• Eric Sandeen's avatar
    xfs: create new metadata UUID field and incompat flag · ce748eaa
    Eric Sandeen authored
    This adds a new superblock field, sb_meta_uuid.  If set, along with
    a new incompat flag, the code will use that field on a V5 filesystem
    to compare to metadata UUIDs, which allows us to change the user-
    visible UUID at will.  Userspace handles the setting and clearing
    of the incompat flag as appropriate, as the UUID gets changed; i.e.
    setting the user-visible UUID back to the original UUID (as stored in
    the new field) will remove the incompatible feature flag.
    
    If the incompat flag is not set, this copies the user-visible UUID into
    into the meta_uuid slot in memory when the superblock is read from disk;
    the meta_uuid field is not written back to disk in this case.
    
    The remainder of this patch simply switches verifiers, initializers,
    etc to use the new sb_meta_uuid field.
    Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
    Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
    Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    
    ce748eaa
xfs_attr_leaf.c 78.7 KB