From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Daeho Jeong <daehojeong@google.com>,
	Sunmin Jeong <s_min.jeong@samsung.com>,
	Chao Yu <chao@kernel.org>,
	Jaegeuk Kim <jaegeuk@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.6.y 4/4] f2fs: fix to migrate all curseg types during free_segment_range
Date: Fri, 11 Sep 2026 18:00:25 -0400
Message-ID: <20260911220025.1624949-4-sashal@kernel.org>
In-Reply-To: <20260911220025.1624949-1-sashal@kernel.org>
References: <2026090946-clumsily-stuck-0ea2@gregkh>
 <20260911220025.1624949-1-sashal@kernel.org>
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From: Daeho Jeong <daehojeong@google.com>

[ Upstream commit 8ec06f50ddd8d201bd7e55b896ae28ed9d4cb7d1 ]

In free_segment_range(), the curseg evacuation loop only iterates up to
NR_CURSEG_PERSIST_TYPE (0..5), missing non-persistent in-memory curseg
types such as CURSEG_COLD_DATA_PINNED and CURSEG_ALL_DATA_ATGC.

Even though these in-memory curseg types are not saved in the on-disk
checkpoint header, they still occupy active physical segments at runtime.
If an active in-memory curseg happens to be allocated within the segment
range being truncated during filesystem shrink, failing to evacuate it
will cause subsequent writes to the curseg attempting out-of-bounds I/O
on the truncated storage range.

Fix this by expanding the curseg evacuation loop upper bound to
NR_CURSEG_TYPE to ensure all active curseg types are safely migrated
out of the target range.

Fixes: d0b9e42ab615 ("f2fs: introduce inmem curseg")
Cc: stable@vger.kernel.org
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Sunmin Jeong <s_min.jeong@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/f2fs/gc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 115b6d6c6bc7a..edeb111c47569 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -2103,7 +2103,7 @@ static int free_segment_range(struct f2fs_sb_info *sbi,
 	mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
 
 	/* Move out cursegs from the target range */
-	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++) {
+	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_TYPE; type++) {
 		err = f2fs_allocate_segment_for_resize(sbi, type, start, end);
 		if (err)
 			goto out;
-- 
2.53.0