Re: [PATCH 2/4] ceph: validate cluster FSID for new device syntax

[Venky Shankar <vshankar@redhat.com>]

On Mon, Jun 28, 2021 at 8:34 PM Jeff Layton <jlayton@redhat.com> wrote:
>
> On Mon, 2021-06-28 at 13:25 +0530, Venky Shankar wrote:
> > The new device syntax requires the cluster FSID as part
> > of the device string. Use this FSID to verify if it matches
> > the cluster FSID we get back from the monitor, failing the
> > mount on mismatch.
> >
> > Signed-off-by: Venky Shankar <vshankar@redhat.com>
> > ---
> >  fs/ceph/super.c              | 9 +++++++++
> >  fs/ceph/super.h              | 1 +
> >  include/linux/ceph/libceph.h | 1 +
> >  net/ceph/ceph_common.c       | 3 ++-
> >  4 files changed, 13 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> > index 950a28ad9c59..84bc06e51680 100644
> > --- a/fs/ceph/super.c
> > +++ b/fs/ceph/super.c
> > @@ -266,6 +266,9 @@ static int ceph_parse_new_source(const char *dev_name, const char *dev_name_end,
> >       if (!fs_name_start)
> >               return invalfc(fc, "missing file system name");
> >
> > +     if (parse_fsid(fsid_start, &fsopt->fsid))
> > +             return invalfc(fc, "invalid fsid format");
> > +
> >       ++fs_name_start; /* start of file system name */
> >       fsopt->mds_namespace = kstrndup(fs_name_start,
> >                                       dev_name_end - fs_name_start, GFP_KERNEL);
> > @@ -748,6 +751,12 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
> >       }
> >       opt = NULL; /* fsc->client now owns this */
> >
> > +     /* help learn fsid */
> > +     if (fsopt->new_dev_syntax) {
> > +             ceph_check_fsid(fsc->client, &fsopt->fsid);
> > +             fsc->client->have_fsid = true;
> > +     }
> > +
> >       fsc->client->extra_mon_dispatch = extra_mon_dispatch;
> >       ceph_set_opt(fsc->client, ABORT_ON_FULL);
> >
> > diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> > index 557348ff3203..cfd8ec25a9a8 100644
> > --- a/fs/ceph/super.h
> > +++ b/fs/ceph/super.h
> > @@ -100,6 +100,7 @@ struct ceph_mount_options {
> >       char *server_path;    /* default NULL (means "/") */
> >       char *fscache_uniq;   /* default NULL */
> >       char *mon_addr;
> > +     struct ceph_fsid fsid;
> >  };
> >
> >  struct ceph_fs_client {
> > diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
> > index 409d8c29bc4f..24c1f4e9144d 100644
> > --- a/include/linux/ceph/libceph.h
> > +++ b/include/linux/ceph/libceph.h
> > @@ -296,6 +296,7 @@ extern bool libceph_compatible(void *data);
> >  extern const char *ceph_msg_type_name(int type);
> >  extern int ceph_check_fsid(struct ceph_client *client, struct ceph_fsid *fsid);
> >  extern void *ceph_kvmalloc(size_t size, gfp_t flags);
> > +extern int parse_fsid(const char *str, struct ceph_fsid *fsid);
> >
> >  struct fs_parameter;
> >  struct fc_log;
> > diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
> > index 97d6ea763e32..db21734462a4 100644
> > --- a/net/ceph/ceph_common.c
> > +++ b/net/ceph/ceph_common.c
> > @@ -217,7 +217,7 @@ void *ceph_kvmalloc(size_t size, gfp_t flags)
> >       return p;
> >  }
> >
> > -static int parse_fsid(const char *str, struct ceph_fsid *fsid)
> > +int parse_fsid(const char *str, struct ceph_fsid *fsid)
> >  {
> >       int i = 0;
> >       char tmp[3];
> > @@ -247,6 +247,7 @@ static int parse_fsid(const char *str, struct ceph_fsid *fsid)
> >       dout("parse_fsid ret %d got fsid %pU\n", err, fsid);
> >       return err;
> >  }
> > +EXPORT_SYMBOL(parse_fsid);
>
> This function name is too generic. Maybe rename it to "ceph_parse_fsid"?

Makes sense. ACK.

>
> >
> >  /*
> >   * ceph options
>
> --
> Jeff Layton <jlayton@redhat.com>
>


-- 
Cheers,
Venky