[PATCH v2 3/4] configure: new --dynamic-libengines build option

[Yigal Korman <ykorman@xxxxxxxxx>]

When enabled, some of the more dependency-heavy internal engines are
converted to "plugin" engines, i.e. they are built into separate object
files and are loaded by fio on demand.
This helps downstream distros package these engines separately and not
force a long list of package dependencies from the base fio package.

Signed-off-by: Yigal Korman <ykorman@xxxxxxxxx>
---
 .gitignore         |  1 +
 Makefile           | 92 ++++++++++++++++++++++++++++++++--------------
 configure          |  8 ++++
 engines/dev-dax.c  |  2 +-
 engines/guasi.c    |  2 +-
 engines/http.c     |  2 +-
 engines/libaio.c   |  2 +-
 engines/libhdfs.c  |  6 +--
 engines/libiscsi.c |  6 +--
 engines/libpmem.c  |  2 +-
 engines/libzbc.c   |  2 +-
 engines/nbd.c      |  2 +-
 engines/pmemblk.c  |  2 +-
 engines/rados.c    |  2 +-
 engines/rbd.c      |  2 +-
 engines/rdma.c     |  9 +++--
 ioengines.c        | 20 +++++++++-
 ioengines.h        |  6 +++
 os/os-linux.h      |  2 +
 19 files changed, 121 insertions(+), 49 deletions(-)

diff --git a/.gitignore b/.gitignore
index b84b0fda..0aa4a361 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 *.d
 *.o
+*.so
 *.exe
 /.depend
 /FIO-VERSION-FILE
diff --git a/Makefile b/Makefile
index 629d8993..8f8d9b9a 100644
--- a/Makefile
+++ b/Makefile
@@ -60,15 +60,17 @@ ifdef CONFIG_LIBHDFS
 endif
 
 ifdef CONFIG_LIBISCSI
-  CFLAGS := $(LIBISCSI_CFLAGS) $(CFLAGS)
-  LIBS += $(LIBISCSI_LIBS)
-  SOURCE += engines/libiscsi.c
+  iscsi_SRCS = engines/libiscsi.c
+  iscsi_LIBS = $(LIBISCSI_LIBS)
+  iscsi_CFLAGS = $(LIBISCSI_LIBS)
+  ENGINES += iscsi
 endif
 
 ifdef CONFIG_LIBNBD
-  CFLAGS := $(LIBNBD_CFLAGS) $(CFLAGS)
-  LIBS += $(LIBNBD_LIBS)
-  SOURCE += engines/nbd.c
+  nbd_SRCS = engines/nbd.c
+  nbd_LIBS = $(LIBNBD_LIBS)
+  nbd_CFLAGS = $(LIBNBD_CFLAGS)
+  ENGINES += nbd
 endif
 
 ifdef CONFIG_64BIT
@@ -78,16 +80,19 @@ ifdef CONFIG_32BIT
   CFLAGS := -DBITS_PER_LONG=32 $(CFLAGS)
 endif
 ifdef CONFIG_LIBAIO
-  SOURCE += engines/libaio.c
+  aio_SRCS = engines/libaio.c
+  aio_LIBS = -laio
   ifdef CONFIG_LIBAIO_URING
-    LIBS += -luring
+    aio_LIBS = -luring
   else
-    LIBS += -laio
+    aio_LIBS = -laio
   endif
+  ENGINES += aio
 endif
 ifdef CONFIG_RDMA
-  SOURCE += engines/rdma.c
-  LIBS += -libverbs -lrdmacm
+  rdma_SRCS = engines/rdma.c
+  rdma_LIBS = -libverbs -lrdmacm
+  ENGINES += rdma
 endif
 ifdef CONFIG_POSIXAIO
   SOURCE += engines/posixaio.c
@@ -102,7 +107,8 @@ ifdef CONFIG_LINUX_SPLICE
   SOURCE += engines/splice.c
 endif
 ifdef CONFIG_GUASI
-  SOURCE += engines/guasi.c
+  guasi_SRCS = engines/guasi.c
+  ENGINES += guasi
 endif
 ifdef CONFIG_SOLARISAIO
   SOURCE += engines/solarisaio.c
@@ -111,16 +117,19 @@ ifdef CONFIG_WINDOWSAIO
   SOURCE += engines/windowsaio.c
 endif
 ifdef CONFIG_RADOS
-  SOURCE += engines/rados.c
-  LIBS += -lrados
+  rados_SRCS = engines/rados.c
+  rados_LIBS = -lrados
+  ENGINES += rados
 endif
 ifdef CONFIG_RBD
-  SOURCE += engines/rbd.c
-  LIBS += -lrbd -lrados
+  rbd_SRCS = engines/rbd.c
+  rbd_LIBS = -lrbd -lrados
+  ENGINES += rbd
 endif
 ifdef CONFIG_HTTP
-  SOURCE += engines/http.c
-  LIBS += -lcurl -lssl -lcrypto
+  http_SRCS = engines/http.c
+  http_LIBS = -lcurl -lssl -lcrypto
+  ENGINES += http
 endif
 SOURCE += oslib/asprintf.c
 ifndef CONFIG_STRSEP
@@ -159,23 +168,27 @@ ifdef CONFIG_MTD
   SOURCE += oslib/libmtd_legacy.c
 endif
 ifdef CONFIG_PMEMBLK
-  SOURCE += engines/pmemblk.c
-  LIBS += -lpmemblk
+  pmemblk_SRCS = engines/pmemblk.c
+  pmemblk_LIBS = -lpmemblk
+  ENGINES += pmemblk
 endif
 ifdef CONFIG_LINUX_DEVDAX
-  SOURCE += engines/dev-dax.c
-  LIBS += -lpmem
+  devdax_SRCS = engines/dev-dax.c
+  devdax_LIBS = -lpmem
+  ENGINES += dev-dax
 endif
 ifdef CONFIG_LIBPMEM
-  SOURCE += engines/libpmem.c
-  LIBS += -lpmem
+  pmem_SRCS = engines/libpmem.c
+  pmem_LIBS = -lpmem
+  ENGINES += pmem
 endif
 ifdef CONFIG_IME
   SOURCE += engines/ime.c
 endif
 ifdef CONFIG_LIBZBC
-  SOURCE += engines/libzbc.c
-  LIBS += -lzbc
+  zbc_SRCS = engines/libzbc.c
+  zbc_LIBS = -lzbc
+  ENGINES += zbc
 endif
 
 ifeq ($(CONFIG_TARGET_OS), Linux)
@@ -237,6 +250,26 @@ ifneq (,$(findstring CYGWIN,$(CONFIG_TARGET_OS)))
   CFLAGS := -DPSAPI_VERSION=1 -Ios/windows/posix/include -Wno-format $(CFLAGS)
 endif
 
+ifdef CONFIG_DYNAMIC_ENGINES
+ DYNAMIC_ENGS := $(ENGINES)
+define engine_template =
+$(1)_OBJS := $$($(1)_SRCS:.c=.o)
+$$($(1)_OBJS): CFLAGS := -fPIC $$($(1)_CFLAGS) $(CFLAGS)
+engines/lib$(1).so: $$($(1)_OBJS)
+	$$(QUIET_LINK)$(CC) -shared -rdynamic -fPIC -Wl,-soname,lib$(1).so.1 $$($(1)_LIBS) -o $$@ $$<
+ENGS_OBJS += engines/lib$(1).so
+all install: $(ENGS_OBJS)
+endef
+else # !CONFIG_DYNAMIC_ENGINES
+define engine_template =
+SOURCE += $$($(1)_SRCS)
+LIBS += $$($(1)_LIBS)
+CFLAGS := $$($(1)_CFLAGS) $(CFLAGS)
+endef
+endif
+
+$(foreach eng,$(ENGINES),$(eval $(call engine_template,$(eng))))
+
 OBJS := $(SOURCE:.c=.o)
 
 FIO_OBJS = $(OBJS) fio.o
@@ -388,6 +421,7 @@ else
 endif
 prefix = $(INSTALL_PREFIX)
 bindir = $(prefix)/bin
+libdir = $(prefix)/lib/fio
 
 ifeq ($(CONFIG_TARGET_OS), Darwin)
 mandir = /usr/share/man
@@ -536,7 +570,7 @@ unittests/unittest: $(UT_OBJS) $(UT_TARGET_OBJS)
 endif
 
 clean: FORCE
-	@rm -f .depend $(FIO_OBJS) $(GFIO_OBJS) $(OBJS) $(T_OBJS) $(UT_OBJS) $(PROGS) $(T_PROGS) $(T_TEST_PROGS) core.* core gfio unittests/unittest FIO-VERSION-FILE *.[do] lib/*.d oslib/*.[do] crc/*.d engines/*.[do] profiles/*.[do] t/*.[do] unittests/*.[do] unittests/*/*.[do] config-host.mak config-host.h y.tab.[ch] lex.yy.c exp/*.[do] lexer.h
+	@rm -f .depend $(FIO_OBJS) $(GFIO_OBJS) $(OBJS) $(T_OBJS) $(UT_OBJS) $(PROGS) $(T_PROGS) $(T_TEST_PROGS) core.* core gfio unittests/unittest FIO-VERSION-FILE *.[do] lib/*.d oslib/*.[do] crc/*.d engines/*.[do] engines/*.so profiles/*.[do] t/*.[do] unittests/*.[do] unittests/*/*.[do] config-host.mak config-host.h y.tab.[ch] lex.yy.c exp/*.[do] lexer.h
 	@rm -f t/fio-btrace2fio t/io_uring t/read-to-pipe-async
 	@rm -rf  doc/output
 
@@ -576,6 +610,10 @@ fulltest:
 install: $(PROGS) $(SCRIPTS) tools/plot/fio2gnuplot.1 FORCE
 	$(INSTALL) -m 755 -d $(DESTDIR)$(bindir)
 	$(INSTALL) $(PROGS) $(SCRIPTS) $(DESTDIR)$(bindir)
+ifdef CONFIG_DYNAMIC_ENGINES
+	$(INSTALL) -m 755 -d $(DESTDIR)$(libdir)
+	$(INSTALL) -m 755 $(SRCDIR)/engines/*.so $(DESTDIR)$(libdir)
+endif
 	$(INSTALL) -m 755 -d $(DESTDIR)$(mandir)/man1
 	$(INSTALL) -m 644 $(SRCDIR)/fio.1 $(DESTDIR)$(mandir)/man1
 	$(INSTALL) -m 644 $(SRCDIR)/tools/fio_generate_plots.1 $(DESTDIR)$(mandir)/man1
diff --git a/configure b/configure
index 5d475bf3..0e8c27b1 100755
--- a/configure
+++ b/configure
@@ -151,6 +151,7 @@ march_set="no"
 libiscsi="no"
 libnbd="no"
 libaio_uring="no"
+dynamic_engines="no"
 prefix=/usr/local
 
 # parse options
@@ -215,6 +216,8 @@ for opt do
   ;;
   --enable-libaio-uring) libaio_uring="yes"
   ;;
+  --dynamic-libengines) dynamic_engines="yes"
+  ;;
   --help)
     show_help="yes"
     ;;
@@ -254,6 +257,7 @@ if test "$show_help" = "yes" ; then
   echo "--enable-libnbd         Enable libnbd (NBD engine) support"
   echo "--disable-tcmalloc	Disable tcmalloc support"
   echo "--enable-libaio-uring   Enable libaio emulated over io_uring"
+  echo "--dynamic-libengines	Lib-based ioengines as dynamic libraries"
   exit $exit_val
 fi
 
@@ -2954,6 +2958,10 @@ if test "$libnbd" = "yes" ; then
   echo "LIBNBD_CFLAGS=$libnbd_cflags" >> $config_host_mak
   echo "LIBNBD_LIBS=$libnbd_libs" >> $config_host_mak
 fi
+if test "$dynamic_engines" = "yes" ; then
+	output_sym "CONFIG_DYNAMIC_ENGINES"
+fi
+print_config "Lib-based ioengines dynamic" "$dynamic_engines"
 cat > $TMPC << EOF
 int main(int argc, char **argv)
 {
diff --git a/engines/dev-dax.c b/engines/dev-dax.c
index 422ea634..1d0f66cb 100644
--- a/engines/dev-dax.c
+++ b/engines/dev-dax.c
@@ -328,7 +328,7 @@ fio_devdax_get_file_size(struct thread_data *td, struct fio_file *f)
 	return 0;
 }
 
-static struct ioengine_ops ioengine = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name		= "dev-dax",
 	.version	= FIO_IOOPS_VERSION,
 	.init		= fio_devdax_init,
diff --git a/engines/guasi.c b/engines/guasi.c
index cb26802c..d4121757 100644
--- a/engines/guasi.c
+++ b/engines/guasi.c
@@ -242,7 +242,7 @@ static int fio_guasi_init(struct thread_data *td)
 	return 0;
 }
 
-static struct ioengine_ops ioengine = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name		= "guasi",
 	.version	= FIO_IOOPS_VERSION,
 	.init		= fio_guasi_init,
diff --git a/engines/http.c b/engines/http.c
index 275fcab5..7a61b132 100644
--- a/engines/http.c
+++ b/engines/http.c
@@ -639,7 +639,7 @@ static int fio_http_invalidate(struct thread_data *td, struct fio_file *f)
 	return 0;
 }
 
-static struct ioengine_ops ioengine = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name = "http",
 	.version		= FIO_IOOPS_VERSION,
 	.flags			= FIO_DISKLESSIO | FIO_SYNCIO,
diff --git a/engines/libaio.c b/engines/libaio.c
index 398fdf91..b909b79e 100644
--- a/engines/libaio.c
+++ b/engines/libaio.c
@@ -445,7 +445,7 @@ static int fio_libaio_init(struct thread_data *td)
 	return 0;
 }
 
-static struct ioengine_ops ioengine = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name			= "libaio",
 	.version		= FIO_IOOPS_VERSION,
 	.flags			= FIO_ASYNCIO_SYNC_TRIM,
diff --git a/engines/libhdfs.c b/engines/libhdfs.c
index c57fcea6..9ca82f78 100644
--- a/engines/libhdfs.c
+++ b/engines/libhdfs.c
@@ -393,7 +393,7 @@ static void fio_hdfsio_io_u_free(struct thread_data *td, struct io_u *io_u)
 	}
 }
 
-static struct ioengine_ops ioengine_hdfs = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name = "libhdfs",
 	.version = FIO_IOOPS_VERSION,
 	.flags = FIO_SYNCIO | FIO_DISKLESSIO | FIO_NODISKUTIL,
@@ -412,10 +412,10 @@ static struct ioengine_ops ioengine_hdfs = {
 
 static void fio_init fio_hdfsio_register(void)
 {
-	register_ioengine(&ioengine_hdfs);
+	register_ioengine(&ioengine);
 }
 
 static void fio_exit fio_hdfsio_unregister(void)
 {
-	unregister_ioengine(&ioengine_hdfs);
+	unregister_ioengine(&ioengine);
 }
diff --git a/engines/libiscsi.c b/engines/libiscsi.c
index 35761a61..c97b5709 100644
--- a/engines/libiscsi.c
+++ b/engines/libiscsi.c
@@ -383,7 +383,7 @@ static struct io_u *fio_iscsi_event(struct thread_data *td, int event)
 	return io_u;
 }
 
-static struct ioengine_ops ioengine_iscsi = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name               = "libiscsi",
 	.version            = FIO_IOOPS_VERSION,
 	.flags              = FIO_SYNCIO | FIO_DISKLESSIO | FIO_NODISKUTIL,
@@ -402,10 +402,10 @@ static struct ioengine_ops ioengine_iscsi = {
 
 static void fio_init fio_iscsi_register(void)
 {
-	register_ioengine(&ioengine_iscsi);
+	register_ioengine(&ioengine);
 }
 
 static void fio_exit fio_iscsi_unregister(void)
 {
-	unregister_ioengine(&ioengine_iscsi);
+	unregister_ioengine(&ioengine);
 }
diff --git a/engines/libpmem.c b/engines/libpmem.c
index 99c7b50d..3f63055c 100644
--- a/engines/libpmem.c
+++ b/engines/libpmem.c
@@ -558,7 +558,7 @@ static int fio_libpmem_close_file(struct thread_data *td, struct fio_file *f)
 	return generic_close_file(td, f);
 }
 
-static struct ioengine_ops ioengine = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name		= "libpmem",
 	.version	= FIO_IOOPS_VERSION,
 	.init		= fio_libpmem_init,
diff --git a/engines/libzbc.c b/engines/libzbc.c
index 9e568334..fdde8ca6 100644
--- a/engines/libzbc.c
+++ b/engines/libzbc.c
@@ -397,7 +397,7 @@ static enum fio_q_status libzbc_queue(struct thread_data *td, struct io_u *io_u)
 	return FIO_Q_COMPLETED;
 }
 
-static struct ioengine_ops ioengine = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name			= "libzbc",
 	.version		= FIO_IOOPS_VERSION,
 	.open_file		= libzbc_open_file,
diff --git a/engines/nbd.c b/engines/nbd.c
index 53237929..b0ba75e6 100644
--- a/engines/nbd.c
+++ b/engines/nbd.c
@@ -328,7 +328,7 @@ static int nbd_invalidate(struct thread_data *td, struct fio_file *f)
 	return 0;
 }
 
-static struct ioengine_ops ioengine = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name			= "nbd",
 	.version		= FIO_IOOPS_VERSION,
 	.options		= options,
diff --git a/engines/pmemblk.c b/engines/pmemblk.c
index e2eaa15e..fc6358e8 100644
--- a/engines/pmemblk.c
+++ b/engines/pmemblk.c
@@ -426,7 +426,7 @@ static int fio_pmemblk_unlink_file(struct thread_data *td, struct fio_file *f)
 	return 0;
 }
 
-static struct ioengine_ops ioengine = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name = "pmemblk",
 	.version = FIO_IOOPS_VERSION,
 	.queue = fio_pmemblk_queue,
diff --git a/engines/rados.c b/engines/rados.c
index d4413427..42ee48ff 100644
--- a/engines/rados.c
+++ b/engines/rados.c
@@ -444,7 +444,7 @@ static int fio_rados_io_u_init(struct thread_data *td, struct io_u *io_u)
 }
 
 /* ioengine_ops for get_ioengine() */
-static struct ioengine_ops ioengine = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name = "rados",
 	.version		= FIO_IOOPS_VERSION,
 	.flags			= FIO_DISKLESSIO,
diff --git a/engines/rbd.c b/engines/rbd.c
index a08f4775..268b6ebd 100644
--- a/engines/rbd.c
+++ b/engines/rbd.c
@@ -668,7 +668,7 @@ static int fio_rbd_io_u_init(struct thread_data *td, struct io_u *io_u)
 	return 0;
 }
 
-static struct ioengine_ops ioengine = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name			= "rbd",
 	.version		= FIO_IOOPS_VERSION,
 	.setup			= fio_rbd_setup,
diff --git a/engines/rdma.c b/engines/rdma.c
index f192f432..f4471869 100644
--- a/engines/rdma.c
+++ b/engines/rdma.c
@@ -226,7 +226,8 @@ static int client_recv(struct thread_data *td, struct ibv_wc *wc)
 		rd->rmt_nr = ntohl(rd->recv_buf.nr);
 
 		for (i = 0; i < rd->rmt_nr; i++) {
-			rd->rmt_us[i].buf = be64_to_cpu(rd->recv_buf.rmt_us[i].buf);
+			rd->rmt_us[i].buf = __be64_to_cpu(
+						rd->recv_buf.rmt_us[i].buf);
 			rd->rmt_us[i].rkey = ntohl(rd->recv_buf.rmt_us[i].rkey);
 			rd->rmt_us[i].size = ntohl(rd->recv_buf.rmt_us[i].size);
 
@@ -1389,7 +1390,7 @@ static int fio_rdmaio_setup(struct thread_data *td)
 	return 0;
 }
 
-static struct ioengine_ops ioengine_rw = {
+FIO_STATIC struct ioengine_ops ioengine = {
 	.name			= "rdma",
 	.version		= FIO_IOOPS_VERSION,
 	.setup			= fio_rdmaio_setup,
@@ -1410,10 +1411,10 @@ static struct ioengine_ops ioengine_rw = {
 
 static void fio_init fio_rdmaio_register(void)
 {
-	register_ioengine(&ioengine_rw);
+	register_ioengine(&ioengine);
 }
 
 static void fio_exit fio_rdmaio_unregister(void)
 {
-	unregister_ioengine(&ioengine_rw);
+	unregister_ioengine(&ioengine);
 }
diff --git a/ioengines.c b/ioengines.c
index 2c7a0df9..78262bc1 100644
--- a/ioengines.c
+++ b/ioengines.c
@@ -75,6 +75,19 @@ static struct ioengine_ops *find_ioengine(const char *name)
 	return NULL;
 }
 
+#ifdef CONFIG_DYNAMIC_ENGINES
+static void *dlopen_external(struct thread_data *td, const char *engine)
+{
+	char engine_path[PATH_MAX];
+
+	sprintf(engine_path, "%s/lib%s.so", FIO_EXT_ENG_DIR, engine);
+
+	return dlopen(engine_path, RTLD_LAZY);
+}
+#else
+#define dlopen_external(td, engine) (NULL)
+#endif
+
 static struct ioengine_ops *dlopen_ioengine(struct thread_data *td,
 					    const char *engine_lib)
 {
@@ -86,8 +99,11 @@ static struct ioengine_ops *dlopen_ioengine(struct thread_data *td,
 	dlerror();
 	dlhandle = dlopen(engine_lib, RTLD_LAZY);
 	if (!dlhandle) {
-		td_vmsg(td, -1, dlerror(), "dlopen");
-		return NULL;
+		dlhandle = dlopen_external(td, engine_lib);
+		if (!dlhandle) {
+			td_vmsg(td, -1, dlerror(), "dlopen");
+			return NULL;
+		}
 	}
 
 	/*
diff --git a/ioengines.h b/ioengines.h
index f48b4db9..54dadba2 100644
--- a/ioengines.h
+++ b/ioengines.h
@@ -10,6 +10,12 @@
 
 #define FIO_IOOPS_VERSION	26
 
+#ifndef CONFIG_DYNAMIC_ENGINES
+#define FIO_STATIC	static
+#else
+#define FIO_STATIC
+#endif
+
 /*
  * io_ops->queue() return values
  */
diff --git a/os/os-linux.h b/os/os-linux.h
index 6ec7243d..65d3b429 100644
--- a/os/os-linux.h
+++ b/os/os-linux.h
@@ -58,6 +58,8 @@
 
 #define OS_MAP_ANON		MAP_ANONYMOUS
 
+#define FIO_EXT_ENG_DIR	"/usr/lib/fio"
+
 typedef cpu_set_t os_cpu_mask_t;
 
 #ifdef CONFIG_3ARG_AFFINITY
-- 
2.17.1