NFS: Optimise nfs_lookup_revalidate()

We don't need to call nfs_revalidate_inode() on the directory if we already
know that the verifiers don't match.

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

1 files changed, 8 insertions, 7 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 34da48586829..cf80cf234e27 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -646,9 +646,14 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
 {
         if (IS_ROOT(dentry))
                 return 1;
-        if (nfs_verify_change_attribute(dir, dentry->d_time))
-                return 1;
-        return 0;
+        if (!nfs_verify_change_attribute(dir, dentry->d_time))
+                return 0;
+        /* Revalidate nfsi->cache_change_attribute before we declare a match */
+        if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
+                return 0;
+        if (!nfs_verify_change_attribute(dir, dentry->d_time))
+                return 0;
+        return 1;
 }
 
 static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
@@ -742,10 +747,6 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
         nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
         inode = dentry->d_inode;
 
-        /* Revalidate parent directory attribute cache */
-        if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
-                goto out_zap_parent;
-
         if (!inode) {
                 if (nfs_neg_need_reval(dir, dentry, nd))
                         goto out_bad;