linux-kernel - [PATCH] f2fs: fix to not account invalid blocks in get_left_section

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Message-ID: <20251128092507.1607278-1-chao@kernel.org>
Date: Fri, 28 Nov 2025 17:25:07 +0800
From: Chao Yu <chao@...nel.org>
To: jaegeuk@...nel.org
Cc: linux-f2fs-devel@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org,
	Chao Yu <chao@...nel.org>,
	stable@...nel.org
Subject: [PATCH] f2fs: fix to not account invalid blocks in get_left_section_blocks()

w/ LFS mode, in get_left_section_blocks(), we should not account the
blocks which were used before and now are invalided, otherwise those
blocks will be counted as freed one in has_curseg_enough_space(), result
in missing to trigger GC in time.

Cc: stable@...nel.org
Fixes: 249ad438e1d9 ("f2fs: add a method for calculating the remaining blocks in the current segment in LFS mode.")
Fixes: bf34c93d2645 ("f2fs: check curseg space before foreground GC")
Signed-off-by: Chao Yu <chao@...nel.org>
---
 fs/f2fs/segment.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 51eecb861a78..b08f18274440 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -612,10 +612,12 @@ static inline int reserved_sections(struct f2fs_sb_info *sbi)
 static inline unsigned int get_left_section_blocks(struct f2fs_sb_info *sbi,
 					enum log_type type, unsigned int segno)
 {
-	if (f2fs_lfs_mode(sbi) && __is_large_section(sbi))
-		return CAP_BLKS_PER_SEC(sbi) - SEGS_TO_BLKS(sbi,
-			(segno - GET_START_SEG_FROM_SEC(sbi, segno))) -
+	if (f2fs_lfs_mode(sbi)) {
+		unsigned int used_blocks = __is_large_section(sbi) ? SEGS_TO_BLKS(sbi,
+				(segno - GET_START_SEG_FROM_SEC(sbi, segno))) : 0;
+		return CAP_BLKS_PER_SEC(sbi) - used_blocks -
 			CURSEG_I(sbi, type)->next_blkoff;
+	}
 	return CAP_BLKS_PER_SEC(sbi) - get_ckpt_valid_blocks(sbi, segno, true);
 }
 
-- 
2.49.0