Re: Why Unionfs is better than Aufs

> > First reason
> 	:::
> > If we have a "save partition" on top, we also have the SFS files in
> > that partition. Aufs will refuse to mount those SFS files as they are
> > already inside a branch. Consequently, we are forced to copy the main
> > SFS file into RAM and mount it from there. However, Unionfs is quite
> > happy with mounting SFS files that are actually present in another
> > branch.
>
> Because I had experienced a recursive lock (deadlock) by a loopback
> branch (fs image in a branch fs), aufs rejects it.
> But it was a long time ago. It was early stage in aufs1 era.
> I will check it again with recent kernel.

It may work.
At least, my simple tests are passed.
Here is a patch for you. Test it well, if you want.


J. R. Okajima


diff --git a/fs/aufs/loop.c b/fs/aufs/loop.c
index 5fceec7..2a78a8d 100644
--- a/fs/aufs/loop.c
+++ b/fs/aufs/loop.c
@@ -32,6 +32,7 @@ int au_test_loopback_overlap(struct super_block *sb, struct dentry *h_d1,
 	struct inode *h_inode;
 	struct loop_device *l;
 
+	return 0;
 	h_inode = h_d1->d_inode;
 	if (MAJOR(h_inode->i_sb->s_dev) != LOOP_MAJOR)
 		return 0;