84d9c625bf
- Fix for possible unset uid/gid in toproto
- Fix for default mtree style
- Update libelf
- Importing libexecinfo
- Resynchronize GCC, mpc, gmp, mpfr
- build.sh: Replace params with show-params.
This has been done as the make target has been renamed in the same
way, while a new target named params has been added. This new
target generates a file containing all the parameters, instead of
printing it on the console.
- Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org)
get getservbyport() out of the inner loop
Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
130 lines
5.3 KiB
C
130 lines
5.3 KiB
C
/* $NetBSD: ulfs_dirhash.h,v 1.5 2013/06/08 02:14:46 dholland Exp $ */
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/* from NetBSD: dirhash.h,v 1.6 2008/06/04 11:33:19 ad Exp */
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/*
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* Copyright (c) 2001 Ian Dowse. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD: src/sys/ufs/ufs/dirhash.h,v 1.2.2.2 2004/12/08 11:54:13 dwmalone Exp $
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*/
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#ifndef _UFS_LFS_ULFS_DIRHASH_H_
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#define _UFS_LFS_ULFS_DIRHASH_H_
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/*
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* For fast operations on large directories, we maintain a hash
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* that maps the file name to the offset of the directory entry within
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* the directory file.
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*
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* The hashing uses a dumb spillover to the next free slot on
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* collisions, so we must keep the utilisation low to avoid
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* long linear searches. Deleted entries that are not the last
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* in a chain must be marked DIRHASH_DEL.
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*
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* We also maintain information about free space in each block
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* to speed up creations.
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*/
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#define DIRHASH_EMPTY (-1) /* entry unused */
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#define DIRHASH_DEL (-2) /* deleted entry; may be part of chain */
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#define DIRALIGN 4
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#define DH_NFSTATS (LFS_DIRECTSIZ(LFS_MAXNAMLEN + 1) / DIRALIGN)
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/* max DIRALIGN words in a directory entry */
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/*
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* Dirhash uses a score mechanism to achieve a hybrid between a
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* least-recently-used and a least-often-used algorithm for entry
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* recycling. The score is incremented when a directory is used, and
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* decremented when the directory is a candidate for recycling. When
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* the score reaches zero, the hash is recycled. Hashes are linked
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* together on a TAILQ list, and hashes with higher scores filter
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* towards the tail (most recently used) end of the list.
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*
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* New hash entries are given an inital score of DH_SCOREINIT and are
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* placed at the most-recently-used end of the list. This helps a lot
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* in the worst-case case scenario where every directory access is
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* to a directory that is not hashed (i.e. the working set of hash
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* candidates is much larger than the configured memry limit). In this
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* case it limits the number of hash builds to 1/DH_SCOREINIT of the
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* number of accesses.
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*/
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#define DH_SCOREINIT 8 /* initial dh_score when dirhash built */
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#define DH_SCOREMAX 64 /* max dh_score value */
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/*
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* The main hash table has 2 levels. It is an array of pointers to
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* blocks of DH_NBLKOFF offsets.
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*/
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#define DH_BLKOFFSHIFT 8
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#define DH_NBLKOFF (1 << DH_BLKOFFSHIFT)
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#define DH_BLKOFFMASK (DH_NBLKOFF - 1)
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#define DH_ENTRY(dh, slot) \
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((dh)->dh_hash[(slot) >> DH_BLKOFFSHIFT][(slot) & DH_BLKOFFMASK])
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struct dirhash {
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kmutex_t dh_lock; /* protects all fields except dh_list */
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doff_t **dh_hash; /* the hash array (2-level) */
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size_t dh_hashsz;
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int dh_narrays; /* number of entries in dh_hash */
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int dh_hlen; /* total slots in the 2-level hash array */
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int dh_hused; /* entries in use */
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u_int8_t *dh_blkfree; /* free DIRALIGN words in each dir block */
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size_t dh_blkfreesz;
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int dh_nblk; /* size of dh_blkfree array */
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int dh_dirblks; /* number of DIRBLKSIZ blocks in dir */
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int dh_firstfree[DH_NFSTATS + 1]; /* first blk with N words free */
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int dh_seqopt; /* sequential access optimisation enabled */
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doff_t dh_seqoff; /* sequential access optimisation offset */
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int dh_score; /* access count for this dirhash */
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int dh_onlist; /* true if on the ulfsdirhash_list chain */
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/* Protected by ulfsdirhash_lock. */
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TAILQ_ENTRY(dirhash) dh_list; /* chain of all dirhashes */
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};
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/*
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* Dirhash functions.
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*/
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int ulfsdirhash_build(struct inode *);
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doff_t ulfsdirhash_findfree(struct inode *, int, int *);
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doff_t ulfsdirhash_enduseful(struct inode *);
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int ulfsdirhash_lookup(struct inode *, const char *, int, doff_t *,
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struct buf **, doff_t *);
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void ulfsdirhash_newblk(struct inode *, doff_t);
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void ulfsdirhash_add(struct inode *, struct lfs_direct *, doff_t);
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void ulfsdirhash_remove(struct inode *, struct lfs_direct *, doff_t);
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void ulfsdirhash_move(struct inode *, struct lfs_direct *, doff_t, doff_t);
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void ulfsdirhash_dirtrunc(struct inode *, doff_t);
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void ulfsdirhash_free(struct inode *);
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void ulfsdirhash_checkblock(struct inode *, char *, doff_t);
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void ulfsdirhash_init(void);
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void ulfsdirhash_done(void);
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#endif /* !_UFS_LFS_ULFS_DIRHASH_H_ */
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