Created attachment 512728 [details]
an online fsck check

Description of problem:

I've written an online fsck which creates snapshot volumes, but I cannot remove the snapshot volume reliably:  it shows up as open even though nothing should be using it.  There are monitoring messages in dmesg, but disabling monitoring makes no difference.

Version-Release number of selected component (if applicable):
lvm2-2.02.83-3.el6.x86_64

How reproducible:
It doesn't happen on every lvremove, but often enough that I cannot put the script into cron.


Steps to Reproduce:
1. run "online_fsck -a -v" script
2. observe process -- when destroying snapshot volume it may fail
3. even manually trying to remove it will fail, although after time it does allow removal.  various combinations of vgscan, lvscan, starting or stopping lvm2-monitor and sync hasn't improved or degraded the situation.
  
Actual results:

logical volume 'stuck' in open state.

Expected results:

removal of snapshot volumes

Additional info:

I've attached my script that triggers it, but I suspect it could be triggered by just entering the commands by hand.  This is the script I'm using on my servers, but I don't make any promises that it won't mess up your machine or run over your pet goldfish.

The core commands it is using are:

lvcreate -s -l 5%ORIGIN -n $lv-snap $vg/$lv # create lv snapshot
(nice e2fsck -p $FSCK_OPTS /dev/$filesystem-snap) && e2fsck -fy -Fttv -C0 /dev/$filesystem-snap  # the filesystem check
tune2fs -C0 -T now /dev/$filesystem   # if it has an ok fsck
lvremove -f $vg/$lv-snap # this is what fails