1 /* 2 * Copyright (c) 2002 Red Hat, Inc. All rights reserved. 3 * 4 * This software may be freely redistributed under the terms of the 5 * GNU General Public License. 6 * 7 * You should have received a copy of the GNU General Public License 8 * along with this program; if not, write to the Free Software 9 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 10 * 11 * Authors: David Woodhouse <dwmw2@infradead.org> 12 * David Howells <dhowells@redhat.com> 13 * 14 */ 15 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/init.h> 19 #include <linux/fs.h> 20 #include <linux/pagemap.h> 21 #include <linux/sched.h> 22 #include <linux/mount.h> 23 #include <linux/namei.h> 24 #include <linux/iversion.h> 25 #include "internal.h" 26 27 static const struct inode_operations afs_symlink_inode_operations = { 28 .get_link = page_get_link, 29 .listxattr = afs_listxattr, 30 }; 31 32 /* 33 * map the AFS file status to the inode member variables 34 */ 35 static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key) 36 { 37 struct inode *inode = AFS_VNODE_TO_I(vnode); 38 bool changed; 39 40 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu", 41 vnode->status.type, 42 vnode->status.nlink, 43 (unsigned long long) vnode->status.size, 44 vnode->status.data_version, 45 vnode->status.mode); 46 47 read_seqlock_excl(&vnode->cb_lock); 48 49 switch (vnode->status.type) { 50 case AFS_FTYPE_FILE: 51 inode->i_mode = S_IFREG | vnode->status.mode; 52 inode->i_op = &afs_file_inode_operations; 53 inode->i_fop = &afs_file_operations; 54 break; 55 case AFS_FTYPE_DIR: 56 inode->i_mode = S_IFDIR | vnode->status.mode; 57 inode->i_op = &afs_dir_inode_operations; 58 inode->i_fop = &afs_dir_file_operations; 59 break; 60 case AFS_FTYPE_SYMLINK: 61 /* Symlinks with a mode of 0644 are actually mountpoints. */ 62 if ((vnode->status.mode & 0777) == 0644) { 63 inode->i_flags |= S_AUTOMOUNT; 64 65 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags); 66 67 inode->i_mode = S_IFDIR | 0555; 68 inode->i_op = &afs_mntpt_inode_operations; 69 inode->i_fop = &afs_mntpt_file_operations; 70 } else { 71 inode->i_mode = S_IFLNK | vnode->status.mode; 72 inode->i_op = &afs_symlink_inode_operations; 73 } 74 inode_nohighmem(inode); 75 break; 76 default: 77 printk("kAFS: AFS vnode with undefined type\n"); 78 read_sequnlock_excl(&vnode->cb_lock); 79 return -EBADMSG; 80 } 81 82 changed = (vnode->status.size != inode->i_size); 83 84 set_nlink(inode, vnode->status.nlink); 85 inode->i_uid = vnode->status.owner; 86 inode->i_gid = vnode->status.group; 87 inode->i_size = vnode->status.size; 88 inode->i_ctime.tv_sec = vnode->status.mtime_client; 89 inode->i_ctime.tv_nsec = 0; 90 inode->i_atime = inode->i_mtime = inode->i_ctime; 91 inode->i_blocks = 0; 92 inode->i_generation = vnode->fid.unique; 93 inode_set_iversion_raw(inode, vnode->status.data_version); 94 inode->i_mapping->a_ops = &afs_fs_aops; 95 96 read_sequnlock_excl(&vnode->cb_lock); 97 98 #ifdef CONFIG_AFS_FSCACHE 99 if (changed) 100 fscache_attr_changed(vnode->cache); 101 #endif 102 return 0; 103 } 104 105 /* 106 * Fetch file status from the volume. 107 */ 108 int afs_fetch_status(struct afs_vnode *vnode, struct key *key) 109 { 110 struct afs_fs_cursor fc; 111 int ret; 112 113 _enter("%s,{%x:%u.%u,S=%lx}", 114 vnode->volume->name, 115 vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique, 116 vnode->flags); 117 118 ret = -ERESTARTSYS; 119 if (afs_begin_vnode_operation(&fc, vnode, key)) { 120 while (afs_select_fileserver(&fc)) { 121 fc.cb_break = vnode->cb_break + vnode->cb_s_break; 122 afs_fs_fetch_file_status(&fc, NULL); 123 } 124 125 afs_check_for_remote_deletion(&fc, fc.vnode); 126 afs_vnode_commit_status(&fc, vnode, fc.cb_break); 127 ret = afs_end_vnode_operation(&fc); 128 } 129 130 _leave(" = %d", ret); 131 return ret; 132 } 133 134 /* 135 * iget5() comparator 136 */ 137 int afs_iget5_test(struct inode *inode, void *opaque) 138 { 139 struct afs_iget_data *data = opaque; 140 141 return inode->i_ino == data->fid.vnode && 142 inode->i_generation == data->fid.unique; 143 } 144 145 /* 146 * iget5() comparator for inode created by autocell operations 147 * 148 * These pseudo inodes don't match anything. 149 */ 150 static int afs_iget5_autocell_test(struct inode *inode, void *opaque) 151 { 152 return 0; 153 } 154 155 /* 156 * iget5() inode initialiser 157 */ 158 static int afs_iget5_set(struct inode *inode, void *opaque) 159 { 160 struct afs_iget_data *data = opaque; 161 struct afs_vnode *vnode = AFS_FS_I(inode); 162 163 inode->i_ino = data->fid.vnode; 164 inode->i_generation = data->fid.unique; 165 vnode->fid = data->fid; 166 vnode->volume = data->volume; 167 168 return 0; 169 } 170 171 /* 172 * inode retrieval for autocell 173 */ 174 struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name, 175 int namesz, struct key *key) 176 { 177 struct afs_iget_data data; 178 struct afs_super_info *as; 179 struct afs_vnode *vnode; 180 struct super_block *sb; 181 struct inode *inode; 182 static atomic_t afs_autocell_ino; 183 184 _enter("{%x:%u},%*.*s,", 185 AFS_FS_I(dir)->fid.vid, AFS_FS_I(dir)->fid.vnode, 186 namesz, namesz, dev_name ?: ""); 187 188 sb = dir->i_sb; 189 as = sb->s_fs_info; 190 data.volume = as->volume; 191 data.fid.vid = as->volume->vid; 192 data.fid.unique = 0; 193 data.fid.vnode = 0; 194 195 inode = iget5_locked(sb, atomic_inc_return(&afs_autocell_ino), 196 afs_iget5_autocell_test, afs_iget5_set, 197 &data); 198 if (!inode) { 199 _leave(" = -ENOMEM"); 200 return ERR_PTR(-ENOMEM); 201 } 202 203 _debug("GOT INODE %p { ino=%lu, vl=%x, vn=%x, u=%x }", 204 inode, inode->i_ino, data.fid.vid, data.fid.vnode, 205 data.fid.unique); 206 207 vnode = AFS_FS_I(inode); 208 209 /* there shouldn't be an existing inode */ 210 BUG_ON(!(inode->i_state & I_NEW)); 211 212 inode->i_size = 0; 213 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO; 214 inode->i_op = &afs_autocell_inode_operations; 215 set_nlink(inode, 2); 216 inode->i_uid = GLOBAL_ROOT_UID; 217 inode->i_gid = GLOBAL_ROOT_GID; 218 inode->i_ctime.tv_sec = get_seconds(); 219 inode->i_ctime.tv_nsec = 0; 220 inode->i_atime = inode->i_mtime = inode->i_ctime; 221 inode->i_blocks = 0; 222 inode_set_iversion_raw(inode, 0); 223 inode->i_generation = 0; 224 225 set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags); 226 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags); 227 inode->i_flags |= S_AUTOMOUNT | S_NOATIME; 228 unlock_new_inode(inode); 229 _leave(" = %p", inode); 230 return inode; 231 } 232 233 /* 234 * inode retrieval 235 */ 236 struct inode *afs_iget(struct super_block *sb, struct key *key, 237 struct afs_fid *fid, struct afs_file_status *status, 238 struct afs_callback *cb, struct afs_cb_interest *cbi) 239 { 240 struct afs_iget_data data = { .fid = *fid }; 241 struct afs_super_info *as; 242 struct afs_vnode *vnode; 243 struct inode *inode; 244 int ret; 245 246 _enter(",{%x:%u.%u},,", fid->vid, fid->vnode, fid->unique); 247 248 as = sb->s_fs_info; 249 data.volume = as->volume; 250 251 inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set, 252 &data); 253 if (!inode) { 254 _leave(" = -ENOMEM"); 255 return ERR_PTR(-ENOMEM); 256 } 257 258 _debug("GOT INODE %p { vl=%x vn=%x, u=%x }", 259 inode, fid->vid, fid->vnode, fid->unique); 260 261 vnode = AFS_FS_I(inode); 262 263 /* deal with an existing inode */ 264 if (!(inode->i_state & I_NEW)) { 265 _leave(" = %p", inode); 266 return inode; 267 } 268 269 if (!status) { 270 /* it's a remotely extant inode */ 271 ret = afs_fetch_status(vnode, key); 272 if (ret < 0) 273 goto bad_inode; 274 } else { 275 /* it's an inode we just created */ 276 memcpy(&vnode->status, status, sizeof(vnode->status)); 277 278 if (!cb) { 279 /* it's a symlink we just created (the fileserver 280 * didn't give us a callback) */ 281 vnode->cb_version = 0; 282 vnode->cb_type = 0; 283 vnode->cb_expires_at = 0; 284 } else { 285 vnode->cb_version = cb->version; 286 vnode->cb_type = cb->type; 287 vnode->cb_expires_at = cb->expiry; 288 vnode->cb_interest = afs_get_cb_interest(cbi); 289 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags); 290 } 291 292 vnode->cb_expires_at += ktime_get_real_seconds(); 293 } 294 295 /* set up caching before mapping the status, as map-status reads the 296 * first page of symlinks to see if they're really mountpoints */ 297 inode->i_size = vnode->status.size; 298 #ifdef CONFIG_AFS_FSCACHE 299 vnode->cache = fscache_acquire_cookie(vnode->volume->cache, 300 &afs_vnode_cache_index_def, 301 vnode, true); 302 #endif 303 304 ret = afs_inode_map_status(vnode, key); 305 if (ret < 0) 306 goto bad_inode; 307 308 /* success */ 309 clear_bit(AFS_VNODE_UNSET, &vnode->flags); 310 inode->i_flags |= S_NOATIME; 311 unlock_new_inode(inode); 312 _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type); 313 return inode; 314 315 /* failure */ 316 bad_inode: 317 #ifdef CONFIG_AFS_FSCACHE 318 fscache_relinquish_cookie(vnode->cache, 0); 319 vnode->cache = NULL; 320 #endif 321 iget_failed(inode); 322 _leave(" = %d [bad]", ret); 323 return ERR_PTR(ret); 324 } 325 326 /* 327 * mark the data attached to an inode as obsolete due to a write on the server 328 * - might also want to ditch all the outstanding writes and dirty pages 329 */ 330 void afs_zap_data(struct afs_vnode *vnode) 331 { 332 _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode); 333 334 /* nuke all the non-dirty pages that aren't locked, mapped or being 335 * written back in a regular file and completely discard the pages in a 336 * directory or symlink */ 337 if (S_ISREG(vnode->vfs_inode.i_mode)) 338 invalidate_remote_inode(&vnode->vfs_inode); 339 else 340 invalidate_inode_pages2(vnode->vfs_inode.i_mapping); 341 } 342 343 /* 344 * validate a vnode/inode 345 * - there are several things we need to check 346 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link, 347 * symlink) 348 * - parent dir metadata changed (security changes) 349 * - dentry data changed (write, truncate) 350 * - dentry metadata changed (security changes) 351 */ 352 int afs_validate(struct afs_vnode *vnode, struct key *key) 353 { 354 time64_t now = ktime_get_real_seconds(); 355 bool valid = false; 356 int ret; 357 358 _enter("{v={%x:%u} fl=%lx},%x", 359 vnode->fid.vid, vnode->fid.vnode, vnode->flags, 360 key_serial(key)); 361 362 /* Quickly check the callback state. Ideally, we'd use read_seqbegin 363 * here, but we have no way to pass the net namespace to the RCU 364 * cleanup for the server record. 365 */ 366 read_seqlock_excl(&vnode->cb_lock); 367 368 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) { 369 if (vnode->cb_s_break != vnode->cb_interest->server->cb_s_break) { 370 vnode->cb_s_break = vnode->cb_interest->server->cb_s_break; 371 } else if (!test_bit(AFS_VNODE_DIR_MODIFIED, &vnode->flags) && 372 !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) && 373 vnode->cb_expires_at - 10 > now) { 374 valid = true; 375 } 376 } else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { 377 valid = true; 378 } 379 380 read_sequnlock_excl(&vnode->cb_lock); 381 382 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) 383 clear_nlink(&vnode->vfs_inode); 384 385 if (valid) 386 goto valid; 387 388 mutex_lock(&vnode->validate_lock); 389 390 /* if the promise has expired, we need to check the server again to get 391 * a new promise - note that if the (parent) directory's metadata was 392 * changed then the security may be different and we may no longer have 393 * access */ 394 if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) { 395 _debug("not promised"); 396 ret = afs_fetch_status(vnode, key); 397 if (ret < 0) { 398 if (ret == -ENOENT) { 399 set_bit(AFS_VNODE_DELETED, &vnode->flags); 400 ret = -ESTALE; 401 } 402 goto error_unlock; 403 } 404 _debug("new promise [fl=%lx]", vnode->flags); 405 } 406 407 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { 408 _debug("file already deleted"); 409 ret = -ESTALE; 410 goto error_unlock; 411 } 412 413 /* if the vnode's data version number changed then its contents are 414 * different */ 415 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) 416 afs_zap_data(vnode); 417 418 clear_bit(AFS_VNODE_DIR_MODIFIED, &vnode->flags); 419 mutex_unlock(&vnode->validate_lock); 420 valid: 421 _leave(" = 0"); 422 return 0; 423 424 error_unlock: 425 mutex_unlock(&vnode->validate_lock); 426 _leave(" = %d", ret); 427 return ret; 428 } 429 430 /* 431 * read the attributes of an inode 432 */ 433 int afs_getattr(const struct path *path, struct kstat *stat, 434 u32 request_mask, unsigned int query_flags) 435 { 436 struct inode *inode = d_inode(path->dentry); 437 struct afs_vnode *vnode = AFS_FS_I(inode); 438 int seq = 0; 439 440 _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation); 441 442 do { 443 read_seqbegin_or_lock(&vnode->cb_lock, &seq); 444 generic_fillattr(inode, stat); 445 } while (need_seqretry(&vnode->cb_lock, seq)); 446 447 done_seqretry(&vnode->cb_lock, seq); 448 return 0; 449 } 450 451 /* 452 * discard an AFS inode 453 */ 454 int afs_drop_inode(struct inode *inode) 455 { 456 _enter(""); 457 458 if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags)) 459 return generic_delete_inode(inode); 460 else 461 return generic_drop_inode(inode); 462 } 463 464 /* 465 * clear an AFS inode 466 */ 467 void afs_evict_inode(struct inode *inode) 468 { 469 struct afs_vnode *vnode; 470 471 vnode = AFS_FS_I(inode); 472 473 _enter("{%x:%u.%d}", 474 vnode->fid.vid, 475 vnode->fid.vnode, 476 vnode->fid.unique); 477 478 _debug("CLEAR INODE %p", inode); 479 480 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode); 481 482 truncate_inode_pages_final(&inode->i_data); 483 clear_inode(inode); 484 485 if (vnode->cb_interest) { 486 afs_put_cb_interest(afs_i2net(inode), vnode->cb_interest); 487 vnode->cb_interest = NULL; 488 } 489 490 while (!list_empty(&vnode->wb_keys)) { 491 struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next, 492 struct afs_wb_key, vnode_link); 493 list_del(&wbk->vnode_link); 494 afs_put_wb_key(wbk); 495 } 496 497 #ifdef CONFIG_AFS_FSCACHE 498 fscache_relinquish_cookie(vnode->cache, 0); 499 vnode->cache = NULL; 500 #endif 501 502 afs_put_permits(vnode->permit_cache); 503 _leave(""); 504 } 505 506 /* 507 * set the attributes of an inode 508 */ 509 int afs_setattr(struct dentry *dentry, struct iattr *attr) 510 { 511 struct afs_fs_cursor fc; 512 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry)); 513 struct key *key; 514 int ret; 515 516 _enter("{%x:%u},{n=%pd},%x", 517 vnode->fid.vid, vnode->fid.vnode, dentry, 518 attr->ia_valid); 519 520 if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID | 521 ATTR_MTIME))) { 522 _leave(" = 0 [unsupported]"); 523 return 0; 524 } 525 526 /* flush any dirty data outstanding on a regular file */ 527 if (S_ISREG(vnode->vfs_inode.i_mode)) 528 filemap_write_and_wait(vnode->vfs_inode.i_mapping); 529 530 if (attr->ia_valid & ATTR_FILE) { 531 key = afs_file_key(attr->ia_file); 532 } else { 533 key = afs_request_key(vnode->volume->cell); 534 if (IS_ERR(key)) { 535 ret = PTR_ERR(key); 536 goto error; 537 } 538 } 539 540 ret = -ERESTARTSYS; 541 if (afs_begin_vnode_operation(&fc, vnode, key)) { 542 while (afs_select_fileserver(&fc)) { 543 fc.cb_break = vnode->cb_break + vnode->cb_s_break; 544 afs_fs_setattr(&fc, attr); 545 } 546 547 afs_check_for_remote_deletion(&fc, fc.vnode); 548 afs_vnode_commit_status(&fc, vnode, fc.cb_break); 549 ret = afs_end_vnode_operation(&fc); 550 } 551 552 if (!(attr->ia_valid & ATTR_FILE)) 553 key_put(key); 554 555 error: 556 _leave(" = %d", ret); 557 return ret; 558 } 559