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>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 34da485..cf80cf2 100644 (file)
--- 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;