Re: [f2fs-dev] [PATCH v2] f2fs: fix to skip empty sections in f2fs_get_victim

[Chao Yu]

On 2026/3/17 02:59, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@xxxxxxxxxx>
>
> 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 <daehojeong@xxxxxxxxxx>

Reviewed-by: Chao Yu <chao@xxxxxxxxxx>

Thanks,