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isert: fix a race between calling to rdma_disconnect and connect flow

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1) The race can happen after unreachable event handler close isert connection
and calling to rdma_disconnect from another thread on illegal cm_id.
For example call rdma_disconnect from isert_portal_release function.

2) It is also possible to get ESTABLISHED RDMACM event while rdma_disconnect
is called from another thread.
In established event we need to check conn is not in
teardown flow by checking the connection state with a mutex.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@6950 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This commit is contained in:
Israel Rukshin
2016-08-17 07:28:16 +00:00
parent 79949e9b4c
commit 87902c8722
2 changed files with 29 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files
iscsi-scst/kernel/isert-scst/iser.h
+1
View File
@@ -188,6 +188,7 @@ struct isert_connection {
struct isert_cq *cq_desc;
enum isert_conn_state state;
struct mutex state_mutex;
u32 responder_resources;
u32 initiator_depth;
iscsi-scst/kernel/isert-scst/iser_rdma.c
+28 -11
View File
@@ -204,6 +204,7 @@ void isert_conn_disconnect(struct isert_connection *isert_conn)
{
int err;
mutex_lock(&isert_conn->state_mutex);
if (isert_conn->state != ISER_CONN_CLOSING) {
isert_conn->state = ISER_CONN_CLOSING;
@@ -212,6 +213,7 @@ void isert_conn_disconnect(struct isert_connection *isert_conn)
if (unlikely(err))
PRINT_ERROR("Failed to rdma disconnect, err:%d", err);
}
mutex_unlock(&isert_conn->state_mutex);
}
static int isert_pdu_handle_hello_req(struct isert_cmnd *pdu)
@@ -1309,6 +1311,7 @@ static struct isert_connection *isert_conn_create(struct rdma_cm_id *cm_id,
}
kref_init(&isert_conn->kref);
mutex_init(&isert_conn->state_mutex);
TRACE_EXIT();
return isert_conn;
@@ -1397,6 +1400,20 @@ static int isert_cm_disconnected_handler(struct rdma_cm_id *cm_id,
return 0;
}
static void isert_immediate_conn_close(struct isert_connection* isert_conn)
{
set_bit(ISERT_CONNECTION_ABORTED, &isert_conn->flags);
set_bit(ISERT_CONNECTION_CLOSE, &isert_conn->flags);
isert_conn->state = ISER_CONN_CLOSING;
/*
* reaching here must be with the isert_conn refcount of 2,
* one from the init and one from the connect request,
* thus it is safe to deref directly before the sched_conn_free.
*/
isert_conn_free(isert_conn);
isert_sched_conn_free(isert_conn);
}
static int isert_cm_conn_req_handler(struct rdma_cm_id *cm_id,
struct rdma_cm_event *event)
{
@@ -1530,14 +1547,17 @@ static int isert_cm_connect_handler(struct rdma_cm_id *cm_id,
{
struct isert_connection *isert_conn = cm_id->qp->qp_context;
int push_saved_pdu = 0;
int ret;
int ret = 0;
TRACE_ENTRY();
mutex_lock(&isert_conn->state_mutex);
if (isert_conn->state == ISER_CONN_HANDSHAKE)
isert_conn->state = ISER_CONN_ACTIVE;
else if (isert_conn->state == ISER_CONN_ACTIVE)
push_saved_pdu = 1;
else if (isert_conn->state == ISER_CONN_CLOSING)
goto out;
ret = isert_get_addr_size((struct sockaddr *)&isert_conn->peer_addr,
&isert_conn->peer_addrsz);
@@ -1566,6 +1586,7 @@ static int isert_cm_connect_handler(struct rdma_cm_id *cm_id,
}
out:
mutex_unlock(&isert_conn->state_mutex);
TRACE_EXIT_RES(ret);
return ret;
}
@@ -1711,17 +1732,13 @@ static int isert_cm_evt_handler(struct rdma_cm_id *cm_id,
/* We can receive this instead of RDMA_CM_EVENT_ESTABLISHED */
case RDMA_CM_EVENT_UNREACHABLE:
{
struct isert_connection *isert_conn;
struct isert_connection *isert_conn = cm_id->qp->qp_context;
isert_conn = cm_id->qp->qp_context;
set_bit(ISERT_CONNECTION_ABORTED, &isert_conn->flags);
/*
* reaching here must be with the isert_conn refcount of 2,
* one from the init and one from the connect request,
* thus it is safe to deref directly before the sched_conn_free.
*/
isert_conn_free(isert_conn);
isert_sched_conn_free(isert_conn);
mutex_lock(&isert_conn->state_mutex);
if (isert_conn->state != ISER_CONN_CLOSING) {
isert_immediate_conn_close(isert_conn);
}
mutex_unlock(&isert_conn->state_mutex);
err = 0;
}
break;