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