lkml.org 
[lkml]   [2002]   [Sep]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Race in shrink_cache
Daniel Phillips wrote:
>
> Hi Marcelo,
>
> This looks really suspicious, vmscan.c#435:
>
> spin_unlock(&pagemap_lru_lock);
> if (put_page_testzero(page))
> __free_pages_ok(page, 0);
> /* avoid to free a locked page */
> page_cache_get(page);
>
> /* whoops, double free coming */
>
> I suggest you bump the page count before releasing the lru lock. The race
> shown above may not in fact be possible, but the current code is fragile.
>

That's OK. The page has a ref because of nonzero ->buffers And it
is locked, which pins page->buffers.
-
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: 2005-03-22 13:28    [W:0.140 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site