1 /* 2 * linux/fs/9p/vfs_file.c 3 * 4 * This file contians vfs file ops for 9P2000. 5 * 6 * Copyright (C) 2004 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/sched.h> 30 #include <linux/file.h> 31 #include <linux/stat.h> 32 #include <linux/string.h> 33 #include <linux/smp_lock.h> 34 #include <linux/inet.h> 35 #include <linux/list.h> 36 #include <asm/uaccess.h> 37 #include <linux/idr.h> 38 39 #include "debug.h" 40 #include "v9fs.h" 41 #include "9p.h" 42 #include "v9fs_vfs.h" 43 #include "fid.h" 44 45 /** 46 * v9fs_file_open - open a file (or directory) 47 * @inode: inode to be opened 48 * @file: file being opened 49 * 50 */ 51 52 int v9fs_file_open(struct inode *inode, struct file *file) 53 { 54 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 55 struct v9fs_fid *vfid; 56 struct v9fs_fcall *fcall = NULL; 57 int omode; 58 int err; 59 60 dprintk(DEBUG_VFS, "inode: %p file: %p \n", inode, file); 61 62 vfid = v9fs_fid_clone(file->f_path.dentry); 63 if (IS_ERR(vfid)) 64 return PTR_ERR(vfid); 65 66 omode = v9fs_uflags2omode(file->f_flags); 67 err = v9fs_t_open(v9ses, vfid->fid, omode, &fcall); 68 if (err < 0) { 69 PRINT_FCALL_ERROR("open failed", fcall); 70 goto Clunk_Fid; 71 } 72 73 file->private_data = vfid; 74 vfid->fidopen = 1; 75 vfid->fidclunked = 0; 76 vfid->iounit = fcall->params.ropen.iounit; 77 vfid->rdir_pos = 0; 78 vfid->rdir_fcall = NULL; 79 vfid->filp = file; 80 kfree(fcall); 81 82 return 0; 83 84 Clunk_Fid: 85 v9fs_fid_clunk(v9ses, vfid); 86 kfree(fcall); 87 88 return err; 89 } 90 91 /** 92 * v9fs_file_lock - lock a file (or directory) 93 * @inode: inode to be opened 94 * @file: file being opened 95 * 96 * XXX - this looks like a local only lock, we should extend into 9P 97 * by using open exclusive 98 */ 99 100 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) 101 { 102 int res = 0; 103 struct inode *inode = filp->f_path.dentry->d_inode; 104 105 dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); 106 107 /* No mandatory locks */ 108 if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID) 109 return -ENOLCK; 110 111 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { 112 filemap_write_and_wait(inode->i_mapping); 113 invalidate_mapping_pages(&inode->i_data, 0, -1); 114 } 115 116 return res; 117 } 118 119 /** 120 * v9fs_file_read - read from a file 121 * @filep: file pointer to read 122 * @data: data buffer to read data into 123 * @count: size of buffer 124 * @offset: offset at which to read data 125 * 126 */ 127 static ssize_t 128 v9fs_file_read(struct file *filp, char __user * data, size_t count, 129 loff_t * offset) 130 { 131 struct inode *inode = filp->f_path.dentry->d_inode; 132 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 133 struct v9fs_fid *v9f = filp->private_data; 134 struct v9fs_fcall *fcall = NULL; 135 int fid = v9f->fid; 136 int rsize = 0; 137 int result = 0; 138 int total = 0; 139 int n; 140 141 dprintk(DEBUG_VFS, "\n"); 142 143 rsize = v9ses->maxdata - V9FS_IOHDRSZ; 144 if (v9f->iounit != 0 && rsize > v9f->iounit) 145 rsize = v9f->iounit; 146 147 do { 148 if (count < rsize) 149 rsize = count; 150 151 result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall); 152 153 if (result < 0) { 154 printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n", 155 result); 156 157 kfree(fcall); 158 return total; 159 } else 160 *offset += result; 161 162 n = copy_to_user(data, fcall->params.rread.data, result); 163 if (n) { 164 dprintk(DEBUG_ERROR, "Problem copying to user %d\n", n); 165 kfree(fcall); 166 return -EFAULT; 167 } 168 169 count -= result; 170 data += result; 171 total += result; 172 173 kfree(fcall); 174 175 if (result < rsize) 176 break; 177 } while (count); 178 179 return total; 180 } 181 182 /** 183 * v9fs_file_write - write to a file 184 * @filep: file pointer to write 185 * @data: data buffer to write data from 186 * @count: size of buffer 187 * @offset: offset at which to write data 188 * 189 */ 190 191 static ssize_t 192 v9fs_file_write(struct file *filp, const char __user * data, 193 size_t count, loff_t * offset) 194 { 195 struct inode *inode = filp->f_path.dentry->d_inode; 196 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 197 struct v9fs_fid *v9fid = filp->private_data; 198 struct v9fs_fcall *fcall; 199 int fid = v9fid->fid; 200 int result = -EIO; 201 int rsize = 0; 202 int total = 0; 203 204 dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count, 205 (int)*offset); 206 rsize = v9ses->maxdata - V9FS_IOHDRSZ; 207 if (v9fid->iounit != 0 && rsize > v9fid->iounit) 208 rsize = v9fid->iounit; 209 210 do { 211 if (count < rsize) 212 rsize = count; 213 214 result = v9fs_t_write(v9ses, fid, *offset, rsize, data, &fcall); 215 if (result < 0) { 216 PRINT_FCALL_ERROR("error while writing", fcall); 217 kfree(fcall); 218 return result; 219 } else 220 *offset += result; 221 222 kfree(fcall); 223 fcall = NULL; 224 225 if (result != rsize) { 226 eprintk(KERN_ERR, 227 "short write: v9fs_t_write returned %d\n", 228 result); 229 break; 230 } 231 232 count -= result; 233 data += result; 234 total += result; 235 } while (count); 236 237 invalidate_inode_pages2(inode->i_mapping); 238 return total; 239 } 240 241 const struct file_operations v9fs_file_operations = { 242 .llseek = generic_file_llseek, 243 .read = v9fs_file_read, 244 .write = v9fs_file_write, 245 .open = v9fs_file_open, 246 .release = v9fs_dir_release, 247 .lock = v9fs_file_lock, 248 .mmap = generic_file_mmap, 249 }; 250