From a1e3eb25c3e3db59a702246e5272dea90c0f0bbb Mon Sep 17 00:00:00 2001
From: Al Viro <viro@ZenIV.linux.org.uk>
Date: Mon, 7 Nov 2011 21:21:26 +0000
Subject: [PATCH] --- yaml --- r: 275112 b: refs/heads/master c:
 a3fbbde70a0cec017f2431e8f8de208708c76acc h: refs/heads/master v: v3

---
 [refs]           |  2 +-
 trunk/fs/namei.c | 16 +++++++++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 1dca3e8d5ab0..4c02a4d62c64 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 54a0f91301950af3d6ae2ff2bf710c9c68a9bfea
+refs/heads/master: a3fbbde70a0cec017f2431e8f8de208708c76acc
diff --git a/trunk/fs/namei.c b/trunk/fs/namei.c
index ac6d214da827..5008f01787f5 100644
--- a/trunk/fs/namei.c
+++ b/trunk/fs/namei.c
@@ -852,7 +852,7 @@ static int follow_managed(struct path *path, unsigned flags)
 		mntput(path->mnt);
 	if (ret == -EISDIR)
 		ret = 0;
-	return ret;
+	return ret < 0 ? ret : need_mntput;
 }
 
 int follow_down_one(struct path *path)
@@ -900,6 +900,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
 			break;
 		path->mnt = mounted;
 		path->dentry = mounted->mnt_root;
+		nd->flags |= LOOKUP_JUMPED;
 		nd->seq = read_seqcount_begin(&path->dentry->d_seq);
 		/*
 		 * Update the inode too. We don't need to re-check the
@@ -1213,6 +1214,8 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
 		path_put_conditional(path, nd);
 		return err;
 	}
+	if (err)
+		nd->flags |= LOOKUP_JUMPED;
 	*inode = path->dentry->d_inode;
 	return 0;
 }
@@ -2146,6 +2149,10 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	}
 
 	/* create side of things */
+	/*
+	 * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED has been
+	 * cleared when we got to the last component we are about to look up
+	 */
 	error = complete_walk(nd);
 	if (error)
 		return ERR_PTR(error);
@@ -2214,6 +2221,9 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 	if (error < 0)
 		goto exit_dput;
 
+	if (error)
+		nd->flags |= LOOKUP_JUMPED;
+
 	error = -ENOENT;
 	if (!path->dentry->d_inode)
 		goto exit_dput;
@@ -2223,6 +2233,10 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
 
 	path_to_nameidata(path, nd);
 	nd->inode = path->dentry->d_inode;
+	/* Why this, you ask?  _Now_ we might have grown LOOKUP_JUMPED... */
+	error = complete_walk(nd);
+	if (error)
+		goto exit;
 	error = -EISDIR;
 	if (S_ISDIR(nd->inode->i_mode))
 		goto exit;