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 <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 make_bad_inode(inode); 200 unlock_new_inode(inode); 201 iput(inode); 202 203 _leave(" = %d [bad]", ret); 204 return ERR_PTR(ret); 205 } 206 207 /* 208 * mark the data attached to an inode as obsolete due to a write on the server 209 * - might also want to ditch all the outstanding writes and dirty pages 210 */ 211 void afs_zap_data(struct afs_vnode *vnode) 212 { 213 _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode); 214 215 /* nuke all the non-dirty pages that aren't locked, mapped or being 216 * written back in a regular file and completely discard the pages in a 217 * directory or symlink */ 218 if (S_ISREG(vnode->vfs_inode.i_mode)) 219 invalidate_remote_inode(&vnode->vfs_inode); 220 else 221 invalidate_inode_pages2(vnode->vfs_inode.i_mapping); 222 } 223 224 /* 225 * validate a vnode/inode 226 * - there are several things we need to check 227 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link, 228 * symlink) 229 * - parent dir metadata changed (security changes) 230 * - dentry data changed (write, truncate) 231 * - dentry metadata changed (security changes) 232 */ 233 int afs_validate(struct afs_vnode *vnode, struct key *key) 234 { 235 int ret; 236 237 _enter("{v={%x:%u} fl=%lx},%x", 238 vnode->fid.vid, vnode->fid.vnode, vnode->flags, 239 key_serial(key)); 240 241 if (vnode->cb_promised && 242 !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) && 243 !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) && 244 !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) { 245 if (vnode->cb_expires < get_seconds() + 10) { 246 _debug("callback expired"); 247 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); 248 } else { 249 goto valid; 250 } 251 } 252 253 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) 254 goto valid; 255 256 mutex_lock(&vnode->validate_lock); 257 258 /* if the promise has expired, we need to check the server again to get 259 * a new promise - note that if the (parent) directory's metadata was 260 * changed then the security may be different and we may no longer have 261 * access */ 262 if (!vnode->cb_promised || 263 test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) { 264 _debug("not promised"); 265 ret = afs_vnode_fetch_status(vnode, NULL, key); 266 if (ret < 0) 267 goto error_unlock; 268 _debug("new promise [fl=%lx]", vnode->flags); 269 } 270 271 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { 272 _debug("file already deleted"); 273 ret = -ESTALE; 274 goto error_unlock; 275 } 276 277 /* if the vnode's data version number changed then its contents are 278 * different */ 279 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) 280 afs_zap_data(vnode); 281 282 clear_bit(AFS_VNODE_MODIFIED, &vnode->flags); 283 mutex_unlock(&vnode->validate_lock); 284 valid: 285 _leave(" = 0"); 286 return 0; 287 288 error_unlock: 289 mutex_unlock(&vnode->validate_lock); 290 _leave(" = %d", ret); 291 return ret; 292 } 293 294 /* 295 * read the attributes of an inode 296 */ 297 int afs_getattr(struct vfsmount *mnt, struct dentry *dentry, 298 struct kstat *stat) 299 { 300 struct inode *inode; 301 302 inode = dentry->d_inode; 303 304 _enter("{ ino=%lu v=%llu }", inode->i_ino, 305 (unsigned long long)inode->i_version); 306 307 generic_fillattr(inode, stat); 308 return 0; 309 } 310 311 /* 312 * clear an AFS inode 313 */ 314 void afs_clear_inode(struct inode *inode) 315 { 316 struct afs_permits *permits; 317 struct afs_vnode *vnode; 318 319 vnode = AFS_FS_I(inode); 320 321 _enter("{%x:%u.%d} v=%u x=%u t=%u }", 322 vnode->fid.vid, 323 vnode->fid.vnode, 324 vnode->fid.unique, 325 vnode->cb_version, 326 vnode->cb_expiry, 327 vnode->cb_type); 328 329 _debug("CLEAR INODE %p", inode); 330 331 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode); 332 333 afs_give_up_callback(vnode); 334 335 if (vnode->server) { 336 spin_lock(&vnode->server->fs_lock); 337 rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes); 338 spin_unlock(&vnode->server->fs_lock); 339 afs_put_server(vnode->server); 340 vnode->server = NULL; 341 } 342 343 ASSERT(list_empty(&vnode->writebacks)); 344 ASSERT(!vnode->cb_promised); 345 346 #ifdef AFS_CACHING_SUPPORT 347 cachefs_relinquish_cookie(vnode->cache, 0); 348 vnode->cache = NULL; 349 #endif 350 351 mutex_lock(&vnode->permits_lock); 352 permits = vnode->permits; 353 rcu_assign_pointer(vnode->permits, NULL); 354 mutex_unlock(&vnode->permits_lock); 355 if (permits) 356 call_rcu(&permits->rcu, afs_zap_permits); 357 358 _leave(""); 359 } 360 361 /* 362 * set the attributes of an inode 363 */ 364 int afs_setattr(struct dentry *dentry, struct iattr *attr) 365 { 366 struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode); 367 struct key *key; 368 int ret; 369 370 _enter("{%x:%u},{n=%s},%x", 371 vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name, 372 attr->ia_valid); 373 374 if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID | 375 ATTR_MTIME))) { 376 _leave(" = 0 [unsupported]"); 377 return 0; 378 } 379 380 /* flush any dirty data outstanding on a regular file */ 381 if (S_ISREG(vnode->vfs_inode.i_mode)) { 382 filemap_write_and_wait(vnode->vfs_inode.i_mapping); 383 afs_writeback_all(vnode); 384 } 385 386 if (attr->ia_valid & ATTR_FILE) { 387 key = attr->ia_file->private_data; 388 } else { 389 key = afs_request_key(vnode->volume->cell); 390 if (IS_ERR(key)) { 391 ret = PTR_ERR(key); 392 goto error; 393 } 394 } 395 396 ret = afs_vnode_setattr(vnode, key, attr); 397 if (!(attr->ia_valid & ATTR_FILE)) 398 key_put(key); 399 400 error: 401 _leave(" = %d", ret); 402 return ret; 403 } 404