[merged mm-stable] mm-memory_failure-clarify-the-mf_delayed-definition.patch removed from -mm tree

[merged mm-stable] mm-memory_failure-clarify-the-mf_delayed-definition.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm: memory_failure: clarify the MF_DELAYED definition
has been removed from the -mm tree.  Its filename was
     mm-memory_failure-clarify-the-mf_delayed-definition.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Lisa Wang <wyihan@google.com>
Subject: mm: memory_failure: clarify the MF_DELAYED definition
Date: Thu, 17 Sep 2026 20:43:47 +0000

Patch series "mm: Fix MF_DELAYED handling on memory failure", v6.

This series addresses an issue in the memory failure handling path where
MF_DELAYED is incorrectly treated as an error.  This issue was discovered
while testing memory failure handling for guest_memfd.

The proposed solution involves -
1. Clarifying the definition of MF_DELAYED to mean that memory failure
   handling is only partially completed, and that the metadata for the
   memory that failed (as in struct page/folio) is still referenced.
2. Updating shmems handling to align with the clarified definition.
3. Updating how the result of .error_remove_folio() is interpreted.


This patch (of 5):

This patch clarifies the definition of MF_DELAYED to represent cases where
a folio's removal is initiated but not immediately completed (e.g., due to
remaining metadata references).

Link: https://lore.kernel.org/20260917-memory-failure-mf-delayed-fix-v6-0-4b00856b5364@google.com
Link: https://lore.kernel.org/20260917-memory-failure-mf-delayed-fix-v6-1-4b00856b5364@google.com
Signed-off-by: Lisa Wang <wyihan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Fuad Tabba <tabba@google.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Isaku Yamahata <isaku.yamahata@intel.com>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michael Roth <michael.roth@amd.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Annapurve <vannapurve@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: Yu Zhang <yu.c.zhang@linux.intel.com>
---

 mm/memory-failure.c |   15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

--- a/mm/memory-failure.c~mm-memory_failure-clarify-the-mf_delayed-definition
+++ a/mm/memory-failure.c
@@ -847,24 +847,25 @@ static int kill_accessing_process(struct
 }
 
 /*
- * MF_IGNORED - The m-f() handler marks the page as PG_hwpoisoned'ed.
+ * MF_IGNORED - The m-f() handler marks the page as PG_hwpoison'ed.
  * But it could not do more to isolate the page from being accessed again,
  * nor does it kill the process. This is extremely rare and one of the
  * potential causes is that the page state has been changed due to
  * underlying race condition. This is the most severe outcomes.
  *
- * MF_FAILED - The m-f() handler marks the page as PG_hwpoisoned'ed.
+ * MF_FAILED - The m-f() handler marks the page as PG_hwpoison'ed.
  * It should have killed the process, but it can't isolate the page,
  * due to conditions such as extra pin, unmap failure, etc. Accessing
  * the page again may trigger another MCE and the process will be killed
  * by the m-f() handler immediately.
  *
- * MF_DELAYED - The m-f() handler marks the page as PG_hwpoisoned'ed.
- * The page is unmapped, and is removed from the LRU or file mapping.
- * An attempt to access the page again will trigger page fault and the
- * PF handler will kill the process.
+ * MF_DELAYED - The m-f() handler marks the page as PG_hwpoison'ed.
+ * It means the page was unmapped and partially isolated (e.g. removed from
+ * file mapping or the LRU) but full cleanup is deferred (e.g. the metadata
+ * for the memory, as in struct page/folio, is still referenced). Any
+ * further access to the page will result in the process being killed.
  *
- * MF_RECOVERED - The m-f() handler marks the page as PG_hwpoisoned'ed.
+ * MF_RECOVERED - The m-f() handler marks the page as PG_hwpoison'ed.
  * The page has been completely isolated, that is, unmapped, taken out of
  * the buddy system, or hole-punched out of the file mapping.
  */
_

Patches currently in -mm which might be from wyihan@google.com are