libblkid: (ntfs) enlarge cluster limit to 2MB

Windows 10 Creators edition has extended the ntfs cluster limit to
2MB. As a consequence blkid does not identify recent partitions with
clusters beyond 65K as ntfs ones.

Addresses: https://github.com/karelzak/util-linux/issues/641
Signed-off-by: Karel Zak <kzak@redhat.com>
Co-Author: Jean-Pierre André <jean-pierre.andre@wanadoo.fr>

diff --git a/libblkid/src/superblocks/ntfs.c b/libblkid/src/superblocks/ntfs.c
index 3a9d5cb017639211381a3968d61bd8f2af029c44..723d275030b79859733f91dffb10d2de2c0e2e7a 100644 (file)
--- a/libblkid/src/superblocks/ntfs.c
+++ b/libblkid/src/superblocks/ntfs.c
@@ -72,7 +72,8 @@ struct file_attribute {
 } __attribute__((__packed__));
 
 #define MFT_RECORD_VOLUME      3
-#define NTFS_MAX_CLUSTER_SIZE  (64 * 1024)
+/* Windows 10 Creators edition has extended the cluster size limit to 2MB */
+#define NTFS_MAX_CLUSTER_SIZE  (2 * 1024 * 1024)
 
 enum {
        MFT_RECORD_ATTR_VOLUME_NAME             = 0x60,
@@ -97,16 +98,19 @@ static int probe_ntfs(blkid_probe pr, const struct blkid_idmag *mag)
         * Check bios parameters block
         */
        sector_size = le16_to_cpu(ns->bpb.sector_size);
-       sectors_per_cluster = ns->bpb.sectors_per_cluster;
 
        if (sector_size < 256 || sector_size > 4096)
                return 1;
 
-       switch (sectors_per_cluster) {
+       switch (ns->bpb.sectors_per_cluster) {
        case 1: case 2: case 4: case 8: case 16: case 32: case 64: case 128:
+               sectors_per_cluster = ns->bpb.sectors_per_cluster;
                break;
        default:
-               return 1;
+               if ((ns->bpb.sectors_per_cluster < 240)
+                   || (ns->bpb.sectors_per_cluster > 249))
+                       return 1;
+               sectors_per_cluster = 1 << (256 - ns->bpb.sectors_per_cluster);
        }
 
        if ((uint16_t) le16_to_cpu(ns->bpb.sector_size) *