// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2007 Oracle. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "delayed-inode.h" #include "ctree.h" #include "disk-io.h" #include "transaction.h" #include "btrfs_inode.h" #include "print-tree.h" #include "props.h" #include "xattr.h" #include "volumes.h" #include "export.h" #include "compression.h" #include "rcu-string.h" #include "dev-replace.h" #include "free-space-cache.h" #include "backref.h" #include "tests/btrfs-tests.h" #include "qgroup.h" #define CREATE_TRACE_POINTS #include static const struct super_operations btrfs_super_ops; /* * Types for mounting the default subvolume and a subvolume explicitly * requested by subvol=/path. That way the callchain is straightforward and we * don't have to play tricks with the mount options and recursive calls to * btrfs_mount. * * The new btrfs_root_fs_type also servers as a tag for the bdev_holder. */ static struct file_system_type btrfs_fs_type; static struct file_system_type btrfs_root_fs_type; static int btrfs_remount(struct super_block *sb, int *flags, char *data); const char *btrfs_decode_error(int errno) { char *errstr = "unknown"; switch (errno) { case -EIO: errstr = "IO failure"; break; case -ENOMEM: errstr = "Out of memory"; break; case -EROFS: errstr = "Readonly filesystem"; break; case -EEXIST: errstr = "Object already exists"; break; case -ENOSPC: errstr = "No space left"; break; case -ENOENT: errstr = "No such entry"; break; } return errstr; } /* * __btrfs_handle_fs_error decodes expected errors from the caller and * invokes the approciate error response. */ __cold void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function, unsigned int line, int errno, const char *fmt, ...) { struct super_block *sb = fs_info->sb; #ifdef CONFIG_PRINTK const char *errstr; #endif /* * Special case: if the error is EROFS, and we're already * under SB_RDONLY, then it is safe here. */ if (errno == -EROFS && sb_rdonly(sb)) return; #ifdef CONFIG_PRINTK errstr = btrfs_decode_error(errno); if (fmt) { struct va_format vaf; va_list args; va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n", sb->s_id, function, line, errno, errstr, &vaf); va_end(args); } else { pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n", sb->s_id, function, line, errno, errstr); } #endif /* * Today we only save the error info to memory. Long term we'll * also send it down to the disk */ set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state); /* Don't go through full error handling during mount */ if (!(sb->s_flags & SB_BORN)) return; if (sb_rdonly(sb)) return; /* btrfs handle error by forcing the filesystem readonly */ sb->s_flags |= SB_RDONLY; btrfs_info(fs_info, "forced readonly"); /* * Note that a running device replace operation is not canceled here * although there is no way to update the progress. It would add the * risk of a deadlock, therefore the canceling is omitted. The only * penalty is that some I/O remains active until the procedure * completes. The next time when the filesystem is mounted writeable * again, the device replace operation continues. */ } #ifdef CONFIG_PRINTK static const char * const logtypes[] = { "emergency", "alert", "critical", "error", "warning", "notice", "info", "debug", }; /* * Use one ratelimit state per log level so that a flood of less important * messages doesn't cause more important ones to be dropped. */ static struct ratelimit_state printk_limits[] = { RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100), RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100), RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100), RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100), RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100), RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100), RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100), RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100), }; void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...) { char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0"; struct va_format vaf; va_list args; int kern_level; const char *type = logtypes[4]; struct ratelimit_state *ratelimit = &printk_limits[4]; va_start(args, fmt); while ((kern_level = printk_get_level(fmt)) != 0) { size_t size = printk_skip_level(fmt) - fmt; if (kern_level >= '0' && kern_level <= '7') { memcpy(lvl, fmt, size); lvl[size] = '\0'; type = logtypes[kern_level - '0']; ratelimit = &printk_limits[kern_level - '0']; } fmt += size; } vaf.fmt = fmt; vaf.va = &args; if (__ratelimit(ratelimit)) printk("%sBTRFS %s (device %s): %pV\n", lvl, type, fs_info ? fs_info->sb->s_id : "", &vaf); va_end(args); } #endif /* * We only mark the transaction aborted and then set the file system read-only. * This will prevent new transactions from starting or trying to join this * one. * * This means that error recovery at the call site is limited to freeing * any local memory allocations and passing the error code up without * further cleanup. The transaction should complete as it normally would * in the call path but will return -EIO. * * We'll complete the cleanup in btrfs_end_transaction and * btrfs_commit_transaction. */ __cold void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, const char *function, unsigned int line, int errno) { struct btrfs_fs_info *fs_info = trans->fs_info; trans->aborted = errno; /* Nothing used. The other threads that have joined this * transaction may be able to continue. */ if (!trans->dirty && list_empty(&trans->new_bgs)) { const char *errstr; errstr = btrfs_decode_error(errno); btrfs_warn(fs_info, "%s:%d: Aborting unused transaction(%s).", function, line, errstr); return; } WRITE_ONCE(trans->transaction->aborted, errno); /* Wake up anybody who may be waiting on this transaction */ wake_up(&fs_info->transaction_wait); wake_up(&fs_info->transaction_blocked_wait); __btrfs_handle_fs_error(fs_info, function, line, errno, NULL); } /* * __btrfs_panic decodes unexpected, fatal errors from the caller, * issues an alert, and either panics or BUGs, depending on mount options. */ __cold void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, unsigned int line, int errno, const char *fmt, ...) { char *s_id = ""; const char *errstr; struct va_format vaf = { .fmt = fmt }; va_list args; if (fs_info) s_id = fs_info->sb->s_id; va_start(args, fmt); vaf.va = &args; errstr = btrfs_decode_error(errno); if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR))) panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n", s_id, function, line, &vaf, errno, errstr); btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)", function, line, &vaf, errno, errstr); va_end(args); /* Caller calls BUG() */ } static void btrfs_put_super(struct super_block *sb) { close_ctree(btrfs_sb(sb)); } enum { Opt_acl, Opt_noacl, Opt_clear_cache, Opt_commit_interval, Opt_compress, Opt_compress_force, Opt_compress_force_type, Opt_compress_type, Opt_degraded, Opt_device, Opt_fatal_errors, Opt_flushoncommit, Opt_noflushoncommit, Opt_inode_cache, Opt_noinode_cache, Opt_max_inline, Opt_barrier, Opt_nobarrier, Opt_datacow, Opt_nodatacow, Opt_datasum, Opt_nodatasum, Opt_defrag, Opt_nodefrag, Opt_discard, Opt_nodiscard, Opt_nologreplay, Opt_norecovery, Opt_ratio, Opt_rescan_uuid_tree, Opt_skip_balance, Opt_space_cache, Opt_no_space_cache, Opt_space_cache_version, Opt_ssd, Opt_nossd, Opt_ssd_spread, Opt_nossd_spread, Opt_subvol, Opt_subvol_empty, Opt_subvolid, Opt_thread_pool, Opt_treelog, Opt_notreelog, Opt_usebackuproot, Opt_user_subvol_rm_allowed, /* Deprecated options */ Opt_alloc_start, Opt_recovery, Opt_subvolrootid, /* Debugging options */ Opt_check_integrity, Opt_check_integrity_including_extent_data, Opt_check_integrity_print_mask, Opt_enospc_debug, Opt_noenospc_debug, #ifdef CONFIG_BTRFS_DEBUG Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all, #endif #ifdef CONFIG_BTRFS_FS_REF_VERIFY Opt_ref_verify, #endif Opt_err, }; static const match_table_t tokens = { {Opt_acl, "acl"}, {Opt_noacl, "noacl"}, {Opt_clear_cache, "clear_cache"}, {Opt_commit_interval, "commit=%u"}, {Opt_compress, "compress"}, {Opt_compress_type, "compress=%s"}, {Opt_compress_force, "compress-force"}, {Opt_compress_force_type, "compress-force=%s"}, {Opt_degraded, "degraded"}, {Opt_device, "device=%s"}, {Opt_fatal_errors, "fatal_errors=%s"}, {Opt_flushoncommit, "flushoncommit"}, {Opt_noflushoncommit, "noflushoncommit"}, {Opt_inode_cache, "inode_cache"}, {Opt_noinode_cache, "noinode_cache"}, {Opt_max_inline, "max_inline=%s"}, {Opt_barrier, "barrier"}, {Opt_nobarrier, "nobarrier"}, {Opt_datacow, "datacow"}, {Opt_nodatacow, "nodatacow"}, {Opt_datasum, "datasum"}, {Opt_nodatasum, "nodatasum"}, {Opt_defrag, "autodefrag"}, {Opt_nodefrag, "noautodefrag"}, {Opt_discard, "discard"}, {Opt_nodiscard, "nodiscard"}, {Opt_nologreplay, "nologreplay"}, {Opt_norecovery, "norecovery"}, {Opt_ratio, "metadata_ratio=%u"}, {Opt_rescan_uuid_tree, "rescan_uuid_tree"}, {Opt_skip_balance, "skip_balance"}, {Opt_space_cache, "space_cache"}, {Opt_no_space_cache, "nospace_cache"}, {Opt_space_cache_version, "space_cache=%s"}, {Opt_ssd, "ssd"}, {Opt_nossd, "nossd"}, {Opt_ssd_spread, "ssd_spread"}, {Opt_nossd_spread, "nossd_spread"}, {Opt_subvol, "subvol=%s"}, {Opt_subvol_empty, "subvol="}, {Opt_subvolid, "subvolid=%s"}, {Opt_thread_pool, "thread_pool=%u"}, {Opt_treelog, "treelog"}, {Opt_notreelog, "notreelog"}, {Opt_usebackuproot, "usebackuproot"}, {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, /* Deprecated options */ {Opt_alloc_start, "alloc_start=%s"}, {Opt_recovery, "recovery"}, {Opt_subvolrootid, "subvolrootid=%d"}, /* Debugging options */ {Opt_check_integrity, "check_int"}, {Opt_check_integrity_including_extent_data, "check_int_data"}, {Opt_check_integrity_print_mask, "check_int_print_mask=%u"}, {Opt_enospc_debug, "enospc_debug"}, {Opt_noenospc_debug, "noenospc_debug"}, #ifdef CONFIG_BTRFS_DEBUG {Opt_fragment_data, "fragment=data"}, {Opt_fragment_metadata, "fragment=metadata"}, {Opt_fragment_all, "fragment=all"}, #endif #ifdef CONFIG_BTRFS_FS_REF_VERIFY {Opt_ref_verify, "ref_verify"}, #endif {Opt_err, NULL}, }; /* * Regular mount options parser. Everything that is needed only when * reading in a new superblock is parsed here. * XXX JDM: This needs to be cleaned up for remount. */ int btrfs_parse_options(struct btrfs_fs_info *info, char *options, unsigned long new_flags) { substring_t args[MAX_OPT_ARGS]; char *p, *num; u64 cache_gen; int intarg; int ret = 0; char *compress_type; bool compress_force = false; enum btrfs_compression_type saved_compress_type; int saved_compress_level; bool saved_compress_force; int no_compress = 0; cache_gen = btrfs_super_cache_generation(info->super_copy); if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE)) btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE); else if (cache_gen) btrfs_set_opt(info->mount_opt, SPACE_CACHE); /* * Even the options are empty, we still need to do extra check * against new flags */ if (!options) goto check; while ((p = strsep(&options, ",")) != NULL) { int token; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case Opt_degraded: btrfs_info(info, "allowing degraded mounts"); btrfs_set_opt(info->mount_opt, DEGRADED); break; case Opt_subvol: case Opt_subvol_empty: case Opt_subvolid: case Opt_subvolrootid: case Opt_device: /* * These are parsed by btrfs_parse_subvol_options or * btrfs_parse_device_options and can be ignored here. */ break; case Opt_nodatasum: btrfs_set_and_info(info, NODATASUM, "setting nodatasum"); break; case Opt_datasum: if (btrfs_test_opt(info, NODATASUM)) { if (btrfs_test_opt(info, NODATACOW)) btrfs_info(info, "setting datasum, datacow enabled"); else btrfs_info(info, "setting datasum"); } btrfs_clear_opt(info->mount_opt, NODATACOW); btrfs_clear_opt(info->mount_opt, NODATASUM); break; case Opt_nodatacow: if (!btrfs_test_opt(info, NODATACOW)) { if (!btrfs_test_opt(info, COMPRESS) || !btrfs_test_opt(info, FORCE_COMPRESS)) { btrfs_info(info, "setting nodatacow, compression disabled"); } else { btrfs_info(info, "setting nodatacow"); } } btrfs_clear_opt(info->mount_opt, COMPRESS); btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); btrfs_set_opt(info->mount_opt, NODATACOW); btrfs_set_opt(info->mount_opt, NODATASUM); break; case Opt_datacow: btrfs_clear_and_info(info, NODATACOW, "setting datacow"); break; case Opt_compress_force: case Opt_compress_force_type: compress_force = true; /* Fallthrough */ case Opt_compress: case Opt_compress_type: saved_compress_type = btrfs_test_opt(info, COMPRESS) ? info->compress_type : BTRFS_COMPRESS_NONE; saved_compress_force = btrfs_test_opt(info, FORCE_COMPRESS); saved_compress_level = info->compress_level; if (token == Opt_compress || token == Opt_compress_force || strncmp(args[0].from, "zlib", 4) == 0) { compress_type = "zlib"; info->compress_type = BTRFS_COMPRESS_ZLIB; info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL; /* * args[0] contains uninitialized data since * for these tokens we don't expect any * parameter. */ if (token != Opt_compress && token != Opt_compress_force) info->compress_level = btrfs_compress_str2level(args[0].from); btrfs_set_opt(info->mount_opt, COMPRESS); btrfs_clear_opt(info->mount_opt, NODATACOW); btrfs_clear_opt(info->mount_opt, NODATASUM); no_compress = 0; } else if (strncmp(args[0].from, "lzo", 3) == 0) { compress_type = "lzo"; info->compress_type = BTRFS_COMPRESS_LZO; info->compress_level = 0; btrfs_set_opt(info->mount_opt, COMPRESS); btrfs_clear_opt(info->mount_opt, NODATACOW); btrfs_clear_opt(info->mount_opt, NODATASUM); btrfs_set_fs_incompat(info, COMPRESS_LZO); no_compress = 0; } else if (strcmp(args[0].from, "zstd") == 0) { compress_type = "zstd"; info->compress_type = BTRFS_COMPRESS_ZSTD; btrfs_set_opt(info->mount_opt, COMPRESS); btrfs_clear_opt(info->mount_opt, NODATACOW); btrfs_clear_opt(info->mount_opt, NODATASUM); btrfs_set_fs_incompat(info, COMPRESS_ZSTD); no_compress = 0; } else if (strncmp(args[0].from, "no", 2) == 0) { compress_type = "no"; info->compress_level = 0; info->compress_type = 0; btrfs_clear_opt(info->mount_opt, COMPRESS); btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); compress_force = false; no_compress++; } else { ret = -EINVAL; goto out; } if (compress_force) { btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); } else { /* * If we remount from compress-force=xxx to * compress=xxx, we need clear FORCE_COMPRESS * flag, otherwise, there is no way for users * to disable forcible compression separately. */ btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); } if (no_compress == 1) { btrfs_info(info, "use no compression"); } else if ((info->compress_type != saved_compress_type) || (compress_force != saved_compress_force) || (info->compress_level != saved_compress_level)) { btrfs_info(info, "%s %s compression, level %d", (compress_force) ? "force" : "use", compress_type, info->compress_level); } compress_force = false; break; case Opt_ssd: btrfs_set_and_info(info, SSD, "enabling ssd optimizations"); btrfs_clear_opt(info->mount_opt, NOSSD); break; case Opt_ssd_spread: btrfs_set_and_info(info, SSD, "enabling ssd optimizations"); btrfs_set_and_info(info, SSD_SPREAD, "using spread ssd allocation scheme"); btrfs_clear_opt(info->mount_opt, NOSSD); break; case Opt_nossd: btrfs_set_opt(info->mount_opt, NOSSD); btrfs_clear_and_info(info, SSD, "not using ssd optimizations"); /* Fallthrough */ case Opt_nossd_spread: btrfs_clear_and_info(info, SSD_SPREAD, "not using spread ssd allocation scheme"); break; case Opt_barrier: btrfs_clear_and_info(info, NOBARRIER, "turning on barriers"); break; case Opt_nobarrier: btrfs_set_and_info(info, NOBARRIER, "turning off barriers"); break; case Opt_thread_pool: ret = match_int(&args[0], &intarg); if (ret) { goto out; } else if (intarg == 0) { ret = -EINVAL; goto out; } info->thread_pool_size = intarg; break; case Opt_max_inline: num = match_strdup(&args[0]); if (num) { info->max_inline = memparse(num, NULL); kfree(num); if (info->max_inline) { info->max_inline = min_t(u64, info->max_inline, info->sectorsize); } btrfs_info(info, "max_inline at %llu", info->max_inline); } else { ret = -ENOMEM; goto out; } break; case Opt_alloc_start: btrfs_info(info, "option alloc_start is obsolete, ignored"); break; case Opt_acl: #ifdef CONFIG_BTRFS_FS_POSIX_ACL info->sb->s_flags |= SB_POSIXACL; break; #else btrfs_err(info, "support for ACL not compiled in!"); ret = -EINVAL; goto out; #endif case Opt_noacl: info->sb->s_flags &= ~SB_POSIXACL; break; case Opt_notreelog: btrfs_set_and_info(info, NOTREELOG, "disabling tree log"); break; case Opt_treelog: btrfs_clear_and_info(info, NOTREELOG, "enabling tree log"); break; case Opt_norecovery: case Opt_nologreplay: btrfs_set_and_info(info, NOLOGREPLAY, "disabling log replay at mount time"); break; case Opt_flushoncommit: btrfs_set_and_info(info, FLUSHONCOMMIT, "turning on flush-on-commit"); break; case Opt_noflushoncommit: btrfs_clear_and_info(info, FLUSHONCOMMIT, "turning off flush-on-commit"); break; case Opt_ratio: ret = match_int(&args[0], &intarg); if (ret) goto out; info->metadata_ratio = intarg; btrfs_info(info, "metadata ratio %u", info->metadata_ratio); break; case Opt_discard: btrfs_set_and_info(info, DISCARD, "turning on discard"); break; case Opt_nodiscard: btrfs_clear_and_info(info, DISCARD, "turning off discard"); break; case Opt_space_cache: case Opt_space_cache_version: if (token == Opt_space_cache || strcmp(args[0].from, "v1") == 0) { btrfs_clear_opt(info->mount_opt, FREE_SPACE_TREE); btrfs_set_and_info(info, SPACE_CACHE, "enabling disk space caching"); } else if (strcmp(args[0].from, "v2") == 0) { btrfs_clear_opt(info->mount_opt, SPACE_CACHE); btrfs_set_and_info(info, FREE_SPACE_TREE, "enabling free space tree"); } else { ret = -EINVAL; goto out; } break; case Opt_rescan_uuid_tree: btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE); break; case Opt_no_space_cache: if (btrfs_test_opt(info, SPACE_CACHE)) { btrfs_clear_and_info(info, SPACE_CACHE, "disabling disk space caching"); } if (btrfs_test_opt(info, FREE_SPACE_TREE)) { btrfs_clear_and_info(info, FREE_SPACE_TREE, "disabling free space tree"); } break; case Opt_inode_cache: btrfs_set_pending_and_info(info, INODE_MAP_CACHE, "enabling inode map caching"); break; case Opt_noinode_cache: btrfs_clear_pending_and_info(info, INODE_MAP_CACHE, "disabling inode map caching"); break; case Opt_clear_cache: btrfs_set_and_info(info, CLEAR_CACHE, "force clearing of disk cache"); break; case Opt_user_subvol_rm_allowed: btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); break; case Opt_enospc_debug: btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); break; case Opt_noenospc_debug: btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG); break; case Opt_defrag: btrfs_set_and_info(info, AUTO_DEFRAG, "enabling auto defrag"); break; case Opt_nodefrag: btrfs_clear_and_info(info, AUTO_DEFRAG, "disabling auto defrag"); break; case Opt_recovery: btrfs_warn(info, "'recovery' is deprecated, use 'usebackuproot' instead"); /* fall through */ case Opt_usebackuproot: btrfs_info(info, "trying to use backup root at mount time"); btrfs_set_opt(info->mount_opt, USEBACKUPROOT); break; case Opt_skip_balance: btrfs_set_opt(info->mount_opt, SKIP_BALANCE); break; #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY case Opt_check_integrity_including_extent_data: btrfs_info(info, "enabling check integrity including extent data"); btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA); btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); break; case Opt_check_integrity: btrfs_info(info, "enabling check integrity"); btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); break; case Opt_check_integrity_print_mask: ret = match_int(&args[0], &intarg); if (ret) goto out; info->check_integrity_print_mask = intarg; btrfs_info(info, "check_integrity_print_mask 0x%x", info->check_integrity_print_mask); break; #else case Opt_check_integrity_including_extent_data: case Opt_check_integrity: case Opt_check_integrity_print_mask: btrfs_err(info, "support for check_integrity* not compiled in!"); ret = -EINVAL; goto out; #endif case Opt_fatal_errors: if (strcmp(args[0].from, "panic") == 0) btrfs_set_opt(info->mount_opt, PANIC_ON_FATAL_ERROR); else if (strcmp(args[0].from, "bug") == 0) btrfs_clear_opt(info->mount_opt, PANIC_ON_FATAL_ERROR); else { ret = -EINVAL; goto out; } break; case Opt_commit_interval: intarg = 0; ret = match_int(&args[0], &intarg); if (ret) goto out; if (intarg == 0) { btrfs_info(info, "using default commit interval %us", BTRFS_DEFAULT_COMMIT_INTERVAL); intarg = BTRFS_DEFAULT_COMMIT_INTERVAL; } else if (intarg > 300) { btrfs_warn(info, "excessive commit interval %d", intarg); } info->commit_interval = intarg; break; #ifdef CONFIG_BTRFS_DEBUG case Opt_fragment_all: btrfs_info(info, "fragmenting all space"); btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA); break; case Opt_fragment_metadata: btrfs_info(info, "fragmenting metadata"); btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA); break; case Opt_fragment_data: btrfs_info(info, "fragmenting data"); btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); break; #endif #ifdef CONFIG_BTRFS_FS_REF_VERIFY case Opt_ref_verify: btrfs_info(info, "doing ref verification"); btrfs_set_opt(info->mount_opt, REF_VERIFY); break; #endif case Opt_err: btrfs_info(info, "unrecognized mount option '%s'", p); ret = -EINVAL; goto out; default: break; } } check: /* * Extra check for current option against current flag */ if (btrfs_test_opt(info, NOLOGREPLAY) && !(new_flags & SB_RDONLY)) { btrfs_err(info, "nologreplay must be used with ro mount option"); ret = -EINVAL; } out: if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) && !btrfs_test_opt(info, FREE_SPACE_TREE) && !btrfs_test_opt(info, CLEAR_CACHE)) { btrfs_err(info, "cannot disable free space tree"); ret = -EINVAL; } if (!ret && btrfs_test_opt(info, SPACE_CACHE)) btrfs_info(info, "disk space caching is enabled"); if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE)) btrfs_info(info, "using free space tree"); return ret; } /* * Parse mount options that are required early in the mount process. * * All other options will be parsed on much later in the mount process and * only when we need to allocate a new super block. */ static int btrfs_parse_device_options(const char *options, fmode_t flags, void *holder) { substring_t args[MAX_OPT_ARGS]; char *device_name, *opts, *orig, *p; struct btrfs_device *device = NULL; int error = 0; lockdep_assert_held(&uuid_mutex); if (!options) return 0; /* * strsep changes the string, duplicate it because btrfs_parse_options * gets called later */ opts = kstrdup(options, GFP_KERNEL); if (!opts) return -ENOMEM; orig = opts; while ((p = strsep(&opts, ",")) != NULL) { int token; if (!*p) continue; token = match_token(p, tokens, args); if (token == Opt_device) { device_name = match_strdup(&args[0]); if (!device_name) { error = -ENOMEM; goto out; } device = btrfs_scan_one_device(device_name, flags, holder); kfree(device_name); if (IS_ERR(device)) { error = PTR_ERR(device); goto out; } } } out: kfree(orig); return error; } /* * Parse mount options that are related to subvolume id * * The value is later passed to mount_subvol() */ static int btrfs_parse_subvol_options(const char *options, char **subvol_name, u64 *subvol_objectid) { substring_t args[MAX_OPT_ARGS]; char *opts, *orig, *p; int error = 0; u64 subvolid; if (!options) return 0; /* * strsep changes the string, duplicate it because * btrfs_parse_device_options gets called later */ opts = kstrdup(options, GFP_KERNEL); if (!opts) return -ENOMEM; orig = opts; while ((p = strsep(&opts, ",")) != NULL) { int token; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case Opt_subvol: kfree(*subvol_name); *subvol_name = match_strdup(&args[0]); if (!*subvol_name) { error = -ENOMEM; goto out; } break; case Opt_subvolid: error = match_u64(&args[0], &subvolid); if (error) goto out; /* we want the original fs_tree */ if (subvolid == 0) subvolid = BTRFS_FS_TREE_OBJECTID; *subvol_objectid = subvolid; break; case Opt_subvolrootid: pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n"); break; default: break; } } out: kfree(orig); return error; } char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, u64 subvol_objectid) { struct btrfs_root *root = fs_info->tree_root; struct btrfs_root *fs_root; struct btrfs_root_ref *root_ref; struct btrfs_inode_ref *inode_ref; struct btrfs_key key; struct btrfs_path *path = NULL; char *name = NULL, *ptr; u64 dirid; int len; int ret; path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto err; } path->leave_spinning = 1; name = kmalloc(PATH_MAX, GFP_KERNEL); if (!name) { ret = -ENOMEM; goto err; } ptr = name + PATH_MAX - 1; ptr[0] = '\0'; /* * Walk up the subvolume trees in the tree of tree roots by root * backrefs until we hit the top-level subvolume. */ while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) { key.objectid = subvol_objectid; key.type = BTRFS_ROOT_BACKREF_KEY; key.offset = (u64)-1; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) { goto err; } else if (ret > 0) { ret = btrfs_previous_item(root, path, subvol_objectid, BTRFS_ROOT_BACKREF_KEY); if (ret < 0) { goto err; } else if (ret > 0) { ret = -ENOENT; goto err; } } btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); subvol_objectid = key.offset; root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_root_ref); len = btrfs_root_ref_name_len(path->nodes[0], root_ref); ptr -= len + 1; if (ptr < name) { ret = -ENAMETOOLONG; goto err; } read_extent_buffer(path->nodes[0], ptr + 1, (unsigned long)(root_ref + 1), len); ptr[0] = '/'; dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref); btrfs_release_path(path); key.objectid = subvol_objectid; key.type = BTRFS_ROOT_ITEM_KEY; key.offset = (u64)-1; fs_root = btrfs_read_fs_root_no_name(fs_info, &key); if (IS_ERR(fs_root)) { ret = PTR_ERR(fs_root); goto err; } /* * Walk up the filesystem tree by inode refs until we hit the * root directory. */ while (dirid != BTRFS_FIRST_FREE_OBJECTID) { key.objectid = dirid; key.type = BTRFS_INODE_REF_KEY; key.offset = (u64)-1; ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); if (ret < 0) { goto err; } else if (ret > 0) { ret = btrfs_previous_item(fs_root, path, dirid, BTRFS_INODE_REF_KEY); if (ret < 0) { goto err; } else if (ret > 0) { ret = -ENOENT; goto err; } } btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); dirid = key.offset; inode_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_ref); len = btrfs_inode_ref_name_len(path->nodes[0], inode_ref); ptr -= len + 1; if (ptr < name) { ret = -ENAMETOOLONG; goto err; } read_extent_buffer(path->nodes[0], ptr + 1, (unsigned long)(inode_ref + 1), len); ptr[0] = '/'; btrfs_release_path(path); } } btrfs_free_path(path); if (ptr == name + PATH_MAX - 1) { name[0] = '/'; name[1] = '\0'; } else { memmove(name, ptr, name + PATH_MAX - ptr); } return name; err: btrfs_free_path(path); kfree(name); return ERR_PTR(ret); } static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid) { struct btrfs_root *root = fs_info->tree_root; struct btrfs_dir_item *di; struct btrfs_path *path; struct btrfs_key location; u64 dir_id; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->leave_spinning = 1; /* * Find the "default" dir item which points to the root item that we * will mount by default if we haven't been given a specific subvolume * to mount. */ dir_id = btrfs_super_root_dir(fs_info->super_copy); di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); if (IS_ERR(di)) { btrfs_free_path(path); return PTR_ERR(di); } if (!di) { /* * Ok the default dir item isn't there. This is weird since * it's always been there, but don't freak out, just try and * mount the top-level subvolume. */ btrfs_free_path(path); *objectid = BTRFS_FS_TREE_OBJECTID; return 0; } btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); btrfs_free_path(path); *objectid = location.objectid; return 0; } static int btrfs_fill_super(struct super_block *sb, struct btrfs_fs_devices *fs_devices, void *data) { struct inode *inode; struct btrfs_fs_info *fs_info = btrfs_sb(sb); struct btrfs_key key; int err; sb->s_maxbytes = MAX_LFS_FILESIZE; sb->s_magic = BTRFS_SUPER_MAGIC; sb->s_op = &btrfs_super_ops; sb->s_d_op = &btrfs_dentry_operations; sb->s_export_op = &btrfs_export_ops; sb->s_xattr = btrfs_xattr_handlers; sb->s_time_gran = 1; #ifdef CONFIG_BTRFS_FS_POSIX_ACL sb->s_flags |= SB_POSIXACL; #endif sb->s_flags |= SB_I_VERSION; sb->s_iflags |= SB_I_CGROUPWB; err = super_setup_bdi(sb); if (err) { btrfs_err(fs_info, "super_setup_bdi failed"); return err; } err = open_ctree(sb, fs_devices, (char *)data); if (err) { btrfs_err(fs_info, "open_ctree failed"); return err; } key.objectid = BTRFS_FIRST_FREE_OBJECTID; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto fail_close; } sb->s_root = d_make_root(inode); if (!sb->s_root) { err = -ENOMEM; goto fail_close; } cleancache_init_fs(sb); sb->s_flags |= SB_ACTIVE; return 0; fail_close: close_ctree(fs_info); return err; } int btrfs_sync_fs(struct super_block *sb, int wait) { struct btrfs_trans_handle *trans; struct btrfs_fs_info *fs_info = btrfs_sb(sb); struct btrfs_root *root = fs_info->tree_root; trace_btrfs_sync_fs(fs_info, wait); if (!wait) { filemap_flush(fs_info->btree_inode->i_mapping); return 0; } btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); trans = btrfs_attach_transaction_barrier(root); if (IS_ERR(trans)) { /* no transaction, don't bother */ if (PTR_ERR(trans) == -ENOENT) { /* * Exit unless we have some pending changes * that need to go through commit */ if (fs_info->pending_changes == 0) return 0; /* * A non-blocking test if the fs is frozen. We must not * start a new transaction here otherwise a deadlock * happens. The pending operations are delayed to the * next commit after thawing. */ if (sb_start_write_trylock(sb)) sb_end_write(sb); else return 0; trans = btrfs_start_transaction(root, 0); } if (IS_ERR(trans)) return PTR_ERR(trans); } return btrfs_commit_transaction(trans); } static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) { struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); const char *compress_type; const char *subvol_name; if (btrfs_test_opt(info, DEGRADED)) seq_puts(seq, ",degraded"); if (btrfs_test_opt(info, NODATASUM)) seq_puts(seq, ",nodatasum"); if (btrfs_test_opt(info, NODATACOW)) seq_puts(seq, ",nodatacow"); if (btrfs_test_opt(info, NOBARRIER)) seq_puts(seq, ",nobarrier"); if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE) seq_printf(seq, ",max_inline=%llu", info->max_inline); if (info->thread_pool_size != min_t(unsigned long, num_online_cpus() + 2, 8)) seq_printf(seq, ",thread_pool=%u", info->thread_pool_size); if (btrfs_test_opt(info, COMPRESS)) { compress_type = btrfs_compress_type2str(info->compress_type); if (btrfs_test_opt(info, FORCE_COMPRESS)) seq_printf(seq, ",compress-force=%s", compress_type); else seq_printf(seq, ",compress=%s", compress_type); if (info->compress_level) seq_printf(seq, ":%d", info->compress_level); } if (btrfs_test_opt(info, NOSSD)) seq_puts(seq, ",nossd"); if (btrfs_test_opt(info, SSD_SPREAD)) seq_puts(seq, ",ssd_spread"); else if (btrfs_test_opt(info, SSD)) seq_puts(seq, ",ssd"); if (btrfs_test_opt(info, NOTREELOG)) seq_puts(seq, ",notreelog"); if (btrfs_test_opt(info, NOLOGREPLAY)) seq_puts(seq, ",nologreplay"); if (btrfs_test_opt(info, FLUSHONCOMMIT)) seq_puts(seq, ",flushoncommit"); if (btrfs_test_opt(info, DISCARD)) seq_puts(seq, ",discard"); if (!(info->sb->s_flags & SB_POSIXACL)) seq_puts(seq, ",noacl"); if (btrfs_test_opt(info, SPACE_CACHE)) seq_puts(seq, ",space_cache"); else if (btrfs_test_opt(info, FREE_SPACE_TREE)) seq_puts(seq, ",space_cache=v2"); else seq_puts(seq, ",nospace_cache"); if (btrfs_test_opt(info, RESCAN_UUID_TREE)) seq_puts(seq, ",rescan_uuid_tree"); if (btrfs_test_opt(info, CLEAR_CACHE)) seq_puts(seq, ",clear_cache"); if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED)) seq_puts(seq, ",user_subvol_rm_allowed"); if (btrfs_test_opt(info, ENOSPC_DEBUG)) seq_puts(seq, ",enospc_debug"); if (btrfs_test_opt(info, AUTO_DEFRAG)) seq_puts(seq, ",autodefrag"); if (btrfs_test_opt(info, INODE_MAP_CACHE)) seq_puts(seq, ",inode_cache"); if (btrfs_test_opt(info, SKIP_BALANCE)) seq_puts(seq, ",skip_balance"); #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA)) seq_puts(seq, ",check_int_data"); else if (btrfs_test_opt(info, CHECK_INTEGRITY)) seq_puts(seq, ",check_int"); if (info->check_integrity_print_mask) seq_printf(seq, ",check_int_print_mask=%d", info->check_integrity_print_mask); #endif if (info->metadata_ratio) seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio); if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR)) seq_puts(seq, ",fatal_errors=panic"); if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL) seq_printf(seq, ",commit=%u", info->commit_interval); #ifdef CONFIG_BTRFS_DEBUG if (btrfs_test_opt(info, FRAGMENT_DATA)) seq_puts(seq, ",fragment=data"); if (btrfs_test_opt(info, FRAGMENT_METADATA)) seq_puts(seq, ",fragment=metadata"); #endif if (btrfs_test_opt(info, REF_VERIFY)) seq_puts(seq, ",ref_verify"); seq_printf(seq, ",subvolid=%llu", BTRFS_I(d_inode(dentry))->root->root_key.objectid); subvol_name = btrfs_get_subvol_name_from_objectid(info, BTRFS_I(d_inode(dentry))->root->root_key.objectid); if (!IS_ERR(subvol_name)) { seq_puts(seq, ",subvol="); seq_escape(seq, subvol_name, " \t\n\\"); kfree(subvol_name); } return 0; } static int btrfs_test_super(struct super_block *s, void *data) { struct btrfs_fs_info *p = data; struct btrfs_fs_info *fs_info = btrfs_sb(s); return fs_info->fs_devices == p->fs_devices; } static int btrfs_set_super(struct super_block *s, void *data) { int err = set_anon_super(s, data); if (!err) s->s_fs_info = data; return err; } /* * subvolumes are identified by ino 256 */ static inline int is_subvolume_inode(struct inode *inode) { if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) return 1; return 0; } static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid, const char *device_name, struct vfsmount *mnt) { struct dentry *root; int ret; if (!subvol_name) { if (!subvol_objectid) { ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb), &subvol_objectid); if (ret) { root = ERR_PTR(ret); goto out; } } subvol_name = btrfs_get_subvol_name_from_objectid( btrfs_sb(mnt->mnt_sb), subvol_objectid); if (IS_ERR(subvol_name)) { root = ERR_CAST(subvol_name); subvol_name = NULL; goto out; } } root = mount_subtree(mnt, subvol_name); /* mount_subtree() drops our reference on the vfsmount. */ mnt = NULL; if (!IS_ERR(root)) { struct super_block *s = root->d_sb; struct btrfs_fs_info *fs_info = btrfs_sb(s); struct inode *root_inode = d_inode(root); u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid; ret = 0; if (!is_subvolume_inode(root_inode)) { btrfs_err(fs_info, "'%s' is not a valid subvolume", subvol_name); ret = -EINVAL; } if (subvol_objectid && root_objectid != subvol_objectid) { /* * This will also catch a race condition where a * subvolume which was passed by ID is renamed and * another subvolume is renamed over the old location. */ btrfs_err(fs_info, "subvol '%s' does not match subvolid %llu", subvol_name, subvol_objectid); ret = -EINVAL; } if (ret) { dput(root); root = ERR_PTR(ret); deactivate_locked_super(s); } } out: mntput(mnt); kfree(subvol_name); return root; } static int parse_security_options(char *orig_opts, struct security_mnt_opts *sec_opts) { char *secdata = NULL; int ret = 0; secdata = alloc_secdata(); if (!secdata) return -ENOMEM; ret = security_sb_copy_data(orig_opts, secdata); if (ret) { free_secdata(secdata); return ret; } ret = security_sb_parse_opts_str(secdata, sec_opts); free_secdata(secdata); return ret; } static int setup_security_options(struct btrfs_fs_info *fs_info, struct super_block *sb, struct security_mnt_opts *sec_opts) { int ret = 0; /* * Call security_sb_set_mnt_opts() to check whether new sec_opts * is valid. */ ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL); if (ret) return ret; #ifdef CONFIG_SECURITY if (!fs_info->security_opts.num_mnt_opts) { /* first time security setup, copy sec_opts to fs_info */ memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts)); } else { /* * Since SELinux (the only one supporting security_mnt_opts) * does NOT support changing context during remount/mount of * the same sb, this must be the same or part of the same * security options, just free it. */ security_free_mnt_opts(sec_opts); } #endif return ret; } /* * Find a superblock for the given device / mount point. * * Note: This is based on mount_bdev from fs/super.c with a few additions * for multiple device setup. Make sure to keep it in sync. */ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, int flags, const char *device_name, void *data) { struct block_device *bdev = NULL; struct super_block *s; struct btrfs_device *device = NULL; struct btrfs_fs_devices *fs_devices = NULL; struct btrfs_fs_info *fs_info = NULL; struct security_mnt_opts new_sec_opts; fmode_t mode = FMODE_READ; int error = 0; if (!(flags & SB_RDONLY)) mode |= FMODE_WRITE; security_init_mnt_opts(&new_sec_opts); if (data) { error = parse_security_options(data, &new_sec_opts); if (error) return ERR_PTR(error); } /* * Setup a dummy root and fs_info for test/set super. This is because * we don't actually fill this stuff out until open_ctree, but we need * it for searching for existing supers, so this lets us do that and * then open_ctree will properly initialize everything later. */ fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL); if (!fs_info) { error = -ENOMEM; goto error_sec_opts; } fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); security_init_mnt_opts(&fs_info->security_opts); if (!fs_info->super_copy || !fs_info->super_for_commit) { error = -ENOMEM; goto error_fs_info; } mutex_lock(&uuid_mutex); error = btrfs_parse_device_options(data, mode, fs_type); if (error) { mutex_unlock(&uuid_mutex); goto error_fs_info; } device = btrfs_scan_one_device(device_name, mode, fs_type); if (IS_ERR(device)) { mutex_unlock(&uuid_mutex); error = PTR_ERR(device); goto error_fs_info; } fs_devices = device->fs_devices; fs_info->fs_devices = fs_devices; error = btrfs_open_devices(fs_devices, mode, fs_type); mutex_unlock(&uuid_mutex); if (error) goto error_fs_info; if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) { error = -EACCES; goto error_close_devices; } bdev = fs_devices->latest_bdev; s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC, fs_info); if (IS_ERR(s)) { error = PTR_ERR(s); goto error_close_devices; } if (s->s_root) { btrfs_close_devices(fs_devices); free_fs_info(fs_info); if ((flags ^ s->s_flags) & SB_RDONLY) error = -EBUSY; } else { snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); btrfs_sb(s)->bdev_holder = fs_type; error = btrfs_fill_super(s, fs_devices, data); } if (error) { deactivate_locked_super(s); goto error_sec_opts; } fs_info = btrfs_sb(s); error = setup_security_options(fs_info, s, &new_sec_opts); if (error) { deactivate_locked_super(s); goto error_sec_opts; } return dget(s->s_root); error_close_devices: btrfs_close_devices(fs_devices); error_fs_info: free_fs_info(fs_info); error_sec_opts: security_free_mnt_opts(&new_sec_opts); return ERR_PTR(error); } /* * Mount function which is called by VFS layer. * * In order to allow mounting a subvolume directly, btrfs uses mount_subtree() * which needs vfsmount* of device's root (/). This means device's root has to * be mounted internally in any case. * * Operation flow: * 1. Parse subvol id related options for later use in mount_subvol(). * * 2. Mount device's root (/) by calling vfs_kern_mount(). * * NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the * first place. In order to avoid calling btrfs_mount() again, we use * different file_system_type which is not registered to VFS by * register_filesystem() (btrfs_root_fs_type). As a result, * btrfs_mount_root() is called. The return value will be used by * mount_subtree() in mount_subvol(). * * 3. Call mount_subvol() to get the dentry of subvolume. Since there is * "btrfs subvolume set-default", mount_subvol() is called always. */ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, const char *device_name, void *data) { struct vfsmount *mnt_root; struct dentry *root; fmode_t mode = FMODE_READ; char *subvol_name = NULL; u64 subvol_objectid = 0; int error = 0; if (!(flags & SB_RDONLY)) mode |= FMODE_WRITE; error = btrfs_parse_subvol_options(data, &subvol_name, &subvol_objectid); if (error) { kfree(subvol_name); return ERR_PTR(error); } /* mount device's root (/) */ mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data); if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) { if (flags & SB_RDONLY) { mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags & ~SB_RDONLY, device_name, data); } else { mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags | SB_RDONLY, device_name, data); if (IS_ERR(mnt_root)) { root = ERR_CAST(mnt_root); kfree(subvol_name); goto out; } down_write(&mnt_root->mnt_sb->s_umount); error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL); up_write(&mnt_root->mnt_sb->s_umount); if (error < 0) { root = ERR_PTR(error); mntput(mnt_root); kfree(subvol_name); goto out; } } } if (IS_ERR(mnt_root)) { root = ERR_CAST(mnt_root); kfree(subvol_name); goto out; } /* mount_subvol() will free subvol_name and mnt_root */ root = mount_subvol(subvol_name, subvol_objectid, device_name, mnt_root); out: return root; } static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, u32 new_pool_size, u32 old_pool_size) { if (new_pool_size == old_pool_size) return; fs_info->thread_pool_size = new_pool_size; btrfs_info(fs_info, "resize thread pool %d -> %d", old_pool_size, new_pool_size); btrfs_workqueue_set_max(fs_info->workers, new_pool_size); btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size); btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size); btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size); btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size); btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size); btrfs_workqueue_set_max(fs_info->endio_meta_write_workers, new_pool_size); btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size); btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size); btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size); btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size); btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers, new_pool_size); } static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info) { set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); } static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info, unsigned long old_opts, int flags) { if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || (flags & SB_RDONLY))) { /* wait for any defraggers to finish */ wait_event(fs_info->transaction_wait, (atomic_read(&fs_info->defrag_running) == 0)); if (flags & SB_RDONLY) sync_filesystem(fs_info->sb); } } static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info, unsigned long old_opts) { /* * We need to cleanup all defragable inodes if the autodefragment is * close or the filesystem is read only. */ if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) { btrfs_cleanup_defrag_inodes(fs_info); } clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); } static int btrfs_remount(struct super_block *sb, int *flags, char *data) { struct btrfs_fs_info *fs_info = btrfs_sb(sb); struct btrfs_root *root = fs_info->tree_root; unsigned old_flags = sb->s_flags; unsigned long old_opts = fs_info->mount_opt; unsigned long old_compress_type = fs_info->compress_type; u64 old_max_inline = fs_info->max_inline; u32 old_thread_pool_size = fs_info->thread_pool_size; u32 old_metadata_ratio = fs_info->metadata_ratio; int ret; sync_filesystem(sb); btrfs_remount_prepare(fs_info); if (data) { struct security_mnt_opts new_sec_opts; security_init_mnt_opts(&new_sec_opts); ret = parse_security_options(data, &new_sec_opts); if (ret) goto restore; ret = setup_security_options(fs_info, sb, &new_sec_opts); if (ret) { security_free_mnt_opts(&new_sec_opts); goto restore; } } ret = btrfs_parse_options(fs_info, data, *flags); if (ret) goto restore; btrfs_remount_begin(fs_info, old_opts, *flags); btrfs_resize_thread_pool(fs_info, fs_info->thread_pool_size, old_thread_pool_size); if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb)) goto out; if (*flags & SB_RDONLY) { /* * this also happens on 'umount -rf' or on shutdown, when * the filesystem is busy. */ cancel_work_sync(&fs_info->async_reclaim_work); /* wait for the uuid_scan task to finish */ down(&fs_info->uuid_tree_rescan_sem); /* avoid complains from lockdep et al. */ up(&fs_info->uuid_tree_rescan_sem); sb->s_flags |= SB_RDONLY; /* * Setting SB_RDONLY will put the cleaner thread to * sleep at the next loop if it's already active. * If it's already asleep, we'll leave unused block * groups on disk until we're mounted read-write again * unless we clean them up here. */ btrfs_delete_unused_bgs(fs_info); btrfs_dev_replace_suspend_for_unmount(fs_info); btrfs_scrub_cancel(fs_info); btrfs_pause_balance(fs_info); ret = btrfs_commit_super(fs_info); if (ret) goto restore; } else { if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { btrfs_err(fs_info, "Remounting read-write after error is not allowed"); ret = -EINVAL; goto restore; } if (fs_info->fs_devices->rw_devices == 0) { ret = -EACCES; goto restore; } if (!btrfs_check_rw_degradable(fs_info, NULL)) { btrfs_warn(fs_info, "too many missing devices, writeable remount is not allowed"); ret = -EACCES; goto restore; } if (btrfs_super_log_root(fs_info->super_copy) != 0) { btrfs_warn(fs_info, "mount required to replay tree-log, cannot remount read-write"); ret = -EINVAL; goto restore; } ret = btrfs_cleanup_fs_roots(fs_info); if (ret) goto restore; /* recover relocation */ mutex_lock(&fs_info->cleaner_mutex); ret = btrfs_recover_relocation(root); mutex_unlock(&fs_info->cleaner_mutex); if (ret) goto restore; ret = btrfs_resume_balance_async(fs_info); if (ret) goto restore; ret = btrfs_resume_dev_replace_async(fs_info); if (ret) { btrfs_warn(fs_info, "failed to resume dev_replace"); goto restore; } btrfs_qgroup_rescan_resume(fs_info); if (!fs_info->uuid_root) { btrfs_info(fs_info, "creating UUID tree"); ret = btrfs_create_uuid_tree(fs_info); if (ret) { btrfs_warn(fs_info, "failed to create the UUID tree %d", ret); goto restore; } } sb->s_flags &= ~SB_RDONLY; set_bit(BTRFS_FS_OPEN, &fs_info->flags); } out: wake_up_process(fs_info->transaction_kthread); btrfs_remount_cleanup(fs_info, old_opts); return 0; restore: /* We've hit an error - don't reset SB_RDONLY */ if (sb_rdonly(sb)) old_flags |= SB_RDONLY; sb->s_flags = old_flags; fs_info->mount_opt = old_opts; fs_info->compress_type = old_compress_type; fs_info->max_inline = old_max_inline; btrfs_resize_thread_pool(fs_info, old_thread_pool_size, fs_info->thread_pool_size); fs_info->metadata_ratio = old_metadata_ratio; btrfs_remount_cleanup(fs_info, old_opts); return ret; } /* Used to sort the devices by max_avail(descending sort) */ static inline int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2) { if (((struct btrfs_device_info *)dev_info1)->max_avail > ((struct btrfs_device_info *)dev_info2)->max_avail) return -1; else if (((struct btrfs_device_info *)dev_info1)->max_avail < ((struct btrfs_device_info *)dev_info2)->max_avail) return 1; else return 0; } /* * sort the devices by max_avail, in which max free extent size of each device * is stored.(Descending Sort) */ static inline void btrfs_descending_sort_devices( struct btrfs_device_info *devices, size_t nr_devices) { sort(devices, nr_devices, sizeof(struct btrfs_device_info), btrfs_cmp_device_free_bytes, NULL); } /* * The helper to calc the free space on the devices that can be used to store * file data. */ static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info, u64 *free_bytes) { struct btrfs_device_info *devices_info; struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; struct btrfs_device *device; u64 skip_space; u64 type; u64 avail_space; u64 min_stripe_size; int min_stripes = 1, num_stripes = 1; int i = 0, nr_devices; /* * We aren't under the device list lock, so this is racy-ish, but good * enough for our purposes. */ nr_devices = fs_info->fs_devices->open_devices; if (!nr_devices) { smp_mb(); nr_devices = fs_info->fs_devices->open_devices; ASSERT(nr_devices); if (!nr_devices) { *free_bytes = 0; return 0; } } devices_info = kmalloc_array(nr_devices, sizeof(*devices_info), GFP_KERNEL); if (!devices_info) return -ENOMEM; /* calc min stripe number for data space allocation */ type = btrfs_data_alloc_profile(fs_info); if (type & BTRFS_BLOCK_GROUP_RAID0) { min_stripes = 2; num_stripes = nr_devices; } else if (type & BTRFS_BLOCK_GROUP_RAID1) { min_stripes = 2; num_stripes = 2; } else if (type & BTRFS_BLOCK_GROUP_RAID10) { min_stripes = 4; num_stripes = 4; } if (type & BTRFS_BLOCK_GROUP_DUP) min_stripe_size = 2 * BTRFS_STRIPE_LEN; else min_stripe_size = BTRFS_STRIPE_LEN; rcu_read_lock(); list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state) || !device->bdev || test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) continue; if (i >= nr_devices) break; avail_space = device->total_bytes - device->bytes_used; /* align with stripe_len */ avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN); avail_space *= BTRFS_STRIPE_LEN; /* * In order to avoid overwriting the superblock on the drive, * btrfs starts at an offset of at least 1MB when doing chunk * allocation. */ skip_space = SZ_1M; /* * we can use the free space in [0, skip_space - 1], subtract * it from the total. */ if (avail_space && avail_space >= skip_space) avail_space -= skip_space; else avail_space = 0; if (avail_space < min_stripe_size) continue; devices_info[i].dev = device; devices_info[i].max_avail = avail_space; i++; } rcu_read_unlock(); nr_devices = i; btrfs_descending_sort_devices(devices_info, nr_devices); i = nr_devices - 1; avail_space = 0; while (nr_devices >= min_stripes) { if (num_stripes > nr_devices) num_stripes = nr_devices; if (devices_info[i].max_avail >= min_stripe_size) { int j; u64 alloc_size; avail_space += devices_info[i].max_avail * num_stripes; alloc_size = devices_info[i].max_avail; for (j = i + 1 - num_stripes; j <= i; j++) devices_info[j].max_avail -= alloc_size; } i--; nr_devices--; } kfree(devices_info); *free_bytes = avail_space; return 0; } /* * Calculate numbers for 'df', pessimistic in case of mixed raid profiles. * * If there's a redundant raid level at DATA block groups, use the respective * multiplier to scale the sizes. * * Unused device space usage is based on simulating the chunk allocator * algorithm that respects the device sizes and order of allocations. This is * a close approximation of the actual use but there are other factors that may * change the result (like a new metadata chunk). * * If metadata is exhausted, f_bavail will be 0. */ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); struct btrfs_super_block *disk_super = fs_info->super_copy; struct list_head *head = &fs_info->space_info; struct btrfs_space_info *found; u64 total_used = 0; u64 total_free_data = 0; u64 total_free_meta = 0; int bits = dentry->d_sb->s_blocksize_bits; __be32 *fsid = (__be32 *)fs_info->fsid; unsigned factor = 1; struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; int ret; u64 thresh = 0; int mixed = 0; rcu_read_lock(); list_for_each_entry_rcu(found, head, list) { if (found->flags & BTRFS_BLOCK_GROUP_DATA) { int i; total_free_data += found->disk_total - found->disk_used; total_free_data -= btrfs_account_ro_block_groups_free_space(found); for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { if (!list_empty(&found->block_groups[i])) factor = btrfs_bg_type_to_factor( btrfs_raid_array[i].bg_flag); } } /* * Metadata in mixed block goup profiles are accounted in data */ if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) { if (found->flags & BTRFS_BLOCK_GROUP_DATA) mixed = 1; else total_free_meta += found->disk_total - found->disk_used; } total_used += found->disk_used; } rcu_read_unlock(); buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor); buf->f_blocks >>= bits; buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits); /* Account global block reserve as used, it's in logical size already */ spin_lock(&block_rsv->lock); /* Mixed block groups accounting is not byte-accurate, avoid overflow */ if (buf->f_bfree >= block_rsv->size >> bits) buf->f_bfree -= block_rsv->size >> bits; else buf->f_bfree = 0; spin_unlock(&block_rsv->lock); buf->f_bavail = div_u64(total_free_data, factor); ret = btrfs_calc_avail_data_space(fs_info, &total_free_data); if (ret) return ret; buf->f_bavail += div_u64(total_free_data, factor); buf->f_bavail = buf->f_bavail >> bits; /* * We calculate the remaining metadata space minus global reserve. If * this is (supposedly) smaller than zero, there's no space. But this * does not hold in practice, the exhausted state happens where's still * some positive delta. So we apply some guesswork and compare the * delta to a 4M threshold. (Practically observed delta was ~2M.) * * We probably cannot calculate the exact threshold value because this * depends on the internal reservations requested by various * operations, so some operations that consume a few metadata will * succeed even if the Avail is zero. But this is better than the other * way around. */ thresh = SZ_4M; /* * We only want to claim there's no available space if we can no longer * allocate chunks for our metadata profile and our global reserve will * not fit in the free metadata space. If we aren't ->full then we * still can allocate chunks and thus are fine using the currently * calculated f_bavail. */ if (!mixed && block_rsv->space_info->full && total_free_meta - thresh < block_rsv->size) buf->f_bavail = 0; buf->f_type = BTRFS_SUPER_MAGIC; buf->f_bsize = dentry->d_sb->s_blocksize; buf->f_namelen = BTRFS_NAME_LEN; /* We treat it as constant endianness (it doesn't matter _which_) because we want the fsid to come out the same whether mounted on a big-endian or little-endian host */ buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); /* Mask in the root object ID too, to disambiguate subvols */ buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32; buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid; return 0; } static void btrfs_kill_super(struct super_block *sb) { struct btrfs_fs_info *fs_info = btrfs_sb(sb); kill_anon_super(sb); free_fs_info(fs_info); } static struct file_system_type btrfs_fs_type = { .owner = THIS_MODULE, .name = "btrfs", .mount = btrfs_mount, .kill_sb = btrfs_kill_super, .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA, }; static struct file_system_type btrfs_root_fs_type = { .owner = THIS_MODULE, .name = "btrfs", .mount = btrfs_mount_root, .kill_sb = btrfs_kill_super, .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA, }; MODULE_ALIAS_FS("btrfs"); static int btrfs_control_open(struct inode *inode, struct file *file) { /* * The control file's private_data is used to hold the * transaction when it is started and is used to keep * track of whether a transaction is already in progress. */ file->private_data = NULL; return 0; } /* * used by btrfsctl to scan devices when no FS is mounted */ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct btrfs_ioctl_vol_args *vol; struct btrfs_device *device = NULL; int ret = -ENOTTY; if (!capable(CAP_SYS_ADMIN)) return -EPERM; vol = memdup_user((void __user *)arg, sizeof(*vol)); if (IS_ERR(vol)) return PTR_ERR(vol); vol->name[BTRFS_PATH_NAME_MAX] = '\0'; switch (cmd) { case BTRFS_IOC_SCAN_DEV: mutex_lock(&uuid_mutex); device = btrfs_scan_one_device(vol->name, FMODE_READ, &btrfs_root_fs_type); ret = PTR_ERR_OR_ZERO(device); mutex_unlock(&uuid_mutex); break; case BTRFS_IOC_DEVICES_READY: mutex_lock(&uuid_mutex); device = btrfs_scan_one_device(vol->name, FMODE_READ, &btrfs_root_fs_type); if (IS_ERR(device)) { mutex_unlock(&uuid_mutex); ret = PTR_ERR(device); break; } ret = !(device->fs_devices->num_devices == device->fs_devices->total_devices); mutex_unlock(&uuid_mutex); break; case BTRFS_IOC_GET_SUPPORTED_FEATURES: ret = btrfs_ioctl_get_supported_features((void __user*)arg); break; } kfree(vol); return ret; } static int btrfs_freeze(struct super_block *sb) { struct btrfs_trans_handle *trans; struct btrfs_fs_info *fs_info = btrfs_sb(sb); struct btrfs_root *root = fs_info->tree_root; set_bit(BTRFS_FS_FROZEN, &fs_info->flags); /* * We don't need a barrier here, we'll wait for any transaction that * could be in progress on other threads (and do delayed iputs that * we want to avoid on a frozen filesystem), or do the commit * ourselves. */ trans = btrfs_attach_transaction_barrier(root); if (IS_ERR(trans)) { /* no transaction, don't bother */ if (PTR_ERR(trans) == -ENOENT) return 0; return PTR_ERR(trans); } return btrfs_commit_transaction(trans); } static int btrfs_unfreeze(struct super_block *sb) { struct btrfs_fs_info *fs_info = btrfs_sb(sb); clear_bit(BTRFS_FS_FROZEN, &fs_info->flags); return 0; } static int btrfs_show_devname(struct seq_file *m, struct dentry *root) { struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb); struct btrfs_device *dev, *first_dev = NULL; /* * Lightweight locking of the devices. We should not need * device_list_mutex here as we only read the device data and the list * is protected by RCU. Even if a device is deleted during the list * traversals, we'll get valid data, the freeing callback will wait at * least until until the rcu_read_unlock. */ rcu_read_lock(); list_for_each_entry_rcu(dev, &fs_info->fs_devices->devices, dev_list) { if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) continue; if (!dev->name) continue; if (!first_dev || dev->devid < first_dev->devid) first_dev = dev; } if (first_dev) seq_escape(m, rcu_str_deref(first_dev->name), " \t\n\\"); else WARN_ON(1); rcu_read_unlock(); return 0; } static const struct super_operations btrfs_super_ops = { .drop_inode = btrfs_drop_inode, .evict_inode = btrfs_evict_inode, .put_super = btrfs_put_super, .sync_fs = btrfs_sync_fs, .show_options = btrfs_show_options, .show_devname = btrfs_show_devname, .alloc_inode = btrfs_alloc_inode, .destroy_inode = btrfs_destroy_inode, .statfs = btrfs_statfs, .remount_fs = btrfs_remount, .freeze_fs = btrfs_freeze, .unfreeze_fs = btrfs_unfreeze, }; static const struct file_operations btrfs_ctl_fops = { .open = btrfs_control_open, .unlocked_ioctl = btrfs_control_ioctl, .compat_ioctl = btrfs_control_ioctl, .owner = THIS_MODULE, .llseek = noop_llseek, }; static struct miscdevice btrfs_misc = { .minor = BTRFS_MINOR, .name = "btrfs-control", .fops = &btrfs_ctl_fops }; MODULE_ALIAS_MISCDEV(BTRFS_MINOR); MODULE_ALIAS("devname:btrfs-control"); static int __init btrfs_interface_init(void) { return misc_register(&btrfs_misc); } static __cold void btrfs_interface_exit(void) { misc_deregister(&btrfs_misc); } static void __init btrfs_print_mod_info(void) { static const char options[] = "" #ifdef CONFIG_BTRFS_DEBUG ", debug=on" #endif #ifdef CONFIG_BTRFS_ASSERT ", assert=on" #endif #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY ", integrity-checker=on" #endif #ifdef CONFIG_BTRFS_FS_REF_VERIFY ", ref-verify=on" #endif ; pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options); } static int __init init_btrfs_fs(void) { int err; btrfs_props_init(); err = btrfs_init_sysfs(); if (err) return err; btrfs_init_compress(); err = btrfs_init_cachep(); if (err) goto free_compress; err = extent_io_init(); if (err) goto free_cachep; err = extent_map_init(); if (err) goto free_extent_io; err = ordered_data_init(); if (err) goto free_extent_map; err = btrfs_delayed_inode_init(); if (err) goto free_ordered_data; err = btrfs_auto_defrag_init(); if (err) goto free_delayed_inode; err = btrfs_delayed_ref_init(); if (err) goto free_auto_defrag; err = btrfs_prelim_ref_init(); if (err) goto free_delayed_ref; err = btrfs_end_io_wq_init(); if (err) goto free_prelim_ref; err = btrfs_interface_init(); if (err) goto free_end_io_wq; btrfs_init_lockdep(); btrfs_print_mod_info(); err = btrfs_run_sanity_tests(); if (err) goto unregister_ioctl; err = register_filesystem(&btrfs_fs_type); if (err) goto unregister_ioctl; return 0; unregister_ioctl: btrfs_interface_exit(); free_end_io_wq: btrfs_end_io_wq_exit(); free_prelim_ref: btrfs_prelim_ref_exit(); free_delayed_ref: btrfs_delayed_ref_exit(); free_auto_defrag: btrfs_auto_defrag_exit(); free_delayed_inode: btrfs_delayed_inode_exit(); free_ordered_data: ordered_data_exit(); free_extent_map: extent_map_exit(); free_extent_io: extent_io_exit(); free_cachep: btrfs_destroy_cachep(); free_compress: btrfs_exit_compress(); btrfs_exit_sysfs(); return err; } static void __exit exit_btrfs_fs(void) { btrfs_destroy_cachep(); btrfs_delayed_ref_exit(); btrfs_auto_defrag_exit(); btrfs_delayed_inode_exit(); btrfs_prelim_ref_exit(); ordered_data_exit(); extent_map_exit(); extent_io_exit(); btrfs_interface_exit(); btrfs_end_io_wq_exit(); unregister_filesystem(&btrfs_fs_type); btrfs_exit_sysfs(); btrfs_cleanup_fs_uuids(); btrfs_exit_compress(); } late_initcall(init_btrfs_fs); module_exit(exit_btrfs_fs) MODULE_LICENSE("GPL");