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/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/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 /** 45 * v9fs_file_open - open a file (or directory) 46 * @inode: inode to be opened 47 * @file: file being opened 48 * 49 */ 50 51 int v9fs_file_open(struct inode *inode, struct file *file) 52 { 53 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 54 struct v9fs_fid *vfid; 55 struct v9fs_fcall *fcall = NULL; 56 int omode; 57 int fid = V9FS_NOFID; 58 int err; 59 60 dprintk(DEBUG_VFS, "inode: %p file: %p \n", inode, file); 61 62 vfid = v9fs_fid_lookup(file->f_dentry); 63 if (!vfid) { 64 dprintk(DEBUG_ERROR, "Couldn't resolve fid from dentry\n"); 65 return -EBADF; 66 } 67 68 fid = v9fs_get_idpool(&v9ses->fidpool); 69 if (fid < 0) { 70 eprintk(KERN_WARNING, "newfid fails!\n"); 71 return -ENOSPC; 72 } 73 74 err = v9fs_t_walk(v9ses, vfid->fid, fid, NULL, &fcall); 75 if (err < 0) { 76 dprintk(DEBUG_ERROR, "rewalk didn't work\n"); 77 if (fcall && fcall->id == RWALK) 78 goto clunk_fid; 79 else { 80 v9fs_put_idpool(fid, &v9ses->fidpool); 81 goto free_fcall; 82 } 83 } 84 kfree(fcall); 85 86 /* TODO: do special things for O_EXCL, O_NOFOLLOW, O_SYNC */ 87 /* translate open mode appropriately */ 88 omode = v9fs_uflags2omode(file->f_flags); 89 err = v9fs_t_open(v9ses, fid, omode, &fcall); 90 if (err < 0) { 91 PRINT_FCALL_ERROR("open failed", fcall); 92 goto clunk_fid; 93 } 94 95 vfid = kmalloc(sizeof(struct v9fs_fid), GFP_KERNEL); 96 if (vfid == NULL) { 97 dprintk(DEBUG_ERROR, "out of memory\n"); 98 err = -ENOMEM; 99 goto clunk_fid; 100 } 101 102 file->private_data = vfid; 103 vfid->fid = fid; 104 vfid->fidopen = 1; 105 vfid->fidclunked = 0; 106 vfid->iounit = fcall->params.ropen.iounit; 107 vfid->rdir_pos = 0; 108 vfid->rdir_fcall = NULL; 109 vfid->filp = file; 110 kfree(fcall); 111 112 return 0; 113 114 clunk_fid: 115 v9fs_t_clunk(v9ses, fid); 116 117 free_fcall: 118 kfree(fcall); 119 120 return err; 121 } 122 123 /** 124 * v9fs_file_lock - lock a file (or directory) 125 * @inode: inode to be opened 126 * @file: file being opened 127 * 128 * XXX - this looks like a local only lock, we should extend into 9P 129 * by using open exclusive 130 */ 131 132 static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) 133 { 134 int res = 0; 135 struct inode *inode = filp->f_dentry->d_inode; 136 137 dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); 138 139 /* No mandatory locks */ 140 if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID) 141 return -ENOLCK; 142 143 if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { 144 filemap_write_and_wait(inode->i_mapping); 145 invalidate_inode_pages(&inode->i_data); 146 } 147 148 return res; 149 } 150 151 /** 152 * v9fs_file_read - read from a file 153 * @filep: file pointer to read 154 * @data: data buffer to read data into 155 * @count: size of buffer 156 * @offset: offset at which to read data 157 * 158 */ 159 static ssize_t 160 v9fs_file_read(struct file *filp, char __user * data, size_t count, 161 loff_t * offset) 162 { 163 struct inode *inode = filp->f_dentry->d_inode; 164 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 165 struct v9fs_fid *v9f = filp->private_data; 166 struct v9fs_fcall *fcall = NULL; 167 int fid = v9f->fid; 168 int rsize = 0; 169 int result = 0; 170 int total = 0; 171 int n; 172 173 dprintk(DEBUG_VFS, "\n"); 174 175 rsize = v9ses->maxdata - V9FS_IOHDRSZ; 176 if (v9f->iounit != 0 && rsize > v9f->iounit) 177 rsize = v9f->iounit; 178 179 do { 180 if (count < rsize) 181 rsize = count; 182 183 result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall); 184 185 if (result < 0) { 186 printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n", 187 result); 188 189 kfree(fcall); 190 return total; 191 } else 192 *offset += result; 193 194 n = copy_to_user(data, fcall->params.rread.data, result); 195 if (n) { 196 dprintk(DEBUG_ERROR, "Problem copying to user %d\n", n); 197 kfree(fcall); 198 return -EFAULT; 199 } 200 201 count -= result; 202 data += result; 203 total += result; 204 205 kfree(fcall); 206 207 if (result < rsize) 208 break; 209 } while (count); 210 211 return total; 212 } 213 214 /** 215 * v9fs_file_write - write to a file 216 * @filep: file pointer to write 217 * @data: data buffer to write data from 218 * @count: size of buffer 219 * @offset: offset at which to write data 220 * 221 */ 222 223 static ssize_t 224 v9fs_file_write(struct file *filp, const char __user * data, 225 size_t count, loff_t * offset) 226 { 227 struct inode *inode = filp->f_dentry->d_inode; 228 struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); 229 struct v9fs_fid *v9fid = filp->private_data; 230 struct v9fs_fcall *fcall; 231 int fid = v9fid->fid; 232 int result = -EIO; 233 int rsize = 0; 234 int total = 0; 235 236 dprintk(DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count, 237 (int)*offset); 238 rsize = v9ses->maxdata - V9FS_IOHDRSZ; 239 if (v9fid->iounit != 0 && rsize > v9fid->iounit) 240 rsize = v9fid->iounit; 241 242 do { 243 if (count < rsize) 244 rsize = count; 245 246 result = v9fs_t_write(v9ses, fid, *offset, rsize, data, &fcall); 247 if (result < 0) { 248 PRINT_FCALL_ERROR("error while writing", fcall); 249 kfree(fcall); 250 return result; 251 } else 252 *offset += result; 253 254 kfree(fcall); 255 fcall = NULL; 256 257 if (result != rsize) { 258 eprintk(KERN_ERR, 259 "short write: v9fs_t_write returned %d\n", 260 result); 261 break; 262 } 263 264 count -= result; 265 data += result; 266 total += result; 267 } while (count); 268 269 invalidate_inode_pages2(inode->i_mapping); 270 return total; 271 } 272 273 const struct file_operations v9fs_file_operations = { 274 .llseek = generic_file_llseek, 275 .read = v9fs_file_read, 276 .write = v9fs_file_write, 277 .open = v9fs_file_open, 278 .release = v9fs_dir_release, 279 .lock = v9fs_file_lock, 280 .mmap = generic_file_mmap, 281 }; 282