[SCSI] bnx2i: Added fix for NOP-Out response panic from unsolicited N…

…OP-In

The patch fixes the following situations where NOP-Out pkt is called for:
- local unsolicited NOP-Out requests (requesting no NOP-In response)
- local NOP-Out responses to unsolicited NOP-In requests

kernel panic is observed due to double session spin_lock requests; one in the
bnx2i_process_nopin_local_cmpl routine in bnx2i_hwi.c and the other in the
iscsi_put_task routine in libiscsi.c

The proposed fix is to export the currently static __iscsi_put_task() routine
and have bnx2i call it directly instead of the iscsi_put_task() routine which
holds the session spin lock.

Signed-off-by: Eddie Wai <eddie.wai@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Reviewed-by: Anil Veerabhadrappa <anilgv@broadcom.com>
Acked-by: Benjamin Li <benli@broadcom.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/bnx2i/bnx2i_hwi.c

@@ -1513,7 +1513,7 @@ static void bnx2i_process_nopin_local_cmpl(struct iscsi_session *session,
 	task = iscsi_itt_to_task(conn,
 				 nop_in->itt & ISCSI_NOP_IN_MSG_INDEX);
 	if (task)
-		iscsi_put_task(task);
+		__iscsi_put_task(task);
 	spin_unlock(&session->lock);
 }
 

drivers/scsi/libiscsi.c

@@ -539,11 +539,12 @@ void __iscsi_get_task(struct iscsi_task *task)
 }
 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 
-static void __iscsi_put_task(struct iscsi_task *task)
+void __iscsi_put_task(struct iscsi_task *task)
 {
 	if (atomic_dec_and_test(&task->refcount))
 		iscsi_free_task(task);
 }
+EXPORT_SYMBOL_GPL(__iscsi_put_task);
 
 void iscsi_put_task(struct iscsi_task *task)
 {

include/scsi/libiscsi.h

@@ -419,6 +419,7 @@ extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
 extern void iscsi_requeue_task(struct iscsi_task *task);
 extern void iscsi_put_task(struct iscsi_task *task);
+extern void __iscsi_put_task(struct iscsi_task *task);
 extern void __iscsi_get_task(struct iscsi_task *task);
 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
 				     uint32_t exp_cmdsn, uint32_t max_cmdsn);