PSARC 2002/240 ZFS

6338653 Integrate ZFS
PSARC 2004/652 - DKIOCFLUSH
5096886 Write caching disks need mechanism to flush cache to physical media

1 files changed, 286 insertions, 0 deletions

diff --git a/usr/src/uts/common/fs/zfs/vdev_queue.c b/usr/src/uts/common/fs/zfs/vdev_queue.c
new file mode 100644
index 0000000000..09831e1504
--- /dev/null
+++ b/usr/src/uts/common/fs/zfs/vdev_queue.c
@@ -0,0 +1,286 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+#include <sys/zfs_context.h>
+#include <sys/spa.h>
+#include <sys/vdev_impl.h>
+#include <sys/zio.h>
+#include <sys/avl.h>
+
+/*
+ * Virtual device vector for disk I/O scheduling.
+ */
+int
+vdev_queue_deadline_compare(const void *x1, const void *x2)
+{
+	const zio_t *z1 = x1;
+	const zio_t *z2 = x2;
+
+	if (z1->io_deadline < z2->io_deadline)
+		return (-1);
+	if (z1->io_deadline > z2->io_deadline)
+		return (1);
+
+	if (z1->io_offset < z2->io_offset)
+		return (-1);
+	if (z1->io_offset > z2->io_offset)
+		return (1);
+
+	if (z1 < z2)
+		return (-1);
+	if (z1 > z2)
+		return (1);
+
+	return (0);
+}
+
+int
+vdev_queue_offset_compare(const void *x1, const void *x2)
+{
+	const zio_t *z1 = x1;
+	const zio_t *z2 = x2;
+
+	if (z1->io_offset < z2->io_offset)
+		return (-1);
+	if (z1->io_offset > z2->io_offset)
+		return (1);
+
+	if (z1 < z2)
+		return (-1);
+	if (z1 > z2)
+		return (1);
+
+	return (0);
+}
+
+void
+vdev_queue_init(vdev_t *vd)
+{
+	vdev_queue_t *vq = &vd->vdev_queue;
+
+	mutex_init(&vq->vq_lock, NULL, MUTEX_DEFAULT, NULL);
+
+	avl_create(&vq->vq_deadline_tree, vdev_queue_deadline_compare,
+	    sizeof (zio_t), offsetof(struct zio, io_deadline_node));
+
+	avl_create(&vq->vq_read_tree, vdev_queue_offset_compare,
+	    sizeof (zio_t), offsetof(struct zio, io_offset_node));
+
+	avl_create(&vq->vq_write_tree, vdev_queue_offset_compare,
+	    sizeof (zio_t), offsetof(struct zio, io_offset_node));
+
+	avl_create(&vq->vq_pending_tree, vdev_queue_offset_compare,
+	    sizeof (zio_t), offsetof(struct zio, io_offset_node));
+}
+
+void
+vdev_queue_fini(vdev_t *vd)
+{
+	vdev_queue_t *vq = &vd->vdev_queue;
+
+	avl_destroy(&vq->vq_deadline_tree);
+	avl_destroy(&vq->vq_read_tree);
+	avl_destroy(&vq->vq_write_tree);
+	avl_destroy(&vq->vq_pending_tree);
+
+	mutex_destroy(&vq->vq_lock);
+}
+
+static void
+vdev_queue_agg_io_done(zio_t *aio)
+{
+	zio_t *dio;
+	uint64_t offset = 0;
+
+	while ((dio = aio->io_delegate_list) != NULL) {
+		if (aio->io_type == ZIO_TYPE_READ)
+			bcopy((char *)aio->io_data + offset, dio->io_data,
+			    dio->io_size);
+		offset += dio->io_size;
+		aio->io_delegate_list = dio->io_delegate_next;
+		dio->io_delegate_next = NULL;
+		dio->io_error = aio->io_error;
+		zio_next_stage(dio);
+	}
+	ASSERT3U(offset, ==, aio->io_size);
+
+	zio_buf_free(aio->io_data, aio->io_size);
+}
+
+#define	IS_ADJACENT(io, nio) \
+	((io)->io_offset + (io)->io_size == (nio)->io_offset)
+
+typedef void zio_issue_func_t(zio_t *);
+
+static zio_t *
+vdev_queue_io_to_issue(vdev_queue_t *vq, uint64_t pending_limit,
+	zio_issue_func_t **funcp)
+{
+	zio_t *fio, *lio, *aio, *dio;
+	avl_tree_t *tree;
+	uint64_t size;
+
+	ASSERT(MUTEX_HELD(&vq->vq_lock));
+
+	*funcp = NULL;
+
+	if (avl_numnodes(&vq->vq_pending_tree) >= pending_limit ||
+	    avl_numnodes(&vq->vq_deadline_tree) == 0)
+		return (NULL);
+
+	fio = lio = avl_first(&vq->vq_deadline_tree);
+
+	tree = fio->io_vdev_tree;
+	size = fio->io_size;
+
+	while ((dio = AVL_PREV(tree, fio)) != NULL && IS_ADJACENT(dio, fio) &&
+	    size + dio->io_size <= vq->vq_agg_limit) {
+		dio->io_delegate_next = fio;
+		fio = dio;
+		size += dio->io_size;
+	}
+
+	while ((dio = AVL_NEXT(tree, lio)) != NULL && IS_ADJACENT(lio, dio) &&
+	    size + dio->io_size <= vq->vq_agg_limit) {
+		lio->io_delegate_next = dio;
+		lio = dio;
+		size += dio->io_size;
+	}
+
+	if (fio != lio) {
+		char *buf = zio_buf_alloc(size);
+		uint64_t offset = 0;
+		int nagg = 0;
+
+		ASSERT(size <= vq->vq_agg_limit);
+
+		aio = zio_vdev_child_io(fio, NULL, fio->io_vd,
+		    fio->io_offset, buf, size, fio->io_type,
+		    ZIO_PRIORITY_NOW, ZIO_FLAG_DONT_QUEUE |
+		    ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_PROPAGATE,
+		    vdev_queue_agg_io_done, NULL);
+
+		aio->io_delegate_list = fio;
+
+		for (dio = fio; dio != NULL; dio = dio->io_delegate_next) {
+			ASSERT(dio->io_type == aio->io_type);
+			if (dio->io_type == ZIO_TYPE_WRITE)
+				bcopy(dio->io_data, buf + offset, dio->io_size);
+			offset += dio->io_size;
+			avl_remove(&vq->vq_deadline_tree, dio);
+			avl_remove(tree, dio);
+			zio_vdev_io_bypass(dio);
+			nagg++;
+		}
+
+		ASSERT(offset == size);
+
+		dprintf("%5s  T=%llu  off=%8llx  agg=%3d  "
+		    "old=%5llx  new=%5llx\n",
+		    zio_type_name[fio->io_type],
+		    fio->io_deadline, fio->io_offset, nagg, fio->io_size, size);
+
+		avl_add(&vq->vq_pending_tree, aio);
+
+		*funcp = zio_nowait;
+		return (aio);
+	}
+
+	avl_remove(&vq->vq_deadline_tree, fio);
+	avl_remove(tree, fio);
+
+	avl_add(&vq->vq_pending_tree, fio);
+
+	*funcp = zio_next_stage;
+
+	return (fio);
+}
+
+zio_t *
+vdev_queue_io(zio_t *zio)
+{
+	vdev_queue_t *vq = &zio->io_vd->vdev_queue;
+	zio_t *nio;
+	zio_issue_func_t *func;
+
+	ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
+
+	if (zio->io_flags & ZIO_FLAG_DONT_QUEUE)
+		return (zio);
+
+	zio->io_flags |= ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE;
+
+	if (zio->io_type == ZIO_TYPE_READ)
+		zio->io_vdev_tree = &vq->vq_read_tree;
+	else
+		zio->io_vdev_tree = &vq->vq_write_tree;
+
+	mutex_enter(&vq->vq_lock);
+
+	zio->io_deadline = (zio->io_timestamp >> vq->vq_time_shift) +
+	    zio->io_priority;
+
+	avl_add(&vq->vq_deadline_tree, zio);
+	avl_add(zio->io_vdev_tree, zio);
+
+	nio = vdev_queue_io_to_issue(vq, vq->vq_min_pending, &func);
+
+	mutex_exit(&vq->vq_lock);
+
+	if (nio == NULL || func != zio_nowait)
+		return (nio);
+
+	func(nio);
+	return (NULL);
+}
+
+void
+vdev_queue_io_done(zio_t *zio)
+{
+	vdev_queue_t *vq = &zio->io_vd->vdev_queue;
+	zio_t *nio;
+	zio_issue_func_t *func;
+	int i;
+
+	mutex_enter(&vq->vq_lock);
+
+	avl_remove(&vq->vq_pending_tree, zio);
+
+	for (i = 0; i < vq->vq_ramp_rate; i++) {
+		nio = vdev_queue_io_to_issue(vq, vq->vq_max_pending, &func);
+		if (nio == NULL)
+			break;
+		mutex_exit(&vq->vq_lock);
+		if (func == zio_next_stage)
+			zio_vdev_io_reissue(nio);
+		func(nio);
+		mutex_enter(&vq->vq_lock);
+	}
+
+	mutex_exit(&vq->vq_lock);
+}