md/raid5: let stripe batch bm_seq comparison wrap-safe

Once the 32-bit seq wraps, a newer bm_seq can look smaller
than old, so .. covert to wrap-safe calculate way.

Signed-off-by: Chen Cheng <chencheng@fnnas.com>
Link: https://patch.msgid.link/20260618025735.915113-1-chencheng@fnnas.com
Signed-off-by: Yu Kuai <yukuai@fygo.io>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 180ff06..f35c2a7 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -996,7 +996,7 @@ static void stripe_add_to_batch_list(struct r5conf *conf,
        if (test_and_clear_bit(STRIPE_BIT_DELAY, &sh->state)) {
                int seq = sh->bm_seq;
                if (test_bit(STRIPE_BIT_DELAY, &sh->batch_head->state) &&
-                   sh->batch_head->bm_seq > seq)
+                   sh->batch_head->bm_seq - seq > 0)
                        seq = sh->batch_head->bm_seq;
                set_bit(STRIPE_BIT_DELAY, &sh->batch_head->state);
                sh->batch_head->bm_seq = seq;