First set of changes to eliminate the ad-hoc device buffer queues,

replacing them with TAILQ's as appropriate.  The SCSI code is the
first to be changed -- until the changes are complete, both b_act and
b_actf will be in the buf structure.  b_actf will eventually be removed.

7 files changed, 61 insertions, 77 deletions

diff --git a/sys/scsi/cd.c b/sys/scsi/cd.c
index 981530c..c3fb6ff 100644
--- a/sys/scsi/cd.c
+++ b/sys/scsi/cd.c
@@ -14,7 +14,7 @@
  *
  * Ported to run under 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
  *
- *      $Id: cd.c,v 1.42 1995/10/21 23:13:06 phk Exp $
+ *      $Id: cd.c,v 1.43 1995/11/15 03:27:14 asami Exp $
  */
 
 #define SPLCD splbio
@@ -83,7 +83,7 @@ struct scsi_data {
 #define CDOPEN	0x01
 	u_int32 openparts;	/* one bit for each open partition */
 	u_int32 xfer_block_wait;
-	struct buf buf_queue;
+	struct buf_queue_head buf_queue;
 	int dkunit;
 };
 
@@ -180,6 +180,7 @@ cdattach(struct scsi_link *sc_link)
 	unit = sc_link->dev_unit;
 	dp = &(cd->params);
 
+	TAILQ_INIT(&cd->buf_queue);
 	if (sc_link->opennings > CDOUTSTANDING)
 		sc_link->opennings = CDOUTSTANDING;
 	/*
@@ -359,7 +360,6 @@ cd_close(dev_t dev, int flag, int fmt, struct proc *p,
 void
 cd_strategy(struct buf *bp, struct scsi_link *sc_link)
 {
-	struct buf *dp;
 	u_int32 opri;
 	u_int32 unit = CDUNIT((bp->b_dev));
 	struct scsi_data *cd = sc_link->sd;
@@ -396,7 +396,6 @@ cd_strategy(struct buf *bp, struct scsi_link *sc_link)
 		bp->b_resid = 0;
 	}
 	opri = SPLCD();
-	dp = &cd->buf_queue;
 
 	/*
 	 * Use a bounce buffer if necessary
@@ -409,7 +408,7 @@ cd_strategy(struct buf *bp, struct scsi_link *sc_link)
 	/*
 	 * Place it in the queue of disk activities for this disk
 	 */
-	disksort(dp, bp);
+	TAILQ_INSERT_TAIL(&cd->buf_queue, bp, b_act);
 
 	/*
 	 * Tell the device to get going on the transfer if it's
@@ -453,7 +452,6 @@ cdstart(unit, flags)
 	u_int32 flags;
 {
 	register struct buf *bp = 0;
-	register struct buf *dp;
 	struct scsi_rw_big cmd;
 	u_int32 blkno, nblk;
 	struct partition *p;
@@ -471,12 +469,13 @@ cdstart(unit, flags)
 	if (sc_link->flags & SDEV_WAITING) {	/* is room, but a special waits */
 		return;		/* give the special that's waiting a chance to run */
 	}
-	dp = &cd->buf_queue;
-	if ((bp = dp->b_actf) != NULL) {	/* yes, an assign */
-		dp->b_actf = bp->b_actf;
-	} else {
+
+	bp = cd->buf_queue.tqh_first;
+	if (bp == NULL) {	/* yes, an assign */
 		return;
 	}
+	TAILQ_REMOVE( &cd->buf_queue, bp, b_act);
+
 	/*
 	 * Should reject all queued entries if SDEV_MEDIA_LOADED is not true.
 	 */
diff --git a/sys/scsi/od.c b/sys/scsi/od.c
index c0c1e48..e17bfbf 100644
--- a/sys/scsi/od.c
+++ b/sys/scsi/od.c
@@ -28,7 +28,7 @@
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  *
- *	$Id: od.c,v 1.7 1995/07/04 15:12:53 shun Exp $
+ *	$Id: od.c,v 1.1 1995/10/31 17:25:58 joerg Exp $
  */
 
 /*
@@ -93,7 +93,7 @@ struct scsi_data {
 		u_int32 disksize;	/* total number sectors */
 	} params;
 	struct diskslices *dk_slices;	/* virtual drives */
-	struct buf buf_queue;
+	struct buf_queue_head buf_queue;
 	int dkunit;		/* disk stats unit number */
 };
 
@@ -191,6 +191,8 @@ odattach(struct scsi_link *sc_link)
 
 	if (sc_link->opennings > ODOUTSTANDING)
 		sc_link->opennings = ODOUTSTANDING;
+
+	TAILQ_INIT(&od->buf_queue);
 	/*
 	 * Use the subdriver to request information regarding
 	 * the drive. We cannot use interrupts yet, so the
@@ -381,7 +383,6 @@ od_close(dev, fflag, fmt, p, sc_link)
 void
 od_strategy(struct buf *bp, struct scsi_link *sc_link)
 {
-	struct buf *dp;
 	u_int32 opri;
 	struct scsi_data *od;
 	u_int32 unit;
@@ -412,7 +413,6 @@ od_strategy(struct buf *bp, struct scsi_link *sc_link)
 		goto done;	/* XXX check b_resid */
 
 	opri = SPLOD();
-	dp = &od->buf_queue;
 
 	/*
 	 * Use a bounce buffer if necessary
@@ -425,7 +425,7 @@ od_strategy(struct buf *bp, struct scsi_link *sc_link)
 	/*
 	 * Place it in the queue of disk activities for this disk
 	 */
-	disksort(dp, bp);
+	TAILQ_INSERT_TAIL(&od->buf_queue, bp, b_act);
 
 	/*
 	 * Tell the device to get going on the transfer if it's
@@ -479,7 +479,6 @@ odstart(u_int32 unit, u_int32 flags)
 	register struct	scsi_link *sc_link = SCSI_LINK(&od_switch, unit);
 	register struct scsi_data *od = sc_link->sd;
 	struct buf *bp = 0;
-	struct buf *dp;
 	struct scsi_rw_big cmd;
 	u_int32 blkno, nblk;
 
@@ -500,11 +499,11 @@ odstart(u_int32 unit, u_int32 flags)
 		/*
 		 * See if there is a buf with work for us to do..
 		 */
-		dp = &od->buf_queue;
-		if ((bp = dp->b_actf) == NULL) {	/* yes, an assign */
+		bp = od->buf_queue.tqh_first;
+		if (bp == NULL) {	/* yes, an assign */
 			return;
 		}
-		dp->b_actf = bp->b_actf;
+		TAILQ_REMOVE( &od->buf_queue, bp, b_act);
 
 		/*
 		 *  If the device has become invalid, abort all the
diff --git a/sys/scsi/pt.c b/sys/scsi/pt.c
index 2d1a10b..6ecc795 100644
--- a/sys/scsi/pt.c
+++ b/sys/scsi/pt.c
@@ -37,7 +37,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *      $Id: pt.c,v 1.4 1995/05/03 18:09:09 dufault Exp $
+ *      $Id: pt.c,v 1.5 1995/05/30 08:13:23 rgrimes Exp $
  */
 
 /*
@@ -54,7 +54,7 @@
 #include <scsi/scsiconf.h>
 
 struct scsi_data {
-	struct buf *buf_queue;		/* the queue of pending IO operations */
+	struct buf_queue_head buf_queue;
 };
 
 void ptstart(u_int32 unit, u_int32 flags);
@@ -131,10 +131,12 @@ ptstart(unit, flags)
 			wakeup((caddr_t)sc_link);
 			return;
 		}
-		if ((bp = pt->buf_queue) == NULL) {
-			return;	/* no work to bother with */
+
+		bp = pt->buf_queue.tqh_first;
+		if (bp == NULL) {	/* yes, an assign */
+			return;
 		}
-		pt->buf_queue = bp->b_actf;
+		TAILQ_REMOVE( &pt->buf_queue, bp, b_act);
 
 		/*
 		 *  Fill out the scsi command
@@ -196,12 +198,7 @@ pt_strategy(struct buf *bp, struct scsi_link *sc_link)
 	 * at the end (a bit silly because we only have one user..
 	 * (but it could fork() ))
 	 */
-	dp = &(pt->buf_queue);
-	while (*dp) {
-		dp = &((*dp)->b_actf);
-	}
-	*dp = bp;
-	bp->b_actf = NULL;
+	TAILQ_INSERT_TAIL( &pt->buf_queue, bp, b_act);
 
 	/*
 	 * Tell the device to get going on the transfer if it's
diff --git a/sys/scsi/sctarg.c b/sys/scsi/sctarg.c
index 597c263..e7346a1 100644
--- a/sys/scsi/sctarg.c
+++ b/sys/scsi/sctarg.c
@@ -37,7 +37,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *      $Id: sctarg.c,v 1.3 1995/05/30 08:13:49 rgrimes Exp $
+ *      $Id: sctarg.c,v 1.4 1995/07/13 16:08:57 bde Exp $
  */
 
 /*
@@ -56,7 +56,7 @@
 #define OPEN 0x01
 
 struct scsi_data {
-	struct buf *buf_queue;		/* the queue of pending IO operations */
+	struct buf_queue_head buf_queue;
 	int flags;					/* Already open */
 };
 
@@ -189,10 +189,12 @@ sctargstart(unit, unused_flags)
 			wakeup((caddr_t)sc_link);
 			return;
 		}
-		if ((bp = sctarg->buf_queue) == NULL) {
-			return;	/* no work to bother with */
+
+		bp = sctarg->buf_queue.tqh_first;
+		if (bp == NULL) {	/* yes, an assign */
+			return;
 		}
-		sctarg->buf_queue = bp->b_actf;
+		TAILQ_REMOVE( &pt->buf_queue, bp, b_act);
 
 		/*
 		 *  Fill out the scsi command
@@ -253,12 +255,7 @@ sctarg_strategy(struct buf *bp, struct scsi_link *sc_link)
 	/*
 	 * Place it at the end of the queue of activities for this device.
 	 */
-	dp = &(sctarg->buf_queue);
-	while (*dp) {
-		dp = &((*dp)->b_actf);
-	}
-	*dp = bp;
-	bp->b_actf = NULL;
+	TAILQ_INSERT_TAIL( &sctarg->buf_queue, bp, b_act);
 
 	/*
 	 * Tell the device to get going on the transfer if it's
diff --git a/sys/scsi/sd.c b/sys/scsi/sd.c
index 1182bb6..75ac07d 100644
--- a/sys/scsi/sd.c
+++ b/sys/scsi/sd.c
@@ -14,7 +14,7 @@
  *
  * Ported to run under 386BSD by Julian Elischer (julian@dialix.oz.au) Sept 1992
  *
- *      $Id: sd.c,v 1.68 1995/10/21 23:13:09 phk Exp $
+ *      $Id: sd.c,v 1.69 1995/11/06 08:19:24 davidg Exp $
  */
 
 #define SPLSD splbio
@@ -74,7 +74,7 @@ struct scsi_data {
 		u_int32 disksize;	/* total number sectors */
 	} params;
 	struct diskslices *dk_slices;	/* virtual drives */
-	struct buf buf_queue;
+	struct buf_queue_head buf_queue;
 	int dkunit;		/* disk stats unit number */
 };
 
@@ -172,6 +172,8 @@ sdattach(struct scsi_link *sc_link)
 
 	if (sc_link->opennings > SDOUTSTANDING)
 		sc_link->opennings = SDOUTSTANDING;
+
+	TAILQ_INIT(&sd->buf_queue);
 	/*
 	 * Use the subdriver to request information regarding
 	 * the drive. We cannot use interrupts yet, so the
@@ -357,7 +359,6 @@ sd_close(dev, fflag, fmt, p, sc_link)
 void
 sd_strategy(struct buf *bp, struct scsi_link *sc_link)
 {
-	struct buf *dp;
 	u_int32 opri;
 	struct scsi_data *sd;
 	u_int32 unit;
@@ -392,8 +393,6 @@ sd_strategy(struct buf *bp, struct scsi_link *sc_link)
 		goto done;	/* XXX check b_resid */
 
 	opri = SPLSD();
-	dp = &sd->buf_queue;
-
 	/*
 	 * Use a bounce buffer if necessary
 	 */
@@ -405,7 +404,7 @@ sd_strategy(struct buf *bp, struct scsi_link *sc_link)
 	/*
 	 * Place it in the queue of disk activities for this disk
 	 */
-	disksort(dp, bp);
+	TAILQ_INSERT_TAIL(&sd->buf_queue, bp, b_act);
 
 	/*
 	 * Tell the device to get going on the transfer if it's
@@ -459,7 +458,6 @@ sdstart(u_int32 unit, u_int32 flags)
 	register struct	scsi_link *sc_link = SCSI_LINK(&sd_switch, unit);
 	register struct scsi_data *sd = sc_link->sd;
 	struct buf *bp = 0;
-	struct buf *dp;
 	struct scsi_rw_big cmd;
 	u_int32 blkno, nblk;
 
@@ -480,12 +478,12 @@ sdstart(u_int32 unit, u_int32 flags)
 		/*
 		 * See if there is a buf with work for us to do..
 		 */
-		dp = &sd->buf_queue;
-		if ((bp = dp->b_actf) == NULL) {	/* yes, an assign */
+		bp = sd->buf_queue.tqh_first;
+		if (bp == NULL) {	/* yes, an assign */
 			return;
 		}
-		dp->b_actf = bp->b_actf;
-		bp->b_actf = NULL;
+		TAILQ_REMOVE( &sd->buf_queue, bp, b_act);
+
 
 		/*
 		 *  If the device has become invalid, abort all the
diff --git a/sys/scsi/st.c b/sys/scsi/st.c
index 9910c42..a4cbdb6 100644
--- a/sys/scsi/st.c
+++ b/sys/scsi/st.c
@@ -12,7 +12,7 @@
  * on the understanding that TFS is not responsible for the correct
  * functioning of this software in any circumstances.
  *
- * $Id: st.c,v 1.41 1995/10/21 23:13:10 phk Exp $
+ * $Id: st.c,v 1.42 1995/11/04 13:25:23 bde Exp $
  */
 
 /*
@@ -218,7 +218,7 @@ struct scsi_data {
 					 * additional sense data needed
 					 * for mode sense/select.
 					 */
-	struct buf *buf_queue;		/* the queue of pending IO operations */
+	struct buf_queue_head buf_queue;
 	struct scsi_xfer scsi_xfer;	/* scsi xfer struct for this drive */
 	u_int32 xfer_block_wait;	/* is a process waiting? */
 };
@@ -328,6 +328,7 @@ stattach(struct scsi_link *sc_link)
 
 	unit = sc_link->dev_unit;
 
+	TAILQ_INIT(&st->buf_queue);
 	/*
 	 * Check if the drive is a known criminal and take
 	 * Any steps needed to bring it into line
@@ -362,7 +363,6 @@ stattach(struct scsi_link *sc_link)
 	/*
 	 * Set up the buf queue for this device
 	 */
-	st->buf_queue = 0;
 	st->flags |= ST_INITIALIZED;
 	st_registerdev(unit);
 
@@ -899,7 +899,6 @@ done:
 void
 st_strategy(struct buf *bp, struct scsi_link *sc_link)
 {
-	struct buf **dp;
 	unsigned char unit;	/* XXX Everywhere else unit is "u_int32". Please int? */
 	u_int32 opri;
 	struct scsi_data *st;
@@ -962,12 +961,7 @@ st_strategy(struct buf *bp, struct scsi_link *sc_link)
 	 * at the end (a bit silly because we only have on user..
 	 * (but it could fork() ))
 	 */
-	dp = &(st->buf_queue);
-	while (*dp) {
-		dp = &((*dp)->b_actf);
-	}
-	*dp = bp;
-	bp->b_actf = NULL;
+	TAILQ_INSERT_TAIL(&st->buf_queue, bp, b_act);
 
 	/*
 	 * Tell the device to get going on the transfer if it's
@@ -1025,10 +1019,12 @@ ststart(unit, flags)
 			wakeup((caddr_t)sc_link);
 			return;
 		}
-		if ((bp = st->buf_queue) == NULL) {
-			return;	/* no work to bother with */
+
+		bp = st->buf_queue.tqh_first;
+		if (bp == NULL) {	/* yes, an assign */
+			return;
 		}
-		st->buf_queue = bp->b_actf;
+		TAILQ_REMOVE( &st->buf_queue, bp, b_act);
 
 		/*
 		 * if the device has been unmounted by the user
diff --git a/sys/scsi/worm.c b/sys/scsi/worm.c
index a717c82..ef8c983 100644
--- a/sys/scsi/worm.c
+++ b/sys/scsi/worm.c
@@ -37,7 +37,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *      $Id: worm.c,v 1.8 1995/10/09 15:15:01 joerg Exp $
+ *      $Id: worm.c,v 1.9 1995/10/21 23:13:11 phk Exp $
  */
 
 /* XXX This is PRELIMINARY.
@@ -60,8 +60,7 @@
 #include <scsi/scsi_disk.h>
 
 struct scsi_data {
-	struct buf *buf_queue;		/* the queue of pending IO operations */
-
+	struct buf_queue_head buf_queue;
 	u_int32 n_blks;				/* Number of blocks (0 for bogus) */
 	u_int32 blk_size;			/* Size of each blocks */
 };
@@ -131,6 +130,8 @@ wormattach(struct scsi_link *sc_link)
 {
 	struct scsi_data *worm = sc_link->sd;
 
+	TAILQ_INIT(&worm->buf_queue);
+
 	printf("- UNTESTED ");
 
 	if (worm_size(sc_link, SCSI_NOSLEEP | SCSI_NOMASK) == 0)
@@ -204,10 +205,12 @@ wormstart(unit, flags)
 			wakeup(sc_link);
 			return;
 		}
-		if ((bp = worm->buf_queue) == NULL) {
-			return;	/* no work to bother with */
+
+		bp = worm->buf_queue.tqh_first;
+		if (bp == NULL) {	/* yes, an assign */
+			return;
 		}
-		worm->buf_queue = bp->b_actf;
+		TAILQ_REMOVE( &worm->buf_queue, bp, b_act);
 
 		/*
 		 *  Fill out the scsi command
@@ -289,12 +292,7 @@ worm_strategy(struct buf *bp, struct scsi_link *sc_link)
 	 * Place it in the queue of activities for this device
 	 * at the end.
 	 */
-	dp = &(worm->buf_queue);
-	while (*dp) {
-		dp = &((*dp)->b_actf);
-	}
-	*dp = bp;
-	bp->b_actf = NULL;
+	TAILQ_INSERT_TAIL(&worm->buf_queue, bp, b_act);
 
 	wormstart(unit, 0);