On Fri, 2 Jun 2006 10:43:27 +0200
Olaf Hering <[email protected]> wrote:
> On Thu, Jun 01, Andrew Morton wrote:
>
>
> > > Do you want it like that?
> > >
> > > lock_page(page);
> > > if (PageUptodate(page)) {
> > > SetPageDirty(page);
> > > mb();
> > > return page;
> > > }
> >
> > Not really ;) It's hacky. It'd be better to take a lock.
>
> Which lock exactly?
Ah, sorry, there isn't such a lock. I was just carrying on.
> I'm not sure how to proceed from here.
I'd suggest you run SetPagePrivate() and SetPageChecked() on the locked
page and implement a_ops.releasepage(), which will fail if PageChecked(),
and will succeed otherwise:
/*
* cramfs_releasepage() will fail if cramfs_read() set PG_checked. This
* is so that invalidate_inode_pages() cannot zap the page while
* cramfs_read() is trying to get at its contents.
*/
cramfs_releasepage(...)
{
if (PageChecked(page))
return 0;
return 1;
}
cramfs_read(...)
{
lock_page(page);
SetPagePrivate(page);
SetPageChecked(page);
read_mapping_page(...);
lock_page(page);
if (page->mapping == NULL) {
/* truncate got there first */
unlock_page(page);
bale();
}
memcpy();
ClearPageChecked(page);
ClearPagePrivate(page);
unlock_page(page);
}
PG_checked is a filesystem-private flag. It'll soon be renamed to
PG_fs_misc.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
