On Fri, 2019-10-04 at 11:52 -0400, Brian Foster wrote:
> On Thu, Oct 03, 2019 at 06:26:12PM +0800, Ian Kent wrote:
> > Add the fs_context_operations method .get_tree that validates
> > mount options and fills the super block as previously done
> > by the file_system_type .mount method.
> >
> > Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
> > ---
> > fs/xfs/xfs_super.c | 50
> > ++++++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 50 insertions(+)
> >
> > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> > index cc2da9093e34..b984120667da 100644
> > --- a/fs/xfs/xfs_super.c
> > +++ b/fs/xfs/xfs_super.c
> > @@ -1925,6 +1925,51 @@ xfs_fs_fill_super(
> > return error;
> > }
> >
> > +STATIC int
> > +xfs_fill_super(
> > + struct super_block *sb,
> > + struct fs_context *fc)
> > +{
> > + struct xfs_fs_context *ctx = fc->fs_private;
> > + struct xfs_mount *mp = sb->s_fs_info;
> > + int silent = fc->sb_flags & SB_SILENT;
> > + int error = -ENOMEM;
> > +
> > + mp->m_super = sb;
> > +
> > + /*
> > + * set up the mount name first so all the errors will refer to
> > the
> > + * correct device.
> > + */
> > + mp->m_fsname = kstrndup(sb->s_id, MAXNAMELEN, GFP_KERNEL);
> > + if (!mp->m_fsname)
> > + goto out_free_fsname;
> > + mp->m_fsname_len = strlen(mp->m_fsname) + 1;
> > +
> > + error = xfs_validate_params(mp, ctx, false);
> > + if (error)
> > + goto out_free_fsname;
> > +
> > + error = __xfs_fs_fill_super(mp, silent);
> > + if (error)
> > + goto out_free_fsname;
> > +
> > + return 0;
> > +
> > + out_free_fsname:
> > + sb->s_fs_info = NULL;
> > + xfs_free_fsname(mp);
> > + kfree(mp);
> > + return error;
>
> Ok, I think I have a better understanding of how this is supposed to
> work with the background context. mp starts off in fc->s_fs_info,
> ends
> up transferred to sb->s_fs_info and passed into here. We allocate
> ->m_fsname and carry on from here with ownership of mp.
>
> The only thing I'll note is that the out_free_fsname label is
> misnamed
> and probably could be out_free or out_free_mp or something. With that
> nit addressed:
Or out_error perhaps, IIRC I remember thinking I needed to do that but
it slipped my mind?
>
> Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
>
> > +}
> > +
> > +STATIC int
> > +xfs_get_tree(
> > + struct fs_context *fc)
> > +{
> > + return get_tree_bdev(fc, xfs_fill_super);
> > +}
> > +
> > STATIC void
> > xfs_fs_put_super(
> > struct super_block *sb)
> > @@ -1995,6 +2040,11 @@ static const struct super_operations
> > xfs_super_operations = {
> > .free_cached_objects = xfs_fs_free_cached_objects,
> > };
> >
> > +static const struct fs_context_operations xfs_context_ops = {
> > + .parse_param = xfs_parse_param,
> > + .get_tree = xfs_get_tree,
> > +};
> > +
> > static struct file_system_type xfs_fs_type = {
> > .owner = THIS_MODULE,
> > .name = "xfs",
> >
