[2/3] target: iscsi: forbid call iscsit_close_session() from atomic context

Commit Message

Dmitry Bogdanov Oct. 3, 2022, 8:27 p.m. UTC

Since all calls iscsit_close_session() are now from non-atomic context,
remove can_sleep argument and forbid call iscsit_close_session() from
an atomic context in the future.

Signed-off-by: Dmitry Bogdanov <[e-mail]>
---
 drivers/target/iscsi/iscsi_target.c      | 22 +++++++++-------------
 drivers/target/iscsi/iscsi_target.h      |  2 +-
 drivers/target/iscsi/iscsi_target_util.c |  5 +----
 drivers/target/iscsi/iscsi_target_util.h |  2 +-
 4 files changed, 12 insertions(+), 19 deletions(-)

Patch

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 36166eabf595..3e91523e540b 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4460,7 +4460,7 @@  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, true);
+		iscsit_close_session(sess);
 
 		return 0;
 	} else if (atomic_read(&sess->session_logout)) {
@@ -4470,7 +4470,7 @@  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, true);
+			iscsit_close_session(sess);
 		} else {
 			spin_unlock_bh(&sess->conn_lock);
 		}
@@ -4486,7 +4486,7 @@  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, true);
+			iscsit_close_session(sess);
 		} else {
 			spin_unlock_bh(&sess->conn_lock);
 		}
@@ -4500,18 +4500,20 @@  void iscsit_session_close_worker(struct work_struct *workp)
 	struct iscsit_session *sess = container_of(workp, struct iscsit_session,
 						   session_close_worker);
 
-	iscsit_close_session(sess, true);
+	iscsit_close_session(sess);
 }
 
 /*
  * If the iSCSI Session for the iSCSI Initiator Node exists,
  * forcefully shutdown the iSCSI NEXUS.
  */
-int iscsit_close_session(struct iscsit_session *sess, bool can_sleep)
+int iscsit_close_session(struct iscsit_session *sess)
 {
 	struct iscsi_portal_group *tpg = sess->tpg;
 	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
 
+	might_sleep();
+
 	if (atomic_read(&sess->nconn)) {
 		pr_err("%d connection(s) still exist for iSCSI session"
 			" to %s\n", atomic_read(&sess->nconn),
@@ -4536,15 +4538,9 @@  int iscsit_close_session(struct iscsit_session *sess, bool can_sleep)
 
 	/*
 	 * If any other processes are accessing this session pointer we must
-	 * wait until they have completed.  If we are in an interrupt (the
-	 * time2retain handler) and contain and active session usage count we
-	 * restart the timer and exit.
+	 * wait until they have completed.
 	 */
-	if (iscsit_check_session_usage_count(sess, can_sleep)) {
-		atomic_set(&sess->session_logout, 0);
-		iscsit_start_time2retain_handler(sess);
-		return 0;
-	}
+	iscsit_check_session_usage_count(sess);
 
 	transport_deregister_session(sess->se_sess);
 
diff --git a/drivers/target/iscsi/iscsi_target.h b/drivers/target/iscsi/iscsi_target.h
index a529294a21ce..054a47711bed 100644
--- 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 iscsit_conn *);
 extern int iscsi_target_tx_thread(void *);
 extern int iscsi_target_rx_thread(void *);
 extern int iscsit_close_connection(struct iscsit_conn *);
-extern int iscsit_close_session(struct iscsit_session *, bool can_sleep);
+extern int iscsit_close_session(struct iscsit_session *sess);
 extern void iscsit_session_close_worker(struct work_struct *workp);
 extern void iscsit_fail_session(struct iscsit_session *);
 extern void iscsit_stop_session(struct iscsit_session *, int, int);
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 8d9f21372b67..b618468e766c 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -762,15 +762,12 @@  void iscsit_free_cmd(struct iscsit_cmd *cmd, bool shutdown)
 }
 EXPORT_SYMBOL(iscsit_free_cmd);
 
-bool iscsit_check_session_usage_count(struct iscsit_session *sess,
-				      bool can_sleep)
+bool iscsit_check_session_usage_count(struct iscsit_session *sess)
 {
 	spin_lock_bh(&sess->session_usage_lock);
 	if (sess->session_usage_count != 0) {
 		sess->session_waiting_on_uc = 1;
 		spin_unlock_bh(&sess->session_usage_lock);
-		if (!can_sleep)
-			return true;
 
 		wait_for_completion(&sess->session_waiting_on_uc_comp);
 		return false;
diff --git a/drivers/target/iscsi/iscsi_target_util.h b/drivers/target/iscsi/iscsi_target_util.h
index 33ea799a0850..8f99971c0f2d 100644
--- a/drivers/target/iscsi/iscsi_target_util.h
+++ b/drivers/target/iscsi/iscsi_target_util.h
@@ -40,7 +40,7 @@  extern void iscsit_free_queue_reqs_for_conn(struct iscsit_conn *);
 extern void iscsit_release_cmd(struct iscsit_cmd *);
 extern void __iscsit_free_cmd(struct iscsit_cmd *, bool);
 extern void iscsit_free_cmd(struct iscsit_cmd *, bool);
-extern bool iscsit_check_session_usage_count(struct iscsit_session *sess, bool can_sleep);
+extern bool iscsit_check_session_usage_count(struct iscsit_session *sess);
 extern void iscsit_dec_session_usage_count(struct iscsit_session *);
 extern void iscsit_inc_session_usage_count(struct iscsit_session *);
 extern struct iscsit_conn *iscsit_get_conn_from_cid(struct iscsit_session *, u16);