From cad69b00e8d1fda4214a6048f8e164f776b2e19a Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@infradead.org>
Date: Mon, 18 Jun 2012 10:47:04 -0400
Subject: [PATCH] --- yaml --- r: 312933 b: refs/heads/master c:
 b5fb63c18315c5510c1d0636179c057e0c761c77 h: refs/heads/master i:   312931:
 99ff91bef258678c66cf243973b18f2e499c9300 v: v3

---
 [refs]                      |  2 +-
 trunk/fs/namei.c            | 27 +++++++++++++++++----------
 trunk/fs/proc/base.c        |  3 +--
 trunk/include/linux/namei.h |  2 ++
 4 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/[refs] b/[refs]
index 6e2a4ed9d1b6..7d16cfffa40b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 408ef013cc9e2f94a14f7ccbbe52ddfb18437a99
+refs/heads/master: b5fb63c18315c5510c1d0636179c057e0c761c77
diff --git a/trunk/fs/namei.c b/trunk/fs/namei.c
index a9b94c62c303..0e1b9c3eb36d 100644
--- a/trunk/fs/namei.c
+++ b/trunk/fs/namei.c
@@ -586,6 +586,21 @@ static inline void path_to_nameidata(const struct path *path,
 	nd->path.dentry = path->dentry;
 }
 
+/*
+ * Helper to directly jump to a known parsed path from ->follow_link,
+ * caller must have taken a reference to path beforehand.
+ */
+void nd_jump_link(struct nameidata *nd, struct path *path)
+{
+	path_put(&nd->path);
+
+	nd->path = *path;
+	nd->inode = nd->path.dentry->d_inode;
+	nd->flags |= LOOKUP_JUMPED;
+
+	BUG_ON(nd->inode->i_op->follow_link);
+}
+
 static inline void put_link(struct nameidata *nd, struct path *link, void *cookie)
 {
 	struct inode *inode = link->dentry->d_inode;
@@ -630,17 +645,9 @@ follow_link(struct path *link, struct nameidata *nd, void **p)
 	s = nd_get_link(nd);
 	if (s) {
 		error = __vfs_follow_link(nd, s);
-	} else if (nd->last_type == LAST_BIND) {
-		nd->flags |= LOOKUP_JUMPED;
-		nd->inode = nd->path.dentry->d_inode;
-		if (nd->inode->i_op->follow_link) {
-			/* stepped on a _really_ weird one */
-			path_put(&nd->path);
-			error = -ELOOP;
-		}
+		if (unlikely(error))
+			put_link(nd, link, *p);
 	}
-	if (unlikely(error))
-		put_link(nd, link, *p);
 
 	return error;
 
diff --git a/trunk/fs/proc/base.c b/trunk/fs/proc/base.c
index 3bd5ac1ff018..2772208338f8 100644
--- a/trunk/fs/proc/base.c
+++ b/trunk/fs/proc/base.c
@@ -1438,8 +1438,7 @@ static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
 	if (error)
 		goto out;
 
-	path_put(&nd->path);
-	nd->path = path;
+	nd_jump_link(nd, &path);
 	return NULL;
 out:
 	return ERR_PTR(error);
diff --git a/trunk/include/linux/namei.h b/trunk/include/linux/namei.h
index f5931489e150..d2ef8b34b967 100644
--- a/trunk/include/linux/namei.h
+++ b/trunk/include/linux/namei.h
@@ -80,6 +80,8 @@ extern int follow_up(struct path *);
 extern struct dentry *lock_rename(struct dentry *, struct dentry *);
 extern void unlock_rename(struct dentry *, struct dentry *);
 
+extern void nd_jump_link(struct nameidata *nd, struct path *path);
+
 static inline void nd_set_link(struct nameidata *nd, char *path)
 {
 	nd->saved_names[nd->depth] = path;