[SERVER] Fix create_image() by adding fallback solutions for fallocate()

7 files changed, 41 insertions, 20 deletions

diff --git a/src/server/globals.c b/src/server/globals.c
index d84e3f7..182b2cc 100644
--- a/src/server/globals.c
+++ b/src/server/globals.c
@@ -29,8 +29,15 @@ void globals_loadConfig()
 	if ( name == NULL ) return;
 	ini_parse( name, &ini_handler, NULL );
 	free( name );
-	if ( _basePath != NULL && _basePath[0] != '/' ) {
+	if ( _basePath == NULL || _basePath[0] == '\0' ) {
+		memlogf( "[ERROR] Need to specify basePath in " CONFIG_FILENAME );
+		exit( EXIT_FAILURE );
+	}
+	if ( _basePath[0] != '/' ) {
 		memlogf( "[ERROR] _basePath must be absolute!" );
 		exit( EXIT_FAILURE );
 	}
+	char *end = _basePath + strlen( _basePath ) - 1;
+	while ( end >= _basePath && *end == '/' )
+		*end-- = '\0';
 }
diff --git a/src/server/globals.h b/src/server/globals.h
index 2dd6e13..b063fc3 100644
--- a/src/server/globals.h
+++ b/src/server/globals.h
@@ -117,6 +117,7 @@ struct _dnbd3_client
 
 // #######################################################
 #define CONFIG_FILENAME "server.conf"
+
 /**
  * Base directory where the configuration files reside. Will never have a trailing slash.
  */
diff --git a/src/server/helper.c b/src/server/helper.c
index b028ad1..65239ea 100644
--- a/src/server/helper.c
+++ b/src/server/helper.c
@@ -162,3 +162,12 @@ int mkdir_p(const char* path)
 	if ( mkdir( buffer, 0750 ) != 0 && errno != EEXIST ) return FALSE;
 	return TRUE;
 }
+
+int file_alloc(int fd, uint64_t offset, uint64_t size)
+{
+	if ( fallocate( fd, 0, offset, size ) == 0 ) return TRUE; // fast way
+	if ( posix_fallocate( fd, offset, size ) == 0 ) return TRUE; // slow way
+	if ( lseek( fd, offset + size - 1, SEEK_SET ) != offset ) return FALSE; // dumb way
+	if ( write( fd, "", 1 ) != 1 ) return FALSE;
+	return TRUE;
+}
diff --git a/src/server/helper.h b/src/server/helper.h
index c212720..6c116ef 100644
--- a/src/server/helper.h
+++ b/src/server/helper.h
@@ -19,6 +19,7 @@ void trim_right(char * const string);
 int file_exists(char *file);
 int file_writable(char *file);
 int mkdir_p(const char* path);
+int file_alloc(int fd, uint64_t offset, uint64_t size);
 
 static inline int is_same_server(const dnbd3_host_t * const a, const dnbd3_host_t * const b)
 {
diff --git a/src/server/image.c b/src/server/image.c
index 556e83b..6b6fb99 100644
--- a/src/server/image.c
+++ b/src/server/image.c
@@ -14,7 +14,6 @@
 #include <dirent.h>
 #include <zlib.h>
 #include <inttypes.h>
-#include <fcntl.h>
 
 // ##########################################
 
@@ -555,7 +554,7 @@ int image_create(char *image, int revision, uint64_t size)
 	assert( image != NULL );
 	assert( size >= DNBD3_BLOCK_SIZE );
 	if ( revision <= 0 ) {
-		printf( "[ERROR] revision id invalid: %d\n", revision );
+		memlogf( "[ERROR] revision id invalid: %d", revision );
 		return FALSE;
 	}
 	const int PATHLEN = 2000;
@@ -571,7 +570,7 @@ int image_create(char *image, int revision, uint64_t size)
 		snprintf( path, PATHLEN, "%s/%s.r%d", _basePath, image, revision );
 	}
 	if ( file_exists( path ) ) {
-		printf( "[ERROR] Image %s with rid %d already exists!\n", image, revision );
+		memlogf( "[ERROR] Image %s with rid %d already exists!", image, revision );
 		return FALSE;
 	}
 	snprintf( cache, PATHLEN, "%s.map", path );
@@ -579,26 +578,26 @@ int image_create(char *image, int revision, uint64_t size)
 	const int mapsize = IMGSIZE_TO_MAPBYTES(size);
 	// Write files
 	int fdImage = -1, fdCache = -1;
-	fdImage = open( path, O_WRONLY | O_TRUNC, 0640 );
-	fdCache = open( cache, O_WRONLY | O_TRUNC, 0640 );
+	fdImage = open( path, O_RDWR | O_TRUNC | O_CREAT, 0640 );
+	fdCache = open( cache, O_RDWR | O_TRUNC | O_CREAT, 0640 );
 	if ( fdImage < 0 ) {
-		printf( "[ERROR] Could not open %s for writing.\n", path );
+		memlogf( "[ERROR] Could not open %s for writing.", path );
 		goto failure_cleanup;
 	}
 	if ( fdCache < 0 ) {
-		printf( "[ERROR] Could not open %s for writing.\n", cache );
+		memlogf( "[ERROR] Could not open %s for writing.", cache );
 		goto failure_cleanup;
 	}
 	// Try cache map first
-	if ( fallocate( fdCache, 0, 0, mapsize ) != 0 ) {
+	if ( !file_alloc( fdCache, 0, mapsize ) ) {
 		const int err = errno;
-		printf( "[ERROR] Could not allocate %d bytes for %s (errno=%d)", mapsize, cache, err );
+		memlogf( "[ERROR] Could not allocate %d bytes for %s (errno=%d)", mapsize, cache, err );
 		goto failure_cleanup;
 	}
 	// Now write image
-	if ( fallocate( fdImage, 0, 0, size ) != 0 ) {
+	if ( !file_alloc( fdImage, 0, size ) ) {
 		const int err = errno;
-		printf( "[ERROR] Could not allocate %" PRIu64 " bytes for %s (errno=%d)", size, path, err );
+		memlogf( "[ERROR] Could not allocate %" PRIu64 " bytes for %s (errno=%d)", size, path, err );
 		goto failure_cleanup;
 	}
 	close( fdImage );
diff --git a/src/server/memlog.c b/src/server/memlog.c
index 447d232..12de858 100644
--- a/src/server/memlog.c
+++ b/src/server/memlog.c
@@ -60,6 +60,7 @@ void memlogf(const char *fmt, ...)
 		va_start( ap, fmt );
 		vprintf( fmt, ap );
 		va_end( ap );
+		printf( "\n" );
 		return; // Not initialized yet
 	}
 	va_list ap;
diff --git a/src/server/server.c b/src/server/server.c
index 9b6ff30..12b437b 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -82,7 +82,8 @@ void dnbd3_print_help(char *argv_0)
 	printf( "Management functions:\n" );
 	printf( "--crc [image-file]  Generate crc block list for given image\n" );
 	printf( "--create [image-name] --revision [rid] --size [filesize]\n"
-			"\tCreate a local empty image file with a zeroed cache-map for the specified image" );
+			"\tCreate a local empty image file with a zeroed cache-map for the specified image\n" );
+	printf( "\n" );
 	exit( 0 );
 }
 
@@ -215,13 +216,7 @@ int main(int argc, char *argv[])
 		opt = getopt_long( argc, argv, optString, longOpts, &longIndex );
 	}
 
-	// One-shots first:
-
-	if ( paramCreate != NULL ) {
-		return image_create( paramCreate, paramRevision, paramSize ) ? 0 : EXIT_FAILURE;
-	}
-
-	// No one-shot detected, normal server operation
+	// Load general config
 
 	if ( _configDir == NULL ) _configDir = strdup( "/etc/dnbd3-server" );
 	globals_loadConfig();
@@ -230,6 +225,14 @@ int main(int argc, char *argv[])
 		exit( EXIT_FAILURE );
 	}
 
+	// One-shots first:
+
+	if ( paramCreate != NULL ) {
+		return image_create( paramCreate, paramRevision, paramSize ) ? 0 : EXIT_FAILURE;
+	}
+
+	// No one-shot detected, normal server operation
+
 	if ( demonize ) daemon( 1, 0 );
 	initmemlog();
 	spin_init( &_clients_lock, PTHREAD_PROCESS_PRIVATE );