NFS engine via libnfs

HOWTO

@@ -1168,7 +1168,7 @@ I/O type
 
 		**1**
 			Backward-compatible alias for **mixed**.
-		
+
 		**2**
 			Alias for **both**.
 
@@ -2091,6 +2091,12 @@ I/O engine
 			I/O engine supporting asynchronous read and write operations to the
 			DAOS File System (DFS) via libdfs.
 
+		**nfs**
+			I/O engine supporting asynchronous read and write operations to
+			NFS filesystems from userspace via libnfs. This is useful for
+			achieving higher concurrency and thus throughput than is possible
+			via kernel NFS.
+
 I/O engine specific parameters
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -2508,6 +2514,11 @@ with the caveat that when used on the command line, they must come after the
 	Specificy a different object class for the dfs file.
 	Use DAOS container's object class by default.
 
+.. option:: nfs_url=str : [nfs]
+
+	URL in libnfs format, eg nfs://<server|ipv4|ipv6>/path[?arg=val[&arg=val]*]
+	Refer to the libnfs README for more details.
+
 I/O depth
 ~~~~~~~~~
 

Makefile

@@ -79,6 +79,12 @@ ifdef CONFIG_LIBNBD
   ENGINES += nbd
 endif
 
+ifdef CONFIG_LIBNFS
+  CFLAGS += $(LIBNFS_CFLAGS)
+  LIBS += $(LIBNFS_LIBS)
+  SOURCE += engines/nfs.c
+endif
+
 ifdef CONFIG_64BIT
   CPPFLAGS += -DBITS_PER_LONG=64
 else ifdef CONFIG_32BIT

configure

@@ -170,6 +170,7 @@ disable_native="no"
 march_set="no"
 libiscsi="no"
 libnbd="no"
+libnfs="no"
 libzbc=""
 dfs=""
 dynamic_engines="no"
@@ -241,6 +242,8 @@ for opt do
   ;;
   --disable-tcmalloc) disable_tcmalloc="yes"
   ;;
+  --disable-nfs) disable_nfs="yes"
+  ;;
   --dynamic-libengines) dynamic_engines="yes"
   ;;
   --disable-dfs) dfs="no"
@@ -271,8 +274,10 @@ if test "$show_help" = "yes" ; then
   echo "--disable-rados         Disable Rados support even if found"
   echo "--disable-rbd           Disable Rados Block Device even if found"
   echo "--disable-http          Disable HTTP support even if found"
+  echo "--disable-nfs           Disable userspace NFS support even if found"
   echo "--disable-gfapi         Disable gfapi"
   echo "--enable-libhdfs        Enable hdfs support"
+  echo "--enable-libnfs         Enable nfs support"
   echo "--disable-lex           Disable use of lex/yacc for math"
   echo "--disable-pmem          Disable pmem based engines even if found"
   echo "--enable-lex            Enable use of lex/yacc for math"
@@ -2277,6 +2282,21 @@ EOF
 fi
 print_config "DAOS File System (dfs) Engine" "$dfs"
 
+##########################################
+# Check if we have libnfs (for userspace nfs support).
+if test "$disable_nfs" != "yes"; then
+  if $(pkg-config libnfs); then
+    libnfs="yes"
+    libnfs_cflags=$(pkg-config --cflags libnfs)
+    libnfs_libs=$(pkg-config --libs libnfs)
+  else
+    if test "$libnfs" = "yes" ; then
+      echo "libnfs" "Install libnfs"
+    fi
+  fi
+fi
+print_config "NFS engine" "$libnfs"
+
 ##########################################
 # Check if we have lex/yacc available
 yacc="no"
@@ -3101,6 +3121,9 @@ fi
 if test "$dfs" = "yes" ; then
   output_sym "CONFIG_DFS"
 fi
+if test "$libnfs" = "yes" ; then
+  output_sym "CONFIG_NFS"
+fi
 if test "$march_set" = "no" && test "$build_native" = "yes" ; then
   output_sym "CONFIG_BUILD_NATIVE"
 fi
@@ -3140,6 +3163,12 @@ if test "$libnbd" = "yes" ; then
   echo "LIBNBD_CFLAGS=$libnbd_cflags" >> $config_host_mak
   echo "LIBNBD_LIBS=$libnbd_libs" >> $config_host_mak
 fi
+if test "$libnfs" = "yes" ; then
+  output_sym "CONFIG_LIBNFS"
+  echo "CONFIG_LIBNFS=m" >> $config_host_mak
+  echo "LIBNFS_CFLAGS=$libnfs_cflags" >> $config_host_mak
+  echo "LIBNFS_LIBS=$libnfs_libs" >> $config_host_mak
+fi
 if test "$dynamic_engines" = "yes" ; then
   output_sym "CONFIG_DYNAMIC_ENGINES"
 fi