On Sat, May 31, 2014 at 10:48 AM, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > > On Sat, 31 May 2014, Josh Boyer wrote: >> >> One of my machines got the lockdep report below when booting a kernel >> that contained these patches. > > I think this is just a lacking annotation. > > We do nest dentry d_lock locking, and in order to avoid ABBA deadlocks the > rule is that we lock things in topological order (parent dentry first). > lock_parent() is very careful about that, but doesn't actually tell > lockdep about it. > > This trivial oneliner should fix it. > > Linus Built the previous kernel with just this applied and it seems to behave correctly on several reboots. I think this looks good. Thanks! josh > > --- > fs/dcache.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/dcache.c b/fs/dcache.c > index bce851dc03ef..be2bea834bf4 100644 > --- a/fs/dcache.c > +++ b/fs/dcache.c > @@ -553,7 +553,7 @@ again: > } > rcu_read_unlock(); > if (parent != dentry) > - spin_lock(&dentry->d_lock); > + spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); > else > parent = NULL; > return parent; -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
