eliminate reallocbuf; merge in ufs_machdep.c

SCCS-vsn: sys/kern/vfs_bio.c 7.31
SCCS-vsn: sys/kern/vfs_cluster.c 7.31

diff --git a/usr/src/sys/kern/vfs_bio.c b/usr/src/sys/kern/vfs_bio.c
index f8410ae..ac04839 100644 (file)
--- a/usr/src/sys/kern/vfs_bio.c
+++ b/usr/src/sys/kern/vfs_bio.c
@@ -4,7 +4,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)vfs_bio.c   7.30 (Berkeley) %G%
+ *     @(#)vfs_bio.c   7.31 (Berkeley) %G%

  */
 
 #include "param.h"
  */
 
 #include "param.h"


@@ -368,9 +368,9 @@ loop:
                return (bp);
        }
        bp = getnewbuf();
                return (bp);
        }
        bp = getnewbuf();

-       bfree(bp);

        bremhash(bp);
        bgetvp(vp, bp);
        bremhash(bp);
        bgetvp(vp, bp);

+       bp->b_bcount = 0;

        bp->b_lblkno = blkno;
 #ifdef SECSIZE
        bp->b_blksize = secsize;
        bp->b_lblkno = blkno;
 #ifdef SECSIZE
        bp->b_blksize = secsize;


@@ -379,7 +379,7 @@ loop:
        bp->b_error = 0;
        bp->b_resid = 0;
        binshash(bp, dp);
        bp->b_error = 0;
        bp->b_resid = 0;
        binshash(bp, dp);

-       brealloc(bp, size);
+       allocbuf(bp, size);

        return (bp);
 }
 
        return (bp);
 }
 


@@ -397,34 +397,88 @@ geteblk(size)
                panic("geteblk: size too big");
        bp = getnewbuf();
        bp->b_flags |= B_INVAL;
                panic("geteblk: size too big");
        bp = getnewbuf();
        bp->b_flags |= B_INVAL;

-       bfree(bp);

        bremhash(bp);
        flist = &bfreelist[BQ_AGE];
        bremhash(bp);
        flist = &bfreelist[BQ_AGE];

+       bp->b_bcount = 0;

 #ifdef SECSIZE
        bp->b_blksize = DEV_BSIZE;
 #endif SECSIZE
        bp->b_error = 0;
        bp->b_resid = 0;
        binshash(bp, flist);
 #ifdef SECSIZE
        bp->b_blksize = DEV_BSIZE;
 #endif SECSIZE
        bp->b_error = 0;
        bp->b_resid = 0;
        binshash(bp, flist);

-       brealloc(bp, size);
+       allocbuf(bp, size);

        return (bp);
 }
 
 /*
        return (bp);
 }
 
 /*

- * Allocate space associated with a buffer.
+ * Expand or contract the actual memory allocated to a buffer.
+ * If no memory is available, release buffer and take error exit

  */
  */

-brealloc(bp, size)
-       register struct buf *bp;
+allocbuf(tp, size)
+       register struct buf *tp;

        int size;
 {
        int size;
 {

-       daddr_t start, last;
-       register struct buf *ep;
-       struct buf *dp;
-       int s;
+       register struct buf *bp, *ep;
+       int sizealloc, take, s;

 
 

-       if (size == bp->b_bcount)
-               return;
-       allocbuf(bp, size);
+       sizealloc = roundup(size, CLBYTES);
+       /*
+        * Buffer size does not change
+        */
+       if (sizealloc == tp->b_bufsize)
+               goto out;
+       /*
+        * Buffer size is shrinking.
+        * Place excess space in a buffer header taken from the
+        * BQ_EMPTY buffer list and placed on the "most free" list.
+        * If no extra buffer headers are available, leave the
+        * extra space in the present buffer.
+        */
+       if (sizealloc < tp->b_bufsize) {
+               ep = bfreelist[BQ_EMPTY].av_forw;
+               if (ep == &bfreelist[BQ_EMPTY])
+                       goto out;
+               s = splbio();
+               bremfree(ep);
+               ep->b_flags |= B_BUSY;
+               splx(s);
+               pagemove(tp->b_un.b_addr + sizealloc, ep->b_un.b_addr,
+                   (int)tp->b_bufsize - sizealloc);
+               ep->b_bufsize = tp->b_bufsize - sizealloc;
+               tp->b_bufsize = sizealloc;
+               ep->b_flags |= B_INVAL;
+               ep->b_bcount = 0;
+               brelse(ep);
+               goto out;
+       }
+       /*
+        * More buffer space is needed. Get it out of buffers on
+        * the "most free" list, placing the empty headers on the
+        * BQ_EMPTY buffer header list.
+        */
+       while (tp->b_bufsize < sizealloc) {
+               take = sizealloc - tp->b_bufsize;
+               bp = getnewbuf();
+               if (take >= bp->b_bufsize)
+                       take = bp->b_bufsize;
+               pagemove(&bp->b_un.b_addr[bp->b_bufsize - take],
+                   &tp->b_un.b_addr[tp->b_bufsize], take);
+               tp->b_bufsize += take;
+               bp->b_bufsize = bp->b_bufsize - take;
+               if (bp->b_bcount > bp->b_bufsize)
+                       bp->b_bcount = bp->b_bufsize;
+               if (bp->b_bufsize <= 0) {
+                       bremhash(bp);
+                       binshash(bp, &bfreelist[BQ_EMPTY]);
+                       bp->b_dev = (dev_t)NODEV;
+                       bp->b_error = 0;
+                       bp->b_flags |= B_INVAL;
+               }
+               brelse(bp);
+       }
+out:
+       tp->b_bcount = size;
+       return (1);

 }
 
 /*
 }
 
 /*

diff --git a/usr/src/sys/kern/vfs_cluster.c b/usr/src/sys/kern/vfs_cluster.c
index d65f9af..f68e7c4 100644 (file)
--- a/usr/src/sys/kern/vfs_cluster.c
+++ b/usr/src/sys/kern/vfs_cluster.c
@@ -4,7 +4,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)vfs_cluster.c       7.30 (Berkeley) %G%
+ *     @(#)vfs_cluster.c       7.31 (Berkeley) %G%

  */
 
 #include "param.h"
  */
 
 #include "param.h"


@@ -368,9 +368,9 @@ loop:
                return (bp);
        }
        bp = getnewbuf();
                return (bp);
        }
        bp = getnewbuf();

-       bfree(bp);

        bremhash(bp);
        bgetvp(vp, bp);
        bremhash(bp);
        bgetvp(vp, bp);

+       bp->b_bcount = 0;

        bp->b_lblkno = blkno;
 #ifdef SECSIZE
        bp->b_blksize = secsize;
        bp->b_lblkno = blkno;
 #ifdef SECSIZE
        bp->b_blksize = secsize;


@@ -379,7 +379,7 @@ loop:
        bp->b_error = 0;
        bp->b_resid = 0;
        binshash(bp, dp);
        bp->b_error = 0;
        bp->b_resid = 0;
        binshash(bp, dp);

-       brealloc(bp, size);
+       allocbuf(bp, size);

        return (bp);
 }
 
        return (bp);
 }
 


@@ -397,34 +397,88 @@ geteblk(size)
                panic("geteblk: size too big");
        bp = getnewbuf();
        bp->b_flags |= B_INVAL;
                panic("geteblk: size too big");
        bp = getnewbuf();
        bp->b_flags |= B_INVAL;

-       bfree(bp);

        bremhash(bp);
        flist = &bfreelist[BQ_AGE];
        bremhash(bp);
        flist = &bfreelist[BQ_AGE];

+       bp->b_bcount = 0;

 #ifdef SECSIZE
        bp->b_blksize = DEV_BSIZE;
 #endif SECSIZE
        bp->b_error = 0;
        bp->b_resid = 0;
        binshash(bp, flist);
 #ifdef SECSIZE
        bp->b_blksize = DEV_BSIZE;
 #endif SECSIZE
        bp->b_error = 0;
        bp->b_resid = 0;
        binshash(bp, flist);

-       brealloc(bp, size);
+       allocbuf(bp, size);

        return (bp);
 }
 
 /*
        return (bp);
 }
 
 /*

- * Allocate space associated with a buffer.
+ * Expand or contract the actual memory allocated to a buffer.
+ * If no memory is available, release buffer and take error exit

  */
  */

-brealloc(bp, size)
-       register struct buf *bp;
+allocbuf(tp, size)
+       register struct buf *tp;

        int size;
 {
        int size;
 {

-       daddr_t start, last;
-       register struct buf *ep;
-       struct buf *dp;
-       int s;
+       register struct buf *bp, *ep;
+       int sizealloc, take, s;

 
 

-       if (size == bp->b_bcount)
-               return;
-       allocbuf(bp, size);
+       sizealloc = roundup(size, CLBYTES);
+       /*
+        * Buffer size does not change
+        */
+       if (sizealloc == tp->b_bufsize)
+               goto out;
+       /*
+        * Buffer size is shrinking.
+        * Place excess space in a buffer header taken from the
+        * BQ_EMPTY buffer list and placed on the "most free" list.
+        * If no extra buffer headers are available, leave the
+        * extra space in the present buffer.
+        */
+       if (sizealloc < tp->b_bufsize) {
+               ep = bfreelist[BQ_EMPTY].av_forw;
+               if (ep == &bfreelist[BQ_EMPTY])
+                       goto out;
+               s = splbio();
+               bremfree(ep);
+               ep->b_flags |= B_BUSY;
+               splx(s);
+               pagemove(tp->b_un.b_addr + sizealloc, ep->b_un.b_addr,
+                   (int)tp->b_bufsize - sizealloc);
+               ep->b_bufsize = tp->b_bufsize - sizealloc;
+               tp->b_bufsize = sizealloc;
+               ep->b_flags |= B_INVAL;
+               ep->b_bcount = 0;
+               brelse(ep);
+               goto out;
+       }
+       /*
+        * More buffer space is needed. Get it out of buffers on
+        * the "most free" list, placing the empty headers on the
+        * BQ_EMPTY buffer header list.
+        */
+       while (tp->b_bufsize < sizealloc) {
+               take = sizealloc - tp->b_bufsize;
+               bp = getnewbuf();
+               if (take >= bp->b_bufsize)
+                       take = bp->b_bufsize;
+               pagemove(&bp->b_un.b_addr[bp->b_bufsize - take],
+                   &tp->b_un.b_addr[tp->b_bufsize], take);
+               tp->b_bufsize += take;
+               bp->b_bufsize = bp->b_bufsize - take;
+               if (bp->b_bcount > bp->b_bufsize)
+                       bp->b_bcount = bp->b_bufsize;
+               if (bp->b_bufsize <= 0) {
+                       bremhash(bp);
+                       binshash(bp, &bfreelist[BQ_EMPTY]);
+                       bp->b_dev = (dev_t)NODEV;
+                       bp->b_error = 0;
+                       bp->b_flags |= B_INVAL;
+               }
+               brelse(bp);
+       }
+out:
+       tp->b_bcount = size;
+       return (1);

 }
 
 /*
 }
 
 /*