diff options
| -rw-r--r-- | net/rds/ib.c | 129 | ||||
| -rw-r--r-- | net/rds/ib.h | 4 | ||||
| -rw-r--r-- | net/rds/ib_cm.c | 33 | ||||
| -rw-r--r-- | net/rds/ib_rdma.c | 14 |
4 files changed, 125 insertions, 55 deletions
diff --git a/net/rds/ib.c b/net/rds/ib.c index 7d289d7985f..1732f8effb5 100644 --- a/net/rds/ib.c +++ b/net/rds/ib.c @@ -59,6 +59,38 @@ struct list_head rds_ib_devices; DEFINE_SPINLOCK(ib_nodev_conns_lock); LIST_HEAD(ib_nodev_conns); +/* + * rds_ib_destroy_mr_pool() blocks on a few things and mrs drop references + * from interrupt context so we push freing off into a work struct in krdsd. + */ +static void rds_ib_dev_free(struct work_struct *work) +{ + struct rds_ib_ipaddr *i_ipaddr, *i_next; + struct rds_ib_device *rds_ibdev = container_of(work, + struct rds_ib_device, free_work); + + if (rds_ibdev->mr_pool) + rds_ib_destroy_mr_pool(rds_ibdev->mr_pool); + if (rds_ibdev->mr) + ib_dereg_mr(rds_ibdev->mr); + if (rds_ibdev->pd) + ib_dealloc_pd(rds_ibdev->pd); + + list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) { + list_del(&i_ipaddr->list); + kfree(i_ipaddr); + } + + kfree(rds_ibdev); +} + +void rds_ib_dev_put(struct rds_ib_device *rds_ibdev) +{ + BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0); + if (atomic_dec_and_test(&rds_ibdev->refcount)) + queue_work(rds_wq, &rds_ibdev->free_work); +} + void rds_ib_add_one(struct ib_device *device) { struct rds_ib_device *rds_ibdev; @@ -77,11 +109,14 @@ void rds_ib_add_one(struct ib_device *device) goto free_attr; } - rds_ibdev = kmalloc_node(sizeof *rds_ibdev, GFP_KERNEL, ibdev_to_node(device)); + rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL, + ibdev_to_node(device)); if (!rds_ibdev) goto free_attr; spin_lock_init(&rds_ibdev->spinlock); + atomic_set(&rds_ibdev->refcount, 1); + INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free); rds_ibdev->max_wrs = dev_attr->max_qp_wr; rds_ibdev->max_sge = min(dev_attr->max_sge, RDS_IB_MAX_SGE); @@ -96,67 +131,93 @@ void rds_ib_add_one(struct ib_device *device) rds_ibdev->dev = device; rds_ibdev->pd = ib_alloc_pd(device); - if (IS_ERR(rds_ibdev->pd)) - goto free_dev; + if (IS_ERR(rds_ibdev->pd)) { + rds_ibdev->pd = NULL; + goto put_dev; + } - rds_ibdev->mr = ib_get_dma_mr(rds_ibdev->pd, - IB_ACCESS_LOCAL_WRITE); - if (IS_ERR(rds_ibdev->mr)) - goto err_pd; + rds_ibdev->mr = ib_get_dma_mr(rds_ibdev->pd, IB_ACCESS_LOCAL_WRITE); + if (IS_ERR(rds_ibdev->mr)) { + rds_ibdev->mr = NULL; + goto put_dev; + } rds_ibdev->mr_pool = rds_ib_create_mr_pool(rds_ibdev); if (IS_ERR(rds_ibdev->mr_pool)) { rds_ibdev->mr_pool = NULL; - goto err_mr; + goto put_dev; } INIT_LIST_HEAD(&rds_ibdev->ipaddr_list); INIT_LIST_HEAD(&rds_ibdev->conn_list); list_add_tail(&rds_ibdev->list, &rds_ib_devices); + atomic_inc(&rds_ibdev->refcount); ib_set_client_data(device, &rds_ib_client, rds_ibdev); + atomic_inc(&rds_ibdev->refcount); - goto free_attr; - -err_mr: - ib_dereg_mr(rds_ibdev->mr); -err_pd: - ib_dealloc_pd(rds_ibdev->pd); -free_dev: - kfree(rds_ibdev); +put_dev: + rds_ib_dev_put(rds_ibdev); free_attr: kfree(dev_attr); } +/* + * New connections use this to find the device to associate with the + * connection. It's not in the fast path so we're not concerned about the + * performance of the IB call. (As of this writing, it uses an interrupt + * blocking spinlock to serialize walking a per-device list of all registered + * clients.) + * + * RCU is used to handle incoming connections racing with device teardown. + * Rather than use a lock to serialize removal from the client_data and + * getting a new reference, we use an RCU grace period. The destruction + * path removes the device from client_data and then waits for all RCU + * readers to finish. + * + * A new connection can get NULL from this if its arriving on a + * device that is in the process of being removed. + */ +struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device) +{ + struct rds_ib_device *rds_ibdev; + + rcu_read_lock(); + rds_ibdev = ib_get_client_data(device, &rds_ib_client); + if (rds_ibdev) + atomic_inc(&rds_ibdev->refcount); + rcu_read_unlock(); + return rds_ibdev; +} + +/* + * The IB stack is letting us know that a device is going away. This can + * happen if the underlying HCA driver is removed or if PCI hotplug is removing + * the pci function, for example. + * + * This can be called at any time and can be racing with any other RDS path. + */ void rds_ib_remove_one(struct ib_device *device) { struct rds_ib_device *rds_ibdev; - struct rds_ib_ipaddr *i_ipaddr, *i_next; rds_ibdev = ib_get_client_data(device, &rds_ib_client); if (!rds_ibdev) return; - synchronize_rcu(); - list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) { - list_del(&i_ipaddr->list); - kfree(i_ipaddr); - } - rds_ib_destroy_conns(rds_ibdev); - if (rds_ibdev->mr_pool) - rds_ib_destroy_mr_pool(rds_ibdev->mr_pool); - - ib_dereg_mr(rds_ibdev->mr); - - while (ib_dealloc_pd(rds_ibdev->pd)) { - rdsdebug("Failed to dealloc pd %p\n", rds_ibdev->pd); - msleep(1); - } + /* + * prevent future connection attempts from getting a reference to this + * device and wait for currently racing connection attempts to finish + * getting their reference + */ + ib_set_client_data(device, &rds_ib_client, NULL); + synchronize_rcu(); + rds_ib_dev_put(rds_ibdev); list_del(&rds_ibdev->list); - kfree(rds_ibdev); + rds_ib_dev_put(rds_ibdev); } struct ib_client rds_ib_client = { @@ -190,7 +251,7 @@ static int rds_ib_conn_info_visitor(struct rds_connection *conn, rdma_addr_get_sgid(dev_addr, (union ib_gid *) &iinfo->src_gid); rdma_addr_get_dgid(dev_addr, (union ib_gid *) &iinfo->dst_gid); - rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client); + rds_ibdev = ic->rds_ibdev; iinfo->max_send_wr = ic->i_send_ring.w_nr; iinfo->max_recv_wr = ic->i_recv_ring.w_nr; iinfo->max_send_sge = rds_ibdev->max_sge; diff --git a/net/rds/ib.h b/net/rds/ib.h index 4bc3e2fba25..282ec69fe28 100644 --- a/net/rds/ib.h +++ b/net/rds/ib.h @@ -167,6 +167,8 @@ struct rds_ib_device { unsigned int max_initiator_depth; unsigned int max_responder_resources; spinlock_t spinlock; /* protect the above */ + atomic_t refcount; + struct work_struct free_work; }; #define pcidev_to_node(pcidev) pcibus_to_node(pcidev->bus) @@ -251,6 +253,8 @@ static inline void rds_ib_dma_sync_sg_for_device(struct ib_device *dev, extern struct rds_transport rds_ib_transport; extern void rds_ib_add_one(struct ib_device *device); extern void rds_ib_remove_one(struct ib_device *device); +struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device); +void rds_ib_dev_put(struct rds_ib_device *rds_ibdev); extern struct ib_client rds_ib_client; extern unsigned int fmr_pool_size; diff --git a/net/rds/ib_cm.c b/net/rds/ib_cm.c index 73253f7c1fa..a9fb917c00b 100644 --- a/net/rds/ib_cm.c +++ b/net/rds/ib_cm.c @@ -95,7 +95,6 @@ void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_even { const struct rds_ib_connect_private *dp = NULL; struct rds_ib_connection *ic = conn->c_transport_data; - struct rds_ib_device *rds_ibdev; struct ib_qp_attr qp_attr; int err; @@ -145,12 +144,11 @@ void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_even if (err) printk(KERN_NOTICE "ib_modify_qp(IB_QP_STATE, RTS): err=%d\n", err); - /* update ib_device with this local ipaddr & conn */ - rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client); - err = rds_ib_update_ipaddr(rds_ibdev, conn->c_laddr); + /* update ib_device with this local ipaddr */ + err = rds_ib_update_ipaddr(ic->rds_ibdev, conn->c_laddr); if (err) - printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n", err); - rds_ib_add_conn(rds_ibdev, conn); + printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n", + err); /* If the peer gave us the last packet it saw, process this as if * we had received a regular ACK. */ @@ -168,12 +166,10 @@ static void rds_ib_cm_fill_conn_param(struct rds_connection *conn, u32 max_initiator_depth) { struct rds_ib_connection *ic = conn->c_transport_data; - struct rds_ib_device *rds_ibdev; + struct rds_ib_device *rds_ibdev = ic->rds_ibdev; memset(conn_param, 0, sizeof(struct rdma_conn_param)); - rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client); - conn_param->responder_resources = min_t(u32, rds_ibdev->max_responder_resources, max_responder_resources); conn_param->initiator_depth = @@ -241,18 +237,16 @@ static int rds_ib_setup_qp(struct rds_connection *conn) struct rds_ib_device *rds_ibdev; int ret; - /* rds_ib_add_one creates a rds_ib_device object per IB device, - * and allocates a protection domain, memory range and FMR pool - * for each. If that fails for any reason, it will not register - * the rds_ibdev at all. + /* + * It's normal to see a null device if an incoming connection races + * with device removal, so we don't print a warning. */ - rds_ibdev = ib_get_client_data(dev, &rds_ib_client); - if (!rds_ibdev) { - if (printk_ratelimit()) - printk(KERN_NOTICE "RDS/IB: No client_data for device %s\n", - dev->name); + rds_ibdev = rds_ib_get_client_data(dev); + if (!rds_ibdev) return -EOPNOTSUPP; - } + + /* add the conn now so that connection establishment has the dev */ + rds_ib_add_conn(rds_ibdev, conn); if (rds_ibdev->max_wrs < ic->i_send_ring.w_nr + 1) rds_ib_ring_resize(&ic->i_send_ring, rds_ibdev->max_wrs - 1); @@ -371,6 +365,7 @@ static int rds_ib_setup_qp(struct rds_connection *conn) ic->i_send_cq, ic->i_recv_cq); out: + rds_ib_dev_put(rds_ibdev); return ret; } diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c index 4ba01b9ffd4..64b5ede037c 100644 --- a/net/rds/ib_rdma.c +++ b/net/rds/ib_rdma.c @@ -87,6 +87,7 @@ static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr) rcu_read_lock(); list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) { if (i_ipaddr->ipaddr == ipaddr) { + atomic_inc(&rds_ibdev->refcount); rcu_read_unlock(); return rds_ibdev; } @@ -141,8 +142,10 @@ int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr) struct rds_ib_device *rds_ibdev_old; rds_ibdev_old = rds_ib_get_device(ipaddr); - if (rds_ibdev_old) + if (rds_ibdev_old) { rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr); + rds_ib_dev_put(rds_ibdev_old); + } return rds_ib_add_ipaddr(rds_ibdev, ipaddr); } @@ -163,6 +166,7 @@ void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *con spin_unlock_irq(&ib_nodev_conns_lock); ic->rds_ibdev = rds_ibdev; + atomic_inc(&rds_ibdev->refcount); } void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn) @@ -182,6 +186,7 @@ void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection * spin_unlock(&ib_nodev_conns_lock); ic->rds_ibdev = NULL; + rds_ib_dev_put(rds_ibdev); } void __rds_ib_destroy_conns(struct list_head *list, spinlock_t *list_lock) @@ -240,7 +245,7 @@ void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_co void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool) { - flush_workqueue(rds_wq); + cancel_work_sync(&pool->flush_worker); rds_ib_flush_mr_pool(pool, 1); WARN_ON(atomic_read(&pool->item_count)); WARN_ON(atomic_read(&pool->free_pinned)); @@ -597,6 +602,8 @@ void rds_ib_free_mr(void *trans_private, int invalidate) queue_work(rds_wq, &pool->flush_worker); } } + + rds_ib_dev_put(rds_ibdev); } void rds_ib_flush_mrs(void) @@ -640,6 +647,7 @@ void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents, printk(KERN_WARNING "RDS/IB: map_fmr failed (errno=%d)\n", ret); ibmr->device = rds_ibdev; + rds_ibdev = NULL; out: if (ret) { @@ -647,5 +655,7 @@ void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents, rds_ib_free_mr(ibmr, 0); ibmr = ERR_PTR(ret); } + if (rds_ibdev) + rds_ib_dev_put(rds_ibdev); return ibmr; } |