[Samba] poor samba performance with many smaller files

[Jeremy Allison]

On Thu, Apr 28, 2016 at 02:06:30PM +0200, Peter Bulin wrote:
> I removed the O_CREAT|O_EXCL checks and added check to exclude O_DIRECTORY,
> but it is not working, opening of files fails and I don't know why.
> I can see in strace logs that openat syscall in vfs_aio_pthread was
> successful, but it still fails and this messages are logged:
> 
> [2016/04/28 13:28:59.691782,  5, pid=5623, effective(32697, 10513),
> real(32697, 0)] ../source3/smbd/open.c:2551(open_file_ntcreate)
>   open_file_ntcreate: FILE_OPEN requested for file subor and file doesn't
> exist.
> 
> [2016/04/28 13:28:59.693969, 10, pid=5623, effective(32697, 10513),
> real(32697, 0)] ../source3/smbd/open.c:4806(create_file_unixpath)
>   create_file_unixpath: NT_STATUS_OBJECT_NAME_NOT_FOUND
> 
> Any idea what is wrong?

Nope, you'll have to dig into this yourself for now.

> And if stat() is the problem, could SMB_VFS_STAT be implemented in
> vfs_aio_pthread module the same way SMB_VFS_OPEN is implemented?

No. Stat's are expected to be *fast*. Really *fast*.

If stat is very slow, you have other problems.