NFS: Fix dcache revalidation bugs

We don't need to force a dentry lookup just because we're making changes to
the directory.

Don't update nfsi->cache_change_attribute in nfs_end_data_update: that
overrides the NFSv3/v4 weak consistency checking that tells us our update
was the only one, and that tells us the dcache is still valid.

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

2 files changed, 3 insertions, 8 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 2b5e611352c5..6518b098e625 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -650,15 +650,11 @@ static int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync)
  */
 static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
 {
-        unsigned long verf;
-
         if (IS_ROOT(dentry))
                 return 1;
-        verf = dentry->d_time;
-        if (nfs_caches_unstable(dir)
-                        || verf != NFS_I(dir)->cache_change_attribute)
-                return 0;
-        return 1;
+        if (dentry->d_time == NFS_I(dir)->cache_change_attribute)
+                return 1;
+        return 0;
 }
 
 static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index ed035a81eea2..cca1ab2922bf 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -785,7 +785,6 @@ void nfs_end_data_update(struct inode *inode)
                 nfsi->cache_validity |= NFS_INO_INVALID_DATA;
                 spin_unlock(&inode->i_lock);
         }
-        nfsi->cache_change_attribute = jiffies;
         atomic_dec(&nfsi->data_updates);
 }