Commit 121d947d authored by Samuel Cabrero's avatar Samuel Cabrero Committed by Steve French
Browse files

cifs: Handle witness client move notification 



This message is sent to tell a client to close its current connection
and connect to the specified address.

Signed-off-by: default avatarSamuel Cabrero <scabrero@suse.de>
Reviewed-by: default avatarAurelien Aptel <aaptel@suse.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent af1e40d9

fs/cifs/cifs_swn.c

+138 −2
Original line number Diff line number Diff line
@@ -78,6 +78,7 @@ static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg) 
	struct sk_buff *skb;

	struct genlmsghdr *hdr;

	enum securityEnum authtype;

	struct sockaddr_storage *addr;

	int ret;



	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
@@ -104,8 +105,18 @@ static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg) 
	if (ret < 0)

		goto nlmsg_fail;



	ret = nla_put(skb, CIFS_GENL_ATTR_SWN_IP, sizeof(struct sockaddr_storage),

			&swnreg->tcon->ses->server->dstaddr);

	/*

	 * If there is an address stored use it instead of the server address, because we are

	 * in the process of reconnecting to it after a share has been moved or we have been

	 * told to switch to it (client move message). In these cases we unregister from the

	 * server address and register to the new address when we receive the notification.

	 */

	if (swnreg->tcon->ses->server->use_swn_dstaddr)

		addr = &swnreg->tcon->ses->server->swn_dstaddr;

	else

		addr = &swnreg->tcon->ses->server->dstaddr;



	ret = nla_put(skb, CIFS_GENL_ATTR_SWN_IP, sizeof(struct sockaddr_storage), addr);

	if (ret < 0)

		goto nlmsg_fail;
@@ -413,6 +424,120 @@ static int cifs_swn_resource_state_changed(struct cifs_swn_reg *swnreg, const ch 
	return 0;

}



static bool cifs_sockaddr_equal(struct sockaddr_storage *addr1, struct sockaddr_storage *addr2)

{

	if (addr1->ss_family != addr2->ss_family)

		return false;



	if (addr1->ss_family == AF_INET) {

		return (memcmp(&((const struct sockaddr_in *)addr1)->sin_addr,

				&((const struct sockaddr_in *)addr2)->sin_addr,

				sizeof(struct in_addr)) == 0);

	}



	if (addr1->ss_family == AF_INET6) {

		return (memcmp(&((const struct sockaddr_in6 *)addr1)->sin6_addr,

				&((const struct sockaddr_in6 *)addr2)->sin6_addr,

				sizeof(struct in6_addr)) == 0);

	}



	return false;

}



static int cifs_swn_store_swn_addr(const struct sockaddr_storage *new,

				   const struct sockaddr_storage *old,

				   struct sockaddr_storage *dst)

{

	__be16 port;



	if (old->ss_family == AF_INET) {

		struct sockaddr_in *ipv4 = (struct sockaddr_in *)old;



		port = ipv4->sin_port;

	}



	if (old->ss_family == AF_INET6) {

		struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)old;



		port = ipv6->sin6_port;

	}



	if (new->ss_family == AF_INET) {

		struct sockaddr_in *ipv4 = (struct sockaddr_in *)new;



		ipv4->sin_port = port;

	}



	if (new->ss_family == AF_INET6) {

		struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)new;



		ipv6->sin6_port = port;

	}



	*dst = *new;



	return 0;

}



static int cifs_swn_reconnect(struct cifs_tcon *tcon, struct sockaddr_storage *addr)

{

	/* Store the reconnect address */

	mutex_lock(&tcon->ses->server->srv_mutex);

	if (!cifs_sockaddr_equal(&tcon->ses->server->dstaddr, addr)) {

		int ret;



		ret = cifs_swn_store_swn_addr(addr, &tcon->ses->server->dstaddr,

				&tcon->ses->server->swn_dstaddr);

		if (ret < 0) {

			cifs_dbg(VFS, "%s: failed to store address: %d\n", __func__, ret);

			return ret;

		}

		tcon->ses->server->use_swn_dstaddr = true;



		/*

		 * Unregister to stop receiving notifications for the old IP address.

		 */

		ret = cifs_swn_unregister(tcon);

		if (ret < 0) {

			cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",

					__func__, ret);

			return ret;

		}



		/*

		 * And register to receive notifications for the new IP address now that we have

		 * stored the new address.

		 */

		ret = cifs_swn_register(tcon);

		if (ret < 0) {

			cifs_dbg(VFS, "%s: Failed to register for witness notifications: %d\n",

					__func__, ret);

			return ret;

		}



		spin_lock(&GlobalMid_Lock);

		if (tcon->ses->server->tcpStatus != CifsExiting)

			tcon->ses->server->tcpStatus = CifsNeedReconnect;

		spin_unlock(&GlobalMid_Lock);

	}

	mutex_unlock(&tcon->ses->server->srv_mutex);



	return 0;

}



static int cifs_swn_client_move(struct cifs_swn_reg *swnreg, struct sockaddr_storage *addr)

{

	struct sockaddr_in *ipv4 = (struct sockaddr_in *)addr;

	struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)addr;



	if (addr->ss_family == AF_INET)

		cifs_dbg(FYI, "%s: move to %pI4\n", __func__, &ipv4->sin_addr);

	else if (addr->ss_family == AF_INET6)

		cifs_dbg(FYI, "%s: move to %pI6\n", __func__, &ipv6->sin6_addr);



	return cifs_swn_reconnect(swnreg->tcon, addr);

}



int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info)

{

	struct cifs_swn_reg *swnreg;
@@ -461,6 +586,17 @@ int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info) 
		}

		return cifs_swn_resource_state_changed(swnreg, name, state);

	}

	case CIFS_SWN_NOTIFICATION_CLIENT_MOVE: {

		struct sockaddr_storage addr;



		if (info->attrs[CIFS_GENL_ATTR_SWN_IP]) {

			nla_memcpy(&addr, info->attrs[CIFS_GENL_ATTR_SWN_IP], sizeof(addr));

		} else {

			cifs_dbg(FYI, "%s: missing IP address attribute\n", __func__);

			return -EINVAL;

		}

		return cifs_swn_client_move(swnreg, &addr);

	}

	default:

		cifs_dbg(FYI, "%s: unknown notification type %d\n", __func__, type);

		break;

fs/cifs/cifsglob.h

+4 −0
Original line number Diff line number Diff line
@@ -687,6 +687,10 @@ struct TCP_Server_Info { 
	int nr_targets;

	bool noblockcnt; /* use non-blocking connect() */

	bool is_channel; /* if a session channel */

#ifdef CONFIG_CIFS_SWN_UPCALL

	bool use_swn_dstaddr;

	struct sockaddr_storage swn_dstaddr;

#endif

};



struct cifs_credits {

fs/cifs/connect.c

+20 −6
Original line number Diff line number Diff line
@@ -312,6 +312,13 @@ cifs_reconnect(struct TCP_Server_Info *server) 
		try_to_freeze();



		mutex_lock(&server->srv_mutex);



#ifdef CONFIG_CIFS_SWN_UPCALL

		if (server->use_swn_dstaddr) {

			server->dstaddr = server->swn_dstaddr;

		} else {

#endif



#ifdef CONFIG_CIFS_DFS_UPCALL

			/*

			 * Set up next DFS target server (if any) for reconnect. If DFS
@@ -321,6 +328,10 @@ cifs_reconnect(struct TCP_Server_Info *server) 
			reconn_set_next_dfs_target(server, cifs_sb, &tgt_list, &tgt_it);

#endif



#ifdef CONFIG_CIFS_SWN_UPCALL

		}

#endif



		if (cifs_rdma_enabled(server))

			rc = smbd_reconnect(server);

		else
@@ -336,6 +347,9 @@ cifs_reconnect(struct TCP_Server_Info *server) 
			if (server->tcpStatus != CifsExiting)

				server->tcpStatus = CifsNeedNegotiate;

			spin_unlock(&GlobalMid_Lock);

#ifdef CONFIG_CIFS_SWN_UPCALL

			server->use_swn_dstaddr = false;

#endif

			mutex_unlock(&server->srv_mutex);

		}

	} while (server->tcpStatus == CifsNeedReconnect);

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