From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38653) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d1Amm-0007bt-HV for qemu-devel@nongnu.org; Thu, 20 Apr 2017 08:02:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d1Amc-00031g-9i for qemu-devel@nongnu.org; Thu, 20 Apr 2017 08:02:08 -0400 From: Paolo Bonzini Date: Thu, 20 Apr 2017 14:00:43 +0200 Message-Id: <20170420120058.28404-3-pbonzini@redhat.com> In-Reply-To: <20170420120058.28404-1-pbonzini@redhat.com> References: <20170420120058.28404-1-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 02/17] block: access quiesce_counter with atomic ops List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org Signed-off-by: Paolo Bonzini --- block/io.c | 4 ++-- include/block/block_int.h | 1 + 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/block/io.c b/block/io.c index 08de488..3a27fd5 100644 --- a/block/io.c +++ b/block/io.c @@ -241,7 +241,7 @@ void bdrv_drained_begin(BlockDriverState *bs) return; } - if (!bs->quiesce_counter++) { + if (atomic_fetch_inc(&bs->quiesce_counter) == 0) { aio_disable_external(bdrv_get_aio_context(bs)); bdrv_parent_drained_begin(bs); } @@ -252,7 +252,7 @@ void bdrv_drained_begin(BlockDriverState *bs) void bdrv_drained_end(BlockDriverState *bs) { assert(bs->quiesce_counter > 0); - if (--bs->quiesce_counter > 0) { + if (atomic_fetch_dec(&bs->quiesce_counter) > 1) { return; } diff --git a/include/block/block_int.h b/include/block/block_int.h index d0b88ff..a43fe78 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -623,6 +623,7 @@ struct BlockDriverState { /* do we need to tell the quest if we have a volatile write cache? */ int enable_write_cache; + /* Accessed with atomic ops. */ int quiesce_counter; }; -- 2.9.3