diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index e6b75ccd2850a4296598e48f4b7b365338776c09..d9308c38a8f270c740f2775b99bf070e3e9ccf56 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1239,6 +1239,7 @@ get_old_root(struct btrfs_root *root, u64 time_seq) struct tree_mod_root *old_root = NULL; u64 old_generation = 0; u64 logical; + u32 blocksize; eb = btrfs_read_lock_root_node(root); tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq); @@ -1254,12 +1255,28 @@ get_old_root(struct btrfs_root *root, u64 time_seq) } tm = tree_mod_log_search(root->fs_info, logical, time_seq); - if (old_root) + if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { + btrfs_tree_read_unlock(root->node); + free_extent_buffer(root->node); + blocksize = btrfs_level_size(root, old_root->level); + eb = read_tree_block(root, logical, blocksize, 0); + if (!eb) { + pr_warn("btrfs: failed to read tree block %llu from get_old_root\n", + logical); + WARN_ON(1); + } else { + eb = btrfs_clone_extent_buffer(eb); + } + } else if (old_root) { + btrfs_tree_read_unlock(root->node); + free_extent_buffer(root->node); eb = alloc_dummy_extent_buffer(logical, root->nodesize); - else + } else { eb = btrfs_clone_extent_buffer(root->node); - btrfs_tree_read_unlock(root->node); - free_extent_buffer(root->node); + btrfs_tree_read_unlock(root->node); + free_extent_buffer(root->node); + } + if (!eb) return NULL; btrfs_tree_read_lock(eb);