[folded-merged] mm-hwposion-support-recovery-from-ksm_might_need_to_copy-v3.patch removed from -mm tree

[folded-merged] mm-hwposion-support-recovery-from-ksm_might_need_to_copy-v3.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm: hwposion: support recovery from ksm_might_need_to_copy()
has been removed from the -mm tree.  Its filename was
     mm-hwposion-support-recovery-from-ksm_might_need_to_copy-v3.patch

This patch was dropped because it was folded into mm-hwposion-support-recovery-from-ksm_might_need_to_copy.patch

------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: mm: hwposion: support recovery from ksm_might_need_to_copy()
Date: Tue, 13 Dec 2022 20:05:23 +0800

- enhance unuse_pte() if ksm_might_need_to_copy() return -EHWPOISON
- fix issue found by lkp 

Link: https://lkml.kernel.org/r/20221213120523.141588-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/mm/swapfile.c~mm-hwposion-support-recovery-from-ksm_might_need_to_copy-v3
+++ a/mm/swapfile.c
@@ -1764,12 +1764,15 @@ static int unuse_pte(struct vm_area_stru
 	struct page *swapcache;
 	spinlock_t *ptl;
 	pte_t *pte, new_pte;
+	bool hwposioned = false;
 	int ret = 1;
 
 	swapcache = page;
 	page = ksm_might_need_to_copy(page, vma, addr);
-	if (IS_ERR_OR_NULL(page))
+	if (unlikely(!page))
 		return -ENOMEM;
+	else if (unlikely(PTR_ERR(page) == -EHWPOISON))
+		hwposioned = true;
 
 	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
 	if (unlikely(!pte_same_as_swp(*pte, swp_entry_to_pte(entry)))) {
@@ -1777,15 +1780,19 @@ static int unuse_pte(struct vm_area_stru
 		goto out;
 	}
 
-	if (unlikely(!PageUptodate(page))) {
-		pte_t pteval;
+	if (hwposioned || !PageUptodate(page)) {
+		swp_entry_t swp_entry;
 
 		dec_mm_counter(vma->vm_mm, MM_SWAPENTS);
-		pteval = swp_entry_to_pte(make_swapin_error_entry());
-		set_pte_at(vma->vm_mm, addr, pte, pteval);
-		swap_free(entry);
+		if (hwposioned) {
+			swp_entry = make_hwpoison_entry(swapcache);
+			page = swapcache;
+		} else {
+			swp_entry = make_swapin_error_entry();
+		}
+		new_pte = swp_entry_to_pte(swp_entry);
 		ret = 0;
-		goto out;
+		goto setpte;
 	}
 
 	/* See do_swap_page() */
@@ -1817,6 +1824,7 @@ static int unuse_pte(struct vm_area_stru
 		new_pte = pte_mksoft_dirty(new_pte);
 	if (pte_swp_uffd_wp(*pte))
 		new_pte = pte_mkuffd_wp(new_pte);
+setpte:
 	set_pte_at(vma->vm_mm, addr, pte, new_pte);
 	swap_free(entry);
 out:
_

Patches currently in -mm which might be from wangkefeng.wang@huawei.com are

mm-hwposion-support-recovery-from-ksm_might_need_to_copy.patch
mm-hwposion-support-recovery-from-ksm_might_need_to_copy-v4.patch