[LU-7233] parallelize lmv_statfs() implementation

• Type: Improvement
• Resolution: Low Priority
• Priority: Minor
• Affects Version/s: Lustre 2.8.0
• Labels: dne2 dne3 medium
• Assignee: Mikhail Pershin
• Reporter: Andreas Dilger

Description

In ll_statfs_internal() the call to obd_statfs->lmv_statfs() sends the MDS_STATFS RPC(s) serially for each MDT in the filesystem, unlike the obd_statfs_rqset->lov_statfs_async() call that sends the OST_STATFS RPCs in parallel to all OSTs.

It would be good to clean this code up so the MDT RPCs are also sent in a single request set, in case there are a lot of MDTs in the filesystem.

I also notice in lmv_statfs() that it isn't adding in os_bfree from the secondary MDTs into osfs. While this isn't critical for correctness today (the os_b* fields are discarded by ll_statfs_internal() for returning to userspace) this will be necessary for Data-on-MDT and is just more correct.

Also, lmv_statfs() doesn't handle the case where the individual mdc_statfs() calls return a different os_bsize, unlike lov_update_statfs() does.

Issue Links

• is related to: LU-10018 MDT as a statfs proxy