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path: root/drivers/infiniband/core/device.c
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Diffstat (limited to 'drivers/infiniband/core/device.c')
-rw-r--r--drivers/infiniband/core/device.c37
1 files changed, 22 insertions, 15 deletions
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 3a9b9a28d..453188db3 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -1730,7 +1730,7 @@ static int assign_client_id(struct ib_client *client)
{
int ret;
- down_write(&clients_rwsem);
+ lockdep_assert_held(&clients_rwsem);
/*
* The add/remove callbacks must be called in FIFO/LIFO order. To
* achieve this we assign client_ids so they are sorted in
@@ -1739,14 +1739,11 @@ static int assign_client_id(struct ib_client *client)
client->client_id = highest_client_id;
ret = xa_insert(&clients, client->client_id, client, GFP_KERNEL);
if (ret)
- goto out;
+ return ret;
highest_client_id++;
xa_set_mark(&clients, client->client_id, CLIENT_REGISTERED);
-
-out:
- up_write(&clients_rwsem);
- return ret;
+ return 0;
}
static void remove_client_id(struct ib_client *client)
@@ -1776,25 +1773,35 @@ int ib_register_client(struct ib_client *client)
{
struct ib_device *device;
unsigned long index;
+ bool need_unreg = false;
int ret;
refcount_set(&client->uses, 1);
init_completion(&client->uses_zero);
+
+ /*
+ * The devices_rwsem is held in write mode to ensure that a racing
+ * ib_register_device() sees a consisent view of clients and devices.
+ */
+ down_write(&devices_rwsem);
+ down_write(&clients_rwsem);
ret = assign_client_id(client);
if (ret)
- return ret;
+ goto out;
- down_read(&devices_rwsem);
+ need_unreg = true;
xa_for_each_marked (&devices, index, device, DEVICE_REGISTERED) {
ret = add_client_context(device, client);
- if (ret) {
- up_read(&devices_rwsem);
- ib_unregister_client(client);
- return ret;
- }
+ if (ret)
+ goto out;
}
- up_read(&devices_rwsem);
- return 0;
+ ret = 0;
+out:
+ up_write(&clients_rwsem);
+ up_write(&devices_rwsem);
+ if (need_unreg && ret)
+ ib_unregister_client(client);
+ return ret;
}
EXPORT_SYMBOL(ib_register_client);