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charset=UTF-8 In-Reply-To: <20251124025737.203571-3-ckulkarnilinux@gmail.com> Subject: Re: [PATCH V2 2/5] dm: ignore discard return value Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251124025737.203571-1-ckulkarnilinux@gmail.com> <20251124025737.203571-3-ckulkarnilinux@gmail.com> User-Agent: Mozilla Thunderbird Received: from [192.168.1.104] ([39.182.0.153]) by smtp.feishu.cn with ESMTPS; Mon, 24 Nov 2025 14:24:08 +0800 Reply-To: yukuai@fnnas.com To: "Chaitanya Kulkarni" , , , , , , , , , , , , "Yu Kuai" Cc: , , , , , , , From: "Yu Kuai" Message-Id: Content-Language: en-US X-Lms-Return-Path: Content-Transfer-Encoding: quoted-printable Hi, =E5=9C=A8 2025/11/24 10:57, Chaitanya Kulkarni =E5=86=99=E9=81=93: > __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() hardcod value > of r to 0 that matches only value returned from > __blkdev_issue_discard(). > > md part is simplified to only check !discard_bio by ignoring the > __blkdev_issue_discard() value. > > Signed-off-by: Chaitanya Kulkarni > --- > drivers/md/dm-thin.c | 12 +++++------- > drivers/md/md.c | 4 ++-- > 2 files changed, 7 insertions(+), 9 deletions(-) mdraid and dm are different drivers, please split them. > > diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c > index c84149ba4e38..77c76f75c85f 100644 > --- a/drivers/md/dm-thin.c > +++ b/drivers/md/dm-thin.c > @@ -395,13 +395,13 @@ static void begin_discard(struct discard_op *op, st= ruct thin_c *tc, struct bio * > op->bio =3D NULL; > } > =20 > -static int issue_discard(struct discard_op *op, dm_block_t data_b, dm_bl= ock_t data_e) > +static void issue_discard(struct discard_op *op, dm_block_t data_b, dm_b= lock_t data_e) > { > struct thin_c *tc =3D op->tc; > sector_t s =3D block_to_sectors(tc->pool, data_b); > sector_t len =3D block_to_sectors(tc->pool, data_e - data_b); > =20 > - 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); > } > =20 > 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; > } > =20 > - r =3D issue_discard(&op, b, e); > - if (r) > - goto out; > + issue_discard(&op, b, e); > =20 > b =3D e; > } > @@ -1188,8 +1186,8 @@ static void process_prepared_discard_passdown_pt1(s= truct dm_thin_new_mapping *m) > struct discard_op op; > =20 > begin_discard(&op, tc, discard_parent); > - r =3D issue_discard(&op, m->data_block, data_end); > - end_discard(&op, r); > + issue_discard(&op, m->data_block, data_end); > + end_discard(&op, 0); > } > } > =20 > diff --git a/drivers/md/md.c b/drivers/md/md.c > index 7b5c5967568f..aeb62df39828 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -9132,8 +9132,8 @@ void md_submit_discard_bio(struct mddev *mddev, str= uct md_rdev *rdev, > { > struct bio *discard_bio =3D NULL; > =20 > - if (__blkdev_issue_discard(rdev->bdev, start, size, GFP_NOIO, > - &discard_bio) || !discard_bio) > + __blkdev_issue_discard(rdev->bdev, start, size, GFP_NOIO, &discard_bio)= ; > + if (!discard_bio) > return; > =20 > bio_chain(discard_bio, bio); --=20 Thanks Kuai