X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/0e1f75043abf8c39b3a89ec716521ba0c8a31609..refs/tags/BSD-4_3_Net_2:/usr/src/sys/kern/kern_physio.c

diff --git a/usr/src/sys/kern/kern_physio.c b/usr/src/sys/kern/kern_physio.c
index fd58e7d8a1..bf6dc965e6 100644
--- a/usr/src/sys/kern/kern_physio.c
+++ b/usr/src/sys/kern/kern_physio.c
@@ -1,246 +1,111 @@
-/*	kern_physio.c	4.39	83/01/20	*/
-
-#include "../machine/pte.h"
-
-#include "../h/param.h"
-#include "../h/systm.h"
-#include "../h/dir.h"
-#include "../h/user.h"
-#include "../h/buf.h"
-#include "../h/conf.h"
-#include "../h/proc.h"
-#include "../h/seg.h"
-#include "../h/vm.h"
-#include "../h/trace.h"
-#include "../h/uio.h"
-
 /*
- * Swap IO headers -
- * They contain the necessary information for the swap I/O.
- * At any given time, a swap header can be in three
- * different lists. When free it is in the free list, 
- * when allocated and the I/O queued, it is on the swap 
- * device list, and finally, if the operation was a dirty 
- * page push, when the I/O completes, it is inserted 
- * in a list of cleaned pages to be processed by the pageout daemon.
+ * Copyright (c) 1982, 1986, 1990 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	from: @(#)kern_physio.c	7.20 (Berkeley) 5/11/91
  */
-struct	buf *swbuf;
-short	*swsize;		/* CAN WE JUST USE B_BCOUNT? */
-int	*swpf;
+
+#include "param.h"
+#include "systm.h"
+#include "buf.h"
+#include "conf.h"
+#include "proc.h"
+#include "seg.h"
+#include "trace.h"
+#include "map.h"
+#include "vnode.h"
+#include "specdev.h"
+
+#ifdef HPUXCOMPAT
+#include "user.h"
+#endif
 
 /*
- * swap I/O -
+ * This routine does raw device I/O for a user process.
  *
- * If the flag indicates a dirty page push initiated
- * by the pageout daemon, we map the page into the i th
- * virtual page of process 2 (the daemon itself) where i is
- * the index of the swap header that has been allocated.
- * We simply initialize the header and queue the I/O but
- * do not wait for completion. When the I/O completes,
- * iodone() will link the header to a list of cleaned
- * pages to be processed by the pageout daemon.
+ * If the user has the proper access privileges, the process is
+ * marked 'delayed unlock' and the pages involved in the I/O are
+ * faulted and locked. After the completion of the I/O, the pages
+ * are unlocked.
  */
-swap(p, dblkno, addr, nbytes, rdflg, flag, dev, pfcent)
-	struct proc *p;
-	swblk_t dblkno;
-	caddr_t addr;
-	int nbytes, rdflg, flag;
+physio(strat, bp, dev, rw, mincnt, uio)
+	int (*strat)(); 
+	register struct buf *bp;
 	dev_t dev;
-	u_int pfcent;
+	int rw;
+	u_int (*mincnt)();
+	struct uio *uio;
 {
-	register struct buf *bp;
-	register u_int c;
-	int p2dp;
-	register struct pte *dpte, *vpte;
-	int s;
-
-	s = spl6();
-	while (bswlist.av_forw == NULL) {
-		bswlist.b_flags |= B_WANTED;
-		sleep((caddr_t)&bswlist, PSWP+1);
-	}
-	bp = bswlist.av_forw;
-	bswlist.av_forw = bp->av_forw;
-	splx(s);
 
-	bp->b_flags = B_BUSY | B_PHYS | rdflg | flag;
-	if ((bp->b_flags & (B_DIRTY|B_PGIN)) == 0)
-		if (rdflg == B_READ)
-			sum.v_pswpin += btoc(nbytes);
-		else
-			sum.v_pswpout += btoc(nbytes);
-	bp->b_proc = p;
-	if (flag & B_DIRTY) {
-		p2dp = ((bp - swbuf) * CLSIZE) * KLMAX;
-		dpte = dptopte(&proc[2], p2dp);
-		vpte = vtopte(p, btop(addr));
-		for (c = 0; c < nbytes; c += NBPG) {
-			if (vpte->pg_pfnum == 0 || vpte->pg_fod)
-				panic("swap bad pte");
-			*dpte++ = *vpte++;
-		}
-		bp->b_un.b_addr = (caddr_t)ctob(p2dp);
-	} else
-		bp->b_un.b_addr = addr;
-	while (nbytes > 0) {
-		bp->b_bcount = nbytes;
-		minphys(bp);
-		c = bp->b_bcount;
-		bp->b_blkno = dblkno;
-		bp->b_dev = dev;
-		if (flag & B_DIRTY) {
-			swpf[bp - swbuf] = pfcent;
-			swsize[bp - swbuf] = nbytes;
-		}
-#ifdef TRACE
-		trace(TR_SWAPIO, dev, bp->b_blkno);
-#endif
-		physstrat(bp, bdevsw[major(dev)].d_strategy, PSWP);
-		if (flag & B_DIRTY) {
-			if (c < nbytes)
-				panic("big push");
-			return;
-		}
-		bp->b_un.b_addr += c;
-		bp->b_flags &= ~B_DONE;
-		if (bp->b_flags & B_ERROR) {
-			if ((flag & (B_UAREA|B_PAGET)) || rdflg == B_WRITE)
-				panic("hard IO err in swap");
-			swkill(p, (char *)0);
-		}
-		nbytes -= c;
-		dblkno += c / DEV_BSIZE;
-	}
-	s = spl6();
-	bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS|B_PAGET|B_UAREA|B_DIRTY);
-	bp->av_forw = bswlist.av_forw;
-	bswlist.av_forw = bp;
-	if (bswlist.b_flags & B_WANTED) {
-		bswlist.b_flags &= ~B_WANTED;
-		wakeup((caddr_t)&bswlist);
-		wakeup((caddr_t)&proc[2]);
-	}
-	splx(s);
+	/*
+	 * Body deleted.
+	 */
+	return (EIO);
 }
 
 /*
- * If rout == 0 then killed on swap error, else
- * rout is the name of the routine where we ran out of
- * swap space.
+ * Calculate the maximum size of I/O request that can be requested
+ * in a single operation. This limit is necessary to prevent a single
+ * process from being able to lock more than a fixed amount of memory
+ * in the kernel.
  */
-swkill(p, rout)
-	struct proc *p;
-	char *rout;
+u_int
+minphys(bp)
+	struct buf *bp;
 {
-	char *mesg;
 
-	printf("pid %d: ", p->p_pid);
-	if (rout)
-		printf(mesg = "killed due to no swap space\n");
-	else
-		printf(mesg = "killed on swap error\n");
-	uprintf("sorry, pid %d was %s", p->p_pid, mesg);
 	/*
-	 * To be sure no looping (e.g. in vmsched trying to
-	 * swap out) mark process locked in core (as though
-	 * done by user) after killing it so noone will try
-	 * to swap it out.
+	 * Body deleted.
 	 */
-	psignal(p, SIGKILL);
-	p->p_flag |= SULOCK;
+	return;
 }
 
 /*
- * Raw I/O. The arguments are
- *	The strategy routine for the device
- *	A buffer, which will always be a special buffer
- *	  header owned exclusively by the device for this purpose
- *	The device number
- *	Read/write flag
- * Essentially all the work is computing physical addresses and
- * validating them.
- * If the user has the proper access privilidges, the process is
- * marked 'delayed unlock' and the pages involved in the I/O are
- * faulted and locked. After the completion of the I/O, the above pages
- * are unlocked.
+ * Do a read on a device for a user process.
  */
-physio(strat, bp, dev, rw, mincnt, uio)
-	int (*strat)(); 
-	register struct buf *bp;
+rawread(dev, uio)
 	dev_t dev;
-	int rw;
-	unsigned (*mincnt)();
 	struct uio *uio;
 {
-	register struct iovec *iov = uio->uio_iov;
-	register int c;
-	char *a;
-	int s, error = 0;
-
-nextiov:
-	if (uio->uio_iovcnt == 0)
-		return (0);
-	if (useracc(iov->iov_base,(u_int)iov->iov_len,rw==B_READ?B_WRITE:B_READ) == NULL)
-		return (EFAULT);
-	s = spl6();
-	while (bp->b_flags&B_BUSY) {
-		bp->b_flags |= B_WANTED;
-		sleep((caddr_t)bp, PRIBIO+1);
-	}
-	splx(s);
-	bp->b_error = 0;
-	bp->b_proc = u.u_procp;
-	bp->b_un.b_addr = iov->iov_base;
-	while (iov->iov_len > 0) {
-		bp->b_flags = B_BUSY | B_PHYS | rw;
-		bp->b_dev = dev;
-		bp->b_blkno = uio->uio_offset / DEV_BSIZE;
-		bp->b_bcount = iov->iov_len;
-		(*mincnt)(bp);
-		c = bp->b_bcount;
-		u.u_procp->p_flag |= SPHYSIO;
-		vslock(a = bp->b_un.b_addr, c);
-		physstrat(bp, strat, PRIBIO);
-		(void) spl6();
-		vsunlock(a, c, rw);
-		u.u_procp->p_flag &= ~SPHYSIO;
-		if (bp->b_flags&B_WANTED)
-			wakeup((caddr_t)bp);
-		splx(s);
-		c -= bp->b_resid;
-		bp->b_un.b_addr += c;
-		iov->iov_len -= c;
-		uio->uio_resid -= c;
-		uio->uio_offset += c;
-		/* temp kludge for tape drives */
-		if (bp->b_resid || (bp->b_flags&B_ERROR))
-			break;
-	}
-	bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS);
-	error = geterror(bp);
-	/* temp kludge for tape drives */
-	if (bp->b_resid || error)
-		return (error);
-	uio->uio_iov++;
-	uio->uio_iovcnt--;
-	goto nextiov;
+	return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL,
+	    dev, B_READ, minphys, uio));
 }
 
-#define	MAXPHYS	(63 * 1024)
-
-/* network disk brain damage */
-#include "nd.h"
-#if NND > 0
-#undef MAXPHYS
-#define	MAXPHYS	(32 * 1024)
-#endif
-
-unsigned
-minphys(bp)
-	struct buf *bp;
+/*
+ * Do a write on a device for a user process.
+ */
+rawwrite(dev, uio)
+	dev_t dev;
+	struct uio *uio;
 {
-
-	if (bp->b_bcount > MAXPHYS)
-		bp->b_bcount = MAXPHYS;
+	return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL,
+	    dev, B_WRITE, minphys, uio));
 }
-