[LU-9399] lctl conf_param and lctl set_param -P are broken for llite parameters

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.10.0
• Affects Version/s: Lustre 2.10.0
• Severity: 3
• Assignee: Emoly Liu
• Reporter: John Hammond

Description

lctl conf_param and lctl set_param -P are broken for llite parameters (probably due to an ordering issue between the processing of the config logs and creation of the subdirectory of /proc/fs/llite corresponding to the mount point. Both work as expected for a client that was mounted when the parameter was set but fail for subsequently mounted clients.

Using lctl conf_param:

m:~# llmount.sh
...
m:~# lctl get_param llite.*.xattr_cache
llite.lustre-ffff880036686000.xattr_cache=1
m:~# lctl conf_param lustre.llite.xattr_cache=0
m:~# lctl get_param llite.*.xattr_cache
llite.lustre-ffff880036686000.xattr_cache=1
m:~# lctl get_param llite.*.xattr_cache
llite.lustre-ffff880036686000.xattr_cache=0
m:~# umount /mnt/lustre
m:~# mount m@tcp:/lustre /mnt/lustre -t lustre -o user_xattr,flock
m:~# lctl get_param llite.*.xattr_cache
llite.lustre-ffff88001017d800.xattr_cache=1
m:~# sleep 60 && lctl get_param llite.*.xattr_cache
llite.lustre-ffff88001017d800.xattr_cache=1
m:~# sleep 60 && lctl get_param llite.*.xattr_cache
llite.lustre-ffff88001017d800.xattr_cache=1
m:~# llmountcleanup.sh
...

Using lctl set_param -P:

m:~# mllmount.sh
...
m:~# lctl get_param llite.*.xattr_cache
llite.lustre-ffff88000ee70800.xattr_cache=1
m:~# lctl set_param -P llite.*.xattr_cache=0
m:~# lctl get_param llite.*.xattr_cache
llite.lustre-ffff88000ee70800.xattr_cache=1
m:~# sleep 10 && lctl get_param llite.*.xattr_cache
llite.lustre-ffff88000ee70800.xattr_cache=0
m:~# umount /mnt/lustre
m:~# mount m@tcp:/lustre /mnt/lustre -t lustre -o user_xattr,flock
m:~# lctl get_param llite.*.xattr_cache
llite.lustre-ffff880007858000.xattr_cache=1
m:~# sleep 60 && lctl get_param llite.*.xattr_cache
llite.lustre-ffff880007858000.xattr_cache=1
m:~# sleep 60 && lctl get_param llite.*.xattr_cache
llite.lustre-ffff880007858000.xattr_cache=1

If a second client is mounted (on the same node) then the param will
be set correctly on the first mount point but not on the second.

m:~# mount m@tcp:/lustre /mnt/lustre2 -t lustre -o user_xattr,flock
m:~# lctl get_param llite.*.xattr_cache
llite.lustre-ffff880007858000.xattr_cache=0
llite.lustre-ffff88006cddb800.xattr_cache=1

Issue Links

• is related to: LU-17778 conf-sanity test_76d: 'llite.*.xattr_cache != 0 on client /mnt/lustre'
• is related to: LU-7183 lctl set_param -P does not work for sptlrpc flavor
• is related to: LU-8066 Move lustre procfs handling to sysfs and debugfs.
• is related to: LU-7004 fix "lctl set_param -P" to allow deprecation of "lctl conf_param"

Comments

[Peter Jones]

Landed for 2.10

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/27241/
Subject: LU-9399 llite: register mountpoint before process llog
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: fa1bff8f6f3afb858618a563b039af3bbf46153b

[Gerrit Updater]

Emoly Liu ([e-mail]) uploaded a new patch: https://review.whamcloud.com/27241
Subject: LU-9399 llite: register mountpoint before process llog
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 35efc9b025c910028317b60398d0d40f446db3f2

[Emoly Liu]

As John said, this is an ordering issue. process_param2_config() calls "/usr/sbin/lctl set_param llite.*.xattr_cache=0" during mounting before the client's /proc/fs/lustre/llite/xxx proc entry is created.
I will see how to fix it.

[Emoly Liu]

I will look into it.

[James A Simmons]

Can you try my llite sysfs patch https://review.whamcloud.com/#/c/24031. Test conf-sanity 28 will reveal this problem. Currently it fails because of it.

[Peter Jones]

Emoly

Could you please assist with this issue?

Thanks

Peter