Adding upstream version 252.22.upstream/252.22

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 847 insertions, 0 deletions

diff --git a/src/gpt-auto-generator/gpt-auto-generator.c b/src/gpt-auto-generator/gpt-auto-generator.c
new file mode 100644
index 0000000..2e60b82
--- /dev/null
+++ b/src/gpt-auto-generator/gpt-auto-generator.c
@@ -0,0 +1,847 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <stdlib.h>
+#include <sys/file.h>
+#include <unistd.h>
+
+#include "sd-device.h"
+#include "sd-id128.h"
+
+#include "alloc-util.h"
+#include "blkid-util.h"
+#include "blockdev-util.h"
+#include "btrfs-util.h"
+#include "device-util.h"
+#include "devnum-util.h"
+#include "dirent-util.h"
+#include "dissect-image.h"
+#include "dropin.h"
+#include "efi-loader.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fs-util.h"
+#include "fstab-util.h"
+#include "generator.h"
+#include "gpt.h"
+#include "mkdir.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"
+
+static const char *arg_dest = NULL;
+static bool arg_enabled = true;
+static bool arg_root_enabled = true;
+static int arg_root_rw = -1;
+
+static int add_cryptsetup(
+                const char *id,
+                const char *what,
+                bool rw,
+                bool require,
+                char **ret_device) {
+
+#if HAVE_LIBCRYPTSETUP
+        _cleanup_free_ char *e = NULL, *n = NULL, *d = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        assert(id);
+        assert(what);
+
+        r = unit_name_from_path(what, ".device", &d);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        e = unit_name_escape(id);
+        if (!e)
+                return log_oom();
+
+        r = unit_name_build("systemd-cryptsetup", e, ".service", &n);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        r = generator_open_unit_file(arg_dest, NULL, n, &f);
+        if (r < 0)
+                return r;
+
+        r = generator_write_cryptsetup_unit_section(f, NULL);
+        if (r < 0)
+                return r;
+
+        fprintf(f,
+                "Before=umount.target cryptsetup.target\n"
+                "Conflicts=umount.target\n"
+                "BindsTo=%s\n"
+                "After=%s\n",
+                d, d);
+
+        r = generator_write_cryptsetup_service_section(f, id, what, NULL, rw ? NULL : "read-only");
+        if (r < 0)
+                return r;
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write file %s: %m", n);
+
+        r = generator_add_symlink(arg_dest, d, "wants", n);
+        if (r < 0)
+                return r;
+
+        const char *dmname;
+        dmname = strjoina("dev-mapper-", e, ".device");
+
+        if (require) {
+                r = generator_add_symlink(arg_dest, "cryptsetup.target", "requires", n);
+                if (r < 0)
+                        return r;
+
+                r = generator_add_symlink(arg_dest, dmname, "requires", n);
+                if (r < 0)
+                        return r;
+        }
+
+        r = write_drop_in_format(arg_dest, dmname, 50, "job-timeout",
+                                 "# Automatically generated by systemd-gpt-auto-generator\n\n"
+                                 "[Unit]\n"
+                                 "JobTimeoutSec=0"); /* the binary handles timeouts anyway */
+        if (r < 0)
+                log_warning_errno(r, "Failed to write device timeout drop-in, ignoring: %m");
+
+        if (ret_device) {
+                char *s;
+
+                s = path_join("/dev/mapper", id);
+                if (!s)
+                        return log_oom();
+
+                *ret_device = s;
+        }
+
+        return 0;
+#else
+        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Partition is encrypted, but the project was compiled without libcryptsetup support");
+#endif
+}
+
+static int add_mount(
+                const char *id,
+                const char *what,
+                const char *where,
+                const char *fstype,
+                bool rw,
+                bool growfs,
+                const char *options,
+                const char *description,
+                const char *post) {
+
+        _cleanup_free_ char *unit = NULL, *crypto_what = NULL, *p = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        /* Note that we don't apply specifier escaping on the input strings here, since we know they are not configured
+         * externally, but all originate from our own sources here, and hence we know they contain no % characters that
+         * could potentially be understood as specifiers. */
+
+        assert(id);
+        assert(what);
+        assert(where);
+        assert(description);
+
+        log_debug("Adding %s: %s fstype=%s", where, what, fstype ?: "(any)");
+
+        if (streq_ptr(fstype, "crypto_LUKS")) {
+                r = add_cryptsetup(id, what, rw, true, &crypto_what);
+                if (r < 0)
+                        return r;
+
+                what = crypto_what;
+                fstype = NULL;
+        }
+
+        r = unit_name_from_path(where, ".mount", &unit);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        p = path_join(empty_to_root(arg_dest), unit);
+        if (!p)
+                return log_oom();
+
+        f = fopen(p, "wxe");
+        if (!f)
+                return log_error_errno(errno, "Failed to create unit file %s: %m", unit);
+
+        fprintf(f,
+                "# Automatically generated by systemd-gpt-auto-generator\n\n"
+                "[Unit]\n"
+                "Description=%s\n"
+                "Documentation=man:systemd-gpt-auto-generator(8)\n",
+                description);
+
+        if (post)
+                fprintf(f, "Before=%s\n", post);
+
+        r = generator_write_fsck_deps(f, arg_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"
+                "What=%s\n"
+                "Where=%s\n",
+                what, where);
+
+        if (fstype)
+                fprintf(f, "Type=%s\n", fstype);
+
+        if (options)
+                fprintf(f, "Options=%s,%s\n", options, rw ? "rw" : "ro");
+        else
+                fprintf(f, "Options=%s\n", rw ? "rw" : "ro");
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write unit file %s: %m", p);
+
+        if (growfs) {
+                r = generator_hook_up_growfs(arg_dest, where, post);
+                if (r < 0)
+                        return r;
+        }
+
+        if (post) {
+                r = generator_add_symlink(arg_dest, post, "requires", unit);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+static int path_is_busy(const char *where) {
+        int r;
+
+        /* already a mountpoint; generators run during reload */
+        r = path_is_mount_point(where, NULL, AT_SYMLINK_FOLLOW);
+        if (r > 0)
+                return false;
+
+        /* the directory might not exist on a stateless system */
+        if (r == -ENOENT)
+                return false;
+
+        if (r < 0)
+                return log_warning_errno(r, "Cannot check if \"%s\" is a mount point: %m", where);
+
+        /* not a mountpoint but it contains files */
+        r = dir_is_empty(where, /* ignore_hidden_or_backup= */ false);
+        if (r < 0)
+                return log_warning_errno(r, "Cannot check if \"%s\" is empty: %m", where);
+        if (r > 0)
+                return false;
+
+        log_debug("\"%s\" already populated, ignoring.", where);
+        return true;
+}
+
+static int add_partition_mount(
+                DissectedPartition *p,
+                const char *id,
+                const char *where,
+                const char *description) {
+
+        int r;
+        assert(p);
+
+        r = path_is_busy(where);
+        if (r != 0)
+                return r < 0 ? r : 0;
+
+        return add_mount(
+                        id,
+                        p->node,
+                        where,
+                        p->fstype,
+                        p->rw,
+                        p->growfs,
+                        NULL,
+                        description,
+                        SPECIAL_LOCAL_FS_TARGET);
+}
+
+static int add_partition_swap(DissectedPartition *p) {
+        const char *what;
+        _cleanup_free_ char *name = NULL, *unit = NULL, *crypto_what = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        assert(p);
+        assert(p->node);
+
+        /* Disable the swap auto logic if at least one swap is defined in /etc/fstab, see #6192. */
+        r = fstab_has_fstype("swap");
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse fstab: %m");
+        if (r > 0) {
+                log_debug("swap specified in fstab, ignoring.");
+                return 0;
+        }
+
+        if (streq_ptr(p->fstype, "crypto_LUKS")) {
+                r = add_cryptsetup("swap", p->node, true, true, &crypto_what);
+                if (r < 0)
+                        return r;
+                what = crypto_what;
+        } else
+                what = p->node;
+
+        log_debug("Adding swap: %s", what);
+
+        r = unit_name_from_path(what, ".swap", &name);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        unit = path_join(empty_to_root(arg_dest), name);
+        if (!unit)
+                return log_oom();
+
+        f = fopen(unit, "wxe");
+        if (!f)
+                return log_error_errno(errno, "Failed to create unit file %s: %m", unit);
+
+        fprintf(f,
+                "# Automatically generated by systemd-gpt-auto-generator\n\n"
+                "[Unit]\n"
+                "Description=Swap Partition\n"
+                "Documentation=man:systemd-gpt-auto-generator(8)\n");
+
+        r = generator_write_blockdev_dependency(f, what);
+        if (r < 0)
+                return r;
+
+        fprintf(f,
+                "\n"
+                "[Swap]\n"
+                "What=%s\n",
+                what);
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write unit file %s: %m", unit);
+
+        return generator_add_symlink(arg_dest, SPECIAL_SWAP_TARGET, "wants", name);
+}
+
+static int add_automount(
+                const char *id,
+                const char *what,
+                const char *where,
+                const char *fstype,
+                bool rw,
+                bool growfs,
+                const char *options,
+                const char *description,
+                usec_t timeout) {
+
+        _cleanup_free_ char *unit = NULL, *p = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        const char *opt = "noauto";
+        int r;
+
+        assert(id);
+        assert(where);
+        assert(description);
+
+        if (options)
+                opt = strjoina(options, ",", opt);
+
+        r = add_mount(id,
+                      what,
+                      where,
+                      fstype,
+                      rw,
+                      growfs,
+                      opt,
+                      description,
+                      NULL);
+        if (r < 0)
+                return r;
+
+        r = unit_name_from_path(where, ".automount", &unit);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        p = path_join(arg_dest, unit);
+        if (!p)
+                return log_oom();
+
+        f = fopen(p, "wxe");
+        if (!f)
+                return log_error_errno(errno, "Failed to create unit file %s: %m", unit);
+
+        fprintf(f,
+                "# Automatically generated by systemd-gpt-auto-generator\n\n"
+                "[Unit]\n"
+                "Description=%s\n"
+                "Documentation=man:systemd-gpt-auto-generator(8)\n"
+                "[Automount]\n"
+                "Where=%s\n"
+                "TimeoutIdleSec="USEC_FMT"\n",
+                description,
+                where,
+                timeout / USEC_PER_SEC);
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write unit file %s: %m", p);
+
+        return generator_add_symlink(arg_dest, SPECIAL_LOCAL_FS_TARGET, "wants", unit);
+}
+
+static const char *esp_or_xbootldr_options(const DissectedPartition *p) {
+        assert(p);
+
+        /* Discoveried ESP and XBOOTLDR partition are always hardened with "noexec,nosuid,nodev".
+         * If we probed vfat or have no idea about the file system then assume these file systems are vfat
+         * and thus understand "umask=0077". */
+
+        if (!p->fstype || streq(p->fstype, "vfat"))
+                return "umask=0077,noexec,nosuid,nodev";
+
+        return "noexec,nosuid,nodev";
+}
+
+static int add_partition_xbootldr(DissectedPartition *p) {
+        int r;
+
+        assert(p);
+
+        if (in_initrd()) {
+                log_debug("In initrd, ignoring the XBOOTLDR partition.");
+                return 0;
+        }
+
+        r = fstab_is_mount_point("/boot");
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse fstab: %m");
+        if (r > 0) {
+                log_debug("/boot specified in fstab, ignoring XBOOTLDR partition.");
+                return 0;
+        }
+
+        r = path_is_busy("/boot");
+        if (r < 0)
+                return r;
+        if (r > 0)
+                return 0;
+
+        return add_automount("boot",
+                             p->node,
+                             "/boot",
+                             p->fstype,
+                             /* rw= */ true,
+                             /* growfs= */ false,
+                             esp_or_xbootldr_options(p),
+                             "Boot Loader Partition",
+                             120 * USEC_PER_SEC);
+}
+
+#if ENABLE_EFI
+static int add_partition_esp(DissectedPartition *p, bool has_xbootldr) {
+        const char *esp_path = NULL, *id = NULL;
+        int r;
+
+        assert(p);
+
+        if (in_initrd()) {
+                log_debug("In initrd, ignoring the ESP.");
+                return 0;
+        }
+
+        /* If /efi exists we'll use that. Otherwise we'll use /boot, as that's usually the better choice, but
+         * only if there's no explicit XBOOTLDR partition around. */
+        if (access("/efi", F_OK) < 0) {
+                if (errno != ENOENT)
+                        return log_error_errno(errno, "Failed to determine whether /efi exists: %m");
+
+                /* Use /boot as fallback, but only if there's no XBOOTLDR partition */
+                if (!has_xbootldr) {
+                        esp_path = "/boot";
+                        id = "boot";
+                }
+        }
+        if (!esp_path)
+                esp_path = "/efi";
+        if (!id)
+                id = "efi";
+
+        /* We create an .automount which is not overridden by the .mount from the fstab generator. */
+        r = fstab_is_mount_point(esp_path);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse fstab: %m");
+        if (r > 0) {
+                log_debug("%s specified in fstab, ignoring.", esp_path);
+                return 0;
+        }
+
+        r = path_is_busy(esp_path);
+        if (r < 0)
+                return r;
+        if (r > 0)
+                return 0;
+
+        if (is_efi_boot()) {
+                sd_id128_t loader_uuid;
+
+                /* If this is an EFI boot, be extra careful, and only mount the ESP if it was the ESP used for booting. */
+
+                r = efi_loader_get_device_part_uuid(&loader_uuid);
+                if (r == -ENOENT) {
+                        log_debug("EFI loader partition unknown.");
+                        return 0;
+                }
+                if (r < 0)
+                        return log_error_errno(r, "Failed to read ESP partition UUID: %m");
+
+                if (!sd_id128_equal(p->uuid, loader_uuid)) {
+                        log_debug("Partition for %s does not appear to be the partition we are booted from.", p->node);
+                        return 0;
+                }
+        } else
+                log_debug("Not an EFI boot, skipping ESP check.");
+
+        return add_automount(id,
+                             p->node,
+                             esp_path,
+                             p->fstype,
+                             /* rw= */ true,
+                             /* growfs= */ false,
+                             esp_or_xbootldr_options(p),
+                             "EFI System Partition Automount",
+                             120 * USEC_PER_SEC);
+}
+#else
+static int add_partition_esp(DissectedPartition *p, bool has_xbootldr) {
+        return 0;
+}
+#endif
+
+static int add_partition_root_rw(DissectedPartition *p) {
+        const char *path;
+        int r;
+
+        assert(p);
+
+        if (in_initrd()) {
+                log_debug("In initrd, not generating drop-in for systemd-remount-fs.service.");
+                return 0;
+        }
+
+        if (arg_root_rw >= 0) {
+                log_debug("Parameter ro/rw specified on kernel command line, not generating drop-in for systemd-remount-fs.service.");
+                return 0;
+        }
+
+        if (!p->rw) {
+                log_debug("Root partition marked read-only in GPT partition table, not generating drop-in for systemd-remount-fs.service.");
+                return 0;
+        }
+
+        (void) generator_enable_remount_fs_service(arg_dest);
+
+        path = strjoina(arg_dest, "/systemd-remount-fs.service.d/50-remount-rw.conf");
+
+        r = write_string_file(path,
+                              "# Automatically generated by systemd-gpt-auto-generator\n\n"
+                              "[Service]\n"
+                              "Environment=SYSTEMD_REMOUNT_ROOT_RW=1\n",
+                              WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_NOFOLLOW|WRITE_STRING_FILE_MKDIR_0755);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write drop-in file %s: %m", path);
+
+        return 0;
+}
+
+#if ENABLE_EFI
+static int add_root_cryptsetup(void) {
+#if HAVE_LIBCRYPTSETUP
+
+        /* If a device /dev/gpt-auto-root-luks appears, then make it pull in systemd-cryptsetup-root.service, which
+         * sets it up, and causes /dev/gpt-auto-root to appear which is all we are looking for. */
+
+        return add_cryptsetup("root", "/dev/gpt-auto-root-luks", true, false, NULL);
+#else
+        return 0;
+#endif
+}
+#endif
+
+static int add_root_mount(void) {
+#if ENABLE_EFI
+        int r;
+
+        if (!is_efi_boot()) {
+                log_debug("Not an EFI boot, not creating root mount.");
+                return 0;
+        }
+
+        r = efi_loader_get_device_part_uuid(NULL);
+        if (r == -ENOENT) {
+                log_notice("EFI loader partition unknown, exiting.\n"
+                           "(The boot loader did not set EFI variable LoaderDevicePartUUID.)");
+                return 0;
+        } else if (r < 0)
+                return log_error_errno(r, "Failed to read ESP partition UUID: %m");
+
+        /* OK, we have an ESP partition, this is fantastic, so let's wait for a root device to show up. A
+         * udev rule will create the link for us under the right name. */
+
+        if (in_initrd()) {
+                r = generator_write_initrd_root_device_deps(arg_dest, "/dev/gpt-auto-root");
+                if (r < 0)
+                        return 0;
+
+                r = add_root_cryptsetup();
+                if (r < 0)
+                        return r;
+        }
+
+        /* Note that we do not need to enable systemd-remount-fs.service here. If
+         * /etc/fstab exists, systemd-fstab-generator will pull it in for us. */
+
+        return add_mount(
+                        "root",
+                        "/dev/gpt-auto-root",
+                        in_initrd() ? "/sysroot" : "/",
+                        NULL,
+                        /* rw= */ arg_root_rw > 0,
+                        /* growfs= */ false,
+                        NULL,
+                        "Root Partition",
+                        in_initrd() ? SPECIAL_INITRD_ROOT_FS_TARGET : SPECIAL_LOCAL_FS_TARGET);
+#else
+        return 0;
+#endif
+}
+
+static int enumerate_partitions(dev_t devnum) {
+        _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
+        _cleanup_(loop_device_unrefp) LoopDevice *loop = NULL;
+        _cleanup_free_ char *devname = NULL;
+        int r, k;
+
+        r = block_get_whole_disk(devnum, &devnum);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to get whole block device for " DEVNUM_FORMAT_STR ": %m",
+                                       DEVNUM_FORMAT_VAL(devnum));
+
+        r = devname_from_devnum(S_IFBLK, devnum, &devname);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to get device node of " DEVNUM_FORMAT_STR ": %m",
+                                       DEVNUM_FORMAT_VAL(devnum));
+
+        /* Let's take a LOCK_SH lock on the block device, in case udevd is already running. If we don't take
+         * the lock, udevd might end up issuing BLKRRPART in the middle, and we don't want that, since that
+         * might remove all partitions while we are operating on them. */
+        r = loop_device_open_from_path(devname, O_RDONLY, LOCK_SH, &loop);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to open %s: %m", devname);
+
+        r = dissect_loop_device(
+                        loop,
+                        NULL, NULL,
+                        DISSECT_IMAGE_GPT_ONLY|
+                        DISSECT_IMAGE_USR_NO_ROOT,
+                        /* NB! Unlike most other places where we dissect block devices we do not use
+                         * DISSECT_IMAGE_ADD_PARTITION_DEVICES here: we want that the kernel finds the
+                         * devices, and udev probes them before we mount them via .mount units much later
+                         * on. And thus we also don't set DISSECT_IMAGE_PIN_PARTITION_DEVICES here, because
+                         * we don't actually mount anything immediately. */
+                        &m);
+        if (r == -ENOPKG) {
+                log_debug_errno(r, "No suitable partition table found, ignoring.");
+                return 0;
+        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to dissect: %m");
+
+        if (m->partitions[PARTITION_SWAP].found) {
+                k = add_partition_swap(m->partitions + PARTITION_SWAP);
+                if (k < 0)
+                        r = k;
+        }
+
+        if (m->partitions[PARTITION_XBOOTLDR].found) {
+                k = add_partition_xbootldr(m->partitions + PARTITION_XBOOTLDR);
+                if (k < 0)
+                        r = k;
+        }
+
+        if (m->partitions[PARTITION_ESP].found) {
+                k = add_partition_esp(m->partitions + PARTITION_ESP, m->partitions[PARTITION_XBOOTLDR].found);
+                if (k < 0)
+                        r = k;
+        }
+
+        if (m->partitions[PARTITION_HOME].found) {
+                k = add_partition_mount(m->partitions + PARTITION_HOME, "home", "/home", "Home Partition");
+                if (k < 0)
+                        r = k;
+        }
+
+        if (m->partitions[PARTITION_SRV].found) {
+                k = add_partition_mount(m->partitions + PARTITION_SRV, "srv", "/srv", "Server Data Partition");
+                if (k < 0)
+                        r = k;
+        }
+
+        if (m->partitions[PARTITION_VAR].found) {
+                k = add_partition_mount(m->partitions + PARTITION_VAR, "var", "/var", "Variable Data Partition");
+                if (k < 0)
+                        r = k;
+        }
+
+        if (m->partitions[PARTITION_TMP].found) {
+                k = add_partition_mount(m->partitions + PARTITION_TMP, "var-tmp", "/var/tmp", "Temporary Data Partition");
+                if (k < 0)
+                        r = k;
+        }
+
+        if (m->partitions[PARTITION_ROOT].found) {
+                k = add_partition_root_rw(m->partitions + PARTITION_ROOT);
+                if (k < 0)
+                        r = k;
+        }
+
+        return r;
+}
+
+static int add_mounts(void) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+        dev_t devno;
+
+        /* If the root mount has been replaced by some form of volatile file system (overlayfs), the
+         * original root block device node is symlinked in /run/systemd/volatile-root. Let's read that
+         * here. */
+        r = readlink_malloc("/run/systemd/volatile-root", &p);
+        if (r == -ENOENT) { /* volatile-root not found */
+                r = get_block_device_harder("/", &devno);
+                if (r == -EUCLEAN)
+                        return btrfs_log_dev_root(LOG_ERR, r, "root file system");
+                if (r < 0)
+                        return log_error_errno(r, "Failed to determine block device of root file system: %m");
+                if (r == 0) { /* Not backed by a single block device. (Could be NFS or so, or could be multi-device RAID or so) */
+                        r = get_block_device_harder("/usr", &devno);
+                        if (r == -EUCLEAN)
+                                return btrfs_log_dev_root(LOG_ERR, r, "/usr");
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to determine block device of /usr/ file system: %m");
+                        if (r == 0) { /* /usr/ not backed by single block device, either. */
+                                log_debug("Neither root nor /usr/ file system are on a (single) block device.");
+                                return 0;
+                        }
+                }
+        } else if (r < 0)
+                return log_error_errno(r, "Failed to read symlink /run/systemd/volatile-root: %m");
+        else {
+                mode_t m;
+                r = device_path_parse_major_minor(p, &m, &devno);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to parse major/minor device node: %m");
+                if (!S_ISBLK(m))
+                        return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "Volatile root device is of wrong type.");
+        }
+
+        return enumerate_partitions(devno);
+}
+
+static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
+        int r;
+
+        assert(key);
+
+        if (proc_cmdline_key_streq(key, "systemd.gpt_auto") ||
+            proc_cmdline_key_streq(key, "rd.systemd.gpt_auto")) {
+
+                r = value ? parse_boolean(value) : 1;
+                if (r < 0)
+                        log_warning_errno(r, "Failed to parse gpt-auto switch \"%s\", ignoring: %m", value);
+                else
+                        arg_enabled = r;
+
+        } else if (proc_cmdline_key_streq(key, "root")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                /* Disable root disk logic if there's a root= value
+                 * specified (unless it happens to be "gpt-auto") */
+
+                if (!streq(value, "gpt-auto")) {
+                        arg_root_enabled = false;
+                        log_debug("Disabling root partition auto-detection, root= is defined.");
+                }
+
+        } else if (proc_cmdline_key_streq(key, "roothash")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                /* Disable root disk logic if there's roothash= defined (i.e. verity enabled) */
+
+                arg_root_enabled = false;
+
+        } else if (proc_cmdline_key_streq(key, "rw") && !value)
+                arg_root_rw = true;
+        else if (proc_cmdline_key_streq(key, "ro") && !value)
+                arg_root_rw = false;
+
+        return 0;
+}
+
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
+        int r, k;
+
+        assert_se(arg_dest = dest_late);
+
+        if (detect_container() > 0) {
+                log_debug("In a container, exiting.");
+                return 0;
+        }
+
+        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");
+
+        if (!arg_enabled) {
+                log_debug("Disabled, exiting.");
+                return 0;
+        }
+
+        if (arg_root_enabled)
+                r = add_root_mount();
+
+        if (!in_initrd()) {
+                k = add_mounts();
+                if (r >= 0)
+                        r = k;
+        }
+
+        return r;
+}
+
+DEFINE_MAIN_GENERATOR_FUNCTION(run);