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authorLennart Poettering <lennart@poettering.net>2013-08-13 10:13:45 +0200
committerLennart Poettering <lennart@poettering.net>2013-08-13 10:13:45 +0200
commit1a14a53cfded6e78c6e8dfb73fdff0039971d642 (patch)
treed2dcc3df291667d0ccea70e582e85b366f38578e /src
parentbed2e820dba48591853547547a46ba4de04f86ad (diff)
gpt-auto-generator: add basic auto-discovery of GPT partitions
This adds a simple generator that is capable of automatically discovering certain GPT partitions by their type UUID and mount/enable them. This currently covers swap partitions and /home partitions, but is expected to grow more features soon. This currently doesn't handle LUKS encrypted /home. This enables all swap partitions of type 0657fd6da4ab43c484e50933c84b4f4f, if found. This mounts the first partition of type 933ac7e12eb44f13b8440e14e2aef915 as /home, if it is found.
Diffstat (limited to 'src')
-rw-r--r--src/gpt-auto-generator/gpt-auto-generator.c492
1 files changed, 492 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 0000000000..0c7635bfe4
--- /dev/null
+++ b/src/gpt-auto-generator/gpt-auto-generator.c
@@ -0,0 +1,492 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2013 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <linux/btrfs.h>
+#include <sys/ioctl.h>
+#include <sys/statfs.h>
+#include <blkid.h>
+
+#include "path-util.h"
+#include "util.h"
+#include "mkdir.h"
+#include "missing.h"
+#include "sd-id128.h"
+#include "libudev.h"
+#include "special.h"
+#include "unit-name.h"
+
+/* TODO:
+ *
+ * - Properly handle cryptsetup partitions
+ * - Define new partition type for encrypted swap
+ *
+ */
+
+static const char *arg_dest = "/tmp";
+
+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) {
+ _cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL;
+ _cleanup_fclose_ FILE *f = NULL;
+
+ log_debug("Adding swap: %s %s", path, fstype);
+
+ name = unit_name_from_path(path, ".swap");
+ if (!name)
+ return log_oom();
+
+ unit = strjoin(arg_dest, "/", name, NULL);
+ if (!unit)
+ return log_oom();
+
+ f = fopen(unit, "wxe");
+ if (!f) {
+ log_error("Failed to create unit file %s: %m", unit);
+ return -errno;
+ }
+
+ 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"
+ "[Mount]\n"
+ "What=%s\n",
+ path);
+
+ fflush(f);
+ if (ferror(f)) {
+ log_error("Failed to write unit file %s: %m", unit);
+ return -errno;
+ }
+
+ 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;
+ }
+
+ return 0;
+}
+
+static int add_home(const char *path, const char *fstype) {
+ _cleanup_free_ char *unit = NULL, *lnk = NULL;
+ _cleanup_fclose_ FILE *f = NULL;
+
+ log_debug("Adding home: %s %s", path, fstype);
+
+ unit = strappend(arg_dest, "/home.mount");
+ if (!unit)
+ return log_oom();
+
+ f = fopen(unit, "wxe");
+ if (!f) {
+ log_error("Failed to create unit file %s: %m", unit);
+ return -errno;
+ }
+
+ 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"
+ "[Mount]\n"
+ "What=%s\n"
+ "Where=/home\n"
+ "Type=%s\n"
+ "FsckPassNo=2\n",
+ path, fstype);
+
+ fflush(f);
+ if (ferror(f)) {
+ log_error("Failed to write unit file %s: %m", unit);
+ return -errno;
+ }
+
+ lnk = strjoin(arg_dest, "/" SPECIAL_LOCAL_FS_TARGET ".requires/home.mount", 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;
+ }
+
+ return 0;
+}
+
+static int enumerate_partitions(dev_t dev) {
+ struct udev *udev;
+ struct udev_enumerate *e = NULL;
+ struct udev_device *parent = NULL, *d = NULL;
+ struct udev_list_entry *first, *item;
+ unsigned home_nr = (unsigned) -1;
+ _cleanup_free_ char *home = NULL, *home_fstype = NULL;
+ int r;
+
+ 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', dev);
+ if (!d) {
+ r = log_oom();
+ goto finish;
+ }
+
+ parent = udev_device_get_parent(d);
+ if (!parent) {
+ r = log_oom();
+ goto finish;
+ }
+
+ r = udev_enumerate_add_match_parent(e, parent);
+ if (r < 0) {
+ r = log_oom();
+ goto finish;
+ }
+
+ r = udev_enumerate_add_match_subsystem(e, "block");
+ if (r < 0) {
+ r = log_oom();
+ goto finish;
+ }
+
+ r = udev_enumerate_scan_devices(e);
+ if (r < 0) {
+ log_error("Failed to enumerate partitions: %s", strerror(-r));
+ goto finish;
+ }
+
+ 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;
+ sd_id128_t type_id;
+ unsigned nr;
+
+ q = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
+ if (!q) {
+ r = log_oom();
+ goto finish;
+ }
+
+ if (udev_device_get_devnum(q) == udev_device_get_devnum(d))
+ goto skip;
+
+ if (udev_device_get_devnum(q) == udev_device_get_devnum(parent))
+ goto skip;
+
+ node = udev_device_get_devnode(q);
+ if (!node) {
+ r = log_oom();
+ goto finish;
+ }
+
+ 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;
+ }
+ }
+
+ skip:
+ udev_device_unref(q);
+ }
+
+ if (home && home_fstype)
+ add_home(home, home_fstype);
+
+finish:
+ if (d)
+ udev_device_unref(d);
+
+ if (e)
+ udev_enumerate_unref(e);
+
+ if (udev)
+ udev_unref(udev);
+
+ 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;
+
+ zero(fsi);
+ 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;
+ struct stat st;
+
+ zero(di);
+ di.devid = id;
+
+ 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;
+
+ *dev = st.st_rdev;
+ return 1;
+ }
+
+ return -ENODEV;
+}
+
+static int get_block_device(const char *path, dev_t *dev) {
+ struct stat st;
+ struct statfs sfs;
+
+ assert(path);
+ assert(dev);
+
+ if (lstat("/", &st))
+ return -errno;
+
+ if (major(st.st_dev) != 0) {
+ *dev = st.st_dev;
+ return 1;
+ }
+
+ if (statfs("/", &sfs) < 0)
+ return -errno;
+
+ if (F_TYPE_CMP(sfs.f_type, BTRFS_SUPER_MAGIC))
+ return get_btrfs_block_device(path, dev);
+
+ return 0;
+}
+
+int main(int argc, char *argv[]) {
+ dev_t dev;
+ int r;
+
+ if (argc > 1 && argc != 4) {
+ log_error("This program takes three or no arguments.");
+ return EXIT_FAILURE;
+ }
+
+ if (argc > 1)
+ arg_dest = argv[3];
+
+ log_set_target(LOG_TARGET_SAFE);
+ log_parse_environment();
+ log_open();
+
+ umask(0022);
+
+ if (in_initrd())
+ 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));
+ return EXIT_FAILURE;
+ }
+ if (r == 0) {
+ log_debug("Root file system not on a (single) block device.");
+ return EXIT_SUCCESS;
+ }
+
+ log_debug("Root device %u:%u.", major(dev), minor(dev));
+
+ 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;
+
+ r = enumerate_partitions(dev);
+
+ return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}