/* * Copyright (c) 2018-2020, Andreas Kling * * SPDX-License-Identifier: BSD-2-Clause */ #include #include #include #include #include #include #include #include #include #include namespace Kernel { KResultOr Process::sys$mount(Userspace user_params) { VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this) if (!is_superuser()) return EPERM; REQUIRE_NO_PROMISES; Syscall::SC_mount_params params; if (!copy_from_user(¶ms, user_params)) return EFAULT; auto source_fd = params.source_fd; auto target = copy_string_from_user(params.target); if (target.is_null()) return EFAULT; auto fs_type = copy_string_from_user(params.fs_type); if (fs_type.is_null()) return EFAULT; auto description = fds().file_description(source_fd); if (!description.is_null()) dbgln("mount {}: source fd {} @ {}", fs_type, source_fd, target); else dbgln("mount {} @ {}", fs_type, target); auto custody_or_error = VirtualFileSystem::the().resolve_path(target, current_directory()); if (custody_or_error.is_error()) return custody_or_error.error(); auto& target_custody = custody_or_error.value(); if (params.flags & MS_REMOUNT) { // We're not creating a new mount, we're updating an existing one! return VirtualFileSystem::the().remount(target_custody, params.flags & ~MS_REMOUNT); } if (params.flags & MS_BIND) { // We're doing a bind mount. if (description.is_null()) return EBADF; if (!description->custody()) { // We only support bind-mounting inodes, not arbitrary files. return ENODEV; } return VirtualFileSystem::the().bind_mount(*description->custody(), target_custody, params.flags); } RefPtr fs; if (fs_type == "ext2"sv || fs_type == "Ext2FS"sv) { if (description.is_null()) return EBADF; if (!description->file().is_block_device()) return ENOTBLK; if (!description->file().is_seekable()) { dbgln("mount: this is not a seekable file"); return ENODEV; } dbgln("mount: attempting to mount {} on {}", description->absolute_path(), target); fs = Ext2FS::create(*description); } else if (fs_type == "9p"sv || fs_type == "Plan9FS"sv) { if (description.is_null()) return EBADF; fs = Plan9FS::create(*description); } else if (fs_type == "proc"sv || fs_type == "ProcFS"sv) { fs = ProcFS::create(); } else if (fs_type == "devpts"sv || fs_type == "DevPtsFS"sv) { fs = DevPtsFS::create(); } else if (fs_type == "dev"sv || fs_type == "DevFS"sv) { fs = DevFS::create(); } else if (fs_type == "sys"sv || fs_type == "SysFS"sv) { fs = SysFS::create(); } else if (fs_type == "tmp"sv || fs_type == "TmpFS"sv) { fs = TmpFS::create(); } else { return ENODEV; } if (!fs) return ENOMEM; if (!fs->initialize()) { dbgln("mount: failed to initialize {} filesystem, fd={}", fs_type, source_fd); return ENODEV; } auto result = VirtualFileSystem::the().mount(fs.release_nonnull(), target_custody, params.flags); if (!description.is_null()) dbgln("mount: successfully mounted {} on {}", description->absolute_path(), target); else dbgln("mount: successfully mounted {}", target); return result; } KResultOr Process::sys$umount(Userspace user_mountpoint, size_t mountpoint_length) { VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this) if (!is_superuser()) return EPERM; REQUIRE_NO_PROMISES; auto mountpoint = get_syscall_path_argument(user_mountpoint, mountpoint_length); if (mountpoint.is_error()) return mountpoint.error(); auto custody_or_error = VirtualFileSystem::the().resolve_path(mountpoint.value()->view(), current_directory()); if (custody_or_error.is_error()) return custody_or_error.error(); auto& guest_inode = custody_or_error.value()->inode(); return VirtualFileSystem::the().unmount(guest_inode); } }