+ mm-shmem-fix-shmem-folio-swapoff-hang.patch added to mm-stable branch

+ mm-shmem-fix-shmem-folio-swapoff-hang.patch added to mm-stable branch

[Andrew Morton]

The patch titled
     Subject: mm/shmem: fix shmem folio swapoff hang
has been added to the -mm mm-stable branch.  Its filename is
     mm-shmem-fix-shmem-folio-swapoff-hang.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-shmem-folio-swapoff-hang.patch

This patch will later appear in the mm-stable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Hugh Dickins <hughd@google.com>
Subject: mm/shmem: fix shmem folio swapoff hang
Date: Sat, 21 May 2022 19:53:04 -0700 (PDT)

Shmem swapoff makes no progress: the index to indices is not incremented. 
But "ret" is no longer a return value, so use folio_batch_count() instead.

Link: https://lkml.kernel.org/r/c32bee8a-f0aa-245-f94e-24dd271924fa@google.com
Fixes: da08e9b79323 ("mm/shmem: convert shmem_swapin_page() to shmem_swapin_folio()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/shmem.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/mm/shmem.c~mm-shmem-fix-shmem-folio-swapoff-hang
+++ a/mm/shmem.c
@@ -1165,7 +1165,6 @@ static int shmem_find_swap_entries(struc
 	XA_STATE(xas, &mapping->i_pages, start);
 	struct folio *folio;
 	swp_entry_t entry;
-	unsigned int ret = 0;
 
 	rcu_read_lock();
 	xas_for_each(&xas, folio, ULONG_MAX) {
@@ -1179,7 +1178,7 @@ static int shmem_find_swap_entries(struc
 		if (swp_type(entry) != type)
 			continue;
 
-		indices[ret] = xas.xa_index;
+		indices[folio_batch_count(fbatch)] = xas.xa_index;
 		if (!folio_batch_add(fbatch, folio))
 			break;
 
_

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

mm-shmem-fix-shmem-folio-swapoff-hang.patch