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