Rechecks the hash of imported files before using them.

TODO

@@ -5,6 +5,10 @@ This is the list of TODO items for SnapRAID.
 
 - v3.1
 
+* In the import list, uses also all the blocks in the array.
+But we must cover the case of bad blocks. Likely we can just check the
+hash after reading, and in case, skip it, and retry with another copy.
+
 * If a content file is missing, sync should rewrite it, even if no change was done at the content.
 
 * A new 'init' command to differentiate the first 'sync' operation.

check.c

@@ -275,11 +275,11 @@ static int repair(struct snapraid_state* state, unsigned pos, unsigned diskmax,
 				}
 			} else {
 				assert(block_state == BLOCK_STATE_CHG || block_state == BLOCK_STATE_NEW);
-			
+
 				/* otherwise it's CHG or NEW and we try to recover it */
 				failed_map[n] = j;
 				++n;
-				
+
 				/* we have something to try to recover */
 				something_to_recover = 1;
 			}

import.c

@@ -125,6 +125,7 @@ int state_import_fetch(struct snapraid_state* state, const unsigned char* hash,
 	int f;
 	unsigned block_size = state->block_size;
 	unsigned read_size;
+	unsigned char buffer_hash[HASH_SIZE];
 	const char* path;
 
 	block = tommy_hashdyn_search(&state->importset, import_block_compare, hash, import_block_hash(hash));
@@ -162,6 +163,15 @@ int state_import_fetch(struct snapraid_state* state, const unsigned char* hash,
 		memset(buffer + read_size, 0, block_size - read_size);
 	}
 
+	/* recheck the hash */
+	memhash(state->hash, buffer_hash, buffer, read_size);
+
+	if (memcmp(buffer_hash, hash, HASH_SIZE) != 0) {
+		fprintf(stderr, "Error in data reading file '%s'.\n", path);
+		fprintf(stderr, "Please don't change imported files while running.\n");
+		exit(EXIT_FAILURE);
+	}
+
 	return 0;
 }