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-rw-r--r--src/fstab-generator/fstab-generator.c964
1 files changed, 964 insertions, 0 deletions
diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c
new file mode 100644
index 0000000..15f5892
--- /dev/null
+++ b/src/fstab-generator/fstab-generator.c
@@ -0,0 +1,964 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "fstab-util.h"
+#include "generator.h"
+#include "log.h"
+#include "main-func.h"
+#include "mkdir.h"
+#include "mount-setup.h"
+#include "mount-util.h"
+#include "mountpoint-util.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "proc-cmdline.h"
+#include "special.h"
+#include "specifier.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"
+
+typedef enum MountpointFlags {
+ NOAUTO = 1 << 0,
+ NOFAIL = 1 << 1,
+ AUTOMOUNT = 1 << 2,
+ MAKEFS = 1 << 3,
+ GROWFS = 1 << 4,
+ RWONLY = 1 << 5,
+} MountpointFlags;
+
+static const char *arg_dest = NULL;
+static const char *arg_dest_late = NULL;
+static bool arg_fstab_enabled = true;
+static bool arg_swap_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_DESTRUCTOR_REGISTER(arg_root_what, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_root_fstype, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_root_options, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_root_hash, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_usr_what, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_usr_fstype, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_usr_options, freep);
+
+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 = specifier_escape(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 = specifier_escape(what);
+ if (!w)
+ return log_oom();
+
+ fprintf(f, "What=%s\n", w);
+ return 1;
+}
+
+static int add_swap(
+ const char *what,
+ struct mntent *me,
+ MountpointFlags flags) {
+
+ _cleanup_free_ char *name = NULL;
+ _cleanup_fclose_ FILE *f = NULL;
+ int r;
+
+ assert(what);
+ assert(me);
+
+ if (!arg_swap_enabled) {
+ log_info("Swap unit generation disabled on kernel command line, ignoring fstab swap entry for %s.", what);
+ return 0;
+ }
+
+ 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");
+
+ r = generator_open_unit_file(arg_dest, fstab_path(), name, &f);
+ if (r < 0)
+ return r;
+
+ fprintf(f,
+ "[Unit]\n"
+ "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n"
+ "SourcePath=%s\n",
+ fstab_path());
+
+ r = generator_write_blockdev_dependency(f, what);
+ if (r < 0)
+ return r;
+
+ fprintf(f,
+ "\n"
+ "[Swap]\n");
+
+ 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", name);
+
+ /* 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 (flags & MAKEFS) {
+ r = generator_hook_up_mkswap(arg_dest, what);
+ if (r < 0)
+ return r;
+ }
+
+ if (flags & GROWFS)
+ /* TODO: swap devices must be wiped and recreated */
+ log_warning("%s: growing swap devices is currently unsupported.", what);
+
+ if (!(flags & NOAUTO)) {
+ r = generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET,
+ (flags & 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, "as dependency", 0, ".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();
+
+ DISABLE_WARNING_FORMAT_NONLITERAL;
+ fprintf(f, format, res);
+ REENABLE_WARNING;
+ }
+
+ 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, **paths_escaped = 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;
+
+ r = specifier_escape_strv(paths, &paths_escaped);
+ if (r < 0)
+ return log_error_errno(r, "Failed to escape paths: %m");
+
+ res = strv_join(paths_escaped, " ");
+ if (!res)
+ return log_oom();
+
+ fprintf(f, "RequiresMountsFor=%s\n", res);
+
+ return 0;
+}
+
+static int write_extra_dependencies(FILE *f, const char *opts) {
+ int r;
+
+ assert(f);
+
+ 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;
+ }
+
+ 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,
+ MountpointFlags flags,
+ const char *post,
+ const char *source) {
+
+ _cleanup_free_ char
+ *name = NULL,
+ *automount_name = NULL,
+ *filtered = NULL,
+ *where_escaped = NULL;
+ _cleanup_strv_free_ char **wanted_by = NULL, **required_by = 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;
+
+ r = fstab_extract_values(opts, "x-systemd.wanted-by", &wanted_by);
+ if (r < 0)
+ return r;
+
+ r = fstab_extract_values(opts, "x-systemd.required-by", &required_by);
+ if (r < 0)
+ return r;
+
+ if (path_equal(where, "/")) {
+ if (flags & NOAUTO)
+ log_warning("Ignoring \"noauto\" for root device");
+ if (flags & NOFAIL)
+ log_warning("Ignoring \"nofail\" for root device");
+ if (flags & AUTOMOUNT)
+ log_warning("Ignoring automount option for root device");
+ if (!strv_isempty(wanted_by))
+ log_warning("Ignoring \"x-systemd.wanted-by=\" for root device");
+ if (!strv_isempty(required_by))
+ log_warning("Ignoring \"x-systemd.required-by=\" for root device");
+
+ required_by = strv_free(required_by);
+ wanted_by = strv_free(wanted_by);
+ SET_FLAG(flags, 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");
+
+ r = generator_open_unit_file(dest, fstab_path(), name, &f);
+ if (r < 0)
+ return r;
+
+ fprintf(f,
+ "[Unit]\n"
+ "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n"
+ "SourcePath=%s\n",
+ source);
+
+ if (STRPTR_IN_SET(fstype, "nfs", "nfs4") && !(flags & 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,nofail,", opts, ",fg");
+ SET_FLAG(flags, NOFAIL, true);
+ }
+
+ r = write_extra_dependencies(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;
+ }
+
+ r = generator_write_blockdev_dependency(f, what);
+ if (r < 0)
+ return r;
+
+ fprintf(f,
+ "\n"
+ "[Mount]\n");
+
+ if (original_where)
+ fprintf(f, "# Canonicalized from %s\n", original_where);
+
+ where_escaped = specifier_escape(where);
+ if (!where_escaped)
+ return log_oom();
+ fprintf(f, "Where=%s\n", where_escaped);
+
+ r = write_what(f, what);
+ if (r < 0)
+ return r;
+
+ if (!isempty(fstype) && !streq(fstype, "auto")) {
+ _cleanup_free_ char *t;
+
+ t = specifier_escape(fstype);
+ if (!t)
+ return -ENOMEM;
+
+ fprintf(f, "Type=%s\n", t);
+ }
+
+ 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;
+
+ if (flags & RWONLY)
+ fprintf(f, "ReadWriteOnly=yes\n");
+
+ r = fflush_and_check(f);
+ if (r < 0)
+ return log_error_errno(r, "Failed to write unit file %s: %m", name);
+
+ if (flags & MAKEFS) {
+ r = generator_hook_up_mkfs(dest, what, where, fstype);
+ if (r < 0)
+ return r;
+ }
+
+ if (flags & GROWFS) {
+ r = generator_hook_up_growfs(dest, where, post);
+ if (r < 0)
+ return r;
+ }
+
+ if (!FLAGS_SET(flags, AUTOMOUNT)) {
+ if (!FLAGS_SET(flags, NOAUTO) && strv_isempty(wanted_by) && strv_isempty(required_by)) {
+ r = generator_add_symlink(dest, post,
+ (flags & NOFAIL) ? "wants" : "requires", name);
+ if (r < 0)
+ return r;
+ } else {
+ char **s;
+
+ STRV_FOREACH(s, wanted_by) {
+ r = generator_add_symlink(dest, *s, "wants", name);
+ if (r < 0)
+ return r;
+ }
+
+ STRV_FOREACH(s, required_by) {
+ r = generator_add_symlink(dest, *s, "requires", name);
+ if (r < 0)
+ return r;
+ }
+ }
+ } else {
+ r = unit_name_from_path(where, ".automount", &automount_name);
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate unit name: %m");
+
+ f = safe_fclose(f);
+
+ r = generator_open_unit_file(dest, fstab_path(), automount_name, &f);
+ if (r < 0)
+ return r;
+
+ fprintf(f,
+ "[Unit]\n"
+ "SourcePath=%s\n"
+ "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
+ source);
+
+ fprintf(f,
+ "\n"
+ "[Automount]\n"
+ "Where=%s\n",
+ where_escaped);
+
+ 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_name);
+
+ r = generator_add_symlink(dest, post,
+ (flags & 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;
+ struct mntent *me;
+ int r = 0;
+
+ fstab = initrd ? "/sysroot/etc/fstab" : fstab_path();
+ log_debug("Parsing %s...", fstab);
+
+ f = setmntent(fstab, "re");
+ if (!f) {
+ if (errno == ENOENT)
+ return 0;
+
+ return log_error_errno(errno, "Failed to open %s: %m", fstab);
+ }
+
+ while ((me = getmntent(f))) {
+ _cleanup_free_ char *where = NULL, *what = NULL, *canonical_where = NULL;
+ bool makefs, growfs, noauto, nofail, rwonly;
+ 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_simplify(where, false);
+
+ /* 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, NULL);
+ if (r < 0) /* If we can't canonicalize we continue on as if it wasn't a symlink */
+ log_debug_errno(r, "Failed to read symlink target for %s, ignoring: %m", where);
+ else if (streq(canonical_where, where)) /* If it was fully canonicalized, suppress the change */
+ canonical_where = mfree(canonical_where);
+ else
+ log_debug("Canonicalized what=%s where=%s to %s", what, where, canonical_where);
+ }
+
+ makefs = fstab_test_option(me->mnt_opts, "x-systemd.makefs\0");
+ growfs = fstab_test_option(me->mnt_opts, "x-systemd.growfs\0");
+ rwonly = fstab_test_option(me->mnt_opts, "x-systemd.rw-only\0");
+ 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 makefs=%s growfs=%s noauto=%s nofail=%s",
+ what, where, me->mnt_type,
+ yes_no(makefs), yes_no(growfs),
+ yes_no(noauto), yes_no(nofail));
+
+ if (streq(me->mnt_type, "swap"))
+ k = add_swap(what, me,
+ makefs*MAKEFS | growfs*GROWFS | noauto*NOAUTO | nofail*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,
+ makefs*MAKEFS | growfs*GROWFS | noauto*NOAUTO | nofail*NOFAIL | automount*AUTOMOUNT | rwonly*RWONLY,
+ post,
+ fstab);
+ }
+
+ if (r >= 0 && 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 */
+ 0, /* makefs off, growfs off, noauto off, nofail off, 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 */
+ 0,
+ SPECIAL_INITRD_FS_TARGET,
+ "/proc/cmdline");
+}
+
+static int add_volatile_root(void) {
+
+ /* Let's add in systemd-remount-volatile.service which will remount the root device to tmpfs if this is
+ * requested (or as an overlayfs), leaving only /usr from the root mount inside. */
+
+ if (!IN_SET(arg_volatile_mode, VOLATILE_YES, VOLATILE_OVERLAY))
+ return 0;
+
+ return generator_add_symlink(arg_dest, SPECIAL_INITRD_ROOT_FS_TARGET, "requires",
+ SYSTEM_DATA_UNIT_PATH "/" SPECIAL_VOLATILE_ROOT_SERVICE);
+}
+
+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" TMPFS_LIMITS_VAR,
+ 0,
+ 0,
+ 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")) {
+
+ if (proc_cmdline_value_missing(key, value))
+ return 0;
+
+ if (!strextend_with_separator(&arg_root_options, ",", value, NULL))
+ return log_oom();
+
+ } 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")) {
+
+ if (proc_cmdline_value_missing(key, value))
+ return 0;
+
+ if (!strextend_with_separator(&arg_usr_options, ",", value, NULL))
+ return log_oom();
+
+ } 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;
+
+ } else if (streq(key, "systemd.swap")) {
+
+ r = value ? parse_boolean(value) : 1;
+ if (r < 0)
+ log_warning("Failed to parse systemd.swap switch %s. Ignoring.", value);
+ else
+ arg_swap_enabled = r;
+ }
+
+ 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;
+}
+
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
+ int r, r2 = 0, r3 = 0;
+
+ assert_se(arg_dest = dest);
+ assert_se(arg_dest_late = dest_late);
+
+ 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()) {
+ r = add_sysroot_mount();
+
+ r2 = add_sysroot_usr_mount();
+
+ r3 = add_volatile_root();
+ } else
+ r = add_volatile_var();
+
+ /* Honour /etc/fstab only when that's enabled */
+ if (arg_fstab_enabled) {
+ /* Parse the local /etc/fstab, possibly from the initrd */
+ r2 = parse_fstab(false);
+
+ /* If running in the initrd also parse the /etc/fstab from the host */
+ if (in_initrd())
+ r3 = parse_fstab(true);
+ else
+ r3 = generator_enable_remount_fs_service(arg_dest);
+ }
+
+ return r < 0 ? r : r2 < 0 ? r2 : r3;
+}
+
+DEFINE_MAIN_GENERATOR_FUNCTION(run);