Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [PATCH] [3/18] BKL-removal: Convert ext3 to use unlocked_ioctl | Date | Mon, 28 Jan 2008 07:02:15 +0100 |
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On Monday 28 January 2008 06:33, Andrew Morton wrote: > On Sun, 27 Jan 2008 03:17:09 +0100 (CET) Andi Kleen <ak@suse.de> 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
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