On Thu, May 07, 2020 at 04:52:39PM +0800, Ming Lei wrote: > gendisk can't be gone when there is IO activity, so not hold > part0's refcount in IO path. > > Cc: Yufen Yu <yuyufen@xxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> > Cc: Hou Tao <houtao1@xxxxxxxxxx> > Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> > --- > block/blk-core.c | 3 ++- > block/genhd.c | 1 - > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index 826a8980997d..56cc61354671 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1343,7 +1343,8 @@ void blk_account_io_done(struct request *req, u64 now) > part_stat_add(part, nsecs[sgrp], now - req->start_time_ns); > part_dec_in_flight(req->q, part, rq_data_dir(req)); > > - hd_struct_put(part); > + if (part->partno) > + hd_struct_put(part); > part_stat_unlock(); Doesn't blk_account_io_merge needs the check as well? Maybe it should go into hd_struct_put and the other helpers to be centralized? Otherwise this looks fine to me.
