[dm-devel] [PATCH] udev: create symlinks and watch even in suspended state

[mwilck at suse.com]

From: Martin Wilck <mwilck at suse.com>

If a dm device is suspended, we can't run blkid on it. But earlier
rules (e.g. 11-dm-parts.rules) might have imported previously scanned
properties from the udev db, in particular if the device had been correctly
set up beforehand (DM_UDEV_PRIMARY_SOURCE_FLAG==1). Symlinks for existing
ID_FS_xyz properties must be preserved in this case. Otherwise lower-priority
devices (such as multipath components) might take over the symlink
temporarily.

Likewise, we should't stop watching a temporarily suspended, but previously
correctly configured dm device.

Signed-off-by: Martin Wilck <mwilck at suse.com>
---
 udev/13-dm-disk.rules.in | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/udev/13-dm-disk.rules.in b/udev/13-dm-disk.rules.in
index 535581070..5cc08121e 100644
--- a/udev/13-dm-disk.rules.in
+++ b/udev/13-dm-disk.rules.in
@@ -17,10 +17,14 @@ ENV{DM_UDEV_DISABLE_DISK_RULES_FLAG}=="1", GOTO="dm_end"
 SYMLINK+="disk/by-id/dm-name-$env{DM_NAME}"
 ENV{DM_UUID}=="?*", SYMLINK+="disk/by-id/dm-uuid-$env{DM_UUID}"
 
+ENV{DM_SUSPENDED}=="1", ENV{DM_UDEV_PRIMARY_SOURCE_FLAG}=="1", GOTO="dm_link"
+ENV{DM_NOSCAN}=="1", ENV{DM_UDEV_PRIMARY_SOURCE_FLAG}=="1", GOTO="dm_link"
 ENV{DM_SUSPENDED}=="1", GOTO="dm_end"
 ENV{DM_NOSCAN}=="1", GOTO="dm_watch"
 
 (BLKID_RULE)
+
+LABEL="dm_link"
 ENV{DM_UDEV_LOW_PRIORITY_FLAG}=="1", OPTIONS="link_priority=-100"
 ENV{ID_FS_USAGE}=="filesystem|other|crypto", ENV{ID_FS_UUID_ENC}=="?*", SYMLINK+="disk/by-uuid/$env{ID_FS_UUID_ENC}"
 ENV{ID_FS_USAGE}=="filesystem|other", ENV{ID_FS_LABEL_ENC}=="?*", SYMLINK+="disk/by-label/$env{ID_FS_LABEL_ENC}"
-- 
2.34.1