/* * mount 'source_mnt' under the destination 'dest_mnt' at * dentry 'dest_dentry'. And propagate that mount to * all the peer and slave mounts of 'dest_mnt'. * Link all the new mounts into a propagation tree headed at * source_mnt. Also link all the new mounts using ->mnt_list * headed at source_mnt's ->mnt_list * * @dest_mnt: destination mount. * @dest_dentry: destination dentry. * @source_mnt: source mount. * @tree_list : list of heads of trees to be attached. */ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp, struct mount *source_mnt, struct hlist_head *tree_list) { struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns; struct mount *m, *child; int ret = 0; struct mount *prev_dest_mnt = dest_mnt; struct mount *prev_src_mnt = source_mnt; HLIST_HEAD(tmp_list); for (m = propagation_next(dest_mnt, dest_mnt); m; m = propagation_next(m, dest_mnt)) { int type; struct mount *source; if (IS_MNT_NEW(m)) continue; source = get_source(m, prev_dest_mnt, prev_src_mnt, &type); /* Notice when we are propagating across user namespaces */ if (m->mnt_ns->user_ns != user_ns) type |= CL_UNPRIVILEGED; child = copy_tree(source, source->mnt.mnt_root, type); if (IS_ERR(child)) { ret = PTR_ERR(child); tmp_list = *tree_list; tmp_list.first->pprev = &tmp_list.first; INIT_HLIST_HEAD(tree_list); goto out; } if (is_subdir(dest_mp->m_dentry, m->mnt.mnt_root)) { mnt_set_mountpoint(m, dest_mp, child); hlist_add_head(&child->mnt_hash, tree_list); } else { /* * This can happen if the parent mount was bind mounted * on some subdirectory of a shared/slave mount. */ hlist_add_head(&child->mnt_hash, &tmp_list); } prev_dest_mnt = m; prev_src_mnt = child; } out: lock_mount_hash(); while (!hlist_empty(&tmp_list)) { child = hlist_entry(tmp_list.first, struct mount, mnt_hash); umount_tree(child, 0); } unlock_mount_hash(); return ret; }
/* * mount 'source_mnt' under the destination 'dest_mnt' at * dentry 'dest_dentry'. And propagate that mount to * all the peer and slave mounts of 'dest_mnt'. * Link all the new mounts into a propagation tree headed at * source_mnt. Also link all the new mounts using ->mnt_list * headed at source_mnt's ->mnt_list * * @dest_mnt: destination mount. * @dest_dentry: destination dentry. * @source_mnt: source mount. * @tree_list : list of heads of trees to be attached. */ int propagate_mnt(struct mount *dest_mnt, struct dentry *dest_dentry, struct mount *source_mnt, struct list_head *tree_list) { struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns; struct mount *m, *child; int ret = 0; struct mount *prev_dest_mnt = dest_mnt; struct mount *prev_src_mnt = source_mnt; LIST_HEAD(tmp_list); LIST_HEAD(umount_list); for (m = propagation_next(dest_mnt, dest_mnt); m; m = propagation_next(m, dest_mnt)) { int type; struct mount *source; if (IS_MNT_NEW(m)) continue; source = get_source(m, prev_dest_mnt, prev_src_mnt, &type); /* Notice when we are propagating across user namespaces */ if (m->mnt_ns->user_ns != user_ns) type |= CL_UNPRIVILEGED; child = copy_tree(source, source->mnt.mnt_root, type); if (IS_ERR(child)) { ret = PTR_ERR(child); list_splice(tree_list, tmp_list.prev); goto out; } if (is_subdir(dest_dentry, m->mnt.mnt_root)) { mnt_set_mountpoint(m, dest_dentry, child); list_add_tail(&child->mnt_hash, tree_list); } else { /* * This can happen if the parent mount was bind mounted * on some subdirectory of a shared/slave mount. */ list_add_tail(&child->mnt_hash, &tmp_list); } prev_dest_mnt = m; prev_src_mnt = child; } out: br_write_lock(&vfsmount_lock); while (!list_empty(&tmp_list)) { child = list_first_entry(&tmp_list, struct mount, mnt_hash); umount_tree(child, 0, &umount_list); } br_write_unlock(&vfsmount_lock); release_mounts(&umount_list); return ret; }
static int propagate_one(struct mount *m) { struct mount *child; int type; /* skip ones added by this propagate_mnt() */ if (IS_MNT_NEW(m)) return 0; /* skip if mountpoint isn't covered by it */ if (!is_subdir(mp->m_dentry, m->mnt.mnt_root)) return 0; if (m->mnt_group_id == last_dest->mnt_group_id) { type = CL_MAKE_SHARED; } else { struct mount *n, *p; for (n = m; ; n = p) { p = n->mnt_master; if (p == dest_master || IS_MNT_MARKED(p)) { while (last_dest->mnt_master != p) { last_source = last_source->mnt_master; last_dest = last_source->mnt_parent; } if (n->mnt_group_id != last_dest->mnt_group_id) { last_source = last_source->mnt_master; last_dest = last_source->mnt_parent; } break; } } type = CL_SLAVE; /* beginning of peer group among the slaves? */ if (IS_MNT_SHARED(m)) type |= CL_MAKE_SHARED; } /* Notice when we are propagating across user namespaces */ if (m->mnt_ns->user_ns != user_ns) type |= CL_UNPRIVILEGED; child = copy_tree(last_source, last_source->mnt.mnt_root, type); if (IS_ERR(child)) return PTR_ERR(child); child->mnt.mnt_flags &= ~MNT_LOCKED; mnt_set_mountpoint(m, mp, child); last_dest = m; last_source = child; if (m->mnt_master != dest_master) { read_seqlock_excl(&mount_lock); SET_MNT_MARK(m->mnt_master); read_sequnlock_excl(&mount_lock); } hlist_add_head(&child->mnt_hash, list); return 0; }
/* * mount 'source_mnt' under the destination 'dest_mnt' at * dentry 'dest_dentry'. And propagate that mount to * all the peer and slave mounts of 'dest_mnt'. * Link all the new mounts into a propagation tree headed at * source_mnt. Also link all the new mounts using ->mnt_list * headed at source_mnt's ->mnt_list * * @dest_mnt: destination mount. * @dest_dentry: destination dentry. * @source_mnt: source mount. * @tree_list : list of heads of trees to be attached. */ int propagate_mnt(struct vfsmount *dest_mnt, struct dentry *dest_dentry, struct vfsmount *source_mnt, struct list_head *tree_list) { struct vfsmount *m, *child; int ret = 0; struct vfsmount *prev_dest_mnt = dest_mnt; struct vfsmount *prev_src_mnt = source_mnt; LIST_HEAD(tmp_list); LIST_HEAD(umount_list); for (m = propagation_next(dest_mnt, dest_mnt); m; m = propagation_next(m, dest_mnt)) { int type; struct vfsmount *source; if (IS_MNT_NEW(m)) continue; source = get_source(m, prev_dest_mnt, prev_src_mnt, &type); if (!(child = copy_tree(source, source->mnt_root, type))) { ret = -ENOMEM; list_splice(tree_list, tmp_list.prev); goto out; } if (is_subdir(dest_dentry, m->mnt_root)) { mnt_set_mountpoint(m, dest_dentry, child); list_add_tail(&child->mnt_hash, tree_list); } else { /* * This can happen if the parent mount was bind mounted * on some subdirectory of a shared/slave mount. */ list_add_tail(&child->mnt_hash, &tmp_list); } prev_dest_mnt = m; prev_src_mnt = child; } out: spin_lock(&vfsmount_lock); while (!list_empty(&tmp_list)) { child = list_entry(tmp_list.next, struct vfsmount, mnt_hash); list_del_init(&child->mnt_hash); umount_tree(child, 0, &umount_list); } spin_unlock(&vfsmount_lock); release_mounts(&umount_list); return ret; }
int propagate_mnt(struct mount *dest_mnt, struct dentry *dest_dentry, struct mount *source_mnt, struct list_head *tree_list) { struct mount *m, *child; int ret = 0; struct mount *prev_dest_mnt = dest_mnt; struct mount *prev_src_mnt = source_mnt; LIST_HEAD(tmp_list); LIST_HEAD(umount_list); for (m = propagation_next(dest_mnt, dest_mnt); m; m = propagation_next(m, dest_mnt)) { int type; struct mount *source; if (IS_MNT_NEW(m)) continue; source = get_source(m, prev_dest_mnt, prev_src_mnt, &type); if (!(child = copy_tree(source, source->mnt.mnt_root, type))) { ret = -ENOMEM; list_splice(tree_list, tmp_list.prev); goto out; } if (is_subdir(dest_dentry, m->mnt.mnt_root)) { mnt_set_mountpoint(m, dest_dentry, child); list_add_tail(&child->mnt_hash, tree_list); } else { list_add_tail(&child->mnt_hash, &tmp_list); } prev_dest_mnt = m; prev_src_mnt = child; } out: br_write_lock(vfsmount_lock); while (!list_empty(&tmp_list)) { child = list_first_entry(&tmp_list, struct mount, mnt_hash); umount_tree(child, 0, &umount_list); } br_write_unlock(vfsmount_lock); release_mounts(&umount_list); return ret; }