udev: allow for udev attribute reading bug.

There is a bug in udev (which will hopefully get fixed, but
we should allow for it anways).
When reading a sysfs attribute, it first reads the whole
value of the attribute, then reads again expecting to get
a read of 0 bytes, like you would with an ordinary file.
If the sysfs attribute changed between these two reads, it can
get a mixture of two values.

In particular, if it reads when 'array_state' is changing from
'clear' to 'inactive', it can find the value as "clear\nve".

This causes the test for "|clear|active" to fail, so systemd is allowed
to think that the array is ready - when it isn't.

So change the pattern to allow for this but adding a wildcard at
the end.
Also don't allow for an empty string - reading array_state will
never return an empty string - if it exists at all, it will be
non-empty.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

diff --git a/udev-md-raid-arrays.rules b/udev-md-raid-arrays.rules
index d3916651cf5c1f4e6b820f609acfdc20d9d8d492..c8fa8e89ef69ea183081c5562e70a5801d4e3735 100644 (file)
--- a/udev-md-raid-arrays.rules
+++ b/udev-md-raid-arrays.rules
@@ -14,7 +14,7 @@ ENV{DEVTYPE}=="partition", GOTO="md_ignore_state"
 # never leave state 'inactive'
 ATTR{md/metadata_version}=="external:[A-Za-z]*", ATTR{md/array_state}=="inactive", GOTO="md_ignore_state"
 TEST!="md/array_state", ENV{SYSTEMD_READY}="0", GOTO="md_end"
-ATTR{md/array_state}=="|clear|inactive", ENV{SYSTEMD_READY}="0", GOTO="md_end"
+ATTR{md/array_state}=="clear*|inactive", ENV{SYSTEMD_READY}="0", GOTO="md_end"
 LABEL="md_ignore_state"
 
 IMPORT{program}="BINDIR/mdadm --detail --no-devices --export $devnode"