One failed raid device can't umount automatically

[Xiao Ni <xni@xxxxxxxxxx>]

Hi all

We support to umount one failed raid device automatically. But it can't 
work now.
For example, one 3 disks raid5 device /dev/md0. I unplug two disks one 
by one.
The udev rule udev-md-raid-assembly.rules is triggered when unplug disk.

In this udev rule, it calls `mdadm -If $disk` when unplug one disk. 
Function IncrementalRemove
is called. When the raid doesn't have enough disks to be active, it 
tries to stop the array.
Before stopping the array, it tries to umount the raid device first.

Now it uses udisks to umount raid device. I printed logs during test. It 
gives error message
"Permission denied". Then I tried with umount directly, it failed with 
the same error message.

diff --git a/Incremental.c b/Incremental.c
index e849bdd..96ba234 100644
--- a/Incremental.c
+++ b/Incremental.c
@@ -1620,6 +1620,7 @@ static void run_udisks(char *arg1, char *arg2)
                manage_fork_fds(1);
                execl("/usr/bin/udisks", "udisks", arg1, arg2, NULL);
                execl("/bin/udisks", "udisks", arg1, arg2, NULL);
+               execl("/usr/bin/umount", "umount", arg2, NULL);
                exit(1);
        }
        while (pid > 0 && wait(&status) != pid)

Does anyone know how to fix this problem?

Regards
Xiao