From 8c963d1738fdca400082ff5f9d99e083de4f4e70 Mon Sep 17 00:00:00 2001 From: Daeho Jeong Date: Mon, 24 Aug 2026 18:53:03 -0700 Subject: [PATCH] f2fs: accurately adjust free_sections during free_segment_range In free_segment_range(), MAIN_SECS(sbi) is temporarily reduced by `secs` to restrict block allocation to the safe remaining main area while valid blocks in the truncated range are evacuated by GC. However, FREE_I(sbi)->free_sections tracks the total number of free sections across the whole filesystem. If any sections within the truncated range were already free upon entering free_segment_range(), failing to deduct them from free_sections causes the filesystem to overestimate available free sections in the active, reduced main area. This leads to inconsistent free section accounting during GC data migration and can trigger unexpected allocation failures or assertion errors when space is tight. Fix this by calculating the number of already-free sections in the truncated range, deducting them from free_sections upon entering free_segment_range(), and restoring them on exit. Fixes: b4b10061ef98 ("f2fs: refactor resize_fs to avoid meta updates in progress") Cc: stable@vger.kernel.org Signed-off-by: Daeho Jeong Signed-off-by: Sunmin Jeong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/gc.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 0c17038fcfd7..0a00180c21dc 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -2231,17 +2231,27 @@ void f2fs_reset_gc_victim_resource(struct f2fs_sb_info *sbi, static int free_segment_range(struct f2fs_sb_info *sbi, unsigned int secs, bool dry_run) { - unsigned int next_inuse, start, end; + unsigned int secno, next_inuse, start, end, end_secno; struct cp_control cpc = { CP_RESIZE, 0, 0, 0 }; + unsigned int freed_secs = 0; int err = 0; int type; MAIN_SECS(sbi) -= secs; start = MAIN_SECS(sbi) * SEGS_PER_SEC(sbi); end = MAIN_SEGS(sbi) - 1; + end_secno = GET_SEC_FROM_SEG(sbi, end); f2fs_reset_gc_victim_resource(sbi, start, end); + spin_lock(&FREE_I(sbi)->segmap_lock); + for (secno = MAIN_SECS(sbi); secno <= end_secno; secno++) { + if (!test_bit(secno, FREE_I(sbi)->free_secmap)) + freed_secs++; + } + FREE_I(sbi)->free_sections -= freed_secs; + spin_unlock(&FREE_I(sbi)->segmap_lock); + /* Move out cursegs from the target range */ for (type = CURSEG_HOT_DATA; type < NR_CURSEG_TYPE; type++) { err = f2fs_allocate_segment_for_resize(sbi, type, start, end); @@ -2266,6 +2276,9 @@ static int free_segment_range(struct f2fs_sb_info *sbi, f2fs_bug_on(sbi, 1); } out: + spin_lock(&FREE_I(sbi)->segmap_lock); + FREE_I(sbi)->free_sections += freed_secs; + spin_unlock(&FREE_I(sbi)->segmap_lock); MAIN_SECS(sbi) += secs; return err; }