diff options
author | Nikolay Borisov <nborisov@suse.com> | 2019-10-15 18:42:20 +0300 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2019-11-18 17:51:46 +0100 |
commit | b8522a1e5f421e003a8d2a8937eb3a095ce33f5d (patch) | |
tree | 5c4ce9efdf2fb3a492e1b54152105d903359048e | |
parent | bd2336b2ac119e65457261528883d9623d41315f (diff) | |
download | linux-b8522a1e5f421e003a8d2a8937eb3a095ce33f5d.tar.gz linux-b8522a1e5f421e003a8d2a8937eb3a095ce33f5d.tar.bz2 linux-b8522a1e5f421e003a8d2a8937eb3a095ce33f5d.zip |
btrfs: Factor out tree roots initialization during mount
The code responsible for reading and initializing tree roots is
scattered in open_ctree among 2 labels, emulating a loop. This is rather
confusing to reason about. Instead, factor the code to a new function,
init_tree_roots which implements the same logical flow.
There are a couple of notable differences, namely:
* Instead of using next_backup_root it's using the newly introduced
read_backup_root.
* If read_backup_root returns an error init_tree_roots propagates the
error and there is no special handling of that case e.g. the code jumps
straight to 'fail_tree_roots' label. The old code, however, was
(erroneously) jumping to 'fail_block_groups' label if next_backup_root
did fail, this was unnecessary since the tree roots init logic doesn't
modify the state of block groups.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
-rw-r--r-- | fs/btrfs/disk-io.c | 142 |
1 files changed, 85 insertions, 57 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 4d061facb416..1b1f051ef33f 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2610,6 +2610,89 @@ out: return ret; } +int __cold init_tree_roots(struct btrfs_fs_info *fs_info) +{ + struct btrfs_super_block *sb = fs_info->super_copy; + struct btrfs_root *tree_root = fs_info->tree_root; + bool handle_error = false; + int ret = 0; + int i; + + for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) { + u64 generation; + int level; + + if (handle_error) { + if (!IS_ERR(tree_root->node)) + free_extent_buffer(tree_root->node); + tree_root->node = NULL; + + if (!btrfs_test_opt(fs_info, USEBACKUPROOT)) + break; + + free_root_pointers(fs_info, 0); + + /* + * Don't use the log in recovery mode, it won't be + * valid + */ + btrfs_set_super_log_root(sb, 0); + + /* We can't trust the free space cache either */ + btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE); + + ret = read_backup_root(fs_info, i); + if (ret < 0) + return ret; + } + generation = btrfs_super_generation(sb); + level = btrfs_super_root_level(sb); + tree_root->node = read_tree_block(fs_info, btrfs_super_root(sb), + generation, level, NULL); + if (IS_ERR(tree_root->node) || + !extent_buffer_uptodate(tree_root->node)) { + handle_error = true; + + if (IS_ERR(tree_root->node)) + ret = PTR_ERR(tree_root->node); + else if (!extent_buffer_uptodate(tree_root->node)) + ret = -EUCLEAN; + + btrfs_warn(fs_info, "failed to read tree root"); + continue; + } + + btrfs_set_root_node(&tree_root->root_item, tree_root->node); + tree_root->commit_root = btrfs_root_node(tree_root); + btrfs_set_root_refs(&tree_root->root_item, 1); + + mutex_lock(&tree_root->objectid_mutex); + ret = btrfs_find_highest_objectid(tree_root, + &tree_root->highest_objectid); + if (ret < 0) { + mutex_unlock(&tree_root->objectid_mutex); + handle_error = true; + continue; + } + + ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID); + mutex_unlock(&tree_root->objectid_mutex); + + ret = btrfs_read_roots(fs_info); + if (ret < 0) { + handle_error = true; + continue; + } + + /* All successful */ + fs_info->generation = generation; + fs_info->last_trans_committed = generation; + break; + } + + return ret; +} + int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices, char *options) @@ -2628,8 +2711,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_root *chunk_root; int ret; int err = -EINVAL; - int num_backups_tried = 0; - int backup_index = 0; int clear_free_space_tree = 0; int level; @@ -3051,44 +3132,9 @@ int __cold open_ctree(struct super_block *sb, goto fail_tree_roots; } -retry_root_backup: - generation = btrfs_super_generation(disk_super); - level = btrfs_super_root_level(disk_super); - - tree_root->node = read_tree_block(fs_info, - btrfs_super_root(disk_super), - generation, level, NULL); - if (IS_ERR(tree_root->node) || - !extent_buffer_uptodate(tree_root->node)) { - btrfs_warn(fs_info, "failed to read tree root"); - if (!IS_ERR(tree_root->node)) - free_extent_buffer(tree_root->node); - tree_root->node = NULL; - goto recovery_tree_root; - } - - btrfs_set_root_node(&tree_root->root_item, tree_root->node); - tree_root->commit_root = btrfs_root_node(tree_root); - btrfs_set_root_refs(&tree_root->root_item, 1); - - mutex_lock(&tree_root->objectid_mutex); - ret = btrfs_find_highest_objectid(tree_root, - &tree_root->highest_objectid); - if (ret) { - mutex_unlock(&tree_root->objectid_mutex); - goto recovery_tree_root; - } - - ASSERT(tree_root->highest_objectid <= BTRFS_LAST_FREE_OBJECTID); - - mutex_unlock(&tree_root->objectid_mutex); - - ret = btrfs_read_roots(fs_info); + ret = init_tree_roots(fs_info); if (ret) - goto recovery_tree_root; - - fs_info->generation = generation; - fs_info->last_trans_committed = generation; + goto fail_tree_roots; ret = btrfs_verify_dev_extents(fs_info); if (ret) { @@ -3383,24 +3429,6 @@ fail: btrfs_free_stripe_hash_table(fs_info); btrfs_close_devices(fs_info->fs_devices); return err; - -recovery_tree_root: - if (!btrfs_test_opt(fs_info, USEBACKUPROOT)) - goto fail_tree_roots; - - free_root_pointers(fs_info, false); - - /* don't use the log in recovery mode, it won't be valid */ - btrfs_set_super_log_root(disk_super, 0); - - /* we can't trust the free space cache either */ - btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE); - - ret = next_root_backup(fs_info, fs_info->super_copy, - &num_backups_tried, &backup_index); - if (ret == -1) - goto fail_block_groups; - goto retry_root_backup; } ALLOW_ERROR_INJECTION(open_ctree, ERRNO); |