From 19e8ac2721148a475833d7b5f893f9b81fbb0045 Mon Sep 17 00:00:00 2001
From: Jie Liu <jeff.liu@oracle.com>
Date: Tue, 21 Jan 2014 15:48:34 -0800
Subject: 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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 fs/ocfs2/ioctl.c | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'fs/ocfs2/ioctl.c')

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;
 
-- 
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