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 /* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
  * Copyright (c) 2013 Red Hat, Inc.
  * All Rights Reserved.
  */
 #ifndef __XFS_DA_FORMAT_H__
 #define __XFS_DA_FORMAT_H__
 
 /*
  * This structure is common to both leaf nodes and non-leaf nodes in the Btree.
  *
  * It is used to manage a doubly linked list of all blocks at the same
  * level in the Btree, and to identify which type of block this is.
  */
 #define XFS_DA_NODE_MAGIC   0xfebe  /* magic number: non-leaf blocks */
 #define XFS_ATTR_LEAF_MAGIC 0xfbee  /* magic number: attribute leaf blks */
 #define XFS_DIR2_LEAF1_MAGIC    0xd2f1  /* magic number: v2 dirlf single blks */
 #define XFS_DIR2_LEAFN_MAGIC    0xd2ff  /* magic number: v2 dirlf multi blks */
 
 typedef struct xfs_da_blkinfo {
     __be32      forw;           /* previous block in list */
     __be32      back;           /* following block in list */
     __be16      magic;          /* validity check on block */
     __be16      pad;            /* unused */
 } xfs_da_blkinfo_t;
 
 /*
  * CRC enabled directory structure types
  *
  * The headers change size for the additional verification information, but
  * otherwise the tree layouts and contents are unchanged. Hence the da btree
  * code can use the struct xfs_da_blkinfo for manipulating the tree links and
  * magic numbers without modification for both v2 and v3 nodes.
  */
 #define XFS_DA3_NODE_MAGIC  0x3ebe  /* magic number: non-leaf blocks */
 #define XFS_ATTR3_LEAF_MAGIC    0x3bee  /* magic number: attribute leaf blks */
 #define XFS_DIR3_LEAF1_MAGIC    0x3df1  /* magic number: v3 dirlf single blks */
 #define XFS_DIR3_LEAFN_MAGIC    0x3dff  /* magic number: v3 dirlf multi blks */
 
 struct xfs_da3_blkinfo {
     /*
      * the node link manipulation code relies on the fact that the first
      * element of this structure is the struct xfs_da_blkinfo so it can
      * ignore the differences in the rest of the structures.
      */
     struct xfs_da_blkinfo   hdr;
     __be32          crc;    /* CRC of block */
     __be64          blkno;  /* first block of the buffer */
     __be64          lsn;    /* sequence number of last write */
     uuid_t          uuid;   /* filesystem we belong to */
     __be64          owner;  /* inode that owns the block */
 };
 
 /*
  * This is the structure of the root and intermediate nodes in the Btree.
  * The leaf nodes are defined above.
  *
  * Entries are not packed.
  *
  * Since we have duplicate keys, use a binary search but always follow
  * all match in the block, not just the first match found.
  */
 #define XFS_DA_NODE_MAXDEPTH    5   /* max depth of Btree */
 
 typedef struct xfs_da_node_hdr {
     struct xfs_da_blkinfo   info;   /* block type, links, etc. */
     __be16          __count; /* count of active entries */
     __be16          __level; /* level above leaves (leaf == 0) */
 } xfs_da_node_hdr_t;
 
 struct xfs_da3_node_hdr {
     struct xfs_da3_blkinfo  info;   /* block type, links, etc. */
     __be16          __count; /* count of active entries */
     __be16          __level; /* level above leaves (leaf == 0) */
     __be32          __pad32;
 };
 
 #define XFS_DA3_NODE_CRC_OFF    (offsetof(struct xfs_da3_node_hdr, info.crc))
 
 typedef struct xfs_da_node_entry {
     __be32  hashval;    /* hash value for this descendant */
     __be32  before;     /* Btree block before this key */
 } xfs_da_node_entry_t;
 
 typedef struct xfs_da_intnode {
     struct xfs_da_node_hdr  hdr;
     struct xfs_da_node_entry __btree[];
 } xfs_da_intnode_t;
 
 struct xfs_da3_intnode {
     struct xfs_da3_node_hdr hdr;
     struct xfs_da_node_entry __btree[];
 };
 
 /*
  * Directory version 2.
  *
  * There are 4 possible formats:
  *  - shortform - embedded into the inode
  *  - single block - data with embedded leaf at the end
  *  - multiple data blocks, single leaf+freeindex block
  *  - data blocks, node and leaf blocks (btree), freeindex blocks
  *
  * Note: many node blocks structures and constants are shared with the attr
  * code and defined in xfs_da_btree.h.
  */
 
 #define XFS_DIR2_BLOCK_MAGIC    0x58443242  /* XD2B: single block dirs */
 #define XFS_DIR2_DATA_MAGIC 0x58443244  /* XD2D: multiblock dirs */
 #define XFS_DIR2_FREE_MAGIC 0x58443246  /* XD2F: free index blocks */
 
 /*
  * Directory Version 3 With CRCs.
  *
  * The tree formats are the same as for version 2 directories.  The difference
  * is in the block header and dirent formats. In many cases the v3 structures
  * use v2 definitions as they are no different and this makes code sharing much
  * easier.
  *
  * Also, the xfs_dir3_*() functions handle both v2 and v3 formats - if the
  * format is v2 then they switch to the existing v2 code, or the format is v3
  * they implement the v3 functionality. This means the existing dir2 is a mix of
  * xfs_dir2/xfs_dir3 calls and functions. The xfs_dir3 functions are called
  * where there is a difference in the formats, otherwise the code is unchanged.
  *
  * Where it is possible, the code decides what to do based on the magic numbers
  * in the blocks rather than feature bits in the superblock. This means the code
  * is as independent of the external XFS code as possible as doesn't require
  * passing struct xfs_mount pointers into places where it isn't really
  * necessary.
  *
  * Version 3 includes:
  *
  *  - a larger block header for CRC and identification purposes and so the
  *  offsets of all the structures inside the blocks are different.
  *
  *  - new magic numbers to be able to detect the v2/v3 types on the fly.
  */
 
 #define XFS_DIR3_BLOCK_MAGIC    0x58444233  /* XDB3: single block dirs */
 #define XFS_DIR3_DATA_MAGIC 0x58444433  /* XDD3: multiblock dirs */
 #define XFS_DIR3_FREE_MAGIC 0x58444633  /* XDF3: free index blocks */
 
 /*
  * Dirents in version 3 directories have a file type field. Additions to this
  * list are an on-disk format change, requiring feature bits. Valid values
  * are as follows:
  */
 #define XFS_DIR3_FT_UNKNOWN     0
 #define XFS_DIR3_FT_REG_FILE        1
 #define XFS_DIR3_FT_DIR         2
 #define XFS_DIR3_FT_CHRDEV      3
 #define XFS_DIR3_FT_BLKDEV      4
 #define XFS_DIR3_FT_FIFO        5
 #define XFS_DIR3_FT_SOCK        6
 #define XFS_DIR3_FT_SYMLINK     7
 #define XFS_DIR3_FT_WHT         8
 
 #define XFS_DIR3_FT_MAX         9
 
 /*
  * Byte offset in data block and shortform entry.
  */
 typedef uint16_t    xfs_dir2_data_off_t;
 #define NULLDATAOFF 0xffffU
 typedef uint        xfs_dir2_data_aoff_t;   /* argument form */
 
 /*
  * Offset in data space of a data entry.
  */
 typedef uint32_t    xfs_dir2_dataptr_t;
 #define XFS_DIR2_MAX_DATAPTR    ((xfs_dir2_dataptr_t)0xffffffff)
 #define XFS_DIR2_NULL_DATAPTR   ((xfs_dir2_dataptr_t)0)
 
 /*
  * Byte offset in a directory.
  */
 typedef xfs_off_t   xfs_dir2_off_t;
 
 /*
  * Directory block number (logical dirblk in file)
  */
 typedef uint32_t    xfs_dir2_db_t;
 
 #define XFS_INO32_SIZE  4
 #define XFS_INO64_SIZE  8
 #define XFS_INO64_DIFF  (XFS_INO64_SIZE - XFS_INO32_SIZE)
 
 #define XFS_DIR2_MAX_SHORT_INUM ((xfs_ino_t)0xffffffffULL)
 
 /*
  * Directory layout when stored internal to an inode.
  *
  * Small directories are packed as tightly as possible so as to fit into the
  * literal area of the inode.  These "shortform" directories consist of a
  * single xfs_dir2_sf_hdr header followed by zero or more xfs_dir2_sf_entry
  * structures.  Due the different inode number storage size and the variable
  * length name field in the xfs_dir2_sf_entry all these structure are
  * variable length, and the accessors in this file should be used to iterate
  * over them.
  */
 typedef struct xfs_dir2_sf_hdr {
     uint8_t         count;      /* count of entries */
     uint8_t         i8count;    /* count of 8-byte inode #s */
     uint8_t         parent[8];  /* parent dir inode number */
 } __packed xfs_dir2_sf_hdr_t;
 
 typedef struct xfs_dir2_sf_entry {
     __u8            namelen;    /* actual name length */
     __u8            offset[2];  /* saved offset */
     __u8            name[];     /* name, variable size */
     /*
      * A single byte containing the file type field follows the inode
      * number for version 3 directory entries.
      *
      * A 64-bit or 32-bit inode number follows here, at a variable offset
      * after the name.
      */
 } __packed xfs_dir2_sf_entry_t;
 
 static inline int xfs_dir2_sf_hdr_size(int i8count)
 {
     return sizeof(struct xfs_dir2_sf_hdr) -
         (i8count == 0) * XFS_INO64_DIFF;
 }
 
 static inline xfs_dir2_data_aoff_t
 xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
 {
     return get_unaligned_be16(sfep->offset);
 }
 
 static inline void
 xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t *sfep, xfs_dir2_data_aoff_t off)
 {
     put_unaligned_be16(off, sfep->offset);
 }
 
 static inline struct xfs_dir2_sf_entry *
 xfs_dir2_sf_firstentry(struct xfs_dir2_sf_hdr *hdr)
 {
     return (struct xfs_dir2_sf_entry *)
         ((char *)hdr + xfs_dir2_sf_hdr_size(hdr->i8count));
 }
 
 /*
  * Data block structures.
  *
  * A pure data block looks like the following drawing on disk:
  *
  *    +-------------------------------------------------+
  *    | xfs_dir2_data_hdr_t                             |
  *    +-------------------------------------------------+
  *    | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
  *    | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
  *    | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
  *    | ...                                             |
  *    +-------------------------------------------------+
  *    | unused space                                    |
  *    +-------------------------------------------------+
  *
  * As all the entries are variable size structures the accessors below should
  * be used to iterate over them.
  *
  * In addition to the pure data blocks for the data and node formats,
  * most structures are also used for the combined data/freespace "block"
  * format below.
  */
 
 #define XFS_DIR2_DATA_ALIGN_LOG 3       /* i.e., 8 bytes */
 #define XFS_DIR2_DATA_ALIGN (1 << XFS_DIR2_DATA_ALIGN_LOG)
 #define XFS_DIR2_DATA_FREE_TAG  0xffff
 #define XFS_DIR2_DATA_FD_COUNT  3
 
 /*
  * Directory address space divided into sections,
  * spaces separated by 32GB.
  */
 #define XFS_DIR2_MAX_SPACES 3
 #define XFS_DIR2_SPACE_SIZE (1ULL << (32 + XFS_DIR2_DATA_ALIGN_LOG))
 #define XFS_DIR2_DATA_SPACE 0
 #define XFS_DIR2_DATA_OFFSET    (XFS_DIR2_DATA_SPACE * XFS_DIR2_SPACE_SIZE)
 
 /*
  * Describe a free area in the data block.
  *
  * The freespace will be formatted as a xfs_dir2_data_unused_t.
  */
 typedef struct xfs_dir2_data_free {
     __be16          offset;     /* start of freespace */
     __be16          length;     /* length of freespace */
 } xfs_dir2_data_free_t;
 
 /*
  * Header for the data blocks.
  *
  * The code knows that XFS_DIR2_DATA_FD_COUNT is 3.
  */
 typedef struct xfs_dir2_data_hdr {
     __be32          magic;      /* XFS_DIR2_DATA_MAGIC or */
                         /* XFS_DIR2_BLOCK_MAGIC */
     xfs_dir2_data_free_t    bestfree[XFS_DIR2_DATA_FD_COUNT];
 } xfs_dir2_data_hdr_t;
 
 /*
  * define a structure for all the verification fields we are adding to the
  * directory block structures. This will be used in several structures.
  * The magic number must be the first entry to align with all the dir2
  * structures so we determine how to decode them just by the magic number.
  */
 struct xfs_dir3_blk_hdr {
     __be32          magic;  /* magic number */
     __be32          crc;    /* CRC of block */
     __be64          blkno;  /* first block of the buffer */
     __be64          lsn;    /* sequence number of last write */
     uuid_t          uuid;   /* filesystem we belong to */
     __be64          owner;  /* inode that owns the block */
 };
 
 struct xfs_dir3_data_hdr {
     struct xfs_dir3_blk_hdr hdr;
     xfs_dir2_data_free_t    best_free[XFS_DIR2_DATA_FD_COUNT];
     __be32          pad;    /* 64 bit alignment */
 };
 
 #define XFS_DIR3_DATA_CRC_OFF  offsetof(struct xfs_dir3_data_hdr, hdr.crc)
 
 /*
  * Active entry in a data block.
  *
  * Aligned to 8 bytes.  After the variable length name field there is a
  * 2 byte tag field, which can be accessed using xfs_dir3_data_entry_tag_p.
  *
  * For dir3 structures, there is file type field between the name and the tag.
  * This can only be manipulated by helper functions. It is packed hard against
  * the end of the name so any padding for rounding is between the file type and
  * the tag.
  */
 typedef struct xfs_dir2_data_entry {
     __be64          inumber;    /* inode number */
     __u8            namelen;    /* name length */
     __u8            name[];     /* name bytes, no null */
      /* __u8            filetype; */    /* type of inode we point to */
      /* __be16                  tag; */     /* starting offset of us */
 } xfs_dir2_data_entry_t;
 
 /*
  * Unused entry in a data block.
  *
  * Aligned to 8 bytes.  Tag appears as the last 2 bytes and must be accessed
  * using xfs_dir2_data_unused_tag_p.
  */
 typedef struct xfs_dir2_data_unused {
     __be16          freetag;    /* XFS_DIR2_DATA_FREE_TAG */
     __be16          length;     /* total free length */
                         /* variable offset */
     __be16          tag;        /* starting offset of us */
 } xfs_dir2_data_unused_t;
 
 /*
  * Pointer to a freespace's tag word.
  */
 static inline __be16 *
 xfs_dir2_data_unused_tag_p(struct xfs_dir2_data_unused *dup)
 {
     return (__be16 *)((char *)dup +
             be16_to_cpu(dup->length) - sizeof(__be16));
 }
 
 /*
  * Leaf block structures.
  *
  * A pure leaf block looks like the following drawing on disk:
  *
  *    +---------------------------+
  *    | xfs_dir2_leaf_hdr_t       |
  *    +---------------------------+
  *    | xfs_dir2_leaf_entry_t     |
  *    | xfs_dir2_leaf_entry_t     |
  *    | xfs_dir2_leaf_entry_t     |
  *    | xfs_dir2_leaf_entry_t     |
  *    | ...                       |
  *    +---------------------------+
  *    | xfs_dir2_data_off_t       |
  *    | xfs_dir2_data_off_t       |
  *    | xfs_dir2_data_off_t       |
  *    | ...                       |
  *    +---------------------------+
  *    | xfs_dir2_leaf_tail_t      |
  *    +---------------------------+
  *
  * The xfs_dir2_data_off_t members (bests) and tail are at the end of the block
  * for single-leaf (magic = XFS_DIR2_LEAF1_MAGIC) blocks only, but not present
  * for directories with separate leaf nodes and free space blocks
  * (magic = XFS_DIR2_LEAFN_MAGIC).
  *
  * As all the entries are variable size structures the accessors below should
  * be used to iterate over them.
  */
 
 /*
  * Offset of the leaf/node space.  First block in this space
  * is the btree root.
  */
 #define XFS_DIR2_LEAF_SPACE 1
 #define XFS_DIR2_LEAF_OFFSET    (XFS_DIR2_LEAF_SPACE * XFS_DIR2_SPACE_SIZE)
 
 /*
  * Leaf block header.
  */
 typedef struct xfs_dir2_leaf_hdr {
     xfs_da_blkinfo_t    info;       /* header for da routines */
     __be16          count;      /* count of entries */
     __be16          stale;      /* count of stale entries */
 } xfs_dir2_leaf_hdr_t;
 
 struct xfs_dir3_leaf_hdr {
     struct xfs_da3_blkinfo  info;       /* header for da routines */
     __be16          count;      /* count of entries */
     __be16          stale;      /* count of stale entries */
     __be32          pad;        /* 64 bit alignment */
 };
 
 /*
  * Leaf block entry.
  */
 typedef struct xfs_dir2_leaf_entry {
     __be32          hashval;    /* hash value of name */
     __be32          address;    /* address of data entry */
 } xfs_dir2_leaf_entry_t;
 
 /*
  * Leaf block tail.
  */
 typedef struct xfs_dir2_leaf_tail {
     __be32          bestcount;
 } xfs_dir2_leaf_tail_t;
 
 /*
  * Leaf block.
  */
 typedef struct xfs_dir2_leaf {
     xfs_dir2_leaf_hdr_t hdr;            /* leaf header */
     xfs_dir2_leaf_entry_t   __ents[];       /* entries */
 } xfs_dir2_leaf_t;
 
 struct xfs_dir3_leaf {
     struct xfs_dir3_leaf_hdr    hdr;        /* leaf header */
     struct xfs_dir2_leaf_entry  __ents[];   /* entries */
 };
 
 #define XFS_DIR3_LEAF_CRC_OFF  offsetof(struct xfs_dir3_leaf_hdr, info.crc)
 
 /*
  * Get address of the bests array in the single-leaf block.
  */
 static inline __be16 *
 xfs_dir2_leaf_bests_p(struct xfs_dir2_leaf_tail *ltp)
 {
     return (__be16 *)ltp - be32_to_cpu(ltp->bestcount);
 }
 
 /*
  * Free space block definitions for the node format.
  */
 
 /*
  * Offset of the freespace index.
  */
 #define XFS_DIR2_FREE_SPACE 2
 #define XFS_DIR2_FREE_OFFSET    (XFS_DIR2_FREE_SPACE * XFS_DIR2_SPACE_SIZE)
 
 typedef struct xfs_dir2_free_hdr {
     __be32          magic;      /* XFS_DIR2_FREE_MAGIC */
     __be32          firstdb;    /* db of first entry */
     __be32          nvalid;     /* count of valid entries */
     __be32          nused;      /* count of used entries */
 } xfs_dir2_free_hdr_t;
 
 typedef struct xfs_dir2_free {
     xfs_dir2_free_hdr_t hdr;        /* block header */
     __be16          bests[];    /* best free counts */
                         /* unused entries are -1 */
 } xfs_dir2_free_t;
 
 struct xfs_dir3_free_hdr {
     struct xfs_dir3_blk_hdr hdr;
     __be32          firstdb;    /* db of first entry */
     __be32          nvalid;     /* count of valid entries */
     __be32          nused;      /* count of used entries */
     __be32          pad;        /* 64 bit alignment */
 };
 
 struct xfs_dir3_free {
     struct xfs_dir3_free_hdr hdr;
     __be16          bests[];    /* best free counts */
                         /* unused entries are -1 */
 };
 
 #define XFS_DIR3_FREE_CRC_OFF  offsetof(struct xfs_dir3_free, hdr.hdr.crc)
 
 /*
  * Single block format.
  *
  * The single block format looks like the following drawing on disk:
  *
  *    +-------------------------------------------------+
  *    | xfs_dir2_data_hdr_t                             |
  *    +-------------------------------------------------+
  *    | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
  *    | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t |
  *    | xfs_dir2_data_entry_t OR xfs_dir2_data_unused_t :
  *    | ...                                             |
  *    +-------------------------------------------------+
  *    | unused space                                    |
  *    +-------------------------------------------------+
  *    | ...                                             |
  *    | xfs_dir2_leaf_entry_t                           |
  *    | xfs_dir2_leaf_entry_t                           |
  *    +-------------------------------------------------+
  *    | xfs_dir2_block_tail_t                           |
  *    +-------------------------------------------------+
  *
  * As all the entries are variable size structures the accessors below should
  * be used to iterate over them.
  */
 
 typedef struct xfs_dir2_block_tail {
     __be32      count;          /* count of leaf entries */
     __be32      stale;          /* count of stale lf entries */
 } xfs_dir2_block_tail_t;
 
 /*
  * Pointer to the leaf entries embedded in a data block (1-block format)
  */
 static inline struct xfs_dir2_leaf_entry *
 xfs_dir2_block_leaf_p(struct xfs_dir2_block_tail *btp)
 {
     return ((struct xfs_dir2_leaf_entry *)btp) - be32_to_cpu(btp->count);
 }
 
 
 /*
  * Attribute storage layout
  *
  * Attribute lists are structured around Btrees where all the data
  * elements are in the leaf nodes.  Attribute names are hashed into an int,
  * then that int is used as the index into the Btree.  Since the hashval
  * of an attribute name may not be unique, we may have duplicate keys.  The
  * internal links in the Btree are logical block offsets into the file.
  *
  * Struct leaf_entry's are packed from the top.  Name/values grow from the
  * bottom but are not packed.  The freemap contains run-length-encoded entries
  * for the free bytes after the leaf_entry's, but only the N largest such,
  * smaller runs are dropped.  When the freemap doesn't show enough space
  * for an allocation, we compact the name/value area and try again.  If we
  * still don't have enough space, then we have to split the block.  The
  * name/value structs (both local and remote versions) must be 32bit aligned.
  *
  * Since we have duplicate hash keys, for each key that matches, compare
  * the actual name string.  The root and intermediate node search always
  * takes the first-in-the-block key match found, so we should only have
  * to work "forw"ard.  If none matches, continue with the "forw"ard leaf
  * nodes until the hash key changes or the attribute name is found.
  *
  * We store the fact that an attribute is a ROOT/USER/SECURE attribute in
  * the leaf_entry.  The namespaces are independent only because we also look
  * at the namespace bit when we are looking for a matching attribute name.
  *
  * We also store an "incomplete" bit in the leaf_entry.  It shows that an
  * attribute is in the middle of being created and should not be shown to
  * the user if we crash during the time that the bit is set.  We clear the
  * bit when we have finished setting up the attribute.  We do this because
  * we cannot create some large attributes inside a single transaction, and we
  * need some indication that we weren't finished if we crash in the middle.
  */
 #define XFS_ATTR_LEAF_MAPSIZE   3   /* how many freespace slots */
 
 /*
  * Entries are packed toward the top as tight as possible.
  */
 struct xfs_attr_shortform {
     struct xfs_attr_sf_hdr {    /* constant-structure header block */
         __be16  totsize;    /* total bytes in shortform list */
         __u8    count;  /* count of active entries */
         __u8    padding;
     } hdr;
     struct xfs_attr_sf_entry {
         uint8_t namelen;    /* actual length of name (no NULL) */
         uint8_t valuelen;   /* actual length of value (no NULL) */
         uint8_t flags;  /* flags bits (see xfs_attr_leaf.h) */
         uint8_t nameval[];  /* name & value bytes concatenated */
     } list[1];          /* variable sized array */
 };
 
 typedef struct xfs_attr_leaf_map {  /* RLE map of free bytes */
     __be16  base;             /* base of free region */
     __be16  size;             /* length of free region */
 } xfs_attr_leaf_map_t;
 
 typedef struct xfs_attr_leaf_hdr {  /* constant-structure header block */
     xfs_da_blkinfo_t info;      /* block type, links, etc. */
     __be16  count;          /* count of active leaf_entry's */
     __be16  usedbytes;      /* num bytes of names/values stored */
     __be16  firstused;      /* first used byte in name area */
     __u8    holes;          /* != 0 if blk needs compaction */
     __u8    pad1;
     xfs_attr_leaf_map_t freemap[XFS_ATTR_LEAF_MAPSIZE];
                     /* N largest free regions */
 } xfs_attr_leaf_hdr_t;
 
 typedef struct xfs_attr_leaf_entry {    /* sorted on key, not name */
     __be32  hashval;        /* hash value of name */
     __be16  nameidx;        /* index into buffer of name/value */
     __u8    flags;          /* LOCAL/ROOT/SECURE/INCOMPLETE flag */
     __u8    pad2;           /* unused pad byte */
 } xfs_attr_leaf_entry_t;
 
 typedef struct xfs_attr_leaf_name_local {
     __be16  valuelen;       /* number of bytes in value */
     __u8    namelen;        /* length of name bytes */
     __u8    nameval[1];     /* name/value bytes */
 } xfs_attr_leaf_name_local_t;
 
 typedef struct xfs_attr_leaf_name_remote {
     __be32  valueblk;       /* block number of value bytes */
     __be32  valuelen;       /* number of bytes in value */
     __u8    namelen;        /* length of name bytes */
     __u8    name[1];        /* name bytes */
 } xfs_attr_leaf_name_remote_t;
 
 typedef struct xfs_attr_leafblock {
     xfs_attr_leaf_hdr_t hdr;    /* constant-structure header block */
     xfs_attr_leaf_entry_t   entries[1]; /* sorted on key, not name */
     /*
      * The rest of the block contains the following structures after the
      * leaf entries, growing from the bottom up. The variables are never
      * referenced and definining them can actually make gcc optimize away
      * accesses to the 'entries' array above index 0 so don't do that.
      *
      * xfs_attr_leaf_name_local_t namelist;
      * xfs_attr_leaf_name_remote_t valuelist;
      */
 } xfs_attr_leafblock_t;
 
 /*
  * CRC enabled leaf structures. Called "version 3" structures to match the
  * version number of the directory and dablk structures for this feature, and
  * attr2 is already taken by the variable inode attribute fork size feature.
  */
 struct xfs_attr3_leaf_hdr {
     struct xfs_da3_blkinfo  info;
     __be16          count;
     __be16          usedbytes;
     __be16          firstused;
     __u8            holes;
     __u8            pad1;
     struct xfs_attr_leaf_map freemap[XFS_ATTR_LEAF_MAPSIZE];
     __be32          pad2;       /* 64 bit alignment */
 };
 
 #define XFS_ATTR3_LEAF_CRC_OFF  (offsetof(struct xfs_attr3_leaf_hdr, info.crc))
 
 struct xfs_attr3_leafblock {
     struct xfs_attr3_leaf_hdr   hdr;
     struct xfs_attr_leaf_entry  entries[1];
 
     /*
      * The rest of the block contains the following structures after the
      * leaf entries, growing from the bottom up. The variables are never
      * referenced, the locations accessed purely from helper functions.
      *
      * struct xfs_attr_leaf_name_local
      * struct xfs_attr_leaf_name_remote
      */
 };
 
 /*
  * Special value to represent fs block size in the leaf header firstused field.
  * Only used when block size overflows the 2-bytes available on disk.
  */
 #define XFS_ATTR3_LEAF_NULLOFF  0
 
 /*
  * Flags used in the leaf_entry[i].flags field.
  */
 #define XFS_ATTR_LOCAL_BIT  0   /* attr is stored locally */
 #define XFS_ATTR_ROOT_BIT   1   /* limit access to trusted attrs */
 #define XFS_ATTR_SECURE_BIT 2   /* limit access to secure attrs */
 #define XFS_ATTR_INCOMPLETE_BIT 7   /* attr in middle of create/delete */
 #define XFS_ATTR_LOCAL      (1u << XFS_ATTR_LOCAL_BIT)
 #define XFS_ATTR_ROOT       (1u << XFS_ATTR_ROOT_BIT)
 #define XFS_ATTR_SECURE     (1u << XFS_ATTR_SECURE_BIT)
 #define XFS_ATTR_INCOMPLETE (1u << XFS_ATTR_INCOMPLETE_BIT)
 #define XFS_ATTR_NSP_ONDISK_MASK    (XFS_ATTR_ROOT | XFS_ATTR_SECURE)
 
 /*
  * Alignment for namelist and valuelist entries (since they are mixed
  * there can be only one alignment value)
  */
 #define XFS_ATTR_LEAF_NAME_ALIGN    ((uint)sizeof(xfs_dablk_t))
 
 static inline int
 xfs_attr3_leaf_hdr_size(struct xfs_attr_leafblock *leafp)
 {
     if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
         return sizeof(struct xfs_attr3_leaf_hdr);
     return sizeof(struct xfs_attr_leaf_hdr);
 }
 
 static inline struct xfs_attr_leaf_entry *
 xfs_attr3_leaf_entryp(xfs_attr_leafblock_t *leafp)
 {
     if (leafp->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC))
         return &((struct xfs_attr3_leafblock *)leafp)->entries[0];
     return &leafp->entries[0];
 }
 
 /*
  * Cast typed pointers for "local" and "remote" name/value structs.
  */
 static inline char *
 xfs_attr3_leaf_name(xfs_attr_leafblock_t *leafp, int idx)
 {
     struct xfs_attr_leaf_entry *entries = xfs_attr3_leaf_entryp(leafp);
 
     return &((char *)leafp)[be16_to_cpu(entries[idx].nameidx)];
 }
 
 static inline xfs_attr_leaf_name_remote_t *
 xfs_attr3_leaf_name_remote(xfs_attr_leafblock_t *leafp, int idx)
 {
     return (xfs_attr_leaf_name_remote_t *)xfs_attr3_leaf_name(leafp, idx);
 }
 
 static inline xfs_attr_leaf_name_local_t *
 xfs_attr3_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx)
 {
     return (xfs_attr_leaf_name_local_t *)xfs_attr3_leaf_name(leafp, idx);
 }
 
 /*
  * Calculate total bytes used (including trailing pad for alignment) for
  * a "local" name/value structure, a "remote" name/value structure, and
  * a pointer which might be either.
  */
 static inline int xfs_attr_leaf_entsize_remote(int nlen)
 {
     return round_up(sizeof(struct xfs_attr_leaf_name_remote) - 1 +
             nlen, XFS_ATTR_LEAF_NAME_ALIGN);
 }
 
 static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen)
 {
     return round_up(sizeof(struct xfs_attr_leaf_name_local) - 1 +
             nlen + vlen, XFS_ATTR_LEAF_NAME_ALIGN);
 }
 
 static inline int xfs_attr_leaf_entsize_local_max(int bsize)
 {
     return (((bsize) >> 1) + ((bsize) >> 2));
 }
 
 
 
 /*
  * Remote attribute block format definition
  *
  * There is one of these headers per filesystem block in a remote attribute.
  * This is done to ensure there is a 1:1 mapping between the attribute value
  * length and the number of blocks needed to store the attribute. This makes the
  * verification of a buffer a little more complex, but greatly simplifies the
  * allocation, reading and writing of these attributes as we don't have to guess
  * the number of blocks needed to store the attribute data.
  */
 #define XFS_ATTR3_RMT_MAGIC 0x5841524d  /* XARM */
 
 struct xfs_attr3_rmt_hdr {
     __be32  rm_magic;
     __be32  rm_offset;
     __be32  rm_bytes;
     __be32  rm_crc;
     uuid_t  rm_uuid;
     __be64  rm_owner;
     __be64  rm_blkno;
     __be64  rm_lsn;
 };
 
 #define XFS_ATTR3_RMT_CRC_OFF   offsetof(struct xfs_attr3_rmt_hdr, rm_crc)
 
 #define XFS_ATTR3_RMT_BUF_SPACE(mp, bufsize)    \
     ((bufsize) - (xfs_has_crc((mp)) ? \
             sizeof(struct xfs_attr3_rmt_hdr) : 0))
 
 /* Number of bytes in a directory block. */
 static inline unsigned int xfs_dir2_dirblock_bytes(struct xfs_sb *sbp)
 {
     return 1 << (sbp->sb_blocklog + sbp->sb_dirblklog);
 }
 
 xfs_failaddr_t xfs_da3_blkinfo_verify(struct xfs_buf *bp,
                       struct xfs_da3_blkinfo *hdr3);
 
 #endif /* __XFS_DA_FORMAT_H__ */

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