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NBD: set uninitialized devices to size 0
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CommitLineData
1da177e4
LT
1/*
2 * Network block device - make block devices work over TCP
3 *
4 * Note that you can not swap over this thing, yet. Seems to work but
5 * deadlocks sometimes - you can not swap over TCP in general.
6 *
7 * Copyright 1997-2000 Pavel Machek <pavel@ucw.cz>
8 * Parts copyright 2001 Steven Whitehouse <steve@chygwyn.com>
9 *
dbf492d6 10 * This file is released under GPLv2 or later.
1da177e4 11 *
dbf492d6 12 * (part of code stolen from loop.c)
1da177e4
LT
13 */
14
15#include <linux/major.h>
16
17#include <linux/blkdev.h>
18#include <linux/module.h>
19#include <linux/init.h>
20#include <linux/sched.h>
21#include <linux/fs.h>
22#include <linux/bio.h>
23#include <linux/stat.h>
24#include <linux/errno.h>
25#include <linux/file.h>
26#include <linux/ioctl.h>
4b2f0260
HX
27#include <linux/compiler.h>
28#include <linux/err.h>
29#include <linux/kernel.h>
1da177e4
LT
30#include <net/sock.h>
31
1da177e4 32#include <asm/uaccess.h>
4b2f0260 33#include <asm/system.h>
1da177e4
LT
34#include <asm/types.h>
35
36#include <linux/nbd.h>
37
38#define LO_MAGIC 0x68797548
39
40#ifdef NDEBUG
41#define dprintk(flags, fmt...)
42#else /* NDEBUG */
43#define dprintk(flags, fmt...) do { \
44 if (debugflags & (flags)) printk(KERN_DEBUG fmt); \
45} while (0)
46#define DBG_IOCTL 0x0004
47#define DBG_INIT 0x0010
48#define DBG_EXIT 0x0020
49#define DBG_BLKDEV 0x0100
50#define DBG_RX 0x0200
51#define DBG_TX 0x0400
52static unsigned int debugflags;
53#endif /* NDEBUG */
54
9c7a4169 55static unsigned int nbds_max = 16;
1da177e4
LT
56static struct nbd_device nbd_dev[MAX_NBD];
57
58/*
59 * Use just one lock (or at most 1 per NIC). Two arguments for this:
60 * 1. Each NIC is essentially a synchronization point for all servers
61 * accessed through that NIC so there's no need to have more locks
62 * than NICs anyway.
63 * 2. More locks lead to more "Dirty cache line bouncing" which will slow
64 * down each lock to the point where they're actually slower than just
65 * a single lock.
66 * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this!
67 */
68static DEFINE_SPINLOCK(nbd_lock);
69
70#ifndef NDEBUG
71static const char *ioctl_cmd_to_ascii(int cmd)
72{
73 switch (cmd) {
74 case NBD_SET_SOCK: return "set-sock";
75 case NBD_SET_BLKSIZE: return "set-blksize";
76 case NBD_SET_SIZE: return "set-size";
77 case NBD_DO_IT: return "do-it";
78 case NBD_CLEAR_SOCK: return "clear-sock";
79 case NBD_CLEAR_QUE: return "clear-que";
80 case NBD_PRINT_DEBUG: return "print-debug";
81 case NBD_SET_SIZE_BLOCKS: return "set-size-blocks";
82 case NBD_DISCONNECT: return "disconnect";
83 case BLKROSET: return "set-read-only";
84 case BLKFLSBUF: return "flush-buffer-cache";
85 }
86 return "unknown";
87}
88
89static const char *nbdcmd_to_ascii(int cmd)
90{
91 switch (cmd) {
92 case NBD_CMD_READ: return "read";
93 case NBD_CMD_WRITE: return "write";
94 case NBD_CMD_DISC: return "disconnect";
95 }
96 return "invalid";
97}
98#endif /* NDEBUG */
99
100static void nbd_end_request(struct request *req)
101{
102 int uptodate = (req->errors == 0) ? 1 : 0;
165125e1 103 struct request_queue *q = req->q;
1da177e4
LT
104 unsigned long flags;
105
106 dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name,
107 req, uptodate? "done": "failed");
108
109 spin_lock_irqsave(q->queue_lock, flags);
110 if (!end_that_request_first(req, uptodate, req->nr_sectors)) {
8ffdc655 111 end_that_request_last(req, uptodate);
1da177e4
LT
112 }
113 spin_unlock_irqrestore(q->queue_lock, flags);
114}
115
116/*
117 * Send or receive packet.
118 */
119static int sock_xmit(struct socket *sock, int send, void *buf, int size,
120 int msg_flags)
121{
122 int result;
123 struct msghdr msg;
124 struct kvec iov;
be0ef957 125 sigset_t blocked, oldset;
1da177e4
LT
126
127 /* Allow interception of SIGKILL only
128 * Don't allow other signals to interrupt the transmission */
be0ef957
ON
129 siginitsetinv(&blocked, sigmask(SIGKILL));
130 sigprocmask(SIG_SETMASK, &blocked, &oldset);
1da177e4
LT
131
132 do {
133 sock->sk->sk_allocation = GFP_NOIO;
134 iov.iov_base = buf;
135 iov.iov_len = size;
136 msg.msg_name = NULL;
137 msg.msg_namelen = 0;
138 msg.msg_control = NULL;
139 msg.msg_controllen = 0;
1da177e4
LT
140 msg.msg_flags = msg_flags | MSG_NOSIGNAL;
141
142 if (send)
143 result = kernel_sendmsg(sock, &msg, &iov, 1, size);
144 else
145 result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0);
146
147 if (signal_pending(current)) {
148 siginfo_t info;
1da177e4 149 printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n",
be0ef957
ON
150 current->pid, current->comm,
151 dequeue_signal_lock(current, &current->blocked, &info));
1da177e4
LT
152 result = -EINTR;
153 break;
154 }
155
156 if (result <= 0) {
157 if (result == 0)
158 result = -EPIPE; /* short read */
159 break;
160 }
161 size -= result;
162 buf += result;
163 } while (size > 0);
164
be0ef957 165 sigprocmask(SIG_SETMASK, &oldset, NULL);
1da177e4
LT
166
167 return result;
168}
169
170static inline int sock_send_bvec(struct socket *sock, struct bio_vec *bvec,
171 int flags)
172{
173 int result;
174 void *kaddr = kmap(bvec->bv_page);
175 result = sock_xmit(sock, 1, kaddr + bvec->bv_offset, bvec->bv_len,
176 flags);
177 kunmap(bvec->bv_page);
178 return result;
179}
180
181static int nbd_send_req(struct nbd_device *lo, struct request *req)
182{
5705f702 183 int result, flags;
1da177e4
LT
184 struct nbd_request request;
185 unsigned long size = req->nr_sectors << 9;
186 struct socket *sock = lo->sock;
187
188 request.magic = htonl(NBD_REQUEST_MAGIC);
189 request.type = htonl(nbd_cmd(req));
190 request.from = cpu_to_be64((u64) req->sector << 9);
191 request.len = htonl(size);
192 memcpy(request.handle, &req, sizeof(req));
193
1da177e4
LT
194 dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n",
195 lo->disk->disk_name, req,
196 nbdcmd_to_ascii(nbd_cmd(req)),
197 (unsigned long long)req->sector << 9,
198 req->nr_sectors << 9);
199 result = sock_xmit(sock, 1, &request, sizeof(request),
200 (nbd_cmd(req) == NBD_CMD_WRITE)? MSG_MORE: 0);
201 if (result <= 0) {
202 printk(KERN_ERR "%s: Send control failed (result %d)\n",
203 lo->disk->disk_name, result);
204 goto error_out;
205 }
206
207 if (nbd_cmd(req) == NBD_CMD_WRITE) {
5705f702
N
208 struct req_iterator iter;
209 struct bio_vec *bvec;
1da177e4
LT
210 /*
211 * we are really probing at internals to determine
212 * whether to set MSG_MORE or not...
213 */
5705f702 214 rq_for_each_segment(bvec, req, iter) {
6c92e699
JA
215 flags = 0;
216 if (!rq_iter_last(req, iter))
217 flags = MSG_MORE;
218 dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n",
219 lo->disk->disk_name, req, bvec->bv_len);
220 result = sock_send_bvec(sock, bvec, flags);
221 if (result <= 0) {
222 printk(KERN_ERR "%s: Send data failed (result %d)\n",
223 lo->disk->disk_name, result);
224 goto error_out;
225 }
1da177e4
LT
226 }
227 }
1da177e4
LT
228 return 0;
229
230error_out:
1da177e4
LT
231 return 1;
232}
233
0cbc591b
DC
234static struct request *nbd_find_request(struct nbd_device *lo,
235 struct request *xreq)
1da177e4 236{
d2c9740b 237 struct request *req, *tmp;
4b2f0260 238 int err;
1da177e4 239
4b2f0260
HX
240 err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq);
241 if (unlikely(err))
242 goto out;
243
1da177e4 244 spin_lock(&lo->queue_lock);
d2c9740b 245 list_for_each_entry_safe(req, tmp, &lo->queue_head, queuelist) {
1da177e4
LT
246 if (req != xreq)
247 continue;
248 list_del_init(&req->queuelist);
249 spin_unlock(&lo->queue_lock);
250 return req;
251 }
252 spin_unlock(&lo->queue_lock);
4b2f0260
HX
253
254 err = -ENOENT;
255
256out:
257 return ERR_PTR(err);
1da177e4
LT
258}
259
260static inline int sock_recv_bvec(struct socket *sock, struct bio_vec *bvec)
261{
262 int result;
263 void *kaddr = kmap(bvec->bv_page);
264 result = sock_xmit(sock, 0, kaddr + bvec->bv_offset, bvec->bv_len,
265 MSG_WAITALL);
266 kunmap(bvec->bv_page);
267 return result;
268}
269
270/* NULL returned = something went wrong, inform userspace */
271static struct request *nbd_read_stat(struct nbd_device *lo)
272{
273 int result;
274 struct nbd_reply reply;
275 struct request *req;
276 struct socket *sock = lo->sock;
277
278 reply.magic = 0;
279 result = sock_xmit(sock, 0, &reply, sizeof(reply), MSG_WAITALL);
280 if (result <= 0) {
281 printk(KERN_ERR "%s: Receive control failed (result %d)\n",
282 lo->disk->disk_name, result);
283 goto harderror;
284 }
e4b57e08
MF
285
286 if (ntohl(reply.magic) != NBD_REPLY_MAGIC) {
287 printk(KERN_ERR "%s: Wrong magic (0x%lx)\n",
288 lo->disk->disk_name,
289 (unsigned long)ntohl(reply.magic));
290 result = -EPROTO;
291 goto harderror;
292 }
293
0cbc591b 294 req = nbd_find_request(lo, *(struct request **)reply.handle);
4b2f0260
HX
295 if (unlikely(IS_ERR(req))) {
296 result = PTR_ERR(req);
297 if (result != -ENOENT)
298 goto harderror;
299
1da177e4
LT
300 printk(KERN_ERR "%s: Unexpected reply (%p)\n",
301 lo->disk->disk_name, reply.handle);
302 result = -EBADR;
303 goto harderror;
304 }
305
1da177e4
LT
306 if (ntohl(reply.error)) {
307 printk(KERN_ERR "%s: Other side returned error (%d)\n",
308 lo->disk->disk_name, ntohl(reply.error));
309 req->errors++;
310 return req;
311 }
312
313 dprintk(DBG_RX, "%s: request %p: got reply\n",
314 lo->disk->disk_name, req);
315 if (nbd_cmd(req) == NBD_CMD_READ) {
5705f702
N
316 struct req_iterator iter;
317 struct bio_vec *bvec;
318
319 rq_for_each_segment(bvec, req, iter) {
6c92e699
JA
320 result = sock_recv_bvec(sock, bvec);
321 if (result <= 0) {
322 printk(KERN_ERR "%s: Receive data failed (result %d)\n",
323 lo->disk->disk_name, result);
324 req->errors++;
325 return req;
326 }
327 dprintk(DBG_RX, "%s: request %p: got %d bytes data\n",
328 lo->disk->disk_name, req, bvec->bv_len);
1da177e4
LT
329 }
330 }
331 return req;
332harderror:
333 lo->harderror = result;
334 return NULL;
335}
336
6b39bb65
PC
337static ssize_t pid_show(struct gendisk *disk, char *page)
338{
339 return sprintf(page, "%ld\n",
340 (long) ((struct nbd_device *)disk->private_data)->pid);
341}
342
343static struct disk_attribute pid_attr = {
344 .attr = { .name = "pid", .mode = S_IRUGO },
345 .show = pid_show,
346};
347
84963048 348static int nbd_do_it(struct nbd_device *lo)
1da177e4
LT
349{
350 struct request *req;
84963048 351 int ret;
1da177e4
LT
352
353 BUG_ON(lo->magic != LO_MAGIC);
354
6b39bb65 355 lo->pid = current->pid;
84963048
WC
356 ret = sysfs_create_file(&lo->disk->kobj, &pid_attr.attr);
357 if (ret) {
358 printk(KERN_ERR "nbd: sysfs_create_file failed!");
359 return ret;
360 }
6b39bb65 361
1da177e4
LT
362 while ((req = nbd_read_stat(lo)) != NULL)
363 nbd_end_request(req);
6b39bb65
PC
364
365 sysfs_remove_file(&lo->disk->kobj, &pid_attr.attr);
84963048 366 return 0;
1da177e4
LT
367}
368
369static void nbd_clear_que(struct nbd_device *lo)
370{
371 struct request *req;
372
373 BUG_ON(lo->magic != LO_MAGIC);
374
4b2f0260
HX
375 /*
376 * Because we have set lo->sock to NULL under the tx_lock, all
377 * modifications to the list must have completed by now. For
378 * the same reason, the active_req must be NULL.
379 *
380 * As a consequence, we don't need to take the spin lock while
381 * purging the list here.
382 */
383 BUG_ON(lo->sock);
384 BUG_ON(lo->active_req);
385
386 while (!list_empty(&lo->queue_head)) {
387 req = list_entry(lo->queue_head.next, struct request,
388 queuelist);
389 list_del_init(&req->queuelist);
390 req->errors++;
391 nbd_end_request(req);
392 }
1da177e4
LT
393}
394
395/*
396 * We always wait for result of write, for now. It would be nice to make it optional
397 * in future
e654bc43 398 * if ((rq_data_dir(req) == WRITE) && (lo->flags & NBD_WRITE_NOCHK))
1da177e4
LT
399 * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); }
400 */
401
165125e1 402static void do_nbd_request(struct request_queue * q)
1da177e4
LT
403{
404 struct request *req;
405
406 while ((req = elv_next_request(q)) != NULL) {
407 struct nbd_device *lo;
408
409 blkdev_dequeue_request(req);
4aff5e23
JA
410 dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n",
411 req->rq_disk->disk_name, req, req->cmd_type);
1da177e4 412
4aff5e23 413 if (!blk_fs_request(req))
1da177e4
LT
414 goto error_out;
415
416 lo = req->rq_disk->private_data;
417
418 BUG_ON(lo->magic != LO_MAGIC);
419
1da177e4
LT
420 nbd_cmd(req) = NBD_CMD_READ;
421 if (rq_data_dir(req) == WRITE) {
422 nbd_cmd(req) = NBD_CMD_WRITE;
423 if (lo->flags & NBD_READ_ONLY) {
424 printk(KERN_ERR "%s: Write on read-only\n",
425 lo->disk->disk_name);
426 goto error_out;
427 }
428 }
429
430 req->errors = 0;
431 spin_unlock_irq(q->queue_lock);
432
82d4dc5a 433 mutex_lock(&lo->tx_lock);
4b2f0260 434 if (unlikely(!lo->sock)) {
82d4dc5a 435 mutex_unlock(&lo->tx_lock);
4b2f0260
HX
436 printk(KERN_ERR "%s: Attempted send on closed socket\n",
437 lo->disk->disk_name);
1da177e4
LT
438 req->errors++;
439 nbd_end_request(req);
440 spin_lock_irq(q->queue_lock);
441 continue;
442 }
443
4b2f0260 444 lo->active_req = req;
1da177e4
LT
445
446 if (nbd_send_req(lo, req) != 0) {
447 printk(KERN_ERR "%s: Request send failed\n",
448 lo->disk->disk_name);
4b2f0260
HX
449 req->errors++;
450 nbd_end_request(req);
451 } else {
452 spin_lock(&lo->queue_lock);
453 list_add(&req->queuelist, &lo->queue_head);
454 spin_unlock(&lo->queue_lock);
1da177e4
LT
455 }
456
4b2f0260 457 lo->active_req = NULL;
82d4dc5a 458 mutex_unlock(&lo->tx_lock);
4b2f0260
HX
459 wake_up_all(&lo->active_wq);
460
1da177e4
LT
461 spin_lock_irq(q->queue_lock);
462 continue;
463
464error_out:
465 req->errors++;
466 spin_unlock(q->queue_lock);
467 nbd_end_request(req);
468 spin_lock(q->queue_lock);
469 }
470 return;
471}
472
473static int nbd_ioctl(struct inode *inode, struct file *file,
474 unsigned int cmd, unsigned long arg)
475{
476 struct nbd_device *lo = inode->i_bdev->bd_disk->private_data;
477 int error;
478 struct request sreq ;
479
480 if (!capable(CAP_SYS_ADMIN))
481 return -EPERM;
482
483 BUG_ON(lo->magic != LO_MAGIC);
484
485 /* Anyone capable of this syscall can do *real bad* things */
486 dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n",
487 lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg);
488
489 switch (cmd) {
490 case NBD_DISCONNECT:
491 printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name);
4aff5e23 492 sreq.cmd_type = REQ_TYPE_SPECIAL;
1da177e4
LT
493 nbd_cmd(&sreq) = NBD_CMD_DISC;
494 /*
495 * Set these to sane values in case server implementation
496 * fails to check the request type first and also to keep
497 * debugging output cleaner.
498 */
499 sreq.sector = 0;
500 sreq.nr_sectors = 0;
501 if (!lo->sock)
502 return -EINVAL;
503 nbd_send_req(lo, &sreq);
504 return 0;
505
506 case NBD_CLEAR_SOCK:
507 error = 0;
82d4dc5a 508 mutex_lock(&lo->tx_lock);
1da177e4 509 lo->sock = NULL;
82d4dc5a 510 mutex_unlock(&lo->tx_lock);
1da177e4
LT
511 file = lo->file;
512 lo->file = NULL;
1da177e4 513 nbd_clear_que(lo);
4b2f0260 514 BUG_ON(!list_empty(&lo->queue_head));
1da177e4
LT
515 if (file)
516 fput(file);
517 return error;
518 case NBD_SET_SOCK:
519 if (lo->file)
520 return -EBUSY;
521 error = -EINVAL;
522 file = fget(arg);
523 if (file) {
17506041 524 inode = file->f_path.dentry->d_inode;
1da177e4
LT
525 if (S_ISSOCK(inode->i_mode)) {
526 lo->file = file;
527 lo->sock = SOCKET_I(inode);
528 error = 0;
529 } else {
530 fput(file);
531 }
532 }
533 return error;
534 case NBD_SET_BLKSIZE:
535 lo->blksize = arg;
536 lo->bytesize &= ~(lo->blksize-1);
537 inode->i_bdev->bd_inode->i_size = lo->bytesize;
538 set_blocksize(inode->i_bdev, lo->blksize);
539 set_capacity(lo->disk, lo->bytesize >> 9);
540 return 0;
541 case NBD_SET_SIZE:
542 lo->bytesize = arg & ~(lo->blksize-1);
543 inode->i_bdev->bd_inode->i_size = lo->bytesize;
544 set_blocksize(inode->i_bdev, lo->blksize);
545 set_capacity(lo->disk, lo->bytesize >> 9);
546 return 0;
547 case NBD_SET_SIZE_BLOCKS:
548 lo->bytesize = ((u64) arg) * lo->blksize;
549 inode->i_bdev->bd_inode->i_size = lo->bytesize;
550 set_blocksize(inode->i_bdev, lo->blksize);
551 set_capacity(lo->disk, lo->bytesize >> 9);
552 return 0;
553 case NBD_DO_IT:
554 if (!lo->file)
555 return -EINVAL;
84963048
WC
556 error = nbd_do_it(lo);
557 if (error)
558 return error;
1da177e4
LT
559 /* on return tidy up in case we have a signal */
560 /* Forcibly shutdown the socket causing all listeners
561 * to error
562 *
563 * FIXME: This code is duplicated from sys_shutdown, but
564 * there should be a more generic interface rather than
565 * calling socket ops directly here */
82d4dc5a 566 mutex_lock(&lo->tx_lock);
1da177e4
LT
567 if (lo->sock) {
568 printk(KERN_WARNING "%s: shutting down socket\n",
569 lo->disk->disk_name);
570 lo->sock->ops->shutdown(lo->sock,
571 SEND_SHUTDOWN|RCV_SHUTDOWN);
572 lo->sock = NULL;
573 }
82d4dc5a 574 mutex_unlock(&lo->tx_lock);
1da177e4
LT
575 file = lo->file;
576 lo->file = NULL;
1da177e4
LT
577 nbd_clear_que(lo);
578 printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name);
579 if (file)
580 fput(file);
4b86a872
PC
581 lo->bytesize = 0;
582 inode->i_bdev->bd_inode->i_size = 0;
583 set_capacity(lo->disk, 0);
1da177e4
LT
584 return lo->harderror;
585 case NBD_CLEAR_QUE:
4b2f0260
HX
586 /*
587 * This is for compatibility only. The queue is always cleared
588 * by NBD_DO_IT or NBD_CLEAR_SOCK.
589 */
590 BUG_ON(!lo->sock && !list_empty(&lo->queue_head));
1da177e4
LT
591 return 0;
592 case NBD_PRINT_DEBUG:
593 printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n",
594 inode->i_bdev->bd_disk->disk_name,
595 lo->queue_head.next, lo->queue_head.prev,
596 &lo->queue_head);
597 return 0;
598 }
599 return -EINVAL;
600}
601
602static struct block_device_operations nbd_fops =
603{
604 .owner = THIS_MODULE,
605 .ioctl = nbd_ioctl,
606};
607
608/*
609 * And here should be modules and kernel interface
610 * (Just smiley confuses emacs :-)
611 */
612
613static int __init nbd_init(void)
614{
615 int err = -ENOMEM;
616 int i;
617
5b7b18cc 618 BUILD_BUG_ON(sizeof(struct nbd_request) != 28);
1da177e4 619
40be0c28
LMB
620 if (nbds_max > MAX_NBD) {
621 printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD,
622 nbds_max);
623 return -EINVAL;
624 }
625
626 for (i = 0; i < nbds_max; i++) {
1da177e4
LT
627 struct gendisk *disk = alloc_disk(1);
628 if (!disk)
629 goto out;
630 nbd_dev[i].disk = disk;
631 /*
632 * The new linux 2.5 block layer implementation requires
633 * every gendisk to have its very own request_queue struct.
634 * These structs are big so we dynamically allocate them.
635 */
636 disk->queue = blk_init_queue(do_nbd_request, &nbd_lock);
637 if (!disk->queue) {
638 put_disk(disk);
639 goto out;
640 }
641 }
642
643 if (register_blkdev(NBD_MAJOR, "nbd")) {
644 err = -EIO;
645 goto out;
646 }
647
648 printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR);
649 dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags);
650
40be0c28 651 for (i = 0; i < nbds_max; i++) {
1da177e4
LT
652 struct gendisk *disk = nbd_dev[i].disk;
653 nbd_dev[i].file = NULL;
654 nbd_dev[i].magic = LO_MAGIC;
655 nbd_dev[i].flags = 0;
656 spin_lock_init(&nbd_dev[i].queue_lock);
657 INIT_LIST_HEAD(&nbd_dev[i].queue_head);
82d4dc5a 658 mutex_init(&nbd_dev[i].tx_lock);
4b2f0260 659 init_waitqueue_head(&nbd_dev[i].active_wq);
1da177e4 660 nbd_dev[i].blksize = 1024;
4b86a872 661 nbd_dev[i].bytesize = 0;
1da177e4
LT
662 disk->major = NBD_MAJOR;
663 disk->first_minor = i;
664 disk->fops = &nbd_fops;
665 disk->private_data = &nbd_dev[i];
666 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
667 sprintf(disk->disk_name, "nbd%d", i);
4b86a872 668 set_capacity(disk, 0);
1da177e4
LT
669 add_disk(disk);
670 }
671
672 return 0;
673out:
674 while (i--) {
675 blk_cleanup_queue(nbd_dev[i].disk->queue);
676 put_disk(nbd_dev[i].disk);
677 }
678 return err;
679}
680
681static void __exit nbd_cleanup(void)
682{
683 int i;
40be0c28 684 for (i = 0; i < nbds_max; i++) {
1da177e4 685 struct gendisk *disk = nbd_dev[i].disk;
40be0c28 686 nbd_dev[i].magic = 0;
1da177e4
LT
687 if (disk) {
688 del_gendisk(disk);
689 blk_cleanup_queue(disk->queue);
690 put_disk(disk);
691 }
692 }
1da177e4
LT
693 unregister_blkdev(NBD_MAJOR, "nbd");
694 printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR);
695}
696
697module_init(nbd_init);
698module_exit(nbd_cleanup);
699
700MODULE_DESCRIPTION("Network Block Device");
701MODULE_LICENSE("GPL");
702
40be0c28
LMB
703module_param(nbds_max, int, 0444);
704MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize.");
1da177e4
LT
705#ifndef NDEBUG
706module_param(debugflags, int, 0644);
707MODULE_PARM_DESC(debugflags, "flags for controlling debug output");
708#endif