systemd/src/udev/udev-builtin-blkid.c

/*
 * probe disks for filesystems and partitions
 *
 * Copyright (C) 2011 Kay Sievers <kay@vrfy.org>
 * Copyright (C) 2011 Karel Zak <kzak@redhat.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <sys/stat.h>
#include <blkid/blkid.h>

#include "udev.h"

static void print_property(struct udev_device *dev, bool test, const char *name, const char *value)
{
        char s[265];

        s[0] = '\0';

        if (streq(name, "TYPE")) {
                udev_builtin_add_property(dev, test, "ID_FS_TYPE", value);

        } else if (streq(name, "USAGE")) {
                udev_builtin_add_property(dev, test, "ID_FS_USAGE", value);

        } else if (streq(name, "VERSION")) {
                udev_builtin_add_property(dev, test, "ID_FS_VERSION", value);

        } else if (streq(name, "UUID")) {
                blkid_safe_string(value, s, sizeof(s));
                udev_builtin_add_property(dev, test, "ID_FS_UUID", s);
                blkid_encode_string(value, s, sizeof(s));
                udev_builtin_add_property(dev, test, "ID_FS_UUID_ENC", s);

        } else if (streq(name, "UUID_SUB")) {
                blkid_safe_string(value, s, sizeof(s));
                udev_builtin_add_property(dev, test, "ID_FS_UUID_SUB", s);
                blkid_encode_string(value, s, sizeof(s));
                udev_builtin_add_property(dev, test, "ID_FS_UUID_SUB_ENC", s);

        } else if (streq(name, "LABEL")) {
                blkid_safe_string(value, s, sizeof(s));
                udev_builtin_add_property(dev, test, "ID_FS_LABEL", s);
                blkid_encode_string(value, s, sizeof(s));
                udev_builtin_add_property(dev, test, "ID_FS_LABEL_ENC", s);

        } else if (streq(name, "PTTYPE")) {
                udev_builtin_add_property(dev, test, "ID_PART_TABLE_TYPE", value);

        } else if (streq(name, "PART_ENTRY_NAME")) {
                blkid_encode_string(value, s, sizeof(s));
                udev_builtin_add_property(dev, test, "ID_PART_ENTRY_NAME", s);

        } else if (streq(name, "PART_ENTRY_TYPE")) {
                blkid_encode_string(value, s, sizeof(s));
                udev_builtin_add_property(dev, test, "ID_PART_ENTRY_TYPE", s);

        } else if (startswith(name, "PART_ENTRY_")) {
                util_strscpyl(s, sizeof(s), "ID_", name, NULL);
                udev_builtin_add_property(dev, test, s, value);
        }
}

static int probe_superblocks(blkid_probe pr)
{
        struct stat st;
        int rc;

        if (fstat(blkid_probe_get_fd(pr), &st))
                return -1;

        blkid_probe_enable_partitions(pr, 1);

        if (!S_ISCHR(st.st_mode) && blkid_probe_get_size(pr) <= 1024 * 1440 &&
            blkid_probe_is_wholedisk(pr)) {
                /*
                 * check if the small disk is partitioned, if yes then
                 * don't probe for filesystems.
                 */
                blkid_probe_enable_superblocks(pr, 0);

                rc = blkid_do_fullprobe(pr);
                if (rc < 0)
                        return rc;        /* -1 = error, 1 = nothing, 0 = succes */

                if (blkid_probe_lookup_value(pr, "PTTYPE", NULL, NULL) == 0)
                        return 0;        /* partition table detected */
        }

        blkid_probe_set_partitions_flags(pr, BLKID_PARTS_ENTRY_DETAILS);
        blkid_probe_enable_superblocks(pr, 1);

        return blkid_do_safeprobe(pr);
}

static int builtin_blkid(struct udev_device *dev, int argc, char *argv[], bool test)
{
        int64_t offset = 0;
        bool noraid = false;
        int fd = -1;
        blkid_probe pr;
        const char *data;
        const char *name;
        int nvals;
        int i;
        size_t len;
        int err = 0;

        static const struct option options[] = {
                { "offset", optional_argument, NULL, 'o' },
                { "noraid", no_argument, NULL, 'R' },
                {}
        };

        for (;;) {
                int option;

                option = getopt_long(argc, argv, "oR", options, NULL);
                if (option == -1)
                        break;

                switch (option) {
                case 'o':
                        offset = strtoull(optarg, NULL, 0);
                        break;
                case 'R':
                        noraid = true;
                        break;
                }
        }

        pr = blkid_new_probe();
        if (!pr)
                return EXIT_FAILURE;

        blkid_probe_set_superblocks_flags(pr,
                BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID |
                BLKID_SUBLKS_TYPE | BLKID_SUBLKS_SECTYPE |
                BLKID_SUBLKS_USAGE | BLKID_SUBLKS_VERSION);

        if (noraid)
                blkid_probe_filter_superblocks_usage(pr, BLKID_FLTR_NOTIN, BLKID_USAGE_RAID);

        fd = open(udev_device_get_devnode(dev), O_RDONLY|O_CLOEXEC);
        if (fd < 0) {
                fprintf(stderr, "error: %s: %m\n", udev_device_get_devnode(dev));
                goto out;
        }

        err = blkid_probe_set_device(pr, fd, offset, 0);
        if (err < 0)
                goto out;

        log_debug("probe %s %sraid offset=%llu\n",
                  udev_device_get_devnode(dev),
                  noraid ? "no" : "", (unsigned long long) offset);

        err = probe_superblocks(pr);
        if (err < 0)
                goto out;

        nvals = blkid_probe_numof_values(pr);
        for (i = 0; i < nvals; i++) {
                if (blkid_probe_get_value(pr, i, &name, &data, &len))
                        continue;
                len = strnlen((char *) data, len);
                print_property(dev, test, name, (char *) data);
        }

        blkid_free_probe(pr);
out:
        if (fd > 0)
                close(fd);
        if (err < 0)
                return EXIT_FAILURE;
        return EXIT_SUCCESS;
}

const struct udev_builtin udev_builtin_blkid = {
        .name = "blkid",
        .cmd = builtin_blkid,
        .help = "filesystem and partition probing",
        .run_once = true,
};