Ian Kent wrote:

On Fri, 2007-10-26 at 12:59 +0100, Massimo Mongardini wrote:

Hi everyone,
    I am experiencing an issue in the following circumstances:

os: rhel4.5
kernel client: 2.6.9-55.0.9.ELsmp
kernel server: 2.6.9-55.0.2.ELsmp
autofs version 4.1.3-199.3

server exports folder /nfs/folder with parameters:
async,rw,fsid=1,no_root_squash

client automounts /nfs/folder with:

auto.master:
/nfs    /etc/auto.nfs

auto.nfs:
folder        -fstype=nfs,udp,rsize=32768,wsize=32768,noatime
fs-cluster:/nfs/folder

default values for automount are --timeout 60

If I run a script that checks with a series of increasing sleep
intervals < 120 if an exported file is executable,
I notice that if there is a coincidence between an unmount request and a
file request the file test fails


This sounds like the mount/expire race patch and it's friends that
aren't present in that kernel.

There have been a few issues discussed around these patches (or the lack
of them) on this list lately.

Thu Oct 25 17:00:28 GMT 2007 Error at DELAY: 38
Oct 25 17:00:28 server mountd[8014]: authenticated unmount request from
client:989 for /nfs/folder (/nfs/folder)
Fri Oct 26 04:48:41 GMT 2007 Error at DELAY: 25
Oct 26 04:48:41 server mountd[8014]: authenticated unmount request from
client:846 for /nfs/folder (/nfs/folder)

the test script looks like this:

EXECUTABLE="/nfs/folder/somepath/exec"
DELAY="1"
STOPCOUNT=120
OUT=$1
while true
do
 while [ "$DELAY" -lt "$STOPCOUNT" ]
  do
   test -x $EXECUTABLE
   if [ "$?" -ne "0" ]
    then
        echo "$(date) Error at DELAY: $DELAY" >> $OUT
    else
        echo "$(date) Executable found at DELAY: $DELAY" >> $OUT
   fi
   sleep $DELAY
  (( DELAY++ ))
 done
done

any help is much appreciated

cheers,
Massimo

Ian,
thanks for your answer.
I saw that bug but I thought was just related to autofs4. Since the client is running a maybe-patched 2.6.9-55.0.9.ELsmp version I thought would be wnough. Am I missing something or some useful post?

$ rpm -q --changelog kernel-smp-2.6.9-55.0.9.EL | grep -e autofs | grep race
-revert: autofs4 fix for race between mount and expire [248126]
-autofs4: fix race between mount and expire (Ian Kent) [248126]
-autofs4: fix race between mount/expire (Jeff Moyer) [175778]

The server has just:
$ rpm -q --changelog kernel-smp-2.6.9-55.0.2.EL | grep -e autofs | grep race
-autofs4: fix race between mount/expire (Jeff Moyer) [175778]

cheers,
Massimo

-- 
Massimo Mongardini

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