fixing redundant network opens on Linux file creation

[Jan Hudec]

On Mon, Jan 06, 2003 at 07:18:30PM -0300, Marcos Dione wrote:
> On Mon, Jan 06, 2003 at 11:25:32AM -0600, Steven French wrote:
> > The creat() system call results (for the Linux kernel) in calls to create
> > (via vfs_create) then later a call to open (via dentry_open) both of which
> > eventually end up (for the cifs vfs) doing a network open of the file from
> > the perspective of the CIFS protocol which degrades performance (because
> 
>     why not implement create as a separate feature? you can use a
> different message and mknod(2) on the server.
> 
>     I'm asking 'cause I'll have the same problem when implementing my
> thesis.

That won't help. You are still doing two upcalls, it still isn't atomic
etc. etc. The problem is, that vfs always calls ->create and then
->open, both for open(O_CREAT) and create.

-------------------------------------------------------------------------------
						 Jan 'Bulb' Hudec <bulb at ucw.cz>