constify get_dcookie() and friends

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/powerpc/oprofile/cell/spu_task_sync.c

@@ -295,7 +295,7 @@ static int release_cached_info(int spu_index)
  * dcookie user still being registered (namely, the reader
  * of the event buffer).
  */
-static inline unsigned long fast_get_dcookie(struct path *path)
+static inline unsigned long fast_get_dcookie(const struct path *path)
 {
 	unsigned long cookie;
 

drivers/oprofile/buffer_sync.c

@@ -206,7 +206,7 @@ void sync_stop(void)
  * because we cannot reach this code without at least one
  * dcookie user still being registered (namely, the reader
  * of the event buffer). */
-static inline unsigned long fast_get_dcookie(struct path *path)
+static inline unsigned long fast_get_dcookie(const struct path *path)
 {
 	unsigned long cookie;
 

fs/dcookies.c

@@ -90,7 +90,7 @@ static void hash_dcookie(struct dcookie_struct * dcs)
 }
 
 
-static struct dcookie_struct *alloc_dcookie(struct path *path)
+static struct dcookie_struct *alloc_dcookie(const struct path *path)
 {
 	struct dcookie_struct *dcs = kmem_cache_alloc(dcookie_cache,
 							GFP_KERNEL);
@@ -113,7 +113,7 @@ static struct dcookie_struct *alloc_dcookie(struct path *path)
 /* This is the main kernel-side routine that retrieves the cookie
  * value for a dentry/vfsmnt pair.
  */
-int get_dcookie(struct path *path, unsigned long *cookie)
+int get_dcookie(const struct path *path, unsigned long *cookie)
 {
 	int err = 0;
 	struct dcookie_struct * dcs;

include/linux/dcookies.h

@@ -44,7 +44,7 @@ void dcookie_unregister(struct dcookie_user * user);
  *
  * Returns 0 on success, with *cookie filled in
  */
-int get_dcookie(struct path *path, unsigned long *cookie);
+int get_dcookie(const struct path *path, unsigned long *cookie);
 
 #else
 
@@ -58,7 +58,7 @@ static inline void dcookie_unregister(struct dcookie_user * user)
 	return;
 }
 
-static inline int get_dcookie(struct path *path, unsigned long *cookie)
+static inline int get_dcookie(const struct path *path, unsigned long *cookie)
 {
 	return -ENOSYS;
 }