X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fgpt-auto-generator%2Fgpt-auto-generator.c;h=4927919b81d5d3c446ba535998dc66d352a4a91e;hp=a26655f096fe6ddf4a62b1c8bec58b7d79a18330;hb=fa041593fe04b12ffd7e81d8b3598a7a6f313fb3;hpb=4b357e15876b730343db08719c877fdb45b6ad42

diff --git a/src/gpt-auto-generator/gpt-auto-generator.c b/src/gpt-auto-generator/gpt-auto-generator.c
index a26655f09..4927919b8 100644
--- a/src/gpt-auto-generator/gpt-auto-generator.c
+++ b/src/gpt-auto-generator/gpt-auto-generator.c
@@ -24,139 +24,40 @@
 #include <fcntl.h>
 #include <sys/ioctl.h>
 #include <sys/statfs.h>
-#include <blkid.h>
+#include <blkid/blkid.h>
 
 #ifdef HAVE_LINUX_BTRFS_H
 #include <linux/btrfs.h>
 #endif
 
+#include "sd-id128.h"
+#include "libudev.h"
 #include "path-util.h"
 #include "util.h"
 #include "mkdir.h"
 #include "missing.h"
-#include "sd-id128.h"
-#include "libudev.h"
+#include "udev-util.h"
 #include "special.h"
 #include "unit-name.h"
-
-/* TODO:
- *
- * - Properly handle cryptsetup partitions
- * - Define new partition type for encrypted swap
- * - Make /home automount rather than mount
- *
- */
+#include "virt.h"
+#include "generator.h"
+#include "gpt.h"
+#include "fileio.h"
+#include "efivars.h"
+#include "blkid-util.h"
 
 static const char *arg_dest = "/tmp";
+static bool arg_enabled = true;
+static bool arg_root_enabled = true;
+static bool arg_root_rw = false;
 
-static int verify_gpt_partition(dev_t dev, sd_id128_t *type, unsigned *nr, char **fstype) {
-        _cleanup_free_ char *t = NULL;
-        blkid_probe b = NULL;
-        const char *v;
-        int r;
-
-        r = asprintf(&t, "/dev/block/%u:%u", major(dev), minor(dev));
-        if (r < 0)
-                return -ENOMEM;
-
-        errno = 0;
-        b = blkid_new_probe_from_filename(t);
-        if (!b) {
-                if (errno != 0)
-                        return -errno;
-
-                return -ENOMEM;
-        }
-
-        blkid_probe_enable_superblocks(b, 1);
-        blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
-        blkid_probe_enable_partitions(b, 1);
-        blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS);
-
-        errno = 0;
-        r = blkid_do_safeprobe(b);
-        if (r == -2) {
-                r = -ENODEV;
-                goto finish;
-        } else if (r == 1) {
-                r = -ENODEV;
-                goto finish;
-        } else if (r != 0) {
-                r = errno ? -errno : -EIO;
-                goto finish;
-        }
-
-        errno = 0;
-        r = blkid_probe_lookup_value(b, "PART_ENTRY_SCHEME", &v, NULL);
-        if (r != 0) {
-                r = errno ? -errno : -EIO;
-                goto finish;
-        }
-
-        if (strcmp(v, "gpt") != 0) {
-                r = 0;
-                goto finish;
-        }
-
-        if (type) {
-                errno = 0;
-                r = blkid_probe_lookup_value(b, "PART_ENTRY_TYPE", &v, NULL);
-                if (r != 0) {
-                        r = errno ? -errno : -EIO;
-                        goto finish;
-                }
-
-                r = sd_id128_from_string(v, type);
-                if (r < 0)
-                        return r;
-        }
-
-        if (nr) {
-                errno = 0;
-                r = blkid_probe_lookup_value(b, "PART_ENTRY_NUMBER", &v, NULL);
-                if (r != 0) {
-                        r = errno ? -errno : -EIO;
-                        goto finish;
-                }
-
-                r = safe_atou(v, nr);
-                if (r < 0)
-                        return r;
-        }
-
-
-        if (fstype) {
-                char *fst;
-
-                errno = 0;
-                r = blkid_probe_lookup_value(b, "TYPE", &v, NULL);
-                if (r != 0)
-                        *fstype = NULL;
-                else {
-                        fst = strdup(v);
-                        if (!fst) {
-                                r = -ENOMEM;
-                                goto finish;
-                        }
-
-                        *fstype = fst;
-                }
-        }
-
-        return 1;
-
-finish:
-        if (b)
-                blkid_free_probe(b);
-
-        return r;
-}
-
-static int add_swap(const char *path, const char *fstype) {
+static int add_swap(const char *path) {
         _cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL;
         _cleanup_fclose_ FILE *f = NULL;
 
-        log_debug("Adding swap: %s %s", path, fstype);
+        assert(path);
+
+        log_debug("Adding swap: %s", path);
 
         name = unit_name_from_path(path, ".swap");
         if (!name)
@@ -175,9 +76,8 @@ static int add_swap(const char *path, const char *fstype) {
         fprintf(f,
                 "# Automatically generated by systemd-gpt-auto-generator\n\n"
                 "[Unit]\n"
-                "DefaultDependencies=no\n"
-                "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
-                "Before=" SPECIAL_UMOUNT_TARGET " " SPECIAL_SWAP_TARGET "\n\n"
+                "Description=Swap Partition\n"
+                "Documentation=man:systemd-gpt-auto-generator(8)\n\n"
                 "[Swap]\n"
                 "What=%s\n",
                 path);
@@ -201,20 +101,162 @@ static int add_swap(const char *path, const char *fstype) {
         return 0;
 }
 
-static int add_home(const char *path, const char *fstype) {
-        _cleanup_free_ char *unit = NULL, *lnk = NULL;
+static int add_cryptsetup(const char *id, const char *what, bool rw, char **device) {
+        _cleanup_free_ char *e = NULL, *n = NULL, *p = NULL, *d = NULL, *to = NULL;
         _cleanup_fclose_ FILE *f = NULL;
+        char *from, *ret;
+        int r;
 
-        if (dir_is_empty("/home") <= 0)
-                return 0;
+        assert(id);
+        assert(what);
+        assert(device);
+
+        d = unit_name_from_path(what, ".device");
+        if (!d)
+                return log_oom();
+
+        e = unit_name_escape(id);
+        if (!e)
+                return log_oom();
+
+        n = unit_name_build("systemd-cryptsetup", e, ".service");
+        if (!n)
+                return log_oom();
+
+        p = strjoin(arg_dest, "/", n, NULL);
+        if (!n)
+                return log_oom();
+
+        f = fopen(p, "wxe");
+        if (!f) {
+                log_error("Failed to create unit file %s: %m", p);
+                return -errno;
+        }
 
-        log_debug("Adding home: %s %s", path, fstype);
+        fprintf(f,
+                "# Automatically generated by systemd-gpt-auto-generator\n\n"
+                "[Unit]\n"
+                "Description=Cryptography Setup for %%I\n"
+                "Documentation=man:systemd-gpt-auto-generator(8) man:systemd-cryptsetup@.service(8)\n"
+                "DefaultDependencies=no\n"
+                "Conflicts=umount.target\n"
+                "BindsTo=dev-mapper-%%i.device %s\n"
+                "Before=umount.target cryptsetup.target\n"
+                "After=%s\n"
+                "IgnoreOnIsolate=true\n"
+                "After=systemd-readahead-collect.service systemd-readahead-replay.service\n\n"
+                "[Service]\n"
+                "Type=oneshot\n"
+                "RemainAfterExit=yes\n"
+                "TimeoutSec=0\n" /* the binary handles timeouts anyway */
+                "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '' '%s'\n"
+                "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
+                d, d,
+                id, what, rw ? "" : "read-only",
+                id);
 
-        unit = strappend(arg_dest, "/home.mount");
+        fflush(f);
+        if (ferror(f)) {
+                log_error("Failed to write file %s: %m", p);
+                return -errno;
+        }
+
+        from = strappenda("../", n);
+
+        to = strjoin(arg_dest, "/", d, ".wants/", n, NULL);
+        if (!to)
+                return log_oom();
+
+        mkdir_parents_label(to, 0755);
+        if (symlink(from, to) < 0) {
+                log_error("Failed to create symlink %s: %m", to);
+                return -errno;
+        }
+
+        free(to);
+        to = strjoin(arg_dest, "/cryptsetup.target.requires/", n, NULL);
+        if (!to)
+                return log_oom();
+
+        mkdir_parents_label(to, 0755);
+        if (symlink(from, to) < 0) {
+                log_error("Failed to create symlink %s: %m", to);
+                return -errno;
+        }
+
+        free(to);
+        to = strjoin(arg_dest, "/dev-mapper-", e, ".device.requires/", n, NULL);
+        if (!to)
+                return log_oom();
+
+        mkdir_parents_label(to, 0755);
+        if (symlink(from, to) < 0) {
+                log_error("Failed to create symlink %s: %m", to);
+                return -errno;
+        }
+
+        free(p);
+        p = strjoin(arg_dest, "/dev-mapper-", e, ".device.d/50-job-timeout-sec-0.conf", NULL);
+        if (!p)
+                return log_oom();
+
+        mkdir_parents_label(p, 0755);
+        r = write_string_file(p,
+                        "# Automatically generated by systemd-gpt-auto-generator\n\n"
+                        "[Unit]\n"
+                        "JobTimeoutSec=0\n"); /* the binary handles timeouts anyway */
+        if (r < 0) {
+                log_error("Failed to write device drop-in: %s", strerror(-r));
+                return r;
+        }
+
+        ret = strappend("/dev/mapper/", id);
+        if (!ret)
+                return log_oom();
+
+        *device = ret;
+        return 0;
+}
+
+static int add_mount(
+                const char *id,
+                const char *what,
+                const char *where,
+                const char *fstype,
+                bool rw,
+                const char *description,
+                const char *post) {
+
+        _cleanup_free_ char *unit = NULL, *lnk = NULL, *crypto_what = NULL, *p = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        assert(id);
+        assert(what);
+        assert(where);
+        assert(description);
+
+        log_debug("Adding %s: %s %s", where, what, strna(fstype));
+
+        if (streq_ptr(fstype, "crypto_LUKS")) {
+
+                r = add_cryptsetup(id, what, rw, &crypto_what);
+                if (r < 0)
+                        return r;
+
+                what = crypto_what;
+                fstype = NULL;
+        }
+
+        unit = unit_name_from_path(where, ".mount");
         if (!unit)
                 return log_oom();
 
-        f = fopen(unit, "wxe");
+        p = strjoin(arg_dest, "/", unit, NULL);
+        if (!p)
+                return log_oom();
+
+        f = fopen(p, "wxe");
         if (!f) {
                 log_error("Failed to create unit file %s: %m", unit);
                 return -errno;
@@ -223,163 +265,344 @@ static int add_home(const char *path, const char *fstype) {
         fprintf(f,
                 "# Automatically generated by systemd-gpt-auto-generator\n\n"
                 "[Unit]\n"
-                "DefaultDependencies=no\n"
-                "After=" SPECIAL_LOCAL_FS_PRE_TARGET "\n"
-                "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
-                "Before=" SPECIAL_UMOUNT_TARGET " " SPECIAL_LOCAL_FS_TARGET "\n\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;
+
+        fprintf(f,
+                "\n"
                 "[Mount]\n"
                 "What=%s\n"
-                "Where=/home\n"
-                "Type=%s\n"
-                "FsckPassNo=2\n",
-                path, fstype);
+                "Where=%s\n",
+                what, where);
+
+        if (fstype)
+                fprintf(f, "Type=%s\n", fstype);
+
+        fprintf(f, "Options=%s\n", rw ? "rw" : "ro");
 
         fflush(f);
         if (ferror(f)) {
-                log_error("Failed to write unit file %s: %m", unit);
+                log_error("Failed to write unit file %s: %m", p);
                 return -errno;
         }
 
-        lnk = strjoin(arg_dest, "/" SPECIAL_LOCAL_FS_TARGET ".requires/home.mount", NULL);
-        if (!lnk)
-                return log_oom();
+        if (post) {
+                lnk = strjoin(arg_dest, "/", post, ".requires/", unit, NULL);
+                if (!lnk)
+                        return log_oom();
 
+                mkdir_parents_label(lnk, 0755);
+                if (symlink(p, lnk) < 0) {
+                        log_error("Failed to create symlink %s: %m", lnk);
+                        return -errno;
+                }
+        }
 
-        mkdir_parents_label(lnk, 0755);
-        if (symlink(unit, lnk) < 0) {
-                log_error("Failed to create symlink %s: %m", lnk);
+        return 0;
+}
+
+static int probe_and_add_mount(
+                const char *id,
+                const char *what,
+                const char *where,
+                bool rw,
+                const char *description,
+                const char *post) {
+
+        _cleanup_blkid_free_probe_ blkid_probe b = NULL;
+        const char *fstype;
+        int r;
+
+        assert(id);
+        assert(what);
+        assert(where);
+        assert(description);
+
+        if (path_is_mount_point(where, true) <= 0 &&
+            dir_is_empty(where) <= 0) {
+                log_debug("%s already populated, ignoring.", where);
+                return 0;
+        }
+
+        /* Let's check the partition type here, so that we know
+         * whether to do LUKS magic. */
+
+        errno = 0;
+        b = blkid_new_probe_from_filename(what);
+        if (!b) {
+                if (errno == 0)
+                        return log_oom();
+                log_error("Failed to allocate prober: %m");
                 return -errno;
         }
 
-        return 0;
+        blkid_probe_enable_superblocks(b, 1);
+        blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
+
+        errno = 0;
+        r = blkid_do_safeprobe(b);
+        if (r == -2 || r == 1) /* no result or uncertain */
+                return 0;
+        else if (r != 0) {
+                if (errno == 0)
+                        errno = EIO;
+                log_error("Failed to probe %s: %m", what);
+                return -errno;
+        }
+
+        blkid_probe_lookup_value(b, "TYPE", &fstype, NULL);
+
+        return add_mount(
+                        id,
+                        what,
+                        where,
+                        fstype,
+                        rw,
+                        description,
+                        post);
 }
 
-static int enumerate_partitions(dev_t dev) {
-        struct udev *udev;
-        struct udev_enumerate *e = NULL;
-        struct udev_device *parent = NULL, *d = NULL;
+static int enumerate_partitions(dev_t devnum) {
+
+        _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
+        _cleanup_udev_device_unref_ struct udev_device *d = NULL;
+        _cleanup_blkid_free_probe_ blkid_probe b = NULL;
+        _cleanup_udev_unref_ struct udev *udev = NULL;
+        _cleanup_free_ char *home = NULL, *srv = NULL;
         struct udev_list_entry *first, *item;
-        unsigned home_nr = (unsigned) -1;
-        _cleanup_free_ char *home = NULL, *home_fstype = NULL;
-        int r;
+        struct udev_device *parent = NULL;
+        const char *node, *pttype, *devtype;
+        int home_nr = -1, srv_nr = -1;
+        bool home_rw = true, srv_rw = true;
+        blkid_partlist pl;
+        int r, k;
+        dev_t pn;
 
         udev = udev_new();
         if (!udev)
                 return log_oom();
 
-        e = udev_enumerate_new(udev);
-        if (!e) {
-                r = log_oom();
-                goto finish;
+        d = udev_device_new_from_devnum(udev, 'b', devnum);
+        if (!d)
+                return log_oom();
+
+        parent = udev_device_get_parent(d);
+        if (!parent) {
+                log_debug("Not a partitioned device, ignoring.");
+                return 0;
         }
 
-        d = udev_device_new_from_devnum(udev, 'b', dev);
-        if (!d) {
-                r = log_oom();
-                goto finish;
+        /* Does it have a devtype? */
+        devtype = udev_device_get_devtype(parent);
+        if (!devtype) {
+                log_debug("Parent doesn't have a device type, ignoring.");
+                return 0;
         }
 
-        parent = udev_device_get_parent(d);
-        if (!parent) {
-                r = log_oom();
-                goto finish;
+        /* Is this a disk or a partition? We only care for disks... */
+        if (!streq(devtype, "disk")) {
+                log_debug("Parent isn't a raw disk, ignoring.");
+                return 0;
         }
 
-        r = udev_enumerate_add_match_parent(e, parent);
-        if (r < 0) {
-                r = log_oom();
-                goto finish;
+        /* Does it have a device node? */
+        node = udev_device_get_devnode(parent);
+        if (!node) {
+                log_debug("Parent device does not have device node, ignoring.");
+                return 0;
         }
 
-        r = udev_enumerate_add_match_subsystem(e, "block");
-        if (r < 0) {
-                r = log_oom();
-                goto finish;
+        log_debug("Root device %s.", node);
+
+        pn = udev_device_get_devnum(parent);
+        if (major(pn) == 0)
+                return 0;
+
+        errno = 0;
+        b = blkid_new_probe_from_filename(node);
+        if (!b) {
+                if (errno == 0)
+                        return log_oom();
+
+                log_error("Failed allocate prober: %m");
+                return -errno;
         }
 
+        blkid_probe_enable_superblocks(b, 1);
+        blkid_probe_set_superblocks_flags(b, BLKID_SUBLKS_TYPE);
+        blkid_probe_enable_partitions(b, 1);
+        blkid_probe_set_partitions_flags(b, BLKID_PARTS_ENTRY_DETAILS);
+
+        errno = 0;
+        r = blkid_do_safeprobe(b);
+        if (r == -2 || r == 1) /* no result or uncertain */
+                return 0;
+        else if (r != 0) {
+                if (errno == 0)
+                        errno = EIO;
+                log_error("Failed to probe %s: %m", node);
+                return -errno;
+        }
+
+        errno = 0;
+        r = blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL);
+        if (r != 0) {
+                if (errno == 0)
+                        errno = EIO;
+                log_error("Failed to determine partition table type of %s: %m", node);
+                return -errno;
+        }
+
+        /* We only do this all for GPT... */
+        if (!streq_ptr(pttype, "gpt")) {
+                log_debug("Not a GPT partition table, ignoring.");
+                return 0;
+        }
+
+        errno = 0;
+        pl = blkid_probe_get_partitions(b);
+        if (!pl) {
+                if (errno == 0)
+                        return log_oom();
+
+                log_error("Failed to list partitions of %s: %m", node);
+                return -errno;
+        }
+
+        e = udev_enumerate_new(udev);
+        if (!e)
+                return log_oom();
+
+        r = udev_enumerate_add_match_parent(e, parent);
+        if (r < 0)
+                return log_oom();
+
+        r = udev_enumerate_add_match_subsystem(e, "block");
+        if (r < 0)
+                return log_oom();
+
         r = udev_enumerate_scan_devices(e);
         if (r < 0) {
-                log_error("Failed to enumerate partitions: %s", strerror(-r));
-                goto finish;
+                log_error("Failed to enumerate partitions on %s: %s", node, strerror(-r));
+                return r;
         }
 
         first = udev_enumerate_get_list_entry(e);
         udev_list_entry_foreach(item, first) {
-                _cleanup_free_ char *fstype = NULL;
-                const char *node = NULL;
-                struct udev_device *q;
+                _cleanup_udev_device_unref_ struct udev_device *q;
+                const char *stype, *subnode;
                 sd_id128_t type_id;
-                unsigned nr;
+                blkid_partition pp;
+                dev_t qn;
+                int nr;
+                unsigned long long flags;
 
                 q = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
-                if (!q) {
-                        r = log_oom();
-                        goto finish;
-                }
+                if (!q)
+                        continue;
 
-                if (udev_device_get_devnum(q) == udev_device_get_devnum(d))
-                        goto skip;
+                qn = udev_device_get_devnum(q);
+                if (major(qn) == 0)
+                        continue;
 
-                if (udev_device_get_devnum(q) == udev_device_get_devnum(parent))
-                        goto skip;
+                if (qn == devnum)
+                        continue;
 
-                node = udev_device_get_devnode(q);
-                if (!node) {
-                        r = log_oom();
-                        goto finish;
-                }
+                if (qn == pn)
+                        continue;
 
-                r = verify_gpt_partition(udev_device_get_devnum(q), &type_id, &nr, &fstype);
-                if (r < 0) {
-                        log_error("Failed to verify GPT partition: %s", strerror(-r));
-                        udev_device_unref(q);
-                        goto finish;
-                }
-                if (r == 0)
-                        goto skip;
-
-                if (sd_id128_equal(type_id, SD_ID128_MAKE(06,57,fd,6d,a4,ab,43,c4,84,e5,09,33,c8,4b,4f,4f)))
-                        add_swap(node, fstype);
-                else if (sd_id128_equal(type_id, SD_ID128_MAKE(93,3a,c7,e1,2e,b4,4f,13,b8,44,0e,14,e2,ae,f9,15))) {
-
-                        if (!home || nr < home_nr) {
-                                free(home);
-                                home = strdup(node);
-                                if (!home) {
-                                        r = log_oom();
-                                        goto finish;
-                                }
-
-                                home_nr = nr;
-
-                                free(home_fstype);
-                                home_fstype = fstype;
-                                fstype = NULL;
+                subnode = udev_device_get_devnode(q);
+                if (!subnode)
+                        continue;
+
+                pp = blkid_partlist_devno_to_partition(pl, qn);
+                if (!pp)
+                        continue;
+
+                flags = blkid_partition_get_flags(pp);
+
+                /* Ignore partitions that are not marked for automatic
+                 * mounting on discovery */
+                if (flags & GPT_FLAG_NO_AUTO)
+                        continue;
+
+                nr = blkid_partition_get_partno(pp);
+                if (nr < 0)
+                        continue;
+
+                stype = blkid_partition_get_type_string(pp);
+                if (!stype)
+                        continue;
+
+                if (sd_id128_from_string(stype, &type_id) < 0)
+                        continue;
+
+                if (sd_id128_equal(type_id, GPT_SWAP)) {
+
+                        if (flags & GPT_FLAG_READ_ONLY) {
+                                log_debug("%s marked as read-only swap partition, which is bogus, ignoring.", subnode);
+                                continue;
                         }
-                }
 
-        skip:
-                udev_device_unref(q);
-        }
+                        k = add_swap(subnode);
+                        if (k < 0)
+                                r = k;
 
-        if (home && home_fstype)
-                add_home(home, home_fstype);
+                } else if (sd_id128_equal(type_id, GPT_HOME)) {
 
-finish:
-        if (d)
-                udev_device_unref(d);
+                        /* We only care for the first /home partition */
+                        if (home && nr >= home_nr)
+                                continue;
 
-        if (e)
-                udev_enumerate_unref(e);
+                        home_nr = nr;
+                        home_rw = !(flags & GPT_FLAG_READ_ONLY),
 
-        if (udev)
-                udev_unref(udev);
+                        free(home);
+                        home = strdup(subnode);
+                        if (!home)
+                                return log_oom();
+
+                } else if (sd_id128_equal(type_id, GPT_SRV)) {
+
+                        /* We only care for the first /srv partition */
+                        if (srv && nr >= srv_nr)
+                                continue;
+
+                        srv_nr = nr;
+                        srv_rw = !(flags & GPT_FLAG_READ_ONLY),
+
+                        free(srv);
+                        srv = strdup(node);
+                        if (!srv)
+                                return log_oom();
+                }
+        }
+
+        if (home) {
+                k = probe_and_add_mount("home", home, "/home", home_rw, "Home Partition", SPECIAL_LOCAL_FS_TARGET);
+                if (k < 0)
+                        r = k;
+        }
+
+        if (srv) {
+                k = probe_and_add_mount("srv", srv, "/srv", srv_rw, "Server Data Partition", SPECIAL_LOCAL_FS_TARGET);
+                if (k < 0)
+                        r = k;
+        }
 
         return r;
 }
 
 static int get_btrfs_block_device(const char *path, dev_t *dev) {
-        struct btrfs_ioctl_fs_info_args fsi;
+        struct btrfs_ioctl_fs_info_args fsi = {};
         _cleanup_close_ int fd = -1;
         uint64_t id;
 
@@ -390,7 +613,6 @@ static int get_btrfs_block_device(const char *path, dev_t *dev) {
         if (fd < 0)
                 return -errno;
 
-        zero(fsi);
         if (ioctl(fd, BTRFS_IOC_FS_INFO, &fsi) < 0)
                 return -errno;
 
@@ -399,12 +621,11 @@ static int get_btrfs_block_device(const char *path, dev_t *dev) {
                 return 0;
 
         for (id = 1; id <= fsi.max_id; id++) {
-                struct btrfs_ioctl_dev_info_args di;
+                struct btrfs_ioctl_dev_info_args di = {
+                        .devid = id,
+                };
                 struct stat st;
 
-                zero(di);
-                di.devid = id;
-
                 if (ioctl(fd, BTRFS_IOC_DEV_INFO, &di) < 0) {
                         if (errno == ENODEV)
                                 continue;
@@ -435,7 +656,7 @@ static int get_block_device(const char *path, dev_t *dev) {
         assert(path);
         assert(dev);
 
-        if (lstat("/", &st))
+        if (lstat(path, &st))
                 return -errno;
 
         if (major(st.st_dev) != 0) {
@@ -443,19 +664,100 @@ static int get_block_device(const char *path, dev_t *dev) {
                 return 1;
         }
 
-        if (statfs("/", &sfs) < 0)
+        if (statfs(path, &sfs) < 0)
                 return -errno;
 
-        if (F_TYPE_CMP(sfs.f_type, BTRFS_SUPER_MAGIC))
+        if (F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC))
                 return get_btrfs_block_device(path, dev);
 
         return 0;
 }
 
-int main(int argc, char *argv[]) {
-        dev_t dev;
+static int parse_proc_cmdline_item(const char *key, const char *value) {
+        int r;
+
+        assert(key);
+
+        if (STR_IN_SET(key, "systemd.gpt_auto", "rd.systemd.gpt_auto") && value) {
+
+                r = parse_boolean(value);
+                if (r < 0)
+                        log_warning("Failed to parse gpt-auto switch %s. Ignoring.", value);
+
+                arg_enabled = r;
+
+        } else if (streq(key, "root") && value) {
+
+                /* Disable root disk logic if there's a root= value
+                 * specified (unless it happens to be "gpt-auto") */
+
+                arg_root_enabled = streq(value, "gpt-auto");
+
+        } else if (streq(key, "rw") && !value)
+                arg_root_rw = true;
+        else if (streq(key, "ro") && !value)
+                arg_root_rw = false;
+        else if (startswith(key, "systemd.gpt-auto.") || startswith(key, "rd.systemd.gpt-auto."))
+                log_warning("Unknown kernel switch %s. Ignoring.", key);
+
+        return 0;
+}
+
+static int add_root_mount(void) {
+
+#ifdef ENABLE_EFI
         int r;
 
+        if (!is_efi_boot()) {
+                log_debug("Not a EFI boot, not creating root mount.");
+                return 0;
+        }
+
+        r = efi_loader_get_device_part_uuid(NULL);
+        if (r == -ENOENT) {
+                log_debug("EFI loader partition unknown, exiting.");
+                return 0;
+        } else if (r < 0) {
+                log_error("Failed to read ESP partition UUID: %s", strerror(-r));
+                return r;
+        }
+
+        /* 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. */
+
+        return add_mount(
+                        "root",
+                        "/dev/gpt-auto-root",
+                        in_initrd() ? "/sysroot" : "/",
+                        NULL,
+                        arg_root_rw,
+                        "Root Partition",
+                        in_initrd() ? SPECIAL_INITRD_ROOT_FS_TARGET : SPECIAL_LOCAL_FS_TARGET);
+#else
+        return 0;
+#endif
+}
+
+static int add_mounts(void) {
+        dev_t devno;
+        int r;
+
+        r = get_block_device("/", &devno);
+        if (r < 0) {
+                log_error("Failed to determine block device of root file system: %s", strerror(-r));
+                return r;
+        } else if (r == 0) {
+                log_debug("Root file system not on a (single) block device.");
+                return 0;
+        }
+
+        return enumerate_partitions(devno);
+}
+
+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;
@@ -470,30 +772,29 @@ int main(int argc, char *argv[]) {
 
         umask(0022);
 
-        if (in_initrd())
+        if (detect_container(NULL) > 0) {
+                log_debug("In a container, exiting.");
                 return EXIT_SUCCESS;
+        }
 
-        r = get_block_device("/", &dev);
-        if (r < 0) {
-                log_error("Failed to determine block device of root file system: %s", strerror(-r));
+        if (parse_proc_cmdline(parse_proc_cmdline_item) < 0)
                 return EXIT_FAILURE;
-        }
-        if (r == 0) {
-                log_debug("Root file system not on a (single) block device.");
+
+        if (!arg_enabled) {
+                log_debug("Disabled, exiting.");
                 return EXIT_SUCCESS;
         }
 
-        log_debug("Root device %u:%u.", major(dev), minor(dev));
+        if (arg_root_enabled)
+                r = add_root_mount();
 
-        r = verify_gpt_partition(dev, NULL, NULL, NULL);
-        if (r < 0) {
-                log_error("Failed to verify GPT partition: %s", strerror(-r));
-                return EXIT_FAILURE;
-        }
-        if (r == 0)
-                return EXIT_SUCCESS;
+        if (!in_initrd()) {
+                int k;
 
-        r = enumerate_partitions(dev);
+                k = add_mounts();
+                if (k < 0)
+                        r = k;
+        }
 
         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }