xref: /linux/fs/afs/inode.c (revision 778e73d2411abc8f3a2d60dbf038acaec218792e)
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 parameters for the netfs library
58  */
59 static void afs_set_netfs_context(struct afs_vnode *vnode)
60 {
61 	netfs_inode_init(&vnode->netfs, &afs_req_ops);
62 }
63 
64 /*
65  * Initialise an inode from the vnode status.
66  */
67 static int afs_inode_init_from_status(struct afs_operation *op,
68 				      struct afs_vnode_param *vp,
69 				      struct afs_vnode *vnode)
70 {
71 	struct afs_file_status *status = &vp->scb.status;
72 	struct inode *inode = AFS_VNODE_TO_I(vnode);
73 	struct timespec64 t;
74 
75 	_enter("{%llx:%llu.%u} %s",
76 	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
77 	       op->type ? op->type->name : "???");
78 
79 	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
80 	       status->type,
81 	       status->nlink,
82 	       (unsigned long long) status->size,
83 	       status->data_version,
84 	       status->mode);
85 
86 	write_seqlock(&vnode->cb_lock);
87 
88 	vnode->cb_v_check = op->cb_v_break;
89 	vnode->status = *status;
90 
91 	t = status->mtime_client;
92 	inode_set_ctime_to_ts(inode, t);
93 	inode_set_mtime_to_ts(inode, t);
94 	inode_set_atime_to_ts(inode, t);
95 	inode->i_flags |= S_NOATIME;
96 	inode->i_uid = make_kuid(&init_user_ns, status->owner);
97 	inode->i_gid = make_kgid(&init_user_ns, status->group);
98 	set_nlink(&vnode->netfs.inode, status->nlink);
99 
100 	switch (status->type) {
101 	case AFS_FTYPE_FILE:
102 		inode->i_mode	= S_IFREG | (status->mode & S_IALLUGO);
103 		inode->i_op	= &afs_file_inode_operations;
104 		inode->i_fop	= &afs_file_operations;
105 		inode->i_mapping->a_ops	= &afs_file_aops;
106 		mapping_set_large_folios(inode->i_mapping);
107 		break;
108 	case AFS_FTYPE_DIR:
109 		inode->i_mode	= S_IFDIR |  (status->mode & S_IALLUGO);
110 		inode->i_op	= &afs_dir_inode_operations;
111 		inode->i_fop	= &afs_dir_file_operations;
112 		inode->i_mapping->a_ops	= &afs_dir_aops;
113 		mapping_set_large_folios(inode->i_mapping);
114 		break;
115 	case AFS_FTYPE_SYMLINK:
116 		/* Symlinks with a mode of 0644 are actually mountpoints. */
117 		if ((status->mode & 0777) == 0644) {
118 			inode->i_flags |= S_AUTOMOUNT;
119 
120 			set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
121 
122 			inode->i_mode	= S_IFDIR | 0555;
123 			inode->i_op	= &afs_mntpt_inode_operations;
124 			inode->i_fop	= &afs_mntpt_file_operations;
125 			inode->i_mapping->a_ops	= &afs_symlink_aops;
126 		} else {
127 			inode->i_mode	= S_IFLNK | status->mode;
128 			inode->i_op	= &afs_symlink_inode_operations;
129 			inode->i_mapping->a_ops	= &afs_symlink_aops;
130 		}
131 		inode_nohighmem(inode);
132 		break;
133 	default:
134 		dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
135 		write_sequnlock(&vnode->cb_lock);
136 		return afs_protocol_error(NULL, afs_eproto_file_type);
137 	}
138 
139 	afs_set_i_size(vnode, status->size);
140 	afs_set_netfs_context(vnode);
141 
142 	vnode->invalid_before	= status->data_version;
143 	inode_set_iversion_raw(&vnode->netfs.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 		atomic64_set(&vnode->cb_expires_at, AFS_NO_CB_PROMISE);
149 	} else {
150 		vnode->cb_server = op->server;
151 		atomic64_set(&vnode->cb_expires_at, vp->scb.callback.expires_at);
152 	}
153 
154 	write_sequnlock(&vnode->cb_lock);
155 	return 0;
156 }
157 
158 /*
159  * Update the core inode struct from a returned status record.
160  */
161 static void afs_apply_status(struct afs_operation *op,
162 			     struct afs_vnode_param *vp)
163 {
164 	struct afs_file_status *status = &vp->scb.status;
165 	struct afs_vnode *vnode = vp->vnode;
166 	struct inode *inode = &vnode->netfs.inode;
167 	struct timespec64 t;
168 	umode_t mode;
169 	bool data_changed = false;
170 	bool change_size = vp->set_size;
171 
172 	_enter("{%llx:%llu.%u} %s",
173 	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
174 	       op->type ? op->type->name : "???");
175 
176 	BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
177 
178 	if (status->type != vnode->status.type) {
179 		pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
180 			vnode->fid.vid,
181 			vnode->fid.vnode,
182 			vnode->fid.unique,
183 			status->type, vnode->status.type);
184 		afs_protocol_error(NULL, afs_eproto_bad_status);
185 		return;
186 	}
187 
188 	if (status->nlink != vnode->status.nlink)
189 		set_nlink(inode, status->nlink);
190 
191 	if (status->owner != vnode->status.owner)
192 		inode->i_uid = make_kuid(&init_user_ns, status->owner);
193 
194 	if (status->group != vnode->status.group)
195 		inode->i_gid = make_kgid(&init_user_ns, status->group);
196 
197 	if (status->mode != vnode->status.mode) {
198 		mode = inode->i_mode;
199 		mode &= ~S_IALLUGO;
200 		mode |= status->mode & S_IALLUGO;
201 		WRITE_ONCE(inode->i_mode, mode);
202 	}
203 
204 	t = status->mtime_client;
205 	inode_set_mtime_to_ts(inode, t);
206 	if (vp->update_ctime)
207 		inode_set_ctime_to_ts(inode, op->ctime);
208 
209 	if (vnode->status.data_version != status->data_version)
210 		data_changed = true;
211 
212 	vnode->status = *status;
213 
214 	if (vp->dv_before + vp->dv_delta != status->data_version) {
215 		if (vnode->cb_ro_snapshot == atomic_read(&vnode->volume->cb_ro_snapshot) &&
216 		    atomic64_read(&vnode->cb_expires_at) != AFS_NO_CB_PROMISE)
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 		data_changed = true;
233 	} else if (vnode->status.type == AFS_FTYPE_DIR) {
234 		/* Expected directory change is handled elsewhere so
235 		 * that we can locally edit the directory and save on a
236 		 * download.
237 		 */
238 		if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
239 			data_changed = false;
240 		change_size = true;
241 	}
242 
243 	if (data_changed) {
244 		inode_set_iversion_raw(inode, status->data_version);
245 
246 		/* Only update the size if the data version jumped.  If the
247 		 * file is being modified locally, then we might have our own
248 		 * idea of what the size should be that's not the same as
249 		 * what's on the server.
250 		 */
251 		vnode->netfs.remote_i_size = status->size;
252 		if (change_size) {
253 			afs_set_i_size(vnode, status->size);
254 			inode_set_ctime_to_ts(inode, t);
255 			inode_set_atime_to_ts(inode, t);
256 		}
257 	}
258 }
259 
260 /*
261  * Apply a callback to a vnode.
262  */
263 static void afs_apply_callback(struct afs_operation *op,
264 			       struct afs_vnode_param *vp)
265 {
266 	struct afs_callback *cb = &vp->scb.callback;
267 	struct afs_vnode *vnode = vp->vnode;
268 
269 	if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
270 		if (op->volume->type == AFSVL_RWVOL)
271 			vnode->cb_server = op->server;
272 		atomic64_set(&vnode->cb_expires_at, cb->expires_at);
273 	}
274 }
275 
276 /*
277  * Apply the received status and callback to an inode all in the same critical
278  * section to avoid races with afs_validate().
279  */
280 void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
281 {
282 	struct afs_vnode *vnode = vp->vnode;
283 
284 	_enter("");
285 
286 	write_seqlock(&vnode->cb_lock);
287 
288 	if (vp->scb.have_error) {
289 		/* A YFS server will return this from RemoveFile2 and AFS and
290 		 * YFS will return this from InlineBulkStatus.
291 		 */
292 		if (vp->scb.status.abort_code == VNOVNODE) {
293 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
294 			clear_nlink(&vnode->netfs.inode);
295 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
296 			op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
297 		}
298 	} else if (vp->scb.have_status) {
299 		if (vp->speculative &&
300 		    (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
301 		     vp->dv_before != vnode->status.data_version))
302 			/* Ignore the result of a speculative bulk status fetch
303 			 * if it splits around a modification op, thereby
304 			 * appearing to regress the data version.
305 			 */
306 			goto out;
307 		afs_apply_status(op, vp);
308 		if (vp->scb.have_cb)
309 			afs_apply_callback(op, vp);
310 	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
311 		drop_nlink(&vnode->netfs.inode);
312 		if (vnode->netfs.inode.i_nlink == 0) {
313 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
314 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
315 		}
316 	}
317 
318 out:
319 	write_sequnlock(&vnode->cb_lock);
320 
321 	if (vp->scb.have_status)
322 		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
323 }
324 
325 static void afs_fetch_status_success(struct afs_operation *op)
326 {
327 	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
328 	struct afs_vnode *vnode = vp->vnode;
329 	int ret;
330 
331 	if (vnode->netfs.inode.i_state & I_NEW) {
332 		ret = afs_inode_init_from_status(op, vp, vnode);
333 		afs_op_set_error(op, ret);
334 		if (ret == 0)
335 			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
336 	} else {
337 		afs_vnode_commit_status(op, vp);
338 	}
339 }
340 
341 const struct afs_operation_ops afs_fetch_status_operation = {
342 	.issue_afs_rpc	= afs_fs_fetch_status,
343 	.issue_yfs_rpc	= yfs_fs_fetch_status,
344 	.success	= afs_fetch_status_success,
345 	.aborted	= afs_check_for_remote_deletion,
346 };
347 
348 /*
349  * Fetch file status from the volume.
350  */
351 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
352 		     afs_access_t *_caller_access)
353 {
354 	struct afs_operation *op;
355 
356 	_enter("%s,{%llx:%llu.%u,S=%lx}",
357 	       vnode->volume->name,
358 	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
359 	       vnode->flags);
360 
361 	op = afs_alloc_operation(key, vnode->volume);
362 	if (IS_ERR(op))
363 		return PTR_ERR(op);
364 
365 	afs_op_set_vnode(op, 0, vnode);
366 
367 	op->nr_files	= 1;
368 	op->ops		= &afs_fetch_status_operation;
369 	afs_begin_vnode_operation(op);
370 	afs_wait_for_operation(op);
371 
372 	if (_caller_access)
373 		*_caller_access = op->file[0].scb.status.caller_access;
374 	return afs_put_operation(op);
375 }
376 
377 /*
378  * ilookup() comparator
379  */
380 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
381 {
382 	struct afs_vnode *vnode = AFS_FS_I(inode);
383 	struct afs_fid *fid = opaque;
384 
385 	return (fid->vnode == vnode->fid.vnode &&
386 		fid->vnode_hi == vnode->fid.vnode_hi &&
387 		fid->unique == vnode->fid.unique);
388 }
389 
390 /*
391  * iget5() comparator
392  */
393 static int afs_iget5_test(struct inode *inode, void *opaque)
394 {
395 	struct afs_vnode_param *vp = opaque;
396 	//struct afs_vnode *vnode = AFS_FS_I(inode);
397 
398 	return afs_ilookup5_test_by_fid(inode, &vp->fid);
399 }
400 
401 /*
402  * iget5() inode initialiser
403  */
404 static int afs_iget5_set(struct inode *inode, void *opaque)
405 {
406 	struct afs_vnode_param *vp = opaque;
407 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
408 	struct afs_vnode *vnode = AFS_FS_I(inode);
409 
410 	vnode->volume		= as->volume;
411 	vnode->fid		= vp->fid;
412 
413 	/* YFS supports 96-bit vnode IDs, but Linux only supports
414 	 * 64-bit inode numbers.
415 	 */
416 	inode->i_ino		= vnode->fid.vnode;
417 	inode->i_generation	= vnode->fid.unique;
418 	return 0;
419 }
420 
421 /*
422  * Get a cache cookie for an inode.
423  */
424 static void afs_get_inode_cache(struct afs_vnode *vnode)
425 {
426 #ifdef CONFIG_AFS_FSCACHE
427 	struct {
428 		__be32 vnode_id;
429 		__be32 unique;
430 		__be32 vnode_id_ext[2];	/* Allow for a 96-bit key */
431 	} __packed key;
432 	struct afs_vnode_cache_aux aux;
433 
434 	if (vnode->status.type != AFS_FTYPE_FILE) {
435 		vnode->netfs.cache = NULL;
436 		return;
437 	}
438 
439 	key.vnode_id		= htonl(vnode->fid.vnode);
440 	key.unique		= htonl(vnode->fid.unique);
441 	key.vnode_id_ext[0]	= htonl(vnode->fid.vnode >> 32);
442 	key.vnode_id_ext[1]	= htonl(vnode->fid.vnode_hi);
443 	afs_set_cache_aux(vnode, &aux);
444 
445 	afs_vnode_set_cache(vnode,
446 			    fscache_acquire_cookie(
447 				    vnode->volume->cache,
448 				    vnode->status.type == AFS_FTYPE_FILE ?
449 				    0 : FSCACHE_ADV_SINGLE_CHUNK,
450 				    &key, sizeof(key),
451 				    &aux, sizeof(aux),
452 				    i_size_read(&vnode->netfs.inode)));
453 #endif
454 }
455 
456 /*
457  * inode retrieval
458  */
459 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
460 {
461 	struct afs_vnode_param *dvp = &op->file[0];
462 	struct super_block *sb = dvp->vnode->netfs.inode.i_sb;
463 	struct afs_vnode *vnode;
464 	struct inode *inode;
465 	int ret;
466 
467 	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
468 
469 	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
470 	if (!inode) {
471 		_leave(" = -ENOMEM");
472 		return ERR_PTR(-ENOMEM);
473 	}
474 
475 	vnode = AFS_FS_I(inode);
476 
477 	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
478 	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
479 
480 	/* deal with an existing inode */
481 	if (!(inode->i_state & I_NEW)) {
482 		_leave(" = %p", inode);
483 		return inode;
484 	}
485 
486 	ret = afs_inode_init_from_status(op, vp, vnode);
487 	if (ret < 0)
488 		goto bad_inode;
489 
490 	afs_get_inode_cache(vnode);
491 
492 	/* success */
493 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
494 	unlock_new_inode(inode);
495 	_leave(" = %p", inode);
496 	return inode;
497 
498 	/* failure */
499 bad_inode:
500 	iget_failed(inode);
501 	_leave(" = %d [bad]", ret);
502 	return ERR_PTR(ret);
503 }
504 
505 static int afs_iget5_set_root(struct inode *inode, void *opaque)
506 {
507 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
508 	struct afs_vnode *vnode = AFS_FS_I(inode);
509 
510 	vnode->volume		= as->volume;
511 	vnode->fid.vid		= as->volume->vid,
512 	vnode->fid.vnode	= 1;
513 	vnode->fid.unique	= 1;
514 	inode->i_ino		= 1;
515 	inode->i_generation	= 1;
516 	return 0;
517 }
518 
519 /*
520  * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
521  * the volume.
522  */
523 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
524 {
525 	struct afs_super_info *as = AFS_FS_S(sb);
526 	struct afs_operation *op;
527 	struct afs_vnode *vnode;
528 	struct inode *inode;
529 	int ret;
530 
531 	_enter(",{%llx},,", as->volume->vid);
532 
533 	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
534 	if (!inode) {
535 		_leave(" = -ENOMEM");
536 		return ERR_PTR(-ENOMEM);
537 	}
538 
539 	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
540 
541 	BUG_ON(!(inode->i_state & I_NEW));
542 
543 	vnode = AFS_FS_I(inode);
544 	vnode->cb_v_check = atomic_read(&as->volume->cb_v_break),
545 	afs_set_netfs_context(vnode);
546 
547 	op = afs_alloc_operation(key, as->volume);
548 	if (IS_ERR(op)) {
549 		ret = PTR_ERR(op);
550 		goto error;
551 	}
552 
553 	afs_op_set_vnode(op, 0, vnode);
554 
555 	op->nr_files	= 1;
556 	op->ops		= &afs_fetch_status_operation;
557 	ret = afs_do_sync_operation(op);
558 	if (ret < 0)
559 		goto error;
560 
561 	afs_get_inode_cache(vnode);
562 
563 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
564 	unlock_new_inode(inode);
565 	_leave(" = %p", inode);
566 	return inode;
567 
568 error:
569 	iget_failed(inode);
570 	_leave(" = %d [bad]", ret);
571 	return ERR_PTR(ret);
572 }
573 
574 /*
575  * read the attributes of an inode
576  */
577 int afs_getattr(struct mnt_idmap *idmap, const struct path *path,
578 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
579 {
580 	struct inode *inode = d_inode(path->dentry);
581 	struct afs_vnode *vnode = AFS_FS_I(inode);
582 	struct key *key;
583 	int ret, seq;
584 
585 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
586 
587 	if (vnode->volume &&
588 	    !(query_flags & AT_STATX_DONT_SYNC) &&
589 	    atomic64_read(&vnode->cb_expires_at) == AFS_NO_CB_PROMISE) {
590 		key = afs_request_key(vnode->volume->cell);
591 		if (IS_ERR(key))
592 			return PTR_ERR(key);
593 		ret = afs_validate(vnode, key);
594 		key_put(key);
595 		if (ret < 0)
596 			return ret;
597 	}
598 
599 	do {
600 		seq = read_seqbegin(&vnode->cb_lock);
601 		generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
602 		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
603 		    stat->nlink > 0)
604 			stat->nlink -= 1;
605 
606 		/* Lie about the size of directories.  We maintain a locally
607 		 * edited copy and may make different allocation decisions on
608 		 * it, but we need to give userspace the server's size.
609 		 */
610 		if (S_ISDIR(inode->i_mode))
611 			stat->size = vnode->netfs.remote_i_size;
612 	} while (read_seqretry(&vnode->cb_lock, seq));
613 
614 	return 0;
615 }
616 
617 /*
618  * discard an AFS inode
619  */
620 int afs_drop_inode(struct inode *inode)
621 {
622 	_enter("");
623 
624 	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
625 		return generic_delete_inode(inode);
626 	else
627 		return generic_drop_inode(inode);
628 }
629 
630 /*
631  * clear an AFS inode
632  */
633 void afs_evict_inode(struct inode *inode)
634 {
635 	struct afs_vnode_cache_aux aux;
636 	struct afs_vnode *vnode = AFS_FS_I(inode);
637 
638 	_enter("{%llx:%llu.%d}",
639 	       vnode->fid.vid,
640 	       vnode->fid.vnode,
641 	       vnode->fid.unique);
642 
643 	_debug("CLEAR INODE %p", inode);
644 
645 	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
646 
647 	truncate_inode_pages_final(&inode->i_data);
648 
649 	afs_set_cache_aux(vnode, &aux);
650 	fscache_clear_inode_writeback(afs_vnode_cache(vnode), inode, &aux);
651 	clear_inode(inode);
652 
653 	while (!list_empty(&vnode->wb_keys)) {
654 		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
655 						    struct afs_wb_key, vnode_link);
656 		list_del(&wbk->vnode_link);
657 		afs_put_wb_key(wbk);
658 	}
659 
660 	fscache_relinquish_cookie(afs_vnode_cache(vnode),
661 				  test_bit(AFS_VNODE_DELETED, &vnode->flags));
662 
663 	afs_prune_wb_keys(vnode);
664 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
665 	key_put(vnode->silly_key);
666 	vnode->silly_key = NULL;
667 	key_put(vnode->lock_key);
668 	vnode->lock_key = NULL;
669 	_leave("");
670 }
671 
672 static void afs_setattr_success(struct afs_operation *op)
673 {
674 	struct afs_vnode_param *vp = &op->file[0];
675 	struct inode *inode = &vp->vnode->netfs.inode;
676 	loff_t old_i_size = i_size_read(inode);
677 
678 	op->setattr.old_i_size = old_i_size;
679 	afs_vnode_commit_status(op, vp);
680 	/* inode->i_size has now been changed. */
681 
682 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
683 		loff_t size = op->setattr.attr->ia_size;
684 		if (size > old_i_size)
685 			pagecache_isize_extended(inode, old_i_size, size);
686 	}
687 }
688 
689 static void afs_setattr_edit_file(struct afs_operation *op)
690 {
691 	struct afs_vnode_param *vp = &op->file[0];
692 	struct inode *inode = &vp->vnode->netfs.inode;
693 
694 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
695 		loff_t size = op->setattr.attr->ia_size;
696 		loff_t i_size = op->setattr.old_i_size;
697 
698 		if (size < i_size)
699 			truncate_pagecache(inode, size);
700 		if (size != i_size)
701 			fscache_resize_cookie(afs_vnode_cache(vp->vnode),
702 					      vp->scb.status.size);
703 	}
704 }
705 
706 static const struct afs_operation_ops afs_setattr_operation = {
707 	.issue_afs_rpc	= afs_fs_setattr,
708 	.issue_yfs_rpc	= yfs_fs_setattr,
709 	.success	= afs_setattr_success,
710 	.edit_dir	= afs_setattr_edit_file,
711 };
712 
713 /*
714  * set the attributes of an inode
715  */
716 int afs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
717 		struct iattr *attr)
718 {
719 	const unsigned int supported =
720 		ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
721 		ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET | ATTR_TOUCH;
722 	struct afs_operation *op;
723 	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
724 	struct inode *inode = &vnode->netfs.inode;
725 	loff_t i_size;
726 	int ret;
727 
728 	_enter("{%llx:%llu},{n=%pd},%x",
729 	       vnode->fid.vid, vnode->fid.vnode, dentry,
730 	       attr->ia_valid);
731 
732 	if (!(attr->ia_valid & supported)) {
733 		_leave(" = 0 [unsupported]");
734 		return 0;
735 	}
736 
737 	i_size = i_size_read(inode);
738 	if (attr->ia_valid & ATTR_SIZE) {
739 		if (!S_ISREG(inode->i_mode))
740 			return -EISDIR;
741 
742 		ret = inode_newsize_ok(inode, attr->ia_size);
743 		if (ret)
744 			return ret;
745 
746 		if (attr->ia_size == i_size)
747 			attr->ia_valid &= ~ATTR_SIZE;
748 	}
749 
750 	fscache_use_cookie(afs_vnode_cache(vnode), true);
751 
752 	/* Prevent any new writebacks from starting whilst we do this. */
753 	down_write(&vnode->validate_lock);
754 
755 	if ((attr->ia_valid & ATTR_SIZE) && S_ISREG(inode->i_mode)) {
756 		loff_t size = attr->ia_size;
757 
758 		/* Wait for any outstanding writes to the server to complete */
759 		loff_t from = min(size, i_size);
760 		loff_t to = max(size, i_size);
761 		ret = filemap_fdatawait_range(inode->i_mapping, from, to);
762 		if (ret < 0)
763 			goto out_unlock;
764 
765 		/* Don't talk to the server if we're just shortening in-memory
766 		 * writes that haven't gone to the server yet.
767 		 */
768 		if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
769 		    attr->ia_size < i_size &&
770 		    attr->ia_size > vnode->status.size) {
771 			truncate_pagecache(inode, attr->ia_size);
772 			fscache_resize_cookie(afs_vnode_cache(vnode),
773 					      attr->ia_size);
774 			i_size_write(inode, attr->ia_size);
775 			ret = 0;
776 			goto out_unlock;
777 		}
778 	}
779 
780 	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
781 				  afs_file_key(attr->ia_file) : NULL),
782 				 vnode->volume);
783 	if (IS_ERR(op)) {
784 		ret = PTR_ERR(op);
785 		goto out_unlock;
786 	}
787 
788 	afs_op_set_vnode(op, 0, vnode);
789 	op->setattr.attr = attr;
790 
791 	if (attr->ia_valid & ATTR_SIZE) {
792 		op->file[0].dv_delta = 1;
793 		op->file[0].set_size = true;
794 	}
795 	op->ctime = attr->ia_ctime;
796 	op->file[0].update_ctime = 1;
797 	op->file[0].modification = true;
798 
799 	op->ops = &afs_setattr_operation;
800 	ret = afs_do_sync_operation(op);
801 
802 out_unlock:
803 	up_write(&vnode->validate_lock);
804 	fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
805 	_leave(" = %d", ret);
806 	return ret;
807 }
808