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 * 10 * (part of code stolen from loop.c) 11 * 12 * 97-3-25 compiled 0-th version, not yet tested it 13 * (it did not work, BTW) (later that day) HEY! it works! 14 * (bit later) hmm, not that much... 2:00am next day: 15 * yes, it works, but it gives something like 50kB/sec 16 * 97-4-01 complete rewrite to make it possible for many requests at 17 * once to be processed 18 * 97-4-11 Making protocol independent of endianity etc. 19 * 97-9-13 Cosmetic changes 20 * 98-5-13 Attempt to make 64-bit-clean on 64-bit machines 21 * 99-1-11 Attempt to make 64-bit-clean on 32-bit machines <ankry@mif.pg.gda.pl> 22 * 01-2-27 Fix to store proper blockcount for kernel (calculated using 23 * BLOCK_SIZE_BITS, not device blocksize) <aga@permonline.ru> 24 * 01-3-11 Make nbd work with new Linux block layer code. It now supports 25 * plugging like all the other block devices. Also added in MSG_MORE to 26 * reduce number of partial TCP segments sent. <steve@chygwyn.com> 27 * 01-12-6 Fix deadlock condition by making queue locks independent of 28 * the transmit lock. <steve@chygwyn.com> 29 * 02-10-11 Allow hung xmit to be aborted via SIGKILL & various fixes. 30 * <Paul.Clements@SteelEye.com> <James.Bottomley@SteelEye.com> 31 * 03-06-22 Make nbd work with new linux 2.5 block layer design. This fixes 32 * memory corruption from module removal and possible memory corruption 33 * from sending/receiving disk data. <ldl@aros.net> 34 * 03-06-23 Cosmetic changes. <ldl@aros.net> 35 * 03-06-23 Enhance diagnostics support. <ldl@aros.net> 36 * 03-06-24 Remove unneeded blksize_bits field from nbd_device struct. 37 * <ldl@aros.net> 38 * 03-06-24 Cleanup PARANOIA usage & code. <ldl@aros.net> 39 * 04-02-19 Remove PARANOIA, plus various cleanups (Paul Clements) 40 * possible FIXME: make set_sock / set_blksize / set_size / do_it one syscall 41 * why not: would need access_ok and friends, would share yet another 42 * structure with userland 43 */ 44 45 #include <linux/major.h> 46 47 #include <linux/blkdev.h> 48 #include <linux/module.h> 49 #include <linux/init.h> 50 #include <linux/sched.h> 51 #include <linux/fs.h> 52 #include <linux/bio.h> 53 #include <linux/stat.h> 54 #include <linux/errno.h> 55 #include <linux/file.h> 56 #include <linux/ioctl.h> 57 #include <linux/compiler.h> 58 #include <linux/err.h> 59 #include <linux/kernel.h> 60 #include <net/sock.h> 61 62 #include <linux/devfs_fs_kernel.h> 63 64 #include <asm/uaccess.h> 65 #include <asm/system.h> 66 #include <asm/types.h> 67 68 #include <linux/nbd.h> 69 70 #define LO_MAGIC 0x68797548 71 72 #ifdef NDEBUG 73 #define dprintk(flags, fmt...) 74 #else /* NDEBUG */ 75 #define dprintk(flags, fmt...) do { \ 76 if (debugflags & (flags)) printk(KERN_DEBUG fmt); \ 77 } while (0) 78 #define DBG_IOCTL 0x0004 79 #define DBG_INIT 0x0010 80 #define DBG_EXIT 0x0020 81 #define DBG_BLKDEV 0x0100 82 #define DBG_RX 0x0200 83 #define DBG_TX 0x0400 84 static unsigned int debugflags; 85 static unsigned int nbds_max = 16; 86 #endif /* NDEBUG */ 87 88 static struct nbd_device nbd_dev[MAX_NBD]; 89 90 /* 91 * Use just one lock (or at most 1 per NIC). Two arguments for this: 92 * 1. Each NIC is essentially a synchronization point for all servers 93 * accessed through that NIC so there's no need to have more locks 94 * than NICs anyway. 95 * 2. More locks lead to more "Dirty cache line bouncing" which will slow 96 * down each lock to the point where they're actually slower than just 97 * a single lock. 98 * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! 99 */ 100 static DEFINE_SPINLOCK(nbd_lock); 101 102 #ifndef NDEBUG 103 static const char *ioctl_cmd_to_ascii(int cmd) 104 { 105 switch (cmd) { 106 case NBD_SET_SOCK: return "set-sock"; 107 case NBD_SET_BLKSIZE: return "set-blksize"; 108 case NBD_SET_SIZE: return "set-size"; 109 case NBD_DO_IT: return "do-it"; 110 case NBD_CLEAR_SOCK: return "clear-sock"; 111 case NBD_CLEAR_QUE: return "clear-que"; 112 case NBD_PRINT_DEBUG: return "print-debug"; 113 case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; 114 case NBD_DISCONNECT: return "disconnect"; 115 case BLKROSET: return "set-read-only"; 116 case BLKFLSBUF: return "flush-buffer-cache"; 117 } 118 return "unknown"; 119 } 120 121 static const char *nbdcmd_to_ascii(int cmd) 122 { 123 switch (cmd) { 124 case NBD_CMD_READ: return "read"; 125 case NBD_CMD_WRITE: return "write"; 126 case NBD_CMD_DISC: return "disconnect"; 127 } 128 return "invalid"; 129 } 130 #endif /* NDEBUG */ 131 132 static void nbd_end_request(struct request *req) 133 { 134 int uptodate = (req->errors == 0) ? 1 : 0; 135 request_queue_t *q = req->q; 136 unsigned long flags; 137 138 dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, 139 req, uptodate? "done": "failed"); 140 141 spin_lock_irqsave(q->queue_lock, flags); 142 if (!end_that_request_first(req, uptodate, req->nr_sectors)) { 143 end_that_request_last(req, uptodate); 144 } 145 spin_unlock_irqrestore(q->queue_lock, flags); 146 } 147 148 /* 149 * Send or receive packet. 150 */ 151 static int sock_xmit(struct socket *sock, int send, void *buf, int size, 152 int msg_flags) 153 { 154 int result; 155 struct msghdr msg; 156 struct kvec iov; 157 unsigned long flags; 158 sigset_t oldset; 159 160 /* Allow interception of SIGKILL only 161 * Don't allow other signals to interrupt the transmission */ 162 spin_lock_irqsave(¤t->sighand->siglock, flags); 163 oldset = current->blocked; 164 sigfillset(¤t->blocked); 165 sigdelsetmask(¤t->blocked, sigmask(SIGKILL)); 166 recalc_sigpending(); 167 spin_unlock_irqrestore(¤t->sighand->siglock, flags); 168 169 do { 170 sock->sk->sk_allocation = GFP_NOIO; 171 iov.iov_base = buf; 172 iov.iov_len = size; 173 msg.msg_name = NULL; 174 msg.msg_namelen = 0; 175 msg.msg_control = NULL; 176 msg.msg_controllen = 0; 177 msg.msg_flags = msg_flags | MSG_NOSIGNAL; 178 179 if (send) 180 result = kernel_sendmsg(sock, &msg, &iov, 1, size); 181 else 182 result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); 183 184 if (signal_pending(current)) { 185 siginfo_t info; 186 spin_lock_irqsave(¤t->sighand->siglock, flags); 187 printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", 188 current->pid, current->comm, 189 dequeue_signal(current, ¤t->blocked, &info)); 190 spin_unlock_irqrestore(¤t->sighand->siglock, flags); 191 result = -EINTR; 192 break; 193 } 194 195 if (result <= 0) { 196 if (result == 0) 197 result = -EPIPE; /* short read */ 198 break; 199 } 200 size -= result; 201 buf += result; 202 } while (size > 0); 203 204 spin_lock_irqsave(¤t->sighand->siglock, flags); 205 current->blocked = oldset; 206 recalc_sigpending(); 207 spin_unlock_irqrestore(¤t->sighand->siglock, flags); 208 209 return result; 210 } 211 212 static inline int sock_send_bvec(struct socket *sock, struct bio_vec *bvec, 213 int flags) 214 { 215 int result; 216 void *kaddr = kmap(bvec->bv_page); 217 result = sock_xmit(sock, 1, kaddr + bvec->bv_offset, bvec->bv_len, 218 flags); 219 kunmap(bvec->bv_page); 220 return result; 221 } 222 223 static int nbd_send_req(struct nbd_device *lo, struct request *req) 224 { 225 int result, i, flags; 226 struct nbd_request request; 227 unsigned long size = req->nr_sectors << 9; 228 struct socket *sock = lo->sock; 229 230 request.magic = htonl(NBD_REQUEST_MAGIC); 231 request.type = htonl(nbd_cmd(req)); 232 request.from = cpu_to_be64((u64) req->sector << 9); 233 request.len = htonl(size); 234 memcpy(request.handle, &req, sizeof(req)); 235 236 dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", 237 lo->disk->disk_name, req, 238 nbdcmd_to_ascii(nbd_cmd(req)), 239 (unsigned long long)req->sector << 9, 240 req->nr_sectors << 9); 241 result = sock_xmit(sock, 1, &request, sizeof(request), 242 (nbd_cmd(req) == NBD_CMD_WRITE)? MSG_MORE: 0); 243 if (result <= 0) { 244 printk(KERN_ERR "%s: Send control failed (result %d)\n", 245 lo->disk->disk_name, result); 246 goto error_out; 247 } 248 249 if (nbd_cmd(req) == NBD_CMD_WRITE) { 250 struct bio *bio; 251 /* 252 * we are really probing at internals to determine 253 * whether to set MSG_MORE or not... 254 */ 255 rq_for_each_bio(bio, req) { 256 struct bio_vec *bvec; 257 bio_for_each_segment(bvec, bio, i) { 258 flags = 0; 259 if ((i < (bio->bi_vcnt - 1)) || bio->bi_next) 260 flags = MSG_MORE; 261 dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", 262 lo->disk->disk_name, req, 263 bvec->bv_len); 264 result = sock_send_bvec(sock, bvec, flags); 265 if (result <= 0) { 266 printk(KERN_ERR "%s: Send data failed (result %d)\n", 267 lo->disk->disk_name, 268 result); 269 goto error_out; 270 } 271 } 272 } 273 } 274 return 0; 275 276 error_out: 277 return 1; 278 } 279 280 static struct request *nbd_find_request(struct nbd_device *lo, char *handle) 281 { 282 struct request *req; 283 struct list_head *tmp; 284 struct request *xreq; 285 int err; 286 287 memcpy(&xreq, handle, sizeof(xreq)); 288 289 err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); 290 if (unlikely(err)) 291 goto out; 292 293 spin_lock(&lo->queue_lock); 294 list_for_each(tmp, &lo->queue_head) { 295 req = list_entry(tmp, struct request, queuelist); 296 if (req != xreq) 297 continue; 298 list_del_init(&req->queuelist); 299 spin_unlock(&lo->queue_lock); 300 return req; 301 } 302 spin_unlock(&lo->queue_lock); 303 304 err = -ENOENT; 305 306 out: 307 return ERR_PTR(err); 308 } 309 310 static inline int sock_recv_bvec(struct socket *sock, struct bio_vec *bvec) 311 { 312 int result; 313 void *kaddr = kmap(bvec->bv_page); 314 result = sock_xmit(sock, 0, kaddr + bvec->bv_offset, bvec->bv_len, 315 MSG_WAITALL); 316 kunmap(bvec->bv_page); 317 return result; 318 } 319 320 /* NULL returned = something went wrong, inform userspace */ 321 static struct request *nbd_read_stat(struct nbd_device *lo) 322 { 323 int result; 324 struct nbd_reply reply; 325 struct request *req; 326 struct socket *sock = lo->sock; 327 328 reply.magic = 0; 329 result = sock_xmit(sock, 0, &reply, sizeof(reply), MSG_WAITALL); 330 if (result <= 0) { 331 printk(KERN_ERR "%s: Receive control failed (result %d)\n", 332 lo->disk->disk_name, result); 333 goto harderror; 334 } 335 req = nbd_find_request(lo, reply.handle); 336 if (unlikely(IS_ERR(req))) { 337 result = PTR_ERR(req); 338 if (result != -ENOENT) 339 goto harderror; 340 341 printk(KERN_ERR "%s: Unexpected reply (%p)\n", 342 lo->disk->disk_name, reply.handle); 343 result = -EBADR; 344 goto harderror; 345 } 346 347 if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { 348 printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", 349 lo->disk->disk_name, 350 (unsigned long)ntohl(reply.magic)); 351 result = -EPROTO; 352 goto harderror; 353 } 354 if (ntohl(reply.error)) { 355 printk(KERN_ERR "%s: Other side returned error (%d)\n", 356 lo->disk->disk_name, ntohl(reply.error)); 357 req->errors++; 358 return req; 359 } 360 361 dprintk(DBG_RX, "%s: request %p: got reply\n", 362 lo->disk->disk_name, req); 363 if (nbd_cmd(req) == NBD_CMD_READ) { 364 int i; 365 struct bio *bio; 366 rq_for_each_bio(bio, req) { 367 struct bio_vec *bvec; 368 bio_for_each_segment(bvec, bio, i) { 369 result = sock_recv_bvec(sock, bvec); 370 if (result <= 0) { 371 printk(KERN_ERR "%s: Receive data failed (result %d)\n", 372 lo->disk->disk_name, 373 result); 374 goto harderror; 375 } 376 dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", 377 lo->disk->disk_name, req, bvec->bv_len); 378 } 379 } 380 } 381 return req; 382 harderror: 383 lo->harderror = result; 384 return NULL; 385 } 386 387 static void nbd_do_it(struct nbd_device *lo) 388 { 389 struct request *req; 390 391 BUG_ON(lo->magic != LO_MAGIC); 392 393 while ((req = nbd_read_stat(lo)) != NULL) 394 nbd_end_request(req); 395 return; 396 } 397 398 static void nbd_clear_que(struct nbd_device *lo) 399 { 400 struct request *req; 401 402 BUG_ON(lo->magic != LO_MAGIC); 403 404 /* 405 * Because we have set lo->sock to NULL under the tx_lock, all 406 * modifications to the list must have completed by now. For 407 * the same reason, the active_req must be NULL. 408 * 409 * As a consequence, we don't need to take the spin lock while 410 * purging the list here. 411 */ 412 BUG_ON(lo->sock); 413 BUG_ON(lo->active_req); 414 415 while (!list_empty(&lo->queue_head)) { 416 req = list_entry(lo->queue_head.next, struct request, 417 queuelist); 418 list_del_init(&req->queuelist); 419 req->errors++; 420 nbd_end_request(req); 421 } 422 } 423 424 /* 425 * We always wait for result of write, for now. It would be nice to make it optional 426 * in future 427 * if ((req->cmd == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) 428 * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } 429 */ 430 431 static void do_nbd_request(request_queue_t * q) 432 { 433 struct request *req; 434 435 while ((req = elv_next_request(q)) != NULL) { 436 struct nbd_device *lo; 437 438 blkdev_dequeue_request(req); 439 dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%lx)\n", 440 req->rq_disk->disk_name, req, req->flags); 441 442 if (!(req->flags & REQ_CMD)) 443 goto error_out; 444 445 lo = req->rq_disk->private_data; 446 447 BUG_ON(lo->magic != LO_MAGIC); 448 449 nbd_cmd(req) = NBD_CMD_READ; 450 if (rq_data_dir(req) == WRITE) { 451 nbd_cmd(req) = NBD_CMD_WRITE; 452 if (lo->flags & NBD_READ_ONLY) { 453 printk(KERN_ERR "%s: Write on read-only\n", 454 lo->disk->disk_name); 455 goto error_out; 456 } 457 } 458 459 req->errors = 0; 460 spin_unlock_irq(q->queue_lock); 461 462 mutex_lock(&lo->tx_lock); 463 if (unlikely(!lo->sock)) { 464 mutex_unlock(&lo->tx_lock); 465 printk(KERN_ERR "%s: Attempted send on closed socket\n", 466 lo->disk->disk_name); 467 req->errors++; 468 nbd_end_request(req); 469 spin_lock_irq(q->queue_lock); 470 continue; 471 } 472 473 lo->active_req = req; 474 475 if (nbd_send_req(lo, req) != 0) { 476 printk(KERN_ERR "%s: Request send failed\n", 477 lo->disk->disk_name); 478 req->errors++; 479 nbd_end_request(req); 480 } else { 481 spin_lock(&lo->queue_lock); 482 list_add(&req->queuelist, &lo->queue_head); 483 spin_unlock(&lo->queue_lock); 484 } 485 486 lo->active_req = NULL; 487 mutex_unlock(&lo->tx_lock); 488 wake_up_all(&lo->active_wq); 489 490 spin_lock_irq(q->queue_lock); 491 continue; 492 493 error_out: 494 req->errors++; 495 spin_unlock(q->queue_lock); 496 nbd_end_request(req); 497 spin_lock(q->queue_lock); 498 } 499 return; 500 } 501 502 static int nbd_ioctl(struct inode *inode, struct file *file, 503 unsigned int cmd, unsigned long arg) 504 { 505 struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; 506 int error; 507 struct request sreq ; 508 509 if (!capable(CAP_SYS_ADMIN)) 510 return -EPERM; 511 512 BUG_ON(lo->magic != LO_MAGIC); 513 514 /* Anyone capable of this syscall can do *real bad* things */ 515 dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", 516 lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); 517 518 switch (cmd) { 519 case NBD_DISCONNECT: 520 printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name); 521 sreq.flags = REQ_SPECIAL; 522 nbd_cmd(&sreq) = NBD_CMD_DISC; 523 /* 524 * Set these to sane values in case server implementation 525 * fails to check the request type first and also to keep 526 * debugging output cleaner. 527 */ 528 sreq.sector = 0; 529 sreq.nr_sectors = 0; 530 if (!lo->sock) 531 return -EINVAL; 532 nbd_send_req(lo, &sreq); 533 return 0; 534 535 case NBD_CLEAR_SOCK: 536 error = 0; 537 mutex_lock(&lo->tx_lock); 538 lo->sock = NULL; 539 mutex_unlock(&lo->tx_lock); 540 file = lo->file; 541 lo->file = NULL; 542 nbd_clear_que(lo); 543 BUG_ON(!list_empty(&lo->queue_head)); 544 if (file) 545 fput(file); 546 return error; 547 case NBD_SET_SOCK: 548 if (lo->file) 549 return -EBUSY; 550 error = -EINVAL; 551 file = fget(arg); 552 if (file) { 553 inode = file->f_dentry->d_inode; 554 if (S_ISSOCK(inode->i_mode)) { 555 lo->file = file; 556 lo->sock = SOCKET_I(inode); 557 error = 0; 558 } else { 559 fput(file); 560 } 561 } 562 return error; 563 case NBD_SET_BLKSIZE: 564 lo->blksize = arg; 565 lo->bytesize &= ~(lo->blksize-1); 566 inode->i_bdev->bd_inode->i_size = lo->bytesize; 567 set_blocksize(inode->i_bdev, lo->blksize); 568 set_capacity(lo->disk, lo->bytesize >> 9); 569 return 0; 570 case NBD_SET_SIZE: 571 lo->bytesize = arg & ~(lo->blksize-1); 572 inode->i_bdev->bd_inode->i_size = lo->bytesize; 573 set_blocksize(inode->i_bdev, lo->blksize); 574 set_capacity(lo->disk, lo->bytesize >> 9); 575 return 0; 576 case NBD_SET_SIZE_BLOCKS: 577 lo->bytesize = ((u64) arg) * lo->blksize; 578 inode->i_bdev->bd_inode->i_size = lo->bytesize; 579 set_blocksize(inode->i_bdev, lo->blksize); 580 set_capacity(lo->disk, lo->bytesize >> 9); 581 return 0; 582 case NBD_DO_IT: 583 if (!lo->file) 584 return -EINVAL; 585 nbd_do_it(lo); 586 /* on return tidy up in case we have a signal */ 587 /* Forcibly shutdown the socket causing all listeners 588 * to error 589 * 590 * FIXME: This code is duplicated from sys_shutdown, but 591 * there should be a more generic interface rather than 592 * calling socket ops directly here */ 593 mutex_lock(&lo->tx_lock); 594 if (lo->sock) { 595 printk(KERN_WARNING "%s: shutting down socket\n", 596 lo->disk->disk_name); 597 lo->sock->ops->shutdown(lo->sock, 598 SEND_SHUTDOWN|RCV_SHUTDOWN); 599 lo->sock = NULL; 600 } 601 mutex_unlock(&lo->tx_lock); 602 file = lo->file; 603 lo->file = NULL; 604 nbd_clear_que(lo); 605 printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); 606 if (file) 607 fput(file); 608 return lo->harderror; 609 case NBD_CLEAR_QUE: 610 /* 611 * This is for compatibility only. The queue is always cleared 612 * by NBD_DO_IT or NBD_CLEAR_SOCK. 613 */ 614 BUG_ON(!lo->sock && !list_empty(&lo->queue_head)); 615 return 0; 616 case NBD_PRINT_DEBUG: 617 printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n", 618 inode->i_bdev->bd_disk->disk_name, 619 lo->queue_head.next, lo->queue_head.prev, 620 &lo->queue_head); 621 return 0; 622 } 623 return -EINVAL; 624 } 625 626 static struct block_device_operations nbd_fops = 627 { 628 .owner = THIS_MODULE, 629 .ioctl = nbd_ioctl, 630 }; 631 632 /* 633 * And here should be modules and kernel interface 634 * (Just smiley confuses emacs :-) 635 */ 636 637 static int __init nbd_init(void) 638 { 639 int err = -ENOMEM; 640 int i; 641 642 BUILD_BUG_ON(sizeof(struct nbd_request) != 28); 643 644 if (nbds_max > MAX_NBD) { 645 printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD, 646 nbds_max); 647 return -EINVAL; 648 } 649 650 for (i = 0; i < nbds_max; i++) { 651 struct gendisk *disk = alloc_disk(1); 652 if (!disk) 653 goto out; 654 nbd_dev[i].disk = disk; 655 /* 656 * The new linux 2.5 block layer implementation requires 657 * every gendisk to have its very own request_queue struct. 658 * These structs are big so we dynamically allocate them. 659 */ 660 disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); 661 if (!disk->queue) { 662 put_disk(disk); 663 goto out; 664 } 665 } 666 667 if (register_blkdev(NBD_MAJOR, "nbd")) { 668 err = -EIO; 669 goto out; 670 } 671 672 printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); 673 dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); 674 675 devfs_mk_dir("nbd"); 676 for (i = 0; i < nbds_max; i++) { 677 struct gendisk *disk = nbd_dev[i].disk; 678 nbd_dev[i].file = NULL; 679 nbd_dev[i].magic = LO_MAGIC; 680 nbd_dev[i].flags = 0; 681 spin_lock_init(&nbd_dev[i].queue_lock); 682 INIT_LIST_HEAD(&nbd_dev[i].queue_head); 683 mutex_init(&nbd_dev[i].tx_lock); 684 init_waitqueue_head(&nbd_dev[i].active_wq); 685 nbd_dev[i].blksize = 1024; 686 nbd_dev[i].bytesize = 0x7ffffc00ULL << 10; /* 2TB */ 687 disk->major = NBD_MAJOR; 688 disk->first_minor = i; 689 disk->fops = &nbd_fops; 690 disk->private_data = &nbd_dev[i]; 691 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO; 692 sprintf(disk->disk_name, "nbd%d", i); 693 sprintf(disk->devfs_name, "nbd/%d", i); 694 set_capacity(disk, 0x7ffffc00ULL << 1); /* 2 TB */ 695 add_disk(disk); 696 } 697 698 return 0; 699 out: 700 while (i--) { 701 blk_cleanup_queue(nbd_dev[i].disk->queue); 702 put_disk(nbd_dev[i].disk); 703 } 704 return err; 705 } 706 707 static void __exit nbd_cleanup(void) 708 { 709 int i; 710 for (i = 0; i < nbds_max; i++) { 711 struct gendisk *disk = nbd_dev[i].disk; 712 nbd_dev[i].magic = 0; 713 if (disk) { 714 del_gendisk(disk); 715 blk_cleanup_queue(disk->queue); 716 put_disk(disk); 717 } 718 } 719 devfs_remove("nbd"); 720 unregister_blkdev(NBD_MAJOR, "nbd"); 721 printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); 722 } 723 724 module_init(nbd_init); 725 module_exit(nbd_cleanup); 726 727 MODULE_DESCRIPTION("Network Block Device"); 728 MODULE_LICENSE("GPL"); 729 730 module_param(nbds_max, int, 0444); 731 MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize."); 732 #ifndef NDEBUG 733 module_param(debugflags, int, 0644); 734 MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); 735 #endif 736