X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fmigrate.c;h=07f22d4a431f5ce63303632749453e9459ece1ee;hb=557ed1fa2620dc119adb86b34c614e152a629a80;hp=37c73b902008e1dd2083f71995f2ce67975f6512;hpb=440fdb53b4ae58602711b5b8c3a139ace2404dbb;p=linux-2.6

diff --git a/mm/migrate.c b/mm/migrate.c
index 37c73b9020..07f22d4a43 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -611,6 +611,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
 	int rc = 0;
 	int *result = NULL;
 	struct page *newpage = get_new_page(page, private, &result);
+	int rcu_locked = 0;
 
 	if (!newpage)
 		return -ENOMEM;
@@ -636,8 +637,13 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
 	 * we cannot notice that anon_vma is freed while we migrates a page.
 	 * This rcu_read_lock() delays freeing anon_vma pointer until the end
 	 * of migration. File cache pages are no problem because of page_lock()
+	 * File Caches may use write_page() or lock_page() in migration, then,
+	 * just care Anon page here.
 	 */
-	rcu_read_lock();
+	if (PageAnon(page)) {
+		rcu_read_lock();
+		rcu_locked = 1;
+	}
 	/*
 	 * This is a corner case handling.
 	 * When a new swap-cache is read into, it is linked to LRU
@@ -656,7 +662,8 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
 	if (rc)
 		remove_migration_ptes(page, page);
 rcu_unlock:
-	rcu_read_unlock();
+	if (rcu_locked)
+		rcu_read_unlock();
 
 unlock:
 
@@ -965,7 +972,7 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
 	 * array. Return various errors if the user did something wrong.
 	 */
 	for (i = 0; i < nr_pages; i++) {
-		const void *p;
+		const void __user *p;
 
 		err = -EFAULT;
 		if (get_user(p, pages + i))