 LT |
469 | nbd_cmd(req) = NBD_CMD_READ; |
470 | if (rq_data_dir(req) == WRITE) { | |
471 | nbd_cmd(req) = NBD_CMD_WRITE; | |
472 | if (lo->flags & NBD_READ_ONLY) { | |
473 | printk(KERN_ERR "%s: Write on read-only\n", | |
474 | lo->disk->disk_name); | |
475 | goto error_out; | |
476 | } | |
477 | } | |
478 | ||
479 | req->errors = 0; | |
480 | spin_unlock_irq(q->queue_lock); | |
481 | ||
82d4dc5a | 482 | mutex_lock(&lo->tx_lock); |
4b2f0260 | 483 | if (unlikely(!lo->sock)) { |
82d4dc5a | 484 | mutex_unlock(&lo->tx_lock); |
4b2f0260 HX |
485 | printk(KERN_ERR "%s: Attempted send on closed socket\n", |
486 | lo->disk->disk_name); | |
1da177e4 LT |
487 | req->errors++; |
488 | nbd_end_request(req); | |
489 | spin_lock_irq(q->queue_lock); | |
490 | continue; | |
491 | } | |
492 | ||
4b2f0260 | 493 | lo->active_req = req; |
1da177e4 LT |
494 | |
495 | if (nbd_send_req(lo, req) != 0) { | |
496 | printk(KERN_ERR "%s: Request send failed\n", | |
497 | lo->disk->disk_name); | |
4b2f0260 HX |
498 | req->errors++; |
499 | nbd_end_request(req); | |
500 | } else { | |
501 | spin_lock(&lo->queue_lock); | |
502 | list_add(&req->queuelist, &lo->queue_head); | |
503 | spin_unlock(&lo->queue_lock); | |
1da177e4 LT |
504 | } |
505 | ||
4b2f0260 | 506 | lo->active_req = NULL; |
82d4dc5a | 507 | mutex_unlock(&lo->tx_lock); |
4b2f0260 HX |
508 | wake_up_all(&lo->active_wq); |
509 | ||
1da177e4 LT |
510 | spin_lock_irq(q->queue_lock); |
511 | continue; | |
512 | ||
513 | error_out: | |
514 | req->errors++; | |
515 | spin_unlock(q->queue_lock); | |
516 | nbd_end_request(req); | |
517 | spin_lock(q->queue_lock); | |
518 | } | |
1da177e4 LT |
519 | } |
520 | ||
521 | static int nbd_ioctl(struct inode *inode, struct file *file, | |
522 | unsigned int cmd, unsigned long arg) | |
523 | { | |
524 | struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; | |
525 | int error; | |
526 | struct request sreq ; | |
527 | ||
528 | if (!capable(CAP_SYS_ADMIN)) | |
529 | return -EPERM; | |
530 | ||
531 | BUG_ON(lo->magic != LO_MAGIC); | |
532 | ||
533 | /* Anyone capable of this syscall can do *real bad* things */ | |
534 | dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", | |
535 | lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); | |
536 | ||
537 | switch (cmd) { | |
538 | case NBD_DISCONNECT: | |
539 | printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name); | |
4aff5e23 | 540 | sreq.cmd_type = REQ_TYPE_SPECIAL; |
1da177e4 LT |
541 | nbd_cmd(&sreq) = NBD_CMD_DISC; |
542 | /* | |
543 | * Set these to sane values in case server implementation | |
544 | * fails to check the request type first and also to keep | |
545 | * debugging output cleaner. | |
546 | */ | |
547 | sreq.sector = 0; | |
548 | sreq.nr_sectors = 0; | |
549 | if (!lo->sock) | |
550 | return -EINVAL; | |
7fdfd406 | 551 | mutex_lock(&lo->tx_lock); |
1da177e4 | 552 | nbd_send_req(lo, &sreq); |
7fdfd406 | 553 | mutex_unlock(&lo->tx_lock); |
1da177e4 LT |
554 | return 0; |
555 | ||
556 | case NBD_CLEAR_SOCK: | |
557 | error = 0; | |
82d4dc5a | 558 | mutex_lock(&lo->tx_lock); |
1da177e4 | 559 | lo->sock = NULL; |
82d4dc5a | 560 | mutex_unlock(&lo->tx_lock); |
1da177e4 LT |
561 | file = lo->file; |
562 | lo->file = NULL; | |
1da177e4 | 563 | nbd_clear_que(lo); |
4b2f0260 | 564 | BUG_ON(!list_empty(&lo->queue_head)); |
1da177e4 LT |
565 | if (file) |
566 | fput(file); | |
567 | return error; | |
568 | case NBD_SET_SOCK: | |
569 | if (lo->file) | |
570 | return -EBUSY; | |
571 | error = -EINVAL; | |
572 | file = fget(arg); | |
573 | if (file) { | |
17506041 | 574 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
575 | if (S_ISSOCK(inode->i_mode)) { |
576 | lo->file = file; | |
577 | lo->sock = SOCKET_I(inode); | |
578 | error = 0; | |
579 | } else { | |
580 | fput(file); | |
581 | } | |
582 | } | |
583 | return error; | |
584 | case NBD_SET_BLKSIZE: | |
585 | lo->blksize = arg; | |
586 | lo->bytesize &= ~(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; | |
591 | case NBD_SET_SIZE: | |
592 | lo->bytesize = arg & ~(lo->blksize-1); | |
593 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
594 | set_blocksize(inode->i_bdev, lo->blksize); | |
595 | set_capacity(lo->disk, lo->bytesize >> 9); | |
596 | return 0; | |
7fdfd406 PC |
597 | case NBD_SET_TIMEOUT: |
598 | lo->xmit_timeout = arg * HZ; | |
599 | return 0; | |
1da177e4 LT |
600 | case NBD_SET_SIZE_BLOCKS: |
601 | lo->bytesize = ((u64) arg) * lo->blksize; | |
602 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
603 | set_blocksize(inode->i_bdev, lo->blksize); | |
604 | set_capacity(lo->disk, lo->bytesize >> 9); | |
605 | return 0; | |
606 | case NBD_DO_IT: | |
607 | if (!lo->file) | |
608 | return -EINVAL; | |
84963048 WC |
609 | error = nbd_do_it(lo); |
610 | if (error) | |
611 | return error; | |
7fdfd406 | 612 | sock_shutdown(lo, 1); |
1da177e4 LT |
613 | file = lo->file; |
614 | lo->file = NULL; | |
1da177e4 LT |
615 | nbd_clear_que(lo); |
616 | printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); | |
617 | if (file) | |
618 | fput(file); | |
4b86a872 PC |
619 | lo->bytesize = 0; |
620 | inode->i_bdev->bd_inode->i_size = 0; | |
621 | set_capacity(lo->disk, 0); | |
1da177e4 LT |
622 | return lo->harderror; |
623 | case NBD_CLEAR_QUE: | |
4b2f0260 HX |
624 | /* |
625 | * This is for compatibility only. The queue is always cleared | |
626 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
627 | */ | |
628 | BUG_ON(!lo->sock && !list_empty(&lo->queue_head)); | |
1da177e4 LT |
629 | return 0; |
630 | case NBD_PRINT_DEBUG: | |
631 | printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n", | |
632 | inode->i_bdev->bd_disk->disk_name, | |
633 | lo->queue_head.next, lo->queue_head.prev, | |
634 | &lo->queue_head); | |
635 | return 0; | |
636 | } | |
637 | return -EINVAL; | |
638 | } | |
639 | ||
640 | static struct block_device_operations nbd_fops = | |
641 | { | |
642 | .owner = THIS_MODULE, | |
643 | .ioctl = nbd_ioctl, | |
644 | }; | |
645 | ||
646 | /* | |
647 | * And here should be modules and kernel interface | |
648 | * (Just smiley confuses emacs :-) | |
649 | */ | |
650 | ||
651 | static int __init nbd_init(void) | |
652 | { | |
653 | int err = -ENOMEM; | |
654 | int i; | |
655 | ||
5b7b18cc | 656 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 657 | |
20a8143e PC |
658 | nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL); |
659 | if (!nbd_dev) | |
660 | return -ENOMEM; | |
40be0c28 LMB |
661 | |
662 | for (i = 0; i < nbds_max; i++) { | |
1da177e4 | 663 | struct gendisk *disk = alloc_disk(1); |
48f15b93 | 664 | elevator_t *old_e; |
1da177e4 LT |
665 | if (!disk) |
666 | goto out; | |
667 | nbd_dev[i].disk = disk; | |
668 | /* | |
669 | * The new linux 2.5 block layer implementation requires | |
670 | * every gendisk to have its very own request_queue struct. | |
671 | * These structs are big so we dynamically allocate them. | |
672 | */ | |
673 | disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); | |
674 | if (!disk->queue) { | |
675 | put_disk(disk); | |
676 | goto out; | |
677 | } | |
48f15b93 PC |
678 | old_e = disk->queue->elevator; |
679 | if (elevator_init(disk->queue, "deadline") == 0 || | |
680 | elevator_init(disk->queue, "noop") == 0) { | |
681 | elevator_exit(old_e); | |
682 | } | |
1da177e4 LT |
683 | } |
684 | ||
685 | if (register_blkdev(NBD_MAJOR, "nbd")) { | |
686 | err = -EIO; | |
687 | goto out; | |
688 | } | |
689 | ||
690 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); | |
691 | dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); | |
692 | ||
40be0c28 | 693 | for (i = 0; i < nbds_max; i++) { |
1da177e4 LT |
694 | struct gendisk *disk = nbd_dev[i].disk; |
695 | nbd_dev[i].file = NULL; | |
696 | nbd_dev[i].magic = LO_MAGIC; | |
697 | nbd_dev[i].flags = 0; | |
698 | spin_lock_init(&nbd_dev[i].queue_lock); | |
699 | INIT_LIST_HEAD(&nbd_dev[i].queue_head); | |
82d4dc5a | 700 | mutex_init(&nbd_dev[i].tx_lock); |
4b2f0260 | 701 | init_waitqueue_head(&nbd_dev[i].active_wq); |
1da177e4 | 702 | nbd_dev[i].blksize = 1024; |
4b86a872 | 703 | nbd_dev[i].bytesize = 0; |
1da177e4 LT |
704 | disk->major = NBD_MAJOR; |
705 | disk->first_minor = i; | |
706 | disk->fops = &nbd_fops; | |
707 | disk->private_data = &nbd_dev[i]; | |
708 | disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO; | |
709 | sprintf(disk->disk_name, "nbd%d", i); | |
4b86a872 | 710 | set_capacity(disk, 0); |
1da177e4 LT |
711 | add_disk(disk); |
712 | } | |
713 | ||
714 | return 0; | |
715 | out: | |
716 | while (i--) { | |
717 | blk_cleanup_queue(nbd_dev[i].disk->queue); | |
718 | put_disk(nbd_dev[i].disk); | |
719 | } | |
720 | return err; | |
721 | } | |
722 | ||
723 | static void __exit nbd_cleanup(void) | |
724 | { | |
725 | int i; | |
40be0c28 | 726 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 727 | struct gendisk *disk = nbd_dev[i].disk; |
40be0c28 | 728 | nbd_dev[i].magic = 0; |
1da177e4 LT |
729 | if (disk) { |
730 | del_gendisk(disk); | |
731 | blk_cleanup_queue(disk->queue); | |
732 | put_disk(disk); | |
733 | } | |
734 | } | |
1da177e4 LT |
735 | unregister_blkdev(NBD_MAJOR, "nbd"); |
736 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); | |
737 | } | |
738 | ||
739 | module_init(nbd_init); | |
740 | module_exit(nbd_cleanup); | |
741 | ||
742 | MODULE_DESCRIPTION("Network Block Device"); | |
743 | MODULE_LICENSE("GPL"); | |
744 | ||
40be0c28 LMB |
745 | module_param(nbds_max, int, 0444); |
746 | MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize."); | |
1da177e4 LT |
747 | #ifndef NDEBUG |
748 | module_param(debugflags, int, 0644); | |
749 | MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); | |
750 | #endif |