xref: /linux/fs/afs/inode.c (revision 8de4ed75bd14ed197119ac509c6902a8561e0c1c)
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, true);
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 unexpected_jump = false;
170 	bool data_changed = false;
171 	bool change_size = vp->set_size;
172 
173 	_enter("{%llx:%llu.%u} %s",
174 	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
175 	       op->type ? op->type->name : "???");
176 
177 	BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
178 
179 	if (status->type != vnode->status.type) {
180 		pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
181 			vnode->fid.vid,
182 			vnode->fid.vnode,
183 			vnode->fid.unique,
184 			status->type, vnode->status.type);
185 		afs_protocol_error(NULL, afs_eproto_bad_status);
186 		return;
187 	}
188 
189 	if (status->nlink != vnode->status.nlink)
190 		set_nlink(inode, status->nlink);
191 
192 	if (status->owner != vnode->status.owner)
193 		inode->i_uid = make_kuid(&init_user_ns, status->owner);
194 
195 	if (status->group != vnode->status.group)
196 		inode->i_gid = make_kgid(&init_user_ns, status->group);
197 
198 	if (status->mode != vnode->status.mode) {
199 		mode = inode->i_mode;
200 		mode &= ~S_IALLUGO;
201 		mode |= status->mode & S_IALLUGO;
202 		WRITE_ONCE(inode->i_mode, mode);
203 	}
204 
205 	t = status->mtime_client;
206 	inode_set_mtime_to_ts(inode, t);
207 	if (vp->update_ctime)
208 		inode_set_ctime_to_ts(inode, 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 (vnode->cb_ro_snapshot == atomic_read(&vnode->volume->cb_ro_snapshot) &&
217 		    atomic64_read(&vnode->cb_expires_at) != AFS_NO_CB_PROMISE)
218 			pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s (op=%x)\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 				op->debug_id);
224 
225 		vnode->invalid_before = status->data_version;
226 		if (vnode->status.type == AFS_FTYPE_DIR) {
227 			if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
228 				afs_stat_v(vnode, n_inval);
229 		} else {
230 			set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
231 		}
232 		change_size = true;
233 		data_changed = true;
234 		unexpected_jump = true;
235 	} else if (vnode->status.type == AFS_FTYPE_DIR) {
236 		/* Expected directory change is handled elsewhere so
237 		 * that we can locally edit the directory and save on a
238 		 * download.
239 		 */
240 		if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
241 			data_changed = false;
242 		change_size = true;
243 	}
244 
245 	if (data_changed) {
246 		inode_set_iversion_raw(inode, status->data_version);
247 
248 		/* Only update the size if the data version jumped.  If the
249 		 * file is being modified locally, then we might have our own
250 		 * idea of what the size should be that's not the same as
251 		 * what's on the server.
252 		 */
253 		vnode->netfs.remote_i_size = status->size;
254 		if (change_size || status->size > i_size_read(inode)) {
255 			afs_set_i_size(vnode, status->size);
256 			if (unexpected_jump)
257 				vnode->netfs.zero_point = status->size;
258 			inode_set_ctime_to_ts(inode, t);
259 			inode_set_atime_to_ts(inode, t);
260 		}
261 	}
262 }
263 
264 /*
265  * Apply a callback to a vnode.
266  */
267 static void afs_apply_callback(struct afs_operation *op,
268 			       struct afs_vnode_param *vp)
269 {
270 	struct afs_callback *cb = &vp->scb.callback;
271 	struct afs_vnode *vnode = vp->vnode;
272 
273 	if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
274 		if (op->volume->type == AFSVL_RWVOL)
275 			vnode->cb_server = op->server;
276 		atomic64_set(&vnode->cb_expires_at, cb->expires_at);
277 	}
278 }
279 
280 /*
281  * Apply the received status and callback to an inode all in the same critical
282  * section to avoid races with afs_validate().
283  */
284 void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
285 {
286 	struct afs_vnode *vnode = vp->vnode;
287 
288 	_enter("");
289 
290 	write_seqlock(&vnode->cb_lock);
291 
292 	if (vp->scb.have_error) {
293 		/* A YFS server will return this from RemoveFile2 and AFS and
294 		 * YFS will return this from InlineBulkStatus.
295 		 */
296 		if (vp->scb.status.abort_code == VNOVNODE) {
297 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
298 			clear_nlink(&vnode->netfs.inode);
299 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
300 			op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
301 		}
302 	} else if (vp->scb.have_status) {
303 		if (vp->speculative &&
304 		    (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
305 		     vp->dv_before != vnode->status.data_version))
306 			/* Ignore the result of a speculative bulk status fetch
307 			 * if it splits around a modification op, thereby
308 			 * appearing to regress the data version.
309 			 */
310 			goto out;
311 		afs_apply_status(op, vp);
312 		if (vp->scb.have_cb)
313 			afs_apply_callback(op, vp);
314 	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
315 		drop_nlink(&vnode->netfs.inode);
316 		if (vnode->netfs.inode.i_nlink == 0) {
317 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
318 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
319 		}
320 	}
321 
322 out:
323 	write_sequnlock(&vnode->cb_lock);
324 
325 	if (vp->scb.have_status)
326 		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
327 }
328 
329 static void afs_fetch_status_success(struct afs_operation *op)
330 {
331 	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
332 	struct afs_vnode *vnode = vp->vnode;
333 	int ret;
334 
335 	if (vnode->netfs.inode.i_state & I_NEW) {
336 		ret = afs_inode_init_from_status(op, vp, vnode);
337 		afs_op_set_error(op, ret);
338 		if (ret == 0)
339 			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
340 	} else {
341 		afs_vnode_commit_status(op, vp);
342 	}
343 }
344 
345 const struct afs_operation_ops afs_fetch_status_operation = {
346 	.issue_afs_rpc	= afs_fs_fetch_status,
347 	.issue_yfs_rpc	= yfs_fs_fetch_status,
348 	.success	= afs_fetch_status_success,
349 	.aborted	= afs_check_for_remote_deletion,
350 };
351 
352 /*
353  * Fetch file status from the volume.
354  */
355 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
356 		     afs_access_t *_caller_access)
357 {
358 	struct afs_operation *op;
359 
360 	_enter("%s,{%llx:%llu.%u,S=%lx}",
361 	       vnode->volume->name,
362 	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
363 	       vnode->flags);
364 
365 	op = afs_alloc_operation(key, vnode->volume);
366 	if (IS_ERR(op))
367 		return PTR_ERR(op);
368 
369 	afs_op_set_vnode(op, 0, vnode);
370 
371 	op->nr_files	= 1;
372 	op->ops		= &afs_fetch_status_operation;
373 	afs_begin_vnode_operation(op);
374 	afs_wait_for_operation(op);
375 
376 	if (_caller_access)
377 		*_caller_access = op->file[0].scb.status.caller_access;
378 	return afs_put_operation(op);
379 }
380 
381 /*
382  * ilookup() comparator
383  */
384 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
385 {
386 	struct afs_vnode *vnode = AFS_FS_I(inode);
387 	struct afs_fid *fid = opaque;
388 
389 	return (fid->vnode == vnode->fid.vnode &&
390 		fid->vnode_hi == vnode->fid.vnode_hi &&
391 		fid->unique == vnode->fid.unique);
392 }
393 
394 /*
395  * iget5() comparator
396  */
397 static int afs_iget5_test(struct inode *inode, void *opaque)
398 {
399 	struct afs_vnode_param *vp = opaque;
400 	//struct afs_vnode *vnode = AFS_FS_I(inode);
401 
402 	return afs_ilookup5_test_by_fid(inode, &vp->fid);
403 }
404 
405 /*
406  * iget5() inode initialiser
407  */
408 static int afs_iget5_set(struct inode *inode, void *opaque)
409 {
410 	struct afs_vnode_param *vp = opaque;
411 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
412 	struct afs_vnode *vnode = AFS_FS_I(inode);
413 
414 	vnode->volume		= as->volume;
415 	vnode->fid		= vp->fid;
416 
417 	/* YFS supports 96-bit vnode IDs, but Linux only supports
418 	 * 64-bit inode numbers.
419 	 */
420 	inode->i_ino		= vnode->fid.vnode;
421 	inode->i_generation	= vnode->fid.unique;
422 	return 0;
423 }
424 
425 /*
426  * Get a cache cookie for an inode.
427  */
428 static void afs_get_inode_cache(struct afs_vnode *vnode)
429 {
430 #ifdef CONFIG_AFS_FSCACHE
431 	struct {
432 		__be32 vnode_id;
433 		__be32 unique;
434 		__be32 vnode_id_ext[2];	/* Allow for a 96-bit key */
435 	} __packed key;
436 	struct afs_vnode_cache_aux aux;
437 
438 	if (vnode->status.type != AFS_FTYPE_FILE) {
439 		vnode->netfs.cache = NULL;
440 		return;
441 	}
442 
443 	key.vnode_id		= htonl(vnode->fid.vnode);
444 	key.unique		= htonl(vnode->fid.unique);
445 	key.vnode_id_ext[0]	= htonl(vnode->fid.vnode >> 32);
446 	key.vnode_id_ext[1]	= htonl(vnode->fid.vnode_hi);
447 	afs_set_cache_aux(vnode, &aux);
448 
449 	afs_vnode_set_cache(vnode,
450 			    fscache_acquire_cookie(
451 				    vnode->volume->cache,
452 				    vnode->status.type == AFS_FTYPE_FILE ?
453 				    0 : FSCACHE_ADV_SINGLE_CHUNK,
454 				    &key, sizeof(key),
455 				    &aux, sizeof(aux),
456 				    i_size_read(&vnode->netfs.inode)));
457 #endif
458 }
459 
460 /*
461  * inode retrieval
462  */
463 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
464 {
465 	struct afs_vnode_param *dvp = &op->file[0];
466 	struct super_block *sb = dvp->vnode->netfs.inode.i_sb;
467 	struct afs_vnode *vnode;
468 	struct inode *inode;
469 	int ret;
470 
471 	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
472 
473 	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
474 	if (!inode) {
475 		_leave(" = -ENOMEM");
476 		return ERR_PTR(-ENOMEM);
477 	}
478 
479 	vnode = AFS_FS_I(inode);
480 
481 	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
482 	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
483 
484 	/* deal with an existing inode */
485 	if (!(inode->i_state & I_NEW)) {
486 		_leave(" = %p", inode);
487 		return inode;
488 	}
489 
490 	ret = afs_inode_init_from_status(op, vp, vnode);
491 	if (ret < 0)
492 		goto bad_inode;
493 
494 	afs_get_inode_cache(vnode);
495 
496 	/* success */
497 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
498 	unlock_new_inode(inode);
499 	_leave(" = %p", inode);
500 	return inode;
501 
502 	/* failure */
503 bad_inode:
504 	iget_failed(inode);
505 	_leave(" = %d [bad]", ret);
506 	return ERR_PTR(ret);
507 }
508 
509 static int afs_iget5_set_root(struct inode *inode, void *opaque)
510 {
511 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
512 	struct afs_vnode *vnode = AFS_FS_I(inode);
513 
514 	vnode->volume		= as->volume;
515 	vnode->fid.vid		= as->volume->vid,
516 	vnode->fid.vnode	= 1;
517 	vnode->fid.unique	= 1;
518 	inode->i_ino		= 1;
519 	inode->i_generation	= 1;
520 	return 0;
521 }
522 
523 /*
524  * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
525  * the volume.
526  */
527 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
528 {
529 	struct afs_super_info *as = AFS_FS_S(sb);
530 	struct afs_operation *op;
531 	struct afs_vnode *vnode;
532 	struct inode *inode;
533 	int ret;
534 
535 	_enter(",{%llx},,", as->volume->vid);
536 
537 	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
538 	if (!inode) {
539 		_leave(" = -ENOMEM");
540 		return ERR_PTR(-ENOMEM);
541 	}
542 
543 	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
544 
545 	BUG_ON(!(inode->i_state & I_NEW));
546 
547 	vnode = AFS_FS_I(inode);
548 	vnode->cb_v_check = atomic_read(&as->volume->cb_v_break),
549 	afs_set_netfs_context(vnode);
550 
551 	op = afs_alloc_operation(key, as->volume);
552 	if (IS_ERR(op)) {
553 		ret = PTR_ERR(op);
554 		goto error;
555 	}
556 
557 	afs_op_set_vnode(op, 0, vnode);
558 
559 	op->nr_files	= 1;
560 	op->ops		= &afs_fetch_status_operation;
561 	ret = afs_do_sync_operation(op);
562 	if (ret < 0)
563 		goto error;
564 
565 	afs_get_inode_cache(vnode);
566 
567 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
568 	unlock_new_inode(inode);
569 	_leave(" = %p", inode);
570 	return inode;
571 
572 error:
573 	iget_failed(inode);
574 	_leave(" = %d [bad]", ret);
575 	return ERR_PTR(ret);
576 }
577 
578 /*
579  * read the attributes of an inode
580  */
581 int afs_getattr(struct mnt_idmap *idmap, const struct path *path,
582 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
583 {
584 	struct inode *inode = d_inode(path->dentry);
585 	struct afs_vnode *vnode = AFS_FS_I(inode);
586 	struct key *key;
587 	int ret, seq;
588 
589 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
590 
591 	if (vnode->volume &&
592 	    !(query_flags & AT_STATX_DONT_SYNC) &&
593 	    atomic64_read(&vnode->cb_expires_at) == AFS_NO_CB_PROMISE) {
594 		key = afs_request_key(vnode->volume->cell);
595 		if (IS_ERR(key))
596 			return PTR_ERR(key);
597 		ret = afs_validate(vnode, key);
598 		key_put(key);
599 		if (ret < 0)
600 			return ret;
601 	}
602 
603 	do {
604 		seq = read_seqbegin(&vnode->cb_lock);
605 		generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
606 		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
607 		    stat->nlink > 0)
608 			stat->nlink -= 1;
609 
610 		/* Lie about the size of directories.  We maintain a locally
611 		 * edited copy and may make different allocation decisions on
612 		 * it, but we need to give userspace the server's size.
613 		 */
614 		if (S_ISDIR(inode->i_mode))
615 			stat->size = vnode->netfs.remote_i_size;
616 	} while (read_seqretry(&vnode->cb_lock, seq));
617 
618 	return 0;
619 }
620 
621 /*
622  * discard an AFS inode
623  */
624 int afs_drop_inode(struct inode *inode)
625 {
626 	_enter("");
627 
628 	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
629 		return generic_delete_inode(inode);
630 	else
631 		return generic_drop_inode(inode);
632 }
633 
634 /*
635  * clear an AFS inode
636  */
637 void afs_evict_inode(struct inode *inode)
638 {
639 	struct afs_vnode_cache_aux aux;
640 	struct afs_vnode *vnode = AFS_FS_I(inode);
641 
642 	_enter("{%llx:%llu.%d}",
643 	       vnode->fid.vid,
644 	       vnode->fid.vnode,
645 	       vnode->fid.unique);
646 
647 	_debug("CLEAR INODE %p", inode);
648 
649 	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
650 
651 	netfs_wait_for_outstanding_io(inode);
652 	truncate_inode_pages_final(&inode->i_data);
653 
654 	afs_set_cache_aux(vnode, &aux);
655 	netfs_clear_inode_writeback(inode, &aux);
656 	clear_inode(inode);
657 
658 	while (!list_empty(&vnode->wb_keys)) {
659 		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
660 						    struct afs_wb_key, vnode_link);
661 		list_del(&wbk->vnode_link);
662 		afs_put_wb_key(wbk);
663 	}
664 
665 	fscache_relinquish_cookie(afs_vnode_cache(vnode),
666 				  test_bit(AFS_VNODE_DELETED, &vnode->flags));
667 
668 	afs_prune_wb_keys(vnode);
669 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
670 	key_put(vnode->silly_key);
671 	vnode->silly_key = NULL;
672 	key_put(vnode->lock_key);
673 	vnode->lock_key = NULL;
674 	_leave("");
675 }
676 
677 static void afs_setattr_success(struct afs_operation *op)
678 {
679 	struct afs_vnode_param *vp = &op->file[0];
680 	struct inode *inode = &vp->vnode->netfs.inode;
681 	loff_t old_i_size = i_size_read(inode);
682 
683 	op->setattr.old_i_size = old_i_size;
684 	afs_vnode_commit_status(op, vp);
685 	/* inode->i_size has now been changed. */
686 
687 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
688 		loff_t size = op->setattr.attr->ia_size;
689 		if (size > old_i_size)
690 			pagecache_isize_extended(inode, old_i_size, size);
691 	}
692 }
693 
694 static void afs_setattr_edit_file(struct afs_operation *op)
695 {
696 	struct afs_vnode_param *vp = &op->file[0];
697 	struct afs_vnode *vnode = vp->vnode;
698 
699 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
700 		loff_t size = op->setattr.attr->ia_size;
701 		loff_t i_size = op->setattr.old_i_size;
702 
703 		if (size != i_size) {
704 			truncate_setsize(&vnode->netfs.inode, size);
705 			netfs_resize_file(&vnode->netfs, size, true);
706 			fscache_resize_cookie(afs_vnode_cache(vnode), size);
707 		}
708 	}
709 }
710 
711 static const struct afs_operation_ops afs_setattr_operation = {
712 	.issue_afs_rpc	= afs_fs_setattr,
713 	.issue_yfs_rpc	= yfs_fs_setattr,
714 	.success	= afs_setattr_success,
715 	.edit_dir	= afs_setattr_edit_file,
716 };
717 
718 /*
719  * set the attributes of an inode
720  */
721 int afs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
722 		struct iattr *attr)
723 {
724 	const unsigned int supported =
725 		ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
726 		ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET | ATTR_TOUCH;
727 	struct afs_operation *op;
728 	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
729 	struct inode *inode = &vnode->netfs.inode;
730 	loff_t i_size;
731 	int ret;
732 
733 	_enter("{%llx:%llu},{n=%pd},%x",
734 	       vnode->fid.vid, vnode->fid.vnode, dentry,
735 	       attr->ia_valid);
736 
737 	if (!(attr->ia_valid & supported)) {
738 		_leave(" = 0 [unsupported]");
739 		return 0;
740 	}
741 
742 	i_size = i_size_read(inode);
743 	if (attr->ia_valid & ATTR_SIZE) {
744 		if (!S_ISREG(inode->i_mode))
745 			return -EISDIR;
746 
747 		ret = inode_newsize_ok(inode, attr->ia_size);
748 		if (ret)
749 			return ret;
750 
751 		if (attr->ia_size == i_size)
752 			attr->ia_valid &= ~ATTR_SIZE;
753 	}
754 
755 	fscache_use_cookie(afs_vnode_cache(vnode), true);
756 
757 	/* Prevent any new writebacks from starting whilst we do this. */
758 	down_write(&vnode->validate_lock);
759 
760 	if ((attr->ia_valid & ATTR_SIZE) && S_ISREG(inode->i_mode)) {
761 		loff_t size = attr->ia_size;
762 
763 		/* Wait for any outstanding writes to the server to complete */
764 		loff_t from = min(size, i_size);
765 		loff_t to = max(size, i_size);
766 		ret = filemap_fdatawait_range(inode->i_mapping, from, to);
767 		if (ret < 0)
768 			goto out_unlock;
769 
770 		/* Don't talk to the server if we're just shortening in-memory
771 		 * writes that haven't gone to the server yet.
772 		 */
773 		if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
774 		    attr->ia_size < i_size &&
775 		    attr->ia_size > vnode->netfs.remote_i_size) {
776 			truncate_setsize(inode, attr->ia_size);
777 			netfs_resize_file(&vnode->netfs, size, false);
778 			fscache_resize_cookie(afs_vnode_cache(vnode),
779 					      attr->ia_size);
780 			ret = 0;
781 			goto out_unlock;
782 		}
783 	}
784 
785 	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
786 				  afs_file_key(attr->ia_file) : NULL),
787 				 vnode->volume);
788 	if (IS_ERR(op)) {
789 		ret = PTR_ERR(op);
790 		goto out_unlock;
791 	}
792 
793 	afs_op_set_vnode(op, 0, vnode);
794 	op->setattr.attr = attr;
795 
796 	if (attr->ia_valid & ATTR_SIZE) {
797 		op->file[0].dv_delta = 1;
798 		op->file[0].set_size = true;
799 	}
800 	op->ctime = attr->ia_ctime;
801 	op->file[0].update_ctime = 1;
802 	op->file[0].modification = true;
803 
804 	op->ops = &afs_setattr_operation;
805 	ret = afs_do_sync_operation(op);
806 
807 out_unlock:
808 	up_write(&vnode->validate_lock);
809 	fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
810 	_leave(" = %d", ret);
811 	return ret;
812 }
813