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, 3 insertions, 4 deletions

diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c
index 9ef54a7..10b1eab 100644
--- a/sys/kern/vfs_aio.c
+++ b/sys/kern/vfs_aio.c
@@ -996,20 +996,20 @@ aio_qphysio(struct proc *p, struct aiocblist *aiocbe)
 
 	bp->b_bcount = cb->aio_nbytes;
 	bp->b_bufsize = cb->aio_nbytes;
-	bp->b_flags = B_PHYS | B_CALL;
+	bp->b_flags = B_PHYS;
 	bp->b_iodone = aio_physwakeup;
 	bp->b_saveaddr = bp->b_data;
 	bp->b_data = (void *)cb->aio_buf;
 	bp->b_blkno = btodb(cb->aio_offset);
 
 	if (cb->aio_lio_opcode == LIO_WRITE) {
-		bp->b_flags |= B_WRITE;
+		bp->b_iocmd = BIO_WRITE;
 		if (!useracc(bp->b_data, bp->b_bufsize, VM_PROT_READ)) {
 			error = EFAULT;
 			goto doerror;
 		}
 	} else {
-		bp->b_flags |= B_READ;
+		bp->b_iocmd = BIO_READ;
 		if (!useracc(bp->b_data, bp->b_bufsize, VM_PROT_WRITE)) {
 			error = EFAULT;
 			goto doerror;
@@ -2132,7 +2132,6 @@ aio_physwakeup(struct buf *bp)
 	s = splbio();
 
 	wakeup((caddr_t)bp);
-	bp->b_flags &= ~B_CALL;
 	bp->b_flags |= B_DONE;
 
 	aiocbe = (struct aiocblist *)bp->b_spc;