[PATCH 2/8] dm-mpath, scsi_dh: request scsi_dh modules in scsi_dh, not dm-mpath

Christoph Hellwig
2015-05-10T18:42:20Z

This way we can reused the same code any attachment method, not just those
requested from dm-mpath.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm-mpath.c | 6 ------
drivers/scsi/device_handler/scsi_dh.c | 35 ++++++++++++++++++-----------------
include/scsi/scsi_dh.h | 5 -----
3 files changed, 18 insertions(+), 28 deletions(-)

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 0517b61..ccc5759 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -723,12 +723,6 @@ static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m)
return 0;

m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL);
- if (!try_then_request_module(scsi_dh_handler_exist(m->hw_handler_name),
- "scsi_dh_%s", m->hw_handler_name)) {
- ti->error = "unknown hardware handler type";
- ret = -EINVAL;
- goto fail;
- }

if (hw_argc > 1) {
char *p;
diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c
index 869b5bd..5bd0af6 100644
--- a/drivers/scsi/device_handler/scsi_dh.c
+++ b/drivers/scsi/device_handler/scsi_dh.c
@@ -29,7 +29,7 @@
static DEFINE_SPINLOCK(list_lock);
static LIST_HEAD(scsi_dh_list);

-static struct scsi_device_handler *get_device_handler(const char *name)
+static struct scsi_device_handler *__scsi_dh_lookup(const char *name)
{
struct scsi_device_handler *tmp, *found = NULL;

@@ -44,6 +44,19 @@ static struct scsi_device_handler *get_device_handler(const char *name)
return found;
}

+static struct scsi_device_handler *scsi_dh_lookup(const char *name)
+{
+ struct scsi_device_handler *dh;
+
+ dh = __scsi_dh_lookup(name);
+ if (!dh) {
+ request_module(name);
+ dh = __scsi_dh_lookup(name);
+ }
+
+ return dh;
+}
+
/*
* device_handler_match_function - Match a device handler to a device
* @sdev - SCSI device to be tested
@@ -158,7 +171,7 @@ store_dh_state(struct device *dev, struct device_attribute *attr,
/*
* Attach to a device handler
*/
- if (!(scsi_dh = get_device_handler(buf)))
+ if (!(scsi_dh = scsi_dh_lookup(buf)))
return err;
err = scsi_dh_handler_attach(sdev, scsi_dh);
} else {
@@ -322,8 +335,7 @@ static int scsi_dh_notifier_remove(struct device *dev, void *data)
*/
int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
{
-
- if (get_device_handler(scsi_dh->name))
+ if (__scsi_dh_lookup(scsi_dh->name))
return -EBUSY;

if (!scsi_dh->attach || !scsi_dh->detach)
@@ -350,7 +362,7 @@ EXPORT_SYMBOL_GPL(scsi_register_device_handler);
int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
{

- if (!get_device_handler(scsi_dh->name))
+ if (!__scsi_dh_lookup(scsi_dh->name))
return -ENODEV;

bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh,
@@ -455,17 +467,6 @@ int scsi_dh_set_params(struct request_queue *q, const char *params)
EXPORT_SYMBOL_GPL(scsi_dh_set_params);

/*
- * scsi_dh_handler_exist - Return TRUE(1) if a device handler exists for
- * the given name. FALSE(0) otherwise.
- * @name - name of the device handler.
- */
-int scsi_dh_handler_exist(const char *name)
-{
- return (get_device_handler(name) != NULL);
-}
-EXPORT_SYMBOL_GPL(scsi_dh_handler_exist);
-
-/*
* scsi_dh_attach - Attach device handler
* @q - Request queue that is associated with the scsi_device
* the handler should be attached to
@@ -478,7 +479,7 @@ int scsi_dh_attach(struct request_queue *q, const char *name)
struct scsi_device_handler *scsi_dh;
int err = 0;

- scsi_dh = get_device_handler(name);
+ scsi_dh = scsi_dh_lookup(name);
if (!scsi_dh)
return -EINVAL;

diff --git a/include/scsi/scsi_dh.h b/include/scsi/scsi_dh.h
index 99c9196..966b921 100644
--- a/include/scsi/scsi_dh.h
+++ b/include/scsi/scsi_dh.h
@@ -57,7 +57,6 @@ enum {
};
#if defined(CONFIG_SCSI_DH) || defined(CONFIG_SCSI_DH_MODULE)
extern int scsi_dh_activate(struct request_queue *, activate_complete, void *);
-extern int scsi_dh_handler_exist(const char *);
extern int scsi_dh_attach(struct request_queue *, const char *);
extern const char *scsi_dh_attached_handler_name(struct request_queue *, gfp_t);
extern int scsi_dh_set_params(struct request_queue *, const char *);
@@ -68,10 +67,6 @@ static inline int scsi_dh_activate(struct request_queue *req,
fn(data, 0);
return 0;
}
-static inline int scsi_dh_handler_exist(const char *name)
-{
- return 0;
-}
static inline int scsi_dh_attach(struct request_queue *req, const char *name)
{
return SCSI_DH_NOSYS;
--
1.9.1