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 | * | |
15746fca | 7 | * Copyright 1997-2000, 2008 Pavel Machek <pavel@suse.cz> |
1da177e4 LT |
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> | |
5a0e3ad6 | 30 | #include <linux/slab.h> |
1da177e4 | 31 | #include <net/sock.h> |
91cf45f0 | 32 | #include <linux/net.h> |
48cf6061 | 33 | #include <linux/kthread.h> |
1da177e4 | 34 | |
1da177e4 | 35 | #include <asm/uaccess.h> |
4b2f0260 | 36 | #include <asm/system.h> |
1da177e4 LT |
37 | #include <asm/types.h> |
38 | ||
39 | #include <linux/nbd.h> | |
40 | ||
41 | #define LO_MAGIC 0x68797548 | |
42 | ||
43 | #ifdef NDEBUG | |
44 | #define dprintk(flags, fmt...) | |
45 | #else /* NDEBUG */ | |
46 | #define dprintk(flags, fmt...) do { \ | |
47 | if (debugflags & (flags)) printk(KERN_DEBUG fmt); \ | |
48 | } while (0) | |
49 | #define DBG_IOCTL 0x0004 | |
50 | #define DBG_INIT 0x0010 | |
51 | #define DBG_EXIT 0x0020 | |
52 | #define DBG_BLKDEV 0x0100 | |
53 | #define DBG_RX 0x0200 | |
54 | #define DBG_TX 0x0400 | |
55 | static unsigned int debugflags; | |
56 | #endif /* NDEBUG */ | |
57 | ||
9c7a4169 | 58 | static unsigned int nbds_max = 16; |
20a8143e | 59 | static struct nbd_device *nbd_dev; |
d71a6d73 | 60 | static int max_part; |
1da177e4 LT |
61 | |
62 | /* | |
63 | * Use just one lock (or at most 1 per NIC). Two arguments for this: | |
64 | * 1. Each NIC is essentially a synchronization point for all servers | |
65 | * accessed through that NIC so there's no need to have more locks | |
66 | * than NICs anyway. | |
67 | * 2. More locks lead to more "Dirty cache line bouncing" which will slow | |
68 | * down each lock to the point where they're actually slower than just | |
69 | * a single lock. | |
70 | * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! | |
71 | */ | |
72 | static DEFINE_SPINLOCK(nbd_lock); | |
73 | ||
74 | #ifndef NDEBUG | |
75 | static const char *ioctl_cmd_to_ascii(int cmd) | |
76 | { | |
77 | switch (cmd) { | |
78 | case NBD_SET_SOCK: return "set-sock"; | |
79 | case NBD_SET_BLKSIZE: return "set-blksize"; | |
80 | case NBD_SET_SIZE: return "set-size"; | |
81 | case NBD_DO_IT: return "do-it"; | |
82 | case NBD_CLEAR_SOCK: return "clear-sock"; | |
83 | case NBD_CLEAR_QUE: return "clear-que"; | |
84 | case NBD_PRINT_DEBUG: return "print-debug"; | |
85 | case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; | |
86 | case NBD_DISCONNECT: return "disconnect"; | |
87 | case BLKROSET: return "set-read-only"; | |
88 | case BLKFLSBUF: return "flush-buffer-cache"; | |
89 | } | |
90 | return "unknown"; | |
91 | } | |
92 | ||
93 | static const char *nbdcmd_to_ascii(int cmd) | |
94 | { | |
95 | switch (cmd) { | |
96 | case NBD_CMD_READ: return "read"; | |
97 | case NBD_CMD_WRITE: return "write"; | |
98 | case NBD_CMD_DISC: return "disconnect"; | |
99 | } | |
100 | return "invalid"; | |
101 | } | |
102 | #endif /* NDEBUG */ | |
103 | ||
104 | static void nbd_end_request(struct request *req) | |
105 | { | |
097c94a4 | 106 | int error = req->errors ? -EIO : 0; |
165125e1 | 107 | struct request_queue *q = req->q; |
1da177e4 LT |
108 | unsigned long flags; |
109 | ||
110 | dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, | |
097c94a4 | 111 | req, error ? "failed" : "done"); |
1da177e4 LT |
112 | |
113 | spin_lock_irqsave(q->queue_lock, flags); | |
1011c1b9 | 114 | __blk_end_request_all(req, error); |
1da177e4 LT |
115 | spin_unlock_irqrestore(q->queue_lock, flags); |
116 | } | |
117 | ||
7fdfd406 PC |
118 | static void sock_shutdown(struct nbd_device *lo, int lock) |
119 | { | |
120 | /* Forcibly shutdown the socket causing all listeners | |
121 | * to error | |
122 | * | |
123 | * FIXME: This code is duplicated from sys_shutdown, but | |
124 | * there should be a more generic interface rather than | |
125 | * calling socket ops directly here */ | |
126 | if (lock) | |
127 | mutex_lock(&lo->tx_lock); | |
128 | if (lo->sock) { | |
129 | printk(KERN_WARNING "%s: shutting down socket\n", | |
130 | lo->disk->disk_name); | |
91cf45f0 | 131 | kernel_sock_shutdown(lo->sock, SHUT_RDWR); |
7fdfd406 PC |
132 | lo->sock = NULL; |
133 | } | |
134 | if (lock) | |
135 | mutex_unlock(&lo->tx_lock); | |
136 | } | |
137 | ||
138 | static void nbd_xmit_timeout(unsigned long arg) | |
139 | { | |
140 | struct task_struct *task = (struct task_struct *)arg; | |
141 | ||
142 | printk(KERN_WARNING "nbd: killing hung xmit (%s, pid: %d)\n", | |
143 | task->comm, task->pid); | |
144 | force_sig(SIGKILL, task); | |
145 | } | |
146 | ||
1da177e4 LT |
147 | /* |
148 | * Send or receive packet. | |
149 | */ | |
7fdfd406 | 150 | static int sock_xmit(struct nbd_device *lo, int send, void *buf, int size, |
1da177e4 LT |
151 | int msg_flags) |
152 | { | |
7fdfd406 | 153 | struct socket *sock = lo->sock; |
1da177e4 LT |
154 | int result; |
155 | struct msghdr msg; | |
156 | struct kvec iov; | |
be0ef957 | 157 | sigset_t blocked, oldset; |
1da177e4 | 158 | |
ffc41cf8 MS |
159 | if (unlikely(!sock)) { |
160 | printk(KERN_ERR "%s: Attempted %s on closed socket in sock_xmit\n", | |
161 | lo->disk->disk_name, (send ? "send" : "recv")); | |
162 | return -EINVAL; | |
163 | } | |
164 | ||
1da177e4 LT |
165 | /* Allow interception of SIGKILL only |
166 | * Don't allow other signals to interrupt the transmission */ | |
be0ef957 ON |
167 | siginitsetinv(&blocked, sigmask(SIGKILL)); |
168 | sigprocmask(SIG_SETMASK, &blocked, &oldset); | |
1da177e4 LT |
169 | |
170 | do { | |
171 | sock->sk->sk_allocation = GFP_NOIO; | |
172 | iov.iov_base = buf; | |
173 | iov.iov_len = size; | |
174 | msg.msg_name = NULL; | |
175 | msg.msg_namelen = 0; | |
176 | msg.msg_control = NULL; | |
177 | msg.msg_controllen = 0; | |
1da177e4 LT |
178 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
179 | ||
7fdfd406 PC |
180 | if (send) { |
181 | struct timer_list ti; | |
182 | ||
183 | if (lo->xmit_timeout) { | |
184 | init_timer(&ti); | |
185 | ti.function = nbd_xmit_timeout; | |
186 | ti.data = (unsigned long)current; | |
187 | ti.expires = jiffies + lo->xmit_timeout; | |
188 | add_timer(&ti); | |
189 | } | |
1da177e4 | 190 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
7fdfd406 PC |
191 | if (lo->xmit_timeout) |
192 | del_timer_sync(&ti); | |
193 | } else | |
1da177e4 LT |
194 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); |
195 | ||
196 | if (signal_pending(current)) { | |
197 | siginfo_t info; | |
1da177e4 | 198 | printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", |
ba25f9dc | 199 | task_pid_nr(current), current->comm, |
be0ef957 | 200 | dequeue_signal_lock(current, ¤t->blocked, &info)); |
1da177e4 | 201 | result = -EINTR; |
7fdfd406 | 202 | sock_shutdown(lo, !send); |
1da177e4 LT |
203 | break; |
204 | } | |
205 | ||
206 | if (result <= 0) { | |
207 | if (result == 0) | |
208 | result = -EPIPE; /* short read */ | |
209 | break; | |
210 | } | |
211 | size -= result; | |
212 | buf += result; | |
213 | } while (size > 0); | |
214 | ||
be0ef957 | 215 | sigprocmask(SIG_SETMASK, &oldset, NULL); |
1da177e4 LT |
216 | |
217 | return result; | |
218 | } | |
219 | ||
7fdfd406 | 220 | static inline int sock_send_bvec(struct nbd_device *lo, struct bio_vec *bvec, |
1da177e4 LT |
221 | int flags) |
222 | { | |
223 | int result; | |
224 | void *kaddr = kmap(bvec->bv_page); | |
7fdfd406 | 225 | result = sock_xmit(lo, 1, kaddr + bvec->bv_offset, bvec->bv_len, flags); |
1da177e4 LT |
226 | kunmap(bvec->bv_page); |
227 | return result; | |
228 | } | |
229 | ||
7fdfd406 | 230 | /* always call with the tx_lock held */ |
1da177e4 LT |
231 | static int nbd_send_req(struct nbd_device *lo, struct request *req) |
232 | { | |
5705f702 | 233 | int result, flags; |
1da177e4 | 234 | struct nbd_request request; |
1011c1b9 | 235 | unsigned long size = blk_rq_bytes(req); |
1da177e4 LT |
236 | |
237 | request.magic = htonl(NBD_REQUEST_MAGIC); | |
238 | request.type = htonl(nbd_cmd(req)); | |
83096ebf | 239 | request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); |
1da177e4 LT |
240 | request.len = htonl(size); |
241 | memcpy(request.handle, &req, sizeof(req)); | |
242 | ||
83096ebf | 243 | dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%uB)\n", |
1da177e4 LT |
244 | lo->disk->disk_name, req, |
245 | nbdcmd_to_ascii(nbd_cmd(req)), | |
83096ebf | 246 | (unsigned long long)blk_rq_pos(req) << 9, |
1011c1b9 | 247 | blk_rq_bytes(req)); |
7fdfd406 PC |
248 | result = sock_xmit(lo, 1, &request, sizeof(request), |
249 | (nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0); | |
1da177e4 LT |
250 | if (result <= 0) { |
251 | printk(KERN_ERR "%s: Send control failed (result %d)\n", | |
252 | lo->disk->disk_name, result); | |
253 | goto error_out; | |
254 | } | |
255 | ||
256 | if (nbd_cmd(req) == NBD_CMD_WRITE) { | |
5705f702 N |
257 | struct req_iterator iter; |
258 | struct bio_vec *bvec; | |
1da177e4 LT |
259 | /* |
260 | * we are really probing at internals to determine | |
261 | * whether to set MSG_MORE or not... | |
262 | */ | |
5705f702 | 263 | rq_for_each_segment(bvec, req, iter) { |
6c92e699 JA |
264 | flags = 0; |
265 | if (!rq_iter_last(req, iter)) | |
266 | flags = MSG_MORE; | |
267 | dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", | |
268 | lo->disk->disk_name, req, bvec->bv_len); | |
7fdfd406 | 269 | result = sock_send_bvec(lo, bvec, flags); |
6c92e699 JA |
270 | if (result <= 0) { |
271 | printk(KERN_ERR "%s: Send data failed (result %d)\n", | |
272 | lo->disk->disk_name, result); | |
273 | goto error_out; | |
274 | } | |
1da177e4 LT |
275 | } |
276 | } | |
1da177e4 LT |
277 | return 0; |
278 | ||
279 | error_out: | |
15746fca | 280 | return -EIO; |
1da177e4 LT |
281 | } |
282 | ||
0cbc591b DC |
283 | static struct request *nbd_find_request(struct nbd_device *lo, |
284 | struct request *xreq) | |
1da177e4 | 285 | { |
d2c9740b | 286 | struct request *req, *tmp; |
4b2f0260 | 287 | int err; |
1da177e4 | 288 | |
4b2f0260 HX |
289 | err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); |
290 | if (unlikely(err)) | |
291 | goto out; | |
292 | ||
1da177e4 | 293 | spin_lock(&lo->queue_lock); |
d2c9740b | 294 | list_for_each_entry_safe(req, tmp, &lo->queue_head, queuelist) { |
1da177e4 LT |
295 | if (req != xreq) |
296 | continue; | |
297 | list_del_init(&req->queuelist); | |
298 | spin_unlock(&lo->queue_lock); | |
299 | return req; | |
300 | } | |
301 | spin_unlock(&lo->queue_lock); | |
4b2f0260 HX |
302 | |
303 | err = -ENOENT; | |
304 | ||
305 | out: | |
306 | return ERR_PTR(err); | |
1da177e4 LT |
307 | } |
308 | ||
7fdfd406 | 309 | static inline int sock_recv_bvec(struct nbd_device *lo, struct bio_vec *bvec) |
1da177e4 LT |
310 | { |
311 | int result; | |
312 | void *kaddr = kmap(bvec->bv_page); | |
7fdfd406 | 313 | result = sock_xmit(lo, 0, kaddr + bvec->bv_offset, bvec->bv_len, |
1da177e4 LT |
314 | MSG_WAITALL); |
315 | kunmap(bvec->bv_page); | |
316 | return result; | |
317 | } | |
318 | ||
319 | /* NULL returned = something went wrong, inform userspace */ | |
320 | static struct request *nbd_read_stat(struct nbd_device *lo) | |
321 | { | |
322 | int result; | |
323 | struct nbd_reply reply; | |
324 | struct request *req; | |
1da177e4 LT |
325 | |
326 | reply.magic = 0; | |
7fdfd406 | 327 | result = sock_xmit(lo, 0, &reply, sizeof(reply), MSG_WAITALL); |
1da177e4 LT |
328 | if (result <= 0) { |
329 | printk(KERN_ERR "%s: Receive control failed (result %d)\n", | |
330 | lo->disk->disk_name, result); | |
331 | goto harderror; | |
332 | } | |
e4b57e08 MF |
333 | |
334 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { | |
335 | printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", | |
336 | lo->disk->disk_name, | |
337 | (unsigned long)ntohl(reply.magic)); | |
338 | result = -EPROTO; | |
339 | goto harderror; | |
340 | } | |
341 | ||
0cbc591b | 342 | req = nbd_find_request(lo, *(struct request **)reply.handle); |
801678c5 | 343 | if (IS_ERR(req)) { |
4b2f0260 HX |
344 | result = PTR_ERR(req); |
345 | if (result != -ENOENT) | |
346 | goto harderror; | |
347 | ||
1da177e4 LT |
348 | printk(KERN_ERR "%s: Unexpected reply (%p)\n", |
349 | lo->disk->disk_name, reply.handle); | |
350 | result = -EBADR; | |
351 | goto harderror; | |
352 | } | |
353 | ||
1da177e4 LT |
354 | if (ntohl(reply.error)) { |
355 | printk(KERN_ERR "%s: Other side returned error (%d)\n", | |
356 | lo->disk->disk_name, ntohl(reply.error)); | |
357 | req->errors++; | |
358 | return req; | |
359 | } | |
360 | ||
361 | dprintk(DBG_RX, "%s: request %p: got reply\n", | |
362 | lo->disk->disk_name, req); | |
363 | if (nbd_cmd(req) == NBD_CMD_READ) { | |
5705f702 N |
364 | struct req_iterator iter; |
365 | struct bio_vec *bvec; | |
366 | ||
367 | rq_for_each_segment(bvec, req, iter) { | |
7fdfd406 | 368 | result = sock_recv_bvec(lo, bvec); |
6c92e699 JA |
369 | if (result <= 0) { |
370 | printk(KERN_ERR "%s: Receive data failed (result %d)\n", | |
371 | lo->disk->disk_name, result); | |
372 | req->errors++; | |
373 | return req; | |
374 | } | |
375 | dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", | |
376 | lo->disk->disk_name, req, bvec->bv_len); | |
1da177e4 LT |
377 | } |
378 | } | |
379 | return req; | |
380 | harderror: | |
381 | lo->harderror = result; | |
382 | return NULL; | |
383 | } | |
384 | ||
edfaa7c3 KS |
385 | static ssize_t pid_show(struct device *dev, |
386 | struct device_attribute *attr, char *buf) | |
6b39bb65 | 387 | { |
edfaa7c3 KS |
388 | struct gendisk *disk = dev_to_disk(dev); |
389 | ||
390 | return sprintf(buf, "%ld\n", | |
6b39bb65 PC |
391 | (long) ((struct nbd_device *)disk->private_data)->pid); |
392 | } | |
393 | ||
edfaa7c3 | 394 | static struct device_attribute pid_attr = { |
01e8ef11 | 395 | .attr = { .name = "pid", .mode = S_IRUGO}, |
6b39bb65 PC |
396 | .show = pid_show, |
397 | }; | |
398 | ||
84963048 | 399 | static int nbd_do_it(struct nbd_device *lo) |
1da177e4 LT |
400 | { |
401 | struct request *req; | |
84963048 | 402 | int ret; |
1da177e4 LT |
403 | |
404 | BUG_ON(lo->magic != LO_MAGIC); | |
405 | ||
6b39bb65 | 406 | lo->pid = current->pid; |
ed9e1982 | 407 | ret = sysfs_create_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr); |
84963048 WC |
408 | if (ret) { |
409 | printk(KERN_ERR "nbd: sysfs_create_file failed!"); | |
c91192d6 | 410 | lo->pid = 0; |
84963048 WC |
411 | return ret; |
412 | } | |
6b39bb65 | 413 | |
1da177e4 LT |
414 | while ((req = nbd_read_stat(lo)) != NULL) |
415 | nbd_end_request(req); | |
6b39bb65 | 416 | |
ed9e1982 | 417 | sysfs_remove_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr); |
c91192d6 | 418 | lo->pid = 0; |
84963048 | 419 | return 0; |
1da177e4 LT |
420 | } |
421 | ||
422 | static void nbd_clear_que(struct nbd_device *lo) | |
423 | { | |
424 | struct request *req; | |
425 | ||
426 | BUG_ON(lo->magic != LO_MAGIC); | |
427 | ||
4b2f0260 HX |
428 | /* |
429 | * Because we have set lo->sock to NULL under the tx_lock, all | |
430 | * modifications to the list must have completed by now. For | |
431 | * the same reason, the active_req must be NULL. | |
432 | * | |
433 | * As a consequence, we don't need to take the spin lock while | |
434 | * purging the list here. | |
435 | */ | |
436 | BUG_ON(lo->sock); | |
437 | BUG_ON(lo->active_req); | |
438 | ||
439 | while (!list_empty(&lo->queue_head)) { | |
440 | req = list_entry(lo->queue_head.next, struct request, | |
441 | queuelist); | |
442 | list_del_init(&req->queuelist); | |
443 | req->errors++; | |
444 | nbd_end_request(req); | |
445 | } | |
1da177e4 LT |
446 | } |
447 | ||
7fdfd406 | 448 | |
48cf6061 LV |
449 | static void nbd_handle_req(struct nbd_device *lo, struct request *req) |
450 | { | |
451 | if (!blk_fs_request(req)) | |
452 | goto error_out; | |
453 | ||
454 | nbd_cmd(req) = NBD_CMD_READ; | |
455 | if (rq_data_dir(req) == WRITE) { | |
456 | nbd_cmd(req) = NBD_CMD_WRITE; | |
457 | if (lo->flags & NBD_READ_ONLY) { | |
458 | printk(KERN_ERR "%s: Write on read-only\n", | |
459 | lo->disk->disk_name); | |
460 | goto error_out; | |
461 | } | |
462 | } | |
463 | ||
464 | req->errors = 0; | |
465 | ||
466 | mutex_lock(&lo->tx_lock); | |
467 | if (unlikely(!lo->sock)) { | |
468 | mutex_unlock(&lo->tx_lock); | |
469 | printk(KERN_ERR "%s: Attempted send on closed socket\n", | |
470 | lo->disk->disk_name); | |
15746fca | 471 | goto error_out; |
48cf6061 LV |
472 | } |
473 | ||
474 | lo->active_req = req; | |
475 | ||
476 | if (nbd_send_req(lo, req) != 0) { | |
477 | printk(KERN_ERR "%s: Request send failed\n", | |
478 | lo->disk->disk_name); | |
479 | req->errors++; | |
480 | nbd_end_request(req); | |
481 | } else { | |
482 | spin_lock(&lo->queue_lock); | |
483 | list_add(&req->queuelist, &lo->queue_head); | |
484 | spin_unlock(&lo->queue_lock); | |
485 | } | |
486 | ||
487 | lo->active_req = NULL; | |
488 | mutex_unlock(&lo->tx_lock); | |
489 | wake_up_all(&lo->active_wq); | |
490 | ||
491 | return; | |
492 | ||
493 | error_out: | |
494 | req->errors++; | |
495 | nbd_end_request(req); | |
496 | } | |
497 | ||
498 | static int nbd_thread(void *data) | |
499 | { | |
500 | struct nbd_device *lo = data; | |
501 | struct request *req; | |
502 | ||
503 | set_user_nice(current, -20); | |
504 | while (!kthread_should_stop() || !list_empty(&lo->waiting_queue)) { | |
505 | /* wait for something to do */ | |
506 | wait_event_interruptible(lo->waiting_wq, | |
507 | kthread_should_stop() || | |
508 | !list_empty(&lo->waiting_queue)); | |
509 | ||
510 | /* extract request */ | |
511 | if (list_empty(&lo->waiting_queue)) | |
512 | continue; | |
513 | ||
514 | spin_lock_irq(&lo->queue_lock); | |
515 | req = list_entry(lo->waiting_queue.next, struct request, | |
516 | queuelist); | |
517 | list_del_init(&req->queuelist); | |
518 | spin_unlock_irq(&lo->queue_lock); | |
519 | ||
520 | /* handle request */ | |
521 | nbd_handle_req(lo, req); | |
522 | } | |
523 | return 0; | |
524 | } | |
525 | ||
1da177e4 LT |
526 | /* |
527 | * We always wait for result of write, for now. It would be nice to make it optional | |
528 | * in future | |
e654bc43 | 529 | * if ((rq_data_dir(req) == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) |
1da177e4 LT |
530 | * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } |
531 | */ | |
532 | ||
15746fca | 533 | static void do_nbd_request(struct request_queue *q) |
1da177e4 LT |
534 | { |
535 | struct request *req; | |
536 | ||
9934c8c0 | 537 | while ((req = blk_fetch_request(q)) != NULL) { |
1da177e4 LT |
538 | struct nbd_device *lo; |
539 | ||
48cf6061 LV |
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 | ||
4d48a542 PC |
549 | if (unlikely(!lo->sock)) { |
550 | printk(KERN_ERR "%s: Attempted send on closed socket\n", | |
551 | lo->disk->disk_name); | |
552 | req->errors++; | |
553 | nbd_end_request(req); | |
554 | spin_lock_irq(q->queue_lock); | |
555 | continue; | |
556 | } | |
557 | ||
48cf6061 LV |
558 | spin_lock_irq(&lo->queue_lock); |
559 | list_add_tail(&req->queuelist, &lo->waiting_queue); | |
560 | spin_unlock_irq(&lo->queue_lock); | |
1da177e4 | 561 | |
48cf6061 | 562 | wake_up(&lo->waiting_wq); |
4b2f0260 | 563 | |
1da177e4 | 564 | spin_lock_irq(q->queue_lock); |
1da177e4 | 565 | } |
1da177e4 LT |
566 | } |
567 | ||
1a2ad211 | 568 | /* Must be called with tx_lock held */ |
1da177e4 | 569 | |
1a2ad211 PM |
570 | static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo, |
571 | unsigned int cmd, unsigned long arg) | |
572 | { | |
1da177e4 | 573 | switch (cmd) { |
1a2ad211 PM |
574 | case NBD_DISCONNECT: { |
575 | struct request sreq; | |
576 | ||
1da177e4 | 577 | printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name); |
1a2ad211 | 578 | |
4f54eec8 | 579 | blk_rq_init(NULL, &sreq); |
4aff5e23 | 580 | sreq.cmd_type = REQ_TYPE_SPECIAL; |
1da177e4 | 581 | nbd_cmd(&sreq) = NBD_CMD_DISC; |
1a2ad211 | 582 | if (!lo->sock) |
1da177e4 | 583 | return -EINVAL; |
1a2ad211 | 584 | nbd_send_req(lo, &sreq); |
1da177e4 | 585 | return 0; |
1a2ad211 | 586 | } |
1da177e4 | 587 | |
1a2ad211 PM |
588 | case NBD_CLEAR_SOCK: { |
589 | struct file *file; | |
590 | ||
1da177e4 | 591 | lo->sock = NULL; |
1da177e4 LT |
592 | file = lo->file; |
593 | lo->file = NULL; | |
1da177e4 | 594 | nbd_clear_que(lo); |
4b2f0260 | 595 | BUG_ON(!list_empty(&lo->queue_head)); |
1da177e4 LT |
596 | if (file) |
597 | fput(file); | |
1a2ad211 PM |
598 | return 0; |
599 | } | |
600 | ||
601 | case NBD_SET_SOCK: { | |
602 | struct file *file; | |
1da177e4 LT |
603 | if (lo->file) |
604 | return -EBUSY; | |
1da177e4 LT |
605 | file = fget(arg); |
606 | if (file) { | |
a8cdc308 | 607 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
608 | if (S_ISSOCK(inode->i_mode)) { |
609 | lo->file = file; | |
610 | lo->sock = SOCKET_I(inode); | |
d71a6d73 LV |
611 | if (max_part > 0) |
612 | bdev->bd_invalidated = 1; | |
1a2ad211 | 613 | return 0; |
1da177e4 LT |
614 | } else { |
615 | fput(file); | |
616 | } | |
617 | } | |
1a2ad211 PM |
618 | return -EINVAL; |
619 | } | |
620 | ||
1da177e4 LT |
621 | case NBD_SET_BLKSIZE: |
622 | lo->blksize = arg; | |
623 | lo->bytesize &= ~(lo->blksize-1); | |
a8cdc308 AV |
624 | bdev->bd_inode->i_size = lo->bytesize; |
625 | set_blocksize(bdev, lo->blksize); | |
1da177e4 LT |
626 | set_capacity(lo->disk, lo->bytesize >> 9); |
627 | return 0; | |
1a2ad211 | 628 | |
1da177e4 LT |
629 | case NBD_SET_SIZE: |
630 | lo->bytesize = arg & ~(lo->blksize-1); | |
a8cdc308 AV |
631 | bdev->bd_inode->i_size = lo->bytesize; |
632 | set_blocksize(bdev, lo->blksize); | |
1da177e4 LT |
633 | set_capacity(lo->disk, lo->bytesize >> 9); |
634 | return 0; | |
1a2ad211 | 635 | |
7fdfd406 PC |
636 | case NBD_SET_TIMEOUT: |
637 | lo->xmit_timeout = arg * HZ; | |
638 | return 0; | |
1a2ad211 | 639 | |
1da177e4 LT |
640 | case NBD_SET_SIZE_BLOCKS: |
641 | lo->bytesize = ((u64) arg) * lo->blksize; | |
a8cdc308 AV |
642 | bdev->bd_inode->i_size = lo->bytesize; |
643 | set_blocksize(bdev, lo->blksize); | |
1da177e4 LT |
644 | set_capacity(lo->disk, lo->bytesize >> 9); |
645 | return 0; | |
1a2ad211 PM |
646 | |
647 | case NBD_DO_IT: { | |
648 | struct task_struct *thread; | |
649 | struct file *file; | |
650 | int error; | |
651 | ||
c91192d6 PM |
652 | if (lo->pid) |
653 | return -EBUSY; | |
1da177e4 LT |
654 | if (!lo->file) |
655 | return -EINVAL; | |
1a2ad211 PM |
656 | |
657 | mutex_unlock(&lo->tx_lock); | |
658 | ||
48cf6061 | 659 | thread = kthread_create(nbd_thread, lo, lo->disk->disk_name); |
1a2ad211 PM |
660 | if (IS_ERR(thread)) { |
661 | mutex_lock(&lo->tx_lock); | |
48cf6061 | 662 | return PTR_ERR(thread); |
1a2ad211 | 663 | } |
48cf6061 | 664 | wake_up_process(thread); |
84963048 | 665 | error = nbd_do_it(lo); |
48cf6061 | 666 | kthread_stop(thread); |
1a2ad211 PM |
667 | |
668 | mutex_lock(&lo->tx_lock); | |
84963048 WC |
669 | if (error) |
670 | return error; | |
1a2ad211 | 671 | sock_shutdown(lo, 0); |
1da177e4 LT |
672 | file = lo->file; |
673 | lo->file = NULL; | |
1da177e4 LT |
674 | nbd_clear_que(lo); |
675 | printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); | |
676 | if (file) | |
677 | fput(file); | |
4b86a872 | 678 | lo->bytesize = 0; |
a8cdc308 | 679 | bdev->bd_inode->i_size = 0; |
4b86a872 | 680 | set_capacity(lo->disk, 0); |
d71a6d73 | 681 | if (max_part > 0) |
a8cdc308 | 682 | ioctl_by_bdev(bdev, BLKRRPART, 0); |
1da177e4 | 683 | return lo->harderror; |
1a2ad211 PM |
684 | } |
685 | ||
1da177e4 | 686 | case NBD_CLEAR_QUE: |
4b2f0260 HX |
687 | /* |
688 | * This is for compatibility only. The queue is always cleared | |
689 | * by NBD_DO_IT or NBD_CLEAR_SOCK. | |
690 | */ | |
691 | BUG_ON(!lo->sock && !list_empty(&lo->queue_head)); | |
1da177e4 | 692 | return 0; |
1a2ad211 | 693 | |
1da177e4 LT |
694 | case NBD_PRINT_DEBUG: |
695 | printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n", | |
a8cdc308 | 696 | bdev->bd_disk->disk_name, |
1da177e4 LT |
697 | lo->queue_head.next, lo->queue_head.prev, |
698 | &lo->queue_head); | |
699 | return 0; | |
700 | } | |
1a2ad211 PM |
701 | return -ENOTTY; |
702 | } | |
703 | ||
704 | static int nbd_ioctl(struct block_device *bdev, fmode_t mode, | |
705 | unsigned int cmd, unsigned long arg) | |
706 | { | |
707 | struct nbd_device *lo = bdev->bd_disk->private_data; | |
708 | int error; | |
709 | ||
710 | if (!capable(CAP_SYS_ADMIN)) | |
711 | return -EPERM; | |
712 | ||
713 | BUG_ON(lo->magic != LO_MAGIC); | |
714 | ||
715 | /* Anyone capable of this syscall can do *real bad* things */ | |
716 | dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", | |
717 | lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); | |
718 | ||
719 | mutex_lock(&lo->tx_lock); | |
720 | error = __nbd_ioctl(bdev, lo, cmd, arg); | |
721 | mutex_unlock(&lo->tx_lock); | |
722 | ||
723 | return error; | |
1da177e4 LT |
724 | } |
725 | ||
83d5cde4 | 726 | static const struct block_device_operations nbd_fops = |
1da177e4 LT |
727 | { |
728 | .owner = THIS_MODULE, | |
a8cdc308 | 729 | .locked_ioctl = nbd_ioctl, |
1da177e4 LT |
730 | }; |
731 | ||
732 | /* | |
733 | * And here should be modules and kernel interface | |
734 | * (Just smiley confuses emacs :-) | |
735 | */ | |
736 | ||
737 | static int __init nbd_init(void) | |
738 | { | |
739 | int err = -ENOMEM; | |
740 | int i; | |
d71a6d73 | 741 | int part_shift; |
1da177e4 | 742 | |
5b7b18cc | 743 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
1da177e4 | 744 | |
d71a6d73 LV |
745 | if (max_part < 0) { |
746 | printk(KERN_CRIT "nbd: max_part must be >= 0\n"); | |
747 | return -EINVAL; | |
748 | } | |
749 | ||
f3944d61 SW |
750 | nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL); |
751 | if (!nbd_dev) | |
752 | return -ENOMEM; | |
753 | ||
d71a6d73 LV |
754 | part_shift = 0; |
755 | if (max_part > 0) | |
756 | part_shift = fls(max_part); | |
757 | ||
40be0c28 | 758 | for (i = 0; i < nbds_max; i++) { |
d71a6d73 | 759 | struct gendisk *disk = alloc_disk(1 << part_shift); |
1da177e4 LT |
760 | if (!disk) |
761 | goto out; | |
762 | nbd_dev[i].disk = disk; | |
763 | /* | |
764 | * The new linux 2.5 block layer implementation requires | |
765 | * every gendisk to have its very own request_queue struct. | |
766 | * These structs are big so we dynamically allocate them. | |
767 | */ | |
768 | disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); | |
769 | if (!disk->queue) { | |
770 | put_disk(disk); | |
771 | goto out; | |
772 | } | |
31dcfab0 JA |
773 | /* |
774 | * Tell the block layer that we are not a rotational device | |
775 | */ | |
776 | queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue); | |
1da177e4 LT |
777 | } |
778 | ||
779 | if (register_blkdev(NBD_MAJOR, "nbd")) { | |
780 | err = -EIO; | |
781 | goto out; | |
782 | } | |
783 | ||
784 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); | |
785 | dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); | |
786 | ||
40be0c28 | 787 | for (i = 0; i < nbds_max; i++) { |
1da177e4 LT |
788 | struct gendisk *disk = nbd_dev[i].disk; |
789 | nbd_dev[i].file = NULL; | |
790 | nbd_dev[i].magic = LO_MAGIC; | |
791 | nbd_dev[i].flags = 0; | |
48cf6061 | 792 | INIT_LIST_HEAD(&nbd_dev[i].waiting_queue); |
1da177e4 LT |
793 | spin_lock_init(&nbd_dev[i].queue_lock); |
794 | INIT_LIST_HEAD(&nbd_dev[i].queue_head); | |
82d4dc5a | 795 | mutex_init(&nbd_dev[i].tx_lock); |
4b2f0260 | 796 | init_waitqueue_head(&nbd_dev[i].active_wq); |
48cf6061 | 797 | init_waitqueue_head(&nbd_dev[i].waiting_wq); |
1da177e4 | 798 | nbd_dev[i].blksize = 1024; |
4b86a872 | 799 | nbd_dev[i].bytesize = 0; |
1da177e4 | 800 | disk->major = NBD_MAJOR; |
d71a6d73 | 801 | disk->first_minor = i << part_shift; |
1da177e4 LT |
802 | disk->fops = &nbd_fops; |
803 | disk->private_data = &nbd_dev[i]; | |
1da177e4 | 804 | sprintf(disk->disk_name, "nbd%d", i); |
4b86a872 | 805 | set_capacity(disk, 0); |
1da177e4 LT |
806 | add_disk(disk); |
807 | } | |
808 | ||
809 | return 0; | |
810 | out: | |
811 | while (i--) { | |
812 | blk_cleanup_queue(nbd_dev[i].disk->queue); | |
813 | put_disk(nbd_dev[i].disk); | |
814 | } | |
f3944d61 | 815 | kfree(nbd_dev); |
1da177e4 LT |
816 | return err; |
817 | } | |
818 | ||
819 | static void __exit nbd_cleanup(void) | |
820 | { | |
821 | int i; | |
40be0c28 | 822 | for (i = 0; i < nbds_max; i++) { |
1da177e4 | 823 | struct gendisk *disk = nbd_dev[i].disk; |
40be0c28 | 824 | nbd_dev[i].magic = 0; |
1da177e4 LT |
825 | if (disk) { |
826 | del_gendisk(disk); | |
827 | blk_cleanup_queue(disk->queue); | |
828 | put_disk(disk); | |
829 | } | |
830 | } | |
1da177e4 | 831 | unregister_blkdev(NBD_MAJOR, "nbd"); |
f3944d61 | 832 | kfree(nbd_dev); |
1da177e4 LT |
833 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); |
834 | } | |
835 | ||
836 | module_init(nbd_init); | |
837 | module_exit(nbd_cleanup); | |
838 | ||
839 | MODULE_DESCRIPTION("Network Block Device"); | |
840 | MODULE_LICENSE("GPL"); | |
841 | ||
40be0c28 | 842 | module_param(nbds_max, int, 0444); |
d71a6d73 LV |
843 | MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); |
844 | module_param(max_part, int, 0444); | |
845 | MODULE_PARM_DESC(max_part, "number of partitions per device (default: 0)"); | |
1da177e4 LT |
846 | #ifndef NDEBUG |
847 | module_param(debugflags, int, 0644); | |
848 | MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); | |
849 | #endif |