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