Commit 25122d15 authored by Ilya Dryomov's avatar Ilya Dryomov
Browse files

Btrfs: reorder locks and sanity checks in btrfs_ioctl_defrag 



Operation-specific check (whether subvol is readonly or not) should go
after the mutual exclusiveness check.

Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 4ac20c70

fs/btrfs/ioctl.c

+9 −8
Original line number Diff line number Diff line
@@ -2186,19 +2186,20 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp) 
	struct btrfs_ioctl_defrag_range_args *range;

	int ret;



	if (btrfs_root_readonly(root))

		return -EROFS;

	ret = mnt_want_write_file(file);

	if (ret)

		return ret;



	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,

			1)) {

		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");

		mnt_drop_write_file(file);

		return -EINVAL;

	}

	ret = mnt_want_write_file(file);

	if (ret) {

		atomic_set(&root->fs_info->mutually_exclusive_operation_running,

			   0);

		return ret;



	if (btrfs_root_readonly(root)) {

		ret = -EROFS;

		goto out;

	}



	switch (inode->i_mode & S_IFMT) {
@@ -2250,8 +2251,8 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp) 
		ret = -EINVAL;

	}

out:

	mnt_drop_write_file(file);

	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);

	mnt_drop_write_file(file);

	return ret;

}