libblkid: fix FAT super block definition

Signed-off-by: Lawrence Rust <lawrence@softsystem.co.uk>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/shlibs/blkid/src/superblocks/vfat.c b/shlibs/blkid/src/superblocks/vfat.c
index 633e009e35cbf74cb8821e989744d83833740602..8343c65c8e9dd647343cddc7ee21a791d4abe0bc 100644 (file)
--- a/shlibs/blkid/src/superblocks/vfat.c
+++ b/shlibs/blkid/src/superblocks/vfat.c
@@ -45,8 +45,8 @@ struct vfat_super_block {
 /* 43*/        unsigned char   vs_serno[4];
 /* 47*/        unsigned char   vs_label[11];
 /* 52*/        unsigned char   vs_magic[8];
-/* 5a*/        unsigned char   vs_dummy2[164];
-/* fe*/        unsigned char   vs_pmagic[2];
+/* 5a*/        unsigned char   vs_dummy2[0x1fe - 0x5a];
+/*1fe*/        unsigned char   vs_pmagic[2];
 };
 
 /* Yucky misaligned values */
@@ -71,8 +71,8 @@ struct msdos_super_block {
 /* 27*/        unsigned char   ms_serno[4];
 /* 2b*/        unsigned char   ms_label[11];
 /* 36*/        unsigned char   ms_magic[8];
-/* 3e*/        unsigned char   ms_dummy2[192];
-/* fe*/        unsigned char   ms_pmagic[2];
+/* 3e*/        unsigned char   ms_dummy2[0x1fe - 0x3e];
+/*1fe*/        unsigned char   ms_pmagic[2];
 };
 
 struct vfat_dir_entry {
@@ -140,20 +140,15 @@ static unsigned char *search_fat_label(struct vfat_dir_entry *dir, int count)
 static int probe_fat_nomagic(blkid_probe pr, const struct blkid_idmag *mag)
 {
        struct msdos_super_block *ms;
-       unsigned char *buf;
 
-       buf = blkid_probe_get_sector(pr, 0);
-       if (!buf)
+       ms = blkid_probe_get_sb(pr, mag, struct msdos_super_block);
+       if (!ms)
                return -1;
 
        /* Old floppies have a valid MBR signature */
-       if (buf[510] != 0x55 || buf[511] != 0xAA)
+       if (ms->ms_pmagic[0] != 0x55 || ms->ms_pmagic[1] != 0xAA)
                return 1;
 
-       ms = blkid_probe_get_sb(pr, mag, struct msdos_super_block);
-       if (!ms)
-               return -1;
-
        /* heads check */
        if (ms->ms_heads == 0)
                return 1;