The patch titled
Subject: zsmalloc: fix races between modifications of fullness and isolated
has been added to the -mm mm-unstable branch. Its filename is
zsmalloc-fix-races-between-modifications-of-fullness-and-isolated.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zsmalloc-fix-races-between-modifications-of-fullness-and-isolated.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Andrew Yang <andrew.yang@xxxxxxxxxxxx>
Subject: zsmalloc: fix races between modifications of fullness and isolated
Date: Fri, 21 Jul 2023 14:37:01 +0800
Since fullness and isolated share the same unsigned int, modifications of
them should be protected by the same lock.
Link: https://lkml.kernel.org/r/20230721063705.11455-1-andrew.yang@xxxxxxxxxxxx
Fixes: c4549b871102 ("zsmalloc: remove zspage isolation for migration")
Signed-off-by: Andrew Yang <andrew.yang@xxxxxxxxxxxx>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/zsmalloc.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
--- a/mm/zsmalloc.c~zsmalloc-fix-races-between-modifications-of-fullness-and-isolated
+++ a/mm/zsmalloc.c
@@ -1777,6 +1777,7 @@ static void replace_sub_page(struct size
static bool zs_page_isolate(struct page *page, isolate_mode_t mode)
{
+ struct zs_pool *pool;
struct zspage *zspage;
/*
@@ -1786,9 +1787,10 @@ static bool zs_page_isolate(struct page
VM_BUG_ON_PAGE(PageIsolated(page), page);
zspage = get_zspage(page);
- migrate_write_lock(zspage);
+ pool = zspage->pool;
+ spin_lock(&pool->lock);
inc_zspage_isolation(zspage);
- migrate_write_unlock(zspage);
+ spin_unlock(&pool->lock);
return true;
}
@@ -1858,8 +1860,8 @@ static int zs_page_migrate(struct page *
* Since we complete the data copy and set up new zspage structure,
* it's okay to release the pool's lock.
*/
- spin_unlock(&pool->lock);
dec_zspage_isolation(zspage);
+ spin_unlock(&pool->lock);
migrate_write_unlock(zspage);
get_page(newpage);
@@ -1876,14 +1878,16 @@ static int zs_page_migrate(struct page *
static void zs_page_putback(struct page *page)
{
+ struct zs_pool *pool;
struct zspage *zspage;
VM_BUG_ON_PAGE(!PageIsolated(page), page);
zspage = get_zspage(page);
- migrate_write_lock(zspage);
+ pool = zspage->pool;
+ spin_lock(&pool->lock);
dec_zspage_isolation(zspage);
- migrate_write_unlock(zspage);
+ spin_unlock(&pool->lock);
}
static const struct movable_operations zsmalloc_mops = {
_
Patches currently in -mm which might be from andrew.yang@xxxxxxxxxxxx are
fs-drop_caches-draining-pages-before-dropping-caches.patch
zsmalloc-fix-races-between-modifications-of-fullness-and-isolated.patch
