On Fri, May 29, 2009 at 10:23:44PM -0600, Trenton D. Adams wrote: > On Fri, May 29, 2009 at 9:22 PM, Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote: > > On Fri, May 29, 2009 at 09:05:31PM -0600, Trenton D. Adams wrote: > >> On Sat, May 16, 2009 at 12:02 PM, Frederic Weisbecker > >> <fweisbec@xxxxxxxxx> wrote: > >> > While searching a pathname, an inode mutex can be acquired > >> > in do_lookup() which calls reiserfs_lookup() which in turn > >> > acquires the write lock. > >> > > >> > On the other side reiserfs_fill_super() can acquire the write_lock > >> > and then call reiserfs_lookup_privroot() which can acquire an > >> > inode mutex (the root of the mount point). > >> > > >> > So we theoretically risk an AB - BA lock inversion that could lead > >> > to a deadlock. > >> > > >> > As for other lock dependencies found since the bkl to mutex > >> > conversion, the fix is to use reiserfs_mutex_lock_safe() which > >> > drops the lock dependency to the write lock. > >> > > >> > >> I'm curious, did this get applied, and is it related to the following? > >> I was having these in 2.6.30-rc3. I am now on 2.6.30-rc7 as of > >> today. I haven't seen them today. But then again, I only seen this > >> happen one time. > > > > > > Hi, > > > > No, may be it will come for 2.6.31 but for now it is not merged so > > it's not related. > > > > If you see such warning anymore, don't hesitate to tell about > > it! > > > > Thanks! > > > > I was trying to imply that the patch might fix the problem I saw, not > that it was the cause. I only though that because it mentioned a > potential deadlock, and it seems like that is what the problem I saw > was. Ah ok. No it's part of a tree which reworks the reiserfs locking scheme by removing the old one based on the legacy and obsolete bkl (big kernel lock). In this tree I had to fix several deadlocks or at least unsafe lock states because the bkl is converted into a mutex and some new lock dependencies were borned after that. But these issues had nothing to deal with upstream problems. BTW, would you be interested in giving a try with this reiserfs bkl removal tree? I really lack testing and feedbacks from users. Thanks! Frederic. -- To unsubscribe from this list: send the line "unsubscribe reiserfs-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
