From 32c0869370194ae5ac9f9f501953ef693040f6a1 Mon Sep 17 00:00:00 2001 From: Kemeng Shi Date: Sat, 4 Mar 2023 01:21:13 +0800 Subject: [PATCH] ext4: remove ac->ac_found > sbi->s_mb_min_to_scan dead check in ext4_mb_check_limits Only call trace of ext4_mb_check_limits is as following: ext4_mb_complex_scan_group ext4_mb_measure_extent ext4_mb_check_limits(ac, e4b, 0); ext4_mb_check_limits(ac, e4b, 1); If the first ac->ac_found > sbi->s_mb_max_to_scan check in ext4_mb_check_limits is met, we will set ac_status to AC_STATUS_BREAK and call ext4_mb_try_best_found to try to use ac->ac_b_ex. If ext4_mb_try_best_found successes, then block allocation finishs, the removed ac->ac_found > sbi->s_mb_min_to_scan check is not reachable. If ext4_mb_try_best_found fails, then we set EXT4_MB_HINT_FIRST and reset ac->ac_b_ex to retry block allocation. We will use any found free extent in ext4_mb_measure_extent before reach the removed ac->ac_found > sbi->s_mb_min_to_scan check. In summary, the removed ac->ac_found > sbi->s_mb_min_to_scan check is not reachable and we can remove that dead check. Signed-off-by: Kemeng Shi Reviewed-by: Ojaswin Mujoo Link: https://lore.kernel.org/r/20230303172120.3800725-14-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o --- fs/ext4/mballoc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 591bd8e5e5c7..eeafa1bba824 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2039,8 +2039,7 @@ static void ext4_mb_check_limits(struct ext4_allocation_context *ac, if (bex->fe_len < gex->fe_len) return; - if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan) - && bex->fe_group == e4b->bd_group) { + if (finish_group && bex->fe_group == e4b->bd_group) { /* recheck chunk's availability - we don't know * when it was found (within this lock-unlock * period or not) */ -- 2.42.0