On Sun, 27 Jan 2008 03:17:09 +0100 (CET) Andi Kleen <[email protected]> wrote:
>
> I checked ext3_ioctl and it looked largely safe to not be used
> without BKL. So convert it over to unlocked_ioctl.
>
> The only case where I wasn't quite sure was for the
> dynamic fs grow ioctls versus umounting -- I kept the BKL for those.
>
Please cpoy linux-ext4 on ext2/3/4 material.
I skippped a lot of these patches because I just got bored of fixing
rejects. Now is a very optimistic time to be raising patches against
mainline.
I'm going to work on getting a unified devel tree operating: one which
contains everyone's latest stuff and is updated daily. Basically it'll be
-mm without a couple of the quilt trees. People can then prepare patches
against that, as it seems that most can't be bothered patching against -mm,
let alone building and testing it. More later.
> + /* AK: not sure the BKL is needed, but this might prevent
> + * races against umount */
> + lock_kernel();
> err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
> journal_lock_updates(EXT3_SB(sb)->s_journal);
> journal_flush(EXT3_SB(sb)->s_journal);
> journal_unlock_updates(EXT3_SB(sb)->s_journal);
> + unlock_kernel();
>
> return err;
> }
> @@ -245,11 +249,14 @@ flags_err:
> if (copy_from_user(&input, (struct ext3_new_group_input __user *)arg,
> sizeof(input)))
> return -EFAULT;
> -
> + /* AK: not sure the BKL is needed, but this might prevent
> + * races against umount */
> + lock_kernel();
> err = ext3_group_add(sb, &input);
> journal_lock_updates(EXT3_SB(sb)->s_journal);
> journal_flush(EXT3_SB(sb)->s_journal);
> journal_unlock_updates(EXT3_SB(sb)->s_journal);
> + unlock_kernel();
>
The ext3_ioctl() caller has an open fd against the fs - should be
sufficient to keep unmount away?
(gets even more rejects, drops all the fasync patches too)
It's all reached the stage of stupid.
On Monday 28 January 2008 06:33, Andrew Morton wrote:
> On Sun, 27 Jan 2008 03:17:09 +0100 (CET) Andi Kleen <[email protected]> wrote:
> > I checked ext3_ioctl and it looked largely safe to not be used
> > without BKL. So convert it over to unlocked_ioctl.
> >
> > The only case where I wasn't quite sure was for the
> > dynamic fs grow ioctls versus umounting -- I kept the BKL for those.
>
> Please cpoy linux-ext4 on ext2/3/4 material.
Ok I'll resubmit those to tytso/ext4-devel (or perhaps he has already seen
them)
>
> I skippped a lot of these patches because I just got bored of fixing
> rejects. Now is a very optimistic time to be raising patches against
> mainline.
JFS and CIFS are already taken care of by the maintainers. This leaves
remote_llseek which touches a couple of file systems. Could you
perhaps take that one only please? And perhaps Nick's minix
patchkit which looks safe to me and is unlikely to cause conflicts.
> > + /* AK: not sure the BKL is needed, but this might prevent
> > + * races against umount */
> > + lock_kernel();
> > err = ext3_group_add(sb, &input);
> > journal_lock_updates(EXT3_SB(sb)->s_journal);
> > journal_flush(EXT3_SB(sb)->s_journal);
> > journal_unlock_updates(EXT3_SB(sb)->s_journal);
> > + unlock_kernel();
>
> The ext3_ioctl() caller has an open fd against the fs - should be
> sufficient to keep unmount away?
True. I am still conservative because group_add is a lot of code
which I didn't fully check. But with the open fd it's likely safe
to not take the BKL because there is nothing else (except
readdir?) in ext* that takes it.
> It's all reached the stage of stupid.
I'll resubmit ->fasync_unlocked against -mm.
Also I wanted to recheck the ->f_flags locking. I found one bug in those
already and I can extract the bug fix for that one.
-Andi