Messages in this thread | | | Date | Thu, 27 Jan 2011 17:35:53 -0800 | From | Joel Becker <> | Subject | Re: [Ocfs2-devel] fs/ocfs2/dlm: Use GFP_ATOMIC under spin_lock |
| |
On Thu, Jan 27, 2011 at 05:09:48PM -0800, Andrew Morton wrote: > > - local = kmalloc(sizeof(qr->qr_regions), GFP_KERNEL); > > + local = kmalloc(sizeof(qr->qr_regions), GFP_ATOMIC); > > if (!local) { > > status = -ENOMEM; > > goto bail; > > > > Switching to GFP_ATOMIC is the worst of all possible ways of "fixing" > this bug. GFP_ATOMIC is *unreliable*. We don't want to introduce > unreliability deep down inside our filesytems. And fs maintainers who > don't want to make their filesystems less reliable shouldn't blindly > apply patches that do so :(
Fair enough.
> A reliable way of fixing this bug is below. As an added bonus, it > makes the fs faster. > > --- a/fs/ocfs2/dlm/dlmdomain.c~a > +++ a/fs/ocfs2/dlm/dlmdomain.c > @@ -926,9 +926,9 @@ static int dlm_assert_joined_handler(str > } > > static int dlm_match_regions(struct dlm_ctxt *dlm, > - struct dlm_query_region *qr) > + struct dlm_query_region *qr, u8 *local) > { > - char *local = NULL, *remote = qr->qr_regions; > + char *remote = qr->qr_regions;
Won't the stack-depth busybodies hate us for this? I realize we don't go much deeper from here, but it still is 1K of stack.
Joel
--
"When arrows don't penetrate, see... Cupid grabs the pistol."
http://www.jlbec.org/ jlbec@evilplan.org
| |