+#ifdef CONFIG_DEBUG_WRITECOUNT
+static inline void file_take_write(struct file *f)
+{
+ WARN_ON(f->f_mnt_write_state != 0);
+ f->f_mnt_write_state = FILE_MNT_WRITE_TAKEN;
+}
+static inline void file_release_write(struct file *f)
+{
+ f->f_mnt_write_state |= FILE_MNT_WRITE_RELEASED;
+}
+static inline void file_reset_write(struct file *f)
+{
+ f->f_mnt_write_state = 0;
+}
+static inline void file_check_state(struct file *f)
+{
+ /*
+ * At this point, either both or neither of these bits
+ * should be set.
+ */
+ WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN);
+ WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_RELEASED);
+}
+static inline int file_check_writeable(struct file *f)
+{
+ if (f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN)
+ return 0;
+ printk(KERN_WARNING "writeable file with no "
+ "mnt_want_write()\n");
+ WARN_ON(1);
+ return -EINVAL;
+}
+#else /* !CONFIG_DEBUG_WRITECOUNT */
+static inline void file_take_write(struct file *filp) {}
+static inline void file_release_write(struct file *filp) {}
+static inline void file_reset_write(struct file *filp) {}
+static inline void file_check_state(struct file *filp) {}
+static inline int file_check_writeable(struct file *filp)
+{
+ return 0;
+}
+#endif /* CONFIG_DEBUG_WRITECOUNT */
+