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