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/smp_lock.h> 33 #include <linux/inet.h> 34 #include <linux/pagemap.h> 35 #include <linux/idr.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 51 static 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_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 buffer = kmap(page); 67 do { 68 if (count < rsize) 69 rsize = count; 70 71 result = v9fs_t_read(v9ses, fid, offset, rsize, &fcall); 72 73 if (result < 0) { 74 printk(KERN_ERR "v9fs_t_read returned %d\n", 75 result); 76 77 kfree(fcall); 78 goto UnmapAndUnlock; 79 } else 80 offset += result; 81 82 memcpy(buffer, fcall->params.rread.data, result); 83 84 count -= result; 85 buffer += result; 86 total += result; 87 88 kfree(fcall); 89 90 if (result < rsize) 91 break; 92 } while (count); 93 94 memset(buffer, 0, count); 95 flush_dcache_page(page); 96 SetPageUptodate(page); 97 retval = 0; 98 99 UnmapAndUnlock: 100 kunmap(page); 101 unlock_page(page); 102 return retval; 103 } 104 105 const struct address_space_operations v9fs_addr_operations = { 106 .readpage = v9fs_vfs_readpage, 107 }; 108