1/*
2 *  linux/fs/9p/vfs_addr.c
3 *
4 * This file contians vfs address (mmap) ops for 9P2000.
5 *
6 *  Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
7 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8 *
9 *  This program is free software; you can redistribute it and/or modify
10 *  it under the terms of the GNU General Public License version 2
11 *  as published by the Free Software Foundation.
12 *
13 *  This program is distributed in the hope that it will be useful,
14 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 *  GNU General Public License for more details.
17 *
18 *  You should have received a copy of the GNU General Public License
19 *  along with this program; if not, write to:
20 *  Free Software Foundation
21 *  51 Franklin Street, Fifth Floor
22 *  Boston, MA  02111-1301  USA
23 *
24 */
25
26#include <linux/module.h>
27#include <linux/errno.h>
28#include <linux/fs.h>
29#include <linux/file.h>
30#include <linux/stat.h>
31#include <linux/string.h>
32#include <linux/inet.h>
33#include <linux/pagemap.h>
34#include <linux/idr.h>
35#include <linux/sched.h>
36
37#include "debug.h"
38#include "v9fs.h"
39#include "9p.h"
40#include "v9fs_vfs.h"
41#include "fid.h"
42
43/**
44 * v9fs_vfs_readpage - read an entire page in from 9P
45 *
46 * @file: file being read
47 * @page: structure to page
48 *
49 */
50
51static int v9fs_vfs_readpage(struct file *filp, struct page *page)
52{
53	char *buffer = NULL;
54	int retval = -EIO;
55	loff_t offset = page_offset(page);
56	int count = PAGE_CACHE_SIZE;
57	struct inode *inode = filp->f_path.dentry->d_inode;
58	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
59	int rsize = v9ses->maxdata - V9FS_IOHDRSZ;
60	struct v9fs_fid *v9f = filp->private_data;
61	struct v9fs_fcall *fcall = NULL;
62	int fid = v9f->fid;
63	int total = 0;
64	int result = 0;
65
66	dprintk(DEBUG_VFS, "\n");
67
68	buffer = kmap(page);
69	do {
70		if (count < rsize)
71			rsize = count;
72
73		result = v9fs_t_read(v9ses, fid, offset, rsize, &fcall);
74
75		if (result < 0) {
76			printk(KERN_ERR "v9fs_t_read returned %d\n",
77			       result);
78
79			kfree(fcall);
80			goto UnmapAndUnlock;
81		} else
82			offset += result;
83
84		memcpy(buffer, fcall->params.rread.data, result);
85
86		count -= result;
87		buffer += result;
88		total += result;
89
90		kfree(fcall);
91
92		if (result < rsize)
93			break;
94	} while (count);
95
96	memset(buffer, 0, count);
97	flush_dcache_page(page);
98	SetPageUptodate(page);
99	retval = 0;
100
101UnmapAndUnlock:
102	kunmap(page);
103	unlock_page(page);
104	return retval;
105}
106
107const struct address_space_operations v9fs_addr_operations = {
108      .readpage = v9fs_vfs_readpage,
109};
110