dm: use vzalloc

Use vzalloc() instead of vmalloc()+memset().
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

drivers/md/dm-log.c

@@ -492,7 +492,7 @@ static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 	memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
 	lc->sync_count = (sync == NOSYNC) ? region_count : 0;
 
-	lc->recovering_bits = vmalloc(bitset_size);
+	lc->recovering_bits = vzalloc(bitset_size);
 	if (!lc->recovering_bits) {
 		DMWARN("couldn't allocate sync bitset");
 		vfree(lc->sync_bits);
@@ -504,7 +504,6 @@ static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 		kfree(lc);
 		return -ENOMEM;
 	}
-	memset(lc->recovering_bits, 0, bitset_size);
 	lc->sync_search = 0;
 	log->context = lc;
 

drivers/md/dm-snap-persistent.c

@@ -174,10 +174,9 @@ static int alloc_area(struct pstore *ps)
 	if (!ps->area)
 		goto err_area;
 
-	ps->zero_area = vmalloc(len);
+	ps->zero_area = vzalloc(len);
 	if (!ps->zero_area)
 		goto err_zero_area;
-	memset(ps->zero_area, 0, len);
 
 	ps->header_area = vmalloc(len);
 	if (!ps->header_area)

drivers/md/dm-table.c

@@ -153,9 +153,7 @@ void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
 		return NULL;
 
 	size = nmemb * elem_size;
-	addr = vmalloc(size);
-	if (addr)
-		memset(addr, 0, size);
+	addr = vzalloc(size);
 
 	return addr;
 }