Revert "Introduce vnode op supports_operation(), fix devfs_io()"

This reverts commit 98a5231fe5.

src/system/kernel/device_manager/devfs.cpp

@@ -118,6 +118,11 @@ struct devfs_cookie {
 	void*				device_cookie;
 };
 
+struct synchronous_io_cookie {
+	BaseDevice*		device;
+	void*			cookie;
+};
+
 // directory iteration states
 enum {
 	ITERATION_STATE_DOT		= 0,
@@ -767,6 +772,22 @@ get_device_name(struct devfs_vnode* vnode, char* buffer, size_t size)
 }
 
 
+static status_t
+device_read(void* _cookie, off_t offset, void* buffer, size_t* length)
+{
+	synchronous_io_cookie* cookie = (synchronous_io_cookie*)_cookie;
+	return cookie->device->Read(cookie->cookie, offset, buffer, length);
+}
+
+
+static status_t
+device_write(void* _cookie, off_t offset, void* buffer, size_t* length)
+{
+	synchronous_io_cookie* cookie = (synchronous_io_cookie*)_cookie;
+	return cookie->device->Write(cookie->cookie, offset, buffer, length);
+}
+
+
 static int
 dump_node(int argc, char** argv)
 {
@@ -1761,14 +1782,36 @@ devfs_io(fs_volume* volume, fs_vnode* _vnode, void* _cookie,
 	devfs_vnode* vnode = (devfs_vnode*)_vnode->private_node;
 	devfs_cookie* cookie = (devfs_cookie*)_cookie;
 
+	bool isWrite = request->IsWrite();
+
 	if (!S_ISCHR(vnode->stream.type)
-		|| !vnode->stream.u.dev.device->HasIO()
+		|| (((isWrite && !vnode->stream.u.dev.device->HasWrite())
+				|| (!isWrite && !vnode->stream.u.dev.device->HasRead()))
+			&& !vnode->stream.u.dev.device->HasIO())
 		|| cookie == NULL) {
 		request->SetStatusAndNotify(B_NOT_ALLOWED);
 		return B_NOT_ALLOWED;
 	}
 
-	return vnode->stream.u.dev.device->IO(cookie->device_cookie, request);
+	if (vnode->stream.u.dev.partition != NULL) {
+		if (request->Offset() + (off_t)request->Length()
+				> vnode->stream.u.dev.partition->info.size) {
+			request->SetStatusAndNotify(B_BAD_VALUE);
+			return B_BAD_VALUE;
+		}
+		translate_partition_access(vnode->stream.u.dev.partition, request);
+	}
+
+	if (vnode->stream.u.dev.device->HasIO())
+		return vnode->stream.u.dev.device->IO(cookie->device_cookie, request);
+
+	synchronous_io_cookie synchronousCookie = {
+		vnode->stream.u.dev.device,
+		cookie->device_cookie
+	};
+
+	return vfs_synchronous_io(request,
+		request->IsWrite() ? &device_write : &device_read, &synchronousCookie);
 }
 
 
@@ -1858,22 +1901,6 @@ devfs_write_stat(fs_volume* _volume, fs_vnode* _vnode, const struct stat* stat,
 }
 
 
-bool devfs_supports_operation(fs_volume* _volume, fs_vnode* _vnode,
-	BVnodeOperation operation)
-{
-	struct devfs_vnode* vnode = (struct devfs_vnode*)_vnode->private_node;
-
-	switch (operation) {
-		case B_VNODE_OPERATION_IO:
-			return S_ISCHR(vnode->stream.type)
-				&& vnode->stream.u.dev.device->HasIO();
-
-		default:
-			return false;
-	}
-}
-
-
 static status_t
 devfs_std_ops(int32 op, ...)
 {
@@ -1968,36 +1995,8 @@ fs_vnode_ops kVnodeOps = {
 	&devfs_read_dir,
 	&devfs_rewind_dir,
 
-	/* attribute directory */
-	NULL,	// open_attr_dir()
-	NULL,	// close_attr_dir()
-	NULL,	// free_attr_dir_cookie()
-	NULL,	// read_attr_dir()
-	NULL,	// rewind_attr_dir()
-
-	/* attribute */
-	NULL,	// create_attr()
-	NULL,	// open_attr()
-	NULL,	// close_attr()
-	NULL,	// free_attr_cookie()
-	NULL,	// read_attr()
-	NULL,	// write_attr()
-	NULL,	// read_attr_stat()
-	NULL,	// write_attr_stat()
-	NULL,	// rename_attr()
-	NULL,	// remove_attr()
-
-	/* support for node and FS layers */
-	NULL,	// create_special_node()
-	NULL,	// get_super_vnode()
-
-	/* lock operations */
-	NULL,	// test_lock()
-	NULL,	// acquire_lock()
-	NULL,	// release_lock()
-
-	/* supported vnode operations info */
-	&devfs_supports_operation,
+	// attributes operations are not supported
+	NULL,
 };
 
 }	// namespace

src/system/kernel/fs/vfs_request_io.cpp

@@ -133,17 +133,6 @@ private:
 };
 
 
-static bool
-is_vnode_io_operation_supported(struct vnode* vnode)
-{
-	if (!HAS_FS_CALL(vnode, io))
-		return false;
-	if (!HAS_FS_CALL(vnode, supports_operation))
-		return true;
-	return FS_CALL(vnode, supports_operation, B_VNODE_OPERATION_IO);
-}
-
-
 static status_t
 do_iterative_fd_io_iterate(void* _cookie, io_request* request,
 	bool* _partialTransfer)
@@ -371,7 +360,7 @@ status_t
 vfs_vnode_io(struct vnode* vnode, void* cookie, io_request* request)
 {
 	status_t result = B_ERROR;
-	if (!is_vnode_io_operation_supported(vnode)
+	if (!HAS_FS_CALL(vnode, io)
 		|| (result = FS_CALL(vnode, io, cookie, request)) == B_UNSUPPORTED) {
 		// no io() call -- fall back to synchronous I/O
 		VnodeIO io(request->IsWrite(), vnode, cookie);
@@ -481,7 +470,7 @@ do_iterative_fd_io(int fd, io_request* request, iterative_io_get_vecs getVecs,
 
 	CObjectDeleter<file_descriptor> descriptorPutter(descriptor, put_fd);
 
-	if (!is_vnode_io_operation_supported(vnode)) {
+	if (!HAS_FS_CALL(vnode, io)) {
 		// no io() call -- fall back to synchronous I/O
 		return do_synchronous_iterative_vnode_io(vnode, descriptor->cookie,
 			request, getVecs, finished, cookie);