On Wed, 2019-05-29 at 11:08 -0400, Benjamin Coddington wrote: > Hey, here's an interesting one, this seems wrong: > > [root@fedora27_c2_v5 ~]# mkdir /mnt/one > [root@fedora27_c2_v5 ~]# mkdir /mnt/two > [root@fedora27_c2_v5 ~]# mount -t nfs -ov4,noac,sec=sys,nosharecache > 192.168.122.50:/exports /mnt/one > [root@fedora27_c2_v5 ~]# mount -t nfs -ov4,noac,sec=sys,nosharecache > 192.168.122.50:/exports /mnt/two > [root@fedora27_c2_v5 ~]# mkdir /mnt/one/A > [root@fedora27_c2_v5 ~]# mkdir /mnt/one/B > [root@fedora27_c2_v5 ~]# touch /mnt/one/A/foo > [root@fedora27_c2_v5 ~]# cat /mnt/two/A/foo > [root@fedora27_c2_v5 ~]# mv /mnt/two/A/foo /mnt/two/B/foo > [root@fedora27_c2_v5 ~]# mv /mnt/one/B/foo /mnt/one/A/foo > [root@fedora27_c2_v5 ~]# cat /mnt/two/A/foo > [root@fedora27_c2_v5 ~]# stat /mnt/two/B/foo > File: /mnt/two/B/foo > Size: 0 Blocks: 0 IO Block: 262144 regular > empty > file > Device: 2fh/47d Inode: 439603 Links: 1 > Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: > ( 0/ root) > Context: system_u:object_r:nfs_t:s0 > Access: 2019-05-28 14:00:18.929663705 -0400 > Modify: 2019-05-28 14:00:18.929663705 -0400 > Change: 2019-05-28 14:00:58.990124573 -0400 > Birth: - > > > ^^ that lstat should return -ENOENT. > > I think we detect a stale directory by comparing the directory's > change_attr with the dentry's d_time. But, here's a case where they > are > the same! > > Am I wrong about this, or any clever ideas to catch this case? > When you are mounting using 'nosharecache' then you are making /mnt/one and /mnt/two act as if they are different filesystems. The fact that they are the same on the server, means you are setting up a testcase where the files+directories are acting like the "changing on the server" case as far as the client is concerned. If you want the above to work in a sane fashion, then just don't use 'nosharecache'. Cheers Trond -- Trond Myklebust Linux NFS client maintainer, Hammerspace trond.myklebust@xxxxxxxxxxxxxxx
