systemd/udev/udev-builtin-blkid.c

/*
 * probe disks for filesystems and partitions
 *
 * Copyright (C) 2011 Kay Sievers <kay.sievers@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 (!strcmp(name, "TYPE")) {
		udev_builtin_add_property(dev, test, "ID_FS_TYPE", value);

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

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

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

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

	} else if (!strncmp(name, "PART_ENTRY_", 11)) {
		util_strscpyl(s, sizeof(s), "ID_", name, NULL);
		udev_builtin_add_property(dev, test, name, 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)
{
	struct udev *udev = udev_device_get_udev(dev);
	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) {
		err = -ENOMEM;
		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;

	info(udev, "probe %s %sraid offset=%llu",
	     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,
};