ib_client API provides a way to wrap an ib_device with a specific ULP
structure. Using that API local lists and mutexes can be completely
avoided and allocation/removal paths become a bit cleaner.
Signed-off-by: Roman Pen <roman.penyaev@xxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx>
Cc: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
Cc: Doug Ledford <dledford@xxxxxxxxxx>
---
drivers/infiniband/ulp/iser/iscsi_iser.h | 1 +
drivers/infiniband/ulp/isert/ib_isert.c | 94 +++++++++++++++++++++-----------
drivers/infiniband/ulp/isert/ib_isert.h | 3 +-
3 files changed, 66 insertions(+), 32 deletions(-)
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h
index bd87bae65d59..04fb3edad749 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.h
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.h
@@ -44,6 +44,7 @@
#include <linux/types.h>
#include <linux/net.h>
#include <linux/printk.h>
+#include <linux/refcount.h>
#include <scsi/libiscsi.h>
#include <scsi/scsi_transport_iscsi.h>
#include <scsi/scsi_cmnd.h>
diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index b7da1a6ea32c..560c328c32d8 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -42,8 +42,7 @@ static int isert_debug_level;
module_param_named(debug_level, isert_debug_level, int, 0644);
MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:0)");
-static DEFINE_MUTEX(device_list_mutex);
-static LIST_HEAD(device_list);
+static struct ib_client isert_rdma_ib_client;
static struct workqueue_struct *isert_comp_wq;
static struct workqueue_struct *isert_release_wq;
@@ -341,56 +340,51 @@ isert_free_device_ib_res(struct isert_device *device)
static void
isert_device_put(struct isert_device *device)
{
- mutex_lock(&device_list_mutex);
- device->refcount--;
- isert_info("device %p refcount %d\n", device, device->refcount);
- if (!device->refcount) {
+ isert_info("device %p refcount %d\n", device,
+ refcount_read(&device->refcount));
+ if (refcount_dec_and_test(&device->refcount)) {
isert_free_device_ib_res(device);
list_del(&device->dev_node);
kfree(device);
}
- mutex_unlock(&device_list_mutex);
}
static struct isert_device *
isert_device_get(struct rdma_cm_id *cma_id)
{
struct isert_device *device;
- int ret;
- mutex_lock(&device_list_mutex);
- list_for_each_entry(device, &device_list, dev_node) {
- if (device->ib_device->node_guid == cma_id->device->node_guid) {
- device->refcount++;
- isert_info("Found iser device %p refcount %d\n",
- device, device->refcount);
- mutex_unlock(&device_list_mutex);
- return device;
- }
- }
+ /* Paired with isert_ib_client_remove_one() */
+ rcu_read_lock();
+ device = ib_get_client_data(cma_id->device, &isert_rdma_ib_client);
+ if (device && WARN_ON(!refcount_inc_not_zero(&device->refcount)))
+ device = NULL;
+ rcu_read_unlock();
+
+ return device;
+}
+
+static struct isert_device *
+isert_device_alloc(struct ib_device *ib_device)
+{
+ struct isert_device *device;
+ int ret;
- device = kzalloc(sizeof(struct isert_device), GFP_KERNEL);
- if (!device) {
- mutex_unlock(&device_list_mutex);
+ device = kzalloc(sizeof(*device), GFP_KERNEL);
+ if (unlikely(!device))
return ERR_PTR(-ENOMEM);
- }
INIT_LIST_HEAD(&device->dev_node);
mutex_init(&device->comp_mutex);
-
- device->ib_device = cma_id->device;
+ refcount_set(&device->refcount, 1);
+ device->ib_device = ib_device;
ret = isert_create_device_ib_res(device);
if (ret) {
kfree(device);
- mutex_unlock(&device_list_mutex);
return ERR_PTR(ret);
}
-
- device->refcount++;
- list_add_tail(&device->dev_node, &device_list);
isert_info("Created a new iser device %p refcount %d\n",
- device, device->refcount);
- mutex_unlock(&device_list_mutex);
+ device, refcount_read(&device->refcount));
return device;
}
@@ -2681,15 +2675,50 @@ static struct iscsit_transport iser_target_transport = {
.iscsit_get_sup_prot_ops = isert_get_sup_prot_ops,
};
+static void isert_ib_client_add_one(struct ib_device *ib_device)
+{
+ struct isert_device *device;
+
+ device = isert_device_alloc(ib_device);
+ if (!WARN_ON(!device))
+ ib_set_client_data(ib_device, &isert_rdma_ib_client, device);
+}
+
+static void isert_ib_client_remove_one(struct ib_device *ib_device,
+ void *client_data)
+{
+ struct isert_device *device = client_data;
+
+ if (unlikely(!device))
+ return;
+
+ ib_set_client_data(ib_device, &isert_rdma_ib_client, NULL);
+ /* Paired with isert_device_get() */
+ synchronize_rcu();
+ isert_device_put(device);
+}
+
+static struct ib_client isert_rdma_ib_client = {
+ .name = "isert_rdma_ib",
+ .add = isert_ib_client_add_one,
+ .remove = isert_ib_client_remove_one
+};
+
static int __init isert_init(void)
{
int ret;
+ ret = ib_register_client(&isert_rdma_ib_client);
+ if (unlikely(ret)) {
+ isert_err("ib_register_client(): %d\n", ret);
+ return ret;
+ }
isert_comp_wq = alloc_workqueue("isert_comp_wq",
WQ_UNBOUND | WQ_HIGHPRI, 0);
if (!isert_comp_wq) {
isert_err("Unable to allocate isert_comp_wq\n");
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto unregister_client;
}
isert_release_wq = alloc_workqueue("isert_release_wq", WQ_UNBOUND,
@@ -2707,6 +2736,8 @@ static int __init isert_init(void)
destroy_comp_wq:
destroy_workqueue(isert_comp_wq);
+unregister_client:
+ ib_unregister_client(&isert_rdma_ib_client);
return ret;
}
@@ -2717,6 +2748,7 @@ static void __exit isert_exit(void)
destroy_workqueue(isert_release_wq);
destroy_workqueue(isert_comp_wq);
iscsit_unregister_transport(&iser_target_transport);
+ ib_unregister_client(&isert_rdma_ib_client);
isert_info("iSER_TARGET[0] - Released iser_target_transport\n");
}
diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
index 9f0b0a6d87cf..ff08bf29dce4 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -2,6 +2,7 @@
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/in6.h>
+#include <linux/refcount.h>
#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>
#include <rdma/rw.h>
@@ -183,7 +184,7 @@ struct isert_comp {
struct isert_device {
bool pi_capable;
- int refcount;
+ refcount_t refcount;
struct mutex comp_mutex;
struct ib_device *ib_device;
struct ib_pd *pd;
--
2.13.1
--
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