• T
    writeback: move backing_dev_info->state into bdi_writeback · 4452226e
    Tejun Heo 提交于
    Currently, a bdi (backing_dev_info) embeds single wb (bdi_writeback)
    and the role of the separation is unclear.  For cgroup support for
    writeback IOs, a bdi will be updated to host multiple wb's where each
    wb serves writeback IOs of a different cgroup on the bdi.  To achieve
    that, a wb should carry all states necessary for servicing writeback
    IOs for a cgroup independently.
    
    This patch moves bdi->state into wb.
    
    * enum bdi_state is renamed to wb_state and the prefix of all enums is
      changed from BDI_ to WB_.
    
    * Explicit zeroing of bdi->state is removed without adding zeoring of
      wb->state as the whole data structure is zeroed on init anyway.
    
    * As there's still only one bdi_writeback per backing_dev_info, all
      uses of bdi->state are mechanically replaced with bdi->wb.state
      introducing no behavior changes.
    Signed-off-by: NTejun Heo <tj@kernel.org>
    Reviewed-by: NJan Kara <jack@suse.cz>
    Cc: Jens Axboe <axboe@kernel.dk>
    Cc: Wu Fengguang <fengguang.wu@intel.com>
    Cc: drbd-dev@lists.linbit.com
    Cc: Neil Brown <neilb@suse.de>
    Cc: Alasdair Kergon <agk@redhat.com>
    Cc: Mike Snitzer <snitzer@redhat.com>
    Signed-off-by: NJens Axboe <axboe@fb.com>
    4452226e
drbd_main.c 108.5 KB