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IB/core: lock client data with lists_rwsem

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An ib_client callback that is called with the lists_rwsem locked only for
read is protected from changes to the IB client lists, but not from
ib_unregister_device() freeing its client data. This is because
ib_unregister_device() will remove the device from the device list with
lists_rwsem locked for write, but perform the rest of the cleanup,
including the call to remove() without that lock.

Mark client data that is undergoing de-registration with a new going_down
flag in the client data context. Lock the client data list with lists_rwsem
for write in addition to using the spinlock, so that functions calling the
callback would be able to lock only lists_rwsem for read and let callbacks
sleep.

Since ib_unregister_client() now marks the client data context, no need for
remove() to search the context again, so pass the client data directly to
remove() callbacks.

Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Haggai Eran
2015-07-30 17:50:14 +03:00
committed by Doug Ledford
parent 5aa44bb90f
commit 7c1eb45a22
16 changed files with 82 additions and 52 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/infiniband/core/cache.c
View File

@@ -394,7 +394,7 @@ err:
kfree(device->cache.lmc_cache);
}
static void ib_cache_cleanup_one(struct ib_device *device)
static void ib_cache_cleanup_one(struct ib_device *device, void *client_data)
{
int p;

7
drivers/infiniband/core/cm.c
View File

@@ -58,7 +58,7 @@ MODULE_DESCRIPTION("InfiniBand CM");
MODULE_LICENSE("Dual BSD/GPL");
static void cm_add_one(struct ib_device *device);
static void cm_remove_one(struct ib_device *device);
static void cm_remove_one(struct ib_device *device, void *client_data);
static struct ib_client cm_client = {
.name = "cm",
@@ -3886,9 +3886,9 @@ free:
kfree(cm_dev);
}
static void cm_remove_one(struct ib_device *ib_device)
static void cm_remove_one(struct ib_device *ib_device, void *client_data)
{
struct cm_device *cm_dev;
struct cm_device *cm_dev = client_data;
struct cm_port *port;
struct ib_port_modify port_modify = {
.clr_port_cap_mask = IB_PORT_CM_SUP
@@ -3896,7 +3896,6 @@ static void cm_remove_one(struct ib_device *ib_device)
unsigned long flags;
int i;
cm_dev = ib_get_client_data(ib_device, &cm_client);
if (!cm_dev)
return;

7
drivers/infiniband/core/cma.c
View File

@@ -94,7 +94,7 @@ const char *rdma_event_msg(enum rdma_cm_event_type event)
EXPORT_SYMBOL(rdma_event_msg);
static void cma_add_one(struct ib_device *device);
static void cma_remove_one(struct ib_device *device);
static void cma_remove_one(struct ib_device *device, void *client_data);
static struct ib_client cma_client = {
.name = "cma",
@@ -3554,11 +3554,10 @@ static void cma_process_remove(struct cma_device *cma_dev)
wait_for_completion(&cma_dev->comp);
}
static void cma_remove_one(struct ib_device *device)
static void cma_remove_one(struct ib_device *device, void *client_data)
{
struct cma_device *cma_dev;
struct cma_device *cma_dev = client_data;
cma_dev = ib_get_client_data(device, &cma_client);
if (!cma_dev)
return;

53
drivers/infiniband/core/device.c
View File

@@ -50,6 +50,9 @@ struct ib_client_data {
struct list_head list;
struct ib_client *client;
void * data;
/* The device or client is going down. Do not call client or device
* callbacks other than remove(). */
bool going_down;
};
struct workqueue_struct *ib_wq;
@@ -69,6 +72,8 @@ static LIST_HEAD(client_list);
* to the lists must be done with a write lock. A special case is when the
* device_mutex is locked. In this case locking the lists for read access is
* not necessary as the device_mutex implies it.
*
* lists_rwsem also protects access to the client data list.
*/
static DEFINE_MUTEX(device_mutex);
static DECLARE_RWSEM(lists_rwsem);
@@ -210,10 +215,13 @@ static int add_client_context(struct ib_device *device, struct ib_client *client
context->client = client;
context->data = NULL;
context->going_down = false;
down_write(&lists_rwsem);
spin_lock_irqsave(&device->client_data_lock, flags);
list_add(&context->list, &device->client_data_list);
spin_unlock_irqrestore(&device->client_data_lock, flags);
up_write(&lists_rwsem);
return 0;
}
@@ -339,7 +347,6 @@ EXPORT_SYMBOL(ib_register_device);
*/
void ib_unregister_device(struct ib_device *device)
{
struct ib_client *client;
struct ib_client_data *context, *tmp;
unsigned long flags;
@@ -347,20 +354,29 @@ void ib_unregister_device(struct ib_device *device)
down_write(&lists_rwsem);
list_del(&device->core_list);
up_write(&lists_rwsem);
spin_lock_irqsave(&device->client_data_lock, flags);
list_for_each_entry_safe(context, tmp, &device->client_data_list, list)
context->going_down = true;
spin_unlock_irqrestore(&device->client_data_lock, flags);
downgrade_write(&lists_rwsem);
list_for_each_entry_reverse(client, &client_list, list)
if (client->remove)
client->remove(device);
list_for_each_entry_safe(context, tmp, &device->client_data_list,
list) {
if (context->client->remove)
context->client->remove(device, context->data);
}
up_read(&lists_rwsem);
mutex_unlock(&device_mutex);
ib_device_unregister_sysfs(device);
down_write(&lists_rwsem);
spin_lock_irqsave(&device->client_data_lock, flags);
list_for_each_entry_safe(context, tmp, &device->client_data_list, list)
kfree(context);
spin_unlock_irqrestore(&device->client_data_lock, flags);
up_write(&lists_rwsem);
device->reg_state = IB_DEV_UNREGISTERED;
}
@@ -420,16 +436,35 @@ void ib_unregister_client(struct ib_client *client)
up_write(&lists_rwsem);
list_for_each_entry(device, &device_list, core_list) {
if (client->remove)
client->remove(device);
struct ib_client_data *found_context = NULL;
down_write(&lists_rwsem);
spin_lock_irqsave(&device->client_data_lock, flags);
list_for_each_entry_safe(context, tmp, &device->client_data_list, list)
if (context->client == client) {
list_del(&context->list);
kfree(context);
context->going_down = true;
found_context = context;
break;
}
spin_unlock_irqrestore(&device->client_data_lock, flags);
up_write(&lists_rwsem);
if (client->remove)
client->remove(device, found_context ?
found_context->data : NULL);
if (!found_context) {
pr_warn("No client context found for %s/%s\n",
device->name, client->name);
continue;
}
down_write(&lists_rwsem);
spin_lock_irqsave(&device->client_data_lock, flags);
list_del(&found_context->list);
kfree(found_context);
spin_unlock_irqrestore(&device->client_data_lock, flags);
up_write(&lists_rwsem);
}
mutex_unlock(&device_mutex);

2
drivers/infiniband/core/mad.c
View File

@@ -3335,7 +3335,7 @@ error:
}
}
static void ib_mad_remove_device(struct ib_device *device)
static void ib_mad_remove_device(struct ib_device *device, void *client_data)
{
int i;

7
drivers/infiniband/core/multicast.c
View File

@@ -43,7 +43,7 @@
#include "sa.h"
static void mcast_add_one(struct ib_device *device);
static void mcast_remove_one(struct ib_device *device);
static void mcast_remove_one(struct ib_device *device, void *client_data);
static struct ib_client mcast_client = {
.name = "ib_multicast",
@@ -840,13 +840,12 @@ static void mcast_add_one(struct ib_device *device)
ib_register_event_handler(&dev->event_handler);
}
static void mcast_remove_one(struct ib_device *device)
static void mcast_remove_one(struct ib_device *device, void *client_data)
{
struct mcast_device *dev;
struct mcast_device *dev = client_data;
struct mcast_port *port;
int i;
dev = ib_get_client_data(device, &mcast_client);
if (!dev)
return;

6
drivers/infiniband/core/sa_query.c
View File

@@ -107,7 +107,7 @@ struct ib_sa_mcmember_query {
};
static void ib_sa_add_one(struct ib_device *device);
static void ib_sa_remove_one(struct ib_device *device);
static void ib_sa_remove_one(struct ib_device *device, void *client_data);
static struct ib_client sa_client = {
.name = "sa",
@@ -1221,9 +1221,9 @@ free:
return;
}
static void ib_sa_remove_one(struct ib_device *device)
static void ib_sa_remove_one(struct ib_device *device, void *client_data)
{
struct ib_sa_device *sa_dev = ib_get_client_data(device, &sa_client);
struct ib_sa_device *sa_dev = client_data;
int i;
if (!sa_dev)

6
drivers/infiniband/core/ucm.c
View File

@@ -109,7 +109,7 @@ enum {
#define IB_UCM_BASE_DEV MKDEV(IB_UCM_MAJOR, IB_UCM_BASE_MINOR)
static void ib_ucm_add_one(struct ib_device *device);
static void ib_ucm_remove_one(struct ib_device *device);
static void ib_ucm_remove_one(struct ib_device *device, void *client_data);
static struct ib_client ucm_client = {
.name = "ucm",
@@ -1310,9 +1310,9 @@ err:
return;
}
static void ib_ucm_remove_one(struct ib_device *device)
static void ib_ucm_remove_one(struct ib_device *device, void *client_data)
{
struct ib_ucm_device *ucm_dev = ib_get_client_data(device, &ucm_client);
struct ib_ucm_device *ucm_dev = client_data;
if (!ucm_dev)
return;

6
drivers/infiniband/core/user_mad.c
View File

@@ -133,7 +133,7 @@ static DEFINE_SPINLOCK(port_lock);
static DECLARE_BITMAP(dev_map, IB_UMAD_MAX_PORTS);
static void ib_umad_add_one(struct ib_device *device);
static void ib_umad_remove_one(struct ib_device *device);
static void ib_umad_remove_one(struct ib_device *device, void *client_data);
static void ib_umad_release_dev(struct kobject *kobj)
{
@@ -1322,9 +1322,9 @@ free:
kobject_put(&umad_dev->kobj);
}
static void ib_umad_remove_one(struct ib_device *device)
static void ib_umad_remove_one(struct ib_device *device, void *client_data)
{
struct ib_umad_device *umad_dev = ib_get_client_data(device, &umad_client);
struct ib_umad_device *umad_dev = client_data;
int i;
if (!umad_dev)

6
drivers/infiniband/core/uverbs_main.c
View File

@@ -128,7 +128,7 @@ static int (*uverbs_ex_cmd_table[])(struct ib_uverbs_file *file,
};
static void ib_uverbs_add_one(struct ib_device *device);
static void ib_uverbs_remove_one(struct ib_device *device);
static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
static void ib_uverbs_release_dev(struct kref *ref)
{
@@ -948,9 +948,9 @@ err:
return;
}
static void ib_uverbs_remove_one(struct ib_device *device)
static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
{
struct ib_uverbs_device *uverbs_dev = ib_get_client_data(device, &uverbs_client);
struct ib_uverbs_device *uverbs_dev = client_data;
if (!uverbs_dev)
return;