On Mon, Mar 12, 2018 at 9:38 AM, Eddie Horng <eddiehorng.tw@xxxxxxxxx> wrote: > Hello Miklos, > I'd like to report a flock(2) problem to overlay nfs-exported files. > The error return from flock(2) is "Bad file descriptor". > > Environment: > OS: Ubuntu 14.04.2 LTS > Kernel: 4.16.0-041600rc4-generic (from > http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.16-rc4/) > > Reproduce step: > (nfs server side) > mount -t overlay > -orw,lowerdir=/mnt/ro,upperdir=/mnt/u,workdir=/mnt/w,nfs_export=on,index=on > none /mnt/m > touch /mnt/m/foo > (nfs client side) > mount server:/mnt/m /mnt/n > > flock /mnt/n/foo > failed to lock file '/mnt/n/foo': Bad file descriptor > Does not reproduce on my end. I am using v4.16-rc5, but I don't think any of the fixes there are relevant to this failure. This is what I have for underlying fs, overlay and nfs mount options (index and nfs_export are on by default in my kernel): /dev/mapper/storage-lower_layer on /base type xfs (rw,relatime,attr2,inode64,noquota) share on /share type overlay (rw,relatime,lowerdir=/base/lower,upperdir=/base/upper/0,workdir=/base/upper/work0) c800:/share on /mnt/t type nfs (rw,relatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=192.168.91.126,mountvers=3,mountport=49494,mountproto=udp,local_lock=none,addr=192.168.91.126) $ touch /mnt/t/foo $ flock -x -n /mnt/t/foo echo locked locked Please share more information about nfs mount options and underlying filesystem Please check if you see any relevant errors/warnings in dmesg. Thanks, Amir. -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
