/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __FAST_COMMIT_H__
#define __FAST_COMMIT_H__

/*
 * Note this file is present in e2fsprogs/lib/ext2fs/fast_commit.h and
 * linux/fs/ext4/fast_commit.h. These file should always be byte identical.
 */

/* Fast commit tags */
#define EXT4_FC_TAG_ADD_RANGE           0x0001
#define EXT4_FC_TAG_DEL_RANGE           0x0002
#define EXT4_FC_TAG_CREAT               0x0003
#define EXT4_FC_TAG_LINK                0x0004
#define EXT4_FC_TAG_UNLINK              0x0005
#define EXT4_FC_TAG_INODE               0x0006
#define EXT4_FC_TAG_PAD                 0x0007
#define EXT4_FC_TAG_TAIL                0x0008
#define EXT4_FC_TAG_HEAD                0x0009

#define EXT4_FC_SUPPORTED_FEATURES      0x0

/* On disk fast commit tlv value structures */

/* Fast commit on disk tag length structure */
struct ext4_fc_tl {
        __le16 fc_tag;
        __le16 fc_len;
};

/* Value structure for tag EXT4_FC_TAG_HEAD. */
struct ext4_fc_head {
        __le32 fc_features;
        __le32 fc_tid;
};

/* Value structure for EXT4_FC_TAG_ADD_RANGE. */
struct ext4_fc_add_range {
        __le32 fc_ino;
        __u8 fc_ex[12];
};

/* Value structure for tag EXT4_FC_TAG_DEL_RANGE. */
struct ext4_fc_del_range {
        __le32 fc_ino;
        __le32 fc_lblk;
        __le32 fc_len;
};

/*
 * This is the value structure for tags EXT4_FC_TAG_CREAT, EXT4_FC_TAG_LINK
 * and EXT4_FC_TAG_UNLINK.
 */
struct ext4_fc_dentry_info {
        __le32 fc_parent_ino;
        __le32 fc_ino;
        __u8 fc_dname[];
};

/* Value structure for EXT4_FC_TAG_INODE. */
struct ext4_fc_inode {
        __le32 fc_ino;
        __u8 fc_raw_inode[];
};

/* Value structure for tag EXT4_FC_TAG_TAIL. */
struct ext4_fc_tail {
        __le32 fc_tid;
        __le32 fc_crc;
};

/* Tag base length */
#define EXT4_FC_TAG_BASE_LEN (sizeof(struct ext4_fc_tl))

/*
 * Fast commit status codes
 */
enum {
        EXT4_FC_STATUS_OK = 0,
        EXT4_FC_STATUS_INELIGIBLE,
        EXT4_FC_STATUS_SKIPPED,
        EXT4_FC_STATUS_FAILED,
};

/*
 * Fast commit ineligiblity reasons:
 */
enum {
        EXT4_FC_REASON_XATTR = 0,
        EXT4_FC_REASON_CROSS_RENAME,
        EXT4_FC_REASON_JOURNAL_FLAG_CHANGE,
        EXT4_FC_REASON_NOMEM,
        EXT4_FC_REASON_SWAP_BOOT,
        EXT4_FC_REASON_RESIZE,
        EXT4_FC_REASON_RENAME_DIR,
        EXT4_FC_REASON_FALLOC_RANGE,
        EXT4_FC_REASON_INODE_JOURNAL_DATA,
        EXT4_FC_REASON_ENCRYPTED_FILENAME,
        EXT4_FC_REASON_MIGRATE,
        EXT4_FC_REASON_VERITY,
        EXT4_FC_REASON_MOVE_EXT,
        EXT4_FC_REASON_MAX
};

#ifdef __KERNEL__
/*
 * In memory list of dentry updates that are performed on the file
 * system used by fast commit code.
 */
struct ext4_fc_dentry_update {
        int fcd_op;             /* Type of update create / unlink / link */
        int fcd_parent;         /* Parent inode number */
        int fcd_ino;            /* Inode number */
        struct name_snapshot fcd_name;  /* Dirent name */
        struct list_head fcd_list;
        struct list_head fcd_dilist;
};

struct ext4_fc_stats {
        unsigned int fc_ineligible_reason_count[EXT4_FC_REASON_MAX];
        unsigned long fc_num_commits;
        unsigned long fc_ineligible_commits;
        unsigned long fc_failed_commits;
        unsigned long fc_skipped_commits;
        unsigned long fc_numblks;
        u64 s_fc_avg_commit_time;
};

#define EXT4_FC_REPLAY_REALLOC_INCREMENT        4

/*
 * Physical block regions added to different inodes due to fast commit
 * recovery. These are set during the SCAN phase. During the replay phase,
 * our allocator excludes these from its allocation. This ensures that
 * we don't accidentally allocating a block that is going to be used by
 * another inode.
 */
struct ext4_fc_alloc_region {
        ext4_lblk_t lblk;
        ext4_fsblk_t pblk;
        int ino, len;
};

/*
 * Fast commit replay state.
 */
struct ext4_fc_replay_state {
        int fc_replay_num_tags;
        int fc_replay_expected_off;
        int fc_current_pass;
        int fc_cur_tag;
        int fc_crc;
        struct ext4_fc_alloc_region *fc_regions;
        int fc_regions_size, fc_regions_used, fc_regions_valid;
        int *fc_modified_inodes;
        int fc_modified_inodes_used, fc_modified_inodes_size;
};

#define region_last(__region) (((__region)->lblk) + ((__region)->len) - 1)
#endif

static inline const char *tag2str(__u16 tag)
{
        switch (tag) {
        case EXT4_FC_TAG_LINK:
                return "ADD_ENTRY";
        case EXT4_FC_TAG_UNLINK:
                return "DEL_ENTRY";
        case EXT4_FC_TAG_ADD_RANGE:
                return "ADD_RANGE";
        case EXT4_FC_TAG_CREAT:
                return "CREAT_DENTRY";
        case EXT4_FC_TAG_DEL_RANGE:
                return "DEL_RANGE";
        case EXT4_FC_TAG_INODE:
                return "INODE";
        case EXT4_FC_TAG_PAD:
                return "PAD";
        case EXT4_FC_TAG_TAIL:
                return "TAIL";
        case EXT4_FC_TAG_HEAD:
                return "HEAD";
        default:
                return "ERROR";
        }
}

#endif /* __FAST_COMMIT_H__ */