From dccd324fa9bd1a2907a63fa4cc2651f687b2b5d0 Mon Sep 17 00:00:00 2001 From: Daeho Jeong Date: Mon, 16 Mar 2026 11:59:21 -0700 Subject: [PATCH] f2fs: fix to skip empty sections in f2fs_get_victim In age-based victim selection (ATGC, AT_SSR, or GC_CB), f2fs_get_victim can encounter sections with zero valid blocks. This situation often arises when checkpoint is disabled or due to race conditions between SIT updates and dirty list management. In such cases, f2fs_get_section_mtime() returns INVALID_MTIME, which subsequently triggers a fatal f2fs_bug_on(sbi, mtime == INVALID_MTIME) in add_victim_entry() or get_cb_cost(). This patch adds a check in f2fs_get_victim's selection loop to skip sections with no valid blocks. This prevents unnecessary age calculations for empty sections and avoids the associated kernel panic. This change also allows removing redundant checks in add_victim_entry(). Signed-off-by: Daeho Jeong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/gc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 80b8500fa987..4bfc4452f299 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -910,6 +910,9 @@ int f2fs_get_victim(struct f2fs_sb_info *sbi, unsigned int *result, if (!f2fs_segment_has_free_slot(sbi, segno)) goto next; } + + if (!get_valid_blocks(sbi, segno, true)) + goto next; } if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))