185 lines
5.4 KiB
C
185 lines
5.4 KiB
C
/*
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* Copyright (c) 2000,2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef __XFS_DIR2_DATA_H__
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#define __XFS_DIR2_DATA_H__
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/*
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* Directory format 2, data block structures.
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*/
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struct xfs_dabuf;
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struct xfs_da_args;
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struct xfs_inode;
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struct xfs_trans;
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/*
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* Constants.
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*/
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#define XFS_DIR2_DATA_MAGIC 0x58443244 /* XD2D: for multiblock dirs */
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#define XFS_DIR2_DATA_ALIGN_LOG 3 /* i.e., 8 bytes */
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#define XFS_DIR2_DATA_ALIGN (1 << XFS_DIR2_DATA_ALIGN_LOG)
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#define XFS_DIR2_DATA_FREE_TAG 0xffff
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#define XFS_DIR2_DATA_FD_COUNT 3
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/*
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* Directory address space divided into sections,
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* spaces separated by 32GB.
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*/
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#define XFS_DIR2_SPACE_SIZE (1ULL << (32 + XFS_DIR2_DATA_ALIGN_LOG))
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#define XFS_DIR2_DATA_SPACE 0
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#define XFS_DIR2_DATA_OFFSET (XFS_DIR2_DATA_SPACE * XFS_DIR2_SPACE_SIZE)
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#define XFS_DIR2_DATA_FIRSTDB(mp) \
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xfs_dir2_byte_to_db(mp, XFS_DIR2_DATA_OFFSET)
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/*
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* Offsets of . and .. in data space (always block 0)
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*/
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#define XFS_DIR2_DATA_DOT_OFFSET \
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((xfs_dir2_data_aoff_t)sizeof(xfs_dir2_data_hdr_t))
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#define XFS_DIR2_DATA_DOTDOT_OFFSET \
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(XFS_DIR2_DATA_DOT_OFFSET + xfs_dir2_data_entsize(1))
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#define XFS_DIR2_DATA_FIRST_OFFSET \
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(XFS_DIR2_DATA_DOTDOT_OFFSET + xfs_dir2_data_entsize(2))
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/*
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* Structures.
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*/
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/*
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* Describe a free area in the data block.
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* The freespace will be formatted as a xfs_dir2_data_unused_t.
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*/
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typedef struct xfs_dir2_data_free {
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__be16 offset; /* start of freespace */
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__be16 length; /* length of freespace */
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} xfs_dir2_data_free_t;
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/*
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* Header for the data blocks.
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* Always at the beginning of a directory-sized block.
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* The code knows that XFS_DIR2_DATA_FD_COUNT is 3.
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*/
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typedef struct xfs_dir2_data_hdr {
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__be32 magic; /* XFS_DIR2_DATA_MAGIC */
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/* or XFS_DIR2_BLOCK_MAGIC */
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xfs_dir2_data_free_t bestfree[XFS_DIR2_DATA_FD_COUNT];
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} xfs_dir2_data_hdr_t;
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/*
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* Active entry in a data block. Aligned to 8 bytes.
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* Tag appears as the last 2 bytes.
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*/
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typedef struct xfs_dir2_data_entry {
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__be64 inumber; /* inode number */
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__u8 namelen; /* name length */
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__u8 name[1]; /* name bytes, no null */
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/* variable offset */
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__be16 tag; /* starting offset of us */
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} xfs_dir2_data_entry_t;
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/*
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* Unused entry in a data block. Aligned to 8 bytes.
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* Tag appears as the last 2 bytes.
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*/
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typedef struct xfs_dir2_data_unused {
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__be16 freetag; /* XFS_DIR2_DATA_FREE_TAG */
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__be16 length; /* total free length */
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/* variable offset */
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__be16 tag; /* starting offset of us */
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} xfs_dir2_data_unused_t;
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typedef union {
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xfs_dir2_data_entry_t entry;
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xfs_dir2_data_unused_t unused;
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} xfs_dir2_data_union_t;
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/*
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* Generic data block structure, for xfs_db.
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*/
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typedef struct xfs_dir2_data {
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xfs_dir2_data_hdr_t hdr; /* magic XFS_DIR2_DATA_MAGIC */
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xfs_dir2_data_union_t u[1];
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} xfs_dir2_data_t;
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/*
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* Macros.
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*/
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/*
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* Size of a data entry.
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*/
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static inline int xfs_dir2_data_entsize(int n)
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{
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return (int)roundup(offsetof(xfs_dir2_data_entry_t, name[0]) + (n) + \
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(uint)sizeof(xfs_dir2_data_off_t), XFS_DIR2_DATA_ALIGN);
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}
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/*
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* Pointer to an entry's tag word.
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*/
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static inline __be16 *
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xfs_dir2_data_entry_tag_p(xfs_dir2_data_entry_t *dep)
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{
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return (__be16 *)((char *)dep +
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xfs_dir2_data_entsize(dep->namelen) - sizeof(__be16));
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}
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/*
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* Pointer to a freespace's tag word.
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*/
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static inline __be16 *
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xfs_dir2_data_unused_tag_p(xfs_dir2_data_unused_t *dup)
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{
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return (__be16 *)((char *)dup +
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be16_to_cpu(dup->length) - sizeof(__be16));
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}
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/*
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* Function declarations.
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*/
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#ifdef DEBUG
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extern void xfs_dir2_data_check(struct xfs_inode *dp, struct xfs_dabuf *bp);
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#else
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#define xfs_dir2_data_check(dp,bp)
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#endif
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extern xfs_dir2_data_free_t *xfs_dir2_data_freefind(xfs_dir2_data_t *d,
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xfs_dir2_data_unused_t *dup);
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extern xfs_dir2_data_free_t *xfs_dir2_data_freeinsert(xfs_dir2_data_t *d,
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xfs_dir2_data_unused_t *dup, int *loghead);
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extern void xfs_dir2_data_freescan(struct xfs_mount *mp, xfs_dir2_data_t *d,
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int *loghead);
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extern int xfs_dir2_data_init(struct xfs_da_args *args, xfs_dir2_db_t blkno,
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struct xfs_dabuf **bpp);
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extern void xfs_dir2_data_log_entry(struct xfs_trans *tp, struct xfs_dabuf *bp,
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xfs_dir2_data_entry_t *dep);
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extern void xfs_dir2_data_log_header(struct xfs_trans *tp,
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struct xfs_dabuf *bp);
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extern void xfs_dir2_data_log_unused(struct xfs_trans *tp, struct xfs_dabuf *bp,
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xfs_dir2_data_unused_t *dup);
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extern void xfs_dir2_data_make_free(struct xfs_trans *tp, struct xfs_dabuf *bp,
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xfs_dir2_data_aoff_t offset,
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xfs_dir2_data_aoff_t len, int *needlogp,
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int *needscanp);
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extern void xfs_dir2_data_use_free(struct xfs_trans *tp, struct xfs_dabuf *bp,
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xfs_dir2_data_unused_t *dup,
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xfs_dir2_data_aoff_t offset,
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xfs_dir2_data_aoff_t len, int *needlogp,
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int *needscanp);
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#endif /* __XFS_DIR2_DATA_H__ */
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