fs: initial qnx6fs addition

Adds support for qnx6fs readonly support to the linux kernel.

* Mount option
  The option mmi_fs can be used to mount Harman Becker/Audi MMI 3G
  HDD qnx6fs filesystems.

* Documentation
  A high level filesystem stucture description can be found in the
  Documentation/filesystems directory. (qnx6.txt)

* Additional features
  - Active (stable) superblock selection
  - Superblock checksum check (enforced)
  - Supports mount of qnx6 filesystems with to host different endianess
  - Automatic endianess detection
  - Longfilename support (with non-enfocing crc check)
  - All blocksizes (512, 1024, 2048 and 4096 supported)

Signed-off-by: Kai Bankett <chaosman@ontika.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 135 insertions, 0 deletions

diff --git a/include/linux/magic.h b/include/linux/magic.h
index 2d4beab0d5b7..b7ed4759dbb2 100644
--- a/include/linux/magic.h
+++ b/include/linux/magic.h
@@ -42,6 +42,7 @@
 #define OPENPROM_SUPER_MAGIC    0x9fa1
 #define PROC_SUPER_MAGIC        0x9fa0
 #define QNX4_SUPER_MAGIC        0x002f          /* qnx4 fs detection */
+#define QNX6_SUPER_MAGIC        0x68191122      /* qnx6 fs detection */
 
 #define REISERFS_SUPER_MAGIC    0x52654973      /* used by gcc */
                                         /* used by file system utilities that
diff --git a/include/linux/qnx6_fs.h b/include/linux/qnx6_fs.h
new file mode 100644
index 000000000000..26049eab9010
--- /dev/null
+++ b/include/linux/qnx6_fs.h
@@ -0,0 +1,134 @@
+/*
+ *  Name                 : qnx6_fs.h
+ *  Author               : Kai Bankett
+ *  Function             : qnx6 global filesystem definitions
+ *  History              : 17-01-2012 created
+ */
+#ifndef _LINUX_QNX6_FS_H
+#define _LINUX_QNX6_FS_H
+
+#include <linux/types.h>
+#include <linux/magic.h>
+
+#define QNX6_ROOT_INO 1
+
+/* for di_status */
+#define QNX6_FILE_DIRECTORY     0x01
+#define QNX6_FILE_DELETED       0x02
+#define QNX6_FILE_NORMAL        0x03
+
+#define QNX6_SUPERBLOCK_SIZE    0x200   /* superblock always is 512 bytes */
+#define QNX6_SUPERBLOCK_AREA    0x1000  /* area reserved for superblock */
+#define QNX6_BOOTBLOCK_SIZE     0x2000  /* heading bootblock area */
+#define QNX6_DIR_ENTRY_SIZE     0x20    /* dir entry size of 32 bytes */
+#define QNX6_INODE_SIZE         0x80    /* each inode is 128 bytes */
+#define QNX6_INODE_SIZE_BITS    7       /* inode entry size shift */
+
+#define QNX6_NO_DIRECT_POINTERS 16      /* 16 blockptrs in sbl/inode */
+#define QNX6_PTR_MAX_LEVELS     5       /* maximum indirect levels */
+
+/* for filenames */
+#define QNX6_SHORT_NAME_MAX     27
+#define QNX6_LONG_NAME_MAX      510
+
+/* list of mount options */
+#define QNX6_MOUNT_MMI_FS       0x010000 /* mount as Audi MMI 3G fs */
+
+/*
+ * This is the original qnx6 inode layout on disk.
+ * Each inode is 128 byte long.
+ */
+struct qnx6_inode_entry {
+        __fs64          di_size;
+        __fs32          di_uid;
+        __fs32          di_gid;
+        __fs32          di_ftime;
+        __fs32          di_mtime;
+        __fs32          di_atime;
+        __fs32          di_ctime;
+        __fs16          di_mode;
+        __fs16          di_ext_mode;
+        __fs32          di_block_ptr[QNX6_NO_DIRECT_POINTERS];
+        __u8            di_filelevels;
+        __u8            di_status;
+        __u8            di_unknown2[2];
+        __fs32          di_zero2[6];
+};
+
+/*
+ * Each directory entry is maximum 32 bytes long.
+ * If more characters or special characters required it is stored
+ * in the longfilenames structure.
+ */
+struct qnx6_dir_entry {
+        __fs32          de_inode;
+        __u8            de_size;
+        char            de_fname[QNX6_SHORT_NAME_MAX];
+};
+
+/*
+ * Longfilename direntries have a different structure
+ */
+struct qnx6_long_dir_entry {
+        __fs32          de_inode;
+        __u8            de_size;
+        __u8            de_unknown[3];
+        __fs32          de_long_inode;
+        __fs32          de_checksum;
+};
+
+struct qnx6_long_filename {
+        __fs16          lf_size;
+        __u8            lf_fname[QNX6_LONG_NAME_MAX];
+};
+
+struct qnx6_root_node {
+        __fs64          size;
+        __fs32          ptr[QNX6_NO_DIRECT_POINTERS];
+        __u8            levels;
+        __u8            mode;
+        __u8            spare[6];
+};
+
+struct qnx6_super_block {
+        __fs32          sb_magic;
+        __fs32          sb_checksum;
+        __fs64          sb_serial;
+        __fs32          sb_ctime;       /* time the fs was created */
+        __fs32          sb_atime;       /* last access time */
+        __fs32          sb_flags;
+        __fs16          sb_version1;    /* filesystem version information */
+        __fs16          sb_version2;    /* filesystem version information */
+        __u8            sb_volumeid[16];
+        __fs32          sb_blocksize;
+        __fs32          sb_num_inodes;
+        __fs32          sb_free_inodes;
+        __fs32          sb_num_blocks;
+        __fs32          sb_free_blocks;
+        __fs32          sb_allocgroup;
+        struct qnx6_root_node Inode;
+        struct qnx6_root_node Bitmap;
+        struct qnx6_root_node Longfile;
+        struct qnx6_root_node Unknown;
+};
+
+/* Audi MMI 3G superblock layout is different to plain qnx6 */
+struct qnx6_mmi_super_block {
+        __fs32          sb_magic;
+        __fs32          sb_checksum;
+        __fs64          sb_serial;
+        __u8            sb_spare0[12];
+        __u8            sb_id[12];
+        __fs32          sb_blocksize;
+        __fs32          sb_num_inodes;
+        __fs32          sb_free_inodes;
+        __fs32          sb_num_blocks;
+        __fs32          sb_free_blocks;
+        __u8            sb_spare1[4];
+        struct qnx6_root_node Inode;
+        struct qnx6_root_node Bitmap;
+        struct qnx6_root_node Longfile;
+        struct qnx6_root_node Unknown;
+};
+
+#endif