• Mikulas Patocka's avatar
    dm kcopyd: accept zero size jobs · 9ca170a3
    Mikulas Patocka authored
    dm-kcopyd: accept zero-size jobs
    
    This patch changes dm-kcopyd so that it accepts zero-size jobs and completes
    them immediatelly via its completion thread.
    
    It is needed for multisnapshots snapshot resizing. When we are writing to
    a chunk beyond origin end, no copying is done. To simplify the code, we submit
    an empty request to kcopyd and let kcopyd complete it. If we didn't submit
    a request to kcopyd and called the completion routine immediatelly, it would
    violate the principle that completion is called only from one thread and
    it would need additional locking.
    Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
    Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
    9ca170a3
dm-kcopyd.c 14 KB