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->i_ctime = 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 break;
108 case AFS_FTYPE_DIR:
109 inode->i_mode = S_IFDIR | (status->mode & S_IALLUGO);
110 inode->i_op = &afs_dir_inode_operations;
111 inode->i_fop = &afs_dir_file_operations;
112 inode->i_mapping->a_ops = &afs_dir_aops;
113 break;
114 case AFS_FTYPE_SYMLINK:
115 /* Symlinks with a mode of 0644 are actually mountpoints. */
116 if ((status->mode & 0777) == 0644) {
117 inode->i_flags |= S_AUTOMOUNT;
118
119 set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
120
121 inode->i_mode = S_IFDIR | 0555;
122 inode->i_op = &afs_mntpt_inode_operations;
123 inode->i_fop = &afs_mntpt_file_operations;
124 inode->i_mapping->a_ops = &afs_symlink_aops;
125 } else {
126 inode->i_mode = S_IFLNK | status->mode;
127 inode->i_op = &afs_symlink_inode_operations;
128 inode->i_mapping->a_ops = &afs_symlink_aops;
129 }
130 inode_nohighmem(inode);
131 break;
132 default:
133 dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
134 write_sequnlock(&vnode->cb_lock);
135 return afs_protocol_error(NULL, afs_eproto_file_type);
136 }
137
138 afs_set_i_size(vnode, status->size);
139 afs_set_netfs_context(vnode);
140
141 vnode->invalid_before = status->data_version;
142 inode_set_iversion_raw(&vnode->netfs.inode, status->data_version);
143
144 if (!vp->scb.have_cb) {
145 /* it's a symlink we just created (the fileserver
146 * didn't give us a callback) */
147 vnode->cb_expires_at = ktime_get_real_seconds();
148 } else {
149 vnode->cb_expires_at = vp->scb.callback.expires_at;
150 vnode->cb_server = op->server;
151 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
152 }
153
154 write_sequnlock(&vnode->cb_lock);
155 return 0;
156 }
157
158 /*
159 * Update the core inode struct from a returned status record.
160 */
afs_apply_status(struct afs_operation * op,struct afs_vnode_param * vp)161 static void afs_apply_status(struct afs_operation *op,
162 struct afs_vnode_param *vp)
163 {
164 struct afs_file_status *status = &vp->scb.status;
165 struct afs_vnode *vnode = vp->vnode;
166 struct inode *inode = &vnode->netfs.inode;
167 struct timespec64 t;
168 umode_t mode;
169 bool data_changed = false;
170 bool change_size = vp->set_size;
171
172 _enter("{%llx:%llu.%u} %s",
173 vp->fid.vid, vp->fid.vnode, vp->fid.unique,
174 op->type ? op->type->name : "???");
175
176 BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
177
178 if (status->type != vnode->status.type) {
179 pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
180 vnode->fid.vid,
181 vnode->fid.vnode,
182 vnode->fid.unique,
183 status->type, vnode->status.type);
184 afs_protocol_error(NULL, afs_eproto_bad_status);
185 return;
186 }
187
188 if (status->nlink != vnode->status.nlink)
189 set_nlink(inode, status->nlink);
190
191 if (status->owner != vnode->status.owner)
192 inode->i_uid = make_kuid(&init_user_ns, status->owner);
193
194 if (status->group != vnode->status.group)
195 inode->i_gid = make_kgid(&init_user_ns, status->group);
196
197 if (status->mode != vnode->status.mode) {
198 mode = inode->i_mode;
199 mode &= ~S_IALLUGO;
200 mode |= status->mode & S_IALLUGO;
201 WRITE_ONCE(inode->i_mode, mode);
202 }
203
204 t = status->mtime_client;
205 inode->i_mtime = t;
206 if (vp->update_ctime)
207 inode->i_ctime = op->ctime;
208
209 if (vnode->status.data_version != status->data_version)
210 data_changed = true;
211
212 vnode->status = *status;
213
214 if (vp->dv_before + vp->dv_delta != status->data_version) {
215 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
216 pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s (op=%x)\n",
217 vnode->fid.vid, vnode->fid.vnode,
218 (unsigned long long)vp->dv_before + vp->dv_delta,
219 (unsigned long long)status->data_version,
220 op->type ? op->type->name : "???",
221 op->debug_id);
222
223 vnode->invalid_before = status->data_version;
224 if (vnode->status.type == AFS_FTYPE_DIR) {
225 if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
226 afs_stat_v(vnode, n_inval);
227 } else {
228 set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
229 }
230 change_size = 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(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 vnode->netfs.remote_i_size = status->size;
250 if (change_size) {
251 afs_set_i_size(vnode, status->size);
252 inode->i_ctime = t;
253 inode->i_atime = t;
254 }
255 }
256 }
257
258 /*
259 * Apply a callback to a vnode.
260 */
afs_apply_callback(struct afs_operation * op,struct afs_vnode_param * vp)261 static void afs_apply_callback(struct afs_operation *op,
262 struct afs_vnode_param *vp)
263 {
264 struct afs_callback *cb = &vp->scb.callback;
265 struct afs_vnode *vnode = vp->vnode;
266
267 if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
268 vnode->cb_expires_at = cb->expires_at;
269 vnode->cb_server = op->server;
270 set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
271 }
272 }
273
274 /*
275 * Apply the received status and callback to an inode all in the same critical
276 * section to avoid races with afs_validate().
277 */
afs_vnode_commit_status(struct afs_operation * op,struct afs_vnode_param * vp)278 void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
279 {
280 struct afs_vnode *vnode = vp->vnode;
281
282 _enter("");
283
284 write_seqlock(&vnode->cb_lock);
285
286 if (vp->scb.have_error) {
287 /* A YFS server will return this from RemoveFile2 and AFS and
288 * YFS will return this from InlineBulkStatus.
289 */
290 if (vp->scb.status.abort_code == VNOVNODE) {
291 set_bit(AFS_VNODE_DELETED, &vnode->flags);
292 clear_nlink(&vnode->netfs.inode);
293 __afs_break_callback(vnode, afs_cb_break_for_deleted);
294 op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
295 }
296 } else if (vp->scb.have_status) {
297 if (vp->speculative &&
298 (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
299 vp->dv_before != vnode->status.data_version))
300 /* Ignore the result of a speculative bulk status fetch
301 * if it splits around a modification op, thereby
302 * appearing to regress the data version.
303 */
304 goto out;
305 afs_apply_status(op, vp);
306 if (vp->scb.have_cb)
307 afs_apply_callback(op, vp);
308 } else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
309 drop_nlink(&vnode->netfs.inode);
310 if (vnode->netfs.inode.i_nlink == 0) {
311 set_bit(AFS_VNODE_DELETED, &vnode->flags);
312 __afs_break_callback(vnode, afs_cb_break_for_deleted);
313 }
314 }
315
316 out:
317 write_sequnlock(&vnode->cb_lock);
318
319 if (vp->scb.have_status)
320 afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
321 }
322
afs_fetch_status_success(struct afs_operation * op)323 static void afs_fetch_status_success(struct afs_operation *op)
324 {
325 struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
326 struct afs_vnode *vnode = vp->vnode;
327 int ret;
328
329 if (vnode->netfs.inode.i_state & I_NEW) {
330 ret = afs_inode_init_from_status(op, vp, vnode);
331 op->error = ret;
332 if (ret == 0)
333 afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
334 } else {
335 afs_vnode_commit_status(op, vp);
336 }
337 }
338
339 const struct afs_operation_ops afs_fetch_status_operation = {
340 .issue_afs_rpc = afs_fs_fetch_status,
341 .issue_yfs_rpc = yfs_fs_fetch_status,
342 .success = afs_fetch_status_success,
343 .aborted = afs_check_for_remote_deletion,
344 };
345
346 /*
347 * Fetch file status from the volume.
348 */
afs_fetch_status(struct afs_vnode * vnode,struct key * key,bool is_new,afs_access_t * _caller_access)349 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
350 afs_access_t *_caller_access)
351 {
352 struct afs_operation *op;
353
354 _enter("%s,{%llx:%llu.%u,S=%lx}",
355 vnode->volume->name,
356 vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
357 vnode->flags);
358
359 op = afs_alloc_operation(key, vnode->volume);
360 if (IS_ERR(op))
361 return PTR_ERR(op);
362
363 afs_op_set_vnode(op, 0, vnode);
364
365 op->nr_files = 1;
366 op->ops = &afs_fetch_status_operation;
367 afs_begin_vnode_operation(op);
368 afs_wait_for_operation(op);
369
370 if (_caller_access)
371 *_caller_access = op->file[0].scb.status.caller_access;
372 return afs_put_operation(op);
373 }
374
375 /*
376 * ilookup() comparator
377 */
afs_ilookup5_test_by_fid(struct inode * inode,void * opaque)378 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
379 {
380 struct afs_vnode *vnode = AFS_FS_I(inode);
381 struct afs_fid *fid = opaque;
382
383 return (fid->vnode == vnode->fid.vnode &&
384 fid->vnode_hi == vnode->fid.vnode_hi &&
385 fid->unique == vnode->fid.unique);
386 }
387
388 /*
389 * iget5() comparator
390 */
afs_iget5_test(struct inode * inode,void * opaque)391 static int afs_iget5_test(struct inode *inode, void *opaque)
392 {
393 struct afs_vnode_param *vp = opaque;
394 //struct afs_vnode *vnode = AFS_FS_I(inode);
395
396 return afs_ilookup5_test_by_fid(inode, &vp->fid);
397 }
398
399 /*
400 * iget5() inode initialiser
401 */
afs_iget5_set(struct inode * inode,void * opaque)402 static int afs_iget5_set(struct inode *inode, void *opaque)
403 {
404 struct afs_vnode_param *vp = opaque;
405 struct afs_super_info *as = AFS_FS_S(inode->i_sb);
406 struct afs_vnode *vnode = AFS_FS_I(inode);
407
408 vnode->volume = as->volume;
409 vnode->fid = vp->fid;
410
411 /* YFS supports 96-bit vnode IDs, but Linux only supports
412 * 64-bit inode numbers.
413 */
414 inode->i_ino = vnode->fid.vnode;
415 inode->i_generation = vnode->fid.unique;
416 return 0;
417 }
418
419 /*
420 * Get a cache cookie for an inode.
421 */
afs_get_inode_cache(struct afs_vnode * vnode)422 static void afs_get_inode_cache(struct afs_vnode *vnode)
423 {
424 #ifdef CONFIG_AFS_FSCACHE
425 struct {
426 __be32 vnode_id;
427 __be32 unique;
428 __be32 vnode_id_ext[2]; /* Allow for a 96-bit key */
429 } __packed key;
430 struct afs_vnode_cache_aux aux;
431
432 if (vnode->status.type != AFS_FTYPE_FILE) {
433 vnode->netfs.cache = NULL;
434 return;
435 }
436
437 key.vnode_id = htonl(vnode->fid.vnode);
438 key.unique = htonl(vnode->fid.unique);
439 key.vnode_id_ext[0] = htonl(vnode->fid.vnode >> 32);
440 key.vnode_id_ext[1] = htonl(vnode->fid.vnode_hi);
441 afs_set_cache_aux(vnode, &aux);
442
443 afs_vnode_set_cache(vnode,
444 fscache_acquire_cookie(
445 vnode->volume->cache,
446 vnode->status.type == AFS_FTYPE_FILE ?
447 0 : FSCACHE_ADV_SINGLE_CHUNK,
448 &key, sizeof(key),
449 &aux, sizeof(aux),
450 vnode->status.size));
451 #endif
452 }
453
454 /*
455 * inode retrieval
456 */
afs_iget(struct afs_operation * op,struct afs_vnode_param * vp)457 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
458 {
459 struct afs_vnode_param *dvp = &op->file[0];
460 struct super_block *sb = dvp->vnode->netfs.inode.i_sb;
461 struct afs_vnode *vnode;
462 struct inode *inode;
463 int ret;
464
465 _enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
466
467 inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
468 if (!inode) {
469 _leave(" = -ENOMEM");
470 return ERR_PTR(-ENOMEM);
471 }
472
473 vnode = AFS_FS_I(inode);
474
475 _debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
476 inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
477
478 /* deal with an existing inode */
479 if (!(inode->i_state & I_NEW)) {
480 _leave(" = %p", inode);
481 return inode;
482 }
483
484 ret = afs_inode_init_from_status(op, vp, vnode);
485 if (ret < 0)
486 goto bad_inode;
487
488 afs_get_inode_cache(vnode);
489
490 /* success */
491 clear_bit(AFS_VNODE_UNSET, &vnode->flags);
492 unlock_new_inode(inode);
493 _leave(" = %p", inode);
494 return inode;
495
496 /* failure */
497 bad_inode:
498 iget_failed(inode);
499 _leave(" = %d [bad]", ret);
500 return ERR_PTR(ret);
501 }
502
afs_iget5_set_root(struct inode * inode,void * opaque)503 static int afs_iget5_set_root(struct inode *inode, void *opaque)
504 {
505 struct afs_super_info *as = AFS_FS_S(inode->i_sb);
506 struct afs_vnode *vnode = AFS_FS_I(inode);
507
508 vnode->volume = as->volume;
509 vnode->fid.vid = as->volume->vid,
510 vnode->fid.vnode = 1;
511 vnode->fid.unique = 1;
512 inode->i_ino = 1;
513 inode->i_generation = 1;
514 return 0;
515 }
516
517 /*
518 * Set up the root inode for a volume. This is always vnode 1, unique 1 within
519 * the volume.
520 */
afs_root_iget(struct super_block * sb,struct key * key)521 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
522 {
523 struct afs_super_info *as = AFS_FS_S(sb);
524 struct afs_operation *op;
525 struct afs_vnode *vnode;
526 struct inode *inode;
527 int ret;
528
529 _enter(",{%llx},,", as->volume->vid);
530
531 inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
532 if (!inode) {
533 _leave(" = -ENOMEM");
534 return ERR_PTR(-ENOMEM);
535 }
536
537 _debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
538
539 BUG_ON(!(inode->i_state & I_NEW));
540
541 vnode = AFS_FS_I(inode);
542 vnode->cb_v_break = as->volume->cb_v_break,
543 afs_set_netfs_context(vnode);
544
545 op = afs_alloc_operation(key, as->volume);
546 if (IS_ERR(op)) {
547 ret = PTR_ERR(op);
548 goto error;
549 }
550
551 afs_op_set_vnode(op, 0, vnode);
552
553 op->nr_files = 1;
554 op->ops = &afs_fetch_status_operation;
555 ret = afs_do_sync_operation(op);
556 if (ret < 0)
557 goto error;
558
559 afs_get_inode_cache(vnode);
560
561 clear_bit(AFS_VNODE_UNSET, &vnode->flags);
562 unlock_new_inode(inode);
563 _leave(" = %p", inode);
564 return inode;
565
566 error:
567 iget_failed(inode);
568 _leave(" = %d [bad]", ret);
569 return ERR_PTR(ret);
570 }
571
572 /*
573 * mark the data attached to an inode as obsolete due to a write on the server
574 * - might also want to ditch all the outstanding writes and dirty pages
575 */
afs_zap_data(struct afs_vnode * vnode)576 static void afs_zap_data(struct afs_vnode *vnode)
577 {
578 _enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
579
580 afs_invalidate_cache(vnode, 0);
581
582 /* nuke all the non-dirty pages that aren't locked, mapped or being
583 * written back in a regular file and completely discard the pages in a
584 * directory or symlink */
585 if (S_ISREG(vnode->netfs.inode.i_mode))
586 invalidate_remote_inode(&vnode->netfs.inode);
587 else
588 invalidate_inode_pages2(vnode->netfs.inode.i_mapping);
589 }
590
591 /*
592 * Check to see if we have a server currently serving this volume and that it
593 * hasn't been reinitialised or dropped from the list.
594 */
afs_check_server_good(struct afs_vnode * vnode)595 static bool afs_check_server_good(struct afs_vnode *vnode)
596 {
597 struct afs_server_list *slist;
598 struct afs_server *server;
599 bool good;
600 int i;
601
602 if (vnode->cb_fs_s_break == atomic_read(&vnode->volume->cell->fs_s_break))
603 return true;
604
605 rcu_read_lock();
606
607 slist = rcu_dereference(vnode->volume->servers);
608 for (i = 0; i < slist->nr_servers; i++) {
609 server = slist->servers[i].server;
610 if (server == vnode->cb_server) {
611 good = (vnode->cb_s_break == server->cb_s_break);
612 rcu_read_unlock();
613 return good;
614 }
615 }
616
617 rcu_read_unlock();
618 return false;
619 }
620
621 /*
622 * Check the validity of a vnode/inode.
623 */
afs_check_validity(struct afs_vnode * vnode)624 bool afs_check_validity(struct afs_vnode *vnode)
625 {
626 enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
627 time64_t now = ktime_get_real_seconds();
628 unsigned int cb_break;
629 int seq = 0;
630
631 do {
632 read_seqbegin_or_lock(&vnode->cb_lock, &seq);
633 cb_break = vnode->cb_break;
634
635 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
636 if (vnode->cb_v_break != vnode->volume->cb_v_break)
637 need_clear = afs_cb_break_for_v_break;
638 else if (!afs_check_server_good(vnode))
639 need_clear = afs_cb_break_for_s_reinit;
640 else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
641 need_clear = afs_cb_break_for_zap;
642 else if (vnode->cb_expires_at - 10 <= now)
643 need_clear = afs_cb_break_for_lapsed;
644 } else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
645 ;
646 } else {
647 need_clear = afs_cb_break_no_promise;
648 }
649
650 } while (need_seqretry(&vnode->cb_lock, seq));
651
652 done_seqretry(&vnode->cb_lock, seq);
653
654 if (need_clear == afs_cb_break_no_break)
655 return true;
656
657 write_seqlock(&vnode->cb_lock);
658 if (need_clear == afs_cb_break_no_promise)
659 vnode->cb_v_break = vnode->volume->cb_v_break;
660 else if (cb_break == vnode->cb_break)
661 __afs_break_callback(vnode, need_clear);
662 else
663 trace_afs_cb_miss(&vnode->fid, need_clear);
664 write_sequnlock(&vnode->cb_lock);
665 return false;
666 }
667
668 /*
669 * validate a vnode/inode
670 * - there are several things we need to check
671 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
672 * symlink)
673 * - parent dir metadata changed (security changes)
674 * - dentry data changed (write, truncate)
675 * - dentry metadata changed (security changes)
676 */
afs_validate(struct afs_vnode * vnode,struct key * key)677 int afs_validate(struct afs_vnode *vnode, struct key *key)
678 {
679 int ret;
680
681 _enter("{v={%llx:%llu} fl=%lx},%x",
682 vnode->fid.vid, vnode->fid.vnode, vnode->flags,
683 key_serial(key));
684
685 if (unlikely(test_bit(AFS_VNODE_DELETED, &vnode->flags))) {
686 if (vnode->netfs.inode.i_nlink)
687 clear_nlink(&vnode->netfs.inode);
688 goto valid;
689 }
690
691 if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
692 afs_check_validity(vnode))
693 goto valid;
694
695 down_write(&vnode->validate_lock);
696
697 /* if the promise has expired, we need to check the server again to get
698 * a new promise - note that if the (parent) directory's metadata was
699 * changed then the security may be different and we may no longer have
700 * access */
701 if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
702 _debug("not promised");
703 ret = afs_fetch_status(vnode, key, false, NULL);
704 if (ret < 0) {
705 if (ret == -ENOENT) {
706 set_bit(AFS_VNODE_DELETED, &vnode->flags);
707 ret = -ESTALE;
708 }
709 goto error_unlock;
710 }
711 _debug("new promise [fl=%lx]", vnode->flags);
712 }
713
714 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
715 _debug("file already deleted");
716 ret = -ESTALE;
717 goto error_unlock;
718 }
719
720 /* if the vnode's data version number changed then its contents are
721 * different */
722 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
723 afs_zap_data(vnode);
724 up_write(&vnode->validate_lock);
725 valid:
726 _leave(" = 0");
727 return 0;
728
729 error_unlock:
730 up_write(&vnode->validate_lock);
731 _leave(" = %d", ret);
732 return ret;
733 }
734
735 /*
736 * read the attributes of an inode
737 */
afs_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)738 int afs_getattr(struct user_namespace *mnt_userns, const struct path *path,
739 struct kstat *stat, u32 request_mask, unsigned int query_flags)
740 {
741 struct inode *inode = d_inode(path->dentry);
742 struct afs_vnode *vnode = AFS_FS_I(inode);
743 struct key *key;
744 int ret, seq = 0;
745
746 _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
747
748 if (vnode->volume &&
749 !(query_flags & AT_STATX_DONT_SYNC) &&
750 !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
751 key = afs_request_key(vnode->volume->cell);
752 if (IS_ERR(key))
753 return PTR_ERR(key);
754 ret = afs_validate(vnode, key);
755 key_put(key);
756 if (ret < 0)
757 return ret;
758 }
759
760 do {
761 read_seqbegin_or_lock(&vnode->cb_lock, &seq);
762 generic_fillattr(&init_user_ns, inode, stat);
763 if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
764 stat->nlink > 0)
765 stat->nlink -= 1;
766 } while (need_seqretry(&vnode->cb_lock, seq));
767
768 done_seqretry(&vnode->cb_lock, seq);
769 return 0;
770 }
771
772 /*
773 * discard an AFS inode
774 */
afs_drop_inode(struct inode * inode)775 int afs_drop_inode(struct inode *inode)
776 {
777 _enter("");
778
779 if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
780 return generic_delete_inode(inode);
781 else
782 return generic_drop_inode(inode);
783 }
784
785 /*
786 * clear an AFS inode
787 */
afs_evict_inode(struct inode * inode)788 void afs_evict_inode(struct inode *inode)
789 {
790 struct afs_vnode_cache_aux aux;
791 struct afs_vnode *vnode = AFS_FS_I(inode);
792
793 _enter("{%llx:%llu.%d}",
794 vnode->fid.vid,
795 vnode->fid.vnode,
796 vnode->fid.unique);
797
798 _debug("CLEAR INODE %p", inode);
799
800 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
801
802 truncate_inode_pages_final(&inode->i_data);
803
804 afs_set_cache_aux(vnode, &aux);
805 fscache_clear_inode_writeback(afs_vnode_cache(vnode), inode, &aux);
806 clear_inode(inode);
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 fscache_relinquish_cookie(afs_vnode_cache(vnode),
816 test_bit(AFS_VNODE_DELETED, &vnode->flags));
817
818 afs_prune_wb_keys(vnode);
819 afs_put_permits(rcu_access_pointer(vnode->permit_cache));
820 key_put(vnode->silly_key);
821 vnode->silly_key = NULL;
822 key_put(vnode->lock_key);
823 vnode->lock_key = NULL;
824 _leave("");
825 }
826
afs_setattr_success(struct afs_operation * op)827 static void afs_setattr_success(struct afs_operation *op)
828 {
829 struct afs_vnode_param *vp = &op->file[0];
830 struct inode *inode = &vp->vnode->netfs.inode;
831 loff_t old_i_size = i_size_read(inode);
832
833 op->setattr.old_i_size = old_i_size;
834 afs_vnode_commit_status(op, vp);
835 /* inode->i_size has now been changed. */
836
837 if (op->setattr.attr->ia_valid & ATTR_SIZE) {
838 loff_t size = op->setattr.attr->ia_size;
839 if (size > old_i_size)
840 pagecache_isize_extended(inode, old_i_size, size);
841 }
842 }
843
afs_setattr_edit_file(struct afs_operation * op)844 static void afs_setattr_edit_file(struct afs_operation *op)
845 {
846 struct afs_vnode_param *vp = &op->file[0];
847 struct inode *inode = &vp->vnode->netfs.inode;
848
849 if (op->setattr.attr->ia_valid & ATTR_SIZE) {
850 loff_t size = op->setattr.attr->ia_size;
851 loff_t i_size = op->setattr.old_i_size;
852
853 if (size < i_size)
854 truncate_pagecache(inode, size);
855 if (size != i_size)
856 fscache_resize_cookie(afs_vnode_cache(vp->vnode),
857 vp->scb.status.size);
858 }
859 }
860
861 static const struct afs_operation_ops afs_setattr_operation = {
862 .issue_afs_rpc = afs_fs_setattr,
863 .issue_yfs_rpc = yfs_fs_setattr,
864 .success = afs_setattr_success,
865 .edit_dir = afs_setattr_edit_file,
866 };
867
868 /*
869 * set the attributes of an inode
870 */
afs_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * attr)871 int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
872 struct iattr *attr)
873 {
874 const unsigned int supported =
875 ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
876 ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET | ATTR_TOUCH;
877 struct afs_operation *op;
878 struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
879 struct inode *inode = &vnode->netfs.inode;
880 loff_t i_size;
881 int ret;
882
883 _enter("{%llx:%llu},{n=%pd},%x",
884 vnode->fid.vid, vnode->fid.vnode, dentry,
885 attr->ia_valid);
886
887 if (!(attr->ia_valid & supported)) {
888 _leave(" = 0 [unsupported]");
889 return 0;
890 }
891
892 i_size = i_size_read(inode);
893 if (attr->ia_valid & ATTR_SIZE) {
894 if (!S_ISREG(inode->i_mode))
895 return -EISDIR;
896
897 ret = inode_newsize_ok(inode, attr->ia_size);
898 if (ret)
899 return ret;
900
901 if (attr->ia_size == i_size)
902 attr->ia_valid &= ~ATTR_SIZE;
903 }
904
905 fscache_use_cookie(afs_vnode_cache(vnode), true);
906
907 /* Prevent any new writebacks from starting whilst we do this. */
908 down_write(&vnode->validate_lock);
909
910 if ((attr->ia_valid & ATTR_SIZE) && S_ISREG(inode->i_mode)) {
911 loff_t size = attr->ia_size;
912
913 /* Wait for any outstanding writes to the server to complete */
914 loff_t from = min(size, i_size);
915 loff_t to = max(size, i_size);
916 ret = filemap_fdatawait_range(inode->i_mapping, from, to);
917 if (ret < 0)
918 goto out_unlock;
919
920 /* Don't talk to the server if we're just shortening in-memory
921 * writes that haven't gone to the server yet.
922 */
923 if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
924 attr->ia_size < i_size &&
925 attr->ia_size > vnode->status.size) {
926 truncate_pagecache(inode, attr->ia_size);
927 fscache_resize_cookie(afs_vnode_cache(vnode),
928 attr->ia_size);
929 i_size_write(inode, attr->ia_size);
930 ret = 0;
931 goto out_unlock;
932 }
933 }
934
935 op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
936 afs_file_key(attr->ia_file) : NULL),
937 vnode->volume);
938 if (IS_ERR(op)) {
939 ret = PTR_ERR(op);
940 goto out_unlock;
941 }
942
943 afs_op_set_vnode(op, 0, vnode);
944 op->setattr.attr = attr;
945
946 if (attr->ia_valid & ATTR_SIZE) {
947 op->file[0].dv_delta = 1;
948 op->file[0].set_size = true;
949 }
950 op->ctime = attr->ia_ctime;
951 op->file[0].update_ctime = 1;
952 op->file[0].modification = true;
953
954 op->ops = &afs_setattr_operation;
955 ret = afs_do_sync_operation(op);
956
957 out_unlock:
958 up_write(&vnode->validate_lock);
959 fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
960 _leave(" = %d", ret);
961 return ret;
962 }
963