+static int bch2_ioc_goingdown(struct bch_fs *c, u32 __user *arg)
+{
+ u32 flags;
+ int ret = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (get_user(flags, arg))
+ return -EFAULT;
+
+ bch_notice(c, "shutdown by ioctl type %u", flags);
+
+ down_write(&c->vfs_sb->s_umount);
+
+ switch (flags) {
+ case FSOP_GOING_FLAGS_DEFAULT:
+ ret = freeze_bdev(c->vfs_sb->s_bdev);
+ if (ret)
+ goto err;
+
+ bch2_journal_flush(&c->journal);
+ c->vfs_sb->s_flags |= SB_RDONLY;
+ bch2_fs_emergency_read_only(c);
+ thaw_bdev(c->vfs_sb->s_bdev);
+ break;
+
+ case FSOP_GOING_FLAGS_LOGFLUSH:
+ bch2_journal_flush(&c->journal);
+ fallthrough;
+
+ case FSOP_GOING_FLAGS_NOLOGFLUSH:
+ c->vfs_sb->s_flags |= SB_RDONLY;
+ bch2_fs_emergency_read_only(c);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+err:
+ up_write(&c->vfs_sb->s_umount);
+ return ret;
+}
+
+static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
+ struct bch_ioctl_subvolume arg)
+{
+ struct inode *dir;
+ struct bch_inode_info *inode;
+ struct user_namespace *s_user_ns;
+ struct dentry *dst_dentry;
+ struct path src_path, dst_path;
+ int how = LOOKUP_FOLLOW;
+ int error;
+ subvol_inum snapshot_src = { 0 };
+ unsigned lookup_flags = 0;
+ unsigned create_flags = BCH_CREATE_SUBVOL;
+
+ if (arg.flags & ~(BCH_SUBVOL_SNAPSHOT_CREATE|
+ BCH_SUBVOL_SNAPSHOT_RO))
+ return -EINVAL;
+
+ if (!(arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) &&
+ (arg.src_ptr ||
+ (arg.flags & BCH_SUBVOL_SNAPSHOT_RO)))
+ return -EINVAL;
+
+ if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE)
+ create_flags |= BCH_CREATE_SNAPSHOT;
+
+ if (arg.flags & BCH_SUBVOL_SNAPSHOT_RO)
+ create_flags |= BCH_CREATE_SNAPSHOT_RO;
+
+ /* why do we need this lock? */
+ down_read(&c->vfs_sb->s_umount);
+
+ if (arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE)
+ sync_inodes_sb(c->vfs_sb);
+retry:
+ if (arg.src_ptr) {
+ error = user_path_at(arg.dirfd,
+ (const char __user *)(unsigned long)arg.src_ptr,
+ how, &src_path);
+ if (error)
+ goto err1;
+
+ if (src_path.dentry->d_sb->s_fs_info != c) {
+ path_put(&src_path);
+ error = -EXDEV;
+ goto err1;
+ }
+
+ snapshot_src = inode_inum(to_bch_ei(src_path.dentry->d_inode));
+ }
+
+ dst_dentry = user_path_create(arg.dirfd,
+ (const char __user *)(unsigned long)arg.dst_ptr,
+ &dst_path, lookup_flags);
+ error = PTR_ERR_OR_ZERO(dst_dentry);
+ if (error)
+ goto err2;
+
+ if (dst_dentry->d_sb->s_fs_info != c) {
+ error = -EXDEV;
+ goto err3;
+ }
+
+ if (dst_dentry->d_inode) {
+ error = -EEXIST;
+ goto err3;
+ }
+
+ dir = dst_path.dentry->d_inode;
+ if (IS_DEADDIR(dir)) {
+ error = -BCH_ERR_ENOENT_directory_dead;
+ goto err3;
+ }
+
+ s_user_ns = dir->i_sb->s_user_ns;
+ if (!kuid_has_mapping(s_user_ns, current_fsuid()) ||
+ !kgid_has_mapping(s_user_ns, current_fsgid())) {
+ error = -EOVERFLOW;
+ goto err3;
+ }
+
+ error = inode_permission(file_mnt_idmap(filp),
+ dir, MAY_WRITE | MAY_EXEC);
+ if (error)
+ goto err3;
+
+ if (!IS_POSIXACL(dir))
+ arg.mode &= ~current_umask();
+
+ error = security_path_mkdir(&dst_path, dst_dentry, arg.mode);
+ if (error)
+ goto err3;
+
+ if ((arg.flags & BCH_SUBVOL_SNAPSHOT_CREATE) &&
+ !arg.src_ptr)
+ snapshot_src.subvol = to_bch_ei(dir)->ei_inode.bi_subvol;
+
+ inode = __bch2_create(file_mnt_idmap(filp), to_bch_ei(dir),
+ dst_dentry, arg.mode|S_IFDIR,
+ 0, snapshot_src, create_flags);
+ error = PTR_ERR_OR_ZERO(inode);
+ if (error)
+ goto err3;
+
+ d_instantiate(dst_dentry, &inode->v);
+ fsnotify_mkdir(dir, dst_dentry);
+err3:
+ done_path_create(&dst_path, dst_dentry);
+err2:
+ if (arg.src_ptr)
+ path_put(&src_path);
+
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
+err1:
+ up_read(&c->vfs_sb->s_umount);
+
+ return error;
+}
+
+static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
+ struct bch_ioctl_subvolume arg)
+{
+ struct path path;
+ struct inode *dir;
+ int ret = 0;
+
+ if (arg.flags)
+ return -EINVAL;
+
+ ret = user_path_at(arg.dirfd,
+ (const char __user *)(unsigned long)arg.dst_ptr,
+ LOOKUP_FOLLOW, &path);
+ if (ret)
+ return ret;
+
+ if (path.dentry->d_sb->s_fs_info != c) {
+ ret = -EXDEV;
+ goto err;
+ }
+
+ dir = path.dentry->d_parent->d_inode;
+
+ ret = __bch2_unlink(dir, path.dentry, true);
+ if (ret)
+ goto err;
+
+ fsnotify_rmdir(dir, path.dentry);
+ d_delete(path.dentry);
+err:
+ path_put(&path);
+ return ret;
+}
+