[PATCH] oprofile - dcookies

This implements the persistent path-to-dcookies mapping, and adds a
system call for the user-space profiler to look up the profile data, so
it can tag profiles to specific binaries.

2 files changed, 72 insertions, 0 deletions

diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 71708edafce9..76a5085043e1 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -66,6 +66,8 @@ static __inline__ unsigned int full_name_hash(const unsigned char * name, unsign
 
 #define DNAME_INLINE_LEN 16
 
+struct dcookie_struct;
+ 
 struct dentry {
 	atomic_t d_count;
 	unsigned int d_flags;
@@ -84,6 +86,7 @@ struct dentry {
 	unsigned long d_vfs_flags;
 	void * d_fsdata;		/* fs-specific data */
 	unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */
+	struct dcookie_struct * d_cookie; /* cookie, if any */
 };
 
 struct dentry_operations {
diff --git a/include/linux/dcookies.h b/include/linux/dcookies.h
new file mode 100644
index 000000000000..b2ae9692dc05
--- /dev/null
+++ b/include/linux/dcookies.h
@@ -0,0 +1,69 @@
+/*
+ * dcookies.h
+ *
+ * Persistent cookie-path mappings
+ *
+ * Copyright 2002 John Levon <levon@movementarian.org>
+ */
+
+#ifndef DCOOKIES_H
+#define DCOOKIES_H
+ 
+#include <linux/config.h>
+
+#ifdef CONFIG_PROFILING
+ 
+#include <linux/types.h>
+ 
+struct dcookie_user;
+ 
+/**
+ * dcookie_register - register a user of dcookies
+ *
+ * Register as a dcookie user. Returns %NULL on failure.
+ */
+struct dcookie_user * dcookie_register(void);
+
+/**
+ * dcookie_unregister - unregister a user of dcookies
+ *
+ * Unregister as a dcookie user. This may invalidate
+ * any dcookie values returned from get_dcookie().
+ */
+void dcookie_unregister(struct dcookie_user * user);
+  
+/**
+ * get_dcookie - acquire a dcookie
+ *
+ * Convert the given dentry/vfsmount pair into
+ * a cookie value.
+ *
+ * Returns -EINVAL if no living task has registered as a
+ * dcookie user.
+ *
+ * Returns 0 on success, with *cookie filled in
+ */
+int get_dcookie(struct dentry * dentry, struct vfsmount * vfsmnt,
+	unsigned long * cookie);
+
+#else
+
+struct dcookie_user * dcookie_register(void)
+{
+	return 0;
+}
+
+void dcookie_unregister(struct dcookie_user * user)
+{
+	return;
+}
+ 
+static inline int get_dcookie(struct dentry * dentry,
+	struct vfsmount * vfsmnt, unsigned long * cookie)
+{
+	return -ENOSYS;
+} 
+ 
+#endif /* CONFIG_PROFILING */
+ 
+#endif /* DCOOKIES_H */