On Sat, Nov 05, 2016 at 01:26:34PM -0400, je...@suse.com wrote:
> From: Jeff Mahoney <je...@suse.com>
> 
> Commit 3de4586c527 (Btrfs: Allow subvolumes and snapshots anywhere
> in the directory tree) introduced the current system of placing
> snapshots in the directory tree.  It also introduced the behavior of
> creating the snapshot and then creating the directory entries for it.
> 
> We've kept this code around for compatibility reasons, but it turns
> out that no file systems with the old tree_root based snapshots can
> be mounted on newer (>= 2009) kernels anyway.  About a month after the
> above commit, commit 2a7108ad89e (Btrfs: rev the disk format for the
> inode compat and csum selection changes) landed, changing the superblock
> magic number.
> 
> As a result, we know that we'll never encounter tree_root-based dirents
> or have to deal with skipping our own snapshot dirents.  Since that
> also means that we're now only iterating over DIR_INDEX items, which only
> contain one directory entry per leaf item, we don't need to loop over
> the leaf item contents anymore either.
> 
> Signed-off-by: Jeff Mahoney <je...@suse.com>

Reviewed-by: David Sterba <dste...@suse.com>
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