- 根目录:
- fs
- xfs
- xfs_da_format.h
/*
* Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
* Copyright (c) 2013 Red Hat, 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_DA_FORMAT_H__
#define __XFS_DA_FORMAT_H__
/*========================================================================
* Directory Structure when greater than XFS_LBSIZE(mp) bytes.
*========================================================================*/
/*
* 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: v2 dirlf single blks */
#define XFS_DIR3_LEAFN_MAGIC 0x3dff /* magic number: v2 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[];
};
/*
* In-core version of the node header to abstract the differences in the v2 and
* v3 disk format of the headers. Callers need to convert to/from disk format as
* appropriate.
*/
struct xfs_da3_icnode_hdr {
__uint32_t forw;
__uint32_t back;
__uint16_t magic;
__uint16_t count;
__uint16_t level;
};
#define XFS_LBSIZE(mp) (mp)->m_sb.sb_blocksize
/*
* 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 */
/*
* Normalized offset (in a data block) of the entry, really xfs_dir2_data_off_t.
* Only need 16 bits, this is the byte offset into the single block form.
*/
typedef struct { __uint8_t i[2]; } __arch_pack xfs_dir2_sf_off_t;
/*
* 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;
/*
* Inode number stored as 8 8-bit values.
*/
typedef struct { __uint8_t i[8]; } xfs_dir2_ino8_t;
/*
* Inode number stored as 4 8-bit values.
* Works a lot of the time, when all the inode numbers in a directory
* fit in 32 bits.
*/
typedef struct { __uint8_t i[4]; } xfs_dir2_ino4_t;
typedef union {
xfs_dir2_ino8_t i8;
xfs_dir2_ino4_t i4;
} xfs_dir2_inou_t;
#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 */
xfs_dir2_inou_t parent; /* parent dir inode number */
} __arch_pack xfs_dir2_sf_hdr_t;
typedef struct xfs_dir2_sf_entry {
__u8 namelen; /* actual name length */
xfs_dir2_sf_off_t offset; /* 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 xfs_dir2_ino8_t or xfs_dir2_ino4_t follows here, at a
* variable offset after the name.
*/
} __arch_pack xfs_dir2_sf_entry_t;
static inline int xfs_dir2_sf_hdr_size(int i8count)
{
return sizeof(struct xfs_dir2_sf_hdr) -
(i8count == 0) *
(sizeof(xfs_dir2_ino8_t) - sizeof(xfs_dir2_ino4_t));
}
static inline xfs_dir2_data_aoff_t
xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
{
return get_unaligned_be16(&sfep->offset.i);
}
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.i);
}
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_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)
#define XFS_DIR2_DATA_FIRSTDB(mp) \
xfs_dir2_byte_to_db(mp, XFS_DIR2_DATA_OFFSET)
/*
* 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)
#define XFS_DIR2_LEAF_FIRSTDB(mp) \
xfs_dir2_byte_to_db(mp, XFS_DIR2_LEAF_OFFSET)
/*
* 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 */
};
struct xfs_dir3_icleaf_hdr {
__uint32_t forw;
__uint32_t back;
__uint16_t magic;
__uint16_t count;
__uint16_t stale;
};
/*
* 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 bestcount field in the single-leaf block.
*/
static inline struct xfs_dir2_leaf_tail *
xfs_dir2_leaf_tail_p(struct xfs_mount *mp, struct xfs_dir2_leaf *lp)
{
return (struct xfs_dir2_leaf_tail *)
((char *)lp + mp->m_dirblksize -
sizeof(struct xfs_dir2_leaf_tail));
}
/*
* 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);
}
/*
* DB blocks here are logical directory block numbers, not filesystem blocks.
*/
/*
* Convert dataptr to byte in file space
*/
static inline xfs_dir2_off_t
xfs_dir2_dataptr_to_byte(struct xfs_mount *mp, xfs_dir2_dataptr_t dp)
{
return (xfs_dir2_off_t)dp << XFS_DIR2_DATA_ALIGN_LOG;
}
/*
* Convert byte in file space to dataptr. It had better be aligned.
*/
static inline xfs_dir2_dataptr_t
xfs_dir2_byte_to_dataptr(struct xfs_mount *mp, xfs_dir2_off_t by)
{
return (xfs_dir2_dataptr_t)(by >> XFS_DIR2_DATA_ALIGN_LOG);
}
/*
* Convert byte in space to (DB) block
*/
static inline xfs_dir2_db_t
xfs_dir2_byte_to_db(struct xfs_mount *mp, xfs_dir2_off_t by)
{
return (xfs_dir2_db_t)
(by >> (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog));
}
/*
* Convert dataptr to a block number
*/
static inline xfs_dir2_db_t
xfs_dir2_dataptr_to_db(struct xfs_mount *mp, xfs_dir2_dataptr_t dp)
{
return xfs_dir2_byte_to_db(mp, xfs_dir2_dataptr_to_byte(mp, dp));
}
/*
* Convert byte in space to offset in a block
*/
static inline xfs_dir2_data_aoff_t
xfs_dir2_byte_to_off(struct xfs_mount *mp, xfs_dir2_off_t by)
{
return (xfs_dir2_data_aoff_t)(by &
((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) - 1));
}
/*
* Convert dataptr to a byte offset in a block
*/
static inline xfs_dir2_data_aoff_t
xfs_dir2_dataptr_to_off(struct xfs_mount *mp, xfs_dir2_dataptr_t dp)
{
return xfs_dir2_byte_to_off(mp, xfs_dir2_dataptr_to_byte(mp, dp));
}
/*
* Convert block and offset to byte in space
*/
static inline xfs_dir2_off_t
xfs_dir2_db_off_to_byte(struct xfs_mount *mp, xfs_dir2_db_t db,
xfs_dir2_data_aoff_t o)
{
return ((xfs_dir2_off_t)db <<
(mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) + o;
}
/*
* Convert block (DB) to block (dablk)
*/
static inline xfs_dablk_t
xfs_dir2_db_to_da(struct xfs_mount *mp, xfs_dir2_db_t db)
{
return (xfs_dablk_t)(db << mp->m_sb.sb_dirblklog);
}
/*
* Convert byte in space to (DA) block
*/
static inline xfs_dablk_t
xfs_dir2_byte_to_da(struct xfs_mount *mp, xfs_dir2_off_t by)
{
return xfs_dir2_db_to_da(mp, xfs_dir2_byte_to_db(mp, by));
}
/*
* Convert block and offset to dataptr
*/
static inline xfs_dir2_dataptr_t
xfs_dir2_db_off_to_dataptr(struct xfs_mount *mp, xfs_dir2_db_t db,
xfs_dir2_data_aoff_t o)
{
return xfs_dir2_byte_to_dataptr(mp, xfs_dir2_db_off_to_byte(mp, db, o));
}
/*
* Convert block (dablk) to block (DB)
*/
static inline xfs_dir2_db_t
xfs_dir2_da_to_db(struct xfs_mount *mp, xfs_dablk_t da)
{
return (xfs_dir2_db_t)(da >> mp->m_sb.sb_dirblklog);
}
/*
* Convert block (dablk) to byte offset in space
*/
static inline xfs_dir2_off_t
xfs_dir2_da_to_byte(struct xfs_mount *mp, xfs_dablk_t da)
{
return xfs_dir2_db_off_to_byte(mp, xfs_dir2_da_to_db(mp, da), 0);
}
/*
* Free space block defintions 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)
#define XFS_DIR2_FREE_FIRSTDB(mp) \
xfs_dir2_byte_to_db(mp, XFS_DIR2_FREE_OFFSET)
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)
/*
* In core version of the free block header, abstracted away from on-disk format
* differences. Use this in the code, and convert to/from the disk version using
* xfs_dir3_free_hdr_from_disk/xfs_dir3_free_hdr_to_disk.
*/
struct xfs_dir3_icfree_hdr {
__uint32_t magic;
__uint32_t firstdb;
__uint32_t nvalid;
__uint32_t nused;
};
/*
* 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 header embedded in a data block (1-block format)
*/
static inline struct xfs_dir2_block_tail *
xfs_dir2_block_tail_p(struct xfs_mount *mp, struct xfs_dir2_data_hdr *hdr)
{
return ((struct xfs_dir2_block_tail *)
((char *)hdr + mp->m_dirblksize)) - 1;
}
/*
* 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.
*
*========================================================================
* Attribute structure when equal to XFS_LBSIZE(mp) bytes.
*========================================================================
*
* 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 */
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 */
xfs_attr_leaf_name_local_t namelist; /* grows from bottom of buf */
xfs_attr_leaf_name_remote_t valuelist; /* grows from bottom of buf */
} 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
*/
};
/*
* incore, neutral version of the attribute leaf header
*/
struct xfs_attr3_icleaf_hdr {
__uint32_t forw;
__uint32_t back;
__uint16_t magic;
__uint16_t count;
__uint16_t usedbytes;
__uint16_t firstused;
__u8 holes;
struct {
__uint16_t base;
__uint16_t size;
} freemap[XFS_ATTR_LEAF_MAPSIZE];
};
/*
* Flags used in the leaf_entry[i].flags field.
* NOTE: the INCOMPLETE bit must not collide with the flags bits specified
* on the system call, they are "or"ed together for various operations.
*/
#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 (1 << XFS_ATTR_LOCAL_BIT)
#define XFS_ATTR_ROOT (1 << XFS_ATTR_ROOT_BIT)
#define XFS_ATTR_SECURE (1 << XFS_ATTR_SECURE_BIT)
#define XFS_ATTR_INCOMPLETE (1 << XFS_ATTR_INCOMPLETE_BIT)
/*
* Conversion macros for converting namespace bits from argument flags
* to ondisk flags.
*/
#define XFS_ATTR_NSP_ARGS_MASK (ATTR_ROOT | ATTR_SECURE)
#define XFS_ATTR_NSP_ONDISK_MASK (XFS_ATTR_ROOT | XFS_ATTR_SECURE)
#define XFS_ATTR_NSP_ONDISK(flags) ((flags) & XFS_ATTR_NSP_ONDISK_MASK)
#define XFS_ATTR_NSP_ARGS(flags) ((flags) & XFS_ATTR_NSP_ARGS_MASK)
#define XFS_ATTR_NSP_ARGS_TO_ONDISK(x) (((x) & ATTR_ROOT ? XFS_ATTR_ROOT : 0) |\
((x) & ATTR_SECURE ? XFS_ATTR_SECURE : 0))
#define XFS_ATTR_NSP_ONDISK_TO_ARGS(x) (((x) & XFS_ATTR_ROOT ? ATTR_ROOT : 0) |\
((x) & XFS_ATTR_SECURE ? ATTR_SECURE : 0))
/*
* 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 ((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \
XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1);
}
static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen)
{
return ((uint)sizeof(xfs_attr_leaf_name_local_t) - 1 + (nlen) + (vlen) +
XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1);
}
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_sb_version_hascrc(&(mp)->m_sb) ? \
sizeof(struct xfs_attr3_rmt_hdr) : 0))
#endif /* __XFS_DA_FORMAT_H__ */