It's apparent that a number of distributions and their customers remain on long-term stable kernels. We are aware of the scalability problems and other bugs in NFSD in kernels between v5.4 and v6.1. To address the filecache and other scalability problems in those kernels, I'm preparing backported patches of NFSD fixes for several popular LTS kernels. These backports are destined for the official LTS kernel branches so that distributions can easily integrate them into their products. Once this effort is complete, Greg and Sasha will continue to be responsible for backporting NFSD-related fixes from upstream into the LTS kernels. --- I've pushed the NFSD backports to branches in this repo: https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git If you are able, I encourage you to pull these, review them or try them out, and report any issues or successes. I'm currently using the NFS workflows in kdevops as the testing platform, but am planning to include other tests. LTS v5.10.y I've rebased this branch on v5.10.219 and plan to send a PR in the next day or so. You can find this series in the "nfsd-5.10.y" branch in the above repo. Out-of-kernel follow-up work Amir Goldstein made these review requests: - Adjust the LTP test fanotify09 to update the comment with the appropriate 5.15.y version - Update fanotify_init(2) "FAN_REPORT_TARGET_FID (since Linux 5.17)" - Update fanotify_mark(2) "FAN_MARK_EVICTABLE (since Linux 5.19)" - Update fanotify_mark(2) "FAN_RENAME (since Linux 5.17)" - Update fanotify_mark(2) "FAN_FS_ERROR (since Linux 5.16 and 5.15.???)" - Update fanotify_mark(2) "FAN_MARK_IGNORE (since Linux 6.0)" I plan to provide these updates once the NFSD filecache fixes have been merged into the 5.10 LTS kernel. -- Chuck Lever