I have a question about the behaviour of autofs. It seems like it is
very easy to hit a situation where autofs will unmount a file system
and an active process will lose access to a file and fail to read it.
This seems to happen with both direct and indirect mapping.
Specifics about what I am running:
autofs-4.1.3-199.3
kernel - 2.6.9-55.ELsmp
arch - x86_64
OS - Red Hat Enterprise Linux WS release 4 (Nahant Update 5
autofs is configured to use the defaults and has host mapping
enabled. When I run the following simple test:
date;while [[ -r /net/hostname/test ]]; do :; done; date
command output:
Fri Jul 11 09:02:46 MDT 2008
Fri Jul 11 09:03:59 MDT 2008
command output run 2:
Fri Jul 11 09:11:42 MDT 2008
Fri Jul 11 09:12:45 MDT 2008
As you can see, I lose read access typically shortly after the mount is
supposed to time out.
The file system options from /proc/mounts are:
nfs
rw,nosuid,nodev,v3,rsize=32768,wsize=32768,soft,intr,tcp,lock,proto=tcp,timeo=600,retrans=5,addr=farmall
0 0
I believe that after the timeout, autofs tries to unmount file systems and
if they are busy, resets the timeout counter and remounts any unmounted
mount points if it is a host map.
But in general, I would think that I should never lose read access to the
file. Shouldn't autofs just remount it if it has been unmounted?
I see the same behaviour on ubuntu 7.04 autofs version 4.1.4-13
Anyone have any insight?
BTW: am-utils (amd) does not behave this way. I am guessing this
has to do with the fact that it runs in user space.
Thanks.
--
-MichaelC
_______________________________________________
autofs mailing list
autofs@linux.kernel.org
http://linux.kernel.org/mailman/listinfo/autofs
