On Tue, Aug 27, 2013 at 04:25:58PM -0500, Ben Myers wrote:
> On Tue, Aug 27, 2013 at 07:24:23AM +1000, Dave Chinner wrote:
> > On Mon, Aug 26, 2013 at 03:47:30PM -0500, Ben Myers wrote:
> > > Looks like in 48fde701 we removed the iput of the root inode in
> > > xfs_fs_fill_super for the error case. Add it back.
> > >
> > > Signed-off-by: Ben Myers <bpm@xxxxxxx>
> > >
> > > ---
> > > fs/xfs/xfs_super.c | 6 ++++--
> > > 1 file changed, 4 insertions(+), 2 deletions(-)
> > >
> > > Index: b/fs/xfs/xfs_super.c
> > > ===================================================================
> > > --- a/fs/xfs/xfs_super.c 2013-08-26 15:36:09.170848579 -0500
> > > +++ b/fs/xfs/xfs_super.c 2013-08-26 15:40:19.450817933 -0500
> > > @@ -1493,12 +1493,12 @@ xfs_fs_fill_super(
> > > }
> > > if (is_bad_inode(root)) {
> > > error = EINVAL;
> > > - goto out_unmount;
> > > + goto out_iput;
> > > }
> > > sb->s_root = d_make_root(root);
> > > if (!sb->s_root) {
> > > error = ENOMEM;
> > > - goto out_unmount;
> > > + goto out_iput;
> > > }
> >
> > That's wrong. d_make_root() drops the reference to the inode on
> > failure itself, and so the change in 48fde701 is correct and valid.
> >
> > The leak on bad inodes (which, AFAICT, can never happen on XFS) has
> > been around a lot longer than Al's change - this commit introduced
> > it:
> >
> > 2bcf6e9 xfs: start periodic workers later
> >
> > with this hunk:
> >
> > if (is_bad_inode(root)) {
> > error = EINVAL;
> > - goto fail_vnrele;
> > + goto out_syncd_stop;
> > }
>
> Thanks Gents. Here's another try:
>
> xfs: don't leak root inode reference
>
> Looks like in 2bcf6e9 we removed the iput of the root inode in
> xfs_fs_fill_super for the is_bad_inode error case. Add it back.
>
> Signed-off-by: Ben Myers <bpm@xxxxxxx>
I don't think this is right, either.
As I said in my previous reply, I don't think that XFS can ever see
a bad inode. The fact is that we're grabbing mp->m_rootip, which is
we already have a reference to and is in cache and validated thanks
to an xfs_iget() call in xfs_mountfs(). If we fail validation when
reading the root inode into cache then xfs_mountfs() will fail and
we won't ever get to this check.
Further, XFS never marks inodes bad - even on a failed lookup or a
shut down filesystem - and so AFAICT we cannot ever see the root
inode (or any other XFS inode) as a bad inode.
Hence I think that the is_bad_inode(root) check should just go away.
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
_______________________________________________
xfs mailing list
xfs@xxxxxxxxxxx
http://oss.sgi.com/mailman/listinfo/xfs
