[LU-1833] Don't update mtab if it is symlink

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.4.0, Lustre 2.1.4
• Affects Version/s: Lustre 2.3.0, Lustre 2.4.0
• Labels: patch
• Assignee: Keith Mannthey (Inactive)
• Reporter: Peng Tao

Description

some distros (like Fedora 16) link /etc/mtab to /proc/mounts. In such distros, mount.lustre cannot update mtab otherwise we false alarm user with errors.

Issue Links

• is duplicated by: LU-2168 mount.lustre: addmntent: Invalid argument:

Comments

[Tyson Whitehead (Inactive)]

Patch to switch to from readpath to realpath. Can confirm it works with my indirect symlink. Haven't tested a non-symlink setup.

[Tyson Whitehead (Inactive)]

Would add that this patch doesn't work on recent fedora as systemd creates /etc/mtab as a symlink to ../proc/self/mounts which doesn't match the check for it starting with /proc/.

$ readlink /etc/mtab
../proc/self/mounts

A simple hack would be to switch to strstr to see if the symlink contains /proc/ anywhere in it or, to be 100% correct, use realpath to fully get the canonical absolute path.

$ realpath /etc/mtab
/proc/19506/mounts

Cheers! -Tyson

[Alexey Shvetsov (Inactive)]

Gentoo. Client code was build from master + some patches to make 3.8 kernel work

[Keith Mannthey (Inactive)]

What distro are you using?

[Alexey Shvetsov (Inactive)]

This bug still here on 2.4
delta ~ # mount.lustre bootsrv@tcp:/home /home
mount.lustre: addmntent: Invalid argument:

ls -l /etc/mtab
lrwxrwxrwx 1 root root 14 Jun 21 2011 /etc/mtab -> ../proc/mounts

[Peter Jones]

Carlos

This fix was included in the 2.1.4 release. Ihara has already ported the fix to b1_8 and that patch can be applied anywhere that needs it.

Peter

[Carlos Thomaz]

Hi.
Another DDN customer is concerning about this issue. Running Lustre 2.1.3
Any feedback if this patch will be backported to 2.1 and 1.8 versions?

Thanks
Carlos.

[Shuichi Ihara (Inactive)]

Although this was already closed, we needed this backport patches to b2_1 and b1_8 for diskless lustre environment.

http://review.whamcloud.com/#change,4786 (b1_8)
http://review.whamcloud.com/#change,4785 (b2_1)

[Peter Jones]

Landed for 2.4

[Peng Tao]

patch submitted:
http://review.whamcloud.com/3881