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 2d4beab0d5b..b7ed4759dbb 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 00000000000..26049eab901
--- /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