On Sat, Dec 07, 2024 at 12:36:15AM +0100, Martin Wilck wrote:
> Instead, check for missing uevents in the existing mpvec loop.
> Note that if the uevent tick expires, we need to call update_map() rather than
> reload_and_sync_map(), because the paths have not been added to the multipath
> (see wait_for_udev handling ev_add_path()).
>
> Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
> ---
> multipathd/main.c | 40 +++++++++++++++++++---------------------
> 1 file changed, 19 insertions(+), 21 deletions(-)
>
> diff --git a/multipathd/main.c b/multipathd/main.c
> index 4cf5493..4478cc9 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -2011,29 +2011,19 @@ followover_should_failback(struct multipath *mpp)
> return 0;
> }
>
> -static void
> -missing_uev_wait_tick(struct vectors *vecs)
> +/* Returns true if update_map() needs to be called */
> +static bool
> +missing_uev_wait_tick(struct multipath *mpp, bool *timed_out)
> {
> - struct multipath * mpp;
> - int i;
> - int timed_out = 0;
> + if (mpp->wait_for_udev && --mpp->uev_wait_tick <= 0) {
> + int wait = mpp->wait_for_udev;
>
> - vector_foreach_slot (vecs->mpvec, mpp, i) {
> - if (mpp->wait_for_udev && --mpp->uev_wait_tick <= 0) {
> - timed_out = 1;
> - condlog(0, "%s: timeout waiting on creation uevent. enabling reloads", mpp->alias);
> - if (mpp->wait_for_udev > 1 &&
> - update_map(mpp, vecs, 0)) {
> - /* update_map removed map */
> - i--;
> - continue;
> - }
> - mpp->wait_for_udev = 0;
> - }
> + mpp->wait_for_udev = 0;
> + *timed_out = true;
> + condlog(0, "%s: timeout waiting on creation uevent. enabling reloads", mpp->alias);
> + return wait > 1;
> }
> -
> - if (timed_out && !need_to_delay_reconfig(vecs))
> - unblock_reconfigure();
> + return false;
> }
>
> static void
> @@ -2947,9 +2937,16 @@ update_paths(struct vectors *vecs, int *num_paths_p, time_t start_secs)
> static void checker_finished(struct vectors *vecs)
> {
> struct multipath *mpp;
> + bool uev_timed_out = false;
> int i;
>
> vector_foreach_slot(vecs->mpvec, mpp, i) {
> + if (missing_uev_wait_tick(mpp, &uev_timed_out) &&
> + update_map(mpp, vecs, 0)) {
> + /* multipath device deleted */
> + i--;
> + continue;
> + }
Looking at this made me think we should probably be adding a check
in reload_and_sync_map() for mpp->wait_for_udev. If it's no-zero,
we should set it to 2 (and we might want to make it symoblic too)
and skip the reload. Otherwise we'll be reloading when we shouldn't be.
> if ((update_mpp_prio(mpp) ||
> (mpp->need_reload && mpp->synced_count > 0) ||
> deferred_failback_tick(mpp)) &&
> @@ -2959,7 +2956,8 @@ static void checker_finished(struct vectors *vecs)
> else
> retry_count_tick(mpp);
> }
> - missing_uev_wait_tick(vecs);
> + if (uev_timed_out && !need_to_delay_reconfig(vecs))
> + unblock_reconfigure();
> ghost_delay_tick(vecs);
> partial_retrigger_tick(vecs->pathvec);
> }
> --
> 2.47.0
