1 files changed, 20 insertions, 4 deletions

diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index a2e26c242141..556acff3952f 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -171,6 +171,14 @@ static int set_chunk_size(struct dm_exception_store *store,
 	 */
 	chunk_size_ulong = round_up(chunk_size_ulong, PAGE_SIZE >> 9);
 
+	return dm_exception_store_set_chunk_size(store, chunk_size_ulong,
+						 error);
+}
+
+int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
+				      unsigned long chunk_size_ulong,
+				      char **error)
+{
 	/* Check chunk_size is a power of 2 */
 	if (!is_power_of_2(chunk_size_ulong)) {
 		*error = "Chunk size is not a power of 2";
@@ -178,11 +186,16 @@ static int set_chunk_size(struct dm_exception_store *store,
 	}
 
 	/* Validate the chunk size against the device block size */
-	if (chunk_size_ulong % (bdev_hardsect_size(store->cow->bdev) >> 9)) {
+	if (chunk_size_ulong % (bdev_logical_block_size(store->cow->bdev) >> 9)) {
 		*error = "Chunk size is not a multiple of device blocksize";
 		return -EINVAL;
 	}
 
+	if (chunk_size_ulong > INT_MAX >> SECTOR_SHIFT) {
+		*error = "Chunk size is too high";
+		return -EINVAL;
+	}
+
 	store->chunk_size = chunk_size_ulong;
 	store->chunk_mask = chunk_size_ulong - 1;
 	store->chunk_shift = ffs(chunk_size_ulong) - 1;
@@ -195,7 +208,7 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
 			      struct dm_exception_store **store)
 {
 	int r = 0;
-	struct dm_exception_store_type *type;
+	struct dm_exception_store_type *type = NULL;
 	struct dm_exception_store *tmp_store;
 	char persistent;
 
@@ -211,12 +224,15 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
 	}
 
 	persistent = toupper(*argv[1]);
-	if (persistent != 'P' && persistent != 'N') {
+	if (persistent == 'P')
+		type = get_type("P");
+	else if (persistent == 'N')
+		type = get_type("N");
+	else {
 		ti->error = "Persistent flag is not P or N";
 		return -EINVAL;
 	}
 
-	type = get_type(argv[1]);
 	if (!type) {
 		ti->error = "Exception store type not recognised";
 		r = -EINVAL;