[LU-10994] remove unused page layers

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.16.0
• Assignee: John Hammond
• Reporter: John Hammond

Description

The lock layers half of https://review.whamcloud.com/#/c/30161/ landed under LU-10257. We should try to bring the page half of https://review.whamcloud.com/#/c/30161/ back to life and get it landed.

Issue Links

• is related to: LU-16395 obdfilter-survey: Error: 'Timeout occurred after 342 minutes, last suite running was obdfilter-survey'
• is related to: LU-10257 vvp_lock, lov_page, and lovsub_{lock,page} are (more or less) unused
• is related to: LU-12511 Prepare lustre for adoption into the linux kernel
• is related to: LU-13134 try to use slab allocation for cl_page
• is related to: LU-15619 Reduce size of cl_page and associated structures