xref: /openbmc/linux/fs/afs/inode.c (revision 163b0991)
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;
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;
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;
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\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 
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 		if (change_size) {
250 			afs_set_i_size(vnode, status->size);
251 			inode->i_ctime = t;
252 			inode->i_atime = t;
253 		}
254 	}
255 }
256 
257 /*
258  * Apply a callback to a vnode.
259  */
260 static void afs_apply_callback(struct afs_operation *op,
261 			       struct afs_vnode_param *vp)
262 {
263 	struct afs_callback *cb = &vp->scb.callback;
264 	struct afs_vnode *vnode = vp->vnode;
265 
266 	if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
267 		vnode->cb_expires_at	= cb->expires_at;
268 		vnode->cb_server	= op->server;
269 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
270 	}
271 }
272 
273 /*
274  * Apply the received status and callback to an inode all in the same critical
275  * section to avoid races with afs_validate().
276  */
277 void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
278 {
279 	struct afs_vnode *vnode = vp->vnode;
280 
281 	_enter("");
282 
283 	write_seqlock(&vnode->cb_lock);
284 
285 	if (vp->scb.have_error) {
286 		/* A YFS server will return this from RemoveFile2 and AFS and
287 		 * YFS will return this from InlineBulkStatus.
288 		 */
289 		if (vp->scb.status.abort_code == VNOVNODE) {
290 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
291 			clear_nlink(&vnode->vfs_inode);
292 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
293 			op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
294 		}
295 	} else if (vp->scb.have_status) {
296 		if (vp->dv_before + vp->dv_delta != vp->scb.status.data_version &&
297 		    vp->speculative)
298 			/* Ignore the result of a speculative bulk status fetch
299 			 * if it splits around a modification op, thereby
300 			 * appearing to regress the data version.
301 			 */
302 			goto out;
303 		afs_apply_status(op, vp);
304 		if (vp->scb.have_cb)
305 			afs_apply_callback(op, vp);
306 	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
307 		drop_nlink(&vnode->vfs_inode);
308 		if (vnode->vfs_inode.i_nlink == 0) {
309 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
310 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
311 		}
312 	}
313 
314 out:
315 	write_sequnlock(&vnode->cb_lock);
316 
317 	if (vp->scb.have_status)
318 		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
319 }
320 
321 static void afs_fetch_status_success(struct afs_operation *op)
322 {
323 	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
324 	struct afs_vnode *vnode = vp->vnode;
325 	int ret;
326 
327 	if (vnode->vfs_inode.i_state & I_NEW) {
328 		ret = afs_inode_init_from_status(op, vp, vnode);
329 		op->error = ret;
330 		if (ret == 0)
331 			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
332 	} else {
333 		afs_vnode_commit_status(op, vp);
334 	}
335 }
336 
337 const struct afs_operation_ops afs_fetch_status_operation = {
338 	.issue_afs_rpc	= afs_fs_fetch_status,
339 	.issue_yfs_rpc	= yfs_fs_fetch_status,
340 	.success	= afs_fetch_status_success,
341 	.aborted	= afs_check_for_remote_deletion,
342 };
343 
344 /*
345  * Fetch file status from the volume.
346  */
347 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
348 		     afs_access_t *_caller_access)
349 {
350 	struct afs_operation *op;
351 
352 	_enter("%s,{%llx:%llu.%u,S=%lx}",
353 	       vnode->volume->name,
354 	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
355 	       vnode->flags);
356 
357 	op = afs_alloc_operation(key, vnode->volume);
358 	if (IS_ERR(op))
359 		return PTR_ERR(op);
360 
361 	afs_op_set_vnode(op, 0, vnode);
362 
363 	op->nr_files	= 1;
364 	op->ops		= &afs_fetch_status_operation;
365 	afs_begin_vnode_operation(op);
366 	afs_wait_for_operation(op);
367 
368 	if (_caller_access)
369 		*_caller_access = op->file[0].scb.status.caller_access;
370 	return afs_put_operation(op);
371 }
372 
373 /*
374  * ilookup() comparator
375  */
376 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
377 {
378 	struct afs_vnode *vnode = AFS_FS_I(inode);
379 	struct afs_fid *fid = opaque;
380 
381 	return (fid->vnode == vnode->fid.vnode &&
382 		fid->vnode_hi == vnode->fid.vnode_hi &&
383 		fid->unique == vnode->fid.unique);
384 }
385 
386 /*
387  * iget5() comparator
388  */
389 static int afs_iget5_test(struct inode *inode, void *opaque)
390 {
391 	struct afs_vnode_param *vp = opaque;
392 	//struct afs_vnode *vnode = AFS_FS_I(inode);
393 
394 	return afs_ilookup5_test_by_fid(inode, &vp->fid);
395 }
396 
397 /*
398  * iget5() inode initialiser
399  */
400 static int afs_iget5_set(struct inode *inode, void *opaque)
401 {
402 	struct afs_vnode_param *vp = opaque;
403 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
404 	struct afs_vnode *vnode = AFS_FS_I(inode);
405 
406 	vnode->volume		= as->volume;
407 	vnode->fid		= vp->fid;
408 
409 	/* YFS supports 96-bit vnode IDs, but Linux only supports
410 	 * 64-bit inode numbers.
411 	 */
412 	inode->i_ino		= vnode->fid.vnode;
413 	inode->i_generation	= vnode->fid.unique;
414 	return 0;
415 }
416 
417 /*
418  * Get a cache cookie for an inode.
419  */
420 static void afs_get_inode_cache(struct afs_vnode *vnode)
421 {
422 #ifdef CONFIG_AFS_FSCACHE
423 	struct {
424 		u32 vnode_id;
425 		u32 unique;
426 		u32 vnode_id_ext[2];	/* Allow for a 96-bit key */
427 	} __packed key;
428 	struct afs_vnode_cache_aux aux;
429 
430 	if (vnode->status.type == AFS_FTYPE_DIR) {
431 		vnode->cache = NULL;
432 		return;
433 	}
434 
435 	key.vnode_id		= vnode->fid.vnode;
436 	key.unique		= vnode->fid.unique;
437 	key.vnode_id_ext[0]	= vnode->fid.vnode >> 32;
438 	key.vnode_id_ext[1]	= vnode->fid.vnode_hi;
439 	aux.data_version	= vnode->status.data_version;
440 
441 	vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
442 					      &afs_vnode_cache_index_def,
443 					      &key, sizeof(key),
444 					      &aux, sizeof(aux),
445 					      vnode, vnode->status.size, true);
446 #endif
447 }
448 
449 /*
450  * inode retrieval
451  */
452 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
453 {
454 	struct afs_vnode_param *dvp = &op->file[0];
455 	struct super_block *sb = dvp->vnode->vfs_inode.i_sb;
456 	struct afs_vnode *vnode;
457 	struct inode *inode;
458 	int ret;
459 
460 	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
461 
462 	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
463 	if (!inode) {
464 		_leave(" = -ENOMEM");
465 		return ERR_PTR(-ENOMEM);
466 	}
467 
468 	vnode = AFS_FS_I(inode);
469 
470 	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
471 	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
472 
473 	/* deal with an existing inode */
474 	if (!(inode->i_state & I_NEW)) {
475 		_leave(" = %p", inode);
476 		return inode;
477 	}
478 
479 	ret = afs_inode_init_from_status(op, vp, vnode);
480 	if (ret < 0)
481 		goto bad_inode;
482 
483 	afs_get_inode_cache(vnode);
484 
485 	/* success */
486 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
487 	unlock_new_inode(inode);
488 	_leave(" = %p", inode);
489 	return inode;
490 
491 	/* failure */
492 bad_inode:
493 	iget_failed(inode);
494 	_leave(" = %d [bad]", ret);
495 	return ERR_PTR(ret);
496 }
497 
498 static int afs_iget5_set_root(struct inode *inode, void *opaque)
499 {
500 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
501 	struct afs_vnode *vnode = AFS_FS_I(inode);
502 
503 	vnode->volume		= as->volume;
504 	vnode->fid.vid		= as->volume->vid,
505 	vnode->fid.vnode	= 1;
506 	vnode->fid.unique	= 1;
507 	inode->i_ino		= 1;
508 	inode->i_generation	= 1;
509 	return 0;
510 }
511 
512 /*
513  * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
514  * the volume.
515  */
516 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
517 {
518 	struct afs_super_info *as = AFS_FS_S(sb);
519 	struct afs_operation *op;
520 	struct afs_vnode *vnode;
521 	struct inode *inode;
522 	int ret;
523 
524 	_enter(",{%llx},,", as->volume->vid);
525 
526 	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
527 	if (!inode) {
528 		_leave(" = -ENOMEM");
529 		return ERR_PTR(-ENOMEM);
530 	}
531 
532 	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
533 
534 	BUG_ON(!(inode->i_state & I_NEW));
535 
536 	vnode = AFS_FS_I(inode);
537 	vnode->cb_v_break = as->volume->cb_v_break,
538 
539 	op = afs_alloc_operation(key, as->volume);
540 	if (IS_ERR(op)) {
541 		ret = PTR_ERR(op);
542 		goto error;
543 	}
544 
545 	afs_op_set_vnode(op, 0, vnode);
546 
547 	op->nr_files	= 1;
548 	op->ops		= &afs_fetch_status_operation;
549 	ret = afs_do_sync_operation(op);
550 	if (ret < 0)
551 		goto error;
552 
553 	afs_get_inode_cache(vnode);
554 
555 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
556 	unlock_new_inode(inode);
557 	_leave(" = %p", inode);
558 	return inode;
559 
560 error:
561 	iget_failed(inode);
562 	_leave(" = %d [bad]", ret);
563 	return ERR_PTR(ret);
564 }
565 
566 /*
567  * mark the data attached to an inode as obsolete due to a write on the server
568  * - might also want to ditch all the outstanding writes and dirty pages
569  */
570 static void afs_zap_data(struct afs_vnode *vnode)
571 {
572 	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
573 
574 #ifdef CONFIG_AFS_FSCACHE
575 	fscache_invalidate(vnode->cache);
576 #endif
577 
578 	/* nuke all the non-dirty pages that aren't locked, mapped or being
579 	 * written back in a regular file and completely discard the pages in a
580 	 * directory or symlink */
581 	if (S_ISREG(vnode->vfs_inode.i_mode))
582 		invalidate_remote_inode(&vnode->vfs_inode);
583 	else
584 		invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
585 }
586 
587 /*
588  * Get the server reinit counter for a vnode's current server.
589  */
590 static bool afs_get_s_break_rcu(struct afs_vnode *vnode, unsigned int *_s_break)
591 {
592 	struct afs_server_list *slist = rcu_dereference(vnode->volume->servers);
593 	struct afs_server *server;
594 	int i;
595 
596 	for (i = 0; i < slist->nr_servers; i++) {
597 		server = slist->servers[i].server;
598 		if (server == vnode->cb_server) {
599 			*_s_break = READ_ONCE(server->cb_s_break);
600 			return true;
601 		}
602 	}
603 
604 	return false;
605 }
606 
607 /*
608  * Check the validity of a vnode/inode.
609  */
610 bool afs_check_validity(struct afs_vnode *vnode)
611 {
612 	struct afs_volume *volume = vnode->volume;
613 	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
614 	time64_t now = ktime_get_real_seconds();
615 	bool valid;
616 	unsigned int cb_break, cb_s_break, cb_v_break;
617 	int seq = 0;
618 
619 	do {
620 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
621 		cb_v_break = READ_ONCE(volume->cb_v_break);
622 		cb_break = vnode->cb_break;
623 
624 		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
625 		    afs_get_s_break_rcu(vnode, &cb_s_break)) {
626 			if (vnode->cb_s_break != cb_s_break ||
627 			    vnode->cb_v_break != cb_v_break) {
628 				vnode->cb_s_break = cb_s_break;
629 				vnode->cb_v_break = cb_v_break;
630 				need_clear = afs_cb_break_for_vsbreak;
631 				valid = false;
632 			} else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
633 				need_clear = afs_cb_break_for_zap;
634 				valid = false;
635 			} else if (vnode->cb_expires_at - 10 <= now) {
636 				need_clear = afs_cb_break_for_lapsed;
637 				valid = false;
638 			} else {
639 				valid = true;
640 			}
641 		} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
642 			valid = true;
643 		} else {
644 			vnode->cb_v_break = cb_v_break;
645 			valid = false;
646 		}
647 
648 	} while (need_seqretry(&vnode->cb_lock, seq));
649 
650 	done_seqretry(&vnode->cb_lock, seq);
651 
652 	if (need_clear != afs_cb_break_no_break) {
653 		write_seqlock(&vnode->cb_lock);
654 		if (cb_break == vnode->cb_break)
655 			__afs_break_callback(vnode, need_clear);
656 		else
657 			trace_afs_cb_miss(&vnode->fid, need_clear);
658 		write_sequnlock(&vnode->cb_lock);
659 		valid = false;
660 	}
661 
662 	return valid;
663 }
664 
665 /*
666  * validate a vnode/inode
667  * - there are several things we need to check
668  *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
669  *     symlink)
670  *   - parent dir metadata changed (security changes)
671  *   - dentry data changed (write, truncate)
672  *   - dentry metadata changed (security changes)
673  */
674 int afs_validate(struct afs_vnode *vnode, struct key *key)
675 {
676 	bool valid;
677 	int ret;
678 
679 	_enter("{v={%llx:%llu} fl=%lx},%x",
680 	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
681 	       key_serial(key));
682 
683 	rcu_read_lock();
684 	valid = afs_check_validity(vnode);
685 	rcu_read_unlock();
686 
687 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
688 		clear_nlink(&vnode->vfs_inode);
689 
690 	if (valid)
691 		goto valid;
692 
693 	down_write(&vnode->validate_lock);
694 
695 	/* if the promise has expired, we need to check the server again to get
696 	 * a new promise - note that if the (parent) directory's metadata was
697 	 * changed then the security may be different and we may no longer have
698 	 * access */
699 	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
700 		_debug("not promised");
701 		ret = afs_fetch_status(vnode, key, false, NULL);
702 		if (ret < 0) {
703 			if (ret == -ENOENT) {
704 				set_bit(AFS_VNODE_DELETED, &vnode->flags);
705 				ret = -ESTALE;
706 			}
707 			goto error_unlock;
708 		}
709 		_debug("new promise [fl=%lx]", vnode->flags);
710 	}
711 
712 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
713 		_debug("file already deleted");
714 		ret = -ESTALE;
715 		goto error_unlock;
716 	}
717 
718 	/* if the vnode's data version number changed then its contents are
719 	 * different */
720 	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
721 		afs_zap_data(vnode);
722 	up_write(&vnode->validate_lock);
723 valid:
724 	_leave(" = 0");
725 	return 0;
726 
727 error_unlock:
728 	up_write(&vnode->validate_lock);
729 	_leave(" = %d", ret);
730 	return ret;
731 }
732 
733 /*
734  * read the attributes of an inode
735  */
736 int afs_getattr(struct user_namespace *mnt_userns, const struct path *path,
737 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
738 {
739 	struct inode *inode = d_inode(path->dentry);
740 	struct afs_vnode *vnode = AFS_FS_I(inode);
741 	int seq = 0;
742 
743 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
744 
745 	do {
746 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
747 		generic_fillattr(&init_user_ns, inode, stat);
748 		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
749 		    stat->nlink > 0)
750 			stat->nlink -= 1;
751 	} while (need_seqretry(&vnode->cb_lock, seq));
752 
753 	done_seqretry(&vnode->cb_lock, seq);
754 	return 0;
755 }
756 
757 /*
758  * discard an AFS inode
759  */
760 int afs_drop_inode(struct inode *inode)
761 {
762 	_enter("");
763 
764 	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
765 		return generic_delete_inode(inode);
766 	else
767 		return generic_drop_inode(inode);
768 }
769 
770 /*
771  * clear an AFS inode
772  */
773 void afs_evict_inode(struct inode *inode)
774 {
775 	struct afs_vnode *vnode;
776 
777 	vnode = AFS_FS_I(inode);
778 
779 	_enter("{%llx:%llu.%d}",
780 	       vnode->fid.vid,
781 	       vnode->fid.vnode,
782 	       vnode->fid.unique);
783 
784 	_debug("CLEAR INODE %p", inode);
785 
786 	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
787 
788 	truncate_inode_pages_final(&inode->i_data);
789 	clear_inode(inode);
790 
791 	while (!list_empty(&vnode->wb_keys)) {
792 		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
793 						    struct afs_wb_key, vnode_link);
794 		list_del(&wbk->vnode_link);
795 		afs_put_wb_key(wbk);
796 	}
797 
798 #ifdef CONFIG_AFS_FSCACHE
799 	{
800 		struct afs_vnode_cache_aux aux;
801 
802 		aux.data_version = vnode->status.data_version;
803 		fscache_relinquish_cookie(vnode->cache, &aux,
804 					  test_bit(AFS_VNODE_DELETED, &vnode->flags));
805 		vnode->cache = NULL;
806 	}
807 #endif
808 
809 	afs_prune_wb_keys(vnode);
810 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
811 	key_put(vnode->silly_key);
812 	vnode->silly_key = NULL;
813 	key_put(vnode->lock_key);
814 	vnode->lock_key = NULL;
815 	_leave("");
816 }
817 
818 static void afs_setattr_success(struct afs_operation *op)
819 {
820 	struct afs_vnode_param *vp = &op->file[0];
821 	struct inode *inode = &vp->vnode->vfs_inode;
822 	loff_t old_i_size = i_size_read(inode);
823 
824 	op->setattr.old_i_size = old_i_size;
825 	afs_vnode_commit_status(op, vp);
826 	/* inode->i_size has now been changed. */
827 
828 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
829 		loff_t size = op->setattr.attr->ia_size;
830 		if (size > old_i_size)
831 			pagecache_isize_extended(inode, old_i_size, size);
832 	}
833 }
834 
835 static void afs_setattr_edit_file(struct afs_operation *op)
836 {
837 	struct afs_vnode_param *vp = &op->file[0];
838 	struct inode *inode = &vp->vnode->vfs_inode;
839 
840 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
841 		loff_t size = op->setattr.attr->ia_size;
842 		loff_t i_size = op->setattr.old_i_size;
843 
844 		if (size < i_size)
845 			truncate_pagecache(inode, size);
846 	}
847 }
848 
849 static const struct afs_operation_ops afs_setattr_operation = {
850 	.issue_afs_rpc	= afs_fs_setattr,
851 	.issue_yfs_rpc	= yfs_fs_setattr,
852 	.success	= afs_setattr_success,
853 	.edit_dir	= afs_setattr_edit_file,
854 };
855 
856 /*
857  * set the attributes of an inode
858  */
859 int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
860 		struct iattr *attr)
861 {
862 	struct afs_operation *op;
863 	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
864 	int ret;
865 
866 	_enter("{%llx:%llu},{n=%pd},%x",
867 	       vnode->fid.vid, vnode->fid.vnode, dentry,
868 	       attr->ia_valid);
869 
870 	if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
871 				ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET |
872 				ATTR_TOUCH))) {
873 		_leave(" = 0 [unsupported]");
874 		return 0;
875 	}
876 
877 	if (attr->ia_valid & ATTR_SIZE) {
878 		if (!S_ISREG(vnode->vfs_inode.i_mode))
879 			return -EISDIR;
880 
881 		ret = inode_newsize_ok(&vnode->vfs_inode, attr->ia_size);
882 		if (ret)
883 			return ret;
884 
885 		if (attr->ia_size == i_size_read(&vnode->vfs_inode))
886 			attr->ia_valid &= ~ATTR_SIZE;
887 	}
888 
889 	/* flush any dirty data outstanding on a regular file */
890 	if (S_ISREG(vnode->vfs_inode.i_mode))
891 		filemap_write_and_wait(vnode->vfs_inode.i_mapping);
892 
893 	/* Prevent any new writebacks from starting whilst we do this. */
894 	down_write(&vnode->validate_lock);
895 
896 	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
897 				  afs_file_key(attr->ia_file) : NULL),
898 				 vnode->volume);
899 	if (IS_ERR(op)) {
900 		ret = PTR_ERR(op);
901 		goto out_unlock;
902 	}
903 
904 	afs_op_set_vnode(op, 0, vnode);
905 	op->setattr.attr = attr;
906 
907 	if (attr->ia_valid & ATTR_SIZE) {
908 		op->file[0].dv_delta = 1;
909 		op->file[0].set_size = true;
910 	}
911 	op->ctime = attr->ia_ctime;
912 	op->file[0].update_ctime = 1;
913 
914 	op->ops = &afs_setattr_operation;
915 	ret = afs_do_sync_operation(op);
916 
917 out_unlock:
918 	up_write(&vnode->validate_lock);
919 	_leave(" = %d", ret);
920 	return ret;
921 }
922