[dm-devel] [PATCH v2 2/2] kpartx.rules: check for skip_kpartx on synthetic uevents

[mwilck at suse.com]

From: Martin Wilck <mwilck at suse.com>

The current test to detect "spurious" uevents, and thus whether to
import DM_SUBSYSTEM_UDEV_FLAG1 (the flag for the "skip_kpartx" option)
from the udev db is wrong. In 10-dm.rules, DM_UDEV_PRIMARY_SOURCE_FLAG
is imported from the db if it isn't set, meaning that it's always 1
for active maps. The only events for which DM_SUBSYSTEM_UDEV_FLAG1
must not be loaded from the db are the real "primary" events, which
are "change" events with DM_ACTIVATION=="1".

11-dm-mpath.rules resets DM_ACTIVATION to 0 if nothing should change in upper
layers. In this case importing DM_SUBSYSTEM_UDEV_FLAG1 is correct, too. kpartx
will not be called anyway, because 11-dm-mpath.rules also sets MPATH_UNCHANGED=1.

Signed-off-by: Martin Wilck <mwilck at suse.com>
---
 kpartx/kpartx.rules | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kpartx/kpartx.rules b/kpartx/kpartx.rules
index f1bf31ca..d7527d7d 100644
--- a/kpartx/kpartx.rules
+++ b/kpartx/kpartx.rules
@@ -13,8 +13,11 @@ ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}=="1", GOTO="kpartx_end"
 ENV{DM_UUID}!="mpath-?*", GOTO="mpath_kpartx_end"
 
 # DM_SUBSYSTEM_UDEV_FLAG1 is the "skip_kpartx" flag.
-# For events not generated by libdevmapper, we need to fetch it from db.
-ENV{DM_UDEV_PRIMARY_SOURCE_FLAG}!="1", IMPORT{db}="DM_SUBSYSTEM_UDEV_FLAG1"
+# For events not generated by libdevmapper, we need to fetch it from db:
+# - "change" events with DM_ACTIVATION!="1" (e.g. partition table changes)
+# - "add" events for which rules are not disabled ("coldplug" case)
+ENV{DM_ACTIVATION}!="1", IMPORT{db}="DM_SUBSYSTEM_UDEV_FLAG1"
+ACTION=="add", IMPORT{db}="DM_SUBSYSTEM_UDEV_FLAG1"
 ENV{DM_SUBSYSTEM_UDEV_FLAG1}=="1", GOTO="mpath_kpartx_end"
 
 # 11-dm-mpath.rules sets MPATH_UNCHANGED for events that can be ignored.
-- 
2.25.1