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