747 lines
20 KiB
C
747 lines
20 KiB
C
/*-
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* Copyright (c) 1993
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* The Regents of the University of California. All rights reserved.
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* Modifications/enhancements:
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* Copyright (c) 1995 John S. Dyson. 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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* @(#)vfs_cluster.c 8.7 (Berkeley) 2/13/94
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* $Id: vfs_cluster.c,v 1.22 1995/10/09 03:19:49 dyson Exp $
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/buf.h>
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#include <sys/vnode.h>
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#include <sys/mount.h>
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#include <sys/malloc.h>
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#include <sys/resourcevar.h>
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#include <sys/vmmeter.h>
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#include <miscfs/specfs/specdev.h>
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#include <vm/vm.h>
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#include <vm/vm_object.h>
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#include <vm/vm_page.h>
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#ifdef DEBUG
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#include <vm/vm.h>
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#include <sys/sysctl.h>
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int doreallocblks = 0;
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struct ctldebug debug13 = {"doreallocblks", &doreallocblks};
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#else
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/* XXX for cluster_write */
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#define doreallocblks 0
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#endif
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/*
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* Local declarations
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*/
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static struct buf *cluster_rbuild __P((struct vnode *, u_quad_t,
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daddr_t, daddr_t, long, int));
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struct cluster_save *cluster_collectbufs __P((struct vnode *, struct buf *));
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int totreads;
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int totreadblocks;
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extern vm_page_t bogus_page;
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#ifdef DIAGNOSTIC
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/*
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* Set to 1 if reads of block zero should cause readahead to be done.
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* Set to 0 treats a read of block zero as a non-sequential read.
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*
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* Setting to one assumes that most reads of block zero of files are due to
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* sequential passes over the files (e.g. cat, sum) where additional blocks
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* will soon be needed. Setting to zero assumes that the majority are
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* surgical strikes to get particular info (e.g. size, file) where readahead
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* blocks will not be used and, in fact, push out other potentially useful
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* blocks from the cache. The former seems intuitive, but some quick tests
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* showed that the latter performed better from a system-wide point of view.
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*/
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int doclusterraz = 0;
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#define ISSEQREAD(vp, blk) \
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(((blk) != 0 || doclusterraz) && \
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((blk) == (vp)->v_lastr + 1 || (blk) == (vp)->v_lastr))
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#else
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#define ISSEQREAD(vp, blk) \
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(/* (blk) != 0 && */ ((blk) == (vp)->v_lastr + 1 || (blk) == (vp)->v_lastr))
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#endif
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/*
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* allow for three entire read-aheads... The system will
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* adjust downwards rapidly if needed...
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*/
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#define RA_MULTIPLE_FAST 2
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#define RA_MULTIPLE_SLOW 3
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#define RA_SHIFTDOWN 1 /* approx lg2(RA_MULTIPLE) */
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/*
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* This replaces bread. If this is a bread at the beginning of a file and
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* lastr is 0, we assume this is the first read and we'll read up to two
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* blocks if they are sequential. After that, we'll do regular read ahead
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* in clustered chunks.
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* bp is the block requested.
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* rbp is the read-ahead block.
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* If either is NULL, then you don't have to do the I/O.
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*/
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int
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cluster_read(vp, filesize, lblkno, size, cred, bpp)
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struct vnode *vp;
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u_quad_t filesize;
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daddr_t lblkno;
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long size;
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struct ucred *cred;
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struct buf **bpp;
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{
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struct buf *bp, *rbp;
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daddr_t blkno, rablkno, origlblkno;
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int error, num_ra, alreadyincore;
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int i;
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int seq;
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error = 0;
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/*
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* get the requested block
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*/
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origlblkno = lblkno;
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*bpp = bp = getblk(vp, lblkno, size, 0, 0);
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seq = ISSEQREAD(vp, lblkno);
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/*
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* if it is in the cache, then check to see if the reads have been
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* sequential. If they have, then try some read-ahead, otherwise
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* back-off on prospective read-aheads.
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*/
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if (bp->b_flags & B_CACHE) {
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if (!seq) {
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vp->v_maxra = bp->b_lblkno + bp->b_bcount / size;
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vp->v_ralen >>= RA_SHIFTDOWN;
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return 0;
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} else if( vp->v_maxra > lblkno) {
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if ( (vp->v_maxra + (vp->v_ralen / RA_MULTIPLE_SLOW)) >= (lblkno + vp->v_ralen)) {
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if ((vp->v_ralen + 1) < RA_MULTIPLE_FAST*(MAXPHYS / size))
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++vp->v_ralen;
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return 0;
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}
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lblkno = vp->v_maxra;
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} else {
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lblkno += 1;
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}
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bp = NULL;
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} else {
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/*
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* if it isn't in the cache, then get a chunk from disk if
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* sequential, otherwise just get the block.
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*/
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bp->b_flags |= B_READ;
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lblkno += 1;
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curproc->p_stats->p_ru.ru_inblock++; /* XXX */
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vp->v_ralen = 0;
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}
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/*
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* assume no read-ahead
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*/
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alreadyincore = 1;
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rablkno = lblkno;
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/*
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* if we have been doing sequential I/O, then do some read-ahead
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*/
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if (seq) {
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/*
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* bump ralen a bit...
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*/
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if ((vp->v_ralen + 1) < RA_MULTIPLE_SLOW*(MAXPHYS / size))
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++vp->v_ralen;
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/*
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* this code makes sure that the stuff that we have read-ahead
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* is still in the cache. If it isn't, we have been reading
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* ahead too much, and we need to back-off, otherwise we might
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* try to read more.
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*/
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for (i = 0; i < vp->v_ralen; i++) {
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rablkno = lblkno + i;
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alreadyincore = (int) incore(vp, rablkno);
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if (!alreadyincore) {
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if (inmem(vp, rablkno)) {
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if (vp->v_maxra < rablkno)
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vp->v_maxra = rablkno + 1;
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continue;
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}
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if (rablkno < vp->v_maxra) {
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vp->v_maxra = rablkno;
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vp->v_ralen >>= RA_SHIFTDOWN;
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alreadyincore = 1;
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}
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break;
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} else if (vp->v_maxra < rablkno) {
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vp->v_maxra = rablkno + 1;
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}
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}
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}
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/*
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* we now build the read-ahead buffer if it is desirable.
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*/
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rbp = NULL;
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if (!alreadyincore &&
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(rablkno + 1) * size <= filesize &&
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!(error = VOP_BMAP(vp, rablkno, NULL, &blkno, &num_ra, NULL)) &&
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blkno != -1) {
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if (num_ra > vp->v_ralen)
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num_ra = vp->v_ralen;
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if (num_ra) {
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rbp = cluster_rbuild(vp, filesize, rablkno, blkno, size,
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num_ra + 1);
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} else {
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rbp = getblk(vp, rablkno, size, 0, 0);
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rbp->b_flags |= B_READ | B_ASYNC;
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rbp->b_blkno = blkno;
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}
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}
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/*
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* handle the synchronous read
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*/
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if (bp) {
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if (bp->b_flags & (B_DONE | B_DELWRI))
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panic("cluster_read: DONE bp");
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else {
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vfs_busy_pages(bp, 0);
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error = VOP_STRATEGY(bp);
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vp->v_maxra = bp->b_lblkno + bp->b_bcount / size;
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totreads++;
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totreadblocks += bp->b_bcount / size;
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curproc->p_stats->p_ru.ru_inblock++;
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}
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}
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/*
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* and if we have read-aheads, do them too
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*/
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if (rbp) {
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vp->v_maxra = rbp->b_lblkno + rbp->b_bcount / size;
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if (error || (rbp->b_flags & B_CACHE)) {
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rbp->b_flags &= ~(B_ASYNC | B_READ);
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brelse(rbp);
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} else {
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if ((rbp->b_flags & B_CLUSTER) == 0)
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vfs_busy_pages(rbp, 0);
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(void) VOP_STRATEGY(rbp);
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totreads++;
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totreadblocks += rbp->b_bcount / size;
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curproc->p_stats->p_ru.ru_inblock++;
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}
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}
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if (bp && ((bp->b_flags & B_ASYNC) == 0))
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return (biowait(bp));
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return (error);
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}
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/*
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* If blocks are contiguous on disk, use this to provide clustered
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* read ahead. We will read as many blocks as possible sequentially
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* and then parcel them up into logical blocks in the buffer hash table.
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*/
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static struct buf *
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cluster_rbuild(vp, filesize, lbn, blkno, size, run)
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struct vnode *vp;
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u_quad_t filesize;
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daddr_t lbn;
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daddr_t blkno;
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long size;
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int run;
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{
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struct cluster_save *b_save;
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struct buf *bp, *tbp;
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daddr_t bn;
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int i, inc, j;
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#ifdef DIAGNOSTIC
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if (size != vp->v_mount->mnt_stat.f_iosize)
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panic("cluster_rbuild: size %d != filesize %d\n",
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size, vp->v_mount->mnt_stat.f_iosize);
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#endif
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if (size * (lbn + run) > filesize)
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--run;
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tbp = getblk(vp, lbn, size, 0, 0);
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if (tbp->b_flags & B_CACHE)
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return tbp;
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tbp->b_blkno = blkno;
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tbp->b_flags |= B_ASYNC | B_READ;
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if( ((tbp->b_flags & B_VMIO) == 0) || (run <= 1) )
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return tbp;
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bp = trypbuf();
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if (bp == 0)
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return tbp;
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(vm_offset_t) bp->b_data |= ((vm_offset_t) tbp->b_data) & PAGE_MASK;
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bp->b_flags = B_ASYNC | B_READ | B_CALL | B_BUSY | B_CLUSTER | B_VMIO;
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bp->b_iodone = cluster_callback;
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bp->b_blkno = blkno;
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bp->b_lblkno = lbn;
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pbgetvp(vp, bp);
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b_save = malloc(sizeof(struct buf *) * run +
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sizeof(struct cluster_save), M_SEGMENT, M_WAITOK);
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b_save->bs_nchildren = 0;
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b_save->bs_children = (struct buf **) (b_save + 1);
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bp->b_saveaddr = b_save;
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bp->b_bcount = 0;
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bp->b_bufsize = 0;
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bp->b_npages = 0;
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inc = btodb(size);
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for (bn = blkno, i = 0; i < run; ++i, bn += inc) {
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if (i != 0) {
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if ((bp->b_npages * PAGE_SIZE) + size > MAXPHYS)
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break;
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if (incore(vp, lbn + i))
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break;
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tbp = getblk(vp, lbn + i, size, 0, 0);
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if ((tbp->b_flags & B_CACHE) ||
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(tbp->b_flags & B_VMIO) == 0) {
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brelse(tbp);
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break;
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}
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for (j=0;j<tbp->b_npages;j++) {
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if (tbp->b_pages[j]->valid) {
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break;
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}
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}
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if (j != tbp->b_npages) {
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/*
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* force buffer to be re-constituted later
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*/
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tbp->b_flags |= B_RELBUF;
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brelse(tbp);
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break;
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}
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tbp->b_flags |= B_READ | B_ASYNC;
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if( tbp->b_blkno == tbp->b_lblkno) {
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tbp->b_blkno = bn;
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} else if (tbp->b_blkno != bn) {
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brelse(tbp);
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break;
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}
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}
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++b_save->bs_nchildren;
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b_save->bs_children[i] = tbp;
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for (j = 0; j < tbp->b_npages; j += 1) {
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vm_page_t m;
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m = tbp->b_pages[j];
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++m->busy;
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++m->object->paging_in_progress;
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if ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) {
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m = bogus_page;
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}
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if ((bp->b_npages == 0) ||
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(bp->b_bufsize & PAGE_MASK) == 0) {
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bp->b_pages[bp->b_npages] = m;
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bp->b_npages++;
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} else {
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if ( tbp->b_npages > 1) {
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panic("cluster_rbuild: page unaligned filesystems not supported");
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}
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}
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}
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bp->b_bcount += tbp->b_bcount;
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bp->b_bufsize += tbp->b_bufsize;
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}
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pmap_qenter(trunc_page((vm_offset_t) bp->b_data),
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(vm_page_t *)bp->b_pages, bp->b_npages);
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return (bp);
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}
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/*
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* Cleanup after a clustered read or write.
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* This is complicated by the fact that any of the buffers might have
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* extra memory (if there were no empty buffer headers at allocbuf time)
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* that we will need to shift around.
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*/
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void
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cluster_callback(bp)
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struct buf *bp;
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{
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struct cluster_save *b_save;
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struct buf **bpp, *tbp;
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int error = 0;
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/*
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* Must propogate errors to all the components.
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*/
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if (bp->b_flags & B_ERROR)
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error = bp->b_error;
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b_save = (struct cluster_save *) (bp->b_saveaddr);
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pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_npages);
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/*
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* Move memory from the large cluster buffer into the component
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* buffers and mark IO as done on these.
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*/
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for (bpp = b_save->bs_children; b_save->bs_nchildren--; ++bpp) {
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tbp = *bpp;
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if (error) {
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tbp->b_flags |= B_ERROR;
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tbp->b_error = error;
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}
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biodone(tbp);
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}
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free(b_save, M_SEGMENT);
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relpbuf(bp);
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}
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|
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/*
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* Do clustered write for FFS.
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*
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* Three cases:
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* 1. Write is not sequential (write asynchronously)
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* Write is sequential:
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* 2. beginning of cluster - begin cluster
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* 3. middle of a cluster - add to cluster
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* 4. end of a cluster - asynchronously write cluster
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*/
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void
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cluster_write(bp, filesize)
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struct buf *bp;
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u_quad_t filesize;
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{
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struct vnode *vp;
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daddr_t lbn;
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int maxclen, cursize;
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int lblocksize;
|
|
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vp = bp->b_vp;
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lblocksize = vp->v_mount->mnt_stat.f_iosize;
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lbn = bp->b_lblkno;
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/* Initialize vnode to beginning of file. */
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if (lbn == 0)
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vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
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if (vp->v_clen == 0 || lbn != vp->v_lastw + 1 ||
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(bp->b_blkno != vp->v_lasta + btodb(lblocksize))) {
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maxclen = MAXPHYS / lblocksize - 1;
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if (vp->v_clen != 0) {
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/*
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* Next block is not sequential.
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|
*
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* If we are not writing at end of file, the process
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|
* seeked to another point in the file since its last
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* write, or we have reached our maximum cluster size,
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|
* then push the previous cluster. Otherwise try
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* reallocating to make it sequential.
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|
*/
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|
cursize = vp->v_lastw - vp->v_cstart + 1;
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|
if (!doreallocblks ||
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(lbn + 1) * lblocksize != filesize ||
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lbn != vp->v_lastw + 1 || vp->v_clen <= cursize) {
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cluster_wbuild(vp, NULL, lblocksize,
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vp->v_cstart, cursize, lbn);
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} else {
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|
struct buf **bpp, **endbp;
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struct cluster_save *buflist;
|
|
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buflist = cluster_collectbufs(vp, bp);
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|
endbp = &buflist->bs_children
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|
[buflist->bs_nchildren - 1];
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|
if (VOP_REALLOCBLKS(vp, buflist)) {
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/*
|
|
* Failed, push the previous cluster.
|
|
*/
|
|
for (bpp = buflist->bs_children;
|
|
bpp < endbp; bpp++)
|
|
brelse(*bpp);
|
|
free(buflist, M_SEGMENT);
|
|
cluster_wbuild(vp, NULL, lblocksize,
|
|
vp->v_cstart, cursize, lbn);
|
|
} else {
|
|
/*
|
|
* Succeeded, keep building cluster.
|
|
*/
|
|
for (bpp = buflist->bs_children;
|
|
bpp <= endbp; bpp++)
|
|
bdwrite(*bpp);
|
|
free(buflist, M_SEGMENT);
|
|
vp->v_lastw = lbn;
|
|
vp->v_lasta = bp->b_blkno;
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
* Consider beginning a cluster. If at end of file, make
|
|
* cluster as large as possible, otherwise find size of
|
|
* existing cluster.
|
|
*/
|
|
if ((lbn + 1) * lblocksize != filesize &&
|
|
(bp->b_blkno == bp->b_lblkno) &&
|
|
(VOP_BMAP(vp, lbn, NULL, &bp->b_blkno, &maxclen, NULL) ||
|
|
bp->b_blkno == -1)) {
|
|
bawrite(bp);
|
|
vp->v_clen = 0;
|
|
vp->v_lasta = bp->b_blkno;
|
|
vp->v_cstart = lbn + 1;
|
|
vp->v_lastw = lbn;
|
|
return;
|
|
}
|
|
vp->v_clen = maxclen;
|
|
if (maxclen == 0) { /* I/O not contiguous */
|
|
vp->v_cstart = lbn + 1;
|
|
bawrite(bp);
|
|
} else { /* Wait for rest of cluster */
|
|
vp->v_cstart = lbn;
|
|
bdwrite(bp);
|
|
}
|
|
} else if (lbn == vp->v_cstart + vp->v_clen) {
|
|
/*
|
|
* At end of cluster, write it out.
|
|
*/
|
|
cluster_wbuild(vp, bp, bp->b_bcount, vp->v_cstart,
|
|
vp->v_clen + 1, lbn);
|
|
vp->v_clen = 0;
|
|
vp->v_cstart = lbn + 1;
|
|
} else
|
|
/*
|
|
* In the middle of a cluster, so just delay the I/O for now.
|
|
*/
|
|
bdwrite(bp);
|
|
vp->v_lastw = lbn;
|
|
vp->v_lasta = bp->b_blkno;
|
|
}
|
|
|
|
|
|
/*
|
|
* This is an awful lot like cluster_rbuild...wish they could be combined.
|
|
* The last lbn argument is the current block on which I/O is being
|
|
* performed. Check to see that it doesn't fall in the middle of
|
|
* the current block (if last_bp == NULL).
|
|
*/
|
|
void
|
|
cluster_wbuild(vp, last_bp, size, start_lbn, len, lbn)
|
|
struct vnode *vp;
|
|
struct buf *last_bp;
|
|
long size;
|
|
daddr_t start_lbn;
|
|
int len;
|
|
daddr_t lbn;
|
|
{
|
|
struct cluster_save *b_save;
|
|
struct buf *bp, *tbp, *pb;
|
|
int i, j, s;
|
|
|
|
#ifdef DIAGNOSTIC
|
|
if (size != vp->v_mount->mnt_stat.f_iosize)
|
|
panic("cluster_wbuild: size %d != filesize %d\n",
|
|
size, vp->v_mount->mnt_stat.f_iosize);
|
|
#endif
|
|
redo:
|
|
if( (lbn != -1) || (last_bp == 0)) {
|
|
while ((!(tbp = incore(vp, start_lbn)) || (tbp->b_flags & B_BUSY)
|
|
|| (start_lbn == lbn)) && len) {
|
|
++start_lbn;
|
|
--len;
|
|
}
|
|
|
|
pb = trypbuf();
|
|
/* Get more memory for current buffer */
|
|
if (len <= 1 || pb == NULL) {
|
|
if (pb != NULL)
|
|
relpbuf(pb);
|
|
if (last_bp) {
|
|
bawrite(last_bp);
|
|
} else if (len) {
|
|
bp = getblk(vp, start_lbn, size, 0, 0);
|
|
bawrite(bp);
|
|
}
|
|
return;
|
|
}
|
|
tbp = getblk(vp, start_lbn, size, 0, 0);
|
|
} else {
|
|
tbp = last_bp;
|
|
if( tbp->b_flags & B_BUSY) {
|
|
printf("vfs_cluster: warning: buffer already busy\n");
|
|
}
|
|
tbp->b_flags |= B_BUSY;
|
|
last_bp = 0;
|
|
pb = trypbuf();
|
|
if (pb == NULL) {
|
|
bawrite(tbp);
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (!(tbp->b_flags & B_DELWRI)) {
|
|
relpbuf(pb);
|
|
++start_lbn;
|
|
--len;
|
|
brelse(tbp);
|
|
goto redo;
|
|
}
|
|
/*
|
|
* Extra memory in the buffer, punt on this buffer. XXX we could
|
|
* handle this in most cases, but we would have to push the extra
|
|
* memory down to after our max possible cluster size and then
|
|
* potentially pull it back up if the cluster was terminated
|
|
* prematurely--too much hassle.
|
|
*/
|
|
if (((tbp->b_flags & B_VMIO) == 0) ||
|
|
(tbp->b_bcount != tbp->b_bufsize)) {
|
|
relpbuf(pb);
|
|
++start_lbn;
|
|
--len;
|
|
bawrite(tbp);
|
|
goto redo;
|
|
}
|
|
bp = pb;
|
|
b_save = malloc(sizeof(struct buf *) * (len + 1) + sizeof(struct cluster_save),
|
|
M_SEGMENT, M_WAITOK);
|
|
b_save->bs_nchildren = 0;
|
|
b_save->bs_children = (struct buf **) (b_save + 1);
|
|
bp->b_saveaddr = b_save;
|
|
bp->b_bcount = 0;
|
|
bp->b_bufsize = 0;
|
|
bp->b_npages = 0;
|
|
|
|
if (tbp->b_flags & B_VMIO)
|
|
bp->b_flags |= B_VMIO;
|
|
|
|
bp->b_blkno = tbp->b_blkno;
|
|
bp->b_lblkno = tbp->b_lblkno;
|
|
(vm_offset_t) bp->b_data |= ((vm_offset_t) tbp->b_data) & PAGE_MASK;
|
|
bp->b_flags |= B_CALL | B_BUSY | B_CLUSTER;
|
|
bp->b_iodone = cluster_callback;
|
|
pbgetvp(vp, bp);
|
|
|
|
for (i = 0; i < len; ++i, ++start_lbn) {
|
|
if (i != 0) {
|
|
/*
|
|
* Block is not in core or the non-sequential block
|
|
* ending our cluster was part of the cluster (in
|
|
* which case we don't want to write it twice).
|
|
*/
|
|
if (!(tbp = incore(vp, start_lbn)) ||
|
|
(last_bp == NULL && start_lbn == lbn))
|
|
break;
|
|
|
|
if ((tbp->b_flags & (B_INVAL | B_CLUSTEROK)) != B_CLUSTEROK)
|
|
break;
|
|
|
|
if ((tbp->b_npages + bp->b_npages) > (MAXPHYS / PAGE_SIZE))
|
|
break;
|
|
|
|
if ( (tbp->b_blkno != tbp->b_lblkno) &&
|
|
((bp->b_blkno + btodb(size) * i) != tbp->b_blkno))
|
|
break;
|
|
|
|
/*
|
|
* Get the desired block buffer (unless it is the
|
|
* final sequential block whose buffer was passed in
|
|
* explictly as last_bp).
|
|
*/
|
|
if (last_bp == NULL || start_lbn != lbn) {
|
|
if( tbp->b_flags & B_BUSY)
|
|
break;
|
|
tbp = getblk(vp, start_lbn, size, 0, 0);
|
|
if (!(tbp->b_flags & B_DELWRI) ||
|
|
((tbp->b_flags & B_VMIO) != (bp->b_flags & B_VMIO))) {
|
|
brelse(tbp);
|
|
break;
|
|
}
|
|
} else
|
|
tbp = last_bp;
|
|
}
|
|
for (j = 0; j < tbp->b_npages; j += 1) {
|
|
vm_page_t m;
|
|
m = tbp->b_pages[j];
|
|
++m->busy;
|
|
++m->object->paging_in_progress;
|
|
if ((bp->b_npages == 0) ||
|
|
(bp->b_pages[bp->b_npages - 1] != m)) {
|
|
bp->b_pages[bp->b_npages] = m;
|
|
bp->b_npages++;
|
|
}
|
|
}
|
|
bp->b_bcount += size;
|
|
bp->b_bufsize += size;
|
|
|
|
tbp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI);
|
|
tbp->b_flags |= B_ASYNC;
|
|
s = splbio();
|
|
reassignbuf(tbp, tbp->b_vp); /* put on clean list */
|
|
++tbp->b_vp->v_numoutput;
|
|
splx(s);
|
|
b_save->bs_children[i] = tbp;
|
|
}
|
|
b_save->bs_nchildren = i;
|
|
pmap_qenter(trunc_page((vm_offset_t) bp->b_data),
|
|
(vm_page_t *) bp->b_pages, bp->b_npages);
|
|
bawrite(bp);
|
|
|
|
if (i < len) {
|
|
len -= i;
|
|
goto redo;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Collect together all the buffers in a cluster.
|
|
* Plus add one additional buffer.
|
|
*/
|
|
struct cluster_save *
|
|
cluster_collectbufs(vp, last_bp)
|
|
struct vnode *vp;
|
|
struct buf *last_bp;
|
|
{
|
|
struct cluster_save *buflist;
|
|
daddr_t lbn;
|
|
int i, len;
|
|
|
|
len = vp->v_lastw - vp->v_cstart + 1;
|
|
buflist = malloc(sizeof(struct buf *) * (len + 1) + sizeof(*buflist),
|
|
M_SEGMENT, M_WAITOK);
|
|
buflist->bs_nchildren = 0;
|
|
buflist->bs_children = (struct buf **) (buflist + 1);
|
|
for (lbn = vp->v_cstart, i = 0; i < len; lbn++, i++)
|
|
(void) bread(vp, lbn, last_bp->b_bcount, NOCRED,
|
|
&buflist->bs_children[i]);
|
|
buflist->bs_children[i] = last_bp;
|
|
buflist->bs_nchildren = i + 1;
|
|
return (buflist);
|
|
}
|