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-rw-r--r--net/rds/ib.c129
-rw-r--r--net/rds/ib.h4
-rw-r--r--net/rds/ib_cm.c33
-rw-r--r--net/rds/ib_rdma.c14
4 files changed, 125 insertions, 55 deletions
diff --git a/net/rds/ib.c b/net/rds/ib.c
index 7d289d7..1732f8e 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 4bc3e2f..282ec69 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 73253f7..a9fb917 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 4ba01b9..64b5ede 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;
}
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