Eric Van Hensbergen | e69e7fe | 2005-09-09 13:04:18 -0700 | [diff] [blame^] | 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 as published by |
| 11 | * the Free Software Foundation; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License |
| 20 | * along with this program; if not, write to: |
| 21 | * Free Software Foundation |
| 22 | * 51 Franklin Street, Fifth Floor |
| 23 | * Boston, MA 02111-1301 USA |
| 24 | * |
| 25 | */ |
| 26 | |
| 27 | #include <linux/module.h> |
| 28 | #include <linux/errno.h> |
| 29 | #include <linux/fs.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/version.h> |
| 36 | #include <linux/list.h> |
| 37 | #include <asm/uaccess.h> |
| 38 | #include <linux/idr.h> |
| 39 | |
| 40 | #include "debug.h" |
| 41 | #include "v9fs.h" |
| 42 | #include "9p.h" |
| 43 | #include "v9fs_vfs.h" |
| 44 | #include "fid.h" |
| 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 *v9fid = v9fs_fid_lookup(file->f_dentry, FID_WALK); |
| 57 | struct v9fs_fid *v9newfid = NULL; |
| 58 | struct v9fs_fcall *fcall = NULL; |
| 59 | int open_mode = 0; |
| 60 | unsigned int iounit = 0; |
| 61 | int newfid = -1; |
| 62 | long result = -1; |
| 63 | |
| 64 | dprintk(DEBUG_VFS, "inode: %p file: %p v9fid= %p\n", inode, file, |
| 65 | v9fid); |
| 66 | |
| 67 | if (!v9fid) { |
| 68 | struct dentry *dentry = file->f_dentry; |
| 69 | dprintk(DEBUG_ERROR, "Couldn't resolve fid from dentry\n"); |
| 70 | |
| 71 | /* XXX - some duplication from lookup, generalize later */ |
| 72 | /* basically vfs_lookup is too heavy weight */ |
| 73 | v9fid = v9fs_fid_lookup(file->f_dentry, FID_OP); |
| 74 | if (!v9fid) |
| 75 | return -EBADF; |
| 76 | |
| 77 | v9fid = v9fs_fid_lookup(dentry->d_parent, FID_WALK); |
| 78 | if (!v9fid) |
| 79 | return -EBADF; |
| 80 | |
| 81 | newfid = v9fs_get_idpool(&v9ses->fidpool); |
| 82 | if (newfid < 0) { |
| 83 | eprintk(KERN_WARNING, "newfid fails!\n"); |
| 84 | return -ENOSPC; |
| 85 | } |
| 86 | |
| 87 | result = |
| 88 | v9fs_t_walk(v9ses, v9fid->fid, newfid, |
| 89 | (char *)file->f_dentry->d_name.name, NULL); |
| 90 | if (result < 0) { |
| 91 | v9fs_put_idpool(newfid, &v9ses->fidpool); |
| 92 | dprintk(DEBUG_ERROR, "rewalk didn't work\n"); |
| 93 | return -EBADF; |
| 94 | } |
| 95 | |
| 96 | v9fid = v9fs_fid_create(dentry); |
| 97 | if (v9fid == NULL) { |
| 98 | dprintk(DEBUG_ERROR, "couldn't insert\n"); |
| 99 | return -ENOMEM; |
| 100 | } |
| 101 | v9fid->fid = newfid; |
| 102 | } |
| 103 | |
| 104 | if (v9fid->fidcreate) { |
| 105 | /* create case */ |
| 106 | newfid = v9fid->fid; |
| 107 | iounit = v9fid->iounit; |
| 108 | v9fid->fidcreate = 0; |
| 109 | } else { |
| 110 | if (!S_ISDIR(inode->i_mode)) |
| 111 | newfid = v9fid->fid; |
| 112 | else { |
| 113 | newfid = v9fs_get_idpool(&v9ses->fidpool); |
| 114 | if (newfid < 0) { |
| 115 | eprintk(KERN_WARNING, "allocation failed\n"); |
| 116 | return -ENOSPC; |
| 117 | } |
| 118 | /* This would be a somewhat critical clone */ |
| 119 | result = |
| 120 | v9fs_t_walk(v9ses, v9fid->fid, newfid, NULL, |
| 121 | &fcall); |
| 122 | if (result < 0) { |
| 123 | dprintk(DEBUG_ERROR, "clone error: %s\n", |
| 124 | FCALL_ERROR(fcall)); |
| 125 | kfree(fcall); |
| 126 | return result; |
| 127 | } |
| 128 | |
| 129 | v9newfid = v9fs_fid_create(file->f_dentry); |
| 130 | v9newfid->fid = newfid; |
| 131 | v9newfid->qid = v9fid->qid; |
| 132 | v9newfid->iounit = v9fid->iounit; |
| 133 | v9newfid->fidopen = 0; |
| 134 | v9newfid->fidclunked = 0; |
| 135 | v9newfid->v9ses = v9ses; |
| 136 | v9fid = v9newfid; |
| 137 | kfree(fcall); |
| 138 | } |
| 139 | |
| 140 | /* TODO: do special things for O_EXCL, O_NOFOLLOW, O_SYNC */ |
| 141 | /* translate open mode appropriately */ |
| 142 | open_mode = file->f_flags & 0x3; |
| 143 | |
| 144 | if (file->f_flags & O_EXCL) |
| 145 | open_mode |= V9FS_OEXCL; |
| 146 | |
| 147 | if (v9ses->extended) { |
| 148 | if (file->f_flags & O_TRUNC) |
| 149 | open_mode |= V9FS_OTRUNC; |
| 150 | |
| 151 | if (file->f_flags & O_APPEND) |
| 152 | open_mode |= V9FS_OAPPEND; |
| 153 | } |
| 154 | |
| 155 | result = v9fs_t_open(v9ses, newfid, open_mode, &fcall); |
| 156 | if (result < 0) { |
| 157 | dprintk(DEBUG_ERROR, |
| 158 | "open failed, open_mode 0x%x: %s\n", open_mode, |
| 159 | FCALL_ERROR(fcall)); |
| 160 | kfree(fcall); |
| 161 | return result; |
| 162 | } |
| 163 | |
| 164 | iounit = fcall->params.ropen.iounit; |
| 165 | kfree(fcall); |
| 166 | } |
| 167 | |
| 168 | |
| 169 | file->private_data = v9fid; |
| 170 | |
| 171 | v9fid->rdir_pos = 0; |
| 172 | v9fid->rdir_fcall = NULL; |
| 173 | v9fid->fidopen = 1; |
| 174 | v9fid->filp = file; |
| 175 | v9fid->iounit = iounit; |
| 176 | |
| 177 | return 0; |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * v9fs_file_lock - lock a file (or directory) |
| 182 | * @inode: inode to be opened |
| 183 | * @file: file being opened |
| 184 | * |
| 185 | * XXX - this looks like a local only lock, we should extend into 9P |
| 186 | * by using open exclusive |
| 187 | */ |
| 188 | |
| 189 | static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) |
| 190 | { |
| 191 | int res = 0; |
| 192 | struct inode *inode = filp->f_dentry->d_inode; |
| 193 | |
| 194 | dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); |
| 195 | |
| 196 | /* No mandatory locks */ |
| 197 | if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID) |
| 198 | return -ENOLCK; |
| 199 | |
| 200 | if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { |
| 201 | filemap_fdatawrite(inode->i_mapping); |
| 202 | filemap_fdatawait(inode->i_mapping); |
| 203 | invalidate_inode_pages(&inode->i_data); |
| 204 | } |
| 205 | |
| 206 | return res; |
| 207 | } |
| 208 | |
| 209 | /** |
| 210 | * v9fs_read - read from a file (internal) |
| 211 | * @filep: file pointer to read |
| 212 | * @data: data buffer to read data into |
| 213 | * @count: size of buffer |
| 214 | * @offset: offset at which to read data |
| 215 | * |
| 216 | */ |
| 217 | |
| 218 | static ssize_t |
| 219 | v9fs_read(struct file *filp, char *buffer, size_t count, loff_t * offset) |
| 220 | { |
| 221 | struct inode *inode = filp->f_dentry->d_inode; |
| 222 | struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); |
| 223 | struct v9fs_fid *v9f = filp->private_data; |
| 224 | struct v9fs_fcall *fcall = NULL; |
| 225 | int fid = v9f->fid; |
| 226 | int rsize = 0; |
| 227 | int result = 0; |
| 228 | int total = 0; |
| 229 | |
| 230 | dprintk(DEBUG_VFS, "\n"); |
| 231 | |
| 232 | rsize = v9ses->maxdata - V9FS_IOHDRSZ; |
| 233 | if (v9f->iounit != 0 && rsize > v9f->iounit) |
| 234 | rsize = v9f->iounit; |
| 235 | |
| 236 | do { |
| 237 | if (count < rsize) |
| 238 | rsize = count; |
| 239 | |
| 240 | result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall); |
| 241 | |
| 242 | if (result < 0) { |
| 243 | printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n", |
| 244 | result); |
| 245 | |
| 246 | kfree(fcall); |
| 247 | return total; |
| 248 | } else |
| 249 | *offset += result; |
| 250 | |
| 251 | /* XXX - extra copy */ |
| 252 | memcpy(buffer, fcall->params.rread.data, result); |
| 253 | count -= result; |
| 254 | buffer += result; |
| 255 | total += result; |
| 256 | |
| 257 | kfree(fcall); |
| 258 | |
| 259 | if (result < rsize) |
| 260 | break; |
| 261 | } while (count); |
| 262 | |
| 263 | return total; |
| 264 | } |
| 265 | |
| 266 | /** |
| 267 | * v9fs_file_read - read from a file |
| 268 | * @filep: file pointer to read |
| 269 | * @data: data buffer to read data into |
| 270 | * @count: size of buffer |
| 271 | * @offset: offset at which to read data |
| 272 | * |
| 273 | */ |
| 274 | |
| 275 | static ssize_t |
| 276 | v9fs_file_read(struct file *filp, char __user * data, size_t count, |
| 277 | loff_t * offset) |
| 278 | { |
| 279 | int retval = -1; |
| 280 | int ret = 0; |
| 281 | char *buffer; |
| 282 | |
| 283 | buffer = kmalloc(count, GFP_KERNEL); |
| 284 | if (!buffer) |
| 285 | return -ENOMEM; |
| 286 | |
| 287 | retval = v9fs_read(filp, buffer, count, offset); |
| 288 | if (retval > 0) { |
| 289 | if ((ret = copy_to_user(data, buffer, retval)) != 0) { |
| 290 | dprintk(DEBUG_ERROR, "Problem copying to user %d\n", |
| 291 | ret); |
| 292 | retval = ret; |
| 293 | } |
| 294 | } |
| 295 | |
| 296 | kfree(buffer); |
| 297 | |
| 298 | return retval; |
| 299 | } |
| 300 | |
| 301 | /** |
| 302 | * v9fs_write - write to a file |
| 303 | * @filep: file pointer to write |
| 304 | * @data: data buffer to write data from |
| 305 | * @count: size of buffer |
| 306 | * @offset: offset at which to write data |
| 307 | * |
| 308 | */ |
| 309 | |
| 310 | static ssize_t |
| 311 | v9fs_write(struct file *filp, char *buffer, size_t count, loff_t * offset) |
| 312 | { |
| 313 | struct inode *inode = filp->f_dentry->d_inode; |
| 314 | struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); |
| 315 | struct v9fs_fid *v9fid = filp->private_data; |
| 316 | struct v9fs_fcall *fcall; |
| 317 | int fid = v9fid->fid; |
| 318 | int result = -EIO; |
| 319 | int rsize = 0; |
| 320 | int total = 0; |
| 321 | |
| 322 | dprintk(DEBUG_VFS, "data %p count %d offset %x\n", buffer, (int)count, |
| 323 | (int)*offset); |
| 324 | rsize = v9ses->maxdata - V9FS_IOHDRSZ; |
| 325 | if (v9fid->iounit != 0 && rsize > v9fid->iounit) |
| 326 | rsize = v9fid->iounit; |
| 327 | |
| 328 | dump_data(buffer, count); |
| 329 | |
| 330 | do { |
| 331 | if (count < rsize) |
| 332 | rsize = count; |
| 333 | |
| 334 | result = |
| 335 | v9fs_t_write(v9ses, fid, *offset, rsize, buffer, &fcall); |
| 336 | if (result < 0) { |
| 337 | eprintk(KERN_ERR, "error while writing: %s(%d)\n", |
| 338 | FCALL_ERROR(fcall), result); |
| 339 | kfree(fcall); |
| 340 | return result; |
| 341 | } else |
| 342 | *offset += result; |
| 343 | |
| 344 | kfree(fcall); |
| 345 | |
| 346 | if (result != rsize) { |
| 347 | eprintk(KERN_ERR, |
| 348 | "short write: v9fs_t_write returned %d\n", |
| 349 | result); |
| 350 | break; |
| 351 | } |
| 352 | |
| 353 | count -= result; |
| 354 | buffer += result; |
| 355 | total += result; |
| 356 | } while (count); |
| 357 | |
| 358 | return total; |
| 359 | } |
| 360 | |
| 361 | /** |
| 362 | * v9fs_file_write - write to a file |
| 363 | * @filep: file pointer to write |
| 364 | * @data: data buffer to write data from |
| 365 | * @count: size of buffer |
| 366 | * @offset: offset at which to write data |
| 367 | * |
| 368 | */ |
| 369 | |
| 370 | static ssize_t |
| 371 | v9fs_file_write(struct file *filp, const char __user * data, |
| 372 | size_t count, loff_t * offset) |
| 373 | { |
| 374 | int ret = -1; |
| 375 | char *buffer; |
| 376 | |
| 377 | buffer = kmalloc(count, GFP_KERNEL); |
| 378 | if (buffer == NULL) |
| 379 | return -ENOMEM; |
| 380 | |
| 381 | ret = copy_from_user(buffer, data, count); |
| 382 | if (ret) { |
| 383 | dprintk(DEBUG_ERROR, "Problem copying from user\n"); |
| 384 | ret = -EFAULT; |
| 385 | } else { |
| 386 | ret = v9fs_write(filp, buffer, count, offset); |
| 387 | } |
| 388 | |
| 389 | kfree(buffer); |
| 390 | |
| 391 | return ret; |
| 392 | } |
| 393 | |
| 394 | struct file_operations v9fs_file_operations = { |
| 395 | .llseek = generic_file_llseek, |
| 396 | .read = v9fs_file_read, |
| 397 | .write = v9fs_file_write, |
| 398 | .open = v9fs_file_open, |
| 399 | .release = v9fs_dir_release, |
| 400 | .lock = v9fs_file_lock, |
| 401 | }; |