2 files changed, 71 insertions, 10 deletions

diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c
index c4f0ceaea7e0..db24553d5309 100644
--- a/sys/kern/vfs_bio.c
+++ b/sys/kern/vfs_bio.c
@@ -18,7 +18,7 @@
  * 5. Modifications may be freely made to this file if the above conditions
  *    are met.
  *
- * $Id: vfs_bio.c,v 1.62 1995/09/04 00:20:13 dyson Exp $
+ * $Id: vfs_bio.c,v 1.63 1995/09/09 18:10:14 davidg Exp $
  */
 
 /*
@@ -485,10 +485,23 @@ brelse(struct buf * bp)
 						m->flags &= ~PG_WANTED;
 					}
 					vm_page_test_dirty(m);
-					if ((m->dirty & m->valid) == 0 &&
+					/*
+					 * if page isn't valid, no sense in keeping it around
+					 */
+					if (m->valid == 0) {
+						pmap_page_protect(VM_PAGE_TO_PHYS(m), VM_PROT_NONE);
+						vm_page_free(m);
+					/*
+					 * if page isn't dirty and hasn't been referenced by
+					 * a process, then cache it
+					 */
+					} else if ((m->dirty & m->valid) == 0 &&
 						(m->flags & PG_REFERENCED) == 0 &&
 							!pmap_is_referenced(VM_PAGE_TO_PHYS(m))) {
 						vm_page_cache(m);
+					/*
+					 * otherwise activate it
+					 */
 					} else if ((m->flags & PG_ACTIVE) == 0) {
 						vm_page_activate(m);
 						m->act_count = 0;
@@ -871,11 +884,50 @@ loop:
 		}
 		bp->b_flags |= B_BUSY | B_CACHE;
 		bremfree(bp);
+				
 		/*
-		 * check for size inconsistancies
+		 * check for size inconsistancies (note that they shouldn't happen
+		 * but do when filesystems don't handle the size changes correctly.)
+		 * We are conservative on metadata and don't just extend the buffer
+		 * but write and re-constitute it.
 		 */
 		if (bp->b_bcount != size) {
-			allocbuf(bp, size);
+			if (bp->b_flags & B_VMIO) {
+				allocbuf(bp, size);
+			} else {
+				bp->b_flags |= B_NOCACHE;
+				VOP_BWRITE(bp);
+				goto loop;
+			}
+		}
+		/*
+		 * make sure that all pages in the buffer are valid, if they
+		 * aren't, clear the cache flag.
+		 * ASSUMPTION:
+		 *  if the buffer is greater than 1 page in size, it is assumed
+		 *  that the buffer address starts on a page boundary...
+		 */
+		if (bp->b_flags & B_VMIO) {
+			int szleft, i;
+			szleft = size;
+			for (i=0;i<bp->b_npages;i++) {
+				if (szleft > PAGE_SIZE) {
+					if ((bp->b_pages[i]->valid & VM_PAGE_BITS_ALL) !=
+						VM_PAGE_BITS_ALL) {
+						bp->b_flags &= ~B_CACHE;
+						break;
+					}
+					szleft -= PAGE_SIZE;
+				} else {
+					if (!vm_page_is_valid(bp->b_pages[i],
+						(((vm_offset_t) bp->b_data) & PAGE_MASK),
+						szleft)) {
+						bp->b_flags &= ~B_CACHE;
+						break;
+					}
+					szleft = 0;
+				}
+			}
 		}
 		splx(s);
 		return (bp);
diff --git a/sys/kern/vfs_cluster.c b/sys/kern/vfs_cluster.c
index a78a5e8ac83b..b0aac13f349a 100644
--- a/sys/kern/vfs_cluster.c
+++ b/sys/kern/vfs_cluster.c
@@ -33,7 +33,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)vfs_cluster.c	8.7 (Berkeley) 2/13/94
- * $Id: vfs_cluster.c,v 1.19 1995/09/03 20:32:52 dyson Exp $
+ * $Id: vfs_cluster.c,v 1.20 1995/09/04 00:20:15 dyson Exp $
  */
 
 #include <sys/param.h>
@@ -290,7 +290,7 @@ cluster_rbuild(vp, filesize, lbn, blkno, size, run)
 		panic("cluster_rbuild: size %d != filesize %d\n",
 		    size, vp->v_mount->mnt_stat.f_iosize);
 #endif
-	if (size * (lbn + run + 1) > filesize)
+	if (size * (lbn + run) > filesize)
 		--run;
 
 	tbp = getblk(vp, lbn, size, 0, 0);
@@ -313,8 +313,8 @@ cluster_rbuild(vp, filesize, lbn, blkno, size, run)
 	bp->b_lblkno = lbn;
 	pbgetvp(vp, bp);
 
-	b_save = malloc(sizeof(struct buf *) * run + sizeof(struct cluster_save),
-	    M_SEGMENT, M_WAITOK);
+	b_save = malloc(sizeof(struct buf *) * run +
+		sizeof(struct cluster_save), M_SEGMENT, M_WAITOK);
 	b_save->bs_nchildren = 0;
 	b_save->bs_children = (struct buf **) (b_save + 1);
 	bp->b_saveaddr = b_save;
@@ -328,6 +328,7 @@ cluster_rbuild(vp, filesize, lbn, blkno, size, run)
 		if (i != 0) {
 			if ((bp->b_npages * PAGE_SIZE) + size > MAXPHYS)
 				break;
+
 			if (incore(vp, lbn + i))
 				break;
 			tbp = getblk(vp, lbn + i, size, 0, 0);
@@ -345,6 +346,10 @@ cluster_rbuild(vp, filesize, lbn, blkno, size, run)
 			}
 
 			if (j != tbp->b_npages) {
+				/*
+				 * force buffer to be re-constituted later
+				 */
+				tbp->b_flags |= B_RELBUF;
 				brelse(tbp);
 				break;
 			}
@@ -364,13 +369,17 @@ cluster_rbuild(vp, filesize, lbn, blkno, size, run)
 			m = tbp->b_pages[j];
 			++m->busy;
 			++m->object->paging_in_progress;
-			if (m->valid == VM_PAGE_BITS_ALL) {
+			if ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) {
 				m = bogus_page;
 			}
 			if ((bp->b_npages == 0) ||
-				(bp->b_pages[bp->b_npages - 1] != m)) {
+				(bp->b_bufsize & PAGE_MASK) == 0) {
 				bp->b_pages[bp->b_npages] = m;
 				bp->b_npages++;
+			} else {
+				if ( tbp->b_npages > 1) {
+					panic("cluster_rbuild: page unaligned filesystems not supported");
+				}
 			}
 		}
 		bp->b_bcount += tbp->b_bcount;