Open the underlying file (or device) with O_NOCACHE. This works around a

potential page writer deadlock.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37587 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/tests/system/kernel/file_corruption/driver/checksum_device.cpp

@@ -311,7 +311,12 @@ struct RawDevice : Device, DoublyLinkedListLinkImpl<RawDevice> {
 	status_t Init(const char* fileName)
 	{
 		// open and stat file
-		fFD = open(fileName, O_RDWR);
+		fFD = open(fileName, O_RDWR | O_NOCACHE);
+			// TODO: The O_NOCACHE is a work-around for a page writer problem.
+			// Since it collects pages for writing back without regard for
+			// which caches and file systems they belong to, a deadlock can
+			// result when pages from both the underlying file system and the
+			// one using the checksum device are collected in one run.
 		if (fFD < 0)
 			return errno;