From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54499) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1HvD-0001ft-MS for qemu-devel@nongnu.org; Tue, 24 Nov 2015 13:02:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a1HvC-00063Q-Uv for qemu-devel@nongnu.org; Tue, 24 Nov 2015 13:02:31 -0500 From: Paolo Bonzini Date: Tue, 24 Nov 2015 19:01:20 +0100 Message-Id: <1448388091-117282-30-git-send-email-pbonzini@redhat.com> In-Reply-To: <1448388091-117282-1-git-send-email-pbonzini@redhat.com> References: <1448388091-117282-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 29/40] quorum: use atomics for rewrite_count List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, qemu-block@nongnu.org This is simpler than taking and releasing the AioContext lock. Signed-off-by: Paolo Bonzini --- block/quorum.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/block/quorum.c b/block/quorum.c index b9ba028..3b19c9e 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -250,15 +250,10 @@ static void quorum_rewrite_aio_cb(void *opaque, int ret) { QuorumAIOCB *acb = opaque; - /* one less rewrite to do */ - acb->rewrite_count--; - /* wait until all rewrite callbacks have completed */ - if (acb->rewrite_count) { - return; + if (atomic_fetch_dec(&acb->rewrite_count) == 1) { + quorum_aio_finalize(acb); } - - quorum_aio_finalize(acb); } static BlockAIOCB *read_fifo_child(QuorumAIOCB *acb); @@ -361,7 +356,7 @@ static bool quorum_rewrite_bad_versions(BDRVQuorumState *s, QuorumAIOCB *acb, } /* quorum_rewrite_aio_cb will count down this to zero */ - acb->rewrite_count = count; + atomic_mb_set(&acb->rewrite_count, count); /* now fire the correcting rewrites */ QLIST_FOREACH(version, &acb->votes.vote_list, next) { -- 1.8.3.1