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