Blame SOURCES/0021-BZ-1673167-Fix-miscounting-active-paths.patch

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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Benjamin Marzinski <bmarzins@redhat.com>
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Date: Mon, 18 Feb 2019 13:32:45 -0600
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Subject: [PATCH] BZ 1673167: Fix miscounting active paths
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When multipathd gets a change uevent, it calls pathinfo with DI_NOIO.
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This sets the path state to the return value of path_offline(). If a
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path is in the PATH_DOWN state but path_offline() returns PATH_UP, when
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that path gets a change event, its state will get moved to PATH_UP
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without either reinstating the path, or reloading the map.  The next
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call to check_path() will move the path back to PATH_DOWN. Since
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check_path() simply increments and decrements nr_active instead of
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calculating it based on the actual number of active paths, nr_active
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will get decremented a second time for this failed path, potentially
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putting the multipath device into recovery mode.
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To avoid this situation, pathinfo() will now only set pp->state with
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DI_NOIO if DI_CHECKER is also set. This isn't set in uev_update_path()
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to avoid changing the path state in this case.
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Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
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---
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 libmultipath/discovery.c | 11 ++++++-----
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 multipath/main.c         |  2 +-
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 2 files changed, 7 insertions(+), 6 deletions(-)
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diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
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index b267f07..5de087c 100644
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--- a/libmultipath/discovery.c
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+++ b/libmultipath/discovery.c
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@@ -1914,11 +1914,12 @@ int pathinfo(struct path *pp, struct config *conf, int mask)
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 	if (path_state == PATH_REMOVED)
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 		goto blank;
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 	else if (mask & DI_NOIO) {
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-		/*
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-		 * Avoid any IO on the device itself.
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-		 * Behave like DI_CHECKER in the "path unavailable" case.
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-		 */
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-		pp->chkrstate = pp->state = path_state;
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+		if (mask & DI_CHECKER)
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+			/*
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+			 * Avoid any IO on the device itself.
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+			 * simply use the path_offline() return as its state
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+			 */
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+			pp->chkrstate = pp->state = path_state;
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 		return PATHINFO_OK;
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 	}
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diff --git a/multipath/main.c b/multipath/main.c
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index 2c4054d..0545226 100644
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--- a/multipath/main.c
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+++ b/multipath/main.c
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@@ -345,7 +345,7 @@ static int check_usable_paths(struct config *conf,
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 			pp->udev = get_udev_device(pp->dev_t, DEV_DEVT);
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 			if (pp->udev == NULL)
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 				continue;
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-			if (pathinfo(pp, conf, DI_SYSFS|DI_NOIO) != PATHINFO_OK)
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+			if (pathinfo(pp, conf, DI_SYSFS|DI_NOIO|DI_CHECKER) != PATHINFO_OK)
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 				continue;
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 			if (pp->state == PATH_UP &&
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-- 
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2.17.2
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