Commit 89b021a7 authored by Stefan Metzmacher's avatar Stefan Metzmacher Committed by Steve French
Browse files

smb: server: manage recv credits by counting posted recv_io and granted credits 



(At least for me) the logic maintaining the count of posted
recv_io messages and the count of granted credits is much
easier to understand.

From there we can easily calculate the number of new_credits we'll
grant to the peer in outgoing send_io messages.

This will simplify the move to common logic that can be
shared between client and server in the following patches.

Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: default avatarStefan Metzmacher <metze@samba.org>
Acked-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 113ed9d5

fs/smb/server/transport_rdma.c

+21 −32
Original line number Diff line number Diff line
@@ -92,13 +92,10 @@ struct smb_direct_transport { 


	struct smbdirect_socket socket;



	spinlock_t		receive_credit_lock;

	int			recv_credits;

	atomic_t		recv_credits;

	u16			recv_credit_target;



	spinlock_t		lock_new_recv_credits;

	int			new_recv_credits;



	atomic_t		recv_posted;

	struct work_struct	post_recv_credits_work;

	struct work_struct	send_immediate_work;
@@ -309,9 +306,8 @@ static struct smb_direct_transport *alloc_transport(struct rdma_cm_id *cm_id) 


	sc->ib.dev = sc->rdma.cm_id->device;



	spin_lock_init(&t->receive_credit_lock);



	spin_lock_init(&t->lock_new_recv_credits);

	atomic_set(&t->recv_posted, 0);

	atomic_set(&t->recv_credits, 0);



	INIT_WORK(&t->post_recv_credits_work,

		  smb_direct_post_recv_credits);
@@ -552,9 +548,8 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc) 
				sc->recv_io.reassembly.full_packet_received = true;

		}



		spin_lock(&t->receive_credit_lock);

		t->recv_credits -= 1;

		spin_unlock(&t->receive_credit_lock);

		atomic_dec(&t->recv_posted);

		atomic_dec(&t->recv_credits);



		old_recv_credit_target = t->recv_credit_target;

		t->recv_credit_target =
@@ -758,14 +753,10 @@ static void smb_direct_post_recv_credits(struct work_struct *work) 
	struct smb_direct_transport *t = container_of(work,

		struct smb_direct_transport, post_recv_credits_work);

	struct smbdirect_recv_io *recvmsg;

	int receive_credits, credits = 0;

	int credits = 0;

	int ret;



	spin_lock(&t->receive_credit_lock);

	receive_credits = t->recv_credits;

	spin_unlock(&t->receive_credit_lock);



	if (receive_credits < t->recv_credit_target) {

	if (atomic_read(&t->recv_credits) < t->recv_credit_target) {

		while (true) {

			recvmsg = get_free_recvmsg(t);

			if (!recvmsg)
@@ -780,17 +771,11 @@ static void smb_direct_post_recv_credits(struct work_struct *work) 
				break;

			}

			credits++;



			atomic_inc(&t->recv_posted);

		}

	}



	spin_lock(&t->receive_credit_lock);

	t->recv_credits += credits;

	spin_unlock(&t->receive_credit_lock);



	spin_lock(&t->lock_new_recv_credits);

	t->new_recv_credits += credits;

	spin_unlock(&t->lock_new_recv_credits);



	if (credits)

		queue_work(smb_direct_wq, &t->send_immediate_work);

}
@@ -837,11 +822,18 @@ static int manage_credits_prior_sending(struct smb_direct_transport *t) 
{

	int new_credits;



	spin_lock(&t->lock_new_recv_credits);

	new_credits = t->new_recv_credits;

	t->new_recv_credits = 0;

	spin_unlock(&t->lock_new_recv_credits);

	if (atomic_read(&t->recv_credits) >= t->recv_credit_target)

		return 0;



	new_credits = atomic_read(&t->recv_posted);

	if (new_credits == 0)

		return 0;



	new_credits -= atomic_read(&t->recv_credits);

	if (new_credits <= 0)

		return 0;



	atomic_add(new_credits, &t->recv_credits);

	return new_credits;

}
@@ -1824,11 +1816,8 @@ static int smb_direct_init_params(struct smb_direct_transport *t, 
		return -EINVAL;

	}



	t->recv_credits = 0;



	sp->recv_credit_max = smb_direct_receive_credit_max;

	t->recv_credit_target = 1;

	t->new_recv_credits = 0;



	sp->send_credit_target = smb_direct_send_credit_target;

	atomic_set(&sc->rw_io.credits.count, sc->rw_io.credits.max);