From f91f0ee5648c146bb87001159bbab7adc88b7b00 Mon Sep 17 00:00:00 2001
From: Jie Liu <jeff.liu@oracle.com>
Date: Tue, 17 Dec 2013 10:44:56 +1100
Subject: [PATCH] ocfs2: return EOPNOTSUPP if the device does not support
 discard

For FITRIM ioctl(2), we should return EOPNOTSUPP to inform the user that
the storage device does not support discard if it is, otherwise return
success would confuse the user even though there is no free blocks were
trimmed at all.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 fs/ocfs2/ioctl.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index fa32ce9b455d..4de6a2af592f 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -7,6 +7,7 @@
 
 #include <linux/fs.h>
 #include <linux/mount.h>
+#include <linux/blkdev.h>
 #include <linux/compat.h>
 
 #include <cluster/masklog.h>
@@ -966,12 +967,16 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	case FITRIM:
 	{
 		struct super_block *sb = inode->i_sb;
+		struct request_queue *q = bdev_get_queue(sb->s_bdev);
 		struct fstrim_range range;
 		int ret = 0;
 
 		if (!capable(CAP_SYS_ADMIN))
 			return -EPERM;
 
+		if (!blk_queue_discard(q))
+			return -EOPNOTSUPP;
+
 		if (copy_from_user(&range, argp, sizeof(range)))
 			return -EFAULT;
 
-- 
2.39.5