Re: [PATCH] vhost-scsi: Depend on NET for memcpy_fromiovec

From: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>,
	kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>,
	netdev@vger.kernel.org, Randy Dunlap <rdunlap@infradead.org>,
	linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	target-devel@vger.kernel.org, linux-next@vger.kernel.org
Subject: Re: [PATCH] vhost-scsi: Depend on NET for memcpy_fromiovec
Date: Wed, 15 May 2013 15:37:30 -0700	[thread overview]
Message-ID: <1368657450.6899.29.camel@haakon3.risingtidesystems.com> (raw)
In-Reply-To: <8761yk254u.fsf@rustcorp.com.au>

On Wed, 2013-05-15 at 14:47 +0930, Rusty Russell wrote:
> Asias He <asias@redhat.com> writes:
> > scsi.c includes vhost.c which uses memcpy_fromiovec.
> >
> > This patch fixes this build failure.
> >
> >    From Randy Dunlap:
> >    '''
> >    on x86_64:
> >
> >    ERROR: "memcpy_fromiovec" [drivers/vhost/vhost_scsi.ko] undefined!
> >
> >    It needs to depend on NET since net/core/ provides that function.
> >    '''
> 
> Proper fix please.
> 
> Though I can't see why you thought this was a good idea.  Nonetheless, I
> shan't highlight why: I have far too much respect for your intellects
> and abilities.
> 
> No, don't thank me!

Hi Rusty & Asias,

I assume you mean something like the following patch to allow kbuild to
work when VHOST_NET + VHOST_SCSI are both enabled and sharing vhost.o,
yes..?

Also included is dropping the now unnecessary vhost.c include, and
allowing vhost_work_flush() to be accessed externally as scsi.c
currently requires.

MST, care to pick this up..?

--nab

diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
index 8b9226d..016387f 100644
--- a/drivers/vhost/Kconfig
+++ b/drivers/vhost/Kconfig
@@ -1,3 +1,6 @@
+config VHOST
+       tristate
+
 config VHOST_NET
        tristate "Host kernel accelerator for virtio net"
        depends on NET && EVENTFD && (TUN || !TUN) && (MACVTAP || !MACVTAP)
@@ -12,7 +15,7 @@ config VHOST_NET
 
 config VHOST_SCSI
        tristate "VHOST_SCSI TCM fabric driver"
-       depends on TARGET_CORE && EVENTFD && m
+       depends on NET && EVENTFD && TARGET_CORE
        select VHOST_RING
        default n
        ---help---
diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile
index 654e9afb..e5b5f0b 100644
--- a/drivers/vhost/Makefile
+++ b/drivers/vhost/Makefile
@@ -1,7 +1,9 @@
+obj-$(CONFIG_VHOST) += vhost.o
+
 obj-$(CONFIG_VHOST_NET) += vhost_net.o
-vhost_net-y := vhost.o net.o
+vhost_net-objs := net.o
 
 obj-$(CONFIG_VHOST_SCSI) += vhost_scsi.o
-vhost_scsi-y := scsi.o
+vhost_scsi-objs := scsi.o
 
 obj-$(CONFIG_VHOST_RING) += vringh.o
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 7014202..b5836a2 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -49,7 +49,6 @@
 #include <linux/llist.h>
 #include <linux/bitmap.h>
 
-#include "vhost.c"
 #include "vhost.h"
 
 #define TCM_VHOST_VERSION  "v0.1"
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index beee7f5..8cd1562 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -123,7 +123,7 @@ static bool vhost_work_seq_done(struct vhost_dev *dev, struct vhost_work *work,
        return left <= 0;
 }
 
-static void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
+void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
 {
        unsigned seq;
        int flushing;
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index a7ad635..50ee396 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -44,6 +44,7 @@ void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
                     unsigned long mask, struct vhost_dev *dev);
 int vhost_poll_start(struct vhost_poll *poll, struct file *file);
 void vhost_poll_stop(struct vhost_poll *poll);
+void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
 void vhost_poll_flush(struct vhost_poll *poll);
 void vhost_poll_queue(struct vhost_poll *poll);
