X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fgpt-auto-generator%2Fgpt-auto-generator.c;h=99dc50fe3c3aa3cfe6159a9f25d8755cd594f0b2;hb=a7ed8946137bf16499ef3099013ae22bdac2dfc7;hp=c4109f39b71eb2bde28d35ba34effe0f7d8b4567;hpb=1ebab691c7749779072741f71865bd0e055b7ecf;p=elogind.git

diff --git a/src/gpt-auto-generator/gpt-auto-generator.c b/src/gpt-auto-generator/gpt-auto-generator.c
index c4109f39b..99dc50fe3 100644
--- a/src/gpt-auto-generator/gpt-auto-generator.c
+++ b/src/gpt-auto-generator/gpt-auto-generator.c
@@ -21,15 +21,9 @@
 
 #include <unistd.h>
 #include <stdlib.h>
-#include <fcntl.h>
-#include <sys/ioctl.h>
 #include <sys/statfs.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"
@@ -43,90 +37,22 @@
 #include "generator.h"
 #include "gpt.h"
 #include "fileio.h"
+#include "efivars.h"
+#include "blkid-util.h"
+#include "btrfs-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;
 
-DEFINE_TRIVIAL_CLEANUP_FUNC(blkid_probe, blkid_free_probe);
-#define _cleanup_blkid_freep_probe_ _cleanup_(blkid_free_probep)
-
-static int verify_gpt_partition(const char *node, sd_id128_t *type, unsigned *nr, char **fstype) {
-        _cleanup_blkid_freep_probe_ blkid_probe b = NULL;
-        const char *v;
-        int r;
-
-        errno = 0;
-        b = blkid_new_probe_from_filename(node);
-        if (!b)
-                return errno != 0 ? -errno : -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 == 1) /* no result or uncertain */
-                return -EBADSLT;
-        else if (r != 0)
-                return errno ? -errno : -EIO;
-
-        errno = 0;
-        r = blkid_probe_lookup_value(b, "PART_ENTRY_SCHEME", &v, NULL);
-        if (r != 0)
-                /* return 0 if we're not on GPT */
-                return errno ? -errno : 0;
-
-        if (strcmp(v, "gpt") != 0)
-                return 0;
-
-        if (type) {
-                errno = 0;
-                r = blkid_probe_lookup_value(b, "PART_ENTRY_TYPE", &v, NULL);
-                if (r != 0)
-                        return errno ? -errno : -EIO;
-
-                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)
-                        return errno ? -errno : -EIO;
-
-                r = safe_atou(v, nr);
-                if (r < 0)
-                        return r;
-        }
-
-
-        if (fstype) {
-                errno = 0;
-                r = blkid_probe_lookup_value(b, "TYPE", &v, NULL);
-                if (r != 0)
-                        *fstype = NULL;
-                else {
-                        char *fst;
-
-                        fst = strdup(v);
-                        if (!fst)
-                                return -ENOMEM;
-
-                        *fstype = fst;
-                }
-        }
-
-        return 1;
-}
-
-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)
@@ -137,39 +63,34 @@ static int add_swap(const char *path, const char *fstype) {
                 return log_oom();
 
         f = fopen(unit, "wxe");
-        if (!f) {
-                log_error("Failed to create unit file %s: %m", unit);
-                return -errno;
-        }
+        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\n"
+                "Description=Swap Partition\n"
+                "Documentation=man:systemd-gpt-auto-generator(8)\n\n"
                 "[Swap]\n"
                 "What=%s\n",
                 path);
 
         fflush(f);
-        if (ferror(f)) {
-                log_error("Failed to write unit file %s: %m", unit);
-                return -errno;
-        }
+        if (ferror(f))
+                return log_error_errno(errno, "Failed to write unit file %s: %m", unit);
 
         lnk = strjoin(arg_dest, "/" SPECIAL_SWAP_TARGET ".wants/", name, NULL);
         if (!lnk)
                 return log_oom();
 
         mkdir_parents_label(lnk, 0755);
-        if (symlink(unit, lnk) < 0) {
-                log_error("Failed to create symlink %s: %m", lnk);
-                return -errno;
-        }
+        if (symlink(unit, lnk) < 0)
+                return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
 
         return 0;
 }
 
-static int add_cryptsetup(const char *id, const char *what, char **device) {
+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;
@@ -192,54 +113,47 @@ static int add_cryptsetup(const char *id, const char *what, char **device) {
                 return log_oom();
 
         p = strjoin(arg_dest, "/", n, NULL);
-        if (!n)
+        if (!p)
                 return log_oom();
 
         f = fopen(p, "wxe");
-        if (!f) {
-                log_error("Failed to create unit file %s: %m", p);
-                return -errno;
-        }
+        if (!f)
+                return log_error_errno(errno, "Failed to create unit file %s: %m", p);
 
         fprintf(f,
                 "# Automatically generated by systemd-gpt-auto-generator\n\n"
                 "[Unit]\n"
                 "Description=Cryptography Setup for %%I\n"
-                "Documentation=man:systemd-cryptsetup@.service(8)\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'\n"
+                "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '' '%s'\n"
                 "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n",
                 d, d,
-                id, what,
+                id, what, rw ? "" : "read-only",
                 id);
 
         fflush(f);
-        if (ferror(f)) {
-                log_error("Failed to write file %s: %m", p);
-                return -errno;
-        }
+        if (ferror(f))
+                return log_error_errno(errno, "Failed to write file %s: %m", p);
 
-        from = strappenda("../", n);
+        from = strjoina("../", 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;
-        }
+        if (symlink(from, to) < 0)
+                return log_error_errno(errno, "Failed to create symlink %s: %m", to);
 
         free(to);
         to = strjoin(arg_dest, "/cryptsetup.target.requires/", n, NULL);
@@ -247,10 +161,8 @@ static int add_cryptsetup(const char *id, const char *what, char **device) {
                 return log_oom();
 
         mkdir_parents_label(to, 0755);
-        if (symlink(from, to) < 0) {
-                log_error("Failed to create symlink %s: %m", to);
-                return -errno;
-        }
+        if (symlink(from, to) < 0)
+                return log_error_errno(errno, "Failed to create symlink %s: %m", to);
 
         free(to);
         to = strjoin(arg_dest, "/dev-mapper-", e, ".device.requires/", n, NULL);
@@ -258,10 +170,8 @@ static int add_cryptsetup(const char *id, const char *what, char **device) {
                 return log_oom();
 
         mkdir_parents_label(to, 0755);
-        if (symlink(from, to) < 0) {
-                log_error("Failed to create symlink %s: %m", to);
-                return -errno;
-        }
+        if (symlink(from, to) < 0)
+                return log_error_errno(errno, "Failed to create symlink %s: %m", to);
 
         free(p);
         p = strjoin(arg_dest, "/dev-mapper-", e, ".device.d/50-job-timeout-sec-0.conf", NULL);
@@ -273,10 +183,8 @@ static int add_cryptsetup(const char *id, const char *what, char **device) {
                         "# 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;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to write device drop-in: %m");
 
         ret = strappend("/dev/mapper/", id);
         if (!ret)
@@ -286,7 +194,15 @@ static int add_cryptsetup(const char *id, const char *what, char **device) {
         return 0;
 }
 
-static int add_mount(const char *id, const char *what, const char *where, const char *fstype, const char *description) {
+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;
@@ -294,19 +210,13 @@ static int add_mount(const char *id, const char *what, const char *where, const
         assert(id);
         assert(what);
         assert(where);
-        assert(fstype);
         assert(description);
 
-        if (dir_is_empty(where) <= 0) {
-                log_debug("%s already populated, ignoring.", where);
-                return 0;
-        }
-
-        log_debug("Adding %s: %s %s", where, what, fstype);
+        log_debug("Adding %s: %s %s", where, what, strna(fstype));
 
-        if (streq(fstype, "crypto_LUKS")) {
+        if (streq_ptr(fstype, "crypto_LUKS")) {
 
-                r = add_cryptsetup(id, what, &crypto_what);
+                r = add_cryptsetup(id, what, rw, &crypto_what);
                 if (r < 0)
                         return r;
 
@@ -323,17 +233,19 @@ static int add_mount(const char *id, const char *what, const char *where, const
                 return log_oom();
 
         f = fopen(p, "wxe");
-        if (!f) {
-                log_error("Failed to create unit file %s: %m", unit);
-                return -errno;
-        }
+        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",
+                "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;
@@ -345,50 +257,193 @@ static int add_mount(const char *id, const char *what, const char *where, const
                 "Where=%s\n",
                 what, where);
 
-        if (fstype) {
-                fprintf(f,
-                        "Type=%s\n",
-                        fstype);
-        }
+        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);
-                return -errno;
+        if (ferror(f))
+                return log_error_errno(errno, "Failed to write unit file %s: %m", p);
+
+        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)
+                        return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
         }
 
-        lnk = strjoin(arg_dest, "/" SPECIAL_LOCAL_FS_TARGET ".requires/", unit, NULL);
-        if (!lnk)
-                return log_oom();
+        return 0;
+}
 
-        mkdir_parents_label(lnk, 0755);
-        if (symlink(unit, lnk) < 0) {
-                log_error("Failed to create symlink %s: %m", lnk);
+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 = NULL;
+        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_errno(errno, "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)
+                return log_error_errno(errno ?: EIO, "Failed to probe %s: %m", what);
+
+        /* add_mount is OK with fstype being NULL. */
+        (void) blkid_probe_lookup_value(b, "TYPE", &fstype, NULL);
+
+        return add_mount(
+                        id,
+                        what,
+                        where,
+                        fstype,
+                        rw,
+                        description,
+                        post);
 }
 
-static int enumerate_partitions(struct udev *udev, dev_t dev) {
+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_free_ char *home = NULL, *home_fstype = NULL, *srv = NULL, *srv_fstype = NULL;
-        unsigned home_nr = (unsigned) -1, srv_nr = (unsigned )-1;
+        _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;
         struct udev_device *parent = NULL;
-        int r;
+        const char *name, *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;
 
-        e = udev_enumerate_new(udev);
-        if (!e)
+        udev = udev_new();
+        if (!udev)
                 return log_oom();
 
-        d = udev_device_new_from_devnum(udev, 'b', dev);
+        d = udev_device_new_from_devnum(udev, 'b', devnum);
         if (!d)
                 return log_oom();
 
+        name = udev_device_get_devnode(d);
+        if (!name)
+                name = udev_device_get_syspath(d);
+        if (!name) {
+                log_debug("Device %u:%u does not have a name, ignoring.",
+                          major(devnum), minor(devnum));
+                return 0;
+        }
+
         parent = udev_device_get_parent(d);
-        if (!parent)
+        if (!parent) {
+                log_debug("%s: not a partitioned device, ignoring.", name);
+                return 0;
+        }
+
+        /* Does it have a devtype? */
+        devtype = udev_device_get_devtype(parent);
+        if (!devtype) {
+                log_debug("%s: parent doesn't have a device type, ignoring.", name);
+                return 0;
+        }
+
+        /* Is this a disk or a partition? We only care for disks... */
+        if (!streq(devtype, "disk")) {
+                log_debug("%s: parent isn't a raw disk, ignoring.", name);
+                return 0;
+        }
+
+        /* Does it have a device node? */
+        node = udev_device_get_devnode(parent);
+        if (!node) {
+                log_debug("%s: parent device does not have device node, ignoring.", name);
+                return 0;
+        }
+
+        log_debug("%s: root device %s.", name, 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();
+
+                return log_error_errno(errno, "%s: failed to allocate prober: %m", node);
+        }
+
+        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)
+                return log_error_errno(errno ?: EIO, "%s: failed to probe: %m", node);
+
+        errno = 0;
+        r = blkid_probe_lookup_value(b, "PTTYPE", &pttype, NULL);
+        if (r != 0)
+                return log_error_errno(errno ?: EIO,
+                                       "%s: failed to determine partition table type: %m", node);
+
+        /* We only do this all for GPT... */
+        if (!streq_ptr(pttype, "gpt")) {
+                log_debug("%s: not a GPT partition table, ignoring.", node);
+                return 0;
+        }
+
+        errno = 0;
+        pl = blkid_probe_get_partitions(b);
+        if (!pl) {
+                if (errno == 0)
+                        return log_oom();
+
+                return log_error_errno(errno, "%s: failed to list partitions: %m", node);
+        }
+
+        e = udev_enumerate_new(udev);
+        if (!e)
                 return log_oom();
 
         r = udev_enumerate_add_match_parent(e, parent);
@@ -400,64 +455,84 @@ static int enumerate_partitions(struct udev *udev, dev_t dev) {
                 return log_oom();
 
         r = udev_enumerate_scan_devices(e);
-        if (r < 0) {
-                log_error("Failed to enumerate partitions on /dev/block/%u:%u: %s", major(dev), minor(dev), strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "%s: failed to enumerate partitions: %m", node);
 
         first = udev_enumerate_get_list_entry(e);
         udev_list_entry_foreach(item, first) {
                 _cleanup_udev_device_unref_ struct udev_device *q;
-                _cleanup_free_ char *fstype = NULL;
-                const char *node = NULL;
+                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)
-                        return log_oom();
+                        continue;
 
-                if (udev_device_get_devnum(q) == udev_device_get_devnum(d))
+                qn = udev_device_get_devnum(q);
+                if (major(qn) == 0)
                         continue;
 
-                if (udev_device_get_devnum(q) == udev_device_get_devnum(parent))
+                if (qn == devnum)
                         continue;
 
-                node = udev_device_get_devnode(q);
-                if (!node)
-                        return log_oom();
+                if (qn == pn)
+                        continue;
 
-                r = verify_gpt_partition(node, &type_id, &nr, &fstype);
-                if (r < 0) {
-                        /* skip child devices which are not detected properly */
-                        if (r == -EBADSLT)
-                                continue;
-                        log_error("Failed to verify GPT partition %s: %s", node, strerror(-r));
-                        return r;
-                }
-                if (r == 0)
+                subnode = udev_device_get_devnode(q);
+                if (!subnode)
                         continue;
 
-                if (sd_id128_equal(type_id, GPT_SWAP))
-                        add_swap(node, fstype);
+                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;
 
-                else if (sd_id128_equal(type_id, GPT_HOME)) {
+                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;
+                        }
+
+                        k = add_swap(subnode);
+                        if (k < 0)
+                                r = k;
+
+                } else if (sd_id128_equal(type_id, GPT_HOME)) {
 
                         /* We only care for the first /home partition */
                         if (home && nr >= home_nr)
                                 continue;
 
                         home_nr = nr;
+                        home_rw = !(flags & GPT_FLAG_READ_ONLY),
 
                         free(home);
-                        home = strdup(node);
+                        home = strdup(subnode);
                         if (!home)
                                 return log_oom();
 
-                        free(home_fstype);
-                        home_fstype = fstype;
-                        fstype = NULL;
-
                 } else if (sd_id128_equal(type_id, GPT_SRV)) {
 
                         /* We only care for the first /srv partition */
@@ -465,73 +540,28 @@ static int enumerate_partitions(struct udev *udev, dev_t dev) {
                                 continue;
 
                         srv_nr = nr;
+                        srv_rw = !(flags & GPT_FLAG_READ_ONLY),
 
                         free(srv);
-                        srv = strdup(node);
+                        srv = strdup(subnode);
                         if (!srv)
                                 return log_oom();
-
-                        free(srv_fstype);
-                        srv_fstype = fstype;
-                        fstype = NULL;
                 }
         }
 
-        if (home && home_fstype)
-                add_mount("home", home, "/home", home_fstype, "Home Partition");
-
-        if (srv && srv_fstype)
-                add_mount("srv", srv, "/srv", srv_fstype, "Server Data Partition");
-
-        return r;
-}
-
-static int get_btrfs_block_device(const char *path, dev_t *dev) {
-        struct btrfs_ioctl_fs_info_args fsi = {};
-        _cleanup_close_ int fd = -1;
-        uint64_t id;
-
-        assert(path);
-        assert(dev);
-
-        fd = open(path, O_DIRECTORY|O_CLOEXEC);
-        if (fd < 0)
-                return -errno;
-
-        if (ioctl(fd, BTRFS_IOC_FS_INFO, &fsi) < 0)
-                return -errno;
-
-        /* We won't do this for btrfs RAID */
-        if (fsi.num_devices != 1)
-                return 0;
-
-        for (id = 1; id <= fsi.max_id; id++) {
-                struct btrfs_ioctl_dev_info_args di = {
-                        .devid = id,
-                };
-                struct stat st;
-
-                if (ioctl(fd, BTRFS_IOC_DEV_INFO, &di) < 0) {
-                        if (errno == ENODEV)
-                                continue;
-
-                        return -errno;
-                }
-
-                if (stat((char*) di.path, &st) < 0)
-                        return -errno;
-
-                if (!S_ISBLK(st.st_mode))
-                        return -ENODEV;
-
-                if (major(st.st_rdev) == 0)
-                        return -ENODEV;
+        if (home) {
+                k = probe_and_add_mount("home", home, "/home", home_rw, "Home Partition", SPECIAL_LOCAL_FS_TARGET);
+                if (k < 0)
+                        r = k;
+        }
 
-                *dev = st.st_rdev;
-                return 1;
+        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 -ENODEV;
+        return r;
 }
 
 static int get_block_device(const char *path, dev_t *dev) {
@@ -553,36 +583,89 @@ static int get_block_device(const char *path, dev_t *dev) {
                 return -errno;
 
         if (F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC))
-                return get_btrfs_block_device(path, dev);
+                return btrfs_get_block_device(path, dev);
 
         return 0;
 }
 
-static int devno_to_devnode(struct udev *udev, dev_t devno, char **ret) {
-        _cleanup_udev_device_unref_ struct udev_device *d;
-        const char *t;
-        char *n;
+static int parse_proc_cmdline_item(const char *key, const char *value) {
+        int r;
 
-        d = udev_device_new_from_devnum(udev, 'b', devno);
-        if (!d)
-                return log_oom();
+        assert(key);
 
-        t = udev_device_get_devnode(d);
-        if (!t)
-                return -ENODEV;
+        if (STR_IN_SET(key, "systemd.gpt_auto", "rd.systemd.gpt_auto") && value) {
 
-        n = strdup(t);
-        if (!n)
-                return -ENOMEM;
+                r = parse_boolean(value);
+                if (r < 0)
+                        log_warning("Failed to parse gpt-auto switch \"%s\". Ignoring.", value);
+                else
+                        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;
 
-        *ret = n;
         return 0;
 }
 
-int main(int argc, char *argv[]) {
-        _cleanup_udev_unref_ struct udev *udev = NULL;
-        _cleanup_free_ char *node = NULL;
+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)
+                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. */
+
+        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)
+                return log_error_errno(r, "Failed to determine block device of root file system: %m");
+        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) {
@@ -599,52 +682,30 @@ int main(int argc, char *argv[]) {
 
         umask(0022);
 
-        if (in_initrd()) {
-                log_debug("In initrd, exiting.");
-                return EXIT_SUCCESS;
-        }
-
         if (detect_container(NULL) > 0) {
                 log_debug("In a container, exiting.");
                 return EXIT_SUCCESS;
         }
 
-        r = get_block_device("/", &devno);
-        if (r < 0) {
-                log_error("Failed to determine block device of root file system: %s", strerror(-r));
-                return EXIT_FAILURE;
-        } else if (r == 0) {
-                log_debug("Root file system not on a (single) block device.");
-                return EXIT_SUCCESS;
-        }
+        r = parse_proc_cmdline(parse_proc_cmdline_item);
+        if (r < 0)
+                log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
 
-        udev = udev_new();
-        if (!udev) {
-                log_oom();
-                return EXIT_FAILURE;
+        if (!arg_enabled) {
+                log_debug("Disabled, exiting.");
+                return EXIT_SUCCESS;
         }
 
-        r = devno_to_devnode(udev, devno, &node);
-        if (r < 0) {
-                log_error("Failed to determine block device node from major/minor: %s", strerror(-r));
-                return EXIT_FAILURE;
-        }
+        if (arg_root_enabled)
+                r = add_root_mount();
 
-        log_debug("Root device %s.", node);
+        if (!in_initrd()) {
+                int k;
 
-        r = verify_gpt_partition(node, NULL, NULL, NULL);
-        if (r < 0) {
-                log_error("Failed to verify GPT partition %s: %s", node, strerror(-r));
-                return EXIT_FAILURE;
-        }
-        if (r == 0) {
-                log_debug("Not a GPT disk, exiting.");
-                return EXIT_SUCCESS;
+                k = add_mounts();
+                if (k < 0)
+                        r = k;
         }
 
-        r = enumerate_partitions(udev, devno);
-        if (r < 0)
-                return EXIT_FAILURE;
-
-        return EXIT_SUCCESS;
+        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }