tree 80c294437c0868d90abfa617d873370e6dbe6565
parent 412d582ec1dd59aab2353f8cb7e74f2c79cd20b9
author Chuck Lever <cel@citi.umich.edu> 1124389452 -0700
committer Linus Torvalds <torvalds@g5.osdl.org> 1124394837 -0700

[PATCH] NFS: Introduce the use of inode->i_lock to protect fields in nfsi

Down the road we want to eliminate the use of the global kernel lock entirely
from the NFS client.  To do this, we need to protect the fields in the
nfs_inode structure adequately.  Start by serializing updates to the
"cache_validity" field.

Note this change addresses an SMP hang found by njw@osdl.org, where processes
deadlock because nfs_end_data_update and nfs_revalidate_mapping update the
"cache_validity" field without proper serialization.

Test plan:
 Millions of fsx ops on SMP clients.  Run Nick Wilson's breaknfs program on
 large SMP clients.

Signed-off-by: Chuck Lever <cel@netapp.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>