From: Miaohe Lin <linmiaohe@huawei.com>
Date: Tue, 23 Aug 2022 03:02:06 +0000 (+0800)
Subject: mm-hugetlb-fix-missing-call-to-restore_reserve_on_error-v2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=cdff502cd61c7173a48ca2696c4918b98b42a58a;p=users%2Fjedix%2Flinux-maple.git

mm-hugetlb-fix-missing-call-to-restore_reserve_on_error-v2

remove err == -EEXIST check and retry logic

Link: https://lkml.kernel.org/r/20220823030209.57434-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b69d7808f457..8d52827d9f51 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5563,7 +5563,6 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
 	if (idx >= size)
 		goto out;
 
-retry:
 	new_page = false;
 	page = find_lock_page(mapping, idx);
 	if (!page) {
@@ -5603,10 +5602,15 @@ retry:
 		if (vma->vm_flags & VM_MAYSHARE) {
 			int err = huge_add_to_page_cache(page, mapping, idx);
 			if (err) {
+				/*
+				 * err can't be -EEXIST which implies someone
+				 * else consumed the reservation since hugetlb
+				 * fault mutex is held when add a hugetlb page
+				 * to the page cache. So it's safe to call
+				 * restore_reserve_on_error() here.
+				 */
 				restore_reserve_on_error(h, vma, haddr, page);
 				put_page(page);
-				if (err == -EEXIST)
-					goto retry;
 				goto out;
 			}
 			new_pagecache_page = true;