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

This reverts commit 98a5231fe5.

docs/user/drivers/fs_interface.dox

@@ -92,16 +92,6 @@
 */
 
 
-/*!
-	\enum BVnodeOperation
-	Enumeration type for specifying vnode operations.
-*/
-
-/*!
-	\var BVnodeOperation B_VNODE_OPERATION_IO
-	Refers to the fs_vnode_ops::io operation.
-*/
-
 ///// file_system_module_info /////
 
 
@@ -1708,31 +1698,6 @@
 	\brief TODO: Document!
 */
 
-/* TODO: test_lock(), acquire_lock(), release_lock() */
-
-/*!
-	\fn bool (*fs_vnode_ops::supports_operation)(fs_volume* volume,
-			fs_vnode* vnode, BVnodeOperation operation)
-	\brief Returns whether the specified vnode operation is supported for the
-		specified vnode.
-
-	For most vnode operations the FS can simply indicate that it doesn't support
-	it by setting the respective attribute in the fs_vnode_ops structure to
-	\c NULL. For certain nodes the support of an operation may change over the
-	life time of the node. While in most cases the implementation of the
-	operation can then simply return an error (\c B_NOT_SUPPORTED), for some
-	operations, however, the VFS has to know beforehand whether to call it at
-	all or resort to a different handling. It calls this hook only for
-	operations that aren't set to \c NULL in the fs_vnode_ops structure. If this
-	hook is not present, the VFS behaves as if it was present always returned
-	\c true.
-
-	\param volume The volume object.
-	\param vnode The node object.
-	\param operation The enum value identifying the operation.
-	\return \c true, if the specified operation is currently supported, \c false
-		otherwise.
-*/
 
 //! @}
 

headers/os/drivers/fs_interface.h

@@ -45,11 +45,6 @@ struct file_io_vec {
 #define B_VNODE_DONT_CREATE_SPECIAL_SUB_NODE	0x02
 
 
-enum BVnodeOperation {
-	B_VNODE_OPERATION_IO	= 0
-};
-
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -255,10 +250,6 @@ struct fs_vnode_ops {
 				const struct flock* lock, bool wait);
 	status_t (*release_lock)(fs_volume* volume, fs_vnode* vnode, void* cookie,
 				const struct flock* lock);
-
-	/* supported vnode operations info */
-	bool (*supports_operation)(fs_volume* volume, fs_vnode* vnode,
-				enum BVnodeOperation operation);
 };
 
 struct file_system_module_info {

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 */
+	// attributes operations are not supported
-	NULL,	// open_attr_dir()
+	NULL,
-	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,
 };
 
 }	// 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);