Commit b8a49ae1 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: hold a ref on the root in btrfs_search_path_in_tree_user 



We can wander into a different root, so grab a ref on the root we look
up.  Later on we make root = fs_info->tree_root so we need this separate
out label to make sure we do the right cleanup only in the case we're
looking up a different root.

Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 88234012

fs/btrfs/ioctl.c

+20 −13
Original line number Diff line number Diff line
@@ -2401,7 +2401,7 @@ static int btrfs_search_path_in_tree_user(struct inode *inode, 
	unsigned long item_len;

	struct btrfs_inode_ref *iref;

	struct btrfs_root_ref *rref;

	struct btrfs_root *root;

	struct btrfs_root *root = NULL;

	struct btrfs_path *path;

	struct btrfs_key key, key2;

	struct extent_buffer *leaf;
@@ -2431,6 +2431,10 @@ static int btrfs_search_path_in_tree_user(struct inode *inode, 
			ret = PTR_ERR(root);

			goto out;

		}

		if (!btrfs_grab_fs_root(root)) {

			ret = -ENOENT;

			goto out;

		}



		key.objectid = dirid;

		key.type = BTRFS_INODE_REF_KEY;
@@ -2438,15 +2442,15 @@ static int btrfs_search_path_in_tree_user(struct inode *inode, 
		while (1) {

			ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);

			if (ret < 0) {

				goto out;

				goto out_put;

			} else if (ret > 0) {

				ret = btrfs_previous_item(root, path, dirid,

							  BTRFS_INODE_REF_KEY);

				if (ret < 0) {

					goto out;

					goto out_put;

				} else if (ret > 0) {

					ret = -ENOENT;

					goto out;

					goto out_put;

				}

			}
@@ -2460,7 +2464,7 @@ static int btrfs_search_path_in_tree_user(struct inode *inode, 
			total_len += len + 1;

			if (ptr < args->path) {

				ret = -ENAMETOOLONG;

				goto out;

				goto out_put;

			}



			*(ptr + len) = '/';
@@ -2471,10 +2475,10 @@ static int btrfs_search_path_in_tree_user(struct inode *inode, 
			ret = btrfs_previous_item(root, path, dirid,

						  BTRFS_INODE_ITEM_KEY);

			if (ret < 0) {

				goto out;

				goto out_put;

			} else if (ret > 0) {

				ret = -ENOENT;

				goto out;

				goto out_put;

			}



			leaf = path->nodes[0];
@@ -2482,26 +2486,26 @@ static int btrfs_search_path_in_tree_user(struct inode *inode, 
			btrfs_item_key_to_cpu(leaf, &key2, slot);

			if (key2.objectid != dirid) {

				ret = -ENOENT;

				goto out;

				goto out_put;

			}



			temp_inode = btrfs_iget(sb, &key2, root);

			if (IS_ERR(temp_inode)) {

				ret = PTR_ERR(temp_inode);

				goto out;

				goto out_put;

			}

			ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);

			iput(temp_inode);

			if (ret) {

				ret = -EACCES;

				goto out;

				goto out_put;

			}



			if (key.offset == upper_limit.objectid)

				break;

			if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {

				ret = -EACCES;

				goto out;

				goto out_put;

			}



			btrfs_release_path(path);
@@ -2512,15 +2516,16 @@ static int btrfs_search_path_in_tree_user(struct inode *inode, 


		memmove(args->path, ptr, total_len);

		args->path[total_len] = '\0';

		btrfs_put_fs_root(root);

		root = NULL;

		btrfs_release_path(path);

	}



	/* Get the bottom subvolume's name from ROOT_REF */

	root = fs_info->tree_root;

	key.objectid = treeid;

	key.type = BTRFS_ROOT_REF_KEY;

	key.offset = args->treeid;

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);

	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);

	if (ret < 0) {

		goto out;

	} else if (ret > 0) {
@@ -2547,6 +2552,8 @@ static int btrfs_search_path_in_tree_user(struct inode *inode, 
	read_extent_buffer(leaf, args->name, item_off, item_len);

	args->name[item_len] = 0;



out_put:

	btrfs_put_fs_root(root);

out:

	btrfs_free_path(path);

	return ret;