mm/memory-failure: add macro GET_PAGE_MAX_RETRY_NUM

Add helper macro GET_PAGE_MAX_RETRY_NUM to replace magic number 3.  No
functional change intended.

Link: https://lkml.kernel.org/r/20240612071835.157004-4-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory-failure.c

@@ -1417,6 +1417,8 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags)
 	return 0;
 }
 
+#define GET_PAGE_MAX_RETRY_NUM 3
+
 static int get_any_page(struct page *p, unsigned long flags)
 {
 	int ret = 0, pass = 0;
@@ -1431,12 +1433,12 @@ static int get_any_page(struct page *p, unsigned long flags)
 		if (!ret) {
 			if (page_count(p)) {
 				/* We raced with an allocation, retry. */
-				if (pass++ < 3)
+				if (pass++ < GET_PAGE_MAX_RETRY_NUM)
 					goto try_again;
 				ret = -EBUSY;
 			} else if (!PageHuge(p) && !is_free_buddy_page(p)) {
 				/* We raced with put_page, retry. */
-				if (pass++ < 3)
+				if (pass++ < GET_PAGE_MAX_RETRY_NUM)
 					goto try_again;
 				ret = -EIO;
 			}
@@ -1462,7 +1464,7 @@ static int get_any_page(struct page *p, unsigned long flags)
 		 * A page we cannot handle. Check whether we can turn
 		 * it into something we can handle.
 		 */
-		if (pass++ < 3) {
+		if (pass++ < GET_PAGE_MAX_RETRY_NUM) {
 			put_page(p);
 			shake_page(p);
 			count_increased = false;