From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48874) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aWLO7-0001sr-5b for qemu-devel@nongnu.org; Thu, 18 Feb 2016 05:00:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aWLO2-0007zz-H3 for qemu-devel@nongnu.org; Thu, 18 Feb 2016 05:00:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33740) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aWLO2-0007zl-8q for qemu-devel@nongnu.org; Thu, 18 Feb 2016 05:00:38 -0500 Date: Thu, 18 Feb 2016 10:00:33 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20160218100032.GD2438@work-vm> References: <1455588944-29799-1-git-send-email-xiecl.fnst@cn.fujitsu.com> <1455588944-29799-2-git-send-email-xiecl.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1455588944-29799-2-git-send-email-xiecl.fnst@cn.fujitsu.com> Subject: Re: [Qemu-devel] [PATCH v2 1/1] quorum: Change vote rules for 64 bits hash List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Changlong Xie Cc: Kevin Wolf , Alberto Garcia , qemu devel * Changlong Xie (xiecl.fnst@cn.fujitsu.com) wrote: > If quorum has two children(A, B). A do flush sucessfully, but B flush failed. > We MUST choice A as winner rather than just pick anyone of them. Otherwise > the filesystem of guest will become read-only with following errors: > > end_request: I/O error, dev vda, sector 11159960 > Aborting journal on device vda3-8 > EXT4-fs error (device vda3): ext4_journal_start_sb:327: Detected abort journal > EXT4-fs (vda3): Remounting filesystem read-only > > Signed-off-by: Wen Congyang > Signed-off-by: Changlong Xie Hi, That seems to fix the problem I was seeing; thanks. (I don't know enough about the quorum layer to comment much more). Dave > --- > block/quorum.c | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/block/quorum.c b/block/quorum.c > index 11cc60b..f094208 100644 > --- a/block/quorum.c > +++ b/block/quorum.c > @@ -447,7 +447,8 @@ static int quorum_compute_hash(QuorumAIOCB *acb, int i, QuorumVoteValue *hash) > return 0; > } > > -static QuorumVoteVersion *quorum_get_vote_winner(QuorumVotes *votes) > +static QuorumVoteVersion *quorum_get_vote_winner(QuorumVotes *votes, > + bool vote_error) > { > int max = 0; > QuorumVoteVersion *candidate, *winner = NULL; > @@ -456,6 +457,12 @@ static QuorumVoteVersion *quorum_get_vote_winner(QuorumVotes *votes) > if (candidate->vote_count > max) { > max = candidate->vote_count; > winner = candidate; > + continue; > + } > + /* For 64 bit hash */ > + if (vote_error && candidate->vote_count == max > + && candidate->value.l == 0) { > + winner = candidate; > } > } > > @@ -545,7 +552,7 @@ static int quorum_vote_error(QuorumAIOCB *acb) > } > > if (error) { > - winner = quorum_get_vote_winner(&error_votes); > + winner = quorum_get_vote_winner(&error_votes, false); > ret = winner->value.l; > } > > @@ -610,7 +617,7 @@ static bool quorum_vote(QuorumAIOCB *acb) > } > > /* vote to select the most represented version */ > - winner = quorum_get_vote_winner(&acb->votes); > + winner = quorum_get_vote_winner(&acb->votes, false); > > /* if the winner count is smaller than threshold the read fails */ > if (winner->vote_count < s->threshold) { > @@ -770,7 +777,7 @@ static coroutine_fn int quorum_co_flush(BlockDriverState *bs) > quorum_count_vote(&error_votes, &result_value, i); > } > > - winner = quorum_get_vote_winner(&error_votes); > + winner = quorum_get_vote_winner(&error_votes, true); > result = winner->value.l; > > quorum_free_vote_list(&error_votes); > -- > 1.9.3 > > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK