nilfs2_fs.h

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/*
 * nilfs2_fs.h - NILFS2 on-disk structures and common declarations.
 *
 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Written by Koji Sato <[email protected]>
 *            Ryusuke Konishi <[email protected]>
 */
/*
 *  linux/include/linux/ext2_fs.h
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card ([email protected])
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/include/linux/minix_fs.h
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#ifndef _LINUX_NILFS_FS_H
#define _LINUX_NILFS_FS_H

#include <linux/types.h>
#include <linux/ioctl.h>
#include <linux/magic.h>
#include <linux/bug.h>


#define NILFS_INODE_BMAP_SIZE   7

struct nilfs_inode {
    __le64  i_blocks;
    __le64  i_size;
    __le64  i_ctime;
    __le64  i_mtime;
    __le32  i_ctime_nsec;
    __le32  i_mtime_nsec;
    __le32  i_uid;
    __le32  i_gid;
    __le16  i_mode;
    __le16  i_links_count;
    __le32  i_flags;
    __le64  i_bmap[NILFS_INODE_BMAP_SIZE];
#define i_device_code   i_bmap[0]
    __le64  i_xattr;
    __le32  i_generation;
    __le32  i_pad;
};

struct nilfs_super_root {
    __le32 sr_sum;
    __le16 sr_bytes;
    __le16 sr_flags;
    __le64 sr_nongc_ctime;
    struct nilfs_inode sr_dat;
    struct nilfs_inode sr_cpfile;
    struct nilfs_inode sr_sufile;
};

#define NILFS_SR_MDT_OFFSET(inode_size, i)  \
    ((unsigned long)&((struct nilfs_super_root *)0)->sr_dat + \
            (inode_size) * (i))
#define NILFS_SR_DAT_OFFSET(inode_size)     NILFS_SR_MDT_OFFSET(inode_size, 0)
#define NILFS_SR_CPFILE_OFFSET(inode_size)  NILFS_SR_MDT_OFFSET(inode_size, 1)
#define NILFS_SR_SUFILE_OFFSET(inode_size)  NILFS_SR_MDT_OFFSET(inode_size, 2)
#define NILFS_SR_BYTES(inode_size)      NILFS_SR_MDT_OFFSET(inode_size, 3)

/*
 * Maximal mount counts
 */
#define NILFS_DFL_MAX_MNT_COUNT     50      /* 50 mounts */

/*
 * File system states (sbp->s_state, nilfs->ns_mount_state)
 */
#define NILFS_VALID_FS          0x0001  /* Unmounted cleanly */
#define NILFS_ERROR_FS          0x0002  /* Errors detected */
#define NILFS_RESIZE_FS         0x0004  /* Resize required */

/*
 * Mount flags (sbi->s_mount_opt)
 */
#define NILFS_MOUNT_ERROR_MODE      0x0070  /* Error mode mask */
#define NILFS_MOUNT_ERRORS_CONT     0x0010  /* Continue on errors */
#define NILFS_MOUNT_ERRORS_RO       0x0020  /* Remount fs ro on errors */
#define NILFS_MOUNT_ERRORS_PANIC    0x0040  /* Panic on errors */
#define NILFS_MOUNT_BARRIER     0x1000  /* Use block barriers */
#define NILFS_MOUNT_STRICT_ORDER    0x2000  /* Apply strict in-order
                           semantics also for data */
#define NILFS_MOUNT_NORECOVERY      0x4000  /* Disable write access during
                           mount-time recovery */
#define NILFS_MOUNT_DISCARD     0x8000  /* Issue DISCARD requests */


struct nilfs_super_block {
/*00*/  __le32  s_rev_level;        /* Revision level */
    __le16  s_minor_rev_level;  /* minor revision level */
    __le16  s_magic;        /* Magic signature */

    __le16  s_bytes;        /* Bytes count of CRC calculation
                       for this structure. s_reserved
                       is excluded. */
    __le16  s_flags;        /* flags */
    __le32  s_crc_seed;     /* Seed value of CRC calculation */
/*10*/  __le32  s_sum;          /* Check sum of super block */

    __le32  s_log_block_size;   /* Block size represented as follows
                       blocksize =
                           1 << (s_log_block_size + 10) */
    __le64  s_nsegments;        /* Number of segments in filesystem */
/*20*/  __le64  s_dev_size;     /* block device size in bytes */
    __le64  s_first_data_block; /* 1st seg disk block number */
/*30*/  __le32  s_blocks_per_segment;   /* number of blocks per full segment */
    __le32  s_r_segments_percentage; /* Reserved segments percentage */

    __le64  s_last_cno;     /* Last checkpoint number */
/*40*/  __le64  s_last_pseg;        /* disk block addr pseg written last */
    __le64  s_last_seq;             /* seq. number of seg written last */
/*50*/  __le64  s_free_blocks_count;    /* Free blocks count */

    __le64  s_ctime;        /* Creation time (execution time of
                       newfs) */
/*60*/  __le64  s_mtime;        /* Mount time */
    __le64  s_wtime;        /* Write time */
/*70*/  __le16  s_mnt_count;        /* Mount count */
    __le16  s_max_mnt_count;    /* Maximal mount count */
    __le16  s_state;        /* File system state */
    __le16  s_errors;       /* Behaviour when detecting errors */
    __le64  s_lastcheck;        /* time of last check */

/*80*/  __le32  s_checkinterval;    /* max. time between checks */
    __le32  s_creator_os;       /* OS */
    __le16  s_def_resuid;       /* Default uid for reserved blocks */
    __le16  s_def_resgid;       /* Default gid for reserved blocks */
    __le32  s_first_ino;        /* First non-reserved inode */

/*90*/  __le16  s_inode_size;       /* Size of an inode */
    __le16  s_dat_entry_size;       /* Size of a dat entry */
    __le16  s_checkpoint_size;      /* Size of a checkpoint */
    __le16  s_segment_usage_size;   /* Size of a segment usage */

/*98*/  __u8    s_uuid[16];     /* 128-bit uuid for volume */
/*A8*/  char    s_volume_name[80];  /* volume name */

/*F8*/  __le32  s_c_interval;           /* Commit interval of segment */
    __le32  s_c_block_max;          /* Threshold of data amount for
                       the segment construction */
/*100*/ __le64  s_feature_compat;   /* Compatible feature set */
    __le64  s_feature_compat_ro;    /* Read-only compatible feature set */
    __le64  s_feature_incompat; /* Incompatible feature set */
    __u32   s_reserved[186];    /* padding to the end of the block */
};

/*
 * Codes for operating systems
 */
#define NILFS_OS_LINUX      0
/* Codes from 1 to 4 are reserved to keep compatibility with ext2 creator-OS */

/*
 * Revision levels
 */
#define NILFS_CURRENT_REV   2   /* current major revision */
#define NILFS_MINOR_REV     0   /* minor revision */
#define NILFS_MIN_SUPP_REV  2   /* minimum supported revision */

/*
 * Feature set definitions
 *
 * If there is a bit set in the incompatible feature set that the kernel
 * doesn't know about, it should refuse to mount the filesystem.
 */
#define NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT 0x00000001ULL

#define NILFS_FEATURE_COMPAT_SUPP   0ULL
#define NILFS_FEATURE_COMPAT_RO_SUPP    NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT
#define NILFS_FEATURE_INCOMPAT_SUPP 0ULL

/*
 * Bytes count of super_block for CRC-calculation
 */
#define NILFS_SB_BYTES  \
    ((long)&((struct nilfs_super_block *)0)->s_reserved)

/*
 * Special inode number
 */
#define NILFS_ROOT_INO      2   /* Root file inode */
#define NILFS_DAT_INO       3   /* DAT file */
#define NILFS_CPFILE_INO    4   /* checkpoint file */
#define NILFS_SUFILE_INO    5   /* segment usage file */
#define NILFS_IFILE_INO     6   /* ifile */
#define NILFS_ATIME_INO     7   /* Atime file (reserved) */
#define NILFS_XATTR_INO     8   /* Xattribute file (reserved) */
#define NILFS_SKETCH_INO    10  /* Sketch file */
#define NILFS_USER_INO      11  /* Fisrt user's file inode number */

#define NILFS_SB_OFFSET_BYTES   1024    /* byte offset of nilfs superblock */

#define NILFS_SEG_MIN_BLOCKS    16  /* Minimum number of blocks in
                       a full segment */
#define NILFS_PSEG_MIN_BLOCKS   2   /* Minimum number of blocks in
                       a partial segment */
#define NILFS_MIN_NRSVSEGS  8   /* Minimum number of reserved
                       segments */

/*
 * We call DAT, cpfile, and sufile root metadata files.  Inodes of
 * these files are written in super root block instead of ifile, and
 * garbage collector doesn't keep any past versions of these files.
 */
#define NILFS_ROOT_METADATA_FILE(ino) \
    ((ino) >= NILFS_DAT_INO && (ino) <= NILFS_SUFILE_INO)

/*
 * bytes offset of secondary super block
 */
#define NILFS_SB2_OFFSET_BYTES(devsize) ((((devsize) >> 12) - 1) << 12)

/*
 * Maximal count of links to a file
 */
#define NILFS_LINK_MAX      32000

/*
 * Structure of a directory entry
 *  (Same as ext2)
 */

#define NILFS_NAME_LEN 255

/*
 * Block size limitations
 */
#define NILFS_MIN_BLOCK_SIZE        1024
#define NILFS_MAX_BLOCK_SIZE        65536

/*
 * The new version of the directory entry.  Since V0 structures are
 * stored in intel byte order, and the name_len field could never be
 * bigger than 255 chars, it's safe to reclaim the extra byte for the
 * file_type field.
 */
struct nilfs_dir_entry {
    __le64  inode;          /* Inode number */
    __le16  rec_len;        /* Directory entry length */
    __u8    name_len;       /* Name length */
    __u8    file_type;      /* Dir entry type (file, dir, etc) */
    char    name[NILFS_NAME_LEN];   /* File name */
    char    pad;
};

/*
 * NILFS directory file types.  Only the low 3 bits are used.  The
 * other bits are reserved for now.
 */
enum {
    NILFS_FT_UNKNOWN,
    NILFS_FT_REG_FILE,
    NILFS_FT_DIR,
    NILFS_FT_CHRDEV,
    NILFS_FT_BLKDEV,
    NILFS_FT_FIFO,
    NILFS_FT_SOCK,
    NILFS_FT_SYMLINK,
    NILFS_FT_MAX
};

/*
 * NILFS_DIR_PAD defines the directory entries boundaries
 *
 * NOTE: It must be a multiple of 8
 */
#define NILFS_DIR_PAD           8
#define NILFS_DIR_ROUND         (NILFS_DIR_PAD - 1)
#define NILFS_DIR_REC_LEN(name_len) (((name_len) + 12 + NILFS_DIR_ROUND) & \
                    ~NILFS_DIR_ROUND)
#define NILFS_MAX_REC_LEN       ((1<<16)-1)

static inline unsigned nilfs_rec_len_from_disk(__le16 dlen)
{
    unsigned len = le16_to_cpu(dlen);

#if !defined(__KERNEL__) || (PAGE_CACHE_SIZE >= 65536)
    if (len == NILFS_MAX_REC_LEN)
        return 1 << 16;
#endif
    return len;
}

static inline __le16 nilfs_rec_len_to_disk(unsigned len)
{
#if !defined(__KERNEL__) || (PAGE_CACHE_SIZE >= 65536)
    if (len == (1 << 16))
        return cpu_to_le16(NILFS_MAX_REC_LEN);
    else if (len > (1 << 16))
        BUG();
#endif
    return cpu_to_le16(len);
}

struct nilfs_finfo {
    __le64 fi_ino;
    __le64 fi_cno;
    __le32 fi_nblocks;
    __le32 fi_ndatablk;
    /* array of virtual block numbers */
};

struct nilfs_binfo_v {
    __le64 bi_vblocknr;
    __le64 bi_blkoff;
};

struct nilfs_binfo_dat {
    __le64 bi_blkoff;
    __u8 bi_level;
    __u8 bi_pad[7];
};

union nilfs_binfo {
    struct nilfs_binfo_v bi_v;
    struct nilfs_binfo_dat bi_dat;
};

struct nilfs_segment_summary {
    __le32 ss_datasum;
    __le32 ss_sumsum;
    __le32 ss_magic;
    __le16 ss_bytes;
    __le16 ss_flags;
    __le64 ss_seq;
    __le64 ss_create;
    __le64 ss_next;
    __le32 ss_nblocks;
    __le32 ss_nfinfo;
    __le32 ss_sumbytes;
    __le32 ss_pad;
    __le64 ss_cno;
    /* array of finfo structures */
};

#define NILFS_SEGSUM_MAGIC  0x1eaffa11  /* segment summary magic number */

/*
 * Segment summary flags
 */
#define NILFS_SS_LOGBGN 0x0001  /* begins a logical segment */
#define NILFS_SS_LOGEND 0x0002  /* ends a logical segment */
#define NILFS_SS_SR     0x0004  /* has super root */
#define NILFS_SS_SYNDT  0x0008  /* includes data only updates */
#define NILFS_SS_GC     0x0010  /* segment written for cleaner operation */

struct nilfs_btree_node {
    __u8 bn_flags;
    __u8 bn_level;
    __le16 bn_nchildren;
    __le32 bn_pad;
};

/* flags */
#define NILFS_BTREE_NODE_ROOT   0x01

/* level */
#define NILFS_BTREE_LEVEL_DATA          0
#define NILFS_BTREE_LEVEL_NODE_MIN      (NILFS_BTREE_LEVEL_DATA + 1)
#define NILFS_BTREE_LEVEL_MAX           14

struct nilfs_palloc_group_desc {
    __le32 pg_nfrees;
};

struct nilfs_dat_entry {
    __le64 de_blocknr;
    __le64 de_start;
    __le64 de_end;
    __le64 de_rsv;
};

struct nilfs_snapshot_list {
    __le64 ssl_next;
    __le64 ssl_prev;
};

struct nilfs_checkpoint {
    __le32 cp_flags;
    __le32 cp_checkpoints_count;
    struct nilfs_snapshot_list cp_snapshot_list;
    __le64 cp_cno;
    __le64 cp_create;
    __le64 cp_nblk_inc;
    __le64 cp_inodes_count;
    __le64 cp_blocks_count;

    /* Do not change the byte offset of ifile inode.
       To keep the compatibility of the disk format,
       additional fields should be added behind cp_ifile_inode. */
    struct nilfs_inode cp_ifile_inode;
};

/* checkpoint flags */
enum {
    NILFS_CHECKPOINT_SNAPSHOT,
    NILFS_CHECKPOINT_INVALID,
    NILFS_CHECKPOINT_SKETCH,
    NILFS_CHECKPOINT_MINOR,
};

#define NILFS_CHECKPOINT_FNS(flag, name)                \
static inline void                          \
nilfs_checkpoint_set_##name(struct nilfs_checkpoint *cp)        \
{                                   \
    cp->cp_flags = cpu_to_le32(le32_to_cpu(cp->cp_flags) |      \
                   (1UL << NILFS_CHECKPOINT_##flag));   \
}                                   \
static inline void                          \
nilfs_checkpoint_clear_##name(struct nilfs_checkpoint *cp)      \
{                                   \
    cp->cp_flags = cpu_to_le32(le32_to_cpu(cp->cp_flags) &      \
                   ~(1UL << NILFS_CHECKPOINT_##flag));  \
}                                   \
static inline int                           \
nilfs_checkpoint_##name(const struct nilfs_checkpoint *cp)      \
{                                   \
    return !!(le32_to_cpu(cp->cp_flags) &               \
          (1UL << NILFS_CHECKPOINT_##flag));            \
}

NILFS_CHECKPOINT_FNS(SNAPSHOT, snapshot)
NILFS_CHECKPOINT_FNS(INVALID, invalid)
NILFS_CHECKPOINT_FNS(MINOR, minor)

struct nilfs_cpinfo {
    __u32 ci_flags;
    __u32 ci_pad;
    __u64 ci_cno;
    __u64 ci_create;
    __u64 ci_nblk_inc;
    __u64 ci_inodes_count;
    __u64 ci_blocks_count;
    __u64 ci_next;
};

#define NILFS_CPINFO_FNS(flag, name)                    \
static inline int                           \
nilfs_cpinfo_##name(const struct nilfs_cpinfo *cpinfo)          \
{                                   \
    return !!(cpinfo->ci_flags & (1UL << NILFS_CHECKPOINT_##flag)); \
}

NILFS_CPINFO_FNS(SNAPSHOT, snapshot)
NILFS_CPINFO_FNS(INVALID, invalid)
NILFS_CPINFO_FNS(MINOR, minor)


struct nilfs_cpfile_header {
    __le64 ch_ncheckpoints;
    __le64 ch_nsnapshots;
    struct nilfs_snapshot_list ch_snapshot_list;
};

#define NILFS_CPFILE_FIRST_CHECKPOINT_OFFSET    \
    ((sizeof(struct nilfs_cpfile_header) +              \
      sizeof(struct nilfs_checkpoint) - 1) /            \
            sizeof(struct nilfs_checkpoint))

struct nilfs_segment_usage {
    __le64 su_lastmod;
    __le32 su_nblocks;
    __le32 su_flags;
};

/* segment usage flag */
enum {
    NILFS_SEGMENT_USAGE_ACTIVE,
    NILFS_SEGMENT_USAGE_DIRTY,
    NILFS_SEGMENT_USAGE_ERROR,

    /* ... */
};

#define NILFS_SEGMENT_USAGE_FNS(flag, name)             \
static inline void                          \
nilfs_segment_usage_set_##name(struct nilfs_segment_usage *su)      \
{                                   \
    su->su_flags = cpu_to_le32(le32_to_cpu(su->su_flags) |      \
                   (1UL << NILFS_SEGMENT_USAGE_##flag));\
}                                   \
static inline void                          \
nilfs_segment_usage_clear_##name(struct nilfs_segment_usage *su)    \
{                                   \
    su->su_flags =                          \
        cpu_to_le32(le32_to_cpu(su->su_flags) &         \
                ~(1UL << NILFS_SEGMENT_USAGE_##flag));      \
}                                   \
static inline int                           \
nilfs_segment_usage_##name(const struct nilfs_segment_usage *su)    \
{                                   \
    return !!(le32_to_cpu(su->su_flags) &               \
          (1UL << NILFS_SEGMENT_USAGE_##flag));         \
}

NILFS_SEGMENT_USAGE_FNS(ACTIVE, active)
NILFS_SEGMENT_USAGE_FNS(DIRTY, dirty)
NILFS_SEGMENT_USAGE_FNS(ERROR, error)

static inline void
nilfs_segment_usage_set_clean(struct nilfs_segment_usage *su)
{
    su->su_lastmod = cpu_to_le64(0);
    su->su_nblocks = cpu_to_le32(0);
    su->su_flags = cpu_to_le32(0);
}

static inline int
nilfs_segment_usage_clean(const struct nilfs_segment_usage *su)
{
    return !le32_to_cpu(su->su_flags);
}

struct nilfs_sufile_header {
    __le64 sh_ncleansegs;
    __le64 sh_ndirtysegs;
    __le64 sh_last_alloc;
    /* ... */
};

#define NILFS_SUFILE_FIRST_SEGMENT_USAGE_OFFSET \
    ((sizeof(struct nilfs_sufile_header) +              \
      sizeof(struct nilfs_segment_usage) - 1) /         \
             sizeof(struct nilfs_segment_usage))

struct nilfs_suinfo {
    __u64 sui_lastmod;
    __u32 sui_nblocks;
    __u32 sui_flags;
};

#define NILFS_SUINFO_FNS(flag, name)                    \
static inline int                           \
nilfs_suinfo_##name(const struct nilfs_suinfo *si)          \
{                                   \
    return si->sui_flags & (1UL << NILFS_SEGMENT_USAGE_##flag); \
}

NILFS_SUINFO_FNS(ACTIVE, active)
NILFS_SUINFO_FNS(DIRTY, dirty)
NILFS_SUINFO_FNS(ERROR, error)

static inline int nilfs_suinfo_clean(const struct nilfs_suinfo *si)
{
    return !si->sui_flags;
}

/* ioctl */
enum {
    NILFS_CHECKPOINT,
    NILFS_SNAPSHOT,
};

struct nilfs_cpmode {
    __u64 cm_cno;
    __u32 cm_mode;
    __u32 cm_pad;
};

struct nilfs_argv {
    __u64 v_base;
    __u32 v_nmembs; /* number of members */
    __u16 v_size;   /* size of members */
    __u16 v_flags;
    __u64 v_index;
};

struct nilfs_period {
    __u64 p_start;
    __u64 p_end;
};

struct nilfs_cpstat {
    __u64 cs_cno;
    __u64 cs_ncps;
    __u64 cs_nsss;
};

struct nilfs_sustat {
    __u64 ss_nsegs;
    __u64 ss_ncleansegs;
    __u64 ss_ndirtysegs;
    __u64 ss_ctime;
    __u64 ss_nongc_ctime;
    __u64 ss_prot_seq;
};

struct nilfs_vinfo {
    __u64 vi_vblocknr;
    __u64 vi_start;
    __u64 vi_end;
    __u64 vi_blocknr;
};

struct nilfs_vdesc {
    __u64 vd_ino;
    __u64 vd_cno;
    __u64 vd_vblocknr;
    struct nilfs_period vd_period;
    __u64 vd_blocknr;
    __u64 vd_offset;
    __u32 vd_flags;
    __u32 vd_pad;
};

struct nilfs_bdesc {
    __u64 bd_ino;
    __u64 bd_oblocknr;
    __u64 bd_blocknr;
    __u64 bd_offset;
    __u32 bd_level;
    __u32 bd_pad;
};

#define NILFS_IOCTL_IDENT       'n'

#define NILFS_IOCTL_CHANGE_CPMODE  \
    _IOW(NILFS_IOCTL_IDENT, 0x80, struct nilfs_cpmode)
#define NILFS_IOCTL_DELETE_CHECKPOINT  \
    _IOW(NILFS_IOCTL_IDENT, 0x81, __u64)
#define NILFS_IOCTL_GET_CPINFO  \
    _IOR(NILFS_IOCTL_IDENT, 0x82, struct nilfs_argv)
#define NILFS_IOCTL_GET_CPSTAT  \
    _IOR(NILFS_IOCTL_IDENT, 0x83, struct nilfs_cpstat)
#define NILFS_IOCTL_GET_SUINFO  \
    _IOR(NILFS_IOCTL_IDENT, 0x84, struct nilfs_argv)
#define NILFS_IOCTL_GET_SUSTAT  \
    _IOR(NILFS_IOCTL_IDENT, 0x85, struct nilfs_sustat)
#define NILFS_IOCTL_GET_VINFO  \
    _IOWR(NILFS_IOCTL_IDENT, 0x86, struct nilfs_argv)
#define NILFS_IOCTL_GET_BDESCS  \
    _IOWR(NILFS_IOCTL_IDENT, 0x87, struct nilfs_argv)
#define NILFS_IOCTL_CLEAN_SEGMENTS  \
    _IOW(NILFS_IOCTL_IDENT, 0x88, struct nilfs_argv[5])
#define NILFS_IOCTL_SYNC  \
    _IOR(NILFS_IOCTL_IDENT, 0x8A, __u64)
#define NILFS_IOCTL_RESIZE  \
    _IOW(NILFS_IOCTL_IDENT, 0x8B, __u64)
#define NILFS_IOCTL_SET_ALLOC_RANGE  \
    _IOW(NILFS_IOCTL_IDENT, 0x8C, __u64[2])

#endif  /* _LINUX_NILFS_FS_H */