[PATCH 5.19 459/717] scsi: iscsi: Add recv workqueue helpers

Greg Kroah-Hartman
2022-10-22T08:53:11Z

From: Mike Christie <michael.christie@oracle.com>

[ Upstream commit 8af809966c0b34cfacd8da9a412689b8e9910354 ]

Add helpers to allow the drivers to run their recv paths from libiscsi's
workqueue.

Link: https://lore.kernel.org/r/20220616224557.115234-3-michael.christie@oracle.com
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Stable-dep-of: 57569c37f0ad ("scsi: iscsi: iscsi_tcp: Fix null-ptr-deref while calling getpeername()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/libiscsi.c | 29 +++++++++++++++++++++++++++--
include/scsi/libiscsi.h | 4 ++++
2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 1bd772d9b804..8f73c8d6ef22 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -93,6 +93,16 @@ inline void iscsi_conn_queue_xmit(struct iscsi_conn *conn)
}
EXPORT_SYMBOL_GPL(iscsi_conn_queue_xmit);

+inline void iscsi_conn_queue_recv(struct iscsi_conn *conn)
+{
+ struct Scsi_Host *shost = conn->session->host;
+ struct iscsi_host *ihost = shost_priv(shost);
+
+ if (ihost->workq && !test_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags))
+ queue_work(ihost->workq, &conn->recvwork);
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_queue_recv);
+
static void __iscsi_update_cmdsn(struct iscsi_session *session,
uint32_t exp_cmdsn, uint32_t max_cmdsn)
{
@@ -1943,7 +1953,7 @@ EXPORT_SYMBOL_GPL(iscsi_suspend_queue);

/**
* iscsi_suspend_tx - suspend iscsi_data_xmit
- * @conn: iscsi conn tp stop processing IO on.
+ * @conn: iscsi conn to stop processing IO on.
*
* This function sets the suspend bit to prevent iscsi_data_xmit
* from sending new IO, and if work is queued on the xmit thread
@@ -1956,7 +1966,7 @@ void iscsi_suspend_tx(struct iscsi_conn *conn)

set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
if (ihost->workq)
- flush_workqueue(ihost->workq);
+ flush_work(&conn->xmitwork);
}
EXPORT_SYMBOL_GPL(iscsi_suspend_tx);

@@ -1966,6 +1976,21 @@ static void iscsi_start_tx(struct iscsi_conn *conn)
iscsi_conn_queue_xmit(conn);
}

+/**
+ * iscsi_suspend_rx - Prevent recvwork from running again.
+ * @conn: iscsi conn to stop.
+ */
+void iscsi_suspend_rx(struct iscsi_conn *conn)
+{
+ struct Scsi_Host *shost = conn->session->host;
+ struct iscsi_host *ihost = shost_priv(shost);
+
+ set_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
+ if (ihost->workq)
+ flush_work(&conn->recvwork);
+}
+EXPORT_SYMBOL_GPL(iscsi_suspend_rx);
+
/*
* We want to make sure a ping is in flight. It has timed out.
* And we are not busy processing a pdu that is making
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 51fb0c17815e..5a10e5acfad2 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -213,6 +213,8 @@ struct iscsi_conn {
struct list_head cmdqueue; /* data-path cmd queue */
struct list_head requeue; /* tasks needing another run */
struct work_struct xmitwork; /* per-conn. xmit workqueue */
+ /* recv */
+ struct work_struct recvwork;
unsigned long flags; /* ISCSI_CONN_FLAGs */

/* negotiated params */
@@ -452,8 +454,10 @@ extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
enum iscsi_param param, char *buf);
extern void iscsi_suspend_tx(struct iscsi_conn *conn);
+extern void iscsi_suspend_rx(struct iscsi_conn *conn);
extern void iscsi_suspend_queue(struct iscsi_conn *conn);
extern void iscsi_conn_queue_xmit(struct iscsi_conn *conn);
+extern void iscsi_conn_queue_recv(struct iscsi_conn *conn);

#define iscsi_conn_printk(prefix, _c, fmt, a...) \
iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
--
2.35.1