On Mon, Apr 11, 2022 at 09:18:56AM +0900, Damien Le Moal wrote: > On 4/9/22 02:12, Ming Lei wrote: > > dm_zone_map_bio() is only called from __map_bio in which the io's > > reference is grabbed already, and the reference won't be released > > until the bio is submitted, so no necessary to do it dm_zone_map_bio > > any more. > > I do not think that this patch is correct. Removing the extra reference on > the io can lead to problems if the io is completed in the target > ->map(ti, clone) call or before dm_zone_map_bio_end() is called for the > DM_MAPIO_SUBMITTED or DM_MAPIO_REMAPPED cases. dm_zone_map_bio_end() needs __map_bio(): ... dm_io_inc_pending(io); ... dm_zone_map_bio(tio); ... dm_submit_bio(): dm_split_and_process_bio init_clone_info(&ci, md, map, bio) atomic_set(&io->io_count, 1) ... __map_bio() ... dm_io_dec_pending() The target io can only be completed after the above line returns, so the extra reference in dm_zone_map_bio() doesn't make any difference, does it? Thanks, Ming -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel
