Commit 50b5d1fc authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
Browse files

btrfs: do not BUG_ON() on tree mod log failures at insert_ptr() 



At insert_ptr(), 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 the context of all callers, 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.

This implies making insert_ptr() return an int instead of void, and making
all callers check for returned errors.

Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent f61aa7ba

fs/btrfs/ctree.c

+52 −19
Original line number Diff line number Diff line
@@ -2990,7 +2990,7 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, 
 * slot and level indicate where you want the key to go, and

 * blocknr is the block the key points to.

 */

static void insert_ptr(struct btrfs_trans_handle *trans,

static int insert_ptr(struct btrfs_trans_handle *trans,

		      struct btrfs_path *path,

		      struct btrfs_disk_key *key, u64 bytenr,

		      int slot, int level)
@@ -3009,7 +3009,10 @@ static void insert_ptr(struct btrfs_trans_handle *trans, 
		if (level) {

			ret = btrfs_tree_mod_log_insert_move(lower, slot + 1,

					slot, nritems - slot);

			BUG_ON(ret < 0);

			if (ret < 0) {

				btrfs_abort_transaction(trans, ret);

				return ret;

			}

		}

		memmove_extent_buffer(lower,

			      btrfs_node_key_ptr_offset(lower, slot + 1),
@@ -3019,7 +3022,10 @@ static void insert_ptr(struct btrfs_trans_handle *trans, 
	if (level) {

		ret = btrfs_tree_mod_log_insert_key(lower, slot,

						    BTRFS_MOD_LOG_KEY_ADD);

		BUG_ON(ret < 0);

		if (ret < 0) {

			btrfs_abort_transaction(trans, ret);

			return ret;

		}

	}

	btrfs_set_node_key(lower, key, slot);

	btrfs_set_node_blockptr(lower, slot, bytenr);
@@ -3027,6 +3033,8 @@ static void insert_ptr(struct btrfs_trans_handle *trans, 
	btrfs_set_node_ptr_generation(lower, slot, trans->transid);

	btrfs_set_header_nritems(lower, nritems + 1);

	btrfs_mark_buffer_dirty(lower);



	return 0;

}



/*
@@ -3106,8 +3114,13 @@ static noinline int split_node(struct btrfs_trans_handle *trans, 
	btrfs_mark_buffer_dirty(c);

	btrfs_mark_buffer_dirty(split);



	insert_ptr(trans, path, &disk_key, split->start,

	ret = insert_ptr(trans, path, &disk_key, split->start,

			 path->slots[level + 1] + 1, level + 1);

	if (ret < 0) {

		btrfs_tree_unlock(split);

		free_extent_buffer(split);

		return ret;

	}



	if (path->slots[level] >= mid) {

		path->slots[level] -= mid;
@@ -3584,7 +3597,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root 
 * split the path's leaf in two, making sure there is at least data_size

 * available for the resulting leaf level of the path.

 */

static noinline void copy_for_split(struct btrfs_trans_handle *trans,

static noinline int copy_for_split(struct btrfs_trans_handle *trans,

				   struct btrfs_path *path,

				   struct extent_buffer *l,

				   struct extent_buffer *right,
@@ -3594,6 +3607,7 @@ static noinline void copy_for_split(struct btrfs_trans_handle *trans, 
	int data_copy_size;

	int rt_data_off;

	int i;

	int ret;

	struct btrfs_disk_key disk_key;

	struct btrfs_map_token token;
@@ -3618,7 +3632,9 @@ static noinline void copy_for_split(struct btrfs_trans_handle *trans, 


	btrfs_set_header_nritems(l, mid);

	btrfs_item_key(right, &disk_key, 0);

	insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1);

	ret = insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1);

	if (ret < 0)

		return ret;



	btrfs_mark_buffer_dirty(right);

	btrfs_mark_buffer_dirty(l);
@@ -3636,6 +3652,8 @@ static noinline void copy_for_split(struct btrfs_trans_handle *trans, 
	}



	BUG_ON(path->slots[0] < 0);



	return 0;

}



/*
@@ -3834,8 +3852,13 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans, 
	if (split == 0) {

		if (mid <= slot) {

			btrfs_set_header_nritems(right, 0);

			insert_ptr(trans, path, &disk_key,

			ret = insert_ptr(trans, path, &disk_key,

					 right->start, path->slots[1] + 1, 1);

			if (ret < 0) {

				btrfs_tree_unlock(right);

				free_extent_buffer(right);

				return ret;

			}

			btrfs_tree_unlock(path->nodes[0]);

			free_extent_buffer(path->nodes[0]);

			path->nodes[0] = right;
@@ -3843,8 +3866,13 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans, 
			path->slots[1] += 1;

		} else {

			btrfs_set_header_nritems(right, 0);

			insert_ptr(trans, path, &disk_key,

			ret = insert_ptr(trans, path, &disk_key,

					 right->start, path->slots[1], 1);

			if (ret < 0) {

				btrfs_tree_unlock(right);

				free_extent_buffer(right);

				return ret;

			}

			btrfs_tree_unlock(path->nodes[0]);

			free_extent_buffer(path->nodes[0]);

			path->nodes[0] = right;
@@ -3860,7 +3888,12 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans, 
		return ret;

	}



	copy_for_split(trans, path, l, right, slot, mid, nritems);

	ret = copy_for_split(trans, path, l, right, slot, mid, nritems);

	if (ret < 0) {

		btrfs_tree_unlock(right);

		free_extent_buffer(right);

		return ret;

	}



	if (split == 2) {

		BUG_ON(num_doubles != 0);