On 2019/1/12 10:37, Jason Gunthorpe wrote:
rxe has an open coded version of this that is not as safe as the core
version can be.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
---
drivers/infiniband/core/device.c | 28 +++++++++++++++++++++++++++
drivers/infiniband/sw/rxe/rxe.h | 1 -
drivers/infiniband/sw/rxe/rxe_net.c | 17 ----------------
drivers/infiniband/sw/rxe/rxe_sysfs.c | 8 +++++---
include/rdma/ib_verbs.h | 2 ++
5 files changed, 35 insertions(+), 21 deletions(-)
More usage of device_try_get/put()
Requires the advise_mr series sent to for-rc
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 9b5c72d3c85a88..1311d6e5f28c03 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -181,6 +181,34 @@ static struct ib_device *__ib_device_get_by_name(const char *name)
return NULL;
}
+/**
+ * ib_device_get_by_name - Find an IB device by name
+ * @name: The name to look for
+ * @driver_id: The driver ID that must match (RDMA_DRIVER_UNKNOWN matches all)
+ *
+ * Find and hold an ib_device by its name. The caller must call
+ * ib_device_put() on the returned pointer.
+ */
+struct ib_device *ib_device_get_by_name(const char *name,
+ enum rdma_driver_id driver_id)
+{
+ struct ib_device *device;
+
+ down_read(&lists_rwsem);
+ device = __ib_device_get_by_name(name);
+ if (device && driver_id != RDMA_DRIVER_UNKNOWN &&
+ device->driver_id != driver_id)
+ device = NULL;
+
+ if (device) {
+ if (!ib_device_try_get(device))
In the patch [PATCH for-rc 1/2] RDMA/device: Expose ib_device_try_get((),
+/**
+ * ib_device_try_get: Hold a registration lock
+ * device: The device to lock
+ *
+ * A device under an active registration lock cannot become
unregistered. It
+ * is only possible to obtain a registration lock on a device that is fully
+ * registered, otherwise this function returns false.
+ *
+ * The registration lock is only necessary for actions which require the
+ * device to still be registered. Uses that only require the device
pointer to
+ * be valid should use get_device(&ibdev->dev) to hold the memory.
+ *
+ */
+static inline bool ib_device_try_get(struct ib_device *dev)
+{
+ return refcount_inc_not_zero(&dev->refcount);
+}
+
+ device = NULL;
+ }
+ up_read(&lists_rwsem);
+ return device;
+}
+EXPORT_SYMBOL(ib_device_get_by_name);
+
int ib_device_rename(struct ib_device *ibdev, const char *name)
{
struct ib_device *device;
diff --git a/drivers/infiniband/sw/rxe/rxe.h b/drivers/infiniband/sw/rxe/rxe.h
index 5bde2ad964d277..4f8653c5d1ca5e 100644
--- a/drivers/infiniband/sw/rxe/rxe.h
+++ b/drivers/infiniband/sw/rxe/rxe.h
@@ -106,7 +106,6 @@ static inline void rxe_dev_put(struct rxe_dev *rxe)
kref_put(&rxe->ref_cnt, rxe_release);
}
struct rxe_dev *net_to_rxe(struct net_device *ndev);
-struct rxe_dev *get_rxe_by_name(const char *name);
void rxe_port_up(struct rxe_dev *rxe);
void rxe_port_down(struct rxe_dev *rxe);
diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c
index 8fd03ae20efc17..6a4f58a8656578 100644
--- a/drivers/infiniband/sw/rxe/rxe_net.c
+++ b/drivers/infiniband/sw/rxe/rxe_net.c
@@ -65,23 +65,6 @@ struct rxe_dev *net_to_rxe(struct net_device *ndev)
return found;
}
-struct rxe_dev *get_rxe_by_name(const char *name)
-{
- struct rxe_dev *rxe;
- struct rxe_dev *found = NULL;
-
- spin_lock_bh(&dev_list_lock);
- list_for_each_entry(rxe, &rxe_dev_list, list) {
- if (!strcmp(name, dev_name(&rxe->ib_dev.dev))) {
- found = rxe;
- break;
- }
- }
- spin_unlock_bh(&dev_list_lock);
- return found;
-}
-
-
static struct rxe_recv_sockets recv_sockets;
struct device *rxe_dma_device(struct rxe_dev *rxe)
diff --git a/drivers/infiniband/sw/rxe/rxe_sysfs.c b/drivers/infiniband/sw/rxe/rxe_sysfs.c
index 95a15892f7e659..66c39049cb2d18 100644
--- a/drivers/infiniband/sw/rxe/rxe_sysfs.c
+++ b/drivers/infiniband/sw/rxe/rxe_sysfs.c
@@ -100,6 +100,7 @@ static int rxe_param_set_remove(const char *val, const struct kernel_param *kp)
{
int len;
char intf[32];
+ struct ib_device *ib_dev;
struct rxe_dev *rxe;
len = sanitize_arg(val, intf, sizeof(intf));
@@ -114,15 +115,16 @@ static int rxe_param_set_remove(const char *val, const struct kernel_param *kp)
return 0;
}
- rxe = get_rxe_by_name(intf);
-
- if (!rxe) {
+ ib_dev = ib_device_get_by_name(intf, RDMA_DRIVER_RXE);
+ if (!ib_dev) {
pr_err("not configured on %s\n", intf);
return -EINVAL;
}
+ rxe = container_of(ib_dev, struct rxe_dev, ib_dev);
list_del(&rxe->list);
rxe_remove(rxe);
+ ib_device_put(ib_dev);
return 0;
}
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 85e9dab17b9b92..d4d6bd6c0ae121 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -3944,6 +3944,8 @@ static inline bool ib_device_try_get(struct ib_device *dev)
}
void ib_device_put(struct ib_device *device);
+struct ib_device *ib_device_get_by_name(const char *name,
+ enum rdma_driver_id driver_id);
struct net_device *ib_get_net_dev_by_params(struct ib_device *dev, u8 port,
u16 pkey, const union ib_gid *gid,
const struct sockaddr *addr);
