[LU-19034] 'lfs df' should limit statfs by project quota limits

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Affects Version/s: Lustre 2.16.0
• Labels: easy
• Severity: 3
• Epic Link: MTFL: Stretch goals
• Assignee: WC Triage
• Reporter: Andreas Dilger

Description

Similar to how "df $DIR" (statfs()) on a directory with a project quota limit project will return the project quota bhardlimit and busage as the total/used blocks, "lfs df $DIR" should also return the project quota limits for that PROJID. The same holds for inode limits and "lfs df -i $DIR".

This is a bit more complex to implement, because the space allocation to each OST may be different, and it isn't clear where to assign the unused space/qunits. However, it should be possible to get the per-OST usage/limits in a similar manner as "lfs quota -p", and then distribute any unused space/qunits across the OSTs as evenly as possible (subject to minimum 1MB qunit granularity.

Issue Links

• is related to: LU-15721 projid quota limit statfs() on directories only with PROJINHERIT
• is related to: LU-16771 add client statfs() cache for project quotas
• is related to: LU-9555 "df /path/to/project" should return projid-specific values