Add a new EX_FILLED flag to make extent_create() create an extent map that

has all space allocated such that we can make holes in it using extent_free().

ok miod@

3 files changed, 37 insertions, 13 deletions

diff --git a/share/man/man9/extent.9 b/share/man/man9/extent.9
index 275f208d7f3..ad3b8d8c28a 100644
--- a/share/man/man9/extent.9
+++ b/share/man/man9/extent.9
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: extent.9,v 1.13 2009/04/10 20:57:04 kettenis Exp $
+.\"	$OpenBSD: extent.9,v 1.14 2009/04/19 15:26:52 kettenis Exp $
 .\"	$NetBSD: extent.9,v 1.15 1999/03/16 00:40:47 garbled Exp $
 .\"
 .\" Copyright (c) 1996, 1998 The NetBSD Foundation, Inc.
@@ -28,7 +28,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: April 10 2009 $
+.Dd $Mdocdate: April 19 2009 $
 .Dt EXTENT 9
 .Os
 .Sh NAME
@@ -98,6 +98,12 @@ is set, internal coalescing of regions is disabled,
 and only entire regions may be freed within the extent map, so that
 .Fn extent_free
 will never have to allocate a region descriptor.
+If the flag
+.Dv EX_FILLED
+is set, the entire space managed by the extent map will be allocated
+upon creation of the extent map, such that selected regions may be
+made available through calls to
+.Fn extent_free .
 .Pp
 Some applications may want to use an extent map but
 can't use
@@ -125,6 +131,11 @@ flag
 may be passed to extent requests to indicate that a fixed extent
 map may be extended using a call to
 .Fn malloc .
+Note that passing the flag
+.Dv EX_FILLED
+to
+.Fn extent_create
+will consume a region descriptor upon creation of the extent map.
 .Pp
 The caller should pass the flag
 .Dv EX_WAITOK
diff --git a/sys/kern/subr_extent.c b/sys/kern/subr_extent.c
index 8053c1c9583..c309a1a123a 100644
--- a/sys/kern/subr_extent.c
+++ b/sys/kern/subr_extent.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: subr_extent.c,v 1.36 2009/04/10 20:57:04 kettenis Exp $	*/
+/*	$OpenBSD: subr_extent.c,v 1.37 2009/04/19 15:26:52 kettenis Exp $	*/
 /*	$NetBSD: subr_extent.c,v 1.7 1996/11/21 18:46:34 cgd Exp $	*/
 
 /*-
@@ -228,6 +228,18 @@ extent_create(char *name, u_long start, u_long end, int mtype, caddr_t storage,
 	if (flags & EX_NOCOALESCE)
 		ex->ex_flags |= EXF_NOCOALESCE;
 
+	if (flags & EX_FILLED) {
+		rp = extent_alloc_region_descriptor(ex, flags);
+		if (rp == NULL) {
+			if (!fixed_extent)
+				free(ex, mtype);
+			return (NULL);
+		}
+		rp->er_start = start;
+		rp->er_end = end;
+		LIST_INSERT_HEAD(&ex->ex_regions, rp, er_link);
+	}
+
 #if defined(DIAGNOSTIC) || defined(DDB)
 	extent_register(ex);
 #endif
diff --git a/sys/sys/extent.h b/sys/sys/extent.h
index 5bacde20e01..98e2f45c78e 100644
--- a/sys/sys/extent.h
+++ b/sys/sys/extent.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: extent.h,v 1.11 2009/04/19 11:04:11 kettenis Exp $	*/
+/*	$OpenBSD: extent.h,v 1.12 2009/04/19 15:26:52 kettenis Exp $	*/
 /*	$NetBSD: extent.h,v 1.6 1997/10/09 07:43:05 jtc Exp $	*/
 
 /*-
@@ -74,15 +74,16 @@ struct extent_fixed {
 #define EXF_BITS	"\20\4FLWANTED\3WANTED\2NOCOALESCE\1FIXED"
 
 /* misc. flags passed to extent functions */
-#define EX_NOWAIT	0x00		/* not safe to sleep */
-#define EX_WAITOK	0x01		/* safe to sleep */
-#define EX_FAST		0x02		/* take first fit in extent_alloc() */
-#define EX_CATCH	0x04		/* catch signals while sleeping */
-#define EX_NOCOALESCE	0x08		/* create a non-coalescing extent */
-#define EX_MALLOCOK	0x10		/* safe to call malloc() */
-#define EX_WAITSPACE	0x20		/* wait for space to become free */
-#define EX_BOUNDZERO	0x40		/* boundary lines start at 0 */
-#define EX_CONFLICTOK	0x80		/* allow conflicts */
+#define EX_NOWAIT	0x0000		/* not safe to sleep */
+#define EX_WAITOK	0x0001		/* safe to sleep */
+#define EX_FAST		0x0002		/* take first fit in extent_alloc() */
+#define EX_CATCH	0x0004		/* catch signals while sleeping */
+#define EX_NOCOALESCE	0x0008		/* create a non-coalescing extent */
+#define EX_MALLOCOK	0x0010		/* safe to call malloc() */
+#define EX_WAITSPACE	0x0020		/* wait for space to become free */
+#define EX_BOUNDZERO	0x0040		/* boundary lines start at 0 */
+#define EX_CONFLICTOK	0x0080		/* allow conflicts */
+#define EX_FILLED	0x0100		/* create a filled extent */
 
 /*
  * Special place holders for "alignment" and "boundary" arguments,