| 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/string.h> |
| 28 | #include <linux/smp_lock.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/version.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 | #define BTRFS_SUPER_MAGIC 0x9123683E |
| 55 | |
| 56 | static struct super_operations btrfs_super_ops; |
| 57 | |
| 58 | static void btrfs_put_super(struct super_block *sb) |
| 59 | { |
| 60 | struct btrfs_root *root = btrfs_sb(sb); |
| 61 | int ret; |
| 62 | |
| 63 | ret = close_ctree(root); |
| 64 | sb->s_fs_info = NULL; |
| 65 | } |
| 66 | |
| 67 | enum { |
| 68 | Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow, |
| 69 | Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, |
| 70 | Opt_ssd, Opt_thread_pool, Opt_noacl, Opt_compress, 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_noacl, "noacl"}, |
| 87 | {Opt_err, NULL}, |
| 88 | }; |
| 89 | |
| 90 | u64 btrfs_parse_size(char *str) |
| 91 | { |
| 92 | u64 res; |
| 93 | int mult = 1; |
| 94 | char *end; |
| 95 | char last; |
| 96 | |
| 97 | res = simple_strtoul(str, &end, 10); |
| 98 | |
| 99 | last = end[0]; |
| 100 | if (isalpha(last)) { |
| 101 | last = tolower(last); |
| 102 | switch (last) { |
| 103 | case 'g': |
| 104 | mult *= 1024; |
| 105 | case 'm': |
| 106 | mult *= 1024; |
| 107 | case 'k': |
| 108 | mult *= 1024; |
| 109 | } |
| 110 | res = res * mult; |
| 111 | } |
| 112 | return res; |
| 113 | } |
| 114 | |
| 115 | /* |
| 116 | * Regular mount options parser. Everything that is needed only when |
| 117 | * reading in a new superblock is parsed here. |
| 118 | */ |
| 119 | int btrfs_parse_options(struct btrfs_root *root, char *options) |
| 120 | { |
| 121 | struct btrfs_fs_info *info = root->fs_info; |
| 122 | substring_t args[MAX_OPT_ARGS]; |
| 123 | char *p, *num; |
| 124 | int intarg; |
| 125 | |
| 126 | if (!options) |
| 127 | return 0; |
| 128 | |
| 129 | /* |
| 130 | * strsep changes the string, duplicate it because parse_options |
| 131 | * gets called twice |
| 132 | */ |
| 133 | options = kstrdup(options, GFP_NOFS); |
| 134 | if (!options) |
| 135 | return -ENOMEM; |
| 136 | |
| 137 | |
| 138 | while ((p = strsep(&options, ",")) != NULL) { |
| 139 | int token; |
| 140 | if (!*p) |
| 141 | continue; |
| 142 | |
| 143 | token = match_token(p, tokens, args); |
| 144 | switch (token) { |
| 145 | case Opt_degraded: |
| 146 | printk(KERN_INFO "btrfs: allowing degraded mounts\n"); |
| 147 | btrfs_set_opt(info->mount_opt, DEGRADED); |
| 148 | break; |
| 149 | case Opt_subvol: |
| 150 | case Opt_device: |
| 151 | /* |
| 152 | * These are parsed by btrfs_parse_early_options |
| 153 | * and can be happily ignored here. |
| 154 | */ |
| 155 | break; |
| 156 | case Opt_nodatasum: |
| 157 | printk(KERN_INFO "btrfs: setting nodatacsum\n"); |
| 158 | btrfs_set_opt(info->mount_opt, NODATASUM); |
| 159 | break; |
| 160 | case Opt_nodatacow: |
| 161 | printk(KERN_INFO "btrfs: setting nodatacow\n"); |
| 162 | btrfs_set_opt(info->mount_opt, NODATACOW); |
| 163 | btrfs_set_opt(info->mount_opt, NODATASUM); |
| 164 | break; |
| 165 | case Opt_compress: |
| 166 | printk(KERN_INFO "btrfs: use compression\n"); |
| 167 | btrfs_set_opt(info->mount_opt, COMPRESS); |
| 168 | break; |
| 169 | case Opt_ssd: |
| 170 | printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); |
| 171 | btrfs_set_opt(info->mount_opt, SSD); |
| 172 | break; |
| 173 | case Opt_nobarrier: |
| 174 | printk(KERN_INFO "btrfs: turning off barriers\n"); |
| 175 | btrfs_set_opt(info->mount_opt, NOBARRIER); |
| 176 | break; |
| 177 | case Opt_thread_pool: |
| 178 | intarg = 0; |
| 179 | match_int(&args[0], &intarg); |
| 180 | if (intarg) { |
| 181 | info->thread_pool_size = intarg; |
| 182 | printk(KERN_INFO "btrfs: thread pool %d\n", |
| 183 | info->thread_pool_size); |
| 184 | } |
| 185 | break; |
| 186 | case Opt_max_extent: |
| 187 | num = match_strdup(&args[0]); |
| 188 | if (num) { |
| 189 | info->max_extent = btrfs_parse_size(num); |
| 190 | kfree(num); |
| 191 | |
| 192 | info->max_extent = max_t(u64, |
| 193 | info->max_extent, root->sectorsize); |
| 194 | printk(KERN_INFO "btrfs: max_extent at %llu\n", |
| 195 | info->max_extent); |
| 196 | } |
| 197 | break; |
| 198 | case Opt_max_inline: |
| 199 | num = match_strdup(&args[0]); |
| 200 | if (num) { |
| 201 | info->max_inline = btrfs_parse_size(num); |
| 202 | kfree(num); |
| 203 | |
| 204 | if (info->max_inline) { |
| 205 | info->max_inline = max_t(u64, |
| 206 | info->max_inline, |
| 207 | root->sectorsize); |
| 208 | } |
| 209 | printk(KERN_INFO "btrfs: max_inline at %llu\n", |
| 210 | info->max_inline); |
| 211 | } |
| 212 | break; |
| 213 | case Opt_alloc_start: |
| 214 | num = match_strdup(&args[0]); |
| 215 | if (num) { |
| 216 | info->alloc_start = btrfs_parse_size(num); |
| 217 | kfree(num); |
| 218 | printk(KERN_INFO |
| 219 | "btrfs: allocations start at %llu\n", |
| 220 | info->alloc_start); |
| 221 | } |
| 222 | break; |
| 223 | case Opt_noacl: |
| 224 | root->fs_info->sb->s_flags &= ~MS_POSIXACL; |
| 225 | break; |
| 226 | default: |
| 227 | break; |
| 228 | } |
| 229 | } |
| 230 | kfree(options); |
| 231 | return 0; |
| 232 | } |
| 233 | |
| 234 | /* |
| 235 | * Parse mount options that are required early in the mount process. |
| 236 | * |
| 237 | * All other options will be parsed on much later in the mount process and |
| 238 | * only when we need to allocate a new super block. |
| 239 | */ |
| 240 | static int btrfs_parse_early_options(const char *options, fmode_t flags, |
| 241 | void *holder, char **subvol_name, |
| 242 | struct btrfs_fs_devices **fs_devices) |
| 243 | { |
| 244 | substring_t args[MAX_OPT_ARGS]; |
| 245 | char *opts, *p; |
| 246 | int error = 0; |
| 247 | |
| 248 | if (!options) |
| 249 | goto out; |
| 250 | |
| 251 | /* |
| 252 | * strsep changes the string, duplicate it because parse_options |
| 253 | * gets called twice |
| 254 | */ |
| 255 | opts = kstrdup(options, GFP_KERNEL); |
| 256 | if (!opts) |
| 257 | return -ENOMEM; |
| 258 | |
| 259 | while ((p = strsep(&opts, ",")) != NULL) { |
| 260 | int token; |
| 261 | if (!*p) |
| 262 | continue; |
| 263 | |
| 264 | token = match_token(p, tokens, args); |
| 265 | switch (token) { |
| 266 | case Opt_subvol: |
| 267 | *subvol_name = match_strdup(&args[0]); |
| 268 | break; |
| 269 | case Opt_device: |
| 270 | error = btrfs_scan_one_device(match_strdup(&args[0]), |
| 271 | flags, holder, fs_devices); |
| 272 | if (error) |
| 273 | goto out_free_opts; |
| 274 | break; |
| 275 | default: |
| 276 | break; |
| 277 | } |
| 278 | } |
| 279 | |
| 280 | out_free_opts: |
| 281 | kfree(opts); |
| 282 | out: |
| 283 | /* |
| 284 | * If no subvolume name is specified we use the default one. Allocate |
| 285 | * a copy of the string "." here so that code later in the |
| 286 | * mount path doesn't care if it's the default volume or another one. |
| 287 | */ |
| 288 | if (!*subvol_name) { |
| 289 | *subvol_name = kstrdup(".", GFP_KERNEL); |
| 290 | if (!*subvol_name) |
| 291 | return -ENOMEM; |
| 292 | } |
| 293 | return error; |
| 294 | } |
| 295 | |
| 296 | static int btrfs_fill_super(struct super_block *sb, |
| 297 | struct btrfs_fs_devices *fs_devices, |
| 298 | void *data, int silent) |
| 299 | { |
| 300 | struct inode *inode; |
| 301 | struct dentry *root_dentry; |
| 302 | struct btrfs_super_block *disk_super; |
| 303 | struct btrfs_root *tree_root; |
| 304 | struct btrfs_inode *bi; |
| 305 | int err; |
| 306 | |
| 307 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
| 308 | sb->s_magic = BTRFS_SUPER_MAGIC; |
| 309 | sb->s_op = &btrfs_super_ops; |
| 310 | sb->s_export_op = &btrfs_export_ops; |
| 311 | sb->s_xattr = btrfs_xattr_handlers; |
| 312 | sb->s_time_gran = 1; |
| 313 | sb->s_flags |= MS_POSIXACL; |
| 314 | |
| 315 | tree_root = open_ctree(sb, fs_devices, (char *)data); |
| 316 | |
| 317 | if (IS_ERR(tree_root)) { |
| 318 | printk("btrfs: open_ctree failed\n"); |
| 319 | return PTR_ERR(tree_root); |
| 320 | } |
| 321 | sb->s_fs_info = tree_root; |
| 322 | disk_super = &tree_root->fs_info->super_copy; |
| 323 | inode = btrfs_iget_locked(sb, BTRFS_FIRST_FREE_OBJECTID, |
| 324 | tree_root->fs_info->fs_root); |
| 325 | bi = BTRFS_I(inode); |
| 326 | bi->location.objectid = inode->i_ino; |
| 327 | bi->location.offset = 0; |
| 328 | bi->root = tree_root->fs_info->fs_root; |
| 329 | |
| 330 | btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY); |
| 331 | |
| 332 | if (!inode) { |
| 333 | err = -ENOMEM; |
| 334 | goto fail_close; |
| 335 | } |
| 336 | if (inode->i_state & I_NEW) { |
| 337 | btrfs_read_locked_inode(inode); |
| 338 | unlock_new_inode(inode); |
| 339 | } |
| 340 | |
| 341 | root_dentry = d_alloc_root(inode); |
| 342 | if (!root_dentry) { |
| 343 | iput(inode); |
| 344 | err = -ENOMEM; |
| 345 | goto fail_close; |
| 346 | } |
| 347 | #if 0 |
| 348 | /* this does the super kobj at the same time */ |
| 349 | err = btrfs_sysfs_add_super(tree_root->fs_info); |
| 350 | if (err) |
| 351 | goto fail_close; |
| 352 | #endif |
| 353 | |
| 354 | sb->s_root = root_dentry; |
| 355 | |
| 356 | save_mount_options(sb, data); |
| 357 | return 0; |
| 358 | |
| 359 | fail_close: |
| 360 | close_ctree(tree_root); |
| 361 | return err; |
| 362 | } |
| 363 | |
| 364 | int btrfs_sync_fs(struct super_block *sb, int wait) |
| 365 | { |
| 366 | struct btrfs_trans_handle *trans; |
| 367 | struct btrfs_root *root; |
| 368 | int ret; |
| 369 | root = btrfs_sb(sb); |
| 370 | |
| 371 | if (sb->s_flags & MS_RDONLY) |
| 372 | return 0; |
| 373 | |
| 374 | sb->s_dirt = 0; |
| 375 | if (!wait) { |
| 376 | filemap_flush(root->fs_info->btree_inode->i_mapping); |
| 377 | return 0; |
| 378 | } |
| 379 | |
| 380 | btrfs_start_delalloc_inodes(root); |
| 381 | btrfs_wait_ordered_extents(root, 0); |
| 382 | |
| 383 | btrfs_clean_old_snapshots(root); |
| 384 | trans = btrfs_start_transaction(root, 1); |
| 385 | ret = btrfs_commit_transaction(trans, root); |
| 386 | sb->s_dirt = 0; |
| 387 | return ret; |
| 388 | } |
| 389 | |
| 390 | static void btrfs_write_super(struct super_block *sb) |
| 391 | { |
| 392 | sb->s_dirt = 0; |
| 393 | } |
| 394 | |
| 395 | static int btrfs_test_super(struct super_block *s, void *data) |
| 396 | { |
| 397 | struct btrfs_fs_devices *test_fs_devices = data; |
| 398 | struct btrfs_root *root = btrfs_sb(s); |
| 399 | |
| 400 | return root->fs_info->fs_devices == test_fs_devices; |
| 401 | } |
| 402 | |
| 403 | /* |
| 404 | * Find a superblock for the given device / mount point. |
| 405 | * |
| 406 | * Note: This is based on get_sb_bdev from fs/super.c with a few additions |
| 407 | * for multiple device setup. Make sure to keep it in sync. |
| 408 | */ |
| 409 | static int btrfs_get_sb(struct file_system_type *fs_type, int flags, |
| 410 | const char *dev_name, void *data, struct vfsmount *mnt) |
| 411 | { |
| 412 | char *subvol_name = NULL; |
| 413 | struct block_device *bdev = NULL; |
| 414 | struct super_block *s; |
| 415 | struct dentry *root; |
| 416 | struct btrfs_fs_devices *fs_devices = NULL; |
| 417 | fmode_t mode = FMODE_READ; |
| 418 | int error = 0; |
| 419 | |
| 420 | if (!(flags & MS_RDONLY)) |
| 421 | mode |= FMODE_WRITE; |
| 422 | |
| 423 | error = btrfs_parse_early_options(data, mode, fs_type, |
| 424 | &subvol_name, &fs_devices); |
| 425 | if (error) |
| 426 | return error; |
| 427 | |
| 428 | error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices); |
| 429 | if (error) |
| 430 | goto error_free_subvol_name; |
| 431 | |
| 432 | error = btrfs_open_devices(fs_devices, mode, fs_type); |
| 433 | if (error) |
| 434 | goto error_free_subvol_name; |
| 435 | |
| 436 | if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { |
| 437 | error = -EACCES; |
| 438 | goto error_close_devices; |
| 439 | } |
| 440 | |
| 441 | bdev = fs_devices->latest_bdev; |
| 442 | s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices); |
| 443 | if (IS_ERR(s)) |
| 444 | goto error_s; |
| 445 | |
| 446 | if (s->s_root) { |
| 447 | if ((flags ^ s->s_flags) & MS_RDONLY) { |
| 448 | up_write(&s->s_umount); |
| 449 | deactivate_super(s); |
| 450 | error = -EBUSY; |
| 451 | goto error_close_devices; |
| 452 | } |
| 453 | |
| 454 | btrfs_close_devices(fs_devices); |
| 455 | } else { |
| 456 | char b[BDEVNAME_SIZE]; |
| 457 | |
| 458 | s->s_flags = flags; |
| 459 | strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); |
| 460 | error = btrfs_fill_super(s, fs_devices, data, |
| 461 | flags & MS_SILENT ? 1 : 0); |
| 462 | if (error) { |
| 463 | up_write(&s->s_umount); |
| 464 | deactivate_super(s); |
| 465 | goto error_free_subvol_name; |
| 466 | } |
| 467 | |
| 468 | btrfs_sb(s)->fs_info->bdev_holder = fs_type; |
| 469 | s->s_flags |= MS_ACTIVE; |
| 470 | } |
| 471 | |
| 472 | if (!strcmp(subvol_name, ".")) |
| 473 | root = dget(s->s_root); |
| 474 | else { |
| 475 | mutex_lock(&s->s_root->d_inode->i_mutex); |
| 476 | root = lookup_one_len(subvol_name, s->s_root, |
| 477 | strlen(subvol_name)); |
| 478 | mutex_unlock(&s->s_root->d_inode->i_mutex); |
| 479 | |
| 480 | if (IS_ERR(root)) { |
| 481 | up_write(&s->s_umount); |
| 482 | deactivate_super(s); |
| 483 | error = PTR_ERR(root); |
| 484 | goto error_free_subvol_name; |
| 485 | } |
| 486 | if (!root->d_inode) { |
| 487 | dput(root); |
| 488 | up_write(&s->s_umount); |
| 489 | deactivate_super(s); |
| 490 | error = -ENXIO; |
| 491 | goto error_free_subvol_name; |
| 492 | } |
| 493 | } |
| 494 | |
| 495 | mnt->mnt_sb = s; |
| 496 | mnt->mnt_root = root; |
| 497 | |
| 498 | kfree(subvol_name); |
| 499 | return 0; |
| 500 | |
| 501 | error_s: |
| 502 | error = PTR_ERR(s); |
| 503 | error_close_devices: |
| 504 | btrfs_close_devices(fs_devices); |
| 505 | error_free_subvol_name: |
| 506 | kfree(subvol_name); |
| 507 | return error; |
| 508 | } |
| 509 | |
| 510 | static int btrfs_remount(struct super_block *sb, int *flags, char *data) |
| 511 | { |
| 512 | struct btrfs_root *root = btrfs_sb(sb); |
| 513 | int ret; |
| 514 | |
| 515 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) |
| 516 | return 0; |
| 517 | |
| 518 | if (*flags & MS_RDONLY) { |
| 519 | sb->s_flags |= MS_RDONLY; |
| 520 | |
| 521 | ret = btrfs_commit_super(root); |
| 522 | WARN_ON(ret); |
| 523 | } else { |
| 524 | if (root->fs_info->fs_devices->rw_devices == 0) |
| 525 | return -EACCES; |
| 526 | |
| 527 | if (btrfs_super_log_root(&root->fs_info->super_copy) != 0) |
| 528 | return -EINVAL; |
| 529 | |
| 530 | ret = btrfs_cleanup_reloc_trees(root); |
| 531 | WARN_ON(ret); |
| 532 | |
| 533 | ret = btrfs_cleanup_fs_roots(root->fs_info); |
| 534 | WARN_ON(ret); |
| 535 | |
| 536 | sb->s_flags &= ~MS_RDONLY; |
| 537 | } |
| 538 | |
| 539 | return 0; |
| 540 | } |
| 541 | |
| 542 | static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 543 | { |
| 544 | struct btrfs_root *root = btrfs_sb(dentry->d_sb); |
| 545 | struct btrfs_super_block *disk_super = &root->fs_info->super_copy; |
| 546 | int bits = dentry->d_sb->s_blocksize_bits; |
| 547 | __be32 *fsid = (__be32 *)root->fs_info->fsid; |
| 548 | |
| 549 | buf->f_namelen = BTRFS_NAME_LEN; |
| 550 | buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; |
| 551 | buf->f_bfree = buf->f_blocks - |
| 552 | (btrfs_super_bytes_used(disk_super) >> bits); |
| 553 | buf->f_bavail = buf->f_bfree; |
| 554 | buf->f_bsize = dentry->d_sb->s_blocksize; |
| 555 | buf->f_type = BTRFS_SUPER_MAGIC; |
| 556 | |
| 557 | /* We treat it as constant endianness (it doesn't matter _which_) |
| 558 | because we want the fsid to come out the same whether mounted |
| 559 | on a big-endian or little-endian host */ |
| 560 | buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); |
| 561 | buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); |
| 562 | /* Mask in the root object ID too, to disambiguate subvols */ |
| 563 | buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; |
| 564 | buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; |
| 565 | |
| 566 | return 0; |
| 567 | } |
| 568 | |
| 569 | static struct file_system_type btrfs_fs_type = { |
| 570 | .owner = THIS_MODULE, |
| 571 | .name = "btrfs", |
| 572 | .get_sb = btrfs_get_sb, |
| 573 | .kill_sb = kill_anon_super, |
| 574 | .fs_flags = FS_REQUIRES_DEV, |
| 575 | }; |
| 576 | |
| 577 | /* |
| 578 | * used by btrfsctl to scan devices when no FS is mounted |
| 579 | */ |
| 580 | static long btrfs_control_ioctl(struct file *file, unsigned int cmd, |
| 581 | unsigned long arg) |
| 582 | { |
| 583 | struct btrfs_ioctl_vol_args *vol; |
| 584 | struct btrfs_fs_devices *fs_devices; |
| 585 | int ret = -ENOTTY; |
| 586 | int len; |
| 587 | |
| 588 | if (!capable(CAP_SYS_ADMIN)) |
| 589 | return -EPERM; |
| 590 | |
| 591 | vol = kmalloc(sizeof(*vol), GFP_KERNEL); |
| 592 | if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) { |
| 593 | ret = -EFAULT; |
| 594 | goto out; |
| 595 | } |
| 596 | len = strnlen(vol->name, BTRFS_PATH_NAME_MAX); |
| 597 | |
| 598 | switch (cmd) { |
| 599 | case BTRFS_IOC_SCAN_DEV: |
| 600 | ret = btrfs_scan_one_device(vol->name, FMODE_READ, |
| 601 | &btrfs_fs_type, &fs_devices); |
| 602 | break; |
| 603 | } |
| 604 | out: |
| 605 | kfree(vol); |
| 606 | return ret; |
| 607 | } |
| 608 | |
| 609 | static void btrfs_write_super_lockfs(struct super_block *sb) |
| 610 | { |
| 611 | struct btrfs_root *root = btrfs_sb(sb); |
| 612 | mutex_lock(&root->fs_info->transaction_kthread_mutex); |
| 613 | mutex_lock(&root->fs_info->cleaner_mutex); |
| 614 | } |
| 615 | |
| 616 | static void btrfs_unlockfs(struct super_block *sb) |
| 617 | { |
| 618 | struct btrfs_root *root = btrfs_sb(sb); |
| 619 | mutex_unlock(&root->fs_info->cleaner_mutex); |
| 620 | mutex_unlock(&root->fs_info->transaction_kthread_mutex); |
| 621 | } |
| 622 | |
| 623 | static struct super_operations btrfs_super_ops = { |
| 624 | .delete_inode = btrfs_delete_inode, |
| 625 | .put_super = btrfs_put_super, |
| 626 | .write_super = btrfs_write_super, |
| 627 | .sync_fs = btrfs_sync_fs, |
| 628 | .show_options = generic_show_options, |
| 629 | .write_inode = btrfs_write_inode, |
| 630 | .dirty_inode = btrfs_dirty_inode, |
| 631 | .alloc_inode = btrfs_alloc_inode, |
| 632 | .destroy_inode = btrfs_destroy_inode, |
| 633 | .statfs = btrfs_statfs, |
| 634 | .remount_fs = btrfs_remount, |
| 635 | .write_super_lockfs = btrfs_write_super_lockfs, |
| 636 | .unlockfs = btrfs_unlockfs, |
| 637 | }; |
| 638 | |
| 639 | static const struct file_operations btrfs_ctl_fops = { |
| 640 | .unlocked_ioctl = btrfs_control_ioctl, |
| 641 | .compat_ioctl = btrfs_control_ioctl, |
| 642 | .owner = THIS_MODULE, |
| 643 | }; |
| 644 | |
| 645 | static struct miscdevice btrfs_misc = { |
| 646 | .minor = MISC_DYNAMIC_MINOR, |
| 647 | .name = "btrfs-control", |
| 648 | .fops = &btrfs_ctl_fops |
| 649 | }; |
| 650 | |
| 651 | static int btrfs_interface_init(void) |
| 652 | { |
| 653 | return misc_register(&btrfs_misc); |
| 654 | } |
| 655 | |
| 656 | static void btrfs_interface_exit(void) |
| 657 | { |
| 658 | if (misc_deregister(&btrfs_misc) < 0) |
| 659 | printk(KERN_INFO "misc_deregister failed for control device"); |
| 660 | } |
| 661 | |
| 662 | static int __init init_btrfs_fs(void) |
| 663 | { |
| 664 | int err; |
| 665 | |
| 666 | err = btrfs_init_sysfs(); |
| 667 | if (err) |
| 668 | return err; |
| 669 | |
| 670 | err = btrfs_init_cachep(); |
| 671 | if (err) |
| 672 | goto free_sysfs; |
| 673 | |
| 674 | err = extent_io_init(); |
| 675 | if (err) |
| 676 | goto free_cachep; |
| 677 | |
| 678 | err = extent_map_init(); |
| 679 | if (err) |
| 680 | goto free_extent_io; |
| 681 | |
| 682 | err = btrfs_interface_init(); |
| 683 | if (err) |
| 684 | goto free_extent_map; |
| 685 | |
| 686 | err = register_filesystem(&btrfs_fs_type); |
| 687 | if (err) |
| 688 | goto unregister_ioctl; |
| 689 | |
| 690 | printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); |
| 691 | return 0; |
| 692 | |
| 693 | unregister_ioctl: |
| 694 | btrfs_interface_exit(); |
| 695 | free_extent_map: |
| 696 | extent_map_exit(); |
| 697 | free_extent_io: |
| 698 | extent_io_exit(); |
| 699 | free_cachep: |
| 700 | btrfs_destroy_cachep(); |
| 701 | free_sysfs: |
| 702 | btrfs_exit_sysfs(); |
| 703 | return err; |
| 704 | } |
| 705 | |
| 706 | static void __exit exit_btrfs_fs(void) |
| 707 | { |
| 708 | btrfs_destroy_cachep(); |
| 709 | extent_map_exit(); |
| 710 | extent_io_exit(); |
| 711 | btrfs_interface_exit(); |
| 712 | unregister_filesystem(&btrfs_fs_type); |
| 713 | btrfs_exit_sysfs(); |
| 714 | btrfs_cleanup_fs_uuids(); |
| 715 | btrfs_zlib_exit(); |
| 716 | } |
| 717 | |
| 718 | module_init(init_btrfs_fs) |
| 719 | module_exit(exit_btrfs_fs) |
| 720 | |
| 721 | MODULE_LICENSE("GPL"); |