NFS: Optimise away the close-to-open GETATTR when we have NFSv4 OPEN

NFSv4 should not need to perform an extra close-to-open GETATTR as part
of the process of looking up a regular file, since the OPEN call will
do that for us.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 73f8b43d988cfa2f7b3366b1147dc296b55802ef..4a73bd8b451723c32a4a2bf1188a1a69e7653302 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1012,13 +1012,25 @@ int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
 
        if (IS_AUTOMOUNT(inode))
                return 0;
+
+       if (flags & LOOKUP_OPEN) {
+               switch (inode->i_mode & S_IFMT) {
+               case S_IFREG:
+                       /* A NFSv4 OPEN will revalidate later */
+                       if (server->caps & NFS_CAP_ATOMIC_OPEN)
+                               goto out;
+                       /* Fallthrough */
+               case S_IFDIR:
+                       if (server->flags & NFS_MOUNT_NOCTO)
+                               break;
+                       /* NFS close-to-open cache consistency validation */
+                       goto out_force;
+               }
+       }
+
        /* VFS wants an on-the-wire revalidation */
        if (flags & LOOKUP_REVAL)
                goto out_force;
-       /* This is an open(2) */
-       if ((flags & LOOKUP_OPEN) && !(server->flags & NFS_MOUNT_NOCTO) &&
-           (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
-               goto out_force;
 out:
        return (inode->i_nlink == 0) ? -ENOENT : 0;
 out_force: