4.2 distribution

[unix-history] / usr / src / sys / vm / vm_swap.c

diff --git a/usr/src/sys/vm/vm_swap.c b/usr/src/sys/vm/vm_swap.c
index 1fc3782..e5fa696 100644 (file)
--- a/usr/src/sys/vm/vm_swap.c
+++ b/usr/src/sys/vm/vm_swap.c
@@ -1,4 +1,4 @@
-/*     vm_swap.c       4.17    83/05/10        */
+/*     vm_swap.c       6.1     83/07/29        */

 
 #include "../h/param.h"
 #include "../h/systm.h"
 
 #include "../h/param.h"
 #include "../h/systm.h"


@@ -34,16 +34,24 @@ swstrategy(bp)
                bp->b_blkno += MINIROOTSIZE;
 #endif
        sz = howmany(bp->b_bcount, DEV_BSIZE);
                bp->b_blkno += MINIROOTSIZE;
 #endif
        sz = howmany(bp->b_bcount, DEV_BSIZE);

-       off = bp->b_blkno % DMMAX;
-       if (bp->b_blkno+sz > nswap || off+sz > DMMAX) {
+       if (bp->b_blkno+sz > nswap) {

                bp->b_flags |= B_ERROR;
                iodone(bp);
                return;
        }
                bp->b_flags |= B_ERROR;
                iodone(bp);
                return;
        }

-       seg = bp->b_blkno / DMMAX;
-       dev = swdevt[seg % nswdev].sw_dev;
-       seg /= nswdev;
-       bp->b_blkno = seg*DMMAX + off;
+       if (nswdev > 1) {
+               off = bp->b_blkno % dmmax;
+               if (off+sz > dmmax) {
+                       bp->b_flags |= B_ERROR;
+                       iodone(bp);
+                       return;
+               }
+               seg = bp->b_blkno / dmmax;
+               dev = swdevt[seg % nswdev].sw_dev;
+               seg /= nswdev;
+               bp->b_blkno = seg*dmmax + off;
+       } else
+               dev = swdevt[0].sw_dev;

        bp->b_dev = dev;
        if (dev == 0)
                panic("swstrategy");
        bp->b_dev = dev;
        if (dev == 0)
                panic("swstrategy");


@@ -113,7 +121,7 @@ swapon()
 /*
  * Swfree(index) frees the index'th portion of the swap map.
  * Each of the nswdev devices provides 1/nswdev'th of the swap
 /*
  * Swfree(index) frees the index'th portion of the swap map.
  * Each of the nswdev devices provides 1/nswdev'th of the swap

- * space, which is laid out with blocks of DMMAX pages circularly
+ * space, which is laid out with blocks of dmmax pages circularly

  * among the devices.
  */
 swfree(index)
  * among the devices.
  */
 swfree(index)


@@ -122,14 +130,19 @@ swfree(index)
        register swblk_t vsbase;
        register long blk;
        dev_t dev;
        register swblk_t vsbase;
        register long blk;
        dev_t dev;

+       register swblk_t dvbase;
+       register int nblks;

 
        dev = swdevt[index].sw_dev;
        (*bdevsw[major(dev)].d_open)(dev, FREAD|FWRITE);
        swdevt[index].sw_freed = 1;
 
        dev = swdevt[index].sw_dev;
        (*bdevsw[major(dev)].d_open)(dev, FREAD|FWRITE);
        swdevt[index].sw_freed = 1;

-       for (vsbase = index*DMMAX; vsbase < nswap; vsbase += nswdev*DMMAX) {
-               blk = nswap - vsbase;
-               if (blk > DMMAX)
-                       blk = DMMAX;
+       nblks = swdevt[index].sw_nblks;
+       for (dvbase = 0; dvbase < nblks; dvbase += dmmax) {
+               blk = nblks - dvbase;
+               if ((vsbase = index*dmmax + dvbase*nswdev) >= nswap)
+                       panic("swfree");
+               if (blk > dmmax)
+                       blk = dmmax;

                if (vsbase == 0) {
                        /*
                         * Can't free a block starting at 0 in the swapmap
                if (vsbase == 0) {
                        /*
                         * Can't free a block starting at 0 in the swapmap