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, 375 insertions, 0 deletions

diff --git a/include/sys/dbuf.h b/include/sys/dbuf.h
new file mode 100644
index 000000000..cf1bbc030
--- /dev/null
+++ b/include/sys/dbuf.h
@@ -0,0 +1,375 @@
+/*
+ * 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ */
+
+#ifndef	_SYS_DBUF_H
+#define	_SYS_DBUF_H
+
+#include <sys/dmu.h>
+#include <sys/spa.h>
+#include <sys/txg.h>
+#include <sys/zio.h>
+#include <sys/arc.h>
+#include <sys/zfs_context.h>
+#include <sys/refcount.h>
+#include <sys/zrlock.h>
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+#define	IN_DMU_SYNC 2
+
+/*
+ * define flags for dbuf_read
+ */
+
+#define	DB_RF_MUST_SUCCEED	(1 << 0)
+#define	DB_RF_CANFAIL		(1 << 1)
+#define	DB_RF_HAVESTRUCT	(1 << 2)
+#define	DB_RF_NOPREFETCH	(1 << 3)
+#define	DB_RF_NEVERWAIT		(1 << 4)
+#define	DB_RF_CACHED		(1 << 5)
+
+/*
+ * The simplified state transition diagram for dbufs looks like:
+ *
+ *		+----> READ ----+
+ *		|		|
+ *		|		V
+ *  (alloc)-->UNCACHED	     CACHED-->EVICTING-->(free)
+ *		|		^	 ^
+ *		|		|	 |
+ *		+----> FILL ----+	 |
+ *		|			 |
+ *		|			 |
+ *		+--------> NOFILL -------+
+ */
+typedef enum dbuf_states {
+	DB_UNCACHED,
+	DB_FILL,
+	DB_NOFILL,
+	DB_READ,
+	DB_CACHED,
+	DB_EVICTING
+} dbuf_states_t;
+
+struct dnode;
+struct dmu_tx;
+
+/*
+ * level = 0 means the user data
+ * level = 1 means the single indirect block
+ * etc.
+ */
+
+struct dmu_buf_impl;
+
+typedef enum override_states {
+	DR_NOT_OVERRIDDEN,
+	DR_IN_DMU_SYNC,
+	DR_OVERRIDDEN
+} override_states_t;
+
+typedef struct dbuf_dirty_record {
+	/* link on our parents dirty list */
+	list_node_t dr_dirty_node;
+
+	/* transaction group this data will sync in */
+	uint64_t dr_txg;
+
+	/* zio of outstanding write IO */
+	zio_t *dr_zio;
+
+	/* pointer back to our dbuf */
+	struct dmu_buf_impl *dr_dbuf;
+
+	/* pointer to next dirty record */
+	struct dbuf_dirty_record *dr_next;
+
+	/* pointer to parent dirty record */
+	struct dbuf_dirty_record *dr_parent;
+
+	union dirty_types {
+		struct dirty_indirect {
+
+			/* protect access to list */
+			kmutex_t dr_mtx;
+
+			/* Our list of dirty children */
+			list_t dr_children;
+		} di;
+		struct dirty_leaf {
+
+			/*
+			 * dr_data is set when we dirty the buffer
+			 * so that we can retain the pointer even if it
+			 * gets COW'd in a subsequent transaction group.
+			 */
+			arc_buf_t *dr_data;
+			blkptr_t dr_overridden_by;
+			override_states_t dr_override_state;
+			uint8_t dr_copies;
+		} dl;
+	} dt;
+} dbuf_dirty_record_t;
+
+typedef struct dmu_buf_impl {
+	/*
+	 * The following members are immutable, with the exception of
+	 * db.db_data, which is protected by db_mtx.
+	 */
+
+	/* the publicly visible structure */
+	dmu_buf_t db;
+
+	/* the objset we belong to */
+	struct objset *db_objset;
+
+	/*
+	 * handle to safely access the dnode we belong to (NULL when evicted)
+	 */
+	struct dnode_handle *db_dnode_handle;
+
+	/*
+	 * our parent buffer; if the dnode points to us directly,
+	 * db_parent == db_dnode_handle->dnh_dnode->dn_dbuf
+	 * only accessed by sync thread ???
+	 * (NULL when evicted)
+	 * May change from NULL to non-NULL under the protection of db_mtx
+	 * (see dbuf_check_blkptr())
+	 */
+	struct dmu_buf_impl *db_parent;
+
+	/*
+	 * link for hash table of all dmu_buf_impl_t's
+	 */
+	struct dmu_buf_impl *db_hash_next;
+
+	/* our block number */
+	uint64_t db_blkid;
+
+	/*
+	 * Pointer to the blkptr_t which points to us. May be NULL if we
+	 * don't have one yet. (NULL when evicted)
+	 */
+	blkptr_t *db_blkptr;
+
+	/*
+	 * Our indirection level.  Data buffers have db_level==0.
+	 * Indirect buffers which point to data buffers have
+	 * db_level==1. etc.  Buffers which contain dnodes have
+	 * db_level==0, since the dnodes are stored in a file.
+	 */
+	uint8_t db_level;
+
+	/* db_mtx protects the members below */
+	kmutex_t db_mtx;
+
+	/*
+	 * Current state of the buffer
+	 */
+	dbuf_states_t db_state;
+
+	/*
+	 * Refcount accessed by dmu_buf_{hold,rele}.
+	 * If nonzero, the buffer can't be destroyed.
+	 * Protected by db_mtx.
+	 */
+	refcount_t db_holds;
+
+	/* buffer holding our data */
+	arc_buf_t *db_buf;
+
+	kcondvar_t db_changed;
+	dbuf_dirty_record_t *db_data_pending;
+
+	/* pointer to most recent dirty record for this buffer */
+	dbuf_dirty_record_t *db_last_dirty;
+
+	/*
+	 * Our link on the owner dnodes's dn_dbufs list.
+	 * Protected by its dn_dbufs_mtx.
+	 */
+	list_node_t db_link;
+
+	/* Data which is unique to data (leaf) blocks: */
+
+	/* stuff we store for the user (see dmu_buf_set_user) */
+	void *db_user_ptr;
+	void **db_user_data_ptr_ptr;
+	dmu_buf_evict_func_t *db_evict_func;
+
+	uint8_t db_immediate_evict;
+	uint8_t db_freed_in_flight;
+
+	uint8_t db_dirtycnt;
+} dmu_buf_impl_t;
+
+/* Note: the dbuf hash table is exposed only for the mdb module */
+#define	DBUF_MUTEXES 256
+#define	DBUF_HASH_MUTEX(h, idx) (&(h)->hash_mutexes[(idx) & (DBUF_MUTEXES-1)])
+typedef struct dbuf_hash_table {
+	uint64_t hash_table_mask;
+	dmu_buf_impl_t **hash_table;
+	kmutex_t hash_mutexes[DBUF_MUTEXES];
+} dbuf_hash_table_t;
+
+
+uint64_t dbuf_whichblock(struct dnode *di, uint64_t offset);
+
+dmu_buf_impl_t *dbuf_create_tlib(struct dnode *dn, char *data);
+void dbuf_create_bonus(struct dnode *dn);
+int dbuf_spill_set_blksz(dmu_buf_t *db, uint64_t blksz, dmu_tx_t *tx);
+void dbuf_spill_hold(struct dnode *dn, dmu_buf_impl_t **dbp, void *tag);
+
+void dbuf_rm_spill(struct dnode *dn, dmu_tx_t *tx);
+
+dmu_buf_impl_t *dbuf_hold(struct dnode *dn, uint64_t blkid, void *tag);
+dmu_buf_impl_t *dbuf_hold_level(struct dnode *dn, int level, uint64_t blkid,
+    void *tag);
+int dbuf_hold_impl(struct dnode *dn, uint8_t level, uint64_t blkid, int create,
+    void *tag, dmu_buf_impl_t **dbp);
+
+void dbuf_prefetch(struct dnode *dn, uint64_t blkid);
+
+void dbuf_add_ref(dmu_buf_impl_t *db, void *tag);
+uint64_t dbuf_refcount(dmu_buf_impl_t *db);
+
+void dbuf_rele(dmu_buf_impl_t *db, void *tag);
+void dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag);
+
+dmu_buf_impl_t *dbuf_find(struct dnode *dn, uint8_t level, uint64_t blkid);
+
+int dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags);
+void dbuf_will_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
+void dbuf_fill_done(dmu_buf_impl_t *db, dmu_tx_t *tx);
+void dmu_buf_will_not_fill(dmu_buf_t *db, dmu_tx_t *tx);
+void dmu_buf_will_fill(dmu_buf_t *db, dmu_tx_t *tx);
+void dmu_buf_fill_done(dmu_buf_t *db, dmu_tx_t *tx);
+void dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx);
+dbuf_dirty_record_t *dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
+arc_buf_t *dbuf_loan_arcbuf(dmu_buf_impl_t *db);
+
+void dbuf_clear(dmu_buf_impl_t *db);
+void dbuf_evict(dmu_buf_impl_t *db);
+
+void dbuf_setdirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
+void dbuf_unoverride(dbuf_dirty_record_t *dr);
+void dbuf_sync_list(list_t *list, dmu_tx_t *tx);
+void dbuf_release_bp(dmu_buf_impl_t *db);
+
+void dbuf_free_range(struct dnode *dn, uint64_t start, uint64_t end,
+    struct dmu_tx *);
+
+void dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx);
+
+#define	DB_DNODE(_db)		((_db)->db_dnode_handle->dnh_dnode)
+#define	DB_DNODE_LOCK(_db)	((_db)->db_dnode_handle->dnh_zrlock)
+#define	DB_DNODE_ENTER(_db)	(zrl_add(&DB_DNODE_LOCK(_db)))
+#define	DB_DNODE_EXIT(_db)	(zrl_remove(&DB_DNODE_LOCK(_db)))
+#define	DB_DNODE_HELD(_db)	(!zrl_is_zero(&DB_DNODE_LOCK(_db)))
+#define	DB_GET_SPA(_spa_p, _db) {		\
+	dnode_t *__dn;				\
+	DB_DNODE_ENTER(_db);			\
+	__dn = DB_DNODE(_db);			\
+	*(_spa_p) = __dn->dn_objset->os_spa;	\
+	DB_DNODE_EXIT(_db);			\
+}
+#define	DB_GET_OBJSET(_os_p, _db) {		\
+	dnode_t *__dn;				\
+	DB_DNODE_ENTER(_db);			\
+	__dn = DB_DNODE(_db);			\
+	*(_os_p) = __dn->dn_objset;		\
+	DB_DNODE_EXIT(_db);			\
+}
+
+void dbuf_init(void);
+void dbuf_fini(void);
+
+boolean_t dbuf_is_metadata(dmu_buf_impl_t *db);
+
+#define	DBUF_IS_METADATA(_db)	\
+	(dbuf_is_metadata(_db))
+
+#define	DBUF_GET_BUFC_TYPE(_db)	\
+	(DBUF_IS_METADATA(_db) ? ARC_BUFC_METADATA : ARC_BUFC_DATA)
+
+#define	DBUF_IS_CACHEABLE(_db)						\
+	((_db)->db_objset->os_primary_cache == ZFS_CACHE_ALL ||		\
+	(DBUF_IS_METADATA(_db) &&					\
+	((_db)->db_objset->os_primary_cache == ZFS_CACHE_METADATA)))
+
+#define	DBUF_IS_L2CACHEABLE(_db)					\
+	((_db)->db_objset->os_secondary_cache == ZFS_CACHE_ALL ||	\
+	(DBUF_IS_METADATA(_db) &&					\
+	((_db)->db_objset->os_secondary_cache == ZFS_CACHE_METADATA)))
+
+#ifdef ZFS_DEBUG
+
+/*
+ * There should be a ## between the string literal and fmt, to make it
+ * clear that we're joining two strings together, but gcc does not
+ * support that preprocessor token.
+ */
+#define	dprintf_dbuf(dbuf, fmt, ...) do { \
+	if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
+	char __db_buf[32]; \
+	uint64_t __db_obj = (dbuf)->db.db_object; \
+	if (__db_obj == DMU_META_DNODE_OBJECT) \
+		(void) strcpy(__db_buf, "mdn"); \
+	else \
+		(void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
+		    (u_longlong_t)__db_obj); \
+	dprintf_ds((dbuf)->db_objset->os_dsl_dataset, \
+	    "obj=%s lvl=%u blkid=%lld " fmt, \
+	    __db_buf, (dbuf)->db_level, \
+	    (u_longlong_t)(dbuf)->db_blkid, __VA_ARGS__); \
+	} \
+_NOTE(CONSTCOND) } while (0)
+
+#define	dprintf_dbuf_bp(db, bp, fmt, ...) do {			\
+	if (zfs_flags & ZFS_DEBUG_DPRINTF) {			\
+	char *__blkbuf = kmem_alloc(BP_SPRINTF_LEN, KM_SLEEP);	\
+	sprintf_blkptr(__blkbuf, bp);				\
+	dprintf_dbuf(db, fmt " %s\n", __VA_ARGS__, __blkbuf);	\
+	kmem_free(__blkbuf, BP_SPRINTF_LEN);			\
+	}							\
+_NOTE(CONSTCOND) } while (0)
+
+#define	DBUF_VERIFY(db)	dbuf_verify(db)
+
+#else
+
+#define	dprintf_dbuf(db, fmt, ...)
+#define	dprintf_dbuf_bp(db, bp, fmt, ...)
+#define	DBUF_VERIFY(db)
+
+#endif
+
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif /* _SYS_DBUF_H */