struct xfs_buf;
struct xfs_ifork;
+/*
+ * Allocation group header
+ *
+ * This is divided into three structures, placed in sequential 512-byte
+ * buffers after a copy of the superblock (also in a 512-byte buffer).
+ */
+#define XFS_AGF_MAGIC 0x58414746 /* 'XAGF' */
+#define XFS_AGI_MAGIC 0x58414749 /* 'XAGI' */
+#define XFS_AGFL_MAGIC 0x5841464c /* 'XAFL' */
+#define XFS_AGF_VERSION 1
+#define XFS_AGI_VERSION 1
+
+#define XFS_AGF_GOOD_VERSION(v) ((v) == XFS_AGF_VERSION)
+#define XFS_AGI_GOOD_VERSION(v) ((v) == XFS_AGI_VERSION)
+
+/*
+ * Btree number 0 is bno, 1 is cnt. This value gives the size of the
+ * arrays below.
+ */
+#define XFS_BTNUM_AGF ((int)XFS_BTNUM_CNTi + 1)
+
+/*
+ * The second word of agf_levels in the first a.g. overlaps the EFS
+ * superblock's magic number. Since the magic numbers valid for EFS
+ * are > 64k, our value cannot be confused for an EFS superblock's.
+ */
+
+typedef struct xfs_agf {
+ /*
+ * Common allocation group header information
+ */
+ __be32 agf_magicnum; /* magic number == XFS_AGF_MAGIC */
+ __be32 agf_versionnum; /* header version == XFS_AGF_VERSION */
+ __be32 agf_seqno; /* sequence # starting from 0 */
+ __be32 agf_length; /* size in blocks of a.g. */
+ /*
+ * Freespace information
+ */
+ __be32 agf_roots[XFS_BTNUM_AGF]; /* root blocks */
+ __be32 agf_spare0; /* spare field */
+ __be32 agf_levels[XFS_BTNUM_AGF]; /* btree levels */
+ __be32 agf_spare1; /* spare field */
+
+ __be32 agf_flfirst; /* first freelist block's index */
+ __be32 agf_fllast; /* last freelist block's index */
+ __be32 agf_flcount; /* count of blocks in freelist */
+ __be32 agf_freeblks; /* total free blocks */
+
+ __be32 agf_longest; /* longest free space */
+ __be32 agf_btreeblks; /* # of blocks held in AGF btrees */
+ uuid_t agf_uuid; /* uuid of filesystem */
+
+ /*
+ * reserve some contiguous space for future logged fields before we add
+ * the unlogged fields. This makes the range logging via flags and
+ * structure offsets much simpler.
+ */
+ __be64 agf_spare64[16];
+
+ /* unlogged fields, written during buffer writeback. */
+ __be64 agf_lsn; /* last write sequence */
+ __be32 agf_crc; /* crc of agf sector */
+ __be32 agf_spare2;
+
+ /* structure must be padded to 64 bit alignment */
+} xfs_agf_t;
+
+#define XFS_AGF_CRC_OFF offsetof(struct xfs_agf, agf_crc)
+
+#define XFS_AGF_MAGICNUM 0x00000001
+#define XFS_AGF_VERSIONNUM 0x00000002
+#define XFS_AGF_SEQNO 0x00000004
+#define XFS_AGF_LENGTH 0x00000008
+#define XFS_AGF_ROOTS 0x00000010
+#define XFS_AGF_LEVELS 0x00000020
+#define XFS_AGF_FLFIRST 0x00000040
+#define XFS_AGF_FLLAST 0x00000080
+#define XFS_AGF_FLCOUNT 0x00000100
+#define XFS_AGF_FREEBLKS 0x00000200
+#define XFS_AGF_LONGEST 0x00000400
+#define XFS_AGF_BTREEBLKS 0x00000800
+#define XFS_AGF_UUID 0x00001000
+#define XFS_AGF_NUM_BITS 13
+#define XFS_AGF_ALL_BITS ((1 << XFS_AGF_NUM_BITS) - 1)
+
+#define XFS_AGF_FLAGS \
+ { XFS_AGF_MAGICNUM, "MAGICNUM" }, \
+ { XFS_AGF_VERSIONNUM, "VERSIONNUM" }, \
+ { XFS_AGF_SEQNO, "SEQNO" }, \
+ { XFS_AGF_LENGTH, "LENGTH" }, \
+ { XFS_AGF_ROOTS, "ROOTS" }, \
+ { XFS_AGF_LEVELS, "LEVELS" }, \
+ { XFS_AGF_FLFIRST, "FLFIRST" }, \
+ { XFS_AGF_FLLAST, "FLLAST" }, \
+ { XFS_AGF_FLCOUNT, "FLCOUNT" }, \
+ { XFS_AGF_FREEBLKS, "FREEBLKS" }, \
+ { XFS_AGF_LONGEST, "LONGEST" }, \
+ { XFS_AGF_BTREEBLKS, "BTREEBLKS" }, \
+ { XFS_AGF_UUID, "UUID" }
+
+/* disk block (xfs_daddr_t) in the AG */
+#define XFS_AGF_DADDR(mp) ((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
+#define XFS_AGF_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
+#define XFS_BUF_TO_AGF(bp) ((xfs_agf_t *)((bp)->b_addr))
+
+/*
+ * Size of the unlinked inode hash table in the agi.
+ */
+#define XFS_AGI_UNLINKED_BUCKETS 64
+
+typedef struct xfs_agi {
+ /*
+ * Common allocation group header information
+ */
+ __be32 agi_magicnum; /* magic number == XFS_AGI_MAGIC */
+ __be32 agi_versionnum; /* header version == XFS_AGI_VERSION */
+ __be32 agi_seqno; /* sequence # starting from 0 */
+ __be32 agi_length; /* size in blocks of a.g. */
+ /*
+ * Inode information
+ * Inodes are mapped by interpreting the inode number, so no
+ * mapping data is needed here.
+ */
+ __be32 agi_count; /* count of allocated inodes */
+ __be32 agi_root; /* root of inode btree */
+ __be32 agi_level; /* levels in inode btree */
+ __be32 agi_freecount; /* number of free inodes */
+
+ __be32 agi_newino; /* new inode just allocated */
+ __be32 agi_dirino; /* last directory inode chunk */
+ /*
+ * Hash table of inodes which have been unlinked but are
+ * still being referenced.
+ */
+ __be32 agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
+ /*
+ * This marks the end of logging region 1 and start of logging region 2.
+ */
+ uuid_t agi_uuid; /* uuid of filesystem */
+ __be32 agi_crc; /* crc of agi sector */
+ __be32 agi_pad32;
+ __be64 agi_lsn; /* last write sequence */
+
+ __be32 agi_free_root; /* root of the free inode btree */
+ __be32 agi_free_level;/* levels in free inode btree */
+
+ /* structure must be padded to 64 bit alignment */
+} xfs_agi_t;
+
+#define XFS_AGI_CRC_OFF offsetof(struct xfs_agi, agi_crc)
+
+#define XFS_AGI_MAGICNUM (1 << 0)
+#define XFS_AGI_VERSIONNUM (1 << 1)
+#define XFS_AGI_SEQNO (1 << 2)
+#define XFS_AGI_LENGTH (1 << 3)
+#define XFS_AGI_COUNT (1 << 4)
+#define XFS_AGI_ROOT (1 << 5)
+#define XFS_AGI_LEVEL (1 << 6)
+#define XFS_AGI_FREECOUNT (1 << 7)
+#define XFS_AGI_NEWINO (1 << 8)
+#define XFS_AGI_DIRINO (1 << 9)
+#define XFS_AGI_UNLINKED (1 << 10)
+#define XFS_AGI_NUM_BITS_R1 11 /* end of the 1st agi logging region */
+#define XFS_AGI_ALL_BITS_R1 ((1 << XFS_AGI_NUM_BITS_R1) - 1)
+#define XFS_AGI_FREE_ROOT (1 << 11)
+#define XFS_AGI_FREE_LEVEL (1 << 12)
+#define XFS_AGI_NUM_BITS_R2 13
+
+/* disk block (xfs_daddr_t) in the AG */
+#define XFS_AGI_DADDR(mp) ((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
+#define XFS_AGI_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))
+#define XFS_BUF_TO_AGI(bp) ((xfs_agi_t *)((bp)->b_addr))
+
+/*
+ * The third a.g. block contains the a.g. freelist, an array
+ * of block pointers to blocks owned by the allocation btree code.
+ */
+#define XFS_AGFL_DADDR(mp) ((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
+#define XFS_AGFL_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
+#define XFS_BUF_TO_AGFL(bp) ((xfs_agfl_t *)((bp)->b_addr))
+
+#define XFS_BUF_TO_AGFL_BNO(mp, bp) \
+ (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
+ &(XFS_BUF_TO_AGFL(bp)->agfl_bno[0]) : \
+ (__be32 *)(bp)->b_addr)
+
+/*
+ * Size of the AGFL. For CRC-enabled filesystes we steal a couple of
+ * slots in the beginning of the block for a proper header with the
+ * location information and CRC.
+ */
+#define XFS_AGFL_SIZE(mp) \
+ (((mp)->m_sb.sb_sectsize - \
+ (xfs_sb_version_hascrc(&((mp)->m_sb)) ? \
+ sizeof(struct xfs_agfl) : 0)) / \
+ sizeof(xfs_agblock_t))
+
+typedef struct xfs_agfl {
+ __be32 agfl_magicnum;
+ __be32 agfl_seqno;
+ uuid_t agfl_uuid;
+ __be64 agfl_lsn;
+ __be32 agfl_crc;
+ __be32 agfl_bno[]; /* actually XFS_AGFL_SIZE(mp) */
+} xfs_agfl_t;
+
+#define XFS_AGFL_CRC_OFF offsetof(struct xfs_agfl, agfl_crc)
+
+
+#define XFS_AG_MAXLEVELS(mp) ((mp)->m_ag_maxlevels)
+#define XFS_MIN_FREELIST_RAW(bl,cl,mp) \
+ (MIN(bl + 1, XFS_AG_MAXLEVELS(mp)) + MIN(cl + 1, XFS_AG_MAXLEVELS(mp)))
+#define XFS_MIN_FREELIST(a,mp) \
+ (XFS_MIN_FREELIST_RAW( \
+ be32_to_cpu((a)->agf_levels[XFS_BTNUM_BNOi]), \
+ be32_to_cpu((a)->agf_levels[XFS_BTNUM_CNTi]), mp))
+#define XFS_MIN_FREELIST_PAG(pag,mp) \
+ (XFS_MIN_FREELIST_RAW( \
+ (unsigned int)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
+ (unsigned int)(pag)->pagf_levels[XFS_BTNUM_CNTi], mp))
+
+#define XFS_AGB_TO_FSB(mp,agno,agbno) \
+ (((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
+#define XFS_FSB_TO_AGNO(mp,fsbno) \
+ ((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
+#define XFS_FSB_TO_AGBNO(mp,fsbno) \
+ ((xfs_agblock_t)((fsbno) & xfs_mask32lo((mp)->m_sb.sb_agblklog)))
+#define XFS_AGB_TO_DADDR(mp,agno,agbno) \
+ ((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
+ (xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
+#define XFS_AG_DADDR(mp,agno,d) (XFS_AGB_TO_DADDR(mp, agno, 0) + (d))
+
+/*
+ * For checking for bad ranges of xfs_daddr_t's, covering multiple
+ * allocation groups or a single xfs_daddr_t that's a superblock copy.
+ */
+#define XFS_AG_CHECK_DADDR(mp,d,len) \
+ ((len) == 1 ? \
+ ASSERT((d) == XFS_SB_DADDR || \
+ xfs_daddr_to_agbno(mp, d) != XFS_SB_DADDR) : \
+ ASSERT(xfs_daddr_to_agno(mp, d) == \
+ xfs_daddr_to_agno(mp, (d) + (len) - 1)))
+
+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.
+ *
+ * Note: di_flushiter is only used by v1/2 inodes - it's effectively a zeroed
+ * padding field for v3 inodes.
+ */
+#define XFS_DINODE_MAGIC 0x494e /* 'IN' */
+#define XFS_DINODE_GOOD_VERSION(v) ((v) >= 1 && (v) <= 3)
+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 XFS_DINODE_CRC_OFF offsetof(struct xfs_dinode, di_crc)
+
+#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)))
+
+/*
+ * 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))
+
+/*
+ * 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)
+
+#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)
+
+
/*
* RealTime Device format definitions
*/
#define XFS_BTREE_LBLOCK_CRC_OFF \
offsetof(struct xfs_btree_block, bb_u.l.bb_crc)
+/*
+ * On-disk XFS access control list structure.
+ */
+struct xfs_acl_entry {
+ __be32 ae_tag;
+ __be32 ae_id;
+ __be16 ae_perm;
+ __be16 ae_pad; /* fill the implicit hole in the structure */
+};
+
+struct xfs_acl {
+ __be32 acl_cnt;
+ struct xfs_acl_entry acl_entry[0];
+};
+
+/*
+ * The number of ACL entries allowed is defined by the on-disk format.
+ * For v4 superblocks, that is limited to 25 entries. For v5 superblocks, it is
+ * limited only by the maximum size of the xattr that stores the information.
+ */
+#define XFS_ACL_MAX_ENTRIES(mp) \
+ (xfs_sb_version_hascrc(&mp->m_sb) \
+ ? (XATTR_SIZE_MAX - sizeof(struct xfs_acl)) / \
+ sizeof(struct xfs_acl_entry) \
+ : 25)
+
+#define XFS_ACL_MAX_SIZE(mp) \
+ (sizeof(struct xfs_acl) + \
+ sizeof(struct xfs_acl_entry) * XFS_ACL_MAX_ENTRIES((mp)))
+
+/* On-disk XFS extended attribute names */
+#define SGI_ACL_FILE (unsigned char *)"SGI_ACL_FILE"
+#define SGI_ACL_DEFAULT (unsigned char *)"SGI_ACL_DEFAULT"
+#define SGI_ACL_FILE_SIZE (sizeof(SGI_ACL_FILE)-1)
+#define SGI_ACL_DEFAULT_SIZE (sizeof(SGI_ACL_DEFAULT)-1)
+
#endif /* __XFS_FORMAT_H__ */