On Wed, 26 Sep 2012, Kasatkin, Dmitry wrote: > Hi, > > I have a question. > > How dm target can be sure that data really have been written to storage? > > - for remaped request > bio_end really indicates that? > or data can be stuck in block buffers? No. When bio_endio is called, data may still be in hardware cache in the disk and not yet written to the disk. After you receive bio_endio for a write bio, you must submit another bio with REQ_FLUSH flag to flush the hardware cache (or you can use blkdev_issue_flush to send it). > - for bufio requests > dm_bufio_write_dirty_buffers() provides that ? Yes. dm_bufio_write_dirty_buffers calls dm_bufio_issue_flush and dm_bufio_issue_flush flushes the hardware cache. Mikulas > > Thanks, > Dmitry > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
