From: Jean-Pol Guillement (Jean-Pol.Guillement@math.univ-nantes.fr)
Date: Thu Nov 06 2003 - 09:00:18 EST
Dear managers,
Can somebody explain me the behavior of the lockf function
on a Tru64, 4.0F, Alpha-server 1000A with NFS mounted files ?
The following is a part of a program named testlock:
...
if ((fd=open(atester,O_WRONLY)) < 0) {
printf("impossible ouvrir %s.\n",atester);
exit(1);
}
t=lockf(fd,F_TEST,0);
if (t) {
printf("%s est locke',\nt=%d,errno = %d\n",
atester,t,errno);
printf("EBADF=%d,EACCES=%d,EAGAIN=%d,EDEADLK=%d\n\
EINTR=%d,EINVAL=%d,EOPNOTSUPP=%d\n",
EBADF,EACCES,EAGAIN,EDEADLK,EINTR,EINVAL,
EOPNOTSUPP);
} else {
printf("%s pas locke'.\n",atester);
}
...
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
test 1:
touch /tmp/e; chmod 600 /tmp/e; testlock -> not locked
(and the same on any not nfs mounted file).
test 2:
/usr/users/namath is an nfs mounted directory from a linux box
by the following fstab (lebesgue) entry
/usr/users/namath@condorcet /usr/users/namath nfs
rw,bg,rsize=8192,wsize=8192,hard,intr,nfsvers=3 0 0
and the exports line on the linux system (condorcet)
/usr/users/namath lebesgue(rw,no_root_squash)
cd /usr/users/namath/myhome
touch e; chmod 600 e; testlock -> locked (errno=EACCES)
chmod 640 e; testlock -> locked (errno=EACCES)
chmod 644 e; testlock -> not locked
test 3:
On an other linux box, on the same nfs mounted directory,
testlock gives always not locked.
Thanks in advance,
Jean-Pol Guillement
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