• Alasdair G Kergon's avatar
    Add bvec_merge_data to handle stacked devices and ->merge_bvec() · cc371e66
    Alasdair G Kergon authored
    When devices are stacked, one device's merge_bvec_fn may need to perform
    the mapping and then call one or more functions for its underlying devices.
    The following bio fields are used:
      bio->bi_rw  using bio_data_dir()
    This patch creates a new struct bvec_merge_data holding a copy of those
    fields to avoid having to change them directly in the struct bio when
    going down the stack only to have to change them back again on the way
    back up.  (And then when the bio gets mapped for real, the whole
    exercise gets repeated, but that's a problem for another day...)
    Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
    Cc: Neil Brown <neilb@suse.de>
    Cc: Milan Broz <mbroz@redhat.com>
    Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
raid0.c 14 KB