From 4b5766488fd3549dc47a75331cf4db62f477536c Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Wed, 17 Oct 2018 10:26:25 +0200 Subject: error: Fix use of error_prepend() with &error_fatal, &error_abort MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From include/qapi/error.h: * Pass an existing error to the caller with the message modified: * error_propagate(errp, err); * error_prepend(errp, "Could not frobnicate '%s': ", name); Fei Li pointed out that doing error_propagate() first doesn't work well when @errp is &error_fatal or &error_abort: the error_prepend() is never reached. Since I doubt fixing the documentation will stop people from getting it wrong, introduce error_propagate_prepend(), in the hope that it lures people away from using its constituents in the wrong order. Update the instructions in error.h accordingly. Convert existing error_prepend() next to error_propagate to error_propagate_prepend(). If any of these get reached with &error_fatal or &error_abort, the error messages improve. I didn't check whether that's the case anywhere. Cc: Fei Li Signed-off-by: Markus Armbruster Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Eric Blake Message-Id: <20181017082702.5581-2-armbru@redhat.com> --- block/qcow2.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'block/qcow2.c') diff --git a/block/qcow2.c b/block/qcow2.c index 7277fed..4f8d2fa 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2208,8 +2208,8 @@ static void coroutine_fn qcow2_co_invalidate_cache(BlockDriverState *bs, qemu_co_mutex_unlock(&s->lock); qobject_unref(options); if (local_err) { - error_propagate(errp, local_err); - error_prepend(errp, "Could not reopen qcow2 layer: "); + error_propagate_prepend(errp, local_err, + "Could not reopen qcow2 layer: "); bs->drv = NULL; return; } else if (ret < 0) { -- cgit v1.1