[LU-16771] statfs_max_age not used with statfs() project quotas?

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Fix Version/s: Lustre 2.17.0
• Affects Version/s: Lustre 2.15.2
• Labels: medium
• Environment: 2.12 servers with 2.15 clients
• Severity: 3
• Assignee: Core Lustre Triage
• Reporter: Stephane Thiell

Description

We have noticed that smbd can do lots of statfs() calls, which on our lustre filesystem with project quota enabled will gather project quota info and takes time.
I tried to play with lustre's statfs caching but it doesn't seem to help. Is that not used when project quotas are set?

For example, on Oak we have 464 HDD-based OSTs and when they are loaded, gathering quota info might take a bit of time but statfs caching doesn't seem to help:

[root@oak-h04v20 pmischel]# lctl set_param llite.oak-ffff999f20cf9800.statfs_max_age=600
llite.oak-ffff999f20cf9800.statfs_max_age=600
[root@oak-h04v20 pmischel]# time df .; sleep 1; time df .; sleep 1; time df .
Filesystem                              1K-blocks      Used    Available Use% Mounted on
10.0.2.51@o2ib5:10.0.2.52@o2ib5:/oak 250000000000 349118136 249650881864   1% /oak

real	0m1.786s
user	0m0.002s
sys	0m0.006s
Filesystem                              1K-blocks      Used    Available Use% Mounted on
10.0.2.51@o2ib5:10.0.2.52@o2ib5:/oak 250000000000 349118136 249650881864   1% /oak

real	0m1.253s
user	0m0.000s
sys	0m0.008s
Filesystem                              1K-blocks      Used    Available Use% Mounted on
10.0.2.51@o2ib5:10.0.2.52@o2ib5:/oak 250000000000 349118136 249650881864   1% /oak

real	0m0.272s
user	0m0.002s
sys	0m0.006s

We use the "get quota command" defined in smbd.conf to return filesystem quotas to SMB clients, which is a user-space program for us, that does some caching by itself, so we don't need quota info from statfs() at all. Is there a way to either disable the project quota behavior with statfs() or make statfs() caching work with 2.15 clients and project quotas?

Issue Links

• is related to: LU-17395 df -h is limited by project quota even if quota enforcement is disabled
• is related to: LU-18222 Implement quota aggregation limits by ID range
• is related to: LU-15721 projid quota limit statfs() on directories only with PROJINHERIT
• is related to: LU-17191 sanity-quota test_1b, 1d, 1f, 1i: FAIL: user write success, but expect EDQUOT
• is related to: LU-9555 "df /path/to/project" should return projid-specific values