From 7a118df3ea23820b9922a1b51cd2f24e464f4c17 Mon Sep 17 00:00:00 2001 From: Sean Hefty Date: Tue, 31 Oct 2006 11:12:59 -0800 Subject: [PATCH] RDMA/addr: Use client registration to fix module unload race Require registration with ib_addr module to prevent caller from unloading while a callback is in progress. Signed-off-by: Sean Hefty Signed-off-by: Roland Dreier --- drivers/infiniband/core/addr.c | 28 +++++++++++++++++++++++++++- drivers/infiniband/core/cma.c | 8 ++++++-- include/rdma/ib_addr.h | 20 +++++++++++++++++++- 3 files changed, 52 insertions(+), 4 deletions(-) diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c index 60d3fbdd216c..e11187ecc931 100644 --- a/drivers/infiniband/core/addr.c +++ b/drivers/infiniband/core/addr.c @@ -47,6 +47,7 @@ struct addr_req { struct sockaddr src_addr; struct sockaddr dst_addr; struct rdma_dev_addr *addr; + struct rdma_addr_client *client; void *context; void (*callback)(int status, struct sockaddr *src_addr, struct rdma_dev_addr *addr, void *context); @@ -61,6 +62,26 @@ static LIST_HEAD(req_list); static DECLARE_WORK(work, process_req, NULL); static struct workqueue_struct *addr_wq; +void rdma_addr_register_client(struct rdma_addr_client *client) +{ + atomic_set(&client->refcount, 1); + init_completion(&client->comp); +} +EXPORT_SYMBOL(rdma_addr_register_client); + +static inline void put_client(struct rdma_addr_client *client) +{ + if (atomic_dec_and_test(&client->refcount)) + complete(&client->comp); +} + +void rdma_addr_unregister_client(struct rdma_addr_client *client) +{ + put_client(client); + wait_for_completion(&client->comp); +} +EXPORT_SYMBOL(rdma_addr_unregister_client); + int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev, const unsigned char *dst_dev_addr) { @@ -229,6 +250,7 @@ static void process_req(void *data) list_del(&req->list); req->callback(req->status, &req->src_addr, req->addr, req->context); + put_client(req->client); kfree(req); } } @@ -264,7 +286,8 @@ static int addr_resolve_local(struct sockaddr_in *src_in, return ret; } -int rdma_resolve_ip(struct sockaddr *src_addr, struct sockaddr *dst_addr, +int rdma_resolve_ip(struct rdma_addr_client *client, + struct sockaddr *src_addr, struct sockaddr *dst_addr, struct rdma_dev_addr *addr, int timeout_ms, void (*callback)(int status, struct sockaddr *src_addr, struct rdma_dev_addr *addr, void *context), @@ -285,6 +308,8 @@ int rdma_resolve_ip(struct sockaddr *src_addr, struct sockaddr *dst_addr, req->addr = addr; req->callback = callback; req->context = context; + req->client = client; + atomic_inc(&client->refcount); src_in = (struct sockaddr_in *) &req->src_addr; dst_in = (struct sockaddr_in *) &req->dst_addr; @@ -305,6 +330,7 @@ int rdma_resolve_ip(struct sockaddr *src_addr, struct sockaddr *dst_addr, break; default: ret = req->status; + atomic_dec(&client->refcount); kfree(req); break; } diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index d8ca3c1368b5..845090b0859c 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -63,6 +63,7 @@ static struct ib_client cma_client = { }; static struct ib_sa_client sa_client; +static struct rdma_addr_client addr_client; static LIST_HEAD(dev_list); static LIST_HEAD(listen_any_list); static DEFINE_MUTEX(lock); @@ -1625,8 +1626,8 @@ int rdma_resolve_addr(struct rdma_cm_id *id, struct sockaddr *src_addr, if (cma_any_addr(dst_addr)) ret = cma_resolve_loopback(id_priv); else - ret = rdma_resolve_ip(&id->route.addr.src_addr, dst_addr, - &id->route.addr.dev_addr, + ret = rdma_resolve_ip(&addr_client, &id->route.addr.src_addr, + dst_addr, &id->route.addr.dev_addr, timeout_ms, addr_handler, id_priv); if (ret) goto err; @@ -2217,6 +2218,7 @@ static int cma_init(void) return -ENOMEM; ib_sa_register_client(&sa_client); + rdma_addr_register_client(&addr_client); ret = ib_register_client(&cma_client); if (ret) @@ -2224,6 +2226,7 @@ static int cma_init(void) return 0; err: + rdma_addr_unregister_client(&addr_client); ib_sa_unregister_client(&sa_client); destroy_workqueue(cma_wq); return ret; @@ -2232,6 +2235,7 @@ err: static void cma_cleanup(void) { ib_unregister_client(&cma_client); + rdma_addr_unregister_client(&addr_client); ib_sa_unregister_client(&sa_client); destroy_workqueue(cma_wq); idr_destroy(&sdp_ps); diff --git a/include/rdma/ib_addr.h b/include/rdma/ib_addr.h index 81b62307621d..c094e5012862 100644 --- a/include/rdma/ib_addr.h +++ b/include/rdma/ib_addr.h @@ -36,6 +36,22 @@ #include #include +struct rdma_addr_client { + atomic_t refcount; + struct completion comp; +}; + +/** + * rdma_addr_register_client - Register an address client. + */ +void rdma_addr_register_client(struct rdma_addr_client *client); + +/** + * rdma_addr_unregister_client - Deregister an address client. + * @client: Client object to deregister. + */ +void rdma_addr_unregister_client(struct rdma_addr_client *client); + struct rdma_dev_addr { unsigned char src_dev_addr[MAX_ADDR_LEN]; unsigned char dst_dev_addr[MAX_ADDR_LEN]; @@ -52,6 +68,7 @@ int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr); /** * rdma_resolve_ip - Resolve source and destination IP addresses to * RDMA hardware addresses. + * @client: Address client associated with request. * @src_addr: An optional source address to use in the resolution. If a * source address is not provided, a usable address will be returned via * the callback. @@ -64,7 +81,8 @@ int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr); * or been canceled. A status of 0 indicates success. * @context: User-specified context associated with the call. */ -int rdma_resolve_ip(struct sockaddr *src_addr, struct sockaddr *dst_addr, +int rdma_resolve_ip(struct rdma_addr_client *client, + struct sockaddr *src_addr, struct sockaddr *dst_addr, struct rdma_dev_addr *addr, int timeout_ms, void (*callback)(int status, struct sockaddr *src_addr, struct rdma_dev_addr *addr, void *context), -- 2.34.1