3 files changed, 8 insertions, 3 deletions

diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog
index 52f868a9662b..788e3bd2528b 100644
--- a/fs/ntfs/ChangeLog
+++ b/fs/ntfs/ChangeLog
@@ -111,6 +111,8 @@ ToDo/Notes:
           refusing the mount.  Thanks to Bernd Casimir for pointing this
           problem out.
         - Update attribute definition handling.
+        - Add NTFS_MAX_CLUSTER_SIZE and NTFS_MAX_PAGES_PER_CLUSTER constants.
+        - Use NTFS_MAX_CLUSTER_SIZE in super.c instead of hard coding 0x10000.
 
 2.1.22 - Many bug and race fixes and error handling improvements.
 
diff --git a/fs/ntfs/ntfs.h b/fs/ntfs/ntfs.h
index e85f6e928b1e..446b5014115c 100644
--- a/fs/ntfs/ntfs.h
+++ b/fs/ntfs/ntfs.h
@@ -31,6 +31,7 @@
 #include <linux/fs.h>
 #include <linux/nls.h>
 #include <linux/smp.h>
+#include <linux/pagemap.h>
 
 #include "types.h"
 #include "volume.h"
@@ -42,6 +43,8 @@ typedef enum {
         NTFS_SB_MAGIC           = 0x5346544e,   /* 'NTFS' */
         NTFS_MAX_NAME_LEN       = 255,
         NTFS_MAX_ATTR_NAME_LEN  = 255,
+        NTFS_MAX_CLUSTER_SIZE   = 64 * 1024,    /* 64kiB */
+        NTFS_MAX_PAGES_PER_CLUSTER = NTFS_MAX_CLUSTER_SIZE / PAGE_CACHE_SIZE,
 } NTFS_CONSTANTS;
 
 /* Global variables. */
diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c
index 6f752ea765c3..8e50aa929f1c 100644
--- a/fs/ntfs/super.c
+++ b/fs/ntfs/super.c
@@ -561,9 +561,9 @@ static BOOL is_boot_sector_ntfs(const struct super_block *sb,
         default:
                 goto not_ntfs;
         }
-        /* Check the cluster size is not above 65536 bytes. */
+        /* Check the cluster size is not above the maximum (64kiB). */
         if ((u32)le16_to_cpu(b->bpb.bytes_per_sector) *
-                        b->bpb.sectors_per_cluster > 0x10000)
+                        b->bpb.sectors_per_cluster > NTFS_MAX_CLUSTER_SIZE)
                 goto not_ntfs;
         /* Check reserved/unused fields are really zero. */
         if (le16_to_cpu(b->bpb.reserved_sectors) ||
@@ -2585,7 +2585,7 @@ err_out_now:
  */
 kmem_cache_t *ntfs_name_cache;
 
-/* Slab caches for efficient allocation/deallocation of of inodes. */
+/* Slab caches for efficient allocation/deallocation of inodes. */
 kmem_cache_t *ntfs_inode_cache;
 kmem_cache_t *ntfs_big_inode_cache;