Commit 2874d1a6 authored by Alexander Aring's avatar Alexander Aring Committed by David Teigland
Browse files

fs: dlm: add functionality to re-transmit a message 



This patch introduces a retransmit functionality for a lowcomms message
handle. It's just allocates a new buffer and transmit it again, no
special handling about prioritize it because keeping bytestream in order.

To avoid another connection look some refactor was done to make a new
buffer allocation with a preexisting connection pointer.

Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent 8f2dc78d

fs/dlm/lowcomms.c

+66 −19
Original line number Diff line number Diff line
@@ -126,6 +126,8 @@ struct writequeue_entry { 


struct dlm_msg {

	struct writequeue_entry *entry;

	struct dlm_msg *orig_msg;

	bool retransmit;

	void *ppc;

	int len;

	int idx; /* new()/commit() idx exchange */
@@ -1055,6 +1057,10 @@ static void free_entry(struct writequeue_entry *e) 
	struct dlm_msg *msg, *tmp;



	list_for_each_entry_safe(msg, tmp, &e->msgs, list) {

		if (msg->orig_msg) {

			msg->orig_msg->retransmit = false;

			kref_put(&msg->orig_msg->ref, dlm_msg_release);

		}

		list_del(&msg->list);

		kref_put(&msg->ref, dlm_msg_release);

	}
@@ -1494,11 +1500,37 @@ static struct writequeue_entry *new_wq_entry(struct connection *con, int len, 
	return e;

};



static struct dlm_msg *dlm_lowcomms_new_msg_con(struct connection *con, int len,

						gfp_t allocation, char **ppc,

						void (*cb)(struct dlm_mhandle *mh),

						struct dlm_mhandle *mh)

{

	struct writequeue_entry *e;

	struct dlm_msg *msg;



	msg = kzalloc(sizeof(*msg), allocation);

	if (!msg)

		return NULL;



	kref_init(&msg->ref);



	e = new_wq_entry(con, len, allocation, ppc, cb, mh);

	if (!e) {

		kfree(msg);

		return NULL;

	}



	msg->ppc = *ppc;

	msg->len = len;

	msg->entry = e;



	return msg;

}



struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation,

				     char **ppc, void (*cb)(struct dlm_mhandle *mh),

				     struct dlm_mhandle *mh)

{

	struct writequeue_entry *e;

	struct connection *con;

	struct dlm_msg *msg;

	int idx;
@@ -1518,32 +1550,18 @@ struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation, 
		return NULL;

	}



	msg = kzalloc(sizeof(*msg), allocation);

	msg = dlm_lowcomms_new_msg_con(con, len, allocation, ppc, cb, mh);

	if (!msg) {

		srcu_read_unlock(&connections_srcu, idx);

		return NULL;

	}



	kref_init(&msg->ref);



	e = new_wq_entry(con, len, allocation, ppc, cb, mh);

	if (!e) {

		srcu_read_unlock(&connections_srcu, idx);

		kfree(msg);

		return NULL;

	}



	msg->ppc = *ppc;

	msg->len = len;

	msg->entry = e;



	/* we assume if successful commit must called */

	msg->idx = idx;



	return msg;

}



void dlm_lowcomms_commit_msg(struct dlm_msg *msg)

static void _dlm_lowcomms_commit_msg(struct dlm_msg *msg)

{

	struct writequeue_entry *e = msg->entry;

	struct connection *con = e->con;
@@ -1561,20 +1579,49 @@ void dlm_lowcomms_commit_msg(struct dlm_msg *msg) 
	spin_unlock(&con->writequeue_lock);



	queue_work(send_workqueue, &con->swork);

	srcu_read_unlock(&connections_srcu, msg->idx);

	return;



out:

	spin_unlock(&con->writequeue_lock);

	srcu_read_unlock(&connections_srcu, msg->idx);

	return;

}



void dlm_lowcomms_commit_msg(struct dlm_msg *msg)

{

	_dlm_lowcomms_commit_msg(msg);

	srcu_read_unlock(&connections_srcu, msg->idx);

}



void dlm_lowcomms_put_msg(struct dlm_msg *msg)

{

	kref_put(&msg->ref, dlm_msg_release);

}



/* does not held connections_srcu, usage workqueue only */

int dlm_lowcomms_resend_msg(struct dlm_msg *msg)

{

	struct dlm_msg *msg_resend;

	char *ppc;



	if (msg->retransmit)

		return 1;



	msg_resend = dlm_lowcomms_new_msg_con(msg->entry->con, msg->len,

					      GFP_ATOMIC, &ppc, NULL, NULL);

	if (!msg_resend)

		return -ENOMEM;



	msg->retransmit = true;

	kref_get(&msg->ref);

	msg_resend->orig_msg = msg;



	memcpy(ppc, msg->ppc, msg->len);

	_dlm_lowcomms_commit_msg(msg_resend);

	dlm_lowcomms_put_msg(msg_resend);



	return 0;

}



/* Send a message */

static void send_to_sock(struct connection *con)

{

fs/dlm/lowcomms.h

+1 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation, 
				     struct dlm_mhandle *mh);

void dlm_lowcomms_commit_msg(struct dlm_msg *msg);

void dlm_lowcomms_put_msg(struct dlm_msg *msg);

int dlm_lowcomms_resend_msg(struct dlm_msg *msg);

int dlm_lowcomms_connect_node(int nodeid);

int dlm_lowcomms_nodes_set_mark(int nodeid, unsigned int mark);

int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len);