From f7b939bdbcd5d6fd11a638316138d1752acae78e Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Wed, 30 Mar 2016 23:00:23 +0100
Subject: [PATCH] Add support 32 bit FS_IOC32_{GET|SET}FLAGS compat ioctls

We need 32 bit userspace FS_IOC32_GETFLAGS and FS_IOC32_SETFLAGS
compat ioctls for systems such as powerpc64.  We use the normal
compat ioctl idiom as used by a variety of file systems to provide
this support.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #4477
---
 module/zfs/zpl_file.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/module/zfs/zpl_file.c b/module/zfs/zpl_file.c
index a23bc7d8dd..5c430c7ca8 100644
--- a/module/zfs/zpl_file.c
+++ b/module/zfs/zpl_file.c
@@ -24,6 +24,9 @@
  */
 
 
+#ifdef CONFIG_COMPAT
+#include <linux/compat.h>
+#endif
 #include <sys/dmu_objset.h>
 #include <sys/zfs_vfsops.h>
 #include <sys/zfs_vnops.h>
@@ -798,7 +801,17 @@ zpl_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 static long
 zpl_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
-	return (zpl_ioctl(filp, cmd, arg));
+	switch (cmd) {
+	case FS_IOC32_GETFLAGS:
+		cmd = FS_IOC_GETFLAGS;
+		break;
+	case FS_IOC32_SETFLAGS:
+		cmd = FS_IOC_SETFLAGS;
+		break;
+	default:
+		return (-ENOTTY);
+	}
+	return (zpl_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)));
 }
 #endif /* CONFIG_COMPAT */