Commit e3668b37 authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Andrew Morton
Browse files

zram: do not forget to endio for partial discard requests 

As reported by Qu Wenruo and Avinesh Kumar, the following

 getconf PAGESIZE
 65536
 blkdiscard -p 4k /dev/zram0

takes literally forever to complete.  zram doesn't support partial
discards and just returns immediately w/o doing any discard work in such
cases.  The problem is that we forget to endio on our way out, so
blkdiscard sleeps forever in submit_bio_wait().  Fix this by jumping to
end_bio label, which does bio_endio().

Link: https://lore.kernel.org/20260331074255.777019-1-senozhatsky@chromium.org


Fixes: 0120dd6e ("zram: make zram_bio_discard more self-contained")
Signed-off-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Reported-by: default avatarQu Wenruo <wqu@suse.com>
Closes: https://lore.kernel.org/linux-block/92361cd3-fb8b-482e-bc89-15ff1acb9a59@suse.com


Tested-by: default avatarQu Wenruo <wqu@suse.com>
Reported-by: default avatarAvinesh Kumar <avinesh.kumar@suse.com>
Closes: https://bugzilla.suse.com/show_bug.cgi?id=1256530


Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent af69016d

drivers/block/zram/zram_drv.c

+2 −1
Original line number Diff line number Diff line
@@ -2678,7 +2678,7 @@ static void zram_bio_discard(struct zram *zram, struct bio *bio) 
	 */

	if (offset) {

		if (n <= (PAGE_SIZE - offset))

			return;

			goto end_bio;



		n -= (PAGE_SIZE - offset);

		index++;
@@ -2693,6 +2693,7 @@ static void zram_bio_discard(struct zram *zram, struct bio *bio) 
		n -= PAGE_SIZE;

	}



end_bio:

	bio_endio(bio);

}