From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45033) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cyMOz-0003gT-Oe for qemu-devel@nongnu.org; Wed, 12 Apr 2017 13:49:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cyMOw-00074W-MI for qemu-devel@nongnu.org; Wed, 12 Apr 2017 13:49:57 -0400 From: Eric Blake Date: Wed, 12 Apr 2017 12:49:10 -0500 Message-Id: <20170412174920.8744-3-eblake@redhat.com> In-Reply-To: <20170412174920.8744-1-eblake@redhat.com> References: <20170412174920.8744-1-eblake@redhat.com> Subject: [Qemu-devel] [PATCH 02/12] migration: Don't lose errno across aio context changes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, kwolf@redhat.com, famz@redhat.com, jsnow@redhat.com, qemu-stable@nongnu.org, Stefan Hajnoczi , Juan Quintela , "Dr. David Alan Gilbert" set_drity_tracking() was assuming that the errno value set by bdrv_create_dirty_bitmap() would not be corrupted by either blk_get_aio_context() or aio_context_release(). Rather than audit whether this assumption is safe, rewrite the code to just grab the value of errno sooner. CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake --- migration/block.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/migration/block.c b/migration/block.c index 18d50ff..9a9c214 100644 --- a/migration/block.c +++ b/migration/block.c @@ -350,9 +350,9 @@ static int set_dirty_tracking(void) aio_context_acquire(blk_get_aio_context(bmds->blk)); bmds->dirty_bitmap = bdrv_create_dirty_bitmap(blk_bs(bmds->blk), BLOCK_SIZE, NULL, NULL); + ret = -errno; aio_context_release(blk_get_aio_context(bmds->blk)); if (!bmds->dirty_bitmap) { - ret = -errno; goto fail; } } -- 2.9.3