| 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 <linux/slab.h> |
| 42 | #include <linux/cleancache.h> |
| 43 | #include <linux/ratelimit.h> |
| 44 | #include "compat.h" |
| 45 | #include "delayed-inode.h" |
| 46 | #include "ctree.h" |
| 47 | #include "disk-io.h" |
| 48 | #include "transaction.h" |
| 49 | #include "btrfs_inode.h" |
| 50 | #include "ioctl.h" |
| 51 | #include "print-tree.h" |
| 52 | #include "xattr.h" |
| 53 | #include "volumes.h" |
| 54 | #include "version.h" |
| 55 | #include "export.h" |
| 56 | #include "compression.h" |
| 57 | |
| 58 | #define CREATE_TRACE_POINTS |
| 59 | #include <trace/events/btrfs.h> |
| 60 | |
| 61 | static const struct super_operations btrfs_super_ops; |
| 62 | static struct file_system_type btrfs_fs_type; |
| 63 | |
| 64 | static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno, |
| 65 | char nbuf[16]) |
| 66 | { |
| 67 | char *errstr = NULL; |
| 68 | |
| 69 | switch (errno) { |
| 70 | case -EIO: |
| 71 | errstr = "IO failure"; |
| 72 | break; |
| 73 | case -ENOMEM: |
| 74 | errstr = "Out of memory"; |
| 75 | break; |
| 76 | case -EROFS: |
| 77 | errstr = "Readonly filesystem"; |
| 78 | break; |
| 79 | case -EEXIST: |
| 80 | errstr = "Object already exists"; |
| 81 | break; |
| 82 | default: |
| 83 | if (nbuf) { |
| 84 | if (snprintf(nbuf, 16, "error %d", -errno) >= 0) |
| 85 | errstr = nbuf; |
| 86 | } |
| 87 | break; |
| 88 | } |
| 89 | |
| 90 | return errstr; |
| 91 | } |
| 92 | |
| 93 | static void __save_error_info(struct btrfs_fs_info *fs_info) |
| 94 | { |
| 95 | /* |
| 96 | * today we only save the error info into ram. Long term we'll |
| 97 | * also send it down to the disk |
| 98 | */ |
| 99 | fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR; |
| 100 | } |
| 101 | |
| 102 | /* NOTE: |
| 103 | * We move write_super stuff at umount in order to avoid deadlock |
| 104 | * for umount hold all lock. |
| 105 | */ |
| 106 | static void save_error_info(struct btrfs_fs_info *fs_info) |
| 107 | { |
| 108 | __save_error_info(fs_info); |
| 109 | } |
| 110 | |
| 111 | /* btrfs handle error by forcing the filesystem readonly */ |
| 112 | static void btrfs_handle_error(struct btrfs_fs_info *fs_info) |
| 113 | { |
| 114 | struct super_block *sb = fs_info->sb; |
| 115 | |
| 116 | if (sb->s_flags & MS_RDONLY) |
| 117 | return; |
| 118 | |
| 119 | if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { |
| 120 | sb->s_flags |= MS_RDONLY; |
| 121 | printk(KERN_INFO "btrfs is forced readonly\n"); |
| 122 | __btrfs_scrub_cancel(fs_info); |
| 123 | // WARN_ON(1); |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | /* |
| 128 | * __btrfs_std_error decodes expected errors from the caller and |
| 129 | * invokes the approciate error response. |
| 130 | */ |
| 131 | void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, |
| 132 | unsigned int line, int errno, const char *fmt, ...) |
| 133 | { |
| 134 | struct super_block *sb = fs_info->sb; |
| 135 | char nbuf[16]; |
| 136 | const char *errstr; |
| 137 | va_list args; |
| 138 | va_start(args, fmt); |
| 139 | |
| 140 | /* |
| 141 | * Special case: if the error is EROFS, and we're already |
| 142 | * under MS_RDONLY, then it is safe here. |
| 143 | */ |
| 144 | if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) |
| 145 | return; |
| 146 | |
| 147 | errstr = btrfs_decode_error(fs_info, errno, nbuf); |
| 148 | if (fmt) { |
| 149 | struct va_format vaf = { |
| 150 | .fmt = fmt, |
| 151 | .va = &args, |
| 152 | }; |
| 153 | |
| 154 | printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s (%pV)\n", |
| 155 | sb->s_id, function, line, errstr, &vaf); |
| 156 | } else { |
| 157 | printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n", |
| 158 | sb->s_id, function, line, errstr); |
| 159 | } |
| 160 | |
| 161 | /* Don't go through full error handling during mount */ |
| 162 | if (sb->s_flags & MS_BORN) { |
| 163 | save_error_info(fs_info); |
| 164 | btrfs_handle_error(fs_info); |
| 165 | } |
| 166 | va_end(args); |
| 167 | } |
| 168 | |
| 169 | const char *logtypes[] = { |
| 170 | "emergency", |
| 171 | "alert", |
| 172 | "critical", |
| 173 | "error", |
| 174 | "warning", |
| 175 | "notice", |
| 176 | "info", |
| 177 | "debug", |
| 178 | }; |
| 179 | |
| 180 | void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...) |
| 181 | { |
| 182 | struct super_block *sb = fs_info->sb; |
| 183 | char lvl[4]; |
| 184 | struct va_format vaf; |
| 185 | va_list args; |
| 186 | const char *type = logtypes[4]; |
| 187 | |
| 188 | va_start(args, fmt); |
| 189 | |
| 190 | if (fmt[0] == '<' && isdigit(fmt[1]) && fmt[2] == '>') { |
| 191 | strncpy(lvl, fmt, 3); |
| 192 | fmt += 3; |
| 193 | type = logtypes[fmt[1] - '0']; |
| 194 | } else |
| 195 | *lvl = '\0'; |
| 196 | |
| 197 | vaf.fmt = fmt; |
| 198 | vaf.va = &args; |
| 199 | printk("%sBTRFS %s (device %s): %pV", lvl, type, sb->s_id, &vaf); |
| 200 | } |
| 201 | |
| 202 | /* |
| 203 | * We only mark the transaction aborted and then set the file system read-only. |
| 204 | * This will prevent new transactions from starting or trying to join this |
| 205 | * one. |
| 206 | * |
| 207 | * This means that error recovery at the call site is limited to freeing |
| 208 | * any local memory allocations and passing the error code up without |
| 209 | * further cleanup. The transaction should complete as it normally would |
| 210 | * in the call path but will return -EIO. |
| 211 | * |
| 212 | * We'll complete the cleanup in btrfs_end_transaction and |
| 213 | * btrfs_commit_transaction. |
| 214 | */ |
| 215 | void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, |
| 216 | struct btrfs_root *root, const char *function, |
| 217 | unsigned int line, int errno) |
| 218 | { |
| 219 | WARN_ONCE(1, KERN_DEBUG "btrfs: Transaction aborted"); |
| 220 | trans->aborted = errno; |
| 221 | /* Nothing used. The other threads that have joined this |
| 222 | * transaction may be able to continue. */ |
| 223 | if (!trans->blocks_used) { |
| 224 | btrfs_printk(root->fs_info, "Aborting unused transaction.\n"); |
| 225 | return; |
| 226 | } |
| 227 | trans->transaction->aborted = errno; |
| 228 | __btrfs_std_error(root->fs_info, function, line, errno, NULL); |
| 229 | } |
| 230 | /* |
| 231 | * __btrfs_panic decodes unexpected, fatal errors from the caller, |
| 232 | * issues an alert, and either panics or BUGs, depending on mount options. |
| 233 | */ |
| 234 | void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, |
| 235 | unsigned int line, int errno, const char *fmt, ...) |
| 236 | { |
| 237 | char nbuf[16]; |
| 238 | char *s_id = "<unknown>"; |
| 239 | const char *errstr; |
| 240 | struct va_format vaf = { .fmt = fmt }; |
| 241 | va_list args; |
| 242 | |
| 243 | if (fs_info) |
| 244 | s_id = fs_info->sb->s_id; |
| 245 | |
| 246 | va_start(args, fmt); |
| 247 | vaf.va = &args; |
| 248 | |
| 249 | errstr = btrfs_decode_error(fs_info, errno, nbuf); |
| 250 | if (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR) |
| 251 | panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n", |
| 252 | s_id, function, line, &vaf, errstr); |
| 253 | |
| 254 | printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n", |
| 255 | s_id, function, line, &vaf, errstr); |
| 256 | va_end(args); |
| 257 | /* Caller calls BUG() */ |
| 258 | } |
| 259 | |
| 260 | static void btrfs_put_super(struct super_block *sb) |
| 261 | { |
| 262 | (void)close_ctree(btrfs_sb(sb)->tree_root); |
| 263 | /* FIXME: need to fix VFS to return error? */ |
| 264 | /* AV: return it _where_? ->put_super() can be triggered by any number |
| 265 | * of async events, up to and including delivery of SIGKILL to the |
| 266 | * last process that kept it busy. Or segfault in the aforementioned |
| 267 | * process... Whom would you report that to? |
| 268 | */ |
| 269 | } |
| 270 | |
| 271 | enum { |
| 272 | Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, |
| 273 | Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, |
| 274 | Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, |
| 275 | Opt_compress_type, Opt_compress_force, Opt_compress_force_type, |
| 276 | Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, |
| 277 | Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, |
| 278 | Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache, |
| 279 | Opt_no_space_cache, Opt_recovery, Opt_skip_balance, |
| 280 | Opt_check_integrity, Opt_check_integrity_including_extent_data, |
| 281 | Opt_check_integrity_print_mask, Opt_fatal_errors, |
| 282 | Opt_err, |
| 283 | }; |
| 284 | |
| 285 | static match_table_t tokens = { |
| 286 | {Opt_degraded, "degraded"}, |
| 287 | {Opt_subvol, "subvol=%s"}, |
| 288 | {Opt_subvolid, "subvolid=%d"}, |
| 289 | {Opt_device, "device=%s"}, |
| 290 | {Opt_nodatasum, "nodatasum"}, |
| 291 | {Opt_nodatacow, "nodatacow"}, |
| 292 | {Opt_nobarrier, "nobarrier"}, |
| 293 | {Opt_max_inline, "max_inline=%s"}, |
| 294 | {Opt_alloc_start, "alloc_start=%s"}, |
| 295 | {Opt_thread_pool, "thread_pool=%d"}, |
| 296 | {Opt_compress, "compress"}, |
| 297 | {Opt_compress_type, "compress=%s"}, |
| 298 | {Opt_compress_force, "compress-force"}, |
| 299 | {Opt_compress_force_type, "compress-force=%s"}, |
| 300 | {Opt_ssd, "ssd"}, |
| 301 | {Opt_ssd_spread, "ssd_spread"}, |
| 302 | {Opt_nossd, "nossd"}, |
| 303 | {Opt_noacl, "noacl"}, |
| 304 | {Opt_notreelog, "notreelog"}, |
| 305 | {Opt_flushoncommit, "flushoncommit"}, |
| 306 | {Opt_ratio, "metadata_ratio=%d"}, |
| 307 | {Opt_discard, "discard"}, |
| 308 | {Opt_space_cache, "space_cache"}, |
| 309 | {Opt_clear_cache, "clear_cache"}, |
| 310 | {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, |
| 311 | {Opt_enospc_debug, "enospc_debug"}, |
| 312 | {Opt_subvolrootid, "subvolrootid=%d"}, |
| 313 | {Opt_defrag, "autodefrag"}, |
| 314 | {Opt_inode_cache, "inode_cache"}, |
| 315 | {Opt_no_space_cache, "nospace_cache"}, |
| 316 | {Opt_recovery, "recovery"}, |
| 317 | {Opt_skip_balance, "skip_balance"}, |
| 318 | {Opt_check_integrity, "check_int"}, |
| 319 | {Opt_check_integrity_including_extent_data, "check_int_data"}, |
| 320 | {Opt_check_integrity_print_mask, "check_int_print_mask=%d"}, |
| 321 | {Opt_fatal_errors, "fatal_errors=%s"}, |
| 322 | {Opt_err, NULL}, |
| 323 | }; |
| 324 | |
| 325 | /* |
| 326 | * Regular mount options parser. Everything that is needed only when |
| 327 | * reading in a new superblock is parsed here. |
| 328 | * XXX JDM: This needs to be cleaned up for remount. |
| 329 | */ |
| 330 | int btrfs_parse_options(struct btrfs_root *root, char *options) |
| 331 | { |
| 332 | struct btrfs_fs_info *info = root->fs_info; |
| 333 | substring_t args[MAX_OPT_ARGS]; |
| 334 | char *p, *num, *orig = NULL; |
| 335 | u64 cache_gen; |
| 336 | int intarg; |
| 337 | int ret = 0; |
| 338 | char *compress_type; |
| 339 | bool compress_force = false; |
| 340 | |
| 341 | cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); |
| 342 | if (cache_gen) |
| 343 | btrfs_set_opt(info->mount_opt, SPACE_CACHE); |
| 344 | |
| 345 | if (!options) |
| 346 | goto out; |
| 347 | |
| 348 | /* |
| 349 | * strsep changes the string, duplicate it because parse_options |
| 350 | * gets called twice |
| 351 | */ |
| 352 | options = kstrdup(options, GFP_NOFS); |
| 353 | if (!options) |
| 354 | return -ENOMEM; |
| 355 | |
| 356 | orig = options; |
| 357 | |
| 358 | while ((p = strsep(&options, ",")) != NULL) { |
| 359 | int token; |
| 360 | if (!*p) |
| 361 | continue; |
| 362 | |
| 363 | token = match_token(p, tokens, args); |
| 364 | switch (token) { |
| 365 | case Opt_degraded: |
| 366 | printk(KERN_INFO "btrfs: allowing degraded mounts\n"); |
| 367 | btrfs_set_opt(info->mount_opt, DEGRADED); |
| 368 | break; |
| 369 | case Opt_subvol: |
| 370 | case Opt_subvolid: |
| 371 | case Opt_subvolrootid: |
| 372 | case Opt_device: |
| 373 | /* |
| 374 | * These are parsed by btrfs_parse_early_options |
| 375 | * and can be happily ignored here. |
| 376 | */ |
| 377 | break; |
| 378 | case Opt_nodatasum: |
| 379 | printk(KERN_INFO "btrfs: setting nodatasum\n"); |
| 380 | btrfs_set_opt(info->mount_opt, NODATASUM); |
| 381 | break; |
| 382 | case Opt_nodatacow: |
| 383 | printk(KERN_INFO "btrfs: setting nodatacow\n"); |
| 384 | btrfs_set_opt(info->mount_opt, NODATACOW); |
| 385 | btrfs_set_opt(info->mount_opt, NODATASUM); |
| 386 | break; |
| 387 | case Opt_compress_force: |
| 388 | case Opt_compress_force_type: |
| 389 | compress_force = true; |
| 390 | case Opt_compress: |
| 391 | case Opt_compress_type: |
| 392 | if (token == Opt_compress || |
| 393 | token == Opt_compress_force || |
| 394 | strcmp(args[0].from, "zlib") == 0) { |
| 395 | compress_type = "zlib"; |
| 396 | info->compress_type = BTRFS_COMPRESS_ZLIB; |
| 397 | } else if (strcmp(args[0].from, "lzo") == 0) { |
| 398 | compress_type = "lzo"; |
| 399 | info->compress_type = BTRFS_COMPRESS_LZO; |
| 400 | } else { |
| 401 | ret = -EINVAL; |
| 402 | goto out; |
| 403 | } |
| 404 | |
| 405 | btrfs_set_opt(info->mount_opt, COMPRESS); |
| 406 | if (compress_force) { |
| 407 | btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); |
| 408 | pr_info("btrfs: force %s compression\n", |
| 409 | compress_type); |
| 410 | } else |
| 411 | pr_info("btrfs: use %s compression\n", |
| 412 | compress_type); |
| 413 | break; |
| 414 | case Opt_ssd: |
| 415 | printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); |
| 416 | btrfs_set_opt(info->mount_opt, SSD); |
| 417 | break; |
| 418 | case Opt_ssd_spread: |
| 419 | printk(KERN_INFO "btrfs: use spread ssd " |
| 420 | "allocation scheme\n"); |
| 421 | btrfs_set_opt(info->mount_opt, SSD); |
| 422 | btrfs_set_opt(info->mount_opt, SSD_SPREAD); |
| 423 | break; |
| 424 | case Opt_nossd: |
| 425 | printk(KERN_INFO "btrfs: not using ssd allocation " |
| 426 | "scheme\n"); |
| 427 | btrfs_set_opt(info->mount_opt, NOSSD); |
| 428 | btrfs_clear_opt(info->mount_opt, SSD); |
| 429 | btrfs_clear_opt(info->mount_opt, SSD_SPREAD); |
| 430 | break; |
| 431 | case Opt_nobarrier: |
| 432 | printk(KERN_INFO "btrfs: turning off barriers\n"); |
| 433 | btrfs_set_opt(info->mount_opt, NOBARRIER); |
| 434 | break; |
| 435 | case Opt_thread_pool: |
| 436 | intarg = 0; |
| 437 | match_int(&args[0], &intarg); |
| 438 | if (intarg) { |
| 439 | info->thread_pool_size = intarg; |
| 440 | printk(KERN_INFO "btrfs: thread pool %d\n", |
| 441 | info->thread_pool_size); |
| 442 | } |
| 443 | break; |
| 444 | case Opt_max_inline: |
| 445 | num = match_strdup(&args[0]); |
| 446 | if (num) { |
| 447 | info->max_inline = memparse(num, NULL); |
| 448 | kfree(num); |
| 449 | |
| 450 | if (info->max_inline) { |
| 451 | info->max_inline = max_t(u64, |
| 452 | info->max_inline, |
| 453 | root->sectorsize); |
| 454 | } |
| 455 | printk(KERN_INFO "btrfs: max_inline at %llu\n", |
| 456 | (unsigned long long)info->max_inline); |
| 457 | } |
| 458 | break; |
| 459 | case Opt_alloc_start: |
| 460 | num = match_strdup(&args[0]); |
| 461 | if (num) { |
| 462 | info->alloc_start = memparse(num, NULL); |
| 463 | kfree(num); |
| 464 | printk(KERN_INFO |
| 465 | "btrfs: allocations start at %llu\n", |
| 466 | (unsigned long long)info->alloc_start); |
| 467 | } |
| 468 | break; |
| 469 | case Opt_noacl: |
| 470 | root->fs_info->sb->s_flags &= ~MS_POSIXACL; |
| 471 | break; |
| 472 | case Opt_notreelog: |
| 473 | printk(KERN_INFO "btrfs: disabling tree log\n"); |
| 474 | btrfs_set_opt(info->mount_opt, NOTREELOG); |
| 475 | break; |
| 476 | case Opt_flushoncommit: |
| 477 | printk(KERN_INFO "btrfs: turning on flush-on-commit\n"); |
| 478 | btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT); |
| 479 | break; |
| 480 | case Opt_ratio: |
| 481 | intarg = 0; |
| 482 | match_int(&args[0], &intarg); |
| 483 | if (intarg) { |
| 484 | info->metadata_ratio = intarg; |
| 485 | printk(KERN_INFO "btrfs: metadata ratio %d\n", |
| 486 | info->metadata_ratio); |
| 487 | } |
| 488 | break; |
| 489 | case Opt_discard: |
| 490 | btrfs_set_opt(info->mount_opt, DISCARD); |
| 491 | break; |
| 492 | case Opt_space_cache: |
| 493 | btrfs_set_opt(info->mount_opt, SPACE_CACHE); |
| 494 | break; |
| 495 | case Opt_no_space_cache: |
| 496 | printk(KERN_INFO "btrfs: disabling disk space caching\n"); |
| 497 | btrfs_clear_opt(info->mount_opt, SPACE_CACHE); |
| 498 | break; |
| 499 | case Opt_inode_cache: |
| 500 | printk(KERN_INFO "btrfs: enabling inode map caching\n"); |
| 501 | btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE); |
| 502 | break; |
| 503 | case Opt_clear_cache: |
| 504 | printk(KERN_INFO "btrfs: force clearing of disk cache\n"); |
| 505 | btrfs_set_opt(info->mount_opt, CLEAR_CACHE); |
| 506 | break; |
| 507 | case Opt_user_subvol_rm_allowed: |
| 508 | btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); |
| 509 | break; |
| 510 | case Opt_enospc_debug: |
| 511 | btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); |
| 512 | break; |
| 513 | case Opt_defrag: |
| 514 | printk(KERN_INFO "btrfs: enabling auto defrag"); |
| 515 | btrfs_set_opt(info->mount_opt, AUTO_DEFRAG); |
| 516 | break; |
| 517 | case Opt_recovery: |
| 518 | printk(KERN_INFO "btrfs: enabling auto recovery"); |
| 519 | btrfs_set_opt(info->mount_opt, RECOVERY); |
| 520 | break; |
| 521 | case Opt_skip_balance: |
| 522 | btrfs_set_opt(info->mount_opt, SKIP_BALANCE); |
| 523 | break; |
| 524 | #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY |
| 525 | case Opt_check_integrity_including_extent_data: |
| 526 | printk(KERN_INFO "btrfs: enabling check integrity" |
| 527 | " including extent data\n"); |
| 528 | btrfs_set_opt(info->mount_opt, |
| 529 | CHECK_INTEGRITY_INCLUDING_EXTENT_DATA); |
| 530 | btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); |
| 531 | break; |
| 532 | case Opt_check_integrity: |
| 533 | printk(KERN_INFO "btrfs: enabling check integrity\n"); |
| 534 | btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); |
| 535 | break; |
| 536 | case Opt_check_integrity_print_mask: |
| 537 | intarg = 0; |
| 538 | match_int(&args[0], &intarg); |
| 539 | if (intarg) { |
| 540 | info->check_integrity_print_mask = intarg; |
| 541 | printk(KERN_INFO "btrfs:" |
| 542 | " check_integrity_print_mask 0x%x\n", |
| 543 | info->check_integrity_print_mask); |
| 544 | } |
| 545 | break; |
| 546 | #else |
| 547 | case Opt_check_integrity_including_extent_data: |
| 548 | case Opt_check_integrity: |
| 549 | case Opt_check_integrity_print_mask: |
| 550 | printk(KERN_ERR "btrfs: support for check_integrity*" |
| 551 | " not compiled in!\n"); |
| 552 | ret = -EINVAL; |
| 553 | goto out; |
| 554 | #endif |
| 555 | case Opt_fatal_errors: |
| 556 | if (strcmp(args[0].from, "panic") == 0) |
| 557 | btrfs_set_opt(info->mount_opt, |
| 558 | PANIC_ON_FATAL_ERROR); |
| 559 | else if (strcmp(args[0].from, "bug") == 0) |
| 560 | btrfs_clear_opt(info->mount_opt, |
| 561 | PANIC_ON_FATAL_ERROR); |
| 562 | else { |
| 563 | ret = -EINVAL; |
| 564 | goto out; |
| 565 | } |
| 566 | break; |
| 567 | case Opt_err: |
| 568 | printk(KERN_INFO "btrfs: unrecognized mount option " |
| 569 | "'%s'\n", p); |
| 570 | ret = -EINVAL; |
| 571 | goto out; |
| 572 | default: |
| 573 | break; |
| 574 | } |
| 575 | } |
| 576 | out: |
| 577 | if (!ret && btrfs_test_opt(root, SPACE_CACHE)) |
| 578 | printk(KERN_INFO "btrfs: disk space caching is enabled\n"); |
| 579 | kfree(orig); |
| 580 | return ret; |
| 581 | } |
| 582 | |
| 583 | /* |
| 584 | * Parse mount options that are required early in the mount process. |
| 585 | * |
| 586 | * All other options will be parsed on much later in the mount process and |
| 587 | * only when we need to allocate a new super block. |
| 588 | */ |
| 589 | static int btrfs_parse_early_options(const char *options, fmode_t flags, |
| 590 | void *holder, char **subvol_name, u64 *subvol_objectid, |
| 591 | u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices) |
| 592 | { |
| 593 | substring_t args[MAX_OPT_ARGS]; |
| 594 | char *device_name, *opts, *orig, *p; |
| 595 | int error = 0; |
| 596 | int intarg; |
| 597 | |
| 598 | if (!options) |
| 599 | return 0; |
| 600 | |
| 601 | /* |
| 602 | * strsep changes the string, duplicate it because parse_options |
| 603 | * gets called twice |
| 604 | */ |
| 605 | opts = kstrdup(options, GFP_KERNEL); |
| 606 | if (!opts) |
| 607 | return -ENOMEM; |
| 608 | orig = opts; |
| 609 | |
| 610 | while ((p = strsep(&opts, ",")) != NULL) { |
| 611 | int token; |
| 612 | if (!*p) |
| 613 | continue; |
| 614 | |
| 615 | token = match_token(p, tokens, args); |
| 616 | switch (token) { |
| 617 | case Opt_subvol: |
| 618 | kfree(*subvol_name); |
| 619 | *subvol_name = match_strdup(&args[0]); |
| 620 | break; |
| 621 | case Opt_subvolid: |
| 622 | intarg = 0; |
| 623 | error = match_int(&args[0], &intarg); |
| 624 | if (!error) { |
| 625 | /* we want the original fs_tree */ |
| 626 | if (!intarg) |
| 627 | *subvol_objectid = |
| 628 | BTRFS_FS_TREE_OBJECTID; |
| 629 | else |
| 630 | *subvol_objectid = intarg; |
| 631 | } |
| 632 | break; |
| 633 | case Opt_subvolrootid: |
| 634 | intarg = 0; |
| 635 | error = match_int(&args[0], &intarg); |
| 636 | if (!error) { |
| 637 | /* we want the original fs_tree */ |
| 638 | if (!intarg) |
| 639 | *subvol_rootid = |
| 640 | BTRFS_FS_TREE_OBJECTID; |
| 641 | else |
| 642 | *subvol_rootid = intarg; |
| 643 | } |
| 644 | break; |
| 645 | case Opt_device: |
| 646 | device_name = match_strdup(&args[0]); |
| 647 | if (!device_name) { |
| 648 | error = -ENOMEM; |
| 649 | goto out; |
| 650 | } |
| 651 | error = btrfs_scan_one_device(device_name, |
| 652 | flags, holder, fs_devices); |
| 653 | kfree(device_name); |
| 654 | if (error) |
| 655 | goto out; |
| 656 | break; |
| 657 | default: |
| 658 | break; |
| 659 | } |
| 660 | } |
| 661 | |
| 662 | out: |
| 663 | kfree(orig); |
| 664 | return error; |
| 665 | } |
| 666 | |
| 667 | static struct dentry *get_default_root(struct super_block *sb, |
| 668 | u64 subvol_objectid) |
| 669 | { |
| 670 | struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| 671 | struct btrfs_root *root = fs_info->tree_root; |
| 672 | struct btrfs_root *new_root; |
| 673 | struct btrfs_dir_item *di; |
| 674 | struct btrfs_path *path; |
| 675 | struct btrfs_key location; |
| 676 | struct inode *inode; |
| 677 | u64 dir_id; |
| 678 | int new = 0; |
| 679 | |
| 680 | /* |
| 681 | * We have a specific subvol we want to mount, just setup location and |
| 682 | * go look up the root. |
| 683 | */ |
| 684 | if (subvol_objectid) { |
| 685 | location.objectid = subvol_objectid; |
| 686 | location.type = BTRFS_ROOT_ITEM_KEY; |
| 687 | location.offset = (u64)-1; |
| 688 | goto find_root; |
| 689 | } |
| 690 | |
| 691 | path = btrfs_alloc_path(); |
| 692 | if (!path) |
| 693 | return ERR_PTR(-ENOMEM); |
| 694 | path->leave_spinning = 1; |
| 695 | |
| 696 | /* |
| 697 | * Find the "default" dir item which points to the root item that we |
| 698 | * will mount by default if we haven't been given a specific subvolume |
| 699 | * to mount. |
| 700 | */ |
| 701 | dir_id = btrfs_super_root_dir(fs_info->super_copy); |
| 702 | di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); |
| 703 | if (IS_ERR(di)) { |
| 704 | btrfs_free_path(path); |
| 705 | return ERR_CAST(di); |
| 706 | } |
| 707 | if (!di) { |
| 708 | /* |
| 709 | * Ok the default dir item isn't there. This is weird since |
| 710 | * it's always been there, but don't freak out, just try and |
| 711 | * mount to root most subvolume. |
| 712 | */ |
| 713 | btrfs_free_path(path); |
| 714 | dir_id = BTRFS_FIRST_FREE_OBJECTID; |
| 715 | new_root = fs_info->fs_root; |
| 716 | goto setup_root; |
| 717 | } |
| 718 | |
| 719 | btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); |
| 720 | btrfs_free_path(path); |
| 721 | |
| 722 | find_root: |
| 723 | new_root = btrfs_read_fs_root_no_name(fs_info, &location); |
| 724 | if (IS_ERR(new_root)) |
| 725 | return ERR_CAST(new_root); |
| 726 | |
| 727 | if (btrfs_root_refs(&new_root->root_item) == 0) |
| 728 | return ERR_PTR(-ENOENT); |
| 729 | |
| 730 | dir_id = btrfs_root_dirid(&new_root->root_item); |
| 731 | setup_root: |
| 732 | location.objectid = dir_id; |
| 733 | location.type = BTRFS_INODE_ITEM_KEY; |
| 734 | location.offset = 0; |
| 735 | |
| 736 | inode = btrfs_iget(sb, &location, new_root, &new); |
| 737 | if (IS_ERR(inode)) |
| 738 | return ERR_CAST(inode); |
| 739 | |
| 740 | /* |
| 741 | * If we're just mounting the root most subvol put the inode and return |
| 742 | * a reference to the dentry. We will have already gotten a reference |
| 743 | * to the inode in btrfs_fill_super so we're good to go. |
| 744 | */ |
| 745 | if (!new && sb->s_root->d_inode == inode) { |
| 746 | iput(inode); |
| 747 | return dget(sb->s_root); |
| 748 | } |
| 749 | |
| 750 | return d_obtain_alias(inode); |
| 751 | } |
| 752 | |
| 753 | static int btrfs_fill_super(struct super_block *sb, |
| 754 | struct btrfs_fs_devices *fs_devices, |
| 755 | void *data, int silent) |
| 756 | { |
| 757 | struct inode *inode; |
| 758 | struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| 759 | struct btrfs_key key; |
| 760 | int err; |
| 761 | |
| 762 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
| 763 | sb->s_magic = BTRFS_SUPER_MAGIC; |
| 764 | sb->s_op = &btrfs_super_ops; |
| 765 | sb->s_d_op = &btrfs_dentry_operations; |
| 766 | sb->s_export_op = &btrfs_export_ops; |
| 767 | sb->s_xattr = btrfs_xattr_handlers; |
| 768 | sb->s_time_gran = 1; |
| 769 | #ifdef CONFIG_BTRFS_FS_POSIX_ACL |
| 770 | sb->s_flags |= MS_POSIXACL; |
| 771 | #endif |
| 772 | sb->s_flags |= MS_I_VERSION; |
| 773 | err = open_ctree(sb, fs_devices, (char *)data); |
| 774 | if (err) { |
| 775 | printk("btrfs: open_ctree failed\n"); |
| 776 | return err; |
| 777 | } |
| 778 | |
| 779 | key.objectid = BTRFS_FIRST_FREE_OBJECTID; |
| 780 | key.type = BTRFS_INODE_ITEM_KEY; |
| 781 | key.offset = 0; |
| 782 | inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL); |
| 783 | if (IS_ERR(inode)) { |
| 784 | err = PTR_ERR(inode); |
| 785 | goto fail_close; |
| 786 | } |
| 787 | |
| 788 | sb->s_root = d_make_root(inode); |
| 789 | if (!sb->s_root) { |
| 790 | err = -ENOMEM; |
| 791 | goto fail_close; |
| 792 | } |
| 793 | |
| 794 | save_mount_options(sb, data); |
| 795 | cleancache_init_fs(sb); |
| 796 | sb->s_flags |= MS_ACTIVE; |
| 797 | return 0; |
| 798 | |
| 799 | fail_close: |
| 800 | close_ctree(fs_info->tree_root); |
| 801 | return err; |
| 802 | } |
| 803 | |
| 804 | int btrfs_sync_fs(struct super_block *sb, int wait) |
| 805 | { |
| 806 | struct btrfs_trans_handle *trans; |
| 807 | struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| 808 | struct btrfs_root *root = fs_info->tree_root; |
| 809 | int ret; |
| 810 | |
| 811 | trace_btrfs_sync_fs(wait); |
| 812 | |
| 813 | if (!wait) { |
| 814 | filemap_flush(fs_info->btree_inode->i_mapping); |
| 815 | return 0; |
| 816 | } |
| 817 | |
| 818 | btrfs_wait_ordered_extents(root, 0, 0); |
| 819 | |
| 820 | trans = btrfs_start_transaction(root, 0); |
| 821 | if (IS_ERR(trans)) |
| 822 | return PTR_ERR(trans); |
| 823 | ret = btrfs_commit_transaction(trans, root); |
| 824 | return ret; |
| 825 | } |
| 826 | |
| 827 | static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) |
| 828 | { |
| 829 | struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); |
| 830 | struct btrfs_root *root = info->tree_root; |
| 831 | char *compress_type; |
| 832 | |
| 833 | if (btrfs_test_opt(root, DEGRADED)) |
| 834 | seq_puts(seq, ",degraded"); |
| 835 | if (btrfs_test_opt(root, NODATASUM)) |
| 836 | seq_puts(seq, ",nodatasum"); |
| 837 | if (btrfs_test_opt(root, NODATACOW)) |
| 838 | seq_puts(seq, ",nodatacow"); |
| 839 | if (btrfs_test_opt(root, NOBARRIER)) |
| 840 | seq_puts(seq, ",nobarrier"); |
| 841 | if (info->max_inline != 8192 * 1024) |
| 842 | seq_printf(seq, ",max_inline=%llu", |
| 843 | (unsigned long long)info->max_inline); |
| 844 | if (info->alloc_start != 0) |
| 845 | seq_printf(seq, ",alloc_start=%llu", |
| 846 | (unsigned long long)info->alloc_start); |
| 847 | if (info->thread_pool_size != min_t(unsigned long, |
| 848 | num_online_cpus() + 2, 8)) |
| 849 | seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); |
| 850 | if (btrfs_test_opt(root, COMPRESS)) { |
| 851 | if (info->compress_type == BTRFS_COMPRESS_ZLIB) |
| 852 | compress_type = "zlib"; |
| 853 | else |
| 854 | compress_type = "lzo"; |
| 855 | if (btrfs_test_opt(root, FORCE_COMPRESS)) |
| 856 | seq_printf(seq, ",compress-force=%s", compress_type); |
| 857 | else |
| 858 | seq_printf(seq, ",compress=%s", compress_type); |
| 859 | } |
| 860 | if (btrfs_test_opt(root, NOSSD)) |
| 861 | seq_puts(seq, ",nossd"); |
| 862 | if (btrfs_test_opt(root, SSD_SPREAD)) |
| 863 | seq_puts(seq, ",ssd_spread"); |
| 864 | else if (btrfs_test_opt(root, SSD)) |
| 865 | seq_puts(seq, ",ssd"); |
| 866 | if (btrfs_test_opt(root, NOTREELOG)) |
| 867 | seq_puts(seq, ",notreelog"); |
| 868 | if (btrfs_test_opt(root, FLUSHONCOMMIT)) |
| 869 | seq_puts(seq, ",flushoncommit"); |
| 870 | if (btrfs_test_opt(root, DISCARD)) |
| 871 | seq_puts(seq, ",discard"); |
| 872 | if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) |
| 873 | seq_puts(seq, ",noacl"); |
| 874 | if (btrfs_test_opt(root, SPACE_CACHE)) |
| 875 | seq_puts(seq, ",space_cache"); |
| 876 | else |
| 877 | seq_puts(seq, ",nospace_cache"); |
| 878 | if (btrfs_test_opt(root, CLEAR_CACHE)) |
| 879 | seq_puts(seq, ",clear_cache"); |
| 880 | if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) |
| 881 | seq_puts(seq, ",user_subvol_rm_allowed"); |
| 882 | if (btrfs_test_opt(root, ENOSPC_DEBUG)) |
| 883 | seq_puts(seq, ",enospc_debug"); |
| 884 | if (btrfs_test_opt(root, AUTO_DEFRAG)) |
| 885 | seq_puts(seq, ",autodefrag"); |
| 886 | if (btrfs_test_opt(root, INODE_MAP_CACHE)) |
| 887 | seq_puts(seq, ",inode_cache"); |
| 888 | if (btrfs_test_opt(root, SKIP_BALANCE)) |
| 889 | seq_puts(seq, ",skip_balance"); |
| 890 | if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR)) |
| 891 | seq_puts(seq, ",fatal_errors=panic"); |
| 892 | return 0; |
| 893 | } |
| 894 | |
| 895 | static int btrfs_test_super(struct super_block *s, void *data) |
| 896 | { |
| 897 | struct btrfs_fs_info *p = data; |
| 898 | struct btrfs_fs_info *fs_info = btrfs_sb(s); |
| 899 | |
| 900 | return fs_info->fs_devices == p->fs_devices; |
| 901 | } |
| 902 | |
| 903 | static int btrfs_set_super(struct super_block *s, void *data) |
| 904 | { |
| 905 | int err = set_anon_super(s, data); |
| 906 | if (!err) |
| 907 | s->s_fs_info = data; |
| 908 | return err; |
| 909 | } |
| 910 | |
| 911 | /* |
| 912 | * subvolumes are identified by ino 256 |
| 913 | */ |
| 914 | static inline int is_subvolume_inode(struct inode *inode) |
| 915 | { |
| 916 | if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) |
| 917 | return 1; |
| 918 | return 0; |
| 919 | } |
| 920 | |
| 921 | /* |
| 922 | * This will strip out the subvol=%s argument for an argument string and add |
| 923 | * subvolid=0 to make sure we get the actual tree root for path walking to the |
| 924 | * subvol we want. |
| 925 | */ |
| 926 | static char *setup_root_args(char *args) |
| 927 | { |
| 928 | unsigned copied = 0; |
| 929 | unsigned len = strlen(args) + 2; |
| 930 | char *pos; |
| 931 | char *ret; |
| 932 | |
| 933 | /* |
| 934 | * We need the same args as before, but minus |
| 935 | * |
| 936 | * subvol=a |
| 937 | * |
| 938 | * and add |
| 939 | * |
| 940 | * subvolid=0 |
| 941 | * |
| 942 | * which is a difference of 2 characters, so we allocate strlen(args) + |
| 943 | * 2 characters. |
| 944 | */ |
| 945 | ret = kzalloc(len * sizeof(char), GFP_NOFS); |
| 946 | if (!ret) |
| 947 | return NULL; |
| 948 | pos = strstr(args, "subvol="); |
| 949 | |
| 950 | /* This shouldn't happen, but just in case.. */ |
| 951 | if (!pos) { |
| 952 | kfree(ret); |
| 953 | return NULL; |
| 954 | } |
| 955 | |
| 956 | /* |
| 957 | * The subvol=<> arg is not at the front of the string, copy everybody |
| 958 | * up to that into ret. |
| 959 | */ |
| 960 | if (pos != args) { |
| 961 | *pos = '\0'; |
| 962 | strcpy(ret, args); |
| 963 | copied += strlen(args); |
| 964 | pos++; |
| 965 | } |
| 966 | |
| 967 | strncpy(ret + copied, "subvolid=0", len - copied); |
| 968 | |
| 969 | /* Length of subvolid=0 */ |
| 970 | copied += 10; |
| 971 | |
| 972 | /* |
| 973 | * If there is no , after the subvol= option then we know there's no |
| 974 | * other options and we can just return. |
| 975 | */ |
| 976 | pos = strchr(pos, ','); |
| 977 | if (!pos) |
| 978 | return ret; |
| 979 | |
| 980 | /* Copy the rest of the arguments into our buffer */ |
| 981 | strncpy(ret + copied, pos, len - copied); |
| 982 | copied += strlen(pos); |
| 983 | |
| 984 | return ret; |
| 985 | } |
| 986 | |
| 987 | static struct dentry *mount_subvol(const char *subvol_name, int flags, |
| 988 | const char *device_name, char *data) |
| 989 | { |
| 990 | struct dentry *root; |
| 991 | struct vfsmount *mnt; |
| 992 | char *newargs; |
| 993 | |
| 994 | newargs = setup_root_args(data); |
| 995 | if (!newargs) |
| 996 | return ERR_PTR(-ENOMEM); |
| 997 | mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, |
| 998 | newargs); |
| 999 | kfree(newargs); |
| 1000 | if (IS_ERR(mnt)) |
| 1001 | return ERR_CAST(mnt); |
| 1002 | |
| 1003 | root = mount_subtree(mnt, subvol_name); |
| 1004 | |
| 1005 | if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) { |
| 1006 | struct super_block *s = root->d_sb; |
| 1007 | dput(root); |
| 1008 | root = ERR_PTR(-EINVAL); |
| 1009 | deactivate_locked_super(s); |
| 1010 | printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n", |
| 1011 | subvol_name); |
| 1012 | } |
| 1013 | |
| 1014 | return root; |
| 1015 | } |
| 1016 | |
| 1017 | /* |
| 1018 | * Find a superblock for the given device / mount point. |
| 1019 | * |
| 1020 | * Note: This is based on get_sb_bdev from fs/super.c with a few additions |
| 1021 | * for multiple device setup. Make sure to keep it in sync. |
| 1022 | */ |
| 1023 | static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, |
| 1024 | const char *device_name, void *data) |
| 1025 | { |
| 1026 | struct block_device *bdev = NULL; |
| 1027 | struct super_block *s; |
| 1028 | struct dentry *root; |
| 1029 | struct btrfs_fs_devices *fs_devices = NULL; |
| 1030 | struct btrfs_fs_info *fs_info = NULL; |
| 1031 | fmode_t mode = FMODE_READ; |
| 1032 | char *subvol_name = NULL; |
| 1033 | u64 subvol_objectid = 0; |
| 1034 | u64 subvol_rootid = 0; |
| 1035 | int error = 0; |
| 1036 | |
| 1037 | if (!(flags & MS_RDONLY)) |
| 1038 | mode |= FMODE_WRITE; |
| 1039 | |
| 1040 | error = btrfs_parse_early_options(data, mode, fs_type, |
| 1041 | &subvol_name, &subvol_objectid, |
| 1042 | &subvol_rootid, &fs_devices); |
| 1043 | if (error) { |
| 1044 | kfree(subvol_name); |
| 1045 | return ERR_PTR(error); |
| 1046 | } |
| 1047 | |
| 1048 | if (subvol_name) { |
| 1049 | root = mount_subvol(subvol_name, flags, device_name, data); |
| 1050 | kfree(subvol_name); |
| 1051 | return root; |
| 1052 | } |
| 1053 | |
| 1054 | error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); |
| 1055 | if (error) |
| 1056 | return ERR_PTR(error); |
| 1057 | |
| 1058 | /* |
| 1059 | * Setup a dummy root and fs_info for test/set super. This is because |
| 1060 | * we don't actually fill this stuff out until open_ctree, but we need |
| 1061 | * it for searching for existing supers, so this lets us do that and |
| 1062 | * then open_ctree will properly initialize everything later. |
| 1063 | */ |
| 1064 | fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); |
| 1065 | if (!fs_info) |
| 1066 | return ERR_PTR(-ENOMEM); |
| 1067 | |
| 1068 | fs_info->fs_devices = fs_devices; |
| 1069 | |
| 1070 | fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); |
| 1071 | fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); |
| 1072 | if (!fs_info->super_copy || !fs_info->super_for_commit) { |
| 1073 | error = -ENOMEM; |
| 1074 | goto error_fs_info; |
| 1075 | } |
| 1076 | |
| 1077 | error = btrfs_open_devices(fs_devices, mode, fs_type); |
| 1078 | if (error) |
| 1079 | goto error_fs_info; |
| 1080 | |
| 1081 | if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { |
| 1082 | error = -EACCES; |
| 1083 | goto error_close_devices; |
| 1084 | } |
| 1085 | |
| 1086 | bdev = fs_devices->latest_bdev; |
| 1087 | s = sget(fs_type, btrfs_test_super, btrfs_set_super, fs_info); |
| 1088 | if (IS_ERR(s)) { |
| 1089 | error = PTR_ERR(s); |
| 1090 | goto error_close_devices; |
| 1091 | } |
| 1092 | |
| 1093 | if (s->s_root) { |
| 1094 | btrfs_close_devices(fs_devices); |
| 1095 | free_fs_info(fs_info); |
| 1096 | if ((flags ^ s->s_flags) & MS_RDONLY) |
| 1097 | error = -EBUSY; |
| 1098 | } else { |
| 1099 | char b[BDEVNAME_SIZE]; |
| 1100 | |
| 1101 | s->s_flags = flags | MS_NOSEC; |
| 1102 | strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); |
| 1103 | btrfs_sb(s)->bdev_holder = fs_type; |
| 1104 | error = btrfs_fill_super(s, fs_devices, data, |
| 1105 | flags & MS_SILENT ? 1 : 0); |
| 1106 | } |
| 1107 | |
| 1108 | root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error); |
| 1109 | if (IS_ERR(root)) |
| 1110 | deactivate_locked_super(s); |
| 1111 | |
| 1112 | return root; |
| 1113 | |
| 1114 | error_close_devices: |
| 1115 | btrfs_close_devices(fs_devices); |
| 1116 | error_fs_info: |
| 1117 | free_fs_info(fs_info); |
| 1118 | return ERR_PTR(error); |
| 1119 | } |
| 1120 | |
| 1121 | static int btrfs_remount(struct super_block *sb, int *flags, char *data) |
| 1122 | { |
| 1123 | struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| 1124 | struct btrfs_root *root = fs_info->tree_root; |
| 1125 | unsigned old_flags = sb->s_flags; |
| 1126 | unsigned long old_opts = fs_info->mount_opt; |
| 1127 | unsigned long old_compress_type = fs_info->compress_type; |
| 1128 | u64 old_max_inline = fs_info->max_inline; |
| 1129 | u64 old_alloc_start = fs_info->alloc_start; |
| 1130 | int old_thread_pool_size = fs_info->thread_pool_size; |
| 1131 | unsigned int old_metadata_ratio = fs_info->metadata_ratio; |
| 1132 | int ret; |
| 1133 | |
| 1134 | ret = btrfs_parse_options(root, data); |
| 1135 | if (ret) { |
| 1136 | ret = -EINVAL; |
| 1137 | goto restore; |
| 1138 | } |
| 1139 | |
| 1140 | if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) |
| 1141 | return 0; |
| 1142 | |
| 1143 | if (*flags & MS_RDONLY) { |
| 1144 | sb->s_flags |= MS_RDONLY; |
| 1145 | |
| 1146 | ret = btrfs_commit_super(root); |
| 1147 | if (ret) |
| 1148 | goto restore; |
| 1149 | } else { |
| 1150 | if (fs_info->fs_devices->rw_devices == 0) { |
| 1151 | ret = -EACCES; |
| 1152 | goto restore; |
| 1153 | } |
| 1154 | |
| 1155 | if (btrfs_super_log_root(fs_info->super_copy) != 0) { |
| 1156 | ret = -EINVAL; |
| 1157 | goto restore; |
| 1158 | } |
| 1159 | |
| 1160 | ret = btrfs_cleanup_fs_roots(fs_info); |
| 1161 | if (ret) |
| 1162 | goto restore; |
| 1163 | |
| 1164 | /* recover relocation */ |
| 1165 | ret = btrfs_recover_relocation(root); |
| 1166 | if (ret) |
| 1167 | goto restore; |
| 1168 | |
| 1169 | sb->s_flags &= ~MS_RDONLY; |
| 1170 | } |
| 1171 | |
| 1172 | return 0; |
| 1173 | |
| 1174 | restore: |
| 1175 | /* We've hit an error - don't reset MS_RDONLY */ |
| 1176 | if (sb->s_flags & MS_RDONLY) |
| 1177 | old_flags |= MS_RDONLY; |
| 1178 | sb->s_flags = old_flags; |
| 1179 | fs_info->mount_opt = old_opts; |
| 1180 | fs_info->compress_type = old_compress_type; |
| 1181 | fs_info->max_inline = old_max_inline; |
| 1182 | fs_info->alloc_start = old_alloc_start; |
| 1183 | fs_info->thread_pool_size = old_thread_pool_size; |
| 1184 | fs_info->metadata_ratio = old_metadata_ratio; |
| 1185 | return ret; |
| 1186 | } |
| 1187 | |
| 1188 | /* Used to sort the devices by max_avail(descending sort) */ |
| 1189 | static int btrfs_cmp_device_free_bytes(const void *dev_info1, |
| 1190 | const void *dev_info2) |
| 1191 | { |
| 1192 | if (((struct btrfs_device_info *)dev_info1)->max_avail > |
| 1193 | ((struct btrfs_device_info *)dev_info2)->max_avail) |
| 1194 | return -1; |
| 1195 | else if (((struct btrfs_device_info *)dev_info1)->max_avail < |
| 1196 | ((struct btrfs_device_info *)dev_info2)->max_avail) |
| 1197 | return 1; |
| 1198 | else |
| 1199 | return 0; |
| 1200 | } |
| 1201 | |
| 1202 | /* |
| 1203 | * sort the devices by max_avail, in which max free extent size of each device |
| 1204 | * is stored.(Descending Sort) |
| 1205 | */ |
| 1206 | static inline void btrfs_descending_sort_devices( |
| 1207 | struct btrfs_device_info *devices, |
| 1208 | size_t nr_devices) |
| 1209 | { |
| 1210 | sort(devices, nr_devices, sizeof(struct btrfs_device_info), |
| 1211 | btrfs_cmp_device_free_bytes, NULL); |
| 1212 | } |
| 1213 | |
| 1214 | /* |
| 1215 | * The helper to calc the free space on the devices that can be used to store |
| 1216 | * file data. |
| 1217 | */ |
| 1218 | static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) |
| 1219 | { |
| 1220 | struct btrfs_fs_info *fs_info = root->fs_info; |
| 1221 | struct btrfs_device_info *devices_info; |
| 1222 | struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; |
| 1223 | struct btrfs_device *device; |
| 1224 | u64 skip_space; |
| 1225 | u64 type; |
| 1226 | u64 avail_space; |
| 1227 | u64 used_space; |
| 1228 | u64 min_stripe_size; |
| 1229 | int min_stripes = 1, num_stripes = 1; |
| 1230 | int i = 0, nr_devices; |
| 1231 | int ret; |
| 1232 | |
| 1233 | nr_devices = fs_info->fs_devices->open_devices; |
| 1234 | BUG_ON(!nr_devices); |
| 1235 | |
| 1236 | devices_info = kmalloc(sizeof(*devices_info) * nr_devices, |
| 1237 | GFP_NOFS); |
| 1238 | if (!devices_info) |
| 1239 | return -ENOMEM; |
| 1240 | |
| 1241 | /* calc min stripe number for data space alloction */ |
| 1242 | type = btrfs_get_alloc_profile(root, 1); |
| 1243 | if (type & BTRFS_BLOCK_GROUP_RAID0) { |
| 1244 | min_stripes = 2; |
| 1245 | num_stripes = nr_devices; |
| 1246 | } else if (type & BTRFS_BLOCK_GROUP_RAID1) { |
| 1247 | min_stripes = 2; |
| 1248 | num_stripes = 2; |
| 1249 | } else if (type & BTRFS_BLOCK_GROUP_RAID10) { |
| 1250 | min_stripes = 4; |
| 1251 | num_stripes = 4; |
| 1252 | } |
| 1253 | |
| 1254 | if (type & BTRFS_BLOCK_GROUP_DUP) |
| 1255 | min_stripe_size = 2 * BTRFS_STRIPE_LEN; |
| 1256 | else |
| 1257 | min_stripe_size = BTRFS_STRIPE_LEN; |
| 1258 | |
| 1259 | list_for_each_entry(device, &fs_devices->devices, dev_list) { |
| 1260 | if (!device->in_fs_metadata || !device->bdev) |
| 1261 | continue; |
| 1262 | |
| 1263 | avail_space = device->total_bytes - device->bytes_used; |
| 1264 | |
| 1265 | /* align with stripe_len */ |
| 1266 | do_div(avail_space, BTRFS_STRIPE_LEN); |
| 1267 | avail_space *= BTRFS_STRIPE_LEN; |
| 1268 | |
| 1269 | /* |
| 1270 | * In order to avoid overwritting the superblock on the drive, |
| 1271 | * btrfs starts at an offset of at least 1MB when doing chunk |
| 1272 | * allocation. |
| 1273 | */ |
| 1274 | skip_space = 1024 * 1024; |
| 1275 | |
| 1276 | /* user can set the offset in fs_info->alloc_start. */ |
| 1277 | if (fs_info->alloc_start + BTRFS_STRIPE_LEN <= |
| 1278 | device->total_bytes) |
| 1279 | skip_space = max(fs_info->alloc_start, skip_space); |
| 1280 | |
| 1281 | /* |
| 1282 | * btrfs can not use the free space in [0, skip_space - 1], |
| 1283 | * we must subtract it from the total. In order to implement |
| 1284 | * it, we account the used space in this range first. |
| 1285 | */ |
| 1286 | ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1, |
| 1287 | &used_space); |
| 1288 | if (ret) { |
| 1289 | kfree(devices_info); |
| 1290 | return ret; |
| 1291 | } |
| 1292 | |
| 1293 | /* calc the free space in [0, skip_space - 1] */ |
| 1294 | skip_space -= used_space; |
| 1295 | |
| 1296 | /* |
| 1297 | * we can use the free space in [0, skip_space - 1], subtract |
| 1298 | * it from the total. |
| 1299 | */ |
| 1300 | if (avail_space && avail_space >= skip_space) |
| 1301 | avail_space -= skip_space; |
| 1302 | else |
| 1303 | avail_space = 0; |
| 1304 | |
| 1305 | if (avail_space < min_stripe_size) |
| 1306 | continue; |
| 1307 | |
| 1308 | devices_info[i].dev = device; |
| 1309 | devices_info[i].max_avail = avail_space; |
| 1310 | |
| 1311 | i++; |
| 1312 | } |
| 1313 | |
| 1314 | nr_devices = i; |
| 1315 | |
| 1316 | btrfs_descending_sort_devices(devices_info, nr_devices); |
| 1317 | |
| 1318 | i = nr_devices - 1; |
| 1319 | avail_space = 0; |
| 1320 | while (nr_devices >= min_stripes) { |
| 1321 | if (num_stripes > nr_devices) |
| 1322 | num_stripes = nr_devices; |
| 1323 | |
| 1324 | if (devices_info[i].max_avail >= min_stripe_size) { |
| 1325 | int j; |
| 1326 | u64 alloc_size; |
| 1327 | |
| 1328 | avail_space += devices_info[i].max_avail * num_stripes; |
| 1329 | alloc_size = devices_info[i].max_avail; |
| 1330 | for (j = i + 1 - num_stripes; j <= i; j++) |
| 1331 | devices_info[j].max_avail -= alloc_size; |
| 1332 | } |
| 1333 | i--; |
| 1334 | nr_devices--; |
| 1335 | } |
| 1336 | |
| 1337 | kfree(devices_info); |
| 1338 | *free_bytes = avail_space; |
| 1339 | return 0; |
| 1340 | } |
| 1341 | |
| 1342 | static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 1343 | { |
| 1344 | struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); |
| 1345 | struct btrfs_super_block *disk_super = fs_info->super_copy; |
| 1346 | struct list_head *head = &fs_info->space_info; |
| 1347 | struct btrfs_space_info *found; |
| 1348 | u64 total_used = 0; |
| 1349 | u64 total_free_data = 0; |
| 1350 | int bits = dentry->d_sb->s_blocksize_bits; |
| 1351 | __be32 *fsid = (__be32 *)fs_info->fsid; |
| 1352 | int ret; |
| 1353 | |
| 1354 | /* holding chunk_muext to avoid allocating new chunks */ |
| 1355 | mutex_lock(&fs_info->chunk_mutex); |
| 1356 | rcu_read_lock(); |
| 1357 | list_for_each_entry_rcu(found, head, list) { |
| 1358 | if (found->flags & BTRFS_BLOCK_GROUP_DATA) { |
| 1359 | total_free_data += found->disk_total - found->disk_used; |
| 1360 | total_free_data -= |
| 1361 | btrfs_account_ro_block_groups_free_space(found); |
| 1362 | } |
| 1363 | |
| 1364 | total_used += found->disk_used; |
| 1365 | } |
| 1366 | rcu_read_unlock(); |
| 1367 | |
| 1368 | buf->f_namelen = BTRFS_NAME_LEN; |
| 1369 | buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; |
| 1370 | buf->f_bfree = buf->f_blocks - (total_used >> bits); |
| 1371 | buf->f_bsize = dentry->d_sb->s_blocksize; |
| 1372 | buf->f_type = BTRFS_SUPER_MAGIC; |
| 1373 | buf->f_bavail = total_free_data; |
| 1374 | ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data); |
| 1375 | if (ret) { |
| 1376 | mutex_unlock(&fs_info->chunk_mutex); |
| 1377 | return ret; |
| 1378 | } |
| 1379 | buf->f_bavail += total_free_data; |
| 1380 | buf->f_bavail = buf->f_bavail >> bits; |
| 1381 | mutex_unlock(&fs_info->chunk_mutex); |
| 1382 | |
| 1383 | /* We treat it as constant endianness (it doesn't matter _which_) |
| 1384 | because we want the fsid to come out the same whether mounted |
| 1385 | on a big-endian or little-endian host */ |
| 1386 | buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); |
| 1387 | buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); |
| 1388 | /* Mask in the root object ID too, to disambiguate subvols */ |
| 1389 | buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; |
| 1390 | buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; |
| 1391 | |
| 1392 | return 0; |
| 1393 | } |
| 1394 | |
| 1395 | static void btrfs_kill_super(struct super_block *sb) |
| 1396 | { |
| 1397 | struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| 1398 | kill_anon_super(sb); |
| 1399 | free_fs_info(fs_info); |
| 1400 | } |
| 1401 | |
| 1402 | static struct file_system_type btrfs_fs_type = { |
| 1403 | .owner = THIS_MODULE, |
| 1404 | .name = "btrfs", |
| 1405 | .mount = btrfs_mount, |
| 1406 | .kill_sb = btrfs_kill_super, |
| 1407 | .fs_flags = FS_REQUIRES_DEV, |
| 1408 | }; |
| 1409 | |
| 1410 | /* |
| 1411 | * used by btrfsctl to scan devices when no FS is mounted |
| 1412 | */ |
| 1413 | static long btrfs_control_ioctl(struct file *file, unsigned int cmd, |
| 1414 | unsigned long arg) |
| 1415 | { |
| 1416 | struct btrfs_ioctl_vol_args *vol; |
| 1417 | struct btrfs_fs_devices *fs_devices; |
| 1418 | int ret = -ENOTTY; |
| 1419 | |
| 1420 | if (!capable(CAP_SYS_ADMIN)) |
| 1421 | return -EPERM; |
| 1422 | |
| 1423 | vol = memdup_user((void __user *)arg, sizeof(*vol)); |
| 1424 | if (IS_ERR(vol)) |
| 1425 | return PTR_ERR(vol); |
| 1426 | |
| 1427 | switch (cmd) { |
| 1428 | case BTRFS_IOC_SCAN_DEV: |
| 1429 | ret = btrfs_scan_one_device(vol->name, FMODE_READ, |
| 1430 | &btrfs_fs_type, &fs_devices); |
| 1431 | break; |
| 1432 | } |
| 1433 | |
| 1434 | kfree(vol); |
| 1435 | return ret; |
| 1436 | } |
| 1437 | |
| 1438 | static int btrfs_freeze(struct super_block *sb) |
| 1439 | { |
| 1440 | struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| 1441 | mutex_lock(&fs_info->transaction_kthread_mutex); |
| 1442 | mutex_lock(&fs_info->cleaner_mutex); |
| 1443 | return 0; |
| 1444 | } |
| 1445 | |
| 1446 | static int btrfs_unfreeze(struct super_block *sb) |
| 1447 | { |
| 1448 | struct btrfs_fs_info *fs_info = btrfs_sb(sb); |
| 1449 | mutex_unlock(&fs_info->cleaner_mutex); |
| 1450 | mutex_unlock(&fs_info->transaction_kthread_mutex); |
| 1451 | return 0; |
| 1452 | } |
| 1453 | |
| 1454 | static void btrfs_fs_dirty_inode(struct inode *inode, int flags) |
| 1455 | { |
| 1456 | int ret; |
| 1457 | |
| 1458 | ret = btrfs_dirty_inode(inode); |
| 1459 | if (ret) |
| 1460 | printk_ratelimited(KERN_ERR "btrfs: fail to dirty inode %Lu " |
| 1461 | "error %d\n", btrfs_ino(inode), ret); |
| 1462 | } |
| 1463 | |
| 1464 | static const struct super_operations btrfs_super_ops = { |
| 1465 | .drop_inode = btrfs_drop_inode, |
| 1466 | .evict_inode = btrfs_evict_inode, |
| 1467 | .put_super = btrfs_put_super, |
| 1468 | .sync_fs = btrfs_sync_fs, |
| 1469 | .show_options = btrfs_show_options, |
| 1470 | .write_inode = btrfs_write_inode, |
| 1471 | .dirty_inode = btrfs_fs_dirty_inode, |
| 1472 | .alloc_inode = btrfs_alloc_inode, |
| 1473 | .destroy_inode = btrfs_destroy_inode, |
| 1474 | .statfs = btrfs_statfs, |
| 1475 | .remount_fs = btrfs_remount, |
| 1476 | .freeze_fs = btrfs_freeze, |
| 1477 | .unfreeze_fs = btrfs_unfreeze, |
| 1478 | }; |
| 1479 | |
| 1480 | static const struct file_operations btrfs_ctl_fops = { |
| 1481 | .unlocked_ioctl = btrfs_control_ioctl, |
| 1482 | .compat_ioctl = btrfs_control_ioctl, |
| 1483 | .owner = THIS_MODULE, |
| 1484 | .llseek = noop_llseek, |
| 1485 | }; |
| 1486 | |
| 1487 | static struct miscdevice btrfs_misc = { |
| 1488 | .minor = BTRFS_MINOR, |
| 1489 | .name = "btrfs-control", |
| 1490 | .fops = &btrfs_ctl_fops |
| 1491 | }; |
| 1492 | |
| 1493 | MODULE_ALIAS_MISCDEV(BTRFS_MINOR); |
| 1494 | MODULE_ALIAS("devname:btrfs-control"); |
| 1495 | |
| 1496 | static int btrfs_interface_init(void) |
| 1497 | { |
| 1498 | return misc_register(&btrfs_misc); |
| 1499 | } |
| 1500 | |
| 1501 | static void btrfs_interface_exit(void) |
| 1502 | { |
| 1503 | if (misc_deregister(&btrfs_misc) < 0) |
| 1504 | printk(KERN_INFO "misc_deregister failed for control device"); |
| 1505 | } |
| 1506 | |
| 1507 | static int __init init_btrfs_fs(void) |
| 1508 | { |
| 1509 | int err; |
| 1510 | |
| 1511 | err = btrfs_init_sysfs(); |
| 1512 | if (err) |
| 1513 | return err; |
| 1514 | |
| 1515 | btrfs_init_compress(); |
| 1516 | |
| 1517 | err = btrfs_init_cachep(); |
| 1518 | if (err) |
| 1519 | goto free_compress; |
| 1520 | |
| 1521 | err = extent_io_init(); |
| 1522 | if (err) |
| 1523 | goto free_cachep; |
| 1524 | |
| 1525 | err = extent_map_init(); |
| 1526 | if (err) |
| 1527 | goto free_extent_io; |
| 1528 | |
| 1529 | err = btrfs_delayed_inode_init(); |
| 1530 | if (err) |
| 1531 | goto free_extent_map; |
| 1532 | |
| 1533 | err = btrfs_interface_init(); |
| 1534 | if (err) |
| 1535 | goto free_delayed_inode; |
| 1536 | |
| 1537 | err = register_filesystem(&btrfs_fs_type); |
| 1538 | if (err) |
| 1539 | goto unregister_ioctl; |
| 1540 | |
| 1541 | btrfs_init_lockdep(); |
| 1542 | |
| 1543 | printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); |
| 1544 | return 0; |
| 1545 | |
| 1546 | unregister_ioctl: |
| 1547 | btrfs_interface_exit(); |
| 1548 | free_delayed_inode: |
| 1549 | btrfs_delayed_inode_exit(); |
| 1550 | free_extent_map: |
| 1551 | extent_map_exit(); |
| 1552 | free_extent_io: |
| 1553 | extent_io_exit(); |
| 1554 | free_cachep: |
| 1555 | btrfs_destroy_cachep(); |
| 1556 | free_compress: |
| 1557 | btrfs_exit_compress(); |
| 1558 | btrfs_exit_sysfs(); |
| 1559 | return err; |
| 1560 | } |
| 1561 | |
| 1562 | static void __exit exit_btrfs_fs(void) |
| 1563 | { |
| 1564 | btrfs_destroy_cachep(); |
| 1565 | btrfs_delayed_inode_exit(); |
| 1566 | extent_map_exit(); |
| 1567 | extent_io_exit(); |
| 1568 | btrfs_interface_exit(); |
| 1569 | unregister_filesystem(&btrfs_fs_type); |
| 1570 | btrfs_exit_sysfs(); |
| 1571 | btrfs_cleanup_fs_uuids(); |
| 1572 | btrfs_exit_compress(); |
| 1573 | } |
| 1574 | |
| 1575 | module_init(init_btrfs_fs) |
| 1576 | module_exit(exit_btrfs_fs) |
| 1577 | |
| 1578 | MODULE_LICENSE("GPL"); |