* Re: [PATCH v4 1/2] mm/memory-failure.c: avoid calling invalidate_inode_page() with unexpected pages
2022-03-20 5:13 ` [PATCH v4 1/2] mm/memory-failure.c: avoid calling invalidate_inode_page() with unexpected pages Miaohe Lin
@ 2022-03-19 16:20 ` Matthew Wilcox
2022-03-21 2:18 ` Miaohe Lin
0 siblings, 1 reply; 5+ messages in thread
From: Matthew Wilcox @ 2022-03-19 16:20 UTC (permalink / raw)
To: Miaohe Lin
Cc: akpm, naoya.horiguchi, shy828301, mike.kravetz, david, linux-mm,
linux-kernel
On Sun, Mar 20, 2022 at 01:13:33PM +0800, Miaohe Lin wrote:
> invalidate_inode_page() can invalidate the pages in the swap cache because
> the check of page->mapping != mapping is removed via Matthew's patch titled
> "mm/truncate: Inline invalidate_complete_page() into its one caller". But
> invalidate_inode_page() is not expected to deal with the pages in the swap
> cache. Also non-lru movable page can reach here too. They're not page cache
> pages. Skip these pages by checking PageSwapCache and PageLRU to fix this
> unexpected issue.
I disagree with this changelog.
invalidate_inode_page() should not be called for pages which are not
in the page cache.
And then the patch shouldn't test PageLRU (which is actually wrong) or
PageSwapCache(). It should simply be:
+ if (!PageHuge(page) && !PageAnon(page))
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> ---
> mm/memory-failure.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 5444a8ef4867..ecf45961f3b6 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -2178,7 +2178,7 @@ static int __soft_offline_page(struct page *page)
> return 0;
> }
>
> - if (!PageHuge(page))
> + if (!PageHuge(page) && PageLRU(page) && !PageSwapCache(page))
> /*
> * Try to invalidate first. This should work for
> * non dirty unmapped page cache pages.
> --
> 2.23.0
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v4 0/2] A few fixup patches for memory failure
@ 2022-03-20 5:13 Miaohe Lin
2022-03-20 5:13 ` [PATCH v4 1/2] mm/memory-failure.c: avoid calling invalidate_inode_page() with unexpected pages Miaohe Lin
2022-03-20 5:13 ` [PATCH v4 2/2] mm/memory-failure.c: make non-LRU movable pages unhandlable Miaohe Lin
0 siblings, 2 replies; 5+ messages in thread
From: Miaohe Lin @ 2022-03-20 5:13 UTC (permalink / raw)
To: akpm, naoya.horiguchi, shy828301, mike.kravetz, david
Cc: linux-mm, linux-kernel, linmiaohe
Hi everyone,
This series contains a patch to avoid calling invalidate_inode_page()
with unexpected pages and another one to make non-LRU movable pages
unhandlable. More details can be found in the respective changelogs.
Thanks!
---
v3->v4:
fix typo and drop "bool movable" per David. Thanks David.
v2->v3:
drop patch "mm/memory-failure.c: fix race with changing page compound again"
collect reviewed-by and acked-by tag
fix stale commit id in the commit log
v1->v2:
drop "mm/memory-failure.c: fix wrong user reference report"
make non-LRU movable pages unhandlable
fix confusing commit log and introduce MF_MSG_DIFFERENT_PAGE_SIZE
Many thanks Naoya, Mike and Yang Shi for review!
---
Miaohe Lin (2):
mm/memory-failure.c: avoid calling invalidate_inode_page() with
unexpected pages
mm/memory-failure.c: make non-LRU movable pages unhandlable
mm/memory-failure.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
--
2.23.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v4 1/2] mm/memory-failure.c: avoid calling invalidate_inode_page() with unexpected pages
2022-03-20 5:13 [PATCH v4 0/2] A few fixup patches for memory failure Miaohe Lin
@ 2022-03-20 5:13 ` Miaohe Lin
2022-03-19 16:20 ` Matthew Wilcox
2022-03-20 5:13 ` [PATCH v4 2/2] mm/memory-failure.c: make non-LRU movable pages unhandlable Miaohe Lin
1 sibling, 1 reply; 5+ messages in thread
From: Miaohe Lin @ 2022-03-20 5:13 UTC (permalink / raw)
To: akpm, naoya.horiguchi, shy828301, mike.kravetz, david
Cc: linux-mm, linux-kernel, linmiaohe
invalidate_inode_page() can invalidate the pages in the swap cache because
the check of page->mapping != mapping is removed via Matthew's patch titled
"mm/truncate: Inline invalidate_complete_page() into its one caller". But
invalidate_inode_page() is not expected to deal with the pages in the swap
cache. Also non-lru movable page can reach here too. They're not page cache
pages. Skip these pages by checking PageSwapCache and PageLRU to fix this
unexpected issue.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/memory-failure.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 5444a8ef4867..ecf45961f3b6 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2178,7 +2178,7 @@ static int __soft_offline_page(struct page *page)
return 0;
}
- if (!PageHuge(page))
+ if (!PageHuge(page) && PageLRU(page) && !PageSwapCache(page))
/*
* Try to invalidate first. This should work for
* non dirty unmapped page cache pages.
--
2.23.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v4 2/2] mm/memory-failure.c: make non-LRU movable pages unhandlable
2022-03-20 5:13 [PATCH v4 0/2] A few fixup patches for memory failure Miaohe Lin
2022-03-20 5:13 ` [PATCH v4 1/2] mm/memory-failure.c: avoid calling invalidate_inode_page() with unexpected pages Miaohe Lin
@ 2022-03-20 5:13 ` Miaohe Lin
1 sibling, 0 replies; 5+ messages in thread
From: Miaohe Lin @ 2022-03-20 5:13 UTC (permalink / raw)
To: akpm, naoya.horiguchi, shy828301, mike.kravetz, david
Cc: linux-mm, linux-kernel, linmiaohe
We can not really handle non-LRU movable pages in memory failure. Typically
they are balloon, zsmalloc, etc. Assuming we run into a base (4K) non-LRU
movable page, we could reach as far as identify_page_state(), it should not
fall into any category except me_unknown. For the non-LRU compound movable
pages, they could be taken for transhuge pages but it's unexpected to split
non-LRU movable pages using split_huge_page_to_list in memory_failure. So
we could just simply make non-LRU movable pages unhandlable to avoid these
possible nasty cases.
Suggested-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
---
mm/memory-failure.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ecf45961f3b6..837ceae90d64 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1176,12 +1176,16 @@ void ClearPageHWPoisonTakenOff(struct page *page)
* does not return true for hugetlb or device memory pages, so it's assumed
* to be called only in the context where we never have such pages.
*/
-static inline bool HWPoisonHandlable(struct page *page)
+static inline bool HWPoisonHandlable(struct page *page, unsigned long flags)
{
- return PageLRU(page) || __PageMovable(page) || is_free_buddy_page(page);
+ /* Soft offline could migrate non-LRU movable pages. */
+ if ((flags & MF_SOFT_OFFLINE) && __PageMovable(page))
+ return true;
+
+ return PageLRU(page) || is_free_buddy_page(page);
}
-static int __get_hwpoison_page(struct page *page)
+static int __get_hwpoison_page(struct page *page, unsigned long flags)
{
struct page *head = compound_head(page);
int ret = 0;
@@ -1196,7 +1200,7 @@ static int __get_hwpoison_page(struct page *page)
* for any unsupported type of page in order to reduce the risk of
* unexpected races caused by taking a page refcount.
*/
- if (!HWPoisonHandlable(head))
+ if (!HWPoisonHandlable(head, flags))
return -EBUSY;
if (get_page_unless_zero(head)) {
@@ -1221,7 +1225,7 @@ static int get_any_page(struct page *p, unsigned long flags)
try_again:
if (!count_increased) {
- ret = __get_hwpoison_page(p);
+ ret = __get_hwpoison_page(p, flags);
if (!ret) {
if (page_count(p)) {
/* We raced with an allocation, retry. */
@@ -1249,7 +1253,7 @@ static int get_any_page(struct page *p, unsigned long flags)
}
}
- if (PageHuge(p) || HWPoisonHandlable(p)) {
+ if (PageHuge(p) || HWPoisonHandlable(p, flags)) {
ret = 1;
} else {
/*
@@ -2296,7 +2300,7 @@ int soft_offline_page(unsigned long pfn, int flags)
retry:
get_online_mems();
- ret = get_hwpoison_page(page, flags);
+ ret = get_hwpoison_page(page, flags | MF_SOFT_OFFLINE);
put_online_mems();
if (ret > 0) {
--
2.23.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v4 1/2] mm/memory-failure.c: avoid calling invalidate_inode_page() with unexpected pages
2022-03-19 16:20 ` Matthew Wilcox
@ 2022-03-21 2:18 ` Miaohe Lin
0 siblings, 0 replies; 5+ messages in thread
From: Miaohe Lin @ 2022-03-21 2:18 UTC (permalink / raw)
To: Matthew Wilcox
Cc: akpm, naoya.horiguchi, shy828301, mike.kravetz, david, linux-mm,
linux-kernel
On 2022/3/20 0:20, Matthew Wilcox wrote:
> On Sun, Mar 20, 2022 at 01:13:33PM +0800, Miaohe Lin wrote:
>> invalidate_inode_page() can invalidate the pages in the swap cache because
>> the check of page->mapping != mapping is removed via Matthew's patch titled
>> "mm/truncate: Inline invalidate_complete_page() into its one caller". But
>> invalidate_inode_page() is not expected to deal with the pages in the swap
>> cache. Also non-lru movable page can reach here too. They're not page cache
>> pages. Skip these pages by checking PageSwapCache and PageLRU to fix this
>> unexpected issue.
>
> I disagree with this changelog.
>
> invalidate_inode_page() should not be called for pages which are not
> in the page cache.
>
> And then the patch shouldn't test PageLRU (which is actually wrong) or
> PageSwapCache(). It should simply be:
> > + if (!PageHuge(page) && !PageAnon(page))
If we reach here, the page can be one of the PageHuge, __PageMovable and PageLRU.
If above code is used, __PageMovable can pass the check and enter the invalidate_inode_page
unexpectedly. So I think PageLRU check is necessary here. But it seems PageSwapCache
is only reliable when PageAnon, so might we should do:
+ if (!PageHuge(page) && PageLRU(page) && !PageAnon(page))
Am I miss something? Many thanks for comment.
>
>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
>> ---
>> mm/memory-failure.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
>> index 5444a8ef4867..ecf45961f3b6 100644
>> --- a/mm/memory-failure.c
>> +++ b/mm/memory-failure.c
>> @@ -2178,7 +2178,7 @@ static int __soft_offline_page(struct page *page)
>> return 0;
>> }
>>
>> - if (!PageHuge(page))
>> + if (!PageHuge(page) && PageLRU(page) && !PageSwapCache(page))
>> /*
>> * Try to invalidate first. This should work for
>> * non dirty unmapped page cache pages.
>> --
>> 2.23.0
>>
>>
>
> .
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-03-21 2:18 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2022-03-20 5:13 [PATCH v4 0/2] A few fixup patches for memory failure Miaohe Lin
2022-03-20 5:13 ` [PATCH v4 1/2] mm/memory-failure.c: avoid calling invalidate_inode_page() with unexpected pages Miaohe Lin
2022-03-19 16:20 ` Matthew Wilcox
2022-03-21 2:18 ` Miaohe Lin
2022-03-20 5:13 ` [PATCH v4 2/2] mm/memory-failure.c: make non-LRU movable pages unhandlable Miaohe Lin
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