diff options
Diffstat (limited to 'fs/btrfs/super.c')
| -rw-r--r-- | fs/btrfs/super.c | 2220 |
1 files changed, 2220 insertions, 0 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c new file mode 100644 index 000000000..9e66f5e72 --- /dev/null +++ b/fs/btrfs/super.c @@ -0,0 +1,2220 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include <linux/blkdev.h> +#include <linux/module.h> +#include <linux/buffer_head.h> +#include <linux/fs.h> +#include <linux/pagemap.h> +#include <linux/highmem.h> +#include <linux/time.h> +#include <linux/init.h> +#include <linux/seq_file.h> +#include <linux/string.h> +#include <linux/backing-dev.h> +#include <linux/mount.h> +#include <linux/mpage.h> +#include <linux/swap.h> +#include <linux/writeback.h> +#include <linux/statfs.h> +#include <linux/compat.h> +#include <linux/parser.h> +#include <linux/ctype.h> +#include <linux/namei.h> +#include <linux/miscdevice.h> +#include <linux/magic.h> +#include <linux/slab.h> +#include <linux/cleancache.h> +#include <linux/ratelimit.h> +#include <linux/btrfs.h> +#include "delayed-inode.h" +#include "ctree.h" +#include "disk-io.h" +#include "transaction.h" +#include "btrfs_inode.h" +#include "print-tree.h" +#include "hash.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 <trace/events/btrfs.h> + +static const struct super_operations btrfs_super_ops; +static struct file_system_type btrfs_fs_type; + +static int btrfs_remount(struct super_block *sb, int *flags, char *data); + +static 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; +} + +static void save_error_info(struct btrfs_fs_info *fs_info) +{ + /* + * today we only save the error info into ram. Long term we'll + * also send it down to the disk + */ + set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state); +} + +/* btrfs handle error by forcing the filesystem readonly */ +static void btrfs_handle_error(struct btrfs_fs_info *fs_info) +{ + struct super_block *sb = fs_info->sb; + + if (sb->s_flags & MS_RDONLY) + return; + + if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { + sb->s_flags |= MS_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 ommited. 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 +/* + * __btrfs_std_error decodes expected errors from the caller and + * invokes the approciate error response. + */ +void __btrfs_std_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; + const char *errstr; + + /* + * Special case: if the error is EROFS, and we're already + * under MS_RDONLY, then it is safe here. + */ + if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) + return; + + errstr = btrfs_decode_error(errno); + if (fmt) { + struct va_format vaf; + va_list args; + + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; + + printk(KERN_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 { + printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n", + sb->s_id, function, line, errno, errstr); + } + + /* Don't go through full error handling during mount */ + save_error_info(fs_info); + if (sb->s_flags & MS_BORN) + btrfs_handle_error(fs_info); +} + +static const char * const logtypes[] = { + "emergency", + "alert", + "critical", + "error", + "warning", + "notice", + "info", + "debug", +}; + +void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...) +{ + struct super_block *sb = fs_info->sb; + char lvl[4]; + struct va_format vaf; + va_list args; + const char *type = logtypes[4]; + int kern_level; + + va_start(args, fmt); + + kern_level = printk_get_level(fmt); + if (kern_level) { + size_t size = printk_skip_level(fmt) - fmt; + memcpy(lvl, fmt, size); + lvl[size] = '\0'; + fmt += size; + type = logtypes[kern_level - '0']; + } else + *lvl = '\0'; + + vaf.fmt = fmt; + vaf.va = &args; + + printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf); + + va_end(args); +} + +#else + +void __btrfs_std_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; + + /* + * Special case: if the error is EROFS, and we're already + * under MS_RDONLY, then it is safe here. + */ + if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) + return; + + /* Don't go through full error handling during mount */ + if (sb->s_flags & MS_BORN) { + save_error_info(fs_info); + btrfs_handle_error(fs_info); + } +} +#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. + */ +void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, + struct btrfs_root *root, const char *function, + unsigned int line, int errno) +{ + /* + * Report first abort since mount + */ + if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, + &root->fs_info->fs_state)) { + WARN(1, KERN_DEBUG "BTRFS: Transaction aborted (error %d)\n", + errno); + } + trans->aborted = errno; + /* Nothing used. The other threads that have joined this + * transaction may be able to continue. */ + if (!trans->blocks_used && list_empty(&trans->new_bgs)) { + const char *errstr; + + errstr = btrfs_decode_error(errno); + btrfs_warn(root->fs_info, + "%s:%d: Aborting unused transaction(%s).", + function, line, errstr); + return; + } + ACCESS_ONCE(trans->transaction->aborted) = errno; + /* Wake up anybody who may be waiting on this transaction */ + wake_up(&root->fs_info->transaction_wait); + wake_up(&root->fs_info->transaction_blocked_wait); + __btrfs_std_error(root->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. + */ +void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, + unsigned int line, int errno, const char *fmt, ...) +{ + char *s_id = "<unknown>"; + 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 && (fs_info->mount_opt & BTRFS_MOUNT_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)->tree_root); +} + +enum { + Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, + Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, + Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, + Opt_compress_type, Opt_compress_force, Opt_compress_force_type, + Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, + Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, + Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache, + Opt_no_space_cache, Opt_recovery, Opt_skip_balance, + Opt_check_integrity, Opt_check_integrity_including_extent_data, + Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree, + Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard, + Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow, + Opt_datasum, Opt_treelog, Opt_noinode_cache, + Opt_err, +}; + +static match_table_t tokens = { + {Opt_degraded, "degraded"}, + {Opt_subvol, "subvol=%s"}, + {Opt_subvolid, "subvolid=%s"}, + {Opt_device, "device=%s"}, + {Opt_nodatasum, "nodatasum"}, + {Opt_datasum, "datasum"}, + {Opt_nodatacow, "nodatacow"}, + {Opt_datacow, "datacow"}, + {Opt_nobarrier, "nobarrier"}, + {Opt_barrier, "barrier"}, + {Opt_max_inline, "max_inline=%s"}, + {Opt_alloc_start, "alloc_start=%s"}, + {Opt_thread_pool, "thread_pool=%d"}, + {Opt_compress, "compress"}, + {Opt_compress_type, "compress=%s"}, + {Opt_compress_force, "compress-force"}, + {Opt_compress_force_type, "compress-force=%s"}, + {Opt_ssd, "ssd"}, + {Opt_ssd_spread, "ssd_spread"}, + {Opt_nossd, "nossd"}, + {Opt_acl, "acl"}, + {Opt_noacl, "noacl"}, + {Opt_notreelog, "notreelog"}, + {Opt_treelog, "treelog"}, + {Opt_flushoncommit, "flushoncommit"}, + {Opt_noflushoncommit, "noflushoncommit"}, + {Opt_ratio, "metadata_ratio=%d"}, + {Opt_discard, "discard"}, + {Opt_nodiscard, "nodiscard"}, + {Opt_space_cache, "space_cache"}, + {Opt_clear_cache, "clear_cache"}, + {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, + {Opt_enospc_debug, "enospc_debug"}, + {Opt_noenospc_debug, "noenospc_debug"}, + {Opt_subvolrootid, "subvolrootid=%d"}, + {Opt_defrag, "autodefrag"}, + {Opt_nodefrag, "noautodefrag"}, + {Opt_inode_cache, "inode_cache"}, + {Opt_noinode_cache, "noinode_cache"}, + {Opt_no_space_cache, "nospace_cache"}, + {Opt_recovery, "recovery"}, + {Opt_skip_balance, "skip_balance"}, + {Opt_check_integrity, "check_int"}, + {Opt_check_integrity_including_extent_data, "check_int_data"}, + {Opt_check_integrity_print_mask, "check_int_print_mask=%d"}, + {Opt_rescan_uuid_tree, "rescan_uuid_tree"}, + {Opt_fatal_errors, "fatal_errors=%s"}, + {Opt_commit_interval, "commit=%d"}, + {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_root *root, char *options) +{ + struct btrfs_fs_info *info = root->fs_info; + substring_t args[MAX_OPT_ARGS]; + char *p, *num, *orig = NULL; + u64 cache_gen; + int intarg; + int ret = 0; + char *compress_type; + bool compress_force = false; + + cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); + if (cache_gen) + btrfs_set_opt(info->mount_opt, SPACE_CACHE); + + if (!options) + goto out; + + /* + * strsep changes the string, duplicate it because parse_options + * gets called twice + */ + options = kstrdup(options, GFP_NOFS); + if (!options) + return -ENOMEM; + + orig = options; + + while ((p = strsep(&options, ",")) != NULL) { + int token; + if (!*p) + continue; + + token = match_token(p, tokens, args); + switch (token) { + case Opt_degraded: + btrfs_info(root->fs_info, "allowing degraded mounts"); + btrfs_set_opt(info->mount_opt, DEGRADED); + break; + case Opt_subvol: + case Opt_subvolid: + case Opt_subvolrootid: + case Opt_device: + /* + * These are parsed by btrfs_parse_early_options + * and can be happily ignored here. + */ + break; + case Opt_nodatasum: + btrfs_set_and_info(root, NODATASUM, + "setting nodatasum"); + break; + case Opt_datasum: + if (btrfs_test_opt(root, NODATASUM)) { + if (btrfs_test_opt(root, NODATACOW)) + btrfs_info(root->fs_info, "setting datasum, datacow enabled"); + else + btrfs_info(root->fs_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(root, NODATACOW)) { + if (!btrfs_test_opt(root, COMPRESS) || + !btrfs_test_opt(root, FORCE_COMPRESS)) { + btrfs_info(root->fs_info, + "setting nodatacow, compression disabled"); + } else { + btrfs_info(root->fs_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(root, NODATACOW, + "setting datacow"); + break; + case Opt_compress_force: + case Opt_compress_force_type: + compress_force = true; + /* Fallthrough */ + case Opt_compress: + case Opt_compress_type: + if (token == Opt_compress || + token == Opt_compress_force || + strcmp(args[0].from, "zlib") == 0) { + compress_type = "zlib"; + info->compress_type = BTRFS_COMPRESS_ZLIB; + btrfs_set_opt(info->mount_opt, COMPRESS); + btrfs_clear_opt(info->mount_opt, NODATACOW); + btrfs_clear_opt(info->mount_opt, NODATASUM); + } else if (strcmp(args[0].from, "lzo") == 0) { + compress_type = "lzo"; + info->compress_type = BTRFS_COMPRESS_LZO; + 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); + } else if (strncmp(args[0].from, "no", 2) == 0) { + compress_type = "no"; + btrfs_clear_opt(info->mount_opt, COMPRESS); + btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); + compress_force = false; + } else { + ret = -EINVAL; + goto out; + } + + if (compress_force) { + btrfs_set_and_info(root, FORCE_COMPRESS, + "force %s compression", + compress_type); + } else { + if (!btrfs_test_opt(root, COMPRESS)) + btrfs_info(root->fs_info, + "btrfs: use %s compression", + compress_type); + /* + * 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); + } + break; + case Opt_ssd: + btrfs_set_and_info(root, SSD, + "use ssd allocation scheme"); + break; + case Opt_ssd_spread: + btrfs_set_and_info(root, SSD_SPREAD, + "use spread ssd allocation scheme"); + btrfs_set_opt(info->mount_opt, SSD); + break; + case Opt_nossd: + btrfs_set_and_info(root, NOSSD, + "not using ssd allocation scheme"); + btrfs_clear_opt(info->mount_opt, SSD); + break; + case Opt_barrier: + btrfs_clear_and_info(root, NOBARRIER, + "turning on barriers"); + break; + case Opt_nobarrier: + btrfs_set_and_info(root, NOBARRIER, + "turning off barriers"); + break; + case Opt_thread_pool: + ret = match_int(&args[0], &intarg); + if (ret) { + goto out; + } else if (intarg > 0) { + info->thread_pool_size = intarg; + } else { + ret = -EINVAL; + goto out; + } + 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, + root->sectorsize); + } + btrfs_info(root->fs_info, "max_inline at %llu", + info->max_inline); + } else { + ret = -ENOMEM; + goto out; + } + break; + case Opt_alloc_start: + num = match_strdup(&args[0]); + if (num) { + mutex_lock(&info->chunk_mutex); + info->alloc_start = memparse(num, NULL); + mutex_unlock(&info->chunk_mutex); + kfree(num); + btrfs_info(root->fs_info, "allocations start at %llu", + info->alloc_start); + } else { + ret = -ENOMEM; + goto out; + } + break; + case Opt_acl: +#ifdef CONFIG_BTRFS_FS_POSIX_ACL + root->fs_info->sb->s_flags |= MS_POSIXACL; + break; +#else + btrfs_err(root->fs_info, + "support for ACL not compiled in!"); + ret = -EINVAL; + goto out; +#endif + case Opt_noacl: + root->fs_info->sb->s_flags &= ~MS_POSIXACL; + break; + case Opt_notreelog: + btrfs_set_and_info(root, NOTREELOG, + "disabling tree log"); + break; + case Opt_treelog: + btrfs_clear_and_info(root, NOTREELOG, + "enabling tree log"); + break; + case Opt_flushoncommit: + btrfs_set_and_info(root, FLUSHONCOMMIT, + "turning on flush-on-commit"); + break; + case Opt_noflushoncommit: + btrfs_clear_and_info(root, FLUSHONCOMMIT, + "turning off flush-on-commit"); + break; + case Opt_ratio: + ret = match_int(&args[0], &intarg); + if (ret) { + goto out; + } else if (intarg >= 0) { + info->metadata_ratio = intarg; + btrfs_info(root->fs_info, "metadata ratio %d", + info->metadata_ratio); + } else { + ret = -EINVAL; + goto out; + } + break; + case Opt_discard: + btrfs_set_and_info(root, DISCARD, + "turning on discard"); + break; + case Opt_nodiscard: + btrfs_clear_and_info(root, DISCARD, + "turning off discard"); + break; + case Opt_space_cache: + btrfs_set_and_info(root, SPACE_CACHE, + "enabling disk space caching"); + break; + case Opt_rescan_uuid_tree: + btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE); + break; + case Opt_no_space_cache: + btrfs_clear_and_info(root, SPACE_CACHE, + "disabling disk space caching"); + 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(root, 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(root, AUTO_DEFRAG, + "enabling auto defrag"); + break; + case Opt_nodefrag: + btrfs_clear_and_info(root, AUTO_DEFRAG, + "disabling auto defrag"); + break; + case Opt_recovery: + btrfs_info(root->fs_info, "enabling auto recovery"); + btrfs_set_opt(info->mount_opt, RECOVERY); + 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(root->fs_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(root->fs_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; + } else if (intarg >= 0) { + info->check_integrity_print_mask = intarg; + btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x", + info->check_integrity_print_mask); + } else { + ret = -EINVAL; + goto out; + } + break; +#else + case Opt_check_integrity_including_extent_data: + case Opt_check_integrity: + case Opt_check_integrity_print_mask: + btrfs_err(root->fs_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 < 0) { + btrfs_err(root->fs_info, "invalid commit interval"); + ret = -EINVAL; + goto out; + } + if (intarg > 0) { + if (intarg > 300) { + btrfs_warn(root->fs_info, "excessive commit interval %d", + intarg); + } + info->commit_interval = intarg; + } else { + btrfs_info(root->fs_info, "using default commit interval %ds", + BTRFS_DEFAULT_COMMIT_INTERVAL); + info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL; + } + break; + case Opt_err: + btrfs_info(root->fs_info, "unrecognized mount option '%s'", p); + ret = -EINVAL; + goto out; + default: + break; + } + } +out: + if (!ret && btrfs_test_opt(root, SPACE_CACHE)) + btrfs_info(root->fs_info, "disk space caching is enabled"); + kfree(orig); + 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_early_options(const char *options, fmode_t flags, + void *holder, char **subvol_name, u64 *subvol_objectid, + struct btrfs_fs_devices **fs_devices) +{ + substring_t args[MAX_OPT_ARGS]; + char *device_name, *opts, *orig, *p; + char *num = NULL; + int error = 0; + + if (!options) + return 0; + + /* + * strsep changes the string, duplicate it because parse_options + * gets called twice + */ + 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: + num = match_strdup(&args[0]); + if (num) { + *subvol_objectid = memparse(num, NULL); + kfree(num); + /* we want the original fs_tree */ + if (!*subvol_objectid) + *subvol_objectid = + BTRFS_FS_TREE_OBJECTID; + } else { + error = -EINVAL; + goto out; + } + break; + case Opt_subvolrootid: + printk(KERN_WARNING + "BTRFS: 'subvolrootid' mount option is deprecated and has " + "no effect\n"); + break; + case Opt_device: + device_name = match_strdup(&args[0]); + if (!device_name) { + error = -ENOMEM; + goto out; + } + error = btrfs_scan_one_device(device_name, + flags, holder, fs_devices); + kfree(device_name); + if (error) + goto out; + break; + default: + break; + } + } + +out: + kfree(orig); + return error; +} + +static struct dentry *get_default_root(struct super_block *sb, + u64 subvol_objectid) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(sb); + struct btrfs_root *root = fs_info->tree_root; + struct btrfs_root *new_root; + struct btrfs_dir_item *di; + struct btrfs_path *path; + struct btrfs_key location; + struct inode *inode; + u64 dir_id; + int new = 0; + + /* + * We have a specific subvol we want to mount, just setup location and + * go look up the root. + */ + if (subvol_objectid) { + location.objectid = subvol_objectid; + location.type = BTRFS_ROOT_ITEM_KEY; + location.offset = (u64)-1; + goto find_root; + } + + path = btrfs_alloc_path(); + if (!path) + return ERR_PTR(-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 ERR_CAST(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 to root most subvolume. + */ + btrfs_free_path(path); + dir_id = BTRFS_FIRST_FREE_OBJECTID; + new_root = fs_info->fs_root; + goto setup_root; + } + + btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); + btrfs_free_path(path); + +find_root: + new_root = btrfs_read_fs_root_no_name(fs_info, &location); + if (IS_ERR(new_root)) + return ERR_CAST(new_root); + + if (!(sb->s_flags & MS_RDONLY)) { + int ret; + down_read(&fs_info->cleanup_work_sem); + ret = btrfs_orphan_cleanup(new_root); + up_read(&fs_info->cleanup_work_sem); + if (ret) + return ERR_PTR(ret); + } + + dir_id = btrfs_root_dirid(&new_root->root_item); +setup_root: + location.objectid = dir_id; + location.type = BTRFS_INODE_ITEM_KEY; + location.offset = 0; + + inode = btrfs_iget(sb, &location, new_root, &new); + if (IS_ERR(inode)) + return ERR_CAST(inode); + + /* + * If we're just mounting the root most subvol put the inode and return + * a reference to the dentry. We will have already gotten a reference + * to the inode in btrfs_fill_super so we're good to go. + */ + if (!new && d_inode(sb->s_root) == inode) { + iput(inode); + return dget(sb->s_root); + } + + return d_obtain_root(inode); +} + +static int btrfs_fill_super(struct super_block *sb, + struct btrfs_fs_devices *fs_devices, + void *data, int silent) +{ + 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 |= MS_POSIXACL; +#endif + sb->s_flags |= MS_I_VERSION; + err = open_ctree(sb, fs_devices, (char *)data); + if (err) { + printk(KERN_ERR "BTRFS: open_ctree failed\n"); + 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; + } + + save_mount_options(sb, data); + cleancache_init_fs(sb); + sb->s_flags |= MS_ACTIVE; + return 0; + +fail_close: + close_ctree(fs_info->tree_root); + 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(wait); + + if (!wait) { + filemap_flush(fs_info->btree_inode->i_mapping); + return 0; + } + + btrfs_wait_ordered_roots(fs_info, -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(sb, SB_FREEZE_WRITE, false)) + __sb_end_write(sb, SB_FREEZE_WRITE); + else + return 0; + trans = btrfs_start_transaction(root, 0); + } + if (IS_ERR(trans)) + return PTR_ERR(trans); + } + return btrfs_commit_transaction(trans, root); +} + +static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) +{ + struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); + struct btrfs_root *root = info->tree_root; + char *compress_type; + + if (btrfs_test_opt(root, DEGRADED)) + seq_puts(seq, ",degraded"); + if (btrfs_test_opt(root, NODATASUM)) + seq_puts(seq, ",nodatasum"); + if (btrfs_test_opt(root, NODATACOW)) + seq_puts(seq, ",nodatacow"); + if (btrfs_test_opt(root, NOBARRIER)) + seq_puts(seq, ",nobarrier"); + if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE) + seq_printf(seq, ",max_inline=%llu", info->max_inline); + if (info->alloc_start != 0) + seq_printf(seq, ",alloc_start=%llu", info->alloc_start); + if (info->thread_pool_size != min_t(unsigned long, + num_online_cpus() + 2, 8)) + seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); + if (btrfs_test_opt(root, COMPRESS)) { + if (info->compress_type == BTRFS_COMPRESS_ZLIB) + compress_type = "zlib"; + else + compress_type = "lzo"; + if (btrfs_test_opt(root, FORCE_COMPRESS)) + seq_printf(seq, ",compress-force=%s", compress_type); + else + seq_printf(seq, ",compress=%s", compress_type); + } + if (btrfs_test_opt(root, NOSSD)) + seq_puts(seq, ",nossd"); + if (btrfs_test_opt(root, SSD_SPREAD)) + seq_puts(seq, ",ssd_spread"); + else if (btrfs_test_opt(root, SSD)) + seq_puts(seq, ",ssd"); + if (btrfs_test_opt(root, NOTREELOG)) + seq_puts(seq, ",notreelog"); + if (btrfs_test_opt(root, FLUSHONCOMMIT)) + seq_puts(seq, ",flushoncommit"); + if (btrfs_test_opt(root, DISCARD)) + seq_puts(seq, ",discard"); + if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) + seq_puts(seq, ",noacl"); + if (btrfs_test_opt(root, SPACE_CACHE)) + seq_puts(seq, ",space_cache"); + else + seq_puts(seq, ",nospace_cache"); + if (btrfs_test_opt(root, RESCAN_UUID_TREE)) + seq_puts(seq, ",rescan_uuid_tree"); + if (btrfs_test_opt(root, CLEAR_CACHE)) + seq_puts(seq, ",clear_cache"); + if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) + seq_puts(seq, ",user_subvol_rm_allowed"); + if (btrfs_test_opt(root, ENOSPC_DEBUG)) + seq_puts(seq, ",enospc_debug"); + if (btrfs_test_opt(root, AUTO_DEFRAG)) + seq_puts(seq, ",autodefrag"); + if (btrfs_test_opt(root, INODE_MAP_CACHE)) + seq_puts(seq, ",inode_cache"); + if (btrfs_test_opt(root, SKIP_BALANCE)) + seq_puts(seq, ",skip_balance"); + if (btrfs_test_opt(root, RECOVERY)) + seq_puts(seq, ",recovery"); +#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY + if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA)) + seq_puts(seq, ",check_int_data"); + else if (btrfs_test_opt(root, 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=%d", + info->metadata_ratio); + if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR)) + seq_puts(seq, ",fatal_errors=panic"); + if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL) + seq_printf(seq, ",commit=%d", info->commit_interval); + 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; +} + +/* + * This will strip out the subvol=%s argument for an argument string and add + * subvolid=0 to make sure we get the actual tree root for path walking to the + * subvol we want. + */ +static char *setup_root_args(char *args) +{ + unsigned len = strlen(args) + 2 + 1; + char *src, *dst, *buf; + + /* + * We need the same args as before, but with this substitution: + * s!subvol=[^,]+!subvolid=0! + * + * Since the replacement string is up to 2 bytes longer than the + * original, allocate strlen(args) + 2 + 1 bytes. + */ + + src = strstr(args, "subvol="); + /* This shouldn't happen, but just in case.. */ + if (!src) + return NULL; + + buf = dst = kmalloc(len, GFP_NOFS); + if (!buf) + return NULL; + + /* + * If the subvol= arg is not at the start of the string, + * copy whatever precedes it into buf. + */ + if (src != args) { + *src++ = '\0'; + strcpy(buf, args); + dst += strlen(args); + } + + strcpy(dst, "subvolid=0"); + dst += strlen("subvolid=0"); + + /* + * If there is a "," after the original subvol=... string, + * copy that suffix into our buffer. Otherwise, we're done. + */ + src = strchr(src, ','); + if (src) + strcpy(dst, src); + + return buf; +} + +static struct dentry *mount_subvol(const char *subvol_name, int flags, + const char *device_name, char *data) +{ + struct dentry *root; + struct vfsmount *mnt; + char *newargs; + + newargs = setup_root_args(data); + if (!newargs) + return ERR_PTR(-ENOMEM); + mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, + newargs); + + if (PTR_RET(mnt) == -EBUSY) { + if (flags & MS_RDONLY) { + mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, device_name, + newargs); + } else { + int r; + mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name, + newargs); + if (IS_ERR(mnt)) { + kfree(newargs); + return ERR_CAST(mnt); + } + + r = btrfs_remount(mnt->mnt_sb, &flags, NULL); + if (r < 0) { + /* FIXME: release vfsmount mnt ??*/ + kfree(newargs); + return ERR_PTR(r); + } + } + } + + kfree(newargs); + + if (IS_ERR(mnt)) + return ERR_CAST(mnt); + + root = mount_subtree(mnt, subvol_name); + + if (!IS_ERR(root) && !is_subvolume_inode(d_inode(root))) { + struct super_block *s = root->d_sb; + dput(root); + root = ERR_PTR(-EINVAL); + deactivate_locked_super(s); + printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n", + 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 supports security_mnt_opts) does + * NOT support changing context during remount/mount 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 get_sb_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(struct file_system_type *fs_type, int flags, + const char *device_name, void *data) +{ + struct block_device *bdev = NULL; + struct super_block *s; + struct dentry *root; + 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; + char *subvol_name = NULL; + u64 subvol_objectid = 0; + int error = 0; + + if (!(flags & MS_RDONLY)) + mode |= FMODE_WRITE; + + error = btrfs_parse_early_options(data, mode, fs_type, + &subvol_name, &subvol_objectid, + &fs_devices); + if (error) { + kfree(subvol_name); + return ERR_PTR(error); + } + + if (subvol_name) { + root = mount_subvol(subvol_name, flags, device_name, data); + kfree(subvol_name); + return root; + } + + security_init_mnt_opts(&new_sec_opts); + if (data) { + error = parse_security_options(data, &new_sec_opts); + if (error) + return ERR_PTR(error); + } + + error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); + if (error) + goto error_sec_opts; + + /* + * 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 = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); + if (!fs_info) { + error = -ENOMEM; + goto error_sec_opts; + } + + fs_info->fs_devices = fs_devices; + + fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); + fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); + security_init_mnt_opts(&fs_info->security_opts); + if (!fs_info->super_copy || !fs_info->super_for_commit) { + error = -ENOMEM; + goto error_fs_info; + } + + error = btrfs_open_devices(fs_devices, mode, fs_type); + if (error) + goto error_fs_info; + + if (!(flags & MS_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 | MS_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) & MS_RDONLY) + error = -EBUSY; + } else { + char b[BDEVNAME_SIZE]; + + strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); + btrfs_sb(s)->bdev_holder = fs_type; + error = btrfs_fill_super(s, fs_devices, data, + flags & MS_SILENT ? 1 : 0); + } + + root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error); + if (IS_ERR(root)) { + deactivate_locked_super(s); + error = PTR_ERR(root); + goto error_sec_opts; + } + + fs_info = btrfs_sb(s); + error = setup_security_options(fs_info, s, &new_sec_opts); + if (error) { + dput(root); + deactivate_locked_super(s); + goto error_sec_opts; + } + + return 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); +} + +static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, + int new_pool_size, int 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 & MS_RDONLY))) { + /* wait for any defraggers to finish */ + wait_event(fs_info->transaction_wait, + (atomic_read(&fs_info->defrag_running) == 0)); + if (flags & MS_RDONLY) + sync_filesystem(fs_info->sb); + } +} + +static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info, + unsigned long old_opts) +{ + /* + * We need cleanup all defragable inodes if the autodefragment is + * close or the fs is R/O. + */ + if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && + (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || + (fs_info->sb->s_flags & MS_RDONLY))) { + 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; + u64 old_alloc_start = fs_info->alloc_start; + int old_thread_pool_size = fs_info->thread_pool_size; + unsigned int 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(root, data); + if (ret) { + ret = -EINVAL; + 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 ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) + goto out; + + if (*flags & MS_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 |= MS_RDONLY; + + btrfs_dev_replace_suspend_for_unmount(fs_info); + btrfs_scrub_cancel(fs_info); + btrfs_pause_balance(fs_info); + + ret = btrfs_commit_super(root); + if (ret) + goto restore; + } else { + if (test_bit(BTRFS_FS_STATE_ERROR, &root->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 (fs_info->fs_devices->missing_devices > + fs_info->num_tolerated_disk_barrier_failures && + !(*flags & MS_RDONLY)) { + 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) { + 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; + } + + 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 &= ~MS_RDONLY; + } +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 MS_RDONLY */ + if (sb->s_flags & MS_RDONLY) + old_flags |= MS_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; + mutex_lock(&fs_info->chunk_mutex); + fs_info->alloc_start = old_alloc_start; + mutex_unlock(&fs_info->chunk_mutex); + 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 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 int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + 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 used_space; + u64 min_stripe_size; + int min_stripes = 1, num_stripes = 1; + int i = 0, nr_devices; + int ret; + + /* + * We aren't under the device list lock, so this is racey-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_NOFS); + if (!devices_info) + return -ENOMEM; + + /* calc min stripe number for data space alloction */ + type = btrfs_get_alloc_profile(root, 1); + 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; + + if (fs_info->alloc_start) + mutex_lock(&fs_devices->device_list_mutex); + rcu_read_lock(); + list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { + if (!device->in_fs_metadata || !device->bdev || + device->is_tgtdev_for_dev_replace) + 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 overwritting the superblock on the drive, + * btrfs starts at an offset of at least 1MB when doing chunk + * allocation. + */ + skip_space = 1024 * 1024; + + /* user can set the offset in fs_info->alloc_start. */ + if (fs_info->alloc_start && + fs_info->alloc_start + BTRFS_STRIPE_LEN <= + device->total_bytes) { + rcu_read_unlock(); + skip_space = max(fs_info->alloc_start, skip_space); + + /* + * btrfs can not use the free space in + * [0, skip_space - 1], we must subtract it from the + * total. In order to implement it, we account the used + * space in this range first. + */ + ret = btrfs_account_dev_extents_size(device, 0, + skip_space - 1, + &used_space); + if (ret) { + kfree(devices_info); + mutex_unlock(&fs_devices->device_list_mutex); + return ret; + } + + rcu_read_lock(); + + /* calc the free space in [0, skip_space - 1] */ + skip_space -= used_space; + } + + /* + * 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(); + if (fs_info->alloc_start) + mutex_unlock(&fs_devices->device_list_mutex); + + 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, order of allocations and the + * 'alloc_start' value, this is a close approximation of the actual use but + * there are other factors that may change the result (like a new metadata + * chunk). + * + * FIXME: not accurate for mixed block groups, total and free/used are ok, + * available appears slightly larger. + */ +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; + 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; + + /* + * holding chunk_muext to avoid allocating new chunks, holding + * device_list_mutex to avoid the device being removed + */ + 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])) { + switch (i) { + case BTRFS_RAID_DUP: + case BTRFS_RAID_RAID1: + case BTRFS_RAID_RAID10: + factor = 2; + } + } + } + } + + 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); + buf->f_bfree -= block_rsv->size >> bits; + spin_unlock(&block_rsv->lock); + + buf->f_bavail = div_u64(total_free_data, factor); + ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data); + if (ret) + return ret; + buf->f_bavail += div_u64(total_free_data, factor); + buf->f_bavail = buf->f_bavail >> bits; + + 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, +}; +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_fs_devices *fs_devices; + 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); + + switch (cmd) { + case BTRFS_IOC_SCAN_DEV: + ret = btrfs_scan_one_device(vol->name, FMODE_READ, + &btrfs_fs_type, &fs_devices); + break; + case BTRFS_IOC_DEVICES_READY: + ret = btrfs_scan_one_device(vol->name, FMODE_READ, + &btrfs_fs_type, &fs_devices); + if (ret) + break; + ret = !(fs_devices->num_devices == fs_devices->total_devices); + break; + } + + kfree(vol); + return ret; +} + +static int btrfs_freeze(struct super_block *sb) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = btrfs_sb(sb)->tree_root; + + 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, root); +} + +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_fs_devices *cur_devices; + struct btrfs_device *dev, *first_dev = NULL; + struct list_head *head; + struct rcu_string *name; + + mutex_lock(&fs_info->fs_devices->device_list_mutex); + cur_devices = fs_info->fs_devices; + while (cur_devices) { + head = &cur_devices->devices; + list_for_each_entry(dev, head, dev_list) { + if (dev->missing) + continue; + if (!dev->name) + continue; + if (!first_dev || dev->devid < first_dev->devid) + first_dev = dev; + } + cur_devices = cur_devices->seed; + } + + if (first_dev) { + rcu_read_lock(); + name = rcu_dereference(first_dev->name); + seq_escape(m, name->str, " \t\n\\"); + rcu_read_unlock(); + } else { + WARN_ON(1); + } + mutex_unlock(&fs_info->fs_devices->device_list_mutex); + 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, + .write_inode = btrfs_write_inode, + .alloc_inode = btrfs_alloc_inode, + .destroy_inode = btrfs_destroy_inode, + .statfs = btrfs_statfs, + .remount_fs = btrfs_remount, + .freeze_fs = btrfs_freeze, +}; + +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 btrfs_interface_init(void) +{ + return misc_register(&btrfs_misc); +} + +static void btrfs_interface_exit(void) +{ + if (misc_deregister(&btrfs_misc) < 0) + printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n"); +} + +static void btrfs_print_info(void) +{ + printk(KERN_INFO "Btrfs loaded" +#ifdef CONFIG_BTRFS_DEBUG + ", debug=on" +#endif +#ifdef CONFIG_BTRFS_ASSERT + ", assert=on" +#endif +#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY + ", integrity-checker=on" +#endif + "\n"); +} + +static int btrfs_run_sanity_tests(void) +{ + int ret; + + ret = btrfs_init_test_fs(); + if (ret) + return ret; + + ret = btrfs_test_free_space_cache(); + if (ret) + goto out; + ret = btrfs_test_extent_buffer_operations(); + if (ret) + goto out; + ret = btrfs_test_extent_io(); + if (ret) + goto out; + ret = btrfs_test_inodes(); + if (ret) + goto out; + ret = btrfs_test_qgroups(); +out: + btrfs_destroy_test_fs(); + return ret; +} + +static int __init init_btrfs_fs(void) +{ + int err; + + err = btrfs_hash_init(); + if (err) + return err; + + btrfs_props_init(); + + err = btrfs_init_sysfs(); + if (err) + goto free_hash; + + 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_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(); +free_hash: + btrfs_hash_exit(); + 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(); + btrfs_hash_exit(); +} + +late_initcall(init_btrfs_fs); +module_exit(exit_btrfs_fs) + +MODULE_LICENSE("GPL"); |