bfq: Remove pointless bfq_init_rq() calls

commit 5f550ede5edf846ecc0067be1ba80514e6fe7f8e upstream.

We call bfq_init_rq() from request merging functions where requests we
get should have already gone through bfq_init_rq() during insert and
anyway we want to do anything only if the request is already tracked by
BFQ. So replace calls to bfq_init_rq() with RQ_BFQQ() instead to simply
skip requests untracked by BFQ. We move bfq_init_rq() call in
bfq_insert_request() a bit earlier to cover request merging and thus
can transfer FIFO position in case of a merge.

CC: stable@vger.kernel.org
Tested-by: "yukuai (C)" <yukuai3@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220401102752.8599-6-jack@suse.cz
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 4ecfcb6..1d2eefd 100644 (file)
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -2375,8 +2375,6 @@ static int bfq_request_merge(struct request_queue *q, struct request **req,
        return ELEVATOR_NO_MERGE;
 }
 
-static struct bfq_queue *bfq_init_rq(struct request *rq);
-
 static void bfq_request_merged(struct request_queue *q, struct request *req,
                               enum elv_merge type)
 {
@@ -2385,7 +2383,7 @@ static void bfq_request_merged(struct request_queue *q, struct request *req,
            blk_rq_pos(req) <
            blk_rq_pos(container_of(rb_prev(&req->rb_node),
                                    struct request, rb_node))) {
-               struct bfq_queue *bfqq = bfq_init_rq(req);
+               struct bfq_queue *bfqq = RQ_BFQQ(req);
                struct bfq_data *bfqd;
                struct request *prev, *next_rq;
 
@@ -2437,8 +2435,8 @@ static void bfq_request_merged(struct request_queue *q, struct request *req,
 static void bfq_requests_merged(struct request_queue *q, struct request *rq,
                                struct request *next)
 {
-       struct bfq_queue *bfqq = bfq_init_rq(rq),
-               *next_bfqq = bfq_init_rq(next);
+       struct bfq_queue *bfqq = RQ_BFQQ(rq),
+               *next_bfqq = RQ_BFQQ(next);
 
        if (!bfqq)
                goto remove;
@@ -5991,6 +5989,8 @@ static inline void bfq_update_insert_stats(struct request_queue *q,
                                           unsigned int cmd_flags) {}
 #endif /* CONFIG_BFQ_CGROUP_DEBUG */
 
+static struct bfq_queue *bfq_init_rq(struct request *rq);
+
 static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
                               bool at_head)
 {
@@ -6006,6 +6006,7 @@ static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
                bfqg_stats_update_legacy_io(q, rq);
 #endif
        spin_lock_irq(&bfqd->lock);
+       bfqq = bfq_init_rq(rq);
        if (blk_mq_sched_try_insert_merge(q, rq, &free)) {
                spin_unlock_irq(&bfqd->lock);
                blk_mq_free_requests(&free);
@@ -6014,7 +6015,6 @@ static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
 
        trace_block_rq_insert(rq);
 
-       bfqq = bfq_init_rq(rq);
        if (!bfqq || at_head) {
                if (at_head)
                        list_add(&rq->queuelist, &bfqd->dispatch);