exfat: add in-memory and on-disk structures and headers

This adds in-memory and on-disk structures and headers.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/exfat/exfat_raw.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef _EXFAT_RAW_H
+#define _EXFAT_RAW_H
+
+#include <linux/types.h>
+
+#define PBR_SIGNATURE		0xAA55
+
+#define EXFAT_MAX_FILE_LEN	255
+
+#define VOL_CLEAN		0x0000
+#define VOL_DIRTY		0x0002
+
+#define EXFAT_EOF_CLUSTER	0xFFFFFFFFu
+#define EXFAT_BAD_CLUSTER	0xFFFFFFF7u
+#define EXFAT_FREE_CLUSTER	0
+/* Cluster 0, 1 are reserved, the first cluster is 2 in the cluster heap. */
+#define EXFAT_RESERVED_CLUSTERS	2
+#define EXFAT_FIRST_CLUSTER	2
+#define EXFAT_DATA_CLUSTER_COUNT(sbi)	\
+	((sbi)->num_clusters - EXFAT_RESERVED_CLUSTERS)
+
+/* AllocationPossible and NoFatChain field in GeneralSecondaryFlags Field */
+#define ALLOC_FAT_CHAIN		0x01
+#define ALLOC_NO_FAT_CHAIN	0x03
+
+#define DENTRY_SIZE		32 /* directory entry size */
+#define DENTRY_SIZE_BITS	5
+/* exFAT allows 8388608(256MB) directory entries */
+#define MAX_EXFAT_DENTRIES	8388608
+
+/* dentry types */
+#define EXFAT_UNUSED		0x00	/* end of directory */
+#define EXFAT_DELETE		(~0x80)
+#define IS_EXFAT_DELETED(x)	((x) < 0x80) /* deleted file (0x01~0x7F) */
+#define EXFAT_INVAL		0x80	/* invalid value */
+#define EXFAT_BITMAP		0x81	/* allocation bitmap */
+#define EXFAT_UPCASE		0x82	/* upcase table */
+#define EXFAT_VOLUME		0x83	/* volume label */
+#define EXFAT_FILE		0x85	/* file or dir */
+#define EXFAT_GUID		0xA0
+#define EXFAT_PADDING		0xA1
+#define EXFAT_ACLTAB		0xA2
+#define EXFAT_STREAM		0xC0	/* stream entry */
+#define EXFAT_NAME		0xC1	/* file name entry */
+#define EXFAT_ACL		0xC2	/* stream entry */
+
+#define IS_EXFAT_CRITICAL_PRI(x)	(x < 0xA0)
+#define IS_EXFAT_BENIGN_PRI(x)		(x < 0xC0)
+#define IS_EXFAT_CRITICAL_SEC(x)	(x < 0xE0)
+
+/* checksum types */
+#define CS_DIR_ENTRY		0
+#define CS_PBR_SECTOR		1
+#define CS_DEFAULT		2
+
+/* file attributes */
+#define ATTR_READONLY		0x0001
+#define ATTR_HIDDEN		0x0002
+#define ATTR_SYSTEM		0x0004
+#define ATTR_VOLUME		0x0008
+#define ATTR_SUBDIR		0x0010
+#define ATTR_ARCHIVE		0x0020
+
+#define ATTR_RWMASK		(ATTR_HIDDEN | ATTR_SYSTEM | ATTR_VOLUME | \
+				 ATTR_SUBDIR | ATTR_ARCHIVE)
+
+#define PBR64_JUMP_BOOT_LEN		3
+#define PBR64_OEM_NAME_LEN		8
+#define PBR64_RESERVED_LEN		53
+
+#define EXFAT_FILE_NAME_LEN		15
+
+/* EXFAT BIOS parameter block (64 bytes) */
+struct bpb64 {
+	__u8 jmp_boot[PBR64_JUMP_BOOT_LEN];
+	__u8 oem_name[PBR64_OEM_NAME_LEN];
+	__u8 res_zero[PBR64_RESERVED_LEN];
+} __packed;
+
+/* EXFAT EXTEND BIOS parameter block (56 bytes) */
+struct bsx64 {
+	__le64 vol_offset;
+	__le64 vol_length;
+	__le32 fat_offset;
+	__le32 fat_length;
+	__le32 clu_offset;
+	__le32 clu_count;
+	__le32 root_cluster;
+	__le32 vol_serial;
+	__u8 fs_version[2];
+	__le16 vol_flags;
+	__u8 sect_size_bits;
+	__u8 sect_per_clus_bits;
+	__u8 num_fats;
+	__u8 phy_drv_no;
+	__u8 perc_in_use;
+	__u8 reserved2[7];
+} __packed;
+
+/* EXFAT PBR[BPB+BSX] (120 bytes) */
+struct pbr64 {
+	struct bpb64 bpb;
+	struct bsx64 bsx;
+} __packed;
+
+/* Common PBR[Partition Boot Record] (512 bytes) */
+struct pbr {
+	union {
+		__u8 raw[64];
+		struct bpb64 f64;
+	} bpb;
+	union {
+		__u8 raw[56];
+		struct bsx64 f64;
+	} bsx;
+	__u8 boot_code[390];
+	__le16 signature;
+} __packed;
+
+struct exfat_dentry {
+	__u8 type;
+	union {
+		struct {
+			__u8 num_ext;
+			__le16 checksum;
+			__le16 attr;
+			__le16 reserved1;
+			__le16 create_time;
+			__le16 create_date;
+			__le16 modify_time;
+			__le16 modify_date;
+			__le16 access_time;
+			__le16 access_date;
+			__u8 create_time_ms;
+			__u8 modify_time_ms;
+			__u8 create_tz;
+			__u8 modify_tz;
+			__u8 access_tz;
+			__u8 reserved2[7];
+		} __packed file; /* file directory entry */
+		struct {
+			__u8 flags;
+			__u8 reserved1;
+			__u8 name_len;
+			__le16 name_hash;
+			__le16 reserved2;
+			__le64 valid_size;
+			__le32 reserved3;
+			__le32 start_clu;
+			__le64 size;
+		} __packed stream; /* stream extension directory entry */
+		struct {
+			__u8 flags;
+			__le16 unicode_0_14[EXFAT_FILE_NAME_LEN];
+		} __packed name; /* file name directory entry */
+		struct {
+			__u8 flags;
+			__u8 reserved[18];
+			__le32 start_clu;
+			__le64 size;
+		} __packed bitmap; /* allocation bitmap directory entry */
+		struct {
+			__u8 reserved1[3];
+			__le32 checksum;
+			__u8 reserved2[12];
+			__le32 start_clu;
+			__le64 size;
+		} __packed upcase; /* up-case table directory entry */
+	} __packed dentry;
+} __packed;
+
+#define EXFAT_TZ_VALID		(1 << 7)
+
+/* Jan 1 GMT 00:00:00 1980 */
+#define EXFAT_MIN_TIMESTAMP_SECS    315532800LL
+/* Dec 31 GMT 23:59:59 2107 */
+#define EXFAT_MAX_TIMESTAMP_SECS    4354819199LL
+
+#endif /* !_EXFAT_RAW_H */