vfs: hoist the btrfs deduplication ioctl to the vfs

Hoist the btrfs EXTENT_SAME ioctl up to the VFS and make the name
more systematic (FIDEDUPERANGE).

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 38 insertions, 0 deletions

diff --git a/fs/ioctl.c b/fs/ioctl.c
index 84c6e79..fcdd33b 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -568,6 +568,41 @@ static int ioctl_fsthaw(struct file *filp)
 	return thaw_super(sb);
 }
 
+static long ioctl_file_dedupe_range(struct file *file, void __user *arg)
+{
+	struct file_dedupe_range __user *argp = arg;
+	struct file_dedupe_range *same = NULL;
+	int ret;
+	unsigned long size;
+	u16 count;
+
+	if (get_user(count, &argp->dest_count)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	size = offsetof(struct file_dedupe_range __user, info[count]);
+
+	same = memdup_user(argp, size);
+	if (IS_ERR(same)) {
+		ret = PTR_ERR(same);
+		same = NULL;
+		goto out;
+	}
+
+	ret = vfs_dedupe_file_range(file, same);
+	if (ret)
+		goto out;
+
+	ret = copy_to_user(argp, same, size);
+	if (ret)
+		ret = -EFAULT;
+
+out:
+	kfree(same);
+	return ret;
+}
+
 /*
  * When you add any new common ioctls to the switches above and below
  * please update compat_sys_ioctl() too.
@@ -629,6 +664,9 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
 	case FICLONERANGE:
 		return ioctl_file_clone_range(filp, argp);
 
+	case FIDEDUPERANGE:
+		return ioctl_file_dedupe_range(filp, argp);
+
 	default:
 		if (S_ISREG(inode->i_mode))
 			error = file_ioctl(filp, cmd, arg);