LXR busybox/util-linux/volume_id/linux

   1/*
   2 * volume_id - reads filesystem label and uuid
   3 *
   4 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
   5 *
   6 *      This library is free software; you can redistribute it and/or
   7 *      modify it under the terms of the GNU Lesser General Public
   8 *      License as published by the Free Software Foundation; either
   9 *      version 2.1 of the License, or (at your option) any later version.
  10 *
  11 *      This library is distributed in the hope that it will be useful,
  12 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14 *      Lesser General Public License for more details.
  15 *
  16 *      You should have received a copy of the GNU Lesser General Public
  17 *      License along with this library; if not, write to the Free Software
  18 *      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19 */
  20
  21//kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_LINUXSWAP) += linux_swap.o
  22
  23//config:
  24//config:config FEATURE_VOLUMEID_LINUXSWAP
  25//config:       bool "linux swap filesystem"
  26//config:       default y
  27//config:       depends on VOLUMEID
  28//config:       help
  29//config:         TODO
  30//config:
  31
  32#include "volume_id_internal.h"
  33
  34struct swap_header_v1_2 {
  35        uint8_t         bootbits[1024];
  36        uint32_t        version;
  37        uint32_t        last_page;
  38        uint32_t        nr_badpages;
  39        uint8_t         uuid[16];
  40        uint8_t         volume_name[16];
  41} PACKED;
  42
  43#define LARGEST_PAGESIZE                        0x4000
  44
  45int FAST_FUNC volume_id_probe_linux_swap(struct volume_id *id /*,uint64_t off*/)
  46{
  47#define off ((uint64_t)0)
  48        struct swap_header_v1_2 *sw;
  49        const uint8_t *buf;
  50        unsigned page;
  51
  52        dbg("probing at offset 0x%llx", (unsigned long long) off);
  53
  54        /* the swap signature is at the end of the PAGE_SIZE */
  55        for (page = 0x1000; page <= LARGEST_PAGESIZE; page <<= 1) {
  56                        buf = volume_id_get_buffer(id, off + page-10, 10);
  57                        if (buf == NULL)
  58                                return -1;
  59
  60                        if (memcmp(buf, "SWAP-SPACE", 10) == 0) {
  61//                              id->type_version[0] = '1';
  62//                              id->type_version[1] = '\0';
  63                                goto found;
  64                        }
  65
  66                        if (memcmp(buf, "SWAPSPACE2", 10) == 0
  67                         || memcmp(buf, "S1SUSPEND", 9) == 0
  68                         || memcmp(buf, "S2SUSPEND", 9) == 0
  69                         || memcmp(buf, "ULSUSPEND", 9) == 0
  70                        ) {
  71                                sw = volume_id_get_buffer(id, off, sizeof(struct swap_header_v1_2));
  72                                if (sw == NULL)
  73                                        return -1;
  74//                              id->type_version[0] = '2';
  75//                              id->type_version[1] = '\0';
  76//                              volume_id_set_label_raw(id, sw->volume_name, 16);
  77                                volume_id_set_label_string(id, sw->volume_name, 16);
  78                                volume_id_set_uuid(id, sw->uuid, UUID_DCE);
  79                                goto found;
  80                        }
  81        }
  82        return -1;
  83
  84found:
  85//      volume_id_set_usage(id, VOLUME_ID_OTHER);
  86        IF_FEATURE_BLKID_TYPE(id->type = "swap";)
  87
  88        return 0;
  89}
  90