diff options
Diffstat (limited to 'mount/get_label_uuid.c')
| -rw-r--r-- | mount/get_label_uuid.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/mount/get_label_uuid.c b/mount/get_label_uuid.c new file mode 100644 index 000000000..310de6dc8 --- /dev/null +++ b/mount/get_label_uuid.c @@ -0,0 +1,118 @@ +/* + * Get label. Used by both mount and umount. + */ +#include <stdio.h> +#include <fcntl.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> + +#include "linux_fs.h" +#include "get_label_uuid.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 +} + +/* for now, only ext2, ext3, xfs, ocfs are supported */ +int +get_label_uuid(const char *device, char **label, char *uuid) { + int fd; + int rv = 1; + size_t namesize; + 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; + + fd = open(device, O_RDONLY); + if (fd < 0) + return rv; + + /* If there is a RAID partition, or an error, ignore this partition */ + if (is_raid_partition(fd)) { + close(fd); + return rv; + } + + if (lseek(fd, 1024, SEEK_SET) == 1024 + && read(fd, (char *) &e2sb, sizeof(e2sb)) == sizeof(e2sb) + && (ext2magic(e2sb) == EXT2_SUPER_MAGIC)) { + memcpy(uuid, e2sb.s_uuid, sizeof(e2sb.s_uuid)); + namesize = sizeof(e2sb.s_volume_name); + if ((*label = calloc(namesize + 1, 1)) != NULL) + memcpy(*label, e2sb.s_volume_name, namesize); + rv = 0; + } + else if (lseek(fd, 0, SEEK_SET) == 0 + && read(fd, (char *) &xfsb, sizeof(xfsb)) == sizeof(xfsb) + && (strncmp(xfsb.s_magic, XFS_SUPER_MAGIC, 4) == 0)) { + memcpy(uuid, xfsb.s_uuid, sizeof(xfsb.s_uuid)); + namesize = sizeof(xfsb.s_fname); + if ((*label = calloc(namesize + 1, 1)) != NULL) + memcpy(*label, xfsb.s_fname, namesize); + rv = 0; + } + else 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)) { + uuid[0] = '\0'; + namesize = ocfslabellen(olbl); + if ((*label = calloc(namesize + 1, 1)) != NULL) + memcpy(*label, olbl.label, namesize); + rv = 0; + } + else 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)) { + if (assemble4le(jfssb.s_version) == 1) { + /* old (OS/2 compatible) jfs filesystems don't + have UUIDs and only have a very small label. */ + memset(uuid, 0, 16); + namesize = sizeof(jfssb.s_fpack); + if ((*label = calloc(namesize + 1, 1)) != NULL) + memcpy(*label, jfssb.s_fpack, namesize); + } else { + memcpy(uuid, jfssb.s_uuid, sizeof(jfssb.s_uuid)); + namesize = sizeof(jfssb.s_label); + if ((*label = calloc(namesize + 1, 1)) != NULL) + memcpy(*label, jfssb.s_label, namesize); + } + rv = 0; + } + + close(fd); + return rv; +} |