[LU-15837] "lfs find -printf" improvements

• Type: Improvement
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.16.0
• Affects Version/s: Lustre 2.15.0
• Labels: easy lug23dd lug24dd
• Assignee: Max Dilger
• Reporter: Andreas Dilger

Description

Per Rick's LUG presentation, there are still a number of optimizations for "lfs find -printf" that were not included in the original patch https://review.whamcloud.com/45136 "LU-10378 utils: add formatted printf to lfs find" landing that should still be addressed:

• selective fetching of metadata attributes. In particular, fetching the projid for a file requires an extra syscall that is unnecessary if the projid is not being printed, at least until LU-12480 is implemented. Most of the other MDT attributes are "free" once any attribute is read for a file, so it probably doesn't make sense to micro-optimize here.
• pre-parsing of the -printf argument string (assuming this actually shows up in the CPU profile, I'm not sure if it is actually important vs. stat/RPC overhead)
• maybe others, I didn't catch all of them

Issue Links

• is related to: LU-16560 'lfs find -printf %w' does not print birth time
• is related to: LU-16808 lfs find --printf fails on FIFOs and special files
• is related to: LU-17219 lfs find: add ability to print extended attributes
• is related to: LU-16760 "lfs find" support for fscrypt and other file attributes
• is related to: LU-5170 lfs usability
• is related to: LU-12480 add STATX_PROJID to upstream kernel
• is related to: LU-7495 lfs find is missing "-links" support
• is related to: LU-10378 "lfs find" is missing "-printf" support
• is related to: LU-15504 "lfs find" is missing "-ls" support
• is related to: LU-15743 "lfs find" is missing "-xattr" support
• is related to: LU-16798 lfs find: new --jobid option