Add libgeom to the system.

Initially this only contains the functions for accessing the I/O
statistics data.

4 files changed, 362 insertions, 0 deletions

diff --git a/lib/libgeom/Makefile b/lib/libgeom/Makefile
new file mode 100644
index 0000000..041976c
--- /dev/null
+++ b/lib/libgeom/Makefile
@@ -0,0 +1,11 @@
+# $FreeBSD$
+
+LIB=	geom
+SRCS=	geom_stats.c
+INCS=	libgeom.h
+
+WARNS?=	4
+
+MAN=	libgeom.3
+
+.include <bsd.lib.mk>
diff --git a/lib/libgeom/geom_stats.c b/lib/libgeom/geom_stats.c
new file mode 100644
index 0000000..f4ada93
--- /dev/null
+++ b/lib/libgeom/geom_stats.c
@@ -0,0 +1,190 @@
+/*-
+ * Copyright (c) 2003 Poul-Henning Kamp
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The names of the authors may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <paths.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <libgeom.h>
+
+#include <sys/mman.h>
+#include <sys/time.h>
+#include <sys/types.h>
+
+#include <geom/geom_stats.h>
+#if 0
+#include <stdio.h>
+#include <stdint.h>
+#include <err.h>
+#endif
+
+/************************************************************/
+static uint npages, pagesize, spp;
+static int statsfd = -1;
+static u_char *statp;
+
+void
+geom_stats_close(void)
+{
+	if (statsfd == -1)
+		return;
+	munmap(statp, npages *pagesize);
+	statp = NULL;
+	close (statsfd);
+	statsfd = -1;
+}
+
+void
+geom_stats_resync(void)
+{
+	void *p;
+
+	if (statsfd == -1)
+		return;
+	for (;;) {
+		p = mmap(statp, (npages + 1) * pagesize, 
+		    PROT_READ, 0, statsfd, 0);
+		if (p == MAP_FAILED)
+			break;
+		else
+			statp = p;
+		npages++;
+	}
+}
+
+int
+geom_stats_open(void)
+{
+	int error;
+	void *p;
+
+	if (statsfd != -1)
+		return (EBUSY);
+	statsfd = open(_PATH_DEV GEOM_STATS_DEVICE, O_RDONLY);
+	if (statsfd < 0)
+		return (errno);
+	pagesize = getpagesize();
+	spp = pagesize / sizeof(struct g_stat);
+	p = mmap(NULL, pagesize, PROT_READ, 0, statsfd, 0);
+	if (p == MAP_FAILED) {
+		error = errno;
+		close(statsfd);
+		statsfd = -1;
+		errno = error;
+		return (error);
+	}
+	statp = p;
+	npages = 1;
+	geom_stats_resync();
+	return (0);
+}
+
+struct snapshot {
+	u_char		*ptr;
+	uint		pages;
+	uint		pagesize;
+	uint		perpage;
+	struct timespec	time;
+	/* used by getnext: */
+	uint		u, v;
+};
+
+void *
+geom_stats_snapshot_get(void)
+{
+	struct snapshot *sp;
+
+	sp = malloc(sizeof *sp);
+	if (sp == NULL)
+		return (NULL);
+	memset(sp, 0, sizeof *sp);
+	sp->ptr = malloc(pagesize * npages);
+	if (sp->ptr == NULL) {
+		free(sp);
+		return (NULL);
+	}
+	memset(sp->ptr, 0, pagesize * npages); 	/* page in, cache */
+	clock_gettime(CLOCK_REALTIME, &sp->time);
+	memset(sp->ptr, 0, pagesize * npages); 	/* page in, cache */
+	memcpy(sp->ptr, statp, pagesize * npages);
+	sp->pages = npages;
+	sp->perpage = spp;
+	sp->pagesize = pagesize;
+	return (sp);
+}
+
+void
+geom_stats_snapshot_free(void *arg)
+{
+	struct snapshot *sp;
+
+	sp = arg;
+	free(sp->ptr);
+	free(sp);
+}
+
+void
+geom_stats_snapshot_timestamp(void *arg, struct timespec *tp)
+{
+	struct snapshot *sp;
+
+	sp = arg;
+	*tp = sp->time;
+}
+
+void
+geom_stats_snapshot_reset(void *arg)
+{
+	struct snapshot *sp;
+
+	sp = arg;
+	sp->u = sp->v = 0;
+}
+
+struct g_stat *
+geom_stats_snapshot_next(void *arg)
+{
+	struct g_stat *gsp;
+	struct snapshot *sp;
+
+	sp = arg;
+	gsp = (struct g_stat *)
+	    (sp->ptr + sp->u * pagesize + sp->v * sizeof *gsp);
+	if (++sp->v >= sp->perpage) {
+		if (++sp->u >= sp->pages)
+			return (NULL);
+		else
+			sp->v = 0;
+	}
+	return (gsp);
+}
diff --git a/lib/libgeom/libgeom.3 b/lib/libgeom/libgeom.3
new file mode 100644
index 0000000..f22a9636
--- /dev/null
+++ b/lib/libgeom/libgeom.3
@@ -0,0 +1,116 @@
+.\" Copyright (c) 2003 Poul-Henning Kamp
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. The names of the authors may not be used to endorse or promote
+.\"    products derived from this software without specific prior written
+.\"    permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd February 8, 2003
+.Dt LIBGEOM 3
+.Os
+.Sh NAME
+.Nm geom_stats_open ,
+.Nm geom_stats_close ,
+.Nm geom_stats_resync ,
+.Nm geom_stats_snapshot_get ,
+.Nm geom_stats_snapshot_free ,
+.Nm geom_stats_snapshot_timestamp ,
+.Nm geom_stats_snapshot_reset ,
+.Nm geom_stats_snapshot_next
+.Sh LIBRARY
+.Lb geom
+.Sh SYNOPSIS
+.In libgeom.h
+.Ss "Statistics functions"
+.Ft void
+.Fn geom_stats_close void
+.Ft int
+.Fn geom_stats_open void
+.Ft void
+.Fn geom_stats_resync void
+.Ft void *
+.Fn geom_stats_snapshot_get void
+.Ft void
+.Fn geom_stats_snapshot_free "void *arg"
+.Ft void
+.Fn geom_stats_snapshot_timestamp "void *arg" "struct timespec *tp"
+.Ft void
+.Fn geom_stats_snapshot_reset "void *arg"
+.Ft struct g_stat *
+.Fn geom_stats_snapshot_next "void *arg"
+.Sh DESCRIPTION
+.Nm Libgeom
+is the library which contains the official and publicized API for
+interacting with the GEOM subsystem in the kernel.
+.Ss "Statistics functions"
+GEOM collects statistics data for all consumers and providers, but does
+not perform any normalization or presentation on the raw data, this is
+left as an excercize for user-land presentation utilities.
+.Pp
+The
+.Nm geom_stats_open
+and 
+.Nm geom_stats_close
+functions opens and closes the necessary pathways to access the raw 
+statistics information in the kernel.  These functions are likely to
+open one or more files and cache the filedescriptors locally.
+.Nm geom_stats_open
+returns zero on success, and sets errno if not.
+.Pp
+The
+.Nm geom_stats_resync
+function will check if more statistics collection points have been
+added in the kernel since
+.Nm geom_stats_open
+or the previous call to
+.Nm geom_stats_resync .
+.Pp
+.Nm geom_stats_snapshot_get
+will aquire a snapshot of the raw data from the kernel and while a
+reasonable effort is made to make this snapshot as atomic and consistent
+as possible, no guarantee is given that it will actually be so.
+The snapshot must be freed again using the
+.Nm geom_stats_snapshot_free
+function.
+.Nm geom_stats_snapshot_get
+returns NULL on failure.
+.Pp
+.Nm geom_stats_snapshot_timestamp
+provides access to the timestamp aquired in the snapshot.
+.Pp
+.Nm geom_stats_snapshot_reset
+and
+.Nm geom_stats_snapshot_next
+provides an iterator over the statistics slots in the snapshot.
+.Nm geom_stats_snapshot_reset
+forces the internal pointer in the snapshot back to before the first item.
+.Nm geom_stats_snapshot_next
+returns the next item and NULL if there are no more items in the snapshot.
+.Sh AUTHORS
+.An Poul-Henning Kamp Aq phk@FreeBSD.org
+.Sh HISTORY
+.Nm geom
+library appeard in
+.Fx 5.1 .
diff --git a/lib/libgeom/libgeom.h b/lib/libgeom/libgeom.h
new file mode 100644
index 0000000..e9a9f28
--- /dev/null
+++ b/lib/libgeom/libgeom.h
@@ -0,0 +1,45 @@
+/*-
+ * Copyright (c) 2003 Poul-Henning Kamp
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The names of the authors may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+#ifndef _LIBGEOM_H_
+#define _LIBGEOM_H_
+
+#include <geom/geom_stats.h>
+
+void geom_stats_close(void);
+void geom_stats_resync(void);
+int geom_stats_open(void);
+void *geom_stats_snapshot_get(void);
+void geom_stats_snapshot_free(void *arg);
+void geom_stats_snapshot_timestamp(void *arg, struct timespec *tp);
+void geom_stats_snapshot_reset(void *arg);
+struct g_stat *geom_stats_snapshot_next(void *arg);
+
+#endif /* _LIBGEOM_H_ */