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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  * Initialise an inode from the vnode status.
58  */
afs_inode_init_from_status(struct afs_operation * op,struct afs_vnode_param * vp,struct afs_vnode * vnode)59 static int afs_inode_init_from_status(struct afs_operation *op,
60 				      struct afs_vnode_param *vp,
61 				      struct afs_vnode *vnode)
62 {
63 	struct afs_file_status *status = &vp->scb.status;
64 	struct inode *inode = AFS_VNODE_TO_I(vnode);
65 	struct timespec64 t;
66 
67 	_enter("{%llx:%llu.%u} %s",
68 	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
69 	       op->type ? op->type->name : "???");
70 
71 	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
72 	       status->type,
73 	       status->nlink,
74 	       (unsigned long long) status->size,
75 	       status->data_version,
76 	       status->mode);
77 
78 	write_seqlock(&vnode->cb_lock);
79 
80 	vnode->cb_v_break = op->cb_v_break;
81 	vnode->cb_s_break = op->cb_s_break;
82 	vnode->status = *status;
83 
84 	t = status->mtime_client;
85 	inode->i_ctime = t;
86 	inode->i_mtime = t;
87 	inode->i_atime = t;
88 	inode->i_flags |= S_NOATIME;
89 	inode->i_uid = make_kuid(&init_user_ns, status->owner);
90 	inode->i_gid = make_kgid(&init_user_ns, status->group);
91 	set_nlink(&vnode->vfs_inode, status->nlink);
92 
93 	switch (status->type) {
94 	case AFS_FTYPE_FILE:
95 		inode->i_mode	= S_IFREG | (status->mode & S_IALLUGO);
96 		inode->i_op	= &afs_file_inode_operations;
97 		inode->i_fop	= &afs_file_operations;
98 		inode->i_mapping->a_ops	= &afs_fs_aops;
99 		break;
100 	case AFS_FTYPE_DIR:
101 		inode->i_mode	= S_IFDIR |  (status->mode & S_IALLUGO);
102 		inode->i_op	= &afs_dir_inode_operations;
103 		inode->i_fop	= &afs_dir_file_operations;
104 		inode->i_mapping->a_ops	= &afs_dir_aops;
105 		break;
106 	case AFS_FTYPE_SYMLINK:
107 		/* Symlinks with a mode of 0644 are actually mountpoints. */
108 		if ((status->mode & 0777) == 0644) {
109 			inode->i_flags |= S_AUTOMOUNT;
110 
111 			set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
112 
113 			inode->i_mode	= S_IFDIR | 0555;
114 			inode->i_op	= &afs_mntpt_inode_operations;
115 			inode->i_fop	= &afs_mntpt_file_operations;
116 			inode->i_mapping->a_ops	= &afs_fs_aops;
117 		} else {
118 			inode->i_mode	= S_IFLNK | status->mode;
119 			inode->i_op	= &afs_symlink_inode_operations;
120 			inode->i_mapping->a_ops	= &afs_fs_aops;
121 		}
122 		inode_nohighmem(inode);
123 		break;
124 	default:
125 		dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
126 		write_sequnlock(&vnode->cb_lock);
127 		return afs_protocol_error(NULL, afs_eproto_file_type);
128 	}
129 
130 	afs_set_i_size(vnode, status->size);
131 
132 	vnode->invalid_before	= status->data_version;
133 	inode_set_iversion_raw(&vnode->vfs_inode, status->data_version);
134 
135 	if (!vp->scb.have_cb) {
136 		/* it's a symlink we just created (the fileserver
137 		 * didn't give us a callback) */
138 		vnode->cb_expires_at = ktime_get_real_seconds();
139 	} else {
140 		vnode->cb_expires_at = vp->scb.callback.expires_at;
141 		vnode->cb_server = op->server;
142 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
143 	}
144 
145 	write_sequnlock(&vnode->cb_lock);
146 	return 0;
147 }
148 
149 /*
150  * Update the core inode struct from a returned status record.
151  */
afs_apply_status(struct afs_operation * op,struct afs_vnode_param * vp)152 static void afs_apply_status(struct afs_operation *op,
153 			     struct afs_vnode_param *vp)
154 {
155 	struct afs_file_status *status = &vp->scb.status;
156 	struct afs_vnode *vnode = vp->vnode;
157 	struct inode *inode = &vnode->vfs_inode;
158 	struct timespec64 t;
159 	umode_t mode;
160 	bool data_changed = false;
161 	bool change_size = vp->set_size;
162 
163 	_enter("{%llx:%llu.%u} %s",
164 	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
165 	       op->type ? op->type->name : "???");
166 
167 	BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
168 
169 	if (status->type != vnode->status.type) {
170 		pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
171 			vnode->fid.vid,
172 			vnode->fid.vnode,
173 			vnode->fid.unique,
174 			status->type, vnode->status.type);
175 		afs_protocol_error(NULL, afs_eproto_bad_status);
176 		return;
177 	}
178 
179 	if (status->nlink != vnode->status.nlink)
180 		set_nlink(inode, status->nlink);
181 
182 	if (status->owner != vnode->status.owner)
183 		inode->i_uid = make_kuid(&init_user_ns, status->owner);
184 
185 	if (status->group != vnode->status.group)
186 		inode->i_gid = make_kgid(&init_user_ns, status->group);
187 
188 	if (status->mode != vnode->status.mode) {
189 		mode = inode->i_mode;
190 		mode &= ~S_IALLUGO;
191 		mode |= status->mode & S_IALLUGO;
192 		WRITE_ONCE(inode->i_mode, mode);
193 	}
194 
195 	t = status->mtime_client;
196 	inode->i_mtime = t;
197 	if (vp->update_ctime)
198 		inode->i_ctime = op->ctime;
199 
200 	if (vnode->status.data_version != status->data_version)
201 		data_changed = true;
202 
203 	vnode->status = *status;
204 
205 	if (vp->dv_before + vp->dv_delta != status->data_version) {
206 		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags))
207 			pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s\n",
208 				vnode->fid.vid, vnode->fid.vnode,
209 				(unsigned long long)vp->dv_before + vp->dv_delta,
210 				(unsigned long long)status->data_version,
211 				op->type ? op->type->name : "???");
212 
213 		vnode->invalid_before = status->data_version;
214 		if (vnode->status.type == AFS_FTYPE_DIR) {
215 			if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
216 				afs_stat_v(vnode, n_inval);
217 		} else {
218 			set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
219 		}
220 		change_size = true;
221 	} else if (vnode->status.type == AFS_FTYPE_DIR) {
222 		/* Expected directory change is handled elsewhere so
223 		 * that we can locally edit the directory and save on a
224 		 * download.
225 		 */
226 		if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
227 			data_changed = false;
228 		change_size = true;
229 	}
230 
231 	if (data_changed) {
232 		inode_set_iversion_raw(inode, status->data_version);
233 
234 		/* Only update the size if the data version jumped.  If the
235 		 * file is being modified locally, then we might have our own
236 		 * idea of what the size should be that's not the same as
237 		 * what's on the server.
238 		 */
239 		if (change_size) {
240 			afs_set_i_size(vnode, status->size);
241 			inode->i_ctime = t;
242 			inode->i_atime = t;
243 		}
244 	}
245 }
246 
247 /*
248  * Apply a callback to a vnode.
249  */
afs_apply_callback(struct afs_operation * op,struct afs_vnode_param * vp)250 static void afs_apply_callback(struct afs_operation *op,
251 			       struct afs_vnode_param *vp)
252 {
253 	struct afs_callback *cb = &vp->scb.callback;
254 	struct afs_vnode *vnode = vp->vnode;
255 
256 	if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
257 		vnode->cb_expires_at	= cb->expires_at;
258 		vnode->cb_server	= op->server;
259 		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
260 	}
261 }
262 
263 /*
264  * Apply the received status and callback to an inode all in the same critical
265  * section to avoid races with afs_validate().
266  */
afs_vnode_commit_status(struct afs_operation * op,struct afs_vnode_param * vp)267 void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
268 {
269 	struct afs_vnode *vnode = vp->vnode;
270 
271 	_enter("");
272 
273 	write_seqlock(&vnode->cb_lock);
274 
275 	if (vp->scb.have_error) {
276 		/* A YFS server will return this from RemoveFile2 and AFS and
277 		 * YFS will return this from InlineBulkStatus.
278 		 */
279 		if (vp->scb.status.abort_code == VNOVNODE) {
280 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
281 			clear_nlink(&vnode->vfs_inode);
282 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
283 			op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
284 		}
285 	} else if (vp->scb.have_status) {
286 		if (vp->speculative &&
287 		    (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
288 		     vp->dv_before != vnode->status.data_version))
289 			/* Ignore the result of a speculative bulk status fetch
290 			 * if it splits around a modification op, thereby
291 			 * appearing to regress the data version.
292 			 */
293 			goto out;
294 		afs_apply_status(op, vp);
295 		if (vp->scb.have_cb)
296 			afs_apply_callback(op, vp);
297 	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
298 		drop_nlink(&vnode->vfs_inode);
299 		if (vnode->vfs_inode.i_nlink == 0) {
300 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
301 			__afs_break_callback(vnode, afs_cb_break_for_deleted);
302 		}
303 	}
304 
305 out:
306 	write_sequnlock(&vnode->cb_lock);
307 
308 	if (vp->scb.have_status)
309 		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
310 }
311 
afs_fetch_status_success(struct afs_operation * op)312 static void afs_fetch_status_success(struct afs_operation *op)
313 {
314 	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
315 	struct afs_vnode *vnode = vp->vnode;
316 	int ret;
317 
318 	if (vnode->vfs_inode.i_state & I_NEW) {
319 		ret = afs_inode_init_from_status(op, vp, vnode);
320 		op->error = ret;
321 		if (ret == 0)
322 			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
323 	} else {
324 		afs_vnode_commit_status(op, vp);
325 	}
326 }
327 
328 const struct afs_operation_ops afs_fetch_status_operation = {
329 	.issue_afs_rpc	= afs_fs_fetch_status,
330 	.issue_yfs_rpc	= yfs_fs_fetch_status,
331 	.success	= afs_fetch_status_success,
332 	.aborted	= afs_check_for_remote_deletion,
333 };
334 
335 /*
336  * Fetch file status from the volume.
337  */
afs_fetch_status(struct afs_vnode * vnode,struct key * key,bool is_new,afs_access_t * _caller_access)338 int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
339 		     afs_access_t *_caller_access)
340 {
341 	struct afs_operation *op;
342 
343 	_enter("%s,{%llx:%llu.%u,S=%lx}",
344 	       vnode->volume->name,
345 	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
346 	       vnode->flags);
347 
348 	op = afs_alloc_operation(key, vnode->volume);
349 	if (IS_ERR(op))
350 		return PTR_ERR(op);
351 
352 	afs_op_set_vnode(op, 0, vnode);
353 
354 	op->nr_files	= 1;
355 	op->ops		= &afs_fetch_status_operation;
356 	afs_begin_vnode_operation(op);
357 	afs_wait_for_operation(op);
358 
359 	if (_caller_access)
360 		*_caller_access = op->file[0].scb.status.caller_access;
361 	return afs_put_operation(op);
362 }
363 
364 /*
365  * ilookup() comparator
366  */
afs_ilookup5_test_by_fid(struct inode * inode,void * opaque)367 int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
368 {
369 	struct afs_vnode *vnode = AFS_FS_I(inode);
370 	struct afs_fid *fid = opaque;
371 
372 	return (fid->vnode == vnode->fid.vnode &&
373 		fid->vnode_hi == vnode->fid.vnode_hi &&
374 		fid->unique == vnode->fid.unique);
375 }
376 
377 /*
378  * iget5() comparator
379  */
afs_iget5_test(struct inode * inode,void * opaque)380 static int afs_iget5_test(struct inode *inode, void *opaque)
381 {
382 	struct afs_vnode_param *vp = opaque;
383 	//struct afs_vnode *vnode = AFS_FS_I(inode);
384 
385 	return afs_ilookup5_test_by_fid(inode, &vp->fid);
386 }
387 
388 /*
389  * iget5() inode initialiser
390  */
afs_iget5_set(struct inode * inode,void * opaque)391 static int afs_iget5_set(struct inode *inode, void *opaque)
392 {
393 	struct afs_vnode_param *vp = opaque;
394 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
395 	struct afs_vnode *vnode = AFS_FS_I(inode);
396 
397 	vnode->volume		= as->volume;
398 	vnode->fid		= vp->fid;
399 
400 	/* YFS supports 96-bit vnode IDs, but Linux only supports
401 	 * 64-bit inode numbers.
402 	 */
403 	inode->i_ino		= vnode->fid.vnode;
404 	inode->i_generation	= vnode->fid.unique;
405 	return 0;
406 }
407 
408 /*
409  * Get a cache cookie for an inode.
410  */
afs_get_inode_cache(struct afs_vnode * vnode)411 static void afs_get_inode_cache(struct afs_vnode *vnode)
412 {
413 #ifdef CONFIG_AFS_FSCACHE
414 	struct {
415 		u32 vnode_id;
416 		u32 unique;
417 		u32 vnode_id_ext[2];	/* Allow for a 96-bit key */
418 	} __packed key;
419 	struct afs_vnode_cache_aux aux;
420 
421 	if (vnode->status.type == AFS_FTYPE_DIR) {
422 		vnode->cache = NULL;
423 		return;
424 	}
425 
426 	key.vnode_id		= vnode->fid.vnode;
427 	key.unique		= vnode->fid.unique;
428 	key.vnode_id_ext[0]	= vnode->fid.vnode >> 32;
429 	key.vnode_id_ext[1]	= vnode->fid.vnode_hi;
430 	aux.data_version	= vnode->status.data_version;
431 
432 	vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
433 					      &afs_vnode_cache_index_def,
434 					      &key, sizeof(key),
435 					      &aux, sizeof(aux),
436 					      vnode, vnode->status.size, true);
437 #endif
438 }
439 
440 /*
441  * inode retrieval
442  */
afs_iget(struct afs_operation * op,struct afs_vnode_param * vp)443 struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
444 {
445 	struct afs_vnode_param *dvp = &op->file[0];
446 	struct super_block *sb = dvp->vnode->vfs_inode.i_sb;
447 	struct afs_vnode *vnode;
448 	struct inode *inode;
449 	int ret;
450 
451 	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
452 
453 	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
454 	if (!inode) {
455 		_leave(" = -ENOMEM");
456 		return ERR_PTR(-ENOMEM);
457 	}
458 
459 	vnode = AFS_FS_I(inode);
460 
461 	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
462 	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
463 
464 	/* deal with an existing inode */
465 	if (!(inode->i_state & I_NEW)) {
466 		_leave(" = %p", inode);
467 		return inode;
468 	}
469 
470 	ret = afs_inode_init_from_status(op, vp, vnode);
471 	if (ret < 0)
472 		goto bad_inode;
473 
474 	afs_get_inode_cache(vnode);
475 
476 	/* success */
477 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
478 	unlock_new_inode(inode);
479 	_leave(" = %p", inode);
480 	return inode;
481 
482 	/* failure */
483 bad_inode:
484 	iget_failed(inode);
485 	_leave(" = %d [bad]", ret);
486 	return ERR_PTR(ret);
487 }
488 
afs_iget5_set_root(struct inode * inode,void * opaque)489 static int afs_iget5_set_root(struct inode *inode, void *opaque)
490 {
491 	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
492 	struct afs_vnode *vnode = AFS_FS_I(inode);
493 
494 	vnode->volume		= as->volume;
495 	vnode->fid.vid		= as->volume->vid,
496 	vnode->fid.vnode	= 1;
497 	vnode->fid.unique	= 1;
498 	inode->i_ino		= 1;
499 	inode->i_generation	= 1;
500 	return 0;
501 }
502 
503 /*
504  * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
505  * the volume.
506  */
afs_root_iget(struct super_block * sb,struct key * key)507 struct inode *afs_root_iget(struct super_block *sb, struct key *key)
508 {
509 	struct afs_super_info *as = AFS_FS_S(sb);
510 	struct afs_operation *op;
511 	struct afs_vnode *vnode;
512 	struct inode *inode;
513 	int ret;
514 
515 	_enter(",{%llx},,", as->volume->vid);
516 
517 	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
518 	if (!inode) {
519 		_leave(" = -ENOMEM");
520 		return ERR_PTR(-ENOMEM);
521 	}
522 
523 	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
524 
525 	BUG_ON(!(inode->i_state & I_NEW));
526 
527 	vnode = AFS_FS_I(inode);
528 	vnode->cb_v_break = as->volume->cb_v_break,
529 
530 	op = afs_alloc_operation(key, as->volume);
531 	if (IS_ERR(op)) {
532 		ret = PTR_ERR(op);
533 		goto error;
534 	}
535 
536 	afs_op_set_vnode(op, 0, vnode);
537 
538 	op->nr_files	= 1;
539 	op->ops		= &afs_fetch_status_operation;
540 	ret = afs_do_sync_operation(op);
541 	if (ret < 0)
542 		goto error;
543 
544 	afs_get_inode_cache(vnode);
545 
546 	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
547 	unlock_new_inode(inode);
548 	_leave(" = %p", inode);
549 	return inode;
550 
551 error:
552 	iget_failed(inode);
553 	_leave(" = %d [bad]", ret);
554 	return ERR_PTR(ret);
555 }
556 
557 /*
558  * mark the data attached to an inode as obsolete due to a write on the server
559  * - might also want to ditch all the outstanding writes and dirty pages
560  */
afs_zap_data(struct afs_vnode * vnode)561 static void afs_zap_data(struct afs_vnode *vnode)
562 {
563 	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
564 
565 #ifdef CONFIG_AFS_FSCACHE
566 	fscache_invalidate(vnode->cache);
567 #endif
568 
569 	/* nuke all the non-dirty pages that aren't locked, mapped or being
570 	 * written back in a regular file and completely discard the pages in a
571 	 * directory or symlink */
572 	if (S_ISREG(vnode->vfs_inode.i_mode))
573 		invalidate_remote_inode(&vnode->vfs_inode);
574 	else
575 		invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
576 }
577 
578 /*
579  * Get the server reinit counter for a vnode's current server.
580  */
afs_get_s_break_rcu(struct afs_vnode * vnode,unsigned int * _s_break)581 static bool afs_get_s_break_rcu(struct afs_vnode *vnode, unsigned int *_s_break)
582 {
583 	struct afs_server_list *slist = rcu_dereference(vnode->volume->servers);
584 	struct afs_server *server;
585 	int i;
586 
587 	for (i = 0; i < slist->nr_servers; i++) {
588 		server = slist->servers[i].server;
589 		if (server == vnode->cb_server) {
590 			*_s_break = READ_ONCE(server->cb_s_break);
591 			return true;
592 		}
593 	}
594 
595 	return false;
596 }
597 
598 /*
599  * Check the validity of a vnode/inode.
600  */
afs_check_validity(struct afs_vnode * vnode)601 bool afs_check_validity(struct afs_vnode *vnode)
602 {
603 	struct afs_volume *volume = vnode->volume;
604 	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
605 	time64_t now = ktime_get_real_seconds();
606 	bool valid;
607 	unsigned int cb_break, cb_s_break, cb_v_break;
608 	int seq = 0;
609 
610 	do {
611 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
612 		cb_v_break = READ_ONCE(volume->cb_v_break);
613 		cb_break = vnode->cb_break;
614 
615 		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
616 		    afs_get_s_break_rcu(vnode, &cb_s_break)) {
617 			if (vnode->cb_s_break != cb_s_break ||
618 			    vnode->cb_v_break != cb_v_break) {
619 				vnode->cb_s_break = cb_s_break;
620 				vnode->cb_v_break = cb_v_break;
621 				need_clear = afs_cb_break_for_vsbreak;
622 				valid = false;
623 			} else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
624 				need_clear = afs_cb_break_for_zap;
625 				valid = false;
626 			} else if (vnode->cb_expires_at - 10 <= now) {
627 				need_clear = afs_cb_break_for_lapsed;
628 				valid = false;
629 			} else {
630 				valid = true;
631 			}
632 		} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
633 			valid = true;
634 		} else {
635 			vnode->cb_v_break = cb_v_break;
636 			valid = false;
637 		}
638 
639 	} while (need_seqretry(&vnode->cb_lock, seq));
640 
641 	done_seqretry(&vnode->cb_lock, seq);
642 
643 	if (need_clear != afs_cb_break_no_break) {
644 		write_seqlock(&vnode->cb_lock);
645 		if (cb_break == vnode->cb_break)
646 			__afs_break_callback(vnode, need_clear);
647 		else
648 			trace_afs_cb_miss(&vnode->fid, need_clear);
649 		write_sequnlock(&vnode->cb_lock);
650 		valid = false;
651 	}
652 
653 	return valid;
654 }
655 
656 /*
657  * validate a vnode/inode
658  * - there are several things we need to check
659  *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
660  *     symlink)
661  *   - parent dir metadata changed (security changes)
662  *   - dentry data changed (write, truncate)
663  *   - dentry metadata changed (security changes)
664  */
afs_validate(struct afs_vnode * vnode,struct key * key)665 int afs_validate(struct afs_vnode *vnode, struct key *key)
666 {
667 	bool valid;
668 	int ret;
669 
670 	_enter("{v={%llx:%llu} fl=%lx},%x",
671 	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
672 	       key_serial(key));
673 
674 	rcu_read_lock();
675 	valid = afs_check_validity(vnode);
676 	rcu_read_unlock();
677 
678 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
679 		clear_nlink(&vnode->vfs_inode);
680 
681 	if (valid)
682 		goto valid;
683 
684 	down_write(&vnode->validate_lock);
685 
686 	/* if the promise has expired, we need to check the server again to get
687 	 * a new promise - note that if the (parent) directory's metadata was
688 	 * changed then the security may be different and we may no longer have
689 	 * access */
690 	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
691 		_debug("not promised");
692 		ret = afs_fetch_status(vnode, key, false, NULL);
693 		if (ret < 0) {
694 			if (ret == -ENOENT) {
695 				set_bit(AFS_VNODE_DELETED, &vnode->flags);
696 				ret = -ESTALE;
697 			}
698 			goto error_unlock;
699 		}
700 		_debug("new promise [fl=%lx]", vnode->flags);
701 	}
702 
703 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
704 		_debug("file already deleted");
705 		ret = -ESTALE;
706 		goto error_unlock;
707 	}
708 
709 	/* if the vnode's data version number changed then its contents are
710 	 * different */
711 	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
712 		afs_zap_data(vnode);
713 	up_write(&vnode->validate_lock);
714 valid:
715 	_leave(" = 0");
716 	return 0;
717 
718 error_unlock:
719 	up_write(&vnode->validate_lock);
720 	_leave(" = %d", ret);
721 	return ret;
722 }
723 
724 /*
725  * read the attributes of an inode
726  */
afs_getattr(const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)727 int afs_getattr(const struct path *path, struct kstat *stat,
728 		u32 request_mask, unsigned int query_flags)
729 {
730 	struct inode *inode = d_inode(path->dentry);
731 	struct afs_vnode *vnode = AFS_FS_I(inode);
732 	struct key *key;
733 	int ret, seq = 0;
734 
735 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
736 
737 	if (vnode->volume &&
738 	    !(query_flags & AT_STATX_DONT_SYNC) &&
739 	    !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
740 		key = afs_request_key(vnode->volume->cell);
741 		if (IS_ERR(key))
742 			return PTR_ERR(key);
743 		ret = afs_validate(vnode, key);
744 		key_put(key);
745 		if (ret < 0)
746 			return ret;
747 	}
748 
749 	do {
750 		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
751 		generic_fillattr(inode, stat);
752 		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
753 		    stat->nlink > 0)
754 			stat->nlink -= 1;
755 	} while (need_seqretry(&vnode->cb_lock, seq));
756 
757 	done_seqretry(&vnode->cb_lock, seq);
758 	return 0;
759 }
760 
761 /*
762  * discard an AFS inode
763  */
afs_drop_inode(struct inode * inode)764 int afs_drop_inode(struct inode *inode)
765 {
766 	_enter("");
767 
768 	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
769 		return generic_delete_inode(inode);
770 	else
771 		return generic_drop_inode(inode);
772 }
773 
774 /*
775  * clear an AFS inode
776  */
afs_evict_inode(struct inode * inode)777 void afs_evict_inode(struct inode *inode)
778 {
779 	struct afs_vnode *vnode;
780 
781 	vnode = AFS_FS_I(inode);
782 
783 	_enter("{%llx:%llu.%d}",
784 	       vnode->fid.vid,
785 	       vnode->fid.vnode,
786 	       vnode->fid.unique);
787 
788 	_debug("CLEAR INODE %p", inode);
789 
790 	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
791 
792 	truncate_inode_pages_final(&inode->i_data);
793 	clear_inode(inode);
794 
795 	while (!list_empty(&vnode->wb_keys)) {
796 		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
797 						    struct afs_wb_key, vnode_link);
798 		list_del(&wbk->vnode_link);
799 		afs_put_wb_key(wbk);
800 	}
801 
802 #ifdef CONFIG_AFS_FSCACHE
803 	{
804 		struct afs_vnode_cache_aux aux;
805 
806 		aux.data_version = vnode->status.data_version;
807 		fscache_relinquish_cookie(vnode->cache, &aux,
808 					  test_bit(AFS_VNODE_DELETED, &vnode->flags));
809 		vnode->cache = NULL;
810 	}
811 #endif
812 
813 	afs_prune_wb_keys(vnode);
814 	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
815 	key_put(vnode->silly_key);
816 	vnode->silly_key = NULL;
817 	key_put(vnode->lock_key);
818 	vnode->lock_key = NULL;
819 	_leave("");
820 }
821 
afs_setattr_success(struct afs_operation * op)822 static void afs_setattr_success(struct afs_operation *op)
823 {
824 	struct afs_vnode_param *vp = &op->file[0];
825 	struct inode *inode = &vp->vnode->vfs_inode;
826 	loff_t old_i_size = i_size_read(inode);
827 
828 	op->setattr.old_i_size = old_i_size;
829 	afs_vnode_commit_status(op, vp);
830 	/* inode->i_size has now been changed. */
831 
832 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
833 		loff_t size = op->setattr.attr->ia_size;
834 		if (size > old_i_size)
835 			pagecache_isize_extended(inode, old_i_size, size);
836 	}
837 }
838 
afs_setattr_edit_file(struct afs_operation * op)839 static void afs_setattr_edit_file(struct afs_operation *op)
840 {
841 	struct afs_vnode_param *vp = &op->file[0];
842 	struct inode *inode = &vp->vnode->vfs_inode;
843 
844 	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
845 		loff_t size = op->setattr.attr->ia_size;
846 		loff_t i_size = op->setattr.old_i_size;
847 
848 		if (size < i_size)
849 			truncate_pagecache(inode, size);
850 	}
851 }
852 
853 static const struct afs_operation_ops afs_setattr_operation = {
854 	.issue_afs_rpc	= afs_fs_setattr,
855 	.issue_yfs_rpc	= yfs_fs_setattr,
856 	.success	= afs_setattr_success,
857 	.edit_dir	= afs_setattr_edit_file,
858 };
859 
860 /*
861  * set the attributes of an inode
862  */
afs_setattr(struct dentry * dentry,struct iattr * attr)863 int afs_setattr(struct dentry *dentry, struct iattr *attr)
864 {
865 	struct afs_operation *op;
866 	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
867 	int ret;
868 
869 	_enter("{%llx:%llu},{n=%pd},%x",
870 	       vnode->fid.vid, vnode->fid.vnode, dentry,
871 	       attr->ia_valid);
872 
873 	if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
874 				ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET |
875 				ATTR_TOUCH))) {
876 		_leave(" = 0 [unsupported]");
877 		return 0;
878 	}
879 
880 	if (attr->ia_valid & ATTR_SIZE) {
881 		if (!S_ISREG(vnode->vfs_inode.i_mode))
882 			return -EISDIR;
883 
884 		ret = inode_newsize_ok(&vnode->vfs_inode, attr->ia_size);
885 		if (ret)
886 			return ret;
887 
888 		if (attr->ia_size == i_size_read(&vnode->vfs_inode))
889 			attr->ia_valid &= ~ATTR_SIZE;
890 	}
891 
892 	/* flush any dirty data outstanding on a regular file */
893 	if (S_ISREG(vnode->vfs_inode.i_mode))
894 		filemap_write_and_wait(vnode->vfs_inode.i_mapping);
895 
896 	/* Prevent any new writebacks from starting whilst we do this. */
897 	down_write(&vnode->validate_lock);
898 
899 	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
900 				  afs_file_key(attr->ia_file) : NULL),
901 				 vnode->volume);
902 	if (IS_ERR(op)) {
903 		ret = PTR_ERR(op);
904 		goto out_unlock;
905 	}
906 
907 	afs_op_set_vnode(op, 0, vnode);
908 	op->setattr.attr = attr;
909 
910 	if (attr->ia_valid & ATTR_SIZE) {
911 		op->file[0].dv_delta = 1;
912 		op->file[0].set_size = true;
913 	}
914 	op->ctime = attr->ia_ctime;
915 	op->file[0].update_ctime = 1;
916 	op->file[0].modification = true;
917 
918 	op->ops = &afs_setattr_operation;
919 	ret = afs_do_sync_operation(op);
920 
921 out_unlock:
922 	up_write(&vnode->validate_lock);
923 	_leave(" = %d", ret);
924 	return ret;
925 }
926