On Tue, Sep 03, 2019 at 01:37:19PM +0100, Al Viro wrote: > On Tue, Sep 03, 2019 at 12:21:36AM -0400, Qian Cai wrote: > > The linux-next commit "fs/namei.c: keep track of nd->root refcount status” [1] causes boot panic on all > > architectures here on today’s linux-next (0902). Reverted it will fix the issue. > > <swearing> > > OK, I see what's going on. Incremental to be folded in: > > diff --git a/include/linux/namei.h b/include/linux/namei.h > index 20ce2f917ef4..2ed0942a67f8 100644 > --- a/include/linux/namei.h > +++ b/include/linux/namei.h > @@ -20,8 +20,8 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; > #define LOOKUP_FOLLOW 0x0001 /* follow links at the end */ > #define LOOKUP_DIRECTORY 0x0002 /* require a directory */ > #define LOOKUP_AUTOMOUNT 0x0004 /* force terminal automount */ > -#define LOOKUP_EMPTY 0x4000 /* accept empty path [user_... only] */ > -#define LOOKUP_DOWN 0x8000 /* follow mounts in the starting point */ > +#define LOOKUP_EMPTY 0x8000 /* accept empty path [user_... only] */ > +#define LOOKUP_DOWN 0x10000 /* follow mounts in the starting point */ > > #define LOOKUP_REVAL 0x0020 /* tell ->d_revalidate() to trust no cache */ > #define LOOKUP_RCU 0x0040 /* RCU pathwalk mode; semi-internal */ Any chance to keep these ordered numerically to avoid someone else introdcing this kind of bug again later on?