From patchwork Mon Jul 22 23:23:06 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Marzinski X-Patchwork-Id: 13739210 X-Patchwork-Delegate: christophe.varoqui@free.fr Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 03E544655D for ; Mon, 22 Jul 2024 23:23:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721690596; cv=none; b=UBbdUhuU67zQj36PfPPHjMw38XTH+0aMRipIOPeS2oBD4gGh15OlFoR7dojCk+dIKf7ri58M5fFcCwR0E/BNDyEPX5G5bV1AXy5nLawrz76YXlN9LHt28ZQ6fYDdt5kfayXe1lU9+5bw02Yr3/9iITX0oLyWgvhikHDaMjncQL8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721690596; c=relaxed/simple; bh=Pu+NqVb0gPk578O4g04CAFKqoU9m69NaTa32DpagoVA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=KATh0P0xrAO9z+f5fTPD90yEYLsZwZhl89KyEhQkoxOKZE9jfOG1AISXItwYD6mHdyjhiBL2YwzHww75HTBfHRoewwIcNtMOU5ipaN75lDbk1tlTTNts5acqdOGhNJDZb5M6uaSSDca+J0tkLYwJA4+yfYI/yjgNyuBYao/0BrA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=BTZt0YEA; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BTZt0YEA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1721690594; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jKAxwQfCVFf+VtmqI2pODjom3UDr+YzGOJxoV+jjPiA=; b=BTZt0YEALHPuphNVba1fJaFx72OokoQ/1Pv2JJp/LAuDpcAK42+WkACbuIElCNjTSobiqg wm9Q9IgbW/pCEjAIe7LwFlt0FXQpn6XnCYjORDqU0gsKzuH2qN7ABhcSkiBxYXyqNYAi9G SS6HQ82Q91Qo47SnzCWzMuNyyGISX9c= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-628-6svh4T4dOSu_KCG3vLNX4A-1; Mon, 22 Jul 2024 19:23:12 -0400 X-MC-Unique: 6svh4T4dOSu_KCG3vLNX4A-1 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 595D51956095; Mon, 22 Jul 2024 23:23:11 +0000 (UTC) Received: from bmarzins-01.fast.eng.rdu2.dc.redhat.com (bmarzins-01.fast.eng.rdu2.dc.redhat.com [10.6.23.12]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A1F051955D44; Mon, 22 Jul 2024 23:23:10 +0000 (UTC) Received: from bmarzins-01.fast.eng.rdu2.dc.redhat.com (localhost [127.0.0.1]) by bmarzins-01.fast.eng.rdu2.dc.redhat.com (8.17.2/8.17.1) with ESMTPS id 46MNN9ow2495972 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Mon, 22 Jul 2024 19:23:09 -0400 Received: (from bmarzins@localhost) by bmarzins-01.fast.eng.rdu2.dc.redhat.com (8.17.2/8.17.2/Submit) id 46MNN96s2495971; Mon, 22 Jul 2024 19:23:09 -0400 From: Benjamin Marzinski To: Christophe Varoqui Cc: device-mapper development , Martin Wilck Subject: [PATCH v3 10/20] multipathd: adjust when mpp is synced with the kernel Date: Mon, 22 Jul 2024 19:23:06 -0400 Message-ID: <20240722232308.2495956-2-bmarzins@redhat.com> In-Reply-To: <20240722232308.2495956-1-bmarzins@redhat.com> References: <20240722232308.2495956-1-bmarzins@redhat.com> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Move the code to sync the mpp device state into a helper function and add a counter to to make sure that the device is synced at least once every max_checkint secs. This makes sure that multipath devices with no paths will still get synced with the kernel. Also, if multiple paths are checked in the same loop, the multipath device will only be synced with the kernel once, since every time the mpp is synced in any code path, mpp->sync_tick is reset. The code still syncs the mpp before updating the path state for two main reasons. 1. Sometimes multipathd leaves the mpp with a garbage state. Future patches will fix most of these cases, but the code intentially does not remove the mpp is resyncing fails while checking paths. But this does leave the mpp with a garbage state. 2. The kernel chages the multipath state independently of multipathd. If the kernel fails a path, a uevent will arrive shortly. But the kernel doesn't provide any notification when it switches the active path group or if it ends up picking a different one than multipathd selected. Multipathd needs to know the actual current pathgroup to know when it should be switching them. Signed-off-by: Benjamin Marzinski --- libmultipath/configure.c | 1 + libmultipath/structs.h | 2 ++ libmultipath/structs_vec.c | 5 +++ multipathd/main.c | 64 +++++++++++++++++++++++++------------- 4 files changed, 50 insertions(+), 22 deletions(-) diff --git a/libmultipath/configure.c b/libmultipath/configure.c index b4de863c..34158e31 100644 --- a/libmultipath/configure.c +++ b/libmultipath/configure.c @@ -358,6 +358,7 @@ int setup_map(struct multipath *mpp, char **params, struct vectors *vecs) sysfs_set_scsi_tmo(conf, mpp); marginal_pathgroups = conf->marginal_pathgroups; + mpp->sync_tick = conf->max_checkint; pthread_cleanup_pop(1); if (!mpp->features || !mpp->hwhandler || !mpp->selector) { diff --git a/libmultipath/structs.h b/libmultipath/structs.h index 3b91e39c..002eeae1 100644 --- a/libmultipath/structs.h +++ b/libmultipath/structs.h @@ -453,6 +453,8 @@ struct multipath { int ghost_delay; int ghost_delay_tick; int queue_mode; + unsigned int sync_tick; + bool is_checked; uid_t uid; gid_t gid; mode_t mode; diff --git a/libmultipath/structs_vec.c b/libmultipath/structs_vec.c index d58ef5a7..7f267ba0 100644 --- a/libmultipath/structs_vec.c +++ b/libmultipath/structs_vec.c @@ -505,11 +505,16 @@ update_multipath_table (struct multipath *mpp, vector pathvec, int flags) char __attribute__((cleanup(cleanup_charp))) *params = NULL; char __attribute__((cleanup(cleanup_charp))) *status = NULL; unsigned long long size; + struct config *conf; if (!mpp) return r; size = mpp->size; + conf = get_multipath_config(); + mpp->sync_tick = conf->max_checkint; + put_multipath_config(conf); + r = libmp_mapinfo(DM_MAP_BY_NAME | MAPINFO_MPATH_ONLY, (mapid_t) { .str = mpp->alias }, (mapinfo_t) { diff --git a/multipathd/main.c b/multipathd/main.c index 86f7ab1f..ae40f599 100644 --- a/multipathd/main.c +++ b/multipathd/main.c @@ -2342,6 +2342,37 @@ check_path_state(struct path *pp) return newstate; } +static void +do_sync_mpp(struct vectors * vecs, struct multipath *mpp) +{ + int i, ret; + struct path *pp; + + mpp->is_checked = true; + ret = update_multipath_strings(mpp, vecs->pathvec); + if (ret != DMP_OK) { + condlog(1, "%s: %s", mpp->alias, ret == DMP_NOT_FOUND ? + "device not found" : + "couldn't synchronize with kernel state"); + vector_foreach_slot (mpp->paths, pp, i) + pp->dmstate = PSTATE_UNDEF; + return; + } + set_no_path_retry(mpp); +} + +static void +sync_mpp(struct vectors * vecs, struct multipath *mpp, unsigned int ticks) +{ + if (mpp->sync_tick) + mpp->sync_tick -= (mpp->sync_tick > ticks) ? ticks : + mpp->sync_tick; + if (mpp->sync_tick) + return; + + do_sync_mpp(vecs, mpp); +} + /* * Returns '1' if the path has been checked and '0' otherwise */ @@ -2356,7 +2387,6 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) unsigned int checkint, max_checkint; struct config *conf; int marginal_pathgroups, marginal_changed = 0; - int ret; bool need_reload; if (pp->initialized == INIT_REMOVED) @@ -2395,26 +2425,6 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) pp->tick = 1; return 0; } - /* - * Synchronize with kernel state - */ - ret = update_multipath_strings(pp->mpp, vecs->pathvec); - 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 ? 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 */ - if (!pp->mpp) - return 0; - set_no_path_retry(pp->mpp); - if (pp->recheck_wwid == RECHECK_WWID_ON && (newstate == PATH_UP || newstate == PATH_GHOST) && ((pp->state != PATH_UP && pp->state != PATH_GHOST) || @@ -2424,7 +2434,12 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) handle_path_wwid_change(pp, vecs); return 0; } - + if (!pp->mpp->is_checked) { + do_sync_mpp(vecs, pp->mpp); + /* if update_multipath_strings orphaned the path, quit early */ + if (!pp->mpp) + return 0; + } if ((newstate != PATH_UP && newstate != PATH_GHOST && newstate != PATH_PENDING) && (pp->state == PATH_DELAYED)) { /* If path state become failed again cancel path delay state */ @@ -2752,12 +2767,17 @@ checkerloop (void *ap) while (checker_state != CHECKER_FINISHED) { unsigned int paths_checked = 0, i; struct timespec chk_start_time; + struct multipath *mpp; pthread_cleanup_push(cleanup_lock, &vecs->lock); lock(&vecs->lock); pthread_testcancel(); + vector_foreach_slot(vecs->mpvec, mpp, i) + mpp->is_checked = false; get_monotonic_time(&chk_start_time); if (checker_state == CHECKER_STARTING) { + vector_foreach_slot(vecs->mpvec, mpp, i) + sync_mpp(vecs, mpp, ticks); vector_foreach_slot(vecs->pathvec, pp, i) pp->is_checked = false; checker_state = CHECKER_RUNNING; From patchwork Mon Jul 22 23:23:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Marzinski X-Patchwork-Id: 13739212 X-Patchwork-Delegate: christophe.varoqui@free.fr Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C3E44D5AA for ; Mon, 22 Jul 2024 23:23:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; 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Mon, 22 Jul 2024 19:23:09 -0400 Received: (from bmarzins@localhost) by bmarzins-01.fast.eng.rdu2.dc.redhat.com (8.17.2/8.17.2/Submit) id 46MNN9VA2495975; Mon, 22 Jul 2024 19:23:09 -0400 From: Benjamin Marzinski To: Christophe Varoqui Cc: device-mapper development , Martin Wilck Subject: [PATCH v3 11/20] multipathd: resync map after setup_map in ev_remove_path Date: Mon, 22 Jul 2024 19:23:07 -0400 Message-ID: <20240722232308.2495956-3-bmarzins@redhat.com> In-Reply-To: <20240722232308.2495956-1-bmarzins@redhat.com> References: <20240722232308.2495956-1-bmarzins@redhat.com> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com In ev_remove_path() it was possible to exit after calling setup_map() without resyncing the mpp state with the kernel. This meant that the mpp state in multipathd might not match with the kernel state at all. It's safe to exit before calling setup_map() if either wait_for_udev is set or need_do_map is not set. In both cases, setup_map() will later be called, either by a uevent or by the calling function. Once setup_map() has been called, setup_multipath() and sync_map_state() are now always called, to make sure the mpp matches the kernel state. Signed-off-by: Benjamin Marzinski --- multipathd/main.c | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-) diff --git a/multipathd/main.c b/multipathd/main.c index ae40f599..6a027213 100644 --- a/multipathd/main.c +++ b/multipathd/main.c @@ -1395,6 +1395,8 @@ ev_remove_path (struct path *pp, struct vectors * vecs, int need_do_map) * avoid referring to the map of an orphaned path */ if ((mpp = pp->mpp)) { + char devt[BLK_DEV_SIZE]; + /* * Mark the path as removed. In case of success, we * will delete it for good. Otherwise, it will be deleted @@ -1428,12 +1430,6 @@ ev_remove_path (struct path *pp, struct vectors * vecs, int need_do_map) flush_map_nopaths(mpp, vecs)) goto out; - if (setup_map(mpp, ¶ms, vecs)) { - condlog(0, "%s: failed to setup map for" - " removal of path %s", mpp->alias, pp->dev); - goto fail; - } - if (mpp->wait_for_udev) { mpp->wait_for_udev = 2; retval = REMOVE_PATH_DELAY; @@ -1444,6 +1440,12 @@ ev_remove_path (struct path *pp, struct vectors * vecs, int need_do_map) retval = REMOVE_PATH_DELAY; goto out; } + + if (setup_map(mpp, ¶ms, vecs)) { + condlog(0, "%s: failed to setup map for" + " removal of path %s", mpp->alias, pp->dev); + goto fail; + } /* * reload the map */ @@ -1453,24 +1455,20 @@ ev_remove_path (struct path *pp, struct vectors * vecs, int need_do_map) "removal of path %s", mpp->alias, pp->dev); retval = REMOVE_PATH_FAILURE; - } else { - /* - * update our state from kernel - */ - char devt[BLK_DEV_SIZE]; - - strlcpy(devt, pp->dev_t, sizeof(devt)); - - /* setup_multipath will free the path - * regardless of whether it succeeds or - * fails */ - if (setup_multipath(vecs, mpp)) - return REMOVE_PATH_MAP_ERROR; 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Mon, 22 Jul 2024 19:23:09 -0400 Received: (from bmarzins@localhost) by bmarzins-01.fast.eng.rdu2.dc.redhat.com (8.17.2/8.17.2/Submit) id 46MNN9V02495979; Mon, 22 Jul 2024 19:23:09 -0400 From: Benjamin Marzinski To: Christophe Varoqui Cc: device-mapper development , Martin Wilck Subject: [PATCH v3 17/20] multipathd: make multipath devices manage their path check times Date: Mon, 22 Jul 2024 19:23:08 -0400 Message-ID: <20240722232308.2495956-4-bmarzins@redhat.com> In-Reply-To: <20240722232308.2495956-1-bmarzins@redhat.com> References: <20240722232308.2495956-1-bmarzins@redhat.com> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com multipathd's path checking can be very bursty, with all the paths running their path checkers at the same time, and then all doing nothing while waiting for the next check time. Alternatively, the paths in a multipath device might all run their path checkers at a different time, which can keep the multipath device from having a coherent view of the state of all of its paths. This patch makes all the paths of a multipath device converge to running their checkers at the same time, and spreads out when this time is for the different multipath devices. To do this, the checking time is divided into adjustment intervals (conf->adjust_int), so that the checkers run at some index within this interval. conf->adjust_int is chosen so that it is a multiple of all possible pp->checkint values. This means that regardless of pp->checkint, the path should always be checked on the same indexes, each adjustement interval. Each multipath device has a goal index. These are evenly spread out between 0 and conf->max_checkint. Every conf->adjust_int seconds, each multipath device should try to check all of its paths on its goal index. If the multipath device's check times are not aligned with the goal index, then pp->tick for the next check will be decremented by one, to align it over time. In order for the path checkers to run every pp->checkint seconds, multipathd needs to track how long a path check has been pending for, and subtract that time from the number of ticks till the checker is run again. If the checker has been pending for more that pp->checkint, the path will be rechecked on the next tick after the checker returns. Signed-off-by: Benjamin Marzinski --- libmultipath/config.c | 12 ++++++ libmultipath/config.h | 1 + libmultipath/structs.c | 1 + libmultipath/structs.h | 1 + multipathd/main.c | 91 ++++++++++++++++++++++++++++++++++-------- 5 files changed, 89 insertions(+), 17 deletions(-) diff --git a/libmultipath/config.c b/libmultipath/config.c index 83fa7369..a59533b5 100644 --- a/libmultipath/config.c +++ b/libmultipath/config.c @@ -982,6 +982,18 @@ int _init_config (const char *file, struct config *conf) conf->checkint = conf->max_checkint; condlog(3, "polling interval: %d, max: %d", conf->checkint, conf->max_checkint); + /* + * make sure that that adjust_int is a multiple of all possible values + * of pp->checkint. + */ + if (conf->max_checkint % conf->checkint == 0) { + conf->adjust_int = conf->max_checkint; + } else { + conf->adjust_int = conf->checkint; + while (2 * conf->adjust_int < conf->max_checkint) + conf->adjust_int *= 2; + conf->adjust_int *= conf->max_checkint; + } if (conf->blist_devnode == NULL) { conf->blist_devnode = vector_alloc(); diff --git a/libmultipath/config.h b/libmultipath/config.h index 384193ab..800c0ca9 100644 --- a/libmultipath/config.h +++ b/libmultipath/config.h @@ -147,6 +147,7 @@ struct config { int minio_rq; unsigned int checkint; unsigned int max_checkint; + unsigned int adjust_int; bool use_watchdog; int pgfailback; int rr_weight; diff --git a/libmultipath/structs.c b/libmultipath/structs.c index 0a26096a..232b4230 100644 --- a/libmultipath/structs.c +++ b/libmultipath/structs.c @@ -149,6 +149,7 @@ uninitialize_path(struct path *pp) pp->state = PATH_UNCHECKED; pp->uid_attribute = NULL; pp->checker_timeout = 0; + pp->pending_ticks = 0; if (checker_selected(&pp->checker)) checker_put(&pp->checker); diff --git a/libmultipath/structs.h b/libmultipath/structs.h index 002eeae1..457d7836 100644 --- a/libmultipath/structs.h +++ b/libmultipath/structs.h @@ -360,6 +360,7 @@ struct path { unsigned long long size; unsigned int checkint; unsigned int tick; + unsigned int pending_ticks; int bus; int offline; int state; diff --git a/multipathd/main.c b/multipathd/main.c index 36e54587..b075b057 100644 --- a/multipathd/main.c +++ b/multipathd/main.c @@ -2388,7 +2388,7 @@ enum check_path_return { }; static int -check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) +do_check_path (struct vectors * vecs, struct path * pp) { int newstate; int new_path_up = 0; @@ -2400,14 +2400,6 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) int marginal_pathgroups, marginal_changed = 0; bool need_reload; - if (pp->initialized == INIT_REMOVED) - return CHECK_PATH_SKIPPED; - - if (pp->tick) - pp->tick -= (pp->tick > ticks) ? ticks : pp->tick; - if (pp->tick) - return CHECK_PATH_SKIPPED; - conf = get_multipath_config(); checkint = conf->checkint; max_checkint = conf->max_checkint; @@ -2419,12 +2411,6 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) pp->checkint = checkint; }; - /* - * provision a next check soonest, - * in case we exit abnormally from here - */ - pp->tick = checkint; - newstate = check_path_state(pp); if (newstate == PATH_WILD || newstate == PATH_UNCHECKED) return CHECK_PATH_SKIPPED; @@ -2587,7 +2573,6 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) condlog(4, "%s: delay next check %is", pp->dev_t, pp->checkint); } - pp->tick = pp->checkint; } } else if (newstate != PATH_UP && newstate != PATH_GHOST) { @@ -2640,6 +2625,77 @@ check_path (struct vectors * vecs, struct path * pp, unsigned int ticks) return CHECK_PATH_CHECKED; } +static int +check_path (struct vectors * vecs, struct path * pp, unsigned int ticks, + time_t start_secs) +{ + int r; + unsigned int adjust_int, max_checkint; + struct config *conf; + time_t next_idx, goal_idx; + + if (pp->initialized == INIT_REMOVED) + return CHECK_PATH_SKIPPED; + + if (pp->tick) + pp->tick -= (pp->tick > ticks) ? ticks : pp->tick; + if (pp->tick) + return CHECK_PATH_SKIPPED; + + conf = get_multipath_config(); + max_checkint = conf->max_checkint; + adjust_int = conf->adjust_int; + put_multipath_config(conf); + + r = do_check_path(vecs, pp); + + /* + * do_check_path() removed or orphaned the path. + */ + if (r == CHECK_PATH_REMOVED || !pp->mpp) + return r; + + if (pp->tick != 0) { + /* the path checker is pending */ + if (pp->state != PATH_DELAYED) + pp->pending_ticks++; + else + pp->pending_ticks = 0; + return r; + } + + /* schedule the next check */ + pp->tick = pp->checkint; + if (pp->pending_ticks >= pp->tick) + pp->tick = 1; + else + pp->tick -= pp->pending_ticks; + pp->pending_ticks = 0; + + if (pp->tick == 1) + return r; + + /* + * every mpp has a goal_idx in the range of + * 0 <= goal_idx < conf->max_checkint + * + * The next check has an index, next_idx, in the range of + * 0 <= next_idx < conf->adjust_int + * + * If the difference between the goal index and the next check index + * is not a multiple of pp->checkint, then the device is not checking + * the paths at its goal index, and pp->tick will be decremented by + * one, to align it over time. + */ + goal_idx = (find_slot(vecs->mpvec, pp->mpp)) * + max_checkint / VECTOR_SIZE(vecs->mpvec); + next_idx = (start_secs + pp->tick) % adjust_int; + if ((goal_idx - next_idx) % pp->checkint != 0) + pp->tick--; + + return r; +} + static int handle_uninitialized_path(struct vectors * vecs, struct path * pp, unsigned int ticks) @@ -2799,7 +2855,8 @@ checkerloop (void *ap) continue; pp->is_checked = true; if (pp->mpp) - rc = check_path(vecs, pp, ticks); + rc = check_path(vecs, pp, ticks, + chk_start_time.tv_sec); else rc = handle_uninitialized_path(vecs, pp, ticks);