xref: /openbmc/linux/fs/afs/inode.c (revision f3d7c2cd)
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 
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  */
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  */
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 	} else if (vnode->status.type == AFS_FTYPE_DIR) {
223 		/* Expected directory change is handled elsewhere so
224 		 * that we can locally edit the directory and save on a
225 		 * download.
226 		 */
227 		if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
228 			data_changed = false;
229 		change_size = true;
230 	}
231 
232 	if (data_changed) {
233 		inode_set_iversion_raw(inode, status->data_version);
234 
235 		/* Only update the size if the data version jumped.  If the
236 		 * file is being modified locally, then we might have our own
237 		 * idea of what the size should be that's not the same as
238 		 * what's on the server.
239 		 */
240 		if (change_size) {
241 			afs_set_i_size(vnode, status->size);
242 			inode->i_ctime = t;
243 			inode->i_atime = t;
244 		}
245 	}
246 }
247 
248 /*
249  * Apply a callback to a vnode.
250  */
251 static void afs_apply_callback(struct afs_operation *op,
252 			       struct afs_vnode_param *vp)
253 {
254 	struct afs_callback *cb = &vp->scb.callback;
255 	struct afs_vnode *vnode = vp->vnode;
256 
257 	if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
258 		vnode->cb_expires_at	= cb->expires_at;
259 		vnode->cb_server	= op->server;
260 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
261 	}
262 }
263 
264 /*
265  * Apply the received status and callback to an inode all in the same critical
266  * section to avoid races with afs_validate().
267  */
268 void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
269 {
270 	struct afs_vnode *vnode = vp->vnode;
271 
272 	_enter("");
273 
274 	write_seqlock(&vnode->cb_lock);
275 
276 	if (vp->scb.have_error) {
277 		/* A YFS server will return this from RemoveFile2 and AFS and
278 		 * YFS will return this from InlineBulkStatus.
279 		 */
280 		if (vp->scb.status.abort_code == VNOVNODE) {
281 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
282 			clear_nlink(&vnode->vfs_inode);
283 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
284 			op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
285 		}
286 	} else if (vp->scb.have_status) {
287 		if (vp->speculative &&
288 		    (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
289 		     vp->dv_before != vnode->status.data_version))
290 			/* Ignore the result of a speculative bulk status fetch
291 			 * if it splits around a modification op, thereby
292 			 * appearing to regress the data version.
293 			 */
294 			goto out;
295 		afs_apply_status(op, vp);
296 		if (vp->scb.have_cb)
297 			afs_apply_callback(op, vp);
298 	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
299 		drop_nlink(&vnode->vfs_inode);
300 		if (vnode->vfs_inode.i_nlink == 0) {
301 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
302 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
303 		}
304 	}
305 
306 out:
307 	write_sequnlock(&vnode->cb_lock);
308 
309 	if (vp->scb.have_status)
310 		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
311 }
312 
313 static void afs_fetch_status_success(struct afs_operation *op)
314 {
315 	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
316 	struct afs_vnode *vnode = vp->vnode;
317 	int ret;
318 
319 	if (vnode->vfs_inode.i_state & I_NEW) {
320 		ret = afs_inode_init_from_status(op, vp, vnode);
321 		op->error = ret;
322 		if (ret == 0)
323 			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
324 	} else {
325 		afs_vnode_commit_status(op, vp);
326 	}
327 }
328 
329 const struct afs_operation_ops afs_fetch_status_operation = {
330 	.issue_afs_rpc	= afs_fs_fetch_status,
331 	.issue_yfs_rpc	= yfs_fs_fetch_status,
332 	.success	= afs_fetch_status_success,
333 	.aborted	= afs_check_for_remote_deletion,
334 };
335 
336 /*
337  * Fetch file status from the volume.
338  */
339 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
340 		     afs_access_t *_caller_access)
341 {
342 	struct afs_operation *op;
343 
344 	_enter("%s,{%llx:%llu.%u,S=%lx}",
345 	       vnode->volume->name,
346 	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
347 	       vnode->flags);
348 
349 	op = afs_alloc_operation(key, vnode->volume);
350 	if (IS_ERR(op))
351 		return PTR_ERR(op);
352 
353 	afs_op_set_vnode(op, 0, vnode);
354 
355 	op->nr_files	= 1;
356 	op->ops		= &afs_fetch_status_operation;
357 	afs_begin_vnode_operation(op);
358 	afs_wait_for_operation(op);
359 
360 	if (_caller_access)
361 		*_caller_access = op->file[0].scb.status.caller_access;
362 	return afs_put_operation(op);
363 }
364 
365 /*
366  * ilookup() comparator
367  */
368 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
369 {
370 	struct afs_vnode *vnode = AFS_FS_I(inode);
371 	struct afs_fid *fid = opaque;
372 
373 	return (fid->vnode == vnode->fid.vnode &&
374 		fid->vnode_hi == vnode->fid.vnode_hi &&
375 		fid->unique == vnode->fid.unique);
376 }
377 
378 /*
379  * iget5() comparator
380  */
381 static int afs_iget5_test(struct inode *inode, void *opaque)
382 {
383 	struct afs_vnode_param *vp = opaque;
384 	//struct afs_vnode *vnode = AFS_FS_I(inode);
385 
386 	return afs_ilookup5_test_by_fid(inode, &vp->fid);
387 }
388 
389 /*
390  * iget5() inode initialiser
391  */
392 static int afs_iget5_set(struct inode *inode, void *opaque)
393 {
394 	struct afs_vnode_param *vp = opaque;
395 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
396 	struct afs_vnode *vnode = AFS_FS_I(inode);
397 
398 	vnode->volume		= as->volume;
399 	vnode->fid		= vp->fid;
400 
401 	/* YFS supports 96-bit vnode IDs, but Linux only supports
402 	 * 64-bit inode numbers.
403 	 */
404 	inode->i_ino		= vnode->fid.vnode;
405 	inode->i_generation	= vnode->fid.unique;
406 	return 0;
407 }
408 
409 /*
410  * Get a cache cookie for an inode.
411  */
412 static void afs_get_inode_cache(struct afs_vnode *vnode)
413 {
414 #ifdef CONFIG_AFS_FSCACHE
415 	struct {
416 		u32 vnode_id;
417 		u32 unique;
418 		u32 vnode_id_ext[2];	/* Allow for a 96-bit key */
419 	} __packed key;
420 	struct afs_vnode_cache_aux aux;
421 
422 	if (vnode->status.type != AFS_FTYPE_FILE) {
423 		vnode->cache = NULL;
424 		return;
425 	}
426 
427 	key.vnode_id		= vnode->fid.vnode;
428 	key.unique		= vnode->fid.unique;
429 	key.vnode_id_ext[0]	= vnode->fid.vnode >> 32;
430 	key.vnode_id_ext[1]	= vnode->fid.vnode_hi;
431 	aux.data_version	= vnode->status.data_version;
432 
433 	vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
434 					      &afs_vnode_cache_index_def,
435 					      &key, sizeof(key),
436 					      &aux, sizeof(aux),
437 					      vnode, vnode->status.size, true);
438 #endif
439 }
440 
441 /*
442  * inode retrieval
443  */
444 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
445 {
446 	struct afs_vnode_param *dvp = &op->file[0];
447 	struct super_block *sb = dvp->vnode->vfs_inode.i_sb;
448 	struct afs_vnode *vnode;
449 	struct inode *inode;
450 	int ret;
451 
452 	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
453 
454 	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
455 	if (!inode) {
456 		_leave(" = -ENOMEM");
457 		return ERR_PTR(-ENOMEM);
458 	}
459 
460 	vnode = AFS_FS_I(inode);
461 
462 	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
463 	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
464 
465 	/* deal with an existing inode */
466 	if (!(inode->i_state & I_NEW)) {
467 		_leave(" = %p", inode);
468 		return inode;
469 	}
470 
471 	ret = afs_inode_init_from_status(op, vp, vnode);
472 	if (ret < 0)
473 		goto bad_inode;
474 
475 	afs_get_inode_cache(vnode);
476 
477 	/* success */
478 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
479 	unlock_new_inode(inode);
480 	_leave(" = %p", inode);
481 	return inode;
482 
483 	/* failure */
484 bad_inode:
485 	iget_failed(inode);
486 	_leave(" = %d [bad]", ret);
487 	return ERR_PTR(ret);
488 }
489 
490 static int afs_iget5_set_root(struct inode *inode, void *opaque)
491 {
492 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
493 	struct afs_vnode *vnode = AFS_FS_I(inode);
494 
495 	vnode->volume		= as->volume;
496 	vnode->fid.vid		= as->volume->vid,
497 	vnode->fid.vnode	= 1;
498 	vnode->fid.unique	= 1;
499 	inode->i_ino		= 1;
500 	inode->i_generation	= 1;
501 	return 0;
502 }
503 
504 /*
505  * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
506  * the volume.
507  */
508 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
509 {
510 	struct afs_super_info *as = AFS_FS_S(sb);
511 	struct afs_operation *op;
512 	struct afs_vnode *vnode;
513 	struct inode *inode;
514 	int ret;
515 
516 	_enter(",{%llx},,", as->volume->vid);
517 
518 	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
519 	if (!inode) {
520 		_leave(" = -ENOMEM");
521 		return ERR_PTR(-ENOMEM);
522 	}
523 
524 	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
525 
526 	BUG_ON(!(inode->i_state & I_NEW));
527 
528 	vnode = AFS_FS_I(inode);
529 	vnode->cb_v_break = as->volume->cb_v_break,
530 
531 	op = afs_alloc_operation(key, as->volume);
532 	if (IS_ERR(op)) {
533 		ret = PTR_ERR(op);
534 		goto error;
535 	}
536 
537 	afs_op_set_vnode(op, 0, vnode);
538 
539 	op->nr_files	= 1;
540 	op->ops		= &afs_fetch_status_operation;
541 	ret = afs_do_sync_operation(op);
542 	if (ret < 0)
543 		goto error;
544 
545 	afs_get_inode_cache(vnode);
546 
547 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
548 	unlock_new_inode(inode);
549 	_leave(" = %p", inode);
550 	return inode;
551 
552 error:
553 	iget_failed(inode);
554 	_leave(" = %d [bad]", ret);
555 	return ERR_PTR(ret);
556 }
557 
558 /*
559  * mark the data attached to an inode as obsolete due to a write on the server
560  * - might also want to ditch all the outstanding writes and dirty pages
561  */
562 static void afs_zap_data(struct afs_vnode *vnode)
563 {
564 	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
565 
566 #ifdef CONFIG_AFS_FSCACHE
567 	fscache_invalidate(vnode->cache);
568 #endif
569 
570 	/* nuke all the non-dirty pages that aren't locked, mapped or being
571 	 * written back in a regular file and completely discard the pages in a
572 	 * directory or symlink */
573 	if (S_ISREG(vnode->vfs_inode.i_mode))
574 		invalidate_remote_inode(&vnode->vfs_inode);
575 	else
576 		invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
577 }
578 
579 /*
580  * Check to see if we have a server currently serving this volume and that it
581  * hasn't been reinitialised or dropped from the list.
582  */
583 static bool afs_check_server_good(struct afs_vnode *vnode)
584 {
585 	struct afs_server_list *slist;
586 	struct afs_server *server;
587 	bool good;
588 	int i;
589 
590 	if (vnode->cb_fs_s_break == atomic_read(&vnode->volume->cell->fs_s_break))
591 		return true;
592 
593 	rcu_read_lock();
594 
595 	slist = rcu_dereference(vnode->volume->servers);
596 	for (i = 0; i < slist->nr_servers; i++) {
597 		server = slist->servers[i].server;
598 		if (server == vnode->cb_server) {
599 			good = (vnode->cb_s_break == server->cb_s_break);
600 			rcu_read_unlock();
601 			return good;
602 		}
603 	}
604 
605 	rcu_read_unlock();
606 	return false;
607 }
608 
609 /*
610  * Check the validity of a vnode/inode.
611  */
612 bool afs_check_validity(struct afs_vnode *vnode)
613 {
614 	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
615 	time64_t now = ktime_get_real_seconds();
616 	unsigned int cb_break;
617 	int seq = 0;
618 
619 	do {
620 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
621 		cb_break = vnode->cb_break;
622 
623 		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
624 			if (vnode->cb_v_break != vnode->volume->cb_v_break)
625 				need_clear = afs_cb_break_for_v_break;
626 			else if (!afs_check_server_good(vnode))
627 				need_clear = afs_cb_break_for_s_reinit;
628 			else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
629 				need_clear = afs_cb_break_for_zap;
630 			else if (vnode->cb_expires_at - 10 <= now)
631 				need_clear = afs_cb_break_for_lapsed;
632 		} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
633 			;
634 		} else {
635 			need_clear = afs_cb_break_no_promise;
636 		}
637 
638 	} while (need_seqretry(&vnode->cb_lock, seq));
639 
640 	done_seqretry(&vnode->cb_lock, seq);
641 
642 	if (need_clear == afs_cb_break_no_break)
643 		return true;
644 
645 	write_seqlock(&vnode->cb_lock);
646 	if (need_clear == afs_cb_break_no_promise)
647 		vnode->cb_v_break = vnode->volume->cb_v_break;
648 	else if (cb_break == vnode->cb_break)
649 		__afs_break_callback(vnode, need_clear);
650 	else
651 		trace_afs_cb_miss(&vnode->fid, need_clear);
652 	write_sequnlock(&vnode->cb_lock);
653 	return false;
654 }
655 
656 /*
657  * validate a vnode/inode
658  * - there are several things we need to check
659  *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
660  *     symlink)
661  *   - parent dir metadata changed (security changes)
662  *   - dentry data changed (write, truncate)
663  *   - dentry metadata changed (security changes)
664  */
665 int afs_validate(struct afs_vnode *vnode, struct key *key)
666 {
667 	int ret;
668 
669 	_enter("{v={%llx:%llu} fl=%lx},%x",
670 	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
671 	       key_serial(key));
672 
673 	if (unlikely(test_bit(AFS_VNODE_DELETED, &vnode->flags))) {
674 		if (vnode->vfs_inode.i_nlink)
675 			clear_nlink(&vnode->vfs_inode);
676 		goto valid;
677 	}
678 
679 	if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
680 	    afs_check_validity(vnode))
681 		goto valid;
682 
683 	down_write(&vnode->validate_lock);
684 
685 	/* if the promise has expired, we need to check the server again to get
686 	 * a new promise - note that if the (parent) directory's metadata was
687 	 * changed then the security may be different and we may no longer have
688 	 * access */
689 	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
690 		_debug("not promised");
691 		ret = afs_fetch_status(vnode, key, false, NULL);
692 		if (ret < 0) {
693 			if (ret == -ENOENT) {
694 				set_bit(AFS_VNODE_DELETED, &vnode->flags);
695 				ret = -ESTALE;
696 			}
697 			goto error_unlock;
698 		}
699 		_debug("new promise [fl=%lx]", vnode->flags);
700 	}
701 
702 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
703 		_debug("file already deleted");
704 		ret = -ESTALE;
705 		goto error_unlock;
706 	}
707 
708 	/* if the vnode's data version number changed then its contents are
709 	 * different */
710 	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
711 		afs_zap_data(vnode);
712 	up_write(&vnode->validate_lock);
713 valid:
714 	_leave(" = 0");
715 	return 0;
716 
717 error_unlock:
718 	up_write(&vnode->validate_lock);
719 	_leave(" = %d", ret);
720 	return ret;
721 }
722 
723 /*
724  * read the attributes of an inode
725  */
726 int afs_getattr(struct user_namespace *mnt_userns, const struct path *path,
727 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
728 {
729 	struct inode *inode = d_inode(path->dentry);
730 	struct afs_vnode *vnode = AFS_FS_I(inode);
731 	int seq = 0;
732 
733 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
734 
735 	do {
736 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
737 		generic_fillattr(&init_user_ns, inode, stat);
738 		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
739 		    stat->nlink > 0)
740 			stat->nlink -= 1;
741 	} while (need_seqretry(&vnode->cb_lock, seq));
742 
743 	done_seqretry(&vnode->cb_lock, seq);
744 	return 0;
745 }
746 
747 /*
748  * discard an AFS inode
749  */
750 int afs_drop_inode(struct inode *inode)
751 {
752 	_enter("");
753 
754 	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
755 		return generic_delete_inode(inode);
756 	else
757 		return generic_drop_inode(inode);
758 }
759 
760 /*
761  * clear an AFS inode
762  */
763 void afs_evict_inode(struct inode *inode)
764 {
765 	struct afs_vnode *vnode;
766 
767 	vnode = AFS_FS_I(inode);
768 
769 	_enter("{%llx:%llu.%d}",
770 	       vnode->fid.vid,
771 	       vnode->fid.vnode,
772 	       vnode->fid.unique);
773 
774 	_debug("CLEAR INODE %p", inode);
775 
776 	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
777 
778 	truncate_inode_pages_final(&inode->i_data);
779 	clear_inode(inode);
780 
781 	while (!list_empty(&vnode->wb_keys)) {
782 		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
783 						    struct afs_wb_key, vnode_link);
784 		list_del(&wbk->vnode_link);
785 		afs_put_wb_key(wbk);
786 	}
787 
788 #ifdef CONFIG_AFS_FSCACHE
789 	{
790 		struct afs_vnode_cache_aux aux;
791 
792 		aux.data_version = vnode->status.data_version;
793 		fscache_relinquish_cookie(vnode->cache, &aux,
794 					  test_bit(AFS_VNODE_DELETED, &vnode->flags));
795 		vnode->cache = NULL;
796 	}
797 #endif
798 
799 	afs_prune_wb_keys(vnode);
800 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
801 	key_put(vnode->silly_key);
802 	vnode->silly_key = NULL;
803 	key_put(vnode->lock_key);
804 	vnode->lock_key = NULL;
805 	_leave("");
806 }
807 
808 static void afs_setattr_success(struct afs_operation *op)
809 {
810 	struct afs_vnode_param *vp = &op->file[0];
811 	struct inode *inode = &vp->vnode->vfs_inode;
812 	loff_t old_i_size = i_size_read(inode);
813 
814 	op->setattr.old_i_size = old_i_size;
815 	afs_vnode_commit_status(op, vp);
816 	/* inode->i_size has now been changed. */
817 
818 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
819 		loff_t size = op->setattr.attr->ia_size;
820 		if (size > old_i_size)
821 			pagecache_isize_extended(inode, old_i_size, size);
822 	}
823 }
824 
825 static void afs_setattr_edit_file(struct afs_operation *op)
826 {
827 	struct afs_vnode_param *vp = &op->file[0];
828 	struct inode *inode = &vp->vnode->vfs_inode;
829 
830 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
831 		loff_t size = op->setattr.attr->ia_size;
832 		loff_t i_size = op->setattr.old_i_size;
833 
834 		if (size < i_size)
835 			truncate_pagecache(inode, size);
836 	}
837 }
838 
839 static const struct afs_operation_ops afs_setattr_operation = {
840 	.issue_afs_rpc	= afs_fs_setattr,
841 	.issue_yfs_rpc	= yfs_fs_setattr,
842 	.success	= afs_setattr_success,
843 	.edit_dir	= afs_setattr_edit_file,
844 };
845 
846 /*
847  * set the attributes of an inode
848  */
849 int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
850 		struct iattr *attr)
851 {
852 	struct afs_operation *op;
853 	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
854 	int ret;
855 
856 	_enter("{%llx:%llu},{n=%pd},%x",
857 	       vnode->fid.vid, vnode->fid.vnode, dentry,
858 	       attr->ia_valid);
859 
860 	if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
861 				ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET |
862 				ATTR_TOUCH))) {
863 		_leave(" = 0 [unsupported]");
864 		return 0;
865 	}
866 
867 	if (attr->ia_valid & ATTR_SIZE) {
868 		if (!S_ISREG(vnode->vfs_inode.i_mode))
869 			return -EISDIR;
870 
871 		ret = inode_newsize_ok(&vnode->vfs_inode, attr->ia_size);
872 		if (ret)
873 			return ret;
874 
875 		if (attr->ia_size == i_size_read(&vnode->vfs_inode))
876 			attr->ia_valid &= ~ATTR_SIZE;
877 	}
878 
879 	/* flush any dirty data outstanding on a regular file */
880 	if (S_ISREG(vnode->vfs_inode.i_mode))
881 		filemap_write_and_wait(vnode->vfs_inode.i_mapping);
882 
883 	/* Prevent any new writebacks from starting whilst we do this. */
884 	down_write(&vnode->validate_lock);
885 
886 	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
887 				  afs_file_key(attr->ia_file) : NULL),
888 				 vnode->volume);
889 	if (IS_ERR(op)) {
890 		ret = PTR_ERR(op);
891 		goto out_unlock;
892 	}
893 
894 	afs_op_set_vnode(op, 0, vnode);
895 	op->setattr.attr = attr;
896 
897 	if (attr->ia_valid & ATTR_SIZE) {
898 		op->file[0].dv_delta = 1;
899 		op->file[0].set_size = true;
900 	}
901 	op->ctime = attr->ia_ctime;
902 	op->file[0].update_ctime = 1;
903 	op->file[0].modification = true;
904 
905 	op->ops = &afs_setattr_operation;
906 	ret = afs_do_sync_operation(op);
907 
908 out_unlock:
909 	up_write(&vnode->validate_lock);
910 	_leave(" = %d", ret);
911 	return ret;
912 }
913