On Tue, 2011-01-04 at 15:49 -0800, Simon Kirby wrote: > Hello, > > In testing NFSv4, I found that this lock test script fails with EIO: > > #!/usr/bin/perl > > $|=1; > use Fcntl qw(:DEFAULT :flock); > open(IN, "< locktest.pl") or die "open: $!"; > print "Locking...\n"; > flock(IN,LOCK_EX) or die "flock $filename: $!"; > print "Locked.\n"; > sleep(4); > print "Unlocking...\n"; > close(IN); > exit(0); > > This just locks itself (assuming it's called locktest.pl). This works > fine over NFSv3, but with NFSv4, I'm seeing: > > flock(3, LOCK_EX) = -1 EIO (Input/output error) > > tcpdump and NFS debugging shows status "10038", which as far as I can > tell is "NFS4ERR_OPENMODE". That is known and expected behaviour. We have to map flock() onto byte range locks (i.e. POSIX locks), and since LOCK_EX has to map to a write lock in order to give exclusive semantics, the server will not allow it when you only have the file open for reading. Cheers Trond -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@xxxxxxxxxx www.netapp.com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
