__get_user_pages_locked(): get rid of notify_drop argument

Al Viro · Al Viro · commit e716712f83b6 · 2017-12-02T20:29:13.000-05:00
The only caller that doesn't pass true in it is get_user_pages() and
it passes NULL in locked.  The only place where we check it is
	if (notify_locked &amp;&amp; lock_dropped &amp;&amp; *locked)
and lock_dropped can become true only if we have locked != NULL.
In other words, the second part of condition will be false when
called by get_user_pages().

Just get rid of the argument and turn the condition into
	if (lock_dropped &amp;&amp; *locked)

Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
diff --git a/mm/gup.c b/mm/gup.c
@@ -848,7 +848,7 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk,
 						unsigned long nr_pages,
 						struct page **pages,
 						struct vm_area_struct **vmas,
-						int *locked, bool notify_drop,
+						int *locked,
 						unsigned int flags)
 {
 	long ret, pages_done;
@@ -922,7 +922,7 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk,
 		pages++;
 		start += PAGE_SIZE;
 	}
-	if (notify_drop && lock_dropped && *locked) {
+	if (lock_dropped && *locked) {
 		/*
 		 * We must let the caller know we temporarily dropped the lock
 		 * and so the critical section protected by it was lost.
@@ -959,7 +959,7 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
 			   int *locked)
 {
 	return __get_user_pages_locked(current, current->mm, start, nr_pages,
-				       pages, NULL, locked, true,
+				       pages, NULL, locked,
 				       gup_flags | FOLL_TOUCH);
 }
 EXPORT_SYMBOL(get_user_pages_locked);
@@ -988,7 +988,7 @@ long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
 
 	down_read(&mm->mmap_sem);
 	ret = __get_user_pages_locked(current, mm, start, nr_pages, pages, NULL,
-				      &locked, true, gup_flags | FOLL_TOUCH);
+				      &locked, gup_flags | FOLL_TOUCH);
 	if (locked)
 		up_read(&mm->mmap_sem);
 	return ret;
@@ -1057,7 +1057,7 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm,
 		struct vm_area_struct **vmas, int *locked)
 {
 	return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas,
-				       locked, true,
+				       locked,
 				       gup_flags | FOLL_TOUCH | FOLL_REMOTE);
 }
 EXPORT_SYMBOL(get_user_pages_remote);
@@ -1074,7 +1074,7 @@ long get_user_pages(unsigned long start, unsigned long nr_pages,
 		struct vm_area_struct **vmas)
 {
 	return __get_user_pages_locked(current, current->mm, start, nr_pages,
-				       pages, vmas, NULL, false,
+				       pages, vmas, NULL,
 				       gup_flags | FOLL_TOUCH);
 }
 EXPORT_SYMBOL(get_user_pages);
