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

[Eric Blake <eblake@xxxxxxxxxx>]

On 7/7/20 11:50 AM, Markus Armbruster wrote:
> From: Vladimir Sementsov-Ogievskiy <vsementsov@xxxxxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Reported-by: Greg Kurz <groug@xxxxxxxx>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@xxxxxxxxxxxxx>
> Reviewed-by: Markus Armbruster <armbru@xxxxxxxxxx>
> [Commit message tweaked]
> Signed-off-by: Markus Armbruster <armbru@xxxxxxxxxx>
> ---
Reviewed-by: Eric Blake <eblake@xxxxxxxxxx>

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