On 08/20/2013 07:46 PM, Ronnie Sahlberg wrote:
Tomo,
Please find a second version of the patch to make the backing stores
into loadable modules so that distributors can ship core tgtd as one
package and individual backends as separate packages. This prevents
having just a single module for everyone which depends on and
requires a huge set of dependent packets.
This is version 2 This version only changes bs.c into a shared
library that the backend modules can link with at runtimie instead of
as in the first patch changing all of tgtd into a shared library.
regards ronnie sahlberg
Hi Ronnie,
I think you may be able to avoid making bs.c into a shared library if
you link tgtd with the -E linker option.
I've attached a patch that Fedora tgt carried for a little while that
modularized iser. I think my approach to iser modularization was bad and
it got dropped, but you could loot it for some Makefile magic :)
Regards -- Andy
commit 1aa20610d4a3afc22e9a0b24efa4bbb7b02dfab2
Author: Andy Grover <agrover@xxxxxxxxxx>
Date: Wed Sep 28 11:21:38 2011 -0700
Compile iser driver as a loadable module
Drivers are already modularized in the code, so it is straightforward to
change the build to target a separate loadable module. Also, modify
get_driver_index to try to load a module when lld is unknown.
This will allow packaging of base tgtd and iser module separately, so
the majority of users will not have to install dependencies they don't
need.
Signed-off-by: Andy Grover <agrover@xxxxxxxxxx>
diff --git a/usr/Makefile b/usr/Makefile
index e15ff6a..b8ab805 100644
--- a/usr/Makefile
+++ b/usr/Makefile
@@ -1,4 +1,5 @@
sbindir ?= $(PREFIX)/sbin
+libdir ?= $(PREFIX)/lib/tgt
ifneq ($(shell test -e /usr/include/linux/signalfd.h && echo 1),)
CFLAGS += -DUSE_SIGNALFD
@@ -13,11 +14,6 @@ TGTD_OBJS += $(addprefix iscsi/, conn.o param.o session.o \
isns.o)
TGTD_OBJS += bs_rdwr.o bs_aio.o
-ifneq ($(ISCSI_RDMA),)
-TGTD_OBJS += iscsi/iser.o iscsi/iser_text.o
-LIBS += -libverbs -lrdmacm
-endif
-
INCLUDES += -I.
CFLAGS += -D_GNU_SOURCE
@@ -30,9 +26,13 @@ endif
CFLAGS += -Wall -Wstrict-prototypes -fPIC
CFLAGS += -DTGT_VERSION=\"$(VERSION)$(EXTRAVERSION)\"
-LIBS += -lpthread
+LIBS += -lpthread -ldl
PROGRAMS += tgtd tgtadm tgtimg
+ifneq ($(ISCSI_RDMA),)
+DRIVERS += tgt-iser.so
+endif
+
TGTD_OBJS += tgtd.o mgmt.o target.o scsi.o log.o driver.o util.o work.o \
parser.o spc.o sbc.o mmc.o osd.o scc.o smc.o \
ssc.o bs_ssc.o libssc.o \
@@ -41,10 +41,12 @@ TGTD_OBJS += tgtd.o mgmt.o target.o scsi.o log.o driver.o util.o work.o \
TGTD_DEP = $(TGTD_OBJS:.o=.d)
.PHONY:all
-all: $(PROGRAMS)
+all: $(PROGRAMS) $(DRIVERS)
+
+LDFLAGS = -Wl,-E,-rpath=$(libdir)
tgtd: $(TGTD_OBJS)
- $(CC) $^ -o $@ $(LIBS)
+ $(CC) $^ -o $@ $(LDFLAGS) $(LIBS)
-include $(TGTD_DEP)
@@ -58,15 +60,23 @@ tgtimg: tgtimg.o libssc.o libcrc32c.o
-include tgtimg.d libssc.d
+tgt-iser.so: CFLAGS += -shared -libverbs -lrdmacm
+tgt-iser.so: iscsi/iser.o iscsi/iser_text.o
+ $(CC) $(CFLAGS) -o $@ $^
+
%.o: %.c
$(CC) -c $(CFLAGS) $*.c -o $*.o
@$(CC) -MM $(CFLAGS) -MF $*.d -MT $*.o $*.c
.PHONY: install
-install: $(PROGRAMS)
+install: $(PROGRAMS) $(DRIVERS)
install -d -m 755 $(DESTDIR)$(sbindir)
install -m 755 $(PROGRAMS) $(DESTDIR)$(sbindir)
+ifneq ($(DRIVERS),)
+ install -d -m 755 $(DESTDIR)$(libdir)
+ install -m 755 $(DRIVERS) $(DESTDIR)$(libdir)
+endif
.PHONY: clean
clean:
- rm -f *.[od] $(PROGRAMS) iscsi/*.[od] ibmvio/*.[od] fc/*.[od]
+ rm -f *.[od] $(PROGRAMS) *.so iscsi/*.[od] ibmvio/*.[od] fc/*.[od]
diff --git a/usr/tgtd.c b/usr/tgtd.c
index 30d5e9d..a9b2027 100644
--- a/usr/tgtd.c
+++ b/usr/tgtd.c
@@ -35,6 +35,7 @@
#include <sys/epoll.h>
#include <sys/types.h>
#include <sys/wait.h>
+#include <dlfcn.h>
#include "list.h"
#include "tgtd.h"
@@ -411,6 +412,9 @@ static int lld_init(char *args)
{
int i, err, nr;
+ /* iser is modular, try to load it */
+ dlopen("tgt-iser.so", RTLD_LAZY);
+
for (i = nr = 0; tgt_drivers[i]; i++) {
if (tgt_drivers[i]->init) {
err = tgt_drivers[i]->init(i, args);
