| /* SPDX-License-Identifier: LGPL-2.1+ */ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <linux/loop.h> |
| #include <signal.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/file.h> |
| #include <sys/ioctl.h> |
| #include <sys/mount.h> |
| #include <sys/prctl.h> |
| #include <sys/stat.h> |
| #include <sys/statfs.h> |
| #include <sys/statvfs.h> |
| #include <unistd.h> |
| |
| #include "sd-bus-protocol.h" |
| #include "sd-bus.h" |
| |
| #include "alloc-util.h" |
| #include "btrfs-util.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "fs-util.h" |
| #include "label.h" |
| #include "lockfile-util.h" |
| #include "log.h" |
| #include "machine-pool.h" |
| #include "macro.h" |
| #include "missing.h" |
| #include "mkdir.h" |
| #include "mount-util.h" |
| #include "parse-util.h" |
| #include "path-util.h" |
| #include "process-util.h" |
| #include "signal-util.h" |
| #include "stat-util.h" |
| #include "string-util.h" |
| |
| #define VAR_LIB_MACHINES_SIZE_START (1024UL*1024UL*500UL) |
| #define VAR_LIB_MACHINES_FREE_MIN (1024UL*1024UL*750UL) |
| |
| static int check_btrfs(void) { |
| struct statfs sfs; |
| |
| if (statfs("/var/lib/machines", &sfs) < 0) { |
| if (errno != ENOENT) |
| return -errno; |
| |
| if (statfs("/var/lib", &sfs) < 0) |
| return -errno; |
| } |
| |
| return F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC); |
| } |
| |
| static int setup_machine_raw(uint64_t size, sd_bus_error *error) { |
| _cleanup_free_ char *tmp = NULL; |
| _cleanup_close_ int fd = -1; |
| struct statvfs ss; |
| pid_t pid = 0; |
| int r; |
| |
| /* We want to be able to make use of btrfs-specific file |
| * system features, in particular subvolumes, reflinks and |
| * quota. Hence, if we detect that /var/lib/machines.raw is |
| * not located on btrfs, let's create a loopback file, place a |
| * btrfs file system into it, and mount it to |
| * /var/lib/machines. */ |
| |
| fd = open("/var/lib/machines.raw", O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); |
| if (fd >= 0) |
| return TAKE_FD(fd); |
| |
| if (errno != ENOENT) |
| return sd_bus_error_set_errnof(error, errno, "Failed to open /var/lib/machines.raw: %m"); |
| |
| r = tempfn_xxxxxx("/var/lib/machines.raw", NULL, &tmp); |
| if (r < 0) |
| return r; |
| |
| (void) mkdir_p_label("/var/lib", 0755); |
| fd = open(tmp, O_RDWR|O_CREAT|O_EXCL|O_NOCTTY|O_CLOEXEC, 0600); |
| if (fd < 0) |
| return sd_bus_error_set_errnof(error, errno, "Failed to create /var/lib/machines.raw: %m"); |
| |
| if (fstatvfs(fd, &ss) < 0) { |
| r = sd_bus_error_set_errnof(error, errno, "Failed to determine free space on /var/lib/machines.raw: %m"); |
| goto fail; |
| } |
| |
| if (ss.f_bsize * ss.f_bavail < VAR_LIB_MACHINES_FREE_MIN) { |
| r = sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Not enough free disk space to set up /var/lib/machines."); |
| goto fail; |
| } |
| |
| if (ftruncate(fd, size) < 0) { |
| r = sd_bus_error_set_errnof(error, errno, "Failed to enlarge /var/lib/machines.raw: %m"); |
| goto fail; |
| } |
| |
| r = safe_fork("(mkfs)", FORK_RESET_SIGNALS|FORK_DEATHSIG, &pid); |
| if (r < 0) { |
| sd_bus_error_set_errnof(error, r, "Failed to fork mkfs.btrfs: %m"); |
| goto fail; |
| } |
| if (r == 0) { |
| |
| /* Child */ |
| |
| fd = safe_close(fd); |
| |
| execlp("mkfs.btrfs", "-Lvar-lib-machines", tmp, NULL); |
| if (errno == ENOENT) |
| _exit(99); |
| |
| _exit(EXIT_FAILURE); |
| } |
| |
| r = wait_for_terminate_and_check("mkfs", pid, 0); |
| pid = 0; |
| |
| if (r < 0) { |
| sd_bus_error_set_errnof(error, r, "Failed to wait for mkfs.btrfs: %m"); |
| goto fail; |
| } |
| if (r == 99) { |
| r = sd_bus_error_set_errnof(error, ENOENT, "Cannot set up /var/lib/machines, mkfs.btrfs is missing"); |
| goto fail; |
| } |
| if (r != EXIT_SUCCESS) { |
| r = sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "mkfs.btrfs failed with error code %i", r); |
| goto fail; |
| } |
| |
| r = rename_noreplace(AT_FDCWD, tmp, AT_FDCWD, "/var/lib/machines.raw"); |
| if (r < 0) { |
| sd_bus_error_set_errnof(error, r, "Failed to move /var/lib/machines.raw into place: %m"); |
| goto fail; |
| } |
| |
| return TAKE_FD(fd); |
| |
| fail: |
| unlink_noerrno(tmp); |
| |
| if (pid > 1) |
| kill_and_sigcont(pid, SIGKILL); |
| |
| return r; |
| } |
| |
| int setup_machine_directory(uint64_t size, sd_bus_error *error) { |
| _cleanup_(release_lock_file) LockFile lock_file = LOCK_FILE_INIT; |
| struct loop_info64 info = { |
| .lo_flags = LO_FLAGS_AUTOCLEAR, |
| }; |
| _cleanup_close_ int fd = -1, control = -1, loop = -1; |
| _cleanup_free_ char* loopdev = NULL; |
| char tmpdir[] = "/tmp/machine-pool.XXXXXX", *mntdir = NULL; |
| bool tmpdir_made = false, mntdir_made = false, mntdir_mounted = false; |
| char buf[FORMAT_BYTES_MAX]; |
| int r, nr = -1; |
| |
| /* btrfs cannot handle file systems < 16M, hence use this as minimum */ |
| if (size == (uint64_t) -1) |
| size = VAR_LIB_MACHINES_SIZE_START; |
| else if (size < 16*1024*1024) |
| size = 16*1024*1024; |
| |
| /* Make sure we only set the directory up once at a time */ |
| r = make_lock_file("/run/systemd/machines.lock", LOCK_EX, &lock_file); |
| if (r < 0) |
| return r; |
| |
| r = check_btrfs(); |
| if (r < 0) |
| return sd_bus_error_set_errnof(error, r, "Failed to determine whether /var/lib/machines is located on btrfs: %m"); |
| if (r > 0) { |
| (void) btrfs_subvol_make_label("/var/lib/machines"); |
| |
| r = btrfs_quota_enable("/var/lib/machines", true); |
| if (r < 0) |
| log_warning_errno(r, "Failed to enable quota for /var/lib/machines, ignoring: %m"); |
| |
| r = btrfs_subvol_auto_qgroup("/var/lib/machines", 0, true); |
| if (r < 0) |
| log_warning_errno(r, "Failed to set up default quota hierarchy for /var/lib/machines, ignoring: %m"); |
| |
| return 1; |
| } |
| |
| if (path_is_mount_point("/var/lib/machines", NULL, AT_SYMLINK_FOLLOW) > 0) { |
| log_debug("/var/lib/machines is already a mount point, not creating loopback file for it."); |
| return 0; |
| } |
| |
| r = dir_is_populated("/var/lib/machines"); |
| if (r < 0 && r != -ENOENT) |
| return r; |
| if (r > 0) { |
| log_debug("/var/log/machines is already populated, not creating loopback file for it."); |
| return 0; |
| } |
| |
| r = mkfs_exists("btrfs"); |
| if (r == 0) |
| return sd_bus_error_set_errnof(error, ENOENT, "Cannot set up /var/lib/machines, mkfs.btrfs is missing"); |
| if (r < 0) |
| return r; |
| |
| fd = setup_machine_raw(size, error); |
| if (fd < 0) |
| return fd; |
| |
| control = open("/dev/loop-control", O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK); |
| if (control < 0) |
| return sd_bus_error_set_errnof(error, errno, "Failed to open /dev/loop-control: %m"); |
| |
| nr = ioctl(control, LOOP_CTL_GET_FREE); |
| if (nr < 0) |
| return sd_bus_error_set_errnof(error, errno, "Failed to allocate loop device: %m"); |
| |
| if (asprintf(&loopdev, "/dev/loop%i", nr) < 0) { |
| r = -ENOMEM; |
| goto fail; |
| } |
| |
| loop = open(loopdev, O_CLOEXEC|O_RDWR|O_NOCTTY|O_NONBLOCK); |
| if (loop < 0) { |
| r = sd_bus_error_set_errnof(error, errno, "Failed to open loopback device: %m"); |
| goto fail; |
| } |
| |
| if (ioctl(loop, LOOP_SET_FD, fd) < 0) { |
| r = sd_bus_error_set_errnof(error, errno, "Failed to bind loopback device: %m"); |
| goto fail; |
| } |
| |
| if (ioctl(loop, LOOP_SET_STATUS64, &info) < 0) { |
| r = sd_bus_error_set_errnof(error, errno, "Failed to enable auto-clear for loopback device: %m"); |
| goto fail; |
| } |
| |
| /* We need to make sure the new /var/lib/machines directory |
| * has an access mode of 0700 at the time it is first made |
| * available. mkfs will create it with 0755 however. Hence, |
| * let's mount the directory into an inaccessible directory |
| * below /tmp first, fix the access mode, and move it to the |
| * public place then. */ |
| |
| if (!mkdtemp(tmpdir)) { |
| r = sd_bus_error_set_errnof(error, errno, "Failed to create temporary mount parent directory: %m"); |
| goto fail; |
| } |
| tmpdir_made = true; |
| |
| mntdir = strjoina(tmpdir, "/mnt"); |
| if (mkdir(mntdir, 0700) < 0) { |
| r = sd_bus_error_set_errnof(error, errno, "Failed to create temporary mount directory: %m"); |
| goto fail; |
| } |
| mntdir_made = true; |
| |
| if (mount(loopdev, mntdir, "btrfs", 0, NULL) < 0) { |
| r = sd_bus_error_set_errnof(error, errno, "Failed to mount loopback device: %m"); |
| goto fail; |
| } |
| mntdir_mounted = true; |
| |
| r = btrfs_quota_enable(mntdir, true); |
| if (r < 0) |
| log_warning_errno(r, "Failed to enable quota, ignoring: %m"); |
| |
| r = btrfs_subvol_auto_qgroup(mntdir, 0, true); |
| if (r < 0) |
| log_warning_errno(r, "Failed to set up default quota hierarchy, ignoring: %m"); |
| |
| if (chmod(mntdir, 0700) < 0) { |
| r = sd_bus_error_set_errnof(error, errno, "Failed to fix owner: %m"); |
| goto fail; |
| } |
| |
| (void) mkdir_p_label("/var/lib/machines", 0700); |
| |
| if (mount(mntdir, "/var/lib/machines", NULL, MS_BIND, NULL) < 0) { |
| r = sd_bus_error_set_errnof(error, errno, "Failed to mount directory into right place: %m"); |
| goto fail; |
| } |
| |
| (void) syncfs(fd); |
| |
| log_info("Set up /var/lib/machines as btrfs loopback file system of size %s mounted on /var/lib/machines.raw.", format_bytes(buf, sizeof(buf), size)); |
| |
| (void) umount2(mntdir, MNT_DETACH); |
| (void) rmdir(mntdir); |
| (void) rmdir(tmpdir); |
| |
| return 1; |
| |
| fail: |
| if (mntdir_mounted) |
| (void) umount2(mntdir, MNT_DETACH); |
| |
| if (mntdir_made) |
| (void) rmdir(mntdir); |
| if (tmpdir_made) |
| (void) rmdir(tmpdir); |
| |
| if (loop >= 0) { |
| (void) ioctl(loop, LOOP_CLR_FD); |
| loop = safe_close(loop); |
| } |
| |
| if (control >= 0 && nr >= 0) |
| (void) ioctl(control, LOOP_CTL_REMOVE, nr); |
| |
| return r; |
| } |
| |
| static int sync_path(const char *p) { |
| _cleanup_close_ int fd = -1; |
| |
| fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY); |
| if (fd < 0) |
| return -errno; |
| |
| if (syncfs(fd) < 0) |
| return -errno; |
| |
| return 0; |
| } |
| |
| int grow_machine_directory(void) { |
| char buf[FORMAT_BYTES_MAX]; |
| struct statvfs a, b; |
| uint64_t old_size, new_size, max_add; |
| int r; |
| |
| /* Ensure the disk space data is accurate */ |
| sync_path("/var/lib/machines"); |
| sync_path("/var/lib/machines.raw"); |
| |
| if (statvfs("/var/lib/machines.raw", &a) < 0) |
| return -errno; |
| |
| if (statvfs("/var/lib/machines", &b) < 0) |
| return -errno; |
| |
| /* Don't grow if not enough disk space is available on the host */ |
| if (((uint64_t) a.f_bavail * (uint64_t) a.f_bsize) <= VAR_LIB_MACHINES_FREE_MIN) |
| return 0; |
| |
| /* Don't grow if at least 1/3th of the fs is still free */ |
| if (b.f_bavail > b.f_blocks / 3) |
| return 0; |
| |
| /* Calculate how much we are willing to add at most */ |
| max_add = ((uint64_t) a.f_bavail * (uint64_t) a.f_bsize) - VAR_LIB_MACHINES_FREE_MIN; |
| |
| /* Calculate the old size */ |
| old_size = (uint64_t) b.f_blocks * (uint64_t) b.f_bsize; |
| |
| /* Calculate the new size as three times the size of what is used right now */ |
| new_size = ((uint64_t) b.f_blocks - (uint64_t) b.f_bavail) * (uint64_t) b.f_bsize * 3; |
| |
| /* Always, grow at least to the start size */ |
| if (new_size < VAR_LIB_MACHINES_SIZE_START) |
| new_size = VAR_LIB_MACHINES_SIZE_START; |
| |
| /* If the new size is smaller than the old size, don't grow */ |
| if (new_size < old_size) |
| return 0; |
| |
| /* Ensure we never add more than the maximum */ |
| if (new_size > old_size + max_add) |
| new_size = old_size + max_add; |
| |
| r = btrfs_resize_loopback("/var/lib/machines", new_size, true); |
| if (r <= 0) |
| return r; |
| |
| /* Also bump the quota, of both the subvolume leaf qgroup, as |
| * well as of any subtree quota group by the same id but a |
| * higher level, if it exists. */ |
| (void) btrfs_qgroup_set_limit("/var/lib/machines", 0, new_size); |
| (void) btrfs_subvol_set_subtree_quota_limit("/var/lib/machines", 0, new_size); |
| |
| log_info("Grew /var/lib/machines btrfs loopback file system to %s.", format_bytes(buf, sizeof(buf), new_size)); |
| return 1; |
| } |