[Samba] windows oddity related to alternate data streams

[Bart]

Hi all,


I was just looking into what was causing the lag when I open my samba
(3.0.27a) shares from windows (XP, SP2).

strace showed that directories were being opened and closed a lot, in
sequence. Playing with Process Monitor suggests windows is trying to
create alternate data streams on for the directory entires: it does a
CreateFile with :{4c8cc155-6c1e-11d1-8e41-00c04fb9386d} appended to
the directory name.

Samba seems to fail those creates, and windows seems to react to this
rather poorly.

The sequence of events (process monitor log, edited for readability):
(Note that BUFFER OVERFLOW is not an error.
 I'd remove the lines, but the functions called may be relevant)

12:20:26.8111613 AM	CreateFile	O:\technical	SUCCESS
12:20:26.8129029 AM	ReadFile	O:\technical	INVALID DEVICE REQUEST
12:20:26.8130925 AM	QueryInformationVolume	O:\technical	BUFFER OVERFLOW
12:20:26.8132141 AM	QueryAllInformationFile	O:\technical	BUFFER OVERFLOW
12:20:26.8156088
AM	CreateFile	O:\technical:{4c8cc155-6c1e-11d1-8e41-00c04fb9386d}	PATH
NOT FOUND
12:20:26.8159856 AM	CloseFile	O:\technical	SUCCESS
12:20:26.8175923 AM	CreateFile	O:\technical	SUCCESS
12:20:26.8191648 AM	ReadFile	O:\technical	INVALID DEVICE REQUEST
12:20:26.8192031 AM	QueryInformationVolume	O:\technical	BUFFER OVERFLOW
12:20:26.8192252 AM	QueryAllInformationFile	O:\technical	BUFFER OVERFLOW
12:20:26.8228748
AM	CreateFile	O:\technical:{4c8cc155-6c1e-11d1-8e41-00c04fb9386d}	PATH
NOT FOUND
12:20:26.8235760 AM	CloseFile	O:\technical	SUCCESS
12:20:26.8252307 AM	CreateFile	O:\technical	SUCCESS
12:20:26.8271502 AM	ReadFile	O:\technical	INVALID DEVICE REQUEST
12:20:26.8272061 AM	QueryInformationVolume	O:\technical	BUFFER OVERFLOW
12:20:26.8272290 AM	QueryAllInformationFile	O:\technical	BUFFER OVERFLOW
12:20:26.8291879
AM	CreateFile	O:\technical:{4c8cc155-6c1e-11d1-8e41-00c04fb9386d}	PATH
NOT FOUND
12:20:26.8294594 AM	CloseFile	O:\technical	SUCCESS
12:20:26.8319192 AM	CreateFile	O:\technical	SUCCESS
12:20:26.8342349 AM	ReadFile	O:\technical	INVALID DEVICE REQUEST
12:20:26.8342734 AM	QueryInformationVolume	O:\technical	BUFFER OVERFLOW
12:20:26.8342952 AM	QueryAllInformationFile	O:\technical	BUFFER OVERFLOW

...and so on. It seems to over sixty attempts (by a quick count) per
directory entry in a directory. Looking around my shares, it seems
that those with more directories indeed seem to lag more.

Anyway, now that I know its cause, I'd like this lag gone.
It seems support for alternate streams are a planned feature, but in
the meantime, does anyone know of some way to avoid windows being
demented about this?

Could samba tell windows it's not possible? (did I misconfigure samba?)
Could I tell windows not to try?


Regards,
--Bart