Merge pull request #339 from imjfckm/check-max-cache-size

Detect cache devices that would overflow ocf_cacheline_t

env/posix/ocf_env.h

@@ -180,7 +180,7 @@ static inline void env_secure_free(const void *ptr, size_t size)
 
 static inline uint64_t env_get_free_memory(void)
 {
-	return sysconf(_SC_PAGESIZE) * sysconf(_SC_AVPHYS_PAGES);
+	return (uint64_t)(-1);
 }
 
 /* ALLOCATOR */

src/metadata/metadata_hash.c

@@ -912,6 +912,7 @@ static int ocf_metadata_hash_init_variable_size(struct ocf_cache *cache,
 	struct ocf_cache_line_settings *settings =
 		(struct ocf_cache_line_settings *)&cache->metadata.settings;
 	ocf_flush_page_synch_t lock_page, unlock_page;
+	uint64_t device_lines;
 
 	OCF_DEBUG_TRACE(cache);
 
@@ -919,7 +920,16 @@ static int ocf_metadata_hash_init_variable_size(struct ocf_cache *cache,
 
 	ctrl = cache->metadata.iface_priv;
 
-	ctrl->device_lines = device_size / cache_line_size;
+	device_lines = device_size / cache_line_size;
+	if (device_lines >= (ocf_cache_line_t)(-1)){
+		/* TODO: This is just a rough check. Most optimal one would be
+		 * located in calculate_metadata_size. */
+		ocf_cache_log(cache, log_err, "Device exceeds maximum suported size "
+				"with this cache line size. Try bigger cache line size.");
+		return -OCF_ERR_INVAL_CACHE_DEV;
+	}
+
+	ctrl->device_lines = device_lines;
 
 	if (settings->size != cache_line_size)
 		/* Re-initialize settings with different cache line size */

tests/functional/tests/management/test_start_stop.py

@@ -4,7 +4,7 @@
 #
 
 import logging
-from ctypes import c_int, c_void_p, byref
+from ctypes import c_int, c_void_p, byref, c_uint32
 from random import randrange
 from itertools import count
 
@@ -330,6 +330,31 @@ def test_start_cache_same_id(pyocf_ctx, mode, cls):
     cache.get_stats()
 
 
+@pytest.mark.parametrize("cls", CacheLineSize)
+def test_start_cache_huge_device(pyocf_ctx_log_buffer, cls):
+    """
+    Test whether we can start cache which would overflow ocf_cache_line_t type.
+    pass_criteria:
+      - Starting cache on device too big to handle should fail
+    """
+    class HugeDevice(Volume):
+        def get_length(self):
+            return Size.from_B((cls * c_uint32(-1).value))
+
+        def submit_io(self, io):
+            io.contents._end(io, 0)
+
+    cache_device = HugeDevice(Size.from_MiB(20))
+
+    with pytest.raises(OcfError, match="OCF_ERR_START_CACHE_FAIL"):
+        cache = Cache.start_on_device(cache_device, cache_line_size=cls, metadata_volatile=True)
+
+    assert any(
+        [line.find("exceeds maximum") > 0 for line in pyocf_ctx_log_buffer.get_lines()]
+    ), "Expected to find log notifying that max size was exceeded"
+
+
+
 @pytest.mark.parametrize("mode", CacheMode)
 @pytest.mark.parametrize("cls", CacheLineSize)
 def test_start_cache_same_device(pyocf_ctx, mode, cls):