• Alasdair G Kergon's avatar
    dm: add target num_write_bios fn · b0d8ed4d
    Alasdair G Kergon authored
    Add a num_write_bios function to struct target.
    
    If an instance of a target sets this, it will be queried before the
    target's mapping function is called on a write bio, and the response
    controls the number of copies of the write bio that the target will
    receive.
    
    This provides a convenient way for a target to send the same data to
    more than one device.  The new cache target uses this in writethrough
    mode, to send the data both to the cache and the backing device.
    Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
    b0d8ed4d
dm.c 62.5 KB