diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h index 3a8b0911c3bc..9d07378b5b42 100644 --- a/drivers/infiniband/core/core_priv.h +++ b/drivers/infiniband/core/core_priv.h @@ -199,6 +199,7 @@ void ib_mad_cleanup(void); int ib_sa_init(void); void ib_sa_cleanup(void); +void rdma_nl_init(void); void rdma_nl_exit(void); int ib_nl_handle_resolve_resp(struct sk_buff *skb, diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index 2dd2cfe9b561..50a92442c4f7 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -2716,6 +2716,8 @@ static int __init ib_core_init(void) goto err_comp_unbound; } + rdma_nl_init(); + ret = addr_init(); if (ret) { pr_warn("Could't init IB address resolution\n"); diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c index 81dbd5f41bed..8cd31ef25eff 100644 --- a/drivers/infiniband/core/netlink.c +++ b/drivers/infiniband/core/netlink.c @@ -42,9 +42,12 @@ #include #include "core_priv.h" -static DEFINE_MUTEX(rdma_nl_mutex); static struct { - const struct rdma_nl_cbs *cb_table; + const struct rdma_nl_cbs *cb_table; + /* Synchronizes between ongoing netlink commands and netlink client + * unregistration. + */ + struct rw_semaphore sem; } rdma_nl_types[RDMA_NL_NUM_CLIENTS]; bool rdma_nl_chk_listeners(unsigned int group) @@ -75,70 +78,53 @@ static bool is_nl_msg_valid(unsigned int type, unsigned int op) return (op < max_num_ops[type]) ? true : false; } -static bool -is_nl_valid(const struct sk_buff *skb, unsigned int type, unsigned int op) +static const struct rdma_nl_cbs * +get_cb_table(const struct sk_buff *skb, unsigned int type, unsigned int op) { const struct rdma_nl_cbs *cb_table; - if (!is_nl_msg_valid(type, op)) - return false; - /* * Currently only NLDEV client is supporting netlink commands in * non init_net net namespace. */ if (sock_net(skb->sk) != &init_net && type != RDMA_NL_NLDEV) - return false; + return NULL; + + cb_table = READ_ONCE(rdma_nl_types[type].cb_table); + if (!cb_table) { + /* + * Didn't get valid reference of the table, attempt module + * load once. + */ + up_read(&rdma_nl_types[type].sem); - if (!rdma_nl_types[type].cb_table) { - mutex_unlock(&rdma_nl_mutex); request_module("rdma-netlink-subsys-%d", type); - mutex_lock(&rdma_nl_mutex); + + down_read(&rdma_nl_types[type].sem); + cb_table = READ_ONCE(rdma_nl_types[type].cb_table); } - - cb_table = rdma_nl_types[type].cb_table; - if (!cb_table || (!cb_table[op].dump && !cb_table[op].doit)) - return false; - return true; + return NULL; + return cb_table; } void rdma_nl_register(unsigned int index, const struct rdma_nl_cbs cb_table[]) { - mutex_lock(&rdma_nl_mutex); - if (!is_nl_msg_valid(index, 0)) { - /* - * All clients are not interesting in success/failure of - * this call. They want to see the print to error log and - * continue their initialization. Print warning for them, - * because it is programmer's error to be here. - */ - mutex_unlock(&rdma_nl_mutex); - WARN(true, - "The not-valid %u index was supplied to RDMA netlink\n", - index); + if (WARN_ON(!is_nl_msg_valid(index, 0)) || + WARN_ON(READ_ONCE(rdma_nl_types[index].cb_table))) return; - } - if (rdma_nl_types[index].cb_table) { - mutex_unlock(&rdma_nl_mutex); - WARN(true, - "The %u index is already registered in RDMA netlink\n", - index); - return; - } - - rdma_nl_types[index].cb_table = cb_table; - mutex_unlock(&rdma_nl_mutex); + /* Pairs with the READ_ONCE in is_nl_valid() */ + smp_store_release(&rdma_nl_types[index].cb_table, cb_table); } EXPORT_SYMBOL(rdma_nl_register); void rdma_nl_unregister(unsigned int index) { - mutex_lock(&rdma_nl_mutex); + down_write(&rdma_nl_types[index].sem); rdma_nl_types[index].cb_table = NULL; - mutex_unlock(&rdma_nl_mutex); + up_write(&rdma_nl_types[index].sem); } EXPORT_SYMBOL(rdma_nl_unregister); @@ -170,15 +156,21 @@ static int rdma_nl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, unsigned int index = RDMA_NL_GET_CLIENT(type); unsigned int op = RDMA_NL_GET_OP(type); const struct rdma_nl_cbs *cb_table; + int err = -EINVAL; - if (!is_nl_valid(skb, index, op)) + if (!is_nl_msg_valid(index, op)) return -EINVAL; - cb_table = rdma_nl_types[index].cb_table; + down_read(&rdma_nl_types[index].sem); + cb_table = get_cb_table(skb, index, op); + if (!cb_table) + goto done; if ((cb_table[op].flags & RDMA_NL_ADMIN_PERM) && - !netlink_capable(skb, CAP_NET_ADMIN)) - return -EPERM; + !netlink_capable(skb, CAP_NET_ADMIN)) { + err = -EPERM; + goto done; + } /* * LS responses overload the 0x100 (NLM_F_ROOT) flag. Don't @@ -186,8 +178,8 @@ static int rdma_nl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, */ if (index == RDMA_NL_LS) { if (cb_table[op].doit) - return cb_table[op].doit(skb, nlh, extack); - return -EINVAL; + err = cb_table[op].doit(skb, nlh, extack); + goto done; } /* FIXME: Convert IWCM to properly handle doit callbacks */ if ((nlh->nlmsg_flags & NLM_F_DUMP) || index == RDMA_NL_IWCM) { @@ -195,14 +187,15 @@ static int rdma_nl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, .dump = cb_table[op].dump, }; if (c.dump) - return netlink_dump_start(skb->sk, skb, nlh, &c); - return -EINVAL; + err = netlink_dump_start(skb->sk, skb, nlh, &c); + goto done; } if (cb_table[op].doit) - return cb_table[op].doit(skb, nlh, extack); - - return 0; + err = cb_table[op].doit(skb, nlh, extack); +done: + up_read(&rdma_nl_types[index].sem); + return err; } /* @@ -263,9 +256,7 @@ static int rdma_nl_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, static void rdma_nl_rcv(struct sk_buff *skb) { - mutex_lock(&rdma_nl_mutex); rdma_nl_rcv_skb(skb, &rdma_nl_rcv_msg); - mutex_unlock(&rdma_nl_mutex); } int rdma_nl_unicast(struct net *net, struct sk_buff *skb, u32 pid) @@ -297,6 +288,14 @@ int rdma_nl_multicast(struct net *net, struct sk_buff *skb, } EXPORT_SYMBOL(rdma_nl_multicast); +void rdma_nl_init(void) +{ + int idx; + + for (idx = 0; idx < RDMA_NL_NUM_CLIENTS; idx++) + init_rwsem(&rdma_nl_types[idx].sem); +} + void rdma_nl_exit(void) { int idx;