xref: /openbmc/linux/fs/afs/inode.c (revision fa0dadde)
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_break = op->cb_v_break;
89 	vnode->cb_s_break = op->cb_s_break;
90 	vnode->status = *status;
91 
92 	t = status->mtime_client;
93 	inode->i_ctime = t;
94 	inode->i_mtime = t;
95 	inode->i_atime = t;
96 	inode->i_flags |= S_NOATIME;
97 	inode->i_uid = make_kuid(&init_user_ns, status->owner);
98 	inode->i_gid = make_kgid(&init_user_ns, status->group);
99 	set_nlink(&vnode->netfs.inode, status->nlink);
100 
101 	switch (status->type) {
102 	case AFS_FTYPE_FILE:
103 		inode->i_mode	= S_IFREG | (status->mode & S_IALLUGO);
104 		inode->i_op	= &afs_file_inode_operations;
105 		inode->i_fop	= &afs_file_operations;
106 		inode->i_mapping->a_ops	= &afs_file_aops;
107 		mapping_set_large_folios(inode->i_mapping);
108 		break;
109 	case AFS_FTYPE_DIR:
110 		inode->i_mode	= S_IFDIR |  (status->mode & S_IALLUGO);
111 		inode->i_op	= &afs_dir_inode_operations;
112 		inode->i_fop	= &afs_dir_file_operations;
113 		inode->i_mapping->a_ops	= &afs_dir_aops;
114 		mapping_set_large_folios(inode->i_mapping);
115 		break;
116 	case AFS_FTYPE_SYMLINK:
117 		/* Symlinks with a mode of 0644 are actually mountpoints. */
118 		if ((status->mode & 0777) == 0644) {
119 			inode->i_flags |= S_AUTOMOUNT;
120 
121 			set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
122 
123 			inode->i_mode	= S_IFDIR | 0555;
124 			inode->i_op	= &afs_mntpt_inode_operations;
125 			inode->i_fop	= &afs_mntpt_file_operations;
126 			inode->i_mapping->a_ops	= &afs_symlink_aops;
127 		} else {
128 			inode->i_mode	= S_IFLNK | status->mode;
129 			inode->i_op	= &afs_symlink_inode_operations;
130 			inode->i_mapping->a_ops	= &afs_symlink_aops;
131 		}
132 		inode_nohighmem(inode);
133 		break;
134 	default:
135 		dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
136 		write_sequnlock(&vnode->cb_lock);
137 		return afs_protocol_error(NULL, afs_eproto_file_type);
138 	}
139 
140 	afs_set_i_size(vnode, status->size);
141 	afs_set_netfs_context(vnode);
142 
143 	vnode->invalid_before	= status->data_version;
144 	inode_set_iversion_raw(&vnode->netfs.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->netfs.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 & S_IALLUGO;
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 (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 	} else if (vnode->status.type == AFS_FTYPE_DIR) {
235 		/* Expected directory change is handled elsewhere so
236 		 * that we can locally edit the directory and save on a
237 		 * download.
238 		 */
239 		if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
240 			data_changed = false;
241 		change_size = true;
242 	}
243 
244 	if (data_changed) {
245 		inode_set_iversion_raw(inode, status->data_version);
246 
247 		/* Only update the size if the data version jumped.  If the
248 		 * file is being modified locally, then we might have our own
249 		 * idea of what the size should be that's not the same as
250 		 * what's on the server.
251 		 */
252 		vnode->netfs.remote_i_size = status->size;
253 		if (change_size) {
254 			afs_set_i_size(vnode, status->size);
255 			inode->i_ctime = t;
256 			inode->i_atime = t;
257 		}
258 	}
259 }
260 
261 /*
262  * Apply a callback to a vnode.
263  */
264 static void afs_apply_callback(struct afs_operation *op,
265 			       struct afs_vnode_param *vp)
266 {
267 	struct afs_callback *cb = &vp->scb.callback;
268 	struct afs_vnode *vnode = vp->vnode;
269 
270 	if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
271 		vnode->cb_expires_at	= cb->expires_at;
272 		vnode->cb_server	= op->server;
273 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
274 	}
275 }
276 
277 /*
278  * Apply the received status and callback to an inode all in the same critical
279  * section to avoid races with afs_validate().
280  */
281 void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
282 {
283 	struct afs_vnode *vnode = vp->vnode;
284 
285 	_enter("");
286 
287 	write_seqlock(&vnode->cb_lock);
288 
289 	if (vp->scb.have_error) {
290 		/* A YFS server will return this from RemoveFile2 and AFS and
291 		 * YFS will return this from InlineBulkStatus.
292 		 */
293 		if (vp->scb.status.abort_code == VNOVNODE) {
294 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
295 			clear_nlink(&vnode->netfs.inode);
296 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
297 			op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
298 		}
299 	} else if (vp->scb.have_status) {
300 		if (vp->speculative &&
301 		    (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
302 		     vp->dv_before != vnode->status.data_version))
303 			/* Ignore the result of a speculative bulk status fetch
304 			 * if it splits around a modification op, thereby
305 			 * appearing to regress the data version.
306 			 */
307 			goto out;
308 		afs_apply_status(op, vp);
309 		if (vp->scb.have_cb)
310 			afs_apply_callback(op, vp);
311 	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
312 		drop_nlink(&vnode->netfs.inode);
313 		if (vnode->netfs.inode.i_nlink == 0) {
314 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
315 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
316 		}
317 	}
318 
319 out:
320 	write_sequnlock(&vnode->cb_lock);
321 
322 	if (vp->scb.have_status)
323 		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
324 }
325 
326 static void afs_fetch_status_success(struct afs_operation *op)
327 {
328 	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
329 	struct afs_vnode *vnode = vp->vnode;
330 	int ret;
331 
332 	if (vnode->netfs.inode.i_state & I_NEW) {
333 		ret = afs_inode_init_from_status(op, vp, vnode);
334 		op->error = ret;
335 		if (ret == 0)
336 			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
337 	} else {
338 		afs_vnode_commit_status(op, vp);
339 	}
340 }
341 
342 const struct afs_operation_ops afs_fetch_status_operation = {
343 	.issue_afs_rpc	= afs_fs_fetch_status,
344 	.issue_yfs_rpc	= yfs_fs_fetch_status,
345 	.success	= afs_fetch_status_success,
346 	.aborted	= afs_check_for_remote_deletion,
347 };
348 
349 /*
350  * Fetch file status from the volume.
351  */
352 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
353 		     afs_access_t *_caller_access)
354 {
355 	struct afs_operation *op;
356 
357 	_enter("%s,{%llx:%llu.%u,S=%lx}",
358 	       vnode->volume->name,
359 	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
360 	       vnode->flags);
361 
362 	op = afs_alloc_operation(key, vnode->volume);
363 	if (IS_ERR(op))
364 		return PTR_ERR(op);
365 
366 	afs_op_set_vnode(op, 0, vnode);
367 
368 	op->nr_files	= 1;
369 	op->ops		= &afs_fetch_status_operation;
370 	afs_begin_vnode_operation(op);
371 	afs_wait_for_operation(op);
372 
373 	if (_caller_access)
374 		*_caller_access = op->file[0].scb.status.caller_access;
375 	return afs_put_operation(op);
376 }
377 
378 /*
379  * ilookup() comparator
380  */
381 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
382 {
383 	struct afs_vnode *vnode = AFS_FS_I(inode);
384 	struct afs_fid *fid = opaque;
385 
386 	return (fid->vnode == vnode->fid.vnode &&
387 		fid->vnode_hi == vnode->fid.vnode_hi &&
388 		fid->unique == vnode->fid.unique);
389 }
390 
391 /*
392  * iget5() comparator
393  */
394 static int afs_iget5_test(struct inode *inode, void *opaque)
395 {
396 	struct afs_vnode_param *vp = opaque;
397 	//struct afs_vnode *vnode = AFS_FS_I(inode);
398 
399 	return afs_ilookup5_test_by_fid(inode, &vp->fid);
400 }
401 
402 /*
403  * iget5() inode initialiser
404  */
405 static int afs_iget5_set(struct inode *inode, void *opaque)
406 {
407 	struct afs_vnode_param *vp = opaque;
408 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
409 	struct afs_vnode *vnode = AFS_FS_I(inode);
410 
411 	vnode->volume		= as->volume;
412 	vnode->fid		= vp->fid;
413 
414 	/* YFS supports 96-bit vnode IDs, but Linux only supports
415 	 * 64-bit inode numbers.
416 	 */
417 	inode->i_ino		= vnode->fid.vnode;
418 	inode->i_generation	= vnode->fid.unique;
419 	return 0;
420 }
421 
422 /*
423  * Get a cache cookie for an inode.
424  */
425 static void afs_get_inode_cache(struct afs_vnode *vnode)
426 {
427 #ifdef CONFIG_AFS_FSCACHE
428 	struct {
429 		__be32 vnode_id;
430 		__be32 unique;
431 		__be32 vnode_id_ext[2];	/* Allow for a 96-bit key */
432 	} __packed key;
433 	struct afs_vnode_cache_aux aux;
434 
435 	if (vnode->status.type != AFS_FTYPE_FILE) {
436 		vnode->netfs.cache = NULL;
437 		return;
438 	}
439 
440 	key.vnode_id		= htonl(vnode->fid.vnode);
441 	key.unique		= htonl(vnode->fid.unique);
442 	key.vnode_id_ext[0]	= htonl(vnode->fid.vnode >> 32);
443 	key.vnode_id_ext[1]	= htonl(vnode->fid.vnode_hi);
444 	afs_set_cache_aux(vnode, &aux);
445 
446 	afs_vnode_set_cache(vnode,
447 			    fscache_acquire_cookie(
448 				    vnode->volume->cache,
449 				    vnode->status.type == AFS_FTYPE_FILE ?
450 				    0 : FSCACHE_ADV_SINGLE_CHUNK,
451 				    &key, sizeof(key),
452 				    &aux, sizeof(aux),
453 				    i_size_read(&vnode->netfs.inode)));
454 #endif
455 }
456 
457 /*
458  * inode retrieval
459  */
460 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
461 {
462 	struct afs_vnode_param *dvp = &op->file[0];
463 	struct super_block *sb = dvp->vnode->netfs.inode.i_sb;
464 	struct afs_vnode *vnode;
465 	struct inode *inode;
466 	int ret;
467 
468 	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
469 
470 	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
471 	if (!inode) {
472 		_leave(" = -ENOMEM");
473 		return ERR_PTR(-ENOMEM);
474 	}
475 
476 	vnode = AFS_FS_I(inode);
477 
478 	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
479 	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
480 
481 	/* deal with an existing inode */
482 	if (!(inode->i_state & I_NEW)) {
483 		_leave(" = %p", inode);
484 		return inode;
485 	}
486 
487 	ret = afs_inode_init_from_status(op, vp, vnode);
488 	if (ret < 0)
489 		goto bad_inode;
490 
491 	afs_get_inode_cache(vnode);
492 
493 	/* success */
494 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
495 	unlock_new_inode(inode);
496 	_leave(" = %p", inode);
497 	return inode;
498 
499 	/* failure */
500 bad_inode:
501 	iget_failed(inode);
502 	_leave(" = %d [bad]", ret);
503 	return ERR_PTR(ret);
504 }
505 
506 static int afs_iget5_set_root(struct inode *inode, void *opaque)
507 {
508 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
509 	struct afs_vnode *vnode = AFS_FS_I(inode);
510 
511 	vnode->volume		= as->volume;
512 	vnode->fid.vid		= as->volume->vid,
513 	vnode->fid.vnode	= 1;
514 	vnode->fid.unique	= 1;
515 	inode->i_ino		= 1;
516 	inode->i_generation	= 1;
517 	return 0;
518 }
519 
520 /*
521  * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
522  * the volume.
523  */
524 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
525 {
526 	struct afs_super_info *as = AFS_FS_S(sb);
527 	struct afs_operation *op;
528 	struct afs_vnode *vnode;
529 	struct inode *inode;
530 	int ret;
531 
532 	_enter(",{%llx},,", as->volume->vid);
533 
534 	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
535 	if (!inode) {
536 		_leave(" = -ENOMEM");
537 		return ERR_PTR(-ENOMEM);
538 	}
539 
540 	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
541 
542 	BUG_ON(!(inode->i_state & I_NEW));
543 
544 	vnode = AFS_FS_I(inode);
545 	vnode->cb_v_break = as->volume->cb_v_break,
546 	afs_set_netfs_context(vnode);
547 
548 	op = afs_alloc_operation(key, as->volume);
549 	if (IS_ERR(op)) {
550 		ret = PTR_ERR(op);
551 		goto error;
552 	}
553 
554 	afs_op_set_vnode(op, 0, vnode);
555 
556 	op->nr_files	= 1;
557 	op->ops		= &afs_fetch_status_operation;
558 	ret = afs_do_sync_operation(op);
559 	if (ret < 0)
560 		goto error;
561 
562 	afs_get_inode_cache(vnode);
563 
564 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
565 	unlock_new_inode(inode);
566 	_leave(" = %p", inode);
567 	return inode;
568 
569 error:
570 	iget_failed(inode);
571 	_leave(" = %d [bad]", ret);
572 	return ERR_PTR(ret);
573 }
574 
575 /*
576  * mark the data attached to an inode as obsolete due to a write on the server
577  * - might also want to ditch all the outstanding writes and dirty pages
578  */
579 static void afs_zap_data(struct afs_vnode *vnode)
580 {
581 	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
582 
583 	afs_invalidate_cache(vnode, 0);
584 
585 	/* nuke all the non-dirty pages that aren't locked, mapped or being
586 	 * written back in a regular file and completely discard the pages in a
587 	 * directory or symlink */
588 	if (S_ISREG(vnode->netfs.inode.i_mode))
589 		invalidate_remote_inode(&vnode->netfs.inode);
590 	else
591 		invalidate_inode_pages2(vnode->netfs.inode.i_mapping);
592 }
593 
594 /*
595  * Check to see if we have a server currently serving this volume and that it
596  * hasn't been reinitialised or dropped from the list.
597  */
598 static bool afs_check_server_good(struct afs_vnode *vnode)
599 {
600 	struct afs_server_list *slist;
601 	struct afs_server *server;
602 	bool good;
603 	int i;
604 
605 	if (vnode->cb_fs_s_break == atomic_read(&vnode->volume->cell->fs_s_break))
606 		return true;
607 
608 	rcu_read_lock();
609 
610 	slist = rcu_dereference(vnode->volume->servers);
611 	for (i = 0; i < slist->nr_servers; i++) {
612 		server = slist->servers[i].server;
613 		if (server == vnode->cb_server) {
614 			good = (vnode->cb_s_break == server->cb_s_break);
615 			rcu_read_unlock();
616 			return good;
617 		}
618 	}
619 
620 	rcu_read_unlock();
621 	return false;
622 }
623 
624 /*
625  * Check the validity of a vnode/inode.
626  */
627 bool afs_check_validity(struct afs_vnode *vnode)
628 {
629 	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
630 	time64_t now = ktime_get_real_seconds();
631 	unsigned int cb_break;
632 	int seq = 0;
633 
634 	do {
635 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
636 		cb_break = vnode->cb_break;
637 
638 		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
639 			if (vnode->cb_v_break != vnode->volume->cb_v_break)
640 				need_clear = afs_cb_break_for_v_break;
641 			else if (!afs_check_server_good(vnode))
642 				need_clear = afs_cb_break_for_s_reinit;
643 			else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
644 				need_clear = afs_cb_break_for_zap;
645 			else if (vnode->cb_expires_at - 10 <= now)
646 				need_clear = afs_cb_break_for_lapsed;
647 		} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
648 			;
649 		} else {
650 			need_clear = afs_cb_break_no_promise;
651 		}
652 
653 	} while (need_seqretry(&vnode->cb_lock, seq));
654 
655 	done_seqretry(&vnode->cb_lock, seq);
656 
657 	if (need_clear == afs_cb_break_no_break)
658 		return true;
659 
660 	write_seqlock(&vnode->cb_lock);
661 	if (need_clear == afs_cb_break_no_promise)
662 		vnode->cb_v_break = vnode->volume->cb_v_break;
663 	else if (cb_break == vnode->cb_break)
664 		__afs_break_callback(vnode, need_clear);
665 	else
666 		trace_afs_cb_miss(&vnode->fid, need_clear);
667 	write_sequnlock(&vnode->cb_lock);
668 	return false;
669 }
670 
671 /*
672  * Returns true if the pagecache is still valid.  Does not sleep.
673  */
674 bool afs_pagecache_valid(struct afs_vnode *vnode)
675 {
676 	if (unlikely(test_bit(AFS_VNODE_DELETED, &vnode->flags))) {
677 		if (vnode->netfs.inode.i_nlink)
678 			clear_nlink(&vnode->netfs.inode);
679 		return true;
680 	}
681 
682 	if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
683 	    afs_check_validity(vnode))
684 		return true;
685 
686 	return false;
687 }
688 
689 /*
690  * validate a vnode/inode
691  * - there are several things we need to check
692  *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
693  *     symlink)
694  *   - parent dir metadata changed (security changes)
695  *   - dentry data changed (write, truncate)
696  *   - dentry metadata changed (security changes)
697  */
698 int afs_validate(struct afs_vnode *vnode, struct key *key)
699 {
700 	int ret;
701 
702 	_enter("{v={%llx:%llu} fl=%lx},%x",
703 	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
704 	       key_serial(key));
705 
706 	if (afs_pagecache_valid(vnode))
707 		goto valid;
708 
709 	down_write(&vnode->validate_lock);
710 
711 	/* if the promise has expired, we need to check the server again to get
712 	 * a new promise - note that if the (parent) directory's metadata was
713 	 * changed then the security may be different and we may no longer have
714 	 * access */
715 	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
716 		_debug("not promised");
717 		ret = afs_fetch_status(vnode, key, false, NULL);
718 		if (ret < 0) {
719 			if (ret == -ENOENT) {
720 				set_bit(AFS_VNODE_DELETED, &vnode->flags);
721 				ret = -ESTALE;
722 			}
723 			goto error_unlock;
724 		}
725 		_debug("new promise [fl=%lx]", vnode->flags);
726 	}
727 
728 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
729 		_debug("file already deleted");
730 		ret = -ESTALE;
731 		goto error_unlock;
732 	}
733 
734 	/* if the vnode's data version number changed then its contents are
735 	 * different */
736 	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
737 		afs_zap_data(vnode);
738 	up_write(&vnode->validate_lock);
739 valid:
740 	_leave(" = 0");
741 	return 0;
742 
743 error_unlock:
744 	up_write(&vnode->validate_lock);
745 	_leave(" = %d", ret);
746 	return ret;
747 }
748 
749 /*
750  * read the attributes of an inode
751  */
752 int afs_getattr(struct mnt_idmap *idmap, const struct path *path,
753 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
754 {
755 	struct inode *inode = d_inode(path->dentry);
756 	struct afs_vnode *vnode = AFS_FS_I(inode);
757 	struct key *key;
758 	int ret, seq = 0;
759 
760 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
761 
762 	if (vnode->volume &&
763 	    !(query_flags & AT_STATX_DONT_SYNC) &&
764 	    !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
765 		key = afs_request_key(vnode->volume->cell);
766 		if (IS_ERR(key))
767 			return PTR_ERR(key);
768 		ret = afs_validate(vnode, key);
769 		key_put(key);
770 		if (ret < 0)
771 			return ret;
772 	}
773 
774 	do {
775 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
776 		generic_fillattr(&nop_mnt_idmap, inode, stat);
777 		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
778 		    stat->nlink > 0)
779 			stat->nlink -= 1;
780 
781 		/* Lie about the size of directories.  We maintain a locally
782 		 * edited copy and may make different allocation decisions on
783 		 * it, but we need to give userspace the server's size.
784 		 */
785 		if (S_ISDIR(inode->i_mode))
786 			stat->size = vnode->netfs.remote_i_size;
787 	} while (need_seqretry(&vnode->cb_lock, seq));
788 
789 	done_seqretry(&vnode->cb_lock, seq);
790 	return 0;
791 }
792 
793 /*
794  * discard an AFS inode
795  */
796 int afs_drop_inode(struct inode *inode)
797 {
798 	_enter("");
799 
800 	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
801 		return generic_delete_inode(inode);
802 	else
803 		return generic_drop_inode(inode);
804 }
805 
806 /*
807  * clear an AFS inode
808  */
809 void afs_evict_inode(struct inode *inode)
810 {
811 	struct afs_vnode_cache_aux aux;
812 	struct afs_vnode *vnode = AFS_FS_I(inode);
813 
814 	_enter("{%llx:%llu.%d}",
815 	       vnode->fid.vid,
816 	       vnode->fid.vnode,
817 	       vnode->fid.unique);
818 
819 	_debug("CLEAR INODE %p", inode);
820 
821 	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
822 
823 	truncate_inode_pages_final(&inode->i_data);
824 
825 	afs_set_cache_aux(vnode, &aux);
826 	fscache_clear_inode_writeback(afs_vnode_cache(vnode), inode, &aux);
827 	clear_inode(inode);
828 
829 	while (!list_empty(&vnode->wb_keys)) {
830 		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
831 						    struct afs_wb_key, vnode_link);
832 		list_del(&wbk->vnode_link);
833 		afs_put_wb_key(wbk);
834 	}
835 
836 	fscache_relinquish_cookie(afs_vnode_cache(vnode),
837 				  test_bit(AFS_VNODE_DELETED, &vnode->flags));
838 
839 	afs_prune_wb_keys(vnode);
840 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
841 	key_put(vnode->silly_key);
842 	vnode->silly_key = NULL;
843 	key_put(vnode->lock_key);
844 	vnode->lock_key = NULL;
845 	_leave("");
846 }
847 
848 static void afs_setattr_success(struct afs_operation *op)
849 {
850 	struct afs_vnode_param *vp = &op->file[0];
851 	struct inode *inode = &vp->vnode->netfs.inode;
852 	loff_t old_i_size = i_size_read(inode);
853 
854 	op->setattr.old_i_size = old_i_size;
855 	afs_vnode_commit_status(op, vp);
856 	/* inode->i_size has now been changed. */
857 
858 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
859 		loff_t size = op->setattr.attr->ia_size;
860 		if (size > old_i_size)
861 			pagecache_isize_extended(inode, old_i_size, size);
862 	}
863 }
864 
865 static void afs_setattr_edit_file(struct afs_operation *op)
866 {
867 	struct afs_vnode_param *vp = &op->file[0];
868 	struct inode *inode = &vp->vnode->netfs.inode;
869 
870 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
871 		loff_t size = op->setattr.attr->ia_size;
872 		loff_t i_size = op->setattr.old_i_size;
873 
874 		if (size < i_size)
875 			truncate_pagecache(inode, size);
876 		if (size != i_size)
877 			fscache_resize_cookie(afs_vnode_cache(vp->vnode),
878 					      vp->scb.status.size);
879 	}
880 }
881 
882 static const struct afs_operation_ops afs_setattr_operation = {
883 	.issue_afs_rpc	= afs_fs_setattr,
884 	.issue_yfs_rpc	= yfs_fs_setattr,
885 	.success	= afs_setattr_success,
886 	.edit_dir	= afs_setattr_edit_file,
887 };
888 
889 /*
890  * set the attributes of an inode
891  */
892 int afs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
893 		struct iattr *attr)
894 {
895 	const unsigned int supported =
896 		ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
897 		ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET | ATTR_TOUCH;
898 	struct afs_operation *op;
899 	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
900 	struct inode *inode = &vnode->netfs.inode;
901 	loff_t i_size;
902 	int ret;
903 
904 	_enter("{%llx:%llu},{n=%pd},%x",
905 	       vnode->fid.vid, vnode->fid.vnode, dentry,
906 	       attr->ia_valid);
907 
908 	if (!(attr->ia_valid & supported)) {
909 		_leave(" = 0 [unsupported]");
910 		return 0;
911 	}
912 
913 	i_size = i_size_read(inode);
914 	if (attr->ia_valid & ATTR_SIZE) {
915 		if (!S_ISREG(inode->i_mode))
916 			return -EISDIR;
917 
918 		ret = inode_newsize_ok(inode, attr->ia_size);
919 		if (ret)
920 			return ret;
921 
922 		if (attr->ia_size == i_size)
923 			attr->ia_valid &= ~ATTR_SIZE;
924 	}
925 
926 	fscache_use_cookie(afs_vnode_cache(vnode), true);
927 
928 	/* Prevent any new writebacks from starting whilst we do this. */
929 	down_write(&vnode->validate_lock);
930 
931 	if ((attr->ia_valid & ATTR_SIZE) && S_ISREG(inode->i_mode)) {
932 		loff_t size = attr->ia_size;
933 
934 		/* Wait for any outstanding writes to the server to complete */
935 		loff_t from = min(size, i_size);
936 		loff_t to = max(size, i_size);
937 		ret = filemap_fdatawait_range(inode->i_mapping, from, to);
938 		if (ret < 0)
939 			goto out_unlock;
940 
941 		/* Don't talk to the server if we're just shortening in-memory
942 		 * writes that haven't gone to the server yet.
943 		 */
944 		if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
945 		    attr->ia_size < i_size &&
946 		    attr->ia_size > vnode->status.size) {
947 			truncate_pagecache(inode, attr->ia_size);
948 			fscache_resize_cookie(afs_vnode_cache(vnode),
949 					      attr->ia_size);
950 			i_size_write(inode, attr->ia_size);
951 			ret = 0;
952 			goto out_unlock;
953 		}
954 	}
955 
956 	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
957 				  afs_file_key(attr->ia_file) : NULL),
958 				 vnode->volume);
959 	if (IS_ERR(op)) {
960 		ret = PTR_ERR(op);
961 		goto out_unlock;
962 	}
963 
964 	afs_op_set_vnode(op, 0, vnode);
965 	op->setattr.attr = attr;
966 
967 	if (attr->ia_valid & ATTR_SIZE) {
968 		op->file[0].dv_delta = 1;
969 		op->file[0].set_size = true;
970 	}
971 	op->ctime = attr->ia_ctime;
972 	op->file[0].update_ctime = 1;
973 	op->file[0].modification = true;
974 
975 	op->ops = &afs_setattr_operation;
976 	ret = afs_do_sync_operation(op);
977 
978 out_unlock:
979 	up_write(&vnode->validate_lock);
980 	fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
981 	_leave(" = %d", ret);
982 	return ret;
983 }
984