NFS: Fix the resolution problem with nfs_inode_attrs_need_update()

It appears that 'jiffies' timestamps do not have high enough resolution for
nfs_inode_attrs_need_update(). One problem is that a GETATTR can be
launched within < 1 jiffy of the last operation that updated the attribute.
Another problem is that RPC calls can take < 1 jiffy to execute.

We can fix this by switching the variables to use a simple global counter
that gets incremented every time we start another GETATTR call.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 6ee6ae3f095..c1c31acb8a2 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -56,6 +56,7 @@ struct nfs_fattr {
         __u64                   change_attr;    /* NFSv4 change attribute */
         __u64                   pre_change_attr;/* pre-op NFSv4 change attribute */
         unsigned long           time_start;
+        unsigned long           gencount;
 };
 
 #define NFS_ATTR_WCC            0x0001          /* pre-op WCC data    */