LXR linux/fs/xfs/xfs

   1/*
   2 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#ifndef __XFS_DINODE_H__
  19#define __XFS_DINODE_H__
  20
  21#define XFS_DINODE_MAGIC                0x494e  /* 'IN' */
  22#define XFS_DINODE_GOOD_VERSION(v)      ((v) >= 1 && (v) <= 3)
  23
  24typedef struct xfs_timestamp {
  25        __be32          t_sec;          /* timestamp seconds */
  26        __be32          t_nsec;         /* timestamp nanoseconds */
  27} xfs_timestamp_t;
  28
  29/*
  30 * On-disk inode structure.
  31 *
  32 * This is just the header or "dinode core", the inode is expanded to fill a
  33 * variable size the leftover area split into a data and an attribute fork.
  34 * The format of the data and attribute fork depends on the format of the
  35 * inode as indicated by di_format and di_aformat.  To access the data and
  36 * attribute use the XFS_DFORK_DPTR, XFS_DFORK_APTR, and XFS_DFORK_PTR macros
  37 * below.
  38 *
  39 * There is a very similar struct icdinode in xfs_inode which matches the
  40 * layout of the first 96 bytes of this structure, but is kept in native
  41 * format instead of big endian.
  42 *
  43 * Note: di_flushiter is only used by v1/2 inodes - it's effectively a zeroed
  44 * padding field for v3 inodes.
  45 */
  46typedef struct xfs_dinode {
  47        __be16          di_magic;       /* inode magic # = XFS_DINODE_MAGIC */
  48        __be16          di_mode;        /* mode and type of file */
  49        __u8            di_version;     /* inode version */
  50        __u8            di_format;      /* format of di_c data */
  51        __be16          di_onlink;      /* old number of links to file */
  52        __be32          di_uid;         /* owner's user id */
  53        __be32          di_gid;         /* owner's group id */
  54        __be32          di_nlink;       /* number of links to file */
  55        __be16          di_projid_lo;   /* lower part of owner's project id */
  56        __be16          di_projid_hi;   /* higher part owner's project id */
  57        __u8            di_pad[6];      /* unused, zeroed space */
  58        __be16          di_flushiter;   /* incremented on flush */
  59        xfs_timestamp_t di_atime;       /* time last accessed */
  60        xfs_timestamp_t di_mtime;       /* time last modified */
  61        xfs_timestamp_t di_ctime;       /* time created/inode modified */
  62        __be64          di_size;        /* number of bytes in file */
  63        __be64          di_nblocks;     /* # of direct & btree blocks used */
  64        __be32          di_extsize;     /* basic/minimum extent size for file */
  65        __be32          di_nextents;    /* number of extents in data fork */
  66        __be16          di_anextents;   /* number of extents in attribute fork*/
  67        __u8            di_forkoff;     /* attr fork offs, <<3 for 64b align */
  68        __s8            di_aformat;     /* format of attr fork's data */
  69        __be32          di_dmevmask;    /* DMIG event mask */
  70        __be16          di_dmstate;     /* DMIG state info */
  71        __be16          di_flags;       /* random flags, XFS_DIFLAG_... */
  72        __be32          di_gen;         /* generation number */
  73
  74        /* di_next_unlinked is the only non-core field in the old dinode */
  75        __be32          di_next_unlinked;/* agi unlinked list ptr */
  76
  77        /* start of the extended dinode, writable fields */
  78        __le32          di_crc;         /* CRC of the inode */
  79        __be64          di_changecount; /* number of attribute changes */
  80        __be64          di_lsn;         /* flush sequence */
  81        __be64          di_flags2;      /* more random flags */
  82        __u8            di_pad2[16];    /* more padding for future expansion */
  83
  84        /* fields only written to during inode creation */
  85        xfs_timestamp_t di_crtime;      /* time created */
  86        __be64          di_ino;         /* inode number */
  87        uuid_t          di_uuid;        /* UUID of the filesystem */
  88
  89        /* structure must be padded to 64 bit alignment */
  90} xfs_dinode_t;
  91
  92#define DI_MAX_FLUSH 0xffff
  93
  94/*
  95 * Size of the core inode on disk.  Version 1 and 2 inodes have
  96 * the same size, but version 3 has grown a few additional fields.
  97 */
  98static inline uint xfs_dinode_size(int version)
  99{
 100        if (version == 3)
 101                return sizeof(struct xfs_dinode);
 102        return offsetof(struct xfs_dinode, di_crc);
 103}
 104
 105/*
 106 * The 32 bit link count in the inode theoretically maxes out at UINT_MAX.
 107 * Since the pathconf interface is signed, we use 2^31 - 1 instead.
 108 * The old inode format had a 16 bit link count, so its maximum is USHRT_MAX.
 109 */
 110#define XFS_MAXLINK             ((1U << 31) - 1U)
 111#define XFS_MAXLINK_1           65535U
 112
 113/*
 114 * Values for di_format
 115 */
 116typedef enum xfs_dinode_fmt {
 117        XFS_DINODE_FMT_DEV,             /* xfs_dev_t */
 118        XFS_DINODE_FMT_LOCAL,           /* bulk data */
 119        XFS_DINODE_FMT_EXTENTS,         /* struct xfs_bmbt_rec */
 120        XFS_DINODE_FMT_BTREE,           /* struct xfs_bmdr_block */
 121        XFS_DINODE_FMT_UUID             /* uuid_t */
 122} xfs_dinode_fmt_t;
 123
 124/*
 125 * Inode minimum and maximum sizes.
 126 */
 127#define XFS_DINODE_MIN_LOG      8
 128#define XFS_DINODE_MAX_LOG      11
 129#define XFS_DINODE_MIN_SIZE     (1 << XFS_DINODE_MIN_LOG)
 130#define XFS_DINODE_MAX_SIZE     (1 << XFS_DINODE_MAX_LOG)
 131
 132/*
 133 * Inode size for given fs.
 134 */
 135#define XFS_LITINO(mp, version) \
 136        ((int)(((mp)->m_sb.sb_inodesize) - xfs_dinode_size(version)))
 137
 138/*
 139 * Inode data & attribute fork sizes, per inode.
 140 */
 141#define XFS_DFORK_Q(dip)                ((dip)->di_forkoff != 0)
 142#define XFS_DFORK_BOFF(dip)             ((int)((dip)->di_forkoff << 3))
 143
 144#define XFS_DFORK_DSIZE(dip,mp) \
 145        (XFS_DFORK_Q(dip) ? \
 146                XFS_DFORK_BOFF(dip) : \
 147                XFS_LITINO(mp, (dip)->di_version))
 148#define XFS_DFORK_ASIZE(dip,mp) \
 149        (XFS_DFORK_Q(dip) ? \
 150                XFS_LITINO(mp, (dip)->di_version) - XFS_DFORK_BOFF(dip) : \
 151                0)
 152#define XFS_DFORK_SIZE(dip,mp,w) \
 153        ((w) == XFS_DATA_FORK ? \
 154                XFS_DFORK_DSIZE(dip, mp) : \
 155                XFS_DFORK_ASIZE(dip, mp))
 156
 157/*
 158 * Return pointers to the data or attribute forks.
 159 */
 160#define XFS_DFORK_DPTR(dip) \
 161        ((char *)dip + xfs_dinode_size(dip->di_version))
 162#define XFS_DFORK_APTR(dip)     \
 163        (XFS_DFORK_DPTR(dip) + XFS_DFORK_BOFF(dip))
 164#define XFS_DFORK_PTR(dip,w)    \
 165        ((w) == XFS_DATA_FORK ? XFS_DFORK_DPTR(dip) : XFS_DFORK_APTR(dip))
 166
 167#define XFS_DFORK_FORMAT(dip,w) \
 168        ((w) == XFS_DATA_FORK ? \
 169                (dip)->di_format : \
 170                (dip)->di_aformat)
 171#define XFS_DFORK_NEXTENTS(dip,w) \
 172        ((w) == XFS_DATA_FORK ? \
 173                be32_to_cpu((dip)->di_nextents) : \
 174                be16_to_cpu((dip)->di_anextents))
 175
 176#define XFS_BUF_TO_DINODE(bp)   ((xfs_dinode_t *)((bp)->b_addr))
 177
 178/*
 179 * For block and character special files the 32bit dev_t is stored at the
 180 * beginning of the data fork.
 181 */
 182static inline xfs_dev_t xfs_dinode_get_rdev(struct xfs_dinode *dip)
 183{
 184        return be32_to_cpu(*(__be32 *)XFS_DFORK_DPTR(dip));
 185}
 186
 187static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
 188{
 189        *(__be32 *)XFS_DFORK_DPTR(dip) = cpu_to_be32(rdev);
 190}
 191
 192/*
 193 * Values for di_flags
 194 * There should be a one-to-one correspondence between these flags and the
 195 * XFS_XFLAG_s.
 196 */
 197#define XFS_DIFLAG_REALTIME_BIT  0      /* file's blocks come from rt area */
 198#define XFS_DIFLAG_PREALLOC_BIT  1      /* file space has been preallocated */
 199#define XFS_DIFLAG_NEWRTBM_BIT   2      /* for rtbitmap inode, new format */
 200#define XFS_DIFLAG_IMMUTABLE_BIT 3      /* inode is immutable */
 201#define XFS_DIFLAG_APPEND_BIT    4      /* inode is append-only */
 202#define XFS_DIFLAG_SYNC_BIT      5      /* inode is written synchronously */
 203#define XFS_DIFLAG_NOATIME_BIT   6      /* do not update atime */
 204#define XFS_DIFLAG_NODUMP_BIT    7      /* do not dump */
 205#define XFS_DIFLAG_RTINHERIT_BIT 8      /* create with realtime bit set */
 206#define XFS_DIFLAG_PROJINHERIT_BIT   9  /* create with parents projid */
 207#define XFS_DIFLAG_NOSYMLINKS_BIT   10  /* disallow symlink creation */
 208#define XFS_DIFLAG_EXTSIZE_BIT      11  /* inode extent size allocator hint */
 209#define XFS_DIFLAG_EXTSZINHERIT_BIT 12  /* inherit inode extent size */
 210#define XFS_DIFLAG_NODEFRAG_BIT     13  /* do not reorganize/defragment */
 211#define XFS_DIFLAG_FILESTREAM_BIT   14  /* use filestream allocator */
 212#define XFS_DIFLAG_REALTIME      (1 << XFS_DIFLAG_REALTIME_BIT)
 213#define XFS_DIFLAG_PREALLOC      (1 << XFS_DIFLAG_PREALLOC_BIT)
 214#define XFS_DIFLAG_NEWRTBM       (1 << XFS_DIFLAG_NEWRTBM_BIT)
 215#define XFS_DIFLAG_IMMUTABLE     (1 << XFS_DIFLAG_IMMUTABLE_BIT)
 216#define XFS_DIFLAG_APPEND        (1 << XFS_DIFLAG_APPEND_BIT)
 217#define XFS_DIFLAG_SYNC          (1 << XFS_DIFLAG_SYNC_BIT)
 218#define XFS_DIFLAG_NOATIME       (1 << XFS_DIFLAG_NOATIME_BIT)
 219#define XFS_DIFLAG_NODUMP        (1 << XFS_DIFLAG_NODUMP_BIT)
 220#define XFS_DIFLAG_RTINHERIT     (1 << XFS_DIFLAG_RTINHERIT_BIT)
 221#define XFS_DIFLAG_PROJINHERIT   (1 << XFS_DIFLAG_PROJINHERIT_BIT)
 222#define XFS_DIFLAG_NOSYMLINKS    (1 << XFS_DIFLAG_NOSYMLINKS_BIT)
 223#define XFS_DIFLAG_EXTSIZE       (1 << XFS_DIFLAG_EXTSIZE_BIT)
 224#define XFS_DIFLAG_EXTSZINHERIT  (1 << XFS_DIFLAG_EXTSZINHERIT_BIT)
 225#define XFS_DIFLAG_NODEFRAG      (1 << XFS_DIFLAG_NODEFRAG_BIT)
 226#define XFS_DIFLAG_FILESTREAM    (1 << XFS_DIFLAG_FILESTREAM_BIT)
 227
 228#ifdef CONFIG_XFS_RT
 229#define XFS_IS_REALTIME_INODE(ip) ((ip)->i_d.di_flags & XFS_DIFLAG_REALTIME)
 230#else
 231#define XFS_IS_REALTIME_INODE(ip) (0)
 232#endif
 233
 234#define XFS_DIFLAG_ANY \
 235        (XFS_DIFLAG_REALTIME | XFS_DIFLAG_PREALLOC | XFS_DIFLAG_NEWRTBM | \
 236         XFS_DIFLAG_IMMUTABLE | XFS_DIFLAG_APPEND | XFS_DIFLAG_SYNC | \
 237         XFS_DIFLAG_NOATIME | XFS_DIFLAG_NODUMP | XFS_DIFLAG_RTINHERIT | \
 238         XFS_DIFLAG_PROJINHERIT | XFS_DIFLAG_NOSYMLINKS | XFS_DIFLAG_EXTSIZE | \
 239         XFS_DIFLAG_EXTSZINHERIT | XFS_DIFLAG_NODEFRAG | XFS_DIFLAG_FILESTREAM)
 240
 241#endif  /* __XFS_DINODE_H__ */
 242