> From: Nicolin Chen <nicolinc@xxxxxxxxxx> > Sent: Thursday, March 23, 2023 4:33 PM > > +int iommufd_access_replace(struct iommufd_access *access, u32 ioas_id) > +{ > + struct iommufd_ioas *new_ioas; > + > + mutex_lock(&access->ioas_lock); > + if (!access->ioas) { > mutex_unlock(&access->ioas_lock); > - iommufd_put_object(obj); > - return rc; > + return -ENOENT; > + } > + if (access->ioas->obj.id == ioas_id) { > + mutex_unlock(&access->ioas_lock); > + return 0; > } > - iommufd_ref_to_users(obj); > > + new_ioas = iommufd_access_change_pt(access, ioas_id); > + if (IS_ERR(new_ioas)) { > + mutex_unlock(&access->ioas_lock); > + return PTR_ERR(new_ioas); > + } > + __iommufd_access_detach(access); > access->ioas = new_ioas; > access->ioas_unpin = new_ioas; Above three lines can be moved into iommufd_access_change_pt(): If (access->ioas) __iommufd_access_detach(access); access->ioas = new_ioas; access->ioas_unpin = new_ioas; Then both attach/replace can end by calling the common function.