From f8e9e0b07be0464e12366631da3da73a1a62449c Mon Sep 17 00:00:00 2001 From: Arne Jansen Date: Wed, 14 Dec 2011 20:12:02 -0500 Subject: [PATCH] btrfs: keep orphans for subvolume deletion Since we have the free space caches, btrfs_orphan_cleanup also runs for the tree_root. Unfortunately this also cleans up the orphans used to mark subvol deletions in progress. Currently if a subvol deletion gets interrupted twice by umount/mount, the deletion will not be continued and the space permanently lost, though it would be possible to write a tool to recover those lost subvol deletions. This patch checks if the orphan belongs to a subvol (dead root) and skips the deletion. Signed-off-by: Arne Jansen Signed-off-by: Chris Mason --- fs/btrfs/inode.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index f1c4bceed072..4a31493d97ac 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2158,6 +2158,38 @@ int btrfs_orphan_cleanup(struct btrfs_root *root) if (ret && ret != -ESTALE) goto out; + if (ret == -ESTALE && root == root->fs_info->tree_root) { + struct btrfs_root *dead_root; + struct btrfs_fs_info *fs_info = root->fs_info; + int is_dead_root = 0; + + /* + * this is an orphan in the tree root. Currently these + * could come from 2 sources: + * a) a snapshot deletion in progress + * b) a free space cache inode + * We need to distinguish those two, as the snapshot + * orphan must not get deleted. + * find_dead_roots already ran before us, so if this + * is a snapshot deletion, we should find the root + * in the dead_roots list + */ + spin_lock(&fs_info->trans_lock); + list_for_each_entry(dead_root, &fs_info->dead_roots, + root_list) { + if (dead_root->root_key.objectid == + found_key.objectid) { + is_dead_root = 1; + break; + } + } + spin_unlock(&fs_info->trans_lock); + if (is_dead_root) { + /* prevent this orphan from being found again */ + key.offset = found_key.objectid - 1; + continue; + } + } /* * Inode is already gone but the orphan item is still there, * kill the orphan item. -- 2.20.1