[PATCH] Btrfs-progs: fsck: disable --init-extent-tree option when using snapshots

Wang Shilong
2014-03-10T10:41:35Z

We haven't supported to rebuild extent tree if there are any *FULL BACKREF*
with broken filesystem, disable this option when detecting snapshots.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
---
cmds-check.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)

diff --git a/cmds-check.c b/cmds-check.c
index d1cafe1..ddee897 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -6143,6 +6143,56 @@ static int reset_block_groups(struct btrfs_fs_info *fs_info)
return 0;
}

+static int is_snapshot_exist(struct btrfs_fs_info *fs_info)
+{
+ struct btrfs_root *root = fs_info->tree_root;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ int ret;
+ int found = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = BTRFS_FIRST_FREE_OBJECTID;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ while (1) {
+ if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret)
+ goto out;
+ }
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+
+ if (key.type != BTRFS_ROOT_ITEM_KEY ||
+ key.objectid < BTRFS_FIRST_FREE_OBJECTID) {
+ path->slots[0]++;
+ continue;
+ }
+ if (key.offset > 0) {
+ found = 1;
+ break;
+ }
+ path->slots[0]++;
+ }
+out:
+ btrfs_free_path(path);
+ if (found)
+ return 1;
+ else if (ret >= 0)
+ return 0;
+ return ret;
+}
+
static int reset_balance(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info)
{
@@ -6537,6 +6587,18 @@ int cmd_check(int argc, char **argv)
ret = -EIO;
goto close_out;
}
+ if (init_extent_tree) {
+ ret = is_snapshot_exist(info);
+ if (ret < 0) {
+ fprintf(stderr, "ERROR: fail to check if there are snapshots in btrfs filesystem\n");
+ ret = 1;
+ goto close_out;
+ } else if (ret) {
+ fprintf(stderr, "Snapshots detected, unable to rebuild extent tree for such case.\n");
+ ret = 1;
+ goto close_out;
+ }
+ }

if (init_extent_tree || init_csum_tree) {
struct btrfs_trans_handle *trans;
--
1.9.0