/* SPDX-License-Identifier: LGPL-2.1+ */
/***
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 .
***/
#include
#include
#include
#include
#include
#include "alloc-util.h"
#include "fd-util.h"
#include "fs-util.h"
#include "fileio.h"
#include "fstab-util.h"
#include "generator.h"
#include "log.h"
#include "mkdir.h"
#include "mount-setup.h"
#include "mount-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "proc-cmdline.h"
#include "special.h"
#include "stat-util.h"
#include "string-util.h"
#include "strv.h"
#include "unit-name.h"
#include "util.h"
#include "virt.h"
#include "volatile-util.h"
static const char *arg_dest = "/tmp";
static const char *arg_dest_late = "/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 char *arg_root_hash = NULL;
static int arg_root_rw = -1;
static char *arg_usr_what = NULL;
static char *arg_usr_fstype = NULL;
static char *arg_usr_options = NULL;
static VolatileMode arg_volatile_mode = _VOLATILE_MODE_INVALID;
static int write_options(FILE *f, const char *options) {
_cleanup_free_ char *o = NULL;
if (isempty(options))
return 0;
if (streq(options, "defaults"))
return 0;
o = strreplace(options, "%", "%%");
if (!o)
return log_oom();
fprintf(f, "Options=%s\n", o);
return 1;
}
static int write_what(FILE *f, const char *what) {
_cleanup_free_ char *w = NULL;
w = strreplace(what, "%", "%%");
if (!w)
return log_oom();
fprintf(f, "What=%s\n", w);
return 1;
}
static int add_swap(
const char *what,
struct mntent *me,
bool noauto,
bool nofail) {
_cleanup_free_ char *name = NULL, *unit = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
assert(what);
assert(me);
if (access("/proc/swaps", F_OK) < 0) {
log_info("Swap not supported, ignoring fstab swap entry for %s.", what);
return 0;
}
if (detect_container() > 0) {
log_info("Running in a container, ignoring fstab swap entry for %s.", what);
return 0;
}
r = unit_name_from_path(what, ".swap", &name);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
unit = strjoin(arg_dest, "/", name);
if (!unit)
return log_oom();
f = fopen(unit, "wxe");
if (!f)
return log_error_errno(errno,
errno == EEXIST ?
"Failed to create swap unit file %s, as it already exists. Duplicate entry in /etc/fstab?" :
"Failed to create unit file %s: %m",
unit);
fputs_unlocked("# 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", f);
r = write_what(f, what);
if (r < 0)
return r;
r = write_options(f, me->mnt_opts);
if (r < 0)
return r;
r = fflush_and_check(f);
if (r < 0)
return log_error_errno(r, "Failed to write unit file %s: %m", unit);
/* 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) {
r = generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET,
nofail ? "wants" : "requires", name);
if (r < 0)
return r;
}
return 0;
}
static bool mount_is_network(struct mntent *me) {
assert(me);
return fstab_test_option(me->mnt_opts, "_netdev\0") ||
fstype_is_network(me->mnt_type);
}
static bool mount_in_initrd(struct mntent *me) {
assert(me);
return fstab_test_option(me->mnt_opts, "x-initrd.mount\0") ||
streq(me->mnt_dir, "/usr");
}
static int write_timeout(FILE *f, const char *where, const char *opts,
const char *filter, const char *variable) {
_cleanup_free_ char *timeout = NULL;
char timespan[FORMAT_TIMESPAN_MAX];
usec_t u;
int r;
r = fstab_filter_options(opts, filter, NULL, &timeout, NULL);
if (r < 0)
return log_warning_errno(r, "Failed to parse options: %m");
if (r == 0)
return 0;
r = parse_sec_fix_0(timeout, &u);
if (r < 0) {
log_warning("Failed to parse timeout for %s, ignoring: %s", where, timeout);
return 0;
}
fprintf(f, "%s=%s\n", variable, format_timespan(timespan, sizeof(timespan), u, 0));
return 0;
}
static int write_idle_timeout(FILE *f, const char *where, const char *opts) {
return write_timeout(f, where, opts,
"x-systemd.idle-timeout\0", "TimeoutIdleSec");
}
static int write_mount_timeout(FILE *f, const char *where, const char *opts) {
return write_timeout(f, where, opts,
"x-systemd.mount-timeout\0", "TimeoutSec");
}
static int write_dependency(FILE *f, const char *opts,
const char *filter, const char *format) {
_cleanup_strv_free_ char **names = NULL, **units = NULL;
_cleanup_free_ char *res = NULL;
char **s;
int r;
assert(f);
assert(opts);
r = fstab_extract_values(opts, filter, &names);
if (r < 0)
return log_warning_errno(r, "Failed to parse options: %m");
if (r == 0)
return 0;
STRV_FOREACH(s, names) {
char *x;
r = unit_name_mangle_with_suffix(*s, UNIT_NAME_NOGLOB, ".mount", &x);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
r = strv_consume(&units, x);
if (r < 0)
return log_oom();
}
if (units) {
res = strv_join(units, " ");
if (!res)
return log_oom();
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
fprintf(f, format, res);
#pragma GCC diagnostic pop
}
return 0;
}
static int write_after(FILE *f, const char *opts) {
return write_dependency(f, opts, "x-systemd.after", "After=%1$s\n");
}
static int write_requires_after(FILE *f, const char *opts) {
return write_dependency(f, opts,
"x-systemd.requires", "After=%1$s\nRequires=%1$s\n");
}
static int write_before(FILE *f, const char *opts) {
return write_dependency(f, opts,
"x-systemd.before", "Before=%1$s\n");
}
static int write_requires_mounts_for(FILE *f, const char *opts) {
_cleanup_strv_free_ char **paths = NULL;
_cleanup_free_ char *res = NULL;
int r;
assert(f);
assert(opts);
r = fstab_extract_values(opts, "x-systemd.requires-mounts-for", &paths);
if (r < 0)
return log_warning_errno(r, "Failed to parse options: %m");
if (r == 0)
return 0;
res = strv_join(paths, " ");
if (!res)
return log_oom();
fprintf(f, "RequiresMountsFor=%s\n", res);
return 0;
}
static int add_mount(
const char *dest,
const char *what,
const char *where,
const char *original_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,
*automount_name = NULL, *automount_unit = NULL,
*filtered = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
assert(what);
assert(where);
assert(opts);
assert(post);
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, "/")) {
if (noauto)
log_warning("Ignoring \"noauto\" for root device");
if (nofail)
log_warning("Ignoring \"nofail\" for root device");
if (automount)
log_warning("Ignoring automount option for root device");
noauto = nofail = automount = false;
}
r = unit_name_from_path(where, ".mount", &name);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
unit = strjoin(dest, "/", name);
if (!unit)
return log_oom();
f = fopen(unit, "wxe");
if (!f)
return log_error_errno(errno,
errno == EEXIST ?
"Failed to create mount unit file %s, as it already exists. Duplicate entry in /etc/fstab?" :
"Failed to create unit file %s: %m",
unit);
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 (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !automount &&
fstab_test_yes_no_option(opts, "bg\0" "fg\0")) {
/* The default retry timeout that mount.nfs uses for 'bg' mounts
* is 10000 minutes, where as it uses 2 minutes for 'fg' mounts.
* As we are making 'bg' mounts look like an 'fg' mount to
* mount.nfs (so systemd can manage the job-control aspects of 'bg'),
* we need to explicitly preserve that default, and also ensure
* the systemd mount-timeout doesn't interfere.
* By placing these options first, they can be over-ridden by
* settings in /etc/fstab. */
opts = strjoina("x-systemd.mount-timeout=infinity,retry=10000,", opts, ",fg");
nofail = true;
}
if (!nofail && !automount)
fprintf(f, "Before=%s\n", post);
if (!automount && opts) {
r = write_after(f, opts);
if (r < 0)
return r;
r = write_requires_after(f, opts);
if (r < 0)
return r;
r = write_before(f, opts);
if (r < 0)
return r;
r = write_requires_mounts_for(f, opts);
if (r < 0)
return r;
}
if (passno != 0) {
r = generator_write_fsck_deps(f, dest, what, where, fstype);
if (r < 0)
return r;
}
fprintf(f, "\n[Mount]\n");
if (original_where)
fprintf(f, "# Canonicalized from %s\n", original_where);
fprintf(f, "Where=%s\n", where);
r = write_what(f, what);
if (r < 0)
return r;
if (!isempty(fstype) && !streq(fstype, "auto"))
fprintf(f, "Type=%s\n", fstype);
r = generator_write_timeouts(dest, what, where, opts, &filtered);
if (r < 0)
return r;
r = generator_write_device_deps(dest, what, where, opts);
if (r < 0)
return r;
r = write_mount_timeout(f, where, opts);
if (r < 0)
return r;
r = write_options(f, filtered);
if (r < 0)
return r;
r = fflush_and_check(f);
if (r < 0)
return log_error_errno(r, "Failed to write unit file %s: %m", unit);
if (!noauto && !automount) {
r = generator_add_symlink(dest, post,
nofail ? "wants" : "requires", name);
if (r < 0)
return r;
}
if (automount) {
r = unit_name_from_path(where, ".automount", &automount_name);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
automount_unit = strjoin(dest, "/", automount_name);
if (!automount_unit)
return log_oom();
fclose(f);
f = fopen(automount_unit, "wxe");
if (!f)
return log_error_errno(errno, "Failed to create unit file %s: %m", automount_unit);
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);
fprintf(f, "Before=%s\n", post);
if (opts) {
r = write_after(f, opts);
if (r < 0)
return r;
r = write_requires_after(f, opts);
if (r < 0)
return r;
r = write_before(f, opts);
if (r < 0)
return r;
r = write_requires_mounts_for(f, opts);
if (r < 0)
return r;
}
fprintf(f,
"\n"
"[Automount]\n"
"Where=%s\n",
where);
r = write_idle_timeout(f, where, opts);
if (r < 0)
return r;
r = fflush_and_check(f);
if (r < 0)
return log_error_errno(r, "Failed to write unit file %s: %m", automount_unit);
r = generator_add_symlink(dest, post,
nofail ? "wants" : "requires", automount_name);
if (r < 0)
return r;
}
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;
return log_error_errno(errno, "Failed to open %s: %m", fstab_path);
}
while ((me = getmntent(f))) {
_cleanup_free_ char *where = NULL, *what = NULL, *canonical_where = NULL;
bool noauto, nofail;
int k;
if (initrd && !mount_in_initrd(me))
continue;
what = fstab_node_to_udev_node(me->mnt_fsname);
if (!what)
return log_oom();
if (is_device_path(what) && path_is_read_only_fs("sys") > 0) {
log_info("Running in a container, ignoring fstab device entry for %s.", what);
continue;
}
where = strdup(me->mnt_dir);
if (!where)
return log_oom();
if (is_path(where)) {
path_kill_slashes(where);
/* Follow symlinks here; see 5261ba901845c084de5a8fd06500ed09bfb0bd80 which makes sense for
* mount units, but causes problems since it historically worked to have symlinks in e.g.
* /etc/fstab. So we canonicalize here. Note that we use CHASE_NONEXISTENT to handle the case
* where a symlink refers to another mount target; this works assuming the sub-mountpoint
* target is the final directory.
*/
r = chase_symlinks(where, initrd ? "/sysroot" : NULL,
CHASE_PREFIX_ROOT | CHASE_NONEXISTENT,
&canonical_where);
if (r < 0)
/* In this case for now we continue on as if it wasn't a symlink */
log_warning_errno(r, "Failed to read symlink target for %s: %m", where);
else {
if (streq(canonical_where, where))
canonical_where = mfree(canonical_where);
else
log_debug("Canonicalized what=%s where=%s to %s",
what, where, canonical_where);
}
}
noauto = fstab_test_yes_no_option(me->mnt_opts, "noauto\0" "auto\0");
nofail = fstab_test_yes_no_option(me->mnt_opts, "nofail\0" "fail\0");
log_debug("Found entry what=%s where=%s type=%s nofail=%s noauto=%s",
what, where, me->mnt_type,
yes_no(noauto), yes_no(nofail));
if (streq(me->mnt_type, "swap"))
k = add_swap(what, me, noauto, nofail);
else {
bool automount;
const char *post;
automount = fstab_test_option(me->mnt_opts,
"comment=systemd.automount\0"
"x-systemd.automount\0");
if (initrd)
post = SPECIAL_INITRD_FS_TARGET;
else if (mount_is_network(me))
post = SPECIAL_REMOTE_FS_TARGET;
else
post = SPECIAL_LOCAL_FS_TARGET;
k = add_mount(arg_dest,
what,
canonical_where ?: where,
canonical_where ? where: NULL,
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_sysroot_mount(void) {
_cleanup_free_ char *what = NULL;
const char *opts;
int r;
if (isempty(arg_root_what)) {
log_debug("Could not find a root= entry on the kernel command line.");
return 0;
}
if (streq(arg_root_what, "gpt-auto")) {
/* This is handled by the gpt-auto generator */
log_debug("Skipping root directory handling, as gpt-auto was requested.");
return 0;
}
if (path_equal(arg_root_what, "/dev/nfs")) {
/* This is handled by the kernel or the initrd */
log_debug("Skipping root directory handling, as /dev/nfs was requested.");
return 0;
}
what = fstab_node_to_udev_node(arg_root_what);
if (!what)
return log_oom();
if (!arg_root_options)
opts = arg_root_rw > 0 ? "rw" : "ro";
else if (arg_root_rw >= 0 ||
!fstab_test_option(arg_root_options, "ro\0" "rw\0"))
opts = strjoina(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));
if (is_device_path(what)) {
r = generator_write_initrd_root_device_deps(arg_dest, what);
if (r < 0)
return r;
}
return add_mount(arg_dest,
what,
"/sysroot",
NULL,
arg_root_fstype,
opts,
is_device_path(what) ? 1 : 0, /* passno */
false, /* noauto off */
false, /* nofail off */
false, /* automount off */
SPECIAL_INITRD_ROOT_FS_TARGET,
"/proc/cmdline");
}
static int add_sysroot_usr_mount(void) {
_cleanup_free_ char *what = NULL;
const char *opts;
if (!arg_usr_what && !arg_usr_fstype && !arg_usr_options)
return 0;
if (arg_root_what && !arg_usr_what) {
/* Copy over the root device, in case the /usr mount just differs in a mount option (consider btrfs subvolumes) */
arg_usr_what = strdup(arg_root_what);
if (!arg_usr_what)
return log_oom();
}
if (arg_root_fstype && !arg_usr_fstype) {
arg_usr_fstype = strdup(arg_root_fstype);
if (!arg_usr_fstype)
return log_oom();
}
if (arg_root_options && !arg_usr_options) {
arg_usr_options = strdup(arg_root_options);
if (!arg_usr_options)
return log_oom();
}
if (!arg_usr_what)
return 0;
what = fstab_node_to_udev_node(arg_usr_what);
if (!what)
return log_oom();
if (!arg_usr_options)
opts = arg_root_rw > 0 ? "rw" : "ro";
else if (!fstab_test_option(arg_usr_options, "ro\0" "rw\0"))
opts = strjoina(arg_usr_options, ",", arg_root_rw > 0 ? "rw" : "ro");
else
opts = arg_usr_options;
log_debug("Found entry what=%s where=/sysroot/usr type=%s", what, strna(arg_usr_fstype));
return add_mount(arg_dest,
what,
"/sysroot/usr",
NULL,
arg_usr_fstype,
opts,
is_device_path(what) ? 1 : 0, /* passno */
false, /* noauto off */
false, /* nofail off */
false, /* automount off */
SPECIAL_INITRD_FS_TARGET,
"/proc/cmdline");
}
static int add_volatile_root(void) {
const char *from, *to;
if (arg_volatile_mode != VOLATILE_YES)
return 0;
/* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
* requested, leaving only /usr from the root mount inside. */
from = strjoina(SYSTEM_DATA_UNIT_PATH "/systemd-volatile-root.service");
to = strjoina(arg_dest, "/" SPECIAL_INITRD_ROOT_FS_TARGET, ".requires/systemd-volatile-root.service");
(void) mkdir_parents(to, 0755);
if (symlink(from, to) < 0)
return log_error_errno(errno, "Failed to hook in volatile remount service: %m");
return 0;
}
static int add_volatile_var(void) {
if (arg_volatile_mode != VOLATILE_STATE)
return 0;
/* If requested, mount /var as tmpfs, but do so only if there's nothing else defined for this. */
return add_mount(arg_dest_late,
"tmpfs",
"/var",
NULL,
"tmpfs",
"mode=0755",
0,
false,
false,
false,
SPECIAL_LOCAL_FS_TARGET,
"/proc/cmdline");
}
static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
int r;
/* root=, usr=, usrfstype= and roofstype= may occur more than once, the last
* instance should take precedence. In the case of multiple rootflags=
* or usrflags= the arguments should be concatenated */
if (STR_IN_SET(key, "fstab", "rd.fstab")) {
r = value ? parse_boolean(value) : 1;
if (r < 0)
log_warning("Failed to parse fstab switch %s. Ignoring.", value);
else
arg_fstab_enabled = r;
} else if (streq(key, "root")) {
if (proc_cmdline_value_missing(key, value))
return 0;
if (free_and_strdup(&arg_root_what, value) < 0)
return log_oom();
} else if (streq(key, "rootfstype")) {
if (proc_cmdline_value_missing(key, value))
return 0;
if (free_and_strdup(&arg_root_fstype, value) < 0)
return log_oom();
} else if (streq(key, "rootflags")) {
char *o;
if (proc_cmdline_value_missing(key, value))
return 0;
o = arg_root_options ?
strjoin(arg_root_options, ",", value) :
strdup(value);
if (!o)
return log_oom();
free(arg_root_options);
arg_root_options = o;
} else if (streq(key, "roothash")) {
if (proc_cmdline_value_missing(key, value))
return 0;
if (free_and_strdup(&arg_root_hash, value) < 0)
return log_oom();
} else if (streq(key, "mount.usr")) {
if (proc_cmdline_value_missing(key, value))
return 0;
if (free_and_strdup(&arg_usr_what, value) < 0)
return log_oom();
} else if (streq(key, "mount.usrfstype")) {
if (proc_cmdline_value_missing(key, value))
return 0;
if (free_and_strdup(&arg_usr_fstype, value) < 0)
return log_oom();
} else if (streq(key, "mount.usrflags")) {
char *o;
if (proc_cmdline_value_missing(key, value))
return 0;
o = arg_usr_options ?
strjoin(arg_usr_options, ",", value) :
strdup(value);
if (!o)
return log_oom();
free(arg_usr_options);
arg_usr_options = o;
} else if (streq(key, "rw") && !value)
arg_root_rw = true;
else if (streq(key, "ro") && !value)
arg_root_rw = false;
else if (streq(key, "systemd.volatile")) {
VolatileMode m;
if (value) {
m = volatile_mode_from_string(value);
if (m < 0)
log_warning("Failed to parse systemd.volatile= argument: %s", value);
else
arg_volatile_mode = m;
} else
arg_volatile_mode = VOLATILE_YES;
}
return 0;
}
static int determine_root(void) {
/* If we have a root hash but no root device then Verity is used, and we use the "root" DM device as root. */
if (arg_root_what)
return 0;
if (!arg_root_hash)
return 0;
arg_root_what = strdup("/dev/mapper/root");
if (!arg_root_what)
return log_oom();
log_info("Using verity root device %s.", arg_root_what);
return 1;
}
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];
if (argc > 3)
arg_dest_late = argv[3];
log_set_target(LOG_TARGET_SAFE);
log_parse_environment();
log_open();
umask(0022);
r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, 0);
if (r < 0)
log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
(void) determine_root();
/* Always honour root= and usr= in the kernel command line if we are in an initrd */
if (in_initrd()) {
int k;
r = add_sysroot_mount();
k = add_sysroot_usr_mount();
if (k < 0)
r = k;
k = add_volatile_root();
if (k < 0)
r = k;
} else
r = add_volatile_var();
/* 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);
free(arg_root_fstype);
free(arg_root_options);
free(arg_root_hash);
free(arg_usr_what);
free(arg_usr_fstype);
free(arg_usr_options);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}