[PATCH v3 5/6] 11-dm-mpath.rules: clear DM_DISABLE_OTHER_RULES_FLAG for coldplug events

[Martin Wilck <martin.wilck@suse.com>]

For all "spurious" events, which includes coldplug events,
DM_DISABLE_OTHER_RULES_FLAG will be read from the udev DB in
10-dm.rules. Thus if a previous event saw the device in suspended
state, the flag will be set even if the device has meanwhile
resumed. Reset the flag if none of the conditions hold that
would cause it to be set in a genuine uevent in 10-dm.rules.

It would be cleaner to do this in 10-dm.rules directly, but it
cannot be done easily, because the flag can also have an origin
inside lvm itself; lvm sets it for various kinds of logical
volumes. For generic (non-LVM) dm devices, the flag is only set
in 10-dm.rules though, so doing this is safe for multipath.

Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 multipath/11-dm-mpath.rules.in | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/multipath/11-dm-mpath.rules.in b/multipath/11-dm-mpath.rules.in
index cada176..82b0204 100644
--- a/multipath/11-dm-mpath.rules.in
+++ b/multipath/11-dm-mpath.rules.in
@@ -9,6 +9,13 @@ ACTION=="add", ENV{DM_ACTIVATION}=="1", ENV{DM_SUSPENDED}=="1", \
 	PROGRAM="/bin/logger -t 11-dm-mpath.rules -p daemon.warning \"Coldplug event for suspended device\"", \
 	ENV{DM_COLDPLUG_SUSPENDED}="1", GOTO="scan_import"
 
+# Coldplug event. DM_UDEV_DISABLE_OTHER_RULES_FLAG has been restored
+# from DB in 10-dm.rules. If the device is not suspended, clear the flag.
+# This is safe for multipath where DM_UDEV_DISABLE_OTHER_RULES_FLAG is basically
+# equivalent to DM_SUSPENDED==1 || DISK_RO==1
+ACTION=="add", ENV{DM_ACTIVATION}=="1", ENV{DM_SUSPENDED}!="1", ENV{DISK_RO}!="1", \
+	ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}="", GOTO="scan_import"
+
 # If this uevent didn't come from dm, don't try to update the
 # device state
 ENV{DM_COOKIE}!="?*", ENV{DM_ACTION}!="PATH_*", \
-- 
2.43.0