Commit 98e1b60e authored by Mike Christie's avatar Mike Christie Committed by David Teigland
Browse files

dlm: try other IPs when sctp init assoc fails 



Currently, if we cannot create a association to the first IP addr
that is added to DLM, the SCTP init assoc code will just retry
the same IP. This patch adds a simple failover schemes where we
will try one of the addresses that was passed into DLM.

Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent b390ca38

fs/dlm/lowcomms.c

+50 −11
Original line number Diff line number Diff line
@@ -126,6 +126,7 @@ struct connection { 
	struct connection *othercon;

	struct work_struct rwork; /* Receive workqueue */

	struct work_struct swork; /* Send workqueue */

	bool try_new_addr;

};

#define sock2con(x) ((struct connection *)(x)->sk_user_data)
@@ -144,6 +145,7 @@ struct dlm_node_addr { 
	struct list_head list;

	int nodeid;

	int addr_count;

	int curr_addr_index;

	struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];

};
@@ -310,7 +312,7 @@ static int addr_compare(struct sockaddr_storage *x, struct sockaddr_storage *y) 
}



static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out,

			  struct sockaddr *sa_out)

			  struct sockaddr *sa_out, bool try_new_addr)

{

	struct sockaddr_storage sas;

	struct dlm_node_addr *na;
@@ -320,8 +322,16 @@ static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out, 


	spin_lock(&dlm_node_addrs_spin);

	na = find_node_addr(nodeid);

	if (na && na->addr_count)

		memcpy(&sas, na->addr[0], sizeof(struct sockaddr_storage));

	if (na && na->addr_count) {

		if (try_new_addr) {

			na->curr_addr_index++;

			if (na->curr_addr_index == na->addr_count)

				na->curr_addr_index = 0;

		}



		memcpy(&sas, na->addr[na->curr_addr_index ],

			sizeof(struct sockaddr_storage));

	}

	spin_unlock(&dlm_node_addrs_spin);



	if (!na)
@@ -353,19 +363,22 @@ static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid) 
{

	struct dlm_node_addr *na;

	int rv = -EEXIST;

	int addr_i;



	spin_lock(&dlm_node_addrs_spin);

	list_for_each_entry(na, &dlm_node_addrs, list) {

		if (!na->addr_count)

			continue;



		if (!addr_compare(na->addr[0], addr))

			continue;



		for (addr_i = 0; addr_i < na->addr_count; addr_i++) {

			if (addr_compare(na->addr[addr_i], addr)) {

				*nodeid = na->nodeid;

				rv = 0;

		break;

				goto unlock;

			}

		}

	}

unlock:

	spin_unlock(&dlm_node_addrs_spin);

	return rv;

}
@@ -561,6 +574,21 @@ static void sctp_send_shutdown(sctp_assoc_t associd) 


static void sctp_init_failed_foreach(struct connection *con)

{



	/*

	 * Don't try to recover base con and handle race where the

	 * other node's assoc init creates a assoc and we get that

	 * notification, then we get a notification that our attempt

	 * failed due. This happens when we are still trying the primary

	 * address, but the other node has already tried secondary addrs

	 * and found one that worked.

	 */

	if (!con->nodeid || con->sctp_assoc)

		return;



	log_print("Retrying SCTP association init for node %d\n", con->nodeid);



	con->try_new_addr = true;

	con->sctp_assoc = 0;

	if (test_and_clear_bit(CF_INIT_PENDING, &con->flags)) {

		if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
@@ -663,6 +691,7 @@ static void process_sctp_notification(struct connection *con, 
				 nodeid, (int)sn->sn_assoc_change.sac_assoc_id);



			new_con->sctp_assoc = sn->sn_assoc_change.sac_assoc_id;

			new_con->try_new_addr = false;

			/* Send any pending writes */

			clear_bit(CF_CONNECT_PENDING, &new_con->flags);

			clear_bit(CF_INIT_PENDING, &new_con->flags);
@@ -984,7 +1013,8 @@ static void sctp_init_assoc(struct connection *con) 
	if (con->retries++ > MAX_CONNECT_RETRIES)

		return;



	if (nodeid_to_addr(con->nodeid, NULL, (struct sockaddr *)&rem_addr)) {

	if (nodeid_to_addr(con->nodeid, NULL, (struct sockaddr *)&rem_addr,

			   con->try_new_addr)) {

		log_print("no address for nodeid %d", con->nodeid);

		return;

	}
@@ -1016,6 +1046,14 @@ static void sctp_init_assoc(struct connection *con) 
	iov[0].iov_base = page_address(e->page)+offset;

	iov[0].iov_len = len;



	if (rem_addr.ss_family == AF_INET) {

		struct sockaddr_in *sin = (struct sockaddr_in *)&rem_addr;

		log_print("Trying to connect to %pI4", &sin->sin_addr.s_addr);

	} else {

		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&rem_addr;

		log_print("Trying to connect to %pI6", &sin6->sin6_addr);

	}



	cmsg = CMSG_FIRSTHDR(&outmessage);

	cmsg->cmsg_level = IPPROTO_SCTP;

	cmsg->cmsg_type = SCTP_SNDRCV;
@@ -1024,6 +1062,7 @@ static void sctp_init_assoc(struct connection *con) 
	memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));

	sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid());

	outmessage.msg_controllen = cmsg->cmsg_len;

	sinfo->sinfo_flags |= SCTP_ADDR_OVER;



	ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len);

	if (ret < 0) {
@@ -1076,7 +1115,7 @@ static void tcp_connect_to_sock(struct connection *con) 
		goto out_err;



	memset(&saddr, 0, sizeof(saddr));

	result = nodeid_to_addr(con->nodeid, &saddr, NULL);

	result = nodeid_to_addr(con->nodeid, &saddr, NULL, false);

	if (result < 0) {

		log_print("no address for nodeid %d", con->nodeid);

		goto out_err;

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