1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 Copyright 2012 Lennart Poettering
11 #include <stdio_ext.h>
13 #include "alloc-util.h"
17 #include "fstab-util.h"
18 #include "generator.h"
21 #include "mount-setup.h"
22 #include "mount-util.h"
23 #include "parse-util.h"
24 #include "path-util.h"
25 #include "proc-cmdline.h"
27 #include "specifier.h"
28 #include "stat-util.h"
29 #include "string-util.h"
31 #include "unit-name.h"
34 #include "volatile-util.h"
36 typedef enum MountpointFlags
{
44 static const char *arg_dest
= "/tmp";
45 static const char *arg_dest_late
= "/tmp";
46 static bool arg_fstab_enabled
= true;
47 static char *arg_root_what
= NULL
;
48 static char *arg_root_fstype
= NULL
;
49 static char *arg_root_options
= NULL
;
50 static char *arg_root_hash
= NULL
;
51 static int arg_root_rw
= -1;
52 static char *arg_usr_what
= NULL
;
53 static char *arg_usr_fstype
= NULL
;
54 static char *arg_usr_options
= NULL
;
55 static VolatileMode arg_volatile_mode
= _VOLATILE_MODE_INVALID
;
57 static int write_options(FILE *f
, const char *options
) {
58 _cleanup_free_
char *o
= NULL
;
63 if (streq(options
, "defaults"))
66 o
= specifier_escape(options
);
70 fprintf(f
, "Options=%s\n", o
);
74 static int write_what(FILE *f
, const char *what
) {
75 _cleanup_free_
char *w
= NULL
;
77 w
= specifier_escape(what
);
81 fprintf(f
, "What=%s\n", w
);
88 MountpointFlags flags
) {
90 _cleanup_free_
char *name
= NULL
;
91 _cleanup_fclose_
FILE *f
= NULL
;
97 if (access("/proc/swaps", F_OK
) < 0) {
98 log_info("Swap not supported, ignoring fstab swap entry for %s.", what
);
102 if (detect_container() > 0) {
103 log_info("Running in a container, ignoring fstab swap entry for %s.", what
);
107 r
= unit_name_from_path(what
, ".swap", &name
);
109 return log_error_errno(r
, "Failed to generate unit name: %m");
111 r
= generator_open_unit_file(arg_dest
, "/etc/fstab", name
, &f
);
115 fputs("# Automatically generated by systemd-fstab-generator\n\n"
117 "SourcePath=/etc/fstab\n"
118 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n\n"
121 r
= write_what(f
, what
);
125 r
= write_options(f
, me
->mnt_opts
);
129 r
= fflush_and_check(f
);
131 return log_error_errno(r
, "Failed to write unit file %s: %m", name
);
133 /* use what as where, to have a nicer error message */
134 r
= generator_write_timeouts(arg_dest
, what
, what
, me
->mnt_opts
, NULL
);
138 if (flags
& MAKEFS
) {
139 r
= generator_hook_up_mkswap(arg_dest
, what
);
145 /* TODO: swap devices must be wiped and recreated */
146 log_warning("%s: growing swap devices is currently unsupported.", what
);
148 if (!(flags
& NOAUTO
)) {
149 r
= generator_add_symlink(arg_dest
, SPECIAL_SWAP_TARGET
,
150 (flags
& NOFAIL
) ? "wants" : "requires", name
);
158 static bool mount_is_network(struct mntent
*me
) {
161 return fstab_test_option(me
->mnt_opts
, "_netdev\0") ||
162 fstype_is_network(me
->mnt_type
);
165 static bool mount_in_initrd(struct mntent
*me
) {
168 return fstab_test_option(me
->mnt_opts
, "x-initrd.mount\0") ||
169 streq(me
->mnt_dir
, "/usr");
172 static int write_timeout(FILE *f
, const char *where
, const char *opts
,
173 const char *filter
, const char *variable
) {
174 _cleanup_free_
char *timeout
= NULL
;
175 char timespan
[FORMAT_TIMESPAN_MAX
];
179 r
= fstab_filter_options(opts
, filter
, NULL
, &timeout
, NULL
);
181 return log_warning_errno(r
, "Failed to parse options: %m");
185 r
= parse_sec_fix_0(timeout
, &u
);
187 log_warning("Failed to parse timeout for %s, ignoring: %s", where
, timeout
);
191 fprintf(f
, "%s=%s\n", variable
, format_timespan(timespan
, sizeof(timespan
), u
, 0));
196 static int write_idle_timeout(FILE *f
, const char *where
, const char *opts
) {
197 return write_timeout(f
, where
, opts
,
198 "x-systemd.idle-timeout\0", "TimeoutIdleSec");
201 static int write_mount_timeout(FILE *f
, const char *where
, const char *opts
) {
202 return write_timeout(f
, where
, opts
,
203 "x-systemd.mount-timeout\0", "TimeoutSec");
206 static int write_dependency(FILE *f
, const char *opts
,
207 const char *filter
, const char *format
) {
208 _cleanup_strv_free_
char **names
= NULL
, **units
= NULL
;
209 _cleanup_free_
char *res
= NULL
;
216 r
= fstab_extract_values(opts
, filter
, &names
);
218 return log_warning_errno(r
, "Failed to parse options: %m");
222 STRV_FOREACH(s
, names
) {
225 r
= unit_name_mangle_with_suffix(*s
, 0, ".mount", &x
);
227 return log_error_errno(r
, "Failed to generate unit name: %m");
228 r
= strv_consume(&units
, x
);
234 res
= strv_join(units
, " ");
237 #pragma GCC diagnostic push
238 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
239 fprintf(f
, format
, res
);
240 #pragma GCC diagnostic pop
246 static int write_after(FILE *f
, const char *opts
) {
247 return write_dependency(f
, opts
, "x-systemd.after", "After=%1$s\n");
250 static int write_requires_after(FILE *f
, const char *opts
) {
251 return write_dependency(f
, opts
,
252 "x-systemd.requires", "After=%1$s\nRequires=%1$s\n");
255 static int write_before(FILE *f
, const char *opts
) {
256 return write_dependency(f
, opts
,
257 "x-systemd.before", "Before=%1$s\n");
260 static int write_requires_mounts_for(FILE *f
, const char *opts
) {
261 _cleanup_strv_free_
char **paths
= NULL
, **paths_escaped
= NULL
;
262 _cleanup_free_
char *res
= NULL
;
268 r
= fstab_extract_values(opts
, "x-systemd.requires-mounts-for", &paths
);
270 return log_warning_errno(r
, "Failed to parse options: %m");
274 r
= specifier_escape_strv(paths
, &paths_escaped
);
276 return log_error_errno(r
, "Failed to escape paths: %m");
278 res
= strv_join(paths_escaped
, " ");
282 fprintf(f
, "RequiresMountsFor=%s\n", res
);
287 static int add_mount(
291 const char *original_where
,
295 MountpointFlags flags
,
297 const char *source
) {
301 *automount_name
= NULL
,
303 *where_escaped
= NULL
;
304 _cleanup_fclose_
FILE *f
= NULL
;
313 if (streq_ptr(fstype
, "autofs"))
316 if (!is_path(where
)) {
317 log_warning("Mount point %s is not a valid path, ignoring.", where
);
321 if (mount_point_is_api(where
) ||
322 mount_point_ignore(where
))
325 if (path_equal(where
, "/")) {
327 log_warning("Ignoring \"noauto\" for root device");
329 log_warning("Ignoring \"nofail\" for root device");
330 if (flags
& AUTOMOUNT
)
331 log_warning("Ignoring automount option for root device");
333 SET_FLAG(flags
, NOAUTO
| NOFAIL
| AUTOMOUNT
, false);
336 r
= unit_name_from_path(where
, ".mount", &name
);
338 return log_error_errno(r
, "Failed to generate unit name: %m");
340 r
= generator_open_unit_file(dest
, "/etc/fstab", name
, &f
);
347 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
350 if (STRPTR_IN_SET(fstype
, "nfs", "nfs4") && !(flags
& AUTOMOUNT
) &&
351 fstab_test_yes_no_option(opts
, "bg\0" "fg\0")) {
352 /* The default retry timeout that mount.nfs uses for 'bg' mounts
353 * is 10000 minutes, where as it uses 2 minutes for 'fg' mounts.
354 * As we are making 'bg' mounts look like an 'fg' mount to
355 * mount.nfs (so systemd can manage the job-control aspects of 'bg'),
356 * we need to explicitly preserve that default, and also ensure
357 * the systemd mount-timeout doesn't interfere.
358 * By placing these options first, they can be over-ridden by
359 * settings in /etc/fstab. */
360 opts
= strjoina("x-systemd.mount-timeout=infinity,retry=10000,", opts
, ",fg");
361 SET_FLAG(flags
, NOFAIL
, true);
364 if (!(flags
& NOFAIL
) && !(flags
& AUTOMOUNT
))
365 fprintf(f
, "Before=%s\n", post
);
367 if (!(flags
& AUTOMOUNT
) && opts
) {
368 r
= write_after(f
, opts
);
371 r
= write_requires_after(f
, opts
);
374 r
= write_before(f
, opts
);
377 r
= write_requires_mounts_for(f
, opts
);
383 r
= generator_write_fsck_deps(f
, dest
, what
, where
, fstype
);
388 fprintf(f
, "\n[Mount]\n");
390 fprintf(f
, "# Canonicalized from %s\n", original_where
);
392 where_escaped
= specifier_escape(where
);
395 fprintf(f
, "Where=%s\n", where_escaped
);
397 r
= write_what(f
, what
);
401 if (!isempty(fstype
) && !streq(fstype
, "auto")) {
402 _cleanup_free_
char *t
;
404 t
= specifier_escape(fstype
);
408 fprintf(f
, "Type=%s\n", t
);
411 r
= generator_write_timeouts(dest
, what
, where
, opts
, &filtered
);
415 r
= generator_write_device_deps(dest
, what
, where
, opts
);
419 r
= write_mount_timeout(f
, where
, opts
);
423 r
= write_options(f
, filtered
);
427 r
= fflush_and_check(f
);
429 return log_error_errno(r
, "Failed to write unit file %s: %m", name
);
431 if (flags
& MAKEFS
) {
432 r
= generator_hook_up_mkfs(dest
, what
, where
, fstype
);
437 if (flags
& GROWFS
) {
438 r
= generator_hook_up_growfs(dest
, where
, post
);
443 if (!(flags
& NOAUTO
) && !(flags
& AUTOMOUNT
)) {
444 r
= generator_add_symlink(dest
, post
,
445 (flags
& NOFAIL
) ? "wants" : "requires", name
);
450 if (flags
& AUTOMOUNT
) {
451 r
= unit_name_from_path(where
, ".automount", &automount_name
);
453 return log_error_errno(r
, "Failed to generate unit name: %m");
457 r
= generator_open_unit_file(dest
, "/etc/fstab", automount_name
, &f
);
464 "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
467 fprintf(f
, "Before=%s\n", post
);
470 r
= write_after(f
, opts
);
473 r
= write_requires_after(f
, opts
);
476 r
= write_before(f
, opts
);
479 r
= write_requires_mounts_for(f
, opts
);
490 r
= write_idle_timeout(f
, where
, opts
);
494 r
= fflush_and_check(f
);
496 return log_error_errno(r
, "Failed to write unit file %s: %m", automount_name
);
498 r
= generator_add_symlink(dest
, post
,
499 (flags
& NOFAIL
) ? "wants" : "requires", automount_name
);
507 static int parse_fstab(bool initrd
) {
508 _cleanup_endmntent_
FILE *f
= NULL
;
509 const char *fstab_path
;
513 fstab_path
= initrd
? "/sysroot/etc/fstab" : "/etc/fstab";
514 f
= setmntent(fstab_path
, "re");
519 return log_error_errno(errno
, "Failed to open %s: %m", fstab_path
);
522 while ((me
= getmntent(f
))) {
523 _cleanup_free_
char *where
= NULL
, *what
= NULL
, *canonical_where
= NULL
;
524 bool makefs
, growfs
, noauto
, nofail
;
527 if (initrd
&& !mount_in_initrd(me
))
530 what
= fstab_node_to_udev_node(me
->mnt_fsname
);
534 if (is_device_path(what
) && path_is_read_only_fs("sys") > 0) {
535 log_info("Running in a container, ignoring fstab device entry for %s.", what
);
539 where
= strdup(me
->mnt_dir
);
543 if (is_path(where
)) {
544 path_simplify(where
, false);
546 /* Follow symlinks here; see 5261ba901845c084de5a8fd06500ed09bfb0bd80 which makes sense for
547 * mount units, but causes problems since it historically worked to have symlinks in e.g.
548 * /etc/fstab. So we canonicalize here. Note that we use CHASE_NONEXISTENT to handle the case
549 * where a symlink refers to another mount target; this works assuming the sub-mountpoint
550 * target is the final directory. */
551 r
= chase_symlinks(where
, initrd
? "/sysroot" : NULL
,
552 CHASE_PREFIX_ROOT
| CHASE_NONEXISTENT
,
554 if (r
< 0) /* If we can't canonicalize we continue on as if it wasn't a symlink */
555 log_debug_errno(r
, "Failed to read symlink target for %s, ignoring: %m", where
);
556 else if (streq(canonical_where
, where
)) /* If it was fully canonicalized, suppress the change */
557 canonical_where
= mfree(canonical_where
);
559 log_debug("Canonicalized what=%s where=%s to %s", what
, where
, canonical_where
);
562 makefs
= fstab_test_option(me
->mnt_opts
, "x-systemd.makefs\0");
563 growfs
= fstab_test_option(me
->mnt_opts
, "x-systemd.growfs\0");
564 noauto
= fstab_test_yes_no_option(me
->mnt_opts
, "noauto\0" "auto\0");
565 nofail
= fstab_test_yes_no_option(me
->mnt_opts
, "nofail\0" "fail\0");
567 log_debug("Found entry what=%s where=%s type=%s makefs=%s nofail=%s noauto=%s",
568 what
, where
, me
->mnt_type
,
570 yes_no(noauto
), yes_no(nofail
));
572 if (streq(me
->mnt_type
, "swap"))
573 k
= add_swap(what
, me
,
574 makefs
*MAKEFS
| growfs
*GROWFS
| noauto
*NOAUTO
| nofail
*NOFAIL
);
579 automount
= fstab_test_option(me
->mnt_opts
,
580 "comment=systemd.automount\0"
581 "x-systemd.automount\0");
583 post
= SPECIAL_INITRD_FS_TARGET
;
584 else if (mount_is_network(me
))
585 post
= SPECIAL_REMOTE_FS_TARGET
;
587 post
= SPECIAL_LOCAL_FS_TARGET
;
589 k
= add_mount(arg_dest
,
591 canonical_where
?: where
,
592 canonical_where
? where
: NULL
,
596 makefs
*MAKEFS
| growfs
*GROWFS
| noauto
*NOAUTO
| nofail
*NOFAIL
| automount
*AUTOMOUNT
,
608 static int add_sysroot_mount(void) {
609 _cleanup_free_
char *what
= NULL
;
613 if (isempty(arg_root_what
)) {
614 log_debug("Could not find a root= entry on the kernel command line.");
618 if (streq(arg_root_what
, "gpt-auto")) {
619 /* This is handled by the gpt-auto generator */
620 log_debug("Skipping root directory handling, as gpt-auto was requested.");
624 if (path_equal(arg_root_what
, "/dev/nfs")) {
625 /* This is handled by the kernel or the initrd */
626 log_debug("Skipping root directory handling, as /dev/nfs was requested.");
630 what
= fstab_node_to_udev_node(arg_root_what
);
634 if (!arg_root_options
)
635 opts
= arg_root_rw
> 0 ? "rw" : "ro";
636 else if (arg_root_rw
>= 0 ||
637 !fstab_test_option(arg_root_options
, "ro\0" "rw\0"))
638 opts
= strjoina(arg_root_options
, ",", arg_root_rw
> 0 ? "rw" : "ro");
640 opts
= arg_root_options
;
642 log_debug("Found entry what=%s where=/sysroot type=%s", what
, strna(arg_root_fstype
));
644 if (is_device_path(what
)) {
645 r
= generator_write_initrd_root_device_deps(arg_dest
, what
);
650 return add_mount(arg_dest
,
656 is_device_path(what
) ? 1 : 0, /* passno */
657 0, /* makefs off, growfs off, noauto off, nofail off, automount off */
658 SPECIAL_INITRD_ROOT_FS_TARGET
,
662 static int add_sysroot_usr_mount(void) {
663 _cleanup_free_
char *what
= NULL
;
666 if (!arg_usr_what
&& !arg_usr_fstype
&& !arg_usr_options
)
669 if (arg_root_what
&& !arg_usr_what
) {
670 /* Copy over the root device, in case the /usr mount just differs in a mount option (consider btrfs subvolumes) */
671 arg_usr_what
= strdup(arg_root_what
);
676 if (arg_root_fstype
&& !arg_usr_fstype
) {
677 arg_usr_fstype
= strdup(arg_root_fstype
);
682 if (arg_root_options
&& !arg_usr_options
) {
683 arg_usr_options
= strdup(arg_root_options
);
684 if (!arg_usr_options
)
691 what
= fstab_node_to_udev_node(arg_usr_what
);
695 if (!arg_usr_options
)
696 opts
= arg_root_rw
> 0 ? "rw" : "ro";
697 else if (!fstab_test_option(arg_usr_options
, "ro\0" "rw\0"))
698 opts
= strjoina(arg_usr_options
, ",", arg_root_rw
> 0 ? "rw" : "ro");
700 opts
= arg_usr_options
;
702 log_debug("Found entry what=%s where=/sysroot/usr type=%s", what
, strna(arg_usr_fstype
));
703 return add_mount(arg_dest
,
709 is_device_path(what
) ? 1 : 0, /* passno */
711 SPECIAL_INITRD_FS_TARGET
,
715 static int add_volatile_root(void) {
716 const char *from
, *to
;
718 if (arg_volatile_mode
!= VOLATILE_YES
)
721 /* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
722 * requested, leaving only /usr from the root mount inside. */
724 from
= strjoina(SYSTEM_DATA_UNIT_PATH
"/systemd-volatile-root.service");
725 to
= strjoina(arg_dest
, "/" SPECIAL_INITRD_ROOT_FS_TARGET
, ".requires/systemd-volatile-root.service");
727 (void) mkdir_parents(to
, 0755);
729 if (symlink(from
, to
) < 0)
730 return log_error_errno(errno
, "Failed to hook in volatile remount service: %m");
735 static int add_volatile_var(void) {
737 if (arg_volatile_mode
!= VOLATILE_STATE
)
740 /* If requested, mount /var as tmpfs, but do so only if there's nothing else defined for this. */
742 return add_mount(arg_dest_late
,
750 SPECIAL_LOCAL_FS_TARGET
,
754 static int parse_proc_cmdline_item(const char *key
, const char *value
, void *data
) {
757 /* root=, usr=, usrfstype= and roofstype= may occur more than once, the last
758 * instance should take precedence. In the case of multiple rootflags=
759 * or usrflags= the arguments should be concatenated */
761 if (STR_IN_SET(key
, "fstab", "rd.fstab")) {
763 r
= value
? parse_boolean(value
) : 1;
765 log_warning("Failed to parse fstab switch %s. Ignoring.", value
);
767 arg_fstab_enabled
= r
;
769 } else if (streq(key
, "root")) {
771 if (proc_cmdline_value_missing(key
, value
))
774 if (free_and_strdup(&arg_root_what
, value
) < 0)
777 } else if (streq(key
, "rootfstype")) {
779 if (proc_cmdline_value_missing(key
, value
))
782 if (free_and_strdup(&arg_root_fstype
, value
) < 0)
785 } else if (streq(key
, "rootflags")) {
787 if (proc_cmdline_value_missing(key
, value
))
790 if (!strextend_with_separator(&arg_root_options
, ",", value
, NULL
))
793 } else if (streq(key
, "roothash")) {
795 if (proc_cmdline_value_missing(key
, value
))
798 if (free_and_strdup(&arg_root_hash
, value
) < 0)
801 } else if (streq(key
, "mount.usr")) {
803 if (proc_cmdline_value_missing(key
, value
))
806 if (free_and_strdup(&arg_usr_what
, value
) < 0)
809 } else if (streq(key
, "mount.usrfstype")) {
811 if (proc_cmdline_value_missing(key
, value
))
814 if (free_and_strdup(&arg_usr_fstype
, value
) < 0)
817 } else if (streq(key
, "mount.usrflags")) {
819 if (proc_cmdline_value_missing(key
, value
))
822 if (!strextend_with_separator(&arg_usr_options
, ",", value
, NULL
))
825 } else if (streq(key
, "rw") && !value
)
827 else if (streq(key
, "ro") && !value
)
829 else if (streq(key
, "systemd.volatile")) {
833 m
= volatile_mode_from_string(value
);
835 log_warning("Failed to parse systemd.volatile= argument: %s", value
);
837 arg_volatile_mode
= m
;
839 arg_volatile_mode
= VOLATILE_YES
;
845 static int determine_root(void) {
846 /* If we have a root hash but no root device then Verity is used, and we use the "root" DM device as root. */
854 arg_root_what
= strdup("/dev/mapper/root");
858 log_info("Using verity root device %s.", arg_root_what
);
863 int main(int argc
, char *argv
[]) {
866 if (argc
> 1 && argc
!= 4) {
867 log_error("This program takes three or no arguments.");
874 arg_dest_late
= argv
[3];
876 log_set_prohibit_ipc(true);
877 log_set_target(LOG_TARGET_AUTO
);
878 log_parse_environment();
883 r
= proc_cmdline_parse(parse_proc_cmdline_item
, NULL
, 0);
885 log_warning_errno(r
, "Failed to parse kernel command line, ignoring: %m");
887 (void) determine_root();
889 /* Always honour root= and usr= in the kernel command line if we are in an initrd */
893 r
= add_sysroot_mount();
895 k
= add_sysroot_usr_mount();
899 k
= add_volatile_root();
903 r
= add_volatile_var();
905 /* Honour /etc/fstab only when that's enabled */
906 if (arg_fstab_enabled
) {
909 log_debug("Parsing /etc/fstab");
911 /* Parse the local /etc/fstab, possibly from the initrd */
912 k
= parse_fstab(false);
916 /* If running in the initrd also parse the /etc/fstab from the host */
918 log_debug("Parsing /sysroot/etc/fstab");
920 k
= parse_fstab(true);
927 free(arg_root_fstype
);
928 free(arg_root_options
);
932 free(arg_usr_fstype
);
933 free(arg_usr_options
);
935 return r
< 0 ? EXIT_FAILURE
: EXIT_SUCCESS
;