[PATCH 15/21] ext4: use best found when complex scan of group finishs

From: Kemeng Shi
Date: Thu Feb 09 2023 - 06:58:03 EST


If any bex which meets bex->fe_len >= gex->fe_len is found, then it will
always be used when complex scan of group that bex belongs to finishs.
So there will not be any lock-unlock period.

Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
---
fs/ext4/mballoc.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index e53f84de5018..c684758d6dbb 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2019,8 +2019,6 @@ static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
struct ext4_free_extent *bex = &ac->ac_b_ex;
struct ext4_free_extent *gex = &ac->ac_g_ex;
- struct ext4_free_extent ex;
- int max;

if (ac->ac_status == AC_STATUS_FOUND)
return;
@@ -2039,16 +2037,8 @@ static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
if (bex->fe_len < gex->fe_len)
return;

- 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) */
- max = mb_find_extent(e4b, bex->fe_start, gex->fe_len, &ex);
- if (max >= gex->fe_len) {
- ext4_mb_use_best_found(ac, e4b);
- return;
- }
- }
+ if (finish_group)
+ ext4_mb_use_best_found(ac, e4b);
}

/*
--
2.30.0