-
-/*
- * 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;
-}
-
-/*
- * swap I/O -
- *
- * 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.
- */
-swap(p, dblkno, addr, nbytes, rdflg, flag, dev, pfcent)
- struct proc *p;
- swblk_t dblkno;
- caddr_t addr;
- int flag, nbytes;
- dev_t dev;
- unsigned pfcent;
-{
- register struct buf *bp;
- register int c;
- int p2dp;
- register struct pte *dpte, *vpte;
-
- (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->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) {
- c = imin(ctob(120), nbytes);
- bp->b_bcount = c;
- bp->b_blkno = dblkno;
- bp->b_dev = dev;
- if (flag & B_DIRTY) {
- swpf[bp - swbuf] = pfcent;
- swsize[bp - swbuf] = nbytes;
- }
- (*bdevsw[major(dev)].d_strategy)(bp);
- if (flag & B_DIRTY) {
- if (c < nbytes)
- panic("big push");
- return;
- }
- (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);
- }
- nbytes -= c;
- dblkno += btoc(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);
- wakeup((caddr_t)&proc[2]);
- }
- (void) spl0();
-}
-
-/*
- * If rout == 0 then killed on swap error, else
- * rout is the name of the routine where we ran out of
- * swap space.
- */
-swkill(p, rout)
- struct proc *p;
- 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");
- /*
- * 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, 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;
- register struct buf *flist;
-
-loop:
- (void) spl6();
- for (flist = bfreelist; flist < &bfreelist[BQUEUES]; flist++)
- for (bp = flist->av_forw; bp != flist; 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
- * 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.
- */
-physio(strat, bp, dev, rw, mincnt)
-int (*strat)();
-register struct buf *bp;
-unsigned (*mincnt)();
-{
- 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;
- }
- bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS);
- u.u_count = bp->b_resid;
- geterror(bp);
-}
-
-/*ARGSUSED*/
-unsigned
-minphys(bp)
-struct buf *bp;
-{
-
- if (bp->b_bcount > 60 * 1024)
- bp->b_bcount = 60 * 1024;
-}
-
-/*
- * 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;
-{
-
- if (bp->b_flags&B_ERROR)
- if ((u.u_error = bp->b_error)==0)
- u.u_error = EIO;
-}
-
-/*
- * Invalidate in core blocks belonging to closed or umounted filesystem
- *
- * This is not nicely done at all - the buffer ought to be removed from the
- * hash chains & have its dev/blkno fields clobbered, but unfortunately we
- * can't do that here, as it is quite possible that the block is still
- * being used for i/o. Eventually, all disc drivers should be forced to
- * have a close routine, which ought ensure that the queue is empty, then
- * properly flush the queues. Until that happy day, this suffices for
- * correctness. ... kre
- */
-binval(dev)
-dev_t dev;
-{
- register struct buf *bp, *dp;
-
- dp = bdevsw[major(dev)].d_tab;
- for (bp = dp->b_forw; bp != dp; bp = bp->b_forw)
- if (bp->b_dev == dev)
- bp->b_flags |= B_INVAL;
-}