On Fri, Nov 06, 2020 at 02:07:30PM -0600, Eric Sandeen wrote:
> The dynamic engine loading for libaio (and some others) currently
> fails because the dlopen routine is looking for ("lib%s", enginename)
> which translates into "liblibiscsi.so":
>
> openat(AT_FDCWD, "/usr/lib64/fio/liblibiscsi.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
> Engine libiscsi not found; Either name is invalid, was not built, or fio-engine-libiscsi package is missing.
> fio: engine libiscsi not loadable
> IO engine libiscsi not found
>
> The Makefile decide to name this engine "iscsi" instead of "libiscsi",
> which leads to "libiscsi.so" not "liblibiscsi.so" hence the mismatch.
>
> OTOH, "liblibiscsi.so" seems a bit bonkers.
>
> Try to resolve all this by:
>
> 1) make all of the engine names match the documented engine names
> in the Makefile, i.e. "iscsi" -> "libiscsi"
> 2) change the created library filenames to "fio-$(ENGINENAME)"
> from "lib$(ENGINENAME)" to avoid the "liblib" prefix.
>
> So now we consistently have the libraries named "fio-$(ENGINENAME).so"
>
> fio-http.so
> fio-libaio.so
>
> etc.
>
> Fixes: 5a8a6a03 ("configure: new --dynamic-libengines build option")
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> ---
>
> This depends on the previous patch to fix the dynamic
> engine library build process.
>
> I could split this into 2 patches if desired, but it's really just
> the last 2 hunks that implement 2) above
>
> diff --git a/Makefile b/Makefile
> index b0b9f864..ac3a590c 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -66,10 +66,10 @@ ifdef CONFIG_LIBHDFS
> endif
>
> ifdef CONFIG_LIBISCSI
> - iscsi_SRCS = engines/libiscsi.c
> - iscsi_LIBS = $(LIBISCSI_LIBS)
> - iscsi_CFLAGS = $(LIBISCSI_CFLAGS)
> - ENGINES += iscsi
> + libiscsi_SRCS = engines/libiscsi.c
> + libiscsi_LIBS = $(LIBISCSI_LIBS)
> + libiscsi_CFLAGS = $(LIBISCSI_CFLAGS)
> + ENGINES += libiscsi
> endif
>
> ifdef CONFIG_LIBNBD
> @@ -85,14 +85,14 @@ else ifdef CONFIG_32BIT
> CPPFLAGS += -DBITS_PER_LONG=32
> endif
> ifdef CONFIG_LIBAIO
> - aio_SRCS = engines/libaio.c
> - aio_LIBS = -laio
> + libaio_SRCS = engines/libaio.c
> + libaio_LIBS = -laio
> ifdef CONFIG_LIBAIO_URING
> - aio_LIBS = -luring
> + libaio_LIBS = -luring
> else
> - aio_LIBS = -laio
> + libaio_LIBS = -laio
> endif
> - ENGINES += aio
> + ENGINES += libaio
> endif
> ifdef CONFIG_RDMA
> rdma_SRCS = engines/rdma.c
> @@ -179,17 +179,17 @@ ifdef CONFIG_LINUX_DEVDAX
> ENGINES += dev-dax
> endif
> ifdef CONFIG_LIBPMEM
> - pmem_SRCS = engines/libpmem.c
> - pmem_LIBS = -lpmem
> - ENGINES += pmem
> + libpmem_SRCS = engines/libpmem.c
> + libpmem_LIBS = -lpmem
> + ENGINES += libpmem
> endif
> ifdef CONFIG_IME
> SOURCE += engines/ime.c
> endif
> ifdef CONFIG_LIBZBC
> - zbc_SRCS = engines/libzbc.c
> - zbc_LIBS = -lzbc
> - ENGINES += zbc
> + libzbc_SRCS = engines/libzbc.c
> + libzbc_LIBS = -lzbc
> + ENGINES += libzbc
> endif
>
> ifeq ($(CONFIG_TARGET_OS), Linux)
> @@ -256,9 +256,9 @@ ifdef CONFIG_DYNAMIC_ENGINES
> define engine_template =
> $(1)_OBJS := $$($(1)_SRCS:.c=.o)
> $$($(1)_OBJS): CFLAGS := -fPIC $$($(1)_CFLAGS) $(CFLAGS)
> -engines/lib$(1).so: $$($(1)_OBJS)
> +engines/fio-$(1).so: $$($(1)_OBJS)
> $$(QUIET_LINK)$(CC) -shared -rdynamic -fPIC -Wl,-soname,fio-$(1).so.1 $$($(1)_LIBS) -o $$@ $$<
> -ENGS_OBJS += engines/lib$(1).so
> +ENGS_OBJS += engines/fio-$(1).so
> endef
> else # !CONFIG_DYNAMIC_ENGINES
> define engine_template =
> diff --git a/ioengines.c b/ioengines.c
> index 3e43ef2f..fb59349a 100644
> --- a/ioengines.c
> +++ b/ioengines.c
> @@ -91,7 +91,7 @@ static void *dlopen_external(struct thread_data *td, const char *engine)
> char engine_path[PATH_MAX];
> void *dlhandle;
>
> - sprintf(engine_path, "%s/lib%s.so", FIO_EXT_ENG_DIR, engine);
> + sprintf(engine_path, "%s/fio-%s.so", FIO_EXT_ENG_DIR, engine);
>
> dlhandle = dlopen(engine_path, RTLD_LAZY);
> if (!dlhandle)
This seems a better way of doing it. dlopen'd plug-ins don't need to
be called "lib*.so".
If fio was using libtool (which it isn't) then I'd suggest doing
something like this instead:
https://github.com/libguestfs/nbdkit/blob/194958d153f568389db0a128d19507e488ed9bf9/plugins/curl/Makefile.am#L64
https://www.gnu.org/software/automake/manual/html_node/Libtool-Modules.html
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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