--- /dev/null
+#ifndef __LUNAIX_EXT2_H
+#define __LUNAIX_EXT2_H
+
+#include <lunaix/fs/api.h>
+#include <lunaix/types.h>
+#include <lunaix/ds/llist.h>
+#include <lunaix/ds/hashtable.h>
+#include <lunaix/ds/lru.h>
+
+#define FEAT_COMPRESSION 0b00000001
+#define FEAT_RESIZE_INO 0b00000010
+#define FEAT_FILETYPE 0b00000100
+#define FEAT_SPARSE_SB 0b00001000
+#define FEAT_LARGE_FILE 0b00010000
+
+#define IMODE_IFSOCK 0xC000
+#define IMODE_IFLNK 0xA000
+#define IMODE_IFREG 0x8000
+#define IMODE_IFBLK 0x6000
+#define IMODE_IFDIR 0x4000
+#define IMODE_IFCHR 0x2000
+#define IMODE_IFFIFO 0x1000
+
+#define IMODE_URD 0x0100
+#define IMODE_UWR 0x0080
+#define IMODE_UEX 0x0040
+#define IMODE_GRD 0x0020
+#define IMODE_GWR 0x0010
+#define IMODE_GEX 0x0008
+#define IMODE_ORD 0x0004
+#define IMODE_OWR 0x0002
+#define IMODE_OEX 0x0001
+
+#define ext2_aligned compact align(4)
+#define to_ext2ino_id(fsblock_id) ((fsblock_id) + 1)
+#define to_fsblock_id(ext2_ino) ((ext2_ino) - 1)
+
+extern bcache_zone_t gdesc_bcache_zone;
+
+struct ext2b_super {
+ u32_t s_ino_cnt;
+ u32_t s_blk_cnt;
+ u32_t s_r_blk_cnt;
+ u32_t s_free_blk_cnt;
+ u32_t s_free_ino_cnt;
+ u32_t s_first_data_cnt;
+
+ u32_t s_log_blk_size;
+ u32_t s_log_frg_size;
+
+ u32_t s_blk_per_grp;
+ u32_t s_frg_per_grp;
+ u32_t s_ino_per_grp;
+
+ u32_t s_mtime;
+ u32_t s_wtime;
+
+ u16_t s_mnt_cnt;
+ u16_t s_max_mnt_cnt;
+ u16_t s_magic;
+ u16_t s_state;
+ u16_t s_error;
+ u16_t s_minor_rev;
+
+ u32_t s_last_check;
+ u32_t s_checkinterval;
+ u32_t s_creator_os;
+ u32_t s_rev;
+
+ u16_t s_def_resuid;
+ u16_t s_def_resgid;
+
+ // EXT2_DYNAMIC_REV
+
+ struct {
+ u32_t s_first_ino;
+ u16_t s_ino_size;
+ u16_t s_blkgrp_nr;
+ u32_t s_optional_feat;
+ u32_t s_required_feat;
+ u32_t s_ro_feat;
+ u8_t s_uuid[16];
+ u8_t s_volname[16];
+ u8_t s_last_mnt[64];
+ u32_t s_algo_bmp;
+ } compact;
+
+} ext2_aligned;
+
+struct ext2b_gdesc
+{
+ u32_t bg_blk_map;
+ u32_t bg_ino_map;
+ u32_t bg_ino_tab;
+
+ u16_t bg_free_blk_cnt;
+ u16_t bg_free_ino_cnt;
+ u16_t bg_used_dir_cnt;
+ u16_t bg_pad;
+} align(32) compact;
+
+struct ext2b_inode
+{
+ u16_t i_mode;
+ u16_t i_uid;
+ union {
+ u32_t i_size;
+ u32_t i_size_l32;
+ };
+
+ u32_t i_atime;
+ u32_t i_ctime;
+ u32_t i_mtime;
+ u32_t i_dtime;
+
+ u16_t i_gid;
+ u16_t i_lnk_cnt;
+
+ u32_t i_blocks;
+ u32_t i_flags;
+ u32_t i_osd1;
+
+ union {
+ struct
+ {
+ u32_t directs[12]; // directum
+ union {
+ struct {
+ u32_t ind1; // prima indirecta
+ u32_t ind23[2]; // secunda et tertia indirecta
+ } ext2_aligned;
+ u32_t inds[3];
+ };
+ } ext2_aligned i_block;
+ u32_t i_block_arr[15];
+ };
+
+ u32_t i_gen;
+ u32_t i_file_acl;
+ union {
+ u32_t i_dir_acl;
+ u32_t i_size_h32;
+ };
+ u32_t i_faddr;
+
+ u8_t i_osd2[12];
+} ext2_aligned;
+
+struct ext2b_dirent
+{
+ u32_t inode;
+ u16_t rec_len;
+ u8_t name_len;
+ u8_t file_type;
+ char name[256];
+} ext2_aligned;
+#define EXT2_DRE(v_dnode) (fsapi_impl_data(v_dnode, struct ext2b_dirent))
+
+
+#define GDESC_INO_SEL 0
+#define GDESC_BLK_SEL 1
+
+#define GDESC_FREE_LISTS \
+ union { \
+ struct { \
+ struct llist_header free_grps_ino; \
+ struct llist_header free_grps_blk; \
+ }; \
+ struct llist_header free_list_sel[2]; \
+ }
+
+#define check_gdesc_type_sel(sel) \
+ assert_msg(sel == GDESC_INO_SEL || sel == GDESC_BLK_SEL, \
+ "invalid type_sel");
+
+struct ext2_sbinfo
+{
+ /**
+ * @brief
+ * offset to inode table (in terms of blocks) within each block group.
+ * to account the difference of backup presence between rev 0/1
+ */
+ int ino_tab_len;
+
+ bool read_only;
+ unsigned int block_size;
+ unsigned int nr_gdesc_pb;
+ unsigned int nr_gdesc;
+ unsigned int all_feature;
+
+ struct device* bdev;
+ struct v_superblock* vsb;
+
+ struct ext2b_super* raw;
+ bbuf_t* gdt_frag;
+ struct bcache gd_caches;
+
+ bbuf_t buf;
+
+ struct {
+ struct llist_header gds;
+ GDESC_FREE_LISTS;
+ };
+};
+#define EXT2_SB(vsb) (fsapi_impl_data(vsb, struct ext2_sbinfo))
+
+
+struct ext2_bmp
+{
+ bbuf_t raw;
+ u8_t* bmp;
+ unsigned int nr_bytes;
+ int next_free;
+};
+
+struct ext2_gdesc
+{
+ struct llist_header groups;
+ GDESC_FREE_LISTS;
+
+ union {
+ struct {
+ struct ext2_bmp ino_bmp;
+ struct ext2_bmp blk_bmp;
+ };
+ struct ext2_bmp bmps[2];
+ };
+
+ unsigned int base;
+ unsigned int ino_base;
+
+ struct ext2b_gdesc* info;
+ struct ext2_sbinfo* sb;
+ bbuf_t buf;
+ bcobj_t cache_ref;
+};
+
+/*
+ Indriection Block Translation Look-aside Buffer
+
+ Provide a look-aside buffer for all last-level indirect block
+ that is at least two indirection away.
+
+ For 4KiB block size:
+ 16 sets, 256 ways, capacity 4096 blocks
+*/
+
+struct ext2_btlb_entry
+{
+ unsigned int tag;
+ bbuf_t block;
+};
+
+#define BTLB_SETS 16
+struct ext2_btlb
+{
+ struct ext2_btlb_entry buffer[BTLB_SETS];
+};
+
+struct ext2_fast_inode
+{
+ struct ext2b_inode* ino;
+ bbuf_t buf;
+};
+
+struct ext2_inode
+{
+ bbuf_t buf; // partial inotab that holds this inode
+ unsigned int inds_lgents; // log2(# of block in an indirection level)
+ unsigned int ino_id;
+ size_t indirect_blocks;
+ size_t isize;
+
+ struct ext2b_inode* ino; // raw ext2 inode
+ struct ext2_btlb* btlb; // block-TLB
+ struct ext2_gdesc* blk_grp; // block group
+
+ union {
+ struct {
+ /*
+ (future)
+ dirent fragmentation degree, we will perform
+ full reconstruction on dirent table when this goes too high.
+ */
+ unsigned int dir_fragdeg;
+ };
+ };
+
+ // prefetched block for 1st order of indirection
+ bbuf_t ind_ord1;
+ char* symlink;
+};
+#define EXT2_INO(v_inode) (fsapi_impl_data(v_inode, struct ext2_inode))
+
+struct ext2_dnode_sub
+{
+ bbuf_t buf;
+ struct ext2b_dirent* dirent;
+};
+
+struct ext2_dnode
+{
+ struct ext2_dnode_sub self;
+ struct ext2_dnode_sub prev;
+};
+#define EXT2_DNO(v_dnode) (fsapi_impl_data(v_dnode, struct ext2_dnode))
+
+
+/**
+ * @brief General purpose iterator for ext2 objects
+ *
+ */
+struct ext2_iterator
+{
+ struct v_inode* inode;
+
+ union {
+ struct ext2b_dirent* dirent;
+ void* data;
+ };
+
+ union {
+ struct {
+ bool has_error:1;
+ };
+ unsigned int flags;
+ };
+
+ size_t pos;
+ unsigned int blksz;
+ size_t end_pos;
+ bbuf_t sel_buf;
+};
+
+struct ext2_file
+{
+ struct ext2_iterator iter;
+ struct ext2_inode* b_ino;
+};
+#define EXT2_FILE(v_file) (fsapi_impl_data(v_file, struct ext2_file))
+
+
+#define MAX_INDS_DEPTH 4
+
+struct walk_stack
+{
+ unsigned int tables[MAX_INDS_DEPTH];
+ unsigned int indices[MAX_INDS_DEPTH];
+};
+
+struct walk_state
+{
+ unsigned int* slot_ref;
+ bbuf_t table;
+ int indirections;
+ int level;
+
+ struct walk_stack stack;
+};
+
+static inline unsigned int
+ext2_datablock(struct v_superblock* vsb, unsigned int id)
+{
+ return EXT2_SB(vsb)->raw->s_first_data_cnt + id;
+}
+
+static inline bool
+ext2_feature(struct v_superblock* vsb, unsigned int feat)
+{
+ return !!(EXT2_SB(vsb)->all_feature & feat);
+}
+
+/* ************ Inodes ************ */
+
+void
+ext2ino_init(struct v_superblock* vsb, struct v_inode* inode);
+
+int
+ext2ino_get(struct v_superblock* vsb,
+ unsigned int ino, struct ext2_inode** out);
+
+int
+ext2ino_get_fast(struct v_superblock* vsb,
+ unsigned int ino, struct ext2_fast_inode* fast_ino);
+
+int
+ext2ino_fill(struct v_inode* inode, ino_t ino_id);
+
+int
+ext2ino_make(struct v_superblock* vsb, unsigned int itype,
+ struct ext2_inode* hint, struct v_inode** out);
+
+void
+ext2ino_update(struct v_inode* inode);
+
+int
+ext2ino_resizing(struct v_inode* inode, size_t new_size);
+
+static inline void
+ext2ino_linkto(struct ext2_inode* e_ino, struct ext2b_dirent* dirent)
+{
+ dirent->inode = e_ino->ino_id;
+ e_ino->ino->i_lnk_cnt++;
+ fsblock_dirty(e_ino->buf);
+}
+
+void
+ext2db_itbegin(struct ext2_iterator* iter, struct v_inode* inode);
+
+void
+ext2db_itend(struct ext2_iterator* iter);
+
+bool
+ext2db_itnext(struct ext2_iterator* iter);
+
+int
+ext2db_itffw(struct ext2_iterator* iter, int count);
+
+void
+ext2db_itreset(struct ext2_iterator* iter);
+
+
+/**
+ * @brief Get the data block at given data pos associated with the
+ * inode, return NULL if not present
+ *
+ * @param inode
+ * @param data_pos
+ * @return bbuf_t
+ */
+bbuf_t
+ext2db_get(struct v_inode* inode, unsigned int data_pos);
+
+/**
+ * @brief Get the data block at given data pos associated with the
+ * inode, allocate one if not present.
+ *
+ * @param inode
+ * @param data_pos
+ * @param out
+ * @return int
+ */
+int
+ext2db_acquire(struct v_inode* inode, unsigned int data_pos, bbuf_t* out);
+
+void
+ext2db_free_pos(struct v_inode* inode, unsigned int block_pos);
+
+/* ************* Walker ************* */
+
+static inline void
+ext2walk_init_state(struct walk_state* state)
+{
+ *state = (struct walk_state) { };
+}
+
+static inline void
+ext2walk_free_state(struct walk_state* state)
+{
+ fsblock_put(state->table);
+}
+
+/* ************* Iterator ************* */
+
+static inline bool
+ext2_iterror(struct ext2_iterator* iter) {
+ return iter->has_error;
+}
+
+static inline bool
+ext2_itcheckbuf(struct ext2_iterator* iter) {
+ return !(iter->has_error = blkbuf_errbuf(iter->sel_buf));
+}
+
+#define itstate_sel(iter, value) \
+ (ext2_iterror(iter) ? EIO : (int)(value))
+
+
+/* ************ Block Group ************ */
+
+void
+ext2gd_prepare_gdt(struct v_superblock* vsb);
+
+void
+ext2gd_release_gdt(struct v_superblock* vsb);
+
+int
+ext2gd_take(struct v_superblock* vsb,
+ unsigned int index, struct ext2_gdesc** out);
+
+static inline void
+ext2gd_put(struct ext2_gdesc* gd) {
+ bcache_return(gd->cache_ref);
+}
+
+
+/* ************ Directory ************ */
+
+int
+ext2dr_lookup(struct v_inode* this, struct v_dnode* dnode);
+
+int
+ext2dr_read(struct v_file *file, struct dir_context *dctx);
+
+void
+ext2dr_itbegin(struct ext2_iterator* iter, struct v_inode* inode);
+
+void
+ext2dr_itend(struct ext2_iterator* iter);
+
+static inline bool
+ext2dr_itdrain(struct ext2_iterator* iter)
+{
+ return iter->pos > iter->end_pos;
+}
+
+bool
+ext2dr_itnext(struct ext2_iterator* iter);
+
+int
+ext2dr_itffw(struct ext2_iterator* iter, int count);
+
+void
+ext2dr_itreset(struct ext2_iterator* iter);
+
+int
+ext2dr_open(struct v_inode* this, struct v_file* file);
+
+int
+ext2dr_close(struct v_inode* this, struct v_file* file);
+
+int
+ext2dr_seek(struct v_file* file, size_t offset);
+
+int
+ext2dr_insert(struct v_inode* this, struct ext2b_dirent* dirent,
+ struct ext2_dnode** e_dno_out);
+
+int
+ext2dr_remove(struct ext2_dnode* e_dno);
+
+int
+ext2_rmdir(struct v_inode* parent, struct v_dnode* dnode);
+
+int
+ext2_mkdir(struct v_inode* parent, struct v_dnode* dnode);
+
+int
+ext2_rename(struct v_inode* from_inode, struct v_dnode* from_dnode,
+ struct v_dnode* to_dnode);
+
+void
+ext2dr_setup_dirent(struct ext2b_dirent* dirent,
+ struct v_inode* inode, struct hstr* name);
+
+
+/* ************ Files ************ */
+
+int
+ext2_open_inode(struct v_inode* this, struct v_file* file);
+
+int
+ext2_close_inode(struct v_file* file);
+
+int
+ext2_sync_inode(struct v_inode* inode);
+
+int
+ext2_file_sync(struct v_file* file);
+
+int
+ext2_inode_read(struct v_inode *inode, void *buffer, size_t len, size_t fpos);
+
+int
+ext2_inode_read_page(struct v_inode *inode, void *buffer, size_t fpos);
+
+int
+ext2_inode_write(struct v_inode *inode, void *buffer, size_t len, size_t fpos);
+
+int
+ext2_inode_write_page(struct v_inode *inode, void *buffer, size_t fpos);
+
+int
+ext2_seek_inode(struct v_file* file, size_t offset);
+
+int
+ext2_create(struct v_inode* this, struct v_dnode* dnode, unsigned int itype);
+
+int
+ext2_link(struct v_inode* this, struct v_dnode* new_name);
+
+int
+ext2_unlink(struct v_inode* this, struct v_dnode* name);
+
+int
+ext2_get_symlink(struct v_inode *this, const char **path_out);
+
+int
+ext2_set_symlink(struct v_inode *this, const char *target);
+
+/* *********** Bitmap *********** */
+
+void
+ext2bmp_init(struct ext2_bmp* e_bmp, bbuf_t bmp_buf, unsigned int nr_bits);
+
+bool
+ext2bmp_check_free(struct ext2_bmp* e_bmp);
+
+int
+ext2bmp_alloc_one(struct ext2_bmp* e_bmp);
+
+void
+ext2bmp_free_one(struct ext2_bmp* e_bmp, unsigned int pos);
+
+void
+ext2bmp_discard(struct ext2_bmp* e_bmp);
+
+/* *********** Allocations *********** */
+
+#define ALLOC_FAIL -1
+
+static inline bool
+valid_bmp_slot(int slot)
+{
+ return slot != ALLOC_FAIL;
+}
+
+int
+ext2gd_alloc_slot(struct ext2_gdesc* gd, int type_sel);
+
+void
+ext2gd_free_slot(struct ext2_gdesc* gd, int type_sel, int slot);
+
+static inline int
+ext2gd_alloc_inode(struct ext2_gdesc* gd)
+{
+ return ext2gd_alloc_slot(gd, GDESC_INO_SEL);
+}
+
+static inline int
+ext2gd_alloc_block(struct ext2_gdesc* gd)
+{
+ return ext2gd_alloc_slot(gd, GDESC_BLK_SEL);
+}
+
+static inline void
+ext2gd_free_inode(struct ext2_gdesc* gd, int slot)
+{
+ ext2gd_free_slot(gd, GDESC_INO_SEL, slot);
+}
+
+static inline void
+ext2gd_free_block(struct ext2_gdesc* gd, int slot)
+{
+ ext2gd_free_slot(gd, GDESC_BLK_SEL, slot);
+}
+
+
+/**
+ * @brief Allocate a free inode
+ *
+ * @param vsb
+ * @param hint locality hint
+ * @param out
+ * @return int
+ */
+int
+ext2ino_alloc(struct v_superblock* vsb,
+ struct ext2_inode* hint, struct ext2_inode** out);
+
+/**
+ * @brief Allocate a free data block
+ *
+ * @param inode inode where the data block goes, also used as locality hint
+ * @return bbuf_t
+ */
+int
+ext2db_alloc(struct v_inode* inode, bbuf_t* out);
+
+/**
+ * @brief free an inode
+ *
+ * @param vsb
+ * @param hint locality hint
+ * @param out
+ * @return int
+ */
+int
+ext2ino_free(struct v_inode* inode);
+
+/**
+ * @brief Free a data block
+ *
+ * @param inode inode where the data block goes, also used as locality hint
+ * @return bbuf_t
+ */
+int
+ext2db_free(struct v_inode* inode, bbuf_t buf);
+
+int
+ext2ino_alloc_slot(struct v_superblock* vsb, struct ext2_gdesc** gd_out);
+
+int
+ext2db_alloc_slot(struct v_superblock* vsb, struct ext2_gdesc** gd_out);
+
+
+#endif /* __LUNAIX_EXT2_H */