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 #include <net/9p/9p.h> 37 #include <net/9p/client.h> 38 39 #include "v9fs.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 * @filp: file being read 47 * @page: structure to page 48 * 49 */ 50 51 static int v9fs_vfs_readpage(struct file *filp, struct page *page) 52 { 53 int retval; 54 loff_t offset; 55 char *buffer; 56 struct p9_fid *fid; 57 58 P9_DPRINTK(P9_DEBUG_VFS, "\n"); 59 fid = filp->private_data; 60 buffer = kmap(page); 61 offset = page_offset(page); 62 63 retval = p9_client_readn(fid, buffer, offset, PAGE_CACHE_SIZE); 64 if (retval < 0) 65 goto done; 66 67 memset(buffer + retval, 0, PAGE_CACHE_SIZE - retval); 68 flush_dcache_page(page); 69 SetPageUptodate(page); 70 retval = 0; 71 72 done: 73 kunmap(page); 74 unlock_page(page); 75 return retval; 76 } 77 78 const struct address_space_operations v9fs_addr_operations = { 79 .readpage = v9fs_vfs_readpage, 80 }; 81