135 lines
5.1 KiB
C
135 lines
5.1 KiB
C
/*-
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. 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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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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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* @(#)config.h 8.2 (Berkeley) 4/22/94
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*/
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/*
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* The first boot and super blocks are given in absolute disk addresses.
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* The byte-offset forms are preferred, as they don't imply a sector size.
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*/
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#define BBSIZE 8192
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#define SBSIZE 8192
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/*
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* The following two constants set the default block and fragment sizes.
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* Both constants must be a power of 2 and meet the following constraints:
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* MINBSIZE <= DESBLKSIZE <= MAXBSIZE
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* sectorsize <= DESFRAGSIZE <= DESBLKSIZE
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* DESBLKSIZE / DESFRAGSIZE <= 8
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*/
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#define DFL_FRAGSIZE 1024
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#define DFL_BLKSIZE 8192
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/*
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* Cylinder groups may have up to many cylinders. The actual
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* number used depends upon how much information can be stored
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* on a single cylinder. The default is to use 16 cylinders
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* per group.
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*/
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#define DESCPG 16 /* desired fs_cpg */
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/*
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* MINFREE gives the minimum acceptable percentage of file system
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* blocks which may be free. If the freelist drops below this level
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* only the superuser may continue to allocate blocks. This may
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* be set to 0 if no reserve of free blocks is deemed necessary,
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* however throughput drops by fifty percent if the file system
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* is run at between 90% and 100% full; thus the default value of
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* fs_minfree is 10%. With 10% free space, fragmentation is not a
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* problem, so we choose to optimize for time.
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*/
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#define MINFREE 10
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#define DEFAULTOPT FS_OPTTIME
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/*
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* Preference for optimization.
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*/
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#define FS_OPTTIME 0 /* minimize allocation time */
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#define FS_OPTSPACE 1 /* minimize disk fragmentation */
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/*
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* ROTDELAY gives the minimum number of milliseconds to initiate
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* another disk transfer on the same cylinder. It is used in
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* determining the rotationally optimal layout for disk blocks
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* within a file; the default of fs_rotdelay is 4ms.
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*/
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#define ROTDELAY 4
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/*
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* MAXCONTIG sets the default for the maximum number of blocks
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* that may be allocated sequentially. Since UNIX drivers are
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* not capable of scheduling multi-block transfers, this defaults
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* to 1 (ie no contiguous blocks are allocated).
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*/
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#define MAXCONTIG 1
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/*
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* MAXBLKPG determines the maximum number of data blocks which are
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* placed in a single cylinder group. The default is one indirect
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* block worth of data blocks.
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*/
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#define MAXBLKPG(bsize) ((bsize) / sizeof(daddr_t))
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/*
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* Each file system has a number of inodes statically allocated.
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* We allocate one inode slot per NFPI fragments, expecting this
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* to be far more than we will ever need.
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*/
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#define NFPI 4
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/*
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* For each cylinder we keep track of the availability of blocks at different
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* rotational positions, so that we can lay out the data to be picked
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* up with minimum rotational latency. NRPOS is the default number of
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* rotational positions that we distinguish. With NRPOS of 8 the resolution
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* of our summary information is 2ms for a typical 3600 rpm drive.
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*/
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#define NRPOS 8 /* number distinct rotational positions */
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/*
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* The following constants set the default block and segment size for a log
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* structured file system. Both must be powers of two and the segment size
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* must be a multiple of the block size. We also set minimum block and segment
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* sizes.
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*/
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#define LFS_MINSEGSIZE (64*1024)
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#define DFL_LFSSEG (1024 * 1024)
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#define DFL_LFSSEG_SHIFT 20
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#define DFL_LFSSEG_MASK 0xFFFFF
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#define LFS_MINBLOCKSIZE 1024
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#define DFL_LFSBLOCK 4096
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#define DFL_LFSBLOCK_SHIFT 12
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#define DFL_LFSBLOCK_MASK 0xFFF
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