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/slab.h> 20 #include <linux/fs.h> 21 #include <linux/pagemap.h> 22 #include <linux/sched.h> 23 #include "internal.h" 24 25 struct afs_iget_data { 26 struct afs_fid fid; 27 struct afs_volume *volume; /* volume on which resides */ 28 }; 29 30 /* 31 * map the AFS file status to the inode member variables 32 */ 33 static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key) 34 { 35 struct inode *inode = AFS_VNODE_TO_I(vnode); 36 37 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu", 38 vnode->status.type, 39 vnode->status.nlink, 40 (unsigned long long) vnode->status.size, 41 vnode->status.data_version, 42 vnode->status.mode); 43 44 switch (vnode->status.type) { 45 case AFS_FTYPE_FILE: 46 inode->i_mode = S_IFREG | vnode->status.mode; 47 inode->i_op = &afs_file_inode_operations; 48 inode->i_fop = &afs_file_operations; 49 break; 50 case AFS_FTYPE_DIR: 51 inode->i_mode = S_IFDIR | vnode->status.mode; 52 inode->i_op = &afs_dir_inode_operations; 53 inode->i_fop = &afs_dir_file_operations; 54 break; 55 case AFS_FTYPE_SYMLINK: 56 inode->i_mode = S_IFLNK | vnode->status.mode; 57 inode->i_op = &page_symlink_inode_operations; 58 break; 59 default: 60 printk("kAFS: AFS vnode with undefined type\n"); 61 return -EBADMSG; 62 } 63 64 #ifdef CONFIG_AFS_FSCACHE 65 if (vnode->status.size != inode->i_size) 66 fscache_attr_changed(vnode->cache); 67 #endif 68 69 inode->i_nlink = vnode->status.nlink; 70 inode->i_uid = vnode->status.owner; 71 inode->i_gid = 0; 72 inode->i_size = vnode->status.size; 73 inode->i_ctime.tv_sec = vnode->status.mtime_server; 74 inode->i_ctime.tv_nsec = 0; 75 inode->i_atime = inode->i_mtime = inode->i_ctime; 76 inode->i_blocks = 0; 77 inode->i_version = vnode->fid.unique; 78 inode->i_mapping->a_ops = &afs_fs_aops; 79 80 /* check to see whether a symbolic link is really a mountpoint */ 81 if (vnode->status.type == AFS_FTYPE_SYMLINK) { 82 afs_mntpt_check_symlink(vnode, key); 83 84 if (test_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags)) { 85 inode->i_mode = S_IFDIR | vnode->status.mode; 86 inode->i_op = &afs_mntpt_inode_operations; 87 inode->i_fop = &afs_mntpt_file_operations; 88 } 89 } 90 91 return 0; 92 } 93 94 /* 95 * iget5() comparator 96 */ 97 static int afs_iget5_test(struct inode *inode, void *opaque) 98 { 99 struct afs_iget_data *data = opaque; 100 101 return inode->i_ino == data->fid.vnode && 102 inode->i_version == data->fid.unique; 103 } 104 105 /* 106 * iget5() inode initialiser 107 */ 108 static int afs_iget5_set(struct inode *inode, void *opaque) 109 { 110 struct afs_iget_data *data = opaque; 111 struct afs_vnode *vnode = AFS_FS_I(inode); 112 113 inode->i_ino = data->fid.vnode; 114 inode->i_version = data->fid.unique; 115 vnode->fid = data->fid; 116 vnode->volume = data->volume; 117 118 return 0; 119 } 120 121 /* 122 * inode retrieval 123 */ 124 struct inode *afs_iget(struct super_block *sb, struct key *key, 125 struct afs_fid *fid, struct afs_file_status *status, 126 struct afs_callback *cb) 127 { 128 struct afs_iget_data data = { .fid = *fid }; 129 struct afs_super_info *as; 130 struct afs_vnode *vnode; 131 struct inode *inode; 132 int ret; 133 134 _enter(",{%x:%u.%u},,", fid->vid, fid->vnode, fid->unique); 135 136 as = sb->s_fs_info; 137 data.volume = as->volume; 138 139 inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set, 140 &data); 141 if (!inode) { 142 _leave(" = -ENOMEM"); 143 return ERR_PTR(-ENOMEM); 144 } 145 146 _debug("GOT INODE %p { vl=%x vn=%x, u=%x }", 147 inode, fid->vid, fid->vnode, fid->unique); 148 149 vnode = AFS_FS_I(inode); 150 151 /* deal with an existing inode */ 152 if (!(inode->i_state & I_NEW)) { 153 _leave(" = %p", inode); 154 return inode; 155 } 156 157 if (!status) { 158 /* it's a remotely extant inode */ 159 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); 160 ret = afs_vnode_fetch_status(vnode, NULL, key); 161 if (ret < 0) 162 goto bad_inode; 163 } else { 164 /* it's an inode we just created */ 165 memcpy(&vnode->status, status, sizeof(vnode->status)); 166 167 if (!cb) { 168 /* it's a symlink we just created (the fileserver 169 * didn't give us a callback) */ 170 vnode->cb_version = 0; 171 vnode->cb_expiry = 0; 172 vnode->cb_type = 0; 173 vnode->cb_expires = get_seconds(); 174 } else { 175 vnode->cb_version = cb->version; 176 vnode->cb_expiry = cb->expiry; 177 vnode->cb_type = cb->type; 178 vnode->cb_expires = vnode->cb_expiry + get_seconds(); 179 } 180 } 181 182 /* set up caching before mapping the status, as map-status reads the 183 * first page of symlinks to see if they're really mountpoints */ 184 inode->i_size = vnode->status.size; 185 #ifdef CONFIG_AFS_FSCACHE 186 vnode->cache = fscache_acquire_cookie(vnode->volume->cache, 187 &afs_vnode_cache_index_def, 188 vnode); 189 #endif 190 191 ret = afs_inode_map_status(vnode, key); 192 if (ret < 0) 193 goto bad_inode; 194 195 /* success */ 196 clear_bit(AFS_VNODE_UNSET, &vnode->flags); 197 inode->i_flags |= S_NOATIME; 198 unlock_new_inode(inode); 199 _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type); 200 return inode; 201 202 /* failure */ 203 bad_inode: 204 #ifdef CONFIG_AFS_FSCACHE 205 fscache_relinquish_cookie(vnode->cache, 0); 206 vnode->cache = NULL; 207 #endif 208 iget_failed(inode); 209 _leave(" = %d [bad]", ret); 210 return ERR_PTR(ret); 211 } 212 213 /* 214 * mark the data attached to an inode as obsolete due to a write on the server 215 * - might also want to ditch all the outstanding writes and dirty pages 216 */ 217 void afs_zap_data(struct afs_vnode *vnode) 218 { 219 _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode); 220 221 /* nuke all the non-dirty pages that aren't locked, mapped or being 222 * written back in a regular file and completely discard the pages in a 223 * directory or symlink */ 224 if (S_ISREG(vnode->vfs_inode.i_mode)) 225 invalidate_remote_inode(&vnode->vfs_inode); 226 else 227 invalidate_inode_pages2(vnode->vfs_inode.i_mapping); 228 } 229 230 /* 231 * validate a vnode/inode 232 * - there are several things we need to check 233 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link, 234 * symlink) 235 * - parent dir metadata changed (security changes) 236 * - dentry data changed (write, truncate) 237 * - dentry metadata changed (security changes) 238 */ 239 int afs_validate(struct afs_vnode *vnode, struct key *key) 240 { 241 int ret; 242 243 _enter("{v={%x:%u} fl=%lx},%x", 244 vnode->fid.vid, vnode->fid.vnode, vnode->flags, 245 key_serial(key)); 246 247 if (vnode->cb_promised && 248 !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) && 249 !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) && 250 !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) { 251 if (vnode->cb_expires < get_seconds() + 10) { 252 _debug("callback expired"); 253 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); 254 } else { 255 goto valid; 256 } 257 } 258 259 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) 260 goto valid; 261 262 mutex_lock(&vnode->validate_lock); 263 264 /* if the promise has expired, we need to check the server again to get 265 * a new promise - note that if the (parent) directory's metadata was 266 * changed then the security may be different and we may no longer have 267 * access */ 268 if (!vnode->cb_promised || 269 test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) { 270 _debug("not promised"); 271 ret = afs_vnode_fetch_status(vnode, NULL, key); 272 if (ret < 0) 273 goto error_unlock; 274 _debug("new promise [fl=%lx]", vnode->flags); 275 } 276 277 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { 278 _debug("file already deleted"); 279 ret = -ESTALE; 280 goto error_unlock; 281 } 282 283 /* if the vnode's data version number changed then its contents are 284 * different */ 285 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) 286 afs_zap_data(vnode); 287 288 clear_bit(AFS_VNODE_MODIFIED, &vnode->flags); 289 mutex_unlock(&vnode->validate_lock); 290 valid: 291 _leave(" = 0"); 292 return 0; 293 294 error_unlock: 295 mutex_unlock(&vnode->validate_lock); 296 _leave(" = %d", ret); 297 return ret; 298 } 299 300 /* 301 * read the attributes of an inode 302 */ 303 int afs_getattr(struct vfsmount *mnt, struct dentry *dentry, 304 struct kstat *stat) 305 { 306 struct inode *inode; 307 308 inode = dentry->d_inode; 309 310 _enter("{ ino=%lu v=%llu }", inode->i_ino, 311 (unsigned long long)inode->i_version); 312 313 generic_fillattr(inode, stat); 314 return 0; 315 } 316 317 /* 318 * clear an AFS inode 319 */ 320 void afs_clear_inode(struct inode *inode) 321 { 322 struct afs_permits *permits; 323 struct afs_vnode *vnode; 324 325 vnode = AFS_FS_I(inode); 326 327 _enter("{%x:%u.%d} v=%u x=%u t=%u }", 328 vnode->fid.vid, 329 vnode->fid.vnode, 330 vnode->fid.unique, 331 vnode->cb_version, 332 vnode->cb_expiry, 333 vnode->cb_type); 334 335 _debug("CLEAR INODE %p", inode); 336 337 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode); 338 339 afs_give_up_callback(vnode); 340 341 if (vnode->server) { 342 spin_lock(&vnode->server->fs_lock); 343 rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes); 344 spin_unlock(&vnode->server->fs_lock); 345 afs_put_server(vnode->server); 346 vnode->server = NULL; 347 } 348 349 ASSERT(list_empty(&vnode->writebacks)); 350 ASSERT(!vnode->cb_promised); 351 352 #ifdef CONFIG_AFS_FSCACHE 353 fscache_relinquish_cookie(vnode->cache, 0); 354 vnode->cache = NULL; 355 #endif 356 357 mutex_lock(&vnode->permits_lock); 358 permits = vnode->permits; 359 rcu_assign_pointer(vnode->permits, NULL); 360 mutex_unlock(&vnode->permits_lock); 361 if (permits) 362 call_rcu(&permits->rcu, afs_zap_permits); 363 364 _leave(""); 365 } 366 367 /* 368 * set the attributes of an inode 369 */ 370 int afs_setattr(struct dentry *dentry, struct iattr *attr) 371 { 372 struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode); 373 struct key *key; 374 int ret; 375 376 _enter("{%x:%u},{n=%s},%x", 377 vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name, 378 attr->ia_valid); 379 380 if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID | 381 ATTR_MTIME))) { 382 _leave(" = 0 [unsupported]"); 383 return 0; 384 } 385 386 /* flush any dirty data outstanding on a regular file */ 387 if (S_ISREG(vnode->vfs_inode.i_mode)) { 388 filemap_write_and_wait(vnode->vfs_inode.i_mapping); 389 afs_writeback_all(vnode); 390 } 391 392 if (attr->ia_valid & ATTR_FILE) { 393 key = attr->ia_file->private_data; 394 } else { 395 key = afs_request_key(vnode->volume->cell); 396 if (IS_ERR(key)) { 397 ret = PTR_ERR(key); 398 goto error; 399 } 400 } 401 402 ret = afs_vnode_setattr(vnode, key, attr); 403 if (!(attr->ia_valid & ATTR_FILE)) 404 key_put(key); 405 406 error: 407 _leave(" = %d", ret); 408 return ret; 409 } 410