From: Filipe Manana fdmanana@suse.com
commit d09c51521f22f9cbdfb1cf63e5c456077c622c84 upstream.
When COWing an extent buffer that is not the root node, we need to log in the tree mod log that we replaced a pointer in the parent node, otherwise a tree mod log user doing a search on the b+tree can return incorrect results (that miss something). We are doing the call to btrfs_tree_mod_log_insert_key() but we totally ignore its return value.
So fix this by adding the missing error handling, resulting in a transaction abort and freeing the COWed extent buffer.
Fixes: f230475e62f7 ("Btrfs: put all block modifications into the tree mod log") CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo wqu@suse.com Signed-off-by: Filipe Manana fdmanana@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/ctree.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
--- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -594,8 +594,14 @@ static noinline int __btrfs_cow_block(st add_root_to_dirty_list(root); } else { WARN_ON(trans->transid != btrfs_header_generation(parent)); - btrfs_tree_mod_log_insert_key(parent, parent_slot, - BTRFS_MOD_LOG_KEY_REPLACE); + ret = btrfs_tree_mod_log_insert_key(parent, parent_slot, + BTRFS_MOD_LOG_KEY_REPLACE); + if (ret) { + btrfs_tree_unlock(cow); + free_extent_buffer(cow); + btrfs_abort_transaction(trans, ret); + return ret; + } btrfs_set_node_blockptr(parent, parent_slot, cow->start); btrfs_set_node_ptr_generation(parent, parent_slot,