scst_vdisk: lower severity of message about not supported fallocate(FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE) and print it only once

git-svn-id: http://svn.code.sf.net/p/scst/svn/branches/3.3.x@7582 d57e44dd-8a1f-0410-8b47-8ef2f437770f

scst/include/scst_debug.h

@@ -399,4 +399,13 @@ do {									\
 #define SCST_SLAB_FLAGS 0L
 #endif
 
+#define PRINT_WARNING_ONCE(format, args...)			\
+do {								\
+	static bool __warned;					\
+	if (!__warned) {					\
+		__warned = true;				\
+		PRINT_WARNING(format, ## args);			\
+	}							\
+} while(0)
+
 #endif /* __SCST_DEBUG_H */

scst/src/dev_handlers/scst_vdisk.c

@@ -3847,7 +3847,7 @@ static int vdisk_unmap_file_range(struct scst_cmd *cmd,
 	res = fd->f_op->fallocate(fd,
 		FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, off, len);
 	if (unlikely(res != 0)) {
-		PRINT_ERROR("fallocate() for %lld, len %lld "
+		PRINT_WARNING_ONCE("fallocate() for %lld, len %lld "
 			"failed: %d", (unsigned long long)off,
 			(unsigned long long)len, res);
 		scst_set_cmd_error(cmd,