NFS: teach nfs_lookup_verify_inode to handle LOOKUP_RCU

It fails with -ECHILD rather than make an RPC call.

This allows nfs_lookup_revalidate to call it in RCU-walk mode.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index dcd4fe5..2bfbde0 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1050,6 +1050,8 @@ int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
 out:
        return (inode->i_nlink == 0) ? -ENOENT : 0;
 out_force:
+       if (flags & LOOKUP_RCU)
+               return -ECHILD;
        ret = __nfs_revalidate_inode(server, inode);
        if (ret != 0)
                return ret;
@@ -1135,11 +1137,11 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
        if (!nfs_is_exclusive_create(dir, flags) &&
            nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) {
 
-               if (flags & LOOKUP_RCU)
-                       return -ECHILD;
-
-               if (nfs_lookup_verify_inode(inode, flags))
+               if (nfs_lookup_verify_inode(inode, flags)) {
+                       if (flags & LOOKUP_RCU)
+                               return -ECHILD;
                        goto out_zap_parent;
+               }
                goto out_valid;
        }