1 /* 2 * Copyright (C) 2007 Oracle. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 19 #include <linux/blkdev.h> 20 #include <linux/module.h> 21 #include <linux/buffer_head.h> 22 #include <linux/fs.h> 23 #include <linux/pagemap.h> 24 #include <linux/highmem.h> 25 #include <linux/time.h> 26 #include <linux/init.h> 27 #include <linux/seq_file.h> 28 #include <linux/string.h> 29 #include <linux/backing-dev.h> 30 #include <linux/mount.h> 31 #include <linux/mpage.h> 32 #include <linux/swap.h> 33 #include <linux/writeback.h> 34 #include <linux/statfs.h> 35 #include <linux/compat.h> 36 #include <linux/parser.h> 37 #include <linux/ctype.h> 38 #include <linux/namei.h> 39 #include <linux/miscdevice.h> 40 #include <linux/magic.h> 41 #include "compat.h" 42 #include "ctree.h" 43 #include "disk-io.h" 44 #include "transaction.h" 45 #include "btrfs_inode.h" 46 #include "ioctl.h" 47 #include "print-tree.h" 48 #include "xattr.h" 49 #include "volumes.h" 50 #include "version.h" 51 #include "export.h" 52 #include "compression.h" 53 54 static const struct super_operations btrfs_super_ops; 55 56 static void btrfs_put_super(struct super_block *sb) 57 { 58 struct btrfs_root *root = btrfs_sb(sb); 59 int ret; 60 61 ret = close_ctree(root); 62 sb->s_fs_info = NULL; 63 } 64 65 enum { 66 Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow, 67 Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, 68 Opt_ssd, Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, 69 Opt_compress, Opt_notreelog, Opt_ratio, Opt_flushoncommit, 70 Opt_discard, Opt_err, 71 }; 72 73 static match_table_t tokens = { 74 {Opt_degraded, "degraded"}, 75 {Opt_subvol, "subvol=%s"}, 76 {Opt_device, "device=%s"}, 77 {Opt_nodatasum, "nodatasum"}, 78 {Opt_nodatacow, "nodatacow"}, 79 {Opt_nobarrier, "nobarrier"}, 80 {Opt_max_extent, "max_extent=%s"}, 81 {Opt_max_inline, "max_inline=%s"}, 82 {Opt_alloc_start, "alloc_start=%s"}, 83 {Opt_thread_pool, "thread_pool=%d"}, 84 {Opt_compress, "compress"}, 85 {Opt_ssd, "ssd"}, 86 {Opt_ssd_spread, "ssd_spread"}, 87 {Opt_nossd, "nossd"}, 88 {Opt_noacl, "noacl"}, 89 {Opt_notreelog, "notreelog"}, 90 {Opt_flushoncommit, "flushoncommit"}, 91 {Opt_ratio, "metadata_ratio=%d"}, 92 {Opt_discard, "discard"}, 93 {Opt_err, NULL}, 94 }; 95 96 u64 btrfs_parse_size(char *str) 97 { 98 u64 res; 99 int mult = 1; 100 char *end; 101 char last; 102 103 res = simple_strtoul(str, &end, 10); 104 105 last = end[0]; 106 if (isalpha(last)) { 107 last = tolower(last); 108 switch (last) { 109 case 'g': 110 mult *= 1024; 111 case 'm': 112 mult *= 1024; 113 case 'k': 114 mult *= 1024; 115 } 116 res = res * mult; 117 } 118 return res; 119 } 120 121 /* 122 * Regular mount options parser. Everything that is needed only when 123 * reading in a new superblock is parsed here. 124 */ 125 int btrfs_parse_options(struct btrfs_root *root, char *options) 126 { 127 struct btrfs_fs_info *info = root->fs_info; 128 substring_t args[MAX_OPT_ARGS]; 129 char *p, *num; 130 int intarg; 131 int ret = 0; 132 133 if (!options) 134 return 0; 135 136 /* 137 * strsep changes the string, duplicate it because parse_options 138 * gets called twice 139 */ 140 options = kstrdup(options, GFP_NOFS); 141 if (!options) 142 return -ENOMEM; 143 144 145 while ((p = strsep(&options, ",")) != NULL) { 146 int token; 147 if (!*p) 148 continue; 149 150 token = match_token(p, tokens, args); 151 switch (token) { 152 case Opt_degraded: 153 printk(KERN_INFO "btrfs: allowing degraded mounts\n"); 154 btrfs_set_opt(info->mount_opt, DEGRADED); 155 break; 156 case Opt_subvol: 157 case Opt_device: 158 /* 159 * These are parsed by btrfs_parse_early_options 160 * and can be happily ignored here. 161 */ 162 break; 163 case Opt_nodatasum: 164 printk(KERN_INFO "btrfs: setting nodatasum\n"); 165 btrfs_set_opt(info->mount_opt, NODATASUM); 166 break; 167 case Opt_nodatacow: 168 printk(KERN_INFO "btrfs: setting nodatacow\n"); 169 btrfs_set_opt(info->mount_opt, NODATACOW); 170 btrfs_set_opt(info->mount_opt, NODATASUM); 171 break; 172 case Opt_compress: 173 printk(KERN_INFO "btrfs: use compression\n"); 174 btrfs_set_opt(info->mount_opt, COMPRESS); 175 break; 176 case Opt_ssd: 177 printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); 178 btrfs_set_opt(info->mount_opt, SSD); 179 break; 180 case Opt_ssd_spread: 181 printk(KERN_INFO "btrfs: use spread ssd " 182 "allocation scheme\n"); 183 btrfs_set_opt(info->mount_opt, SSD); 184 btrfs_set_opt(info->mount_opt, SSD_SPREAD); 185 break; 186 case Opt_nossd: 187 printk(KERN_INFO "btrfs: not using ssd allocation " 188 "scheme\n"); 189 btrfs_set_opt(info->mount_opt, NOSSD); 190 btrfs_clear_opt(info->mount_opt, SSD); 191 btrfs_clear_opt(info->mount_opt, SSD_SPREAD); 192 break; 193 case Opt_nobarrier: 194 printk(KERN_INFO "btrfs: turning off barriers\n"); 195 btrfs_set_opt(info->mount_opt, NOBARRIER); 196 break; 197 case Opt_thread_pool: 198 intarg = 0; 199 match_int(&args[0], &intarg); 200 if (intarg) { 201 info->thread_pool_size = intarg; 202 printk(KERN_INFO "btrfs: thread pool %d\n", 203 info->thread_pool_size); 204 } 205 break; 206 case Opt_max_extent: 207 num = match_strdup(&args[0]); 208 if (num) { 209 info->max_extent = btrfs_parse_size(num); 210 kfree(num); 211 212 info->max_extent = max_t(u64, 213 info->max_extent, root->sectorsize); 214 printk(KERN_INFO "btrfs: max_extent at %llu\n", 215 (unsigned long long)info->max_extent); 216 } 217 break; 218 case Opt_max_inline: 219 num = match_strdup(&args[0]); 220 if (num) { 221 info->max_inline = btrfs_parse_size(num); 222 kfree(num); 223 224 if (info->max_inline) { 225 info->max_inline = max_t(u64, 226 info->max_inline, 227 root->sectorsize); 228 } 229 printk(KERN_INFO "btrfs: max_inline at %llu\n", 230 (unsigned long long)info->max_inline); 231 } 232 break; 233 case Opt_alloc_start: 234 num = match_strdup(&args[0]); 235 if (num) { 236 info->alloc_start = btrfs_parse_size(num); 237 kfree(num); 238 printk(KERN_INFO 239 "btrfs: allocations start at %llu\n", 240 (unsigned long long)info->alloc_start); 241 } 242 break; 243 case Opt_noacl: 244 root->fs_info->sb->s_flags &= ~MS_POSIXACL; 245 break; 246 case Opt_notreelog: 247 printk(KERN_INFO "btrfs: disabling tree log\n"); 248 btrfs_set_opt(info->mount_opt, NOTREELOG); 249 break; 250 case Opt_flushoncommit: 251 printk(KERN_INFO "btrfs: turning on flush-on-commit\n"); 252 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT); 253 break; 254 case Opt_ratio: 255 intarg = 0; 256 match_int(&args[0], &intarg); 257 if (intarg) { 258 info->metadata_ratio = intarg; 259 printk(KERN_INFO "btrfs: metadata ratio %d\n", 260 info->metadata_ratio); 261 } 262 break; 263 case Opt_discard: 264 btrfs_set_opt(info->mount_opt, DISCARD); 265 break; 266 case Opt_err: 267 printk(KERN_INFO "btrfs: unrecognized mount option " 268 "'%s'\n", p); 269 ret = -EINVAL; 270 goto out; 271 default: 272 break; 273 } 274 } 275 out: 276 kfree(options); 277 return ret; 278 } 279 280 /* 281 * Parse mount options that are required early in the mount process. 282 * 283 * All other options will be parsed on much later in the mount process and 284 * only when we need to allocate a new super block. 285 */ 286 static int btrfs_parse_early_options(const char *options, fmode_t flags, 287 void *holder, char **subvol_name, 288 struct btrfs_fs_devices **fs_devices) 289 { 290 substring_t args[MAX_OPT_ARGS]; 291 char *opts, *p; 292 int error = 0; 293 294 if (!options) 295 goto out; 296 297 /* 298 * strsep changes the string, duplicate it because parse_options 299 * gets called twice 300 */ 301 opts = kstrdup(options, GFP_KERNEL); 302 if (!opts) 303 return -ENOMEM; 304 305 while ((p = strsep(&opts, ",")) != NULL) { 306 int token; 307 if (!*p) 308 continue; 309 310 token = match_token(p, tokens, args); 311 switch (token) { 312 case Opt_subvol: 313 *subvol_name = match_strdup(&args[0]); 314 break; 315 case Opt_device: 316 error = btrfs_scan_one_device(match_strdup(&args[0]), 317 flags, holder, fs_devices); 318 if (error) 319 goto out_free_opts; 320 break; 321 default: 322 break; 323 } 324 } 325 326 out_free_opts: 327 kfree(opts); 328 out: 329 /* 330 * If no subvolume name is specified we use the default one. Allocate 331 * a copy of the string "." here so that code later in the 332 * mount path doesn't care if it's the default volume or another one. 333 */ 334 if (!*subvol_name) { 335 *subvol_name = kstrdup(".", GFP_KERNEL); 336 if (!*subvol_name) 337 return -ENOMEM; 338 } 339 return error; 340 } 341 342 static int btrfs_fill_super(struct super_block *sb, 343 struct btrfs_fs_devices *fs_devices, 344 void *data, int silent) 345 { 346 struct inode *inode; 347 struct dentry *root_dentry; 348 struct btrfs_super_block *disk_super; 349 struct btrfs_root *tree_root; 350 struct btrfs_key key; 351 int err; 352 353 sb->s_maxbytes = MAX_LFS_FILESIZE; 354 sb->s_magic = BTRFS_SUPER_MAGIC; 355 sb->s_op = &btrfs_super_ops; 356 sb->s_export_op = &btrfs_export_ops; 357 sb->s_xattr = btrfs_xattr_handlers; 358 sb->s_time_gran = 1; 359 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 360 sb->s_flags |= MS_POSIXACL; 361 #endif 362 363 tree_root = open_ctree(sb, fs_devices, (char *)data); 364 365 if (IS_ERR(tree_root)) { 366 printk("btrfs: open_ctree failed\n"); 367 return PTR_ERR(tree_root); 368 } 369 sb->s_fs_info = tree_root; 370 disk_super = &tree_root->fs_info->super_copy; 371 372 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 373 key.type = BTRFS_INODE_ITEM_KEY; 374 key.offset = 0; 375 inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root); 376 if (IS_ERR(inode)) { 377 err = PTR_ERR(inode); 378 goto fail_close; 379 } 380 381 root_dentry = d_alloc_root(inode); 382 if (!root_dentry) { 383 iput(inode); 384 err = -ENOMEM; 385 goto fail_close; 386 } 387 #if 0 388 /* this does the super kobj at the same time */ 389 err = btrfs_sysfs_add_super(tree_root->fs_info); 390 if (err) 391 goto fail_close; 392 #endif 393 394 sb->s_root = root_dentry; 395 396 save_mount_options(sb, data); 397 return 0; 398 399 fail_close: 400 close_ctree(tree_root); 401 return err; 402 } 403 404 int btrfs_sync_fs(struct super_block *sb, int wait) 405 { 406 struct btrfs_trans_handle *trans; 407 struct btrfs_root *root = btrfs_sb(sb); 408 int ret; 409 410 if (!wait) { 411 filemap_flush(root->fs_info->btree_inode->i_mapping); 412 return 0; 413 } 414 415 btrfs_start_delalloc_inodes(root, 0); 416 btrfs_wait_ordered_extents(root, 0, 0); 417 418 trans = btrfs_start_transaction(root, 1); 419 ret = btrfs_commit_transaction(trans, root); 420 return ret; 421 } 422 423 static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) 424 { 425 struct btrfs_root *root = btrfs_sb(vfs->mnt_sb); 426 struct btrfs_fs_info *info = root->fs_info; 427 428 if (btrfs_test_opt(root, DEGRADED)) 429 seq_puts(seq, ",degraded"); 430 if (btrfs_test_opt(root, NODATASUM)) 431 seq_puts(seq, ",nodatasum"); 432 if (btrfs_test_opt(root, NODATACOW)) 433 seq_puts(seq, ",nodatacow"); 434 if (btrfs_test_opt(root, NOBARRIER)) 435 seq_puts(seq, ",nobarrier"); 436 if (info->max_extent != (u64)-1) 437 seq_printf(seq, ",max_extent=%llu", 438 (unsigned long long)info->max_extent); 439 if (info->max_inline != 8192 * 1024) 440 seq_printf(seq, ",max_inline=%llu", 441 (unsigned long long)info->max_inline); 442 if (info->alloc_start != 0) 443 seq_printf(seq, ",alloc_start=%llu", 444 (unsigned long long)info->alloc_start); 445 if (info->thread_pool_size != min_t(unsigned long, 446 num_online_cpus() + 2, 8)) 447 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 448 if (btrfs_test_opt(root, COMPRESS)) 449 seq_puts(seq, ",compress"); 450 if (btrfs_test_opt(root, NOSSD)) 451 seq_puts(seq, ",nossd"); 452 if (btrfs_test_opt(root, SSD_SPREAD)) 453 seq_puts(seq, ",ssd_spread"); 454 else if (btrfs_test_opt(root, SSD)) 455 seq_puts(seq, ",ssd"); 456 if (btrfs_test_opt(root, NOTREELOG)) 457 seq_puts(seq, ",notreelog"); 458 if (btrfs_test_opt(root, FLUSHONCOMMIT)) 459 seq_puts(seq, ",flushoncommit"); 460 if (btrfs_test_opt(root, DISCARD)) 461 seq_puts(seq, ",discard"); 462 if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) 463 seq_puts(seq, ",noacl"); 464 return 0; 465 } 466 467 static int btrfs_test_super(struct super_block *s, void *data) 468 { 469 struct btrfs_fs_devices *test_fs_devices = data; 470 struct btrfs_root *root = btrfs_sb(s); 471 472 return root->fs_info->fs_devices == test_fs_devices; 473 } 474 475 /* 476 * Find a superblock for the given device / mount point. 477 * 478 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 479 * for multiple device setup. Make sure to keep it in sync. 480 */ 481 static int btrfs_get_sb(struct file_system_type *fs_type, int flags, 482 const char *dev_name, void *data, struct vfsmount *mnt) 483 { 484 char *subvol_name = NULL; 485 struct block_device *bdev = NULL; 486 struct super_block *s; 487 struct dentry *root; 488 struct btrfs_fs_devices *fs_devices = NULL; 489 fmode_t mode = FMODE_READ; 490 int error = 0; 491 492 if (!(flags & MS_RDONLY)) 493 mode |= FMODE_WRITE; 494 495 error = btrfs_parse_early_options(data, mode, fs_type, 496 &subvol_name, &fs_devices); 497 if (error) 498 return error; 499 500 error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices); 501 if (error) 502 goto error_free_subvol_name; 503 504 error = btrfs_open_devices(fs_devices, mode, fs_type); 505 if (error) 506 goto error_free_subvol_name; 507 508 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 509 error = -EACCES; 510 goto error_close_devices; 511 } 512 513 bdev = fs_devices->latest_bdev; 514 s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices); 515 if (IS_ERR(s)) 516 goto error_s; 517 518 if (s->s_root) { 519 if ((flags ^ s->s_flags) & MS_RDONLY) { 520 deactivate_locked_super(s); 521 error = -EBUSY; 522 goto error_close_devices; 523 } 524 525 btrfs_close_devices(fs_devices); 526 } else { 527 char b[BDEVNAME_SIZE]; 528 529 s->s_flags = flags; 530 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); 531 error = btrfs_fill_super(s, fs_devices, data, 532 flags & MS_SILENT ? 1 : 0); 533 if (error) { 534 deactivate_locked_super(s); 535 goto error_free_subvol_name; 536 } 537 538 btrfs_sb(s)->fs_info->bdev_holder = fs_type; 539 s->s_flags |= MS_ACTIVE; 540 } 541 542 if (!strcmp(subvol_name, ".")) 543 root = dget(s->s_root); 544 else { 545 mutex_lock(&s->s_root->d_inode->i_mutex); 546 root = lookup_one_len(subvol_name, s->s_root, 547 strlen(subvol_name)); 548 mutex_unlock(&s->s_root->d_inode->i_mutex); 549 550 if (IS_ERR(root)) { 551 deactivate_locked_super(s); 552 error = PTR_ERR(root); 553 goto error_free_subvol_name; 554 } 555 if (!root->d_inode) { 556 dput(root); 557 deactivate_locked_super(s); 558 error = -ENXIO; 559 goto error_free_subvol_name; 560 } 561 } 562 563 mnt->mnt_sb = s; 564 mnt->mnt_root = root; 565 566 kfree(subvol_name); 567 return 0; 568 569 error_s: 570 error = PTR_ERR(s); 571 error_close_devices: 572 btrfs_close_devices(fs_devices); 573 error_free_subvol_name: 574 kfree(subvol_name); 575 return error; 576 } 577 578 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 579 { 580 struct btrfs_root *root = btrfs_sb(sb); 581 int ret; 582 583 ret = btrfs_parse_options(root, data); 584 if (ret) 585 return -EINVAL; 586 587 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 588 return 0; 589 590 if (*flags & MS_RDONLY) { 591 sb->s_flags |= MS_RDONLY; 592 593 ret = btrfs_commit_super(root); 594 WARN_ON(ret); 595 } else { 596 if (root->fs_info->fs_devices->rw_devices == 0) 597 return -EACCES; 598 599 if (btrfs_super_log_root(&root->fs_info->super_copy) != 0) 600 return -EINVAL; 601 602 /* recover relocation */ 603 ret = btrfs_recover_relocation(root); 604 WARN_ON(ret); 605 606 ret = btrfs_cleanup_fs_roots(root->fs_info); 607 WARN_ON(ret); 608 609 sb->s_flags &= ~MS_RDONLY; 610 } 611 612 return 0; 613 } 614 615 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 616 { 617 struct btrfs_root *root = btrfs_sb(dentry->d_sb); 618 struct btrfs_super_block *disk_super = &root->fs_info->super_copy; 619 int bits = dentry->d_sb->s_blocksize_bits; 620 __be32 *fsid = (__be32 *)root->fs_info->fsid; 621 622 buf->f_namelen = BTRFS_NAME_LEN; 623 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; 624 buf->f_bfree = buf->f_blocks - 625 (btrfs_super_bytes_used(disk_super) >> bits); 626 buf->f_bavail = buf->f_bfree; 627 buf->f_bsize = dentry->d_sb->s_blocksize; 628 buf->f_type = BTRFS_SUPER_MAGIC; 629 630 /* We treat it as constant endianness (it doesn't matter _which_) 631 because we want the fsid to come out the same whether mounted 632 on a big-endian or little-endian host */ 633 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 634 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 635 /* Mask in the root object ID too, to disambiguate subvols */ 636 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; 637 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; 638 639 return 0; 640 } 641 642 static struct file_system_type btrfs_fs_type = { 643 .owner = THIS_MODULE, 644 .name = "btrfs", 645 .get_sb = btrfs_get_sb, 646 .kill_sb = kill_anon_super, 647 .fs_flags = FS_REQUIRES_DEV, 648 }; 649 650 /* 651 * used by btrfsctl to scan devices when no FS is mounted 652 */ 653 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 654 unsigned long arg) 655 { 656 struct btrfs_ioctl_vol_args *vol; 657 struct btrfs_fs_devices *fs_devices; 658 int ret = -ENOTTY; 659 660 if (!capable(CAP_SYS_ADMIN)) 661 return -EPERM; 662 663 vol = memdup_user((void __user *)arg, sizeof(*vol)); 664 if (IS_ERR(vol)) 665 return PTR_ERR(vol); 666 667 switch (cmd) { 668 case BTRFS_IOC_SCAN_DEV: 669 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 670 &btrfs_fs_type, &fs_devices); 671 break; 672 } 673 674 kfree(vol); 675 return ret; 676 } 677 678 static int btrfs_freeze(struct super_block *sb) 679 { 680 struct btrfs_root *root = btrfs_sb(sb); 681 mutex_lock(&root->fs_info->transaction_kthread_mutex); 682 mutex_lock(&root->fs_info->cleaner_mutex); 683 return 0; 684 } 685 686 static int btrfs_unfreeze(struct super_block *sb) 687 { 688 struct btrfs_root *root = btrfs_sb(sb); 689 mutex_unlock(&root->fs_info->cleaner_mutex); 690 mutex_unlock(&root->fs_info->transaction_kthread_mutex); 691 return 0; 692 } 693 694 static const struct super_operations btrfs_super_ops = { 695 .drop_inode = btrfs_drop_inode, 696 .delete_inode = btrfs_delete_inode, 697 .put_super = btrfs_put_super, 698 .sync_fs = btrfs_sync_fs, 699 .show_options = btrfs_show_options, 700 .write_inode = btrfs_write_inode, 701 .dirty_inode = btrfs_dirty_inode, 702 .alloc_inode = btrfs_alloc_inode, 703 .destroy_inode = btrfs_destroy_inode, 704 .statfs = btrfs_statfs, 705 .remount_fs = btrfs_remount, 706 .freeze_fs = btrfs_freeze, 707 .unfreeze_fs = btrfs_unfreeze, 708 }; 709 710 static const struct file_operations btrfs_ctl_fops = { 711 .unlocked_ioctl = btrfs_control_ioctl, 712 .compat_ioctl = btrfs_control_ioctl, 713 .owner = THIS_MODULE, 714 }; 715 716 static struct miscdevice btrfs_misc = { 717 .minor = MISC_DYNAMIC_MINOR, 718 .name = "btrfs-control", 719 .fops = &btrfs_ctl_fops 720 }; 721 722 static int btrfs_interface_init(void) 723 { 724 return misc_register(&btrfs_misc); 725 } 726 727 static void btrfs_interface_exit(void) 728 { 729 if (misc_deregister(&btrfs_misc) < 0) 730 printk(KERN_INFO "misc_deregister failed for control device"); 731 } 732 733 static int __init init_btrfs_fs(void) 734 { 735 int err; 736 737 err = btrfs_init_sysfs(); 738 if (err) 739 return err; 740 741 err = btrfs_init_cachep(); 742 if (err) 743 goto free_sysfs; 744 745 err = extent_io_init(); 746 if (err) 747 goto free_cachep; 748 749 err = extent_map_init(); 750 if (err) 751 goto free_extent_io; 752 753 err = btrfs_interface_init(); 754 if (err) 755 goto free_extent_map; 756 757 err = register_filesystem(&btrfs_fs_type); 758 if (err) 759 goto unregister_ioctl; 760 761 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); 762 return 0; 763 764 unregister_ioctl: 765 btrfs_interface_exit(); 766 free_extent_map: 767 extent_map_exit(); 768 free_extent_io: 769 extent_io_exit(); 770 free_cachep: 771 btrfs_destroy_cachep(); 772 free_sysfs: 773 btrfs_exit_sysfs(); 774 return err; 775 } 776 777 static void __exit exit_btrfs_fs(void) 778 { 779 btrfs_destroy_cachep(); 780 extent_map_exit(); 781 extent_io_exit(); 782 btrfs_interface_exit(); 783 unregister_filesystem(&btrfs_fs_type); 784 btrfs_exit_sysfs(); 785 btrfs_cleanup_fs_uuids(); 786 btrfs_zlib_exit(); 787 } 788 789 module_init(init_btrfs_fs) 790 module_exit(exit_btrfs_fs) 791 792 MODULE_LICENSE("GPL"); 793