From ddc6d7e1606cec39baddb1206aebc272a0b2c8d4 Mon Sep 17 00:00:00 2001
From: Taylor R Campbell <riastradh@NetBSD.org>
Date: Sat, 15 Feb 2020 02:54:10 +0000
Subject: [PATCH] Experimental support for TRIM in ZFS.

WARNING: THIS MAY OBLITERATE YOUR DATA IF I MADE A MISTAKE.  AND NOT
THE DATA YOU MEANT TO OBLITERATE BY USING TRIM.
---
 .../osnet/dist/uts/common/fs/zfs/vdev_disk.c  | 92 ++++++++++++-------
 .../osnet/dist/uts/common/fs/zfs/zfs_ioctl.c  |  3 -
 2 files changed, 60 insertions(+), 35 deletions(-)

diff --git a/external/cddl/osnet/dist/uts/common/fs/zfs/vdev_disk.c b/external/cddl/osnet/dist/uts/common/fs/zfs/vdev_disk.c
index 000174281f46..58511e8dff92 100644
--- a/external/cddl/osnet/dist/uts/common/fs/zfs/vdev_disk.c
+++ b/external/cddl/osnet/dist/uts/common/fs/zfs/vdev_disk.c
@@ -119,23 +119,43 @@ vdev_disk_rele(vdev_t *vd)
 }
 
 static void
-vdev_disk_flush(struct work *work, void *cookie)
+vdev_async_cmd(struct work *work, void *cookie)
 {
 	vdev_disk_t *dvd;
 	int error, cmd;
 	buf_t *bp;
+	zio_t *zio;
 	vnode_t *vp;
 
-	bp = (struct buf *)work;
+	bp = container_of(work, struct buf, b_work);
+	zio = bp->b_private;
 	vp = bp->b_vp;
 	dvd = cookie;
 
 	KASSERT(vp == dvd->vd_vp);
 
-	cmd = 1;
-	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
-	error = VOP_IOCTL(vp, DIOCCACHESYNC, &cmd, FREAD|FWRITE, kcred);
-	VOP_UNLOCK(vp, 0);
+	switch (zio->io_type) {
+	case ZIO_TYPE_IOCTL:
+		switch (zio->io_cmd) {
+		case DKIOCFLUSHWRITECACHE:
+			cmd = 1;
+			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+			error = VOP_IOCTL(vp, DIOCCACHESYNC, &cmd,
+			    FREAD|FWRITE, kcred);
+			VOP_UNLOCK(vp, 0);
+			break;
+		default:
+			error = ENOTSUP;
+			break;
+		}
+		break;
+	case ZIO_TYPE_FREE:
+		error = VOP_FDISCARD(vp, zio->io_offset, zio->io_size);
+		break;
+	default:
+		error = ENOTSUP;
+		break;
+	}
 	bp->b_error = error;
 	vdev_disk_io_intr(bp);
 }
@@ -256,10 +276,11 @@ vdev_disk_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
 	 */
 
 	/*
-	 * Create a workqueue to process cache-flushes concurrently.
+	 * Create a workqueue to process cache-flushes and TRIM
+	 * commands concurrently.
 	 */
 	error = workqueue_create(&dvd->vd_wq, "vdevsync",
-	    vdev_disk_flush, dvd, PRI_NONE, IPL_NONE, WQ_MPSAFE);
+	    vdev_async_cmd, dvd, PRI_NONE, IPL_NONE, WQ_MPSAFE);
 	if (error != 0) {
 		vrele(vp);
 		return (SET_ERROR(error));
@@ -456,37 +477,44 @@ vdev_disk_io_start(zio_t *zio)
 	ASSERT3U(dvd->vd_maxphys, >, 0);
 	vp = dvd->vd_vp;
 #endif
-
-	if (zio->io_type == ZIO_TYPE_IOCTL) {
-		/* XXPOLICY */
-		if (!vdev_readable(vd)) {
-			zio->io_error = SET_ERROR(ENXIO);
-			zio_interrupt(zio);
-			return;
-		}
-
+	switch (zio->io_type) {
+	case ZIO_TYPE_READ:
+	case ZIO_TYPE_WRITE:
+		break;
+	case ZIO_TYPE_IOCTL:
 		switch (zio->io_cmd) {
 		case DKIOCFLUSHWRITECACHE:
-
-			if (zfs_nocacheflush)
-				break;
-
+			if (zfs_nocacheflush) {
+				/* XXX Set error? */
+				zio_interrupt(zio);
+				return;
+			}
 			if (vd->vdev_nowritecache) {
-				zio->io_error = ENOTSUP;
-				break;
+				zio->io_error = SET_ERROR(ENOTSUP);
+				zio_interrupt(zio);
+				return;
 			}
-
-			bp = getiobuf(vp, true);
-			bp->b_private = zio;
-			workqueue_enqueue(dvd->vd_wq, &bp->b_work, NULL);
-			return;
-
+			break;
 		default:
 			zio->io_error = SET_ERROR(ENOTSUP);
-			break;
+			zio_interrupt(zio);
+			return;
 		}
-
-		zio_execute(zio);
+		/*FALLTHROUGH*/
+	case ZIO_TYPE_FREE:
+		/* XXPOLICY */
+		if (!vdev_readable(vd)) {
+			zio->io_error = SET_ERROR(ENXIO);
+			zio_interrupt(zio);
+			return;
+		}
+		bp = getiobuf(vp, true);
+		bp->b_private = zio;
+		workqueue_enqueue(dvd->vd_wq, &bp->b_work, NULL);
+		return;
+	default:
+		zio->io_error = SET_ERROR(ENOTSUP);
+		zio_interrupt(zio);
 		return;
 	}
 
diff --git a/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_ioctl.c b/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_ioctl.c
index e7a6bc79378c..e370b2adfb28 100644
--- a/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_ioctl.c
+++ b/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_ioctl.c
@@ -7168,9 +7168,6 @@ zfs_modcmd(modcmd_t cmd, void *arg)
 
 	switch (cmd) {
 	case MODULE_CMD_INIT:
-		/* XXXNETBSD trim is not supported yet */
-		zfs_trim_enabled = B_FALSE;
-
 		printf("WARNING: ZFS on NetBSD is under development\n");
 		availrmem = (uint64_t)physmem * PAGE_SIZE / 1048576;
 		if (availrmem < ZFS_MIN_MEGS * 80 / 100) {