driver-core: constify data for class_find_device()

All in-kernel users of class_find_device() don't really need mutable
data for match callback.

In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c)
this patch changes match callbacks to use const search data.

The const is propagated to rtc_class_open() and power_supply_get_by_name()
parameters.

Note that there's a dev reference leak in suspend_test.c that's not
touched in this patch.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 13 insertions, 21 deletions

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 593085a..df0c3c7 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -468,10 +468,10 @@ void scsi_unregister(struct Scsi_Host *shost)
 }
 EXPORT_SYMBOL(scsi_unregister);
 
-static int __scsi_host_match(struct device *dev, void *data)
+static int __scsi_host_match(struct device *dev, const void *data)
 {
 	struct Scsi_Host *p;
-	unsigned short *hostnum = (unsigned short *)data;
+	const unsigned short *hostnum = data;
 
 	p = class_to_shost(dev);
 	return p->host_no == *hostnum;
diff --git a/drivers/scsi/osd/osd_uld.c b/drivers/scsi/osd/osd_uld.c
index 4375417..0fab6b5 100644
--- a/drivers/scsi/osd/osd_uld.c
+++ b/drivers/scsi/osd/osd_uld.c
@@ -268,18 +268,11 @@ static inline bool _the_same_or_null(const u8 *a1, unsigned a1_len,
 	return 0 == memcmp(a1, a2, a1_len);
 }
 
-struct find_oud_t {
-	const struct osd_dev_info *odi;
-	struct device *dev;
-	struct osd_uld_device *oud;
-} ;
-
-int _mach_odi(struct device *dev, void *find_data)
+static int _match_odi(struct device *dev, const void *find_data)
 {
 	struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,
 						  class_dev);
-	struct find_oud_t *fot = find_data;
-	const struct osd_dev_info *odi = fot->odi;
+	const struct osd_dev_info *odi = find_data;
 
 	if (_the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
 			      odi->systemid, odi->systemid_len) &&
@@ -287,7 +280,6 @@ int _mach_odi(struct device *dev, void *find_data)
 			      odi->osdname, odi->osdname_len)) {
 		OSD_DEBUG("found device sysid_len=%d osdname=%d\n",
 			  odi->systemid_len, odi->osdname_len);
-		fot->oud = oud;
 		return 1;
 	} else {
 		return 0;
@@ -301,19 +293,19 @@ int _mach_odi(struct device *dev, void *find_data)
  */
 struct osd_dev *osduld_info_lookup(const struct osd_dev_info *odi)
 {
-	struct find_oud_t find = {.odi = odi};
-
-	find.dev = class_find_device(&osd_uld_class, NULL, &find, _mach_odi);
-	if (likely(find.dev)) {
+	struct device *dev = class_find_device(&osd_uld_class, NULL, odi, _match_odi);
+	if (likely(dev)) {
 		struct osd_dev_handle *odh = kzalloc(sizeof(*odh), GFP_KERNEL);
+		struct osd_uld_device *oud = container_of(dev,
+			struct osd_uld_device, class_dev);
 
 		if (unlikely(!odh)) {
-			put_device(find.dev);
+			put_device(dev);
 			return ERR_PTR(-ENOMEM);
 		}
 
-		odh->od = find.oud->od;
-		odh->oud = find.oud;
+		odh->od = oud->od;
+		odh->oud = oud;
 
 		return &odh->od;
 	}
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 31969f2..59d427b 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -183,10 +183,10 @@ static struct attribute_group iscsi_endpoint_group = {
 
 #define ISCSI_MAX_EPID -1
 
-static int iscsi_match_epid(struct device *dev, void *data)
+static int iscsi_match_epid(struct device *dev, const void *data)
 {
 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
-	uint64_t *epid = (uint64_t *) data;
+	const uint64_t *epid = data;
 
 	return *epid == ep->id;
 }