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 
dump_vnode(struct afs_vnode * vnode,struct afs_vnode * parent_vnode)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  */
afs_set_netfs_context(struct afs_vnode * vnode)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  */
afs_inode_init_from_status(struct afs_operation * op,struct afs_vnode_param * vp,struct afs_vnode * vnode)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 		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 		break;
114 	case AFS_FTYPE_SYMLINK:
115 		/* Symlinks with a mode of 0644 are actually mountpoints. */
116 		if ((status->mode & 0777) == 0644) {
117 			inode->i_flags |= S_AUTOMOUNT;
118 
119 			set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
120 
121 			inode->i_mode	= S_IFDIR | 0555;
122 			inode->i_op	= &afs_mntpt_inode_operations;
123 			inode->i_fop	= &afs_mntpt_file_operations;
124 			inode->i_mapping->a_ops	= &afs_symlink_aops;
125 		} else {
126 			inode->i_mode	= S_IFLNK | status->mode;
127 			inode->i_op	= &afs_symlink_inode_operations;
128 			inode->i_mapping->a_ops	= &afs_symlink_aops;
129 		}
130 		inode_nohighmem(inode);
131 		break;
132 	default:
133 		dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
134 		write_sequnlock(&vnode->cb_lock);
135 		return afs_protocol_error(NULL, afs_eproto_file_type);
136 	}
137 
138 	afs_set_i_size(vnode, status->size);
139 	afs_set_netfs_context(vnode);
140 
141 	vnode->invalid_before	= status->data_version;
142 	inode_set_iversion_raw(&vnode->netfs.inode, status->data_version);
143 
144 	if (!vp->scb.have_cb) {
145 		/* it's a symlink we just created (the fileserver
146 		 * didn't give us a callback) */
147 		vnode->cb_expires_at = ktime_get_real_seconds();
148 	} else {
149 		vnode->cb_expires_at = vp->scb.callback.expires_at;
150 		vnode->cb_server = op->server;
151 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
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  */
afs_apply_status(struct afs_operation * op,struct afs_vnode_param * vp)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->i_mtime = t;
206 	if (vp->update_ctime)
207 		inode->i_ctime = 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 (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
216 			pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s (op=%x)\n",
217 				vnode->fid.vid, vnode->fid.vnode,
218 				(unsigned long long)vp->dv_before + vp->dv_delta,
219 				(unsigned long long)status->data_version,
220 				op->type ? op->type->name : "???",
221 				op->debug_id);
222 
223 		vnode->invalid_before = status->data_version;
224 		if (vnode->status.type == AFS_FTYPE_DIR) {
225 			if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
226 				afs_stat_v(vnode, n_inval);
227 		} else {
228 			set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
229 		}
230 		change_size = true;
231 	} else if (vnode->status.type == AFS_FTYPE_DIR) {
232 		/* Expected directory change is handled elsewhere so
233 		 * that we can locally edit the directory and save on a
234 		 * download.
235 		 */
236 		if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
237 			data_changed = false;
238 		change_size = true;
239 	}
240 
241 	if (data_changed) {
242 		inode_set_iversion_raw(inode, status->data_version);
243 
244 		/* Only update the size if the data version jumped.  If the
245 		 * file is being modified locally, then we might have our own
246 		 * idea of what the size should be that's not the same as
247 		 * what's on the server.
248 		 */
249 		vnode->netfs.remote_i_size = status->size;
250 		if (change_size) {
251 			afs_set_i_size(vnode, status->size);
252 			inode->i_ctime = t;
253 			inode->i_atime = t;
254 		}
255 	}
256 }
257 
258 /*
259  * Apply a callback to a vnode.
260  */
afs_apply_callback(struct afs_operation * op,struct afs_vnode_param * vp)261 static void afs_apply_callback(struct afs_operation *op,
262 			       struct afs_vnode_param *vp)
263 {
264 	struct afs_callback *cb = &vp->scb.callback;
265 	struct afs_vnode *vnode = vp->vnode;
266 
267 	if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
268 		vnode->cb_expires_at	= cb->expires_at;
269 		vnode->cb_server	= op->server;
270 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
271 	}
272 }
273 
274 /*
275  * Apply the received status and callback to an inode all in the same critical
276  * section to avoid races with afs_validate().
277  */
afs_vnode_commit_status(struct afs_operation * op,struct afs_vnode_param * vp)278 void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
279 {
280 	struct afs_vnode *vnode = vp->vnode;
281 
282 	_enter("");
283 
284 	write_seqlock(&vnode->cb_lock);
285 
286 	if (vp->scb.have_error) {
287 		/* A YFS server will return this from RemoveFile2 and AFS and
288 		 * YFS will return this from InlineBulkStatus.
289 		 */
290 		if (vp->scb.status.abort_code == VNOVNODE) {
291 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
292 			clear_nlink(&vnode->netfs.inode);
293 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
294 			op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
295 		}
296 	} else if (vp->scb.have_status) {
297 		if (vp->speculative &&
298 		    (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
299 		     vp->dv_before != vnode->status.data_version))
300 			/* Ignore the result of a speculative bulk status fetch
301 			 * if it splits around a modification op, thereby
302 			 * appearing to regress the data version.
303 			 */
304 			goto out;
305 		afs_apply_status(op, vp);
306 		if (vp->scb.have_cb)
307 			afs_apply_callback(op, vp);
308 	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
309 		drop_nlink(&vnode->netfs.inode);
310 		if (vnode->netfs.inode.i_nlink == 0) {
311 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
312 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
313 		}
314 	}
315 
316 out:
317 	write_sequnlock(&vnode->cb_lock);
318 
319 	if (vp->scb.have_status)
320 		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
321 }
322 
afs_fetch_status_success(struct afs_operation * op)323 static void afs_fetch_status_success(struct afs_operation *op)
324 {
325 	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
326 	struct afs_vnode *vnode = vp->vnode;
327 	int ret;
328 
329 	if (vnode->netfs.inode.i_state & I_NEW) {
330 		ret = afs_inode_init_from_status(op, vp, vnode);
331 		op->error = ret;
332 		if (ret == 0)
333 			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
334 	} else {
335 		afs_vnode_commit_status(op, vp);
336 	}
337 }
338 
339 const struct afs_operation_ops afs_fetch_status_operation = {
340 	.issue_afs_rpc	= afs_fs_fetch_status,
341 	.issue_yfs_rpc	= yfs_fs_fetch_status,
342 	.success	= afs_fetch_status_success,
343 	.aborted	= afs_check_for_remote_deletion,
344 };
345 
346 /*
347  * Fetch file status from the volume.
348  */
afs_fetch_status(struct afs_vnode * vnode,struct key * key,bool is_new,afs_access_t * _caller_access)349 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
350 		     afs_access_t *_caller_access)
351 {
352 	struct afs_operation *op;
353 
354 	_enter("%s,{%llx:%llu.%u,S=%lx}",
355 	       vnode->volume->name,
356 	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
357 	       vnode->flags);
358 
359 	op = afs_alloc_operation(key, vnode->volume);
360 	if (IS_ERR(op))
361 		return PTR_ERR(op);
362 
363 	afs_op_set_vnode(op, 0, vnode);
364 
365 	op->nr_files	= 1;
366 	op->ops		= &afs_fetch_status_operation;
367 	afs_begin_vnode_operation(op);
368 	afs_wait_for_operation(op);
369 
370 	if (_caller_access)
371 		*_caller_access = op->file[0].scb.status.caller_access;
372 	return afs_put_operation(op);
373 }
374 
375 /*
376  * ilookup() comparator
377  */
afs_ilookup5_test_by_fid(struct inode * inode,void * opaque)378 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
379 {
380 	struct afs_vnode *vnode = AFS_FS_I(inode);
381 	struct afs_fid *fid = opaque;
382 
383 	return (fid->vnode == vnode->fid.vnode &&
384 		fid->vnode_hi == vnode->fid.vnode_hi &&
385 		fid->unique == vnode->fid.unique);
386 }
387 
388 /*
389  * iget5() comparator
390  */
afs_iget5_test(struct inode * inode,void * opaque)391 static int afs_iget5_test(struct inode *inode, void *opaque)
392 {
393 	struct afs_vnode_param *vp = opaque;
394 	//struct afs_vnode *vnode = AFS_FS_I(inode);
395 
396 	return afs_ilookup5_test_by_fid(inode, &vp->fid);
397 }
398 
399 /*
400  * iget5() inode initialiser
401  */
afs_iget5_set(struct inode * inode,void * opaque)402 static int afs_iget5_set(struct inode *inode, void *opaque)
403 {
404 	struct afs_vnode_param *vp = opaque;
405 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
406 	struct afs_vnode *vnode = AFS_FS_I(inode);
407 
408 	vnode->volume		= as->volume;
409 	vnode->fid		= vp->fid;
410 
411 	/* YFS supports 96-bit vnode IDs, but Linux only supports
412 	 * 64-bit inode numbers.
413 	 */
414 	inode->i_ino		= vnode->fid.vnode;
415 	inode->i_generation	= vnode->fid.unique;
416 	return 0;
417 }
418 
419 /*
420  * Get a cache cookie for an inode.
421  */
afs_get_inode_cache(struct afs_vnode * vnode)422 static void afs_get_inode_cache(struct afs_vnode *vnode)
423 {
424 #ifdef CONFIG_AFS_FSCACHE
425 	struct {
426 		__be32 vnode_id;
427 		__be32 unique;
428 		__be32 vnode_id_ext[2];	/* Allow for a 96-bit key */
429 	} __packed key;
430 	struct afs_vnode_cache_aux aux;
431 
432 	if (vnode->status.type != AFS_FTYPE_FILE) {
433 		vnode->netfs.cache = NULL;
434 		return;
435 	}
436 
437 	key.vnode_id		= htonl(vnode->fid.vnode);
438 	key.unique		= htonl(vnode->fid.unique);
439 	key.vnode_id_ext[0]	= htonl(vnode->fid.vnode >> 32);
440 	key.vnode_id_ext[1]	= htonl(vnode->fid.vnode_hi);
441 	afs_set_cache_aux(vnode, &aux);
442 
443 	afs_vnode_set_cache(vnode,
444 			    fscache_acquire_cookie(
445 				    vnode->volume->cache,
446 				    vnode->status.type == AFS_FTYPE_FILE ?
447 				    0 : FSCACHE_ADV_SINGLE_CHUNK,
448 				    &key, sizeof(key),
449 				    &aux, sizeof(aux),
450 				    vnode->status.size));
451 #endif
452 }
453 
454 /*
455  * inode retrieval
456  */
afs_iget(struct afs_operation * op,struct afs_vnode_param * vp)457 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
458 {
459 	struct afs_vnode_param *dvp = &op->file[0];
460 	struct super_block *sb = dvp->vnode->netfs.inode.i_sb;
461 	struct afs_vnode *vnode;
462 	struct inode *inode;
463 	int ret;
464 
465 	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
466 
467 	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
468 	if (!inode) {
469 		_leave(" = -ENOMEM");
470 		return ERR_PTR(-ENOMEM);
471 	}
472 
473 	vnode = AFS_FS_I(inode);
474 
475 	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
476 	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
477 
478 	/* deal with an existing inode */
479 	if (!(inode->i_state & I_NEW)) {
480 		_leave(" = %p", inode);
481 		return inode;
482 	}
483 
484 	ret = afs_inode_init_from_status(op, vp, vnode);
485 	if (ret < 0)
486 		goto bad_inode;
487 
488 	afs_get_inode_cache(vnode);
489 
490 	/* success */
491 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
492 	unlock_new_inode(inode);
493 	_leave(" = %p", inode);
494 	return inode;
495 
496 	/* failure */
497 bad_inode:
498 	iget_failed(inode);
499 	_leave(" = %d [bad]", ret);
500 	return ERR_PTR(ret);
501 }
502 
afs_iget5_set_root(struct inode * inode,void * opaque)503 static int afs_iget5_set_root(struct inode *inode, void *opaque)
504 {
505 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
506 	struct afs_vnode *vnode = AFS_FS_I(inode);
507 
508 	vnode->volume		= as->volume;
509 	vnode->fid.vid		= as->volume->vid,
510 	vnode->fid.vnode	= 1;
511 	vnode->fid.unique	= 1;
512 	inode->i_ino		= 1;
513 	inode->i_generation	= 1;
514 	return 0;
515 }
516 
517 /*
518  * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
519  * the volume.
520  */
afs_root_iget(struct super_block * sb,struct key * key)521 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
522 {
523 	struct afs_super_info *as = AFS_FS_S(sb);
524 	struct afs_operation *op;
525 	struct afs_vnode *vnode;
526 	struct inode *inode;
527 	int ret;
528 
529 	_enter(",{%llx},,", as->volume->vid);
530 
531 	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
532 	if (!inode) {
533 		_leave(" = -ENOMEM");
534 		return ERR_PTR(-ENOMEM);
535 	}
536 
537 	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
538 
539 	BUG_ON(!(inode->i_state & I_NEW));
540 
541 	vnode = AFS_FS_I(inode);
542 	vnode->cb_v_break = as->volume->cb_v_break,
543 	afs_set_netfs_context(vnode);
544 
545 	op = afs_alloc_operation(key, as->volume);
546 	if (IS_ERR(op)) {
547 		ret = PTR_ERR(op);
548 		goto error;
549 	}
550 
551 	afs_op_set_vnode(op, 0, vnode);
552 
553 	op->nr_files	= 1;
554 	op->ops		= &afs_fetch_status_operation;
555 	ret = afs_do_sync_operation(op);
556 	if (ret < 0)
557 		goto error;
558 
559 	afs_get_inode_cache(vnode);
560 
561 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
562 	unlock_new_inode(inode);
563 	_leave(" = %p", inode);
564 	return inode;
565 
566 error:
567 	iget_failed(inode);
568 	_leave(" = %d [bad]", ret);
569 	return ERR_PTR(ret);
570 }
571 
572 /*
573  * mark the data attached to an inode as obsolete due to a write on the server
574  * - might also want to ditch all the outstanding writes and dirty pages
575  */
afs_zap_data(struct afs_vnode * vnode)576 static void afs_zap_data(struct afs_vnode *vnode)
577 {
578 	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
579 
580 	afs_invalidate_cache(vnode, 0);
581 
582 	/* nuke all the non-dirty pages that aren't locked, mapped or being
583 	 * written back in a regular file and completely discard the pages in a
584 	 * directory or symlink */
585 	if (S_ISREG(vnode->netfs.inode.i_mode))
586 		invalidate_remote_inode(&vnode->netfs.inode);
587 	else
588 		invalidate_inode_pages2(vnode->netfs.inode.i_mapping);
589 }
590 
591 /*
592  * Check to see if we have a server currently serving this volume and that it
593  * hasn't been reinitialised or dropped from the list.
594  */
afs_check_server_good(struct afs_vnode * vnode)595 static bool afs_check_server_good(struct afs_vnode *vnode)
596 {
597 	struct afs_server_list *slist;
598 	struct afs_server *server;
599 	bool good;
600 	int i;
601 
602 	if (vnode->cb_fs_s_break == atomic_read(&vnode->volume->cell->fs_s_break))
603 		return true;
604 
605 	rcu_read_lock();
606 
607 	slist = rcu_dereference(vnode->volume->servers);
608 	for (i = 0; i < slist->nr_servers; i++) {
609 		server = slist->servers[i].server;
610 		if (server == vnode->cb_server) {
611 			good = (vnode->cb_s_break == server->cb_s_break);
612 			rcu_read_unlock();
613 			return good;
614 		}
615 	}
616 
617 	rcu_read_unlock();
618 	return false;
619 }
620 
621 /*
622  * Check the validity of a vnode/inode.
623  */
afs_check_validity(struct afs_vnode * vnode)624 bool afs_check_validity(struct afs_vnode *vnode)
625 {
626 	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
627 	time64_t now = ktime_get_real_seconds();
628 	unsigned int cb_break;
629 	int seq = 0;
630 
631 	do {
632 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
633 		cb_break = vnode->cb_break;
634 
635 		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
636 			if (vnode->cb_v_break != vnode->volume->cb_v_break)
637 				need_clear = afs_cb_break_for_v_break;
638 			else if (!afs_check_server_good(vnode))
639 				need_clear = afs_cb_break_for_s_reinit;
640 			else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
641 				need_clear = afs_cb_break_for_zap;
642 			else if (vnode->cb_expires_at - 10 <= now)
643 				need_clear = afs_cb_break_for_lapsed;
644 		} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
645 			;
646 		} else {
647 			need_clear = afs_cb_break_no_promise;
648 		}
649 
650 	} while (need_seqretry(&vnode->cb_lock, seq));
651 
652 	done_seqretry(&vnode->cb_lock, seq);
653 
654 	if (need_clear == afs_cb_break_no_break)
655 		return true;
656 
657 	write_seqlock(&vnode->cb_lock);
658 	if (need_clear == afs_cb_break_no_promise)
659 		vnode->cb_v_break = vnode->volume->cb_v_break;
660 	else if (cb_break == vnode->cb_break)
661 		__afs_break_callback(vnode, need_clear);
662 	else
663 		trace_afs_cb_miss(&vnode->fid, need_clear);
664 	write_sequnlock(&vnode->cb_lock);
665 	return false;
666 }
667 
668 /*
669  * validate a vnode/inode
670  * - there are several things we need to check
671  *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
672  *     symlink)
673  *   - parent dir metadata changed (security changes)
674  *   - dentry data changed (write, truncate)
675  *   - dentry metadata changed (security changes)
676  */
afs_validate(struct afs_vnode * vnode,struct key * key)677 int afs_validate(struct afs_vnode *vnode, struct key *key)
678 {
679 	int ret;
680 
681 	_enter("{v={%llx:%llu} fl=%lx},%x",
682 	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
683 	       key_serial(key));
684 
685 	if (unlikely(test_bit(AFS_VNODE_DELETED, &vnode->flags))) {
686 		if (vnode->netfs.inode.i_nlink)
687 			clear_nlink(&vnode->netfs.inode);
688 		goto valid;
689 	}
690 
691 	if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
692 	    afs_check_validity(vnode))
693 		goto valid;
694 
695 	down_write(&vnode->validate_lock);
696 
697 	/* if the promise has expired, we need to check the server again to get
698 	 * a new promise - note that if the (parent) directory's metadata was
699 	 * changed then the security may be different and we may no longer have
700 	 * access */
701 	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
702 		_debug("not promised");
703 		ret = afs_fetch_status(vnode, key, false, NULL);
704 		if (ret < 0) {
705 			if (ret == -ENOENT) {
706 				set_bit(AFS_VNODE_DELETED, &vnode->flags);
707 				ret = -ESTALE;
708 			}
709 			goto error_unlock;
710 		}
711 		_debug("new promise [fl=%lx]", vnode->flags);
712 	}
713 
714 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
715 		_debug("file already deleted");
716 		ret = -ESTALE;
717 		goto error_unlock;
718 	}
719 
720 	/* if the vnode's data version number changed then its contents are
721 	 * different */
722 	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
723 		afs_zap_data(vnode);
724 	up_write(&vnode->validate_lock);
725 valid:
726 	_leave(" = 0");
727 	return 0;
728 
729 error_unlock:
730 	up_write(&vnode->validate_lock);
731 	_leave(" = %d", ret);
732 	return ret;
733 }
734 
735 /*
736  * read the attributes of an inode
737  */
afs_getattr(struct user_namespace * mnt_userns,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)738 int afs_getattr(struct user_namespace *mnt_userns, const struct path *path,
739 		struct kstat *stat, u32 request_mask, unsigned int query_flags)
740 {
741 	struct inode *inode = d_inode(path->dentry);
742 	struct afs_vnode *vnode = AFS_FS_I(inode);
743 	struct key *key;
744 	int ret, seq = 0;
745 
746 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
747 
748 	if (vnode->volume &&
749 	    !(query_flags & AT_STATX_DONT_SYNC) &&
750 	    !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
751 		key = afs_request_key(vnode->volume->cell);
752 		if (IS_ERR(key))
753 			return PTR_ERR(key);
754 		ret = afs_validate(vnode, key);
755 		key_put(key);
756 		if (ret < 0)
757 			return ret;
758 	}
759 
760 	do {
761 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
762 		generic_fillattr(&init_user_ns, inode, stat);
763 		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
764 		    stat->nlink > 0)
765 			stat->nlink -= 1;
766 	} while (need_seqretry(&vnode->cb_lock, seq));
767 
768 	done_seqretry(&vnode->cb_lock, seq);
769 	return 0;
770 }
771 
772 /*
773  * discard an AFS inode
774  */
afs_drop_inode(struct inode * inode)775 int afs_drop_inode(struct inode *inode)
776 {
777 	_enter("");
778 
779 	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
780 		return generic_delete_inode(inode);
781 	else
782 		return generic_drop_inode(inode);
783 }
784 
785 /*
786  * clear an AFS inode
787  */
afs_evict_inode(struct inode * inode)788 void afs_evict_inode(struct inode *inode)
789 {
790 	struct afs_vnode_cache_aux aux;
791 	struct afs_vnode *vnode = AFS_FS_I(inode);
792 
793 	_enter("{%llx:%llu.%d}",
794 	       vnode->fid.vid,
795 	       vnode->fid.vnode,
796 	       vnode->fid.unique);
797 
798 	_debug("CLEAR INODE %p", inode);
799 
800 	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
801 
802 	truncate_inode_pages_final(&inode->i_data);
803 
804 	afs_set_cache_aux(vnode, &aux);
805 	fscache_clear_inode_writeback(afs_vnode_cache(vnode), inode, &aux);
806 	clear_inode(inode);
807 
808 	while (!list_empty(&vnode->wb_keys)) {
809 		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
810 						    struct afs_wb_key, vnode_link);
811 		list_del(&wbk->vnode_link);
812 		afs_put_wb_key(wbk);
813 	}
814 
815 	fscache_relinquish_cookie(afs_vnode_cache(vnode),
816 				  test_bit(AFS_VNODE_DELETED, &vnode->flags));
817 
818 	afs_prune_wb_keys(vnode);
819 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
820 	key_put(vnode->silly_key);
821 	vnode->silly_key = NULL;
822 	key_put(vnode->lock_key);
823 	vnode->lock_key = NULL;
824 	_leave("");
825 }
826 
afs_setattr_success(struct afs_operation * op)827 static void afs_setattr_success(struct afs_operation *op)
828 {
829 	struct afs_vnode_param *vp = &op->file[0];
830 	struct inode *inode = &vp->vnode->netfs.inode;
831 	loff_t old_i_size = i_size_read(inode);
832 
833 	op->setattr.old_i_size = old_i_size;
834 	afs_vnode_commit_status(op, vp);
835 	/* inode->i_size has now been changed. */
836 
837 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
838 		loff_t size = op->setattr.attr->ia_size;
839 		if (size > old_i_size)
840 			pagecache_isize_extended(inode, old_i_size, size);
841 	}
842 }
843 
afs_setattr_edit_file(struct afs_operation * op)844 static void afs_setattr_edit_file(struct afs_operation *op)
845 {
846 	struct afs_vnode_param *vp = &op->file[0];
847 	struct inode *inode = &vp->vnode->netfs.inode;
848 
849 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
850 		loff_t size = op->setattr.attr->ia_size;
851 		loff_t i_size = op->setattr.old_i_size;
852 
853 		if (size < i_size)
854 			truncate_pagecache(inode, size);
855 		if (size != i_size)
856 			fscache_resize_cookie(afs_vnode_cache(vp->vnode),
857 					      vp->scb.status.size);
858 	}
859 }
860 
861 static const struct afs_operation_ops afs_setattr_operation = {
862 	.issue_afs_rpc	= afs_fs_setattr,
863 	.issue_yfs_rpc	= yfs_fs_setattr,
864 	.success	= afs_setattr_success,
865 	.edit_dir	= afs_setattr_edit_file,
866 };
867 
868 /*
869  * set the attributes of an inode
870  */
afs_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * attr)871 int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
872 		struct iattr *attr)
873 {
874 	const unsigned int supported =
875 		ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
876 		ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET | ATTR_TOUCH;
877 	struct afs_operation *op;
878 	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
879 	struct inode *inode = &vnode->netfs.inode;
880 	loff_t i_size;
881 	int ret;
882 
883 	_enter("{%llx:%llu},{n=%pd},%x",
884 	       vnode->fid.vid, vnode->fid.vnode, dentry,
885 	       attr->ia_valid);
886 
887 	if (!(attr->ia_valid & supported)) {
888 		_leave(" = 0 [unsupported]");
889 		return 0;
890 	}
891 
892 	i_size = i_size_read(inode);
893 	if (attr->ia_valid & ATTR_SIZE) {
894 		if (!S_ISREG(inode->i_mode))
895 			return -EISDIR;
896 
897 		ret = inode_newsize_ok(inode, attr->ia_size);
898 		if (ret)
899 			return ret;
900 
901 		if (attr->ia_size == i_size)
902 			attr->ia_valid &= ~ATTR_SIZE;
903 	}
904 
905 	fscache_use_cookie(afs_vnode_cache(vnode), true);
906 
907 	/* Prevent any new writebacks from starting whilst we do this. */
908 	down_write(&vnode->validate_lock);
909 
910 	if ((attr->ia_valid & ATTR_SIZE) && S_ISREG(inode->i_mode)) {
911 		loff_t size = attr->ia_size;
912 
913 		/* Wait for any outstanding writes to the server to complete */
914 		loff_t from = min(size, i_size);
915 		loff_t to = max(size, i_size);
916 		ret = filemap_fdatawait_range(inode->i_mapping, from, to);
917 		if (ret < 0)
918 			goto out_unlock;
919 
920 		/* Don't talk to the server if we're just shortening in-memory
921 		 * writes that haven't gone to the server yet.
922 		 */
923 		if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
924 		    attr->ia_size < i_size &&
925 		    attr->ia_size > vnode->status.size) {
926 			truncate_pagecache(inode, attr->ia_size);
927 			fscache_resize_cookie(afs_vnode_cache(vnode),
928 					      attr->ia_size);
929 			i_size_write(inode, attr->ia_size);
930 			ret = 0;
931 			goto out_unlock;
932 		}
933 	}
934 
935 	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
936 				  afs_file_key(attr->ia_file) : NULL),
937 				 vnode->volume);
938 	if (IS_ERR(op)) {
939 		ret = PTR_ERR(op);
940 		goto out_unlock;
941 	}
942 
943 	afs_op_set_vnode(op, 0, vnode);
944 	op->setattr.attr = attr;
945 
946 	if (attr->ia_valid & ATTR_SIZE) {
947 		op->file[0].dv_delta = 1;
948 		op->file[0].set_size = true;
949 	}
950 	op->ctime = attr->ia_ctime;
951 	op->file[0].update_ctime = 1;
952 	op->file[0].modification = true;
953 
954 	op->ops = &afs_setattr_operation;
955 	ret = afs_do_sync_operation(op);
956 
957 out_unlock:
958 	up_write(&vnode->validate_lock);
959 	fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
960 	_leave(" = %d", ret);
961 	return ret;
962 }
963