constify path_get/path_put and fs_struct.c stuff

Signed-off-by: Al Viro <[e-mail]>

fs/fs_struct.c

···
  * Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values.
  * It can block.
  */
-void set_fs_root(struct fs_struct *fs, struct path *path)
+void set_fs_root(struct fs_struct *fs, const struct path *path)
 {
 	struct path old_root;
 
···
  * Replace the fs->{pwdmnt,pwd} with {mnt,dentry}. Put the old values.
  * It can block.
  */
-void set_fs_pwd(struct fs_struct *fs, struct path *path)
+void set_fs_pwd(struct fs_struct *fs, const struct path *path)
 {
 	struct path old_pwd;
 
···
 	return 1;
 }
 
-void chroot_fs_refs(struct path *old_root, struct path *new_root)
+void chroot_fs_refs(const struct path *old_root, const struct path *new_root)
 {
 	struct task_struct *g, *p;
 	struct fs_struct *fs;

fs/internal.h

···
 /*
  * fs_struct.c
  */
-extern void chroot_fs_refs(struct path *, struct path *);
+extern void chroot_fs_refs(const struct path *, const struct path *);
 
 /*
  * file_table.c

fs/namei.c

···
  *
  * Given a path increment the reference count to the dentry and the vfsmount.
  */
-void path_get(struct path *path)
+void path_get(const struct path *path)
 {
 	mntget(path->mnt);
 	dget(path->dentry);
···
  *
  * Given a path decrement the reference count to the dentry and the vfsmount.
  */
-void path_put(struct path *path)
+void path_put(const struct path *path)
 {
 	dput(path->dentry);
 	mntput(path->mnt);

include/linux/fs_struct.h

···
 extern struct kmem_cache *fs_cachep;
 
 extern void exit_fs(struct task_struct *);
-extern void set_fs_root(struct fs_struct *, struct path *);
-extern void set_fs_pwd(struct fs_struct *, struct path *);
+extern void set_fs_root(struct fs_struct *, const struct path *);
+extern void set_fs_pwd(struct fs_struct *, const struct path *);
 extern struct fs_struct *copy_fs_struct(struct fs_struct *);
 extern void free_fs_struct(struct fs_struct *);
 extern int unshare_fs_struct(void);

include/linux/path.h

···
 	struct dentry *dentry;
 };
 
-extern void path_get(struct path *);
-extern void path_put(struct path *);
+extern void path_get(const struct path *);
+extern void path_put(const struct path *);
 
 static inline int path_equal(const struct path *path1, const struct path *path2)
 {