[Samba] A samba locking question

[Jeremy Allison]

On Wed, Feb 11, 2004 at 02:11:07PM +0100, Patrik Gustavsson wrote:
> 
> Let me the try to communicate in a different way.
> 
> The only thing I want to know if byte range locks
> or file share reservation are propagated to or from UNIX.
> 
> That is:
> 
> a) When a external program is doing a byte range lock through
>    fcntl on file, will that be checked before Samba is 
>    opening the file ?
> 
>    My findings tells me it does.

Yes it will.

> 
> b) When a external program is doing file share reservation
>    through on a file fcntl will that be checked before Samba is opening
>    the file ?
> 
>    My findings tells me it don't.
>  
>    The test-program did file share reservation through fcntl on file
>    with the parameters:
> 	f_access=F_RWACC (Set a  file  share  reservation  for  read 
> 		          and  write access)
> 	f_deny=F_RWDNY   (Set a file share reservation to deny  read 
> 			  and  write)
> 
>    The client could through Samba open and write in that file.

I have never heard of these f_access codes ? This is not POSIX.
I have no clue what system you are using that has these share modes. No
POSIX system has this.

So not suprisingly Samba doesn't know anything about this.

> c) If/When Samba is doing a byte range lock on file will that byte
>    range lock be propagated externaly to UNIX ?
> 
>    I believe it will not.

Yes it will, you are incorrect.

> d) If/When Samba is doing a file share reservation on file will that
>    be propagated externaly to UNIX ?
> 
>    My findings tells me it don't.

Only on Linux, where Samba is compiled with the parameter
HAVE_KERNEL_SHARE_MODES will share modes be understood by the kernel.

Share modes have *NOTHING* to do with byte range locks. The two
are completely orthoganal.

You really need to understand this before you can proceed.

Jeremy.