From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Benjamin Marzinski Date: Thu, 2 Jul 2020 19:07:01 -0500 Subject: [PATCH] multipathd: fix check_path errors with removed map If a multipath device is removed during, or immediately before the call to check_path(), multipathd can behave incorrectly. A missing multpath device will cause update_multipath_strings() to fail, setting pp->dmstate to PSTATE_UNDEF. If the path is up, this state will cause reinstate_path() to be called, which will also fail. This will trigger a reload, restoring the recently removed device. If update_multipath_strings() fails because there is no multipath device, check_path should just quit, since the remove dmevent and uevent are likely already queued up. Also, I don't see any reason to reload the multipath device if reinstate fails. This code was added by fac68d7a99ef17d496079538a5c6836acd7911ab, which clamined that reinstate could fail if the path was disabled. Looking through the current kernel code, I can't see any reason why a reinstate would fail, where a reload would help. If the path was missing from the multipath device, update_multipath_strings() would already catch that, and quit check_path() early, which make more sense to me than reloading does. Signed-off-by: Benjamin Marzinski --- multipathd/main.c | 44 +++++++++++++++++++------------------------- 1 file changed, 19 insertions(+), 25 deletions(-) diff --git a/multipathd/main.c b/multipathd/main.c index ab141fed..daf19a4e 100644 --- a/multipathd/main.c +++ b/multipathd/main.c @@ -1615,22 +1615,18 @@ fail_path (struct path * pp, int del_active) /* * caller must have locked the path list before calling that function */ -static int +static void reinstate_path (struct path * pp) { - int ret = 0; - if (!pp->mpp) - return 0; + return; - if (dm_reinstate_path(pp->mpp->alias, pp->dev_t)) { + if (dm_reinstate_path(pp->mpp->alias, pp->dev_t)) condlog(0, "%s: reinstate failed", pp->dev_t); - ret = 1; - } else { + else { condlog(2, "%s: reinstated", pp->dev_t); update_queue_mode_add_path(pp->mpp); } - return ret; } static void @@ -2091,9 +2087,16 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) /* * Synchronize with kernel state */ - if (update_multipath_strings(pp->mpp, vecs->pathvec, 1) != DMP_OK) { - condlog(1, "%s: Could not synchronize with kernel state", - pp->dev); + ret = update_multipath_strings(pp->mpp, vecs->pathvec, 1); + if (ret != DMP_OK) { + if (ret == DMP_NOT_FOUND) { + /* multipath device missing. Likely removed */ + condlog(1, "%s: multipath device '%s' not found", + pp->dev, pp->mpp->alias); + return 0; + } else + condlog(1, "%s: Couldn't synchronize with kernel state", + pp->dev); pp->dmstate = PSTATE_UNDEF; } /* if update_multipath_strings orphaned the path, quit early */ @@ -2183,12 +2186,8 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) /* * reinstate this path */ - if (!disable_reinstate && reinstate_path(pp)) { - condlog(3, "%s: reload map", pp->dev); - ev_add_path(pp, vecs, 1); - pp->tick = 1; - return 0; - } + if (!disable_reinstate) + reinstate_path(pp); new_path_up = 1; if (oldchkrstate != PATH_UP && oldchkrstate != PATH_GHOST) @@ -2204,15 +2203,10 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) else if (newstate == PATH_UP || newstate == PATH_GHOST) { if ((pp->dmstate == PSTATE_FAILED || pp->dmstate == PSTATE_UNDEF) && - !disable_reinstate) { + !disable_reinstate) /* Clear IO errors */ - if (reinstate_path(pp)) { - condlog(3, "%s: reload map", pp->dev); - ev_add_path(pp, vecs, 1); - pp->tick = 1; - return 0; - } - } else { + reinstate_path(pp); + else { LOG_MSG(4, verbosity, pp); if (pp->checkint != max_checkint) { /* -- 2.17.2