From: Kay Sievers <kay.sievers@suse.de>
Date: Mon, 21 Nov 2005 17:28:56 +0000 (+0100)
Subject: libvolume_id: fix weird fat volume recognition
X-Git-Tag: 174~2451
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=cfd0fc66054cb7eab4989d214e4f8552dc2bf0b8

libvolume_id: fix weird fat volume recognition

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
---

diff --git a/extras/volume_id/libvolume_id/fat.c b/extras/volume_id/libvolume_id/fat.c
index 26d0fe74a..cea5b8cff 100644
--- a/extras/volume_id/libvolume_id/fat.c
+++ b/extras/volume_id/libvolume_id/fat.c
@@ -161,48 +161,45 @@ int volume_id_probe_vfat(struct volume_id *id, uint64_t off)
 		return -1;
 
 	if (memcmp(vs->type.fat32.magic, "MSWIN", 5) == 0)
-		goto valid;
+		goto magic;
 
 	if (memcmp(vs->type.fat32.magic, "FAT32   ", 8) == 0)
-		goto valid;
+		goto magic;
 
 	if (memcmp(vs->type.fat.magic, "FAT16   ", 8) == 0)
-		goto valid;
+		goto magic;
 
 	if (memcmp(vs->type.fat.magic, "MSDOS", 5) == 0)
-		goto valid;
+		goto magic;
 
 	if (memcmp(vs->type.fat.magic, "FAT12   ", 8) == 0)
-		goto valid;
+		goto magic;
 
-	/*
-	 * There are old floppies out there without a magic, so we check
-	 * for well known values and guess if it's a fat volume
-	 */
+	/* some old floppies don't have a magic, so we expect the boot code to match */
 
 	/* boot jump address check */
 	if ((vs->boot_jump[0] != 0xeb || vs->boot_jump[2] != 0x90) &&
 	     vs->boot_jump[0] != 0xe9)
 		return -1;
 
-	/* heads check */
-	if (vs->heads == 0)
+magic:
+	/* reserverd sector count */
+	if (!vs->reserved)
 		return -1;
 
-	/* cluster size check*/	
-	if (vs->sectors_per_cluster == 0 ||
-	    (vs->sectors_per_cluster & (vs->sectors_per_cluster-1)))
+	/* fat count*/
+	if (!vs->fats)
 		return -1;
 
 	/* media check */
 	if (vs->media < 0xf8 && vs->media != 0xf0)
 		return -1;
 
-	/* fat count*/
-	if (vs->fats != 2)
+	/* cluster size check*/	
+	if (vs->sectors_per_cluster == 0 ||
+	    (vs->sectors_per_cluster & (vs->sectors_per_cluster-1)))
 		return -1;
 
-valid:
 	/* sector size check */
 	sector_size = le16_to_cpu(vs->sector_size);
 	if (sector_size != 0x200 && sector_size != 0x400 &&
diff --git a/extras/volume_id/libvolume_id/volume_id.h b/extras/volume_id/libvolume_id/volume_id.h
index 3e3acbde9..ad65fe543 100644
--- a/extras/volume_id/libvolume_id/volume_id.h
+++ b/extras/volume_id/libvolume_id/volume_id.h
@@ -14,7 +14,7 @@
 #include <stdint.h>
 #include <stddef.h>
 
-#define VOLUME_ID_VERSION		54
+#define VOLUME_ID_VERSION		55
 
 #define VOLUME_ID_LABEL_SIZE		64
 #define VOLUME_ID_UUID_SIZE		36