[Patch 08/18] fs/logfs/file.c

[Jörn Engel]

--- /dev/null	2007-03-13 19:15:28.862769062 +0100
+++ linux-2.6.21logfs/fs/logfs/file.c	2007-06-03 19:55:14.000000000 +0200
@@ -0,0 +1,75 @@
+/*
+ * fs/logfs/file.c	- prepare_write, commit_write and friends
+ *
+ * As should be obvious for Linux kernel code, license is GPLv2
+ *
+ * Copyright (c) 2005-2007 Joern Engel
+ */
+#include "logfs.h"
+
+static int logfs_prepare_write(struct file *file, struct page *page,
+		unsigned start, unsigned end)
+{
+	if (PageUptodate(page))
+		return 0;
+
+	if ((start == 0) && (end == PAGE_CACHE_SIZE))
+		return 0;
+
+	return logfs_readpage_nolock(page);
+}
+
+static int logfs_commit_write(struct file *file, struct page *page,
+		unsigned start, unsigned end)
+{
+	struct inode *inode = page->mapping->host;
+	pgoff_t index = page->index;
+	void *buf;
+	int ret;
+
+	BUG_ON(PAGE_CACHE_SIZE != inode->i_sb->s_blocksize);
+	BUG_ON(page->index > I3_BLOCKS);
+
+	if (start == end)
+		return 0; /* FIXME: do we need to update inode? */
+
+	if (i_size_read(inode) < (index << PAGE_CACHE_SHIFT) + end) {
+		i_size_write(inode, (index << PAGE_CACHE_SHIFT) + end);
+		mark_inode_dirty_sync(inode);
+	}
+
+	buf = kmap(page);
+	ret = logfs_write_buf(inode, index, buf);
+	kunmap(page);
+	return ret;
+}
+
+static int logfs_readpage(struct file *file, struct page *page)
+{
+	int ret;
+
+	ret = logfs_readpage_nolock(page);
+	unlock_page(page);
+	return ret;
+}
+
+const struct inode_operations logfs_reg_iops = {
+	.truncate	= logfs_truncate,
+};
+
+const struct file_operations logfs_reg_fops = {
+	.aio_read	= generic_file_aio_read,
+	.aio_write	= generic_file_aio_write,
+	.llseek		= generic_file_llseek,
+	.mmap		= generic_file_readonly_mmap,
+	.open		= generic_file_open,
+	.read		= do_sync_read,
+	.write		= do_sync_write,
+};
+
+const struct address_space_operations logfs_reg_aops = {
+	.commit_write	= logfs_commit_write,
+	.prepare_write	= logfs_prepare_write,
+	.readpage	= logfs_readpage,
+	.set_page_dirty	= __set_page_dirty_nobuffers,
+};