mirror of https://gitee.com/openkylin/linux.git
274 lines
10 KiB
C
274 lines
10 KiB
C
/*
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* Copyright (c) 2000,2002,2005 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_DA_BTREE_H__
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#define __XFS_DA_BTREE_H__
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struct xfs_buf;
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struct xfs_bmap_free;
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struct xfs_inode;
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struct xfs_mount;
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struct xfs_trans;
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struct zone;
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/*========================================================================
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* Directory Structure when greater than XFS_LBSIZE(mp) bytes.
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*========================================================================*/
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/*
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* This structure is common to both leaf nodes and non-leaf nodes in the Btree.
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*
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* Is is used to manage a doubly linked list of all blocks at the same
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* level in the Btree, and to identify which type of block this is.
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*/
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#define XFS_DA_NODE_MAGIC 0xfebe /* magic number: non-leaf blocks */
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#define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */
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#define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */
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#define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */
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typedef struct xfs_da_blkinfo {
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__be32 forw; /* previous block in list */
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__be32 back; /* following block in list */
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__be16 magic; /* validity check on block */
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__be16 pad; /* unused */
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} xfs_da_blkinfo_t;
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/*
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* This is the structure of the root and intermediate nodes in the Btree.
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* The leaf nodes are defined above.
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*
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* Entries are not packed.
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*
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* Since we have duplicate keys, use a binary search but always follow
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* all match in the block, not just the first match found.
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*/
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#define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */
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typedef struct xfs_da_intnode {
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struct xfs_da_node_hdr { /* constant-structure header block */
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xfs_da_blkinfo_t info; /* block type, links, etc. */
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__be16 count; /* count of active entries */
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__be16 level; /* level above leaves (leaf == 0) */
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} hdr;
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struct xfs_da_node_entry {
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__be32 hashval; /* hash value for this descendant */
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__be32 before; /* Btree block before this key */
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} btree[1]; /* variable sized array of keys */
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} xfs_da_intnode_t;
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typedef struct xfs_da_node_hdr xfs_da_node_hdr_t;
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typedef struct xfs_da_node_entry xfs_da_node_entry_t;
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#define XFS_LBSIZE(mp) (mp)->m_sb.sb_blocksize
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/*========================================================================
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* Btree searching and modification structure definitions.
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*========================================================================*/
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/*
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* Search comparison results
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*/
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enum xfs_dacmp {
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XFS_CMP_DIFFERENT, /* names are completely different */
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XFS_CMP_EXACT, /* names are exactly the same */
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XFS_CMP_CASE /* names are same but differ in case */
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};
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/*
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* Structure to ease passing around component names.
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*/
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typedef struct xfs_da_args {
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const __uint8_t *name; /* string (maybe not NULL terminated) */
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int namelen; /* length of string (maybe no NULL) */
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__uint8_t *value; /* set of bytes (maybe contain NULLs) */
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int valuelen; /* length of value */
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int flags; /* argument flags (eg: ATTR_NOCREATE) */
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xfs_dahash_t hashval; /* hash value of name */
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xfs_ino_t inumber; /* input/output inode number */
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struct xfs_inode *dp; /* directory inode to manipulate */
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xfs_fsblock_t *firstblock; /* ptr to firstblock for bmap calls */
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struct xfs_bmap_free *flist; /* ptr to freelist for bmap_finish */
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struct xfs_trans *trans; /* current trans (changes over time) */
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xfs_extlen_t total; /* total blocks needed, for 1st bmap */
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int whichfork; /* data or attribute fork */
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xfs_dablk_t blkno; /* blkno of attr leaf of interest */
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int index; /* index of attr of interest in blk */
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xfs_dablk_t rmtblkno; /* remote attr value starting blkno */
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int rmtblkcnt; /* remote attr value block count */
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xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */
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int index2; /* index of 2nd attr in blk */
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xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */
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int rmtblkcnt2; /* remote attr value block count */
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int op_flags; /* operation flags */
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enum xfs_dacmp cmpresult; /* name compare result for lookups */
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} xfs_da_args_t;
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/*
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* Operation flags:
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*/
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#define XFS_DA_OP_JUSTCHECK 0x0001 /* check for ok with no space */
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#define XFS_DA_OP_RENAME 0x0002 /* this is an atomic rename op */
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#define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */
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#define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */
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#define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */
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/*
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* Structure to describe buffer(s) for a block.
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* This is needed in the directory version 2 format case, when
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* multiple non-contiguous fsblocks might be needed to cover one
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* logical directory block.
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* If the buffer count is 1 then the data pointer points to the
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* same place as the b_addr field for the buffer, else to kmem_alloced memory.
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*/
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typedef struct xfs_dabuf {
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int nbuf; /* number of buffer pointers present */
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short dirty; /* data needs to be copied back */
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short bbcount; /* how large is data in bbs */
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void *data; /* pointer for buffers' data */
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#ifdef XFS_DABUF_DEBUG
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inst_t *ra; /* return address of caller to make */
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struct xfs_dabuf *next; /* next in global chain */
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struct xfs_dabuf *prev; /* previous in global chain */
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struct xfs_buftarg *target; /* device for buffer */
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xfs_daddr_t blkno; /* daddr first in bps[0] */
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#endif
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struct xfs_buf *bps[1]; /* actually nbuf of these */
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} xfs_dabuf_t;
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#define XFS_DA_BUF_SIZE(n) \
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(sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1))
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#ifdef XFS_DABUF_DEBUG
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extern xfs_dabuf_t *xfs_dabuf_global_list;
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#endif
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/*
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* Storage for holding state during Btree searches and split/join ops.
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*
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* Only need space for 5 intermediate nodes. With a minimum of 62-way
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* fanout to the Btree, we can support over 900 million directory blocks,
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* which is slightly more than enough.
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*/
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typedef struct xfs_da_state_blk {
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xfs_dabuf_t *bp; /* buffer containing block */
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xfs_dablk_t blkno; /* filesystem blkno of buffer */
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xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */
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int index; /* relevant index into block */
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xfs_dahash_t hashval; /* last hash value in block */
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int magic; /* blk's magic number, ie: blk type */
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} xfs_da_state_blk_t;
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typedef struct xfs_da_state_path {
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int active; /* number of active levels */
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xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH];
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} xfs_da_state_path_t;
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typedef struct xfs_da_state {
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xfs_da_args_t *args; /* filename arguments */
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struct xfs_mount *mp; /* filesystem mount point */
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unsigned int blocksize; /* logical block size */
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unsigned int node_ents; /* how many entries in danode */
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xfs_da_state_path_t path; /* search/split paths */
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xfs_da_state_path_t altpath; /* alternate path for join */
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unsigned char inleaf; /* insert into 1->lf, 0->splf */
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unsigned char extravalid; /* T/F: extrablk is in use */
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unsigned char extraafter; /* T/F: extrablk is after new */
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xfs_da_state_blk_t extrablk; /* for double-splits on leaves */
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/* for dirv2 extrablk is data */
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} xfs_da_state_t;
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/*
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* Utility macros to aid in logging changed structure fields.
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*/
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#define XFS_DA_LOGOFF(BASE, ADDR) ((char *)(ADDR) - (char *)(BASE))
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#define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \
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(uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
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(uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
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/*
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* Name ops for directory and/or attr name operations
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*/
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struct xfs_nameops {
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xfs_dahash_t (*hashname)(struct xfs_name *);
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enum xfs_dacmp (*compname)(struct xfs_da_args *, const char *, int);
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};
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/*========================================================================
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* Function prototypes.
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*========================================================================*/
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/*
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* Routines used for growing the Btree.
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*/
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int xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
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xfs_dabuf_t **bpp, int whichfork);
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int xfs_da_split(xfs_da_state_t *state);
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/*
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* Routines used for shrinking the Btree.
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*/
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int xfs_da_join(xfs_da_state_t *state);
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void xfs_da_fixhashpath(xfs_da_state_t *state,
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xfs_da_state_path_t *path_to_to_fix);
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/*
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* Routines used for finding things in the Btree.
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*/
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int xfs_da_node_lookup_int(xfs_da_state_t *state, int *result);
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int xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
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int forward, int release, int *result);
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/*
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* Utility routines.
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*/
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int xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
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xfs_da_state_blk_t *new_blk);
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/*
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* Utility routines.
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*/
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int xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
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int xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
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xfs_dablk_t bno, xfs_daddr_t mappedbno,
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xfs_dabuf_t **bp, int whichfork);
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int xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
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xfs_dablk_t bno, xfs_daddr_t mappedbno,
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xfs_dabuf_t **bpp, int whichfork);
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xfs_daddr_t xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp,
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xfs_dablk_t bno, int whichfork);
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int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
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xfs_dabuf_t *dead_buf);
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uint xfs_da_hashname(const __uint8_t *name_string, int name_length);
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enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
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const char *name, int len);
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xfs_da_state_t *xfs_da_state_alloc(void);
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void xfs_da_state_free(xfs_da_state_t *state);
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void xfs_da_buf_done(xfs_dabuf_t *dabuf);
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void xfs_da_log_buf(struct xfs_trans *tp, xfs_dabuf_t *dabuf, uint first,
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uint last);
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void xfs_da_brelse(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
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void xfs_da_binval(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
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xfs_daddr_t xfs_da_blkno(xfs_dabuf_t *dabuf);
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extern struct kmem_zone *xfs_da_state_zone;
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extern struct kmem_zone *xfs_dabuf_zone;
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extern const struct xfs_nameops xfs_default_nameops;
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#endif /* __XFS_DA_BTREE_H__ */
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