Remove B_READ, B_WRITE and B_FREEBUF and replace them with a new

field in struct buf: b_iocmd.  The b_iocmd is enforced to have
exactly one bit set.

B_WRITE was bogusly defined as zero giving rise to obvious coding
mistakes.

Also eliminate the redundant struct buf flag B_CALL, it can just
as efficiently be done by comparing b_iodone to NULL.

Should you get a panic or drop into the debugger, complaining about
"b_iocmd", don't continue.  It is likely to write on your disk
where it should have been reading.

This change is a step in the direction towards a stackable BIO capability.

A lot of this patch were machine generated (Thanks to style(9) compliance!)

Vinum users:  Greg has not had time to test this yet, be careful.

1 files changed, 4 insertions, 3 deletions

diff --git a/sys/i386/isa/wt.c b/sys/i386/isa/wt.c
index 1a1c691..b601b5b 100644
--- a/sys/i386/isa/wt.c
+++ b/sys/i386/isa/wt.c
@@ -527,7 +527,7 @@ wtstrategy (struct buf *bp)
 		goto err2xit;
 	}
 
-	if (bp->b_flags & B_READ) {
+	if (bp->b_iocmd == BIO_READ) {
 		/* Check read access and no previous write to this tape. */
 		if (! (t->flags & TPREAD) || (t->flags & TPWANY))
 			goto errxit;
@@ -566,8 +566,9 @@ wtstrategy (struct buf *bp)
 
 	t->flags &= ~TPEXCEP;
 	s = splbio ();
-	if (wtstart (t, bp->b_flags & B_READ ? ISADMA_READ : ISADMA_WRITE, bp->b_data, bp->b_bcount)) {
-		wtwait (t, 0, (bp->b_flags & B_READ) ? "wtread" : "wtwrite");
+	if (wtstart (t, bp->b_iocmd == BIO_READ ? ISADMA_READ : ISADMA_WRITE, 
+	    bp->b_data, bp->b_bcount)) {
+		wtwait (t, 0, (bp->b_iocmd == BIO_READ) ? "wtread" : "wtwrite");
 		bp->b_resid -= t->dmacount;
 	}
 	splx (s);