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 <linux/mount.h>
23 #include <linux/namei.h>
24 #include "internal.h"
25
26 struct afs_iget_data {
27 struct afs_fid fid;
28 struct afs_volume *volume; /* volume on which resides */
29 };
30
31 /*
32 * map the AFS file status to the inode member variables
33 */
afs_inode_map_status(struct afs_vnode * vnode,struct key * key)34 static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
35 {
36 struct inode *inode = AFS_VNODE_TO_I(vnode);
37
38 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
39 vnode->status.type,
40 vnode->status.nlink,
41 (unsigned long long) vnode->status.size,
42 vnode->status.data_version,
43 vnode->status.mode);
44
45 switch (vnode->status.type) {
46 case AFS_FTYPE_FILE:
47 inode->i_mode = S_IFREG | vnode->status.mode;
48 inode->i_op = &afs_file_inode_operations;
49 inode->i_fop = &afs_file_operations;
50 break;
51 case AFS_FTYPE_DIR:
52 inode->i_mode = S_IFDIR | vnode->status.mode;
53 inode->i_op = &afs_dir_inode_operations;
54 inode->i_fop = &afs_dir_file_operations;
55 break;
56 case AFS_FTYPE_SYMLINK:
57 inode->i_mode = S_IFLNK | vnode->status.mode;
58 inode->i_op = &page_symlink_inode_operations;
59 break;
60 default:
61 printk("kAFS: AFS vnode with undefined type\n");
62 return -EBADMSG;
63 }
64
65 #ifdef CONFIG_AFS_FSCACHE
66 if (vnode->status.size != inode->i_size)
67 fscache_attr_changed(vnode->cache);
68 #endif
69
70 set_nlink(inode, vnode->status.nlink);
71 inode->i_uid = vnode->status.owner;
72 inode->i_gid = 0;
73 inode->i_size = vnode->status.size;
74 inode->i_ctime.tv_sec = vnode->status.mtime_server;
75 inode->i_ctime.tv_nsec = 0;
76 inode->i_atime = inode->i_mtime = inode->i_ctime;
77 inode->i_blocks = 0;
78 inode->i_generation = vnode->fid.unique;
79 inode->i_version = vnode->status.data_version;
80 inode->i_mapping->a_ops = &afs_fs_aops;
81
82 /* check to see whether a symbolic link is really a mountpoint */
83 if (vnode->status.type == AFS_FTYPE_SYMLINK) {
84 afs_mntpt_check_symlink(vnode, key);
85
86 if (test_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags)) {
87 inode->i_mode = S_IFDIR | vnode->status.mode;
88 inode->i_op = &afs_mntpt_inode_operations;
89 inode->i_fop = &afs_mntpt_file_operations;
90 }
91 }
92
93 return 0;
94 }
95
96 /*
97 * iget5() comparator
98 */
afs_iget5_test(struct inode * inode,void * opaque)99 static int afs_iget5_test(struct inode *inode, void *opaque)
100 {
101 struct afs_iget_data *data = opaque;
102
103 return inode->i_ino == data->fid.vnode &&
104 inode->i_generation == data->fid.unique;
105 }
106
107 /*
108 * iget5() comparator for inode created by autocell operations
109 *
110 * These pseudo inodes don't match anything.
111 */
afs_iget5_autocell_test(struct inode * inode,void * opaque)112 static int afs_iget5_autocell_test(struct inode *inode, void *opaque)
113 {
114 return 0;
115 }
116
117 /*
118 * iget5() inode initialiser
119 */
afs_iget5_set(struct inode * inode,void * opaque)120 static int afs_iget5_set(struct inode *inode, void *opaque)
121 {
122 struct afs_iget_data *data = opaque;
123 struct afs_vnode *vnode = AFS_FS_I(inode);
124
125 inode->i_ino = data->fid.vnode;
126 inode->i_generation = data->fid.unique;
127 vnode->fid = data->fid;
128 vnode->volume = data->volume;
129
130 return 0;
131 }
132
133 /*
134 * inode retrieval for autocell
135 */
afs_iget_autocell(struct inode * dir,const char * dev_name,int namesz,struct key * key)136 struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name,
137 int namesz, struct key *key)
138 {
139 struct afs_iget_data data;
140 struct afs_super_info *as;
141 struct afs_vnode *vnode;
142 struct super_block *sb;
143 struct inode *inode;
144 static atomic_t afs_autocell_ino;
145
146 _enter("{%x:%u},%*.*s,",
147 AFS_FS_I(dir)->fid.vid, AFS_FS_I(dir)->fid.vnode,
148 namesz, namesz, dev_name ?: "");
149
150 sb = dir->i_sb;
151 as = sb->s_fs_info;
152 data.volume = as->volume;
153 data.fid.vid = as->volume->vid;
154 data.fid.unique = 0;
155 data.fid.vnode = 0;
156
157 inode = iget5_locked(sb, atomic_inc_return(&afs_autocell_ino),
158 afs_iget5_autocell_test, afs_iget5_set,
159 &data);
160 if (!inode) {
161 _leave(" = -ENOMEM");
162 return ERR_PTR(-ENOMEM);
163 }
164
165 _debug("GOT INODE %p { ino=%lu, vl=%x, vn=%x, u=%x }",
166 inode, inode->i_ino, data.fid.vid, data.fid.vnode,
167 data.fid.unique);
168
169 vnode = AFS_FS_I(inode);
170
171 /* there shouldn't be an existing inode */
172 BUG_ON(!(inode->i_state & I_NEW));
173
174 inode->i_size = 0;
175 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
176 inode->i_op = &afs_autocell_inode_operations;
177 set_nlink(inode, 2);
178 inode->i_uid = 0;
179 inode->i_gid = 0;
180 inode->i_ctime.tv_sec = get_seconds();
181 inode->i_ctime.tv_nsec = 0;
182 inode->i_atime = inode->i_mtime = inode->i_ctime;
183 inode->i_blocks = 0;
184 inode->i_version = 0;
185 inode->i_generation = 0;
186
187 set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
188 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
189 inode->i_flags |= S_AUTOMOUNT | S_NOATIME;
190 unlock_new_inode(inode);
191 _leave(" = %p", inode);
192 return inode;
193 }
194
195 /*
196 * inode retrieval
197 */
afs_iget(struct super_block * sb,struct key * key,struct afs_fid * fid,struct afs_file_status * status,struct afs_callback * cb)198 struct inode *afs_iget(struct super_block *sb, struct key *key,
199 struct afs_fid *fid, struct afs_file_status *status,
200 struct afs_callback *cb)
201 {
202 struct afs_iget_data data = { .fid = *fid };
203 struct afs_super_info *as;
204 struct afs_vnode *vnode;
205 struct inode *inode;
206 int ret;
207
208 _enter(",{%x:%u.%u},,", fid->vid, fid->vnode, fid->unique);
209
210 as = sb->s_fs_info;
211 data.volume = as->volume;
212
213 inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
214 &data);
215 if (!inode) {
216 _leave(" = -ENOMEM");
217 return ERR_PTR(-ENOMEM);
218 }
219
220 _debug("GOT INODE %p { vl=%x vn=%x, u=%x }",
221 inode, fid->vid, fid->vnode, fid->unique);
222
223 vnode = AFS_FS_I(inode);
224
225 /* deal with an existing inode */
226 if (!(inode->i_state & I_NEW)) {
227 _leave(" = %p", inode);
228 return inode;
229 }
230
231 if (!status) {
232 /* it's a remotely extant inode */
233 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
234 ret = afs_vnode_fetch_status(vnode, NULL, key);
235 if (ret < 0)
236 goto bad_inode;
237 } else {
238 /* it's an inode we just created */
239 memcpy(&vnode->status, status, sizeof(vnode->status));
240
241 if (!cb) {
242 /* it's a symlink we just created (the fileserver
243 * didn't give us a callback) */
244 vnode->cb_version = 0;
245 vnode->cb_expiry = 0;
246 vnode->cb_type = 0;
247 vnode->cb_expires = get_seconds();
248 } else {
249 vnode->cb_version = cb->version;
250 vnode->cb_expiry = cb->expiry;
251 vnode->cb_type = cb->type;
252 vnode->cb_expires = vnode->cb_expiry + get_seconds();
253 }
254 }
255
256 /* set up caching before mapping the status, as map-status reads the
257 * first page of symlinks to see if they're really mountpoints */
258 inode->i_size = vnode->status.size;
259 #ifdef CONFIG_AFS_FSCACHE
260 vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
261 &afs_vnode_cache_index_def,
262 vnode);
263 #endif
264
265 ret = afs_inode_map_status(vnode, key);
266 if (ret < 0)
267 goto bad_inode;
268
269 /* success */
270 clear_bit(AFS_VNODE_UNSET, &vnode->flags);
271 inode->i_flags |= S_NOATIME;
272 unlock_new_inode(inode);
273 _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type);
274 return inode;
275
276 /* failure */
277 bad_inode:
278 #ifdef CONFIG_AFS_FSCACHE
279 fscache_relinquish_cookie(vnode->cache, 0);
280 vnode->cache = NULL;
281 #endif
282 iget_failed(inode);
283 _leave(" = %d [bad]", ret);
284 return ERR_PTR(ret);
285 }
286
287 /*
288 * mark the data attached to an inode as obsolete due to a write on the server
289 * - might also want to ditch all the outstanding writes and dirty pages
290 */
afs_zap_data(struct afs_vnode * vnode)291 void afs_zap_data(struct afs_vnode *vnode)
292 {
293 _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);
294
295 /* nuke all the non-dirty pages that aren't locked, mapped or being
296 * written back in a regular file and completely discard the pages in a
297 * directory or symlink */
298 if (S_ISREG(vnode->vfs_inode.i_mode))
299 invalidate_remote_inode(&vnode->vfs_inode);
300 else
301 invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
302 }
303
304 /*
305 * validate a vnode/inode
306 * - there are several things we need to check
307 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
308 * symlink)
309 * - parent dir metadata changed (security changes)
310 * - dentry data changed (write, truncate)
311 * - dentry metadata changed (security changes)
312 */
afs_validate(struct afs_vnode * vnode,struct key * key)313 int afs_validate(struct afs_vnode *vnode, struct key *key)
314 {
315 int ret;
316
317 _enter("{v={%x:%u} fl=%lx},%x",
318 vnode->fid.vid, vnode->fid.vnode, vnode->flags,
319 key_serial(key));
320
321 if (vnode->cb_promised &&
322 !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
323 !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) &&
324 !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
325 if (vnode->cb_expires < get_seconds() + 10) {
326 _debug("callback expired");
327 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
328 } else {
329 goto valid;
330 }
331 }
332
333 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
334 goto valid;
335
336 mutex_lock(&vnode->validate_lock);
337
338 /* if the promise has expired, we need to check the server again to get
339 * a new promise - note that if the (parent) directory's metadata was
340 * changed then the security may be different and we may no longer have
341 * access */
342 if (!vnode->cb_promised ||
343 test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) {
344 _debug("not promised");
345 ret = afs_vnode_fetch_status(vnode, NULL, key);
346 if (ret < 0)
347 goto error_unlock;
348 _debug("new promise [fl=%lx]", vnode->flags);
349 }
350
351 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
352 _debug("file already deleted");
353 ret = -ESTALE;
354 goto error_unlock;
355 }
356
357 /* if the vnode's data version number changed then its contents are
358 * different */
359 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
360 afs_zap_data(vnode);
361
362 clear_bit(AFS_VNODE_MODIFIED, &vnode->flags);
363 mutex_unlock(&vnode->validate_lock);
364 valid:
365 _leave(" = 0");
366 return 0;
367
368 error_unlock:
369 mutex_unlock(&vnode->validate_lock);
370 _leave(" = %d", ret);
371 return ret;
372 }
373
374 /*
375 * read the attributes of an inode
376 */
afs_getattr(struct vfsmount * mnt,struct dentry * dentry,struct kstat * stat)377 int afs_getattr(struct vfsmount *mnt, struct dentry *dentry,
378 struct kstat *stat)
379 {
380 struct inode *inode;
381
382 inode = dentry->d_inode;
383
384 _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
385
386 generic_fillattr(inode, stat);
387 return 0;
388 }
389
390 /*
391 * discard an AFS inode
392 */
afs_drop_inode(struct inode * inode)393 int afs_drop_inode(struct inode *inode)
394 {
395 _enter("");
396
397 if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
398 return generic_delete_inode(inode);
399 else
400 return generic_drop_inode(inode);
401 }
402
403 /*
404 * clear an AFS inode
405 */
afs_evict_inode(struct inode * inode)406 void afs_evict_inode(struct inode *inode)
407 {
408 struct afs_permits *permits;
409 struct afs_vnode *vnode;
410
411 vnode = AFS_FS_I(inode);
412
413 _enter("{%x:%u.%d} v=%u x=%u t=%u }",
414 vnode->fid.vid,
415 vnode->fid.vnode,
416 vnode->fid.unique,
417 vnode->cb_version,
418 vnode->cb_expiry,
419 vnode->cb_type);
420
421 _debug("CLEAR INODE %p", inode);
422
423 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
424
425 truncate_inode_pages(&inode->i_data, 0);
426 end_writeback(inode);
427
428 afs_give_up_callback(vnode);
429
430 if (vnode->server) {
431 spin_lock(&vnode->server->fs_lock);
432 rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes);
433 spin_unlock(&vnode->server->fs_lock);
434 afs_put_server(vnode->server);
435 vnode->server = NULL;
436 }
437
438 ASSERT(list_empty(&vnode->writebacks));
439 ASSERT(!vnode->cb_promised);
440
441 #ifdef CONFIG_AFS_FSCACHE
442 fscache_relinquish_cookie(vnode->cache, 0);
443 vnode->cache = NULL;
444 #endif
445
446 mutex_lock(&vnode->permits_lock);
447 permits = vnode->permits;
448 rcu_assign_pointer(vnode->permits, NULL);
449 mutex_unlock(&vnode->permits_lock);
450 if (permits)
451 call_rcu(&permits->rcu, afs_zap_permits);
452
453 _leave("");
454 }
455
456 /*
457 * set the attributes of an inode
458 */
afs_setattr(struct dentry * dentry,struct iattr * attr)459 int afs_setattr(struct dentry *dentry, struct iattr *attr)
460 {
461 struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode);
462 struct key *key;
463 int ret;
464
465 _enter("{%x:%u},{n=%s},%x",
466 vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name,
467 attr->ia_valid);
468
469 if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
470 ATTR_MTIME))) {
471 _leave(" = 0 [unsupported]");
472 return 0;
473 }
474
475 /* flush any dirty data outstanding on a regular file */
476 if (S_ISREG(vnode->vfs_inode.i_mode)) {
477 filemap_write_and_wait(vnode->vfs_inode.i_mapping);
478 afs_writeback_all(vnode);
479 }
480
481 if (attr->ia_valid & ATTR_FILE) {
482 key = attr->ia_file->private_data;
483 } else {
484 key = afs_request_key(vnode->volume->cell);
485 if (IS_ERR(key)) {
486 ret = PTR_ERR(key);
487 goto error;
488 }
489 }
490
491 ret = afs_vnode_setattr(vnode, key, attr);
492 if (!(attr->ia_valid & ATTR_FILE))
493 key_put(key);
494
495 error:
496 _leave(" = %d", ret);
497 return ret;
498 }
499