+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2015 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <sys/prctl.h>
-#include <sys/vfs.h>
-#include <sys/statvfs.h>
-#include <sys/mount.h>
-
-#include "util.h"
-#include "process-util.h"
-#include "lockfile-util.h"
-#include "mkdir.h"
-#include "btrfs-util.h"
-#include "path-util.h"
-#include "signal-util.h"
-#include "machine-pool.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;
- siginfo_t si;
- 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) {
- r = fd;
- fd = -1;
- return r;
- }
-
- 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;
- }
-
- pid = fork();
- if (pid < 0) {
- r = sd_bus_error_set_errnof(error, errno, "Failed to fork mkfs.btrfs: %m");
- goto fail;
- }
-
- if (pid == 0) {
-
- /* Child */
-
- (void) reset_all_signal_handlers();
- (void) reset_signal_mask();
- assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
-
- fd = safe_close(fd);
-
- execlp("mkfs.btrfs", "-Lvar-lib-machines", tmp, NULL);
- if (errno == ENOENT)
- return 99;
-
- _exit(EXIT_FAILURE);
- }
-
- r = wait_for_terminate(pid, &si);
- if (r < 0) {
- sd_bus_error_set_errnof(error, r, "Failed to wait for mkfs.btrfs: %m");
- goto fail;
- }
-
- pid = 0;
-
- if (si.si_code != CLD_EXITED) {
- r = sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "mkfs.btrfs died abnormally.");
- goto fail;
- }
- if (si.si_status == 99) {
- r = sd_bus_error_set_errnof(error, ENOENT, "Cannot set up /var/lib/machines, mkfs.btrfs is missing");
- goto fail;
- }
- if (si.si_status != 0) {
- r = sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "mkfs.btrfs failed with error code %i", si.si_status);
- 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;
- }
-
- r = fd;
- fd = -1;
-
- return r;
-
-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/import-mount.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, ignoring: %m");
-
- return 0;
- }
-
- if (path_is_mount_point("/var/lib/machines", AT_SYMLINK_FOLLOW) > 0 ||
- dir_is_empty("/var/lib/machines") == 0)
- return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "/var/lib/machines is not a btrfs file system. Operation is not supported on legacy file systems.");
-
- 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");
-
- 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 0;
-
-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 maximum */
- 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;
-
- r = btrfs_quota_limit("/var/lib/machines", new_size);
- if (r < 0)
- return r;
-
- log_info("Grew /var/lib/machines btrfs loopback file system to %s.", format_bytes(buf, sizeof(buf), new_size));
- return 1;
-}
~ianmdlvl / elogind.git / blobdiff