1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
248 lines
9.4 KiB
C
248 lines
9.4 KiB
C
/*
|
|
* Copyright (c) 2000-2001 Silicon Graphics, Inc. All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of version 2 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.
|
|
*
|
|
* Further, this software is distributed without any warranty that it is
|
|
* free of the rightful claim of any third person regarding infringement
|
|
* or the like. Any license provided herein, whether implied or
|
|
* otherwise, applies only to this software file. Patent licenses, if
|
|
* any, provided herein do not apply to combinations of this program with
|
|
* other software, or any other product whatsoever.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write the Free Software Foundation, Inc., 59
|
|
* Temple Place - Suite 330, Boston MA 02111-1307, USA.
|
|
*
|
|
* Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
|
|
* Mountain View, CA 94043, or:
|
|
*
|
|
* http://www.sgi.com
|
|
*
|
|
* For further information regarding this notice, see:
|
|
*
|
|
* http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
|
|
*/
|
|
#ifndef __XFS_DIR_LEAF_H__
|
|
#define __XFS_DIR_LEAF_H__
|
|
|
|
/*
|
|
* Directory layout, internal structure, access macros, etc.
|
|
*
|
|
* Large directories are structured around Btrees where all the data
|
|
* elements are in the leaf nodes. Filenames are hashed into an int,
|
|
* then that int is used as the index into the Btree. Since the hashval
|
|
* of a filename may not be unique, we may have duplicate keys. The
|
|
* internal links in the Btree are logical block offsets into the file.
|
|
*/
|
|
|
|
struct uio;
|
|
struct xfs_bmap_free;
|
|
struct xfs_dabuf;
|
|
struct xfs_da_args;
|
|
struct xfs_da_state;
|
|
struct xfs_da_state_blk;
|
|
struct xfs_dir_put_args;
|
|
struct xfs_inode;
|
|
struct xfs_mount;
|
|
struct xfs_trans;
|
|
|
|
/*========================================================================
|
|
* Directory Structure when equal to XFS_LBSIZE(mp) bytes.
|
|
*========================================================================*/
|
|
|
|
/*
|
|
* This is the structure of the leaf nodes in the Btree.
|
|
*
|
|
* Struct leaf_entry's are packed from the top. Names 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 namelist area and try again. If we
|
|
* still don't have enough space, then we have to split the block.
|
|
*
|
|
* Since we have duplicate hash keys, for each key that matches, compare
|
|
* the actual 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 filename is found.
|
|
*
|
|
* The parent directory and the self-pointer are explicitly represented
|
|
* (ie: there are entries for "." and "..").
|
|
*
|
|
* Note that the count being a __uint16_t limits us to something like a
|
|
* blocksize of 1.3MB in the face of worst case (short) filenames.
|
|
*/
|
|
#define XFS_DIR_LEAF_MAPSIZE 3 /* how many freespace slots */
|
|
|
|
typedef struct xfs_dir_leafblock {
|
|
struct xfs_dir_leaf_hdr { /* constant-structure header block */
|
|
xfs_da_blkinfo_t info; /* block type, links, etc. */
|
|
__uint16_t count; /* count of active leaf_entry's */
|
|
__uint16_t namebytes; /* num bytes of name strings stored */
|
|
__uint16_t firstused; /* first used byte in name area */
|
|
__uint8_t holes; /* != 0 if blk needs compaction */
|
|
__uint8_t pad1;
|
|
struct xfs_dir_leaf_map {/* RLE map of free bytes */
|
|
__uint16_t base; /* base of free region */
|
|
__uint16_t size; /* run length of free region */
|
|
} freemap[XFS_DIR_LEAF_MAPSIZE]; /* N largest free regions */
|
|
} hdr;
|
|
struct xfs_dir_leaf_entry { /* sorted on key, not name */
|
|
xfs_dahash_t hashval; /* hash value of name */
|
|
__uint16_t nameidx; /* index into buffer of name */
|
|
__uint8_t namelen; /* length of name string */
|
|
__uint8_t pad2;
|
|
} entries[1]; /* var sized array */
|
|
struct xfs_dir_leaf_name {
|
|
xfs_dir_ino_t inumber; /* inode number for this key */
|
|
__uint8_t name[1]; /* name string itself */
|
|
} namelist[1]; /* grows from bottom of buf */
|
|
} xfs_dir_leafblock_t;
|
|
typedef struct xfs_dir_leaf_hdr xfs_dir_leaf_hdr_t;
|
|
typedef struct xfs_dir_leaf_map xfs_dir_leaf_map_t;
|
|
typedef struct xfs_dir_leaf_entry xfs_dir_leaf_entry_t;
|
|
typedef struct xfs_dir_leaf_name xfs_dir_leaf_name_t;
|
|
|
|
/*
|
|
* Length of name for which a 512-byte block filesystem
|
|
* can get a double split.
|
|
*/
|
|
#define XFS_DIR_LEAF_CAN_DOUBLE_SPLIT_LEN \
|
|
(512 - (uint)sizeof(xfs_dir_leaf_hdr_t) - \
|
|
(uint)sizeof(xfs_dir_leaf_entry_t) * 2 - \
|
|
(uint)sizeof(xfs_dir_leaf_name_t) * 2 - (MAXNAMELEN - 2) + 1 + 1)
|
|
|
|
typedef int (*xfs_dir_put_t)(struct xfs_dir_put_args *pa);
|
|
|
|
typedef union {
|
|
xfs_off_t o; /* offset (cookie) */
|
|
/*
|
|
* Watch the order here (endian-ness dependent).
|
|
*/
|
|
struct {
|
|
#if __BYTE_ORDER == __LITTLE_ENDIAN
|
|
xfs_dahash_t h; /* hash value */
|
|
__uint32_t be; /* block and entry */
|
|
#else /* __BYTE_ORDER == __BIG_ENDIAN */
|
|
__uint32_t be; /* block and entry */
|
|
xfs_dahash_t h; /* hash value */
|
|
#endif /* __BYTE_ORDER == __BIG_ENDIAN */
|
|
} s;
|
|
} xfs_dircook_t;
|
|
|
|
#define XFS_PUT_COOKIE(c,mp,bno,entry,hash) \
|
|
((c).s.be = XFS_DA_MAKE_BNOENTRY(mp, bno, entry), (c).s.h = (hash))
|
|
|
|
typedef struct xfs_dir_put_args
|
|
{
|
|
xfs_dircook_t cook; /* cookie of (next) entry */
|
|
xfs_intino_t ino; /* inode number */
|
|
struct xfs_dirent *dbp; /* buffer pointer */
|
|
char *name; /* directory entry name */
|
|
int namelen; /* length of name */
|
|
int done; /* output: set if value was stored */
|
|
xfs_dir_put_t put; /* put function ptr (i/o) */
|
|
struct uio *uio; /* uio control structure */
|
|
} xfs_dir_put_args_t;
|
|
|
|
#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR_LEAF_ENTSIZE_BYNAME)
|
|
int xfs_dir_leaf_entsize_byname(int len);
|
|
#define XFS_DIR_LEAF_ENTSIZE_BYNAME(len) xfs_dir_leaf_entsize_byname(len)
|
|
#else
|
|
#define XFS_DIR_LEAF_ENTSIZE_BYNAME(len) /* space a name will use */ \
|
|
((uint)sizeof(xfs_dir_leaf_name_t)-1 + len)
|
|
#endif
|
|
#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR_LEAF_ENTSIZE_BYENTRY)
|
|
int xfs_dir_leaf_entsize_byentry(xfs_dir_leaf_entry_t *entry);
|
|
#define XFS_DIR_LEAF_ENTSIZE_BYENTRY(entry) \
|
|
xfs_dir_leaf_entsize_byentry(entry)
|
|
#else
|
|
#define XFS_DIR_LEAF_ENTSIZE_BYENTRY(entry) /* space an entry will use */ \
|
|
((uint)sizeof(xfs_dir_leaf_name_t)-1 + (entry)->namelen)
|
|
#endif
|
|
#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR_LEAF_NAMESTRUCT)
|
|
xfs_dir_leaf_name_t *
|
|
xfs_dir_leaf_namestruct(xfs_dir_leafblock_t *leafp, int offset);
|
|
#define XFS_DIR_LEAF_NAMESTRUCT(leafp,offset) \
|
|
xfs_dir_leaf_namestruct(leafp,offset)
|
|
#else
|
|
#define XFS_DIR_LEAF_NAMESTRUCT(leafp,offset) /* point to name struct */ \
|
|
((xfs_dir_leaf_name_t *)&((char *)(leafp))[offset])
|
|
#endif
|
|
|
|
/*========================================================================
|
|
* Function prototypes for the kernel.
|
|
*========================================================================*/
|
|
|
|
/*
|
|
* Internal routines when dirsize < XFS_LITINO(mp).
|
|
*/
|
|
int xfs_dir_shortform_create(struct xfs_da_args *args, xfs_ino_t parent);
|
|
int xfs_dir_shortform_addname(struct xfs_da_args *args);
|
|
int xfs_dir_shortform_lookup(struct xfs_da_args *args);
|
|
int xfs_dir_shortform_to_leaf(struct xfs_da_args *args);
|
|
int xfs_dir_shortform_removename(struct xfs_da_args *args);
|
|
int xfs_dir_shortform_getdents(struct xfs_inode *dp, struct uio *uio, int *eofp,
|
|
struct xfs_dirent *dbp, xfs_dir_put_t put);
|
|
int xfs_dir_shortform_replace(struct xfs_da_args *args);
|
|
|
|
/*
|
|
* Internal routines when dirsize == XFS_LBSIZE(mp).
|
|
*/
|
|
int xfs_dir_leaf_to_node(struct xfs_da_args *args);
|
|
int xfs_dir_leaf_to_shortform(struct xfs_da_args *args);
|
|
|
|
/*
|
|
* Routines used for growing the Btree.
|
|
*/
|
|
int xfs_dir_leaf_create(struct xfs_da_args *args, xfs_dablk_t which_block,
|
|
struct xfs_dabuf **bpp);
|
|
int xfs_dir_leaf_split(struct xfs_da_state *state,
|
|
struct xfs_da_state_blk *oldblk,
|
|
struct xfs_da_state_blk *newblk);
|
|
int xfs_dir_leaf_add(struct xfs_dabuf *leaf_buffer,
|
|
struct xfs_da_args *args, int insertion_index);
|
|
int xfs_dir_leaf_addname(struct xfs_da_args *args);
|
|
int xfs_dir_leaf_lookup_int(struct xfs_dabuf *leaf_buffer,
|
|
struct xfs_da_args *args,
|
|
int *index_found_at);
|
|
int xfs_dir_leaf_remove(struct xfs_trans *trans,
|
|
struct xfs_dabuf *leaf_buffer,
|
|
int index_to_remove);
|
|
int xfs_dir_leaf_getdents_int(struct xfs_dabuf *bp, struct xfs_inode *dp,
|
|
xfs_dablk_t bno, struct uio *uio,
|
|
int *eobp, struct xfs_dirent *dbp,
|
|
xfs_dir_put_t put, xfs_daddr_t nextda);
|
|
|
|
/*
|
|
* Routines used for shrinking the Btree.
|
|
*/
|
|
int xfs_dir_leaf_toosmall(struct xfs_da_state *state, int *retval);
|
|
void xfs_dir_leaf_unbalance(struct xfs_da_state *state,
|
|
struct xfs_da_state_blk *drop_blk,
|
|
struct xfs_da_state_blk *save_blk);
|
|
|
|
/*
|
|
* Utility routines.
|
|
*/
|
|
uint xfs_dir_leaf_lasthash(struct xfs_dabuf *bp, int *count);
|
|
int xfs_dir_leaf_order(struct xfs_dabuf *leaf1_bp,
|
|
struct xfs_dabuf *leaf2_bp);
|
|
int xfs_dir_put_dirent64_direct(xfs_dir_put_args_t *pa);
|
|
int xfs_dir_put_dirent64_uio(xfs_dir_put_args_t *pa);
|
|
int xfs_dir_ino_validate(struct xfs_mount *mp, xfs_ino_t ino);
|
|
|
|
|
|
/*
|
|
* Global data.
|
|
*/
|
|
extern xfs_dahash_t xfs_dir_hash_dot, xfs_dir_hash_dotdot;
|
|
|
|
#endif /* __XFS_DIR_LEAF_H__ */
|