[Samba] Quota / OpLock file truncation again

Marc Jacobsen you.can.guess at hp.com
Fri Jun 23 23:02:29 GMT 2006


I am seeing a potentially serious bug with samba 3.0.22 on Linux (Ubuntu 
Dapper Drake).  I found the following old discussions about the same 
problem:

http://lists.samba.org/archive/samba-technical/2004-September/037328.html

and

http://lists.samba.org/archive/samba/2003-July/071081.html

as well as this old closed bug in bugzilla:

https://bugzilla.samba.org/show_bug.cgi?id=679

I couldn't find when or if the problem in the second discussion got 
resolved, and I couldn't find an open bug in bugzilla.

Anyway, what I am seeing is that with quotas turned on in Linux, and 
OpLocks enabled on Samba, if you open a file on a client with notepad, 
expand it past where the quota will allow, then save it, there is no 
error message.  The client will see the file as the size it expected, 
but any data past the quota limit is NULL.  If you turn off OpLocks and 
do the same thing the save will fail and give an error popup window.

If you set "strict allocate" the only difference is that you won't have 
the NULL data past the quota limit, the file will just be truncated at 
the quota limit.  But notepad will not give an error on save, leaving 
the user ignorant of the file truncation, and data loss.  This sounds 
just like what was described in the second discussion from above.

Wordpad and other applications don't exhibit the same behavior.

So I see three possibilities.  There is a workaround (like setting 
"strict allocate") that I am not aware of.  Or Samba has regressed and 
this old bug came back.  Or the bug was only fixed for other apps like 
Wordpad, but it has always been an overlooked bug with notepad.  I can't 
believe that a bug like this would be left in Samba intentionally.

Can anybody please fill me in?

Note: my return address is not valid, I will monitor the mailing list.




More information about the samba mailing list