749 lines
21 KiB
C
749 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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*
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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 1.6 1994/10/08 22:33:41 phk 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/trace.h>
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#include <sys/malloc.h>
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#include <sys/resourcevar.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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struct buf *cluster_newbuf __P((struct vnode *, struct buf *, long, daddr_t,
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daddr_t, long, int));
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struct buf *cluster_rbuild __P((struct vnode *, u_quad_t, struct buf *,
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daddr_t, daddr_t, long, int, long));
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void cluster_wbuild __P((struct vnode *, struct buf *, long,
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daddr_t, int, daddr_t));
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struct cluster_save *cluster_collectbufs __P((struct vnode *, struct buf *));
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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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* 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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*
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* There are 4 or 5 cases depending on how you count:
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* Desired block is in the cache:
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* 1 Not sequential access (0 I/Os).
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* 2 Access is sequential, do read-ahead (1 ASYNC).
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* Desired block is not in cache:
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* 3 Not sequential access (1 SYNC).
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* 4 Sequential access, next block is contiguous (1 SYNC).
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* 5 Sequential access, next block is not contiguous (1 SYNC, 1 ASYNC)
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*
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* There are potentially two buffers that require I/O.
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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, ioblkno;
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long flags;
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int error, num_ra, alreadyincore;
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#ifdef DIAGNOSTIC
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if (size == 0)
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panic("cluster_read: size = 0");
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#endif
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error = 0;
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flags = B_READ;
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*bpp = bp = getblk(vp, lblkno, size, 0, 0);
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if (bp->b_flags & B_CACHE) {
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/*
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* Desired block is in cache; do any readahead ASYNC.
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* Case 1, 2.
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*/
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trace(TR_BREADHIT, pack(vp, size), lblkno);
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flags |= B_ASYNC;
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ioblkno = lblkno + (vp->v_ralen ? vp->v_ralen : 1);
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alreadyincore = (int)incore(vp, ioblkno);
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bp = NULL;
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} else {
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/* Block wasn't in cache, case 3, 4, 5. */
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trace(TR_BREADMISS, pack(vp, size), lblkno);
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bp->b_flags |= B_READ;
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ioblkno = lblkno;
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alreadyincore = 0;
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curproc->p_stats->p_ru.ru_inblock++; /* XXX */
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}
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/*
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* XXX
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* Replace 1 with a window size based on some permutation of
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* maxcontig and rot_delay. This will let you figure out how
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* many blocks you should read-ahead (case 2, 4, 5).
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*
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* If the access isn't sequential, reset the window to 1.
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* Note that a read to the same block is considered sequential.
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* This catches the case where the file is being read sequentially,
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* but at smaller than the filesystem block size.
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*/
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rbp = NULL;
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if (!ISSEQREAD(vp, lblkno)) {
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vp->v_ralen = 0;
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vp->v_maxra = lblkno;
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} else if ((ioblkno + 1) * size <= filesize && !alreadyincore &&
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!(error = VOP_BMAP(vp, ioblkno, NULL, &blkno, &num_ra)) &&
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blkno != -1) {
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/*
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* Reading sequentially, and the next block is not in the
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* cache. We are going to try reading ahead.
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*/
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if (num_ra) {
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/*
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* If our desired readahead block had been read
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* in a previous readahead but is no longer in
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* core, then we may be reading ahead too far
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* or are not using our readahead very rapidly.
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* In this case we scale back the window.
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*/
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if (!alreadyincore && ioblkno <= vp->v_maxra)
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vp->v_ralen = max(vp->v_ralen >> 1, 1);
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/*
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* There are more sequential blocks than our current
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* window allows, scale up. Ideally we want to get
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* in sync with the filesystem maxcontig value.
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*/
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else if (num_ra > vp->v_ralen && lblkno != vp->v_lastr)
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vp->v_ralen = vp->v_ralen ?
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min(num_ra, vp->v_ralen << 1) : 1;
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if (num_ra > vp->v_ralen)
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num_ra = vp->v_ralen;
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}
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if (num_ra) /* case 2, 4 */
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rbp = cluster_rbuild(vp, filesize,
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bp, ioblkno, blkno, size, num_ra, flags);
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else if (ioblkno == lblkno) {
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bp->b_blkno = blkno;
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/* Case 5: check how many blocks to read ahead */
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++ioblkno;
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if ((ioblkno + 1) * size > filesize ||
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incore(vp, ioblkno) || (error = VOP_BMAP(vp,
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ioblkno, NULL, &blkno, &num_ra)) || blkno == -1)
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goto skip_readahead;
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/*
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* Adjust readahead as above
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*/
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if (num_ra) {
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if (!alreadyincore && ioblkno <= vp->v_maxra)
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vp->v_ralen = max(vp->v_ralen >> 1, 1);
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else if (num_ra > vp->v_ralen &&
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lblkno != vp->v_lastr)
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vp->v_ralen = vp->v_ralen ?
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min(num_ra,vp->v_ralen<<1) : 1;
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if (num_ra > vp->v_ralen)
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num_ra = vp->v_ralen;
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}
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flags |= B_ASYNC;
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if (num_ra)
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rbp = cluster_rbuild(vp, filesize,
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NULL, ioblkno, blkno, size, num_ra, flags);
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else {
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rbp = getblk(vp, ioblkno, size, 0, 0);
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rbp->b_flags |= flags;
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rbp->b_blkno = blkno;
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}
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} else {
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/* case 2; read ahead single block */
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rbp = getblk(vp, ioblkno, size, 0, 0);
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rbp->b_flags |= flags;
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rbp->b_blkno = blkno;
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}
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if (rbp == bp) /* case 4 */
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rbp = NULL;
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else if (rbp) { /* case 2, 5 */
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trace(TR_BREADMISSRA,
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pack(vp, (num_ra + 1) * size), ioblkno);
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curproc->p_stats->p_ru.ru_inblock++; /* XXX */
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}
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}
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/* XXX Kirk, do we need to make sure the bp has creds? */
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skip_readahead:
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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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error = VOP_STRATEGY(bp);
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if (rbp)
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if (error || rbp->b_flags & (B_DONE | B_DELWRI)) {
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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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(void) VOP_STRATEGY(rbp);
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/*
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* Recalculate our maximum readahead
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*/
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if (rbp == NULL)
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rbp = bp;
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if (rbp)
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vp->v_maxra = rbp->b_lblkno + (rbp->b_bufsize / size) - 1;
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if (bp)
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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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struct buf *
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cluster_rbuild(vp, filesize, bp, lbn, blkno, size, run, flags)
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struct vnode *vp;
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u_quad_t filesize;
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struct buf *bp;
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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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long flags;
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{
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struct cluster_save *b_save;
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struct buf *tbp;
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daddr_t bn;
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int i, inc;
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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 + 1) > filesize)
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--run;
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if (run == 0) {
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if (!bp) {
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bp = getblk(vp, lbn, size, 0, 0);
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bp->b_blkno = blkno;
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bp->b_flags |= flags;
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}
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return(bp);
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}
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bp = cluster_newbuf(vp, bp, flags, blkno, lbn, size, run + 1);
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if (bp->b_flags & (B_DONE | B_DELWRI))
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return (bp);
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b_save = malloc(sizeof(struct buf *) * (run + 1) + sizeof(struct cluster_save),
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M_SEGMENT, M_WAITOK);
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b_save->bs_bufsize = b_save->bs_bcount = size;
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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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b_save->bs_saveaddr = bp->b_saveaddr;
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bp->b_saveaddr = (caddr_t) b_save;
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inc = btodb(size);
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for (bn = blkno + inc, i = 1; i <= run; ++i, bn += inc) {
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if (incore(vp, lbn + i)) {
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if (i == 1) {
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bp->b_saveaddr = b_save->bs_saveaddr;
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bp->b_flags &= ~B_CALL;
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bp->b_iodone = NULL;
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allocbuf(bp, size);
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free(b_save, M_SEGMENT);
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} else
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allocbuf(bp, size * i);
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break;
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}
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tbp = getblk(vp, lbn + i, 0, 0, 0);
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/*
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* getblk may return some memory in the buffer if there were
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* no empty buffers to shed it to. If there is currently
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* memory in the buffer, we move it down size bytes to make
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* room for the valid pages that cluster_callback will insert.
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* We do this now so we don't have to do it at interrupt time
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* in the callback routine.
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*/
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if (tbp->b_bufsize != 0) {
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caddr_t bdata = (char *)tbp->b_data;
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if (tbp->b_bufsize + size > MAXBSIZE)
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panic("cluster_rbuild: too much memory");
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if (tbp->b_bufsize > size) {
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/*
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* XXX if the source and destination regions
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* overlap we have to copy backward to avoid
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* clobbering any valid pages (i.e. pagemove
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* implementations typically can't handle
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* overlap).
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*/
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bdata += tbp->b_bufsize;
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while (bdata > (char *)tbp->b_data) {
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bdata -= CLBYTES;
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pagemove(bdata, bdata + size, CLBYTES);
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}
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} else
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pagemove(bdata, bdata + size, tbp->b_bufsize);
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}
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tbp->b_blkno = bn;
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tbp->b_flags |= flags | B_READ | B_ASYNC;
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++b_save->bs_nchildren;
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b_save->bs_children[i - 1] = tbp;
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}
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return(bp);
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}
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/*
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* Either get a new buffer or grow the existing one.
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*/
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struct buf *
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cluster_newbuf(vp, bp, flags, blkno, lblkno, size, run)
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struct vnode *vp;
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struct buf *bp;
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long flags;
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daddr_t blkno;
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daddr_t lblkno;
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long size;
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int run;
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{
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if (!bp) {
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bp = getblk(vp, lblkno, size, 0, 0);
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if (bp->b_flags & (B_DONE | B_DELWRI)) {
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bp->b_blkno = blkno;
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return(bp);
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}
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}
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allocbuf(bp, run * size);
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bp->b_blkno = blkno;
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bp->b_iodone = cluster_callback;
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bp->b_flags |= flags | B_CALL;
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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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long bsize;
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caddr_t cp;
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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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bp->b_saveaddr = b_save->bs_saveaddr;
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bsize = b_save->bs_bufsize;
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cp = (char *)bp->b_data + bsize;
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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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pagemove(cp, tbp->b_data, bsize);
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tbp->b_bufsize += bsize;
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tbp->b_bcount = bsize;
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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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bp->b_bufsize -= bsize;
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cp += bsize;
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}
|
|
/*
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|
* If there was excess memory in the cluster buffer,
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* slide it up adjacent to the remaining valid data.
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*/
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|
if (bp->b_bufsize != bsize) {
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if (bp->b_bufsize < bsize)
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panic("cluster_callback: too little memory");
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pagemove(cp, (char *)bp->b_data + bsize, bp->b_bufsize - bsize);
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}
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|
bp->b_bcount = bsize;
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|
bp->b_iodone = NULL;
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|
free(b_save, M_SEGMENT);
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|
if (bp->b_flags & B_ASYNC)
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|
brelse(bp);
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|
else {
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|
bp->b_flags &= ~B_WANTED;
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|
wakeup((caddr_t)bp);
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|
}
|
|
}
|
|
|
|
/*
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|
* Do clustered write for FFS.
|
|
*
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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
|
|
*/
|
|
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;
|
|
|
|
vp = bp->b_vp;
|
|
lbn = bp->b_lblkno;
|
|
|
|
/* 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(bp->b_bcount))) {
|
|
maxclen = MAXBSIZE / vp->v_mount->mnt_stat.f_iosize - 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 (!doreallocblks ||
|
|
(lbn + 1) * bp->b_bcount != filesize ||
|
|
lbn != vp->v_lastw + 1 || vp->v_clen <= cursize) {
|
|
cluster_wbuild(vp, NULL, bp->b_bcount,
|
|
vp->v_cstart, cursize, lbn);
|
|
} 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, NULL, bp->b_bcount,
|
|
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) * bp->b_bcount != filesize &&
|
|
(VOP_BMAP(vp, lbn, NULL, &bp->b_blkno, &maxclen) ||
|
|
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;
|
|
caddr_t cp;
|
|
int i, 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:
|
|
while ((!incore(vp, start_lbn) || start_lbn == lbn) && len) {
|
|
++start_lbn;
|
|
--len;
|
|
}
|
|
|
|
/* Get more memory for current buffer */
|
|
if (len <= 1) {
|
|
if (last_bp) {
|
|
bawrite(last_bp);
|
|
} else if (len) {
|
|
bp = getblk(vp, start_lbn, size, 0, 0);
|
|
bawrite(bp);
|
|
}
|
|
return;
|
|
}
|
|
|
|
bp = getblk(vp, start_lbn, size, 0, 0);
|
|
if (!(bp->b_flags & B_DELWRI)) {
|
|
++start_lbn;
|
|
--len;
|
|
brelse(bp);
|
|
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 (bp->b_bcount != bp->b_bufsize) {
|
|
++start_lbn;
|
|
--len;
|
|
bawrite(bp);
|
|
goto redo;
|
|
}
|
|
|
|
--len;
|
|
b_save = malloc(sizeof(struct buf *) * len + sizeof(struct cluster_save),
|
|
M_SEGMENT, M_WAITOK);
|
|
b_save->bs_bcount = bp->b_bcount;
|
|
b_save->bs_bufsize = bp->b_bufsize;
|
|
b_save->bs_nchildren = 0;
|
|
b_save->bs_children = (struct buf **)(b_save + 1);
|
|
b_save->bs_saveaddr = bp->b_saveaddr;
|
|
bp->b_saveaddr = (caddr_t) b_save;
|
|
|
|
bp->b_flags |= B_CALL;
|
|
bp->b_iodone = cluster_callback;
|
|
cp = (char *)bp->b_data + size;
|
|
for (++start_lbn, i = 0; i < len; ++i, ++start_lbn) {
|
|
/*
|
|
* 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 (!incore(vp, start_lbn) ||
|
|
(last_bp == NULL && start_lbn == lbn))
|
|
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) {
|
|
tbp = getblk(vp, start_lbn, size, 0, 0);
|
|
if (!(tbp->b_flags & B_DELWRI)) {
|
|
brelse(tbp);
|
|
break;
|
|
}
|
|
} else
|
|
tbp = last_bp;
|
|
|
|
++b_save->bs_nchildren;
|
|
|
|
/* Move memory from children to parent */
|
|
if (tbp->b_blkno != (bp->b_blkno + btodb(bp->b_bufsize))) {
|
|
printf("Clustered Block: %lu addr %lx bufsize: %ld\n",
|
|
(u_long)bp->b_lblkno, bp->b_blkno, bp->b_bufsize);
|
|
printf("Child Block: %lu addr: %lx\n",
|
|
(u_long)tbp->b_lblkno, tbp->b_blkno);
|
|
panic("Clustered write to wrong blocks");
|
|
}
|
|
|
|
pagemove(tbp->b_data, cp, size);
|
|
bp->b_bcount += size;
|
|
bp->b_bufsize += size;
|
|
|
|
tbp->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;
|
|
|
|
cp += size;
|
|
}
|
|
|
|
if (i == 0) {
|
|
/* None to cluster */
|
|
bp->b_saveaddr = b_save->bs_saveaddr;
|
|
bp->b_flags &= ~B_CALL;
|
|
bp->b_iodone = NULL;
|
|
free(b_save, M_SEGMENT);
|
|
}
|
|
bawrite(bp);
|
|
if (i < len) {
|
|
len -= i + 1;
|
|
start_lbn += 1;
|
|
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);
|
|
}
|