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>

1 files changed, 6 insertions, 4 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index dcd4fe5831d6..2bfbde0f7176 100644
--- 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;
         }