• Mike Snitzer's avatar
    dm cache: add support for discard passdown to the origin device · de7180ff
    Mike Snitzer authored
    DM cache now defaults to passing discards down to the origin device.
    User may disable this using the "no_discard_passdown" feature when
    creating the cache device.
    
    If the cache's underlying origin device doesn't support discards then
    passdown is disabled (with warning).  Similarly, if the underlying
    origin device's max_discard_sectors is less than a cache block discard
    passdown will be disabled (this is required because sizing of the cache
    internal discard bitset depends on it).
    Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
    de7180ff
cache.txt 12.5 KB