Add CANCEL command which allows to remove one request from the queue or

all requests from the queue if request number is not given.

Bump version number.

Approved by:	re (scottl)

2 files changed, 53 insertions, 4 deletions

diff --git a/sys/geom/gate/g_gate.c b/sys/geom/gate/g_gate.c
index 4e5e92b..9734cbe 100644
--- a/sys/geom/gate/g_gate.c
+++ b/sys/geom/gate/g_gate.c
@@ -442,8 +442,11 @@ g_gate_create(struct g_gate_ctl_create *ggio)
 }
 
 #define	G_GATE_CHECK_VERSION(ggio)	do {				\
-	if ((ggio)->gctl_version != G_GATE_VERSION)			\
+	if ((ggio)->gctl_version != G_GATE_VERSION) {			\
+		printf("Version mismatch %d != %d.\n",			\
+		    ggio->gctl_version, G_GATE_VERSION);		\
 		return (EINVAL);					\
+	}								\
 } while (0)
 static int
 g_gate_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td)
@@ -488,6 +491,44 @@ g_gate_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct threa
 		g_gate_release(sc);
 		return (error);
 	    }
+	case G_GATE_CMD_CANCEL:
+	    {
+		struct g_gate_ctl_cancel *ggio = (void *)addr;
+		struct bio *tbp, *lbp;
+
+		G_GATE_CHECK_VERSION(ggio);
+		sc = g_gate_hold(ggio->gctl_unit);
+		if (sc == NULL)
+			return (ENXIO);
+		lbp = NULL;
+		mtx_lock(&sc->sc_queue_mtx);
+		TAILQ_FOREACH_SAFE(bp, &sc->sc_outqueue.queue, bio_queue, tbp) {
+			if (ggio->gctl_seq == 0 ||
+			    ggio->gctl_seq == (uintptr_t)bp->bio_driver1) {
+				G_GATE_LOGREQ(1, bp, "Request canceled.");
+				bioq_remove(&sc->sc_outqueue, bp);
+				/*
+				 * Be sure to put requests back onto incoming
+				 * queue in the proper order.
+				 */
+				if (lbp == NULL)
+					bioq_insert_head(&sc->sc_inqueue, bp);
+				else {
+					TAILQ_INSERT_AFTER(&sc->sc_inqueue.queue,
+					    lbp, bp, bio_queue);
+				}
+				lbp = bp;
+				/*
+				 * If only one request was canceled, leave now.
+				 */
+				if (ggio->gctl_seq != 0)
+					break;
+			}
+		}
+		mtx_unlock(&sc->sc_queue_mtx);
+		g_gate_release(sc);
+		return (error);
+	    }
 	case G_GATE_CMD_START:
 	    {
 		struct g_gate_ctl_io *ggio = (void *)addr;
@@ -526,6 +567,7 @@ g_gate_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct threa
 		ggio->gctl_seq = (uintptr_t)bp->bio_driver1;
 		ggio->gctl_offset = bp->bio_offset;
 		ggio->gctl_length = bp->bio_length;
+
 		switch (bp->bio_cmd) {
 		case BIO_READ:
 			break;
diff --git a/sys/geom/gate/g_gate.h b/sys/geom/gate/g_gate.h
index 63e5a3f..5e655d5 100644
--- a/sys/geom/gate/g_gate.h
+++ b/sys/geom/gate/g_gate.h
@@ -41,7 +41,7 @@
 #define	G_GATE_MOD_NAME		"ggate"
 #define	G_GATE_CTL_NAME		"ggctl"
 
-#define G_GATE_VERSION		0
+#define G_GATE_VERSION		1
 
 /*
  * Maximum number of request that can be stored in
@@ -56,8 +56,9 @@
 
 #define G_GATE_CMD_CREATE	_IOWR('m', 0, struct g_gate_ctl_create)
 #define G_GATE_CMD_DESTROY	_IOWR('m', 1, struct g_gate_ctl_destroy)
-#define G_GATE_CMD_START	_IOWR('m', 2, struct g_gate_ctl_io)
-#define G_GATE_CMD_DONE		_IOWR('m', 3, struct g_gate_ctl_io)
+#define G_GATE_CMD_CANCEL	_IOWR('m', 2, struct g_gate_ctl_cancel)
+#define G_GATE_CMD_START	_IOWR('m', 3, struct g_gate_ctl_io)
+#define G_GATE_CMD_DONE		_IOWR('m', 4, struct g_gate_ctl_io)
 
 #define	G_GATE_INFOSIZE		2048
 
@@ -129,6 +130,12 @@ struct g_gate_ctl_destroy {
 	int	gctl_force;
 };
 
+struct g_gate_ctl_cancel {
+	u_int		gctl_version;
+	int		gctl_unit;
+	uintptr_t	gctl_seq;
+};
+
 struct g_gate_ctl_io {
 	u_int		 gctl_version;
 	int		 gctl_unit;