The patch titled
Subject: mm: shmem: fix the update of 'shmem_falloc->nr_unswapped'
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-shmem-fix-the-update-of-shmem_falloc-nr_unswapped.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-shmem-fix-the-update-of-shmem_falloc-nr_unswapped.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Subject: mm: shmem: fix the update of 'shmem_falloc->nr_unswapped'
Date: Thu, 19 Dec 2024 15:30:09 +0800
The 'shmem_falloc->nr_unswapped' is used to record how many writepage
refused to swap out because fallocate() is allocating, but after shmem
supports large folio swap out, the update of 'shmem_falloc->nr_unswapped'
does not use the correct number of pages in the large folio, which may
lead to fallocate() not exiting as soon as possible.
Anyway, this is found through code inspection, and I am not sure whether
it would actually cause serious issues.
Link: https://lkml.kernel.org/r/f66a0119d0564c2c37c84f045835b870d1b2196f.1734593154.git.baolin.wang@xxxxxxxxxxxxxxxxx
Fixes: 809bc86517cc ("mm: shmem: support large folio swap out")
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/shmem.c~mm-shmem-fix-the-update-of-shmem_falloc-nr_unswapped
+++ a/mm/shmem.c
@@ -1535,7 +1535,7 @@ try_split:
!shmem_falloc->waitq &&
index >= shmem_falloc->start &&
index < shmem_falloc->next)
- shmem_falloc->nr_unswapped++;
+ shmem_falloc->nr_unswapped += nr_pages;
else
shmem_falloc = NULL;
spin_unlock(&inode->i_lock);
_
Patches currently in -mm which might be from baolin.wang@xxxxxxxxxxxxxxxxx are
docs-mm-fix-the-incorrect-filehugemapped-field.patch
mm-shmem-fix-incorrect-index-alignment-for-within_size-policy.patch
mm-shmem-fix-the-update-of-shmem_falloc-nr_unswapped.patch
mm-factor-out-the-order-calculation-into-a-new-helper.patch
mm-shmem-change-shmem_huge_global_enabled-to-return-huge-order-bitmap.patch
mm-shmem-add-large-folio-support-for-tmpfs.patch
mm-shmem-add-a-kernel-command-line-to-change-the-default-huge-policy-for-tmpfs.patch
docs-tmpfs-drop-fadvise-from-the-documentation.patch
