-/* kern_physio.c 3.1 %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/pte.h"
-#include "../h/vm.h"
-
-/* #define DISKMON 1 */
+/*
+ * Copyright (c) 1982, 1986 Regents of the University of California.
+ * All rights reserved. The Berkeley software License Agreement
+ * specifies the terms and conditions for redistribution.
+ *
+ * @(#)kern_physio.c 7.4 (Berkeley) %G%
+ */
-#ifdef DISKMON
-struct {
- int nbuf;
- long nread;
- long nreada;
- long ncache;
- long nwrite;
- long bufcount[NBUF];
-} io_info;
-#endif
+#include "../machine/pte.h"
+
+#include "param.h"
+#include "systm.h"
+#include "dir.h"
+#include "user.h"
+#include "buf.h"
+#include "conf.h"
+#include "proc.h"
+#include "seg.h"
+#include "vm.h"
+#include "trace.h"
+#include "map.h"
+#include "uio.h"
+#ifdef SECSIZE
+#include "file.h"
+#include "ioctl.h"
+#include "disklabel.h"
+#endif SECSIZE
/*
* Swap IO headers -
* page push, when the I/O completes, it is inserted
* in a list of cleaned pages to be processed by the pageout daemon.
*/
-struct buf swbuf[NSWBUF];
-short swsize[NSWBUF]; /* CAN WE JUST USE B_BCOUNT? */
-int swpf[NSWBUF];
-
-/*
- * The following several routines allocate and free
- * buffers with various side effects. In general the
- * arguments to an allocate routine are a device and
- * a block number, and the value is a pointer to
- * to the buffer header; the buffer is marked "busy"
- * so that no one else can touch it. If the block was
- * already in core, no I/O need be done; if it is
- * already busy, the process waits until it becomes free.
- * The following routines allocate a buffer:
- * getblk
- * bread
- * breada
- * baddr (if it is incore)
- * Eventually the buffer must be released, possibly with the
- * side effect of writing it out, by using one of
- * bwrite
- * bdwrite
- * bawrite
- * brelse
- */
-
-#ifdef FASTVAX
-#define notavail(bp) \
-{ \
- int s = spl6(); \
- (bp)->av_back->av_forw = (bp)->av_forw; \
- (bp)->av_forw->av_back = (bp)->av_back; \
- (bp)->b_flags |= B_BUSY; \
- splx(s); \
-}
-#endif
-
-/*
- * Read in (if necessary) the block and return a buffer pointer.
- */
-struct buf *
-bread(dev, blkno)
-dev_t dev;
-daddr_t blkno;
-{
- register struct buf *bp;
-
- bp = getblk(dev, blkno);
- if (bp->b_flags&B_DONE) {
-#ifdef DISKMON
- io_info.ncache++;
-#endif
- return(bp);
- }
- bp->b_flags |= B_READ;
- bp->b_bcount = BSIZE;
- (*bdevsw[major(dev)].d_strategy)(bp);
-#ifdef DISKMON
- io_info.nread++;
-#endif
- u.u_vm.vm_inblk++; /* pay for read */
- iowait(bp);
- return(bp);
-}
-
-/*
- * Read in the block, like bread, but also start I/O on the
- * read-ahead block (which is not allocated to the caller)
- */
-struct buf *
-breada(dev, blkno, rablkno)
-dev_t dev;
-daddr_t blkno, rablkno;
-{
- register struct buf *bp, *rabp;
-
- bp = NULL;
- if (!incore(dev, blkno)) {
- bp = getblk(dev, blkno);
- if ((bp->b_flags&B_DONE) == 0) {
- bp->b_flags |= B_READ;
- bp->b_bcount = BSIZE;
- (*bdevsw[major(dev)].d_strategy)(bp);
-#ifdef DISKMON
- io_info.nread++;
-#endif
- u.u_vm.vm_inblk++; /* pay for read */
- }
- }
- if (rablkno && !incore(dev, rablkno)) {
- rabp = getblk(dev, rablkno);
- if (rabp->b_flags & B_DONE)
- brelse(rabp);
- else {
- rabp->b_flags |= B_READ|B_ASYNC;
- rabp->b_bcount = BSIZE;
- (*bdevsw[major(dev)].d_strategy)(rabp);
-#ifdef DISKMON
- io_info.nreada++;
-#endif
- u.u_vm.vm_inblk++; /* pay in advance */
- }
- }
- if(bp == NULL)
- return(bread(dev, blkno));
- iowait(bp);
- return(bp);
-}
-
-/*
- * Write the buffer, waiting for completion.
- * Then release the buffer.
- */
-bwrite(bp)
-register struct buf *bp;
-{
- register flag;
-
- flag = bp->b_flags;
- bp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI | B_AGE);
- bp->b_bcount = BSIZE;
-#ifdef DISKMON
- io_info.nwrite++;
-#endif
- if ((flag&B_DELWRI) == 0)
- u.u_vm.vm_oublk++; /* noone paid yet */
- (*bdevsw[major(bp->b_dev)].d_strategy)(bp);
- if ((flag&B_ASYNC) == 0) {
- iowait(bp);
- brelse(bp);
- } else if (flag & B_DELWRI)
- bp->b_flags |= B_AGE;
- else
- geterror(bp);
-}
-
-/*
- * Release the buffer, marking it so that if it is grabbed
- * for another purpose it will be written out before being
- * given up (e.g. when writing a partial block where it is
- * assumed that another write for the same block will soon follow).
- * This can't be done for magtape, since writes must be done
- * in the same order as requested.
- */
-bdwrite(bp)
-register struct buf *bp;
-{
- register struct buf *dp;
-
- if ((bp->b_flags&B_DELWRI) == 0)
- u.u_vm.vm_oublk++; /* noone paid yet */
- dp = bdevsw[major(bp->b_dev)].d_tab;
- if(dp->b_flags & B_TAPE)
- bawrite(bp);
- else {
- bp->b_flags |= B_DELWRI | B_DONE;
- brelse(bp);
- }
-}
-
-/*
- * Release the buffer, start I/O on it, but don't wait for completion.
- */
-bawrite(bp)
-register struct buf *bp;
-{
-
- bp->b_flags |= B_ASYNC;
- bwrite(bp);
-}
-
-/*
- * release the buffer, with no I/O implied.
- */
-brelse(bp)
-register struct buf *bp;
-{
- register struct buf **backp;
- register s;
-
- if (bp->b_flags&B_WANTED)
- wakeup((caddr_t)bp);
- if (bfreelist.b_flags&B_WANTED) {
- bfreelist.b_flags &= ~B_WANTED;
- wakeup((caddr_t)&bfreelist);
- }
- if (bp->b_flags&B_ERROR)
- bp->b_dev = NODEV; /* no assoc. on error */
- s = spl6();
- if(bp->b_flags & (B_AGE|B_ERROR)) {
- backp = &bfreelist.av_forw;
- (*backp)->av_back = bp;
- bp->av_forw = *backp;
- *backp = bp;
- bp->av_back = &bfreelist;
- } else {
- backp = &bfreelist.av_back;
- (*backp)->av_forw = bp;
- bp->av_back = *backp;
- *backp = bp;
- bp->av_forw = &bfreelist;
- }
- bp->b_flags &= ~(B_WANTED|B_BUSY|B_ASYNC|B_AGE);
- splx(s);
-}
-
-/*
- * See if the block is associated with some buffer
- * (mainly to avoid getting hung up on a wait in breada)
- */
-incore(dev, blkno)
-dev_t dev;
-daddr_t blkno;
-{
- register struct buf *bp;
- register struct buf *dp;
- register int dblkno = fsbtodb(blkno);
-
- dp = bdevsw[major(dev)].d_tab;
- for (bp=dp->b_forw; bp != dp; bp = bp->b_forw)
- if (bp->b_blkno==dblkno && bp->b_dev==dev)
- return(1);
- return(0);
-}
-
-struct buf *
-baddr(dev, blkno)
-dev_t dev;
-daddr_t blkno;
-{
-
- if (incore(dev, blkno))
- return (bread(dev, blkno));
- return (0);
-}
-
-/*
- * Assign a buffer for the given block. If the appropriate
- * block is already associated, return it; otherwise search
- * for the oldest non-busy buffer and reassign it.
- */
-struct buf *
-getblk(dev, blkno)
-dev_t dev;
-daddr_t blkno;
-{
- register struct buf *bp;
- register struct buf *dp;
-#ifdef DISKMON
- register i;
-#endif
- register int dblkno = fsbtodb(blkno);
-
- if(major(dev) >= nblkdev)
- panic("blkdev");
-
- loop:
- VOID spl0();
- dp = bdevsw[major(dev)].d_tab;
- if(dp == NULL)
- panic("devtab");
- for (bp=dp->b_forw; bp != dp; bp = bp->b_forw) {
- if (bp->b_blkno!=dblkno || bp->b_dev!=dev)
- continue;
- VOID spl6();
- if (bp->b_flags&B_BUSY) {
- bp->b_flags |= B_WANTED;
- sleep((caddr_t)bp, PRIBIO+1);
- goto loop;
- }
- VOID spl0();
-#ifdef DISKMON
- i = 0;
- dp = bp->av_forw;
- while (dp != &bfreelist) {
- i++;
- dp = dp->av_forw;
- }
- if (i<NBUF)
- io_info.bufcount[i]++;
-#endif
- notavail(bp);
- bp->b_flags |= B_CACHE;
- return(bp);
- }
- VOID spl6();
- if (bfreelist.av_forw == &bfreelist) {
- bfreelist.b_flags |= B_WANTED;
- sleep((caddr_t)&bfreelist, PRIBIO+1);
- goto loop;
- }
- spl0();
- bp = bfreelist.av_forw;
- notavail(bp);
- if (bp->b_flags & B_DELWRI) {
- bp->b_flags |= B_ASYNC;
- bwrite(bp);
- goto loop;
- }
- bp->b_flags = B_BUSY;
- bp->b_back->b_forw = bp->b_forw;
- bp->b_forw->b_back = bp->b_back;
- bp->b_forw = dp->b_forw;
- bp->b_back = dp;
- dp->b_forw->b_back = bp;
- dp->b_forw = bp;
- bp->b_dev = dev;
- bp->b_blkno = dblkno;
- return(bp);
-}
-
-/*
- * get an empty block,
- * not assigned to any particular device
- */
-struct buf *
-geteblk()
-{
- register struct buf *bp;
- register struct buf *dp;
-
-loop:
- VOID spl6();
- while (bfreelist.av_forw == &bfreelist) {
- bfreelist.b_flags |= B_WANTED;
- sleep((caddr_t)&bfreelist, PRIBIO+1);
- }
- VOID spl0();
- dp = &bfreelist;
- bp = bfreelist.av_forw;
- notavail(bp);
- if (bp->b_flags & B_DELWRI) {
- bp->b_flags |= B_ASYNC;
- bwrite(bp);
- goto loop;
- }
- bp->b_flags = B_BUSY;
- bp->b_back->b_forw = bp->b_forw;
- bp->b_forw->b_back = bp->b_back;
- bp->b_forw = dp->b_forw;
- bp->b_back = dp;
- dp->b_forw->b_back = bp;
- dp->b_forw = bp;
- bp->b_dev = (dev_t)NODEV;
- return(bp);
-}
-
-/*
- * Wait for I/O completion on the buffer; return errors
- * to the user.
- */
-iowait(bp)
-register struct buf *bp;
-{
-
- VOID spl6();
- while ((bp->b_flags&B_DONE)==0)
- sleep((caddr_t)bp, PRIBIO);
- VOID spl0();
- geterror(bp);
-}
-
-#ifndef FASTVAX
-/*
- * Unlink a buffer from the available list and mark it busy.
- * (internal interface)
- */
-notavail(bp)
-register struct buf *bp;
-{
- register s;
-
- s = spl6();
- bp->av_back->av_forw = bp->av_forw;
- bp->av_forw->av_back = bp->av_back;
- bp->b_flags |= B_BUSY;
- splx(s);
-}
-#endif
-
-/*
- * Mark I/O complete on a buffer. If the header
- * indicates a dirty page push completion, the
- * header is inserted into the ``cleaned'' list
- * to be processed by the pageout daemon. Otherwise
- * release it if I/O is asynchronous, and wake
- * up anyone waiting for it.
- */
-iodone(bp)
-register struct buf *bp;
-{
- register int s;
-
- bp->b_flags |= B_DONE;
- if (bp->b_flags & B_DIRTY) {
- if (bp->b_flags & B_ERROR)
- panic("IO err in push");
- s = spl6();
- cnt.v_pgout++;
- bp->av_forw = bclnlist;
- bp->b_bcount = swsize[bp - swbuf];
- bp->b_pfcent = swpf[bp - swbuf];
- bclnlist = bp;
- if (bswlist.b_flags & B_WANTED)
- wakeup((caddr_t)&proc[2]);
- splx(s);
- }
- if (bp->b_flags&B_ASYNC)
- brelse(bp);
- else {
- bp->b_flags &= ~B_WANTED;
- wakeup((caddr_t)bp);
- }
-}
-
-/*
- * Zero the core associated with a buffer.
- */
-clrbuf(bp)
-struct buf *bp;
-{
- register *p;
- register c;
-
- p = bp->b_un.b_words;
- c = BSIZE/sizeof(int);
- do
- *p++ = 0;
- while (--c);
- bp->b_resid = 0;
-}
+struct buf *swbuf;
/*
* swap I/O -
* 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
+ * biodone() will link the header to a list of cleaned
* pages to be processed by the pageout daemon.
*/
swap(p, dblkno, addr, nbytes, rdflg, flag, dev, pfcent)
struct proc *p;
swblk_t dblkno;
caddr_t addr;
- int flag, nbytes;
+ int nbytes, rdflg, flag;
dev_t dev;
- unsigned pfcent;
+ u_int pfcent;
{
register struct buf *bp;
- register int c;
- int p2dp;
register struct pte *dpte, *vpte;
+ register u_int c;
+ int p2dp, s, error = 0;
+ struct buf *getswbuf();
+ int swdone();
- VOID 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;
- VOID spl0();
-
+ bp = getswbuf(PSWP+1);
bp->b_flags = B_BUSY | B_PHYS | rdflg | flag;
+#ifdef SECSIZE
+ bp->b_blksize = DEV_BSIZE;
+#endif SECSIZE
if ((bp->b_flags & (B_DIRTY|B_PGIN)) == 0)
if (rdflg == B_READ)
sum.v_pswpin += btoc(nbytes);
panic("swap bad pte");
*dpte++ = *vpte++;
}
- bp->b_un.b_addr = (caddr_t)ctob(p2dp);
+ bp->b_un.b_addr = (caddr_t)ctob(dptov(&proc[2], p2dp));
+ bp->b_flags |= B_CALL;
+ bp->b_iodone = swdone;
+ bp->b_pfcent = pfcent;
} else
bp->b_un.b_addr = addr;
while (nbytes > 0) {
- c = imin(ctob(120), nbytes);
- bp->b_bcount = c;
+ bp->b_bcount = nbytes;
+ minphys(bp);
+ c = bp->b_bcount;
bp->b_blkno = dblkno;
bp->b_dev = dev;
- if (dev == swapdev)
- bp->b_blkno += swplo;
+#ifdef TRACE
+ trace(TR_SWAPIO, dev, bp->b_blkno);
+#endif
(*bdevsw[major(dev)].d_strategy)(bp);
+ /* pageout daemon doesn't wait for pushed pages */
if (flag & B_DIRTY) {
if (c < nbytes)
panic("big push");
- swsize[bp - swbuf] = nbytes;
- swpf[bp - swbuf] = pfcent;
- return;
+ return (0);
}
- VOID spl6();
- while((bp->b_flags&B_DONE)==0)
- sleep((caddr_t)bp, PSWP);
- VOID spl0();
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);
+ swkill(p, "swap: read error from swap device");
+ error = EIO;
}
nbytes -= c;
- dblkno += btoc(c);
+#ifdef SECSIZE
+ if (flag & B_PGIN && nbytes > 0)
+ panic("big pgin");
+#endif SECSIZE
+ dblkno += btodb(c);
}
- VOID 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);
+ freeswbuf(bp);
+ return (error);
+}
+
+/*
+ * Put a buffer on the clean list after I/O is done.
+ * Called from biodone.
+ */
+swdone(bp)
+ register struct buf *bp;
+{
+ register int s;
+
+ if (bp->b_flags & B_ERROR)
+ panic("IO err in push");
+ s = splbio();
+ bp->av_forw = bclnlist;
+ cnt.v_pgout++;
+ cnt.v_pgpgout += bp->b_bcount / NBPG;
+ bclnlist = bp;
+ if (bswlist.b_flags & B_WANTED)
wakeup((caddr_t)&proc[2]);
- }
- VOID spl0();
+ splx(s);
}
/*
char *rout;
{
- printf("%d: ", p->p_pid);
- if (rout)
- printf("out of swap space in %s\n", rout);
- else
- printf("killed on swap error\n");
+ printf("pid %d: %s\n", p->p_pid, rout);
+ uprintf("sorry, pid %d was killed in %s\n", p->p_pid, rout);
/*
* 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.
*/
- psignal(p, SIGKIL);
+ psignal(p, SIGKILL);
p->p_flag |= SULOCK;
}
-/*
- * make sure all write-behind blocks
- * on dev (or NODEV for all)
- * are flushed out.
- * (from umount and update)
- */
-bflush(dev)
-dev_t dev;
-{
- register struct buf *bp;
-
-loop:
- VOID spl6();
- for (bp = bfreelist.av_forw; bp != &bfreelist; bp = bp->av_forw) {
- if (bp->b_flags&B_DELWRI && (dev == NODEV||dev==bp->b_dev)) {
- bp->b_flags |= B_ASYNC;
- notavail(bp);
- bwrite(bp);
- goto loop;
- }
- }
- VOID spl0();
-}
-
/*
* 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
+ * A buffer, which will either be a special buffer header owned
+ * exclusively by the device for this purpose, or NULL,
+ * indicating that we should use a swap buffer
* The device number
* Read/write flag
* Essentially all the work is computing physical addresses and
* faulted and locked. After the completion of the I/O, the above pages
* are unlocked.
*/
-physio(strat, bp, dev, rw, mincnt)
-int (*strat)();
-register struct buf *bp;
-unsigned (*mincnt)();
+physio(strat, bp, dev, rw, mincnt, uio)
+ int (*strat)();
+ register struct buf *bp;
+ dev_t dev;
+ int rw;
+ u_int (*mincnt)();
+ struct uio *uio;
{
+ register struct iovec *iov;
register int c;
char *a;
-
- if (useracc(u.u_base,u.u_count,rw==B_READ?B_WRITE:B_READ) == NULL) {
- u.u_error = EFAULT;
- return;
- }
- VOID spl6();
- while (bp->b_flags&B_BUSY) {
- bp->b_flags |= B_WANTED;
- sleep((caddr_t)bp, PRIBIO+1);
- }
- bp->b_error = 0;
- bp->b_proc = u.u_procp;
- bp->b_un.b_addr = u.u_base;
- while (u.u_count != 0 && bp->b_error==0) {
- bp->b_flags = B_BUSY | B_PHYS | rw;
- bp->b_dev = dev;
- bp->b_blkno = u.u_offset >> PGSHIFT;
- bp->b_bcount = u.u_count;
- (*mincnt)(bp);
- c = bp->b_bcount;
- u.u_procp->p_flag |= SPHYSIO;
- vslock(a = bp->b_un.b_addr, c);
- (*strat)(bp);
- VOID spl6();
- while ((bp->b_flags&B_DONE) == 0)
- sleep((caddr_t)bp, PRIBIO);
- vsunlock(a, c, rw);
- u.u_procp->p_flag &= ~SPHYSIO;
- if (bp->b_flags&B_WANTED)
- wakeup((caddr_t)bp);
- VOID spl0();
- bp->b_un.b_addr += c;
- u.u_count -= c;
- u.u_offset += c;
+ int s, allocbuf = 0, error = 0;
+ struct buf *getswbuf();
+#ifdef SECSIZE
+ int bsize;
+ struct partinfo dpart;
+#endif SECSIZE
+
+#ifdef SECSIZE
+ if ((unsigned)major(dev) < nchrdev &&
+ (*cdevsw[major(dev)].d_ioctl)(dev, DIOCGPART, (caddr_t)&dpart,
+ FREAD) == 0)
+ bsize = dpart.disklab->d_secsize;
+ else
+ bsize = DEV_BSIZE;
+#endif SECSIZE
+ for (;;) {
+ if (uio->uio_iovcnt == 0)
+ return (0);
+ iov = uio->uio_iov;
+ if (useracc(iov->iov_base, (u_int)iov->iov_len,
+ rw==B_READ? B_WRITE : B_READ) == NULL)
+ return (EFAULT);
+ s = splbio();
+ while (bp->b_flags&B_BUSY) {
+ bp->b_flags |= B_WANTED;
+ sleep((caddr_t)bp, PRIBIO+1);
+ }
+ if (!allocbuf) { /* only if sharing caller's buffer */
+ s = splbio();
+ 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;
+#ifdef SECSIZE
+ bp->b_blksize = bsize;
+#endif SECSIZE
+ 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;
+#ifdef SECSIZE
+ bp->b_blkno = uio->uio_offset / bsize;
+#else SECSIZE
+ bp->b_blkno = btodb(uio->uio_offset);
+#endif SECSIZE
+ 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) splbio();
+ 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--;
}
- bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS);
- u.u_count = bp->b_resid;
- geterror(bp);
+ if (allocbuf)
+ freeswbuf(bp);
+ return (error);
}
-/*ARGSUSED*/
-unsigned
+u_int
minphys(bp)
-struct buf *bp;
+ struct buf *bp;
+{
+ if (bp->b_bcount > MAXPHYS)
+ bp->b_bcount = MAXPHYS;
+}
+
+static
+struct buf *
+getswbuf(prio)
+ int prio;
{
+ int s;
+ struct buf *bp;
- if (bp->b_bcount > 60 * 1024)
- bp->b_bcount = 60 * 1024;
+ s = splbio();
+ while (bswlist.av_forw == NULL) {
+ bswlist.b_flags |= B_WANTED;
+ sleep((caddr_t)&bswlist, prio);
+ }
+ bp = bswlist.av_forw;
+ bswlist.av_forw = bp->av_forw;
+ splx(s);
+ return (bp);
}
-/*
- * Pick up the device's error number and pass it to the user;
- * if there is an error but the number is 0 set a generalized
- * code. Actually the latter is always true because devices
- * don't yet return specific errors.
- */
-geterror(bp)
-register struct buf *bp;
+static
+freeswbuf(bp)
+ struct buf *bp;
+{
+ int s;
+
+ s = splbio();
+ 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);
+}
+
+rawread(dev, uio)
+ dev_t dev;
+ struct uio *uio;
{
+ return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL,
+ dev, B_READ, minphys, uio));
+}
- if (bp->b_flags&B_ERROR)
- if ((u.u_error = bp->b_error)==0)
- u.u_error = EIO;
+rawwrite(dev, uio)
+ dev_t dev;
+ struct uio *uio;
+{
+ return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL,
+ dev, B_WRITE, minphys, uio));
}