[Samba] Slow population of Properties in Windows Explorer

[Jeremy Allison]

On Fri, Apr 07, 2017 at 04:58:52PM -0400, Andrew Richards wrote:
> I should have noted; we did try an 'ls -R' on the Samba server
> itself on the same directory to try to rule out the local filesystem
> being behind the lag. That command returned almost immediately, which
>led us to believe that something with how Samba is relaying the filesystem metadata to the Windows clients was to blame. 

No, ls -R won't read the xattrs.

> Is Windows Explorer querying all the subordinate ACLs recursively
> along with simply doing a count on the number of file and their aggregate size when a Properties window is opened? I wouldn't expect it to try to query the complete ACL state recursively, though I could see it having to request access to each and every item it is counting. 

We don't know without more data. Can you get comparative wireshark
logs of the SMB2 traffic ?

> Is Samba doing any kind of translation of the xattrs for the sake of Windows?
> We're using 'vfs objects = acl_xattr streams_xattr' in our smb.conf. The streams_xattr module steers ACL data into the XFS xattrs, should we expect significant computational overhead reading them back out? Is Samba having to interpret each xattr entry and translate them on the fly to return the values the Windows clients are expecting? It stands to reason it could be, and that doing so en masse would result in what we're seeing. 

Yes, they're a data store that has to be read.

> Does anyone have insight on what exactly Windows Explorer's
> Properties window is doing when opened on a top-level directory on a large mounted Samba share?

You can get this by using wireshark !