lkml.org 
[lkml]   [2006]   [Aug]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH]: ufs: ufs_get_locked_patch race fix
On Tue, 1 Aug 2006 11:30:43 +0400
Evgeniy Dushistov <dushistov@mail.ru> wrote:

> On Mon, Jul 31, 2006 at 11:02:51PM -0700, Andrew Morton wrote:
> > On Mon, 31 Jul 2006 16:57:02 +0400
> > Evgeniy Dushistov <dushistov@mail.ru> wrote:
> >
> > Looks good to me.
> >
> > Is there any need to be checking ->index? Normally we simply use the
> > sequence:
> >
> > lock_page(page);
> > if (page->mapping == NULL)
> > /* truncate got there first */
> >
> > to handle this case.
>
> Yes, I made it in analogy with `find_lock_page' and missed fact
> that if we increment usage counter of page, we have no need to check
> page->index.

OK. find_lock_page() has the splice stuff in it.

> Need another patch?

Is OK, I updated it.

I'm not sure that the `goto repeat' is needed if truncate got there first,
really - if truncate took the page down then it's now outside i_size and
shouldn't be coming back.

If the page _can_ come back then this code is all rather problematic.
Because this means that the page can come back (via an extending write())
one nanosecond after ufs_get_locked_page() returns NULL. Won't the callers
of ufs_get_locked_page() get confused by that?

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-08-01 09:43    [W:0.055 / U:1.916 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site