[SCSI] scsi_dh: fix kconfig related build errors
Do not automatically "select" SCSI_DH for dm-multipath. If SCSI_DH
doesn't exist,just do not allow hardware handlers to be used.
Handle SCSI_DH being a module also. Make sure it doesn't allow DM_MULTIPATH
to be compiled in when SCSI_DH is a module.
[jejb: added comment for Kconfig syntax]
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index b4a3c7d..07d92c1 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -252,7 +252,11 @@
config DM_MULTIPATH
tristate "Multipath target"
depends on BLK_DEV_DM
- select SCSI_DH
+ # nasty syntax but means make DM_MULTIPATH independent
+ # of SCSI_DH if the latter isn't defined but if
+ # it is, DM_MULTIPATH must depend on it. We get a build
+ # error if SCSI_DH=m and DM_MULTIPATH=y
+ depends on SCSI_DH || !SCSI_DH
---help---
Allow volume managers to support multipath hardware.
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index e8f704a..9f7302d 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -664,6 +664,8 @@
request_module("scsi_dh_%s", m->hw_handler_name);
if (scsi_dh_handler_exist(m->hw_handler_name) == 0) {
ti->error = "unknown hardware handler type";
+ kfree(m->hw_handler_name);
+ m->hw_handler_name = NULL;
return -EINVAL;
}
consume(as, hw_argc - 1);
diff --git a/include/scsi/scsi_dh.h b/include/scsi/scsi_dh.h
index 04d0d84..3ad2303 100644
--- a/include/scsi/scsi_dh.h
+++ b/include/scsi/scsi_dh.h
@@ -54,6 +54,16 @@
SCSI_DH_NOSYS,
SCSI_DH_DRIVER_MAX,
};
-
+#if defined(CONFIG_SCSI_DH) || defined(CONFIG_SCSI_DH_MODULE)
extern int scsi_dh_activate(struct request_queue *);
extern int scsi_dh_handler_exist(const char *);
+#else
+static inline int scsi_dh_activate(struct request_queue *req)
+{
+ return 0;
+}
+static inline int scsi_dh_handler_exist(const char *name)
+{
+ return 0;
+}
+#endif
