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Commit 4867268c authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

Btrfs: don't BUG() during drop snapshot 



Really there's lots of things that can go wrong here, kill all the
BUG_ON()'s and replace the logic ones with ASSERT()'s and return EIO
instead.

Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
[ switched to btrfs_err, errors go to common label ]
Reviewed-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 2fd57fcb

fs/btrfs/extent-tree.c

+27 −11
Original line number Diff line number Diff line
@@ -8886,15 +8886,13 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, 
	ret = btrfs_lookup_extent_info(trans, root, bytenr, level - 1, 1,

				       &wc->refs[level - 1],

				       &wc->flags[level - 1]);

	if (ret < 0) {

		btrfs_tree_unlock(next);

		free_extent_buffer(next);

		return ret;

	}

	if (ret < 0)

		goto out_unlock;



	if (unlikely(wc->refs[level - 1] == 0)) {

		btrfs_err(root->fs_info, "Missing references.");

		BUG();

		ret = -EIO;

		goto out_unlock;

	}

	*lookup_info = 0;
@@ -8946,7 +8944,12 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, 
	}



	level--;

	BUG_ON(level != btrfs_header_level(next));

	ASSERT(level == btrfs_header_level(next));

	if (level != btrfs_header_level(next)) {

		btrfs_err(root->fs_info, "mismatched level");

		ret = -EIO;

		goto out_unlock;

	}

	path->nodes[level] = next;

	path->slots[level] = 0;

	path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
@@ -8961,8 +8964,15 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, 
		if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {

			parent = path->nodes[level]->start;

		} else {

			BUG_ON(root->root_key.objectid !=

			ASSERT(root->root_key.objectid ==

			       btrfs_header_owner(path->nodes[level]));

			if (root->root_key.objectid !=

			    btrfs_header_owner(path->nodes[level])) {

				btrfs_err(root->fs_info,

						"mismatched block owner");

				ret = -EIO;

				goto out_unlock;

			}

			parent = 0;

		}
@@ -8977,12 +8987,18 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans, 
		}

		ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,

				root->root_key.objectid, level - 1, 0);

		BUG_ON(ret); /* -ENOMEM */

		if (ret)

			goto out_unlock;

	}



	*lookup_info = 1;

	ret = 1;



out_unlock:

	btrfs_tree_unlock(next);

	free_extent_buffer(next);

	*lookup_info = 1;

	return 1;



	return ret;

}



/*