fstab-generator.c revision 8085f163c50d998f3e30a6ddfc72c73d5dc57747
/*-*- 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 "fileio.h"
#include "generator.h"
#include "strv.h"
#include "virt.h"
static const char *arg_dest = "/tmp";
static bool arg_fstab_enabled = true;
static char *arg_root_what = NULL;
static char *arg_root_fstype = NULL;
static char *arg_root_options = NULL;
static int arg_root_rw = -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;
_cleanup_fclose_ FILE *f = NULL;
bool noauto;
int r, pri = -1;
assert(what);
assert(me);
if (detect_container(NULL) > 0) {
log_info("Running in a container, ignoring fstab swap entry for %s.", what);
return 0;
}
r = mount_find_pri(me, &pri);
if (r < 0) {
log_error("Failed to parse priority");
return pri;
}
noauto = !!hasmntopt(me, "noauto");
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;
}
fprintf(f,
"# Automatically generated by systemd-fstab-generator\n\n"
"[Unit]\n"
"SourcePath=/etc/fstab\n"
"Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n\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;
}
/* use what as where, to have a nicer error message */
r = generator_write_timeouts(arg_dest, what, what, me->mnt_opts, NULL);
if (r < 0)
return r;
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;
}
}
return 0;
}
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 *fstype,
const char *opts,
int passno,
bool noauto,
bool nofail,
bool automount,
const char *post,
const char *source) {
_cleanup_free_ char
*name = NULL, *unit = NULL, *lnk = NULL,
*automount_name = NULL, *automount_unit = NULL,
*filtered = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
assert(what);
assert(where);
assert(opts);
assert(source);
if (streq_ptr(fstype, "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;
if (path_equal(where, "/")) {
/* The root disk is not an option */
automount = false;
noauto = false;
nofail = false;
}
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"
"Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
source);
if (post && !noauto && !nofail && !automount)
fprintf(f, "Before=%s\n", post);
if (passno != 0) {
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 (!isempty(fstype) && !streq(fstype, "auto"))
fprintf(f, "Type=%s\n", fstype);
r = generator_write_timeouts(arg_dest, what, where, opts, &filtered);
if (r < 0)
return r;
if (!isempty(filtered) && !streq(filtered, "defaults"))
fprintf(f, "Options=%s\n", filtered);
fflush(f);
if (ferror(f)) {
log_error("Failed to write unit file %s: %m", unit);
return -errno;
}
if (!noauto && 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 (automount) {
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"
"Documentation=man:fstab(5) man:systemd-fstab-generator(8)\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(bool initrd) {
_cleanup_endmntent_ FILE *f = NULL;
const char *fstab_path;
struct mntent *me;
int r = 0;
fstab_path = initrd ? "/sysroot/etc/fstab" : "/etc/fstab";
f = setmntent(fstab_path, "re");
if (!f) {
if (errno == ENOENT)
return 0;
log_error("Failed to open %s: %m", fstab_path);
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);
if (!what)
return log_oom();
if (detect_container(NULL) > 0 && is_device_path(what)) {
log_info("Running in a container, ignoring fstab device entry for %s.", what);
continue;
}
where = initrd ? strappend("/sysroot/", me->mnt_dir) : strdup(me->mnt_dir);
if (!where)
return log_oom();
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;
const char *post;
noauto = !!hasmntopt(me, "noauto");
nofail = !!hasmntopt(me, "nofail");
automount =
hasmntopt(me, "comment=systemd.automount") ||
hasmntopt(me, "x-systemd.automount");
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,
post,
fstab_path);
}
if (k < 0)
r = k;
}
return r;
}
static int add_root_mount(void) {
_cleanup_free_ char *what = NULL;
const char *opts;
if (isempty(arg_root_what)) {
log_debug("Could not find a root= entry on the kernel commandline.");
return 0;
}
what = fstab_node_to_udev_node(arg_root_what);
if (!path_is_absolute(what)) {
log_debug("Skipping entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
return 0;
}
if (!arg_root_options)
opts = arg_root_rw > 0 ? "rw" : "ro";
else if (arg_root_rw >= 0 ||
(!mount_test_option(arg_root_options, "ro") &&
!mount_test_option(arg_root_options, "rw")))
opts = strappenda(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
else
opts = arg_root_options;
log_debug("Found entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
return add_mount(what,
"/sysroot",
arg_root_fstype,
opts,
1,
false,
false,
false,
SPECIAL_INITRD_ROOT_FS_TARGET,
"/proc/cmdline");
}
static int parse_proc_cmdline_item(const char *key, const char *value) {
int r;
/* 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 */
if (STR_IN_SET(key, "fstab", "rd.fstab") && value) {
r = parse_boolean(value);
if (r < 0)
log_warning("Failed to parse fstab switch %s. Ignoring.", value);
else
arg_fstab_enabled = r;
} else if (streq(key, "root") && value) {
free(arg_root_what);
arg_root_what = strdup(value);
if (!arg_root_what)
return log_oom();
} else if (streq(key, "rootfstype") && value) {
free(arg_root_fstype);
arg_root_fstype = strdup(value);
if (!arg_root_fstype)
return log_oom();
} else if (streq(key, "rootflags") && value) {
char *o;
o = arg_root_options ?
strjoin(arg_root_options, ",", value, NULL) :
strdup(value);
if (!o)
return log_oom();
free(arg_root_options);
arg_root_options = o;
} else if (streq(key, "rw") && !value)
arg_root_rw = true;
else if (streq(key, "ro") && !value)
arg_root_rw = false;
return 0;
}
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[1];
log_set_target(LOG_TARGET_SAFE);
log_parse_environment();
log_open();
umask(0022);
if (parse_proc_cmdline(parse_proc_cmdline_item) < 0)
return EXIT_FAILURE;
/* Always honour root= in the kernel command line if we are in an initrd */
if (in_initrd())
r = add_root_mount();
/* Honour /etc/fstab only when that's enabled */
if (arg_fstab_enabled) {
int k;
log_debug("Parsing /etc/fstab");
/* Parse the local /etc/fstab, possibly from the initrd */
k = parse_fstab(false);
if (k < 0)
r = k;
/* If running in the initrd also parse the /etc/fstab from the host */
if (in_initrd()) {
log_debug("Parsing /sysroot/etc/fstab");
k = parse_fstab(true);
if (k < 0)
r = k;
}
}
free(arg_root_what);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}