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, 4 deletions

diff --git a/sys/dev/ata/atapi-tape.c b/sys/dev/ata/atapi-tape.c
index 2f737c4..3d08eba 100644
--- a/sys/dev/ata/atapi-tape.c
+++ b/sys/dev/ata/atapi-tape.c
@@ -421,7 +421,7 @@ aststrategy(struct buf *bp)
 	biodone(bp);
 	return;
     }
-    if (!(bp->b_flags & B_READ) && stp->flags & F_WRITEPROTECT) {
+    if (!(bp->b_iocmd == BIO_READ) && stp->flags & F_WRITEPROTECT) {
 	bp->b_error = EPERM;
 	bp->b_flags |= B_ERROR;
 	biodone(bp);
@@ -466,7 +466,7 @@ ast_start(struct atapi_softc *atp)
 
     bzero(ccb, sizeof(ccb));
 
-    if (bp->b_flags & B_READ)
+    if (bp->b_iocmd == BIO_READ)
 	ccb[0] = ATAPI_READ;
     else
 	ccb[0] = ATAPI_WRITE;
@@ -482,7 +482,7 @@ ast_start(struct atapi_softc *atp)
     devstat_start_transaction(&stp->stats);
 
     atapi_queue_cmd(stp->atp, ccb, bp->b_data, blkcount * stp->blksize, 
-		    bp->b_flags & B_READ ? ATPR_F_READ : 0, 60, ast_done, bp);
+		    (bp->b_iocmd == BIO_READ) ? ATPR_F_READ : 0, 60, ast_done, bp);
 }
 
 static int32_t 
@@ -496,7 +496,7 @@ ast_done(struct atapi_request *request)
 	bp->b_flags |= B_ERROR;
     }
     else {
-	if (!(bp->b_flags & B_READ))
+	if (!(bp->b_iocmd == BIO_READ))
 	    stp->flags |= F_DATA_WRITTEN;
 	bp->b_resid = bp->b_bcount - request->donecount;
         ast_total += (bp->b_bcount - bp->b_resid);