From: NeilBrown <neilb@suse.de>
Date: Mon, 14 Jul 2014 01:28:20 +0000 (+1000)
Subject: NFS: teach nfs_lookup_verify_inode to handle LOOKUP_RCU
X-Git-Tag: v3.17-rc1~39^2~5
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=1fa1e38447964d6c96b027f9f999ef105d8cf8aa;p=linux.git

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 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;
 	}