Re: force O_LARGEFILE in sys_swapon() and sys_swapoff()

William Lee Irwin III
2004-07-04T19:31:57Z

On Sat, 3 Jul 2004, William Lee Irwin III wrote:
>> For 32-bit, one quickly discovers that swapon() is not given an fd
>> already opened with O_LARGEFILE to act upon and the forcing of
>> O_LARGEFILE for 64-bit is irrelevant, as the system call's argument is
>> a path. So this patch manually forces it for swapon() and swapoff().

On Sun, Jul 04, 2004 at 08:21:25PM +0100, Hugh Dickins wrote:
> This one looks good, thanks. I'm not so sure of your more general
> patch to open, others know better on that.
> I doubt huge amounts of swap work at all well when used, but you're
> really concerned with commit at present: of course it was silly not
> to have used O_LARGEFILE here.

The story on the more general one is that it silently broke -EFBIG
returns for 32-bit emulation. Arnd posted a patch to consolidate 32-bit
open() emulation, which I followed up with a hoist of the O_LARGEFILE
check to there above filp_open(). The forcing of O_LARGEFILE is still
needed for other, non-open()-related situations, and I may need to
sweep 32-bit emulation for other syscalls. Of course, it's a lose-lose
situation, as 64-bit now can't do internal kernel filp_open() on files
larger than 64-bit unsafe 32-bit apps can. In short, a large headache.

-- wli