Re: [PATCH] NFS support for btrfs - v2

[David Woodhouse <dwmw2@infradead.org>]

On Mon, 2008-08-18 at 12:51 +0100, David Woodhouse wrote:
> The patch below works OK, but doesn't yet handle
> subvolumes -- it gives the same fsid for all subvolumes.

Is this the correct fix?

diff --git a/super.c b/super.c
index 6446ab7..55f4d00 100644
--- a/super.c
+++ b/super.c
@@ -503,6 +503,10 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	   on a big-endian or little-endian host */
 	buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
 	buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
+	/* Mask in the root object ID too, to disambiguate subvols */
+	buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
+	buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
+
 	return 0;
 }
 

-- 
David Woodhouse                            Open Source Technology Centre
David.Woodhouse@intel.com                              Intel Corporation