96334b8fc8
system, the mapping from logical to physical block number may be lost. Hence we have to check for a reconstituted buffer and redo the call to VOP_BMAP if the physical block number has been lost.
846 lines
21 KiB
C
846 lines
21 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 1.73 1998/11/15 14:11:06 bde Exp $
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*/
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#include "opt_debug_cluster.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.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/malloc.h>
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#include <sys/mount.h>
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#include <sys/resourcevar.h>
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#include <vm/vm.h>
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#include <vm/vm_prot.h>
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#include <vm/vm_object.h>
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#include <vm/vm_page.h>
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#if defined(CLUSTERDEBUG)
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#include <sys/sysctl.h>
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static int rcluster= 0;
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SYSCTL_INT(_debug, OID_AUTO, rcluster, CTLFLAG_RW, &rcluster, 0, "");
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#endif
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static MALLOC_DEFINE(M_SEGMENT, "cluster_save buffer", "cluster_save buffer");
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static struct cluster_save *
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cluster_collectbufs __P((struct vnode *vp, struct buf *last_bp));
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static struct buf *
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cluster_rbuild __P((struct vnode *vp, u_quad_t filesize, daddr_t lbn,
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daddr_t blkno, long size, int run, struct buf *fbp));
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extern vm_page_t bogus_page;
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/*
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* Maximum number of blocks for read-ahead.
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*/
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#define MAXRA 32
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/*
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* This replaces bread.
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*/
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int
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cluster_read(vp, filesize, lblkno, size, cred, totread, seqcount, 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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long totread;
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int seqcount;
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struct buf **bpp;
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{
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struct buf *bp, *rbp, *reqbp;
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daddr_t blkno, origblkno;
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int error, num_ra;
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int i;
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int maxra, racluster;
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long origtotread;
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error = 0;
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if (vp->v_maxio == 0)
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vp->v_maxio = DFLTPHYS;
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/*
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* Try to limit the amount of read-ahead by a few
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* ad-hoc parameters. This needs work!!!
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*/
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racluster = vp->v_maxio/size;
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maxra = 2 * racluster + (totread / size);
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if (maxra > MAXRA)
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maxra = MAXRA;
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if (maxra > nbuf/8)
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maxra = nbuf/8;
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/*
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* get the requested block
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*/
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*bpp = reqbp = bp = getblk(vp, lblkno, size, 0, 0);
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origblkno = lblkno;
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origtotread = totread;
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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 (!seqcount) {
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return 0;
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} else if ((bp->b_flags & B_RAM) == 0) {
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return 0;
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} else {
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int s;
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struct buf *tbp;
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bp->b_flags &= ~B_RAM;
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/*
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* We do the spl here so that there is no window
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* between the incore and the b_usecount increment
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* below. We opt to keep the spl out of the loop
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* for efficiency.
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*/
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s = splbio();
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for(i=1;i<maxra;i++) {
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if (!(tbp = incore(vp, lblkno+i))) {
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break;
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}
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/*
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* Set another read-ahead mark so we know to check
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* again.
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*/
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if (((i % racluster) == (racluster - 1)) ||
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(i == (maxra - 1)))
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tbp->b_flags |= B_RAM;
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if ((tbp->b_usecount < 1) &&
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((tbp->b_flags & B_BUSY) == 0) &&
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(tbp->b_qindex == QUEUE_LRU)) {
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TAILQ_REMOVE(&bufqueues[QUEUE_LRU], tbp, b_freelist);
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TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LRU], tbp, b_freelist);
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}
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}
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splx(s);
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if (i >= maxra) {
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return 0;
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}
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lblkno += i;
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}
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reqbp = bp = NULL;
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} else {
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off_t firstread;
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firstread = bp->b_offset;
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#ifdef DIAGNOSTIC
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if (bp->b_offset == NOOFFSET)
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panic("cluster_read: no buffer offset");
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#endif
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if (firstread + totread > filesize)
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totread = filesize - firstread;
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if (totread > size) {
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int nblks = 0;
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int ncontigafter;
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while (totread > 0) {
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nblks++;
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totread -= size;
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}
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if (nblks == 1)
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goto single_block_read;
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if (nblks > racluster)
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nblks = racluster;
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error = VOP_BMAP(vp, lblkno, NULL,
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&blkno, &ncontigafter, NULL);
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if (error)
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goto single_block_read;
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if (blkno == -1)
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goto single_block_read;
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if (ncontigafter == 0)
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goto single_block_read;
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if (ncontigafter + 1 < nblks)
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nblks = ncontigafter + 1;
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bp = cluster_rbuild(vp, filesize, lblkno,
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blkno, size, nblks, bp);
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lblkno += (bp->b_bufsize / size);
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} else {
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single_block_read:
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/*
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* if it isn't in the cache, then get a chunk from
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* disk if sequential, otherwise just get the block.
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*/
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bp->b_flags |= B_READ | B_RAM;
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lblkno += 1;
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}
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}
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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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rbp = NULL;
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if (seqcount && (lblkno < (origblkno + seqcount))) {
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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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if (((u_quad_t)(lblkno + 1) * size) <= filesize &&
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!(error = VOP_BMAP(vp, lblkno, NULL, &blkno, &num_ra, NULL)) &&
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blkno != -1) {
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int nblksread;
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int ntoread = num_ra + 1;
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nblksread = (origtotread + size - 1) / size;
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if (seqcount < nblksread)
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seqcount = nblksread;
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if (seqcount < ntoread)
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ntoread = seqcount;
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if (num_ra) {
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rbp = cluster_rbuild(vp, filesize, lblkno,
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blkno, size, ntoread, NULL);
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} else {
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rbp = getblk(vp, lblkno, size, 0, 0);
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rbp->b_flags |= B_READ | B_ASYNC | B_RAM;
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rbp->b_blkno = blkno;
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}
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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 defined(CLUSTERDEBUG)
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if (rcluster)
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printf("S(%ld,%ld,%d) ",
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(long)bp->b_lblkno, bp->b_bcount, seqcount);
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#endif
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if ((bp->b_flags & B_CLUSTER) == 0)
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vfs_busy_pages(bp, 0);
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error = VOP_STRATEGY(vp, bp);
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curproc->p_stats->p_ru.ru_inblock++;
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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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if (error) {
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rbp->b_flags &= ~(B_ASYNC | B_READ);
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brelse(rbp);
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} else if (rbp->b_flags & B_CACHE) {
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rbp->b_flags &= ~(B_ASYNC | B_READ);
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bqrelse(rbp);
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} else {
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#if defined(CLUSTERDEBUG)
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if (rcluster) {
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if (bp)
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printf("A+(%ld,%ld,%ld,%d) ",
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(long)rbp->b_lblkno, rbp->b_bcount,
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(long)(rbp->b_lblkno - origblkno),
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seqcount);
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else
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printf("A(%ld,%ld,%ld,%d) ",
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(long)rbp->b_lblkno, rbp->b_bcount,
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(long)(rbp->b_lblkno - origblkno),
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seqcount);
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}
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#endif
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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(vp, rbp);
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curproc->p_stats->p_ru.ru_inblock++;
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}
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}
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if (reqbp)
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return (biowait(reqbp));
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else
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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, fbp)
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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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struct buf *fbp;
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{
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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 %ld != filesize %ld\n",
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size, vp->v_mount->mnt_stat.f_iosize);
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#endif
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/*
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* avoid a division
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*/
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while ((u_quad_t) size * (lbn + run) > filesize) {
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--run;
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}
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if (fbp) {
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tbp = fbp;
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tbp->b_flags |= B_READ;
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} else {
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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_flags |= B_ASYNC | B_READ | B_RAM;
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}
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tbp->b_blkno = blkno;
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if( (tbp->b_flags & B_MALLOC) ||
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((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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bp->b_data = (char *)((vm_offset_t)bp->b_data |
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((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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bp->b_offset = tbp->b_offset;
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#ifdef DIAGNOSTIC
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if (bp->b_offset == NOOFFSET)
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panic("cluster_rbuild: no buffer offset");
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#endif
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pbgetvp(vp, bp);
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TAILQ_INIT(&bp->b_cluster.cluster_head);
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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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if (vp->v_maxio == 0)
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vp->v_maxio = DFLTPHYS;
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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) +
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round_page(size) > vp->v_maxio)
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break;
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if (tbp = incore(vp, lbn + i)) {
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if (tbp->b_flags & B_BUSY)
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break;
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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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if (j != tbp->b_npages)
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break;
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if (tbp->b_bcount != size)
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break;
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}
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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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bqrelse(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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if (j != tbp->b_npages) {
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bqrelse(tbp);
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break;
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}
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if ((fbp && (i == 1)) || (i == (run - 1)))
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tbp->b_flags |= B_RAM;
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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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TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head,
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tbp, b_cluster.cluster_entry);
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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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vm_page_io_start(m);
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vm_object_pip_add(m->object, 1);
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if ((bp->b_npages == 0) ||
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(bp->b_pages[bp->b_npages-1] != m)) {
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bp->b_pages[bp->b_npages] = m;
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bp->b_npages++;
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}
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if ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL)
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tbp->b_pages[j] = bogus_page;
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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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for(j=0;j<bp->b_npages;j++) {
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if ((bp->b_pages[j]->valid & VM_PAGE_BITS_ALL) ==
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VM_PAGE_BITS_ALL)
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bp->b_pages[j] = bogus_page;
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}
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if (bp->b_bufsize > bp->b_kvasize)
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panic("cluster_rbuild: b_bufsize(%ld) > b_kvasize(%d)\n",
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bp->b_bufsize, bp->b_kvasize);
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bp->b_kvasize = bp->b_bufsize;
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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 buf *nbp, *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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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 (tbp = TAILQ_FIRST(&bp->b_cluster.cluster_head);
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tbp; tbp = nbp) {
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nbp = TAILQ_NEXT(&tbp->b_cluster, cluster_entry);
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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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} else
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tbp->b_dirtyoff = tbp->b_dirtyend = 0;
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biodone(tbp);
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}
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relpbuf(bp);
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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)
|
|
struct buf *bp;
|
|
u_quad_t filesize;
|
|
{
|
|
struct vnode *vp;
|
|
daddr_t lbn;
|
|
int maxclen, cursize;
|
|
int lblocksize;
|
|
int async;
|
|
|
|
vp = bp->b_vp;
|
|
if (vp->v_maxio == 0)
|
|
vp->v_maxio = DFLTPHYS;
|
|
if (vp->v_type == VREG) {
|
|
async = vp->v_mount->mnt_flag & MNT_ASYNC;
|
|
lblocksize = vp->v_mount->mnt_stat.f_iosize;
|
|
} else {
|
|
async = 0;
|
|
lblocksize = bp->b_bufsize;
|
|
}
|
|
lbn = bp->b_lblkno;
|
|
|
|
#ifdef DIAGNOSTIC
|
|
if (bp->b_offset == NOOFFSET)
|
|
panic("cluster_write: no buffer offset");
|
|
#endif
|
|
|
|
/* Initialize vnode to beginning of file. */
|
|
if (lbn == 0)
|
|
vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
|
|
|
|
if (vp->v_clen == 0 || lbn != vp->v_lastw + 1 ||
|
|
(bp->b_blkno != vp->v_lasta + btodb(lblocksize))) {
|
|
maxclen = vp->v_maxio / lblocksize - 1;
|
|
if (vp->v_clen != 0) {
|
|
/*
|
|
* Next block is not sequential.
|
|
*
|
|
* If we are not writing at end of file, the process
|
|
* seeked to another point in the file since its last
|
|
* write, or we have reached our maximum cluster size,
|
|
* then push the previous cluster. Otherwise try
|
|
* reallocating to make it sequential.
|
|
*/
|
|
cursize = vp->v_lastw - vp->v_cstart + 1;
|
|
if (((u_quad_t) bp->b_offset + lblocksize) != filesize ||
|
|
lbn != vp->v_lastw + 1 || vp->v_clen <= cursize) {
|
|
if (!async)
|
|
cluster_wbuild(vp, lblocksize,
|
|
vp->v_cstart, cursize);
|
|
} else {
|
|
struct buf **bpp, **endbp;
|
|
struct cluster_save *buflist;
|
|
|
|
buflist = cluster_collectbufs(vp, bp);
|
|
endbp = &buflist->bs_children
|
|
[buflist->bs_nchildren - 1];
|
|
if (VOP_REALLOCBLKS(vp, buflist)) {
|
|
/*
|
|
* Failed, push the previous cluster.
|
|
*/
|
|
for (bpp = buflist->bs_children;
|
|
bpp < endbp; bpp++)
|
|
brelse(*bpp);
|
|
free(buflist, M_SEGMENT);
|
|
cluster_wbuild(vp, lblocksize,
|
|
vp->v_cstart, cursize);
|
|
} 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 ((vp->v_type == VREG) &&
|
|
((u_quad_t) bp->b_offset + 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 (!async && 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.
|
|
*/
|
|
bdwrite(bp);
|
|
cluster_wbuild(vp, lblocksize, vp->v_cstart, vp->v_clen + 1);
|
|
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).
|
|
*/
|
|
int
|
|
cluster_wbuild(vp, size, start_lbn, len)
|
|
struct vnode *vp;
|
|
long size;
|
|
daddr_t start_lbn;
|
|
int len;
|
|
{
|
|
struct buf *bp, *tbp;
|
|
int i, j, s;
|
|
int totalwritten = 0;
|
|
int dbsize = btodb(size);
|
|
|
|
if (vp->v_maxio == 0)
|
|
vp->v_maxio = DFLTPHYS;
|
|
while (len > 0) {
|
|
s = splbio();
|
|
if (((tbp = gbincore(vp, start_lbn)) == NULL) ||
|
|
((tbp->b_flags & (B_INVAL|B_BUSY|B_DELWRI)) != B_DELWRI)) {
|
|
++start_lbn;
|
|
--len;
|
|
splx(s);
|
|
continue;
|
|
}
|
|
bremfree(tbp);
|
|
tbp->b_flags |= B_BUSY;
|
|
tbp->b_flags &= ~B_DONE;
|
|
splx(s);
|
|
|
|
/*
|
|
* 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_CLUSTEROK|B_MALLOC)) != B_CLUSTEROK) ||
|
|
(tbp->b_bcount != tbp->b_bufsize) ||
|
|
(tbp->b_bcount != size) ||
|
|
(len == 1) ||
|
|
((bp = trypbuf()) == NULL)) {
|
|
totalwritten += tbp->b_bufsize;
|
|
bawrite(tbp);
|
|
++start_lbn;
|
|
--len;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* We got a pbuf to make the cluster in.
|
|
* so initialise it.
|
|
*/
|
|
TAILQ_INIT(&bp->b_cluster.cluster_head);
|
|
bp->b_bcount = 0;
|
|
bp->b_bufsize = 0;
|
|
bp->b_npages = 0;
|
|
if (tbp->b_wcred != NOCRED) {
|
|
bp->b_wcred = tbp->b_wcred;
|
|
crhold(bp->b_wcred);
|
|
}
|
|
|
|
bp->b_blkno = tbp->b_blkno;
|
|
bp->b_lblkno = tbp->b_lblkno;
|
|
bp->b_offset = tbp->b_offset;
|
|
bp->b_data = (char *)((vm_offset_t)bp->b_data |
|
|
((vm_offset_t)tbp->b_data & PAGE_MASK));
|
|
bp->b_flags |= B_CALL | B_BUSY | B_CLUSTER |
|
|
(tbp->b_flags & (B_VMIO | B_NEEDCOMMIT));
|
|
bp->b_iodone = cluster_callback;
|
|
pbgetvp(vp, bp);
|
|
/*
|
|
* From this location in the file, scan forward to see
|
|
* if there are buffers with adjacent data that need to
|
|
* be written as well.
|
|
*/
|
|
for (i = 0; i < len; ++i, ++start_lbn) {
|
|
if (i != 0) { /* If not the first buffer */
|
|
s = splbio();
|
|
/*
|
|
* If the adjacent data is not even in core it
|
|
* can't need to be written.
|
|
*/
|
|
if ((tbp = gbincore(vp, start_lbn)) == NULL) {
|
|
splx(s);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If it IS in core, but has different
|
|
* characteristics, don't cluster with it.
|
|
*/
|
|
if ((tbp->b_flags &
|
|
(B_VMIO | B_CLUSTEROK | B_INVAL | B_BUSY |
|
|
B_DELWRI | B_NEEDCOMMIT))
|
|
!= (B_DELWRI | B_CLUSTEROK |
|
|
(bp->b_flags & (B_VMIO | B_NEEDCOMMIT)))) {
|
|
splx(s);
|
|
break;
|
|
}
|
|
|
|
if (tbp->b_wcred != bp->b_wcred) {
|
|
splx(s);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Check that the combined cluster
|
|
* would make sense with regard to pages
|
|
* and would not be too large
|
|
*/
|
|
if ((tbp->b_bcount != size) ||
|
|
((bp->b_blkno + (dbsize * i)) !=
|
|
tbp->b_blkno) ||
|
|
((tbp->b_npages + bp->b_npages) >
|
|
(vp->v_maxio / PAGE_SIZE))) {
|
|
splx(s);
|
|
break;
|
|
}
|
|
/*
|
|
* Ok, it's passed all the tests,
|
|
* so remove it from the free list
|
|
* and mark it busy. We will use it.
|
|
*/
|
|
bremfree(tbp);
|
|
tbp->b_flags |= B_BUSY;
|
|
tbp->b_flags &= ~B_DONE;
|
|
splx(s);
|
|
} /* end of code for non-first buffers only */
|
|
/* check for latent dependencies to be handled */
|
|
if ((LIST_FIRST(&tbp->b_dep)) != NULL &&
|
|
bioops.io_start)
|
|
(*bioops.io_start)(tbp);
|
|
/*
|
|
* If the IO is via the VM then we do some
|
|
* special VM hackery. (yuck)
|
|
*/
|
|
if (tbp->b_flags & B_VMIO) {
|
|
vm_page_t m;
|
|
|
|
if (i != 0) { /* if not first buffer */
|
|
for (j = 0; j < tbp->b_npages; j += 1) {
|
|
m = tbp->b_pages[j];
|
|
if (m->flags & PG_BUSY)
|
|
goto finishcluster;
|
|
}
|
|
}
|
|
|
|
for (j = 0; j < tbp->b_npages; j += 1) {
|
|
m = tbp->b_pages[j];
|
|
vm_page_io_start(m);
|
|
vm_object_pip_add(m->object, 1);
|
|
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;
|
|
|
|
s = splbio();
|
|
--numdirtybuffers;
|
|
tbp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI);
|
|
tbp->b_flags |= B_ASYNC;
|
|
reassignbuf(tbp, tbp->b_vp); /* put on clean list */
|
|
++tbp->b_vp->v_numoutput;
|
|
splx(s);
|
|
TAILQ_INSERT_TAIL(&bp->b_cluster.cluster_head,
|
|
tbp, b_cluster.cluster_entry);
|
|
}
|
|
finishcluster:
|
|
pmap_qenter(trunc_page((vm_offset_t) bp->b_data),
|
|
(vm_page_t *) bp->b_pages, bp->b_npages);
|
|
if (bp->b_bufsize > bp->b_kvasize)
|
|
panic(
|
|
"cluster_wbuild: b_bufsize(%ld) > b_kvasize(%d)\n",
|
|
bp->b_bufsize, bp->b_kvasize);
|
|
bp->b_kvasize = bp->b_bufsize;
|
|
totalwritten += bp->b_bufsize;
|
|
bp->b_dirtyoff = 0;
|
|
bp->b_dirtyend = bp->b_bufsize;
|
|
bawrite(bp);
|
|
|
|
len -= i;
|
|
}
|
|
return totalwritten;
|
|
}
|
|
|
|
/*
|
|
* Collect together all the buffers in a cluster.
|
|
* Plus add one additional buffer.
|
|
*/
|
|
static struct cluster_save *
|
|
cluster_collectbufs(vp, last_bp)
|
|
struct vnode *vp;
|
|
struct buf *last_bp;
|
|
{
|
|
struct cluster_save *buflist;
|
|
struct buf *bp;
|
|
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, &bp);
|
|
buflist->bs_children[i] = bp;
|
|
if (bp->b_blkno == bp->b_lblkno)
|
|
VOP_BMAP(bp->b_vp, bp->b_lblkno, NULL, &bp->b_blkno,
|
|
NULL, NULL);
|
|
}
|
|
buflist->bs_children[i] = last_bp;
|
|
buflist->bs_nchildren = i + 1;
|
|
return (buflist);
|
|
}
|