[PATCH BUGFIX 3/3] block, bfq: remove the removal of 'next' rq in bfq_requests_merged

From: Paolo Valente
Date: Thu May 31 2018 - 09:24:07 EST


From: Filippo Muzzini <filippo.muzzini@xxxxxxxxxx>

Since bfq_finish_request() is always called on the request 'next',
after bfq_requests_merged() is finished, and bfq_finish_request()
removes 'next' from its bfq_queue if needed, it isn't necessary to do
such a removal in advance in bfq_merged_requests().

This commit removes such a useless 'next' removal.

Signed-off-by: Filippo Muzzini <filippo.muzzini@xxxxxxxxxx>
Signed-off-by: Paolo Valente <paolo.valente@xxxxxxxxxx>
---
block/bfq-iosched.c | 7 -------
1 file changed, 7 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index df2a9633cf4a..f71a5846b629 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -1897,8 +1897,6 @@ static void bfq_request_merged(struct request_queue *q, struct request *req,
* exploits this hook to address the following issue: if 'next' has a
* fifo_time lower that rq, then the fifo_time of rq must be set to
* the value of 'next', to not forget the greater age of 'next'.
- * Moreover 'next' may be in a bfq_queue, in this case it must be
- * removed.
*
* NOTE: in this function we assume that rq is in a bfq_queue, basing
* on that rq is picked from the hash table q->elevator->hash, which,
@@ -1932,11 +1930,6 @@ static void bfq_requests_merged(struct request_queue *q, struct request *rq,
if (bfqq->next_rq == next)
bfqq->next_rq = rq;

- if (!RB_EMPTY_NODE(&next->rb_node)) {
- bfq_remove_request(q, next);
- bfqg_stats_update_io_remove(bfqq_group(bfqq), next->cmd_flags);
- }
-
bfqg_stats_update_io_merged(bfqq_group(bfqq), next->cmd_flags);
}

--
2.16.1