Question about LTP testcase netns_sysfs on RHEL6.7GA

LTP Jan Stancek 1 participant 1 message Dec 15, 2015 1 message not in the archive

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Jan Stancek

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2015-12-15 09:52 UTC #1 lore raw

----- Original Message -----

Quoted 11 lines

From: "Guangwen Feng" <[email protected]>
To: "Jan Stancek" <[email protected]>
Cc: "Guangwen Feng" <[email protected]>
Sent: Tuesday, 15 December, 2015 4:11:51 AM
Subject: Question about LTP testcase netns_sysfs on RHEL6.7GA
Hello Jan,
I have a question about LTP test case netns_sysfs on RHEL6.7GA, which may need your confirmation, thanks.
I just can't figure out why "/sys" mounts failed in a namespace on RHEL6.7GA.

I can reproduce it as well. The mount fails with:
mount: none already mounted or /sys busy
mount: according to mtab, sysfs is already mounted on /sys

It looks like sysfs is not mount namespace aware in RHEL6:

# unshare -m umount /sys; mount | grep /sys
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)

# ls -la /sys
total 4
drwxr-xr-x. 13 root root    0 Dec 15 11:06 .
dr-xr-xr-x. 25 root root 4096 Dec 15 11:06 ..
drwxr-xr-x.  2 root root    0 Dec 15 11:06 block
drwxr-xr-x. 16 root root    0 Dec 15 11:06 bus
drwxr-xr-x. 37 root root    0 Dec 15 11:06 class
drwxr-xr-x.  4 root root    0 Dec 15 11:06 dev
drwxr-xr-x. 10 root root    0 Dec 15 11:06 devices
drwxr-xr-x.  4 root root    0 Dec 15 11:06 firmware
drwxr-xr-x.  3 root root    0 Dec 15 11:06 fs
drwxr-xr-x.  2 root root    0 Dec 15 11:06 hypervisor
drwxr-xr-x.  5 root root    0 Dec 15 11:06 kernel
drwxr-xr-x. 78 root root    0 Dec 15 11:06 module
drwxr-xr-x.  2 root root    0 Dec 15 11:06 power

Adding Matus (and list) to CC.

Regards,
Jan

Quoted 30 lines

The netns_sysfs fails on my RHEL6.7GA, and reports:
netns_sysfs 1 TFAIL : sysfs in new namespace does not have dummy_test0 interface
netns_sysfs 2 TINFO : sysfs in new namespace should not contain: dummy0 netns_sysfs 2 TINFO : sysfs in new namespace should not contain: eth0 netns_sysfs 2 TINFO : sysfs in new namespace should not contain: virbr0 netns_sysfs 2 TINFO : sysfs in new namespace should not contain: virbr0-nic netns_sysfs 2 TFAIL : sysfs in new namespace has more than lo and dummy_test0 interfaces
netns_sysfs 3 TPASS : sysfs not affected by a separate namespace
In fact, the functionality of the test case just works well since via "ip link list" in the namespace I can just get what it expected. I found that it is caused by mount failure on "/sys" in the namespace. However, In comparison, it does mount normally on RHEL7.2GA.
For test, I just created a namespace both on RHEL6.7GA and RHEL7.2GA with CLONE_NEWNS and CLONE_NEWNET flags, I found that even "/proc" mounts normally both on two systems, but I don't understand why "/sys" mounts unsuccessfully on RHEL6.7GA. Sorry I'm not familiar with LXC, does it mean the implementation of mount or net namespace is not yet complete on RHEL6.7GA? Thanks!
Best Regards,
Guangwen Feng