Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | * |
Pavel Machek | dbf492d | 2006-06-25 05:47:42 -0700 | [diff] [blame] | 10 | * This file is released under GPLv2 or later. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | * |
Pavel Machek | dbf492d | 2006-06-25 05:47:42 -0700 | [diff] [blame] | 12 | * (part of code stolen from loop.c) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 27 | #include <linux/compiler.h> |
| 28 | #include <linux/err.h> |
| 29 | #include <linux/kernel.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include <net/sock.h> |
| 31 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <asm/uaccess.h> |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 33 | #include <asm/system.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
| 52 | static unsigned int debugflags; |
Lars Marowsky-Bree | 40be0c2 | 2005-05-01 08:59:07 -0700 | [diff] [blame] | 53 | static unsigned int nbds_max = 16; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | #endif /* NDEBUG */ |
| 55 | |
| 56 | static 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 | */ |
| 68 | static DEFINE_SPINLOCK(nbd_lock); |
| 69 | |
| 70 | #ifndef NDEBUG |
| 71 | static 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 | |
| 89 | static 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 | |
| 100 | static void nbd_end_request(struct request *req) |
| 101 | { |
| 102 | int uptodate = (req->errors == 0) ? 1 : 0; |
| 103 | request_queue_t *q = req->q; |
| 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)) { |
Tejun Heo | 8ffdc65 | 2006-01-06 09:49:03 +0100 | [diff] [blame] | 111 | end_that_request_last(req, uptodate); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | } |
| 113 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 114 | } |
| 115 | |
| 116 | /* |
| 117 | * Send or receive packet. |
| 118 | */ |
| 119 | static 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; |
| 125 | unsigned long flags; |
| 126 | sigset_t oldset; |
| 127 | |
| 128 | /* Allow interception of SIGKILL only |
| 129 | * Don't allow other signals to interrupt the transmission */ |
| 130 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
| 131 | oldset = current->blocked; |
| 132 | sigfillset(¤t->blocked); |
| 133 | sigdelsetmask(¤t->blocked, sigmask(SIGKILL)); |
| 134 | recalc_sigpending(); |
| 135 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
| 136 | |
| 137 | do { |
| 138 | sock->sk->sk_allocation = GFP_NOIO; |
| 139 | iov.iov_base = buf; |
| 140 | iov.iov_len = size; |
| 141 | msg.msg_name = NULL; |
| 142 | msg.msg_namelen = 0; |
| 143 | msg.msg_control = NULL; |
| 144 | msg.msg_controllen = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
| 146 | |
| 147 | if (send) |
| 148 | result = kernel_sendmsg(sock, &msg, &iov, 1, size); |
| 149 | else |
| 150 | result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); |
| 151 | |
| 152 | if (signal_pending(current)) { |
| 153 | siginfo_t info; |
| 154 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
| 155 | printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", |
| 156 | current->pid, current->comm, |
| 157 | dequeue_signal(current, ¤t->blocked, &info)); |
| 158 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
| 159 | result = -EINTR; |
| 160 | break; |
| 161 | } |
| 162 | |
| 163 | if (result <= 0) { |
| 164 | if (result == 0) |
| 165 | result = -EPIPE; /* short read */ |
| 166 | break; |
| 167 | } |
| 168 | size -= result; |
| 169 | buf += result; |
| 170 | } while (size > 0); |
| 171 | |
| 172 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
| 173 | current->blocked = oldset; |
| 174 | recalc_sigpending(); |
| 175 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
| 176 | |
| 177 | return result; |
| 178 | } |
| 179 | |
| 180 | static inline int sock_send_bvec(struct socket *sock, struct bio_vec *bvec, |
| 181 | int flags) |
| 182 | { |
| 183 | int result; |
| 184 | void *kaddr = kmap(bvec->bv_page); |
| 185 | result = sock_xmit(sock, 1, kaddr + bvec->bv_offset, bvec->bv_len, |
| 186 | flags); |
| 187 | kunmap(bvec->bv_page); |
| 188 | return result; |
| 189 | } |
| 190 | |
| 191 | static int nbd_send_req(struct nbd_device *lo, struct request *req) |
| 192 | { |
| 193 | int result, i, flags; |
| 194 | struct nbd_request request; |
| 195 | unsigned long size = req->nr_sectors << 9; |
| 196 | struct socket *sock = lo->sock; |
| 197 | |
| 198 | request.magic = htonl(NBD_REQUEST_MAGIC); |
| 199 | request.type = htonl(nbd_cmd(req)); |
| 200 | request.from = cpu_to_be64((u64) req->sector << 9); |
| 201 | request.len = htonl(size); |
| 202 | memcpy(request.handle, &req, sizeof(req)); |
| 203 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", |
| 205 | lo->disk->disk_name, req, |
| 206 | nbdcmd_to_ascii(nbd_cmd(req)), |
| 207 | (unsigned long long)req->sector << 9, |
| 208 | req->nr_sectors << 9); |
| 209 | result = sock_xmit(sock, 1, &request, sizeof(request), |
| 210 | (nbd_cmd(req) == NBD_CMD_WRITE)? MSG_MORE: 0); |
| 211 | if (result <= 0) { |
| 212 | printk(KERN_ERR "%s: Send control failed (result %d)\n", |
| 213 | lo->disk->disk_name, result); |
| 214 | goto error_out; |
| 215 | } |
| 216 | |
| 217 | if (nbd_cmd(req) == NBD_CMD_WRITE) { |
| 218 | struct bio *bio; |
| 219 | /* |
| 220 | * we are really probing at internals to determine |
| 221 | * whether to set MSG_MORE or not... |
| 222 | */ |
| 223 | rq_for_each_bio(bio, req) { |
| 224 | struct bio_vec *bvec; |
| 225 | bio_for_each_segment(bvec, bio, i) { |
| 226 | flags = 0; |
| 227 | if ((i < (bio->bi_vcnt - 1)) || bio->bi_next) |
| 228 | flags = MSG_MORE; |
| 229 | dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", |
| 230 | lo->disk->disk_name, req, |
| 231 | bvec->bv_len); |
| 232 | result = sock_send_bvec(sock, bvec, flags); |
| 233 | if (result <= 0) { |
| 234 | printk(KERN_ERR "%s: Send data failed (result %d)\n", |
| 235 | lo->disk->disk_name, |
| 236 | result); |
| 237 | goto error_out; |
| 238 | } |
| 239 | } |
| 240 | } |
| 241 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | return 0; |
| 243 | |
| 244 | error_out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | return 1; |
| 246 | } |
| 247 | |
| 248 | static struct request *nbd_find_request(struct nbd_device *lo, char *handle) |
| 249 | { |
| 250 | struct request *req; |
| 251 | struct list_head *tmp; |
| 252 | struct request *xreq; |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 253 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | |
| 255 | memcpy(&xreq, handle, sizeof(xreq)); |
| 256 | |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 257 | err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); |
| 258 | if (unlikely(err)) |
| 259 | goto out; |
| 260 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | spin_lock(&lo->queue_lock); |
| 262 | list_for_each(tmp, &lo->queue_head) { |
| 263 | req = list_entry(tmp, struct request, queuelist); |
| 264 | if (req != xreq) |
| 265 | continue; |
| 266 | list_del_init(&req->queuelist); |
| 267 | spin_unlock(&lo->queue_lock); |
| 268 | return req; |
| 269 | } |
| 270 | spin_unlock(&lo->queue_lock); |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 271 | |
| 272 | err = -ENOENT; |
| 273 | |
| 274 | out: |
| 275 | return ERR_PTR(err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | } |
| 277 | |
| 278 | static inline int sock_recv_bvec(struct socket *sock, struct bio_vec *bvec) |
| 279 | { |
| 280 | int result; |
| 281 | void *kaddr = kmap(bvec->bv_page); |
| 282 | result = sock_xmit(sock, 0, kaddr + bvec->bv_offset, bvec->bv_len, |
| 283 | MSG_WAITALL); |
| 284 | kunmap(bvec->bv_page); |
| 285 | return result; |
| 286 | } |
| 287 | |
| 288 | /* NULL returned = something went wrong, inform userspace */ |
| 289 | static struct request *nbd_read_stat(struct nbd_device *lo) |
| 290 | { |
| 291 | int result; |
| 292 | struct nbd_reply reply; |
| 293 | struct request *req; |
| 294 | struct socket *sock = lo->sock; |
| 295 | |
| 296 | reply.magic = 0; |
| 297 | result = sock_xmit(sock, 0, &reply, sizeof(reply), MSG_WAITALL); |
| 298 | if (result <= 0) { |
| 299 | printk(KERN_ERR "%s: Receive control failed (result %d)\n", |
| 300 | lo->disk->disk_name, result); |
| 301 | goto harderror; |
| 302 | } |
| 303 | req = nbd_find_request(lo, reply.handle); |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 304 | if (unlikely(IS_ERR(req))) { |
| 305 | result = PTR_ERR(req); |
| 306 | if (result != -ENOENT) |
| 307 | goto harderror; |
| 308 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | printk(KERN_ERR "%s: Unexpected reply (%p)\n", |
| 310 | lo->disk->disk_name, reply.handle); |
| 311 | result = -EBADR; |
| 312 | goto harderror; |
| 313 | } |
| 314 | |
| 315 | if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { |
| 316 | printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", |
| 317 | lo->disk->disk_name, |
| 318 | (unsigned long)ntohl(reply.magic)); |
| 319 | result = -EPROTO; |
| 320 | goto harderror; |
| 321 | } |
| 322 | if (ntohl(reply.error)) { |
| 323 | printk(KERN_ERR "%s: Other side returned error (%d)\n", |
| 324 | lo->disk->disk_name, ntohl(reply.error)); |
| 325 | req->errors++; |
| 326 | return req; |
| 327 | } |
| 328 | |
| 329 | dprintk(DBG_RX, "%s: request %p: got reply\n", |
| 330 | lo->disk->disk_name, req); |
| 331 | if (nbd_cmd(req) == NBD_CMD_READ) { |
| 332 | int i; |
| 333 | struct bio *bio; |
| 334 | rq_for_each_bio(bio, req) { |
| 335 | struct bio_vec *bvec; |
| 336 | bio_for_each_segment(bvec, bio, i) { |
| 337 | result = sock_recv_bvec(sock, bvec); |
| 338 | if (result <= 0) { |
| 339 | printk(KERN_ERR "%s: Receive data failed (result %d)\n", |
| 340 | lo->disk->disk_name, |
| 341 | result); |
| 342 | goto harderror; |
| 343 | } |
| 344 | dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", |
| 345 | lo->disk->disk_name, req, bvec->bv_len); |
| 346 | } |
| 347 | } |
| 348 | } |
| 349 | return req; |
| 350 | harderror: |
| 351 | lo->harderror = result; |
| 352 | return NULL; |
| 353 | } |
| 354 | |
| 355 | static void nbd_do_it(struct nbd_device *lo) |
| 356 | { |
| 357 | struct request *req; |
| 358 | |
| 359 | BUG_ON(lo->magic != LO_MAGIC); |
| 360 | |
| 361 | while ((req = nbd_read_stat(lo)) != NULL) |
| 362 | nbd_end_request(req); |
| 363 | return; |
| 364 | } |
| 365 | |
| 366 | static void nbd_clear_que(struct nbd_device *lo) |
| 367 | { |
| 368 | struct request *req; |
| 369 | |
| 370 | BUG_ON(lo->magic != LO_MAGIC); |
| 371 | |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 372 | /* |
| 373 | * Because we have set lo->sock to NULL under the tx_lock, all |
| 374 | * modifications to the list must have completed by now. For |
| 375 | * the same reason, the active_req must be NULL. |
| 376 | * |
| 377 | * As a consequence, we don't need to take the spin lock while |
| 378 | * purging the list here. |
| 379 | */ |
| 380 | BUG_ON(lo->sock); |
| 381 | BUG_ON(lo->active_req); |
| 382 | |
| 383 | while (!list_empty(&lo->queue_head)) { |
| 384 | req = list_entry(lo->queue_head.next, struct request, |
| 385 | queuelist); |
| 386 | list_del_init(&req->queuelist); |
| 387 | req->errors++; |
| 388 | nbd_end_request(req); |
| 389 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | } |
| 391 | |
| 392 | /* |
| 393 | * We always wait for result of write, for now. It would be nice to make it optional |
| 394 | * in future |
| 395 | * if ((req->cmd == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) |
| 396 | * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } |
| 397 | */ |
| 398 | |
| 399 | static void do_nbd_request(request_queue_t * q) |
| 400 | { |
| 401 | struct request *req; |
| 402 | |
| 403 | while ((req = elv_next_request(q)) != NULL) { |
| 404 | struct nbd_device *lo; |
| 405 | |
| 406 | blkdev_dequeue_request(req); |
| 407 | dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%lx)\n", |
| 408 | req->rq_disk->disk_name, req, req->flags); |
| 409 | |
| 410 | if (!(req->flags & REQ_CMD)) |
| 411 | goto error_out; |
| 412 | |
| 413 | lo = req->rq_disk->private_data; |
| 414 | |
| 415 | BUG_ON(lo->magic != LO_MAGIC); |
| 416 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | nbd_cmd(req) = NBD_CMD_READ; |
| 418 | if (rq_data_dir(req) == WRITE) { |
| 419 | nbd_cmd(req) = NBD_CMD_WRITE; |
| 420 | if (lo->flags & NBD_READ_ONLY) { |
| 421 | printk(KERN_ERR "%s: Write on read-only\n", |
| 422 | lo->disk->disk_name); |
| 423 | goto error_out; |
| 424 | } |
| 425 | } |
| 426 | |
| 427 | req->errors = 0; |
| 428 | spin_unlock_irq(q->queue_lock); |
| 429 | |
Ingo Molnar | 82d4dc5 | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 430 | mutex_lock(&lo->tx_lock); |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 431 | if (unlikely(!lo->sock)) { |
Ingo Molnar | 82d4dc5 | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 432 | mutex_unlock(&lo->tx_lock); |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 433 | printk(KERN_ERR "%s: Attempted send on closed socket\n", |
| 434 | lo->disk->disk_name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | req->errors++; |
| 436 | nbd_end_request(req); |
| 437 | spin_lock_irq(q->queue_lock); |
| 438 | continue; |
| 439 | } |
| 440 | |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 441 | lo->active_req = req; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | |
| 443 | if (nbd_send_req(lo, req) != 0) { |
| 444 | printk(KERN_ERR "%s: Request send failed\n", |
| 445 | lo->disk->disk_name); |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 446 | req->errors++; |
| 447 | nbd_end_request(req); |
| 448 | } else { |
| 449 | spin_lock(&lo->queue_lock); |
| 450 | list_add(&req->queuelist, &lo->queue_head); |
| 451 | spin_unlock(&lo->queue_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | } |
| 453 | |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 454 | lo->active_req = NULL; |
Ingo Molnar | 82d4dc5 | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 455 | mutex_unlock(&lo->tx_lock); |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 456 | wake_up_all(&lo->active_wq); |
| 457 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | spin_lock_irq(q->queue_lock); |
| 459 | continue; |
| 460 | |
| 461 | error_out: |
| 462 | req->errors++; |
| 463 | spin_unlock(q->queue_lock); |
| 464 | nbd_end_request(req); |
| 465 | spin_lock(q->queue_lock); |
| 466 | } |
| 467 | return; |
| 468 | } |
| 469 | |
| 470 | static int nbd_ioctl(struct inode *inode, struct file *file, |
| 471 | unsigned int cmd, unsigned long arg) |
| 472 | { |
| 473 | struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; |
| 474 | int error; |
| 475 | struct request sreq ; |
| 476 | |
| 477 | if (!capable(CAP_SYS_ADMIN)) |
| 478 | return -EPERM; |
| 479 | |
| 480 | BUG_ON(lo->magic != LO_MAGIC); |
| 481 | |
| 482 | /* Anyone capable of this syscall can do *real bad* things */ |
| 483 | dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", |
| 484 | lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); |
| 485 | |
| 486 | switch (cmd) { |
| 487 | case NBD_DISCONNECT: |
| 488 | printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name); |
| 489 | sreq.flags = REQ_SPECIAL; |
| 490 | nbd_cmd(&sreq) = NBD_CMD_DISC; |
| 491 | /* |
| 492 | * Set these to sane values in case server implementation |
| 493 | * fails to check the request type first and also to keep |
| 494 | * debugging output cleaner. |
| 495 | */ |
| 496 | sreq.sector = 0; |
| 497 | sreq.nr_sectors = 0; |
| 498 | if (!lo->sock) |
| 499 | return -EINVAL; |
| 500 | nbd_send_req(lo, &sreq); |
| 501 | return 0; |
| 502 | |
| 503 | case NBD_CLEAR_SOCK: |
| 504 | error = 0; |
Ingo Molnar | 82d4dc5 | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 505 | mutex_lock(&lo->tx_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | lo->sock = NULL; |
Ingo Molnar | 82d4dc5 | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 507 | mutex_unlock(&lo->tx_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | file = lo->file; |
| 509 | lo->file = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | nbd_clear_que(lo); |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 511 | BUG_ON(!list_empty(&lo->queue_head)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | if (file) |
| 513 | fput(file); |
| 514 | return error; |
| 515 | case NBD_SET_SOCK: |
| 516 | if (lo->file) |
| 517 | return -EBUSY; |
| 518 | error = -EINVAL; |
| 519 | file = fget(arg); |
| 520 | if (file) { |
| 521 | inode = file->f_dentry->d_inode; |
| 522 | if (S_ISSOCK(inode->i_mode)) { |
| 523 | lo->file = file; |
| 524 | lo->sock = SOCKET_I(inode); |
| 525 | error = 0; |
| 526 | } else { |
| 527 | fput(file); |
| 528 | } |
| 529 | } |
| 530 | return error; |
| 531 | case NBD_SET_BLKSIZE: |
| 532 | lo->blksize = arg; |
| 533 | lo->bytesize &= ~(lo->blksize-1); |
| 534 | inode->i_bdev->bd_inode->i_size = lo->bytesize; |
| 535 | set_blocksize(inode->i_bdev, lo->blksize); |
| 536 | set_capacity(lo->disk, lo->bytesize >> 9); |
| 537 | return 0; |
| 538 | case NBD_SET_SIZE: |
| 539 | lo->bytesize = arg & ~(lo->blksize-1); |
| 540 | inode->i_bdev->bd_inode->i_size = lo->bytesize; |
| 541 | set_blocksize(inode->i_bdev, lo->blksize); |
| 542 | set_capacity(lo->disk, lo->bytesize >> 9); |
| 543 | return 0; |
| 544 | case NBD_SET_SIZE_BLOCKS: |
| 545 | lo->bytesize = ((u64) arg) * lo->blksize; |
| 546 | inode->i_bdev->bd_inode->i_size = lo->bytesize; |
| 547 | set_blocksize(inode->i_bdev, lo->blksize); |
| 548 | set_capacity(lo->disk, lo->bytesize >> 9); |
| 549 | return 0; |
| 550 | case NBD_DO_IT: |
| 551 | if (!lo->file) |
| 552 | return -EINVAL; |
| 553 | nbd_do_it(lo); |
| 554 | /* on return tidy up in case we have a signal */ |
| 555 | /* Forcibly shutdown the socket causing all listeners |
| 556 | * to error |
| 557 | * |
| 558 | * FIXME: This code is duplicated from sys_shutdown, but |
| 559 | * there should be a more generic interface rather than |
| 560 | * calling socket ops directly here */ |
Ingo Molnar | 82d4dc5 | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 561 | mutex_lock(&lo->tx_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | if (lo->sock) { |
| 563 | printk(KERN_WARNING "%s: shutting down socket\n", |
| 564 | lo->disk->disk_name); |
| 565 | lo->sock->ops->shutdown(lo->sock, |
| 566 | SEND_SHUTDOWN|RCV_SHUTDOWN); |
| 567 | lo->sock = NULL; |
| 568 | } |
Ingo Molnar | 82d4dc5 | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 569 | mutex_unlock(&lo->tx_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | file = lo->file; |
| 571 | lo->file = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | nbd_clear_que(lo); |
| 573 | printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); |
| 574 | if (file) |
| 575 | fput(file); |
| 576 | return lo->harderror; |
| 577 | case NBD_CLEAR_QUE: |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 578 | /* |
| 579 | * This is for compatibility only. The queue is always cleared |
| 580 | * by NBD_DO_IT or NBD_CLEAR_SOCK. |
| 581 | */ |
| 582 | BUG_ON(!lo->sock && !list_empty(&lo->queue_head)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | return 0; |
| 584 | case NBD_PRINT_DEBUG: |
| 585 | printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n", |
| 586 | inode->i_bdev->bd_disk->disk_name, |
| 587 | lo->queue_head.next, lo->queue_head.prev, |
| 588 | &lo->queue_head); |
| 589 | return 0; |
| 590 | } |
| 591 | return -EINVAL; |
| 592 | } |
| 593 | |
| 594 | static struct block_device_operations nbd_fops = |
| 595 | { |
| 596 | .owner = THIS_MODULE, |
| 597 | .ioctl = nbd_ioctl, |
| 598 | }; |
| 599 | |
| 600 | /* |
| 601 | * And here should be modules and kernel interface |
| 602 | * (Just smiley confuses emacs :-) |
| 603 | */ |
| 604 | |
| 605 | static int __init nbd_init(void) |
| 606 | { |
| 607 | int err = -ENOMEM; |
| 608 | int i; |
| 609 | |
Adrian Bunk | 5b7b18c | 2006-03-25 03:07:04 -0800 | [diff] [blame] | 610 | BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | |
Lars Marowsky-Bree | 40be0c2 | 2005-05-01 08:59:07 -0700 | [diff] [blame] | 612 | if (nbds_max > MAX_NBD) { |
| 613 | printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD, |
| 614 | nbds_max); |
| 615 | return -EINVAL; |
| 616 | } |
| 617 | |
| 618 | for (i = 0; i < nbds_max; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | struct gendisk *disk = alloc_disk(1); |
| 620 | if (!disk) |
| 621 | goto out; |
| 622 | nbd_dev[i].disk = disk; |
| 623 | /* |
| 624 | * The new linux 2.5 block layer implementation requires |
| 625 | * every gendisk to have its very own request_queue struct. |
| 626 | * These structs are big so we dynamically allocate them. |
| 627 | */ |
| 628 | disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); |
| 629 | if (!disk->queue) { |
| 630 | put_disk(disk); |
| 631 | goto out; |
| 632 | } |
| 633 | } |
| 634 | |
| 635 | if (register_blkdev(NBD_MAJOR, "nbd")) { |
| 636 | err = -EIO; |
| 637 | goto out; |
| 638 | } |
| 639 | |
| 640 | printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); |
| 641 | dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); |
| 642 | |
Lars Marowsky-Bree | 40be0c2 | 2005-05-01 08:59:07 -0700 | [diff] [blame] | 643 | for (i = 0; i < nbds_max; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | struct gendisk *disk = nbd_dev[i].disk; |
| 645 | nbd_dev[i].file = NULL; |
| 646 | nbd_dev[i].magic = LO_MAGIC; |
| 647 | nbd_dev[i].flags = 0; |
| 648 | spin_lock_init(&nbd_dev[i].queue_lock); |
| 649 | INIT_LIST_HEAD(&nbd_dev[i].queue_head); |
Ingo Molnar | 82d4dc5 | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 650 | mutex_init(&nbd_dev[i].tx_lock); |
Herbert Xu | 4b2f026 | 2006-01-06 00:09:47 -0800 | [diff] [blame] | 651 | init_waitqueue_head(&nbd_dev[i].active_wq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | nbd_dev[i].blksize = 1024; |
| 653 | nbd_dev[i].bytesize = 0x7ffffc00ULL << 10; /* 2TB */ |
| 654 | disk->major = NBD_MAJOR; |
| 655 | disk->first_minor = i; |
| 656 | disk->fops = &nbd_fops; |
| 657 | disk->private_data = &nbd_dev[i]; |
| 658 | disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO; |
| 659 | sprintf(disk->disk_name, "nbd%d", i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | set_capacity(disk, 0x7ffffc00ULL << 1); /* 2 TB */ |
| 661 | add_disk(disk); |
| 662 | } |
| 663 | |
| 664 | return 0; |
| 665 | out: |
| 666 | while (i--) { |
| 667 | blk_cleanup_queue(nbd_dev[i].disk->queue); |
| 668 | put_disk(nbd_dev[i].disk); |
| 669 | } |
| 670 | return err; |
| 671 | } |
| 672 | |
| 673 | static void __exit nbd_cleanup(void) |
| 674 | { |
| 675 | int i; |
Lars Marowsky-Bree | 40be0c2 | 2005-05-01 08:59:07 -0700 | [diff] [blame] | 676 | for (i = 0; i < nbds_max; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | struct gendisk *disk = nbd_dev[i].disk; |
Lars Marowsky-Bree | 40be0c2 | 2005-05-01 08:59:07 -0700 | [diff] [blame] | 678 | nbd_dev[i].magic = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 679 | if (disk) { |
| 680 | del_gendisk(disk); |
| 681 | blk_cleanup_queue(disk->queue); |
| 682 | put_disk(disk); |
| 683 | } |
| 684 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | unregister_blkdev(NBD_MAJOR, "nbd"); |
| 686 | printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); |
| 687 | } |
| 688 | |
| 689 | module_init(nbd_init); |
| 690 | module_exit(nbd_cleanup); |
| 691 | |
| 692 | MODULE_DESCRIPTION("Network Block Device"); |
| 693 | MODULE_LICENSE("GPL"); |
| 694 | |
Lars Marowsky-Bree | 40be0c2 | 2005-05-01 08:59:07 -0700 | [diff] [blame] | 695 | module_param(nbds_max, int, 0444); |
| 696 | MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize."); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | #ifndef NDEBUG |
| 698 | module_param(debugflags, int, 0644); |
| 699 | MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); |
| 700 | #endif |