[LU-4924] /usr/bin/touch removes the setgid bit on directories

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.6.0, Lustre 2.5.2
• Affects Version/s: Lustre 2.6.0, Lustre 2.4.2
• Labels: mn4
• Environment: Centos 6.5/Debian 6 clients, DDN Exascaler servers.
• Severity: 4
• Assignee: Nathaniel Clark
• Reporter: Oz Rentas

Description

MDS/OSS are running Centos 6.4 and Lustre 2.4.2. Clients also running 2.4.2.

Calling "touch -a" to update the atime on a directory clears the setgid bit from that directory.

Example:

$ mkdir foo
$ ls -ld foo
drwxrwx--x 2 user user 4096 Apr 17 11:47 foo
$ chgrp group foo
ls -ld foo
drwxrwx--x 2 user group 4096 Apr 17 11:47 foo
$ chmod g+s foo
$ ls -ld foo
drwxrws--x 2 user group 4096 Apr 17 11:47 foo
$ touch -a foo
$ ls -ld foo
drwxrwx--x 2 user group 4096 Apr 17 11:47 foo

This is unexpected behavior, and seems like a bug. I don't get this behavior on local or NFS filesystems. If it's relevant, our identity_upcall setting is "NONE"

Thanks,
Peter