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/inet.h> 34 #include <linux/list.h> 35 #include <asm/uaccess.h> 36 #include <linux/idr.h> 37 38 #include "debug.h" 39 #include "v9fs.h" 40 #include "9p.h" 41 #include "v9fs_vfs.h" 42 #include "fid.h" 43 44 static const struct file_operations v9fs_cached_file_operations; 45 46 /** 47 * v9fs_file_open - open a file (or directory) 48 * @inode: inode to be opened 49 * @file: file being opened 50 * 51 */ 52 53 int v9fs_file_open(struct inode *inode, struct file *file) 54 { 55 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 56 struct v9fs_fid *vfid; 57 struct v9fs_fcall *fcall = NULL; 58 int omode; 59 int err; 60 61 dprintk(DEBUG_VFS, "inode: %p file: %p \n", inode, file); 62 63 vfid = v9fs_fid_clone(file->f_path.dentry); 64 if (IS_ERR(vfid)) 65 return PTR_ERR(vfid); 66 67 omode = v9fs_uflags2omode(file->f_flags); 68 err = v9fs_t_open(v9ses, vfid->fid, omode, &fcall); 69 if (err < 0) { 70 PRINT_FCALL_ERROR("open failed", fcall); 71 goto Clunk_Fid; 72 } 73 74 file->private_data = vfid; 75 vfid->fidopen = 1; 76 vfid->fidclunked = 0; 77 vfid->iounit = fcall->params.ropen.iounit; 78 vfid->rdir_pos = 0; 79 vfid->rdir_fcall = NULL; 80 vfid->filp = file; 81 kfree(fcall); 82 83 if((vfid->qid.version) && (v9ses->cache)) { 84 dprintk(DEBUG_VFS, "cached"); 85 /* enable cached file options */ 86 if(file->f_op == &v9fs_file_operations) 87 file->f_op = &v9fs_cached_file_operations; 88 } 89 90 return 0; 91 92 Clunk_Fid: 93 v9fs_fid_clunk(v9ses, vfid); 94 kfree(fcall); 95 96 return err; 97 } 98 99 /** 100 * v9fs_file_lock - lock a file (or directory) 101 * @inode: inode to be opened 102 * @file: file being opened 103 * 104 * XXX - this looks like a local only lock, we should extend into 9P 105 * by using open exclusive 106 */ 107 108 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) 109 { 110 int res = 0; 111 struct inode *inode = filp->f_path.dentry->d_inode; 112 113 dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); 114 115 /* No mandatory locks */ 116 if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID) 117 return -ENOLCK; 118 119 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { 120 filemap_write_and_wait(inode->i_mapping); 121 invalidate_mapping_pages(&inode->i_data, 0, -1); 122 } 123 124 return res; 125 } 126 127 /** 128 * v9fs_file_read - read from a file 129 * @filep: file pointer to read 130 * @data: data buffer to read data into 131 * @count: size of buffer 132 * @offset: offset at which to read data 133 * 134 */ 135 static ssize_t 136 v9fs_file_read(struct file *filp, char __user * data, size_t count, 137 loff_t * offset) 138 { 139 struct inode *inode = filp->f_path.dentry->d_inode; 140 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 141 struct v9fs_fid *v9f = filp->private_data; 142 struct v9fs_fcall *fcall = NULL; 143 int fid = v9f->fid; 144 int rsize = 0; 145 int result = 0; 146 int total = 0; 147 int n; 148 149 dprintk(DEBUG_VFS, "\n"); 150 151 rsize = v9ses->maxdata - V9FS_IOHDRSZ; 152 if (v9f->iounit != 0 && rsize > v9f->iounit) 153 rsize = v9f->iounit; 154 155 do { 156 if (count < rsize) 157 rsize = count; 158 159 result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall); 160 161 if (result < 0) { 162 printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n", 163 result); 164 165 kfree(fcall); 166 return total; 167 } else 168 *offset += result; 169 170 n = copy_to_user(data, fcall->params.rread.data, result); 171 if (n) { 172 dprintk(DEBUG_ERROR, "Problem copying to user %d\n", n); 173 kfree(fcall); 174 return -EFAULT; 175 } 176 177 count -= result; 178 data += result; 179 total += result; 180 181 kfree(fcall); 182 183 if (result < rsize) 184 break; 185 } while (count); 186 187 return total; 188 } 189 190 /** 191 * v9fs_file_write - write to a file 192 * @filep: file pointer to write 193 * @data: data buffer to write data from 194 * @count: size of buffer 195 * @offset: offset at which to write data 196 * 197 */ 198 199 static ssize_t 200 v9fs_file_write(struct file *filp, const char __user * data, 201 size_t count, loff_t * offset) 202 { 203 struct inode *inode = filp->f_path.dentry->d_inode; 204 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 205 struct v9fs_fid *v9fid = filp->private_data; 206 struct v9fs_fcall *fcall; 207 int fid = v9fid->fid; 208 int result = -EIO; 209 int rsize = 0; 210 int total = 0; 211 212 dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count, 213 (int)*offset); 214 rsize = v9ses->maxdata - V9FS_IOHDRSZ; 215 if (v9fid->iounit != 0 && rsize > v9fid->iounit) 216 rsize = v9fid->iounit; 217 218 do { 219 if (count < rsize) 220 rsize = count; 221 222 result = v9fs_t_write(v9ses, fid, *offset, rsize, data, &fcall); 223 if (result < 0) { 224 PRINT_FCALL_ERROR("error while writing", fcall); 225 kfree(fcall); 226 return result; 227 } else 228 *offset += result; 229 230 kfree(fcall); 231 fcall = NULL; 232 233 if (result != rsize) { 234 eprintk(KERN_ERR, 235 "short write: v9fs_t_write returned %d\n", 236 result); 237 break; 238 } 239 240 count -= result; 241 data += result; 242 total += result; 243 } while (count); 244 245 invalidate_inode_pages2(inode->i_mapping); 246 return total; 247 } 248 249 static const struct file_operations v9fs_cached_file_operations = { 250 .llseek = generic_file_llseek, 251 .read = do_sync_read, 252 .aio_read = generic_file_aio_read, 253 .write = v9fs_file_write, 254 .open = v9fs_file_open, 255 .release = v9fs_dir_release, 256 .lock = v9fs_file_lock, 257 .mmap = generic_file_mmap, 258 }; 259 260 const struct file_operations v9fs_file_operations = { 261 .llseek = generic_file_llseek, 262 .read = v9fs_file_read, 263 .write = v9fs_file_write, 264 .open = v9fs_file_open, 265 .release = v9fs_dir_release, 266 .lock = v9fs_file_lock, 267 .mmap = generic_file_mmap, 268 }; 269