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?
Ben
