From: Filipe Manana fdmanana@suse.com
commit 39020d8abc7ec62c4de9b260e3d10d4a1c2478ce upstream.
At balance_level(), instead of doing a BUG_ON() in case we fail to record tree mod log operations, do a transaction abort and return the error to the callers. There's really no need for the BUG_ON() as we can release all resources in this context, and we have to abort because other future tree searches that use the tree mod log (btrfs_search_old_slot()) may get inconsistent results if other operations modify the tree after that failure and before the tree mod log based search.
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 | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)
--- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1042,7 +1042,12 @@ static noinline int balance_level(struct }
ret = btrfs_tree_mod_log_insert_root(root->node, child, true); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_tree_unlock(child); + free_extent_buffer(child); + btrfs_abort_transaction(trans, ret); + goto enospc; + } rcu_assign_pointer(root->node, child);
add_root_to_dirty_list(root); @@ -1130,7 +1135,10 @@ static noinline int balance_level(struct btrfs_node_key(right, &right_key, 0); ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, BTRFS_MOD_LOG_KEY_REPLACE); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + goto enospc; + } btrfs_set_node_key(parent, &right_key, pslot + 1); btrfs_mark_buffer_dirty(parent); } @@ -1176,7 +1184,10 @@ static noinline int balance_level(struct btrfs_node_key(mid, &mid_key, 0); ret = btrfs_tree_mod_log_insert_key(parent, pslot, BTRFS_MOD_LOG_KEY_REPLACE); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + goto enospc; + } btrfs_set_node_key(parent, &mid_key, pslot); btrfs_mark_buffer_dirty(parent); }