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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> |
48cf6061 | 32 | #include <linux/kthread.h> |
1da177e4 | 33 | |
1da177e4 | 34 | #include <asm/uaccess.h> |
4b2f0260 | 35 | #include <asm/system.h> |
1da177e4 LT |
36 | #include <asm/types.h> |
37 | ||
38 | #include <linux/nbd.h> | |
39 | ||
40 | #define LO_MAGIC 0x68797548 | |
41 | ||
42 | #ifdef NDEBUG | |
43 | #define dprintk(flags, fmt...) | |
44 | #else /* NDEBUG */ | |
45 | #define dprintk(flags, fmt...) do { \ | |
46 | if (debugflags & (flags)) printk(KERN_DEBUG fmt); \ | |
47 | } while (0) | |
48 | #define DBG_IOCTL 0x0004 | |
49 | #define DBG_INIT 0x0010 | |
50 | #define DBG_EXIT 0x0020 | |
51 | #define DBG_BLKDEV 0x0100 | |
52 | #define DBG_RX 0x0200 | |
53 | #define DBG_TX 0x0400 | |
54 | static unsigned int debugflags; | |
55 | #endif /* NDEBUG */ | |
56 | ||
9c7a4169 | 57 | static unsigned int nbds_max = 16; |
20a8143e | 58 | static struct nbd_device *nbd_dev; |
1da177e4 LT |
59 | |
60 | /* | |
61 | * Use just one lock (or at most 1 per NIC). Two arguments for this: | |
62 | * 1. Each NIC is essentially a synchronization point for all servers | |
63 | * accessed through that NIC so there's no need to have more locks | |
64 | * than NICs anyway. | |
65 | * 2. More locks lead to more "Dirty cache line bouncing" which will slow | |
66 | * down each lock to the point where they're actually slower than just | |
67 | * a single lock. | |
68 | * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! | |
69 | */ | |
70 | static DEFINE_SPINLOCK(nbd_lock); | |
71 | ||
72 | #ifndef NDEBUG | |
73 | static const char *ioctl_cmd_to_ascii(int cmd) | |
74 | { | |
75 | switch (cmd) { | |
76 | case NBD_SET_SOCK: return "set-sock"; | |
77 | case NBD_SET_BLKSIZE: return "set-blksize"; | |
78 | case NBD_SET_SIZE: return "set-size"; | |
79 | case NBD_DO_IT: return "do-it"; | |
80 | case NBD_CLEAR_SOCK: return "clear-sock"; | |
81 | case NBD_CLEAR_QUE: return "clear-que"; | |
82 | case NBD_PRINT_DEBUG: return "print-debug"; | |
83 | case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; | |
84 | case NBD_DISCONNECT: return "disconnect"; | |
85 | case BLKROSET: return "set-read-only"; | |
86 | case BLKFLSBUF: return "flush-buffer-cache"; | |
87 | } | |
88 | return "unknown"; | |
89 | } | |
90 | ||
91 | static const char *nbdcmd_to_ascii(int cmd) | |
92 | { | |
93 | switch (cmd) { | |
94 | case NBD_CMD_READ: return "read"; | |
95 | case NBD_CMD_WRITE: return "write"; | |
96 | case NBD_CMD_DISC: return "disconnect"; | |
97 | } | |
98 | return "invalid"; | |
99 | } | |
100 | #endif /* NDEBUG */ | |
101 | ||
102 | static void nbd_end_request(struct request *req) | |
103 | { | |
097c94a4 | 104 | int error = req->errors ? -EIO : 0; |
165125e1 | 105 | struct request_queue *q = req->q; |
1da177e4 LT |
106 | unsigned long flags; |
107 | ||
108 | dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, | |
097c94a4 | 109 | req, error ? "failed" : "done"); |
1da177e4 LT |
110 | |
111 | spin_lock_irqsave(q->queue_lock, flags); | |
097c94a4 | 112 | __blk_end_request(req, error, req->nr_sectors << 9); |
1da177e4 LT |
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); | |
91cf45f0 | 129 | kernel_sock_shutdown(lo->sock, SHUT_RDWR); |
7fdfd406 PC |
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 | 156 | |
ffc41cf8 MS |
157 | if (unlikely(!sock)) { |
158 | printk(KERN_ERR "%s: Attempted %s on closed socket in sock_xmit\n", | |
159 | lo->disk->disk_name, (send ? "send" : "recv")); | |
160 | return -EINVAL; | |
161 | } | |
162 | ||
1da177e4 LT |
163 | /* Allow interception of SIGKILL only |
164 | * Don't allow other signals to interrupt the transmission */ | |
be0ef957 ON |
165 | siginitsetinv(&blocked, sigmask(SIGKILL)); |
166 | sigprocmask(SIG_SETMASK, &blocked, &oldset); | |
1da177e4 LT |
167 | |
168 | do { | |
169 | sock->sk->sk_allocation = GFP_NOIO; | |
170 | iov.iov_base = buf; | |
171 | iov.iov_len = size; | |
172 | msg.msg_name = NULL; | |
173 | msg.msg_namelen = 0; | |
174 | msg.msg_control = NULL; | |
175 | msg.msg_controllen = 0; | |
1da177e4 LT |
176 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
177 | ||
7fdfd406 PC |
178 | if (send) { |
179 | struct timer_list ti; | |
180 | ||
181 | if (lo->xmit_timeout) { | |
182 | init_timer(&ti); | |
183 | ti.function = nbd_xmit_timeout; | |
184 | ti.data = (unsigned long)current; | |
185 | ti.expires = jiffies + lo->xmit_timeout; | |
186 | add_timer(&ti); | |
187 | } | |
1da177e4 | 188 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
7fdfd406 PC |
189 | if (lo->xmit_timeout) |
190 | del_timer_sync(&ti); | |
191 | } else | |
1da177e4 LT |
192 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); |
193 | ||
194 | if (signal_pending(current)) { | |
195 | siginfo_t info; | |
1da177e4 | 196 | printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", |
ba25f9dc | 197 | task_pid_nr(current), current->comm, |
be0ef957 | 198 | dequeue_signal_lock(current, ¤t->blocked, &info)); |
1da177e4 | 199 | result = -EINTR; |
7fdfd406 | 200 | sock_shutdown(lo, !send); |
1da177e4 LT |
201 | break; |
202 | } | |
203 | ||
204 | if (result <= 0) { | |
205 | if (result == 0) | |
206 | result = -EPIPE; /* short read */ | |
207 | break; | |
208 | } | |
209 | size -= result; | |
210 | buf += result; | |
211 | } while (size > 0); | |
212 | ||
be0ef957 | 213 | sigprocmask(SIG_SETMASK, &oldset, NULL); |
1da177e4 LT |
214 | |
215 | return result; | |
216 | } | |
217 | ||
7fdfd406 | 218 | static inline int sock_send_bvec(struct nbd_device *lo, struct bio_vec *bvec, |
1da177e4 LT |
219 | int flags) |
220 | { | |
221 | int result; | |
222 | void *kaddr = kmap(bvec->bv_page); | |
7fdfd406 | 223 | result = sock_xmit(lo, 1, kaddr + bvec->bv_offset, bvec->bv_len, flags); |
1da177e4 LT |
224 | kunmap(bvec->bv_page); |
225 | return result; | |
226 | } | |
227 | ||
7fdfd406 | 228 | /* always call with the tx_lock held */ |
1da177e4 LT |
229 | static int nbd_send_req(struct nbd_device *lo, struct request *req) |
230 | { | |
5705f702 | 231 | int result, flags; |
1da177e4 LT |
232 | struct nbd_request request; |
233 | unsigned long size = req->nr_sectors << 9; | |
1da177e4 LT |
234 | |
235 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
236 | request.type = htonl(nbd_cmd(req)); | |
237 | request.from = cpu_to_be64((u64) req->sector << 9); | |
238 | request.len = htonl(size); | |
239 | memcpy(request.handle, &req, sizeof(req)); | |
240 | ||
1da177e4 LT |
241 | dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", |
242 | lo->disk->disk_name, req, | |
243 | nbdcmd_to_ascii(nbd_cmd(req)), | |
244 | (unsigned long long)req->sector << 9, | |
245 | req->nr_sectors << 9); | |
7fdfd406 PC |
246 | result = sock_xmit(lo, 1, &request, sizeof(request), |
247 | (nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0); | |
1da177e4 LT |
248 | if (result <= 0) { |
249 | printk(KERN_ERR "%s: Send control failed (result %d)\n", | |
250 | lo->disk->disk_name, result); | |
251 | goto error_out; | |
252 | } | |
253 | ||
254 | if (nbd_cmd(req) == NBD_CMD_WRITE) { | |
5705f702 N |
255 | struct req_iterator iter; |
256 | struct bio_vec *bvec; | |
1da177e4 LT |
257 | /* |
258 | * we are really probing at internals to determine | |
259 | * whether to set MSG_MORE or not... | |
260 | */ | |
5705f702 | 261 | rq_for_each_segment(bvec, req, iter) { |
6c92e699 JA |
262 | flags = 0; |
263 | if (!rq_iter_last(req, iter)) | |
264 | flags = MSG_MORE; | |
265 | dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", | |
266 | lo->disk->disk_name, req, bvec->bv_len); | |
7fdfd406 | 267 | result = sock_send_bvec(lo, bvec, flags); |
6c92e699 JA |
268 | if (result <= 0) { |
269 | printk(KERN_ERR "%s: Send data failed (result %d)\n", | |
270 | lo->disk->disk_name, result); | |
271 | goto error_out; | |
272 | } | |
1da177e4 LT |
273 | } |
274 | } | |
1da177e4 LT |
275 | return 0; |
276 | ||
277 | error_out: | |
1da177e4 LT |
278 | return 1; |
279 | } | |
280 | ||
0cbc591b DC |
281 | static struct request *nbd_find_request(struct nbd_device *lo, |
282 | struct request *xreq) | |
1da177e4 | 283 | { |
d2c9740b | 284 | struct request *req, *tmp; |
4b2f0260 | 285 | int err; |
1da177e4 | 286 | |
4b2f0260 HX |
287 | err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); |
288 | if (unlikely(err)) | |
289 | goto out; | |
290 | ||
1da177e4 | 291 | spin_lock(&lo->queue_lock); |
d2c9740b | 292 | list_for_each_entry_safe(req, tmp, &lo->queue_head, queuelist) { |
1da177e4 LT |
293 | if (req != xreq) |
294 | continue; | |
295 | list_del_init(&req->queuelist); | |
296 | spin_unlock(&lo->queue_lock); | |
297 | return req; | |
298 | } | |
299 | spin_unlock(&lo->queue_lock); | |
4b2f0260 HX |
300 | |
301 | err = -ENOENT; | |
302 | ||
303 | out: | |
304 | return ERR_PTR(err); | |
1da177e4 LT |
305 | } |
306 | ||
7fdfd406 | 307 | static inline int sock_recv_bvec(struct nbd_device *lo, struct bio_vec *bvec) |
1da177e4 LT |
308 | { |
309 | int result; | |
310 | void *kaddr = kmap(bvec->bv_page); | |
7fdfd406 | 311 | result = sock_xmit(lo, 0, kaddr + bvec->bv_offset, bvec->bv_len, |
1da177e4 LT |
312 | MSG_WAITALL); |
313 | kunmap(bvec->bv_page); | |
314 | return result; | |
315 | } | |
316 | ||
317 | /* NULL returned = something went wrong, inform userspace */ | |
318 | static struct request *nbd_read_stat(struct nbd_device *lo) | |
319 | { | |
320 | int result; | |
321 | struct nbd_reply reply; | |
322 | struct request *req; | |
1da177e4 LT |
323 | |
324 | reply.magic = 0; | |
7fdfd406 | 325 | result = sock_xmit(lo, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 LT |
326 | if (result <= 0) { |
327 | printk(KERN_ERR "%s: Receive control failed (result %d)\n", | |
328 | lo->disk->disk_name, result); | |
329 | goto harderror; | |
330 | } | |
e4b57e08 MF |
331 | |
332 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
333 | printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", | |
334 | lo->disk->disk_name, | |
335 | (unsigned long)ntohl(reply.magic)); | |
336 | result = -EPROTO; | |
337 | goto harderror; | |
338 | } | |
339 | ||
0cbc591b | 340 | req = nbd_find_request(lo, *(struct request **)reply.handle); |
4b2f0260 HX |
341 | if (unlikely(IS_ERR(req))) { |
342 | result = PTR_ERR(req); | |
343 | if (result != -ENOENT) | |
344 | goto harderror; | |
345 | ||
1da177e4 LT |
346 | printk(KERN_ERR "%s: Unexpected reply (%p)\n", |
347 | lo->disk->disk_name, reply.handle); | |
348 | result = -EBADR; | |
349 | goto harderror; | |
350 | } | |
351 | ||
1da177e4 LT |
352 | if (ntohl(reply.error)) { |
353 | printk(KERN_ERR "%s: Other side returned error (%d)\n", | |
354 | lo->disk->disk_name, ntohl(reply.error)); | |
355 | req->errors++; | |
356 | return req; | |
357 | } | |
358 | ||
359 | dprintk(DBG_RX, "%s: request %p: got reply\n", | |
360 | lo->disk->disk_name, req); | |
361 | if (nbd_cmd(req) == NBD_CMD_READ) { | |
5705f702 N |
362 | struct req_iterator iter; |
363 | struct bio_vec *bvec; | |
364 | ||
365 | rq_for_each_segment(bvec, req, iter) { | |
7fdfd406 | 366 | result = sock_recv_bvec(lo, bvec); |
6c92e699 JA |
367 | if (result <= 0) { |
368 | printk(KERN_ERR "%s: Receive data failed (result %d)\n", | |
369 | lo->disk->disk_name, result); | |
370 | req->errors++; | |
371 | return req; | |
372 | } | |
373 | dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", | |
374 | lo->disk->disk_name, req, bvec->bv_len); | |
1da177e4 LT |
375 | } |
376 | } | |
377 | return req; | |
378 | harderror: | |
379 | lo->harderror = result; | |
380 | return NULL; | |
381 | } | |
382 | ||
edfaa7c3 KS |
383 | static ssize_t pid_show(struct device *dev, |
384 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 385 | { |
edfaa7c3 KS |
386 | struct gendisk *disk = dev_to_disk(dev); |
387 | ||
388 | return sprintf(buf, "%ld\n", | |
6b39bb65 PC |
389 | (long) ((struct nbd_device *)disk->private_data)->pid); |
390 | } | |
391 | ||
edfaa7c3 KS |
392 | static struct device_attribute pid_attr = { |
393 | .attr = { .name = "pid", .mode = S_IRUGO, .owner = THIS_MODULE }, | |
6b39bb65 PC |
394 | .show = pid_show, |
395 | }; | |
396 | ||
84963048 | 397 | static int nbd_do_it(struct nbd_device *lo) |
1da177e4 LT |
398 | { |
399 | struct request *req; | |
84963048 | 400 | int ret; |
1da177e4 LT |
401 | |
402 | BUG_ON(lo->magic != LO_MAGIC); | |
403 | ||
6b39bb65 | 404 | lo->pid = current->pid; |
edfaa7c3 | 405 | ret = sysfs_create_file(&lo->disk->dev.kobj, &pid_attr.attr); |
84963048 WC |
406 | if (ret) { |
407 | printk(KERN_ERR "nbd: sysfs_create_file failed!"); | |
408 | return ret; | |
409 | } | |
6b39bb65 | 410 | |
1da177e4 LT |
411 | while ((req = nbd_read_stat(lo)) != NULL) |
412 | nbd_end_request(req); | |
6b39bb65 | 413 | |
edfaa7c3 | 414 | sysfs_remove_file(&lo->disk->dev.kobj, &pid_attr.attr); |
84963048 | 415 | return 0; |
1da177e4 LT |
416 | } |
417 | ||
418 | static void nbd_clear_que(struct nbd_device *lo) | |
419 | { | |
420 | struct request *req; | |
421 | ||
422 | BUG_ON(lo->magic != LO_MAGIC); | |
423 | ||
4b2f0260 HX |
424 | /* |
425 | * Because we have set lo->sock to NULL under the tx_lock, all | |
426 | * modifications to the list must have completed by now. For | |
427 | * the same reason, the active_req must be NULL. | |
428 | * | |
429 | * As a consequence, we don't need to take the spin lock while | |
430 | * purging the list here. | |
431 | */ | |
432 | BUG_ON(lo->sock); | |
433 | BUG_ON(lo->active_req); | |
434 | ||
435 | while (!list_empty(&lo->queue_head)) { | |
436 | req = list_entry(lo->queue_head.next, struct request, | |
437 | queuelist); | |
438 | list_del_init(&req->queuelist); | |
439 | req->errors++; | |
440 | nbd_end_request(req); | |
441 | } | |
1da177e4 LT |
442 | } |
443 | ||
7fdfd406 | 444 | |
48cf6061 LV |
445 | static void nbd_handle_req(struct nbd_device *lo, struct request *req) |
446 | { | |
447 | if (!blk_fs_request(req)) | |
448 | goto error_out; | |
449 | ||
450 | nbd_cmd(req) = NBD_CMD_READ; | |
451 | if (rq_data_dir(req) == WRITE) { | |
452 | nbd_cmd(req) = NBD_CMD_WRITE; | |
453 | if (lo->flags & NBD_READ_ONLY) { | |
454 | printk(KERN_ERR "%s: Write on read-only\n", | |
455 | lo->disk->disk_name); | |
456 | goto error_out; | |
457 | } | |
458 | } | |
459 | ||
460 | req->errors = 0; | |
461 | ||
462 | mutex_lock(&lo->tx_lock); | |
463 | if (unlikely(!lo->sock)) { | |
464 | mutex_unlock(&lo->tx_lock); | |
465 | printk(KERN_ERR "%s: Attempted send on closed socket\n", | |
466 | lo->disk->disk_name); | |
467 | req->errors++; | |
468 | nbd_end_request(req); | |
469 | return; | |
470 | } | |
471 | ||
472 | lo->active_req = req; | |
473 | ||
474 | if (nbd_send_req(lo, req) != 0) { | |
475 | printk(KERN_ERR "%s: Request send failed\n", | |
476 | lo->disk->disk_name); | |
477 | req->errors++; | |
478 | nbd_end_request(req); | |
479 | } else { | |
480 | spin_lock(&lo->queue_lock); | |
481 | list_add(&req->queuelist, &lo->queue_head); | |
482 | spin_unlock(&lo->queue_lock); | |
483 | } | |
484 | ||
485 | lo->active_req = NULL; | |
486 | mutex_unlock(&lo->tx_lock); | |
487 | wake_up_all(&lo->active_wq); | |
488 | ||
489 | return; | |
490 | ||
491 | error_out: | |
492 | req->errors++; | |
493 | nbd_end_request(req); | |
494 | } | |
495 | ||
496 | static int nbd_thread(void *data) | |
497 | { | |
498 | struct nbd_device *lo = data; | |
499 | struct request *req; | |
500 | ||
501 | set_user_nice(current, -20); | |
502 | while (!kthread_should_stop() || !list_empty(&lo->waiting_queue)) { | |
503 | /* wait for something to do */ | |
504 | wait_event_interruptible(lo->waiting_wq, | |
505 | kthread_should_stop() || | |
506 | !list_empty(&lo->waiting_queue)); | |
507 | ||
508 | /* extract request */ | |
509 | if (list_empty(&lo->waiting_queue)) | |
510 | continue; | |
511 | ||
512 | spin_lock_irq(&lo->queue_lock); | |
513 | req = list_entry(lo->waiting_queue.next, struct request, | |
514 | queuelist); | |
515 | list_del_init(&req->queuelist); | |
516 | spin_unlock_irq(&lo->queue_lock); | |
517 | ||
518 | /* handle request */ | |
519 | nbd_handle_req(lo, req); | |
520 | } | |
521 | return 0; | |
522 | } | |
523 | ||
1da177e4 LT |
524 | /* |
525 | * We always wait for result of write, for now. It would be nice to make it optional | |
526 | * in future | |
e654bc43 | 527 | * if ((rq_data_dir(req) == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) |
1da177e4 LT |
528 | * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } |
529 | */ | |
530 | ||
165125e1 | 531 | static void do_nbd_request(struct request_queue * q) |
1da177e4 LT |
532 | { |
533 | struct request *req; | |
534 | ||
535 | while ((req = elv_next_request(q)) != NULL) { | |
536 | struct nbd_device *lo; | |
537 | ||
538 | blkdev_dequeue_request(req); | |
48cf6061 LV |
539 | |
540 | spin_unlock_irq(q->queue_lock); | |
541 | ||
4aff5e23 JA |
542 | dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n", |
543 | req->rq_disk->disk_name, req, req->cmd_type); | |
1da177e4 | 544 | |
1da177e4 LT |
545 | lo = req->rq_disk->private_data; |
546 | ||
547 | BUG_ON(lo->magic != LO_MAGIC); | |
548 | ||
48cf6061 LV |
549 | spin_lock_irq(&lo->queue_lock); |
550 | list_add_tail(&req->queuelist, &lo->waiting_queue); | |
551 | spin_unlock_irq(&lo->queue_lock); | |
1da177e4 | 552 | |
48cf6061 | 553 | wake_up(&lo->waiting_wq); |
4b2f0260 | 554 | |
1da177e4 | 555 | spin_lock_irq(q->queue_lock); |
1da177e4 | 556 | } |
1da177e4 LT |
557 | } |
558 | ||
559 | static int nbd_ioctl(struct inode *inode, struct file *file, | |
560 | unsigned int cmd, unsigned long arg) | |
561 | { | |
562 | struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; | |
563 | int error; | |
564 | struct request sreq ; | |
48cf6061 | 565 | struct task_struct *thread; |
1da177e4 LT |
566 | |
567 | if (!capable(CAP_SYS_ADMIN)) | |
568 | return -EPERM; | |
569 | ||
570 | BUG_ON(lo->magic != LO_MAGIC); | |
571 | ||
572 | /* Anyone capable of this syscall can do *real bad* things */ | |
573 | dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", | |
574 | lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); | |
575 | ||
576 | switch (cmd) { | |
577 | case NBD_DISCONNECT: | |
578 | printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name); | |
4aff5e23 | 579 | sreq.cmd_type = REQ_TYPE_SPECIAL; |
1da177e4 LT |
580 | nbd_cmd(&sreq) = NBD_CMD_DISC; |
581 | /* | |
582 | * Set these to sane values in case server implementation | |
583 | * fails to check the request type first and also to keep | |
584 | * debugging output cleaner. | |
585 | */ | |
586 | sreq.sector = 0; | |
587 | sreq.nr_sectors = 0; | |
588 | if (!lo->sock) | |
589 | return -EINVAL; | |
7fdfd406 | 590 | mutex_lock(&lo->tx_lock); |
1da177e4 | 591 | nbd_send_req(lo, &sreq); |
7fdfd406 | 592 | mutex_unlock(&lo->tx_lock); |
1da177e4 LT |
593 | return 0; |
594 | ||
595 | case NBD_CLEAR_SOCK: | |
596 | error = 0; | |
82d4dc5a | 597 | mutex_lock(&lo->tx_lock); |
1da177e4 | 598 | lo->sock = NULL; |
82d4dc5a | 599 | mutex_unlock(&lo->tx_lock); |
1da177e4 LT |
600 | file = lo->file; |
601 | lo->file = NULL; | |
1da177e4 | 602 | nbd_clear_que(lo); |
4b2f0260 | 603 | BUG_ON(!list_empty(&lo->queue_head)); |
1da177e4 LT |
604 | if (file) |
605 | fput(file); | |
606 | return error; | |
607 | case NBD_SET_SOCK: | |
608 | if (lo->file) | |
609 | return -EBUSY; | |
610 | error = -EINVAL; | |
611 | file = fget(arg); | |
612 | if (file) { | |
17506041 | 613 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
614 | if (S_ISSOCK(inode->i_mode)) { |
615 | lo->file = file; | |
616 | lo->sock = SOCKET_I(inode); | |
617 | error = 0; | |
618 | } else { | |
619 | fput(file); | |
620 | } | |
621 | } | |
622 | return error; | |
623 | case NBD_SET_BLKSIZE: | |
624 | lo->blksize = arg; | |
625 | lo->bytesize &= ~(lo->blksize-1); | |
626 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
627 | set_blocksize(inode->i_bdev, lo->blksize); | |
628 | set_capacity(lo->disk, lo->bytesize >> 9); | |
629 | return 0; | |
630 | case NBD_SET_SIZE: | |
631 | lo->bytesize = arg & ~(lo->blksize-1); | |
632 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
633 | set_blocksize(inode->i_bdev, lo->blksize); | |
634 | set_capacity(lo->disk, lo->bytesize >> 9); | |
635 | return 0; | |
7fdfd406 PC |
636 | case NBD_SET_TIMEOUT: |
637 | lo->xmit_timeout = arg * HZ; | |
638 | return 0; | |
1da177e4 LT |
639 | case NBD_SET_SIZE_BLOCKS: |
640 | lo->bytesize = ((u64) arg) * lo->blksize; | |
641 | inode->i_bdev->bd_inode->i_size = lo->bytesize; | |
642 | set_blocksize(inode->i_bdev, lo->blksize); | |
643 | set_capacity(lo->disk, lo->bytesize >> 9); | |
644 | return 0; | |
645 | case NBD_DO_IT: | |
646 | if (!lo->file) | |
647 | return -EINVAL; | |
48cf6061 LV |
648 | thread = kthread_create(nbd_thread, lo, lo->disk->disk_name); |
649 | if (IS_ERR(thread)) | |
650 | return PTR_ERR(thread); | |
651 | wake_up_process(thread); | |
84963048 | 652 | error = nbd_do_it(lo); |
48cf6061 | 653 | kthread_stop(thread); |
84963048 WC |
654 | if (error) |
655 | return error; | |
7fdfd406 | 656 | sock_shutdown(lo, 1); |
1da177e4 LT |
657 | file = lo->file; |
658 | lo->file = NULL; | |
1da177e4 LT |
659 | nbd_clear_que(lo); |
660 | printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); | |
661 | if (file) | |
662 | fput(file); | |
4b86a872 PC |
663 | lo->bytesize = 0; |
664 | inode->i_bdev->bd_inode->i_size = 0; | |
665 | set_capacity(lo->disk, 0); | |
1da177e4 LT |
666 | return lo->harderror; |
667 | case NBD_CLEAR_QUE: | |
4b2f0260 HX |
668 | /* |
669 | * This is for compatibility only. The queue is always cleared | |
670 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
671 | */ | |
672 | BUG_ON(!lo->sock && !list_empty(&lo->queue_head)); | |
1da177e4 LT |
673 | return 0; |
674 | case NBD_PRINT_DEBUG: | |
675 | printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n", | |
676 | inode->i_bdev->bd_disk->disk_name, | |
677 | lo->queue_head.next, lo->queue_head.prev, | |
678 | &lo->queue_head); | |
679 | return 0; | |
680 | } | |
681 | return -EINVAL; | |
682 | } | |
683 | ||
684 | static struct block_device_operations nbd_fops = | |
685 | { | |
686 | .owner = THIS_MODULE, | |
687 | .ioctl = nbd_ioctl, | |
688 | }; | |
689 | ||
690 | /* | |
691 | * And here should be modules and kernel interface | |
692 | * (Just smiley confuses emacs :-) | |
693 | */ | |
694 | ||
695 | static int __init nbd_init(void) | |
696 | { | |
697 | int err = -ENOMEM; | |
698 | int i; | |
699 | ||
5b7b18cc | 700 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 701 | |
20a8143e PC |
702 | nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL); |
703 | if (!nbd_dev) | |
704 | return -ENOMEM; | |
40be0c28 LMB |
705 | |
706 | for (i = 0; i < nbds_max; i++) { | |
1da177e4 | 707 | struct gendisk *disk = alloc_disk(1); |
48f15b93 | 708 | elevator_t *old_e; |
1da177e4 LT |
709 | if (!disk) |
710 | goto out; | |
711 | nbd_dev[i].disk = disk; | |
712 | /* | |
713 | * The new linux 2.5 block layer implementation requires | |
714 | * every gendisk to have its very own request_queue struct. | |
715 | * These structs are big so we dynamically allocate them. | |
716 | */ | |
717 | disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); | |
718 | if (!disk->queue) { | |
719 | put_disk(disk); | |
720 | goto out; | |
721 | } | |
48f15b93 PC |
722 | old_e = disk->queue->elevator; |
723 | if (elevator_init(disk->queue, "deadline") == 0 || | |
724 | elevator_init(disk->queue, "noop") == 0) { | |
725 | elevator_exit(old_e); | |
726 | } | |
1da177e4 LT |
727 | } |
728 | ||
729 | if (register_blkdev(NBD_MAJOR, "nbd")) { | |
730 | err = -EIO; | |
731 | goto out; | |
732 | } | |
733 | ||
734 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); | |
735 | dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); | |
736 | ||
40be0c28 | 737 | for (i = 0; i < nbds_max; i++) { |
1da177e4 LT |
738 | struct gendisk *disk = nbd_dev[i].disk; |
739 | nbd_dev[i].file = NULL; | |
740 | nbd_dev[i].magic = LO_MAGIC; | |
741 | nbd_dev[i].flags = 0; | |
48cf6061 | 742 | INIT_LIST_HEAD(&nbd_dev[i].waiting_queue); |
1da177e4 LT |
743 | spin_lock_init(&nbd_dev[i].queue_lock); |
744 | INIT_LIST_HEAD(&nbd_dev[i].queue_head); | |
82d4dc5a | 745 | mutex_init(&nbd_dev[i].tx_lock); |
4b2f0260 | 746 | init_waitqueue_head(&nbd_dev[i].active_wq); |
48cf6061 | 747 | init_waitqueue_head(&nbd_dev[i].waiting_wq); |
1da177e4 | 748 | nbd_dev[i].blksize = 1024; |
4b86a872 | 749 | nbd_dev[i].bytesize = 0; |
1da177e4 LT |
750 | disk->major = NBD_MAJOR; |
751 | disk->first_minor = i; | |
752 | disk->fops = &nbd_fops; | |
753 | disk->private_data = &nbd_dev[i]; | |
754 | disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO; | |
755 | sprintf(disk->disk_name, "nbd%d", i); | |
4b86a872 | 756 | set_capacity(disk, 0); |
1da177e4 LT |
757 | add_disk(disk); |
758 | } | |
759 | ||
760 | return 0; | |
761 | out: | |
762 | while (i--) { | |
763 | blk_cleanup_queue(nbd_dev[i].disk->queue); | |
764 | put_disk(nbd_dev[i].disk); | |
765 | } | |
766 | return err; | |
767 | } | |
768 | ||
769 | static void __exit nbd_cleanup(void) | |
770 | { | |
771 | int i; | |
40be0c28 | 772 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 773 | struct gendisk *disk = nbd_dev[i].disk; |
40be0c28 | 774 | nbd_dev[i].magic = 0; |
1da177e4 LT |
775 | if (disk) { |
776 | del_gendisk(disk); | |
777 | blk_cleanup_queue(disk->queue); | |
778 | put_disk(disk); | |
779 | } | |
780 | } | |
1da177e4 LT |
781 | unregister_blkdev(NBD_MAJOR, "nbd"); |
782 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); | |
783 | } | |
784 | ||
785 | module_init(nbd_init); | |
786 | module_exit(nbd_cleanup); | |
787 | ||
788 | MODULE_DESCRIPTION("Network Block Device"); | |
789 | MODULE_LICENSE("GPL"); | |
790 | ||
40be0c28 LMB |
791 | module_param(nbds_max, int, 0444); |
792 | MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize."); | |
1da177e4 LT |
793 | #ifndef NDEBUG |
794 | module_param(debugflags, int, 0644); | |
795 | MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); | |
796 | #endif |