Commit f4412c7d authored by Chaitanya Kulkarni's avatar Chaitanya Kulkarni Committed by Mikulas Patocka
Browse files

dm: ignore discard return value 



__blkdev_issue_discard() always returns 0, making all error checking
at call sites dead code.

For dm-thin change issue_discard() return type to void, in
passdown_double_checking_shared_status() remove the r assignment from
return value of the issue_discard(), for end_discard() hardcode value of
r to 0 that matches only value returned from __blkdev_issue_discard().

Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarChaitanya Kulkarni <ckulkarnilinux@gmail.com>
Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
parent 20f85a1b

drivers/md/dm-thin.c

+5 −7
Original line number Diff line number Diff line
@@ -395,13 +395,13 @@ static void begin_discard(struct discard_op *op, struct thin_c *tc, struct bio * 
	op->bio = NULL;

}



static int issue_discard(struct discard_op *op, dm_block_t data_b, dm_block_t data_e)

static void issue_discard(struct discard_op *op, dm_block_t data_b, dm_block_t data_e)

{

	struct thin_c *tc = op->tc;

	sector_t s = block_to_sectors(tc->pool, data_b);

	sector_t len = block_to_sectors(tc->pool, data_e - data_b);



	return __blkdev_issue_discard(tc->pool_dev->bdev, s, len, GFP_NOIO, &op->bio);

	__blkdev_issue_discard(tc->pool_dev->bdev, s, len, GFP_NOIO, &op->bio);

}



static void end_discard(struct discard_op *op, int r)
@@ -1113,9 +1113,7 @@ static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m 
				break;

		}



		r = issue_discard(&op, b, e);

		if (r)

			goto out;

		issue_discard(&op, b, e);



		b = e;

	}
@@ -1188,8 +1186,8 @@ static void process_prepared_discard_passdown_pt1(struct dm_thin_new_mapping *m) 
		struct discard_op op;



		begin_discard(&op, tc, discard_parent);

		r = issue_discard(&op, m->data_block, data_end);

		end_discard(&op, r);

		issue_discard(&op, m->data_block, data_end);

		end_discard(&op, 0);

	}

}