typo

[unix-history] / usr / src / sys / kern / vfs_cluster.c

diff --git a/usr/src/sys/kern/vfs_cluster.c b/usr/src/sys/kern/vfs_cluster.c
index b3e79ad..4f74f8f 100644 (file)
--- a/usr/src/sys/kern/vfs_cluster.c
+++ b/usr/src/sys/kern/vfs_cluster.c
@@ -3,7 +3,7 @@
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *

- *     @(#)vfs_cluster.c       7.2 (Berkeley) %G%
+ *     @(#)vfs_cluster.c       7.3 (Berkeley) %G%

  */
 
 #include "../machine/pte.h"
  */
 
 #include "../machine/pte.h"


@@ -44,7 +44,7 @@ bread(dev, blkno, size)
 #else SECSIZE
        bp = getblk(dev, blkno, size);
 #endif SECSIZE
 #else SECSIZE
        bp = getblk(dev, blkno, size);
 #endif SECSIZE

-       if (bp->b_flags&B_DONE) {
+       if (bp->b_flags&(B_DONE|B_DELWRI)) {

                trace(TR_BREADHIT, pack(dev, size), blkno);
                return (bp);
        }
                trace(TR_BREADHIT, pack(dev, size), blkno);
                return (bp);
        }


@@ -89,7 +89,7 @@ breada(dev, blkno, size, rablkno, rabsize)
 #else SECSIZE
                bp = getblk(dev, blkno, size);
 #endif SECSIZE
 #else SECSIZE
                bp = getblk(dev, blkno, size);
 #endif SECSIZE

-               if ((bp->b_flags&B_DONE) == 0) {
+               if ((bp->b_flags&(B_DONE|B_DELWRI)) == 0) {

                        bp->b_flags |= B_READ;
                        if (bp->b_bcount > bp->b_bufsize)
                                panic("breada");
                        bp->b_flags |= B_READ;
                        if (bp->b_bcount > bp->b_bufsize)
                                panic("breada");


@@ -110,7 +110,7 @@ breada(dev, blkno, size, rablkno, rabsize)
 #else SECSIZE
                rabp = getblk(dev, rablkno, rabsize);
 #endif SECSIZE
 #else SECSIZE
                rabp = getblk(dev, rablkno, rabsize);
 #endif SECSIZE

-               if (rabp->b_flags & B_DONE) {
+               if (rabp->b_flags & (B_DONE|B_DELWRI)) {

                        brelse(rabp);
                        trace(TR_BREADHITRA, pack(dev, rabsize), blkno);
                } else {
                        brelse(rabp);
                        trace(TR_BREADHITRA, pack(dev, rabsize), blkno);
                } else {


@@ -299,6 +299,13 @@ baddr(dev, blkno, size)
  * block is already associated, return it; otherwise search
  * for the oldest non-busy buffer and reassign it.
  *
  * block is already associated, return it; otherwise search
  * for the oldest non-busy buffer and reassign it.
  *

+ * If we find the buffer, but it is dirty (marked DELWRI) and
+ * its size is changing, we must write it out first. When the
+ * buffer is shrinking, the write is done by brealloc to avoid
+ * losing the unwritten data. When the buffer is growing, the
+ * write is done by getblk, so that bread will not read stale
+ * disk data over the modified data in the buffer.
+ *

  * We use splx here because this routine may be called
  * on the interrupt stack during a dump, and we don't
  * want to lower the ipl back to 0.
  * We use splx here because this routine may be called
  * on the interrupt stack during a dump, and we don't
  * want to lower the ipl back to 0.


@@ -351,6 +358,15 @@ loop:
                }
                splx(s);
                notavail(bp);
                }
                splx(s);
                notavail(bp);

+               if (bp->b_bcount != size) {
+                       if (bp->b_bcount < size && (bp->b_flags&B_DELWRI)) {
+                               bp->b_flags &= ~B_ASYNC;
+                               bwrite(bp);
+                               goto loop;
+                       }
+                       if (brealloc(bp, size) == 0)
+                               goto loop;
+               }

                if (bp->b_bcount != size && brealloc(bp, size) == 0)
                        goto loop;
                bp->b_flags |= B_CACHE;
                if (bp->b_bcount != size && brealloc(bp, size) == 0)
                        goto loop;
                bp->b_flags |= B_CACHE;