Re: [PATCH] PAG support only

Jeff Garzik
2003-05-13T16:36:17Z

On Tue, May 13, 2003 at 05:33:11PM +0100, David Howells wrote:
> Due to the slight unpopularity of the AFS multiplexor, here's a patch with

I think of it as "bitter pill we will be forced to swallow", and then
hope and pray that we can use your AFS stuff as a transition step to --
after many years -- migrate people away from AFS altogether. ;-)

Or maybe that's just wishful thinking.

> diff -uNr linux-2.5.69/fs/open.c linux-2.5.69-cred/fs/open.c
> --- linux-2.5.69/fs/open.c 2003-05-06 15:04:45.000000000 +0100
> +++ linux-2.5.69-cred/fs/open.c 2003-05-13 11:28:08.000000000 +0100
> @@ -46,7 +46,7 @@
> struct nameidata nd;
> int error;
>
> - error = user_path_walk(path, &nd);
> + error = user_path_walk(path,&nd);

a bit of noise

> --- linux-2.5.69/include/asm-i386/posix_types.h 2003-05-06 15:04:37.000000000 +0100
> +++ linux-2.5.69-cred/include/asm-i386/posix_types.h 2003-05-12 10:19:15.000000000 +0100
> @@ -13,6 +13,7 @@
> typedef unsigned short __kernel_nlink_t;
> typedef long __kernel_off_t;
> typedef int __kernel_pid_t;
> +typedef int __kernel_pag_t;
> typedef unsigned short __kernel_ipc_pid_t;
> typedef unsigned short __kernel_uid_t;
> typedef unsigned short __kernel_gid_t;
[...]
> +int sys_setpag(pag_t pag)
> +int sys_getpag(void)

Surely you want s/int/long/ here?

Two other comments:

* even though you're referencing 'current', I'm a bit surprised you
don't need any locking at all in sys_getpag. Is that guaranteed
through judicious use of xchg()?

* is it reasonable to make credentials support a config option?
Long term I worry about Linux kernel becoming another Irix, supporting
thousands of rarely used syscalls unconditionally.

Jeff

P.S. Looking forward to the "cachefs" code you have in your cvs repo
hitting mainline. That will be fun for NFS. <grin>