Method queue_cap_snap

src/client/Client.cc:4363–4399

void Client::queue_cap_snap(Inode *in, const SnapContext& old_snapc)
{
  int used = get_caps_used(in);
  int dirty = in->caps_dirty();
  ldout(cct, 10) << __func__ << " " << *in << " snapc " << old_snapc << " used " << ccap_string(used) << dendl;

  if (in->cap_snaps.size() &&
      in->cap_snaps.rbegin()->second.writing) {
    ldout(cct, 10) << __func__ << " already have pending cap_snap on " << *in << dendl;
    return;
  } else if (dirty || (used & CEPH_CAP_FILE_WR)) {
    const auto &capsnapem = in->cap_snaps.emplace(std::piecewise_construct, std::make_tuple(old_snapc.seq), std::make_tuple(in));
    ceph_assert(capsnapem.second); /* element inserted */
    CapSnap &capsnap = capsnapem.first->second;
    capsnap.context = old_snapc;
    capsnap.issued = in->caps_issued();
    capsnap.dirty = dirty;

    capsnap.dirty_data = (used & CEPH_CAP_FILE_BUFFER);

    capsnap.uid = in->uid;
    capsnap.gid = in->gid;
    capsnap.mode = in->mode;
    capsnap.btime = in->btime;
    capsnap.xattrs = in->xattrs;
    capsnap.xattr_version = in->xattr_version;

    if (used & CEPH_CAP_FILE_WR) {
      ldout(cct, 10) << __func__ << " WR used on " << *in << dendl;
      capsnap.writing = 1;
    } else {
      finish_cap_snap(in, capsnap, used);
    }
  } else {
    ldout(cct, 10) << __func__ << " not dirty|writing on " << *in << dendl;
  }
}

void Client::finish_cap_snap(Inode *in, CapSnap &capsnap, int used)
{