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 "internal.h" 23 24 struct afs_iget_data { 25 struct afs_fid fid; 26 struct afs_volume *volume; /* volume on which resides */ 27 }; 28 29 /* 30 * map the AFS file status to the inode member variables 31 */ 32 static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key) 33 { 34 struct inode *inode = AFS_VNODE_TO_I(vnode); 35 36 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu", 37 vnode->status.type, 38 vnode->status.nlink, 39 (unsigned long long) vnode->status.size, 40 vnode->status.data_version, 41 vnode->status.mode); 42 43 switch (vnode->status.type) { 44 case AFS_FTYPE_FILE: 45 inode->i_mode = S_IFREG | vnode->status.mode; 46 inode->i_op = &afs_file_inode_operations; 47 inode->i_fop = &afs_file_operations; 48 break; 49 case AFS_FTYPE_DIR: 50 inode->i_mode = S_IFDIR | vnode->status.mode; 51 inode->i_op = &afs_dir_inode_operations; 52 inode->i_fop = &afs_dir_file_operations; 53 break; 54 case AFS_FTYPE_SYMLINK: 55 inode->i_mode = S_IFLNK | vnode->status.mode; 56 inode->i_op = &page_symlink_inode_operations; 57 break; 58 default: 59 printk("kAFS: AFS vnode with undefined type\n"); 60 return -EBADMSG; 61 } 62 63 #ifdef CONFIG_AFS_FSCACHE 64 if (vnode->status.size != inode->i_size) 65 fscache_attr_changed(vnode->cache); 66 #endif 67 68 inode->i_nlink = vnode->status.nlink; 69 inode->i_uid = vnode->status.owner; 70 inode->i_gid = 0; 71 inode->i_size = vnode->status.size; 72 inode->i_ctime.tv_sec = vnode->status.mtime_server; 73 inode->i_ctime.tv_nsec = 0; 74 inode->i_atime = inode->i_mtime = inode->i_ctime; 75 inode->i_blocks = 0; 76 inode->i_version = vnode->fid.unique; 77 inode->i_mapping->a_ops = &afs_fs_aops; 78 79 /* check to see whether a symbolic link is really a mountpoint */ 80 if (vnode->status.type == AFS_FTYPE_SYMLINK) { 81 afs_mntpt_check_symlink(vnode, key); 82 83 if (test_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags)) { 84 inode->i_mode = S_IFDIR | vnode->status.mode; 85 inode->i_op = &afs_mntpt_inode_operations; 86 inode->i_fop = &afs_mntpt_file_operations; 87 } 88 } 89 90 return 0; 91 } 92 93 /* 94 * iget5() comparator 95 */ 96 static int afs_iget5_test(struct inode *inode, void *opaque) 97 { 98 struct afs_iget_data *data = opaque; 99 100 return inode->i_ino == data->fid.vnode && 101 inode->i_version == data->fid.unique; 102 } 103 104 /* 105 * iget5() inode initialiser 106 */ 107 static int afs_iget5_set(struct inode *inode, void *opaque) 108 { 109 struct afs_iget_data *data = opaque; 110 struct afs_vnode *vnode = AFS_FS_I(inode); 111 112 inode->i_ino = data->fid.vnode; 113 inode->i_version = data->fid.unique; 114 vnode->fid = data->fid; 115 vnode->volume = data->volume; 116 117 return 0; 118 } 119 120 /* 121 * inode retrieval 122 */ 123 struct inode *afs_iget(struct super_block *sb, struct key *key, 124 struct afs_fid *fid, struct afs_file_status *status, 125 struct afs_callback *cb) 126 { 127 struct afs_iget_data data = { .fid = *fid }; 128 struct afs_super_info *as; 129 struct afs_vnode *vnode; 130 struct inode *inode; 131 int ret; 132 133 _enter(",{%x:%u.%u},,", fid->vid, fid->vnode, fid->unique); 134 135 as = sb->s_fs_info; 136 data.volume = as->volume; 137 138 inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set, 139 &data); 140 if (!inode) { 141 _leave(" = -ENOMEM"); 142 return ERR_PTR(-ENOMEM); 143 } 144 145 _debug("GOT INODE %p { vl=%x vn=%x, u=%x }", 146 inode, fid->vid, fid->vnode, fid->unique); 147 148 vnode = AFS_FS_I(inode); 149 150 /* deal with an existing inode */ 151 if (!(inode->i_state & I_NEW)) { 152 _leave(" = %p", inode); 153 return inode; 154 } 155 156 if (!status) { 157 /* it's a remotely extant inode */ 158 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); 159 ret = afs_vnode_fetch_status(vnode, NULL, key); 160 if (ret < 0) 161 goto bad_inode; 162 } else { 163 /* it's an inode we just created */ 164 memcpy(&vnode->status, status, sizeof(vnode->status)); 165 166 if (!cb) { 167 /* it's a symlink we just created (the fileserver 168 * didn't give us a callback) */ 169 vnode->cb_version = 0; 170 vnode->cb_expiry = 0; 171 vnode->cb_type = 0; 172 vnode->cb_expires = get_seconds(); 173 } else { 174 vnode->cb_version = cb->version; 175 vnode->cb_expiry = cb->expiry; 176 vnode->cb_type = cb->type; 177 vnode->cb_expires = vnode->cb_expiry + get_seconds(); 178 } 179 } 180 181 /* set up caching before mapping the status, as map-status reads the 182 * first page of symlinks to see if they're really mountpoints */ 183 inode->i_size = vnode->status.size; 184 #ifdef CONFIG_AFS_FSCACHE 185 vnode->cache = fscache_acquire_cookie(vnode->volume->cache, 186 &afs_vnode_cache_index_def, 187 vnode); 188 #endif 189 190 ret = afs_inode_map_status(vnode, key); 191 if (ret < 0) 192 goto bad_inode; 193 194 /* success */ 195 clear_bit(AFS_VNODE_UNSET, &vnode->flags); 196 inode->i_flags |= S_NOATIME; 197 unlock_new_inode(inode); 198 _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type); 199 return inode; 200 201 /* failure */ 202 bad_inode: 203 #ifdef CONFIG_AFS_FSCACHE 204 fscache_relinquish_cookie(vnode->cache, 0); 205 vnode->cache = NULL; 206 #endif 207 iget_failed(inode); 208 _leave(" = %d [bad]", ret); 209 return ERR_PTR(ret); 210 } 211 212 /* 213 * mark the data attached to an inode as obsolete due to a write on the server 214 * - might also want to ditch all the outstanding writes and dirty pages 215 */ 216 void afs_zap_data(struct afs_vnode *vnode) 217 { 218 _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode); 219 220 /* nuke all the non-dirty pages that aren't locked, mapped or being 221 * written back in a regular file and completely discard the pages in a 222 * directory or symlink */ 223 if (S_ISREG(vnode->vfs_inode.i_mode)) 224 invalidate_remote_inode(&vnode->vfs_inode); 225 else 226 invalidate_inode_pages2(vnode->vfs_inode.i_mapping); 227 } 228 229 /* 230 * validate a vnode/inode 231 * - there are several things we need to check 232 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link, 233 * symlink) 234 * - parent dir metadata changed (security changes) 235 * - dentry data changed (write, truncate) 236 * - dentry metadata changed (security changes) 237 */ 238 int afs_validate(struct afs_vnode *vnode, struct key *key) 239 { 240 int ret; 241 242 _enter("{v={%x:%u} fl=%lx},%x", 243 vnode->fid.vid, vnode->fid.vnode, vnode->flags, 244 key_serial(key)); 245 246 if (vnode->cb_promised && 247 !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) && 248 !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) && 249 !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) { 250 if (vnode->cb_expires < get_seconds() + 10) { 251 _debug("callback expired"); 252 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); 253 } else { 254 goto valid; 255 } 256 } 257 258 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) 259 goto valid; 260 261 mutex_lock(&vnode->validate_lock); 262 263 /* if the promise has expired, we need to check the server again to get 264 * a new promise - note that if the (parent) directory's metadata was 265 * changed then the security may be different and we may no longer have 266 * access */ 267 if (!vnode->cb_promised || 268 test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) { 269 _debug("not promised"); 270 ret = afs_vnode_fetch_status(vnode, NULL, key); 271 if (ret < 0) 272 goto error_unlock; 273 _debug("new promise [fl=%lx]", vnode->flags); 274 } 275 276 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { 277 _debug("file already deleted"); 278 ret = -ESTALE; 279 goto error_unlock; 280 } 281 282 /* if the vnode's data version number changed then its contents are 283 * different */ 284 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) 285 afs_zap_data(vnode); 286 287 clear_bit(AFS_VNODE_MODIFIED, &vnode->flags); 288 mutex_unlock(&vnode->validate_lock); 289 valid: 290 _leave(" = 0"); 291 return 0; 292 293 error_unlock: 294 mutex_unlock(&vnode->validate_lock); 295 _leave(" = %d", ret); 296 return ret; 297 } 298 299 /* 300 * read the attributes of an inode 301 */ 302 int afs_getattr(struct vfsmount *mnt, struct dentry *dentry, 303 struct kstat *stat) 304 { 305 struct inode *inode; 306 307 inode = dentry->d_inode; 308 309 _enter("{ ino=%lu v=%llu }", inode->i_ino, 310 (unsigned long long)inode->i_version); 311 312 generic_fillattr(inode, stat); 313 return 0; 314 } 315 316 /* 317 * clear an AFS inode 318 */ 319 void afs_clear_inode(struct inode *inode) 320 { 321 struct afs_permits *permits; 322 struct afs_vnode *vnode; 323 324 vnode = AFS_FS_I(inode); 325 326 _enter("{%x:%u.%d} v=%u x=%u t=%u }", 327 vnode->fid.vid, 328 vnode->fid.vnode, 329 vnode->fid.unique, 330 vnode->cb_version, 331 vnode->cb_expiry, 332 vnode->cb_type); 333 334 _debug("CLEAR INODE %p", inode); 335 336 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode); 337 338 afs_give_up_callback(vnode); 339 340 if (vnode->server) { 341 spin_lock(&vnode->server->fs_lock); 342 rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes); 343 spin_unlock(&vnode->server->fs_lock); 344 afs_put_server(vnode->server); 345 vnode->server = NULL; 346 } 347 348 ASSERT(list_empty(&vnode->writebacks)); 349 ASSERT(!vnode->cb_promised); 350 351 #ifdef CONFIG_AFS_FSCACHE 352 fscache_relinquish_cookie(vnode->cache, 0); 353 vnode->cache = NULL; 354 #endif 355 356 mutex_lock(&vnode->permits_lock); 357 permits = vnode->permits; 358 rcu_assign_pointer(vnode->permits, NULL); 359 mutex_unlock(&vnode->permits_lock); 360 if (permits) 361 call_rcu(&permits->rcu, afs_zap_permits); 362 363 _leave(""); 364 } 365 366 /* 367 * set the attributes of an inode 368 */ 369 int afs_setattr(struct dentry *dentry, struct iattr *attr) 370 { 371 struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode); 372 struct key *key; 373 int ret; 374 375 _enter("{%x:%u},{n=%s},%x", 376 vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name, 377 attr->ia_valid); 378 379 if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID | 380 ATTR_MTIME))) { 381 _leave(" = 0 [unsupported]"); 382 return 0; 383 } 384 385 /* flush any dirty data outstanding on a regular file */ 386 if (S_ISREG(vnode->vfs_inode.i_mode)) { 387 filemap_write_and_wait(vnode->vfs_inode.i_mapping); 388 afs_writeback_all(vnode); 389 } 390 391 if (attr->ia_valid & ATTR_FILE) { 392 key = attr->ia_file->private_data; 393 } else { 394 key = afs_request_key(vnode->volume->cell); 395 if (IS_ERR(key)) { 396 ret = PTR_ERR(key); 397 goto error; 398 } 399 } 400 401 ret = afs_vnode_setattr(vnode, key, attr); 402 if (!(attr->ia_valid & ATTR_FILE)) 403 key_put(key); 404 405 error: 406 _leave(" = %d", ret); 407 return ret; 408 } 409