Support custom build directories and move includes

One of the neat tricks an autoconf style project is capable of
is allow configurion/building in a directory other than the
source directory.  The major advantage to this is that you can
build the project various different ways while making changes
in a single source tree.

For example, this project is designed to work on various different
Linux distributions each of which work slightly differently.  This
means that changes need to verified on each of those supported
distributions perferably before the change is committed to the
public git repo.

Using nfs and custom build directories makes this much easier.
I now have a single source tree in nfs mounted on several different
systems each running a supported distribution.  When I make a
change to the source base I suspect may break things I can
concurrently build from the same source on all the systems each
in their own subdirectory.

wget -c http://github.com/downloads/behlendorf/zfs/zfs-x.y.z.tar.gz
tar -xzf zfs-x.y.z.tar.gz
cd zfs-x-y-z

------------------------- run concurrently ----------------------
<ubuntu system>  <fedora system>  <debian system>  <rhel6 system>
mkdir ubuntu     mkdir fedora     mkdir debian     mkdir rhel6
cd ubuntu        cd fedora        cd debian        cd rhel6
../configure     ../configure     ../configure     ../configure
make             make             make             make
make check       make check       make check       make check

This change also moves many of the include headers from individual
incude/sys directories under the modules directory in to a single
top level include directory.  This has the advantage of making
the build rules cleaner and logically it makes a bit more sense.

1 files changed, 76 insertions, 0 deletions

diff --git a/include/sys/dmu_zfetch.h b/include/sys/dmu_zfetch.h
new file mode 100644
index 000000000..78cadd2b1
--- /dev/null
+++ b/include/sys/dmu_zfetch.h
@@ -0,0 +1,76 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (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 2009 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#ifndef	_DFETCH_H
+#define	_DFETCH_H
+
+#include <sys/zfs_context.h>
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+extern uint64_t	zfetch_array_rd_sz;
+
+struct dnode;				/* so we can reference dnode */
+
+typedef enum zfetch_dirn {
+	ZFETCH_FORWARD = 1,		/* prefetch increasing block numbers */
+	ZFETCH_BACKWARD	= -1		/* prefetch decreasing block numbers */
+} zfetch_dirn_t;
+
+typedef struct zstream {
+	uint64_t	zst_offset;	/* offset of starting block in range */
+	uint64_t	zst_len;	/* length of range, in blocks */
+	zfetch_dirn_t	zst_direction;	/* direction of prefetch */
+	uint64_t	zst_stride;	/* length of stride, in blocks */
+	uint64_t	zst_ph_offset;	/* prefetch offset, in blocks */
+	uint64_t	zst_cap;	/* prefetch limit (cap), in blocks */
+	kmutex_t	zst_lock;	/* protects stream */
+	clock_t		zst_last;	/* lbolt of last prefetch */
+	avl_node_t	zst_node;	/* embed avl node here */
+} zstream_t;
+
+typedef struct zfetch {
+	krwlock_t	zf_rwlock;	/* protects zfetch structure */
+	list_t		zf_stream;	/* AVL tree of zstream_t's */
+	struct dnode	*zf_dnode;	/* dnode that owns this zfetch */
+	uint32_t	zf_stream_cnt;	/* # of active streams */
+	uint64_t	zf_alloc_fail;	/* # of failed attempts to alloc strm */
+} zfetch_t;
+
+void		zfetch_init(void);
+void		zfetch_fini(void);
+
+void		dmu_zfetch_init(zfetch_t *, struct dnode *);
+void		dmu_zfetch_rele(zfetch_t *);
+void		dmu_zfetch(zfetch_t *, uint64_t, uint64_t, int);
+
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif	/* _DFETCH_H */