1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221
|
#ifndef HAVE_BLKID
/*
* Get label. Used by mount, umount and swapon.
*/
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include "xmalloc.h"
#include "linux_fs.h"
#include "get_label_uuid.h"
#include "../disk-utils/swapheader.h"
/*
* See whether this device has (the magic of) a RAID superblock at the end.
* If so, it probably is, or has been, part of a RAID array.
*
* For the moment this test is switched off - it causes problems.
* "Checking for a disk label should only be done on the full raid,
* not on the disks that form the raid array. This test causes a lot of
* problems when run on my striped promise fasttrak 100 array."
*/
static inline int
is_raid_partition(int fd) {
#if 0
struct mdp_super_block mdsb;
int n;
/* hardcode 4096 here in various places, because that's
what it's defined to be. Note that even if we used
the actual kernel headers, sizeof(mdp_super_t) is
slightly larger in the 2.2 kernel on 64-bit archs,
so using that wouldn't work. */
lseek(fd, -4096, SEEK_END); /* Ignore possible error
about return value overflow */
n = 4096;
if (sizeof(mdsb) < n)
n = sizeof(mdsb);
if (read(fd, &mdsb, n) != n)
return 1; /* error */
return (mdsbmagic(mdsb) == MD_SB_MAGIC);
#else
return 0;
#endif
}
int
reiserfs_magic_version(const char *magic) {
int rc = 0;
if (!strncmp(magic, REISERFS_SUPER_MAGIC_STRING,
strlen(REISERFS_SUPER_MAGIC_STRING)))
rc = 1;
if (!strncmp(magic, REISER2FS_SUPER_MAGIC_STRING,
strlen(REISER2FS_SUPER_MAGIC_STRING)))
rc = 2;
if (!strncmp(magic, REISER3FS_SUPER_MAGIC_STRING,
strlen(REISER3FS_SUPER_MAGIC_STRING)))
rc = 3;
return rc;
}
static void
store_uuid(char *udest, char *usrc) {
if (usrc)
memcpy(udest, usrc, 16);
else
memset(udest, 0, 16);
}
static void
store_label(char **ldest, char *lsrc, int len) {
*ldest = xmalloc(len+1);
memset(*ldest, 0, len+1);
memcpy(*ldest, lsrc, len);
}
static int
is_v1_swap_partition(int fd, char **label, char *uuid) {
int n = getpagesize();
char *buf = xmalloc(n);
struct swap_header_v1_2 *p = (struct swap_header_v1_2 *) buf;
if (lseek(fd, 0, SEEK_SET) == 0
&& read(fd, buf, n) == n
&& !strncmp(buf+n-10, "SWAPSPACE2", 10)
&& p->version == 1) {
store_uuid(uuid, p->uuid);
store_label(label, p->volume_name, 16);
return 1;
}
return 0;
}
/*
* Get both label and uuid.
* For now, only ext2, ext3, xfs, ocfs, ocfs2, reiserfs, swap are supported
*
* Return 0 on success.
*/
int
get_label_uuid(const char *device, char **label, char *uuid) {
int fd;
struct ext2_super_block e2sb;
struct xfs_super_block xfsb;
struct jfs_super_block jfssb;
struct ocfs_volume_header ovh; /* Oracle */
struct ocfs_volume_label olbl;
struct ocfs2_super_block osb;
struct reiserfs_super_block reiserfssb;
int blksize;
int rv = 0;
fd = open(device, O_RDONLY);
if (fd < 0)
return -1;
/* If there is a RAID partition, or an error, ignore this partition */
if (is_raid_partition(fd)) {
rv = 1;
goto done;
}
if (is_v1_swap_partition(fd, label, uuid))
goto done;
if (lseek(fd, 1024, SEEK_SET) == 1024
&& read(fd, (char *) &e2sb, sizeof(e2sb)) == sizeof(e2sb)
&& (ext2magic(e2sb) == EXT2_SUPER_MAGIC)) {
store_uuid(uuid, e2sb.s_uuid);
store_label(label, e2sb.s_volume_name,
sizeof(e2sb.s_volume_name));
goto done;
}
if (lseek(fd, 0, SEEK_SET) == 0
&& read(fd, (char *) &xfsb, sizeof(xfsb)) == sizeof(xfsb)
&& (strncmp(xfsb.s_magic, XFS_SUPER_MAGIC, 4) == 0)) {
store_uuid(uuid, xfsb.s_uuid);
store_label(label, xfsb.s_fname, sizeof(xfsb.s_fname));
goto done;
}
if (lseek(fd, 0, SEEK_SET) == 0
&& read(fd, (char *) &ovh, sizeof(ovh)) == sizeof(ovh)
&& (strncmp(ovh.signature, OCFS_MAGIC, sizeof(OCFS_MAGIC)) == 0)
&& (lseek(fd, 512, SEEK_SET) == 512)
&& read(fd, (char *) &olbl, sizeof(olbl)) == sizeof(olbl)) {
store_uuid(uuid, NULL);
store_label(label, olbl.label, ocfslabellen(olbl));
goto done;
}
if (lseek(fd, JFS_SUPER1_OFF, SEEK_SET) == JFS_SUPER1_OFF
&& read(fd, (char *) &jfssb, sizeof(jfssb)) == sizeof(jfssb)
&& (strncmp(jfssb.s_magic, JFS_MAGIC, 4) == 0)) {
/* The situation for jfs is rather messy. The structure of the
superblock changed a few times, but there seems to be no good way
to check what kind of sb we have.
Old (OS/2 compatible) jfs filesystems don't have UUIDs and have
an 11-byte label in s_fpack[].
Kernel 2.5.6 supports jfs v1; 2.5.8 supports v2; 2.5.18 has label/uuid.
Kernel 2.4.20 supports jfs v2 with label/uuid.
s_version will be 2 for new filesystems using an external log.
Other new filesystems will have version 1.
Label and UUID can be set by jfs_tune. */
/* Let us believe label/uuid on v2, and on v1 only when label agrees
with s_fpack in the first 11 bytes. */
if (assemble4le(jfssb.s_version) == 1 &&
strncmp(jfssb.s_label, jfssb.s_fpack, 11) != 0) {
store_uuid(uuid, NULL);
store_label(label, jfssb.s_fpack,
sizeof(jfssb.s_fpack));
} else {
store_uuid(uuid, jfssb.s_uuid);
store_label(label, jfssb.s_label,
sizeof(jfssb.s_label));
}
goto done;
}
if (lseek(fd, REISERFS_DISK_OFFSET_IN_BYTES, SEEK_SET)
== REISERFS_DISK_OFFSET_IN_BYTES
&& read(fd, (char *) &reiserfssb, sizeof(reiserfssb))
== sizeof(reiserfssb)
/* Only 3.6.x format supers have labels or uuids.
Label and UUID can be set by reiserfstune -l/-u. */
&& reiserfs_magic_version(reiserfssb.s_magic) > 1) {
store_uuid(uuid, reiserfssb.s_uuid);
store_label(label, reiserfssb.s_label,
sizeof(reiserfssb.s_label));
goto done;
}
for (blksize = OCFS2_MIN_BLOCKSIZE;
blksize <= OCFS2_MAX_BLOCKSIZE;
blksize <<= 1) {
int blkoff = blksize * OCFS2_SUPER_BLOCK_BLKNO;
if (lseek(fd, blkoff, SEEK_SET) == blkoff
&& read(fd, (char *) &osb, sizeof(osb)) == sizeof(osb)
&& strncmp(osb.signature,
OCFS2_SUPER_BLOCK_SIGNATURE,
sizeof(OCFS2_SUPER_BLOCK_SIGNATURE)) == 0) {
store_uuid(uuid, osb.s_uuid);
store_label(label, osb.s_label, sizeof(osb.s_label));
goto done;
}
}
rv = 1;
done:
close(fd);
return rv;
}
#endif
|