block, bfq: save also injection state on queue merging

To prevent injection information from being lost on bfq_queue merging,
also the amount of service that a bfq_queue receives must be saved and
restored when the bfq_queue is merged and split, respectively.
Tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/bfq-iosched.c

@@ -1024,6 +1024,10 @@ bfq_bfqq_resume_state(struct bfq_queue *bfqq, struct bfq_data *bfqd,
 	else
 		bfq_clear_bfqq_IO_bound(bfqq);
 
+	bfqq->last_serv_time_ns = bic->saved_last_serv_time_ns;
+	bfqq->inject_limit = bic->saved_inject_limit;
+	bfqq->decrease_time_jif = bic->saved_decrease_time_jif;
+
 	bfqq->entity.new_weight = bic->saved_weight;
 	bfqq->ttime = bic->saved_ttime;
 	bfqq->io_start_time = bic->saved_io_start_time;
@@ -2748,6 +2752,10 @@ static void bfq_bfqq_save_state(struct bfq_queue *bfqq)
 	if (!bic)
 		return;
 
+	bic->saved_last_serv_time_ns = bfqq->last_serv_time_ns;
+	bic->saved_inject_limit = bfqq->inject_limit;
+	bic->saved_decrease_time_jif = bfqq->decrease_time_jif;
+
 	bic->saved_weight = bfqq->entity.orig_weight;
 	bic->saved_ttime = bfqq->ttime;
 	bic->saved_has_short_ttime = bfq_bfqq_has_short_ttime(bfqq);

block/bfq-iosched.h

@@ -444,6 +444,11 @@ struct bfq_io_cq {
 	unsigned long saved_wr_start_at_switch_to_srt;
 	unsigned int saved_wr_cur_max_time;
 	struct bfq_ttime saved_ttime;
+
+	/* Save also injection state */
+	u64 saved_last_serv_time_ns;
+	unsigned int saved_inject_limit;
+	unsigned long saved_decrease_time_jif;
 };
 
 /**