3 files changed, 46 insertions, 9 deletions
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index ca648685f0cc..c2e7390289cc 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -5,6 +5,7 @@
 #include <linux/list.h>
 #include <linux/rculist.h>
 #include <linux/spinlock.h>
+#include <linux/seqlock.h>
 #include <linux/cache.h>
 #include <linux/rcupdate.h>
 
@@ -90,6 +91,7 @@ struct dentry {
 	unsigned int d_count;		/* protected by d_lock */
 	unsigned int d_flags;		/* protected by d_lock */
 	spinlock_t d_lock;		/* per dentry lock */
+	seqcount_t d_seq;		/* per dentry seqlock */
 	int d_mounted;
 	struct inode *d_inode;		/* Where the name belongs to - NULL is
 					 * negative */
@@ -266,9 +268,33 @@ extern void d_move(struct dentry *, struct dentry *);
 extern struct dentry *d_ancestor(struct dentry *, struct dentry *);
 
 /* appendix may either be NULL or be used for transname suffixes */
-extern struct dentry * d_lookup(struct dentry *, struct qstr *);
-extern struct dentry * __d_lookup(struct dentry *, struct qstr *);
-extern struct dentry * d_hash_and_lookup(struct dentry *, struct qstr *);
+extern struct dentry *d_lookup(struct dentry *, struct qstr *);
+extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
+extern struct dentry *__d_lookup(struct dentry *, struct qstr *);
+extern struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
+				unsigned *seq, struct inode **inode);
+
+/**
+ * __d_rcu_to_refcount - take a refcount on dentry if sequence check is ok
+ * @dentry: dentry to take a ref on
+ * @seq: seqcount to verify against
+ * @Returns: 0 on failure, else 1.
+ *
+ * __d_rcu_to_refcount operates on a dentry,seq pair that was returned
+ * by __d_lookup_rcu, to get a reference on an rcu-walk dentry.
+ */
+static inline int __d_rcu_to_refcount(struct dentry *dentry, unsigned seq)
+{
+	int ret = 0;
+
+	assert_spin_locked(&dentry->d_lock);
+	if (!read_seqcount_retry(&dentry->d_seq, seq)) {
+		ret = 1;
+		dentry->d_count++;
+	}
+
+	return ret;
+}
 
 /* validate "insecure" dentry pointer */
 extern int d_validate(struct dentry *, struct dentry *);
diff --git a/include/linux/namei.h b/include/linux/namei.h
index aec730b53935..18d06add0a40 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -19,7 +19,10 @@ struct nameidata {
 	struct path	path;
 	struct qstr	last;
 	struct path	root;
+	struct file	*file;
+	struct inode	*inode; /* path.dentry.d_inode */
 	unsigned int	flags;
+	unsigned	seq;
 	int		last_type;
 	unsigned	depth;
 	char *saved_names[MAX_NESTED_LINKS + 1];
@@ -43,11 +46,13 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
  *  - internal "there are more path components" flag
  *  - dentry cache is untrusted; force a real lookup
  */
-#define LOOKUP_FOLLOW		 1
-#define LOOKUP_DIRECTORY	 2
-#define LOOKUP_CONTINUE		 4
-#define LOOKUP_PARENT		16
-#define LOOKUP_REVAL		64
+#define LOOKUP_FOLLOW		0x0001
+#define LOOKUP_DIRECTORY	0x0002
+#define LOOKUP_CONTINUE		0x0004
+
+#define LOOKUP_PARENT		0x0010
+#define LOOKUP_REVAL		0x0020
+#define LOOKUP_RCU		0x0040
 /*
  * Intent data
  */
diff --git a/include/linux/security.h b/include/linux/security.h
index fd4d55fb8845..ed95401970c7 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -457,7 +457,6 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *	called when the actual read/write operations are performed.
  *	@inode contains the inode structure to check.
  *	@mask contains the permission mask.
- *	@nd contains the nameidata (may be NULL).
  *	Return 0 if permission is granted.
  * @inode_setattr:
  *	Check permission before setting file attributes.  Note that the kernel
@@ -1713,6 +1712,7 @@ int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry,
 int security_inode_readlink(struct dentry *dentry);
 int security_inode_follow_link(struct dentry *dentry, struct nameidata *nd);
 int security_inode_permission(struct inode *inode, int mask);
+int security_inode_exec_permission(struct inode *inode, unsigned int flags);
 int security_inode_setattr(struct dentry *dentry, struct iattr *attr);
 int security_inode_getattr(struct vfsmount *mnt, struct dentry *dentry);
 int security_inode_setxattr(struct dentry *dentry, const char *name,
@@ -2102,6 +2102,12 @@ static inline int security_inode_permission(struct inode *inode, int mask)
 	return 0;
 }
 
+static inline int security_inode_exec_permission(struct inode *inode,
+						  unsigned int flags)
+{
+	return 0;
+}
+
 static inline int security_inode_setattr(struct dentry *dentry,
 					  struct iattr *attr)
 {