iscsi-target: Convert iscsi_session statistics to atomic_long_t

This patch converts a handful of iscsi_session statistics to type
atomic_long_t, instead of using iscsi_session->session_stats_lock
when incrementing these values.

More importantly, go ahead and drop the spinlock usage within
iscsit_setup_scsi_cmd(), iscsit_check_dataout_hdr(),
iscsit_send_datain(), and iscsit_build_rsp_pdu() fast-path code.

(Squash in Roland's  target: Remove write-only stats fields and lock
from struct se_node_acl)

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 6 insertions, 7 deletions

diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index b03ee2ff31e5..f2094d2f8eef 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -651,14 +651,13 @@ struct iscsi_session {
 	/* Used for session reference counting */
 	int			session_usage_count;
 	int			session_waiting_on_uc;
-	u32			cmd_pdus;
-	u32			rsp_pdus;
-	u64			tx_data_octets;
-	u64			rx_data_octets;
-	u32			conn_digest_errors;
-	u32			conn_timeout_errors;
+	atomic_long_t		cmd_pdus;
+	atomic_long_t		rsp_pdus;
+	atomic_long_t		tx_data_octets;
+	atomic_long_t		rx_data_octets;
+	atomic_long_t		conn_digest_errors;
+	atomic_long_t		conn_timeout_errors;
 	u64			creation_time;
-	spinlock_t		session_stats_lock;
 	/* Number of active connections */
 	atomic_t		nconn;
 	atomic_t		session_continuation;