xref: /openbmc/linux/fs/afs/inode.c (revision 0ad53fe3)
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  * Set the file size and block count.  Estimate the number of 512 bytes blocks
58  * used, rounded up to nearest 1K for consistency with other AFS clients.
59  */
60 static void afs_set_i_size(struct afs_vnode *vnode, u64 size)
61 {
62 	i_size_write(&vnode->vfs_inode, size);
63 	vnode->vfs_inode.i_blocks = ((size + 1023) >> 10) << 1;
64 }
65 
66 /*
67  * Initialise an inode from the vnode status.
68  */
69 static int afs_inode_init_from_status(struct afs_operation *op,
70 				      struct afs_vnode_param *vp,
71 				      struct afs_vnode *vnode)
72 {
73 	struct afs_file_status *status = &vp->scb.status;
74 	struct inode *inode = AFS_VNODE_TO_I(vnode);
75 	struct timespec64 t;
76 
77 	_enter("{%llx:%llu.%u} %s",
78 	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
79 	       op->type ? op->type->name : "???");
80 
81 	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
82 	       status->type,
83 	       status->nlink,
84 	       (unsigned long long) status->size,
85 	       status->data_version,
86 	       status->mode);
87 
88 	write_seqlock(&vnode->cb_lock);
89 
90 	vnode->cb_v_break = op->cb_v_break;
91 	vnode->cb_s_break = op->cb_s_break;
92 	vnode->status = *status;
93 
94 	t = status->mtime_client;
95 	inode->i_ctime = t;
96 	inode->i_mtime = t;
97 	inode->i_atime = t;
98 	inode->i_flags |= S_NOATIME;
99 	inode->i_uid = make_kuid(&init_user_ns, status->owner);
100 	inode->i_gid = make_kgid(&init_user_ns, status->group);
101 	set_nlink(&vnode->vfs_inode, status->nlink);
102 
103 	switch (status->type) {
104 	case AFS_FTYPE_FILE:
105 		inode->i_mode	= S_IFREG | (status->mode & S_IALLUGO);
106 		inode->i_op	= &afs_file_inode_operations;
107 		inode->i_fop	= &afs_file_operations;
108 		inode->i_mapping->a_ops	= &afs_fs_aops;
109 		break;
110 	case AFS_FTYPE_DIR:
111 		inode->i_mode	= S_IFDIR |  (status->mode & S_IALLUGO);
112 		inode->i_op	= &afs_dir_inode_operations;
113 		inode->i_fop	= &afs_dir_file_operations;
114 		inode->i_mapping->a_ops	= &afs_dir_aops;
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_fs_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_fs_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 
142 	vnode->invalid_before	= status->data_version;
143 	inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
144 
145 	if (!vp->scb.have_cb) {
146 		/* it's a symlink we just created (the fileserver
147 		 * didn't give us a callback) */
148 		vnode->cb_expires_at = ktime_get_real_seconds();
149 	} else {
150 		vnode->cb_expires_at = vp->scb.callback.expires_at;
151 		vnode->cb_server = op->server;
152 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
153 	}
154 
155 	write_sequnlock(&vnode->cb_lock);
156 	return 0;
157 }
158 
159 /*
160  * Update the core inode struct from a returned status record.
161  */
162 static void afs_apply_status(struct afs_operation *op,
163 			     struct afs_vnode_param *vp)
164 {
165 	struct afs_file_status *status = &vp->scb.status;
166 	struct afs_vnode *vnode = vp->vnode;
167 	struct inode *inode = &vnode->vfs_inode;
168 	struct timespec64 t;
169 	umode_t mode;
170 	bool data_changed = false;
171 	bool change_size = vp->set_size;
172 
173 	_enter("{%llx:%llu.%u} %s",
174 	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
175 	       op->type ? op->type->name : "???");
176 
177 	BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
178 
179 	if (status->type != vnode->status.type) {
180 		pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
181 			vnode->fid.vid,
182 			vnode->fid.vnode,
183 			vnode->fid.unique,
184 			status->type, vnode->status.type);
185 		afs_protocol_error(NULL, afs_eproto_bad_status);
186 		return;
187 	}
188 
189 	if (status->nlink != vnode->status.nlink)
190 		set_nlink(inode, status->nlink);
191 
192 	if (status->owner != vnode->status.owner)
193 		inode->i_uid = make_kuid(&init_user_ns, status->owner);
194 
195 	if (status->group != vnode->status.group)
196 		inode->i_gid = make_kgid(&init_user_ns, status->group);
197 
198 	if (status->mode != vnode->status.mode) {
199 		mode = inode->i_mode;
200 		mode &= ~S_IALLUGO;
201 		mode |= status->mode & S_IALLUGO;
202 		WRITE_ONCE(inode->i_mode, mode);
203 	}
204 
205 	t = status->mtime_client;
206 	inode->i_mtime = t;
207 	if (vp->update_ctime)
208 		inode->i_ctime = op->ctime;
209 
210 	if (vnode->status.data_version != status->data_version)
211 		data_changed = true;
212 
213 	vnode->status = *status;
214 
215 	if (vp->dv_before + vp->dv_delta != status->data_version) {
216 		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
217 			pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s (op=%x)\n",
218 				vnode->fid.vid, vnode->fid.vnode,
219 				(unsigned long long)vp->dv_before + vp->dv_delta,
220 				(unsigned long long)status->data_version,
221 				op->type ? op->type->name : "???",
222 				op->debug_id);
223 
224 		vnode->invalid_before = status->data_version;
225 		if (vnode->status.type == AFS_FTYPE_DIR) {
226 			if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
227 				afs_stat_v(vnode, n_inval);
228 		} else {
229 			set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
230 		}
231 		change_size = true;
232 	} else if (vnode->status.type == AFS_FTYPE_DIR) {
233 		/* Expected directory change is handled elsewhere so
234 		 * that we can locally edit the directory and save on a
235 		 * download.
236 		 */
237 		if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
238 			data_changed = false;
239 		change_size = true;
240 	}
241 
242 	if (data_changed) {
243 		inode_set_iversion_raw(inode, status->data_version);
244 
245 		/* Only update the size if the data version jumped.  If the
246 		 * file is being modified locally, then we might have our own
247 		 * idea of what the size should be that's not the same as
248 		 * what's on the server.
249 		 */
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  */
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  */
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->vfs_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->vfs_inode);
310 		if (vnode->vfs_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 
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->vfs_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  */
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  */
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  */
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  */
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  */
422 static void afs_get_inode_cache(struct afs_vnode *vnode)
423 {
424 #ifdef CONFIG_AFS_FSCACHE
425 	struct {
426 		u32 vnode_id;
427 		u32 unique;
428 		u32 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->cache = NULL;
434 		return;
435 	}
436 
437 	key.vnode_id		= vnode->fid.vnode;
438 	key.unique		= vnode->fid.unique;
439 	key.vnode_id_ext[0]	= vnode->fid.vnode >> 32;
440 	key.vnode_id_ext[1]	= vnode->fid.vnode_hi;
441 	aux.data_version	= vnode->status.data_version;
442 
443 	vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
444 					      &afs_vnode_cache_index_def,
445 					      &key, sizeof(key),
446 					      &aux, sizeof(aux),
447 					      vnode, vnode->status.size, true);
448 #endif
449 }
450 
451 /*
452  * inode retrieval
453  */
454 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
455 {
456 	struct afs_vnode_param *dvp = &op->file[0];
457 	struct super_block *sb = dvp->vnode->vfs_inode.i_sb;
458 	struct afs_vnode *vnode;
459 	struct inode *inode;
460 	int ret;
461 
462 	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
463 
464 	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
465 	if (!inode) {
466 		_leave(" = -ENOMEM");
467 		return ERR_PTR(-ENOMEM);
468 	}
469 
470 	vnode = AFS_FS_I(inode);
471 
472 	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
473 	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
474 
475 	/* deal with an existing inode */
476 	if (!(inode->i_state & I_NEW)) {
477 		_leave(" = %p", inode);
478 		return inode;
479 	}
480 
481 	ret = afs_inode_init_from_status(op, vp, vnode);
482 	if (ret < 0)
483 		goto bad_inode;
484 
485 	afs_get_inode_cache(vnode);
486 
487 	/* success */
488 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
489 	unlock_new_inode(inode);
490 	_leave(" = %p", inode);
491 	return inode;
492 
493 	/* failure */
494 bad_inode:
495 	iget_failed(inode);
496 	_leave(" = %d [bad]", ret);
497 	return ERR_PTR(ret);
498 }
499 
500 static int afs_iget5_set_root(struct inode *inode, void *opaque)
501 {
502 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
503 	struct afs_vnode *vnode = AFS_FS_I(inode);
504 
505 	vnode->volume		= as->volume;
506 	vnode->fid.vid		= as->volume->vid,
507 	vnode->fid.vnode	= 1;
508 	vnode->fid.unique	= 1;
509 	inode->i_ino		= 1;
510 	inode->i_generation	= 1;
511 	return 0;
512 }
513 
514 /*
515  * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
516  * the volume.
517  */
518 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
519 {
520 	struct afs_super_info *as = AFS_FS_S(sb);
521 	struct afs_operation *op;
522 	struct afs_vnode *vnode;
523 	struct inode *inode;
524 	int ret;
525 
526 	_enter(",{%llx},,", as->volume->vid);
527 
528 	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
529 	if (!inode) {
530 		_leave(" = -ENOMEM");
531 		return ERR_PTR(-ENOMEM);
532 	}
533 
534 	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
535 
536 	BUG_ON(!(inode->i_state & I_NEW));
537 
538 	vnode = AFS_FS_I(inode);
539 	vnode->cb_v_break = as->volume->cb_v_break,
540 
541 	op = afs_alloc_operation(key, as->volume);
542 	if (IS_ERR(op)) {
543 		ret = PTR_ERR(op);
544 		goto error;
545 	}
546 
547 	afs_op_set_vnode(op, 0, vnode);
548 
549 	op->nr_files	= 1;
550 	op->ops		= &afs_fetch_status_operation;
551 	ret = afs_do_sync_operation(op);
552 	if (ret < 0)
553 		goto error;
554 
555 	afs_get_inode_cache(vnode);
556 
557 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
558 	unlock_new_inode(inode);
559 	_leave(" = %p", inode);
560 	return inode;
561 
562 error:
563 	iget_failed(inode);
564 	_leave(" = %d [bad]", ret);
565 	return ERR_PTR(ret);
566 }
567 
568 /*
569  * mark the data attached to an inode as obsolete due to a write on the server
570  * - might also want to ditch all the outstanding writes and dirty pages
571  */
572 static void afs_zap_data(struct afs_vnode *vnode)
573 {
574 	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
575 
576 #ifdef CONFIG_AFS_FSCACHE
577 	fscache_invalidate(vnode->cache);
578 #endif
579 
580 	/* nuke all the non-dirty pages that aren't locked, mapped or being
581 	 * written back in a regular file and completely discard the pages in a
582 	 * directory or symlink */
583 	if (S_ISREG(vnode->vfs_inode.i_mode))
584 		invalidate_remote_inode(&vnode->vfs_inode);
585 	else
586 		invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
587 }
588 
589 /*
590  * Get the server reinit counter for a vnode's current server.
591  */
592 static bool afs_get_s_break_rcu(struct afs_vnode *vnode, unsigned int *_s_break)
593 {
594 	struct afs_server_list *slist = rcu_dereference(vnode->volume->servers);
595 	struct afs_server *server;
596 	int i;
597 
598 	for (i = 0; i < slist->nr_servers; i++) {
599 		server = slist->servers[i].server;
600 		if (server == vnode->cb_server) {
601 			*_s_break = READ_ONCE(server->cb_s_break);
602 			return true;
603 		}
604 	}
605 
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 	struct afs_volume *volume = vnode->volume;
615 	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
616 	time64_t now = ktime_get_real_seconds();
617 	bool valid;
618 	unsigned int cb_break, cb_s_break, cb_v_break;
619 	int seq = 0;
620 
621 	do {
622 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
623 		cb_v_break = READ_ONCE(volume->cb_v_break);
624 		cb_break = vnode->cb_break;
625 
626 		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
627 		    afs_get_s_break_rcu(vnode, &cb_s_break)) {
628 			if (vnode->cb_s_break != cb_s_break ||
629 			    vnode->cb_v_break != cb_v_break) {
630 				vnode->cb_s_break = cb_s_break;
631 				vnode->cb_v_break = cb_v_break;
632 				need_clear = afs_cb_break_for_vsbreak;
633 				valid = false;
634 			} else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
635 				need_clear = afs_cb_break_for_zap;
636 				valid = false;
637 			} else if (vnode->cb_expires_at - 10 <= now) {
638 				need_clear = afs_cb_break_for_lapsed;
639 				valid = false;
640 			} else {
641 				valid = true;
642 			}
643 		} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
644 			valid = true;
645 		} else {
646 			vnode->cb_v_break = cb_v_break;
647 			valid = false;
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 		write_seqlock(&vnode->cb_lock);
656 		if (cb_break == vnode->cb_break)
657 			__afs_break_callback(vnode, need_clear);
658 		else
659 			trace_afs_cb_miss(&vnode->fid, need_clear);
660 		write_sequnlock(&vnode->cb_lock);
661 		valid = false;
662 	}
663 
664 	return valid;
665 }
666 
667 /*
668  * validate a vnode/inode
669  * - there are several things we need to check
670  *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
671  *     symlink)
672  *   - parent dir metadata changed (security changes)
673  *   - dentry data changed (write, truncate)
674  *   - dentry metadata changed (security changes)
675  */
676 int afs_validate(struct afs_vnode *vnode, struct key *key)
677 {
678 	bool valid;
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 	rcu_read_lock();
686 	valid = afs_check_validity(vnode);
687 	rcu_read_unlock();
688 
689 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
690 		clear_nlink(&vnode->vfs_inode);
691 
692 	if (valid)
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  */
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 	int seq = 0;
744 
745 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
746 
747 	do {
748 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
749 		generic_fillattr(&init_user_ns, inode, stat);
750 		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
751 		    stat->nlink > 0)
752 			stat->nlink -= 1;
753 	} while (need_seqretry(&vnode->cb_lock, seq));
754 
755 	done_seqretry(&vnode->cb_lock, seq);
756 	return 0;
757 }
758 
759 /*
760  * discard an AFS inode
761  */
762 int afs_drop_inode(struct inode *inode)
763 {
764 	_enter("");
765 
766 	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
767 		return generic_delete_inode(inode);
768 	else
769 		return generic_drop_inode(inode);
770 }
771 
772 /*
773  * clear an AFS inode
774  */
775 void afs_evict_inode(struct inode *inode)
776 {
777 	struct afs_vnode *vnode;
778 
779 	vnode = AFS_FS_I(inode);
780 
781 	_enter("{%llx:%llu.%d}",
782 	       vnode->fid.vid,
783 	       vnode->fid.vnode,
784 	       vnode->fid.unique);
785 
786 	_debug("CLEAR INODE %p", inode);
787 
788 	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
789 
790 	truncate_inode_pages_final(&inode->i_data);
791 	clear_inode(inode);
792 
793 	while (!list_empty(&vnode->wb_keys)) {
794 		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
795 						    struct afs_wb_key, vnode_link);
796 		list_del(&wbk->vnode_link);
797 		afs_put_wb_key(wbk);
798 	}
799 
800 #ifdef CONFIG_AFS_FSCACHE
801 	{
802 		struct afs_vnode_cache_aux aux;
803 
804 		aux.data_version = vnode->status.data_version;
805 		fscache_relinquish_cookie(vnode->cache, &aux,
806 					  test_bit(AFS_VNODE_DELETED, &vnode->flags));
807 		vnode->cache = NULL;
808 	}
809 #endif
810 
811 	afs_prune_wb_keys(vnode);
812 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
813 	key_put(vnode->silly_key);
814 	vnode->silly_key = NULL;
815 	key_put(vnode->lock_key);
816 	vnode->lock_key = NULL;
817 	_leave("");
818 }
819 
820 static void afs_setattr_success(struct afs_operation *op)
821 {
822 	struct afs_vnode_param *vp = &op->file[0];
823 	struct inode *inode = &vp->vnode->vfs_inode;
824 	loff_t old_i_size = i_size_read(inode);
825 
826 	op->setattr.old_i_size = old_i_size;
827 	afs_vnode_commit_status(op, vp);
828 	/* inode->i_size has now been changed. */
829 
830 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
831 		loff_t size = op->setattr.attr->ia_size;
832 		if (size > old_i_size)
833 			pagecache_isize_extended(inode, old_i_size, size);
834 	}
835 }
836 
837 static void afs_setattr_edit_file(struct afs_operation *op)
838 {
839 	struct afs_vnode_param *vp = &op->file[0];
840 	struct inode *inode = &vp->vnode->vfs_inode;
841 
842 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
843 		loff_t size = op->setattr.attr->ia_size;
844 		loff_t i_size = op->setattr.old_i_size;
845 
846 		if (size < i_size)
847 			truncate_pagecache(inode, size);
848 	}
849 }
850 
851 static const struct afs_operation_ops afs_setattr_operation = {
852 	.issue_afs_rpc	= afs_fs_setattr,
853 	.issue_yfs_rpc	= yfs_fs_setattr,
854 	.success	= afs_setattr_success,
855 	.edit_dir	= afs_setattr_edit_file,
856 };
857 
858 /*
859  * set the attributes of an inode
860  */
861 int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
862 		struct iattr *attr)
863 {
864 	struct afs_operation *op;
865 	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
866 	int ret;
867 
868 	_enter("{%llx:%llu},{n=%pd},%x",
869 	       vnode->fid.vid, vnode->fid.vnode, dentry,
870 	       attr->ia_valid);
871 
872 	if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
873 				ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET |
874 				ATTR_TOUCH))) {
875 		_leave(" = 0 [unsupported]");
876 		return 0;
877 	}
878 
879 	if (attr->ia_valid & ATTR_SIZE) {
880 		if (!S_ISREG(vnode->vfs_inode.i_mode))
881 			return -EISDIR;
882 
883 		ret = inode_newsize_ok(&vnode->vfs_inode, attr->ia_size);
884 		if (ret)
885 			return ret;
886 
887 		if (attr->ia_size == i_size_read(&vnode->vfs_inode))
888 			attr->ia_valid &= ~ATTR_SIZE;
889 	}
890 
891 	/* flush any dirty data outstanding on a regular file */
892 	if (S_ISREG(vnode->vfs_inode.i_mode))
893 		filemap_write_and_wait(vnode->vfs_inode.i_mapping);
894 
895 	/* Prevent any new writebacks from starting whilst we do this. */
896 	down_write(&vnode->validate_lock);
897 
898 	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
899 				  afs_file_key(attr->ia_file) : NULL),
900 				 vnode->volume);
901 	if (IS_ERR(op)) {
902 		ret = PTR_ERR(op);
903 		goto out_unlock;
904 	}
905 
906 	afs_op_set_vnode(op, 0, vnode);
907 	op->setattr.attr = attr;
908 
909 	if (attr->ia_valid & ATTR_SIZE) {
910 		op->file[0].dv_delta = 1;
911 		op->file[0].set_size = true;
912 	}
913 	op->ctime = attr->ia_ctime;
914 	op->file[0].update_ctime = 1;
915 	op->file[0].modification = true;
916 
917 	op->ops = &afs_setattr_operation;
918 	ret = afs_do_sync_operation(op);
919 
920 out_unlock:
921 	up_write(&vnode->validate_lock);
922 	_leave(" = %d", ret);
923 	return ret;
924 }
925