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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: target-devel@vger.kernel.org
Cc: linux-scsi@vger.kernel.org,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"Ahmed S . Darwish" <a.darwish@linutronix.de>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [PATCH 2/6] scsi: target: iscsi: Avoid in_interrupt() usage in iscsit_check_session_usage_count().
Date: Sun, 20 Dec 2020 21:36:34 +0100
Message-ID: <20201220203638.43615-3-bigeasy@linutronix.de> (raw)
In-Reply-To: <20201220203638.43615-1-bigeasy@linutronix.de>

iscsit_check_session_usage_count() uses in_interrupt() to find out if it
is safe to invoke wait_for_completion().

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.

There is only one caller of iscsit_check_session_usage_count() which
already has an argument indicating if it is safe to sleep.

Extend iscsit_check_session_usage_count() by an argument indicating if
it may sleep.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/target/iscsi/iscsi_target.c      | 4 ++--
 drivers/target/iscsi/iscsi_target_util.c | 4 ++--
 drivers/target/iscsi/iscsi_target_util.h | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 5abf03125388a..13de37ff9dc9f 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4400,9 +4400,9 @@ int iscsit_close_session(struct iscsi_session *sess, bool can_sleep)
 	 * restart the timer and exit.
 	 */
 	if (can_sleep) {
-		iscsit_check_session_usage_count(sess);
+		iscsit_check_session_usage_count(sess, can_sleep);
 	} else {
-		if (iscsit_check_session_usage_count(sess) == 2) {
+		if (iscsit_check_session_usage_count(sess, can_sleep) == 2) {
 			atomic_set(&sess->session_logout, 0);
 			iscsit_start_time2retain_handler(sess);
 			return 0;
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 45ba07c6ec270..50028b1d3b849 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -779,13 +779,13 @@ void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown)
 }
 EXPORT_SYMBOL(iscsit_free_cmd);
 
-int iscsit_check_session_usage_count(struct iscsi_session *sess)
+int iscsit_check_session_usage_count(struct iscsi_session *sess, bool can_sleep)
 {
 	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 (in_interrupt())
+		if (!can_sleep)
 			return 2;
 
 		wait_for_completion(&sess->session_waiting_on_uc_comp);
diff --git a/drivers/target/iscsi/iscsi_target_util.h b/drivers/target/iscsi/iscsi_target_util.h
index 68e84803b0a1a..a2c2401f29452 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 iscsi_conn *);
 extern void iscsit_release_cmd(struct iscsi_cmd *);
 extern void __iscsit_free_cmd(struct iscsi_cmd *, bool);
 extern void iscsit_free_cmd(struct iscsi_cmd *, bool);
-extern int iscsit_check_session_usage_count(struct iscsi_session *);
+extern int iscsit_check_session_usage_count(struct iscsi_session *sess, bool can_sleep);
 extern void iscsit_dec_session_usage_count(struct iscsi_session *);
 extern void iscsit_inc_session_usage_count(struct iscsi_session *);
 extern struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *, u16);
-- 
2.29.2


  parent reply index

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-20 20:36 [PATCH 0/6] scsi: target: Remove in_interrupt() usage Sebastian Andrzej Siewior
2020-12-20 20:36 ` [PATCH 1/6] scsi: target: iscsi: Avoid in_interrupt() usage in iscsit_close_session() Sebastian Andrzej Siewior
2020-12-20 20:36 ` Sebastian Andrzej Siewior [this message]
2020-12-20 20:36 ` [PATCH 3/6] scsi: target: iscsi: Redo iscsit_check_session_usage_count() return code Sebastian Andrzej Siewior
2020-12-20 20:36 ` [PATCH 4/6] scsi: target: Remove in_interrupt() usage in core_alua_check_nonop_delay() Sebastian Andrzej Siewior
2020-12-20 20:36 ` [PATCH 5/6] scsi: target: Replace in_interrupt() usage in target_submit_cmd_map_sgls() Sebastian Andrzej Siewior
2020-12-20 20:36 ` [PATCH 6/6] scsi: target: Remove in_interrupt() check in transport_handle_cdb_direct() Sebastian Andrzej Siewior
2021-01-22 16:51 ` [PATCH 0/6] scsi: target: Remove in_interrupt() usage Sebastian Andrzej Siewior
2021-01-23  1:28   ` Martin K. Petersen
2021-01-27  4:54 ` Martin K. Petersen

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