[Samba] CIFS VFS: in dmesg when Linux accesses eComStation's (OS/2) FAT filesystem shares

[Jeremy Allison]

On Wed, Apr 29, 2020 at 10:48:34AM -0400, Felix Miata via samba wrote:
> Jeremy Allison via samba composed on 2020-04-24 11:13 (UTC-0700):
> > Looking at that trace the client is doing a QPATHINFO request
> > (SMBtrans2 request) with level 263 - Query File All Info.
> 
> > The OS/2 server doesn't support that, so the client then
> > drops back and does a SMB1 Query Information Request (SMB1
> > request 0x8, what Samba calls SMBgetattr).
> 
> > This doesn't have the links or expanded time information
> > (it only returns one date) so the client isn't then able
> > to synthesize this information.
> 
> > Also the client isn't caching the fact that the server
> > doesn't understand SMBtran2:QPATHINFO:263 and so it
> > keeps issuing these and doing the fallback on every
> > query. This will significantly damage performance.
> 
> Whose performance, client's? Server's? Both? Only between the two? Do you have an
> recommendations that don't involve abandoning the only acceptable means to keep
> (OS/2 for) running my (constantly used) DOS orphan apps that have never had any
> upgrade path?

What I'm saying is that this is a Linux kernel CIFSFS
issue, not a Samba client one. Bug Steve French directly,
his email may be found on the Samba lists and he's a
Samba Team member. He was one of the programmers who
worked on OS/2 so he should be sympathetic.