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 <linux/iversion.h>
25 #include "internal.h"
26 #include "afs_fs.h"
27
28 static const struct inode_operations afs_symlink_inode_operations = {
29 .get_link = page_get_link,
30 };
31
dump_vnode(struct afs_vnode * vnode,struct afs_vnode * parent_vnode)32 static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *parent_vnode)
33 {
34 static unsigned long once_only;
35
36 pr_warn("kAFS: AFS vnode with undefined type %u\n",
37 vnode->status.type);
38 pr_warn("kAFS: A=%d m=%o s=%llx v=%llx\n",
39 vnode->status.abort_code,
40 vnode->status.mode,
41 vnode->status.size,
42 vnode->status.data_version);
43 pr_warn("kAFS: vnode %llx:%llx:%x\n",
44 vnode->fid.vid,
45 vnode->fid.vnode,
46 vnode->fid.unique);
47 if (parent_vnode)
48 pr_warn("kAFS: dir %llx:%llx:%x\n",
49 parent_vnode->fid.vid,
50 parent_vnode->fid.vnode,
51 parent_vnode->fid.unique);
52
53 if (!test_and_set_bit(0, &once_only))
54 dump_stack();
55 }
56
57 /*
58 * Set the file size and block count. Estimate the number of 512 bytes blocks
59 * used, rounded up to nearest 1K for consistency with other AFS clients.
60 */
afs_set_i_size(struct afs_vnode * vnode,u64 size)61 static void afs_set_i_size(struct afs_vnode *vnode, u64 size)
62 {
63 i_size_write(&vnode->vfs_inode, size);
64 vnode->vfs_inode.i_blocks = ((size + 1023) >> 10) << 1;
65 }
66
67 /*
68 * Initialise an inode from the vnode status.
69 */
afs_inode_init_from_status(struct afs_vnode * vnode,struct key * key,struct afs_cb_interest * cbi,struct afs_vnode * parent_vnode,struct afs_status_cb * scb)70 static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key,
71 struct afs_cb_interest *cbi,
72 struct afs_vnode *parent_vnode,
73 struct afs_status_cb *scb)
74 {
75 struct afs_cb_interest *old_cbi = NULL;
76 struct afs_file_status *status = &scb->status;
77 struct inode *inode = AFS_VNODE_TO_I(vnode);
78 struct timespec64 t;
79
80 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
81 status->type,
82 status->nlink,
83 (unsigned long long) status->size,
84 status->data_version,
85 status->mode);
86
87 write_seqlock(&vnode->cb_lock);
88
89 vnode->status = *status;
90
91 t = status->mtime_client;
92 inode->i_ctime = t;
93 inode->i_mtime = t;
94 inode->i_atime = t;
95 inode->i_uid = make_kuid(&init_user_ns, status->owner);
96 inode->i_gid = make_kgid(&init_user_ns, status->group);
97 set_nlink(&vnode->vfs_inode, status->nlink);
98
99 switch (status->type) {
100 case AFS_FTYPE_FILE:
101 inode->i_mode = S_IFREG | status->mode;
102 inode->i_op = &afs_file_inode_operations;
103 inode->i_fop = &afs_file_operations;
104 inode->i_mapping->a_ops = &afs_fs_aops;
105 break;
106 case AFS_FTYPE_DIR:
107 inode->i_mode = S_IFDIR | status->mode;
108 inode->i_op = &afs_dir_inode_operations;
109 inode->i_fop = &afs_dir_file_operations;
110 inode->i_mapping->a_ops = &afs_dir_aops;
111 break;
112 case AFS_FTYPE_SYMLINK:
113 /* Symlinks with a mode of 0644 are actually mountpoints. */
114 if ((status->mode & 0777) == 0644) {
115 inode->i_flags |= S_AUTOMOUNT;
116
117 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
118
119 inode->i_mode = S_IFDIR | 0555;
120 inode->i_op = &afs_mntpt_inode_operations;
121 inode->i_fop = &afs_mntpt_file_operations;
122 inode->i_mapping->a_ops = &afs_fs_aops;
123 } else {
124 inode->i_mode = S_IFLNK | status->mode;
125 inode->i_op = &afs_symlink_inode_operations;
126 inode->i_mapping->a_ops = &afs_fs_aops;
127 }
128 inode_nohighmem(inode);
129 break;
130 default:
131 dump_vnode(vnode, parent_vnode);
132 write_sequnlock(&vnode->cb_lock);
133 return afs_protocol_error(NULL, -EBADMSG, afs_eproto_file_type);
134 }
135
136 afs_set_i_size(vnode, status->size);
137
138 vnode->invalid_before = status->data_version;
139 inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
140
141 if (!scb->have_cb) {
142 /* it's a symlink we just created (the fileserver
143 * didn't give us a callback) */
144 vnode->cb_expires_at = ktime_get_real_seconds();
145 } else {
146 vnode->cb_expires_at = scb->callback.expires_at;
147 old_cbi = rcu_dereference_protected(vnode->cb_interest,
148 lockdep_is_held(&vnode->cb_lock.lock));
149 if (cbi != old_cbi)
150 rcu_assign_pointer(vnode->cb_interest, afs_get_cb_interest(cbi));
151 else
152 old_cbi = NULL;
153 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
154 }
155
156 write_sequnlock(&vnode->cb_lock);
157 afs_put_cb_interest(afs_v2net(vnode), old_cbi);
158 return 0;
159 }
160
161 /*
162 * Update the core inode struct from a returned status record.
163 */
afs_apply_status(struct afs_fs_cursor * fc,struct afs_vnode * vnode,struct afs_status_cb * scb,const afs_dataversion_t * expected_version)164 static void afs_apply_status(struct afs_fs_cursor *fc,
165 struct afs_vnode *vnode,
166 struct afs_status_cb *scb,
167 const afs_dataversion_t *expected_version)
168 {
169 struct afs_file_status *status = &scb->status;
170 struct timespec64 t;
171 umode_t mode;
172 bool data_changed = false;
173 bool change_size = false;
174
175 BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
176
177 if (status->type != vnode->status.type) {
178 pr_warning("Vnode %llx:%llx:%x changed type %u to %u\n",
179 vnode->fid.vid,
180 vnode->fid.vnode,
181 vnode->fid.unique,
182 status->type, vnode->status.type);
183 afs_protocol_error(NULL, -EBADMSG, afs_eproto_bad_status);
184 return;
185 }
186
187 if (status->nlink != vnode->status.nlink)
188 set_nlink(&vnode->vfs_inode, status->nlink);
189
190 if (status->owner != vnode->status.owner)
191 vnode->vfs_inode.i_uid = make_kuid(&init_user_ns, status->owner);
192
193 if (status->group != vnode->status.group)
194 vnode->vfs_inode.i_gid = make_kgid(&init_user_ns, status->group);
195
196 if (status->mode != vnode->status.mode) {
197 mode = vnode->vfs_inode.i_mode;
198 mode &= ~S_IALLUGO;
199 mode |= status->mode;
200 WRITE_ONCE(vnode->vfs_inode.i_mode, mode);
201 }
202
203 t = status->mtime_client;
204 vnode->vfs_inode.i_ctime = t;
205 vnode->vfs_inode.i_mtime = t;
206 vnode->vfs_inode.i_atime = t;
207
208 if (vnode->status.data_version != status->data_version)
209 data_changed = true;
210
211 vnode->status = *status;
212
213 if (expected_version &&
214 *expected_version != status->data_version) {
215 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
216 pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s\n",
217 vnode->fid.vid, vnode->fid.vnode,
218 (unsigned long long)*expected_version,
219 (unsigned long long)status->data_version,
220 fc->type ? fc->type->name : "???");
221
222 vnode->invalid_before = status->data_version;
223 if (vnode->status.type == AFS_FTYPE_DIR) {
224 if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
225 afs_stat_v(vnode, n_inval);
226 } else {
227 set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
228 }
229 change_size = true;
230 data_changed = true;
231 } else if (vnode->status.type == AFS_FTYPE_DIR) {
232 /* Expected directory change is handled elsewhere so
233 * that we can locally edit the directory and save on a
234 * download.
235 */
236 if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
237 data_changed = false;
238 change_size = true;
239 }
240
241 if (data_changed) {
242 inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
243
244 /* Only update the size if the data version jumped. If the
245 * file is being modified locally, then we might have our own
246 * idea of what the size should be that's not the same as
247 * what's on the server.
248 */
249 if (change_size)
250 afs_set_i_size(vnode, status->size);
251 }
252 }
253
254 /*
255 * Apply a callback to a vnode.
256 */
afs_apply_callback(struct afs_fs_cursor * fc,struct afs_vnode * vnode,struct afs_status_cb * scb,unsigned int cb_break)257 static void afs_apply_callback(struct afs_fs_cursor *fc,
258 struct afs_vnode *vnode,
259 struct afs_status_cb *scb,
260 unsigned int cb_break)
261 {
262 struct afs_cb_interest *old;
263 struct afs_callback *cb = &scb->callback;
264
265 if (!afs_cb_is_broken(cb_break, vnode, fc->cbi)) {
266 vnode->cb_expires_at = cb->expires_at;
267 old = rcu_dereference_protected(vnode->cb_interest,
268 lockdep_is_held(&vnode->cb_lock.lock));
269 if (old != fc->cbi) {
270 rcu_assign_pointer(vnode->cb_interest, afs_get_cb_interest(fc->cbi));
271 afs_put_cb_interest(afs_v2net(vnode), old);
272 }
273 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
274 }
275 }
276
277 /*
278 * Apply the received status and callback to an inode all in the same critical
279 * section to avoid races with afs_validate().
280 */
afs_vnode_commit_status(struct afs_fs_cursor * fc,struct afs_vnode * vnode,unsigned int cb_break,const afs_dataversion_t * expected_version,struct afs_status_cb * scb)281 void afs_vnode_commit_status(struct afs_fs_cursor *fc,
282 struct afs_vnode *vnode,
283 unsigned int cb_break,
284 const afs_dataversion_t *expected_version,
285 struct afs_status_cb *scb)
286 {
287 if (fc->ac.error != 0)
288 return;
289
290 write_seqlock(&vnode->cb_lock);
291
292 if (scb->have_error) {
293 if (scb->status.abort_code == VNOVNODE) {
294 set_bit(AFS_VNODE_DELETED, &vnode->flags);
295 clear_nlink(&vnode->vfs_inode);
296 __afs_break_callback(vnode, afs_cb_break_for_deleted);
297 }
298 } else {
299 if (scb->have_status)
300 afs_apply_status(fc, vnode, scb, expected_version);
301 if (scb->have_cb)
302 afs_apply_callback(fc, vnode, scb, cb_break);
303 }
304
305 write_sequnlock(&vnode->cb_lock);
306
307 if (fc->ac.error == 0 && scb->have_status)
308 afs_cache_permit(vnode, fc->key, cb_break, scb);
309 }
310
311 /*
312 * Fetch file status from the volume.
313 */
afs_fetch_status(struct afs_vnode * vnode,struct key * key,bool is_new,afs_access_t * _caller_access)314 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
315 afs_access_t *_caller_access)
316 {
317 struct afs_status_cb *scb;
318 struct afs_fs_cursor fc;
319 int ret;
320
321 _enter("%s,{%llx:%llu.%u,S=%lx}",
322 vnode->volume->name,
323 vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
324 vnode->flags);
325
326 scb = kzalloc(sizeof(struct afs_status_cb), GFP_KERNEL);
327 if (!scb)
328 return -ENOMEM;
329
330 ret = -ERESTARTSYS;
331 if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
332 afs_dataversion_t data_version = vnode->status.data_version;
333
334 while (afs_select_fileserver(&fc)) {
335 fc.cb_break = afs_calc_vnode_cb_break(vnode);
336 afs_fs_fetch_file_status(&fc, scb, NULL);
337 }
338
339 if (fc.error) {
340 /* Do nothing. */
341 } else if (is_new) {
342 ret = afs_inode_init_from_status(vnode, key, fc.cbi,
343 NULL, scb);
344 fc.error = ret;
345 if (ret == 0)
346 afs_cache_permit(vnode, key, fc.cb_break, scb);
347 } else {
348 afs_vnode_commit_status(&fc, vnode, fc.cb_break,
349 &data_version, scb);
350 }
351 afs_check_for_remote_deletion(&fc, vnode);
352 ret = afs_end_vnode_operation(&fc);
353 }
354
355 if (ret == 0 && _caller_access)
356 *_caller_access = scb->status.caller_access;
357 kfree(scb);
358 _leave(" = %d", ret);
359 return ret;
360 }
361
362 /*
363 * iget5() comparator
364 */
afs_iget5_test(struct inode * inode,void * opaque)365 int afs_iget5_test(struct inode *inode, void *opaque)
366 {
367 struct afs_iget_data *iget_data = opaque;
368 struct afs_vnode *vnode = AFS_FS_I(inode);
369
370 return memcmp(&vnode->fid, &iget_data->fid, sizeof(iget_data->fid)) == 0;
371 }
372
373 /*
374 * iget5() comparator for inode created by autocell operations
375 *
376 * These pseudo inodes don't match anything.
377 */
afs_iget5_pseudo_dir_test(struct inode * inode,void * opaque)378 static int afs_iget5_pseudo_dir_test(struct inode *inode, void *opaque)
379 {
380 return 0;
381 }
382
383 /*
384 * iget5() inode initialiser
385 */
afs_iget5_set(struct inode * inode,void * opaque)386 static int afs_iget5_set(struct inode *inode, void *opaque)
387 {
388 struct afs_iget_data *iget_data = opaque;
389 struct afs_vnode *vnode = AFS_FS_I(inode);
390
391 vnode->fid = iget_data->fid;
392 vnode->volume = iget_data->volume;
393 vnode->cb_v_break = iget_data->cb_v_break;
394 vnode->cb_s_break = iget_data->cb_s_break;
395
396 /* YFS supports 96-bit vnode IDs, but Linux only supports
397 * 64-bit inode numbers.
398 */
399 inode->i_ino = iget_data->fid.vnode;
400 inode->i_generation = iget_data->fid.unique;
401 return 0;
402 }
403
404 /*
405 * Create an inode for a dynamic root directory or an autocell dynamic
406 * automount dir.
407 */
afs_iget_pseudo_dir(struct super_block * sb,bool root)408 struct inode *afs_iget_pseudo_dir(struct super_block *sb, bool root)
409 {
410 struct afs_super_info *as;
411 struct afs_vnode *vnode;
412 struct inode *inode;
413 static atomic_t afs_autocell_ino;
414
415 struct afs_iget_data iget_data = {
416 .cb_v_break = 0,
417 .cb_s_break = 0,
418 };
419
420 _enter("");
421
422 as = sb->s_fs_info;
423 if (as->volume) {
424 iget_data.volume = as->volume;
425 iget_data.fid.vid = as->volume->vid;
426 }
427 if (root) {
428 iget_data.fid.vnode = 1;
429 iget_data.fid.unique = 1;
430 } else {
431 iget_data.fid.vnode = atomic_inc_return(&afs_autocell_ino);
432 iget_data.fid.unique = 0;
433 }
434
435 inode = iget5_locked(sb, iget_data.fid.vnode,
436 afs_iget5_pseudo_dir_test, afs_iget5_set,
437 &iget_data);
438 if (!inode) {
439 _leave(" = -ENOMEM");
440 return ERR_PTR(-ENOMEM);
441 }
442
443 _debug("GOT INODE %p { ino=%lu, vl=%llx, vn=%llx, u=%x }",
444 inode, inode->i_ino, iget_data.fid.vid, iget_data.fid.vnode,
445 iget_data.fid.unique);
446
447 vnode = AFS_FS_I(inode);
448
449 /* there shouldn't be an existing inode */
450 BUG_ON(!(inode->i_state & I_NEW));
451
452 inode->i_size = 0;
453 inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
454 if (root) {
455 inode->i_op = &afs_dynroot_inode_operations;
456 inode->i_fop = &simple_dir_operations;
457 } else {
458 inode->i_op = &afs_autocell_inode_operations;
459 }
460 set_nlink(inode, 2);
461 inode->i_uid = GLOBAL_ROOT_UID;
462 inode->i_gid = GLOBAL_ROOT_GID;
463 inode->i_ctime = inode->i_atime = inode->i_mtime = current_time(inode);
464 inode->i_blocks = 0;
465 inode_set_iversion_raw(inode, 0);
466 inode->i_generation = 0;
467
468 set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
469 if (!root) {
470 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
471 inode->i_flags |= S_AUTOMOUNT;
472 }
473
474 inode->i_flags |= S_NOATIME;
475 unlock_new_inode(inode);
476 _leave(" = %p", inode);
477 return inode;
478 }
479
480 /*
481 * Get a cache cookie for an inode.
482 */
afs_get_inode_cache(struct afs_vnode * vnode)483 static void afs_get_inode_cache(struct afs_vnode *vnode)
484 {
485 #ifdef CONFIG_AFS_FSCACHE
486 struct {
487 u32 vnode_id;
488 u32 unique;
489 u32 vnode_id_ext[2]; /* Allow for a 96-bit key */
490 } __packed key;
491 struct afs_vnode_cache_aux aux;
492
493 if (vnode->status.type == AFS_FTYPE_DIR) {
494 vnode->cache = NULL;
495 return;
496 }
497
498 key.vnode_id = vnode->fid.vnode;
499 key.unique = vnode->fid.unique;
500 key.vnode_id_ext[0] = vnode->fid.vnode >> 32;
501 key.vnode_id_ext[1] = vnode->fid.vnode_hi;
502 aux.data_version = vnode->status.data_version;
503
504 vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
505 &afs_vnode_cache_index_def,
506 &key, sizeof(key),
507 &aux, sizeof(aux),
508 vnode, vnode->status.size, true);
509 #endif
510 }
511
512 /*
513 * inode retrieval
514 */
afs_iget(struct super_block * sb,struct key * key,struct afs_iget_data * iget_data,struct afs_status_cb * scb,struct afs_cb_interest * cbi,struct afs_vnode * parent_vnode)515 struct inode *afs_iget(struct super_block *sb, struct key *key,
516 struct afs_iget_data *iget_data,
517 struct afs_status_cb *scb,
518 struct afs_cb_interest *cbi,
519 struct afs_vnode *parent_vnode)
520 {
521 struct afs_super_info *as;
522 struct afs_vnode *vnode;
523 struct afs_fid *fid = &iget_data->fid;
524 struct inode *inode;
525 int ret;
526
527 _enter(",{%llx:%llu.%u},,", fid->vid, fid->vnode, fid->unique);
528
529 as = sb->s_fs_info;
530 iget_data->volume = as->volume;
531
532 inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
533 iget_data);
534 if (!inode) {
535 _leave(" = -ENOMEM");
536 return ERR_PTR(-ENOMEM);
537 }
538
539 _debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
540 inode, fid->vid, fid->vnode, fid->unique);
541
542 vnode = AFS_FS_I(inode);
543
544 /* deal with an existing inode */
545 if (!(inode->i_state & I_NEW)) {
546 _leave(" = %p", inode);
547 return inode;
548 }
549
550 if (!scb) {
551 /* it's a remotely extant inode */
552 ret = afs_fetch_status(vnode, key, true, NULL);
553 if (ret < 0)
554 goto bad_inode;
555 } else {
556 ret = afs_inode_init_from_status(vnode, key, cbi, parent_vnode,
557 scb);
558 if (ret < 0)
559 goto bad_inode;
560 }
561
562 afs_get_inode_cache(vnode);
563
564 /* success */
565 clear_bit(AFS_VNODE_UNSET, &vnode->flags);
566 inode->i_flags |= S_NOATIME;
567 unlock_new_inode(inode);
568 _leave(" = %p", inode);
569 return inode;
570
571 /* failure */
572 bad_inode:
573 iget_failed(inode);
574 _leave(" = %d [bad]", ret);
575 return ERR_PTR(ret);
576 }
577
578 /*
579 * mark the data attached to an inode as obsolete due to a write on the server
580 * - might also want to ditch all the outstanding writes and dirty pages
581 */
afs_zap_data(struct afs_vnode * vnode)582 void afs_zap_data(struct afs_vnode *vnode)
583 {
584 _enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
585
586 #ifdef CONFIG_AFS_FSCACHE
587 fscache_invalidate(vnode->cache);
588 #endif
589
590 /* nuke all the non-dirty pages that aren't locked, mapped or being
591 * written back in a regular file and completely discard the pages in a
592 * directory or symlink */
593 if (S_ISREG(vnode->vfs_inode.i_mode))
594 invalidate_remote_inode(&vnode->vfs_inode);
595 else
596 invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
597 }
598
599 /*
600 * Check the validity of a vnode/inode.
601 */
afs_check_validity(struct afs_vnode * vnode)602 bool afs_check_validity(struct afs_vnode *vnode)
603 {
604 struct afs_cb_interest *cbi;
605 struct afs_server *server;
606 struct afs_volume *volume = vnode->volume;
607 enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
608 time64_t now = ktime_get_real_seconds();
609 bool valid;
610 unsigned int cb_break, cb_s_break, cb_v_break;
611 int seq = 0;
612
613 do {
614 read_seqbegin_or_lock(&vnode->cb_lock, &seq);
615 cb_v_break = READ_ONCE(volume->cb_v_break);
616 cb_break = vnode->cb_break;
617
618 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
619 cbi = rcu_dereference(vnode->cb_interest);
620 server = rcu_dereference(cbi->server);
621 cb_s_break = READ_ONCE(server->cb_s_break);
622
623 if (vnode->cb_s_break != cb_s_break ||
624 vnode->cb_v_break != cb_v_break) {
625 vnode->cb_s_break = cb_s_break;
626 vnode->cb_v_break = cb_v_break;
627 need_clear = afs_cb_break_for_vsbreak;
628 valid = false;
629 } else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
630 need_clear = afs_cb_break_for_zap;
631 valid = false;
632 } else if (vnode->cb_expires_at - 10 <= now) {
633 need_clear = afs_cb_break_for_lapsed;
634 valid = false;
635 } else {
636 valid = true;
637 }
638 } else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
639 valid = true;
640 } else {
641 vnode->cb_v_break = cb_v_break;
642 valid = false;
643 }
644
645 } while (need_seqretry(&vnode->cb_lock, seq));
646
647 done_seqretry(&vnode->cb_lock, seq);
648
649 if (need_clear != afs_cb_break_no_break) {
650 write_seqlock(&vnode->cb_lock);
651 if (cb_break == vnode->cb_break)
652 __afs_break_callback(vnode, need_clear);
653 else
654 trace_afs_cb_miss(&vnode->fid, need_clear);
655 write_sequnlock(&vnode->cb_lock);
656 valid = false;
657 }
658
659 return valid;
660 }
661
662 /*
663 * validate a vnode/inode
664 * - there are several things we need to check
665 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
666 * symlink)
667 * - parent dir metadata changed (security changes)
668 * - dentry data changed (write, truncate)
669 * - dentry metadata changed (security changes)
670 */
afs_validate(struct afs_vnode * vnode,struct key * key)671 int afs_validate(struct afs_vnode *vnode, struct key *key)
672 {
673 bool valid;
674 int ret;
675
676 _enter("{v={%llx:%llu} fl=%lx},%x",
677 vnode->fid.vid, vnode->fid.vnode, vnode->flags,
678 key_serial(key));
679
680 rcu_read_lock();
681 valid = afs_check_validity(vnode);
682 rcu_read_unlock();
683
684 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
685 clear_nlink(&vnode->vfs_inode);
686
687 if (valid)
688 goto valid;
689
690 down_write(&vnode->validate_lock);
691
692 /* if the promise has expired, we need to check the server again to get
693 * a new promise - note that if the (parent) directory's metadata was
694 * changed then the security may be different and we may no longer have
695 * access */
696 if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
697 _debug("not promised");
698 ret = afs_fetch_status(vnode, key, false, NULL);
699 if (ret < 0) {
700 if (ret == -ENOENT) {
701 set_bit(AFS_VNODE_DELETED, &vnode->flags);
702 ret = -ESTALE;
703 }
704 goto error_unlock;
705 }
706 _debug("new promise [fl=%lx]", vnode->flags);
707 }
708
709 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
710 _debug("file already deleted");
711 ret = -ESTALE;
712 goto error_unlock;
713 }
714
715 /* if the vnode's data version number changed then its contents are
716 * different */
717 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
718 afs_zap_data(vnode);
719 up_write(&vnode->validate_lock);
720 valid:
721 _leave(" = 0");
722 return 0;
723
724 error_unlock:
725 up_write(&vnode->validate_lock);
726 _leave(" = %d", ret);
727 return ret;
728 }
729
730 /*
731 * read the attributes of an inode
732 */
afs_getattr(const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)733 int afs_getattr(const struct path *path, struct kstat *stat,
734 u32 request_mask, unsigned int query_flags)
735 {
736 struct inode *inode = d_inode(path->dentry);
737 struct afs_vnode *vnode = AFS_FS_I(inode);
738 struct key *key;
739 int ret, seq = 0;
740
741 _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
742
743 if (vnode->volume &&
744 !(query_flags & AT_STATX_DONT_SYNC) &&
745 !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
746 key = afs_request_key(vnode->volume->cell);
747 if (IS_ERR(key))
748 return PTR_ERR(key);
749 ret = afs_validate(vnode, key);
750 key_put(key);
751 if (ret < 0)
752 return ret;
753 }
754
755 do {
756 read_seqbegin_or_lock(&vnode->cb_lock, &seq);
757 generic_fillattr(inode, stat);
758 } while (need_seqretry(&vnode->cb_lock, seq));
759
760 done_seqretry(&vnode->cb_lock, seq);
761 return 0;
762 }
763
764 /*
765 * discard an AFS inode
766 */
afs_drop_inode(struct inode * inode)767 int afs_drop_inode(struct inode *inode)
768 {
769 _enter("");
770
771 if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
772 return generic_delete_inode(inode);
773 else
774 return generic_drop_inode(inode);
775 }
776
777 /*
778 * clear an AFS inode
779 */
afs_evict_inode(struct inode * inode)780 void afs_evict_inode(struct inode *inode)
781 {
782 struct afs_cb_interest *cbi;
783 struct afs_vnode *vnode;
784
785 vnode = AFS_FS_I(inode);
786
787 _enter("{%llx:%llu.%d}",
788 vnode->fid.vid,
789 vnode->fid.vnode,
790 vnode->fid.unique);
791
792 _debug("CLEAR INODE %p", inode);
793
794 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
795
796 truncate_inode_pages_final(&inode->i_data);
797 clear_inode(inode);
798
799 write_seqlock(&vnode->cb_lock);
800 cbi = rcu_dereference_protected(vnode->cb_interest,
801 lockdep_is_held(&vnode->cb_lock.lock));
802 if (cbi) {
803 afs_put_cb_interest(afs_i2net(inode), cbi);
804 rcu_assign_pointer(vnode->cb_interest, NULL);
805 }
806 write_sequnlock(&vnode->cb_lock);
807
808 while (!list_empty(&vnode->wb_keys)) {
809 struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
810 struct afs_wb_key, vnode_link);
811 list_del(&wbk->vnode_link);
812 afs_put_wb_key(wbk);
813 }
814
815 #ifdef CONFIG_AFS_FSCACHE
816 {
817 struct afs_vnode_cache_aux aux;
818
819 aux.data_version = vnode->status.data_version;
820 fscache_relinquish_cookie(vnode->cache, &aux,
821 test_bit(AFS_VNODE_DELETED, &vnode->flags));
822 vnode->cache = NULL;
823 }
824 #endif
825
826 afs_prune_wb_keys(vnode);
827 afs_put_permits(rcu_access_pointer(vnode->permit_cache));
828 key_put(vnode->silly_key);
829 vnode->silly_key = NULL;
830 key_put(vnode->lock_key);
831 vnode->lock_key = NULL;
832 _leave("");
833 }
834
835 /*
836 * set the attributes of an inode
837 */
afs_setattr(struct dentry * dentry,struct iattr * attr)838 int afs_setattr(struct dentry *dentry, struct iattr *attr)
839 {
840 struct afs_fs_cursor fc;
841 struct afs_status_cb *scb;
842 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
843 struct key *key;
844 int ret = -ENOMEM;
845
846 _enter("{%llx:%llu},{n=%pd},%x",
847 vnode->fid.vid, vnode->fid.vnode, dentry,
848 attr->ia_valid);
849
850 if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
851 ATTR_MTIME))) {
852 _leave(" = 0 [unsupported]");
853 return 0;
854 }
855
856 scb = kzalloc(sizeof(struct afs_status_cb), GFP_KERNEL);
857 if (!scb)
858 goto error;
859
860 /* flush any dirty data outstanding on a regular file */
861 if (S_ISREG(vnode->vfs_inode.i_mode))
862 filemap_write_and_wait(vnode->vfs_inode.i_mapping);
863
864 if (attr->ia_valid & ATTR_FILE) {
865 key = afs_file_key(attr->ia_file);
866 } else {
867 key = afs_request_key(vnode->volume->cell);
868 if (IS_ERR(key)) {
869 ret = PTR_ERR(key);
870 goto error_scb;
871 }
872 }
873
874 ret = -ERESTARTSYS;
875 if (afs_begin_vnode_operation(&fc, vnode, key, false)) {
876 afs_dataversion_t data_version = vnode->status.data_version;
877
878 if (attr->ia_valid & ATTR_SIZE)
879 data_version++;
880
881 while (afs_select_fileserver(&fc)) {
882 fc.cb_break = afs_calc_vnode_cb_break(vnode);
883 afs_fs_setattr(&fc, attr, scb);
884 }
885
886 afs_check_for_remote_deletion(&fc, vnode);
887 afs_vnode_commit_status(&fc, vnode, fc.cb_break,
888 &data_version, scb);
889 ret = afs_end_vnode_operation(&fc);
890 }
891
892 if (!(attr->ia_valid & ATTR_FILE))
893 key_put(key);
894
895 error_scb:
896 kfree(scb);
897 error:
898 _leave(" = %d", ret);
899 return ret;
900 }
901