scsi: iscsi: Stop using the SCSI pointer

Instead of storing the iSCSI task pointer and the session age in the SCSI
pointer, use command-private variables. This patch prepares for removal of
the SCSI pointer from struct scsi_cmnd.

The list of iSCSI drivers has been obtained as follows:
$ git grep -lw iscsi_host_alloc
drivers/infiniband/ulp/iser/iscsi_iser.c
drivers/scsi/be2iscsi/be_main.c
drivers/scsi/bnx2i/bnx2i_iscsi.c
drivers/scsi/cxgbi/libcxgbi.c
drivers/scsi/iscsi_tcp.c
drivers/scsi/libiscsi.c
drivers/scsi/qedi/qedi_main.c
drivers/scsi/qla4xxx/ql4_os.c
include/scsi/libiscsi.h

Note: it is not clear to me how the qla4xxx driver can work without this
patch since it uses the scsi_cmnd::SCp.ptr member for two different
purposes:
- The qla4xxx driver uses this member to store a struct srb pointer.
- libiscsi uses this member to store a struct iscsi_task pointer.

Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Cc: Chris Leech <cleech@redhat.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Nilesh Javali <njavali@marvell.com>
Cc: Manish Rangankar <mrangankar@marvell.com>
Cc: Karen Xie <kxie@chelsio.com>
Cc: Ketan Mukadam <ketan.mukadam@broadcom.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>

iscsi

Link: https://lore.kernel.org/r/20220218195117.25689-26-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 10 insertions, 10 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 059dae8909ee..d69203d19f2c 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -462,7 +462,7 @@ static void iscsi_free_task(struct iscsi_task *task)
 
 	if (sc) {
 		/* SCSI eh reuses commands to verify us */
-		sc->SCp.ptr = NULL;
+		iscsi_cmd(sc)->task = NULL;
 		/*
 		 * queue command may call this to free the task, so
 		 * it will decide how to return sc to scsi-ml.
@@ -1344,10 +1344,10 @@ struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
 	if (!task || !task->sc)
 		return NULL;
 
-	if (task->sc->SCp.phase != conn->session->age) {
+	if (iscsi_cmd(task->sc)->age != conn->session->age) {
 		iscsi_session_printk(KERN_ERR, conn->session,
 				  "task's session age %d, expected %d\n",
-				  task->sc->SCp.phase, conn->session->age);
+				  iscsi_cmd(task->sc)->age, conn->session->age);
 		return NULL;
 	}
 
@@ -1645,8 +1645,8 @@ static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
 			 (void *) &task, sizeof(void *)))
 		return NULL;
 
-	sc->SCp.phase = conn->session->age;
-	sc->SCp.ptr = (char *) task;
+	iscsi_cmd(sc)->age = conn->session->age;
+	iscsi_cmd(sc)->task = task;
 
 	refcount_set(&task->refcount, 1);
 	task->state = ISCSI_TASK_PENDING;
@@ -1683,7 +1683,7 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
 	struct iscsi_task *task = NULL;
 
 	sc->result = 0;
-	sc->SCp.ptr = NULL;
+	iscsi_cmd(sc)->task = NULL;
 
 	ihost = shost_priv(host);
 
@@ -1997,7 +1997,7 @@ enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
 
 	spin_lock_bh(&session->frwd_lock);
 	spin_lock(&session->back_lock);
-	task = (struct iscsi_task *)sc->SCp.ptr;
+	task = iscsi_cmd(sc)->task;
 	if (!task) {
 		/*
 		 * Raced with completion. Blk layer has taken ownership
@@ -2260,7 +2260,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 	 * if session was ISCSI_STATE_IN_RECOVERY then we may not have
 	 * got the command.
 	 */
-	if (!sc->SCp.ptr) {
+	if (!iscsi_cmd(sc)->task) {
 		ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
 				      "it completed.\n");
 		spin_unlock_bh(&session->frwd_lock);
@@ -2273,7 +2273,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 	 * then let the host reset code handle this
 	 */
 	if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
-	    sc->SCp.phase != session->age) {
+	    iscsi_cmd(sc)->age != session->age) {
 		spin_unlock_bh(&session->frwd_lock);
 		mutex_unlock(&session->eh_mutex);
 		ISCSI_DBG_EH(session, "failing abort due to dropped "
@@ -2282,7 +2282,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
 	}
 
 	spin_lock(&session->back_lock);
-	task = (struct iscsi_task *)sc->SCp.ptr;
+	task = iscsi_cmd(sc)->task;
 	if (!task || !task->sc) {
 		/* task completed before time out */
 		ISCSI_DBG_EH(session, "sc completed while abort in progress\n");