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 * Set parameters for the netfs library
58 */
afs_set_netfs_context(struct afs_vnode * vnode)59 static void afs_set_netfs_context(struct afs_vnode *vnode)
60 {
61 netfs_inode_init(&vnode->netfs, &afs_req_ops);
62 }
63
64 /*
65 * Initialise an inode from the vnode status.
66 */
afs_inode_init_from_status(struct afs_operation * op,struct afs_vnode_param * vp,struct afs_vnode * vnode)67 static int afs_inode_init_from_status(struct afs_operation *op,
68 struct afs_vnode_param *vp,
69 struct afs_vnode *vnode)
70 {
71 struct afs_file_status *status = &vp->scb.status;
72 struct inode *inode = AFS_VNODE_TO_I(vnode);
73 struct timespec64 t;
74
75 _enter("{%llx:%llu.%u} %s",
76 vp->fid.vid, vp->fid.vnode, vp->fid.unique,
77 op->type ? op->type->name : "???");
78
79 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
80 status->type,
81 status->nlink,
82 (unsigned long long) status->size,
83 status->data_version,
84 status->mode);
85
86 write_seqlock(&vnode->cb_lock);
87
88 vnode->cb_v_break = op->cb_v_break;
89 vnode->cb_s_break = op->cb_s_break;
90 vnode->status = *status;
91
92 t = status->mtime_client;
93 inode_set_ctime_to_ts(inode, t);
94 inode->i_mtime = t;
95 inode->i_atime = t;
96 inode->i_flags |= S_NOATIME;
97 inode->i_uid = make_kuid(&init_user_ns, status->owner);
98 inode->i_gid = make_kgid(&init_user_ns, status->group);
99 set_nlink(&vnode->netfs.inode, status->nlink);
100
101 switch (status->type) {
102 case AFS_FTYPE_FILE:
103 inode->i_mode = S_IFREG | (status->mode & S_IALLUGO);
104 inode->i_op = &afs_file_inode_operations;
105 inode->i_fop = &afs_file_operations;
106 inode->i_mapping->a_ops = &afs_file_aops;
107 mapping_set_large_folios(inode->i_mapping);
108 break;
109 case AFS_FTYPE_DIR:
110 inode->i_mode = S_IFDIR | (status->mode & S_IALLUGO);
111 inode->i_op = &afs_dir_inode_operations;
112 inode->i_fop = &afs_dir_file_operations;
113 inode->i_mapping->a_ops = &afs_dir_aops;
114 mapping_set_large_folios(inode->i_mapping);
115 break;
116 case AFS_FTYPE_SYMLINK:
117 /* Symlinks with a mode of 0644 are actually mountpoints. */
118 if ((status->mode & 0777) == 0644) {
119 inode->i_flags |= S_AUTOMOUNT;
120
121 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
122
123 inode->i_mode = S_IFDIR | 0555;
124 inode->i_op = &afs_mntpt_inode_operations;
125 inode->i_fop = &afs_mntpt_file_operations;
126 inode->i_mapping->a_ops = &afs_symlink_aops;
127 } else {
128 inode->i_mode = S_IFLNK | status->mode;
129 inode->i_op = &afs_symlink_inode_operations;
130 inode->i_mapping->a_ops = &afs_symlink_aops;
131 }
132 inode_nohighmem(inode);
133 break;
134 default:
135 dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
136 write_sequnlock(&vnode->cb_lock);
137 return afs_protocol_error(NULL, afs_eproto_file_type);
138 }
139
140 afs_set_i_size(vnode, status->size);
141 afs_set_netfs_context(vnode);
142
143 vnode->invalid_before = status->data_version;
144 inode_set_iversion_raw(&vnode->netfs.inode, status->data_version);
145
146 if (!vp->scb.have_cb) {
147 /* it's a symlink we just created (the fileserver
148 * didn't give us a callback) */
149 vnode->cb_expires_at = ktime_get_real_seconds();
150 } else {
151 vnode->cb_expires_at = vp->scb.callback.expires_at;
152 vnode->cb_server = op->server;
153 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
154 }
155
156 write_sequnlock(&vnode->cb_lock);
157 return 0;
158 }
159
160 /*
161 * Update the core inode struct from a returned status record.
162 */
afs_apply_status(struct afs_operation * op,struct afs_vnode_param * vp)163 static void afs_apply_status(struct afs_operation *op,
164 struct afs_vnode_param *vp)
165 {
166 struct afs_file_status *status = &vp->scb.status;
167 struct afs_vnode *vnode = vp->vnode;
168 struct inode *inode = &vnode->netfs.inode;
169 struct timespec64 t;
170 umode_t mode;
171 bool data_changed = false;
172 bool change_size = vp->set_size;
173
174 _enter("{%llx:%llu.%u} %s",
175 vp->fid.vid, vp->fid.vnode, vp->fid.unique,
176 op->type ? op->type->name : "???");
177
178 BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
179
180 if (status->type != vnode->status.type) {
181 pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
182 vnode->fid.vid,
183 vnode->fid.vnode,
184 vnode->fid.unique,
185 status->type, vnode->status.type);
186 afs_protocol_error(NULL, afs_eproto_bad_status);
187 return;
188 }
189
190 if (status->nlink != vnode->status.nlink)
191 set_nlink(inode, status->nlink);
192
193 if (status->owner != vnode->status.owner)
194 inode->i_uid = make_kuid(&init_user_ns, status->owner);
195
196 if (status->group != vnode->status.group)
197 inode->i_gid = make_kgid(&init_user_ns, status->group);
198
199 if (status->mode != vnode->status.mode) {
200 mode = inode->i_mode;
201 mode &= ~S_IALLUGO;
202 mode |= status->mode & S_IALLUGO;
203 WRITE_ONCE(inode->i_mode, mode);
204 }
205
206 t = status->mtime_client;
207 inode->i_mtime = t;
208 if (vp->update_ctime)
209 inode_set_ctime_to_ts(inode, op->ctime);
210
211 if (vnode->status.data_version != status->data_version)
212 data_changed = true;
213
214 vnode->status = *status;
215
216 if (vp->dv_before + vp->dv_delta != status->data_version) {
217 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
218 pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s (op=%x)\n",
219 vnode->fid.vid, vnode->fid.vnode,
220 (unsigned long long)vp->dv_before + vp->dv_delta,
221 (unsigned long long)status->data_version,
222 op->type ? op->type->name : "???",
223 op->debug_id);
224
225 vnode->invalid_before = status->data_version;
226 if (vnode->status.type == AFS_FTYPE_DIR) {
227 if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
228 afs_stat_v(vnode, n_inval);
229 } else {
230 set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
231 }
232 change_size = true;
233 data_changed = true;
234 } else if (vnode->status.type == AFS_FTYPE_DIR) {
235 /* Expected directory change is handled elsewhere so
236 * that we can locally edit the directory and save on a
237 * download.
238 */
239 if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
240 data_changed = false;
241 change_size = true;
242 }
243
244 if (data_changed) {
245 inode_set_iversion_raw(inode, status->data_version);
246
247 /* Only update the size if the data version jumped. If the
248 * file is being modified locally, then we might have our own
249 * idea of what the size should be that's not the same as
250 * what's on the server.
251 */
252 vnode->netfs.remote_i_size = status->size;
253 if (change_size) {
254 afs_set_i_size(vnode, status->size);
255 inode_set_ctime_to_ts(inode, t);
256 inode->i_atime = t;
257 }
258 }
259 }
260
261 /*
262 * Apply a callback to a vnode.
263 */
afs_apply_callback(struct afs_operation * op,struct afs_vnode_param * vp)264 static void afs_apply_callback(struct afs_operation *op,
265 struct afs_vnode_param *vp)
266 {
267 struct afs_callback *cb = &vp->scb.callback;
268 struct afs_vnode *vnode = vp->vnode;
269
270 if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
271 vnode->cb_expires_at = cb->expires_at;
272 vnode->cb_server = op->server;
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_operation * op,struct afs_vnode_param * vp)281 void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
282 {
283 struct afs_vnode *vnode = vp->vnode;
284
285 _enter("");
286
287 write_seqlock(&vnode->cb_lock);
288
289 if (vp->scb.have_error) {
290 /* A YFS server will return this from RemoveFile2 and AFS and
291 * YFS will return this from InlineBulkStatus.
292 */
293 if (vp->scb.status.abort_code == VNOVNODE) {
294 set_bit(AFS_VNODE_DELETED, &vnode->flags);
295 clear_nlink(&vnode->netfs.inode);
296 __afs_break_callback(vnode, afs_cb_break_for_deleted);
297 op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
298 }
299 } else if (vp->scb.have_status) {
300 if (vp->speculative &&
301 (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
302 vp->dv_before != vnode->status.data_version))
303 /* Ignore the result of a speculative bulk status fetch
304 * if it splits around a modification op, thereby
305 * appearing to regress the data version.
306 */
307 goto out;
308 afs_apply_status(op, vp);
309 if (vp->scb.have_cb)
310 afs_apply_callback(op, vp);
311 } else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
312 drop_nlink(&vnode->netfs.inode);
313 if (vnode->netfs.inode.i_nlink == 0) {
314 set_bit(AFS_VNODE_DELETED, &vnode->flags);
315 __afs_break_callback(vnode, afs_cb_break_for_deleted);
316 }
317 }
318
319 out:
320 write_sequnlock(&vnode->cb_lock);
321
322 if (vp->scb.have_status)
323 afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
324 }
325
afs_fetch_status_success(struct afs_operation * op)326 static void afs_fetch_status_success(struct afs_operation *op)
327 {
328 struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
329 struct afs_vnode *vnode = vp->vnode;
330 int ret;
331
332 if (vnode->netfs.inode.i_state & I_NEW) {
333 ret = afs_inode_init_from_status(op, vp, vnode);
334 op->error = ret;
335 if (ret == 0)
336 afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
337 } else {
338 afs_vnode_commit_status(op, vp);
339 }
340 }
341
342 const struct afs_operation_ops afs_fetch_status_operation = {
343 .issue_afs_rpc = afs_fs_fetch_status,
344 .issue_yfs_rpc = yfs_fs_fetch_status,
345 .success = afs_fetch_status_success,
346 .aborted = afs_check_for_remote_deletion,
347 };
348
349 /*
350 * Fetch file status from the volume.
351 */
afs_fetch_status(struct afs_vnode * vnode,struct key * key,bool is_new,afs_access_t * _caller_access)352 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
353 afs_access_t *_caller_access)
354 {
355 struct afs_operation *op;
356
357 _enter("%s,{%llx:%llu.%u,S=%lx}",
358 vnode->volume->name,
359 vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
360 vnode->flags);
361
362 op = afs_alloc_operation(key, vnode->volume);
363 if (IS_ERR(op))
364 return PTR_ERR(op);
365
366 afs_op_set_vnode(op, 0, vnode);
367
368 op->nr_files = 1;
369 op->ops = &afs_fetch_status_operation;
370 afs_begin_vnode_operation(op);
371 afs_wait_for_operation(op);
372
373 if (_caller_access)
374 *_caller_access = op->file[0].scb.status.caller_access;
375 return afs_put_operation(op);
376 }
377
378 /*
379 * ilookup() comparator
380 */
afs_ilookup5_test_by_fid(struct inode * inode,void * opaque)381 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
382 {
383 struct afs_vnode *vnode = AFS_FS_I(inode);
384 struct afs_fid *fid = opaque;
385
386 return (fid->vnode == vnode->fid.vnode &&
387 fid->vnode_hi == vnode->fid.vnode_hi &&
388 fid->unique == vnode->fid.unique);
389 }
390
391 /*
392 * iget5() comparator
393 */
afs_iget5_test(struct inode * inode,void * opaque)394 static int afs_iget5_test(struct inode *inode, void *opaque)
395 {
396 struct afs_vnode_param *vp = opaque;
397 //struct afs_vnode *vnode = AFS_FS_I(inode);
398
399 return afs_ilookup5_test_by_fid(inode, &vp->fid);
400 }
401
402 /*
403 * iget5() inode initialiser
404 */
afs_iget5_set(struct inode * inode,void * opaque)405 static int afs_iget5_set(struct inode *inode, void *opaque)
406 {
407 struct afs_vnode_param *vp = opaque;
408 struct afs_super_info *as = AFS_FS_S(inode->i_sb);
409 struct afs_vnode *vnode = AFS_FS_I(inode);
410
411 vnode->volume = as->volume;
412 vnode->fid = vp->fid;
413
414 /* YFS supports 96-bit vnode IDs, but Linux only supports
415 * 64-bit inode numbers.
416 */
417 inode->i_ino = vnode->fid.vnode;
418 inode->i_generation = vnode->fid.unique;
419 return 0;
420 }
421
422 /*
423 * Get a cache cookie for an inode.
424 */
afs_get_inode_cache(struct afs_vnode * vnode)425 static void afs_get_inode_cache(struct afs_vnode *vnode)
426 {
427 #ifdef CONFIG_AFS_FSCACHE
428 struct {
429 __be32 vnode_id;
430 __be32 unique;
431 __be32 vnode_id_ext[2]; /* Allow for a 96-bit key */
432 } __packed key;
433 struct afs_vnode_cache_aux aux;
434
435 if (vnode->status.type != AFS_FTYPE_FILE) {
436 vnode->netfs.cache = NULL;
437 return;
438 }
439
440 key.vnode_id = htonl(vnode->fid.vnode);
441 key.unique = htonl(vnode->fid.unique);
442 key.vnode_id_ext[0] = htonl(vnode->fid.vnode >> 32);
443 key.vnode_id_ext[1] = htonl(vnode->fid.vnode_hi);
444 afs_set_cache_aux(vnode, &aux);
445
446 afs_vnode_set_cache(vnode,
447 fscache_acquire_cookie(
448 vnode->volume->cache,
449 vnode->status.type == AFS_FTYPE_FILE ?
450 0 : FSCACHE_ADV_SINGLE_CHUNK,
451 &key, sizeof(key),
452 &aux, sizeof(aux),
453 i_size_read(&vnode->netfs.inode)));
454 #endif
455 }
456
457 /*
458 * inode retrieval
459 */
afs_iget(struct afs_operation * op,struct afs_vnode_param * vp)460 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
461 {
462 struct afs_vnode_param *dvp = &op->file[0];
463 struct super_block *sb = dvp->vnode->netfs.inode.i_sb;
464 struct afs_vnode *vnode;
465 struct inode *inode;
466 int ret;
467
468 _enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
469
470 inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
471 if (!inode) {
472 _leave(" = -ENOMEM");
473 return ERR_PTR(-ENOMEM);
474 }
475
476 vnode = AFS_FS_I(inode);
477
478 _debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
479 inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
480
481 /* deal with an existing inode */
482 if (!(inode->i_state & I_NEW)) {
483 _leave(" = %p", inode);
484 return inode;
485 }
486
487 ret = afs_inode_init_from_status(op, vp, vnode);
488 if (ret < 0)
489 goto bad_inode;
490
491 afs_get_inode_cache(vnode);
492
493 /* success */
494 clear_bit(AFS_VNODE_UNSET, &vnode->flags);
495 unlock_new_inode(inode);
496 _leave(" = %p", inode);
497 return inode;
498
499 /* failure */
500 bad_inode:
501 iget_failed(inode);
502 _leave(" = %d [bad]", ret);
503 return ERR_PTR(ret);
504 }
505
afs_iget5_set_root(struct inode * inode,void * opaque)506 static int afs_iget5_set_root(struct inode *inode, void *opaque)
507 {
508 struct afs_super_info *as = AFS_FS_S(inode->i_sb);
509 struct afs_vnode *vnode = AFS_FS_I(inode);
510
511 vnode->volume = as->volume;
512 vnode->fid.vid = as->volume->vid,
513 vnode->fid.vnode = 1;
514 vnode->fid.unique = 1;
515 inode->i_ino = 1;
516 inode->i_generation = 1;
517 return 0;
518 }
519
520 /*
521 * Set up the root inode for a volume. This is always vnode 1, unique 1 within
522 * the volume.
523 */
afs_root_iget(struct super_block * sb,struct key * key)524 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
525 {
526 struct afs_super_info *as = AFS_FS_S(sb);
527 struct afs_operation *op;
528 struct afs_vnode *vnode;
529 struct inode *inode;
530 int ret;
531
532 _enter(",{%llx},,", as->volume->vid);
533
534 inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
535 if (!inode) {
536 _leave(" = -ENOMEM");
537 return ERR_PTR(-ENOMEM);
538 }
539
540 _debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
541
542 BUG_ON(!(inode->i_state & I_NEW));
543
544 vnode = AFS_FS_I(inode);
545 vnode->cb_v_break = as->volume->cb_v_break,
546 afs_set_netfs_context(vnode);
547
548 op = afs_alloc_operation(key, as->volume);
549 if (IS_ERR(op)) {
550 ret = PTR_ERR(op);
551 goto error;
552 }
553
554 afs_op_set_vnode(op, 0, vnode);
555
556 op->nr_files = 1;
557 op->ops = &afs_fetch_status_operation;
558 ret = afs_do_sync_operation(op);
559 if (ret < 0)
560 goto error;
561
562 afs_get_inode_cache(vnode);
563
564 clear_bit(AFS_VNODE_UNSET, &vnode->flags);
565 unlock_new_inode(inode);
566 _leave(" = %p", inode);
567 return inode;
568
569 error:
570 iget_failed(inode);
571 _leave(" = %d [bad]", ret);
572 return ERR_PTR(ret);
573 }
574
575 /*
576 * mark the data attached to an inode as obsolete due to a write on the server
577 * - might also want to ditch all the outstanding writes and dirty pages
578 */
afs_zap_data(struct afs_vnode * vnode)579 static void afs_zap_data(struct afs_vnode *vnode)
580 {
581 _enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
582
583 afs_invalidate_cache(vnode, 0);
584
585 /* nuke all the non-dirty pages that aren't locked, mapped or being
586 * written back in a regular file and completely discard the pages in a
587 * directory or symlink */
588 if (S_ISREG(vnode->netfs.inode.i_mode))
589 invalidate_remote_inode(&vnode->netfs.inode);
590 else
591 invalidate_inode_pages2(vnode->netfs.inode.i_mapping);
592 }
593
594 /*
595 * Check to see if we have a server currently serving this volume and that it
596 * hasn't been reinitialised or dropped from the list.
597 */
afs_check_server_good(struct afs_vnode * vnode)598 static bool afs_check_server_good(struct afs_vnode *vnode)
599 {
600 struct afs_server_list *slist;
601 struct afs_server *server;
602 bool good;
603 int i;
604
605 if (vnode->cb_fs_s_break == atomic_read(&vnode->volume->cell->fs_s_break))
606 return true;
607
608 rcu_read_lock();
609
610 slist = rcu_dereference(vnode->volume->servers);
611 for (i = 0; i < slist->nr_servers; i++) {
612 server = slist->servers[i].server;
613 if (server == vnode->cb_server) {
614 good = (vnode->cb_s_break == server->cb_s_break);
615 rcu_read_unlock();
616 return good;
617 }
618 }
619
620 rcu_read_unlock();
621 return false;
622 }
623
624 /*
625 * Check the validity of a vnode/inode.
626 */
afs_check_validity(struct afs_vnode * vnode)627 bool afs_check_validity(struct afs_vnode *vnode)
628 {
629 enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
630 time64_t now = ktime_get_real_seconds();
631 unsigned int cb_break;
632 int seq = 0;
633
634 do {
635 read_seqbegin_or_lock(&vnode->cb_lock, &seq);
636 cb_break = vnode->cb_break;
637
638 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
639 if (vnode->cb_v_break != vnode->volume->cb_v_break)
640 need_clear = afs_cb_break_for_v_break;
641 else if (!afs_check_server_good(vnode))
642 need_clear = afs_cb_break_for_s_reinit;
643 else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
644 need_clear = afs_cb_break_for_zap;
645 else if (vnode->cb_expires_at - 10 <= now)
646 need_clear = afs_cb_break_for_lapsed;
647 } else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
648 ;
649 } else {
650 need_clear = afs_cb_break_no_promise;
651 }
652
653 } while (need_seqretry(&vnode->cb_lock, seq));
654
655 done_seqretry(&vnode->cb_lock, seq);
656
657 if (need_clear == afs_cb_break_no_break)
658 return true;
659
660 write_seqlock(&vnode->cb_lock);
661 if (need_clear == afs_cb_break_no_promise)
662 vnode->cb_v_break = vnode->volume->cb_v_break;
663 else if (cb_break == vnode->cb_break)
664 __afs_break_callback(vnode, need_clear);
665 else
666 trace_afs_cb_miss(&vnode->fid, need_clear);
667 write_sequnlock(&vnode->cb_lock);
668 return false;
669 }
670
671 /*
672 * Returns true if the pagecache is still valid. Does not sleep.
673 */
afs_pagecache_valid(struct afs_vnode * vnode)674 bool afs_pagecache_valid(struct afs_vnode *vnode)
675 {
676 if (unlikely(test_bit(AFS_VNODE_DELETED, &vnode->flags))) {
677 if (vnode->netfs.inode.i_nlink)
678 clear_nlink(&vnode->netfs.inode);
679 return true;
680 }
681
682 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
683 afs_check_validity(vnode))
684 return true;
685
686 return false;
687 }
688
689 /*
690 * validate a vnode/inode
691 * - there are several things we need to check
692 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
693 * symlink)
694 * - parent dir metadata changed (security changes)
695 * - dentry data changed (write, truncate)
696 * - dentry metadata changed (security changes)
697 */
afs_validate(struct afs_vnode * vnode,struct key * key)698 int afs_validate(struct afs_vnode *vnode, struct key *key)
699 {
700 int ret;
701
702 _enter("{v={%llx:%llu} fl=%lx},%x",
703 vnode->fid.vid, vnode->fid.vnode, vnode->flags,
704 key_serial(key));
705
706 if (afs_pagecache_valid(vnode))
707 goto valid;
708
709 down_write(&vnode->validate_lock);
710
711 /* if the promise has expired, we need to check the server again to get
712 * a new promise - note that if the (parent) directory's metadata was
713 * changed then the security may be different and we may no longer have
714 * access */
715 if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
716 _debug("not promised");
717 ret = afs_fetch_status(vnode, key, false, NULL);
718 if (ret < 0) {
719 if (ret == -ENOENT) {
720 set_bit(AFS_VNODE_DELETED, &vnode->flags);
721 ret = -ESTALE;
722 }
723 goto error_unlock;
724 }
725 _debug("new promise [fl=%lx]", vnode->flags);
726 }
727
728 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
729 _debug("file already deleted");
730 ret = -ESTALE;
731 goto error_unlock;
732 }
733
734 /* if the vnode's data version number changed then its contents are
735 * different */
736 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
737 afs_zap_data(vnode);
738 up_write(&vnode->validate_lock);
739 valid:
740 _leave(" = 0");
741 return 0;
742
743 error_unlock:
744 up_write(&vnode->validate_lock);
745 _leave(" = %d", ret);
746 return ret;
747 }
748
749 /*
750 * read the attributes of an inode
751 */
afs_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)752 int afs_getattr(struct mnt_idmap *idmap, const struct path *path,
753 struct kstat *stat, u32 request_mask, unsigned int query_flags)
754 {
755 struct inode *inode = d_inode(path->dentry);
756 struct afs_vnode *vnode = AFS_FS_I(inode);
757 struct key *key;
758 int ret, seq = 0;
759
760 _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
761
762 if (vnode->volume &&
763 !(query_flags & AT_STATX_DONT_SYNC) &&
764 !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
765 key = afs_request_key(vnode->volume->cell);
766 if (IS_ERR(key))
767 return PTR_ERR(key);
768 ret = afs_validate(vnode, key);
769 key_put(key);
770 if (ret < 0)
771 return ret;
772 }
773
774 do {
775 read_seqbegin_or_lock(&vnode->cb_lock, &seq);
776 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
777 if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
778 stat->nlink > 0)
779 stat->nlink -= 1;
780
781 /* Lie about the size of directories. We maintain a locally
782 * edited copy and may make different allocation decisions on
783 * it, but we need to give userspace the server's size.
784 */
785 if (S_ISDIR(inode->i_mode))
786 stat->size = vnode->netfs.remote_i_size;
787 } while (need_seqretry(&vnode->cb_lock, seq));
788
789 done_seqretry(&vnode->cb_lock, seq);
790 return 0;
791 }
792
793 /*
794 * discard an AFS inode
795 */
afs_drop_inode(struct inode * inode)796 int afs_drop_inode(struct inode *inode)
797 {
798 _enter("");
799
800 if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
801 return generic_delete_inode(inode);
802 else
803 return generic_drop_inode(inode);
804 }
805
806 /*
807 * clear an AFS inode
808 */
afs_evict_inode(struct inode * inode)809 void afs_evict_inode(struct inode *inode)
810 {
811 struct afs_vnode_cache_aux aux;
812 struct afs_vnode *vnode = AFS_FS_I(inode);
813
814 _enter("{%llx:%llu.%d}",
815 vnode->fid.vid,
816 vnode->fid.vnode,
817 vnode->fid.unique);
818
819 _debug("CLEAR INODE %p", inode);
820
821 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
822
823 truncate_inode_pages_final(&inode->i_data);
824
825 afs_set_cache_aux(vnode, &aux);
826 fscache_clear_inode_writeback(afs_vnode_cache(vnode), inode, &aux);
827 clear_inode(inode);
828
829 while (!list_empty(&vnode->wb_keys)) {
830 struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
831 struct afs_wb_key, vnode_link);
832 list_del(&wbk->vnode_link);
833 afs_put_wb_key(wbk);
834 }
835
836 fscache_relinquish_cookie(afs_vnode_cache(vnode),
837 test_bit(AFS_VNODE_DELETED, &vnode->flags));
838
839 afs_prune_wb_keys(vnode);
840 afs_put_permits(rcu_access_pointer(vnode->permit_cache));
841 key_put(vnode->silly_key);
842 vnode->silly_key = NULL;
843 key_put(vnode->lock_key);
844 vnode->lock_key = NULL;
845 _leave("");
846 }
847
afs_setattr_success(struct afs_operation * op)848 static void afs_setattr_success(struct afs_operation *op)
849 {
850 struct afs_vnode_param *vp = &op->file[0];
851 struct inode *inode = &vp->vnode->netfs.inode;
852 loff_t old_i_size = i_size_read(inode);
853
854 op->setattr.old_i_size = old_i_size;
855 afs_vnode_commit_status(op, vp);
856 /* inode->i_size has now been changed. */
857
858 if (op->setattr.attr->ia_valid & ATTR_SIZE) {
859 loff_t size = op->setattr.attr->ia_size;
860 if (size > old_i_size)
861 pagecache_isize_extended(inode, old_i_size, size);
862 }
863 }
864
afs_setattr_edit_file(struct afs_operation * op)865 static void afs_setattr_edit_file(struct afs_operation *op)
866 {
867 struct afs_vnode_param *vp = &op->file[0];
868 struct inode *inode = &vp->vnode->netfs.inode;
869
870 if (op->setattr.attr->ia_valid & ATTR_SIZE) {
871 loff_t size = op->setattr.attr->ia_size;
872 loff_t i_size = op->setattr.old_i_size;
873
874 if (size < i_size)
875 truncate_pagecache(inode, size);
876 if (size != i_size)
877 fscache_resize_cookie(afs_vnode_cache(vp->vnode),
878 vp->scb.status.size);
879 }
880 }
881
882 static const struct afs_operation_ops afs_setattr_operation = {
883 .issue_afs_rpc = afs_fs_setattr,
884 .issue_yfs_rpc = yfs_fs_setattr,
885 .success = afs_setattr_success,
886 .edit_dir = afs_setattr_edit_file,
887 };
888
889 /*
890 * set the attributes of an inode
891 */
afs_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * attr)892 int afs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
893 struct iattr *attr)
894 {
895 const unsigned int supported =
896 ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
897 ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET | ATTR_TOUCH;
898 struct afs_operation *op;
899 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
900 struct inode *inode = &vnode->netfs.inode;
901 loff_t i_size;
902 int ret;
903
904 _enter("{%llx:%llu},{n=%pd},%x",
905 vnode->fid.vid, vnode->fid.vnode, dentry,
906 attr->ia_valid);
907
908 if (!(attr->ia_valid & supported)) {
909 _leave(" = 0 [unsupported]");
910 return 0;
911 }
912
913 i_size = i_size_read(inode);
914 if (attr->ia_valid & ATTR_SIZE) {
915 if (!S_ISREG(inode->i_mode))
916 return -EISDIR;
917
918 ret = inode_newsize_ok(inode, attr->ia_size);
919 if (ret)
920 return ret;
921
922 if (attr->ia_size == i_size)
923 attr->ia_valid &= ~ATTR_SIZE;
924 }
925
926 fscache_use_cookie(afs_vnode_cache(vnode), true);
927
928 /* Prevent any new writebacks from starting whilst we do this. */
929 down_write(&vnode->validate_lock);
930
931 if ((attr->ia_valid & ATTR_SIZE) && S_ISREG(inode->i_mode)) {
932 loff_t size = attr->ia_size;
933
934 /* Wait for any outstanding writes to the server to complete */
935 loff_t from = min(size, i_size);
936 loff_t to = max(size, i_size);
937 ret = filemap_fdatawait_range(inode->i_mapping, from, to);
938 if (ret < 0)
939 goto out_unlock;
940
941 /* Don't talk to the server if we're just shortening in-memory
942 * writes that haven't gone to the server yet.
943 */
944 if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
945 attr->ia_size < i_size &&
946 attr->ia_size > vnode->status.size) {
947 truncate_pagecache(inode, attr->ia_size);
948 fscache_resize_cookie(afs_vnode_cache(vnode),
949 attr->ia_size);
950 i_size_write(inode, attr->ia_size);
951 ret = 0;
952 goto out_unlock;
953 }
954 }
955
956 op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
957 afs_file_key(attr->ia_file) : NULL),
958 vnode->volume);
959 if (IS_ERR(op)) {
960 ret = PTR_ERR(op);
961 goto out_unlock;
962 }
963
964 afs_op_set_vnode(op, 0, vnode);
965 op->setattr.attr = attr;
966
967 if (attr->ia_valid & ATTR_SIZE) {
968 op->file[0].dv_delta = 1;
969 op->file[0].set_size = true;
970 }
971 op->ctime = attr->ia_ctime;
972 op->file[0].update_ctime = 1;
973 op->file[0].modification = true;
974
975 op->ops = &afs_setattr_operation;
976 ret = afs_do_sync_operation(op);
977
978 out_unlock:
979 up_write(&vnode->validate_lock);
980 fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
981 _leave(" = %d", ret);
982 return ret;
983 }
984
