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 <net/sock.h> 58 59 #include <linux/devfs_fs_kernel.h> 60 61 #include <asm/uaccess.h> 62 #include <asm/types.h> 63 64 #include <linux/nbd.h> 65 66 #define LO_MAGIC 0x68797548 67 68 #ifdef NDEBUG 69 #define dprintk(flags, fmt...) 70 #else /* NDEBUG */ 71 #define dprintk(flags, fmt...) do { \ 72 if (debugflags & (flags)) printk(KERN_DEBUG fmt); \ 73 } while (0) 74 #define DBG_IOCTL 0x0004 75 #define DBG_INIT 0x0010 76 #define DBG_EXIT 0x0020 77 #define DBG_BLKDEV 0x0100 78 #define DBG_RX 0x0200 79 #define DBG_TX 0x0400 80 static unsigned int debugflags; 81 static unsigned int nbds_max = 16; 82 #endif /* NDEBUG */ 83 84 static struct nbd_device nbd_dev[MAX_NBD]; 85 86 /* 87 * Use just one lock (or at most 1 per NIC). Two arguments for this: 88 * 1. Each NIC is essentially a synchronization point for all servers 89 * accessed through that NIC so there's no need to have more locks 90 * than NICs anyway. 91 * 2. More locks lead to more "Dirty cache line bouncing" which will slow 92 * down each lock to the point where they're actually slower than just 93 * a single lock. 94 * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! 95 */ 96 static DEFINE_SPINLOCK(nbd_lock); 97 98 #ifndef NDEBUG 99 static const char *ioctl_cmd_to_ascii(int cmd) 100 { 101 switch (cmd) { 102 case NBD_SET_SOCK: return "set-sock"; 103 case NBD_SET_BLKSIZE: return "set-blksize"; 104 case NBD_SET_SIZE: return "set-size"; 105 case NBD_DO_IT: return "do-it"; 106 case NBD_CLEAR_SOCK: return "clear-sock"; 107 case NBD_CLEAR_QUE: return "clear-que"; 108 case NBD_PRINT_DEBUG: return "print-debug"; 109 case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; 110 case NBD_DISCONNECT: return "disconnect"; 111 case BLKROSET: return "set-read-only"; 112 case BLKFLSBUF: return "flush-buffer-cache"; 113 } 114 return "unknown"; 115 } 116 117 static const char *nbdcmd_to_ascii(int cmd) 118 { 119 switch (cmd) { 120 case NBD_CMD_READ: return "read"; 121 case NBD_CMD_WRITE: return "write"; 122 case NBD_CMD_DISC: return "disconnect"; 123 } 124 return "invalid"; 125 } 126 #endif /* NDEBUG */ 127 128 static void nbd_end_request(struct request *req) 129 { 130 int uptodate = (req->errors == 0) ? 1 : 0; 131 request_queue_t *q = req->q; 132 unsigned long flags; 133 134 dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, 135 req, uptodate? "done": "failed"); 136 137 spin_lock_irqsave(q->queue_lock, flags); 138 if (!end_that_request_first(req, uptodate, req->nr_sectors)) { 139 end_that_request_last(req); 140 } 141 spin_unlock_irqrestore(q->queue_lock, flags); 142 } 143 144 /* 145 * Send or receive packet. 146 */ 147 static int sock_xmit(struct socket *sock, int send, void *buf, int size, 148 int msg_flags) 149 { 150 int result; 151 struct msghdr msg; 152 struct kvec iov; 153 unsigned long flags; 154 sigset_t oldset; 155 156 /* Allow interception of SIGKILL only 157 * Don't allow other signals to interrupt the transmission */ 158 spin_lock_irqsave(¤t->sighand->siglock, flags); 159 oldset = current->blocked; 160 sigfillset(¤t->blocked); 161 sigdelsetmask(¤t->blocked, sigmask(SIGKILL)); 162 recalc_sigpending(); 163 spin_unlock_irqrestore(¤t->sighand->siglock, flags); 164 165 do { 166 sock->sk->sk_allocation = GFP_NOIO; 167 iov.iov_base = buf; 168 iov.iov_len = size; 169 msg.msg_name = NULL; 170 msg.msg_namelen = 0; 171 msg.msg_control = NULL; 172 msg.msg_controllen = 0; 173 msg.msg_namelen = 0; 174 msg.msg_flags = msg_flags | MSG_NOSIGNAL; 175 176 if (send) 177 result = kernel_sendmsg(sock, &msg, &iov, 1, size); 178 else 179 result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); 180 181 if (signal_pending(current)) { 182 siginfo_t info; 183 spin_lock_irqsave(¤t->sighand->siglock, flags); 184 printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", 185 current->pid, current->comm, 186 dequeue_signal(current, ¤t->blocked, &info)); 187 spin_unlock_irqrestore(¤t->sighand->siglock, flags); 188 result = -EINTR; 189 break; 190 } 191 192 if (result <= 0) { 193 if (result == 0) 194 result = -EPIPE; /* short read */ 195 break; 196 } 197 size -= result; 198 buf += result; 199 } while (size > 0); 200 201 spin_lock_irqsave(¤t->sighand->siglock, flags); 202 current->blocked = oldset; 203 recalc_sigpending(); 204 spin_unlock_irqrestore(¤t->sighand->siglock, flags); 205 206 return result; 207 } 208 209 static inline int sock_send_bvec(struct socket *sock, struct bio_vec *bvec, 210 int flags) 211 { 212 int result; 213 void *kaddr = kmap(bvec->bv_page); 214 result = sock_xmit(sock, 1, kaddr + bvec->bv_offset, bvec->bv_len, 215 flags); 216 kunmap(bvec->bv_page); 217 return result; 218 } 219 220 static int nbd_send_req(struct nbd_device *lo, struct request *req) 221 { 222 int result, i, flags; 223 struct nbd_request request; 224 unsigned long size = req->nr_sectors << 9; 225 struct socket *sock = lo->sock; 226 227 request.magic = htonl(NBD_REQUEST_MAGIC); 228 request.type = htonl(nbd_cmd(req)); 229 request.from = cpu_to_be64((u64) req->sector << 9); 230 request.len = htonl(size); 231 memcpy(request.handle, &req, sizeof(req)); 232 233 down(&lo->tx_lock); 234 235 if (!sock || !lo->sock) { 236 printk(KERN_ERR "%s: Attempted send on closed socket\n", 237 lo->disk->disk_name); 238 goto error_out; 239 } 240 241 dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", 242 lo->disk->disk_name, req, 243 nbdcmd_to_ascii(nbd_cmd(req)), 244 (unsigned long long)req->sector << 9, 245 req->nr_sectors << 9); 246 result = sock_xmit(sock, 1, &request, sizeof(request), 247 (nbd_cmd(req) == NBD_CMD_WRITE)? MSG_MORE: 0); 248 if (result <= 0) { 249 printk(KERN_ERR "%s: Send control failed (result %d)\n", 250 lo->disk->disk_name, result); 251 goto error_out; 252 } 253 254 if (nbd_cmd(req) == NBD_CMD_WRITE) { 255 struct bio *bio; 256 /* 257 * we are really probing at internals to determine 258 * whether to set MSG_MORE or not... 259 */ 260 rq_for_each_bio(bio, req) { 261 struct bio_vec *bvec; 262 bio_for_each_segment(bvec, bio, i) { 263 flags = 0; 264 if ((i < (bio->bi_vcnt - 1)) || bio->bi_next) 265 flags = MSG_MORE; 266 dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", 267 lo->disk->disk_name, req, 268 bvec->bv_len); 269 result = sock_send_bvec(sock, bvec, flags); 270 if (result <= 0) { 271 printk(KERN_ERR "%s: Send data failed (result %d)\n", 272 lo->disk->disk_name, 273 result); 274 goto error_out; 275 } 276 } 277 } 278 } 279 up(&lo->tx_lock); 280 return 0; 281 282 error_out: 283 up(&lo->tx_lock); 284 return 1; 285 } 286 287 static struct request *nbd_find_request(struct nbd_device *lo, char *handle) 288 { 289 struct request *req; 290 struct list_head *tmp; 291 struct request *xreq; 292 293 memcpy(&xreq, handle, sizeof(xreq)); 294 295 spin_lock(&lo->queue_lock); 296 list_for_each(tmp, &lo->queue_head) { 297 req = list_entry(tmp, struct request, queuelist); 298 if (req != xreq) 299 continue; 300 list_del_init(&req->queuelist); 301 spin_unlock(&lo->queue_lock); 302 return req; 303 } 304 spin_unlock(&lo->queue_lock); 305 return NULL; 306 } 307 308 static inline int sock_recv_bvec(struct socket *sock, struct bio_vec *bvec) 309 { 310 int result; 311 void *kaddr = kmap(bvec->bv_page); 312 result = sock_xmit(sock, 0, kaddr + bvec->bv_offset, bvec->bv_len, 313 MSG_WAITALL); 314 kunmap(bvec->bv_page); 315 return result; 316 } 317 318 /* NULL returned = something went wrong, inform userspace */ 319 static struct request *nbd_read_stat(struct nbd_device *lo) 320 { 321 int result; 322 struct nbd_reply reply; 323 struct request *req; 324 struct socket *sock = lo->sock; 325 326 reply.magic = 0; 327 result = sock_xmit(sock, 0, &reply, sizeof(reply), MSG_WAITALL); 328 if (result <= 0) { 329 printk(KERN_ERR "%s: Receive control failed (result %d)\n", 330 lo->disk->disk_name, result); 331 goto harderror; 332 } 333 req = nbd_find_request(lo, reply.handle); 334 if (req == NULL) { 335 printk(KERN_ERR "%s: Unexpected reply (%p)\n", 336 lo->disk->disk_name, reply.handle); 337 result = -EBADR; 338 goto harderror; 339 } 340 341 if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { 342 printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", 343 lo->disk->disk_name, 344 (unsigned long)ntohl(reply.magic)); 345 result = -EPROTO; 346 goto harderror; 347 } 348 if (ntohl(reply.error)) { 349 printk(KERN_ERR "%s: Other side returned error (%d)\n", 350 lo->disk->disk_name, ntohl(reply.error)); 351 req->errors++; 352 return req; 353 } 354 355 dprintk(DBG_RX, "%s: request %p: got reply\n", 356 lo->disk->disk_name, req); 357 if (nbd_cmd(req) == NBD_CMD_READ) { 358 int i; 359 struct bio *bio; 360 rq_for_each_bio(bio, req) { 361 struct bio_vec *bvec; 362 bio_for_each_segment(bvec, bio, i) { 363 result = sock_recv_bvec(sock, bvec); 364 if (result <= 0) { 365 printk(KERN_ERR "%s: Receive data failed (result %d)\n", 366 lo->disk->disk_name, 367 result); 368 goto harderror; 369 } 370 dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", 371 lo->disk->disk_name, req, bvec->bv_len); 372 } 373 } 374 } 375 return req; 376 harderror: 377 lo->harderror = result; 378 return NULL; 379 } 380 381 static void nbd_do_it(struct nbd_device *lo) 382 { 383 struct request *req; 384 385 BUG_ON(lo->magic != LO_MAGIC); 386 387 while ((req = nbd_read_stat(lo)) != NULL) 388 nbd_end_request(req); 389 return; 390 } 391 392 static void nbd_clear_que(struct nbd_device *lo) 393 { 394 struct request *req; 395 396 BUG_ON(lo->magic != LO_MAGIC); 397 398 do { 399 req = NULL; 400 spin_lock(&lo->queue_lock); 401 if (!list_empty(&lo->queue_head)) { 402 req = list_entry(lo->queue_head.next, struct request, queuelist); 403 list_del_init(&req->queuelist); 404 } 405 spin_unlock(&lo->queue_lock); 406 if (req) { 407 req->errors++; 408 nbd_end_request(req); 409 } 410 } while (req); 411 } 412 413 /* 414 * We always wait for result of write, for now. It would be nice to make it optional 415 * in future 416 * if ((req->cmd == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) 417 * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } 418 */ 419 420 static void do_nbd_request(request_queue_t * q) 421 { 422 struct request *req; 423 424 while ((req = elv_next_request(q)) != NULL) { 425 struct nbd_device *lo; 426 427 blkdev_dequeue_request(req); 428 dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%lx)\n", 429 req->rq_disk->disk_name, req, req->flags); 430 431 if (!(req->flags & REQ_CMD)) 432 goto error_out; 433 434 lo = req->rq_disk->private_data; 435 436 BUG_ON(lo->magic != LO_MAGIC); 437 438 if (!lo->file) { 439 printk(KERN_ERR "%s: Request when not-ready\n", 440 lo->disk->disk_name); 441 goto error_out; 442 } 443 nbd_cmd(req) = NBD_CMD_READ; 444 if (rq_data_dir(req) == WRITE) { 445 nbd_cmd(req) = NBD_CMD_WRITE; 446 if (lo->flags & NBD_READ_ONLY) { 447 printk(KERN_ERR "%s: Write on read-only\n", 448 lo->disk->disk_name); 449 goto error_out; 450 } 451 } 452 453 req->errors = 0; 454 spin_unlock_irq(q->queue_lock); 455 456 spin_lock(&lo->queue_lock); 457 458 if (!lo->file) { 459 spin_unlock(&lo->queue_lock); 460 printk(KERN_ERR "%s: failed between accept and semaphore, file lost\n", 461 lo->disk->disk_name); 462 req->errors++; 463 nbd_end_request(req); 464 spin_lock_irq(q->queue_lock); 465 continue; 466 } 467 468 list_add(&req->queuelist, &lo->queue_head); 469 spin_unlock(&lo->queue_lock); 470 471 if (nbd_send_req(lo, req) != 0) { 472 printk(KERN_ERR "%s: Request send failed\n", 473 lo->disk->disk_name); 474 if (nbd_find_request(lo, (char *)&req) != NULL) { 475 /* we still own req */ 476 req->errors++; 477 nbd_end_request(req); 478 } else /* we're racing with nbd_clear_que */ 479 printk(KERN_DEBUG "nbd: can't find req\n"); 480 } 481 482 spin_lock_irq(q->queue_lock); 483 continue; 484 485 error_out: 486 req->errors++; 487 spin_unlock(q->queue_lock); 488 nbd_end_request(req); 489 spin_lock(q->queue_lock); 490 } 491 return; 492 } 493 494 static int nbd_ioctl(struct inode *inode, struct file *file, 495 unsigned int cmd, unsigned long arg) 496 { 497 struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; 498 int error; 499 struct request sreq ; 500 501 if (!capable(CAP_SYS_ADMIN)) 502 return -EPERM; 503 504 BUG_ON(lo->magic != LO_MAGIC); 505 506 /* Anyone capable of this syscall can do *real bad* things */ 507 dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", 508 lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); 509 510 switch (cmd) { 511 case NBD_DISCONNECT: 512 printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name); 513 sreq.flags = REQ_SPECIAL; 514 nbd_cmd(&sreq) = NBD_CMD_DISC; 515 /* 516 * Set these to sane values in case server implementation 517 * fails to check the request type first and also to keep 518 * debugging output cleaner. 519 */ 520 sreq.sector = 0; 521 sreq.nr_sectors = 0; 522 if (!lo->sock) 523 return -EINVAL; 524 nbd_send_req(lo, &sreq); 525 return 0; 526 527 case NBD_CLEAR_SOCK: 528 error = 0; 529 down(&lo->tx_lock); 530 lo->sock = NULL; 531 up(&lo->tx_lock); 532 spin_lock(&lo->queue_lock); 533 file = lo->file; 534 lo->file = NULL; 535 spin_unlock(&lo->queue_lock); 536 nbd_clear_que(lo); 537 spin_lock(&lo->queue_lock); 538 if (!list_empty(&lo->queue_head)) { 539 printk(KERN_ERR "nbd: disconnect: some requests are in progress -> please try again.\n"); 540 error = -EBUSY; 541 } 542 spin_unlock(&lo->queue_lock); 543 if (file) 544 fput(file); 545 return error; 546 case NBD_SET_SOCK: 547 if (lo->file) 548 return -EBUSY; 549 error = -EINVAL; 550 file = fget(arg); 551 if (file) { 552 inode = file->f_dentry->d_inode; 553 if (S_ISSOCK(inode->i_mode)) { 554 lo->file = file; 555 lo->sock = SOCKET_I(inode); 556 error = 0; 557 } else { 558 fput(file); 559 } 560 } 561 return error; 562 case NBD_SET_BLKSIZE: 563 lo->blksize = arg; 564 lo->bytesize &= ~(lo->blksize-1); 565 inode->i_bdev->bd_inode->i_size = lo->bytesize; 566 set_blocksize(inode->i_bdev, lo->blksize); 567 set_capacity(lo->disk, lo->bytesize >> 9); 568 return 0; 569 case NBD_SET_SIZE: 570 lo->bytesize = arg & ~(lo->blksize-1); 571 inode->i_bdev->bd_inode->i_size = lo->bytesize; 572 set_blocksize(inode->i_bdev, lo->blksize); 573 set_capacity(lo->disk, lo->bytesize >> 9); 574 return 0; 575 case NBD_SET_SIZE_BLOCKS: 576 lo->bytesize = ((u64) arg) * lo->blksize; 577 inode->i_bdev->bd_inode->i_size = lo->bytesize; 578 set_blocksize(inode->i_bdev, lo->blksize); 579 set_capacity(lo->disk, lo->bytesize >> 9); 580 return 0; 581 case NBD_DO_IT: 582 if (!lo->file) 583 return -EINVAL; 584 nbd_do_it(lo); 585 /* on return tidy up in case we have a signal */ 586 /* Forcibly shutdown the socket causing all listeners 587 * to error 588 * 589 * FIXME: This code is duplicated from sys_shutdown, but 590 * there should be a more generic interface rather than 591 * calling socket ops directly here */ 592 down(&lo->tx_lock); 593 if (lo->sock) { 594 printk(KERN_WARNING "%s: shutting down socket\n", 595 lo->disk->disk_name); 596 lo->sock->ops->shutdown(lo->sock, 597 SEND_SHUTDOWN|RCV_SHUTDOWN); 598 lo->sock = NULL; 599 } 600 up(&lo->tx_lock); 601 spin_lock(&lo->queue_lock); 602 file = lo->file; 603 lo->file = NULL; 604 spin_unlock(&lo->queue_lock); 605 nbd_clear_que(lo); 606 printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); 607 if (file) 608 fput(file); 609 return lo->harderror; 610 case NBD_CLEAR_QUE: 611 down(&lo->tx_lock); 612 if (lo->sock) { 613 up(&lo->tx_lock); 614 return 0; /* probably should be error, but that would 615 * break "nbd-client -d", so just return 0 */ 616 } 617 up(&lo->tx_lock); 618 nbd_clear_que(lo); 619 return 0; 620 case NBD_PRINT_DEBUG: 621 printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n", 622 inode->i_bdev->bd_disk->disk_name, 623 lo->queue_head.next, lo->queue_head.prev, 624 &lo->queue_head); 625 return 0; 626 } 627 return -EINVAL; 628 } 629 630 static struct block_device_operations nbd_fops = 631 { 632 .owner = THIS_MODULE, 633 .ioctl = nbd_ioctl, 634 }; 635 636 /* 637 * And here should be modules and kernel interface 638 * (Just smiley confuses emacs :-) 639 */ 640 641 static int __init nbd_init(void) 642 { 643 int err = -ENOMEM; 644 int i; 645 646 if (sizeof(struct nbd_request) != 28) { 647 printk(KERN_CRIT "nbd: sizeof nbd_request needs to be 28 in order to work!\n" ); 648 return -EIO; 649 } 650 651 if (nbds_max > MAX_NBD) { 652 printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD, 653 nbds_max); 654 return -EINVAL; 655 } 656 657 for (i = 0; i < nbds_max; i++) { 658 struct gendisk *disk = alloc_disk(1); 659 if (!disk) 660 goto out; 661 nbd_dev[i].disk = disk; 662 /* 663 * The new linux 2.5 block layer implementation requires 664 * every gendisk to have its very own request_queue struct. 665 * These structs are big so we dynamically allocate them. 666 */ 667 disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); 668 if (!disk->queue) { 669 put_disk(disk); 670 goto out; 671 } 672 } 673 674 if (register_blkdev(NBD_MAJOR, "nbd")) { 675 err = -EIO; 676 goto out; 677 } 678 679 printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); 680 dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); 681 682 devfs_mk_dir("nbd"); 683 for (i = 0; i < nbds_max; i++) { 684 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); 690 init_MUTEX(&nbd_dev[i].tx_lock); 691 nbd_dev[i].blksize = 1024; 692 nbd_dev[i].bytesize = 0x7ffffc00ULL << 10; /* 2TB */ 693 disk->major = NBD_MAJOR; 694 disk->first_minor = i; 695 disk->fops = &nbd_fops; 696 disk->private_data = &nbd_dev[i]; 697 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO; 698 sprintf(disk->disk_name, "nbd%d", i); 699 sprintf(disk->devfs_name, "nbd/%d", i); 700 set_capacity(disk, 0x7ffffc00ULL << 1); /* 2 TB */ 701 add_disk(disk); 702 } 703 704 return 0; 705 out: 706 while (i--) { 707 blk_cleanup_queue(nbd_dev[i].disk->queue); 708 put_disk(nbd_dev[i].disk); 709 } 710 return err; 711 } 712 713 static void __exit nbd_cleanup(void) 714 { 715 int i; 716 for (i = 0; i < nbds_max; i++) { 717 struct gendisk *disk = nbd_dev[i].disk; 718 nbd_dev[i].magic = 0; 719 if (disk) { 720 del_gendisk(disk); 721 blk_cleanup_queue(disk->queue); 722 put_disk(disk); 723 } 724 } 725 devfs_remove("nbd"); 726 unregister_blkdev(NBD_MAJOR, "nbd"); 727 printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); 728 } 729 730 module_init(nbd_init); 731 module_exit(nbd_cleanup); 732 733 MODULE_DESCRIPTION("Network Block Device"); 734 MODULE_LICENSE("GPL"); 735 736 module_param(nbds_max, int, 0444); 737 MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize."); 738 #ifndef NDEBUG 739 module_param(debugflags, int, 0644); 740 MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); 741 #endif 742