changed standart behavior to not overwrite cow file

- in standart cow modus, if an cow file exists it will try to load it, if the given cow file doesn't match with the given image it will exit with an error.
- added -z parameter to force an cow file overwrite.

1 files changed, 13 insertions, 24 deletions

diff --git a/src/fuse/main.c b/src/fuse/main.c
index ee52695..89e1695 100755
--- a/src/fuse/main.c
+++ b/src/fuse/main.c
@@ -156,17 +156,16 @@ static int fillStatsFile(char *buf, size_t size, off_t offset) {
 	memcpy( buf, buffer + offset, len );

 	return len;

 }

-

-static int image_write(const char *path, char *buf, size_t size, off_t offset, struct fuse_file_info *fi UNUSED)

+static int image_write(const char *path, const char *buf, size_t size, off_t offset, struct fuse_file_info *fi UNUSED)

 {

 	if ( path[1] == STATS_PATH[1] ) {

 		return -EIO;

 	}

 	if( ( ( ( size_t ) offset ) + size ) > imageSize ){

 		imageSize = ( ( size_t ) offset ) + size;

-		writeImageSizeToFile( imageSize );

+		cow_writeImageSizeToFile( imageSize );

 	}

-	return writeCow(buf,size, offset);

+	return cow_write(buf,size, offset);

 }

 int imageReadInternal(char *buf,size_t size, off_t offset){

 	dnbd3_async_t request;

@@ -279,10 +278,10 @@ static void image_destroy(void *private_data UNUSED)
 }

 

 

-static int image_truncate(const char *path, off_t size, struct fuse_file_info *fi UNUSED) {

+static int image_truncate(const char *path, off_t size) {

 	if ( strcmp( path, IMAGE_PATH ) == 0 ) {

-		imageSize=size;

-		writeImageSizeToFile((uint64_t)size);

+		imageSize = size;

+		cow_writeImageSizeToFile((uint64_t)size);

 		return 0;

 	}

 	return -1;

@@ -345,7 +344,7 @@ static void printUsage(char *argv0, int exitCode)
 	printf( "   -l --log        Write log to given location\n" );

 	printf( "   -o --option     Mount options to pass to libfuse\n" );

 	printf( "   -d --debug      Don't fork and print debug output (fuse > stderr, dnbd3 > stdout)\n" );

-	printf( "   -c --cow        Path where the cow file should be created");

+	printf( "   -c --cow        Path where the cow file should be created. Use -z to overwrite existing cow files.\n");

 	fuse_main( 2, arg, &dnbd3_fuse_no_operations, NULL );

 	exit( exitCode );

 }

@@ -374,7 +373,7 @@ int main(int argc, char *argv[])
 	int newArgc;

 	int opt, lidx;

 	bool testOpt = false;

-	bool loadCow = false;

+	bool overWrite = false;

 

 	if ( argc <= 1 || strcmp( argv[1], "--help" ) == 0 || strcmp( argv[1], "--usage" ) == 0 ) {

 		printUsage( argv[0], 0 );

@@ -443,7 +442,7 @@ int main(int argc, char *argv[])
 			useCow=true;

 			break;

 		case 'z':

-			loadCow = true;

+			overWrite = true;

 			break;

 		default:

 			printUsage( argv[0], EXIT_FAILURE );

@@ -487,21 +486,11 @@ int main(int argc, char *argv[])
 	}

 	if(useCow){

 		printf("Using Cow");

-		if(loadCow){

-			printf("Loading Cow");

-			uint64_t cowSize = cow_loadFile(cow_path, imageSize);

-

-			if(cowSize == 0){

-				logadd( LOG_ERROR, "Could not load COW FIle. Bye.\n" );

-				return EXIT_FAILURE;

-			} else{

-				imageSize = cowSize;

-			}

+		uint64_t cowSize = cow_init(cow_path, image_Name, imageSize,overWrite);

+		if(cowSize == 0){

+			return EXIT_FAILURE;

 		} else {

-			if(!cow_createFile(cow_path, image_Name, imageSize)){

-				logadd( LOG_ERROR, "Could not create COW FIle. Bye.\n" );

-				return EXIT_FAILURE;

-			}

+			imageSize = cowSize;

 		}

 	}

 	// Since dnbd3 is always read only and the remote image will not change