[Samba] slow directory access, convert_string_internal: Conversion error: Incomplete multibyte sequence

[Jeremy Allison]

On Tue, Nov 29, 2016 at 06:36:02PM -0500, Gaiseric Vandal via samba wrote:
> Mail file is server is a member server is Samba 3.6.26 on Solaris
> 11.    It had been a BDC but a few week ago a switched it back to a
> member server.  The 2 current DC's had been running Samba 3.6.25 but
> switched to Samba 4.4.7.  This is  a classic domain.
> 
> 
> 
> Some Windows users reported that browsing folders shared from the
> member server have become very slow over the last few weeks. Which
> may correlate to either changing server role on the main file server
> or upgrading the DC's to Samba 4.
> 
> 
> I do see this issue intermittently.  I open one file network folder
> with no problems.  I try another, and the progress bar progresses
> really slowly and it may time out.
> 
> 
> Some client machine logs shows things like:
> 
> 
>           smbd_dirptr_get_entry mask=[*] found
>        somedirectory/somedirectory/somefile/@�!�P fname=@�!�P (@�!�P)
>        [2016/11/29 18:23:02.279482,  3]
>        lib/charcnv.c:537(convert_string_talloc)
>           convert_string_talloc: Conversion error: Illegal multibyte
>        sequence(�!�P)
>        [2016/11/29 18:23:02.279560,  3]
>        lib/charcnv.c:528(convert_string_talloc)
>           convert_string_talloc: Conversion error: Incomplete multibyte
>        sequence(�P)
>        [2016/11/29 18:23:02.279628,  3]
>        lib/charcnv.c:161(convert_string_internal)
>           convert_string_internal: Conversion error: Illegal multibyte
>        sequence(�!�P)
>        [2016/11/29 18:23:02.279689,  3]
>        lib/charcnv.c:140(convert_string_internal)
>           convert_string_internal: Conversion error: Incomplete
>        multibyte sequence(�P)
>        [2016/11/29 18:23:02.279845,  3]
>        smbd/dir.c:1049(smbd_dirptr_get_entry)
> 
> 
> 
> which may correlate to directories with files with invalid names
> 
> 
> I don't seem to see entries correlating to directories I was trying
> to open .
> 
> testparm shows
> 
>         dos charset = CP850
>         unix charset = UTF8

My guess is you have filenames on that share
that are not utf8. Look inside:

somedirectory/somedirectory/somefile/