• Mikulas Patocka's avatar
    dm: introduce per_bio_data · c0820cf5
    Mikulas Patocka authored
    Introduce a field per_bio_data_size in struct dm_target.
    
    Targets can set this field in the constructor. If a target sets this
    field to a non-zero value, "per_bio_data_size" bytes of auxiliary data
    are allocated for each bio submitted to the target. These data can be
    used for any purpose by the target and help us improve performance by
    removing some per-target mempools.
    
    Per-bio data is accessed with dm_per_bio_data. The
    argument data_size must be the same as the value per_bio_data_size in
    dm_target.
    
    If the target has a pointer to per_bio_data, it can get a pointer to
    the bio with dm_bio_from_per_bio_data() function (data_size must be the
    same as the value passed to dm_per_bio_data).
    Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
    Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
    c0820cf5
dm.h 4.8 KB