Added support for zfs in ldms

The following plugins were added

1) zfs_zpool
   Stastistics on zfs pools.

2) zfs_leafvdevs
   Statistic on virtual devices leaves only.

3) zfs_topvdevs
   Statidstics on top virtual devices in the device tree (parent only).

configure.ac

@@ -894,6 +894,17 @@ AS_IF([test "x$enable_slingshot" = xyes],[
         [AC_MSG_ERROR([libcxi or its headers not found])])
 ])
 
+AC_ARG_ENABLE([zfs],
+    [AS_HELP_STRING([--enable-zfs], [require the zfs related plugins @<:@default=check@:>@])],
+    [],
+    [enable_zfs="check"])
+AC_SEARCH_LIBS([zpool_vdev_name], [zfs],[HAVE_ZFS=yes])
+AM_CONDITIONAL([ENABLE_ZFS], [test "x$enable_zfs" != xno -a "x$HAVE_ZFS" = xyes])
+AS_IF([test "x$enable_zfs" = xyes],[
+    AS_IF([test "x$HAVE_ZFS" = xno],
+        [AC_MSG_ERROR([libzfs or its headers not found])])
+])
+
 # define substitutions for configvars and other sed-generated files.
 # note carefully the escapes.
 OVIS_DO_SUBST([LDMS_SUBST_RULE], ["sed \
@@ -1054,6 +1065,9 @@ ldms/src/sampler/json/Makefile
 ldms/src/sampler/hweventpapi/Makefile \
 ldms/src/sampler/rapl/Makefile \
 ldms/src/sampler/tsampler/Makefile \
+ldms/src/sampler/zfs_topvdevs/Makefile
+ldms/src/sampler/zfs_leafvdevs/Makefile
+ldms/src/sampler/zfs_zpool/Makefile
 ldms/src/contrib/sampler/Makefile
 ldms/src/contrib/sampler/daos/Makefile
 ldms/src/contrib/sampler/daos/test/Makefile

ldms/src/sampler/Makefile.am

@@ -275,6 +275,12 @@ if ENABLE_BLOB_STREAM
 SUBDIRS += blob_stream
 endif
 
+if ENABLE_ZFS
+SUBDIRS += zfs_topvdevs
+SUBDIRS += zfs_leafvdevs
+SUBDIRS += zfs_zpool
+endif
+
 if ENABLE_SLINGSHOT
 if HAVE_LIBCXI
 SUBDIRS += slingshot_metrics

ldms/src/sampler/zfs_leafvdevs/Makefile.am

@@ -0,0 +1,18 @@
+pkglib_LTLIBRARIES =
+dist_man1_MANS =
+
+AUTOMAKE_OPTIONS = subdir-objects
+
+AM_CPPFLAGS = @OVIS_INCLUDE_ABS@ \
+	      -I/usr/include/libspl \
+	      -I/usr/include/libzfs \
+	      -Wall
+
+AM_LDFLAGS = @OVIS_LIB_ABS@
+COMMON_LIBADD = -lsampler_base -lldms -lovis_util -lcoll \
+		@LDFLAGS_GETTIME@
+
+libzfs_leafvdevs_la_SOURCES = zfs_leafvdevs.c
+libzfs_leafvdevs_la_LIBADD = $(COMMON_LIBADD)
+pkglib_LTLIBRARIES += libzfs_leafvdevs.la
+dist_man7_MANS = Plugin_zfs_leafvdevs.man

ldms/src/sampler/zfs_leafvdevs/Plugin_zfs_leafvdevs.man

@@ -0,0 +1,47 @@
+.\" Manpage for Plugin_zfs_leafvdevs
+.\" Contact [email protected] to correct errors or typos.
+.TH man 7 "19 Apr 2023" "v4" "LDMS Plugin zfs_leafvdevs man page"
+
+.SH NAME
+Plugin_zfs_leafvdevs - man page for the LDMS zfs_leafvdevs plugin
+
+.SH SYNOPSIS
+Within ldmsd_controller or a configuration file:
+.br
+config name=zfs_leafvdevs
+
+.SH DESCRIPTION
+With LDMS (Lightweight Distributed Metric Service), plugins for the ldmsd (ldms
+daemon) are configured via ldmsd_controller or a configuration file. The
+zfs_leafvdevs plugin uses LDMS_V_LIST and LDMS_V_RECORD to provide zfs leaf
+virtual devices using libzfs.
+
+.SH CONFIGURATION ATTRIBUTE SYNTAX
+The zfs_leafvdevs plugin uses the sampler_base base class. This man page covers
+only the configuration attributes, or those with default values, specific to the
+this plugin; see ldms_sampler_base.man for the attributes of the base class.
+
+.TP
+.BR config
+name=<plugin_name>
+.br
+configuration line
+.RS
+.TP
+name=<plugin_name>
+.br
+This MUST be zfs_leafvdevs.
+.RE
+
+.SH EXAMPLES
+.PP
+Within ldmsd_controller or a configuration file:
+.nf
+load name=zfs_leafvdevs
+config name=zfs_leafvdevs producer=${HOSTNAME} instance=${HOSTNAME}/zfs_leafvdevs
+start name=zfs_leafvdevs interval=1000000 offset=0
+.fi
+
+.SH SEE ALSO
+ldmsd(8), ldms_quickstart(7), ldmsd_controller(8), ldms_sampler_base(7),
+Plugin_leafvdevs(7)