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 static const struct file_operations v9fs_cached_file_operations; 46 47 /** 48 * v9fs_file_open - open a file (or directory) 49 * @inode: inode to be opened 50 * @file: file being opened 51 * 52 */ 53 54 int v9fs_file_open(struct inode *inode, struct file *file) 55 { 56 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 57 struct v9fs_fid *vfid; 58 struct v9fs_fcall *fcall = NULL; 59 int omode; 60 int err; 61 62 dprintk(DEBUG_VFS, "inode: %p file: %p \n", inode, file); 63 64 vfid = v9fs_fid_clone(file->f_path.dentry); 65 if (IS_ERR(vfid)) 66 return PTR_ERR(vfid); 67 68 omode = v9fs_uflags2omode(file->f_flags); 69 err = v9fs_t_open(v9ses, vfid->fid, omode, &fcall); 70 if (err < 0) { 71 PRINT_FCALL_ERROR("open failed", fcall); 72 goto Clunk_Fid; 73 } 74 75 file->private_data = vfid; 76 vfid->fidopen = 1; 77 vfid->fidclunked = 0; 78 vfid->iounit = fcall->params.ropen.iounit; 79 vfid->rdir_pos = 0; 80 vfid->rdir_fcall = NULL; 81 vfid->filp = file; 82 kfree(fcall); 83 84 if((vfid->qid.version) && (v9ses->cache)) { 85 dprintk(DEBUG_VFS, "cached"); 86 /* enable cached file options */ 87 if(file->f_op == &v9fs_file_operations) 88 file->f_op = &v9fs_cached_file_operations; 89 } 90 91 return 0; 92 93 Clunk_Fid: 94 v9fs_fid_clunk(v9ses, vfid); 95 kfree(fcall); 96 97 return err; 98 } 99 100 /** 101 * v9fs_file_lock - lock a file (or directory) 102 * @inode: inode to be opened 103 * @file: file being opened 104 * 105 * XXX - this looks like a local only lock, we should extend into 9P 106 * by using open exclusive 107 */ 108 109 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) 110 { 111 int res = 0; 112 struct inode *inode = filp->f_path.dentry->d_inode; 113 114 dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); 115 116 /* No mandatory locks */ 117 if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID) 118 return -ENOLCK; 119 120 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { 121 filemap_write_and_wait(inode->i_mapping); 122 invalidate_mapping_pages(&inode->i_data, 0, -1); 123 } 124 125 return res; 126 } 127 128 /** 129 * v9fs_file_read - read from a file 130 * @filep: file pointer to read 131 * @data: data buffer to read data into 132 * @count: size of buffer 133 * @offset: offset at which to read data 134 * 135 */ 136 static ssize_t 137 v9fs_file_read(struct file *filp, char __user * data, size_t count, 138 loff_t * offset) 139 { 140 struct inode *inode = filp->f_path.dentry->d_inode; 141 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 142 struct v9fs_fid *v9f = filp->private_data; 143 struct v9fs_fcall *fcall = NULL; 144 int fid = v9f->fid; 145 int rsize = 0; 146 int result = 0; 147 int total = 0; 148 int n; 149 150 dprintk(DEBUG_VFS, "\n"); 151 152 rsize = v9ses->maxdata - V9FS_IOHDRSZ; 153 if (v9f->iounit != 0 && rsize > v9f->iounit) 154 rsize = v9f->iounit; 155 156 do { 157 if (count < rsize) 158 rsize = count; 159 160 result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall); 161 162 if (result < 0) { 163 printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n", 164 result); 165 166 kfree(fcall); 167 return total; 168 } else 169 *offset += result; 170 171 n = copy_to_user(data, fcall->params.rread.data, result); 172 if (n) { 173 dprintk(DEBUG_ERROR, "Problem copying to user %d\n", n); 174 kfree(fcall); 175 return -EFAULT; 176 } 177 178 count -= result; 179 data += result; 180 total += result; 181 182 kfree(fcall); 183 184 if (result < rsize) 185 break; 186 } while (count); 187 188 return total; 189 } 190 191 /** 192 * v9fs_file_write - write to a file 193 * @filep: file pointer to write 194 * @data: data buffer to write data from 195 * @count: size of buffer 196 * @offset: offset at which to write data 197 * 198 */ 199 200 static ssize_t 201 v9fs_file_write(struct file *filp, const char __user * data, 202 size_t count, loff_t * offset) 203 { 204 struct inode *inode = filp->f_path.dentry->d_inode; 205 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 206 struct v9fs_fid *v9fid = filp->private_data; 207 struct v9fs_fcall *fcall; 208 int fid = v9fid->fid; 209 int result = -EIO; 210 int rsize = 0; 211 int total = 0; 212 213 dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count, 214 (int)*offset); 215 rsize = v9ses->maxdata - V9FS_IOHDRSZ; 216 if (v9fid->iounit != 0 && rsize > v9fid->iounit) 217 rsize = v9fid->iounit; 218 219 do { 220 if (count < rsize) 221 rsize = count; 222 223 result = v9fs_t_write(v9ses, fid, *offset, rsize, data, &fcall); 224 if (result < 0) { 225 PRINT_FCALL_ERROR("error while writing", fcall); 226 kfree(fcall); 227 return result; 228 } else 229 *offset += result; 230 231 kfree(fcall); 232 fcall = NULL; 233 234 if (result != rsize) { 235 eprintk(KERN_ERR, 236 "short write: v9fs_t_write returned %d\n", 237 result); 238 break; 239 } 240 241 count -= result; 242 data += result; 243 total += result; 244 } while (count); 245 246 invalidate_inode_pages2(inode->i_mapping); 247 return total; 248 } 249 250 static const struct file_operations v9fs_cached_file_operations = { 251 .llseek = generic_file_llseek, 252 .read = do_sync_read, 253 .aio_read = generic_file_aio_read, 254 .write = v9fs_file_write, 255 .open = v9fs_file_open, 256 .release = v9fs_dir_release, 257 .lock = v9fs_file_lock, 258 .mmap = generic_file_mmap, 259 }; 260 261 const struct file_operations v9fs_file_operations = { 262 .llseek = generic_file_llseek, 263 .read = v9fs_file_read, 264 .write = v9fs_file_write, 265 .open = v9fs_file_open, 266 .release = v9fs_dir_release, 267 .lock = v9fs_file_lock, 268 .mmap = generic_file_mmap, 269 }; 270