From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: [PATCH v2 13/26] raid5: use bio_reset() Date: Tue, 11 Sep 2012 15:03:26 +1000 Message-ID: <20120911150326.79f066c0@notabene.brown> References: <1347322957-25260-1-git-send-email-koverstreet@google.com> <1347322957-25260-14-git-send-email-koverstreet@google.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/GuKwZFHvt3YJqbNxrq9M8j+"; protocol="application/pgp-signature" Return-path: In-Reply-To: <1347322957-25260-14-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> Sender: linux-bcache-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Kent Overstreet Cc: linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org List-Id: dm-devel.ids --Sig_/GuKwZFHvt3YJqbNxrq9M8j+ Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Mon, 10 Sep 2012 17:22:24 -0700 Kent Overstreet wrote: > Had to shuffle the code around a bit (where bi_rw and bi_end_io were > set), but shouldn't really be anything tricky here >=20 > Signed-off-by: Kent Overstreet > CC: Jens Axboe > CC: NeilBrown > --- > drivers/md/raid5.c | 28 ++++++++++++++-------------- > 1 file changed, 14 insertions(+), 14 deletions(-) >=20 > diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c > index 7c19dbe..ebe43f7 100644 > --- a/drivers/md/raid5.c > +++ b/drivers/md/raid5.c > @@ -561,14 +561,6 @@ static void ops_run_io(struct stripe_head *sh, struc= t stripe_head_state *s) > bi =3D &sh->dev[i].req; > rbi =3D &sh->dev[i].rreq; /* For writing to replacement */ > =20 > - bi->bi_rw =3D rw; > - rbi->bi_rw =3D rw; > - if (rw & WRITE) { > - bi->bi_end_io =3D raid5_end_write_request; > - rbi->bi_end_io =3D raid5_end_write_request; > - } else > - bi->bi_end_io =3D raid5_end_read_request; > - > rcu_read_lock(); > rrdev =3D rcu_dereference(conf->disks[i].replacement); > smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */ > @@ -643,7 +635,14 @@ static void ops_run_io(struct stripe_head *sh, struc= t stripe_head_state *s) > =20 > set_bit(STRIPE_IO_STARTED, &sh->state); > =20 > + bio_reset(bi); > bi->bi_bdev =3D rdev->bdev; > + bi->bi_rw =3D rw; > + bi->bi_end_io =3D (rw & WRITE) > + ? raid5_end_write_request > + : raid5_end_read_request; > + bi->bi_private =3D sh; > + > pr_debug("%s: for %llu schedule op %ld on disc %d\n", > __func__, (unsigned long long)sh->sector, > bi->bi_rw, i); > @@ -657,12 +656,9 @@ static void ops_run_io(struct stripe_head *sh, struc= t stripe_head_state *s) > if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) > bi->bi_rw |=3D REQ_FLUSH; > =20 > - bi->bi_flags =3D 1 << BIO_UPTODATE; > - bi->bi_idx =3D 0; > bi->bi_io_vec[0].bv_len =3D STRIPE_SIZE; > bi->bi_io_vec[0].bv_offset =3D 0; > bi->bi_size =3D STRIPE_SIZE; > - bi->bi_next =3D NULL; > if (rrdev) > set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags); > generic_make_request(bi); > @@ -674,7 +670,14 @@ static void ops_run_io(struct stripe_head *sh, struc= t stripe_head_state *s) > =20 > set_bit(STRIPE_IO_STARTED, &sh->state); > =20 > + bio_reset(rbi); > rbi->bi_bdev =3D rrdev->bdev; > + rbi->bi_rw =3D rw; > + rbi->bi_end_io =3D (rw & WRITE) > + ? raid5_end_write_request > + : raid5_end_read_request; 'rbi->bi_end_io' can only ever be raid5_end_write_request. We only get here on a write. I'd be OK with=20 BUG_ON(!(rw & WRITE)); but I don't want the condition in the assignment. The rest looks quite sane. Thanks NeilBrown --Sig_/GuKwZFHvt3YJqbNxrq9M8j+ Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBUE7GHjnsnt1WYoG5AQL6kBAAmgyeYyjUqOlRvWLVaXtHo9arv6VWhlsf rfEj057kWkSCOAoIrg8VCXnlzAxJtb5SDDS8QGHlx1Y1m9uLBPNN0osUgnhTWAO7 AqH4LypQ/uqwk4JcSd5p+dnGyXizr7oRlPNp1DrIlbnlpqBa0yBdLO+qljfcMVID Dn5vwK/1XwIPfuPhpsjtse/GgFPUTmVcBSQcrP03uaiYqgpO4EJgLTmAju1WYnMS LcO4Vsd+TfqKz3IjoBPPuom0cm2tX116TWIkI7M4TR4iircph+LkBjqpysXm4VVO WrDY0vyqSFyo0jQJtd3jrfV8l83m5/D6Y59wvbjbovCcnwJucNzjsI6BeVjgg9PB xmsSIYlsxnQuxXAjPkfR9bADnat40clp/hY8ZIrmEugS3fcTa9qmqKF9a28RhNut 4ft6pt0q+wLOjAJ9JhHgbKwgRumxQ/4jORlieDO2LVYHk9oQ+JonqDCnF3q1ZAo1 c/HxFAy5ARu9Fz28O+bPQGJ14fvsG8NhQ+KKqmIKGBJa0DyScwCreLZdMeO4uO0E 8gmaRImIkKvr3V7H1AucTYdW4n96ZPPC1Tzqx6Bu+sUv2k5ipDCiuTfstCfLWWo5 obLM03El8IjYSNcrB3j1+oiGXPz6AuCKaJqx9GpznhmnyHu5dOW8sHSyTEpSuuNn 5SwE7qRS/Q0= =vViI -----END PGP SIGNATURE----- --Sig_/GuKwZFHvt3YJqbNxrq9M8j+--