Re: [PATCH v12 7/8] nbd: Use ERRP_AUTO_PROPAGATE()

From: Eric Blake <eblake@redhat.com>
To: Markus Armbruster <armbru@redhat.com>, qemu-devel@nongnu.org
Cc: "Kevin Wolf" <kwolf@redhat.com>,
	vsementsov@virtuozzo.com, qemu-block@nongnu.org,
	"Paul Durrant" <paul@xen.org>,
	"Philippe Mathieu-Daudé" <philmd@redhat.com>,
	"Christian Schoenebeck" <qemu_oss@crudebyte.com>,
	"Michael Roth" <mdroth@linux.vnet.ibm.com>,
	groug@kaod.org, "Stefano Stabellini" <sstabellini@kernel.org>,
	"Gerd Hoffmann" <kraxel@redhat.com>,
	"Stefan Hajnoczi" <stefanha@redhat.com>,
	"Anthony Perard" <anthony.perard@citrix.com>,
	xen-devel@lists.xenproject.org, "Max Reitz" <mreitz@redhat.com>,
	"Laszlo Ersek" <lersek@redhat.com>
Subject: Re: [PATCH v12 7/8] nbd: Use ERRP_AUTO_PROPAGATE()
Date: Tue, 7 Jul 2020 14:43:54 -0500	[thread overview]
Message-ID: <88ceae2e-eb02-de34-9210-354423bab4a4@redhat.com> (raw)
In-Reply-To: <20200707165037.1026246-8-armbru@redhat.com>

On 7/7/20 11:50 AM, Markus Armbruster wrote:
> From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> 
> If we want to add some info to errp (by error_prepend() or
> error_append_hint()), we must use the ERRP_AUTO_PROPAGATE macro.
> Otherwise, this info will not be added when errp == &error_fatal
> (the program will exit prior to the error_append_hint() or
> error_prepend() call).  Fix such cases.
> 
> If we want to check error after errp-function call, we need to
> introduce local_err and then propagate it to errp. Instead, use
> ERRP_AUTO_PROPAGATE macro, benefits are:
> 1. No need of explicit error_propagate call
> 2. No need of explicit local_err variable: use errp directly
> 3. ERRP_AUTO_PROPAGATE leaves errp as is if it's not NULL or
>     &error_fatal, this means that we don't break error_abort
>     (we'll abort on error_set, not on error_propagate)
> 
> This commit is generated by command
> 
>      sed -n '/^Network Block Device (NBD)$/,/^$/{s/^F: //p}' \
>          MAINTAINERS | \
>      xargs git ls-files | grep '\.[hc]$' | \
>      xargs spatch \
>          --sp-file scripts/coccinelle/auto-propagated-errp.cocci \
>          --macro-file scripts/cocci-macro-file.h \
>          --in-place --no-show-diff --max-width 80
> 
> Reported-by: Kevin Wolf <kwolf@redhat.com>
> Reported-by: Greg Kurz <groug@kaod.org>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> Reviewed-by: Markus Armbruster <armbru@redhat.com>
> [Commit message tweaked]
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org