On Thu, May 18, 2023 at 3:48 AM <xiubli@xxxxxxxxxx> wrote: > > From: Xiubo Li <xiubli@xxxxxxxxxx> > > When the MClientSnap reqeust's op is not CEPH_SNAP_OP_SPLIT the > request may still contain a list of 'split_realms', and we need > to skip it anyway. Or it will be parsed as a corrupt snaptrace. > > Cc: stable@xxxxxxxxxxxxxxx > Cc: Frank Schilder <frans@xxxxxx> > Reported-by: Frank Schilder <frans@xxxxxx> > URL: https://tracker.ceph.com/issues/61200 > Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx> > --- > > V2: > - Add a detail comment for the code. > > > fs/ceph/snap.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c > index 0e59e95a96d9..0f00f977c0f0 100644 > --- a/fs/ceph/snap.c > +++ b/fs/ceph/snap.c > @@ -1114,6 +1114,19 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc, > continue; > adjust_snap_realm_parent(mdsc, child, realm->ino); > } > + } else { > + /* > + * In non-SPLIT op case both the 'num_split_inos' and > + * 'num_split_realms' should always be 0 and this will > + * do nothing. But the MDS has one bug that in one of > + * the UPDATE op cases it will pass a 'split_realms' > + * list by mistake, and then will corrupted the snap > + * trace in ceph_update_snap_trace(). > + * > + * So we should skip them anyway here. > + */ > + p += sizeof(u64) * num_split_inos; > + p += sizeof(u64) * num_split_realms; > } > > /* > -- > 2.40.1 > LGTM, staged for 6.4-rc3 with a slightly amended comment. Thanks, Ilya