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, 131 insertions, 0 deletions

diff --git a/include/sys/txg.h b/include/sys/txg.h
new file mode 100644
index 000000000..e323d5efa
--- /dev/null
+++ b/include/sys/txg.h
@@ -0,0 +1,131 @@
+/*
+ * 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 2010 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#ifndef _SYS_TXG_H
+#define	_SYS_TXG_H
+
+#include <sys/spa.h>
+#include <sys/zfs_context.h>
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+#define	TXG_CONCURRENT_STATES	3	/* open, quiescing, syncing	*/
+#define	TXG_SIZE		4		/* next power of 2	*/
+#define	TXG_MASK		(TXG_SIZE - 1)	/* mask for size	*/
+#define	TXG_INITIAL		TXG_SIZE	/* initial txg 		*/
+#define	TXG_IDX			(txg & TXG_MASK)
+
+/* Number of txgs worth of frees we defer adding to in-core spacemaps */
+#define	TXG_DEFER_SIZE		2
+
+#define	TXG_WAIT		1ULL
+#define	TXG_NOWAIT		2ULL
+
+typedef struct tx_cpu tx_cpu_t;
+
+typedef struct txg_handle {
+	tx_cpu_t	*th_cpu;
+	uint64_t	th_txg;
+} txg_handle_t;
+
+typedef struct txg_node {
+	struct txg_node	*tn_next[TXG_SIZE];
+	uint8_t		tn_member[TXG_SIZE];
+} txg_node_t;
+
+typedef struct txg_list {
+	kmutex_t	tl_lock;
+	size_t		tl_offset;
+	txg_node_t	*tl_head[TXG_SIZE];
+} txg_list_t;
+
+struct dsl_pool;
+
+extern void txg_init(struct dsl_pool *dp, uint64_t txg);
+extern void txg_fini(struct dsl_pool *dp);
+extern void txg_sync_start(struct dsl_pool *dp);
+extern void txg_sync_stop(struct dsl_pool *dp);
+extern uint64_t txg_hold_open(struct dsl_pool *dp, txg_handle_t *txghp);
+extern void txg_rele_to_quiesce(txg_handle_t *txghp);
+extern void txg_rele_to_sync(txg_handle_t *txghp);
+extern void txg_register_callbacks(txg_handle_t *txghp, list_t *tx_callbacks);
+
+/*
+ * Delay the caller by the specified number of ticks or until
+ * the txg closes (whichever comes first).  This is intended
+ * to be used to throttle writers when the system nears its
+ * capacity.
+ */
+extern void txg_delay(struct dsl_pool *dp, uint64_t txg, int ticks);
+
+/*
+ * Wait until the given transaction group has finished syncing.
+ * Try to make this happen as soon as possible (eg. kick off any
+ * necessary syncs immediately).  If txg==0, wait for the currently open
+ * txg to finish syncing.
+ */
+extern void txg_wait_synced(struct dsl_pool *dp, uint64_t txg);
+
+/*
+ * Wait until the given transaction group, or one after it, is
+ * the open transaction group.  Try to make this happen as soon
+ * as possible (eg. kick off any necessary syncs immediately).
+ * If txg == 0, wait for the next open txg.
+ */
+extern void txg_wait_open(struct dsl_pool *dp, uint64_t txg);
+
+/*
+ * Returns TRUE if we are "backed up" waiting for the syncing
+ * transaction to complete; otherwise returns FALSE.
+ */
+extern boolean_t txg_stalled(struct dsl_pool *dp);
+
+/* returns TRUE if someone is waiting for the next txg to sync */
+extern boolean_t txg_sync_waiting(struct dsl_pool *dp);
+
+/*
+ * Per-txg object lists.
+ */
+
+#define	TXG_CLEAN(txg)	((txg) - 1)
+
+extern void txg_list_create(txg_list_t *tl, size_t offset);
+extern void txg_list_destroy(txg_list_t *tl);
+extern int txg_list_empty(txg_list_t *tl, uint64_t txg);
+extern int txg_list_add(txg_list_t *tl, void *p, uint64_t txg);
+extern int txg_list_add_tail(txg_list_t *tl, void *p, uint64_t txg);
+extern void *txg_list_remove(txg_list_t *tl, uint64_t txg);
+extern void *txg_list_remove_this(txg_list_t *tl, void *p, uint64_t txg);
+extern int txg_list_member(txg_list_t *tl, void *p, uint64_t txg);
+extern void *txg_list_head(txg_list_t *tl, uint64_t txg);
+extern void *txg_list_next(txg_list_t *tl, void *p, uint64_t txg);
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif	/* _SYS_TXG_H */