Index: sys/kern/vfs_bio.c
===================================================================
--- sys/kern/vfs_bio.c
+++ sys/kern/vfs_bio.c
@@ -661,8 +661,6 @@
 	long space;
 	int diff;
 
-	KASSERT((bp->b_flags & B_MALLOC) == 0,
-	    ("bufspace_adjust: malloc buf %p", bp));
 	bd = bufdomain(bp);
 	diff = bufsize - bp->b_bufsize;
 	if (diff < 0) {
@@ -851,27 +849,6 @@
 }
 
 /*
- *	bufmallocadjust:
- *
- *	Adjust the reported bufspace for a malloc managed buffer, possibly
- *	waking any waiters.
- */
-static void
-bufmallocadjust(struct buf *bp, int bufsize)
-{
-	int diff;
-
-	KASSERT((bp->b_flags & B_MALLOC) != 0,
-	    ("bufmallocadjust: non-malloc buf %p", bp));
-	diff = bufsize - bp->b_bufsize;
-	if (diff < 0)
-		atomic_subtract_long(&bufmallocspace, -diff);
-	else
-		atomic_add_long(&bufmallocspace, diff);
-	bp->b_bufsize = bufsize;
-}
-
-/*
  *	runningwakeup:
  *
  *	Wake up processes that are waiting on asynchronous writes to fall
@@ -4172,22 +4149,9 @@
 /*
  * Truncate the backing store for a non-vmio buffer.
  */
-static void
+static inline void
 vfs_nonvmio_truncate(struct buf *bp, int newbsize)
 {
-
-	if (bp->b_flags & B_MALLOC) {
-		/*
-		 * malloced buffers are not shrunk
-		 */
-		if (newbsize == 0) {
-			bufmallocadjust(bp, 0);
-			free(bp->b_data, M_BIOBUF);
-			bp->b_data = bp->b_kvabase;
-			bp->b_flags &= ~B_MALLOC;
-		}
-		return;
-	}
 	vm_hold_free_pages(bp, newbsize);
 	bufspace_adjust(bp, newbsize);
 }
@@ -4195,51 +4159,11 @@
 /*
  * Extend the backing for a non-VMIO buffer.
  */
-static void
+static inline void
 vfs_nonvmio_extend(struct buf *bp, int newbsize)
 {
-	caddr_t origbuf;
-	int origbufsize;
-
-	/*
-	 * We only use malloced memory on the first allocation.
-	 * and revert to page-allocated memory when the buffer
-	 * grows.
-	 *
-	 * There is a potential smp race here that could lead
-	 * to bufmallocspace slightly passing the max.  It
-	 * is probably extremely rare and not worth worrying
-	 * over.
-	 */
-	if (bp->b_bufsize == 0 && newbsize <= PAGE_SIZE/2 &&
-	    bufmallocspace < maxbufmallocspace) {
-		bp->b_data = malloc(newbsize, M_BIOBUF, M_WAITOK);
-		bp->b_flags |= B_MALLOC;
-		bufmallocadjust(bp, newbsize);
-		return;
-	}
-
-	/*
-	 * If the buffer is growing on its other-than-first
-	 * allocation then we revert to the page-allocation
-	 * scheme.
-	 */
-	origbuf = NULL;
-	origbufsize = 0;
-	if (bp->b_flags & B_MALLOC) {
-		origbuf = bp->b_data;
-		origbufsize = bp->b_bufsize;
-		bp->b_data = bp->b_kvabase;
-		bufmallocadjust(bp, 0);
-		bp->b_flags &= ~B_MALLOC;
-		newbsize = round_page(newbsize);
-	}
 	vm_hold_load_pages(bp, (vm_offset_t) bp->b_data + bp->b_bufsize,
 	    (vm_offset_t) bp->b_data + newbsize);
-	if (origbuf != NULL) {
-		bcopy(origbuf, bp->b_data, origbufsize);
-		free(origbuf, M_BIOBUF);
-	}
 	bufspace_adjust(bp, newbsize);
 }
 
@@ -4272,8 +4196,7 @@
 
 	newbsize = roundup2(size, DEV_BSIZE);
 	if ((bp->b_flags & B_VMIO) == 0) {
-		if ((bp->b_flags & B_MALLOC) == 0)
-			newbsize = round_page(newbsize);
+		newbsize = round_page(newbsize);
 		/*
 		 * Just get anonymous memory from the kernel.  Don't
 		 * mess with B_CACHE.
@@ -4288,8 +4211,6 @@
 		desiredpages = (size == 0) ? 0 :
 		    num_pages((bp->b_offset & PAGE_MASK) + newbsize);
 
-		if (bp->b_flags & B_MALLOC)
-			panic("allocbuf: VMIO buffer can't be malloced");
 		/*
 		 * Set B_CACHE initially if buffer is 0 length or will become
 		 * 0-length.
@@ -4760,8 +4681,7 @@
 vfs_bio_clrbuf(struct buf *bp) 
 {
 	int i, j, mask, sa, ea, slide;
-
-	if ((bp->b_flags & (B_VMIO | B_MALLOC)) != B_VMIO) {
+	if ((bp->b_flags & B_VMIO) == 0) {
 		clrbuf(bp);
 		return;
 	}
Index: sys/kern/vfs_cluster.c
===================================================================
--- sys/kern/vfs_cluster.c
+++ sys/kern/vfs_cluster.c
@@ -368,8 +368,7 @@
 		tbp->b_iocmd = BIO_READ;
 	}
 	tbp->b_blkno = blkno;
-	if( (tbp->b_flags & B_MALLOC) ||
-		((tbp->b_flags & B_VMIO) == 0) || (run <= 1) )
+	if ( ((tbp->b_flags & B_VMIO) == 0) || (run <= 1) )
 		return tbp;
 
 	bp = trypbuf(&cluster_pbuf_freecnt);
@@ -851,7 +850,7 @@
 		 * up if the cluster was terminated prematurely--too much
 		 * hassle.
 		 */
-		if (((tbp->b_flags & (B_CLUSTEROK | B_MALLOC | B_VMIO)) != 
+		if (((tbp->b_flags & (B_CLUSTEROK | B_VMIO)) !=
 		     (B_CLUSTEROK | B_VMIO)) ||
 		  (tbp->b_bcount != tbp->b_bufsize) ||
 		  (tbp->b_bcount != size) ||
Index: sys/sys/buf.h
===================================================================
--- sys/sys/buf.h
+++ sys/sys/buf.h
@@ -185,9 +185,6 @@
  *			The 'entire buffer' is defined to be the range from
  *			0 through b_bcount.
  *
- *	B_MALLOC	Request that the buffer be allocated from the malloc
- *			pool, DEV_BSIZE aligned instead of PAGE_SIZE aligned.
- *
  *	B_CLUSTEROK	This flag is typically set for B_DELWRI buffers
  *			by filesystems that allow clustering when the buffer
  *			is fully dirty and indicates that it may be clustered
@@ -223,7 +220,6 @@
 #define	B_INVAL		0x00002000	/* Does not contain valid info. */
 #define	B_BARRIER	0x00004000	/* Write this and all preceding first. */
 #define	B_NOCACHE	0x00008000	/* Do not cache block after use. */
-#define	B_MALLOC	0x00010000	/* malloced b_data */
 #define	B_CLUSTEROK	0x00020000	/* Pagein op, so swap() can count it. */
 #define	B_00040000	0x00040000	/* Available flag. */
 #define	B_00080000	0x00080000	/* Available flag. */
Index: sys/ufs/ffs/ffs_alloc.c
===================================================================
--- sys/ufs/ffs/ffs_alloc.c
+++ sys/ufs/ffs/ffs_alloc.c
@@ -338,7 +338,7 @@
 		allocbuf(bp, nsize);
 		bp->b_flags |= B_DONE;
 		vfs_bio_bzero_buf(bp, osize, nsize - osize);
-		if ((bp->b_flags & (B_MALLOC | B_VMIO)) == B_VMIO)
+		if ((bp->b_flags & (B_VMIO)) != 0)
 			vfs_bio_set_valid(bp, osize, nsize - osize);
 		*bpp = bp;
 		return (0);
@@ -406,7 +406,7 @@
 		allocbuf(bp, nsize);
 		bp->b_flags |= B_DONE;
 		vfs_bio_bzero_buf(bp, osize, nsize - osize);
-		if ((bp->b_flags & (B_MALLOC | B_VMIO)) == B_VMIO)
+		if ((bp->b_flags & B_VMIO) != 0)
 			vfs_bio_set_valid(bp, osize, nsize - osize);
 		*bpp = bp;
 		return (0);