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#ifndef HAVE_LIBBLKID
/*
* 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
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