blob: ae3106045ee599d6072b6073fc674061a0d4c4e0 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 *
Pavel Machekdbf492d2006-06-25 05:47:42 -070010 * This file is released under GPLv2 or later.
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 *
Pavel Machekdbf492d2006-06-25 05:47:42 -070012 * (part of code stolen from loop.c)
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 */
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>
Herbert Xu4b2f0262006-01-06 00:09:47 -080027#include <linux/compiler.h>
28#include <linux/err.h>
29#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <net/sock.h>
Trond Myklebust91cf45f2007-11-12 18:10:39 -080031#include <linux/net.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <asm/uaccess.h>
Herbert Xu4b2f0262006-01-06 00:09:47 -080034#include <asm/system.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#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
53static unsigned int debugflags;
54#endif /* NDEBUG */
55
Ingo van Lil9c7a4162006-07-01 04:36:36 -070056static unsigned int nbds_max = 16;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057static struct nbd_device nbd_dev[MAX_NBD];
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 */
69static DEFINE_SPINLOCK(nbd_lock);
70
71#ifndef NDEBUG
72static 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
90static 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
101static void nbd_end_request(struct request *req)
102{
Kiyoshi Ueda097c94a2007-12-11 17:44:06 -0500103 int error = req->errors ? -EIO : 0;
Jens Axboe165125e2007-07-24 09:28:11 +0200104 struct request_queue *q = req->q;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 unsigned long flags;
106
107 dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name,
Kiyoshi Ueda097c94a2007-12-11 17:44:06 -0500108 req, error ? "failed" : "done");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
110 spin_lock_irqsave(q->queue_lock, flags);
Kiyoshi Ueda097c94a2007-12-11 17:44:06 -0500111 __blk_end_request(req, error, req->nr_sectors << 9);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 spin_unlock_irqrestore(q->queue_lock, flags);
113}
114
Paul Clements7fdfd402007-10-16 23:27:37 -0700115static 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);
Trond Myklebust91cf45f2007-11-12 18:10:39 -0800128 kernel_sock_shutdown(lo->sock, SHUT_RDWR);
Paul Clements7fdfd402007-10-16 23:27:37 -0700129 lo->sock = NULL;
130 }
131 if (lock)
132 mutex_unlock(&lo->tx_lock);
133}
134
135static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144/*
145 * Send or receive packet.
146 */
Paul Clements7fdfd402007-10-16 23:27:37 -0700147static int sock_xmit(struct nbd_device *lo, int send, void *buf, int size,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 int msg_flags)
149{
Paul Clements7fdfd402007-10-16 23:27:37 -0700150 struct socket *sock = lo->sock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 int result;
152 struct msghdr msg;
153 struct kvec iov;
Oleg Nesterovbe0ef952007-07-15 23:41:32 -0700154 sigset_t blocked, oldset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156 /* Allow interception of SIGKILL only
157 * Don't allow other signals to interrupt the transmission */
Oleg Nesterovbe0ef952007-07-15 23:41:32 -0700158 siginitsetinv(&blocked, sigmask(SIGKILL));
159 sigprocmask(SIG_SETMASK, &blocked, &oldset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160
161 do {
162 sock->sk->sk_allocation = GFP_NOIO;
163 iov.iov_base = buf;
164 iov.iov_len = size;
165 msg.msg_name = NULL;
166 msg.msg_namelen = 0;
167 msg.msg_control = NULL;
168 msg.msg_controllen = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 msg.msg_flags = msg_flags | MSG_NOSIGNAL;
170
Paul Clements7fdfd402007-10-16 23:27:37 -0700171 if (send) {
172 struct timer_list ti;
173
174 if (lo->xmit_timeout) {
175 init_timer(&ti);
176 ti.function = nbd_xmit_timeout;
177 ti.data = (unsigned long)current;
178 ti.expires = jiffies + lo->xmit_timeout;
179 add_timer(&ti);
180 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 result = kernel_sendmsg(sock, &msg, &iov, 1, size);
Paul Clements7fdfd402007-10-16 23:27:37 -0700182 if (lo->xmit_timeout)
183 del_timer_sync(&ti);
184 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0);
186
187 if (signal_pending(current)) {
188 siginfo_t info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n",
Pavel Emelyanovba25f9d2007-10-18 23:40:40 -0700190 task_pid_nr(current), current->comm,
Oleg Nesterovbe0ef952007-07-15 23:41:32 -0700191 dequeue_signal_lock(current, &current->blocked, &info));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 result = -EINTR;
Paul Clements7fdfd402007-10-16 23:27:37 -0700193 sock_shutdown(lo, !send);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 break;
195 }
196
197 if (result <= 0) {
198 if (result == 0)
199 result = -EPIPE; /* short read */
200 break;
201 }
202 size -= result;
203 buf += result;
204 } while (size > 0);
205
Oleg Nesterovbe0ef952007-07-15 23:41:32 -0700206 sigprocmask(SIG_SETMASK, &oldset, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207
208 return result;
209}
210
Paul Clements7fdfd402007-10-16 23:27:37 -0700211static inline int sock_send_bvec(struct nbd_device *lo, struct bio_vec *bvec,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 int flags)
213{
214 int result;
215 void *kaddr = kmap(bvec->bv_page);
Paul Clements7fdfd402007-10-16 23:27:37 -0700216 result = sock_xmit(lo, 1, kaddr + bvec->bv_offset, bvec->bv_len, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 kunmap(bvec->bv_page);
218 return result;
219}
220
Paul Clements7fdfd402007-10-16 23:27:37 -0700221/* always call with the tx_lock held */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222static int nbd_send_req(struct nbd_device *lo, struct request *req)
223{
NeilBrown5705f702007-09-25 12:35:59 +0200224 int result, flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 struct nbd_request request;
226 unsigned long size = req->nr_sectors << 9;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227
228 request.magic = htonl(NBD_REQUEST_MAGIC);
229 request.type = htonl(nbd_cmd(req));
230 request.from = cpu_to_be64((u64) req->sector << 9);
231 request.len = htonl(size);
232 memcpy(request.handle, &req, sizeof(req));
233
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n",
235 lo->disk->disk_name, req,
236 nbdcmd_to_ascii(nbd_cmd(req)),
237 (unsigned long long)req->sector << 9,
238 req->nr_sectors << 9);
Paul Clements7fdfd402007-10-16 23:27:37 -0700239 result = sock_xmit(lo, 1, &request, sizeof(request),
240 (nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 if (result <= 0) {
242 printk(KERN_ERR "%s: Send control failed (result %d)\n",
243 lo->disk->disk_name, result);
244 goto error_out;
245 }
246
247 if (nbd_cmd(req) == NBD_CMD_WRITE) {
NeilBrown5705f702007-09-25 12:35:59 +0200248 struct req_iterator iter;
249 struct bio_vec *bvec;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 /*
251 * we are really probing at internals to determine
252 * whether to set MSG_MORE or not...
253 */
NeilBrown5705f702007-09-25 12:35:59 +0200254 rq_for_each_segment(bvec, req, iter) {
Jens Axboe6c92e692007-08-16 13:43:12 +0200255 flags = 0;
256 if (!rq_iter_last(req, iter))
257 flags = MSG_MORE;
258 dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n",
259 lo->disk->disk_name, req, bvec->bv_len);
Paul Clements7fdfd402007-10-16 23:27:37 -0700260 result = sock_send_bvec(lo, bvec, flags);
Jens Axboe6c92e692007-08-16 13:43:12 +0200261 if (result <= 0) {
262 printk(KERN_ERR "%s: Send data failed (result %d)\n",
263 lo->disk->disk_name, result);
264 goto error_out;
265 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 }
267 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 return 0;
269
270error_out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 return 1;
272}
273
Denis Cheng0cbc591b2007-10-16 23:26:14 -0700274static struct request *nbd_find_request(struct nbd_device *lo,
275 struct request *xreq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276{
Denis Chengd2c97402007-10-16 23:26:14 -0700277 struct request *req, *tmp;
Herbert Xu4b2f0262006-01-06 00:09:47 -0800278 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
Herbert Xu4b2f0262006-01-06 00:09:47 -0800280 err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq);
281 if (unlikely(err))
282 goto out;
283
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 spin_lock(&lo->queue_lock);
Denis Chengd2c97402007-10-16 23:26:14 -0700285 list_for_each_entry_safe(req, tmp, &lo->queue_head, queuelist) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 if (req != xreq)
287 continue;
288 list_del_init(&req->queuelist);
289 spin_unlock(&lo->queue_lock);
290 return req;
291 }
292 spin_unlock(&lo->queue_lock);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800293
294 err = -ENOENT;
295
296out:
297 return ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298}
299
Paul Clements7fdfd402007-10-16 23:27:37 -0700300static inline int sock_recv_bvec(struct nbd_device *lo, struct bio_vec *bvec)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301{
302 int result;
303 void *kaddr = kmap(bvec->bv_page);
Paul Clements7fdfd402007-10-16 23:27:37 -0700304 result = sock_xmit(lo, 0, kaddr + bvec->bv_offset, bvec->bv_len,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 MSG_WAITALL);
306 kunmap(bvec->bv_page);
307 return result;
308}
309
310/* NULL returned = something went wrong, inform userspace */
311static struct request *nbd_read_stat(struct nbd_device *lo)
312{
313 int result;
314 struct nbd_reply reply;
315 struct request *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
317 reply.magic = 0;
Paul Clements7fdfd402007-10-16 23:27:37 -0700318 result = sock_xmit(lo, 0, &reply, sizeof(reply), MSG_WAITALL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 if (result <= 0) {
320 printk(KERN_ERR "%s: Receive control failed (result %d)\n",
321 lo->disk->disk_name, result);
322 goto harderror;
323 }
Michal Feixe4b57e02006-07-30 03:03:31 -0700324
325 if (ntohl(reply.magic) != NBD_REPLY_MAGIC) {
326 printk(KERN_ERR "%s: Wrong magic (0x%lx)\n",
327 lo->disk->disk_name,
328 (unsigned long)ntohl(reply.magic));
329 result = -EPROTO;
330 goto harderror;
331 }
332
Denis Cheng0cbc591b2007-10-16 23:26:14 -0700333 req = nbd_find_request(lo, *(struct request **)reply.handle);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800334 if (unlikely(IS_ERR(req))) {
335 result = PTR_ERR(req);
336 if (result != -ENOENT)
337 goto harderror;
338
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 printk(KERN_ERR "%s: Unexpected reply (%p)\n",
340 lo->disk->disk_name, reply.handle);
341 result = -EBADR;
342 goto harderror;
343 }
344
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 if (ntohl(reply.error)) {
346 printk(KERN_ERR "%s: Other side returned error (%d)\n",
347 lo->disk->disk_name, ntohl(reply.error));
348 req->errors++;
349 return req;
350 }
351
352 dprintk(DBG_RX, "%s: request %p: got reply\n",
353 lo->disk->disk_name, req);
354 if (nbd_cmd(req) == NBD_CMD_READ) {
NeilBrown5705f702007-09-25 12:35:59 +0200355 struct req_iterator iter;
356 struct bio_vec *bvec;
357
358 rq_for_each_segment(bvec, req, iter) {
Paul Clements7fdfd402007-10-16 23:27:37 -0700359 result = sock_recv_bvec(lo, bvec);
Jens Axboe6c92e692007-08-16 13:43:12 +0200360 if (result <= 0) {
361 printk(KERN_ERR "%s: Receive data failed (result %d)\n",
362 lo->disk->disk_name, result);
363 req->errors++;
364 return req;
365 }
366 dprintk(DBG_RX, "%s: request %p: got %d bytes data\n",
367 lo->disk->disk_name, req, bvec->bv_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 }
369 }
370 return req;
371harderror:
372 lo->harderror = result;
373 return NULL;
374}
375
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200376static ssize_t pid_show(struct device *dev,
377 struct device_attribute *attr, char *buf)
Paul Clements6b39bb62006-12-06 20:40:53 -0800378{
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200379 struct gendisk *disk = dev_to_disk(dev);
380
381 return sprintf(buf, "%ld\n",
Paul Clements6b39bb62006-12-06 20:40:53 -0800382 (long) ((struct nbd_device *)disk->private_data)->pid);
383}
384
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200385static struct device_attribute pid_attr = {
386 .attr = { .name = "pid", .mode = S_IRUGO, .owner = THIS_MODULE },
Paul Clements6b39bb62006-12-06 20:40:53 -0800387 .show = pid_show,
388};
389
WANG Cong84963042007-05-09 02:33:36 -0700390static int nbd_do_it(struct nbd_device *lo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391{
392 struct request *req;
WANG Cong84963042007-05-09 02:33:36 -0700393 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395 BUG_ON(lo->magic != LO_MAGIC);
396
Paul Clements6b39bb62006-12-06 20:40:53 -0800397 lo->pid = current->pid;
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200398 ret = sysfs_create_file(&lo->disk->dev.kobj, &pid_attr.attr);
WANG Cong84963042007-05-09 02:33:36 -0700399 if (ret) {
400 printk(KERN_ERR "nbd: sysfs_create_file failed!");
401 return ret;
402 }
Paul Clements6b39bb62006-12-06 20:40:53 -0800403
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 while ((req = nbd_read_stat(lo)) != NULL)
405 nbd_end_request(req);
Paul Clements6b39bb62006-12-06 20:40:53 -0800406
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200407 sysfs_remove_file(&lo->disk->dev.kobj, &pid_attr.attr);
WANG Cong84963042007-05-09 02:33:36 -0700408 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409}
410
411static void nbd_clear_que(struct nbd_device *lo)
412{
413 struct request *req;
414
415 BUG_ON(lo->magic != LO_MAGIC);
416
Herbert Xu4b2f0262006-01-06 00:09:47 -0800417 /*
418 * Because we have set lo->sock to NULL under the tx_lock, all
419 * modifications to the list must have completed by now. For
420 * the same reason, the active_req must be NULL.
421 *
422 * As a consequence, we don't need to take the spin lock while
423 * purging the list here.
424 */
425 BUG_ON(lo->sock);
426 BUG_ON(lo->active_req);
427
428 while (!list_empty(&lo->queue_head)) {
429 req = list_entry(lo->queue_head.next, struct request,
430 queuelist);
431 list_del_init(&req->queuelist);
432 req->errors++;
433 nbd_end_request(req);
434 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435}
436
Paul Clements7fdfd402007-10-16 23:27:37 -0700437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438/*
439 * We always wait for result of write, for now. It would be nice to make it optional
440 * in future
Boaz Harroshe654bc42007-06-20 13:53:23 +0200441 * if ((rq_data_dir(req) == WRITE) && (lo->flags & NBD_WRITE_NOCHK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); }
443 */
444
Jens Axboe165125e2007-07-24 09:28:11 +0200445static void do_nbd_request(struct request_queue * q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446{
447 struct request *req;
448
449 while ((req = elv_next_request(q)) != NULL) {
450 struct nbd_device *lo;
451
452 blkdev_dequeue_request(req);
Jens Axboe4aff5e22006-08-10 08:44:47 +0200453 dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n",
454 req->rq_disk->disk_name, req, req->cmd_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455
Jens Axboe4aff5e22006-08-10 08:44:47 +0200456 if (!blk_fs_request(req))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 goto error_out;
458
459 lo = req->rq_disk->private_data;
460
461 BUG_ON(lo->magic != LO_MAGIC);
462
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 nbd_cmd(req) = NBD_CMD_READ;
464 if (rq_data_dir(req) == WRITE) {
465 nbd_cmd(req) = NBD_CMD_WRITE;
466 if (lo->flags & NBD_READ_ONLY) {
467 printk(KERN_ERR "%s: Write on read-only\n",
468 lo->disk->disk_name);
469 goto error_out;
470 }
471 }
472
473 req->errors = 0;
474 spin_unlock_irq(q->queue_lock);
475
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800476 mutex_lock(&lo->tx_lock);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800477 if (unlikely(!lo->sock)) {
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800478 mutex_unlock(&lo->tx_lock);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800479 printk(KERN_ERR "%s: Attempted send on closed socket\n",
480 lo->disk->disk_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 req->errors++;
482 nbd_end_request(req);
483 spin_lock_irq(q->queue_lock);
484 continue;
485 }
486
Herbert Xu4b2f0262006-01-06 00:09:47 -0800487 lo->active_req = req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488
489 if (nbd_send_req(lo, req) != 0) {
490 printk(KERN_ERR "%s: Request send failed\n",
491 lo->disk->disk_name);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800492 req->errors++;
493 nbd_end_request(req);
494 } else {
495 spin_lock(&lo->queue_lock);
496 list_add(&req->queuelist, &lo->queue_head);
497 spin_unlock(&lo->queue_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 }
499
Herbert Xu4b2f0262006-01-06 00:09:47 -0800500 lo->active_req = NULL;
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800501 mutex_unlock(&lo->tx_lock);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800502 wake_up_all(&lo->active_wq);
503
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 spin_lock_irq(q->queue_lock);
505 continue;
506
507error_out:
508 req->errors++;
509 spin_unlock(q->queue_lock);
510 nbd_end_request(req);
511 spin_lock(q->queue_lock);
512 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513}
514
515static int nbd_ioctl(struct inode *inode, struct file *file,
516 unsigned int cmd, unsigned long arg)
517{
518 struct nbd_device *lo = inode->i_bdev->bd_disk->private_data;
519 int error;
520 struct request sreq ;
521
522 if (!capable(CAP_SYS_ADMIN))
523 return -EPERM;
524
525 BUG_ON(lo->magic != LO_MAGIC);
526
527 /* Anyone capable of this syscall can do *real bad* things */
528 dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n",
529 lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg);
530
531 switch (cmd) {
532 case NBD_DISCONNECT:
533 printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name);
Jens Axboe4aff5e22006-08-10 08:44:47 +0200534 sreq.cmd_type = REQ_TYPE_SPECIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 nbd_cmd(&sreq) = NBD_CMD_DISC;
536 /*
537 * Set these to sane values in case server implementation
538 * fails to check the request type first and also to keep
539 * debugging output cleaner.
540 */
541 sreq.sector = 0;
542 sreq.nr_sectors = 0;
543 if (!lo->sock)
544 return -EINVAL;
Paul Clements7fdfd402007-10-16 23:27:37 -0700545 mutex_lock(&lo->tx_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 nbd_send_req(lo, &sreq);
Paul Clements7fdfd402007-10-16 23:27:37 -0700547 mutex_unlock(&lo->tx_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 return 0;
549
550 case NBD_CLEAR_SOCK:
551 error = 0;
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800552 mutex_lock(&lo->tx_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 lo->sock = NULL;
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800554 mutex_unlock(&lo->tx_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 file = lo->file;
556 lo->file = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 nbd_clear_que(lo);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800558 BUG_ON(!list_empty(&lo->queue_head));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 if (file)
560 fput(file);
561 return error;
562 case NBD_SET_SOCK:
563 if (lo->file)
564 return -EBUSY;
565 error = -EINVAL;
566 file = fget(arg);
567 if (file) {
Josef Sipek17506042006-12-08 02:37:22 -0800568 inode = file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 if (S_ISSOCK(inode->i_mode)) {
570 lo->file = file;
571 lo->sock = SOCKET_I(inode);
572 error = 0;
573 } else {
574 fput(file);
575 }
576 }
577 return error;
578 case NBD_SET_BLKSIZE:
579 lo->blksize = arg;
580 lo->bytesize &= ~(lo->blksize-1);
581 inode->i_bdev->bd_inode->i_size = lo->bytesize;
582 set_blocksize(inode->i_bdev, lo->blksize);
583 set_capacity(lo->disk, lo->bytesize >> 9);
584 return 0;
585 case NBD_SET_SIZE:
586 lo->bytesize = arg & ~(lo->blksize-1);
587 inode->i_bdev->bd_inode->i_size = lo->bytesize;
588 set_blocksize(inode->i_bdev, lo->blksize);
589 set_capacity(lo->disk, lo->bytesize >> 9);
590 return 0;
Paul Clements7fdfd402007-10-16 23:27:37 -0700591 case NBD_SET_TIMEOUT:
592 lo->xmit_timeout = arg * HZ;
593 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 case NBD_SET_SIZE_BLOCKS:
595 lo->bytesize = ((u64) arg) * lo->blksize;
596 inode->i_bdev->bd_inode->i_size = lo->bytesize;
597 set_blocksize(inode->i_bdev, lo->blksize);
598 set_capacity(lo->disk, lo->bytesize >> 9);
599 return 0;
600 case NBD_DO_IT:
601 if (!lo->file)
602 return -EINVAL;
WANG Cong84963042007-05-09 02:33:36 -0700603 error = nbd_do_it(lo);
604 if (error)
605 return error;
Paul Clements7fdfd402007-10-16 23:27:37 -0700606 sock_shutdown(lo, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 file = lo->file;
608 lo->file = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 nbd_clear_que(lo);
610 printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name);
611 if (file)
612 fput(file);
Paul Clements4b86a872007-10-16 23:27:36 -0700613 lo->bytesize = 0;
614 inode->i_bdev->bd_inode->i_size = 0;
615 set_capacity(lo->disk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 return lo->harderror;
617 case NBD_CLEAR_QUE:
Herbert Xu4b2f0262006-01-06 00:09:47 -0800618 /*
619 * This is for compatibility only. The queue is always cleared
620 * by NBD_DO_IT or NBD_CLEAR_SOCK.
621 */
622 BUG_ON(!lo->sock && !list_empty(&lo->queue_head));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 return 0;
624 case NBD_PRINT_DEBUG:
625 printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n",
626 inode->i_bdev->bd_disk->disk_name,
627 lo->queue_head.next, lo->queue_head.prev,
628 &lo->queue_head);
629 return 0;
630 }
631 return -EINVAL;
632}
633
634static struct block_device_operations nbd_fops =
635{
636 .owner = THIS_MODULE,
637 .ioctl = nbd_ioctl,
638};
639
640/*
641 * And here should be modules and kernel interface
642 * (Just smiley confuses emacs :-)
643 */
644
645static int __init nbd_init(void)
646{
647 int err = -ENOMEM;
648 int i;
649
Adrian Bunk5b7b18c2006-03-25 03:07:04 -0800650 BUILD_BUG_ON(sizeof(struct nbd_request) != 28);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651
Lars Marowsky-Bree40be0c22005-05-01 08:59:07 -0700652 if (nbds_max > MAX_NBD) {
653 printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD,
654 nbds_max);
655 return -EINVAL;
656 }
657
658 for (i = 0; i < nbds_max; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 struct gendisk *disk = alloc_disk(1);
660 if (!disk)
661 goto out;
662 nbd_dev[i].disk = disk;
663 /*
664 * The new linux 2.5 block layer implementation requires
665 * every gendisk to have its very own request_queue struct.
666 * These structs are big so we dynamically allocate them.
667 */
668 disk->queue = blk_init_queue(do_nbd_request, &nbd_lock);
669 if (!disk->queue) {
670 put_disk(disk);
671 goto out;
672 }
673 }
674
675 if (register_blkdev(NBD_MAJOR, "nbd")) {
676 err = -EIO;
677 goto out;
678 }
679
680 printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR);
681 dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags);
682
Lars Marowsky-Bree40be0c22005-05-01 08:59:07 -0700683 for (i = 0; i < nbds_max; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 struct gendisk *disk = nbd_dev[i].disk;
685 nbd_dev[i].file = NULL;
686 nbd_dev[i].magic = LO_MAGIC;
687 nbd_dev[i].flags = 0;
688 spin_lock_init(&nbd_dev[i].queue_lock);
689 INIT_LIST_HEAD(&nbd_dev[i].queue_head);
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800690 mutex_init(&nbd_dev[i].tx_lock);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800691 init_waitqueue_head(&nbd_dev[i].active_wq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 nbd_dev[i].blksize = 1024;
Paul Clements4b86a872007-10-16 23:27:36 -0700693 nbd_dev[i].bytesize = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 disk->major = NBD_MAJOR;
695 disk->first_minor = i;
696 disk->fops = &nbd_fops;
697 disk->private_data = &nbd_dev[i];
698 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
699 sprintf(disk->disk_name, "nbd%d", i);
Paul Clements4b86a872007-10-16 23:27:36 -0700700 set_capacity(disk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 add_disk(disk);
702 }
703
704 return 0;
705out:
706 while (i--) {
707 blk_cleanup_queue(nbd_dev[i].disk->queue);
708 put_disk(nbd_dev[i].disk);
709 }
710 return err;
711}
712
713static void __exit nbd_cleanup(void)
714{
715 int i;
Lars Marowsky-Bree40be0c22005-05-01 08:59:07 -0700716 for (i = 0; i < nbds_max; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 struct gendisk *disk = nbd_dev[i].disk;
Lars Marowsky-Bree40be0c22005-05-01 08:59:07 -0700718 nbd_dev[i].magic = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 if (disk) {
720 del_gendisk(disk);
721 blk_cleanup_queue(disk->queue);
722 put_disk(disk);
723 }
724 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 unregister_blkdev(NBD_MAJOR, "nbd");
726 printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR);
727}
728
729module_init(nbd_init);
730module_exit(nbd_cleanup);
731
732MODULE_DESCRIPTION("Network Block Device");
733MODULE_LICENSE("GPL");
734
Lars Marowsky-Bree40be0c22005-05-01 08:59:07 -0700735module_param(nbds_max, int, 0444);
736MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize.");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737#ifndef NDEBUG
738module_param(debugflags, int, 0644);
739MODULE_PARM_DESC(debugflags, "flags for controlling debug output");
740#endif