fstab-generator.c revision 80c3b720bf3abbcc9427507d540e286c4ceb3e94
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2012 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 <stdio.h>
#include <mntent.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include "log.h"
#include "util.h"
#include "unit-name.h"
#include "path-util.h"
#include "mount-setup.h"
#include "special.h"
#include "mkdir.h"
#include "virt.h"
#include "fileio.h"
static const char *arg_dest = "/tmp";
static bool arg_enabled = true;
static int device_name(const char *path, char **unit) {
char *p;
assert(path);
if (!is_device_path(path))
return 0;
p = unit_name_from_path(path, ".device");
if (!p)
return log_oom();
*unit = p;
return 1;
}
static int mount_find_pri(struct mntent *me, int *ret) {
char *end, *pri;
unsigned long r;
assert(me);
assert(ret);
pri = hasmntopt(me, "pri");
if (!pri)
return 0;
pri += 4;
errno = 0;
r = strtoul(pri, &end, 10);
if (errno > 0)
return -errno;
if (end == pri || (*end != ',' && *end != 0))
return -EINVAL;
*ret = (int) r;
return 1;
}
static int add_swap(const char *what, struct mntent *me) {
_cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL, *device = NULL;
_cleanup_fclose_ FILE *f = NULL;
bool noauto, nofail;
int r, pri = -1;
assert(what);
assert(me);
r = mount_find_pri(me, &pri);
if (r < 0) {
log_error("Failed to parse priority");
return pri;
}
noauto = !!hasmntopt(me, "noauto");
nofail = !!hasmntopt(me, "nofail");
name = unit_name_from_path(what, ".swap");
if (!name)
return log_oom();
unit = strjoin(arg_dest, "/", name, NULL);
if (!unit)
return log_oom();
f = fopen(unit, "wxe");
if (!f) {
if (errno == EEXIST)
log_error("Failed to create swap unit file %s, as it already exists. Duplicate entry in /etc/fstab?", unit);
else
log_error("Failed to create unit file %s: %m", unit);
return -errno;
}
fputs("# Automatically generated by systemd-fstab-generator\n\n"
"[Unit]\n"
"SourcePath=/etc/fstab\n", f);
if (!noauto && !nofail)
fputs("Before=" SPECIAL_SWAP_TARGET "\n", f);
fprintf(f,
"\n"
"[Swap]\n"
"What=%s\n",
what);
if (pri >= 0)
fprintf(f,
"Priority=%i\n",
pri);
fflush(f);
if (ferror(f)) {
log_error("Failed to write unit file %s: %m", unit);
return -errno;
}
if (!noauto) {
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;
}
r = device_name(what, &device);
if (r < 0)
return r;
if (r > 0) {
free(lnk);
lnk = strjoin(arg_dest, "/", device, ".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 bool mount_is_bind(struct mntent *me) {
assert(me);
return
hasmntopt(me, "bind") ||
streq(me->mnt_type, "bind") ||
hasmntopt(me, "rbind") ||
streq(me->mnt_type, "rbind");
}
static bool mount_is_network(struct mntent *me) {
assert(me);
return
hasmntopt(me, "_netdev") ||
fstype_is_network(me->mnt_type);
}
static bool mount_in_initrd(struct mntent *me) {
assert(me);
return
hasmntopt(me, "x-initrd.mount") ||
streq(me->mnt_dir, "/usr");
}
static int add_mount(
const char *what,
const char *where,
const char *type,
const char *opts,
int passno,
bool noauto,
bool nofail,
bool automount,
bool isbind,
const char *post,
const char *source) {
_cleanup_free_ char
*name = NULL, *unit = NULL, *lnk = NULL, *device = NULL,
*automount_name = NULL, *automount_unit = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
assert(what);
assert(where);
assert(type);
assert(opts);
assert(source);
if (streq(type, "autofs"))
return 0;
if (!is_path(where)) {
log_warning("Mount point %s is not a valid path, ignoring.", where);
return 0;
}
if (mount_point_is_api(where) ||
mount_point_ignore(where))
return 0;
name = unit_name_from_path(where, ".mount");
if (!name)
return log_oom();
unit = strjoin(arg_dest, "/", name, NULL);
if (!unit)
return log_oom();
f = fopen(unit, "wxe");
if (!f) {
if (errno == EEXIST)
log_error("Failed to create mount unit file %s, as it already exists. Duplicate entry in /etc/fstab?", unit);
else
log_error("Failed to create unit file %s: %m", unit);
return -errno;
}
fprintf(f,
"# Automatically generated by systemd-fstab-generator\n\n"
"[Unit]\n"
"SourcePath=%s\n",
source);
if (post && !noauto && !nofail && !automount)
fprintf(f,
"Before=%s\n",
post);
fprintf(f,
"\n"
"[Mount]\n"
"What=%s\n"
"Where=%s\n"
"Type=%s\n"
"FsckPassNo=%i\n",
what,
where,
type,
passno);
if (!isempty(opts) &&
!streq(opts, "defaults"))
fprintf(f,
"Options=%s\n",
opts);
fflush(f);
if (ferror(f)) {
log_error("Failed to write unit file %s: %m", unit);
return -errno;
}
if (!noauto) {
if (post) {
lnk = strjoin(arg_dest, "/", post, nofail || automount ? ".wants/" : ".requires/", 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;
}
}
if (!isbind &&
!path_equal(where, "/")) {
r = device_name(what, &device);
if (r < 0)
return r;
if (r > 0) {
free(lnk);
lnk = strjoin(arg_dest, "/", device, ".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;
}
}
}
}
if (automount && !path_equal(where, "/")) {
automount_name = unit_name_from_path(where, ".automount");
if (!automount_name)
return log_oom();
automount_unit = strjoin(arg_dest, "/", automount_name, NULL);
if (!automount_unit)
return log_oom();
fclose(f);
f = fopen(automount_unit, "wxe");
if (!f) {
log_error("Failed to create unit file %s: %m", automount_unit);
return -errno;
}
fprintf(f,
"# Automatically generated by systemd-fstab-generator\n\n"
"[Unit]\n"
"SourcePath=%s\n",
source);
if (post)
fprintf(f,
"Before= %s\n",
post);
fprintf(f,
"[Automount]\n"
"Where=%s\n",
where);
fflush(f);
if (ferror(f)) {
log_error("Failed to write unit file %s: %m", automount_unit);
return -errno;
}
free(lnk);
lnk = strjoin(arg_dest, "/", post, nofail ? ".wants/" : ".requires/", automount_name, NULL);
if (!lnk)
return log_oom();
mkdir_parents_label(lnk, 0755);
if (symlink(automount_unit, lnk) < 0) {
log_error("Failed to create symlink %s: %m", lnk);
return -errno;
}
}
return 0;
}
static int parse_fstab(const char *prefix, bool initrd) {
_cleanup_free_ char *fstab_path = NULL;
FILE *f;
int r = 0;
struct mntent *me;
fstab_path = strjoin(strempty(prefix), "/etc/fstab", NULL);
if (!fstab_path)
return log_oom();
f = setmntent(fstab_path, "r");
if (!f) {
if (errno == ENOENT)
return 0;
log_error("Failed to open %s/etc/fstab: %m", strempty(prefix));
return -errno;
}
while ((me = getmntent(f))) {
_cleanup_free_ char *where = NULL, *what = NULL;
int k;
if (initrd && !mount_in_initrd(me))
continue;
what = fstab_node_to_udev_node(me->mnt_fsname);
where = strjoin(strempty(prefix), me->mnt_dir, NULL);
if (!what || !where) {
r = log_oom();
goto finish;
}
if (is_path(where))
path_kill_slashes(where);
log_debug("Found entry what=%s where=%s type=%s", what, where, me->mnt_type);
if (streq(me->mnt_type, "swap"))
k = add_swap(what, me);
else {
bool noauto, nofail, automount, isbind;
const char *post;
noauto = !!hasmntopt(me, "noauto");
nofail = !!hasmntopt(me, "nofail");
automount =
hasmntopt(me, "comment=systemd.automount") ||
hasmntopt(me, "x-systemd.automount");
isbind = mount_is_bind(me);
if (initrd) {
post = SPECIAL_INITRD_FS_TARGET;
} else if (mount_in_initrd(me)) {
post = SPECIAL_INITRD_ROOT_FS_TARGET;
} else if (mount_is_network(me)) {
post = SPECIAL_REMOTE_FS_TARGET;
} else {
post = SPECIAL_LOCAL_FS_TARGET;
}
k = add_mount(what, where, me->mnt_type, me->mnt_opts,
me->mnt_passno, noauto, nofail, automount,
isbind, post, fstab_path);
}
if (k < 0)
r = k;
}
finish:
endmntent(f);
return r;
}
static int parse_new_root_from_proc_cmdline(void) {
_cleanup_free_ char *what = NULL, *type = NULL, *opts = NULL, *line = NULL;
char *w, *state;
int r;
size_t l;
bool noauto, nofail;
r = read_one_line_file("/proc/cmdline", &line);
if (r < 0) {
log_error("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
return 0;
}
opts = strdup("ro");
type = strdup("auto");
if (!opts || !type)
return log_oom();
/* root= and roofstype= may occur more than once, the last instance should take precedence.
* In the case of multiple rootflags= the arguments should be concatenated */
FOREACH_WORD_QUOTED(w, l, line, state) {
_cleanup_free_ char *word;
word = strndup(w, l);
if (!word)
return log_oom();
else if (startswith(word, "root=")) {
free(what);
what = fstab_node_to_udev_node(word+5);
if (!what)
return log_oom();
} else if (startswith(word, "rootfstype=")) {
free(type);
type = strdup(word + 11);
if (!type)
return log_oom();
} else if (startswith(word, "rootflags=")) {
char *o;
o = strjoin(opts, ",", word + 10, NULL);
if (!o)
return log_oom();
free(opts);
opts = o;
} else if (streq(word, "ro") || streq(word, "rw")) {
char *o;
o = strjoin(opts, ",", word, NULL);
if (!o)
return log_oom();
free(opts);
opts = o;
}
}
noauto = !!strstr(opts, "noauto");
nofail = !!strstr(opts, "nofail");
if (!what) {
log_debug("Could not find a root= entry on the kernel commandline.");
return 0;
}
if (what[0] != '/') {
log_debug("Skipping entry what=%s where=/sysroot type=%s", what, type);
return 0;
}
log_debug("Found entry what=%s where=/sysroot type=%s", what, type);
r = add_mount(what, "/sysroot", type, opts, 0, noauto, nofail, false,
false, SPECIAL_INITRD_ROOT_FS_TARGET, "/proc/cmdline");
return (r < 0) ? r : 0;
}
static int parse_proc_cmdline(void) {
_cleanup_free_ char *line = NULL;
char *w, *state;
int r;
size_t l;
if (detect_container(NULL) > 0)
return 0;
r = read_one_line_file("/proc/cmdline", &line);
if (r < 0) {
log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
return 0;
}
FOREACH_WORD_QUOTED(w, l, line, state) {
_cleanup_free_ char *word = NULL;
word = strndup(w, l);
if (!word)
return log_oom();
if (startswith(word, "fstab=")) {
r = parse_boolean(word + 6);
if (r < 0)
log_warning("Failed to parse fstab switch %s. Ignoring.", word + 6);
else
arg_enabled = r;
} else if (startswith(word, "rd.fstab=")) {
if (in_initrd()) {
r = parse_boolean(word + 9);
if (r < 0)
log_warning("Failed to parse fstab switch %s. Ignoring.", word + 9);
else
arg_enabled = r;
}
} else if (startswith(word, "fstab.") ||
(in_initrd() && startswith(word, "rd.fstab."))) {
log_warning("Unknown kernel switch %s. Ignoring.", word);
}
}
return 0;
}
int main(int argc, char *argv[]) {
int r = 0, k, l = 0;
if (argc > 1 && argc != 4) {
log_error("This program takes three or no arguments.");
return EXIT_FAILURE;
}
if (argc > 1)
arg_dest = argv[1];
log_set_target(LOG_TARGET_SAFE);
log_parse_environment();
log_open();
umask(0022);
if (parse_proc_cmdline() < 0)
return EXIT_FAILURE;
if (in_initrd())
r = parse_new_root_from_proc_cmdline();
if (!arg_enabled)
return (r < 0) ? EXIT_FAILURE : EXIT_SUCCESS;
k = parse_fstab(NULL, false);
if (in_initrd())
l = parse_fstab("/sysroot", true);
return (r < 0) || (k < 0) || (l < 0) ? EXIT_FAILURE : EXIT_SUCCESS;
}