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Diffstat (limited to '')
| -rw-r--r-- | net/rds/transport.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/net/rds/transport.c b/net/rds/transport.c new file mode 100644 index 000000000..f8001ec80 --- /dev/null +++ b/net/rds/transport.c @@ -0,0 +1,169 @@ +/* + * Copyright (c) 2006, 2017 Oracle and/or its affiliates. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/in.h> +#include <linux/ipv6.h> + +#include "rds.h" +#include "loop.h" + +static char * const rds_trans_modules[] = { + [RDS_TRANS_IB] = "rds_rdma", + [RDS_TRANS_GAP] = NULL, + [RDS_TRANS_TCP] = "rds_tcp", +}; + +static struct rds_transport *transports[RDS_TRANS_COUNT]; +static DECLARE_RWSEM(rds_trans_sem); + +void rds_trans_register(struct rds_transport *trans) +{ + BUG_ON(strlen(trans->t_name) + 1 > TRANSNAMSIZ); + + down_write(&rds_trans_sem); + + if (transports[trans->t_type]) + printk(KERN_ERR "RDS Transport type %d already registered\n", + trans->t_type); + else { + transports[trans->t_type] = trans; + printk(KERN_INFO "Registered RDS/%s transport\n", trans->t_name); + } + + up_write(&rds_trans_sem); +} +EXPORT_SYMBOL_GPL(rds_trans_register); + +void rds_trans_unregister(struct rds_transport *trans) +{ + down_write(&rds_trans_sem); + + transports[trans->t_type] = NULL; + printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name); + + up_write(&rds_trans_sem); +} +EXPORT_SYMBOL_GPL(rds_trans_unregister); + +void rds_trans_put(struct rds_transport *trans) +{ + if (trans) + module_put(trans->t_owner); +} + +struct rds_transport *rds_trans_get_preferred(struct net *net, + const struct in6_addr *addr, + __u32 scope_id) +{ + struct rds_transport *ret = NULL; + struct rds_transport *trans; + unsigned int i; + + if (ipv6_addr_v4mapped(addr)) { + if (*(u_int8_t *)&addr->s6_addr32[3] == IN_LOOPBACKNET) + return &rds_loop_transport; + } else if (ipv6_addr_loopback(addr)) { + return &rds_loop_transport; + } + + down_read(&rds_trans_sem); + for (i = 0; i < RDS_TRANS_COUNT; i++) { + trans = transports[i]; + + if (trans && (trans->laddr_check(net, addr, scope_id) == 0) && + (!trans->t_owner || try_module_get(trans->t_owner))) { + ret = trans; + break; + } + } + up_read(&rds_trans_sem); + + return ret; +} + +struct rds_transport *rds_trans_get(int t_type) +{ + struct rds_transport *ret = NULL; + struct rds_transport *trans; + + down_read(&rds_trans_sem); + trans = transports[t_type]; + if (!trans) { + up_read(&rds_trans_sem); + if (rds_trans_modules[t_type]) + request_module(rds_trans_modules[t_type]); + down_read(&rds_trans_sem); + trans = transports[t_type]; + } + if (trans && trans->t_type == t_type && + (!trans->t_owner || try_module_get(trans->t_owner))) + ret = trans; + + up_read(&rds_trans_sem); + + return ret; +} + +/* + * This returns the number of stats entries in the snapshot and only + * copies them using the iter if there is enough space for them. The + * caller passes in the global stats so that we can size and copy while + * holding the lock. + */ +unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter, + unsigned int avail) + +{ + struct rds_transport *trans; + unsigned int total = 0; + unsigned int part; + int i; + + rds_info_iter_unmap(iter); + down_read(&rds_trans_sem); + + for (i = 0; i < RDS_TRANS_COUNT; i++) { + trans = transports[i]; + if (!trans || !trans->stats_info_copy) + continue; + + part = trans->stats_info_copy(iter, avail); + avail -= min(avail, part); + total += part; + } + + up_read(&rds_trans_sem); + + return total; +} |