lkml.org 
[lkml]   [2012]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCHv3] locks: prevent side-effects of locks_release_private before file_lock is initialized
On Fri, Jul 27, 2012 at 04:45:52PM -0400, J. Bruce Fields wrote:
> On Fri, Jul 27, 2012 at 12:42:52AM -0400, Filipe Brandenburger wrote:
> > When calling fcntl(fd, F_SETLEASE, lck) [with lck=F_WRLCK or F_RDLCK],
> > the custom signal or owner (if any were previously set using F_SETSIG
> > or F_SETOWN fcntls) would be reset when F_SETLEASE was called for the
> > second time on the same file descriptor.
> >
> > This bug is a regression of 2.6.37 and is described here:
> > https://bugzilla.kernel.org/show_bug.cgi?id=43336
> >
> > This patch reverts a commit from Oct 2004 (with subject "nfs4 lease:
> > move the f_delown processing") which originally introduced the
> > lm_release_private callback.
>
> Looks fine, thanks. I think can also do something like the following
> (on top of your patch).

(Committing this as well.)--b.

>
> --b.
>
> commit 96d6d59ceaeaacba4088862f3c57fcd011f52832
> Author: J. Bruce Fields <bfields@redhat.com>
> Date: Fri Jul 27 16:18:00 2012 -0400
>
> locks: move lease-specific code out of locks_delete_lock
>
> No point putting something only used by one caller into common code.
>
> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
>
> diff --git a/fs/locks.c b/fs/locks.c
> index 86668dd..541075a 100644
> --- a/fs/locks.c
> +++ b/fs/locks.c
> @@ -570,12 +570,6 @@ static void locks_delete_lock(struct file_lock **thisfl_p)
> fl->fl_next = NULL;
> list_del_init(&fl->fl_link);
>
> - fasync_helper(0, fl->fl_file, 0, &fl->fl_fasync);
> - if (fl->fl_fasync != NULL) {
> - printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync);
> - fl->fl_fasync = NULL;
> - }
> -
> if (fl->fl_nspid) {
> put_pid(fl->fl_nspid);
> fl->fl_nspid = NULL;
> @@ -1150,6 +1144,11 @@ int lease_modify(struct file_lock **before, int arg)
>
> f_delown(filp);
> filp->f_owner.signum = 0;
> + fasync_helper(0, fl->fl_file, 0, &fl->fl_fasync);
> + if (fl->fl_fasync != NULL) {
> + printk(KERN_ERR "locks_delete_lock: fasync == %p\n", fl->fl_fasync);
> + fl->fl_fasync = NULL;
> + }
> locks_delete_lock(before);
> }
> return 0;
> --
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html


\
 
 \ /
  Last update: 2012-07-29 18:41    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site