scsi: target: iscsi: Avoid in_interrupt() usage in iscsit_close_session()

iscsit_close_session() uses in_interrupt() to decide if it needs to check
the return value of iscsit_check_session_usage_count() if it was not able
to sleep.

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated or the context be conveyed in an argument passed by the
caller, which usually knows the context.

iscsit_close_session() has two callers:

 - iscsit_handle_time2retain_timeout()
   A timer_list callback.

 - iscsit_close_connection()
   Runs in preemptible context, acquires a mutex.

Add an argument to iscsit_close_session() indicating if sleeping is
possible.

Link: https://lore.kernel.org/r/20201220203638.43615-2-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 518fac4864cfa61ed82098c9bc50aef0097d9d05..5abf03125388a960763d41a863b69ffaf16ad5a5 100644 (file)
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4327,7 +4327,7 @@ int iscsit_close_connection(
             atomic_read(&sess->session_fall_back_to_erl0)) {
                spin_unlock_bh(&sess->conn_lock);
                complete_all(&sess->session_wait_comp);
-               iscsit_close_session(sess);
+               iscsit_close_session(sess, true);
 
                return 0;
        } else if (atomic_read(&sess->session_logout)) {
@@ -4337,7 +4337,7 @@ int iscsit_close_connection(
                if (atomic_read(&sess->session_close)) {
                        spin_unlock_bh(&sess->conn_lock);
                        complete_all(&sess->session_wait_comp);
-                       iscsit_close_session(sess);
+                       iscsit_close_session(sess, true);
                } else {
                        spin_unlock_bh(&sess->conn_lock);
                }
@@ -4353,7 +4353,7 @@ int iscsit_close_connection(
                if (atomic_read(&sess->session_close)) {
                        spin_unlock_bh(&sess->conn_lock);
                        complete_all(&sess->session_wait_comp);
-                       iscsit_close_session(sess);
+                       iscsit_close_session(sess, true);
                } else {
                        spin_unlock_bh(&sess->conn_lock);
                }
@@ -4366,7 +4366,7 @@ int iscsit_close_connection(
  * If the iSCSI Session for the iSCSI Initiator Node exists,
  * forcefully shutdown the iSCSI NEXUS.
  */
-int iscsit_close_session(struct iscsi_session *sess)
+int iscsit_close_session(struct iscsi_session *sess, bool can_sleep)
 {
        struct iscsi_portal_group *tpg = sess->tpg;
        struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
@@ -4399,7 +4399,7 @@ int iscsit_close_session(struct iscsi_session *sess)
         * time2retain handler) and contain and active session usage count we
         * restart the timer and exit.
         */
-       if (!in_interrupt()) {
+       if (can_sleep) {
                iscsit_check_session_usage_count(sess);
        } else {
                if (iscsit_check_session_usage_count(sess) == 2) {

diff --git a/drivers/target/iscsi/iscsi_target.h b/drivers/target/iscsi/iscsi_target.h
index 7409ce2a66078f75ae3e130577ec29f5e21ddc18..b35a96ded9c19049eff78610e83cf42a23b94458 100644 (file)
--- a/drivers/target/iscsi/iscsi_target.h
+++ b/drivers/target/iscsi/iscsi_target.h
@@ -41,7 +41,7 @@ extern void iscsit_thread_get_cpumask(struct iscsi_conn *);
 extern int iscsi_target_tx_thread(void *);
 extern int iscsi_target_rx_thread(void *);
 extern int iscsit_close_connection(struct iscsi_conn *);
-extern int iscsit_close_session(struct iscsi_session *);
+extern int iscsit_close_session(struct iscsi_session *, bool can_sleep);
 extern void iscsit_fail_session(struct iscsi_session *);
 extern void iscsit_stop_session(struct iscsi_session *, int, int);
 extern int iscsit_release_sessions_for_tpg(struct iscsi_portal_group *, int);

diff --git a/drivers/target/iscsi/iscsi_target_erl0.c b/drivers/target/iscsi/iscsi_target_erl0.c
index b4abd7b68e6da3de03b4a0eee8c47e42d7276ea1..102c9cbf59f38d75f835f8fd9fc7530d3c527efc 100644 (file)
--- a/drivers/target/iscsi/iscsi_target_erl0.c
+++ b/drivers/target/iscsi/iscsi_target_erl0.c
@@ -765,7 +765,7 @@ void iscsit_handle_time2retain_timeout(struct timer_list *t)
 
        iscsit_fill_cxn_timeout_err_stats(sess);
        spin_unlock_bh(&se_tpg->session_lock);
-       iscsit_close_session(sess);
+       iscsit_close_session(sess, false);
 }
 
 void iscsit_start_time2retain_handler(struct iscsi_session *sess)