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authorNikolay Borisov <nborisov@suse.com>2019-10-15 18:42:20 +0300
committerDavid Sterba <dsterba@suse.com>2019-11-18 17:51:46 +0100
commitb8522a1e5f421e003a8d2a8937eb3a095ce33f5d (patch)
tree5c4ce9efdf2fb3a492e1b54152105d903359048e /fs/btrfs
parentbd2336b2ac119e65457261528883d9623d41315f (diff)
downloadlinux-b8522a1e5f421e003a8d2a8937eb3a095ce33f5d.tar.bz2
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>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/disk-io.c142
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);