From: Karel Zak <kzak@redhat.com>
Date: Thu, 13 Nov 2008 16:32:14 +0000 (+0100)
Subject: volume_id: fat - move check for msdos signature (0x55 0xaa)
X-Git-Tag: 174~1321
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=3e39ff63658ed76398d0ee98f361221744fe591f;ds=sidebyside

volume_id: fat - move check for msdos signature (0x55 0xaa)

Make the msdos signature (0x55 0xaa) at 510 and 511 optional when
the standard FAT magic string is present.
---

diff --git a/extras/volume_id/lib/fat.c b/extras/volume_id/lib/fat.c
index 95735c2d2..e30318cf0 100644
--- a/extras/volume_id/lib/fat.c
+++ b/extras/volume_id/lib/fat.c
@@ -281,10 +281,6 @@ int volume_id_probe_vfat(struct volume_id *id, uint64_t off, uint64_t size)
 	if (buf == NULL)
 		return -1;
 
-	/* check signature */
-	if (buf[510] != 0x55 || buf[511] != 0xaa)
-		return -1;
-
 	vs = (struct vfat_super_block *) buf;
 	if (memcmp(vs->sysid, "NTFS", 4) == 0)
 		return -1;
@@ -305,6 +301,10 @@ int volume_id_probe_vfat(struct volume_id *id, uint64_t off, uint64_t size)
 	if (memcmp(vs->type.fat.magic, "FAT12   ", 8) == 0)
 		goto magic;
 
+	/* check signature */
+	if (buf[510] != 0x55 || buf[511] != 0xaa)
+		return -1;
+
 	/* some old floppies don't have a magic, expect the boot jump address to match */
 	if ((vs->boot_jump[0] != 0xeb || vs->boot_jump[2] != 0x90) &&
 	     vs->boot_jump[0] != 0xe9)