ANDROID: dm: android-verity: Allow android-verity to be compiled as an independent module

Exports the device mapper callbacks of linear and dm-verity-target
methods.

Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: I0358be0615c431dce3cc78575aaac4ccfe3aacd7

drivers/md/Kconfig

@@ -501,7 +501,7 @@ config DM_LOG_WRITES
 	  If unsure, say N.
 
 config DM_ANDROID_VERITY
-	bool "Android verity target support"
+	tristate "Android verity target support"
 	depends on DM_VERITY
 	depends on X509_CERTIFICATE_PARSER
 	depends on SYSTEM_TRUSTED_KEYRING
@@ -509,6 +509,7 @@ config DM_ANDROID_VERITY
 	depends on KEYS
 	depends on ASYMMETRIC_KEY_TYPE
 	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+	depends on MD_LINEAR
 	---help---
 	  This device-mapper target is virtually a VERITY target. This
 	  target is setup by reading the metadata contents piggybacked

drivers/md/Makefile

@@ -60,6 +60,7 @@ obj-$(CONFIG_DM_CACHE_SMQ)	+= dm-cache-smq.o
 obj-$(CONFIG_DM_CACHE_CLEANER)	+= dm-cache-cleaner.o
 obj-$(CONFIG_DM_ERA)		+= dm-era.o
 obj-$(CONFIG_DM_LOG_WRITES)	+= dm-log-writes.o
+obj-$(CONFIG_DM_ANDROID_VERITY) += dm-android-verity.o
 
 ifeq ($(CONFIG_DM_UEVENT),y)
 dm-mod-objs			+= dm-uevent.o
@@ -68,7 +69,3 @@ endif
 ifeq ($(CONFIG_DM_VERITY_FEC),y)
 dm-verity-objs			+= dm-verity-fec.o
 endif
-
-ifeq ($(CONFIG_DM_ANDROID_VERITY),y)
-dm-verity-objs			+= dm-android-verity.o
-endif

drivers/md/dm-linear.c

@@ -66,6 +66,7 @@ int dm_linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	kfree(lc);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(dm_linear_ctr);
 
 void dm_linear_dtr(struct dm_target *ti)
 {
@@ -74,6 +75,7 @@ void dm_linear_dtr(struct dm_target *ti)
 	dm_put_device(ti, lc->dev);
 	kfree(lc);
 }
+EXPORT_SYMBOL_GPL(dm_linear_dtr);
 
 static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
 {
@@ -98,6 +100,7 @@ int dm_linear_map(struct dm_target *ti, struct bio *bio)
 
 	return DM_MAPIO_REMAPPED;
 }
+EXPORT_SYMBOL_GPL(dm_linear_map);
 
 void dm_linear_status(struct dm_target *ti, status_type_t type,
 			  unsigned status_flags, char *result, unsigned maxlen)
@@ -115,6 +118,7 @@ void dm_linear_status(struct dm_target *ti, status_type_t type,
 		break;
 	}
 }
+EXPORT_SYMBOL_GPL(dm_linear_status);
 
 int dm_linear_prepare_ioctl(struct dm_target *ti,
 		struct block_device **bdev, fmode_t *mode)
@@ -132,6 +136,7 @@ int dm_linear_prepare_ioctl(struct dm_target *ti,
 		return 1;
 	return 0;
 }
+EXPORT_SYMBOL_GPL(dm_linear_prepare_ioctl);
 
 int dm_linear_iterate_devices(struct dm_target *ti,
 				  iterate_devices_callout_fn fn, void *data)
@@ -140,6 +145,7 @@ int dm_linear_iterate_devices(struct dm_target *ti,
 
 	return fn(ti, lc->dev, lc->start, ti->len, data);
 }
+EXPORT_SYMBOL_GPL(dm_linear_iterate_devices);
 
 static struct target_type linear_target = {
 	.name   = "linear",

drivers/md/dm-verity-target.c

@@ -592,6 +592,7 @@ int verity_map(struct dm_target *ti, struct bio *bio)
 
 	return DM_MAPIO_SUBMITTED;
 }
+EXPORT_SYMBOL_GPL(verity_map);
 
 /*
  * Status: V (valid) or C (corruption found)
@@ -655,6 +656,7 @@ void verity_status(struct dm_target *ti, status_type_t type,
 		break;
 	}
 }
+EXPORT_SYMBOL_GPL(verity_status);
 
 int verity_prepare_ioctl(struct dm_target *ti,
 		struct block_device **bdev, fmode_t *mode)
@@ -668,6 +670,7 @@ int verity_prepare_ioctl(struct dm_target *ti,
 		return 1;
 	return 0;
 }
+EXPORT_SYMBOL_GPL(verity_prepare_ioctl);
 
 int verity_iterate_devices(struct dm_target *ti,
 				  iterate_devices_callout_fn fn, void *data)
@@ -676,6 +679,7 @@ int verity_iterate_devices(struct dm_target *ti,
 
 	return fn(ti, v->data_dev, v->data_start, ti->len, data);
 }
+EXPORT_SYMBOL_GPL(verity_iterate_devices);
 
 void verity_io_hints(struct dm_target *ti, struct queue_limits *limits)
 {
@@ -689,6 +693,7 @@ void verity_io_hints(struct dm_target *ti, struct queue_limits *limits)
 
 	blk_limits_io_min(limits, limits->logical_block_size);
 }
+EXPORT_SYMBOL_GPL(verity_io_hints);
 
 void verity_dtr(struct dm_target *ti)
 {
@@ -719,6 +724,7 @@ void verity_dtr(struct dm_target *ti)
 
 	kfree(v);
 }
+EXPORT_SYMBOL_GPL(verity_dtr);
 
 static int verity_alloc_zero_digest(struct dm_verity *v)
 {
@@ -1053,6 +1059,7 @@ bad:
 
 	return r;
 }
+EXPORT_SYMBOL_GPL(verity_ctr);
 
 static struct target_type verity_target = {
 	.name		= "verity",