xref: /kernel/linux/linux-5.10/fs/afs/inode.c (revision 8c2ecf20)
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
28static const struct inode_operations afs_symlink_inode_operations = {
29	.get_link	= page_get_link,
30};
31
32static 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 */
59static 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 */
152static 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\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
213		vnode->invalid_before = status->data_version;
214		if (vnode->status.type == AFS_FTYPE_DIR) {
215			if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
216				afs_stat_v(vnode, n_inval);
217		} else {
218			set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
219		}
220		change_size = true;
221		data_changed = 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 */
251static 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 */
268void 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
306out:
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
313static 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
329const 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 */
339int 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 */
368int 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 */
381static 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 */
392static 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 */
412static 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_DIR) {
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 */
444struct 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 */
484bad_inode:
485	iget_failed(inode);
486	_leave(" = %d [bad]", ret);
487	return ERR_PTR(ret);
488}
489
490static 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 */
508struct 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
552error:
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 */
562static 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 * Get the server reinit counter for a vnode's current server.
581 */
582static bool afs_get_s_break_rcu(struct afs_vnode *vnode, unsigned int *_s_break)
583{
584	struct afs_server_list *slist = rcu_dereference(vnode->volume->servers);
585	struct afs_server *server;
586	int i;
587
588	for (i = 0; i < slist->nr_servers; i++) {
589		server = slist->servers[i].server;
590		if (server == vnode->cb_server) {
591			*_s_break = READ_ONCE(server->cb_s_break);
592			return true;
593		}
594	}
595
596	return false;
597}
598
599/*
600 * Check the validity of a vnode/inode.
601 */
602bool afs_check_validity(struct afs_vnode *vnode)
603{
604	struct afs_volume *volume = vnode->volume;
605	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
606	time64_t now = ktime_get_real_seconds();
607	bool valid;
608	unsigned int cb_break, cb_s_break, cb_v_break;
609	int seq = 0;
610
611	do {
612		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
613		cb_v_break = READ_ONCE(volume->cb_v_break);
614		cb_break = vnode->cb_break;
615
616		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
617		    afs_get_s_break_rcu(vnode, &cb_s_break)) {
618			if (vnode->cb_s_break != cb_s_break ||
619			    vnode->cb_v_break != cb_v_break) {
620				vnode->cb_s_break = cb_s_break;
621				vnode->cb_v_break = cb_v_break;
622				need_clear = afs_cb_break_for_vsbreak;
623				valid = false;
624			} else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
625				need_clear = afs_cb_break_for_zap;
626				valid = false;
627			} else if (vnode->cb_expires_at - 10 <= now) {
628				need_clear = afs_cb_break_for_lapsed;
629				valid = false;
630			} else {
631				valid = true;
632			}
633		} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
634			valid = true;
635		} else {
636			vnode->cb_v_break = cb_v_break;
637			valid = false;
638		}
639
640	} while (need_seqretry(&vnode->cb_lock, seq));
641
642	done_seqretry(&vnode->cb_lock, seq);
643
644	if (need_clear != afs_cb_break_no_break) {
645		write_seqlock(&vnode->cb_lock);
646		if (cb_break == vnode->cb_break)
647			__afs_break_callback(vnode, need_clear);
648		else
649			trace_afs_cb_miss(&vnode->fid, need_clear);
650		write_sequnlock(&vnode->cb_lock);
651		valid = false;
652	}
653
654	return valid;
655}
656
657/*
658 * validate a vnode/inode
659 * - there are several things we need to check
660 *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
661 *     symlink)
662 *   - parent dir metadata changed (security changes)
663 *   - dentry data changed (write, truncate)
664 *   - dentry metadata changed (security changes)
665 */
666int afs_validate(struct afs_vnode *vnode, struct key *key)
667{
668	bool valid;
669	int ret;
670
671	_enter("{v={%llx:%llu} fl=%lx},%x",
672	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
673	       key_serial(key));
674
675	rcu_read_lock();
676	valid = afs_check_validity(vnode);
677	rcu_read_unlock();
678
679	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
680		clear_nlink(&vnode->vfs_inode);
681
682	if (valid)
683		goto valid;
684
685	down_write(&vnode->validate_lock);
686
687	/* if the promise has expired, we need to check the server again to get
688	 * a new promise - note that if the (parent) directory's metadata was
689	 * changed then the security may be different and we may no longer have
690	 * access */
691	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
692		_debug("not promised");
693		ret = afs_fetch_status(vnode, key, false, NULL);
694		if (ret < 0) {
695			if (ret == -ENOENT) {
696				set_bit(AFS_VNODE_DELETED, &vnode->flags);
697				ret = -ESTALE;
698			}
699			goto error_unlock;
700		}
701		_debug("new promise [fl=%lx]", vnode->flags);
702	}
703
704	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
705		_debug("file already deleted");
706		ret = -ESTALE;
707		goto error_unlock;
708	}
709
710	/* if the vnode's data version number changed then its contents are
711	 * different */
712	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
713		afs_zap_data(vnode);
714	up_write(&vnode->validate_lock);
715valid:
716	_leave(" = 0");
717	return 0;
718
719error_unlock:
720	up_write(&vnode->validate_lock);
721	_leave(" = %d", ret);
722	return ret;
723}
724
725/*
726 * read the attributes of an inode
727 */
728int afs_getattr(const struct path *path, struct kstat *stat,
729		u32 request_mask, unsigned int query_flags)
730{
731	struct inode *inode = d_inode(path->dentry);
732	struct afs_vnode *vnode = AFS_FS_I(inode);
733	struct key *key;
734	int ret, seq = 0;
735
736	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
737
738	if (vnode->volume &&
739	    !(query_flags & AT_STATX_DONT_SYNC) &&
740	    !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
741		key = afs_request_key(vnode->volume->cell);
742		if (IS_ERR(key))
743			return PTR_ERR(key);
744		ret = afs_validate(vnode, key);
745		key_put(key);
746		if (ret < 0)
747			return ret;
748	}
749
750	do {
751		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
752		generic_fillattr(inode, stat);
753		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
754		    stat->nlink > 0)
755			stat->nlink -= 1;
756	} while (need_seqretry(&vnode->cb_lock, seq));
757
758	done_seqretry(&vnode->cb_lock, seq);
759	return 0;
760}
761
762/*
763 * discard an AFS inode
764 */
765int afs_drop_inode(struct inode *inode)
766{
767	_enter("");
768
769	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
770		return generic_delete_inode(inode);
771	else
772		return generic_drop_inode(inode);
773}
774
775/*
776 * clear an AFS inode
777 */
778void afs_evict_inode(struct inode *inode)
779{
780	struct afs_vnode *vnode;
781
782	vnode = AFS_FS_I(inode);
783
784	_enter("{%llx:%llu.%d}",
785	       vnode->fid.vid,
786	       vnode->fid.vnode,
787	       vnode->fid.unique);
788
789	_debug("CLEAR INODE %p", inode);
790
791	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
792
793	truncate_inode_pages_final(&inode->i_data);
794	clear_inode(inode);
795
796	while (!list_empty(&vnode->wb_keys)) {
797		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
798						    struct afs_wb_key, vnode_link);
799		list_del(&wbk->vnode_link);
800		afs_put_wb_key(wbk);
801	}
802
803#ifdef CONFIG_AFS_FSCACHE
804	{
805		struct afs_vnode_cache_aux aux;
806
807		aux.data_version = vnode->status.data_version;
808		fscache_relinquish_cookie(vnode->cache, &aux,
809					  test_bit(AFS_VNODE_DELETED, &vnode->flags));
810		vnode->cache = NULL;
811	}
812#endif
813
814	afs_prune_wb_keys(vnode);
815	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
816	key_put(vnode->silly_key);
817	vnode->silly_key = NULL;
818	key_put(vnode->lock_key);
819	vnode->lock_key = NULL;
820	_leave("");
821}
822
823static void afs_setattr_success(struct afs_operation *op)
824{
825	struct afs_vnode_param *vp = &op->file[0];
826	struct inode *inode = &vp->vnode->vfs_inode;
827	loff_t old_i_size = i_size_read(inode);
828
829	op->setattr.old_i_size = old_i_size;
830	afs_vnode_commit_status(op, vp);
831	/* inode->i_size has now been changed. */
832
833	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
834		loff_t size = op->setattr.attr->ia_size;
835		if (size > old_i_size)
836			pagecache_isize_extended(inode, old_i_size, size);
837	}
838}
839
840static void afs_setattr_edit_file(struct afs_operation *op)
841{
842	struct afs_vnode_param *vp = &op->file[0];
843	struct inode *inode = &vp->vnode->vfs_inode;
844
845	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
846		loff_t size = op->setattr.attr->ia_size;
847		loff_t i_size = op->setattr.old_i_size;
848
849		if (size < i_size)
850			truncate_pagecache(inode, size);
851	}
852}
853
854static const struct afs_operation_ops afs_setattr_operation = {
855	.issue_afs_rpc	= afs_fs_setattr,
856	.issue_yfs_rpc	= yfs_fs_setattr,
857	.success	= afs_setattr_success,
858	.edit_dir	= afs_setattr_edit_file,
859};
860
861/*
862 * set the attributes of an inode
863 */
864int afs_setattr(struct dentry *dentry, struct iattr *attr)
865{
866	struct afs_operation *op;
867	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
868	int ret;
869
870	_enter("{%llx:%llu},{n=%pd},%x",
871	       vnode->fid.vid, vnode->fid.vnode, dentry,
872	       attr->ia_valid);
873
874	if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
875				ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET |
876				ATTR_TOUCH))) {
877		_leave(" = 0 [unsupported]");
878		return 0;
879	}
880
881	if (attr->ia_valid & ATTR_SIZE) {
882		if (!S_ISREG(vnode->vfs_inode.i_mode))
883			return -EISDIR;
884
885		ret = inode_newsize_ok(&vnode->vfs_inode, attr->ia_size);
886		if (ret)
887			return ret;
888
889		if (attr->ia_size == i_size_read(&vnode->vfs_inode))
890			attr->ia_valid &= ~ATTR_SIZE;
891	}
892
893	/* flush any dirty data outstanding on a regular file */
894	if (S_ISREG(vnode->vfs_inode.i_mode))
895		filemap_write_and_wait(vnode->vfs_inode.i_mapping);
896
897	/* Prevent any new writebacks from starting whilst we do this. */
898	down_write(&vnode->validate_lock);
899
900	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
901				  afs_file_key(attr->ia_file) : NULL),
902				 vnode->volume);
903	if (IS_ERR(op)) {
904		ret = PTR_ERR(op);
905		goto out_unlock;
906	}
907
908	afs_op_set_vnode(op, 0, vnode);
909	op->setattr.attr = attr;
910
911	if (attr->ia_valid & ATTR_SIZE) {
912		op->file[0].dv_delta = 1;
913		op->file[0].set_size = true;
914	}
915	op->ctime = attr->ia_ctime;
916	op->file[0].update_ctime = 1;
917	op->file[0].modification = true;
918
919	op->ops = &afs_setattr_operation;
920	ret = afs_do_sync_operation(op);
921
922out_unlock:
923	up_write(&vnode->validate_lock);
924	_leave(" = %d", ret);
925	return ret;
926}
927