1. 根目录:
2. fs
3. xfs
4. xfs_dinode.h

/*
 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_DINODE_H__
#define	__XFS_DINODE_H__

#define	XFS_DINODE_MAGIC		0x494e	/* 'IN' */
#define XFS_DINODE_GOOD_VERSION(v)	((v) >= 1 && (v) <= 3)

typedef struct xfs_timestamp {
	__be32		t_sec;		/* timestamp seconds */
	__be32		t_nsec;		/* timestamp nanoseconds */
} xfs_timestamp_t;

/*
 * On-disk inode structure.
 *
 * This is just the header or "dinode core", the inode is expanded to fill a
 * variable size the leftover area split into a data and an attribute fork.
 * The format of the data and attribute fork depends on the format of the
 * inode as indicated by di_format and di_aformat.  To access the data and
 * attribute use the XFS_DFORK_DPTR, XFS_DFORK_APTR, and XFS_DFORK_PTR macros
 * below.
 *
 * There is a very similar struct icdinode in xfs_inode which matches the
 * layout of the first 96 bytes of this structure, but is kept in native
 * format instead of big endian.
 */
typedef struct xfs_dinode {
	__be16		di_magic;	/* inode magic # = XFS_DINODE_MAGIC */
	__be16		di_mode;	/* mode and type of file */
	__u8		di_version;	/* inode version */
	__u8		di_format;	/* format of di_c data */
	__be16		di_onlink;	/* old number of links to file */
	__be32		di_uid;		/* owner's user id */
	__be32		di_gid;		/* owner's group id */
	__be32		di_nlink;	/* number of links to file */
	__be16		di_projid_lo;	/* lower part of owner's project id */
	__be16		di_projid_hi;	/* higher part owner's project id */
	__u8		di_pad[6];	/* unused, zeroed space */
	__be16		di_flushiter;	/* incremented on flush */
	xfs_timestamp_t	di_atime;	/* time last accessed */
	xfs_timestamp_t	di_mtime;	/* time last modified */
	xfs_timestamp_t	di_ctime;	/* time created/inode modified */
	__be64		di_size;	/* number of bytes in file */
	__be64		di_nblocks;	/* # of direct & btree blocks used */
	__be32		di_extsize;	/* basic/minimum extent size for file */
	__be32		di_nextents;	/* number of extents in data fork */
	__be16		di_anextents;	/* number of extents in attribute fork*/
	__u8		di_forkoff;	/* attr fork offs, <<3 for 64b align */
	__s8		di_aformat;	/* format of attr fork's data */
	__be32		di_dmevmask;	/* DMIG event mask */
	__be16		di_dmstate;	/* DMIG state info */
	__be16		di_flags;	/* random flags, XFS_DIFLAG_... */
	__be32		di_gen;		/* generation number */

	/* di_next_unlinked is the only non-core field in the old dinode */
	__be32		di_next_unlinked;/* agi unlinked list ptr */

	/* start of the extended dinode, writable fields */
	__le32		di_crc;		/* CRC of the inode */
	__be64		di_changecount;	/* number of attribute changes */
	__be64		di_lsn;		/* flush sequence */
	__be64		di_flags2;	/* more random flags */
	__u8		di_pad2[16];	/* more padding for future expansion */

	/* fields only written to during inode creation */
	xfs_timestamp_t	di_crtime;	/* time created */
	__be64		di_ino;		/* inode number */
	uuid_t		di_uuid;	/* UUID of the filesystem */

	/* structure must be padded to 64 bit alignment */
} xfs_dinode_t;

#define DI_MAX_FLUSH 0xffff

/*
 * Size of the core inode on disk.  Version 1 and 2 inodes have
 * the same size, but version 3 has grown a few additional fields.
 */
static inline uint xfs_dinode_size(int version)
{
	if (version == 3)
		return sizeof(struct xfs_dinode);
	return offsetof(struct xfs_dinode, di_crc);
}

/*
 * The 32 bit link count in the inode theoretically maxes out at UINT_MAX.
 * Since the pathconf interface is signed, we use 2^31 - 1 instead.
 * The old inode format had a 16 bit link count, so its maximum is USHRT_MAX.
 */
#define	XFS_MAXLINK		((1U << 31) - 1U)
#define	XFS_MAXLINK_1		65535U

/*
 * Values for di_format
 */
typedef enum xfs_dinode_fmt {
	XFS_DINODE_FMT_DEV,		/* xfs_dev_t */
	XFS_DINODE_FMT_LOCAL,		/* bulk data */
	XFS_DINODE_FMT_EXTENTS,		/* struct xfs_bmbt_rec */
	XFS_DINODE_FMT_BTREE,		/* struct xfs_bmdr_block */
	XFS_DINODE_FMT_UUID		/* uuid_t */
} xfs_dinode_fmt_t;

/*
 * Inode minimum and maximum sizes.
 */
#define	XFS_DINODE_MIN_LOG	8
#define	XFS_DINODE_MAX_LOG	11
#define	XFS_DINODE_MIN_SIZE	(1 << XFS_DINODE_MIN_LOG)
#define	XFS_DINODE_MAX_SIZE	(1 << XFS_DINODE_MAX_LOG)

/*
 * Inode size for given fs.
 */
#define XFS_LITINO(mp, version) \
	((int)(((mp)->m_sb.sb_inodesize) - xfs_dinode_size(version)))

#define XFS_BROOT_SIZE_ADJ(ip) \
	(XFS_BMBT_BLOCK_LEN((ip)->i_mount) - sizeof(xfs_bmdr_block_t))

/*
 * Inode data & attribute fork sizes, per inode.
 */
#define XFS_DFORK_Q(dip)		((dip)->di_forkoff != 0)
#define XFS_DFORK_BOFF(dip)		((int)((dip)->di_forkoff << 3))

#define XFS_DFORK_DSIZE(dip,mp) \
	(XFS_DFORK_Q(dip) ? \
		XFS_DFORK_BOFF(dip) : \
		XFS_LITINO(mp, (dip)->di_version))
#define XFS_DFORK_ASIZE(dip,mp) \
	(XFS_DFORK_Q(dip) ? \
		XFS_LITINO(mp, (dip)->di_version) - XFS_DFORK_BOFF(dip) : \
		0)
#define XFS_DFORK_SIZE(dip,mp,w) \
	((w) == XFS_DATA_FORK ? \
		XFS_DFORK_DSIZE(dip, mp) : \
		XFS_DFORK_ASIZE(dip, mp))

/*
 * Return pointers to the data or attribute forks.
 */
#define XFS_DFORK_DPTR(dip) \
	((char *)dip + xfs_dinode_size(dip->di_version))
#define XFS_DFORK_APTR(dip)	\
	(XFS_DFORK_DPTR(dip) + XFS_DFORK_BOFF(dip))
#define XFS_DFORK_PTR(dip,w)	\
	((w) == XFS_DATA_FORK ? XFS_DFORK_DPTR(dip) : XFS_DFORK_APTR(dip))

#define XFS_DFORK_FORMAT(dip,w) \
	((w) == XFS_DATA_FORK ? \
		(dip)->di_format : \
		(dip)->di_aformat)
#define XFS_DFORK_NEXTENTS(dip,w) \
	((w) == XFS_DATA_FORK ? \
		be32_to_cpu((dip)->di_nextents) : \
		be16_to_cpu((dip)->di_anextents))

#define	XFS_BUF_TO_DINODE(bp)	((xfs_dinode_t *)((bp)->b_addr))

/*
 * For block and character special files the 32bit dev_t is stored at the
 * beginning of the data fork.
 */
static inline xfs_dev_t xfs_dinode_get_rdev(struct xfs_dinode *dip)
{
	return be32_to_cpu(*(__be32 *)XFS_DFORK_DPTR(dip));
}

static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
{
	*(__be32 *)XFS_DFORK_DPTR(dip) = cpu_to_be32(rdev);
}

/*
 * Values for di_flags
 * There should be a one-to-one correspondence between these flags and the
 * XFS_XFLAG_s.
 */
#define XFS_DIFLAG_REALTIME_BIT  0	/* file's blocks come from rt area */
#define XFS_DIFLAG_PREALLOC_BIT  1	/* file space has been preallocated */
#define XFS_DIFLAG_NEWRTBM_BIT   2	/* for rtbitmap inode, new format */
#define XFS_DIFLAG_IMMUTABLE_BIT 3	/* inode is immutable */
#define XFS_DIFLAG_APPEND_BIT    4	/* inode is append-only */
#define XFS_DIFLAG_SYNC_BIT      5	/* inode is written synchronously */
#define XFS_DIFLAG_NOATIME_BIT   6	/* do not update atime */
#define XFS_DIFLAG_NODUMP_BIT    7	/* do not dump */
#define XFS_DIFLAG_RTINHERIT_BIT 8	/* create with realtime bit set */
#define XFS_DIFLAG_PROJINHERIT_BIT   9	/* create with parents projid */
#define XFS_DIFLAG_NOSYMLINKS_BIT   10	/* disallow symlink creation */
#define XFS_DIFLAG_EXTSIZE_BIT      11	/* inode extent size allocator hint */
#define XFS_DIFLAG_EXTSZINHERIT_BIT 12	/* inherit inode extent size */
#define XFS_DIFLAG_NODEFRAG_BIT     13	/* do not reorganize/defragment */
#define XFS_DIFLAG_FILESTREAM_BIT   14  /* use filestream allocator */
#define XFS_DIFLAG_REALTIME      (1 << XFS_DIFLAG_REALTIME_BIT)
#define XFS_DIFLAG_PREALLOC      (1 << XFS_DIFLAG_PREALLOC_BIT)
#define XFS_DIFLAG_NEWRTBM       (1 << XFS_DIFLAG_NEWRTBM_BIT)
#define XFS_DIFLAG_IMMUTABLE     (1 << XFS_DIFLAG_IMMUTABLE_BIT)
#define XFS_DIFLAG_APPEND        (1 << XFS_DIFLAG_APPEND_BIT)
#define XFS_DIFLAG_SYNC          (1 << XFS_DIFLAG_SYNC_BIT)
#define XFS_DIFLAG_NOATIME       (1 << XFS_DIFLAG_NOATIME_BIT)
#define XFS_DIFLAG_NODUMP        (1 << XFS_DIFLAG_NODUMP_BIT)
#define XFS_DIFLAG_RTINHERIT     (1 << XFS_DIFLAG_RTINHERIT_BIT)
#define XFS_DIFLAG_PROJINHERIT   (1 << XFS_DIFLAG_PROJINHERIT_BIT)
#define XFS_DIFLAG_NOSYMLINKS    (1 << XFS_DIFLAG_NOSYMLINKS_BIT)
#define XFS_DIFLAG_EXTSIZE       (1 << XFS_DIFLAG_EXTSIZE_BIT)
#define XFS_DIFLAG_EXTSZINHERIT  (1 << XFS_DIFLAG_EXTSZINHERIT_BIT)
#define XFS_DIFLAG_NODEFRAG      (1 << XFS_DIFLAG_NODEFRAG_BIT)
#define XFS_DIFLAG_FILESTREAM    (1 << XFS_DIFLAG_FILESTREAM_BIT)

#ifdef CONFIG_XFS_RT
#define XFS_IS_REALTIME_INODE(ip) ((ip)->i_d.di_flags & XFS_DIFLAG_REALTIME)
#else
#define XFS_IS_REALTIME_INODE(ip) (0)
#endif

#define XFS_DIFLAG_ANY \
	(XFS_DIFLAG_REALTIME | XFS_DIFLAG_PREALLOC | XFS_DIFLAG_NEWRTBM | \
	 XFS_DIFLAG_IMMUTABLE | XFS_DIFLAG_APPEND | XFS_DIFLAG_SYNC | \
	 XFS_DIFLAG_NOATIME | XFS_DIFLAG_NODUMP | XFS_DIFLAG_RTINHERIT | \
	 XFS_DIFLAG_PROJINHERIT | XFS_DIFLAG_NOSYMLINKS | XFS_DIFLAG_EXTSIZE | \
	 XFS_DIFLAG_EXTSZINHERIT | XFS_DIFLAG_NODEFRAG | XFS_DIFLAG_FILESTREAM)

#endif	/* __XFS_DINODE_H__ */