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.

4 files changed, 12 insertions, 13 deletions

diff --git a/sys/dev/ata/ata-disk.c b/sys/dev/ata/ata-disk.c
index 802a783..cba36c9 100644
--- a/sys/dev/ata/ata-disk.c
+++ b/sys/dev/ata/ata-disk.c
@@ -337,7 +337,7 @@ ad_start(struct ad_softc *adp)
     request->blockaddr = bp->b_pblkno;
     request->bytecount = bp->b_bcount;
     request->data = bp->b_data;
-    request->flags = (bp->b_flags & B_READ) ? ADR_F_READ : 0;
+    request->flags = (bp->b_iocmd == BIO_READ) ? ADR_F_READ : 0;
 
     /* remove from drive queue */
     bufq_remove(&adp->queue, bp); 
diff --git a/sys/dev/ata/atapi-cd.c b/sys/dev/ata/atapi-cd.c
index 4c9da0d..a20cb4c 100644
--- a/sys/dev/ata/atapi-cd.c
+++ b/sys/dev/ata/atapi-cd.c
@@ -1107,7 +1107,6 @@ acd_start(struct atapi_softc *atp)
     }
 
     acd_select_slot(cdp);
-
     bzero(ccb, sizeof(ccb));
     count = (bp->b_bcount + (cdp->block_size - 1)) / cdp->block_size;
     if (bp->b_flags & B_PHYS)
@@ -1115,7 +1114,7 @@ acd_start(struct atapi_softc *atp)
     else
 	lba = bp->b_blkno / (cdp->block_size / DEV_BSIZE);
 
-    if (bp->b_flags & B_READ) {
+    if (bp->b_iocmd == BIO_READ) {
 	/* if transfer goes beyond EOM adjust it to be within limits */
 	if (lba + count > cdp->info.volsize) {
 	    /* if we are entirely beyond EOM return EOF */
@@ -1145,8 +1144,8 @@ acd_start(struct atapi_softc *atp)
 
     devstat_start_transaction(cdp->stats);
 
-    atapi_queue_cmd(cdp->atp, ccb, bp->b_data, count * cdp->block_size,
-		    bp->b_flags&B_READ ? ATPR_F_READ : 0, 30, acd_done, bp);
+    atapi_queue_cmd(cdp->atp, ccb, bp->b_data, bp->b_bcount,
+		    (bp->b_iocmd == BIO_READ)?ATPR_F_READ : 0, 30, acd_done, bp);
 }
 
 static int32_t 
@@ -1161,7 +1160,7 @@ acd_done(struct atapi_request *request)
     }	
     else {
 	bp->b_resid = bp->b_bcount - request->donecount;
-	if (!(bp->b_flags & B_READ))
+	if (bp->b_iocmd == BIO_WRITE)
 	    cdp->flags |= F_WRITTEN;
     }
     devstat_end_transaction_buf(cdp->stats, bp);
diff --git a/sys/dev/ata/atapi-fd.c b/sys/dev/ata/atapi-fd.c
index a27147b..6588684 100644
--- a/sys/dev/ata/atapi-fd.c
+++ b/sys/dev/ata/atapi-fd.c
@@ -321,7 +321,7 @@ afd_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_BIG;
     else
 	ccb[0] = ATAPI_WRITE_BIG;
@@ -338,7 +338,7 @@ afd_start(struct atapi_softc *atp)
 
 	atapi_queue_cmd(fdp->atp, ccb, data_ptr, 
 			fdp->transfersize * fdp->cap.sector_size,
-			(bp->b_flags & B_READ) ? ATPR_F_READ : 0, 30,
+			(bp->b_iocmd == BIO_READ) ? ATPR_F_READ : 0, 30,
 			afd_partial_done, bp);
 
 	count -= fdp->transfersize;
@@ -354,7 +354,7 @@ afd_start(struct atapi_softc *atp)
     ccb[8] = count;
 
     atapi_queue_cmd(fdp->atp, ccb, data_ptr, count * fdp->cap.sector_size,
-		    bp->b_flags&B_READ ? ATPR_F_READ : 0, 30, afd_done, bp);
+		    (bp->b_iocmd == BIO_READ) ? ATPR_F_READ : 0, 30, afd_done, bp);
 }
 
 static int32_t 
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);