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Systemd/src/gpt-auto-generator/gpt-auto-generator.c
Lennart Poettering 61331eab0a gpt-auto-generator: probe only partition table and partitions we are interested in 
Instead of iterating through the list of partitions and probing them all
with blkid, simply probe the partition table and use that information to
only probe the partitions we care for.
2014-03-08 04:06:04 +01:00

777 lines
22 KiB
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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 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 <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/statfs.h>
#include <blkid/blkid.h>
#ifdef HAVE_LINUX_BTRFS_H
#include <linux/btrfs.h>
#endif
#include "sd-id128.h"
#include "libudev.h"
#include "path-util.h"
#include "util.h"
#include "mkdir.h"
#include "missing.h"
#include "udev-util.h"
#include "special.h"
#include "unit-name.h"
#include "virt.h"
#include "generator.h"
#include "gpt.h"
#include "fileio.h"
#include "efivars.h"
static const char *arg_dest = "/tmp";
static bool arg_enabled = true;
static bool arg_root_enabled = true;
static bool arg_root_rw = false;
DEFINE_TRIVIAL_CLEANUP_FUNC(blkid_probe, blkid_free_probe);
#define _cleanup_blkid_free_probe_ _cleanup_(blkid_free_probep)
static int add_swap(const char *path) {
_cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL;
_cleanup_fclose_ FILE *f = NULL;
assert(path);
log_debug("Adding swap: %s", path);
name = unit_name_from_path(path, ".swap");
if (!name)
return log_oom();
unit = strjoin(arg_dest, "/", name, NULL);
if (!unit)
return log_oom();
f = fopen(unit, "wxe");
if (!f) {
log_error("Failed to create unit file %s: %m", unit);
return -errno;
}
fprintf(f,
"# Automatically generated by systemd-gpt-auto-generator\n\n"
"[Unit]\n"
"Description=Swap Partition\n"
"Documentation=man:systemd-gpt-auto-generator(8)\n\n"
"[Swap]\n"
"What=%s\n",
path);
fflush(f);
if (ferror(f)) {
log_error("Failed to write unit file %s: %m", unit);
return -errno;
}
lnk = strjoin(arg_dest, "/" SPECIAL_SWAP_TARGET ".wants/", name, NULL);
if (!lnk)
return log_oom();
mkdir_parents_label(lnk, 0755);
if (symlink(unit, lnk) < 0) {
log_error("Failed to create symlink %s: %m", lnk);
return -errno;
}
return 0;
}
static int add_cryptsetup(const char *id, const char *what, char **device) {
_cleanup_free_ char *e = NULL, *n = NULL, *p = NULL, *d = NULL, *to = NULL;
_cleanup_fclose_ FILE *f = NULL;
char *from, *ret;
int r;
assert(id);
assert(what);
assert(device);
d = unit_name_from_path(what, ".device");
if (!d)
return log_oom();
e = unit_name_escape(id);
if (!e)
return log_oom();
n = unit_name_build("systemd-cryptsetup", e, ".service");
if (!n)
return log_oom();
p = strjoin(arg_dest, "/", n, NULL);
if (!n)
return log_oom();
f = fopen(p, "wxe");
if (!f) {
log_error("Failed to create unit file %s: %m", p);
return -errno;
}
fprintf(f,
"# Automatically generated by systemd-gpt-auto-generator\n\n"
"[Unit]\n"
"Description=Cryptography Setup for %%I\n"
"Documentation=man:systemd-gpt-auto-generator(8) man:systemd-cryptsetup@.service(8)\n"
"DefaultDependencies=no\n"
"Conflicts=umount.target\n"
"BindsTo=dev-mapper-%%i.device %s\n"
"Before=umount.target cryptsetup.target\n"
"After=%s\n"
"IgnoreOnIsolate=true\n"
"After=systemd-readahead-collect.service systemd-readahead-replay.service\n\n"
"[Service]\n"
"Type=oneshot\n"
"RemainAfterExit=yes\n"
"TimeoutSec=0\n" /* the binary handles timeouts anyway */
"ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s'\n"
"ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
d, d,
id, what,
id);
fflush(f);
if (ferror(f)) {
log_error("Failed to write file %s: %m", p);
return -errno;
}
from = strappenda("../", n);
to = strjoin(arg_dest, "/", d, ".wants/", n, NULL);
if (!to)
return log_oom();
mkdir_parents_label(to, 0755);
if (symlink(from, to) < 0) {
log_error("Failed to create symlink %s: %m", to);
return -errno;
}
free(to);
to = strjoin(arg_dest, "/cryptsetup.target.requires/", n, NULL);
if (!to)
return log_oom();
mkdir_parents_label(to, 0755);
if (symlink(from, to) < 0) {
log_error("Failed to create symlink %s: %m", to);
return -errno;
}
free(to);
to = strjoin(arg_dest, "/dev-mapper-", e, ".device.requires/", n, NULL);
if (!to)
return log_oom();
mkdir_parents_label(to, 0755);
if (symlink(from, to) < 0) {
log_error("Failed to create symlink %s: %m", to);
return -errno;
}
free(p);
p = strjoin(arg_dest, "/dev-mapper-", e, ".device.d/50-job-timeout-sec-0.conf", NULL);
if (!p)
return log_oom();
mkdir_parents_label(p, 0755);
r = write_string_file(p,
"# Automatically generated by systemd-gpt-auto-generator\n\n"
"[Unit]\n"
"JobTimeoutSec=0\n"); /* the binary handles timeouts anyway */
if (r < 0) {
log_error("Failed to write device drop-in: %s", strerror(-r));
return r;
}
ret = strappend("/dev/mapper/", id);
if (!ret)
return log_oom();
*device = ret;
return 0;
}
static int add_mount(
const char *id,
const char *what,
const char *where,
const char *fstype,
const char *options,
const char *description,
const char *post) {
_cleanup_free_ char *unit = NULL, *lnk = NULL, *crypto_what = NULL, *p = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
assert(id);
assert(what);
assert(where);
assert(description);
log_debug("Adding %s: %s %s", where, what, strna(fstype));
if (streq_ptr(fstype, "crypto_LUKS")) {
r = add_cryptsetup(id, what, &crypto_what);
if (r < 0)
return r;
what = crypto_what;
fstype = NULL;
}
unit = unit_name_from_path(where, ".mount");
if (!unit)
return log_oom();
p = strjoin(arg_dest, "/", unit, NULL);
if (!p)
return log_oom();
f = fopen(p, "wxe");
if (!f) {
log_error("Failed to create unit file %s: %m", unit);
return -errno;
}
fprintf(f,
"# Automatically generated by systemd-gpt-auto-generator\n\n"
"[Unit]\n"
"Description=%s\n"
"Documentation=man:systemd-gpt-auto-generator(8)\n",
description);
if (post)
fprintf(f, "Before=%s\n", post);
r = generator_write_fsck_deps(f, arg_dest, what, where, fstype);
if (r < 0)
return r;
fprintf(f,
"\n"
"[Mount]\n"
"What=%s\n"
"Where=%s\n",
what, where);
if (fstype)
fprintf(f, "Type=%s\n", fstype);
if (options)
fprintf(f, "Options=%s\n", options);
fflush(f);
if (ferror(f)) {
log_error("Failed to write unit file %s: %m", p);
return -errno;
}
if (post) {
lnk = strjoin(arg_dest, "/", post, ".requires/", unit, NULL);
if (!lnk)
return log_oom();
mkdir_parents_label(lnk, 0755);
if (symlink(p, lnk) < 0) {
log_error("Failed to create symlink %s: %m", lnk);
return -errno;
}
}
return 0;
}
static int probe_and_add_mount(
const char *id,
const char *what,
const char *where,
const char *description,
const char *post) {
_cleanup_blkid_free_probe_ blkid_probe b = NULL;
const char *fstype;
int r;
assert(id);
assert(what);
assert(where);
assert(description);
if (path_is_mount_point(where, true) <= 0 &&
dir_is_empty(where) <= 0) {
log_debug("%s already populated, ignoring.", where);
return 0;
}
/* Let's check the partition type here, so that we know
* whether to do LUKS magic. */
errno = 0;
b = blkid_new_probe_from_filename(what);
if (!b) {
if (errno == 0)
return log_oom();
log_error("Failed to allocate prober: %m");
return -errno;
}
blkid_probe_enable_superblocks(b, 1);
blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
errno = 0;
r = blkid_do_safeprobe(b);
if (r == -2 || r == 1) /* no result or uncertain */
return 0;
else if (r != 0) {
if (errno == 0)
errno = EIO;
log_error("Failed to probe %s: %m", what);
return -errno;
}
blkid_probe_lookup_value(b, "TYPE", &fstype, NULL);
return add_mount(
id,
what,
where,
fstype,
NULL,
description,
post);
}
static int enumerate_partitions(dev_t devnum) {
_cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
_cleanup_udev_device_unref_ struct udev_device *d = NULL;
_cleanup_blkid_free_probe_ blkid_probe b = NULL;
_cleanup_udev_unref_ struct udev *udev = NULL;
_cleanup_free_ char *home = NULL, *srv = NULL;
struct udev_list_entry *first, *item;
struct udev_device *parent = NULL;
const char *node, *pttype, *devtype;
int home_nr = -1, srv_nr = -1;
blkid_partlist pl;
int r, k;
dev_t pn;
udev = udev_new();
if (!udev)
return log_oom();
d = udev_device_new_from_devnum(udev, 'b', devnum);
if (!d)
return log_oom();
parent = udev_device_get_parent(d);
if (!parent)
return log_oom();
/* Does it have a devtype? */
devtype = udev_device_get_devtype(parent);
if (!devtype)
return 0;
/* Is this a disk or a partition? We only care for disks... */
if (!streq(devtype, "disk"))
return 0;
/* Does it have a device node? */
node = udev_device_get_devnode(parent);
if (!node)
return 0;
log_debug("Root device %s.", node);
pn = udev_device_get_devnum(parent);
if (major(pn) == 0)
return 0;
errno = 0;
b = blkid_new_probe_from_filename(node);
if (!b) {
if (errno == 0)
return log_oom();
log_error("Failed allocate prober: %m");
return -errno;
}
blkid_probe_enable_superblocks(b, 1);
blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
blkid_probe_enable_partitions(b, 1);
blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS);
errno = 0;
r = blkid_do_safeprobe(b);
if (r == -2 || r == 1) /* no result or uncertain */
return 0;
else if (r != 0) {
if (errno == 0)
errno = EIO;
log_error("Failed to probe %s: %m", node);
return -errno;
}
errno = 0;
r = blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL);
if (r != 0) {
if (errno == 0)
errno = EIO;
log_error("Failed to determine partition table type of %s: %m", node);
return -errno;
}
/* We only do this all for GPT... */
if (!streq_ptr(pttype, "gpt"))
return 0;
errno = 0;
pl = blkid_probe_get_partitions(b);
if (!pl) {
if (errno == 0)
return log_oom();
log_error("Failed to list of partitions of %s: %m", node);
return -errno;
}
e = udev_enumerate_new(udev);
if (!e)
return log_oom();
r = udev_enumerate_add_match_parent(e, parent);
if (r < 0)
return log_oom();
r = udev_enumerate_add_match_subsystem(e, "block");
if (r < 0)
return log_oom();
r = udev_enumerate_scan_devices(e);
if (r < 0) {
log_error("Failed to enumerate partitions on %s: %s", node, strerror(-r));
return r;
}
first = udev_enumerate_get_list_entry(e);
udev_list_entry_foreach(item, first) {
_cleanup_udev_device_unref_ struct udev_device *q;
const char *stype, *subnode;
sd_id128_t type_id;
blkid_partition pp;
dev_t qn;
int nr;
q = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
if (!q)
continue;
qn = udev_device_get_devnum(q);
if (major(qn) == 0)
continue;
if (qn == devnum)
continue;
if (qn == pn)
continue;
subnode = udev_device_get_devnode(q);
if (!subnode)
continue;
pp = blkid_partlist_devno_to_partition(pl, qn);
if (!pp)
continue;
nr = blkid_partition_get_partno(pp);
if (nr < 0)
continue;
stype = blkid_partition_get_type_string(pp);
if (!stype)
continue;
if (sd_id128_from_string(stype, &type_id) < 0)
continue;
if (sd_id128_equal(type_id, GPT_SWAP)) {
k = add_swap(subnode);
if (k < 0)
r = k;
} else if (sd_id128_equal(type_id, GPT_HOME)) {
/* We only care for the first /home partition */
if (home && nr >= home_nr)
continue;
home_nr = nr;
free(home);
home = strdup(subnode);
if (!home)
return log_oom();
} else if (sd_id128_equal(type_id, GPT_SRV)) {
/* We only care for the first /srv partition */
if (srv && nr >= srv_nr)
continue;
srv_nr = nr;
free(srv);
srv = strdup(node);
if (!srv)
return log_oom();
}
}
if (home) {
k = probe_and_add_mount("home", home, "/home", "Home Partition", SPECIAL_LOCAL_FS_TARGET);
if (k < 0)
r = k;
}
if (srv) {
k = probe_and_add_mount("srv", srv, "/srv", "Server Data Partition", SPECIAL_LOCAL_FS_TARGET);
if (k < 0)
r = k;
}
return r;
}
static int get_btrfs_block_device(const char *path, dev_t *dev) {
struct btrfs_ioctl_fs_info_args fsi = {};
_cleanup_close_ int fd = -1;
uint64_t id;
assert(path);
assert(dev);
fd = open(path, O_DIRECTORY|O_CLOEXEC);
if (fd < 0)
return -errno;
if (ioctl(fd, BTRFS_IOC_FS_INFO, &fsi) < 0)
return -errno;
/* We won't do this for btrfs RAID */
if (fsi.num_devices != 1)
return 0;
for (id = 1; id <= fsi.max_id; id++) {
struct btrfs_ioctl_dev_info_args di = {
.devid = id,
};
struct stat st;
if (ioctl(fd, BTRFS_IOC_DEV_INFO, &di) < 0) {
if (errno == ENODEV)
continue;
return -errno;
}
if (stat((char*) di.path, &st) < 0)
return -errno;
if (!S_ISBLK(st.st_mode))
return -ENODEV;
if (major(st.st_rdev) == 0)
return -ENODEV;
*dev = st.st_rdev;
return 1;
}
return -ENODEV;
}
static int get_block_device(const char *path, dev_t *dev) {
struct stat st;
struct statfs sfs;
assert(path);
assert(dev);
if (lstat(path, &st))
return -errno;
if (major(st.st_dev) != 0) {
*dev = st.st_dev;
return 1;
}
if (statfs(path, &sfs) < 0)
return -errno;
if (F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC))
return get_btrfs_block_device(path, dev);
return 0;
}
static int parse_proc_cmdline_item(const char *key, const char *value) {
int r;
assert(key);
if (STR_IN_SET(key, "systemd.gpt_auto", "rd.systemd.gpt_auto") && value) {
r = parse_boolean(value);
if (r < 0)
log_warning("Failed to parse gpt-auto switch %s. Ignoring.", value);
arg_enabled = r;
} else if (streq(key, "root") && value) {
/* Disable root disk logic if there's a root= value
* specified (unless it happens to be "gpt-auto") */
arg_root_enabled = streq(value, "gpt-auto");
} else if (streq(key, "rw") && !value)
arg_root_rw = true;
else if (streq(key, "ro") && !value)
arg_root_rw = false;
else if (startswith(key, "systemd.gpt-auto.") || startswith(key, "rd.systemd.gpt-auto."))
log_warning("Unknown kernel switch %s. Ignoring.", key);
return 0;
}
static int add_root_mount(void) {
#ifdef ENABLE_EFI
int r;
if (!is_efi_boot()) {
log_debug("Not a EFI boot, not creating root mount.");
return 0;
}
r = efi_loader_get_device_part_uuid(NULL);
if (r == -ENOENT) {
log_debug("EFI loader partition unknown, exiting.");
return 0;
} else if (r < 0) {
log_error("Failed to read ESP partition UUID: %s", strerror(-r));
return r;
}
/* OK, we have an ESP partition, this is fantastic, so let's
* wait for a root device to show up. A udev rule will create
* the link for us under the right name. */
return add_mount(
"root",
"/dev/disk/by-id/gpt-auto-root",
in_initrd() ? "/sysroot" : "/",
NULL,
arg_root_rw ? "rw" : "ro",
"Root Partition",
in_initrd() ? SPECIAL_INITRD_ROOT_FS_TARGET : SPECIAL_LOCAL_FS_TARGET);
#else
return 0;
#endif
}
static int add_mounts(void) {
dev_t devno;
int r;
r = get_block_device("/", &devno);
if (r < 0) {
log_error("Failed to determine block device of root file system: %s", strerror(-r));
return r;
} else if (r == 0) {
log_debug("Root file system not on a (single) block device.");
return 0;
}
return enumerate_partitions(devno);
}
int main(int argc, char *argv[]) {
int r = 0;
if (argc > 1 && argc != 4) {
log_error("This program takes three or no arguments.");
return EXIT_FAILURE;
}
if (argc > 1)
arg_dest = argv[3];
log_set_target(LOG_TARGET_SAFE);
log_parse_environment();
log_open();
umask(0022);
if (detect_container(NULL) > 0) {
log_debug("In a container, exiting.");
return EXIT_SUCCESS;
}
if (parse_proc_cmdline(parse_proc_cmdline_item) < 0)
return EXIT_FAILURE;
if (!arg_enabled) {
log_debug("Disabled, exiting.");
return EXIT_SUCCESS;
}
if (arg_root_enabled)
r = add_root_mount();
if (!in_initrd()) {
int k;
k = add_mounts();
if (k < 0)
r = k;
}
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}
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