From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Date: Thu, 14 Apr 2022 06:07:11 +0000 (-0700)
Subject: Revert "mm/memory-failure.c: fix race with changing page compound again"
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=c4c769f3585f6d89ef87c698abf8b3db455e56fd;p=users%2Fjedix%2Flinux-maple.git

Revert "mm/memory-failure.c: fix race with changing page compound again"

Reverts commit 888af2701db7 ("mm/memory-failure.c: fix race with changing
page compound again") because now we fetch the page refcount under
hugetlb_lock in try_memory_failure_hugetlb() so that the race check is no
longer necessary.

Link: https://lkml.kernel.org/r/20220408135323.1559401-4-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Suggested-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 2bf6bee40b50..a9f1491048cd 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3292,7 +3292,6 @@ enum mf_action_page_type {
 	MF_MSG_BUDDY,
 	MF_MSG_DAX,
 	MF_MSG_UNSPLIT_THP,
-	MF_MSG_DIFFERENT_PAGE_SIZE,
 	MF_MSG_UNKNOWN,
 };
 
diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h
index 1e694fd239b9..d0337a41141c 100644
--- a/include/ras/ras_event.h
+++ b/include/ras/ras_event.h
@@ -374,7 +374,6 @@ TRACE_EVENT(aer_event,
 	EM ( MF_MSG_BUDDY, "free buddy page" )				\
 	EM ( MF_MSG_DAX, "dax page" )					\
 	EM ( MF_MSG_UNSPLIT_THP, "unsplit thp" )			\
-	EM ( MF_MSG_DIFFERENT_PAGE_SIZE, "different page size" )	\
 	EMe ( MF_MSG_UNKNOWN, "unknown page" )
 
 /*
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index a085e4dd3dc3..e3fbff5bd467 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -734,7 +734,6 @@ static const char * const action_page_types[] = {
 	[MF_MSG_BUDDY]			= "free buddy page",
 	[MF_MSG_DAX]			= "dax page",
 	[MF_MSG_UNSPLIT_THP]		= "unsplit thp",
-	[MF_MSG_DIFFERENT_PAGE_SIZE]	= "different page size",
 	[MF_MSG_UNKNOWN]		= "unknown page",
 };
 
@@ -1606,16 +1605,6 @@ retry:
 		return res == MF_RECOVERED ? 0 : -EBUSY;
 	}
 
-	/*
-	 * The page could have changed compound pages due to race window.
-	 * If this happens just bail out.
-	 */
-	if (!PageHuge(p) || compound_head(p) != head) {
-		action_result(pfn, MF_MSG_DIFFERENT_PAGE_SIZE, MF_IGNORED);
-		res = -EBUSY;
-		goto out;
-	}
-
 	page_flags = head->flags;
 
 	/*