blob: 60cc54368b66eaa1c7888ab905f7c9b83c92bd41 [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;
Paul Clements20a81432008-02-08 04:21:51 -080057static struct nbd_device *nbd_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
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
Mike Snitzerffc41cf2008-04-02 13:04:47 -0700156 if (unlikely(!sock)) {
157 printk(KERN_ERR "%s: Attempted %s on closed socket in sock_xmit\n",
158 lo->disk->disk_name, (send ? "send" : "recv"));
159 return -EINVAL;
160 }
161
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 /* Allow interception of SIGKILL only
163 * Don't allow other signals to interrupt the transmission */
Oleg Nesterovbe0ef952007-07-15 23:41:32 -0700164 siginitsetinv(&blocked, sigmask(SIGKILL));
165 sigprocmask(SIG_SETMASK, &blocked, &oldset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
167 do {
168 sock->sk->sk_allocation = GFP_NOIO;
169 iov.iov_base = buf;
170 iov.iov_len = size;
171 msg.msg_name = NULL;
172 msg.msg_namelen = 0;
173 msg.msg_control = NULL;
174 msg.msg_controllen = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 msg.msg_flags = msg_flags | MSG_NOSIGNAL;
176
Paul Clements7fdfd402007-10-16 23:27:37 -0700177 if (send) {
178 struct timer_list ti;
179
180 if (lo->xmit_timeout) {
181 init_timer(&ti);
182 ti.function = nbd_xmit_timeout;
183 ti.data = (unsigned long)current;
184 ti.expires = jiffies + lo->xmit_timeout;
185 add_timer(&ti);
186 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 result = kernel_sendmsg(sock, &msg, &iov, 1, size);
Paul Clements7fdfd402007-10-16 23:27:37 -0700188 if (lo->xmit_timeout)
189 del_timer_sync(&ti);
190 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0);
192
193 if (signal_pending(current)) {
194 siginfo_t info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n",
Pavel Emelyanovba25f9d2007-10-18 23:40:40 -0700196 task_pid_nr(current), current->comm,
Oleg Nesterovbe0ef952007-07-15 23:41:32 -0700197 dequeue_signal_lock(current, &current->blocked, &info));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 result = -EINTR;
Paul Clements7fdfd402007-10-16 23:27:37 -0700199 sock_shutdown(lo, !send);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 break;
201 }
202
203 if (result <= 0) {
204 if (result == 0)
205 result = -EPIPE; /* short read */
206 break;
207 }
208 size -= result;
209 buf += result;
210 } while (size > 0);
211
Oleg Nesterovbe0ef952007-07-15 23:41:32 -0700212 sigprocmask(SIG_SETMASK, &oldset, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
214 return result;
215}
216
Paul Clements7fdfd402007-10-16 23:27:37 -0700217static inline int sock_send_bvec(struct nbd_device *lo, struct bio_vec *bvec,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 int flags)
219{
220 int result;
221 void *kaddr = kmap(bvec->bv_page);
Paul Clements7fdfd402007-10-16 23:27:37 -0700222 result = sock_xmit(lo, 1, kaddr + bvec->bv_offset, bvec->bv_len, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 kunmap(bvec->bv_page);
224 return result;
225}
226
Paul Clements7fdfd402007-10-16 23:27:37 -0700227/* always call with the tx_lock held */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228static int nbd_send_req(struct nbd_device *lo, struct request *req)
229{
NeilBrown5705f702007-09-25 12:35:59 +0200230 int result, flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 struct nbd_request request;
232 unsigned long size = req->nr_sectors << 9;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
234 request.magic = htonl(NBD_REQUEST_MAGIC);
235 request.type = htonl(nbd_cmd(req));
236 request.from = cpu_to_be64((u64) req->sector << 9);
237 request.len = htonl(size);
238 memcpy(request.handle, &req, sizeof(req));
239
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n",
241 lo->disk->disk_name, req,
242 nbdcmd_to_ascii(nbd_cmd(req)),
243 (unsigned long long)req->sector << 9,
244 req->nr_sectors << 9);
Paul Clements7fdfd402007-10-16 23:27:37 -0700245 result = sock_xmit(lo, 1, &request, sizeof(request),
246 (nbd_cmd(req) == NBD_CMD_WRITE) ? MSG_MORE : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 if (result <= 0) {
248 printk(KERN_ERR "%s: Send control failed (result %d)\n",
249 lo->disk->disk_name, result);
250 goto error_out;
251 }
252
253 if (nbd_cmd(req) == NBD_CMD_WRITE) {
NeilBrown5705f702007-09-25 12:35:59 +0200254 struct req_iterator iter;
255 struct bio_vec *bvec;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 /*
257 * we are really probing at internals to determine
258 * whether to set MSG_MORE or not...
259 */
NeilBrown5705f702007-09-25 12:35:59 +0200260 rq_for_each_segment(bvec, req, iter) {
Jens Axboe6c92e692007-08-16 13:43:12 +0200261 flags = 0;
262 if (!rq_iter_last(req, iter))
263 flags = MSG_MORE;
264 dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n",
265 lo->disk->disk_name, req, bvec->bv_len);
Paul Clements7fdfd402007-10-16 23:27:37 -0700266 result = sock_send_bvec(lo, bvec, flags);
Jens Axboe6c92e692007-08-16 13:43:12 +0200267 if (result <= 0) {
268 printk(KERN_ERR "%s: Send data failed (result %d)\n",
269 lo->disk->disk_name, result);
270 goto error_out;
271 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 }
273 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 return 0;
275
276error_out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 return 1;
278}
279
Denis Cheng0cbc591b2007-10-16 23:26:14 -0700280static struct request *nbd_find_request(struct nbd_device *lo,
281 struct request *xreq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282{
Denis Chengd2c97402007-10-16 23:26:14 -0700283 struct request *req, *tmp;
Herbert Xu4b2f0262006-01-06 00:09:47 -0800284 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
Herbert Xu4b2f0262006-01-06 00:09:47 -0800286 err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq);
287 if (unlikely(err))
288 goto out;
289
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 spin_lock(&lo->queue_lock);
Denis Chengd2c97402007-10-16 23:26:14 -0700291 list_for_each_entry_safe(req, tmp, &lo->queue_head, queuelist) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 if (req != xreq)
293 continue;
294 list_del_init(&req->queuelist);
295 spin_unlock(&lo->queue_lock);
296 return req;
297 }
298 spin_unlock(&lo->queue_lock);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800299
300 err = -ENOENT;
301
302out:
303 return ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304}
305
Paul Clements7fdfd402007-10-16 23:27:37 -0700306static inline int sock_recv_bvec(struct nbd_device *lo, struct bio_vec *bvec)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307{
308 int result;
309 void *kaddr = kmap(bvec->bv_page);
Paul Clements7fdfd402007-10-16 23:27:37 -0700310 result = sock_xmit(lo, 0, kaddr + bvec->bv_offset, bvec->bv_len,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 MSG_WAITALL);
312 kunmap(bvec->bv_page);
313 return result;
314}
315
316/* NULL returned = something went wrong, inform userspace */
317static struct request *nbd_read_stat(struct nbd_device *lo)
318{
319 int result;
320 struct nbd_reply reply;
321 struct request *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322
323 reply.magic = 0;
Paul Clements7fdfd402007-10-16 23:27:37 -0700324 result = sock_xmit(lo, 0, &reply, sizeof(reply), MSG_WAITALL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 if (result <= 0) {
326 printk(KERN_ERR "%s: Receive control failed (result %d)\n",
327 lo->disk->disk_name, result);
328 goto harderror;
329 }
Michal Feixe4b57e02006-07-30 03:03:31 -0700330
331 if (ntohl(reply.magic) != NBD_REPLY_MAGIC) {
332 printk(KERN_ERR "%s: Wrong magic (0x%lx)\n",
333 lo->disk->disk_name,
334 (unsigned long)ntohl(reply.magic));
335 result = -EPROTO;
336 goto harderror;
337 }
338
Denis Cheng0cbc591b2007-10-16 23:26:14 -0700339 req = nbd_find_request(lo, *(struct request **)reply.handle);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800340 if (unlikely(IS_ERR(req))) {
341 result = PTR_ERR(req);
342 if (result != -ENOENT)
343 goto harderror;
344
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 printk(KERN_ERR "%s: Unexpected reply (%p)\n",
346 lo->disk->disk_name, reply.handle);
347 result = -EBADR;
348 goto harderror;
349 }
350
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 if (ntohl(reply.error)) {
352 printk(KERN_ERR "%s: Other side returned error (%d)\n",
353 lo->disk->disk_name, ntohl(reply.error));
354 req->errors++;
355 return req;
356 }
357
358 dprintk(DBG_RX, "%s: request %p: got reply\n",
359 lo->disk->disk_name, req);
360 if (nbd_cmd(req) == NBD_CMD_READ) {
NeilBrown5705f702007-09-25 12:35:59 +0200361 struct req_iterator iter;
362 struct bio_vec *bvec;
363
364 rq_for_each_segment(bvec, req, iter) {
Paul Clements7fdfd402007-10-16 23:27:37 -0700365 result = sock_recv_bvec(lo, bvec);
Jens Axboe6c92e692007-08-16 13:43:12 +0200366 if (result <= 0) {
367 printk(KERN_ERR "%s: Receive data failed (result %d)\n",
368 lo->disk->disk_name, result);
369 req->errors++;
370 return req;
371 }
372 dprintk(DBG_RX, "%s: request %p: got %d bytes data\n",
373 lo->disk->disk_name, req, bvec->bv_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 }
375 }
376 return req;
377harderror:
378 lo->harderror = result;
379 return NULL;
380}
381
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200382static ssize_t pid_show(struct device *dev,
383 struct device_attribute *attr, char *buf)
Paul Clements6b39bb62006-12-06 20:40:53 -0800384{
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200385 struct gendisk *disk = dev_to_disk(dev);
386
387 return sprintf(buf, "%ld\n",
Paul Clements6b39bb62006-12-06 20:40:53 -0800388 (long) ((struct nbd_device *)disk->private_data)->pid);
389}
390
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200391static struct device_attribute pid_attr = {
392 .attr = { .name = "pid", .mode = S_IRUGO, .owner = THIS_MODULE },
Paul Clements6b39bb62006-12-06 20:40:53 -0800393 .show = pid_show,
394};
395
WANG Cong84963042007-05-09 02:33:36 -0700396static int nbd_do_it(struct nbd_device *lo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397{
398 struct request *req;
WANG Cong84963042007-05-09 02:33:36 -0700399 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
401 BUG_ON(lo->magic != LO_MAGIC);
402
Paul Clements6b39bb62006-12-06 20:40:53 -0800403 lo->pid = current->pid;
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200404 ret = sysfs_create_file(&lo->disk->dev.kobj, &pid_attr.attr);
WANG Cong84963042007-05-09 02:33:36 -0700405 if (ret) {
406 printk(KERN_ERR "nbd: sysfs_create_file failed!");
407 return ret;
408 }
Paul Clements6b39bb62006-12-06 20:40:53 -0800409
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 while ((req = nbd_read_stat(lo)) != NULL)
411 nbd_end_request(req);
Paul Clements6b39bb62006-12-06 20:40:53 -0800412
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200413 sysfs_remove_file(&lo->disk->dev.kobj, &pid_attr.attr);
WANG Cong84963042007-05-09 02:33:36 -0700414 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415}
416
417static void nbd_clear_que(struct nbd_device *lo)
418{
419 struct request *req;
420
421 BUG_ON(lo->magic != LO_MAGIC);
422
Herbert Xu4b2f0262006-01-06 00:09:47 -0800423 /*
424 * Because we have set lo->sock to NULL under the tx_lock, all
425 * modifications to the list must have completed by now. For
426 * the same reason, the active_req must be NULL.
427 *
428 * As a consequence, we don't need to take the spin lock while
429 * purging the list here.
430 */
431 BUG_ON(lo->sock);
432 BUG_ON(lo->active_req);
433
434 while (!list_empty(&lo->queue_head)) {
435 req = list_entry(lo->queue_head.next, struct request,
436 queuelist);
437 list_del_init(&req->queuelist);
438 req->errors++;
439 nbd_end_request(req);
440 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441}
442
Paul Clements7fdfd402007-10-16 23:27:37 -0700443
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444/*
445 * We always wait for result of write, for now. It would be nice to make it optional
446 * in future
Boaz Harroshe654bc42007-06-20 13:53:23 +0200447 * if ((rq_data_dir(req) == WRITE) && (lo->flags & NBD_WRITE_NOCHK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); }
449 */
450
Jens Axboe165125e2007-07-24 09:28:11 +0200451static void do_nbd_request(struct request_queue * q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452{
453 struct request *req;
454
455 while ((req = elv_next_request(q)) != NULL) {
456 struct nbd_device *lo;
457
458 blkdev_dequeue_request(req);
Jens Axboe4aff5e22006-08-10 08:44:47 +0200459 dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n",
460 req->rq_disk->disk_name, req, req->cmd_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
Jens Axboe4aff5e22006-08-10 08:44:47 +0200462 if (!blk_fs_request(req))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 goto error_out;
464
465 lo = req->rq_disk->private_data;
466
467 BUG_ON(lo->magic != LO_MAGIC);
468
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 nbd_cmd(req) = NBD_CMD_READ;
470 if (rq_data_dir(req) == WRITE) {
471 nbd_cmd(req) = NBD_CMD_WRITE;
472 if (lo->flags & NBD_READ_ONLY) {
473 printk(KERN_ERR "%s: Write on read-only\n",
474 lo->disk->disk_name);
475 goto error_out;
476 }
477 }
478
479 req->errors = 0;
480 spin_unlock_irq(q->queue_lock);
481
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800482 mutex_lock(&lo->tx_lock);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800483 if (unlikely(!lo->sock)) {
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800484 mutex_unlock(&lo->tx_lock);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800485 printk(KERN_ERR "%s: Attempted send on closed socket\n",
486 lo->disk->disk_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 req->errors++;
488 nbd_end_request(req);
489 spin_lock_irq(q->queue_lock);
490 continue;
491 }
492
Herbert Xu4b2f0262006-01-06 00:09:47 -0800493 lo->active_req = req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494
495 if (nbd_send_req(lo, req) != 0) {
496 printk(KERN_ERR "%s: Request send failed\n",
497 lo->disk->disk_name);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800498 req->errors++;
499 nbd_end_request(req);
500 } else {
501 spin_lock(&lo->queue_lock);
502 list_add(&req->queuelist, &lo->queue_head);
503 spin_unlock(&lo->queue_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 }
505
Herbert Xu4b2f0262006-01-06 00:09:47 -0800506 lo->active_req = NULL;
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800507 mutex_unlock(&lo->tx_lock);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800508 wake_up_all(&lo->active_wq);
509
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 spin_lock_irq(q->queue_lock);
511 continue;
512
513error_out:
514 req->errors++;
515 spin_unlock(q->queue_lock);
516 nbd_end_request(req);
517 spin_lock(q->queue_lock);
518 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519}
520
521static int nbd_ioctl(struct inode *inode, struct file *file,
522 unsigned int cmd, unsigned long arg)
523{
524 struct nbd_device *lo = inode->i_bdev->bd_disk->private_data;
525 int error;
526 struct request sreq ;
527
528 if (!capable(CAP_SYS_ADMIN))
529 return -EPERM;
530
531 BUG_ON(lo->magic != LO_MAGIC);
532
533 /* Anyone capable of this syscall can do *real bad* things */
534 dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n",
535 lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg);
536
537 switch (cmd) {
538 case NBD_DISCONNECT:
539 printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name);
Jens Axboe4aff5e22006-08-10 08:44:47 +0200540 sreq.cmd_type = REQ_TYPE_SPECIAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 nbd_cmd(&sreq) = NBD_CMD_DISC;
542 /*
543 * Set these to sane values in case server implementation
544 * fails to check the request type first and also to keep
545 * debugging output cleaner.
546 */
547 sreq.sector = 0;
548 sreq.nr_sectors = 0;
549 if (!lo->sock)
550 return -EINVAL;
Paul Clements7fdfd402007-10-16 23:27:37 -0700551 mutex_lock(&lo->tx_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 nbd_send_req(lo, &sreq);
Paul Clements7fdfd402007-10-16 23:27:37 -0700553 mutex_unlock(&lo->tx_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 return 0;
555
556 case NBD_CLEAR_SOCK:
557 error = 0;
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800558 mutex_lock(&lo->tx_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 lo->sock = NULL;
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800560 mutex_unlock(&lo->tx_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 file = lo->file;
562 lo->file = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 nbd_clear_que(lo);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800564 BUG_ON(!list_empty(&lo->queue_head));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 if (file)
566 fput(file);
567 return error;
568 case NBD_SET_SOCK:
569 if (lo->file)
570 return -EBUSY;
571 error = -EINVAL;
572 file = fget(arg);
573 if (file) {
Josef Sipek17506042006-12-08 02:37:22 -0800574 inode = file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 if (S_ISSOCK(inode->i_mode)) {
576 lo->file = file;
577 lo->sock = SOCKET_I(inode);
578 error = 0;
579 } else {
580 fput(file);
581 }
582 }
583 return error;
584 case NBD_SET_BLKSIZE:
585 lo->blksize = arg;
586 lo->bytesize &= ~(lo->blksize-1);
587 inode->i_bdev->bd_inode->i_size = lo->bytesize;
588 set_blocksize(inode->i_bdev, lo->blksize);
589 set_capacity(lo->disk, lo->bytesize >> 9);
590 return 0;
591 case NBD_SET_SIZE:
592 lo->bytesize = arg & ~(lo->blksize-1);
593 inode->i_bdev->bd_inode->i_size = lo->bytesize;
594 set_blocksize(inode->i_bdev, lo->blksize);
595 set_capacity(lo->disk, lo->bytesize >> 9);
596 return 0;
Paul Clements7fdfd402007-10-16 23:27:37 -0700597 case NBD_SET_TIMEOUT:
598 lo->xmit_timeout = arg * HZ;
599 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 case NBD_SET_SIZE_BLOCKS:
601 lo->bytesize = ((u64) arg) * lo->blksize;
602 inode->i_bdev->bd_inode->i_size = lo->bytesize;
603 set_blocksize(inode->i_bdev, lo->blksize);
604 set_capacity(lo->disk, lo->bytesize >> 9);
605 return 0;
606 case NBD_DO_IT:
607 if (!lo->file)
608 return -EINVAL;
WANG Cong84963042007-05-09 02:33:36 -0700609 error = nbd_do_it(lo);
610 if (error)
611 return error;
Paul Clements7fdfd402007-10-16 23:27:37 -0700612 sock_shutdown(lo, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 file = lo->file;
614 lo->file = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 nbd_clear_que(lo);
616 printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name);
617 if (file)
618 fput(file);
Paul Clements4b86a872007-10-16 23:27:36 -0700619 lo->bytesize = 0;
620 inode->i_bdev->bd_inode->i_size = 0;
621 set_capacity(lo->disk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 return lo->harderror;
623 case NBD_CLEAR_QUE:
Herbert Xu4b2f0262006-01-06 00:09:47 -0800624 /*
625 * This is for compatibility only. The queue is always cleared
626 * by NBD_DO_IT or NBD_CLEAR_SOCK.
627 */
628 BUG_ON(!lo->sock && !list_empty(&lo->queue_head));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 return 0;
630 case NBD_PRINT_DEBUG:
631 printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n",
632 inode->i_bdev->bd_disk->disk_name,
633 lo->queue_head.next, lo->queue_head.prev,
634 &lo->queue_head);
635 return 0;
636 }
637 return -EINVAL;
638}
639
640static struct block_device_operations nbd_fops =
641{
642 .owner = THIS_MODULE,
643 .ioctl = nbd_ioctl,
644};
645
646/*
647 * And here should be modules and kernel interface
648 * (Just smiley confuses emacs :-)
649 */
650
651static int __init nbd_init(void)
652{
653 int err = -ENOMEM;
654 int i;
655
Adrian Bunk5b7b18c2006-03-25 03:07:04 -0800656 BUILD_BUG_ON(sizeof(struct nbd_request) != 28);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
Paul Clements20a81432008-02-08 04:21:51 -0800658 nbd_dev = kcalloc(nbds_max, sizeof(*nbd_dev), GFP_KERNEL);
659 if (!nbd_dev)
660 return -ENOMEM;
Lars Marowsky-Bree40be0c22005-05-01 08:59:07 -0700661
662 for (i = 0; i < nbds_max; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 struct gendisk *disk = alloc_disk(1);
Paul Clements48f15b92008-02-23 15:23:50 -0800664 elevator_t *old_e;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 if (!disk)
666 goto out;
667 nbd_dev[i].disk = disk;
668 /*
669 * The new linux 2.5 block layer implementation requires
670 * every gendisk to have its very own request_queue struct.
671 * These structs are big so we dynamically allocate them.
672 */
673 disk->queue = blk_init_queue(do_nbd_request, &nbd_lock);
674 if (!disk->queue) {
675 put_disk(disk);
676 goto out;
677 }
Paul Clements48f15b92008-02-23 15:23:50 -0800678 old_e = disk->queue->elevator;
679 if (elevator_init(disk->queue, "deadline") == 0 ||
680 elevator_init(disk->queue, "noop") == 0) {
681 elevator_exit(old_e);
682 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 }
684
685 if (register_blkdev(NBD_MAJOR, "nbd")) {
686 err = -EIO;
687 goto out;
688 }
689
690 printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR);
691 dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags);
692
Lars Marowsky-Bree40be0c22005-05-01 08:59:07 -0700693 for (i = 0; i < nbds_max; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 struct gendisk *disk = nbd_dev[i].disk;
695 nbd_dev[i].file = NULL;
696 nbd_dev[i].magic = LO_MAGIC;
697 nbd_dev[i].flags = 0;
698 spin_lock_init(&nbd_dev[i].queue_lock);
699 INIT_LIST_HEAD(&nbd_dev[i].queue_head);
Ingo Molnar82d4dc52006-03-23 03:00:38 -0800700 mutex_init(&nbd_dev[i].tx_lock);
Herbert Xu4b2f0262006-01-06 00:09:47 -0800701 init_waitqueue_head(&nbd_dev[i].active_wq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 nbd_dev[i].blksize = 1024;
Paul Clements4b86a872007-10-16 23:27:36 -0700703 nbd_dev[i].bytesize = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 disk->major = NBD_MAJOR;
705 disk->first_minor = i;
706 disk->fops = &nbd_fops;
707 disk->private_data = &nbd_dev[i];
708 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
709 sprintf(disk->disk_name, "nbd%d", i);
Paul Clements4b86a872007-10-16 23:27:36 -0700710 set_capacity(disk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 add_disk(disk);
712 }
713
714 return 0;
715out:
716 while (i--) {
717 blk_cleanup_queue(nbd_dev[i].disk->queue);
718 put_disk(nbd_dev[i].disk);
719 }
720 return err;
721}
722
723static void __exit nbd_cleanup(void)
724{
725 int i;
Lars Marowsky-Bree40be0c22005-05-01 08:59:07 -0700726 for (i = 0; i < nbds_max; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 struct gendisk *disk = nbd_dev[i].disk;
Lars Marowsky-Bree40be0c22005-05-01 08:59:07 -0700728 nbd_dev[i].magic = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 if (disk) {
730 del_gendisk(disk);
731 blk_cleanup_queue(disk->queue);
732 put_disk(disk);
733 }
734 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 unregister_blkdev(NBD_MAJOR, "nbd");
736 printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR);
737}
738
739module_init(nbd_init);
740module_exit(nbd_cleanup);
741
742MODULE_DESCRIPTION("Network Block Device");
743MODULE_LICENSE("GPL");
744
Lars Marowsky-Bree40be0c22005-05-01 08:59:07 -0700745module_param(nbds_max, int, 0444);
746MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize.");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747#ifndef NDEBUG
748module_param(debugflags, int, 0644);
749MODULE_PARM_DESC(debugflags, "flags for controlling debug output");
750#endif