linux/include
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
..
acpi ACPI and power management updates for 3.17-rc1 2014-08-06 20:34:19 -07:00
asm-generic This is the bulk of GPIO changes for the v3.17 development 2014-08-08 18:00:35 -07:00
clocksource
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2014-08-06 08:06:39 -07:00
drm Merge branch 'linux-3.17' of git://anongit.freedesktop.org/git/nouveau/linux-2.6 2014-08-09 17:46:39 -07:00
dt-bindings Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2014-08-11 07:14:01 -07:00
keys
kvm
linux SUNRPC: get rid of the request wait queue 2014-08-17 12:00:11 -04:00
math-emu
media
memory
misc
net tcp: don't allow syn packets without timestamps to pass tcp_tw_recycle logic 2014-08-14 14:38:54 -07:00
pcmcia
ras
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
rxrpc
scsi SCSI misc on 20140815 2014-08-15 18:28:58 -06:00
soc/tegra
sound ASoC: Updates for v3.17 2014-08-04 18:28:21 +02:00
target
trace Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2014-08-14 10:14:07 -06:00
uapi nfsd: allow turning off nfsv3 readdir_plus 2014-08-18 15:12:14 -04:00
video fbdev changes for 3.17 2014-08-08 18:09:33 -07:00
xen - Remove unused V2 grant table support. 2014-08-07 11:33:15 -07:00
Kbuild