From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Benjamin Marzinski Date: Mon, 5 Feb 2018 21:59:16 -0600 Subject: [PATCH] call start_waiter_thread() before setup_multipath() If setup_multipath() is called before the waiter thread has started, there is a window where a dm event can occur between when setup_multipath() updates the device state and when the waiter thread starts waiting for new events, causing the new event to be missed and the multipath device to not get updated. Signed-off-by: Benjamin Marzinski --- multipathd/main.c | 37 ++++++++++++++++++++----------------- 1 file changed, 20 insertions(+), 17 deletions(-) diff --git a/multipathd/main.c b/multipathd/main.c index 94b2406..efc39d7 100644 --- a/multipathd/main.c +++ b/multipathd/main.c @@ -321,7 +321,7 @@ set_multipath_wwid (struct multipath * mpp) } static int -update_map (struct multipath *mpp, struct vectors *vecs) +update_map (struct multipath *mpp, struct vectors *vecs, int new_map) { int retries = 3; char params[PARAMS_SIZE] = {0}; @@ -351,6 +351,12 @@ retry: dm_lib_release(); fail: + if (new_map && (retries < 0 || start_waiter_thread(mpp, vecs))) { + condlog(0, "%s: failed to create new map", mpp->alias); + remove_map(mpp, vecs, 1); + return 1; + } + if (setup_multipath(vecs, mpp)) return 1; @@ -395,12 +401,9 @@ add_map_without_path (struct vectors *vecs, char *alias) vector_set_slot(vecs->mpvec, mpp); - if (update_map(mpp, vecs) != 0) /* map removed */ + if (update_map(mpp, vecs, 1) != 0) /* map removed */ return NULL; - if (start_waiter_thread(mpp, vecs)) - goto out; - return mpp; out: remove_map(mpp, vecs, PURGE_VEC); @@ -554,7 +557,7 @@ ev_add_map (char * dev, char * alias, struct vectors * vecs) if (mpp->wait_for_udev > 1) { condlog(2, "%s: performing delayed actions", mpp->alias); - if (update_map(mpp, vecs)) + if (update_map(mpp, vecs, 0)) /* setup multipathd removed the map */ return 1; } @@ -865,6 +868,11 @@ retry: } dm_lib_release(); + if ((mpp->action == ACT_CREATE || + (mpp->action == ACT_NOTHING && start_waiter && !mpp->waiter)) && + start_waiter_thread(mpp, vecs)) + goto fail_map; + /* * update our state from kernel regardless of create or reload */ @@ -873,11 +881,6 @@ retry: sync_map_state(mpp); - if ((mpp->action == ACT_CREATE || - (mpp->action == ACT_NOTHING && start_waiter && !mpp->waiter)) && - start_waiter_thread(mpp, vecs)) - goto fail_map; - if (retries >= 0) { condlog(2, "%s [%s]: path added to devmap %s", pp->dev, pp->dev_t, mpp->alias); @@ -1479,7 +1482,8 @@ missing_uev_wait_tick(struct vectors *vecs) 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)) { + if (mpp->wait_for_udev > 1 && + update_map(mpp, vecs, 0)) { /* update_map removed map */ i--; continue; @@ -1511,7 +1515,7 @@ ghost_delay_tick(struct vectors *vecs) condlog(0, "%s: timed out waiting for active path", mpp->alias); mpp->force_udev_reload = 1; - if (update_map(mpp, vecs) != 0) { + if (update_map(mpp, vecs, 0) != 0) { /* update_map removed map */ i--; continue; @@ -2169,14 +2173,13 @@ configure (struct vectors * vecs) * start dm event waiter threads for these new maps */ vector_foreach_slot(vecs->mpvec, mpp, i) { - if (setup_multipath(vecs, mpp)) { - i--; - continue; - } if (start_waiter_thread(mpp, vecs)) { remove_map(mpp, vecs, 1); i--; + continue; } + if (setup_multipath(vecs, mpp)) + i--; } return 0; } -- 2.7.4