[SCSI] iser: fix handling of scsi cmnds during recovery.

After the stop_conn callback has returned the LLD should not
touch the scsi cmds. iscsi_tcp and libiscsi use the
conn->recv_lock and suspend_rx field to halt recv path
processing, but iser does not have any protection.

This patch modifies iser so that userspace can just
call the ep_disconnect callback, which will halt
all recv IO, before calling the stop_conn callback so
we do not have to worry about the conn->recv_lock and
suspend rx field. iser just needs to stop the send side
from accessing the ib conn.

Fixup to handle when the ep poll fails and ep disconnect
is called from Erez.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c
index d19cfe605ebb..5daed2bd710e 100644
--- a/drivers/infiniband/ulp/iser/iser_verbs.c
+++ b/drivers/infiniband/ulp/iser/iser_verbs.c
@@ -328,6 +328,17 @@ static void iser_conn_release(struct iser_conn *ib_conn)
 	kfree(ib_conn);
 }
 
+void iser_conn_get(struct iser_conn *ib_conn)
+{
+	atomic_inc(&ib_conn->refcount);
+}
+
+void iser_conn_put(struct iser_conn *ib_conn)
+{
+	if (atomic_dec_and_test(&ib_conn->refcount))
+		iser_conn_release(ib_conn);
+}
+
 /**
  * triggers start of the disconnect procedures and wait for them to be done
  */
@@ -349,7 +360,7 @@ void iser_conn_terminate(struct iser_conn *ib_conn)
 	wait_event_interruptible(ib_conn->wait,
 				 ib_conn->state == ISER_CONN_DOWN);
 
-	iser_conn_release(ib_conn);
+	iser_conn_put(ib_conn);
 }
 
 static void iser_connect_error(struct rdma_cm_id *cma_id)
@@ -496,6 +507,7 @@ int iser_conn_init(struct iser_conn **ibconn)
 	init_waitqueue_head(&ib_conn->wait);
 	atomic_set(&ib_conn->post_recv_buf_count, 0);
 	atomic_set(&ib_conn->post_send_buf_count, 0);
+	atomic_set(&ib_conn->refcount, 1);
 	INIT_LIST_HEAD(&ib_conn->conn_list);
 	spin_lock_init(&ib_conn->lock);