linux-stable/include/uapi
Rajesh Ghanekar 18c01ab302 nfsd: allow turning off nfsv3 readdir_plus
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.

There's already a corresponding client-side mount option, but an export
option reduces the need for configuration across multiple clients.

This flag affects NFSv3 only.  If it turns out it's needed for NFSv4 as
well then we may have to figure out how to extend the behavior to NFSv4,
but it's not currently obvious how to do that.

Signed-off-by: Rajesh Ghanekar <rajesh_ghanekar@symantec.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-08-18 15:12:14 -04:00
..
asm-generic Cleanups and bug fixes to /dev/random, add a new getrandom(2) system 2014-08-06 08:16:24 -07:00
drm drm/nouveau: expose the full object/event interfaces to userspace 2014-08-10 05:28:18 +10:00
linux nfsd: allow turning off nfsv3 readdir_plus 2014-08-18 15:12:14 -04:00
mtd mtd: lpddr: add driver for LPDDR2-NVM PCM memories 2014-05-20 17:45:17 -07:00
rdma Merge branches 'core', 'cxgb4', 'ipoib', 'iser', 'iwcm', 'mad', 'misc', 'mlx4', 'mlx5', 'ocrdma' and 'srp' into for-next 2014-08-14 08:58:04 -07:00
scsi
sound ALSA: pcm: Introduce protocol version field to sw_params 2014-07-21 09:07:46 +02:00
video
xen xen: install xen/gntdev.h and xen/gntalloc.h 2014-02-11 10:12:36 -05:00
Kbuild