From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37496) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WAI0E-0001ZT-SF for qemu-devel@nongnu.org; Mon, 03 Feb 2014 06:47:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WAI09-00045E-Qx for qemu-devel@nongnu.org; Mon, 03 Feb 2014 06:47:50 -0500 Received: from paradis.irqsave.net ([62.212.105.220]:48912) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WAI09-00045A-8p for qemu-devel@nongnu.org; Mon, 03 Feb 2014 06:47:45 -0500 Date: Mon, 3 Feb 2014 12:47:44 +0100 From: =?iso-8859-1?Q?Beno=EEt?= Canet Message-ID: <20140203114744.GC3078@irqsave.net> References: <1390927974-31325-1-git-send-email-benoit.canet@irqsave.net> <1390927974-31325-10-git-send-email-benoit.canet@irqsave.net> <52EEBC27.2000407@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <52EEBC27.2000407@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH V10 09/13] quorum: Add quorum_co_get_block_status. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz Cc: =?iso-8859-1?Q?Beno=EEt?= Canet , kwolf@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com Le Sunday 02 Feb 2014 =E0 22:44:07 (+0100), Max Reitz a =E9crit : > On 28.01.2014 17:52, Beno=EEt Canet wrote: > >From: Beno=EEt Canet > > > >Signed-off-by: Benoit Canet > >--- > > block/quorum.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++= ++++++++++ > > 1 file changed, 67 insertions(+) > > > >diff --git a/block/quorum.c b/block/quorum.c > >index a47cd33..9b0718b 100644 > >--- a/block/quorum.c > >+++ b/block/quorum.c > >@@ -171,6 +171,22 @@ static int quorum_sha256_compare(QuorumVoteValue = *a, QuorumVoteValue *b) > > return memcmp(a->h, b->h, HASH_LENGTH); > > } > >+static int quorum_64bits_compare(QuorumVoteValue *a, QuorumVoteValue = *b) > >+{ > >+ int64_t i =3D a->l; > >+ int64_t j =3D b->l; > >+ > >+ if (i < j) { > >+ return -1; > >+ } > >+ > >+ if (i > j) { > >+ return 1; > >+ } > >+ > >+ return 0; > >+} > >+ > > static QuorumAIOCB *quorum_aio_get(BDRVQuorumState *s, > > BlockDriverState *bs, > > QEMUIOVector *qiov, > >@@ -587,6 +603,56 @@ static void quorum_invalidate_cache(BlockDriverSt= ate *bs) > > } > > } > >+static int64_t coroutine_fn quorum_co_get_block_status(BlockDriverSta= te *bs, > >+ int64_t sector= _num, > >+ int nb_sectors= , > >+ int *pnum) > >+{ > >+ BDRVQuorumState *s =3D bs->opaque; > >+ QuorumVoteVersion *winner =3D NULL; > >+ QuorumVotes result_votes, num_votes; > >+ QuorumVoteValue result_value, num_value; > >+ int i, num; > >+ int64_t result =3D 0; > >+ > >+ QLIST_INIT(&result_votes.vote_list); > >+ QLIST_INIT(&num_votes.vote_list); > >+ result_votes.compare =3D quorum_64bits_compare; > >+ num_votes.compare =3D quorum_64bits_compare; > >+ > >+ for (i =3D 0; i < s->total; i++) { > >+ result =3D bdrv_get_block_status(s->bs[i], sector_num, nb_sec= tors, &num); > >+ /* skip failed requests */ > >+ if (result < 0) { > >+ continue; > >+ } > >+ result_value.l =3D result & BDRV_BLOCK_DATA; > >+ num_value.l =3D num; > >+ quorum_count_vote(&result_votes, &result_value, i); > >+ quorum_count_vote(&num_votes, &num_value, i); > >+ } > >+ > >+ winner =3D quorum_get_vote_winner(&result_votes); > >+ result =3D winner->value.l; >=20 > Below, you're reading the winning value after checking whether it's > corresponding votes exceeded the threshold. It doesn't matter in the > end, but for the sake of uniformity, I'd do it the same way here > (i.e., move this statement below the if block). >=20 > >+ if (winner->vote_count < s->threshold) { > >+ result =3D -ERANGE; >=20 > Is there any specific reason why you're returning -ERANGE here and > -EIO everywhere else (even in quorum_getlength())? I probably though "It's a comparison so it return -ERANGE". A bad reason so :( >=20 > Max >=20 > >+ goto free_exit; > >+ } > >+ > >+ winner =3D quorum_get_vote_winner(&num_votes); > >+ if (winner->vote_count < s->threshold) { > >+ result =3D -ERANGE; > >+ goto free_exit; > >+ } > >+ *pnum =3D winner->value.l; > >+ > >+free_exit: > >+ quorum_free_vote_list(&result_votes); > >+ quorum_free_vote_list(&num_votes); > >+ > >+ return result; > >+} > >+ > > static BlockDriver bdrv_quorum =3D { > > .format_name =3D "quorum", > > .protocol_name =3D "quorum", > >@@ -598,6 +664,7 @@ static BlockDriver bdrv_quorum =3D { > > .bdrv_aio_readv =3D quorum_aio_readv, > > .bdrv_aio_writev =3D quorum_aio_writev, > > .bdrv_invalidate_cache =3D quorum_invalidate_cache, > >+ .bdrv_co_get_block_status =3D quorum_co_get_block_status, > > }; > > static void bdrv_quorum_init(void) >=20 >=20