Added a basic vnode store, more or less the same as the old one.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@8829 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/core/cache/Jamfile

@@ -2,6 +2,7 @@ SubDir OBOS_TOP src kernel core cache ;
 
 KernelMergeObject kernel_cache.o :
 	block_cache.cpp
+	vnode_store.cpp
 
 	: -fno-pic -Wno-unused -D_KERNEL_MODE=1
 	;

src/kernel/core/cache/vnode_store.cpp

@@ -0,0 +1,115 @@
+/*
+** Copyright 2004, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
+** Distributed under the terms of the Haiku License.
+*/
+
+
+#include "vnode_store.h"
+
+#include <file_cache.h>
+#include <vfs.h>
+#include <vm.h>
+
+#include <stdlib.h>
+
+
+static void
+store_destroy(struct vm_store *store)
+{
+	free(store);
+}
+
+
+static off_t
+store_commit(struct vm_store *_store, off_t size)
+{
+	vnode_store *store = (vnode_store *)_store;
+	// ToDo: enable this again when "size" is maintained correctly
+#if 0
+	// we don't like committing more memory than we have
+	if (size > store->size)
+		size = store->size;
+#endif
+	store->vm.committed_size = size;
+	return size;
+}
+
+
+static int
+store_has_page(struct vm_store *_store, off_t offset)
+{
+	// We always pretend to have the page - even if it's beyond the size of
+	// the file. The read function will only cut down the size of the read,
+	// it won't fail because of that.
+	return 1;
+}
+
+
+static ssize_t
+store_read(struct vm_store *_store, off_t offset, iovecs *vecs)
+{
+	vnode_store *store = (vnode_store *)_store;
+	return vfs_read_page(store->vnode, vecs, offset);
+		// ToDo: the file system must currently clear out the remainder of the last page...
+}
+
+
+static ssize_t
+store_write(struct vm_store *_store, off_t offset, iovecs *vecs)
+{
+	vnode_store *store = (vnode_store *)_store;
+	return vfs_write_page(store->vnode, vecs, offset);
+}
+
+
+static void
+store_acquire_ref(struct vm_store *_store)
+{
+	vnode_store *store = (vnode_store *)_store;
+	vfs_vnode_acquire_ref(store->vnode);
+}
+
+
+static void
+store_release_ref(struct vm_store *_store)
+{
+	vnode_store *store = (vnode_store *)_store;
+	vfs_vnode_release_ref(store->vnode);
+}
+
+
+static vm_store_ops sStoreOps = {
+	&store_destroy,
+	&store_commit,
+	&store_has_page,
+	&store_read,
+	&store_write,
+	NULL,	/* fault */
+	&store_acquire_ref,
+	&store_release_ref
+};
+
+
+//	#pragma mark -
+
+
+extern "C" vm_store *
+vm_create_vnode_store(void *vnode)
+{
+	vnode_store *store = (vnode_store *)malloc(sizeof(struct vnode_store));
+	if (store == NULL) {
+		vfs_vnode_release_ref(vnode);
+		return NULL;
+	}
+
+	store->vm.ops = &sStoreOps;
+	store->vm.cache = NULL;
+	store->vm.committed_size = 0;
+
+	store->vnode = vnode;
+	store->size = 0;
+		// the file system will maintain this field through the file cache API
+
+	return &store->vm;
+}
+

src/kernel/core/cache/vnode_store.h

@@ -0,0 +1,19 @@
+/*
+** Copyright 2004, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
+** Distributed under the terms of the Haiku License.
+*/
+#ifndef VNODE_STORE_H
+#define VNODE_STORE_H
+
+
+#include <vm.h>
+
+
+struct vnode_store {
+	vm_store	vm;
+	void		*vnode;
+	off_t		size;
+		// the file system will maintain this field through the file cache API
+};
+
+#endif	/* VNODE_STORE_H */