1 files changed, 313 insertions, 0 deletions
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
new file mode 100644
index 0000000000..4af7c91560
--- /dev/null
+++ b/fs/erofs/internal.h
@@ -0,0 +1,313 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef __EROFS_INTERNAL_H
+#define __EROFS_INTERNAL_H
+
+#define __packed __attribute__((__packed__))
+
+#include <linux/stat.h>
+#include <linux/bug.h>
+#include <linux/err.h>
+#include <linux/printk.h>
+#include <linux/log2.h>
+#include <inttypes.h>
+#include "erofs_fs.h"
+
+#define erofs_err(fmt, ...)	\
+	pr_err(fmt "\n", ##__VA_ARGS__)
+
+#define erofs_info(fmt, ...)	\
+	pr_info(fmt "\n", ##__VA_ARGS__)
+
+#define erofs_dbg(fmt, ...)	\
+	pr_debug(fmt "\n", ##__VA_ARGS__)
+
+#define DBG_BUGON(condition)	BUG_ON(condition)
+
+/* no obvious reason to support explicit PAGE_SIZE != 4096 for now */
+#if PAGE_SIZE != 4096
+#error incompatible PAGE_SIZE is already defined
+#endif
+
+#define PAGE_MASK		(~(PAGE_SIZE - 1))
+
+#define LOG_BLOCK_SIZE          (12)
+#define EROFS_BLKSIZ            (1U << LOG_BLOCK_SIZE)
+
+#define EROFS_ISLOTBITS		5
+#define EROFS_SLOTSIZE		(1U << EROFS_ISLOTBITS)
+
+typedef u64 erofs_off_t;
+typedef u64 erofs_nid_t;
+/* data type for filesystem-wide blocks number */
+typedef u32 erofs_blk_t;
+
+#define NULL_ADDR	((unsigned int)-1)
+#define NULL_ADDR_UL	((unsigned long)-1)
+
+#define erofs_blknr(addr)       ((addr) / EROFS_BLKSIZ)
+#define erofs_blkoff(addr)      ((addr) % EROFS_BLKSIZ)
+#define blknr_to_addr(nr)       ((erofs_off_t)(nr) * EROFS_BLKSIZ)
+
+#define BLK_ROUND_UP(addr)	DIV_ROUND_UP(addr, EROFS_BLKSIZ)
+
+struct erofs_buffer_head;
+
+struct erofs_device_info {
+	u32 blocks;
+	u32 mapped_blkaddr;
+};
+
+struct erofs_sb_info {
+	struct erofs_device_info *devs;
+
+	u64 total_blocks;
+	u64 primarydevice_blocks;
+
+	erofs_blk_t meta_blkaddr;
+	erofs_blk_t xattr_blkaddr;
+
+	u32 feature_compat;
+	u32 feature_incompat;
+	u64 build_time;
+	u32 build_time_nsec;
+
+	unsigned char islotbits;
+
+	/* what we really care is nid, rather than ino.. */
+	erofs_nid_t root_nid;
+	/* used for statfs, f_files - f_favail */
+	u64 inos;
+
+	u8 uuid[16];
+
+	u16 available_compr_algs;
+	u16 lz4_max_distance;
+	u32 checksum;
+	u16 extra_devices;
+	union {
+		u16 devt_slotoff;		/* used for mkfs */
+		u16 device_id_mask;		/* used for others */
+	};
+};
+
+/* global sbi */
+extern struct erofs_sb_info sbi;
+
+static inline erofs_off_t iloc(erofs_nid_t nid)
+{
+	return blknr_to_addr(sbi.meta_blkaddr) + (nid << sbi.islotbits);
+}
+
+#define EROFS_FEATURE_FUNCS(name, compat, feature) \
+static inline bool erofs_sb_has_##name(void) \
+{ \
+	return sbi.feature_##compat & EROFS_FEATURE_##feature; \
+} \
+static inline void erofs_sb_set_##name(void) \
+{ \
+	sbi.feature_##compat |= EROFS_FEATURE_##feature; \
+} \
+static inline void erofs_sb_clear_##name(void) \
+{ \
+	sbi.feature_##compat &= ~EROFS_FEATURE_##feature; \
+}
+
+EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
+EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
+EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
+EROFS_FEATURE_FUNCS(chunked_file, incompat, INCOMPAT_CHUNKED_FILE)
+EROFS_FEATURE_FUNCS(device_table, incompat, INCOMPAT_DEVICE_TABLE)
+EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
+
+#define EROFS_I_EA_INITED	(1 << 0)
+#define EROFS_I_Z_INITED	(1 << 1)
+
+struct erofs_inode {
+	struct list_head i_hash, i_subdirs, i_xattrs;
+
+	union {
+		/* (erofsfuse) runtime flags */
+		unsigned int flags;
+		/* (mkfs.erofs) device ID containing source file */
+		u32 dev;
+	};
+	unsigned int i_count;
+	struct erofs_inode *i_parent;
+
+	umode_t i_mode;
+	erofs_off_t i_size;
+
+	u64 i_ino[2];
+	u32 i_uid;
+	u32 i_gid;
+	u64 i_ctime;
+	u32 i_ctime_nsec;
+	u32 i_nlink;
+
+	union {
+		u32 i_blkaddr;
+		u32 i_blocks;
+		u32 i_rdev;
+		struct {
+			unsigned short	chunkformat;
+			unsigned char	chunkbits;
+		};
+	} u;
+
+	unsigned char datalayout;
+	unsigned char inode_isize;
+	/* inline tail-end packing size */
+	unsigned short idata_size;
+
+	unsigned int xattr_isize;
+	unsigned int extent_isize;
+
+	erofs_nid_t nid;
+	struct erofs_buffer_head *bh;
+	struct erofs_buffer_head *bh_inline, *bh_data;
+
+	void *idata;
+
+	union {
+		void *compressmeta;
+		void *chunkindexes;
+		struct {
+			uint16_t z_advise;
+			uint8_t  z_algorithmtype[2];
+			uint8_t  z_logical_clusterbits;
+			uint8_t  z_physical_clusterblks;
+		};
+	};
+};
+
+static inline bool is_inode_layout_compression(struct erofs_inode *inode)
+{
+	return erofs_inode_is_data_compressed(inode->datalayout);
+}
+
+static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit,
+					  unsigned int bits)
+{
+	return (value >> bit) & ((1 << bits) - 1);
+}
+
+static inline unsigned int erofs_inode_version(unsigned int value)
+{
+	return erofs_bitrange(value, EROFS_I_VERSION_BIT,
+			      EROFS_I_VERSION_BITS);
+}
+
+static inline unsigned int erofs_inode_datalayout(unsigned int value)
+{
+	return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT,
+			      EROFS_I_DATALAYOUT_BITS);
+}
+
+#define IS_ROOT(x)	((x) == (x)->i_parent)
+
+struct erofs_dentry {
+	struct list_head d_child;	/* child of parent list */
+
+	unsigned int type;
+	char name[EROFS_NAME_LEN];
+	union {
+		struct erofs_inode *inode;
+		erofs_nid_t nid;
+	};
+};
+
+static inline bool is_dot_dotdot(const char *name)
+{
+	if (name[0] != '.')
+		return false;
+
+	return name[1] == '\0' || (name[1] == '.' && name[2] == '\0');
+}
+
+enum {
+	BH_Meta,
+	BH_Mapped,
+	BH_Encoded,
+	BH_FullMapped,
+};
+
+/* Has a disk mapping */
+#define EROFS_MAP_MAPPED	(1 << BH_Mapped)
+/* Located in metadata (could be copied from bd_inode) */
+#define EROFS_MAP_META		(1 << BH_Meta)
+/* The extent is encoded */
+#define EROFS_MAP_ENCODED	(1 << BH_Encoded)
+/* The length of extent is full */
+#define EROFS_MAP_FULL_MAPPED	(1 << BH_FullMapped)
+
+struct erofs_map_blocks {
+	char mpage[EROFS_BLKSIZ];
+
+	erofs_off_t m_pa, m_la;
+	u64 m_plen, m_llen;
+
+	unsigned short m_deviceid;
+	char m_algorithmformat;
+	unsigned int m_flags;
+	erofs_blk_t index;
+};
+
+/*
+ * Used to get the exact decompressed length, e.g. fiemap (consider lookback
+ * approach instead if possible since it's more metadata lightweight.)
+ */
+#define EROFS_GET_BLOCKS_FIEMAP	0x0002
+
+enum {
+	Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX,
+	Z_EROFS_COMPRESSION_RUNTIME_MAX
+};
+
+struct erofs_map_dev {
+	erofs_off_t m_pa;
+	unsigned int m_deviceid;
+};
+
+/* fs.c */
+int erofs_blk_read(void *buf, erofs_blk_t start, u32 nblocks);
+int erofs_dev_read(int device_id, void *buf, u64 offset, size_t len);
+
+/* super.c */
+int erofs_read_superblock(void);
+
+/* namei.c */
+int erofs_read_inode_from_disk(struct erofs_inode *vi);
+int erofs_ilookup(const char *path, struct erofs_inode *vi);
+int erofs_read_inode_from_disk(struct erofs_inode *vi);
+
+/* data.c */
+int erofs_pread(struct erofs_inode *inode, char *buf,
+		erofs_off_t count, erofs_off_t offset);
+int erofs_map_blocks(struct erofs_inode *inode,
+		     struct erofs_map_blocks *map, int flags);
+int erofs_map_dev(struct erofs_sb_info *sbi, struct erofs_map_dev *map);
+/* zmap.c */
+int z_erofs_fill_inode(struct erofs_inode *vi);
+int z_erofs_map_blocks_iter(struct erofs_inode *vi,
+			    struct erofs_map_blocks *map, int flags);
+
+#ifdef EUCLEAN
+#define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
+#else
+#define EFSCORRUPTED	EIO
+#endif
+
+#define CRC32C_POLY_LE	0x82F63B78
+static inline u32 erofs_crc32c(u32 crc, const u8 *in, size_t len)
+{
+	int i;
+
+	while (len--) {
+		crc ^= *in++;
+		for (i = 0; i < 8; i++)
+			crc = (crc >> 1) ^ ((crc & 1) ? CRC32C_POLY_LE : 0);
+	}
+	return crc;
+}
+
+#endif