btrfs: scrub: reject unsupported scrub flags

Since the introduction of scrub interface, the only flag that we support
is BTRFS_SCRUB_READONLY.  Thus there is no sanity checks, if there are
some undefined flags passed in, we just ignore them.

This is problematic if we want to introduce new scrub flags, as we have
no way to determine if such flags are supported.

Address the problem by introducing a check for the flags, and if
unsupported flags are set, return -EOPNOTSUPP to inform the user space.

This check should be backported for all supported kernels before any new
scrub flags are introduced.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2023-04-06 13:00:34 +08:00 committed by David Sterba
parent f263a7c3a5
commit 604e6681e1
2 changed files with 6 additions and 0 deletions

View File

@ -3161,6 +3161,11 @@ static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
if (IS_ERR(sa))
return PTR_ERR(sa);
if (sa->flags & ~BTRFS_SCRUB_SUPPORTED_FLAGS) {
ret = -EOPNOTSUPP;
goto out;
}
if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
ret = mnt_want_write_file(file);
if (ret)

View File

@ -187,6 +187,7 @@ struct btrfs_scrub_progress {
};
#define BTRFS_SCRUB_READONLY 1
#define BTRFS_SCRUB_SUPPORTED_FLAGS (BTRFS_SCRUB_READONLY)
struct btrfs_ioctl_scrub_args {
__u64 devid; /* in */
__u64 start; /* in */