Re: [PATCH v3 04/15] multipathd: emit a warning if a map remains inconsistent after reload

[Benjamin Marzinski <bmarzins@redhat.com>]

On Fri, Jan 17, 2025 at 09:27:27PM +0100, Martin Wilck wrote:
> After reading the kernel device-mapper table, update_pathvec_from_dm()
> sets the mpp->need_reload flag if an inconsistent state was found (often a
> path with wrong WWID). We expect reload_and_sync_map() to fix this situation.
> If this is not the case (need_reload still set after map reloading), it's
> most probably a bug.
> 
> Signed-off-by: Martin Wilck <mwilck@suse.com>

Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>

> ---
>  multipathd/main.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/multipathd/main.c b/multipathd/main.c
> index e4e6bf7..ff3031e 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -3026,13 +3026,20 @@ checkerloop (void *ap)
>  							     start_time.tv_sec);
>  			if (checker_state == CHECKER_FINISHED) {
>  				vector_foreach_slot(vecs->mpvec, mpp, i) {
> +					bool inconsistent;
> +
>  					sync_mpp(vecs, mpp, ticks);
> -					if ((update_mpp_prio(mpp) || mpp->need_reload) &&
> +					inconsistent = mpp->need_reload;
> +					if ((update_mpp_prio(mpp) || inconsistent) &&
>  					    reload_and_sync_map(mpp, vecs) == 2) {
>  						/* multipath device deleted */
>  						i--;
>  						continue;
>  					}
> +					/* need_reload was cleared in dm_addmap and then set again */
> +					if (inconsistent && mpp->need_reload)
> +						condlog(1, "BUG: %s; map remained in inconsistent state after reload",
> +							mpp->alias);
>  				}
>  			}
>  			lock_cleanup_pop(vecs->lock);
> -- 
> 2.47.1