From 159c18b98bd316fb4cac390c631d13bd34f7a130 Mon Sep 17 00:00:00 2001
From: Dominique Martinet <dominique.martinet@cea.fr>
Date: Tue, 19 Sep 2017 12:50:13 +0900
Subject: [PATCH] hfi1/ioctl: only forward ioctl if hfi1_file_ioctl didn't
 handle it

Conflicts:
	kernel/syscall.c
---
 kernel/file_ops.c |  4 ++--
 kernel/syscall.c  | 22 +++++++++++++---------
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/kernel/file_ops.c b/kernel/file_ops.c
index e75ee0f9..730386ab 100644
--- a/kernel/file_ops.c
+++ b/kernel/file_ops.c
@@ -424,7 +424,7 @@ long hfi1_file_ioctl(void *private_data, unsigned int cmd,
 	struct hfi1_ctxtdata *uctxt = fd->uctxt;
 	struct hfi1_tid_info tinfo;
 	unsigned long addr;
-	int ret = 0;
+	int ret = -ENOTSUPP;
 
 	hfi1_cdbg(IOCTL, "IOCTL recv: 0x%x", cmd);
 	if (cmd != HFI1_IOCTL_ASSIGN_CTXT &&
@@ -649,7 +649,7 @@ long hfi1_file_ioctl(void *private_data, unsigned int cmd,
 		break;
 
 	default:
-		return -EINVAL;
+		return -ENOTSUPP;
 	}
 	return ret;
 }
diff --git a/kernel/syscall.c b/kernel/syscall.c
index ebb8a7ad..a8d1aa15 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -3157,24 +3157,28 @@ SYSCALL_DECLARE(ioctl)
 			break;
 	ihk_mc_spinlock_unlock(&proc->mckfd_lock, irqstate);
 
-	if(fdp && fdp->ioctl_cb){
-		//kprintf("ioctl: found system fd %d\n", fd);
-		rc = fdp->ioctl_cb(fdp, ctx);
-	}
-	else{
-		rc = syscall_generic_forwarding(__NR_ioctl, ctx);
-	}
-
 	if (private_data) {
 		extern long hfi1_file_ioctl(void *private_data,
 				unsigned int cmd,
 			    unsigned long arg,
 				unsigned long t_s);
 
-		hfi1_file_ioctl(private_data,
+		rc = hfi1_file_ioctl(private_data,
 				ihk_mc_syscall_arg1(ctx),
 				ihk_mc_syscall_arg2(ctx),
 				t_s);
+		/* continue forwarding iff hfi1 didn't handle it */
+		// TODO: improve heuristics?
+		if (rc != -ENOTSUPP)
+			return rc;
+	}
+
+	if (fdp && fdp->ioctl_cb) {
+		//kprintf("ioctl: found system fd %d\n", fd);
+		rc = fdp->ioctl_cb(fdp, ctx);
+	}
+	else {
+		rc = syscall_generic_forwarding(__NR_ioctl, ctx);
 	}
 
 	return rc;