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", vnode->status.type);
37 pr_warn("kAFS: A=%d m=%o s=%llx v=%llx\n",
38 vnode->status.abort_code,
39 vnode->status.mode,
40 vnode->status.size,
41 vnode->status.data_version);
42 pr_warn("kAFS: vnode %llx:%llx:%x\n",
43 vnode->fid.vid,
44 vnode->fid.vnode,
45 vnode->fid.unique);
46 if (parent_vnode)
47 pr_warn("kAFS: dir %llx:%llx:%x\n",
48 parent_vnode->fid.vid,
49 parent_vnode->fid.vnode,
50 parent_vnode->fid.unique);
51
52 if (!test_and_set_bit(0, &once_only))
53 dump_stack();
54 }
55
56 /*
57 * Initialise an inode from the vnode status.
58 */
afs_inode_init_from_status(struct afs_operation * op,struct afs_vnode_param * vp,struct afs_vnode * vnode)59 static int afs_inode_init_from_status(struct afs_operation *op,
60 struct afs_vnode_param *vp,
61 struct afs_vnode *vnode)
62 {
63 struct afs_file_status *status = &vp->scb.status;
64 struct inode *inode = AFS_VNODE_TO_I(vnode);
65 struct timespec64 t;
66
67 _enter("{%llx:%llu.%u} %s",
68 vp->fid.vid, vp->fid.vnode, vp->fid.unique,
69 op->type ? op->type->name : "???");
70
71 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
72 status->type,
73 status->nlink,
74 (unsigned long long) status->size,
75 status->data_version,
76 status->mode);
77
78 write_seqlock(&vnode->cb_lock);
79
80 vnode->cb_v_break = op->cb_v_break;
81 vnode->cb_s_break = op->cb_s_break;
82 vnode->status = *status;
83
84 t = status->mtime_client;
85 inode->i_ctime = t;
86 inode->i_mtime = t;
87 inode->i_atime = t;
88 inode->i_flags |= S_NOATIME;
89 inode->i_uid = make_kuid(&init_user_ns, status->owner);
90 inode->i_gid = make_kgid(&init_user_ns, status->group);
91 set_nlink(&vnode->vfs_inode, status->nlink);
92
93 switch (status->type) {
94 case AFS_FTYPE_FILE:
95 inode->i_mode = S_IFREG | (status->mode & S_IALLUGO);
96 inode->i_op = &afs_file_inode_operations;
97 inode->i_fop = &afs_file_operations;
98 inode->i_mapping->a_ops = &afs_fs_aops;
99 break;
100 case AFS_FTYPE_DIR:
101 inode->i_mode = S_IFDIR | (status->mode & S_IALLUGO);
102 inode->i_op = &afs_dir_inode_operations;
103 inode->i_fop = &afs_dir_file_operations;
104 inode->i_mapping->a_ops = &afs_dir_aops;
105 break;
106 case AFS_FTYPE_SYMLINK:
107 /* Symlinks with a mode of 0644 are actually mountpoints. */
108 if ((status->mode & 0777) == 0644) {
109 inode->i_flags |= S_AUTOMOUNT;
110
111 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
112
113 inode->i_mode = S_IFDIR | 0555;
114 inode->i_op = &afs_mntpt_inode_operations;
115 inode->i_fop = &afs_mntpt_file_operations;
116 inode->i_mapping->a_ops = &afs_fs_aops;
117 } else {
118 inode->i_mode = S_IFLNK | status->mode;
119 inode->i_op = &afs_symlink_inode_operations;
120 inode->i_mapping->a_ops = &afs_fs_aops;
121 }
122 inode_nohighmem(inode);
123 break;
124 default:
125 dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
126 write_sequnlock(&vnode->cb_lock);
127 return afs_protocol_error(NULL, afs_eproto_file_type);
128 }
129
130 afs_set_i_size(vnode, status->size);
131
132 vnode->invalid_before = status->data_version;
133 inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
134
135 if (!vp->scb.have_cb) {
136 /* it's a symlink we just created (the fileserver
137 * didn't give us a callback) */
138 vnode->cb_expires_at = ktime_get_real_seconds();
139 } else {
140 vnode->cb_expires_at = vp->scb.callback.expires_at;
141 vnode->cb_server = op->server;
142 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
143 }
144
145 write_sequnlock(&vnode->cb_lock);
146 return 0;
147 }
148
149 /*
150 * Update the core inode struct from a returned status record.
151 */
afs_apply_status(struct afs_operation * op,struct afs_vnode_param * vp)152 static void afs_apply_status(struct afs_operation *op,
153 struct afs_vnode_param *vp)
154 {
155 struct afs_file_status *status = &vp->scb.status;
156 struct afs_vnode *vnode = vp->vnode;
157 struct inode *inode = &vnode->vfs_inode;
158 struct timespec64 t;
159 umode_t mode;
160 bool data_changed = false;
161 bool change_size = vp->set_size;
162
163 _enter("{%llx:%llu.%u} %s",
164 vp->fid.vid, vp->fid.vnode, vp->fid.unique,
165 op->type ? op->type->name : "???");
166
167 BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
168
169 if (status->type != vnode->status.type) {
170 pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
171 vnode->fid.vid,
172 vnode->fid.vnode,
173 vnode->fid.unique,
174 status->type, vnode->status.type);
175 afs_protocol_error(NULL, afs_eproto_bad_status);
176 return;
177 }
178
179 if (status->nlink != vnode->status.nlink)
180 set_nlink(inode, status->nlink);
181
182 if (status->owner != vnode->status.owner)
183 inode->i_uid = make_kuid(&init_user_ns, status->owner);
184
185 if (status->group != vnode->status.group)
186 inode->i_gid = make_kgid(&init_user_ns, status->group);
187
188 if (status->mode != vnode->status.mode) {
189 mode = inode->i_mode;
190 mode &= ~S_IALLUGO;
191 mode |= status->mode & S_IALLUGO;
192 WRITE_ONCE(inode->i_mode, mode);
193 }
194
195 t = status->mtime_client;
196 inode->i_mtime = t;
197 if (vp->update_ctime)
198 inode->i_ctime = op->ctime;
199
200 if (vnode->status.data_version != status->data_version)
201 data_changed = true;
202
203 vnode->status = *status;
204
205 if (vp->dv_before + vp->dv_delta != status->data_version) {
206 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
207 pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s (op=%x)\n",
208 vnode->fid.vid, vnode->fid.vnode,
209 (unsigned long long)vp->dv_before + vp->dv_delta,
210 (unsigned long long)status->data_version,
211 op->type ? op->type->name : "???",
212 op->debug_id);
213
214 vnode->invalid_before = status->data_version;
215 if (vnode->status.type == AFS_FTYPE_DIR) {
216 if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
217 afs_stat_v(vnode, n_inval);
218 } else {
219 set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
220 }
221 change_size = true;
222 data_changed = true;
223 } else if (vnode->status.type == AFS_FTYPE_DIR) {
224 /* Expected directory change is handled elsewhere so
225 * that we can locally edit the directory and save on a
226 * download.
227 */
228 if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
229 data_changed = false;
230 change_size = true;
231 }
232
233 if (data_changed) {
234 inode_set_iversion_raw(inode, status->data_version);
235
236 /* Only update the size if the data version jumped. If the
237 * file is being modified locally, then we might have our own
238 * idea of what the size should be that's not the same as
239 * what's on the server.
240 */
241 if (change_size) {
242 afs_set_i_size(vnode, status->size);
243 inode->i_ctime = t;
244 inode->i_atime = t;
245 }
246 }
247 }
248
249 /*
250 * Apply a callback to a vnode.
251 */
afs_apply_callback(struct afs_operation * op,struct afs_vnode_param * vp)252 static void afs_apply_callback(struct afs_operation *op,
253 struct afs_vnode_param *vp)
254 {
255 struct afs_callback *cb = &vp->scb.callback;
256 struct afs_vnode *vnode = vp->vnode;
257
258 if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
259 vnode->cb_expires_at = cb->expires_at;
260 vnode->cb_server = op->server;
261 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
262 }
263 }
264
265 /*
266 * Apply the received status and callback to an inode all in the same critical
267 * section to avoid races with afs_validate().
268 */
afs_vnode_commit_status(struct afs_operation * op,struct afs_vnode_param * vp)269 void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
270 {
271 struct afs_vnode *vnode = vp->vnode;
272
273 _enter("");
274
275 write_seqlock(&vnode->cb_lock);
276
277 if (vp->scb.have_error) {
278 /* A YFS server will return this from RemoveFile2 and AFS and
279 * YFS will return this from InlineBulkStatus.
280 */
281 if (vp->scb.status.abort_code == VNOVNODE) {
282 set_bit(AFS_VNODE_DELETED, &vnode->flags);
283 clear_nlink(&vnode->vfs_inode);
284 __afs_break_callback(vnode, afs_cb_break_for_deleted);
285 op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
286 }
287 } else if (vp->scb.have_status) {
288 if (vp->speculative &&
289 (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
290 vp->dv_before != vnode->status.data_version))
291 /* Ignore the result of a speculative bulk status fetch
292 * if it splits around a modification op, thereby
293 * appearing to regress the data version.
294 */
295 goto out;
296 afs_apply_status(op, vp);
297 if (vp->scb.have_cb)
298 afs_apply_callback(op, vp);
299 } else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
300 drop_nlink(&vnode->vfs_inode);
301 if (vnode->vfs_inode.i_nlink == 0) {
302 set_bit(AFS_VNODE_DELETED, &vnode->flags);
303 __afs_break_callback(vnode, afs_cb_break_for_deleted);
304 }
305 }
306
307 out:
308 write_sequnlock(&vnode->cb_lock);
309
310 if (vp->scb.have_status)
311 afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
312 }
313
afs_fetch_status_success(struct afs_operation * op)314 static void afs_fetch_status_success(struct afs_operation *op)
315 {
316 struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
317 struct afs_vnode *vnode = vp->vnode;
318 int ret;
319
320 if (vnode->vfs_inode.i_state & I_NEW) {
321 ret = afs_inode_init_from_status(op, vp, vnode);
322 op->error = ret;
323 if (ret == 0)
324 afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
325 } else {
326 afs_vnode_commit_status(op, vp);
327 }
328 }
329
330 const struct afs_operation_ops afs_fetch_status_operation = {
331 .issue_afs_rpc = afs_fs_fetch_status,
332 .issue_yfs_rpc = yfs_fs_fetch_status,
333 .success = afs_fetch_status_success,
334 .aborted = afs_check_for_remote_deletion,
335 };
336
337 /*
338 * Fetch file status from the volume.
339 */
afs_fetch_status(struct afs_vnode * vnode,struct key * key,bool is_new,afs_access_t * _caller_access)340 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
341 afs_access_t *_caller_access)
342 {
343 struct afs_operation *op;
344
345 _enter("%s,{%llx:%llu.%u,S=%lx}",
346 vnode->volume->name,
347 vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
348 vnode->flags);
349
350 op = afs_alloc_operation(key, vnode->volume);
351 if (IS_ERR(op))
352 return PTR_ERR(op);
353
354 afs_op_set_vnode(op, 0, vnode);
355
356 op->nr_files = 1;
357 op->ops = &afs_fetch_status_operation;
358 afs_begin_vnode_operation(op);
359 afs_wait_for_operation(op);
360
361 if (_caller_access)
362 *_caller_access = op->file[0].scb.status.caller_access;
363 return afs_put_operation(op);
364 }
365
366 /*
367 * ilookup() comparator
368 */
afs_ilookup5_test_by_fid(struct inode * inode,void * opaque)369 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
370 {
371 struct afs_vnode *vnode = AFS_FS_I(inode);
372 struct afs_fid *fid = opaque;
373
374 return (fid->vnode == vnode->fid.vnode &&
375 fid->vnode_hi == vnode->fid.vnode_hi &&
376 fid->unique == vnode->fid.unique);
377 }
378
379 /*
380 * iget5() comparator
381 */
afs_iget5_test(struct inode * inode,void * opaque)382 static int afs_iget5_test(struct inode *inode, void *opaque)
383 {
384 struct afs_vnode_param *vp = opaque;
385 //struct afs_vnode *vnode = AFS_FS_I(inode);
386
387 return afs_ilookup5_test_by_fid(inode, &vp->fid);
388 }
389
390 /*
391 * iget5() inode initialiser
392 */
afs_iget5_set(struct inode * inode,void * opaque)393 static int afs_iget5_set(struct inode *inode, void *opaque)
394 {
395 struct afs_vnode_param *vp = opaque;
396 struct afs_super_info *as = AFS_FS_S(inode->i_sb);
397 struct afs_vnode *vnode = AFS_FS_I(inode);
398
399 vnode->volume = as->volume;
400 vnode->fid = vp->fid;
401
402 /* YFS supports 96-bit vnode IDs, but Linux only supports
403 * 64-bit inode numbers.
404 */
405 inode->i_ino = vnode->fid.vnode;
406 inode->i_generation = vnode->fid.unique;
407 return 0;
408 }
409
410 /*
411 * Get a cache cookie for an inode.
412 */
afs_get_inode_cache(struct afs_vnode * vnode)413 static void afs_get_inode_cache(struct afs_vnode *vnode)
414 {
415 #ifdef CONFIG_AFS_FSCACHE
416 struct {
417 u32 vnode_id;
418 u32 unique;
419 u32 vnode_id_ext[2]; /* Allow for a 96-bit key */
420 } __packed key;
421 struct afs_vnode_cache_aux aux;
422
423 if (vnode->status.type != AFS_FTYPE_FILE) {
424 vnode->cache = NULL;
425 return;
426 }
427
428 key.vnode_id = vnode->fid.vnode;
429 key.unique = vnode->fid.unique;
430 key.vnode_id_ext[0] = vnode->fid.vnode >> 32;
431 key.vnode_id_ext[1] = vnode->fid.vnode_hi;
432 aux.data_version = vnode->status.data_version;
433
434 vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
435 &afs_vnode_cache_index_def,
436 &key, sizeof(key),
437 &aux, sizeof(aux),
438 vnode, vnode->status.size, true);
439 #endif
440 }
441
442 /*
443 * inode retrieval
444 */
afs_iget(struct afs_operation * op,struct afs_vnode_param * vp)445 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
446 {
447 struct afs_vnode_param *dvp = &op->file[0];
448 struct super_block *sb = dvp->vnode->vfs_inode.i_sb;
449 struct afs_vnode *vnode;
450 struct inode *inode;
451 int ret;
452
453 _enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
454
455 inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
456 if (!inode) {
457 _leave(" = -ENOMEM");
458 return ERR_PTR(-ENOMEM);
459 }
460
461 vnode = AFS_FS_I(inode);
462
463 _debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
464 inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
465
466 /* deal with an existing inode */
467 if (!(inode->i_state & I_NEW)) {
468 _leave(" = %p", inode);
469 return inode;
470 }
471
472 ret = afs_inode_init_from_status(op, vp, vnode);
473 if (ret < 0)
474 goto bad_inode;
475
476 afs_get_inode_cache(vnode);
477
478 /* success */
479 clear_bit(AFS_VNODE_UNSET, &vnode->flags);
480 unlock_new_inode(inode);
481 _leave(" = %p", inode);
482 return inode;
483
484 /* failure */
485 bad_inode:
486 iget_failed(inode);
487 _leave(" = %d [bad]", ret);
488 return ERR_PTR(ret);
489 }
490
afs_iget5_set_root(struct inode * inode,void * opaque)491 static int afs_iget5_set_root(struct inode *inode, void *opaque)
492 {
493 struct afs_super_info *as = AFS_FS_S(inode->i_sb);
494 struct afs_vnode *vnode = AFS_FS_I(inode);
495
496 vnode->volume = as->volume;
497 vnode->fid.vid = as->volume->vid,
498 vnode->fid.vnode = 1;
499 vnode->fid.unique = 1;
500 inode->i_ino = 1;
501 inode->i_generation = 1;
502 return 0;
503 }
504
505 /*
506 * Set up the root inode for a volume. This is always vnode 1, unique 1 within
507 * the volume.
508 */
afs_root_iget(struct super_block * sb,struct key * key)509 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
510 {
511 struct afs_super_info *as = AFS_FS_S(sb);
512 struct afs_operation *op;
513 struct afs_vnode *vnode;
514 struct inode *inode;
515 int ret;
516
517 _enter(",{%llx},,", as->volume->vid);
518
519 inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
520 if (!inode) {
521 _leave(" = -ENOMEM");
522 return ERR_PTR(-ENOMEM);
523 }
524
525 _debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
526
527 BUG_ON(!(inode->i_state & I_NEW));
528
529 vnode = AFS_FS_I(inode);
530 vnode->cb_v_break = as->volume->cb_v_break,
531
532 op = afs_alloc_operation(key, as->volume);
533 if (IS_ERR(op)) {
534 ret = PTR_ERR(op);
535 goto error;
536 }
537
538 afs_op_set_vnode(op, 0, vnode);
539
540 op->nr_files = 1;
541 op->ops = &afs_fetch_status_operation;
542 ret = afs_do_sync_operation(op);
543 if (ret < 0)
544 goto error;
545
546 afs_get_inode_cache(vnode);
547
548 clear_bit(AFS_VNODE_UNSET, &vnode->flags);
549 unlock_new_inode(inode);
550 _leave(" = %p", inode);
551 return inode;
552
553 error:
554 iget_failed(inode);
555 _leave(" = %d [bad]", ret);
556 return ERR_PTR(ret);
557 }
558
559 /*
560 * mark the data attached to an inode as obsolete due to a write on the server
561 * - might also want to ditch all the outstanding writes and dirty pages
562 */
afs_zap_data(struct afs_vnode * vnode)563 static void afs_zap_data(struct afs_vnode *vnode)
564 {
565 _enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
566
567 #ifdef CONFIG_AFS_FSCACHE
568 fscache_invalidate(vnode->cache);
569 #endif
570
571 /* nuke all the non-dirty pages that aren't locked, mapped or being
572 * written back in a regular file and completely discard the pages in a
573 * directory or symlink */
574 if (S_ISREG(vnode->vfs_inode.i_mode))
575 invalidate_remote_inode(&vnode->vfs_inode);
576 else
577 invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
578 }
579
580 /*
581 * Check to see if we have a server currently serving this volume and that it
582 * hasn't been reinitialised or dropped from the list.
583 */
afs_check_server_good(struct afs_vnode * vnode)584 static bool afs_check_server_good(struct afs_vnode *vnode)
585 {
586 struct afs_server_list *slist;
587 struct afs_server *server;
588 bool good;
589 int i;
590
591 if (vnode->cb_fs_s_break == atomic_read(&vnode->volume->cell->fs_s_break))
592 return true;
593
594 rcu_read_lock();
595
596 slist = rcu_dereference(vnode->volume->servers);
597 for (i = 0; i < slist->nr_servers; i++) {
598 server = slist->servers[i].server;
599 if (server == vnode->cb_server) {
600 good = (vnode->cb_s_break == server->cb_s_break);
601 rcu_read_unlock();
602 return good;
603 }
604 }
605
606 rcu_read_unlock();
607 return false;
608 }
609
610 /*
611 * Check the validity of a vnode/inode.
612 */
afs_check_validity(struct afs_vnode * vnode)613 bool afs_check_validity(struct afs_vnode *vnode)
614 {
615 enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
616 time64_t now = ktime_get_real_seconds();
617 unsigned int cb_break;
618 int seq = 0;
619
620 do {
621 read_seqbegin_or_lock(&vnode->cb_lock, &seq);
622 cb_break = vnode->cb_break;
623
624 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
625 if (vnode->cb_v_break != vnode->volume->cb_v_break)
626 need_clear = afs_cb_break_for_v_break;
627 else if (!afs_check_server_good(vnode))
628 need_clear = afs_cb_break_for_s_reinit;
629 else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
630 need_clear = afs_cb_break_for_zap;
631 else if (vnode->cb_expires_at - 10 <= now)
632 need_clear = afs_cb_break_for_lapsed;
633 } else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
634 ;
635 } else {
636 need_clear = afs_cb_break_no_promise;
637 }
638
639 } while (need_seqretry(&vnode->cb_lock, seq));
640
641 done_seqretry(&vnode->cb_lock, seq);
642
643 if (need_clear == afs_cb_break_no_break)
644 return true;
645
646 write_seqlock(&vnode->cb_lock);
647 if (need_clear == afs_cb_break_no_promise)
648 vnode->cb_v_break = vnode->volume->cb_v_break;
649 else if (cb_break == vnode->cb_break)
650 __afs_break_callback(vnode, need_clear);
651 else
652 trace_afs_cb_miss(&vnode->fid, need_clear);
653 write_sequnlock(&vnode->cb_lock);
654 return false;
655 }
656
657 /*
658 * validate a vnode/inode
659 * - there are several things we need to check
660 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
661 * symlink)
662 * - parent dir metadata changed (security changes)
663 * - dentry data changed (write, truncate)
664 * - dentry metadata changed (security changes)
665 */
afs_validate(struct afs_vnode * vnode,struct key * key)666 int afs_validate(struct afs_vnode *vnode, struct key *key)
667 {
668 int ret;
669
670 _enter("{v={%llx:%llu} fl=%lx},%x",
671 vnode->fid.vid, vnode->fid.vnode, vnode->flags,
672 key_serial(key));
673
674 if (unlikely(test_bit(AFS_VNODE_DELETED, &vnode->flags))) {
675 if (vnode->vfs_inode.i_nlink)
676 clear_nlink(&vnode->vfs_inode);
677 goto valid;
678 }
679
680 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
681 afs_check_validity(vnode))
682 goto valid;
683
684 down_write(&vnode->validate_lock);
685
686 /* if the promise has expired, we need to check the server again to get
687 * a new promise - note that if the (parent) directory's metadata was
688 * changed then the security may be different and we may no longer have
689 * access */
690 if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
691 _debug("not promised");
692 ret = afs_fetch_status(vnode, key, false, NULL);
693 if (ret < 0) {
694 if (ret == -ENOENT) {
695 set_bit(AFS_VNODE_DELETED, &vnode->flags);
696 ret = -ESTALE;
697 }
698 goto error_unlock;
699 }
700 _debug("new promise [fl=%lx]", vnode->flags);
701 }
702
703 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
704 _debug("file already deleted");
705 ret = -ESTALE;
706 goto error_unlock;
707 }
708
709 /* if the vnode's data version number changed then its contents are
710 * different */
711 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
712 afs_zap_data(vnode);
713 up_write(&vnode->validate_lock);
714 valid:
715 _leave(" = 0");
716 return 0;
717
718 error_unlock:
719 up_write(&vnode->validate_lock);
720 _leave(" = %d", ret);
721 return ret;
722 }
723
724 /*
725 * read the attributes of an inode
726 */
afs_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)727 int afs_getattr(struct user_namespace *mnt_userns, const struct path *path,
728 struct kstat *stat, u32 request_mask, unsigned int query_flags)
729 {
730 struct inode *inode = d_inode(path->dentry);
731 struct afs_vnode *vnode = AFS_FS_I(inode);
732 struct key *key;
733 int ret, seq = 0;
734
735 _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
736
737 if (vnode->volume &&
738 !(query_flags & AT_STATX_DONT_SYNC) &&
739 !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
740 key = afs_request_key(vnode->volume->cell);
741 if (IS_ERR(key))
742 return PTR_ERR(key);
743 ret = afs_validate(vnode, key);
744 key_put(key);
745 if (ret < 0)
746 return ret;
747 }
748
749 do {
750 read_seqbegin_or_lock(&vnode->cb_lock, &seq);
751 generic_fillattr(&init_user_ns, inode, stat);
752 if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
753 stat->nlink > 0)
754 stat->nlink -= 1;
755 } while (need_seqretry(&vnode->cb_lock, seq));
756
757 done_seqretry(&vnode->cb_lock, seq);
758 return 0;
759 }
760
761 /*
762 * discard an AFS inode
763 */
afs_drop_inode(struct inode * inode)764 int afs_drop_inode(struct inode *inode)
765 {
766 _enter("");
767
768 if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
769 return generic_delete_inode(inode);
770 else
771 return generic_drop_inode(inode);
772 }
773
774 /*
775 * clear an AFS inode
776 */
afs_evict_inode(struct inode * inode)777 void afs_evict_inode(struct inode *inode)
778 {
779 struct afs_vnode *vnode;
780
781 vnode = AFS_FS_I(inode);
782
783 _enter("{%llx:%llu.%d}",
784 vnode->fid.vid,
785 vnode->fid.vnode,
786 vnode->fid.unique);
787
788 _debug("CLEAR INODE %p", inode);
789
790 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
791
792 truncate_inode_pages_final(&inode->i_data);
793 clear_inode(inode);
794
795 while (!list_empty(&vnode->wb_keys)) {
796 struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
797 struct afs_wb_key, vnode_link);
798 list_del(&wbk->vnode_link);
799 afs_put_wb_key(wbk);
800 }
801
802 #ifdef CONFIG_AFS_FSCACHE
803 {
804 struct afs_vnode_cache_aux aux;
805
806 aux.data_version = vnode->status.data_version;
807 fscache_relinquish_cookie(vnode->cache, &aux,
808 test_bit(AFS_VNODE_DELETED, &vnode->flags));
809 vnode->cache = NULL;
810 }
811 #endif
812
813 afs_prune_wb_keys(vnode);
814 afs_put_permits(rcu_access_pointer(vnode->permit_cache));
815 key_put(vnode->silly_key);
816 vnode->silly_key = NULL;
817 key_put(vnode->lock_key);
818 vnode->lock_key = NULL;
819 _leave("");
820 }
821
afs_setattr_success(struct afs_operation * op)822 static void afs_setattr_success(struct afs_operation *op)
823 {
824 struct afs_vnode_param *vp = &op->file[0];
825 struct inode *inode = &vp->vnode->vfs_inode;
826 loff_t old_i_size = i_size_read(inode);
827
828 op->setattr.old_i_size = old_i_size;
829 afs_vnode_commit_status(op, vp);
830 /* inode->i_size has now been changed. */
831
832 if (op->setattr.attr->ia_valid & ATTR_SIZE) {
833 loff_t size = op->setattr.attr->ia_size;
834 if (size > old_i_size)
835 pagecache_isize_extended(inode, old_i_size, size);
836 }
837 }
838
afs_setattr_edit_file(struct afs_operation * op)839 static void afs_setattr_edit_file(struct afs_operation *op)
840 {
841 struct afs_vnode_param *vp = &op->file[0];
842 struct inode *inode = &vp->vnode->vfs_inode;
843
844 if (op->setattr.attr->ia_valid & ATTR_SIZE) {
845 loff_t size = op->setattr.attr->ia_size;
846 loff_t i_size = op->setattr.old_i_size;
847
848 if (size < i_size)
849 truncate_pagecache(inode, size);
850 }
851 }
852
853 static const struct afs_operation_ops afs_setattr_operation = {
854 .issue_afs_rpc = afs_fs_setattr,
855 .issue_yfs_rpc = yfs_fs_setattr,
856 .success = afs_setattr_success,
857 .edit_dir = afs_setattr_edit_file,
858 };
859
860 /*
861 * set the attributes of an inode
862 */
afs_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * attr)863 int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
864 struct iattr *attr)
865 {
866 struct afs_operation *op;
867 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
868 int ret;
869
870 _enter("{%llx:%llu},{n=%pd},%x",
871 vnode->fid.vid, vnode->fid.vnode, dentry,
872 attr->ia_valid);
873
874 if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
875 ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET |
876 ATTR_TOUCH))) {
877 _leave(" = 0 [unsupported]");
878 return 0;
879 }
880
881 if (attr->ia_valid & ATTR_SIZE) {
882 if (!S_ISREG(vnode->vfs_inode.i_mode))
883 return -EISDIR;
884
885 ret = inode_newsize_ok(&vnode->vfs_inode, attr->ia_size);
886 if (ret)
887 return ret;
888
889 if (attr->ia_size == i_size_read(&vnode->vfs_inode))
890 attr->ia_valid &= ~ATTR_SIZE;
891 }
892
893 /* flush any dirty data outstanding on a regular file */
894 if (S_ISREG(vnode->vfs_inode.i_mode))
895 filemap_write_and_wait(vnode->vfs_inode.i_mapping);
896
897 /* Prevent any new writebacks from starting whilst we do this. */
898 down_write(&vnode->validate_lock);
899
900 op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
901 afs_file_key(attr->ia_file) : NULL),
902 vnode->volume);
903 if (IS_ERR(op)) {
904 ret = PTR_ERR(op);
905 goto out_unlock;
906 }
907
908 afs_op_set_vnode(op, 0, vnode);
909 op->setattr.attr = attr;
910
911 if (attr->ia_valid & ATTR_SIZE) {
912 op->file[0].dv_delta = 1;
913 op->file[0].set_size = true;
914 }
915 op->ctime = attr->ia_ctime;
916 op->file[0].update_ctime = 1;
917 op->file[0].modification = true;
918
919 op->ops = &afs_setattr_operation;
920 ret = afs_do_sync_operation(op);
921
922 out_unlock:
923 up_write(&vnode->validate_lock);
924 _leave(" = %d", ret);
925 return ret;
926 }
927