2423 lines
57 KiB
C
2423 lines
57 KiB
C
/*
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* Copyright (c) 1994,1997 John S. Dyson
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* 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 immediately at the beginning of the file, without modification,
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* this list of conditions, and the following disclaimer.
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* 2. Absolutely no warranty of function or purpose is made by the author
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* John S. Dyson.
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*
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* $Id: vfs_bio.c,v 1.179 1998/10/13 08:24:40 dg Exp $
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*/
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/*
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* this file contains a new buffer I/O scheme implementing a coherent
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* VM object and buffer cache scheme. Pains have been taken to make
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* sure that the performance degradation associated with schemes such
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* as this is not realized.
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*
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* Author: John S. Dyson
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* Significant help during the development and debugging phases
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* had been provided by David Greenman, also of the FreeBSD core team.
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*/
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#define VMIO
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/sysproto.h>
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#include <sys/kernel.h>
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#include <sys/sysctl.h>
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#include <sys/proc.h>
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#include <sys/vnode.h>
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#include <sys/vmmeter.h>
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#include <sys/lock.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_param.h>
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#include <vm/vm_prot.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_pageout.h>
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#include <vm/vm_page.h>
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#include <vm/vm_object.h>
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#include <vm/vm_extern.h>
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#include <vm/vm_map.h>
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#include <sys/buf.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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static MALLOC_DEFINE(M_BIOBUF, "BIO buffer", "BIO buffer");
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struct bio_ops bioops; /* I/O operation notification */
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#if 0 /* replaced bu sched_sync */
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static void vfs_update __P((void));
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static struct proc *updateproc;
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static struct kproc_desc up_kp = {
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"update",
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vfs_update,
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&updateproc
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};
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SYSINIT_KT(update, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp)
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#endif
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struct buf *buf; /* buffer header pool */
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struct swqueue bswlist;
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static void vm_hold_free_pages(struct buf * bp, vm_offset_t from,
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vm_offset_t to);
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static void vm_hold_load_pages(struct buf * bp, vm_offset_t from,
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vm_offset_t to);
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static void vfs_buf_set_valid(struct buf *bp, vm_ooffset_t foff,
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vm_offset_t off, vm_offset_t size,
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vm_page_t m);
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static void vfs_page_set_valid(struct buf *bp, vm_ooffset_t off,
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int pageno, vm_page_t m);
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static void vfs_clean_pages(struct buf * bp);
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static void vfs_setdirty(struct buf *bp);
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static void vfs_vmio_release(struct buf *bp);
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static void flushdirtybuffers(int slpflag, int slptimeo);
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int needsbuffer;
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/*
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* Internal update daemon, process 3
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* The variable vfs_update_wakeup allows for internal syncs.
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*/
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int vfs_update_wakeup;
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/*
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* buffers base kva
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*/
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/*
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* bogus page -- for I/O to/from partially complete buffers
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* this is a temporary solution to the problem, but it is not
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* really that bad. it would be better to split the buffer
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* for input in the case of buffers partially already in memory,
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* but the code is intricate enough already.
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*/
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vm_page_t bogus_page;
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static vm_offset_t bogus_offset;
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static int bufspace, maxbufspace, vmiospace, maxvmiobufspace,
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bufmallocspace, maxbufmallocspace;
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int numdirtybuffers;
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static int lodirtybuffers, hidirtybuffers;
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static int numfreebuffers, lofreebuffers, hifreebuffers;
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static int kvafreespace;
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SYSCTL_INT(_vfs, OID_AUTO, numdirtybuffers, CTLFLAG_RD,
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&numdirtybuffers, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, lodirtybuffers, CTLFLAG_RW,
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&lodirtybuffers, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, hidirtybuffers, CTLFLAG_RW,
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&hidirtybuffers, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, numfreebuffers, CTLFLAG_RD,
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&numfreebuffers, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, lofreebuffers, CTLFLAG_RW,
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&lofreebuffers, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, hifreebuffers, CTLFLAG_RW,
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&hifreebuffers, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, maxbufspace, CTLFLAG_RW,
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&maxbufspace, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, bufspace, CTLFLAG_RD,
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&bufspace, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, maxvmiobufspace, CTLFLAG_RW,
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&maxvmiobufspace, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, vmiospace, CTLFLAG_RD,
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&vmiospace, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, maxmallocbufspace, CTLFLAG_RW,
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&maxbufmallocspace, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, bufmallocspace, CTLFLAG_RD,
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&bufmallocspace, 0, "");
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SYSCTL_INT(_vfs, OID_AUTO, kvafreespace, CTLFLAG_RD,
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&kvafreespace, 0, "");
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static LIST_HEAD(bufhashhdr, buf) bufhashtbl[BUFHSZ], invalhash;
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struct bqueues bufqueues[BUFFER_QUEUES] = {0};
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extern int vm_swap_size;
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#define BUF_MAXUSE 24
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#define VFS_BIO_NEED_ANY 1
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#define VFS_BIO_NEED_LOWLIMIT 2
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#define VFS_BIO_NEED_FREE 4
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/*
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* Initialize buffer headers and related structures.
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*/
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void
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bufinit()
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{
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struct buf *bp;
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int i;
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TAILQ_INIT(&bswlist);
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LIST_INIT(&invalhash);
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/* first, make a null hash table */
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for (i = 0; i < BUFHSZ; i++)
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LIST_INIT(&bufhashtbl[i]);
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/* next, make a null set of free lists */
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for (i = 0; i < BUFFER_QUEUES; i++)
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TAILQ_INIT(&bufqueues[i]);
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/* finally, initialize each buffer header and stick on empty q */
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for (i = 0; i < nbuf; i++) {
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bp = &buf[i];
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bzero(bp, sizeof *bp);
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bp->b_flags = B_INVAL; /* we're just an empty header */
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bp->b_dev = NODEV;
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bp->b_rcred = NOCRED;
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bp->b_wcred = NOCRED;
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bp->b_qindex = QUEUE_EMPTY;
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bp->b_vnbufs.le_next = NOLIST;
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LIST_INIT(&bp->b_dep);
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TAILQ_INSERT_TAIL(&bufqueues[QUEUE_EMPTY], bp, b_freelist);
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LIST_INSERT_HEAD(&invalhash, bp, b_hash);
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}
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/*
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* maxbufspace is currently calculated to support all filesystem blocks
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* to be 8K. If you happen to use a 16K filesystem, the size of the buffer
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* cache is still the same as it would be for 8K filesystems. This
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* keeps the size of the buffer cache "in check" for big block filesystems.
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*/
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maxbufspace = (nbuf + 8) * DFLTBSIZE;
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/*
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* reserve 1/3 of the buffers for metadata (VDIR) which might not be VMIO'ed
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*/
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maxvmiobufspace = 2 * maxbufspace / 3;
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/*
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* Limit the amount of malloc memory since it is wired permanently into
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* the kernel space. Even though this is accounted for in the buffer
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* allocation, we don't want the malloced region to grow uncontrolled.
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* The malloc scheme improves memory utilization significantly on average
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* (small) directories.
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*/
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maxbufmallocspace = maxbufspace / 20;
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/*
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* Remove the probability of deadlock conditions by limiting the
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* number of dirty buffers.
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*/
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hidirtybuffers = nbuf / 8 + 20;
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lodirtybuffers = nbuf / 16 + 10;
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numdirtybuffers = 0;
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lofreebuffers = nbuf / 18 + 5;
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hifreebuffers = 2 * lofreebuffers;
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numfreebuffers = nbuf;
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kvafreespace = 0;
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bogus_offset = kmem_alloc_pageable(kernel_map, PAGE_SIZE);
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bogus_page = vm_page_alloc(kernel_object,
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((bogus_offset - VM_MIN_KERNEL_ADDRESS) >> PAGE_SHIFT),
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VM_ALLOC_NORMAL);
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}
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/*
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* Free the kva allocation for a buffer
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* Must be called only at splbio or higher,
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* as this is the only locking for buffer_map.
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*/
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static void
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bfreekva(struct buf * bp)
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{
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if (bp->b_kvasize == 0)
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return;
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vm_map_delete(buffer_map,
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(vm_offset_t) bp->b_kvabase,
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(vm_offset_t) bp->b_kvabase + bp->b_kvasize);
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bp->b_kvasize = 0;
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}
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/*
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* remove the buffer from the appropriate free list
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*/
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void
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bremfree(struct buf * bp)
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{
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int s = splbio();
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if (bp->b_qindex != QUEUE_NONE) {
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if (bp->b_qindex == QUEUE_EMPTY) {
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kvafreespace -= bp->b_kvasize;
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}
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TAILQ_REMOVE(&bufqueues[bp->b_qindex], bp, b_freelist);
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bp->b_qindex = QUEUE_NONE;
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} else {
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#if !defined(MAX_PERF)
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panic("bremfree: removing a buffer when not on a queue");
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#endif
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}
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if ((bp->b_flags & B_INVAL) ||
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(bp->b_flags & (B_DELWRI|B_LOCKED)) == 0)
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--numfreebuffers;
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splx(s);
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}
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/*
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* Get a buffer with the specified data. Look in the cache first.
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*/
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int
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bread(struct vnode * vp, daddr_t blkno, int size, struct ucred * cred,
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struct buf ** bpp)
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{
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struct buf *bp;
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bp = getblk(vp, blkno, size, 0, 0);
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*bpp = bp;
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/* if not found in cache, do some I/O */
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if ((bp->b_flags & B_CACHE) == 0) {
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if (curproc != NULL)
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curproc->p_stats->p_ru.ru_inblock++;
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bp->b_flags |= B_READ;
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bp->b_flags &= ~(B_DONE | B_ERROR | B_INVAL);
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if (bp->b_rcred == NOCRED) {
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if (cred != NOCRED)
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crhold(cred);
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bp->b_rcred = cred;
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}
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vfs_busy_pages(bp, 0);
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VOP_STRATEGY(vp, bp);
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return (biowait(bp));
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}
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return (0);
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}
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/*
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* Operates like bread, but also starts asynchronous I/O on
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* read-ahead blocks.
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*/
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int
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breadn(struct vnode * vp, daddr_t blkno, int size,
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daddr_t * rablkno, int *rabsize,
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int cnt, struct ucred * cred, struct buf ** bpp)
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{
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struct buf *bp, *rabp;
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int i;
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int rv = 0, readwait = 0;
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*bpp = bp = getblk(vp, blkno, size, 0, 0);
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/* if not found in cache, do some I/O */
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if ((bp->b_flags & B_CACHE) == 0) {
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if (curproc != NULL)
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curproc->p_stats->p_ru.ru_inblock++;
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bp->b_flags |= B_READ;
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bp->b_flags &= ~(B_DONE | B_ERROR | B_INVAL);
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if (bp->b_rcred == NOCRED) {
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if (cred != NOCRED)
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crhold(cred);
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bp->b_rcred = cred;
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}
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vfs_busy_pages(bp, 0);
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VOP_STRATEGY(vp, bp);
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++readwait;
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}
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for (i = 0; i < cnt; i++, rablkno++, rabsize++) {
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if (inmem(vp, *rablkno))
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continue;
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rabp = getblk(vp, *rablkno, *rabsize, 0, 0);
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if ((rabp->b_flags & B_CACHE) == 0) {
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if (curproc != NULL)
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curproc->p_stats->p_ru.ru_inblock++;
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rabp->b_flags |= B_READ | B_ASYNC;
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rabp->b_flags &= ~(B_DONE | B_ERROR | B_INVAL);
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if (rabp->b_rcred == NOCRED) {
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if (cred != NOCRED)
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crhold(cred);
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rabp->b_rcred = cred;
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}
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vfs_busy_pages(rabp, 0);
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VOP_STRATEGY(vp, rabp);
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} else {
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brelse(rabp);
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}
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}
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if (readwait) {
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rv = biowait(bp);
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}
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return (rv);
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}
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/*
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* Write, release buffer on completion. (Done by iodone
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* if async.)
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*/
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int
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bwrite(struct buf * bp)
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{
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int oldflags, s;
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struct vnode *vp;
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struct mount *mp;
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if (bp->b_flags & B_INVAL) {
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brelse(bp);
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return (0);
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}
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oldflags = bp->b_flags;
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#if !defined(MAX_PERF)
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if ((bp->b_flags & B_BUSY) == 0)
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panic("bwrite: buffer is not busy???");
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#endif
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bp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI);
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bp->b_flags |= B_WRITEINPROG;
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s = splbio();
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if ((oldflags & B_DELWRI) == B_DELWRI) {
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--numdirtybuffers;
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reassignbuf(bp, bp->b_vp);
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}
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bp->b_vp->v_numoutput++;
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vfs_busy_pages(bp, 1);
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if (curproc != NULL)
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curproc->p_stats->p_ru.ru_oublock++;
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splx(s);
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VOP_STRATEGY(bp->b_vp, bp);
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/*
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* Collect statistics on synchronous and asynchronous writes.
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* Writes to block devices are charged to their associated
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* filesystem (if any).
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*/
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if ((vp = bp->b_vp) != NULL) {
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if (vp->v_type == VBLK)
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mp = vp->v_specmountpoint;
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else
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mp = vp->v_mount;
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if (mp != NULL)
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if ((oldflags & B_ASYNC) == 0)
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mp->mnt_stat.f_syncwrites++;
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else
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mp->mnt_stat.f_asyncwrites++;
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}
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if ((oldflags & B_ASYNC) == 0) {
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int rtval = biowait(bp);
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brelse(bp);
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return (rtval);
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}
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return (0);
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}
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__inline void
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vfs_bio_need_satisfy(void) {
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++numfreebuffers;
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if (!needsbuffer)
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return;
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if (numdirtybuffers < lodirtybuffers) {
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needsbuffer &= ~(VFS_BIO_NEED_ANY | VFS_BIO_NEED_LOWLIMIT);
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} else {
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needsbuffer &= ~VFS_BIO_NEED_ANY;
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}
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if (numfreebuffers >= hifreebuffers) {
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needsbuffer &= ~VFS_BIO_NEED_FREE;
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}
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wakeup(&needsbuffer);
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}
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/*
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* Delayed write. (Buffer is marked dirty).
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*/
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void
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bdwrite(struct buf * bp)
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{
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struct vnode *vp;
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#if !defined(MAX_PERF)
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if ((bp->b_flags & B_BUSY) == 0) {
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panic("bdwrite: buffer is not busy");
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}
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#endif
|
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if (bp->b_flags & B_INVAL) {
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brelse(bp);
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return;
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}
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bp->b_flags &= ~(B_READ|B_RELBUF);
|
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if ((bp->b_flags & B_DELWRI) == 0) {
|
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bp->b_flags |= B_DONE | B_DELWRI;
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reassignbuf(bp, bp->b_vp);
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++numdirtybuffers;
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}
|
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|
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/*
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* This bmap keeps the system from needing to do the bmap later,
|
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* perhaps when the system is attempting to do a sync. Since it
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* is likely that the indirect block -- or whatever other datastructure
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* that the filesystem needs is still in memory now, it is a good
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* thing to do this. Note also, that if the pageout daemon is
|
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* requesting a sync -- there might not be enough memory to do
|
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* the bmap then... So, this is important to do.
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*/
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if (bp->b_lblkno == bp->b_blkno) {
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VOP_BMAP(bp->b_vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL, NULL);
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}
|
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|
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/*
|
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* Set the *dirty* buffer range based upon the VM system dirty pages.
|
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*/
|
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vfs_setdirty(bp);
|
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|
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/*
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* We need to do this here to satisfy the vnode_pager and the
|
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* pageout daemon, so that it thinks that the pages have been
|
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* "cleaned". Note that since the pages are in a delayed write
|
|
* buffer -- the VFS layer "will" see that the pages get written
|
|
* out on the next sync, or perhaps the cluster will be completed.
|
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*/
|
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vfs_clean_pages(bp);
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bqrelse(bp);
|
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|
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/*
|
|
* XXX The soft dependency code is not prepared to
|
|
* have I/O done when a bdwrite is requested. For
|
|
* now we just let the write be delayed if it is
|
|
* requested by the soft dependency code.
|
|
*/
|
|
if ((vp = bp->b_vp) &&
|
|
(vp->v_type == VBLK && vp->v_specmountpoint &&
|
|
(vp->v_specmountpoint->mnt_flag & MNT_SOFTDEP)) ||
|
|
(vp->v_mount && (vp->v_mount->mnt_flag & MNT_SOFTDEP)))
|
|
return;
|
|
|
|
if (numdirtybuffers >= hidirtybuffers)
|
|
flushdirtybuffers(0, 0);
|
|
|
|
return;
|
|
}
|
|
|
|
|
|
/*
|
|
* Same as first half of bdwrite, mark buffer dirty, but do not release it.
|
|
* Check how this compares with vfs_setdirty(); XXX [JRE]
|
|
*/
|
|
void
|
|
bdirty(bp)
|
|
struct buf *bp;
|
|
{
|
|
|
|
bp->b_flags &= ~(B_READ|B_RELBUF); /* XXX ??? check this */
|
|
if ((bp->b_flags & B_DELWRI) == 0) {
|
|
bp->b_flags |= B_DONE | B_DELWRI; /* why done? XXX JRE */
|
|
reassignbuf(bp, bp->b_vp);
|
|
++numdirtybuffers;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Asynchronous write.
|
|
* Start output on a buffer, but do not wait for it to complete.
|
|
* The buffer is released when the output completes.
|
|
*/
|
|
void
|
|
bawrite(struct buf * bp)
|
|
{
|
|
bp->b_flags |= B_ASYNC;
|
|
(void) VOP_BWRITE(bp);
|
|
}
|
|
|
|
/*
|
|
* Ordered write.
|
|
* Start output on a buffer, and flag it so that the device will write
|
|
* it in the order it was queued. The buffer is released when the output
|
|
* completes.
|
|
*/
|
|
int
|
|
bowrite(struct buf * bp)
|
|
{
|
|
bp->b_flags |= B_ORDERED|B_ASYNC;
|
|
return (VOP_BWRITE(bp));
|
|
}
|
|
|
|
/*
|
|
* Release a buffer.
|
|
*/
|
|
void
|
|
brelse(struct buf * bp)
|
|
{
|
|
int s;
|
|
|
|
if (bp->b_flags & B_CLUSTER) {
|
|
relpbuf(bp);
|
|
return;
|
|
}
|
|
|
|
s = splbio();
|
|
|
|
/* anyone need this block? */
|
|
if (bp->b_flags & B_WANTED) {
|
|
bp->b_flags &= ~(B_WANTED | B_AGE);
|
|
wakeup(bp);
|
|
}
|
|
|
|
if (bp->b_flags & B_LOCKED)
|
|
bp->b_flags &= ~B_ERROR;
|
|
|
|
if ((bp->b_flags & (B_NOCACHE | B_INVAL | B_ERROR | B_FREEBUF)) ||
|
|
(bp->b_bufsize <= 0)) {
|
|
bp->b_flags |= B_INVAL;
|
|
if (LIST_FIRST(&bp->b_dep) != NULL && bioops.io_deallocate)
|
|
(*bioops.io_deallocate)(bp);
|
|
if (bp->b_flags & B_DELWRI)
|
|
--numdirtybuffers;
|
|
bp->b_flags &= ~(B_DELWRI | B_CACHE | B_FREEBUF);
|
|
if ((bp->b_flags & B_VMIO) == 0) {
|
|
if (bp->b_bufsize)
|
|
allocbuf(bp, 0);
|
|
if (bp->b_vp)
|
|
brelvp(bp);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We must clear B_RELBUF if B_DELWRI is set. If vfs_vmio_release()
|
|
* is called with B_DELWRI set, the underlying pages may wind up
|
|
* getting freed causing a previous write (bdwrite()) to get 'lost'
|
|
* because pages associated with a B_DELWRI bp are marked clean.
|
|
*
|
|
* We still allow the B_INVAL case to call vfs_vmio_release(), even
|
|
* if B_DELWRI is set.
|
|
*/
|
|
|
|
if (bp->b_flags & B_DELWRI)
|
|
bp->b_flags &= ~B_RELBUF;
|
|
|
|
/*
|
|
* VMIO buffer rundown. It is not very necessary to keep a VMIO buffer
|
|
* constituted, so the B_INVAL flag is used to *invalidate* the buffer,
|
|
* but the VM object is kept around. The B_NOCACHE flag is used to
|
|
* invalidate the pages in the VM object.
|
|
*
|
|
* If the buffer is a partially filled NFS buffer, keep it
|
|
* since invalidating it now will lose informatio. The valid
|
|
* flags in the vm_pages have only DEV_BSIZE resolution but
|
|
* the b_validoff, b_validend fields have byte resolution.
|
|
* This can avoid unnecessary re-reads of the buffer.
|
|
* XXX this seems to cause performance problems.
|
|
*/
|
|
if ((bp->b_flags & B_VMIO)
|
|
&& !(bp->b_vp->v_tag == VT_NFS &&
|
|
bp->b_vp->v_type != VBLK &&
|
|
(bp->b_flags & B_DELWRI) != 0)
|
|
#ifdef notdef
|
|
&& (bp->b_vp->v_tag != VT_NFS
|
|
|| bp->b_vp->v_type == VBLK
|
|
|| (bp->b_flags & (B_NOCACHE | B_INVAL | B_ERROR))
|
|
|| bp->b_validend == 0
|
|
|| (bp->b_validoff == 0
|
|
&& bp->b_validend == bp->b_bufsize))
|
|
#endif
|
|
) {
|
|
|
|
int i, j, resid;
|
|
vm_page_t m;
|
|
off_t foff;
|
|
vm_pindex_t poff;
|
|
vm_object_t obj;
|
|
struct vnode *vp;
|
|
|
|
vp = bp->b_vp;
|
|
|
|
resid = bp->b_bufsize;
|
|
foff = bp->b_offset;
|
|
|
|
for (i = 0; i < bp->b_npages; i++) {
|
|
m = bp->b_pages[i];
|
|
vm_page_flag_clear(m, PG_ZERO);
|
|
if (m == bogus_page) {
|
|
|
|
obj = (vm_object_t) vp->v_object;
|
|
poff = OFF_TO_IDX(bp->b_offset);
|
|
|
|
for (j = i; j < bp->b_npages; j++) {
|
|
m = bp->b_pages[j];
|
|
if (m == bogus_page) {
|
|
m = vm_page_lookup(obj, poff + j);
|
|
#if !defined(MAX_PERF)
|
|
if (!m) {
|
|
panic("brelse: page missing\n");
|
|
}
|
|
#endif
|
|
bp->b_pages[j] = m;
|
|
}
|
|
}
|
|
|
|
if ((bp->b_flags & B_INVAL) == 0) {
|
|
pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages);
|
|
}
|
|
}
|
|
if (bp->b_flags & (B_NOCACHE|B_ERROR)) {
|
|
int poffset = foff & PAGE_MASK;
|
|
int presid = resid > (PAGE_SIZE - poffset) ?
|
|
(PAGE_SIZE - poffset) : resid;
|
|
vm_page_set_invalid(m, poffset, presid);
|
|
}
|
|
resid -= PAGE_SIZE;
|
|
}
|
|
|
|
if (bp->b_flags & (B_INVAL | B_RELBUF))
|
|
vfs_vmio_release(bp);
|
|
|
|
} else if (bp->b_flags & B_VMIO) {
|
|
|
|
if (bp->b_flags & (B_INVAL | B_RELBUF))
|
|
vfs_vmio_release(bp);
|
|
|
|
}
|
|
|
|
#if !defined(MAX_PERF)
|
|
if (bp->b_qindex != QUEUE_NONE)
|
|
panic("brelse: free buffer onto another queue???");
|
|
#endif
|
|
|
|
/* enqueue */
|
|
/* buffers with no memory */
|
|
if (bp->b_bufsize == 0) {
|
|
bp->b_flags |= B_INVAL;
|
|
bp->b_qindex = QUEUE_EMPTY;
|
|
TAILQ_INSERT_HEAD(&bufqueues[QUEUE_EMPTY], bp, b_freelist);
|
|
LIST_REMOVE(bp, b_hash);
|
|
LIST_INSERT_HEAD(&invalhash, bp, b_hash);
|
|
bp->b_dev = NODEV;
|
|
kvafreespace += bp->b_kvasize;
|
|
|
|
/* buffers with junk contents */
|
|
} else if (bp->b_flags & (B_ERROR | B_INVAL | B_NOCACHE | B_RELBUF)) {
|
|
bp->b_flags |= B_INVAL;
|
|
bp->b_qindex = QUEUE_AGE;
|
|
TAILQ_INSERT_HEAD(&bufqueues[QUEUE_AGE], bp, b_freelist);
|
|
LIST_REMOVE(bp, b_hash);
|
|
LIST_INSERT_HEAD(&invalhash, bp, b_hash);
|
|
bp->b_dev = NODEV;
|
|
|
|
/* buffers that are locked */
|
|
} else if (bp->b_flags & B_LOCKED) {
|
|
bp->b_qindex = QUEUE_LOCKED;
|
|
TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LOCKED], bp, b_freelist);
|
|
|
|
/* buffers with stale but valid contents */
|
|
} else if (bp->b_flags & B_AGE) {
|
|
bp->b_qindex = QUEUE_AGE;
|
|
TAILQ_INSERT_TAIL(&bufqueues[QUEUE_AGE], bp, b_freelist);
|
|
|
|
/* buffers with valid and quite potentially reuseable contents */
|
|
} else {
|
|
bp->b_qindex = QUEUE_LRU;
|
|
TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LRU], bp, b_freelist);
|
|
}
|
|
|
|
if ((bp->b_flags & B_INVAL) ||
|
|
(bp->b_flags & (B_LOCKED|B_DELWRI)) == 0) {
|
|
if (bp->b_flags & B_DELWRI) {
|
|
--numdirtybuffers;
|
|
bp->b_flags &= ~B_DELWRI;
|
|
}
|
|
vfs_bio_need_satisfy();
|
|
}
|
|
|
|
/* unlock */
|
|
bp->b_flags &= ~(B_ORDERED | B_WANTED | B_BUSY |
|
|
B_ASYNC | B_NOCACHE | B_AGE | B_RELBUF);
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Release a buffer.
|
|
*/
|
|
void
|
|
bqrelse(struct buf * bp)
|
|
{
|
|
int s;
|
|
|
|
s = splbio();
|
|
|
|
/* anyone need this block? */
|
|
if (bp->b_flags & B_WANTED) {
|
|
bp->b_flags &= ~(B_WANTED | B_AGE);
|
|
wakeup(bp);
|
|
}
|
|
|
|
#if !defined(MAX_PERF)
|
|
if (bp->b_qindex != QUEUE_NONE)
|
|
panic("bqrelse: free buffer onto another queue???");
|
|
#endif
|
|
|
|
if (bp->b_flags & B_LOCKED) {
|
|
bp->b_flags &= ~B_ERROR;
|
|
bp->b_qindex = QUEUE_LOCKED;
|
|
TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LOCKED], bp, b_freelist);
|
|
/* buffers with stale but valid contents */
|
|
} else {
|
|
bp->b_qindex = QUEUE_LRU;
|
|
TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LRU], bp, b_freelist);
|
|
}
|
|
|
|
if ((bp->b_flags & (B_LOCKED|B_DELWRI)) == 0) {
|
|
vfs_bio_need_satisfy();
|
|
}
|
|
|
|
/* unlock */
|
|
bp->b_flags &= ~(B_ORDERED | B_WANTED | B_BUSY |
|
|
B_ASYNC | B_NOCACHE | B_AGE | B_RELBUF);
|
|
splx(s);
|
|
}
|
|
|
|
static void
|
|
vfs_vmio_release(bp)
|
|
struct buf *bp;
|
|
{
|
|
int i;
|
|
vm_page_t m;
|
|
|
|
for (i = 0; i < bp->b_npages; i++) {
|
|
m = bp->b_pages[i];
|
|
bp->b_pages[i] = NULL;
|
|
vm_page_unwire(m);
|
|
|
|
/*
|
|
* We don't mess with busy pages, it is
|
|
* the responsibility of the process that
|
|
* busied the pages to deal with them.
|
|
*/
|
|
if ((m->flags & PG_BUSY) || (m->busy != 0))
|
|
continue;
|
|
|
|
if (m->wire_count == 0) {
|
|
|
|
/*
|
|
* If this is an async free -- we cannot place
|
|
* pages onto the cache queue. If it is an
|
|
* async free, then we don't modify any queues.
|
|
* This is probably in error (for perf reasons),
|
|
* and we will eventually need to build
|
|
* a more complete infrastructure to support I/O
|
|
* rundown.
|
|
*/
|
|
if ((bp->b_flags & B_ASYNC) == 0) {
|
|
|
|
/*
|
|
* In the case of sync buffer frees, we can do pretty much
|
|
* anything to any of the memory queues. Specifically,
|
|
* the cache queue is okay to be modified.
|
|
*/
|
|
if (m->valid) {
|
|
if(m->dirty == 0)
|
|
vm_page_test_dirty(m);
|
|
/*
|
|
* this keeps pressure off of the process memory
|
|
*/
|
|
if (m->dirty == 0 && m->hold_count == 0)
|
|
vm_page_cache(m);
|
|
else
|
|
vm_page_deactivate(m);
|
|
vm_page_flag_clear(m, PG_ZERO);
|
|
} else if (m->hold_count == 0) {
|
|
vm_page_busy(m);
|
|
vm_page_protect(m, VM_PROT_NONE);
|
|
vm_page_free(m);
|
|
}
|
|
} else {
|
|
/*
|
|
* If async, then at least we clear the
|
|
* act_count.
|
|
*/
|
|
m->act_count = 0;
|
|
vm_page_flag_clear(m, PG_ZERO);
|
|
}
|
|
}
|
|
}
|
|
bufspace -= bp->b_bufsize;
|
|
vmiospace -= bp->b_bufsize;
|
|
pmap_qremove(trunc_page((vm_offset_t) bp->b_data), bp->b_npages);
|
|
bp->b_npages = 0;
|
|
bp->b_bufsize = 0;
|
|
bp->b_flags &= ~B_VMIO;
|
|
if (bp->b_vp)
|
|
brelvp(bp);
|
|
}
|
|
|
|
/*
|
|
* Check to see if a block is currently memory resident.
|
|
*/
|
|
struct buf *
|
|
gbincore(struct vnode * vp, daddr_t blkno)
|
|
{
|
|
struct buf *bp;
|
|
struct bufhashhdr *bh;
|
|
|
|
bh = BUFHASH(vp, blkno);
|
|
bp = bh->lh_first;
|
|
|
|
/* Search hash chain */
|
|
while (bp != NULL) {
|
|
/* hit */
|
|
if (bp->b_vp == vp && bp->b_lblkno == blkno &&
|
|
(bp->b_flags & B_INVAL) == 0) {
|
|
break;
|
|
}
|
|
bp = bp->b_hash.le_next;
|
|
}
|
|
return (bp);
|
|
}
|
|
|
|
/*
|
|
* this routine implements clustered async writes for
|
|
* clearing out B_DELWRI buffers... This is much better
|
|
* than the old way of writing only one buffer at a time.
|
|
*/
|
|
int
|
|
vfs_bio_awrite(struct buf * bp)
|
|
{
|
|
int i;
|
|
daddr_t lblkno = bp->b_lblkno;
|
|
struct vnode *vp = bp->b_vp;
|
|
int s;
|
|
int ncl;
|
|
struct buf *bpa;
|
|
int nwritten;
|
|
int size;
|
|
int maxcl;
|
|
|
|
s = splbio();
|
|
/*
|
|
* right now we support clustered writing only to regular files
|
|
*/
|
|
if ((vp->v_type == VREG) &&
|
|
(vp->v_mount != 0) && /* Only on nodes that have the size info */
|
|
(bp->b_flags & (B_CLUSTEROK | B_INVAL)) == B_CLUSTEROK) {
|
|
|
|
size = vp->v_mount->mnt_stat.f_iosize;
|
|
maxcl = MAXPHYS / size;
|
|
|
|
for (i = 1; i < maxcl; i++) {
|
|
if ((bpa = gbincore(vp, lblkno + i)) &&
|
|
((bpa->b_flags & (B_BUSY | B_DELWRI | B_CLUSTEROK | B_INVAL)) ==
|
|
(B_DELWRI | B_CLUSTEROK)) &&
|
|
(bpa->b_bufsize == size)) {
|
|
if ((bpa->b_blkno == bpa->b_lblkno) ||
|
|
(bpa->b_blkno != bp->b_blkno + ((i * size) >> DEV_BSHIFT)))
|
|
break;
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
ncl = i;
|
|
/*
|
|
* this is a possible cluster write
|
|
*/
|
|
if (ncl != 1) {
|
|
nwritten = cluster_wbuild(vp, size, lblkno, ncl);
|
|
splx(s);
|
|
return nwritten;
|
|
}
|
|
}
|
|
|
|
bremfree(bp);
|
|
bp->b_flags |= B_BUSY | B_ASYNC;
|
|
|
|
splx(s);
|
|
/*
|
|
* default (old) behavior, writing out only one block
|
|
*/
|
|
nwritten = bp->b_bufsize;
|
|
(void) VOP_BWRITE(bp);
|
|
return nwritten;
|
|
}
|
|
|
|
|
|
/*
|
|
* Find a buffer header which is available for use.
|
|
*/
|
|
static struct buf *
|
|
getnewbuf(struct vnode *vp, daddr_t blkno,
|
|
int slpflag, int slptimeo, int size, int maxsize)
|
|
{
|
|
struct buf *bp, *bp1;
|
|
int nbyteswritten = 0;
|
|
vm_offset_t addr;
|
|
static int writerecursion = 0;
|
|
|
|
start:
|
|
if (bufspace >= maxbufspace)
|
|
goto trytofreespace;
|
|
|
|
/* can we constitute a new buffer? */
|
|
if ((bp = TAILQ_FIRST(&bufqueues[QUEUE_EMPTY]))) {
|
|
#if !defined(MAX_PERF)
|
|
if (bp->b_qindex != QUEUE_EMPTY)
|
|
panic("getnewbuf: inconsistent EMPTY queue, qindex=%d",
|
|
bp->b_qindex);
|
|
#endif
|
|
bp->b_flags |= B_BUSY;
|
|
bremfree(bp);
|
|
goto fillbuf;
|
|
}
|
|
trytofreespace:
|
|
/*
|
|
* We keep the file I/O from hogging metadata I/O
|
|
* This is desirable because file data is cached in the
|
|
* VM/Buffer cache even if a buffer is freed.
|
|
*/
|
|
if ((bp = TAILQ_FIRST(&bufqueues[QUEUE_AGE]))) {
|
|
#if !defined(MAX_PERF)
|
|
if (bp->b_qindex != QUEUE_AGE)
|
|
panic("getnewbuf: inconsistent AGE queue, qindex=%d",
|
|
bp->b_qindex);
|
|
#endif
|
|
} else if ((bp = TAILQ_FIRST(&bufqueues[QUEUE_LRU]))) {
|
|
#if !defined(MAX_PERF)
|
|
if (bp->b_qindex != QUEUE_LRU)
|
|
panic("getnewbuf: inconsistent LRU queue, qindex=%d",
|
|
bp->b_qindex);
|
|
#endif
|
|
}
|
|
if (!bp) {
|
|
/* wait for a free buffer of any kind */
|
|
needsbuffer |= VFS_BIO_NEED_ANY;
|
|
do
|
|
tsleep(&needsbuffer, (PRIBIO + 4) | slpflag, "newbuf",
|
|
slptimeo);
|
|
while (needsbuffer & VFS_BIO_NEED_ANY);
|
|
return (0);
|
|
}
|
|
|
|
#if defined(DIAGNOSTIC)
|
|
if (bp->b_flags & B_BUSY) {
|
|
panic("getnewbuf: busy buffer on free list\n");
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* We are fairly aggressive about freeing VMIO buffers, but since
|
|
* the buffering is intact without buffer headers, there is not
|
|
* much loss. We gain by maintaining non-VMIOed metadata in buffers.
|
|
*/
|
|
if ((bp->b_qindex == QUEUE_LRU) && (bp->b_usecount > 0)) {
|
|
if ((bp->b_flags & B_VMIO) == 0 ||
|
|
(vmiospace < maxvmiobufspace)) {
|
|
--bp->b_usecount;
|
|
TAILQ_REMOVE(&bufqueues[QUEUE_LRU], bp, b_freelist);
|
|
if (TAILQ_FIRST(&bufqueues[QUEUE_LRU]) != NULL) {
|
|
TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LRU], bp, b_freelist);
|
|
goto start;
|
|
}
|
|
TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LRU], bp, b_freelist);
|
|
}
|
|
}
|
|
|
|
|
|
/* if we are a delayed write, convert to an async write */
|
|
if ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) {
|
|
|
|
/*
|
|
* If our delayed write is likely to be used soon, then
|
|
* recycle back onto the LRU queue.
|
|
*/
|
|
if (vp && (bp->b_vp == vp) && (bp->b_qindex == QUEUE_LRU) &&
|
|
(bp->b_lblkno >= blkno) && (maxsize > 0)) {
|
|
|
|
if (bp->b_usecount > 0) {
|
|
if (bp->b_lblkno < blkno + (MAXPHYS / maxsize)) {
|
|
|
|
TAILQ_REMOVE(&bufqueues[QUEUE_LRU], bp, b_freelist);
|
|
|
|
if (TAILQ_FIRST(&bufqueues[QUEUE_LRU]) != NULL) {
|
|
TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LRU], bp, b_freelist);
|
|
bp->b_usecount--;
|
|
goto start;
|
|
}
|
|
TAILQ_INSERT_TAIL(&bufqueues[QUEUE_LRU], bp, b_freelist);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Certain layered filesystems can recursively re-enter the vfs_bio
|
|
* code, due to delayed writes. This helps keep the system from
|
|
* deadlocking.
|
|
*/
|
|
if (writerecursion > 0) {
|
|
if (writerecursion > 5) {
|
|
bp = TAILQ_FIRST(&bufqueues[QUEUE_AGE]);
|
|
while (bp) {
|
|
if ((bp->b_flags & B_DELWRI) == 0)
|
|
break;
|
|
bp = TAILQ_NEXT(bp, b_freelist);
|
|
}
|
|
if (bp == NULL) {
|
|
bp = TAILQ_FIRST(&bufqueues[QUEUE_LRU]);
|
|
while (bp) {
|
|
if ((bp->b_flags & B_DELWRI) == 0)
|
|
break;
|
|
bp = TAILQ_NEXT(bp, b_freelist);
|
|
}
|
|
}
|
|
if (bp == NULL)
|
|
panic("getnewbuf: cannot get buffer, infinite recursion failure");
|
|
} else {
|
|
bremfree(bp);
|
|
bp->b_flags |= B_BUSY | B_AGE | B_ASYNC;
|
|
nbyteswritten += bp->b_bufsize;
|
|
++writerecursion;
|
|
VOP_BWRITE(bp);
|
|
--writerecursion;
|
|
if (!slpflag && !slptimeo) {
|
|
return (0);
|
|
}
|
|
goto start;
|
|
}
|
|
} else {
|
|
++writerecursion;
|
|
nbyteswritten += vfs_bio_awrite(bp);
|
|
--writerecursion;
|
|
if (!slpflag && !slptimeo) {
|
|
return (0);
|
|
}
|
|
goto start;
|
|
}
|
|
}
|
|
|
|
if (bp->b_flags & B_WANTED) {
|
|
bp->b_flags &= ~B_WANTED;
|
|
wakeup(bp);
|
|
}
|
|
bremfree(bp);
|
|
bp->b_flags |= B_BUSY;
|
|
|
|
if (bp->b_flags & B_VMIO) {
|
|
bp->b_flags &= ~B_ASYNC;
|
|
vfs_vmio_release(bp);
|
|
}
|
|
|
|
if (bp->b_vp)
|
|
brelvp(bp);
|
|
|
|
fillbuf:
|
|
|
|
/* we are not free, nor do we contain interesting data */
|
|
if (bp->b_rcred != NOCRED) {
|
|
crfree(bp->b_rcred);
|
|
bp->b_rcred = NOCRED;
|
|
}
|
|
if (bp->b_wcred != NOCRED) {
|
|
crfree(bp->b_wcred);
|
|
bp->b_wcred = NOCRED;
|
|
}
|
|
if (LIST_FIRST(&bp->b_dep) != NULL &&
|
|
bioops.io_deallocate)
|
|
(*bioops.io_deallocate)(bp);
|
|
|
|
LIST_REMOVE(bp, b_hash);
|
|
LIST_INSERT_HEAD(&invalhash, bp, b_hash);
|
|
if (bp->b_bufsize) {
|
|
allocbuf(bp, 0);
|
|
}
|
|
bp->b_flags = B_BUSY;
|
|
bp->b_dev = NODEV;
|
|
bp->b_vp = NULL;
|
|
bp->b_blkno = bp->b_lblkno = 0;
|
|
bp->b_offset = NOOFFSET;
|
|
bp->b_iodone = 0;
|
|
bp->b_error = 0;
|
|
bp->b_resid = 0;
|
|
bp->b_bcount = 0;
|
|
bp->b_npages = 0;
|
|
bp->b_dirtyoff = bp->b_dirtyend = 0;
|
|
bp->b_validoff = bp->b_validend = 0;
|
|
bp->b_usecount = 5;
|
|
/* Here, not kern_physio.c, is where this should be done*/
|
|
LIST_INIT(&bp->b_dep);
|
|
|
|
maxsize = (maxsize + PAGE_MASK) & ~PAGE_MASK;
|
|
|
|
/*
|
|
* we assume that buffer_map is not at address 0
|
|
*/
|
|
addr = 0;
|
|
if (maxsize != bp->b_kvasize) {
|
|
bfreekva(bp);
|
|
|
|
findkvaspace:
|
|
/*
|
|
* See if we have buffer kva space
|
|
*/
|
|
if (vm_map_findspace(buffer_map,
|
|
vm_map_min(buffer_map), maxsize, &addr)) {
|
|
if (kvafreespace > 0) {
|
|
int totfree = 0, freed;
|
|
do {
|
|
freed = 0;
|
|
for (bp1 = TAILQ_FIRST(&bufqueues[QUEUE_EMPTY]);
|
|
bp1 != NULL; bp1 = TAILQ_NEXT(bp1, b_freelist)) {
|
|
if (bp1->b_kvasize != 0) {
|
|
totfree += bp1->b_kvasize;
|
|
freed = bp1->b_kvasize;
|
|
bremfree(bp1);
|
|
bfreekva(bp1);
|
|
brelse(bp1);
|
|
break;
|
|
}
|
|
}
|
|
} while (freed);
|
|
/*
|
|
* if we found free space, then retry with the same buffer.
|
|
*/
|
|
if (totfree)
|
|
goto findkvaspace;
|
|
}
|
|
bp->b_flags |= B_INVAL;
|
|
brelse(bp);
|
|
goto trytofreespace;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* See if we are below are allocated minimum
|
|
*/
|
|
if (bufspace >= (maxbufspace + nbyteswritten)) {
|
|
bp->b_flags |= B_INVAL;
|
|
brelse(bp);
|
|
goto trytofreespace;
|
|
}
|
|
|
|
/*
|
|
* create a map entry for the buffer -- in essence
|
|
* reserving the kva space.
|
|
*/
|
|
if (addr) {
|
|
vm_map_insert(buffer_map, NULL, 0,
|
|
addr, addr + maxsize,
|
|
VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
|
|
|
|
bp->b_kvabase = (caddr_t) addr;
|
|
bp->b_kvasize = maxsize;
|
|
}
|
|
bp->b_data = bp->b_kvabase;
|
|
|
|
return (bp);
|
|
}
|
|
|
|
static void
|
|
waitfreebuffers(int slpflag, int slptimeo) {
|
|
while (numfreebuffers < hifreebuffers) {
|
|
flushdirtybuffers(slpflag, slptimeo);
|
|
if (numfreebuffers < hifreebuffers)
|
|
break;
|
|
needsbuffer |= VFS_BIO_NEED_FREE;
|
|
if (tsleep(&needsbuffer, (PRIBIO + 4)|slpflag, "biofre", slptimeo))
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void
|
|
flushdirtybuffers(int slpflag, int slptimeo) {
|
|
int s;
|
|
static pid_t flushing = 0;
|
|
|
|
s = splbio();
|
|
|
|
if (flushing) {
|
|
if (flushing == curproc->p_pid) {
|
|
splx(s);
|
|
return;
|
|
}
|
|
while (flushing) {
|
|
if (tsleep(&flushing, (PRIBIO + 4)|slpflag, "biofls", slptimeo)) {
|
|
splx(s);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
flushing = curproc->p_pid;
|
|
|
|
while (numdirtybuffers > lodirtybuffers) {
|
|
struct buf *bp;
|
|
needsbuffer |= VFS_BIO_NEED_LOWLIMIT;
|
|
bp = TAILQ_FIRST(&bufqueues[QUEUE_AGE]);
|
|
if (bp == NULL)
|
|
bp = TAILQ_FIRST(&bufqueues[QUEUE_LRU]);
|
|
|
|
while (bp && ((bp->b_flags & B_DELWRI) == 0)) {
|
|
bp = TAILQ_NEXT(bp, b_freelist);
|
|
}
|
|
|
|
if (bp) {
|
|
vfs_bio_awrite(bp);
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
|
|
flushing = 0;
|
|
wakeup(&flushing);
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Check to see if a block is currently memory resident.
|
|
*/
|
|
struct buf *
|
|
incore(struct vnode * vp, daddr_t blkno)
|
|
{
|
|
struct buf *bp;
|
|
|
|
int s = splbio();
|
|
bp = gbincore(vp, blkno);
|
|
splx(s);
|
|
return (bp);
|
|
}
|
|
|
|
/*
|
|
* Returns true if no I/O is needed to access the
|
|
* associated VM object. This is like incore except
|
|
* it also hunts around in the VM system for the data.
|
|
*/
|
|
|
|
int
|
|
inmem(struct vnode * vp, daddr_t blkno)
|
|
{
|
|
vm_object_t obj;
|
|
vm_offset_t toff, tinc;
|
|
vm_page_t m;
|
|
vm_ooffset_t off;
|
|
|
|
if (incore(vp, blkno))
|
|
return 1;
|
|
if (vp->v_mount == NULL)
|
|
return 0;
|
|
if ((vp->v_object == NULL) || (vp->v_flag & VOBJBUF) == 0)
|
|
return 0;
|
|
|
|
obj = vp->v_object;
|
|
tinc = PAGE_SIZE;
|
|
if (tinc > vp->v_mount->mnt_stat.f_iosize)
|
|
tinc = vp->v_mount->mnt_stat.f_iosize;
|
|
off = blkno * vp->v_mount->mnt_stat.f_iosize;
|
|
|
|
for (toff = 0; toff < vp->v_mount->mnt_stat.f_iosize; toff += tinc) {
|
|
|
|
m = vm_page_lookup(obj, OFF_TO_IDX(off + toff));
|
|
if (!m)
|
|
return 0;
|
|
if (vm_page_is_valid(m,
|
|
(vm_offset_t) ((toff + off) & PAGE_MASK), tinc) == 0)
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* now we set the dirty range for the buffer --
|
|
* for NFS -- if the file is mapped and pages have
|
|
* been written to, let it know. We want the
|
|
* entire range of the buffer to be marked dirty if
|
|
* any of the pages have been written to for consistancy
|
|
* with the b_validoff, b_validend set in the nfs write
|
|
* code, and used by the nfs read code.
|
|
*/
|
|
static void
|
|
vfs_setdirty(struct buf *bp) {
|
|
int i;
|
|
vm_object_t object;
|
|
vm_offset_t boffset, offset;
|
|
/*
|
|
* We qualify the scan for modified pages on whether the
|
|
* object has been flushed yet. The OBJ_WRITEABLE flag
|
|
* is not cleared simply by protecting pages off.
|
|
*/
|
|
if ((bp->b_flags & B_VMIO) &&
|
|
((object = bp->b_pages[0]->object)->flags & (OBJ_WRITEABLE|OBJ_CLEANING))) {
|
|
/*
|
|
* test the pages to see if they have been modified directly
|
|
* by users through the VM system.
|
|
*/
|
|
for (i = 0; i < bp->b_npages; i++) {
|
|
vm_page_flag_clear(bp->b_pages[i], PG_ZERO);
|
|
vm_page_test_dirty(bp->b_pages[i]);
|
|
}
|
|
|
|
/*
|
|
* scan forwards for the first page modified
|
|
*/
|
|
for (i = 0; i < bp->b_npages; i++) {
|
|
if (bp->b_pages[i]->dirty) {
|
|
break;
|
|
}
|
|
}
|
|
boffset = (i << PAGE_SHIFT);
|
|
if (boffset < bp->b_dirtyoff) {
|
|
bp->b_dirtyoff = boffset;
|
|
}
|
|
|
|
/*
|
|
* scan backwards for the last page modified
|
|
*/
|
|
for (i = bp->b_npages - 1; i >= 0; --i) {
|
|
if (bp->b_pages[i]->dirty) {
|
|
break;
|
|
}
|
|
}
|
|
boffset = (i + 1);
|
|
offset = boffset + bp->b_pages[0]->pindex;
|
|
if (offset >= object->size)
|
|
boffset = object->size - bp->b_pages[0]->pindex;
|
|
if (bp->b_dirtyend < (boffset << PAGE_SHIFT))
|
|
bp->b_dirtyend = (boffset << PAGE_SHIFT);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Get a block given a specified block and offset into a file/device.
|
|
*/
|
|
struct buf *
|
|
getblk(struct vnode * vp, daddr_t blkno, int size, int slpflag, int slptimeo)
|
|
{
|
|
struct buf *bp;
|
|
int i, s;
|
|
struct bufhashhdr *bh;
|
|
int maxsize;
|
|
int checksize;
|
|
|
|
if (vp->v_mount) {
|
|
maxsize = vp->v_mount->mnt_stat.f_iosize;
|
|
/*
|
|
* This happens on mount points.
|
|
*/
|
|
if (maxsize < size)
|
|
maxsize = size;
|
|
} else {
|
|
maxsize = size;
|
|
}
|
|
|
|
#if !defined(MAX_PERF)
|
|
if (size > MAXBSIZE)
|
|
panic("getblk: size(%d) > MAXBSIZE(%d)\n", size, MAXBSIZE);
|
|
#endif
|
|
|
|
s = splbio();
|
|
loop:
|
|
if (numfreebuffers < lofreebuffers) {
|
|
waitfreebuffers(slpflag, slptimeo);
|
|
}
|
|
|
|
if ((bp = gbincore(vp, blkno))) {
|
|
if (bp->b_flags & B_BUSY) {
|
|
|
|
bp->b_flags |= B_WANTED;
|
|
if (bp->b_usecount < BUF_MAXUSE)
|
|
++bp->b_usecount;
|
|
|
|
if (!tsleep(bp,
|
|
(PRIBIO + 4) | slpflag, "getblk", slptimeo)) {
|
|
goto loop;
|
|
}
|
|
|
|
splx(s);
|
|
return (struct buf *) NULL;
|
|
}
|
|
bp->b_flags |= B_BUSY | B_CACHE;
|
|
bremfree(bp);
|
|
|
|
/*
|
|
* check for size inconsistancies (note that they shouldn't
|
|
* happen but do when filesystems don't handle the size changes
|
|
* correctly.) We are conservative on metadata and don't just
|
|
* extend the buffer but write (if needed) and re-constitute it.
|
|
*/
|
|
|
|
if (bp->b_bcount != size) {
|
|
if ((bp->b_flags & B_VMIO) && (size <= bp->b_kvasize)) {
|
|
allocbuf(bp, size);
|
|
} else {
|
|
if (bp->b_flags & B_DELWRI) {
|
|
bp->b_flags |= B_NOCACHE;
|
|
VOP_BWRITE(bp);
|
|
} else {
|
|
if ((bp->b_flags & B_VMIO) &&
|
|
(LIST_FIRST(&bp->b_dep) == NULL)) {
|
|
bp->b_flags |= B_RELBUF;
|
|
brelse(bp);
|
|
} else {
|
|
bp->b_flags |= B_NOCACHE;
|
|
VOP_BWRITE(bp);
|
|
}
|
|
}
|
|
goto loop;
|
|
}
|
|
}
|
|
|
|
#ifdef DIAGNOSTIC
|
|
if (bp->b_offset == NOOFFSET)
|
|
panic("getblk: no buffer offset");
|
|
#endif
|
|
|
|
/*
|
|
* Check that the constituted buffer really deserves for the
|
|
* B_CACHE bit to be set. B_VMIO type buffers might not
|
|
* contain fully valid pages. Normal (old-style) buffers
|
|
* should be fully valid.
|
|
*/
|
|
if (bp->b_flags & B_VMIO) {
|
|
checksize = bp->b_bufsize;
|
|
for (i = 0; i < bp->b_npages; i++) {
|
|
int resid;
|
|
int poffset;
|
|
poffset = bp->b_offset & PAGE_MASK;
|
|
resid = (checksize > (PAGE_SIZE - poffset)) ?
|
|
(PAGE_SIZE - poffset) : checksize;
|
|
if (!vm_page_is_valid(bp->b_pages[i], poffset, resid)) {
|
|
bp->b_flags &= ~(B_CACHE | B_DONE);
|
|
break;
|
|
}
|
|
checksize -= resid;
|
|
}
|
|
}
|
|
|
|
if (bp->b_usecount < BUF_MAXUSE)
|
|
++bp->b_usecount;
|
|
splx(s);
|
|
return (bp);
|
|
} else {
|
|
vm_object_t obj;
|
|
|
|
if ((bp = getnewbuf(vp, blkno,
|
|
slpflag, slptimeo, size, maxsize)) == 0) {
|
|
if (slpflag || slptimeo) {
|
|
splx(s);
|
|
return NULL;
|
|
}
|
|
goto loop;
|
|
}
|
|
|
|
/*
|
|
* This code is used to make sure that a buffer is not
|
|
* created while the getnewbuf routine is blocked.
|
|
* Normally the vnode is locked so this isn't a problem.
|
|
* VBLK type I/O requests, however, don't lock the vnode.
|
|
*/
|
|
if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE && gbincore(vp, blkno)) {
|
|
bp->b_flags |= B_INVAL;
|
|
brelse(bp);
|
|
goto loop;
|
|
}
|
|
|
|
/*
|
|
* Insert the buffer into the hash, so that it can
|
|
* be found by incore.
|
|
*/
|
|
bp->b_blkno = bp->b_lblkno = blkno;
|
|
|
|
if (vp->v_type != VBLK)
|
|
bp->b_offset = (off_t) blkno * maxsize;
|
|
else
|
|
bp->b_offset = (off_t) blkno * DEV_BSIZE;
|
|
|
|
bgetvp(vp, bp);
|
|
LIST_REMOVE(bp, b_hash);
|
|
bh = BUFHASH(vp, blkno);
|
|
LIST_INSERT_HEAD(bh, bp, b_hash);
|
|
|
|
if ((obj = vp->v_object) && (vp->v_flag & VOBJBUF)) {
|
|
bp->b_flags |= (B_VMIO | B_CACHE);
|
|
#if defined(VFS_BIO_DEBUG)
|
|
if (vp->v_type != VREG && vp->v_type != VBLK)
|
|
printf("getblk: vmioing file type %d???\n", vp->v_type);
|
|
#endif
|
|
} else {
|
|
bp->b_flags &= ~B_VMIO;
|
|
}
|
|
|
|
allocbuf(bp, size);
|
|
|
|
splx(s);
|
|
return (bp);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Get an empty, disassociated buffer of given size.
|
|
*/
|
|
struct buf *
|
|
geteblk(int size)
|
|
{
|
|
struct buf *bp;
|
|
int s;
|
|
|
|
s = splbio();
|
|
while ((bp = getnewbuf(0, (daddr_t) 0, 0, 0, size, MAXBSIZE)) == 0);
|
|
splx(s);
|
|
allocbuf(bp, size);
|
|
bp->b_flags |= B_INVAL; /* b_dep cleared by getnewbuf() */
|
|
return (bp);
|
|
}
|
|
|
|
|
|
/*
|
|
* This code constitutes the buffer memory from either anonymous system
|
|
* memory (in the case of non-VMIO operations) or from an associated
|
|
* VM object (in the case of VMIO operations).
|
|
*
|
|
* Note that this code is tricky, and has many complications to resolve
|
|
* deadlock or inconsistant data situations. Tread lightly!!!
|
|
*
|
|
* Modify the length of a buffer's underlying buffer storage without
|
|
* destroying information (unless, of course the buffer is shrinking).
|
|
*/
|
|
int
|
|
allocbuf(struct buf * bp, int size)
|
|
{
|
|
|
|
int s;
|
|
int newbsize, mbsize;
|
|
int i;
|
|
|
|
#if !defined(MAX_PERF)
|
|
if (!(bp->b_flags & B_BUSY))
|
|
panic("allocbuf: buffer not busy");
|
|
|
|
if (bp->b_kvasize < size)
|
|
panic("allocbuf: buffer too small");
|
|
#endif
|
|
|
|
if ((bp->b_flags & B_VMIO) == 0) {
|
|
caddr_t origbuf;
|
|
int origbufsize;
|
|
/*
|
|
* Just get anonymous memory from the kernel
|
|
*/
|
|
mbsize = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
|
|
#if !defined(NO_B_MALLOC)
|
|
if (bp->b_flags & B_MALLOC)
|
|
newbsize = mbsize;
|
|
else
|
|
#endif
|
|
newbsize = round_page(size);
|
|
|
|
if (newbsize < bp->b_bufsize) {
|
|
#if !defined(NO_B_MALLOC)
|
|
/*
|
|
* malloced buffers are not shrunk
|
|
*/
|
|
if (bp->b_flags & B_MALLOC) {
|
|
if (newbsize) {
|
|
bp->b_bcount = size;
|
|
} else {
|
|
free(bp->b_data, M_BIOBUF);
|
|
bufspace -= bp->b_bufsize;
|
|
bufmallocspace -= bp->b_bufsize;
|
|
bp->b_data = bp->b_kvabase;
|
|
bp->b_bufsize = 0;
|
|
bp->b_bcount = 0;
|
|
bp->b_flags &= ~B_MALLOC;
|
|
}
|
|
return 1;
|
|
}
|
|
#endif
|
|
vm_hold_free_pages(
|
|
bp,
|
|
(vm_offset_t) bp->b_data + newbsize,
|
|
(vm_offset_t) bp->b_data + bp->b_bufsize);
|
|
} else if (newbsize > bp->b_bufsize) {
|
|
#if !defined(NO_B_MALLOC)
|
|
/*
|
|
* We only use malloced memory on the first allocation.
|
|
* and revert to page-allocated memory when the buffer grows.
|
|
*/
|
|
if ( (bufmallocspace < maxbufmallocspace) &&
|
|
(bp->b_bufsize == 0) &&
|
|
(mbsize <= PAGE_SIZE/2)) {
|
|
|
|
bp->b_data = malloc(mbsize, M_BIOBUF, M_WAITOK);
|
|
bp->b_bufsize = mbsize;
|
|
bp->b_bcount = size;
|
|
bp->b_flags |= B_MALLOC;
|
|
bufspace += mbsize;
|
|
bufmallocspace += mbsize;
|
|
return 1;
|
|
}
|
|
#endif
|
|
origbuf = NULL;
|
|
origbufsize = 0;
|
|
#if !defined(NO_B_MALLOC)
|
|
/*
|
|
* If the buffer is growing on its other-than-first allocation,
|
|
* then we revert to the page-allocation scheme.
|
|
*/
|
|
if (bp->b_flags & B_MALLOC) {
|
|
origbuf = bp->b_data;
|
|
origbufsize = bp->b_bufsize;
|
|
bp->b_data = bp->b_kvabase;
|
|
bufspace -= bp->b_bufsize;
|
|
bufmallocspace -= bp->b_bufsize;
|
|
bp->b_bufsize = 0;
|
|
bp->b_flags &= ~B_MALLOC;
|
|
newbsize = round_page(newbsize);
|
|
}
|
|
#endif
|
|
vm_hold_load_pages(
|
|
bp,
|
|
(vm_offset_t) bp->b_data + bp->b_bufsize,
|
|
(vm_offset_t) bp->b_data + newbsize);
|
|
#if !defined(NO_B_MALLOC)
|
|
if (origbuf) {
|
|
bcopy(origbuf, bp->b_data, origbufsize);
|
|
free(origbuf, M_BIOBUF);
|
|
}
|
|
#endif
|
|
}
|
|
} else {
|
|
vm_page_t m;
|
|
int desiredpages;
|
|
|
|
newbsize = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
|
|
desiredpages = (round_page(newbsize) >> PAGE_SHIFT);
|
|
|
|
#if !defined(NO_B_MALLOC)
|
|
if (bp->b_flags & B_MALLOC)
|
|
panic("allocbuf: VMIO buffer can't be malloced");
|
|
#endif
|
|
|
|
if (newbsize < bp->b_bufsize) {
|
|
if (desiredpages < bp->b_npages) {
|
|
for (i = desiredpages; i < bp->b_npages; i++) {
|
|
/*
|
|
* the page is not freed here -- it
|
|
* is the responsibility of vnode_pager_setsize
|
|
*/
|
|
m = bp->b_pages[i];
|
|
#if defined(DIAGNOSTIC)
|
|
if (m == bogus_page)
|
|
panic("allocbuf: bogus page found");
|
|
#endif
|
|
vm_page_sleep(m, "biodep", &m->busy);
|
|
|
|
bp->b_pages[i] = NULL;
|
|
vm_page_unwire(m);
|
|
}
|
|
pmap_qremove((vm_offset_t) trunc_page((vm_offset_t)bp->b_data) +
|
|
(desiredpages << PAGE_SHIFT), (bp->b_npages - desiredpages));
|
|
bp->b_npages = desiredpages;
|
|
}
|
|
} else if (newbsize > bp->b_bufsize) {
|
|
vm_object_t obj;
|
|
vm_offset_t tinc, toff;
|
|
vm_ooffset_t off;
|
|
vm_pindex_t objoff;
|
|
int pageindex, curbpnpages;
|
|
struct vnode *vp;
|
|
int bsize;
|
|
int orig_validoff = bp->b_validoff;
|
|
int orig_validend = bp->b_validend;
|
|
|
|
vp = bp->b_vp;
|
|
|
|
if (vp->v_type == VBLK)
|
|
bsize = DEV_BSIZE;
|
|
else
|
|
bsize = vp->v_mount->mnt_stat.f_iosize;
|
|
|
|
if (bp->b_npages < desiredpages) {
|
|
obj = vp->v_object;
|
|
tinc = PAGE_SIZE;
|
|
if (tinc > bsize)
|
|
tinc = bsize;
|
|
|
|
off = bp->b_offset;
|
|
#ifdef DIAGNOSTIC
|
|
if (bp->b_offset == NOOFFSET)
|
|
panic("allocbuf: no buffer offset");
|
|
#endif
|
|
|
|
curbpnpages = bp->b_npages;
|
|
doretry:
|
|
bp->b_validoff = orig_validoff;
|
|
bp->b_validend = orig_validend;
|
|
bp->b_flags |= B_CACHE;
|
|
for (toff = 0; toff < newbsize; toff += tinc) {
|
|
int bytesinpage;
|
|
|
|
pageindex = toff >> PAGE_SHIFT;
|
|
objoff = OFF_TO_IDX(off + toff);
|
|
if (pageindex < curbpnpages) {
|
|
|
|
m = bp->b_pages[pageindex];
|
|
#ifdef VFS_BIO_DIAG
|
|
if (m->pindex != objoff)
|
|
panic("allocbuf: page changed offset??!!!?");
|
|
#endif
|
|
bytesinpage = tinc;
|
|
if (tinc > (newbsize - toff))
|
|
bytesinpage = newbsize - toff;
|
|
if (bp->b_flags & B_CACHE)
|
|
vfs_buf_set_valid(bp, off, toff, bytesinpage, m);
|
|
continue;
|
|
}
|
|
m = vm_page_lookup(obj, objoff);
|
|
if (!m) {
|
|
m = vm_page_alloc(obj, objoff, VM_ALLOC_NORMAL);
|
|
if (!m) {
|
|
VM_WAIT;
|
|
vm_pageout_deficit += (desiredpages - bp->b_npages);
|
|
goto doretry;
|
|
}
|
|
|
|
vm_page_wire(m);
|
|
vm_page_flag_clear(m, PG_BUSY);
|
|
bp->b_flags &= ~B_CACHE;
|
|
|
|
} else if (m->flags & PG_BUSY) {
|
|
s = splvm();
|
|
if (m->flags & PG_BUSY) {
|
|
vm_page_flag_set(m, PG_WANTED);
|
|
tsleep(m, PVM, "pgtblk", 0);
|
|
}
|
|
splx(s);
|
|
goto doretry;
|
|
} else {
|
|
if ((curproc != pageproc) &&
|
|
((m->queue - m->pc) == PQ_CACHE) &&
|
|
((cnt.v_free_count + cnt.v_cache_count) <
|
|
(cnt.v_free_min + cnt.v_cache_min))) {
|
|
pagedaemon_wakeup();
|
|
}
|
|
bytesinpage = tinc;
|
|
if (tinc > (newbsize - toff))
|
|
bytesinpage = newbsize - toff;
|
|
if (bp->b_flags & B_CACHE)
|
|
vfs_buf_set_valid(bp, off, toff, bytesinpage, m);
|
|
vm_page_flag_clear(m, PG_ZERO);
|
|
vm_page_wire(m);
|
|
}
|
|
bp->b_pages[pageindex] = m;
|
|
curbpnpages = pageindex + 1;
|
|
}
|
|
if (vp->v_tag == VT_NFS &&
|
|
vp->v_type != VBLK) {
|
|
if (bp->b_dirtyend > 0) {
|
|
bp->b_validoff = min(bp->b_validoff, bp->b_dirtyoff);
|
|
bp->b_validend = max(bp->b_validend, bp->b_dirtyend);
|
|
}
|
|
if (bp->b_validend == 0)
|
|
bp->b_flags &= ~B_CACHE;
|
|
}
|
|
bp->b_data = (caddr_t) trunc_page((vm_offset_t)bp->b_data);
|
|
bp->b_npages = curbpnpages;
|
|
pmap_qenter((vm_offset_t) bp->b_data,
|
|
bp->b_pages, bp->b_npages);
|
|
((vm_offset_t) bp->b_data) |= off & PAGE_MASK;
|
|
}
|
|
}
|
|
}
|
|
if (bp->b_flags & B_VMIO)
|
|
vmiospace += (newbsize - bp->b_bufsize);
|
|
bufspace += (newbsize - bp->b_bufsize);
|
|
bp->b_bufsize = newbsize;
|
|
bp->b_bcount = size;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Wait for buffer I/O completion, returning error status.
|
|
*/
|
|
int
|
|
biowait(register struct buf * bp)
|
|
{
|
|
int s;
|
|
|
|
s = splbio();
|
|
while ((bp->b_flags & B_DONE) == 0)
|
|
#if defined(NO_SCHEDULE_MODS)
|
|
tsleep(bp, PRIBIO, "biowait", 0);
|
|
#else
|
|
if (bp->b_flags & B_READ)
|
|
tsleep(bp, PRIBIO, "biord", 0);
|
|
else
|
|
tsleep(bp, PRIBIO, "biowr", 0);
|
|
#endif
|
|
splx(s);
|
|
if (bp->b_flags & B_EINTR) {
|
|
bp->b_flags &= ~B_EINTR;
|
|
return (EINTR);
|
|
}
|
|
if (bp->b_flags & B_ERROR) {
|
|
return (bp->b_error ? bp->b_error : EIO);
|
|
} else {
|
|
return (0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Finish I/O on a buffer, calling an optional function.
|
|
* This is usually called from interrupt level, so process blocking
|
|
* is not *a good idea*.
|
|
*/
|
|
void
|
|
biodone(register struct buf * bp)
|
|
{
|
|
int s;
|
|
|
|
s = splbio();
|
|
|
|
#if !defined(MAX_PERF)
|
|
if (!(bp->b_flags & B_BUSY))
|
|
panic("biodone: buffer not busy");
|
|
#endif
|
|
|
|
if (bp->b_flags & B_DONE) {
|
|
splx(s);
|
|
#if !defined(MAX_PERF)
|
|
printf("biodone: buffer already done\n");
|
|
#endif
|
|
return;
|
|
}
|
|
bp->b_flags |= B_DONE;
|
|
|
|
if (bp->b_flags & B_FREEBUF) {
|
|
brelse(bp);
|
|
splx(s);
|
|
return;
|
|
}
|
|
|
|
if ((bp->b_flags & B_READ) == 0) {
|
|
vwakeup(bp);
|
|
}
|
|
|
|
/* call optional completion function if requested */
|
|
if (bp->b_flags & B_CALL) {
|
|
bp->b_flags &= ~B_CALL;
|
|
(*bp->b_iodone) (bp);
|
|
splx(s);
|
|
return;
|
|
}
|
|
if (LIST_FIRST(&bp->b_dep) != NULL && bioops.io_complete)
|
|
(*bioops.io_complete)(bp);
|
|
|
|
if (bp->b_flags & B_VMIO) {
|
|
int i, resid;
|
|
vm_ooffset_t foff;
|
|
vm_page_t m;
|
|
vm_object_t obj;
|
|
int iosize;
|
|
struct vnode *vp = bp->b_vp;
|
|
|
|
obj = vp->v_object;
|
|
|
|
#if defined(VFS_BIO_DEBUG)
|
|
if (vp->v_usecount == 0) {
|
|
panic("biodone: zero vnode ref count");
|
|
}
|
|
|
|
if (vp->v_object == NULL) {
|
|
panic("biodone: missing VM object");
|
|
}
|
|
|
|
if ((vp->v_flag & VOBJBUF) == 0) {
|
|
panic("biodone: vnode is not setup for merged cache");
|
|
}
|
|
#endif
|
|
|
|
foff = bp->b_offset;
|
|
#ifdef DIAGNOSTIC
|
|
if (bp->b_offset == NOOFFSET)
|
|
panic("biodone: no buffer offset");
|
|
#endif
|
|
|
|
#if !defined(MAX_PERF)
|
|
if (!obj) {
|
|
panic("biodone: no object");
|
|
}
|
|
#endif
|
|
#if defined(VFS_BIO_DEBUG)
|
|
if (obj->paging_in_progress < bp->b_npages) {
|
|
printf("biodone: paging in progress(%d) < bp->b_npages(%d)\n",
|
|
obj->paging_in_progress, bp->b_npages);
|
|
}
|
|
#endif
|
|
iosize = bp->b_bufsize;
|
|
for (i = 0; i < bp->b_npages; i++) {
|
|
int bogusflag = 0;
|
|
m = bp->b_pages[i];
|
|
if (m == bogus_page) {
|
|
bogusflag = 1;
|
|
m = vm_page_lookup(obj, OFF_TO_IDX(foff));
|
|
if (!m) {
|
|
#if defined(VFS_BIO_DEBUG)
|
|
printf("biodone: page disappeared\n");
|
|
#endif
|
|
vm_object_pip_subtract(obj, 1);
|
|
continue;
|
|
}
|
|
bp->b_pages[i] = m;
|
|
pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages);
|
|
}
|
|
#if defined(VFS_BIO_DEBUG)
|
|
if (OFF_TO_IDX(foff) != m->pindex) {
|
|
printf("biodone: foff(%d)/m->pindex(%d) mismatch\n", foff, m->pindex);
|
|
}
|
|
#endif
|
|
resid = IDX_TO_OFF(m->pindex + 1) - foff;
|
|
if (resid > iosize)
|
|
resid = iosize;
|
|
|
|
/*
|
|
* In the write case, the valid and clean bits are
|
|
* already changed correctly, so we only need to do this
|
|
* here in the read case.
|
|
*/
|
|
if ((bp->b_flags & B_READ) && !bogusflag && resid > 0) {
|
|
vfs_page_set_valid(bp, foff, i, m);
|
|
}
|
|
vm_page_flag_clear(m, PG_ZERO);
|
|
|
|
/*
|
|
* when debugging new filesystems or buffer I/O methods, this
|
|
* is the most common error that pops up. if you see this, you
|
|
* have not set the page busy flag correctly!!!
|
|
*/
|
|
if (m->busy == 0) {
|
|
#if !defined(MAX_PERF)
|
|
printf("biodone: page busy < 0, "
|
|
"pindex: %d, foff: 0x(%x,%x), "
|
|
"resid: %d, index: %d\n",
|
|
(int) m->pindex, (int)(foff >> 32),
|
|
(int) foff & 0xffffffff, resid, i);
|
|
#endif
|
|
if (vp->v_type != VBLK)
|
|
#if !defined(MAX_PERF)
|
|
printf(" iosize: %ld, lblkno: %d, flags: 0x%lx, npages: %d\n",
|
|
bp->b_vp->v_mount->mnt_stat.f_iosize,
|
|
(int) bp->b_lblkno,
|
|
bp->b_flags, bp->b_npages);
|
|
else
|
|
printf(" VDEV, lblkno: %d, flags: 0x%lx, npages: %d\n",
|
|
(int) bp->b_lblkno,
|
|
bp->b_flags, bp->b_npages);
|
|
printf(" valid: 0x%x, dirty: 0x%x, wired: %d\n",
|
|
m->valid, m->dirty, m->wire_count);
|
|
#endif
|
|
panic("biodone: page busy < 0\n");
|
|
}
|
|
vm_page_io_finish(m);
|
|
vm_object_pip_subtract(obj, 1);
|
|
foff += resid;
|
|
iosize -= resid;
|
|
}
|
|
if (obj &&
|
|
(obj->paging_in_progress == 0) &&
|
|
(obj->flags & OBJ_PIPWNT)) {
|
|
vm_object_clear_flag(obj, OBJ_PIPWNT);
|
|
wakeup(obj);
|
|
}
|
|
}
|
|
/*
|
|
* For asynchronous completions, release the buffer now. The brelse
|
|
* checks for B_WANTED and will do the wakeup there if necessary - so
|
|
* no need to do a wakeup here in the async case.
|
|
*/
|
|
|
|
if (bp->b_flags & B_ASYNC) {
|
|
if ((bp->b_flags & (B_NOCACHE | B_INVAL | B_ERROR | B_RELBUF)) != 0)
|
|
brelse(bp);
|
|
else
|
|
bqrelse(bp);
|
|
} else {
|
|
bp->b_flags &= ~B_WANTED;
|
|
wakeup(bp);
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
#if 0 /* not with kirks code */
|
|
static int vfs_update_interval = 30;
|
|
|
|
static void
|
|
vfs_update()
|
|
{
|
|
while (1) {
|
|
tsleep(&vfs_update_wakeup, PUSER, "update",
|
|
hz * vfs_update_interval);
|
|
vfs_update_wakeup = 0;
|
|
sync(curproc, NULL);
|
|
}
|
|
}
|
|
|
|
static int
|
|
sysctl_kern_updateinterval SYSCTL_HANDLER_ARGS
|
|
{
|
|
int error = sysctl_handle_int(oidp,
|
|
oidp->oid_arg1, oidp->oid_arg2, req);
|
|
if (!error)
|
|
wakeup(&vfs_update_wakeup);
|
|
return error;
|
|
}
|
|
|
|
SYSCTL_PROC(_kern, KERN_UPDATEINTERVAL, update, CTLTYPE_INT|CTLFLAG_RW,
|
|
&vfs_update_interval, 0, sysctl_kern_updateinterval, "I", "");
|
|
|
|
#endif
|
|
|
|
|
|
/*
|
|
* This routine is called in lieu of iodone in the case of
|
|
* incomplete I/O. This keeps the busy status for pages
|
|
* consistant.
|
|
*/
|
|
void
|
|
vfs_unbusy_pages(struct buf * bp)
|
|
{
|
|
int i;
|
|
|
|
if (bp->b_flags & B_VMIO) {
|
|
struct vnode *vp = bp->b_vp;
|
|
vm_object_t obj = vp->v_object;
|
|
|
|
for (i = 0; i < bp->b_npages; i++) {
|
|
vm_page_t m = bp->b_pages[i];
|
|
|
|
if (m == bogus_page) {
|
|
m = vm_page_lookup(obj, OFF_TO_IDX(bp->b_offset) + i);
|
|
#if !defined(MAX_PERF)
|
|
if (!m) {
|
|
panic("vfs_unbusy_pages: page missing\n");
|
|
}
|
|
#endif
|
|
bp->b_pages[i] = m;
|
|
pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages);
|
|
}
|
|
vm_object_pip_subtract(obj, 1);
|
|
vm_page_flag_clear(m, PG_ZERO);
|
|
vm_page_io_finish(m);
|
|
}
|
|
if (obj->paging_in_progress == 0 &&
|
|
(obj->flags & OBJ_PIPWNT)) {
|
|
vm_object_clear_flag(obj, OBJ_PIPWNT);
|
|
wakeup(obj);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set NFS' b_validoff and b_validend fields from the valid bits
|
|
* of a page. If the consumer is not NFS, and the page is not
|
|
* valid for the entire range, clear the B_CACHE flag to force
|
|
* the consumer to re-read the page.
|
|
*/
|
|
static void
|
|
vfs_buf_set_valid(struct buf *bp,
|
|
vm_ooffset_t foff, vm_offset_t off, vm_offset_t size,
|
|
vm_page_t m)
|
|
{
|
|
if (bp->b_vp->v_tag == VT_NFS && bp->b_vp->v_type != VBLK) {
|
|
vm_offset_t svalid, evalid;
|
|
int validbits = m->valid;
|
|
|
|
/*
|
|
* This only bothers with the first valid range in the
|
|
* page.
|
|
*/
|
|
svalid = off;
|
|
while (validbits && !(validbits & 1)) {
|
|
svalid += DEV_BSIZE;
|
|
validbits >>= 1;
|
|
}
|
|
evalid = svalid;
|
|
while (validbits & 1) {
|
|
evalid += DEV_BSIZE;
|
|
validbits >>= 1;
|
|
}
|
|
/*
|
|
* Make sure this range is contiguous with the range
|
|
* built up from previous pages. If not, then we will
|
|
* just use the range from the previous pages.
|
|
*/
|
|
if (svalid == bp->b_validend) {
|
|
bp->b_validoff = min(bp->b_validoff, svalid);
|
|
bp->b_validend = max(bp->b_validend, evalid);
|
|
}
|
|
} else if (!vm_page_is_valid(m,
|
|
(vm_offset_t) ((foff + off) & PAGE_MASK),
|
|
size)) {
|
|
bp->b_flags &= ~B_CACHE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set the valid bits in a page, taking care of the b_validoff,
|
|
* b_validend fields which NFS uses to optimise small reads. Off is
|
|
* the offset within the file and pageno is the page index within the buf.
|
|
*/
|
|
static void
|
|
vfs_page_set_valid(struct buf *bp, vm_ooffset_t off, int pageno, vm_page_t m)
|
|
{
|
|
struct vnode *vp = bp->b_vp;
|
|
vm_ooffset_t soff, eoff;
|
|
|
|
soff = off;
|
|
eoff = off + min(PAGE_SIZE, bp->b_bufsize);
|
|
if (vp->v_tag == VT_NFS && vp->v_type != VBLK) {
|
|
vm_ooffset_t sv, ev;
|
|
vm_page_set_invalid(m,
|
|
(vm_offset_t) (soff & PAGE_MASK),
|
|
(vm_offset_t) (eoff - soff));
|
|
off = off - pageno * PAGE_SIZE;
|
|
sv = off + ((bp->b_validoff + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1));
|
|
ev = off + ((bp->b_validend + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1));
|
|
soff = qmax(sv, soff);
|
|
eoff = qmin(ev, eoff);
|
|
}
|
|
if (eoff > soff)
|
|
vm_page_set_validclean(m,
|
|
(vm_offset_t) (soff & PAGE_MASK),
|
|
(vm_offset_t) (eoff - soff));
|
|
}
|
|
|
|
/*
|
|
* This routine is called before a device strategy routine.
|
|
* It is used to tell the VM system that paging I/O is in
|
|
* progress, and treat the pages associated with the buffer
|
|
* almost as being PG_BUSY. Also the object paging_in_progress
|
|
* flag is handled to make sure that the object doesn't become
|
|
* inconsistant.
|
|
*/
|
|
void
|
|
vfs_busy_pages(struct buf * bp, int clear_modify)
|
|
{
|
|
int i;
|
|
|
|
if (bp->b_flags & B_VMIO) {
|
|
struct vnode *vp = bp->b_vp;
|
|
vm_object_t obj = vp->v_object;
|
|
vm_ooffset_t foff;
|
|
|
|
foff = bp->b_offset;
|
|
#ifdef DIAGNOSTIC
|
|
if (bp->b_offset == NOOFFSET)
|
|
panic("vfs_busy_pages: no buffer offset");
|
|
#endif
|
|
|
|
vfs_setdirty(bp);
|
|
|
|
retry:
|
|
for (i = 0; i < bp->b_npages; i++) {
|
|
vm_page_t m = bp->b_pages[i];
|
|
if (vm_page_sleep(m, "vbpage", NULL))
|
|
goto retry;
|
|
}
|
|
|
|
for (i = 0; i < bp->b_npages; i++, foff += PAGE_SIZE) {
|
|
vm_page_t m = bp->b_pages[i];
|
|
|
|
vm_page_flag_clear(m, PG_ZERO);
|
|
if ((bp->b_flags & B_CLUSTER) == 0) {
|
|
vm_object_pip_add(obj, 1);
|
|
vm_page_io_start(m);
|
|
}
|
|
|
|
vm_page_protect(m, VM_PROT_NONE);
|
|
if (clear_modify)
|
|
vfs_page_set_valid(bp, foff, i, m);
|
|
else if (bp->b_bcount >= PAGE_SIZE) {
|
|
if (m->valid && (bp->b_flags & B_CACHE) == 0) {
|
|
bp->b_pages[i] = bogus_page;
|
|
pmap_qenter(trunc_page((vm_offset_t)bp->b_data), bp->b_pages, bp->b_npages);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Tell the VM system that the pages associated with this buffer
|
|
* are clean. This is used for delayed writes where the data is
|
|
* going to go to disk eventually without additional VM intevention.
|
|
*/
|
|
void
|
|
vfs_clean_pages(struct buf * bp)
|
|
{
|
|
int i;
|
|
|
|
if (bp->b_flags & B_VMIO) {
|
|
vm_ooffset_t foff;
|
|
foff = bp->b_offset;
|
|
|
|
#ifdef DIAGNOSTIC
|
|
if (bp->b_offset == NOOFFSET)
|
|
panic("vfs_clean_pages: no buffer offset");
|
|
#endif
|
|
|
|
for (i = 0; i < bp->b_npages; i++, foff += PAGE_SIZE) {
|
|
vm_page_t m = bp->b_pages[i];
|
|
vfs_page_set_valid(bp, foff, i, m);
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
vfs_bio_clrbuf(struct buf *bp) {
|
|
int i;
|
|
if ((bp->b_flags & (B_VMIO | B_MALLOC)) == B_VMIO) {
|
|
if( (bp->b_npages == 1) && (bp->b_bufsize < PAGE_SIZE)) {
|
|
int mask;
|
|
mask = 0;
|
|
for(i=0;i<bp->b_bufsize;i+=DEV_BSIZE)
|
|
mask |= (1 << (i/DEV_BSIZE));
|
|
if(((bp->b_pages[0]->flags & PG_ZERO) == 0) &&
|
|
(bp->b_pages[0]->valid != mask)) {
|
|
bzero(bp->b_data, bp->b_bufsize);
|
|
}
|
|
bp->b_pages[0]->valid = mask;
|
|
bp->b_resid = 0;
|
|
return;
|
|
}
|
|
for(i=0;i<bp->b_npages;i++) {
|
|
if( bp->b_pages[i]->valid == VM_PAGE_BITS_ALL)
|
|
continue;
|
|
if( bp->b_pages[i]->valid == 0) {
|
|
if ((bp->b_pages[i]->flags & PG_ZERO) == 0) {
|
|
bzero(bp->b_data + (i << PAGE_SHIFT), PAGE_SIZE);
|
|
}
|
|
} else {
|
|
int j;
|
|
for(j=0;j<PAGE_SIZE/DEV_BSIZE;j++) {
|
|
if (((bp->b_pages[i]->flags & PG_ZERO) == 0) &&
|
|
(bp->b_pages[i]->valid & (1<<j)) == 0)
|
|
bzero(bp->b_data + (i << PAGE_SHIFT) + j * DEV_BSIZE, DEV_BSIZE);
|
|
}
|
|
}
|
|
bp->b_pages[i]->valid = VM_PAGE_BITS_ALL;
|
|
vm_page_flag_clear(bp->b_pages[i], PG_ZERO);
|
|
}
|
|
bp->b_resid = 0;
|
|
} else {
|
|
clrbuf(bp);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_hold_load_pages and vm_hold_unload pages get pages into
|
|
* a buffers address space. The pages are anonymous and are
|
|
* not associated with a file object.
|
|
*/
|
|
void
|
|
vm_hold_load_pages(struct buf * bp, vm_offset_t from, vm_offset_t to)
|
|
{
|
|
vm_offset_t pg;
|
|
vm_page_t p;
|
|
int index;
|
|
|
|
to = round_page(to);
|
|
from = round_page(from);
|
|
index = (from - trunc_page((vm_offset_t)bp->b_data)) >> PAGE_SHIFT;
|
|
|
|
for (pg = from; pg < to; pg += PAGE_SIZE, index++) {
|
|
|
|
tryagain:
|
|
|
|
p = vm_page_alloc(kernel_object,
|
|
((pg - VM_MIN_KERNEL_ADDRESS) >> PAGE_SHIFT),
|
|
VM_ALLOC_NORMAL);
|
|
if (!p) {
|
|
vm_pageout_deficit += (to - from) >> PAGE_SHIFT;
|
|
VM_WAIT;
|
|
goto tryagain;
|
|
}
|
|
vm_page_wire(p);
|
|
p->valid = VM_PAGE_BITS_ALL;
|
|
vm_page_flag_clear(p, PG_ZERO);
|
|
pmap_kenter(pg, VM_PAGE_TO_PHYS(p));
|
|
bp->b_pages[index] = p;
|
|
vm_page_wakeup(p);
|
|
}
|
|
bp->b_npages = index;
|
|
}
|
|
|
|
void
|
|
vm_hold_free_pages(struct buf * bp, vm_offset_t from, vm_offset_t to)
|
|
{
|
|
vm_offset_t pg;
|
|
vm_page_t p;
|
|
int index, newnpages;
|
|
|
|
from = round_page(from);
|
|
to = round_page(to);
|
|
newnpages = index = (from - trunc_page((vm_offset_t)bp->b_data)) >> PAGE_SHIFT;
|
|
|
|
for (pg = from; pg < to; pg += PAGE_SIZE, index++) {
|
|
p = bp->b_pages[index];
|
|
if (p && (index < bp->b_npages)) {
|
|
#if !defined(MAX_PERF)
|
|
if (p->busy) {
|
|
printf("vm_hold_free_pages: blkno: %d, lblkno: %d\n",
|
|
bp->b_blkno, bp->b_lblkno);
|
|
}
|
|
#endif
|
|
bp->b_pages[index] = NULL;
|
|
pmap_kremove(pg);
|
|
vm_page_busy(p);
|
|
vm_page_unwire(p);
|
|
vm_page_free(p);
|
|
}
|
|
}
|
|
bp->b_npages = newnpages;
|
|
}
|
|
|
|
|
|
#include "opt_ddb.h"
|
|
#ifdef DDB
|
|
#include <ddb/ddb.h>
|
|
|
|
DB_SHOW_COMMAND(buffer, db_show_buffer)
|
|
{
|
|
/* get args */
|
|
struct buf *bp = (struct buf *)addr;
|
|
|
|
if (!have_addr) {
|
|
db_printf("usage: show buffer <addr>\n");
|
|
return;
|
|
}
|
|
|
|
db_printf("b_proc = %p,\nb_flags = 0x%b\n", (void *)bp->b_proc,
|
|
(u_int)bp->b_flags, PRINT_BUF_FLAGS);
|
|
db_printf("b_error = %d, b_bufsize = %ld, b_bcount = %ld, "
|
|
"b_resid = %ld\nb_dev = 0x%x, b_data = %p, "
|
|
"b_blkno = %d, b_pblkno = %d\n",
|
|
bp->b_error, bp->b_bufsize, bp->b_bcount, bp->b_resid,
|
|
bp->b_dev, bp->b_data, bp->b_blkno, bp->b_pblkno);
|
|
if (bp->b_npages) {
|
|
int i;
|
|
db_printf("b_npages = %d, pages(OBJ, IDX, PA): ", bp->b_npages);
|
|
for (i = 0; i < bp->b_npages; i++) {
|
|
vm_page_t m;
|
|
m = bp->b_pages[i];
|
|
db_printf("(%p, 0x%lx, 0x%lx)", (void *)m->object,
|
|
(u_long)m->pindex, (u_long)VM_PAGE_TO_PHYS(m));
|
|
if ((i + 1) < bp->b_npages)
|
|
db_printf(",");
|
|
}
|
|
db_printf("\n");
|
|
}
|
|
}
|
|
#endif /* DDB */
|