[PATCH 2/2] ext3: Add FITRIM handle for ext3

[Lukas Czerner <lczerner@redhat.com>]

It takes fstrim_range structure as an argument. fstrim_range is definec in
the include/linux/fs.h.

After the FITRIM is done, the number of actually discarded Bytes is stored
in fstrim_range.len to give the user better insight on how much storage
space has been really released for wear-leveling.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
---
 fs/ext3/ioctl.c |   22 ++++++++++++++++++++++
 1 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/fs/ext3/ioctl.c b/fs/ext3/ioctl.c
index 8897481..fc080dd 100644
--- a/fs/ext3/ioctl.c
+++ b/fs/ext3/ioctl.c
@@ -276,7 +276,29 @@ group_add_out:
 		mnt_drop_write(filp->f_path.mnt);
 		return err;
 	}
+	case FITRIM: {
 
+		struct super_block *sb = inode->i_sb;
+		struct fstrim_range range;
+		int ret = 0;
+
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (copy_from_user(&range, (struct fstrim_range *)arg,
+				   sizeof(range)))
+			return -EFAULT;
+
+		ret = ext3_trim_fs(sb, &range);
+		if (ret < 0)
+			return ret;
+
+		if (copy_to_user((struct fstrim_range *)arg, &range,
+				 sizeof(range)))
+			return -EFAULT;
+
+		return 0;
+	}
 
 	default:
 		return -ENOTTY;
-- 
1.7.2.3