FAILED: patch "[PATCH] f2fs: fix to check continuousness in f2fs_sync_meta_pages() correctly" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] f2fs: fix to check continuousness in f2fs_sync_meta_pages() correctly" failed to apply to 6.6-stable tree

[Sasha Levin]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 1383cff4ccf3c8833c6255edffa29eb67c6419bb
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107053107-failed-6.6-1383cff4ccf3@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From 1383cff4ccf3c8833c6255edffa29eb67c6419bb Mon Sep 17 00:00:00 2001
From: Chao Yu <chao@kernel.org>
Date: Thu, 1 Oct 2026 00:06:16 +0000
Subject: [PATCH] f2fs: fix to check continuousness in f2fs_sync_meta_pages()
 correctly

In f2fs_sync_meta_pages(), whenever i becomes zero inside while loop,
below check may be skipped, it failed to check the continuousness:

	if (nr_to_write != LONG_MAX && i != 0 &&
		folio->index != prev +
		folio_nr_pages(fbatch.folios[i-1])) {

Cc: stable@kernel.org
Fixes: 580e7a492608 ("f2fs: convert f2fs_sync_meta_pages() to use filemap_get_folios_tag()")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/checkpoint.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 7b89bb838946d..2e5e0ee5feb20 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -606,7 +606,7 @@ void f2fs_write_meta_caches(struct f2fs_sb_info *sbi)
 long f2fs_sync_meta_caches(struct f2fs_sb_info *sbi, long nr_to_write,
 				bool sync, enum iostat_type io_type)
 {
-	pgoff_t index = 0, prev = ULONG_MAX;
+	pgoff_t index = 0, next = ULONG_MAX;
 	struct f2fs_cached_block *entries[F2FS_ONSTACK_CACHES];
 	long nwritten = 0;
 	int nr;
@@ -629,8 +629,8 @@ long f2fs_sync_meta_caches(struct f2fs_sb_info *sbi, long nr_to_write,
 				goto stop;
 			}
 
-			if (background && i != 0 &&
-					entry->index != prev + 1) {
+			if (background && next != ULONG_MAX &&
+					entry->index != next) {
 				f2fs_cache_gang_release(entries, nr);
 				goto stop;
 			}
@@ -657,7 +657,7 @@ long f2fs_sync_meta_caches(struct f2fs_sb_info *sbi, long nr_to_write,
 				break;
 			}
 			nwritten++;
-			prev = entry->index;
+			next = entry->index + 1;
 			if (unlikely(nwritten >= nr_to_write))
 				break;
 		}
-- 
2.53.0

[PATCH 6.6.y] f2fs: fix to check continuousness in f2fs_sync_meta_pages() correctly

[Sasha Levin]

From: Chao Yu <chao@kernel.org>

[ Upstream commit 1383cff4ccf3c8833c6255edffa29eb67c6419bb ]

In f2fs_sync_meta_pages(), whenever i becomes zero inside while loop,
below check may be skipped, it failed to check the continuousness:

	if (nr_to_write != LONG_MAX && i != 0 &&
		folio->index != prev +
		folio_nr_pages(fbatch.folios[i-1])) {

Cc: stable@kernel.org
Fixes: 580e7a492608 ("f2fs: convert f2fs_sync_meta_pages() to use filemap_get_folios_tag()")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
[ sashal: adapted cache-entry handling to folio batches using folio_nr_pages() for index increments ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/f2fs/checkpoint.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 74bdce66f866d..ff8d336c8bffd 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -406,7 +406,7 @@ long f2fs_sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type,
 				long nr_to_write, enum iostat_type io_type)
 {
 	struct address_space *mapping = META_MAPPING(sbi);
-	pgoff_t index = 0, prev = ULONG_MAX;
+	pgoff_t index = 0, next = ULONG_MAX;
 	struct folio_batch fbatch;
 	long nwritten = 0;
 	int nr_folios;
@@ -427,9 +427,8 @@ long f2fs_sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type,
 		for (i = 0; i < nr_folios; i++) {
 			struct folio *folio = fbatch.folios[i];
 
-			if (nr_to_write != LONG_MAX && i != 0 &&
-					folio->index != prev +
-					folio_nr_pages(fbatch.folios[i-1])) {
+			if (nr_to_write != LONG_MAX && next != ULONG_MAX &&
+					folio->index != next) {
 				folio_batch_release(&fbatch);
 				goto stop;
 			}
@@ -458,7 +457,7 @@ long f2fs_sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type,
 				break;
 			}
 			nwritten += folio_nr_pages(folio);
-			prev = folio->index;
+			next = folio->index + folio_nr_pages(folio);
 			if (unlikely(nwritten >= nr_to_write))
 				break;
 		}
-- 
2.53.0