xref: /linux/fs/afs/inode.c (revision 4f3c8320c78cdd11c8fdd23c33787407f719322e)
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 	.listxattr	= afs_listxattr,
31 };
32 
33 static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *parent_vnode)
34 {
35 	static unsigned long once_only;
36 
37 	pr_warn("kAFS: AFS vnode with undefined type %u\n", vnode->status.type);
38 	pr_warn("kAFS: A=%d m=%o s=%llx v=%llx\n",
39 		vnode->status.abort_code,
40 		vnode->status.mode,
41 		vnode->status.size,
42 		vnode->status.data_version);
43 	pr_warn("kAFS: vnode %llx:%llx:%x\n",
44 		vnode->fid.vid,
45 		vnode->fid.vnode,
46 		vnode->fid.unique);
47 	if (parent_vnode)
48 		pr_warn("kAFS: dir %llx:%llx:%x\n",
49 			parent_vnode->fid.vid,
50 			parent_vnode->fid.vnode,
51 			parent_vnode->fid.unique);
52 
53 	if (!test_and_set_bit(0, &once_only))
54 		dump_stack();
55 }
56 
57 /*
58  * Set the file size and block count.  Estimate the number of 512 bytes blocks
59  * used, rounded up to nearest 1K for consistency with other AFS clients.
60  */
61 static void afs_set_i_size(struct afs_vnode *vnode, u64 size)
62 {
63 	i_size_write(&vnode->vfs_inode, size);
64 	vnode->vfs_inode.i_blocks = ((size + 1023) >> 10) << 1;
65 }
66 
67 /*
68  * Initialise an inode from the vnode status.
69  */
70 static int afs_inode_init_from_status(struct afs_operation *op,
71 				      struct afs_vnode_param *vp,
72 				      struct afs_vnode *vnode)
73 {
74 	struct afs_file_status *status = &vp->scb.status;
75 	struct inode *inode = AFS_VNODE_TO_I(vnode);
76 	struct timespec64 t;
77 
78 	_enter("{%llx:%llu.%u} %s",
79 	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
80 	       op->type ? op->type->name : "???");
81 
82 	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
83 	       status->type,
84 	       status->nlink,
85 	       (unsigned long long) status->size,
86 	       status->data_version,
87 	       status->mode);
88 
89 	write_seqlock(&vnode->cb_lock);
90 
91 	vnode->cb_v_break = op->cb_v_break;
92 	vnode->cb_s_break = op->cb_s_break;
93 	vnode->status = *status;
94 
95 	t = status->mtime_client;
96 	inode->i_ctime = t;
97 	inode->i_mtime = t;
98 	inode->i_atime = t;
99 	inode->i_flags |= S_NOATIME;
100 	inode->i_uid = make_kuid(&init_user_ns, status->owner);
101 	inode->i_gid = make_kgid(&init_user_ns, status->group);
102 	set_nlink(&vnode->vfs_inode, status->nlink);
103 
104 	switch (status->type) {
105 	case AFS_FTYPE_FILE:
106 		inode->i_mode	= S_IFREG | status->mode;
107 		inode->i_op	= &afs_file_inode_operations;
108 		inode->i_fop	= &afs_file_operations;
109 		inode->i_mapping->a_ops	= &afs_fs_aops;
110 		break;
111 	case AFS_FTYPE_DIR:
112 		inode->i_mode	= S_IFDIR | status->mode;
113 		inode->i_op	= &afs_dir_inode_operations;
114 		inode->i_fop	= &afs_dir_file_operations;
115 		inode->i_mapping->a_ops	= &afs_dir_aops;
116 		break;
117 	case AFS_FTYPE_SYMLINK:
118 		/* Symlinks with a mode of 0644 are actually mountpoints. */
119 		if ((status->mode & 0777) == 0644) {
120 			inode->i_flags |= S_AUTOMOUNT;
121 
122 			set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
123 
124 			inode->i_mode	= S_IFDIR | 0555;
125 			inode->i_op	= &afs_mntpt_inode_operations;
126 			inode->i_fop	= &afs_mntpt_file_operations;
127 			inode->i_mapping->a_ops	= &afs_fs_aops;
128 		} else {
129 			inode->i_mode	= S_IFLNK | status->mode;
130 			inode->i_op	= &afs_symlink_inode_operations;
131 			inode->i_mapping->a_ops	= &afs_fs_aops;
132 		}
133 		inode_nohighmem(inode);
134 		break;
135 	default:
136 		dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
137 		write_sequnlock(&vnode->cb_lock);
138 		return afs_protocol_error(NULL, afs_eproto_file_type);
139 	}
140 
141 	afs_set_i_size(vnode, status->size);
142 
143 	vnode->invalid_before	= status->data_version;
144 	inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
145 
146 	if (!vp->scb.have_cb) {
147 		/* it's a symlink we just created (the fileserver
148 		 * didn't give us a callback) */
149 		vnode->cb_expires_at = ktime_get_real_seconds();
150 	} else {
151 		vnode->cb_expires_at = vp->scb.callback.expires_at;
152 		vnode->cb_server = op->server;
153 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
154 	}
155 
156 	write_sequnlock(&vnode->cb_lock);
157 	return 0;
158 }
159 
160 /*
161  * Update the core inode struct from a returned status record.
162  */
163 static void afs_apply_status(struct afs_operation *op,
164 			     struct afs_vnode_param *vp)
165 {
166 	struct afs_file_status *status = &vp->scb.status;
167 	struct afs_vnode *vnode = vp->vnode;
168 	struct inode *inode = &vnode->vfs_inode;
169 	struct timespec64 t;
170 	umode_t mode;
171 	bool data_changed = false;
172 	bool change_size = vp->set_size;
173 
174 	_enter("{%llx:%llu.%u} %s",
175 	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
176 	       op->type ? op->type->name : "???");
177 
178 	BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
179 
180 	if (status->type != vnode->status.type) {
181 		pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
182 			vnode->fid.vid,
183 			vnode->fid.vnode,
184 			vnode->fid.unique,
185 			status->type, vnode->status.type);
186 		afs_protocol_error(NULL, afs_eproto_bad_status);
187 		return;
188 	}
189 
190 	if (status->nlink != vnode->status.nlink)
191 		set_nlink(inode, status->nlink);
192 
193 	if (status->owner != vnode->status.owner)
194 		inode->i_uid = make_kuid(&init_user_ns, status->owner);
195 
196 	if (status->group != vnode->status.group)
197 		inode->i_gid = make_kgid(&init_user_ns, status->group);
198 
199 	if (status->mode != vnode->status.mode) {
200 		mode = inode->i_mode;
201 		mode &= ~S_IALLUGO;
202 		mode |= status->mode;
203 		WRITE_ONCE(inode->i_mode, mode);
204 	}
205 
206 	t = status->mtime_client;
207 	inode->i_mtime = t;
208 	if (vp->update_ctime)
209 		inode->i_ctime = op->ctime;
210 
211 	if (vnode->status.data_version != status->data_version)
212 		data_changed = true;
213 
214 	vnode->status = *status;
215 
216 	if (vp->dv_before + vp->dv_delta != status->data_version) {
217 		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
218 			pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s\n",
219 				vnode->fid.vid, vnode->fid.vnode,
220 				(unsigned long long)vp->dv_before + vp->dv_delta,
221 				(unsigned long long)status->data_version,
222 				op->type ? op->type->name : "???");
223 
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->dv_before + vp->dv_delta != vp->scb.status.data_version &&
298 		    vp->speculative)
299 			/* Ignore the result of a speculative bulk status fetch
300 			 * if it splits around a modification op, thereby
301 			 * appearing to regress the data version.
302 			 */
303 			goto out;
304 		afs_apply_status(op, vp);
305 		if (vp->scb.have_cb)
306 			afs_apply_callback(op, vp);
307 	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
308 		drop_nlink(&vnode->vfs_inode);
309 		if (vnode->vfs_inode.i_nlink == 0) {
310 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
311 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
312 		}
313 	}
314 
315 out:
316 	write_sequnlock(&vnode->cb_lock);
317 
318 	if (vp->scb.have_status)
319 		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
320 }
321 
322 static void afs_fetch_status_success(struct afs_operation *op)
323 {
324 	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
325 	struct afs_vnode *vnode = vp->vnode;
326 	int ret;
327 
328 	if (vnode->vfs_inode.i_state & I_NEW) {
329 		ret = afs_inode_init_from_status(op, vp, vnode);
330 		op->error = ret;
331 		if (ret == 0)
332 			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
333 	} else {
334 		afs_vnode_commit_status(op, vp);
335 	}
336 }
337 
338 const struct afs_operation_ops afs_fetch_status_operation = {
339 	.issue_afs_rpc	= afs_fs_fetch_status,
340 	.issue_yfs_rpc	= yfs_fs_fetch_status,
341 	.success	= afs_fetch_status_success,
342 	.aborted	= afs_check_for_remote_deletion,
343 };
344 
345 /*
346  * Fetch file status from the volume.
347  */
348 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
349 		     afs_access_t *_caller_access)
350 {
351 	struct afs_operation *op;
352 
353 	_enter("%s,{%llx:%llu.%u,S=%lx}",
354 	       vnode->volume->name,
355 	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
356 	       vnode->flags);
357 
358 	op = afs_alloc_operation(key, vnode->volume);
359 	if (IS_ERR(op))
360 		return PTR_ERR(op);
361 
362 	afs_op_set_vnode(op, 0, vnode);
363 
364 	op->nr_files	= 1;
365 	op->ops		= &afs_fetch_status_operation;
366 	afs_begin_vnode_operation(op);
367 	afs_wait_for_operation(op);
368 
369 	if (_caller_access)
370 		*_caller_access = op->file[0].scb.status.caller_access;
371 	return afs_put_operation(op);
372 }
373 
374 /*
375  * ilookup() comparator
376  */
377 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
378 {
379 	struct afs_vnode *vnode = AFS_FS_I(inode);
380 	struct afs_fid *fid = opaque;
381 
382 	return (fid->vnode == vnode->fid.vnode &&
383 		fid->vnode_hi == vnode->fid.vnode_hi &&
384 		fid->unique == vnode->fid.unique);
385 }
386 
387 /*
388  * iget5() comparator
389  */
390 static int afs_iget5_test(struct inode *inode, void *opaque)
391 {
392 	struct afs_vnode_param *vp = opaque;
393 	//struct afs_vnode *vnode = AFS_FS_I(inode);
394 
395 	return afs_ilookup5_test_by_fid(inode, &vp->fid);
396 }
397 
398 /*
399  * iget5() inode initialiser
400  */
401 static int afs_iget5_set(struct inode *inode, void *opaque)
402 {
403 	struct afs_vnode_param *vp = opaque;
404 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
405 	struct afs_vnode *vnode = AFS_FS_I(inode);
406 
407 	vnode->volume		= as->volume;
408 	vnode->fid		= vp->fid;
409 
410 	/* YFS supports 96-bit vnode IDs, but Linux only supports
411 	 * 64-bit inode numbers.
412 	 */
413 	inode->i_ino		= vnode->fid.vnode;
414 	inode->i_generation	= vnode->fid.unique;
415 	return 0;
416 }
417 
418 /*
419  * Get a cache cookie for an inode.
420  */
421 static void afs_get_inode_cache(struct afs_vnode *vnode)
422 {
423 #ifdef CONFIG_AFS_FSCACHE
424 	struct {
425 		u32 vnode_id;
426 		u32 unique;
427 		u32 vnode_id_ext[2];	/* Allow for a 96-bit key */
428 	} __packed key;
429 	struct afs_vnode_cache_aux aux;
430 
431 	if (vnode->status.type == AFS_FTYPE_DIR) {
432 		vnode->cache = NULL;
433 		return;
434 	}
435 
436 	key.vnode_id		= vnode->fid.vnode;
437 	key.unique		= vnode->fid.unique;
438 	key.vnode_id_ext[0]	= vnode->fid.vnode >> 32;
439 	key.vnode_id_ext[1]	= vnode->fid.vnode_hi;
440 	aux.data_version	= vnode->status.data_version;
441 
442 	vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
443 					      &afs_vnode_cache_index_def,
444 					      &key, sizeof(key),
445 					      &aux, sizeof(aux),
446 					      vnode, vnode->status.size, true);
447 #endif
448 }
449 
450 /*
451  * inode retrieval
452  */
453 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
454 {
455 	struct afs_vnode_param *dvp = &op->file[0];
456 	struct super_block *sb = dvp->vnode->vfs_inode.i_sb;
457 	struct afs_vnode *vnode;
458 	struct inode *inode;
459 	int ret;
460 
461 	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
462 
463 	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
464 	if (!inode) {
465 		_leave(" = -ENOMEM");
466 		return ERR_PTR(-ENOMEM);
467 	}
468 
469 	vnode = AFS_FS_I(inode);
470 
471 	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
472 	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
473 
474 	/* deal with an existing inode */
475 	if (!(inode->i_state & I_NEW)) {
476 		_leave(" = %p", inode);
477 		return inode;
478 	}
479 
480 	ret = afs_inode_init_from_status(op, vp, vnode);
481 	if (ret < 0)
482 		goto bad_inode;
483 
484 	afs_get_inode_cache(vnode);
485 
486 	/* success */
487 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
488 	unlock_new_inode(inode);
489 	_leave(" = %p", inode);
490 	return inode;
491 
492 	/* failure */
493 bad_inode:
494 	iget_failed(inode);
495 	_leave(" = %d [bad]", ret);
496 	return ERR_PTR(ret);
497 }
498 
499 static int afs_iget5_set_root(struct inode *inode, void *opaque)
500 {
501 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
502 	struct afs_vnode *vnode = AFS_FS_I(inode);
503 
504 	vnode->volume		= as->volume;
505 	vnode->fid.vid		= as->volume->vid,
506 	vnode->fid.vnode	= 1;
507 	vnode->fid.unique	= 1;
508 	inode->i_ino		= 1;
509 	inode->i_generation	= 1;
510 	return 0;
511 }
512 
513 /*
514  * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
515  * the volume.
516  */
517 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
518 {
519 	struct afs_super_info *as = AFS_FS_S(sb);
520 	struct afs_operation *op;
521 	struct afs_vnode *vnode;
522 	struct inode *inode;
523 	int ret;
524 
525 	_enter(",{%llx},,", as->volume->vid);
526 
527 	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
528 	if (!inode) {
529 		_leave(" = -ENOMEM");
530 		return ERR_PTR(-ENOMEM);
531 	}
532 
533 	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
534 
535 	BUG_ON(!(inode->i_state & I_NEW));
536 
537 	vnode = AFS_FS_I(inode);
538 	vnode->cb_v_break = as->volume->cb_v_break,
539 
540 	op = afs_alloc_operation(key, as->volume);
541 	if (IS_ERR(op)) {
542 		ret = PTR_ERR(op);
543 		goto error;
544 	}
545 
546 	afs_op_set_vnode(op, 0, vnode);
547 
548 	op->nr_files	= 1;
549 	op->ops		= &afs_fetch_status_operation;
550 	ret = afs_do_sync_operation(op);
551 	if (ret < 0)
552 		goto error;
553 
554 	afs_get_inode_cache(vnode);
555 
556 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
557 	unlock_new_inode(inode);
558 	_leave(" = %p", inode);
559 	return inode;
560 
561 error:
562 	iget_failed(inode);
563 	_leave(" = %d [bad]", ret);
564 	return ERR_PTR(ret);
565 }
566 
567 /*
568  * mark the data attached to an inode as obsolete due to a write on the server
569  * - might also want to ditch all the outstanding writes and dirty pages
570  */
571 static void afs_zap_data(struct afs_vnode *vnode)
572 {
573 	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
574 
575 #ifdef CONFIG_AFS_FSCACHE
576 	fscache_invalidate(vnode->cache);
577 #endif
578 
579 	/* nuke all the non-dirty pages that aren't locked, mapped or being
580 	 * written back in a regular file and completely discard the pages in a
581 	 * directory or symlink */
582 	if (S_ISREG(vnode->vfs_inode.i_mode))
583 		invalidate_remote_inode(&vnode->vfs_inode);
584 	else
585 		invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
586 }
587 
588 /*
589  * Get the server reinit counter for a vnode's current server.
590  */
591 static bool afs_get_s_break_rcu(struct afs_vnode *vnode, unsigned int *_s_break)
592 {
593 	struct afs_server_list *slist = rcu_dereference(vnode->volume->servers);
594 	struct afs_server *server;
595 	int i;
596 
597 	for (i = 0; i < slist->nr_servers; i++) {
598 		server = slist->servers[i].server;
599 		if (server == vnode->cb_server) {
600 			*_s_break = READ_ONCE(server->cb_s_break);
601 			return true;
602 		}
603 	}
604 
605 	return false;
606 }
607 
608 /*
609  * Check the validity of a vnode/inode.
610  */
611 bool afs_check_validity(struct afs_vnode *vnode)
612 {
613 	struct afs_volume *volume = vnode->volume;
614 	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
615 	time64_t now = ktime_get_real_seconds();
616 	bool valid;
617 	unsigned int cb_break, cb_s_break, cb_v_break;
618 	int seq = 0;
619 
620 	do {
621 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
622 		cb_v_break = READ_ONCE(volume->cb_v_break);
623 		cb_break = vnode->cb_break;
624 
625 		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
626 		    afs_get_s_break_rcu(vnode, &cb_s_break)) {
627 			if (vnode->cb_s_break != cb_s_break ||
628 			    vnode->cb_v_break != cb_v_break) {
629 				vnode->cb_s_break = cb_s_break;
630 				vnode->cb_v_break = cb_v_break;
631 				need_clear = afs_cb_break_for_vsbreak;
632 				valid = false;
633 			} else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
634 				need_clear = afs_cb_break_for_zap;
635 				valid = false;
636 			} else if (vnode->cb_expires_at - 10 <= now) {
637 				need_clear = afs_cb_break_for_lapsed;
638 				valid = false;
639 			} else {
640 				valid = true;
641 			}
642 		} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
643 			valid = true;
644 		} else {
645 			vnode->cb_v_break = cb_v_break;
646 			valid = false;
647 		}
648 
649 	} while (need_seqretry(&vnode->cb_lock, seq));
650 
651 	done_seqretry(&vnode->cb_lock, seq);
652 
653 	if (need_clear != afs_cb_break_no_break) {
654 		write_seqlock(&vnode->cb_lock);
655 		if (cb_break == vnode->cb_break)
656 			__afs_break_callback(vnode, need_clear);
657 		else
658 			trace_afs_cb_miss(&vnode->fid, need_clear);
659 		write_sequnlock(&vnode->cb_lock);
660 		valid = false;
661 	}
662 
663 	return valid;
664 }
665 
666 /*
667  * validate a vnode/inode
668  * - there are several things we need to check
669  *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
670  *     symlink)
671  *   - parent dir metadata changed (security changes)
672  *   - dentry data changed (write, truncate)
673  *   - dentry metadata changed (security changes)
674  */
675 int afs_validate(struct afs_vnode *vnode, struct key *key)
676 {
677 	bool valid;
678 	int ret;
679 
680 	_enter("{v={%llx:%llu} fl=%lx},%x",
681 	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
682 	       key_serial(key));
683 
684 	rcu_read_lock();
685 	valid = afs_check_validity(vnode);
686 	rcu_read_unlock();
687 
688 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
689 		clear_nlink(&vnode->vfs_inode);
690 
691 	if (valid)
692 		goto valid;
693 
694 	down_write(&vnode->validate_lock);
695 
696 	/* if the promise has expired, we need to check the server again to get
697 	 * a new promise - note that if the (parent) directory's metadata was
698 	 * changed then the security may be different and we may no longer have
699 	 * access */
700 	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
701 		_debug("not promised");
702 		ret = afs_fetch_status(vnode, key, false, NULL);
703 		if (ret < 0) {
704 			if (ret == -ENOENT) {
705 				set_bit(AFS_VNODE_DELETED, &vnode->flags);
706 				ret = -ESTALE;
707 			}
708 			goto error_unlock;
709 		}
710 		_debug("new promise [fl=%lx]", vnode->flags);
711 	}
712 
713 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
714 		_debug("file already deleted");
715 		ret = -ESTALE;
716 		goto error_unlock;
717 	}
718 
719 	/* if the vnode's data version number changed then its contents are
720 	 * different */
721 	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
722 		afs_zap_data(vnode);
723 	up_write(&vnode->validate_lock);
724 valid:
725 	_leave(" = 0");
726 	return 0;
727 
728 error_unlock:
729 	up_write(&vnode->validate_lock);
730 	_leave(" = %d", ret);
731 	return ret;
732 }
733 
734 /*
735  * read the attributes of an inode
736  */
737 int afs_getattr(const struct path *path, struct kstat *stat,
738 		u32 request_mask, unsigned int query_flags)
739 {
740 	struct inode *inode = d_inode(path->dentry);
741 	struct afs_vnode *vnode = AFS_FS_I(inode);
742 	int seq = 0;
743 
744 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
745 
746 	do {
747 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
748 		generic_fillattr(inode, stat);
749 		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
750 		    stat->nlink > 0)
751 			stat->nlink -= 1;
752 	} while (need_seqretry(&vnode->cb_lock, seq));
753 
754 	done_seqretry(&vnode->cb_lock, seq);
755 	return 0;
756 }
757 
758 /*
759  * discard an AFS inode
760  */
761 int afs_drop_inode(struct inode *inode)
762 {
763 	_enter("");
764 
765 	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
766 		return generic_delete_inode(inode);
767 	else
768 		return generic_drop_inode(inode);
769 }
770 
771 /*
772  * clear an AFS inode
773  */
774 void afs_evict_inode(struct inode *inode)
775 {
776 	struct afs_vnode *vnode;
777 
778 	vnode = AFS_FS_I(inode);
779 
780 	_enter("{%llx:%llu.%d}",
781 	       vnode->fid.vid,
782 	       vnode->fid.vnode,
783 	       vnode->fid.unique);
784 
785 	_debug("CLEAR INODE %p", inode);
786 
787 	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
788 
789 	truncate_inode_pages_final(&inode->i_data);
790 	clear_inode(inode);
791 
792 	while (!list_empty(&vnode->wb_keys)) {
793 		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
794 						    struct afs_wb_key, vnode_link);
795 		list_del(&wbk->vnode_link);
796 		afs_put_wb_key(wbk);
797 	}
798 
799 #ifdef CONFIG_AFS_FSCACHE
800 	{
801 		struct afs_vnode_cache_aux aux;
802 
803 		aux.data_version = vnode->status.data_version;
804 		fscache_relinquish_cookie(vnode->cache, &aux,
805 					  test_bit(AFS_VNODE_DELETED, &vnode->flags));
806 		vnode->cache = NULL;
807 	}
808 #endif
809 
810 	afs_prune_wb_keys(vnode);
811 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
812 	key_put(vnode->silly_key);
813 	vnode->silly_key = NULL;
814 	key_put(vnode->lock_key);
815 	vnode->lock_key = NULL;
816 	_leave("");
817 }
818 
819 static void afs_setattr_success(struct afs_operation *op)
820 {
821 	struct afs_vnode_param *vp = &op->file[0];
822 	struct inode *inode = &vp->vnode->vfs_inode;
823 	loff_t old_i_size = i_size_read(inode);
824 
825 	op->setattr.old_i_size = old_i_size;
826 	afs_vnode_commit_status(op, vp);
827 	/* inode->i_size has now been changed. */
828 
829 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
830 		loff_t size = op->setattr.attr->ia_size;
831 		if (size > old_i_size)
832 			pagecache_isize_extended(inode, old_i_size, size);
833 	}
834 }
835 
836 static void afs_setattr_edit_file(struct afs_operation *op)
837 {
838 	struct afs_vnode_param *vp = &op->file[0];
839 	struct inode *inode = &vp->vnode->vfs_inode;
840 
841 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
842 		loff_t size = op->setattr.attr->ia_size;
843 		loff_t i_size = op->setattr.old_i_size;
844 
845 		if (size < i_size)
846 			truncate_pagecache(inode, size);
847 	}
848 }
849 
850 static const struct afs_operation_ops afs_setattr_operation = {
851 	.issue_afs_rpc	= afs_fs_setattr,
852 	.issue_yfs_rpc	= yfs_fs_setattr,
853 	.success	= afs_setattr_success,
854 	.edit_dir	= afs_setattr_edit_file,
855 };
856 
857 /*
858  * set the attributes of an inode
859  */
860 int afs_setattr(struct dentry *dentry, 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