lkml.org 
[lkml]   [2009]   [Jan]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [xfs-masters] RFC: Fix f_flags races without the BKL
On Mon, Dec 29, 2008 at 01:50:50PM +0100, Christoph Hellwig wrote:
> On Mon, Dec 29, 2008 at 04:13:52AM -0700, Jonathan Corbet wrote:
> > Accesses to the f_flags field have always involved a read-modify-write
> > operation, and have always been racy in the absence of the BKL. The recent
> > BKL-removal work made this problem worse, but it has been there for a very
> > long time. The race is quite small, and, arguably, has never affected
> > anybody, but it's still worth fixing.
> >
> > After pondering for a while, I couldn't come up with anything better than a
> > global file->f_flags mutex. There's no point in bloating struct file with
> > a mutex just for this purpose; it's hard to imagine that there will be any
> > real contention for this lock.
>
> What speaks against having on in fs_struct so that it's at least not
> globally serialized?

WTF? References to struct file can be shared by tasks with different
associated fs_struct; how the devil can that ever work?


\
 
 \ /
  Last update: 2009-01-02 19:31    [W:0.095 / U:1.768 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site