[PATCH] NFS: Fix cache consistency races

If the data cache has been marked as potentially invalid by nfs_refresh_inode,
we should invalidate it rather than assume that changes are due to our own
activity.

Also ensure that we always start with a valid cache before declaring it
to be protected by a delegation.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index d7f7eb669d03..4a36839f0bbd 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -85,6 +85,10 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
         struct nfs_delegation *delegation;
         int status = 0;
 
+        /* Ensure we first revalidate the attributes and page cache! */
+        if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_ATTR)))
+                __nfs_revalidate_inode(NFS_SERVER(inode), inode);
+
         delegation = nfs_alloc_delegation();
         if (delegation == NULL)
                 return -ENOMEM;