Hi, One of our customer's application only needs file names not file attributes. With directories having 10K+ inodes (assuming buffer cache has directory blocks cached having file names, but inode cache is limited and hence need eviction of older cached inodes), older inodes are evicted periodically. So if they keep on doing readdir(2) from NSF client on multiple directories, some directory's files are periodically removed from inode cache and hence new readdir(2) on same directory requires disk access to bring back inodes again to inode cache. As READDIRPLUS request fetches attributes also, doing getattr on each file on server, it causes unnecessary disk accesses. If READDIRPLUS on NFS client is returned with -ENOTSUPP, NFS client uses READDIR request which just gets the names of the files in a directory, not attributes, hence avoiding disk accesses on server. Can this be per-export tunable so that different application can use it in different ways, some supporting readdirplus and others not supporting readdirplus? I have worked on a patch against 3.15.6 for this. Also I am adding a patch against latest nfs-utils to have an export option for this. Can someone let me know if these patches are adequate or if any other changes are required. Patches attached, although with minimal testing. I would like to know if something like this can be added and if the patch can be reworked if I am missing something for NFSv4. Regards, Rishi Agrawal
Attachment:
patch_linux-kernel-3-15-6
Description: patch_linux-kernel-3-15-6
Attachment:
patch_nfs-utils-1.3
Description: patch_nfs-utils-1.3
