On Tue, May 10, 2022 at 06:08:48PM -0700, Darrick J. Wong wrote:
> On Wed, May 11, 2022 at 11:06:51AM +1000, Dave Chinner wrote:
> > On Tue, May 10, 2022 at 04:12:34PM -0700, Darrick J. Wong wrote:
> > > On Mon, May 09, 2022 at 10:41:25AM +1000, Dave Chinner wrote:
> > > > diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
> > > > index c9c867e3406c..ad52b5dc59e4 100644
> > > > --- a/fs/xfs/libxfs/xfs_attr.h
> > > > +++ b/fs/xfs/libxfs/xfs_attr.h
> > > > @@ -530,4 +553,35 @@ void xfs_attri_destroy_cache(void);
> > > > int __init xfs_attrd_init_cache(void);
> > > > void xfs_attrd_destroy_cache(void);
> > > >
> > > > +/*
> > > > + * Check to see if the attr should be upgraded from non-existent or shortform to
> > > > + * single-leaf-block attribute list.
> > > > + */
> > > > +static inline bool
> > > > +xfs_attr_is_shortform(
> > > > + struct xfs_inode *ip)
> > > > +{
> > > > + return ip->i_afp->if_format == XFS_DINODE_FMT_LOCAL ||
> > > > + (ip->i_afp->if_format == XFS_DINODE_FMT_EXTENTS &&
> > > > + ip->i_afp->if_nextents == 0);
> > > > +}
> > > > +
> > > > +static inline enum xfs_delattr_state
> > > > +xfs_attr_init_add_state(struct xfs_da_args *args)
> > > > +{
> > > > + if (!args->dp->i_afp)
> > > > + return XFS_DAS_DONE;
> > >
> > > If we're in add/replace attr call without an attr fork, why do we go
> > > straight to finished?
> >
> > I suspect I've fixed all the issues that triggered crashes here
> > because args->dp->i_afp was null. THere were transient states in a
> > replace operaiton when the remove takes away the last attr, removes
> > the attr fork, then calls the ADD operation. The add operation
> > assumes that the attr fork has already been set up, and so bad
> > things happened here.
> >
> > This also occurred when setting up recovery operations - recovery of
> > an add/replace could start from that same "there's no attr fork"
> > condition, and so calling xfs_inode_has_attr() or
> > xfs_attr_is_shortform() direct from the reocovery setup code would
> > go splat because ip->i_afp was null.
> >
> > I'm going to leave this for the moment (cleanup note made) because I
> > don't want to have to find out that I missed a corner case somewhere
> > they hard way right now. It's basically there to stop log recovery
> > crashing hard, which only occurs when the experimental larp code is
> > running, so I think this is safe to leave for a later cleanup.
>
> Hmm, in that case, can this become:
>
> if (!args->dp->i_afp) {
> ASSERT(0);
> return XFS_DAS_DONE;
> }
OK.
> And then you can add:
> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Thanks!
-Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
