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 "internal.h" 25 26struct afs_iget_data { 27 struct afs_fid fid; 28 struct afs_volume *volume; /* volume on which resides */ 29}; 30 31/* 32 * map the AFS file status to the inode member variables 33 */ 34static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key) 35{ 36 struct inode *inode = AFS_VNODE_TO_I(vnode); 37 38 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu", 39 vnode->status.type, 40 vnode->status.nlink, 41 (unsigned long long) vnode->status.size, 42 vnode->status.data_version, 43 vnode->status.mode); 44 45 switch (vnode->status.type) { 46 case AFS_FTYPE_FILE: 47 inode->i_mode = S_IFREG | vnode->status.mode; 48 inode->i_op = &afs_file_inode_operations; 49 inode->i_fop = &afs_file_operations; 50 break; 51 case AFS_FTYPE_DIR: 52 inode->i_mode = S_IFDIR | vnode->status.mode; 53 inode->i_op = &afs_dir_inode_operations; 54 inode->i_fop = &afs_dir_file_operations; 55 break; 56 case AFS_FTYPE_SYMLINK: 57 inode->i_mode = S_IFLNK | vnode->status.mode; 58 inode->i_op = &page_symlink_inode_operations; 59 break; 60 default: 61 printk("kAFS: AFS vnode with undefined type\n"); 62 return -EBADMSG; 63 } 64 65#ifdef CONFIG_AFS_FSCACHE 66 if (vnode->status.size != inode->i_size) 67 fscache_attr_changed(vnode->cache); 68#endif 69 70 inode->i_nlink = vnode->status.nlink; 71 inode->i_uid = vnode->status.owner; 72 inode->i_gid = 0; 73 inode->i_size = vnode->status.size; 74 inode->i_ctime.tv_sec = vnode->status.mtime_server; 75 inode->i_ctime.tv_nsec = 0; 76 inode->i_atime = inode->i_mtime = inode->i_ctime; 77 inode->i_blocks = 0; 78 inode->i_version = vnode->fid.unique; 79 inode->i_mapping->a_ops = &afs_fs_aops; 80 81 /* check to see whether a symbolic link is really a mountpoint */ 82 if (vnode->status.type == AFS_FTYPE_SYMLINK) { 83 afs_mntpt_check_symlink(vnode, key); 84 85 if (test_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags)) { 86 inode->i_mode = S_IFDIR | vnode->status.mode; 87 inode->i_op = &afs_mntpt_inode_operations; 88 inode->i_fop = &afs_mntpt_file_operations; 89 } 90 } 91 92 return 0; 93} 94 95/* 96 * iget5() comparator 97 */ 98static int afs_iget5_test(struct inode *inode, void *opaque) 99{ 100 struct afs_iget_data *data = opaque; 101 102 return inode->i_ino == data->fid.vnode && 103 inode->i_version == data->fid.unique; 104} 105 106/* 107 * iget5() comparator for inode created by autocell operations 108 * 109 * These pseudo inodes don't match anything. 110 */ 111static int afs_iget5_autocell_test(struct inode *inode, void *opaque) 112{ 113 return 0; 114} 115 116/* 117 * iget5() inode initialiser 118 */ 119static int afs_iget5_set(struct inode *inode, void *opaque) 120{ 121 struct afs_iget_data *data = opaque; 122 struct afs_vnode *vnode = AFS_FS_I(inode); 123 124 inode->i_ino = data->fid.vnode; 125 inode->i_version = data->fid.unique; 126 vnode->fid = data->fid; 127 vnode->volume = data->volume; 128 129 return 0; 130} 131 132/* 133 * inode retrieval for autocell 134 */ 135struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name, 136 int namesz, struct key *key) 137{ 138 struct afs_iget_data data; 139 struct afs_super_info *as; 140 struct afs_vnode *vnode; 141 struct super_block *sb; 142 struct inode *inode; 143 static atomic_t afs_autocell_ino; 144 145 _enter("{%x:%u},%*.*s,", 146 AFS_FS_I(dir)->fid.vid, AFS_FS_I(dir)->fid.vnode, 147 namesz, namesz, dev_name ?: ""); 148 149 sb = dir->i_sb; 150 as = sb->s_fs_info; 151 data.volume = as->volume; 152 data.fid.vid = as->volume->vid; 153 data.fid.unique = 0; 154 data.fid.vnode = 0; 155 156 inode = iget5_locked(sb, atomic_inc_return(&afs_autocell_ino), 157 afs_iget5_autocell_test, afs_iget5_set, 158 &data); 159 if (!inode) { 160 _leave(" = -ENOMEM"); 161 return ERR_PTR(-ENOMEM); 162 } 163 164 _debug("GOT INODE %p { ino=%lu, vl=%x, vn=%x, u=%x }", 165 inode, inode->i_ino, data.fid.vid, data.fid.vnode, 166 data.fid.unique); 167 168 vnode = AFS_FS_I(inode); 169 170 /* there shouldn't be an existing inode */ 171 BUG_ON(!(inode->i_state & I_NEW)); 172 173 inode->i_size = 0; 174 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO; 175 inode->i_op = &afs_autocell_inode_operations; 176 inode->i_nlink = 2; 177 inode->i_uid = 0; 178 inode->i_gid = 0; 179 inode->i_ctime.tv_sec = get_seconds(); 180 inode->i_ctime.tv_nsec = 0; 181 inode->i_atime = inode->i_mtime = inode->i_ctime; 182 inode->i_blocks = 0; 183 inode->i_version = 0; 184 inode->i_generation = 0; 185 186 set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags); 187 inode->i_flags |= S_NOATIME; 188 unlock_new_inode(inode); 189 _leave(" = %p", inode); 190 return inode; 191} 192 193/* 194 * inode retrieval 195 */ 196struct inode *afs_iget(struct super_block *sb, struct key *key, 197 struct afs_fid *fid, struct afs_file_status *status, 198 struct afs_callback *cb) 199{ 200 struct afs_iget_data data = { .fid = *fid }; 201 struct afs_super_info *as; 202 struct afs_vnode *vnode; 203 struct inode *inode; 204 int ret; 205 206 _enter(",{%x:%u.%u},,", fid->vid, fid->vnode, fid->unique); 207 208 as = sb->s_fs_info; 209 data.volume = as->volume; 210 211 inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set, 212 &data); 213 if (!inode) { 214 _leave(" = -ENOMEM"); 215 return ERR_PTR(-ENOMEM); 216 } 217 218 _debug("GOT INODE %p { vl=%x vn=%x, u=%x }", 219 inode, fid->vid, fid->vnode, fid->unique); 220 221 vnode = AFS_FS_I(inode); 222 223 /* deal with an existing inode */ 224 if (!(inode->i_state & I_NEW)) { 225 _leave(" = %p", inode); 226 return inode; 227 } 228 229 if (!status) { 230 /* it's a remotely extant inode */ 231 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); 232 ret = afs_vnode_fetch_status(vnode, NULL, key); 233 if (ret < 0) 234 goto bad_inode; 235 } else { 236 /* it's an inode we just created */ 237 memcpy(&vnode->status, status, sizeof(vnode->status)); 238 239 if (!cb) { 240 /* it's a symlink we just created (the fileserver 241 * didn't give us a callback) */ 242 vnode->cb_version = 0; 243 vnode->cb_expiry = 0; 244 vnode->cb_type = 0; 245 vnode->cb_expires = get_seconds(); 246 } else { 247 vnode->cb_version = cb->version; 248 vnode->cb_expiry = cb->expiry; 249 vnode->cb_type = cb->type; 250 vnode->cb_expires = vnode->cb_expiry + get_seconds(); 251 } 252 } 253 254 /* set up caching before mapping the status, as map-status reads the 255 * first page of symlinks to see if they're really mountpoints */ 256 inode->i_size = vnode->status.size; 257#ifdef CONFIG_AFS_FSCACHE 258 vnode->cache = fscache_acquire_cookie(vnode->volume->cache, 259 &afs_vnode_cache_index_def, 260 vnode); 261#endif 262 263 ret = afs_inode_map_status(vnode, key); 264 if (ret < 0) 265 goto bad_inode; 266 267 /* success */ 268 clear_bit(AFS_VNODE_UNSET, &vnode->flags); 269 inode->i_flags |= S_NOATIME; 270 unlock_new_inode(inode); 271 _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type); 272 return inode; 273 274 /* failure */ 275bad_inode: 276#ifdef CONFIG_AFS_FSCACHE 277 fscache_relinquish_cookie(vnode->cache, 0); 278 vnode->cache = NULL; 279#endif 280 iget_failed(inode); 281 _leave(" = %d [bad]", ret); 282 return ERR_PTR(ret); 283} 284 285/* 286 * mark the data attached to an inode as obsolete due to a write on the server 287 * - might also want to ditch all the outstanding writes and dirty pages 288 */ 289void afs_zap_data(struct afs_vnode *vnode) 290{ 291 _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode); 292 293 /* nuke all the non-dirty pages that aren't locked, mapped or being 294 * written back in a regular file and completely discard the pages in a 295 * directory or symlink */ 296 if (S_ISREG(vnode->vfs_inode.i_mode)) 297 invalidate_remote_inode(&vnode->vfs_inode); 298 else 299 invalidate_inode_pages2(vnode->vfs_inode.i_mapping); 300} 301 302/* 303 * validate a vnode/inode 304 * - there are several things we need to check 305 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link, 306 * symlink) 307 * - parent dir metadata changed (security changes) 308 * - dentry data changed (write, truncate) 309 * - dentry metadata changed (security changes) 310 */ 311int afs_validate(struct afs_vnode *vnode, struct key *key) 312{ 313 int ret; 314 315 _enter("{v={%x:%u} fl=%lx},%x", 316 vnode->fid.vid, vnode->fid.vnode, vnode->flags, 317 key_serial(key)); 318 319 if (vnode->cb_promised && 320 !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) && 321 !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) && 322 !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) { 323 if (vnode->cb_expires < get_seconds() + 10) { 324 _debug("callback expired"); 325 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); 326 } else { 327 goto valid; 328 } 329 } 330 331 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) 332 goto valid; 333 334 mutex_lock(&vnode->validate_lock); 335 336 /* if the promise has expired, we need to check the server again to get 337 * a new promise - note that if the (parent) directory's metadata was 338 * changed then the security may be different and we may no longer have 339 * access */ 340 if (!vnode->cb_promised || 341 test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) { 342 _debug("not promised"); 343 ret = afs_vnode_fetch_status(vnode, NULL, key); 344 if (ret < 0) 345 goto error_unlock; 346 _debug("new promise [fl=%lx]", vnode->flags); 347 } 348 349 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { 350 _debug("file already deleted"); 351 ret = -ESTALE; 352 goto error_unlock; 353 } 354 355 /* if the vnode's data version number changed then its contents are 356 * different */ 357 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) 358 afs_zap_data(vnode); 359 360 clear_bit(AFS_VNODE_MODIFIED, &vnode->flags); 361 mutex_unlock(&vnode->validate_lock); 362valid: 363 _leave(" = 0"); 364 return 0; 365 366error_unlock: 367 mutex_unlock(&vnode->validate_lock); 368 _leave(" = %d", ret); 369 return ret; 370} 371 372/* 373 * read the attributes of an inode 374 */ 375int afs_getattr(struct vfsmount *mnt, struct dentry *dentry, 376 struct kstat *stat) 377{ 378 struct inode *inode; 379 380 inode = dentry->d_inode; 381 382 _enter("{ ino=%lu v=%llu }", inode->i_ino, 383 (unsigned long long)inode->i_version); 384 385 generic_fillattr(inode, stat); 386 return 0; 387} 388 389/* 390 * discard an AFS inode 391 */ 392int afs_drop_inode(struct inode *inode) 393{ 394 _enter(""); 395 396 if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags)) 397 return generic_delete_inode(inode); 398 else 399 return generic_drop_inode(inode); 400} 401 402/* 403 * clear an AFS inode 404 */ 405void afs_evict_inode(struct inode *inode) 406{ 407 struct afs_permits *permits; 408 struct afs_vnode *vnode; 409 410 vnode = AFS_FS_I(inode); 411 412 _enter("{%x:%u.%d} v=%u x=%u t=%u }", 413 vnode->fid.vid, 414 vnode->fid.vnode, 415 vnode->fid.unique, 416 vnode->cb_version, 417 vnode->cb_expiry, 418 vnode->cb_type); 419 420 _debug("CLEAR INODE %p", inode); 421 422 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode); 423 424 truncate_inode_pages(&inode->i_data, 0); 425 end_writeback(inode); 426 427 afs_give_up_callback(vnode); 428 429 if (vnode->server) { 430 spin_lock(&vnode->server->fs_lock); 431 rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes); 432 spin_unlock(&vnode->server->fs_lock); 433 afs_put_server(vnode->server); 434 vnode->server = NULL; 435 } 436 437 ASSERT(list_empty(&vnode->writebacks)); 438 ASSERT(!vnode->cb_promised); 439 440#ifdef CONFIG_AFS_FSCACHE 441 fscache_relinquish_cookie(vnode->cache, 0); 442 vnode->cache = NULL; 443#endif 444 445 mutex_lock(&vnode->permits_lock); 446 permits = vnode->permits; 447 rcu_assign_pointer(vnode->permits, NULL); 448 mutex_unlock(&vnode->permits_lock); 449 if (permits) 450 call_rcu(&permits->rcu, afs_zap_permits); 451 452 _leave(""); 453} 454 455/* 456 * set the attributes of an inode 457 */ 458int afs_setattr(struct dentry *dentry, struct iattr *attr) 459{ 460 struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode); 461 struct key *key; 462 int ret; 463 464 _enter("{%x:%u},{n=%s},%x", 465 vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name, 466 attr->ia_valid); 467 468 if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID | 469 ATTR_MTIME))) { 470 _leave(" = 0 [unsupported]"); 471 return 0; 472 } 473 474 /* flush any dirty data outstanding on a regular file */ 475 if (S_ISREG(vnode->vfs_inode.i_mode)) { 476 filemap_write_and_wait(vnode->vfs_inode.i_mapping); 477 afs_writeback_all(vnode); 478 } 479 480 if (attr->ia_valid & ATTR_FILE) { 481 key = attr->ia_file->private_data; 482 } else { 483 key = afs_request_key(vnode->volume->cell); 484 if (IS_ERR(key)) { 485 ret = PTR_ERR(key); 486 goto error; 487 } 488 } 489 490 ret = afs_vnode_setattr(vnode, key, attr); 491 if (!(attr->ia_valid & ATTR_FILE)) 492 key_put(key); 493 494error: 495 _leave(" = %d", ret); 496 return ret; 497} 498