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
 28static const struct inode_operations afs_symlink_inode_operations = {
 29	.get_link	= page_get_link,
 30};
 31
 32static 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 */
 59static 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 */
 67static 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 */
163static 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	} else if (vnode->status.type == AFS_FTYPE_DIR) {
234		/* Expected directory change is handled elsewhere so
235		 * that we can locally edit the directory and save on a
236		 * download.
237		 */
238		if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
239			data_changed = false;
240		change_size = true;
241	}
242
243	if (data_changed) {
244		inode_set_iversion_raw(inode, status->data_version);
245
246		/* Only update the size if the data version jumped.  If the
247		 * file is being modified locally, then we might have our own
248		 * idea of what the size should be that's not the same as
249		 * what's on the server.
250		 */
251		vnode->netfs.remote_i_size = status->size;
252		if (change_size) {
253			afs_set_i_size(vnode, status->size);
254			inode->i_ctime = t;
255			inode->i_atime = t;
 
 
256		}
257	}
258}
259
260/*
261 * Apply a callback to a vnode.
262 */
263static void afs_apply_callback(struct afs_operation *op,
264			       struct afs_vnode_param *vp)
265{
266	struct afs_callback *cb = &vp->scb.callback;
267	struct afs_vnode *vnode = vp->vnode;
268
269	if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
270		vnode->cb_expires_at	= cb->expires_at;
271		vnode->cb_server	= op->server;
272		set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
273	}
274}
275
276/*
277 * Apply the received status and callback to an inode all in the same critical
278 * section to avoid races with afs_validate().
279 */
280void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
281{
282	struct afs_vnode *vnode = vp->vnode;
283
284	_enter("");
285
286	write_seqlock(&vnode->cb_lock);
287
288	if (vp->scb.have_error) {
289		/* A YFS server will return this from RemoveFile2 and AFS and
290		 * YFS will return this from InlineBulkStatus.
291		 */
292		if (vp->scb.status.abort_code == VNOVNODE) {
293			set_bit(AFS_VNODE_DELETED, &vnode->flags);
294			clear_nlink(&vnode->netfs.inode);
295			__afs_break_callback(vnode, afs_cb_break_for_deleted);
296			op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
297		}
298	} else if (vp->scb.have_status) {
299		if (vp->speculative &&
300		    (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
301		     vp->dv_before != vnode->status.data_version))
302			/* Ignore the result of a speculative bulk status fetch
303			 * if it splits around a modification op, thereby
304			 * appearing to regress the data version.
305			 */
306			goto out;
307		afs_apply_status(op, vp);
308		if (vp->scb.have_cb)
309			afs_apply_callback(op, vp);
310	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
311		drop_nlink(&vnode->netfs.inode);
312		if (vnode->netfs.inode.i_nlink == 0) {
313			set_bit(AFS_VNODE_DELETED, &vnode->flags);
314			__afs_break_callback(vnode, afs_cb_break_for_deleted);
315		}
316	}
317
318out:
319	write_sequnlock(&vnode->cb_lock);
320
321	if (vp->scb.have_status)
322		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
323}
324
325static void afs_fetch_status_success(struct afs_operation *op)
326{
327	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
328	struct afs_vnode *vnode = vp->vnode;
329	int ret;
330
331	if (vnode->netfs.inode.i_state & I_NEW) {
332		ret = afs_inode_init_from_status(op, vp, vnode);
333		op->error = ret;
334		if (ret == 0)
335			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
336	} else {
337		afs_vnode_commit_status(op, vp);
338	}
339}
340
341const struct afs_operation_ops afs_fetch_status_operation = {
342	.issue_afs_rpc	= afs_fs_fetch_status,
343	.issue_yfs_rpc	= yfs_fs_fetch_status,
344	.success	= afs_fetch_status_success,
345	.aborted	= afs_check_for_remote_deletion,
346};
347
348/*
349 * Fetch file status from the volume.
350 */
351int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
352		     afs_access_t *_caller_access)
353{
354	struct afs_operation *op;
355
356	_enter("%s,{%llx:%llu.%u,S=%lx}",
357	       vnode->volume->name,
358	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
359	       vnode->flags);
360
361	op = afs_alloc_operation(key, vnode->volume);
362	if (IS_ERR(op))
363		return PTR_ERR(op);
364
365	afs_op_set_vnode(op, 0, vnode);
366
367	op->nr_files	= 1;
368	op->ops		= &afs_fetch_status_operation;
369	afs_begin_vnode_operation(op);
370	afs_wait_for_operation(op);
371
372	if (_caller_access)
373		*_caller_access = op->file[0].scb.status.caller_access;
374	return afs_put_operation(op);
375}
376
377/*
378 * ilookup() comparator
379 */
380int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
381{
382	struct afs_vnode *vnode = AFS_FS_I(inode);
383	struct afs_fid *fid = opaque;
384
385	return (fid->vnode == vnode->fid.vnode &&
386		fid->vnode_hi == vnode->fid.vnode_hi &&
387		fid->unique == vnode->fid.unique);
388}
389
390/*
391 * iget5() comparator
392 */
393static int afs_iget5_test(struct inode *inode, void *opaque)
394{
395	struct afs_vnode_param *vp = opaque;
396	//struct afs_vnode *vnode = AFS_FS_I(inode);
397
398	return afs_ilookup5_test_by_fid(inode, &vp->fid);
399}
400
401/*
402 * iget5() inode initialiser
403 */
404static int afs_iget5_set(struct inode *inode, void *opaque)
405{
406	struct afs_vnode_param *vp = opaque;
407	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
408	struct afs_vnode *vnode = AFS_FS_I(inode);
409
410	vnode->volume		= as->volume;
411	vnode->fid		= vp->fid;
412
413	/* YFS supports 96-bit vnode IDs, but Linux only supports
414	 * 64-bit inode numbers.
415	 */
416	inode->i_ino		= vnode->fid.vnode;
417	inode->i_generation	= vnode->fid.unique;
418	return 0;
419}
420
421/*
422 * Get a cache cookie for an inode.
423 */
424static void afs_get_inode_cache(struct afs_vnode *vnode)
425{
426#ifdef CONFIG_AFS_FSCACHE
427	struct {
428		__be32 vnode_id;
429		__be32 unique;
430		__be32 vnode_id_ext[2];	/* Allow for a 96-bit key */
431	} __packed key;
432	struct afs_vnode_cache_aux aux;
433
434	if (vnode->status.type != AFS_FTYPE_FILE) {
435		vnode->netfs.cache = NULL;
436		return;
437	}
438
439	key.vnode_id		= htonl(vnode->fid.vnode);
440	key.unique		= htonl(vnode->fid.unique);
441	key.vnode_id_ext[0]	= htonl(vnode->fid.vnode >> 32);
442	key.vnode_id_ext[1]	= htonl(vnode->fid.vnode_hi);
443	afs_set_cache_aux(vnode, &aux);
444
445	afs_vnode_set_cache(vnode,
446			    fscache_acquire_cookie(
447				    vnode->volume->cache,
448				    vnode->status.type == AFS_FTYPE_FILE ?
449				    0 : FSCACHE_ADV_SINGLE_CHUNK,
450				    &key, sizeof(key),
451				    &aux, sizeof(aux),
452				    vnode->status.size));
453#endif
454}
455
456/*
457 * inode retrieval
458 */
459struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
460{
461	struct afs_vnode_param *dvp = &op->file[0];
462	struct super_block *sb = dvp->vnode->netfs.inode.i_sb;
463	struct afs_vnode *vnode;
464	struct inode *inode;
465	int ret;
466
467	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
468
469	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
470	if (!inode) {
471		_leave(" = -ENOMEM");
472		return ERR_PTR(-ENOMEM);
473	}
474
475	vnode = AFS_FS_I(inode);
476
477	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
478	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
479
480	/* deal with an existing inode */
481	if (!(inode->i_state & I_NEW)) {
482		_leave(" = %p", inode);
483		return inode;
484	}
485
486	ret = afs_inode_init_from_status(op, vp, vnode);
487	if (ret < 0)
488		goto bad_inode;
489
490	afs_get_inode_cache(vnode);
491
492	/* success */
493	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
494	unlock_new_inode(inode);
495	_leave(" = %p", inode);
496	return inode;
497
498	/* failure */
499bad_inode:
500	iget_failed(inode);
501	_leave(" = %d [bad]", ret);
502	return ERR_PTR(ret);
503}
504
505static int afs_iget5_set_root(struct inode *inode, void *opaque)
506{
507	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
508	struct afs_vnode *vnode = AFS_FS_I(inode);
509
510	vnode->volume		= as->volume;
511	vnode->fid.vid		= as->volume->vid,
512	vnode->fid.vnode	= 1;
513	vnode->fid.unique	= 1;
514	inode->i_ino		= 1;
515	inode->i_generation	= 1;
516	return 0;
517}
518
519/*
520 * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
521 * the volume.
522 */
523struct inode *afs_root_iget(struct super_block *sb, struct key *key)
524{
525	struct afs_super_info *as = AFS_FS_S(sb);
526	struct afs_operation *op;
527	struct afs_vnode *vnode;
528	struct inode *inode;
529	int ret;
530
531	_enter(",{%llx},,", as->volume->vid);
532
533	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
534	if (!inode) {
535		_leave(" = -ENOMEM");
536		return ERR_PTR(-ENOMEM);
537	}
538
539	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
540
541	BUG_ON(!(inode->i_state & I_NEW));
542
543	vnode = AFS_FS_I(inode);
544	vnode->cb_v_break = as->volume->cb_v_break,
545	afs_set_netfs_context(vnode);
546
547	op = afs_alloc_operation(key, as->volume);
548	if (IS_ERR(op)) {
549		ret = PTR_ERR(op);
550		goto error;
551	}
552
553	afs_op_set_vnode(op, 0, vnode);
554
555	op->nr_files	= 1;
556	op->ops		= &afs_fetch_status_operation;
557	ret = afs_do_sync_operation(op);
558	if (ret < 0)
559		goto error;
560
561	afs_get_inode_cache(vnode);
562
563	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
564	unlock_new_inode(inode);
565	_leave(" = %p", inode);
566	return inode;
567
568error:
569	iget_failed(inode);
570	_leave(" = %d [bad]", ret);
571	return ERR_PTR(ret);
572}
573
574/*
575 * mark the data attached to an inode as obsolete due to a write on the server
576 * - might also want to ditch all the outstanding writes and dirty pages
577 */
578static void afs_zap_data(struct afs_vnode *vnode)
579{
580	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
581
582	afs_invalidate_cache(vnode, 0);
583
584	/* nuke all the non-dirty pages that aren't locked, mapped or being
585	 * written back in a regular file and completely discard the pages in a
586	 * directory or symlink */
587	if (S_ISREG(vnode->netfs.inode.i_mode))
588		invalidate_remote_inode(&vnode->netfs.inode);
589	else
590		invalidate_inode_pages2(vnode->netfs.inode.i_mapping);
591}
592
593/*
594 * Check to see if we have a server currently serving this volume and that it
595 * hasn't been reinitialised or dropped from the list.
596 */
597static bool afs_check_server_good(struct afs_vnode *vnode)
598{
599	struct afs_server_list *slist;
600	struct afs_server *server;
601	bool good;
602	int i;
603
604	if (vnode->cb_fs_s_break == atomic_read(&vnode->volume->cell->fs_s_break))
605		return true;
606
607	rcu_read_lock();
608
609	slist = rcu_dereference(vnode->volume->servers);
610	for (i = 0; i < slist->nr_servers; i++) {
611		server = slist->servers[i].server;
612		if (server == vnode->cb_server) {
613			good = (vnode->cb_s_break == server->cb_s_break);
614			rcu_read_unlock();
615			return good;
616		}
617	}
618
619	rcu_read_unlock();
620	return false;
621}
622
623/*
624 * Check the validity of a vnode/inode.
625 */
626bool afs_check_validity(struct afs_vnode *vnode)
627{
628	enum afs_cb_break_reason need_clear = afs_cb_break_no_break;
629	time64_t now = ktime_get_real_seconds();
630	unsigned int cb_break;
631	int seq = 0;
632
633	do {
634		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
635		cb_break = vnode->cb_break;
636
637		if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
638			if (vnode->cb_v_break != vnode->volume->cb_v_break)
639				need_clear = afs_cb_break_for_v_break;
640			else if (!afs_check_server_good(vnode))
641				need_clear = afs_cb_break_for_s_reinit;
642			else if (test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
643				need_clear = afs_cb_break_for_zap;
644			else if (vnode->cb_expires_at - 10 <= now)
645				need_clear = afs_cb_break_for_lapsed;
646		} else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
647			;
648		} else {
649			need_clear = afs_cb_break_no_promise;
650		}
651
652	} while (need_seqretry(&vnode->cb_lock, seq));
653
654	done_seqretry(&vnode->cb_lock, seq);
655
656	if (need_clear == afs_cb_break_no_break)
657		return true;
658
659	write_seqlock(&vnode->cb_lock);
660	if (need_clear == afs_cb_break_no_promise)
661		vnode->cb_v_break = vnode->volume->cb_v_break;
662	else if (cb_break == vnode->cb_break)
663		__afs_break_callback(vnode, need_clear);
664	else
665		trace_afs_cb_miss(&vnode->fid, need_clear);
666	write_sequnlock(&vnode->cb_lock);
667	return false;
668}
669
670/*
671 * validate a vnode/inode
672 * - there are several things we need to check
673 *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
674 *     symlink)
675 *   - parent dir metadata changed (security changes)
676 *   - dentry data changed (write, truncate)
677 *   - dentry metadata changed (security changes)
678 */
679int afs_validate(struct afs_vnode *vnode, struct key *key)
680{
681	int ret;
682
683	_enter("{v={%llx:%llu} fl=%lx},%x",
684	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
685	       key_serial(key));
686
687	if (unlikely(test_bit(AFS_VNODE_DELETED, &vnode->flags))) {
688		if (vnode->netfs.inode.i_nlink)
689			clear_nlink(&vnode->netfs.inode);
690		goto valid;
691	}
692
693	if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
694	    afs_check_validity(vnode))
695		goto valid;
696
697	down_write(&vnode->validate_lock);
698
699	/* if the promise has expired, we need to check the server again to get
700	 * a new promise - note that if the (parent) directory's metadata was
701	 * changed then the security may be different and we may no longer have
702	 * access */
703	if (!test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
704		_debug("not promised");
705		ret = afs_fetch_status(vnode, key, false, NULL);
706		if (ret < 0) {
707			if (ret == -ENOENT) {
708				set_bit(AFS_VNODE_DELETED, &vnode->flags);
709				ret = -ESTALE;
710			}
711			goto error_unlock;
712		}
713		_debug("new promise [fl=%lx]", vnode->flags);
714	}
715
716	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
717		_debug("file already deleted");
718		ret = -ESTALE;
719		goto error_unlock;
720	}
721
722	/* if the vnode's data version number changed then its contents are
723	 * different */
724	if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
725		afs_zap_data(vnode);
726	up_write(&vnode->validate_lock);
727valid:
728	_leave(" = 0");
729	return 0;
730
731error_unlock:
732	up_write(&vnode->validate_lock);
733	_leave(" = %d", ret);
734	return ret;
735}
736
737/*
738 * read the attributes of an inode
739 */
740int afs_getattr(struct user_namespace *mnt_userns, const struct path *path,
741		struct kstat *stat, u32 request_mask, unsigned int query_flags)
742{
743	struct inode *inode = d_inode(path->dentry);
744	struct afs_vnode *vnode = AFS_FS_I(inode);
745	struct key *key;
746	int ret, seq = 0;
747
748	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
749
750	if (vnode->volume &&
751	    !(query_flags & AT_STATX_DONT_SYNC) &&
752	    !test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags)) {
753		key = afs_request_key(vnode->volume->cell);
754		if (IS_ERR(key))
755			return PTR_ERR(key);
756		ret = afs_validate(vnode, key);
757		key_put(key);
758		if (ret < 0)
759			return ret;
760	}
761
762	do {
763		read_seqbegin_or_lock(&vnode->cb_lock, &seq);
764		generic_fillattr(&init_user_ns, inode, stat);
765		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
766		    stat->nlink > 0)
767			stat->nlink -= 1;
768	} while (need_seqretry(&vnode->cb_lock, seq));
769
770	done_seqretry(&vnode->cb_lock, seq);
 
 
 
 
 
 
 
771	return 0;
772}
773
774/*
775 * discard an AFS inode
776 */
777int afs_drop_inode(struct inode *inode)
778{
779	_enter("");
780
781	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
782		return generic_delete_inode(inode);
783	else
784		return generic_drop_inode(inode);
785}
786
787/*
788 * clear an AFS inode
789 */
790void afs_evict_inode(struct inode *inode)
791{
792	struct afs_vnode_cache_aux aux;
793	struct afs_vnode *vnode = AFS_FS_I(inode);
794
795	_enter("{%llx:%llu.%d}",
796	       vnode->fid.vid,
797	       vnode->fid.vnode,
798	       vnode->fid.unique);
799
800	_debug("CLEAR INODE %p", inode);
801
802	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
803
804	truncate_inode_pages_final(&inode->i_data);
805
806	afs_set_cache_aux(vnode, &aux);
807	fscache_clear_inode_writeback(afs_vnode_cache(vnode), inode, &aux);
808	clear_inode(inode);
809
810	while (!list_empty(&vnode->wb_keys)) {
811		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
812						    struct afs_wb_key, vnode_link);
813		list_del(&wbk->vnode_link);
814		afs_put_wb_key(wbk);
815	}
816
817	fscache_relinquish_cookie(afs_vnode_cache(vnode),
818				  test_bit(AFS_VNODE_DELETED, &vnode->flags));
819
820	afs_prune_wb_keys(vnode);
821	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
822	key_put(vnode->silly_key);
823	vnode->silly_key = NULL;
824	key_put(vnode->lock_key);
825	vnode->lock_key = NULL;
826	_leave("");
827}
828
829static void afs_setattr_success(struct afs_operation *op)
830{
831	struct afs_vnode_param *vp = &op->file[0];
832	struct inode *inode = &vp->vnode->netfs.inode;
833	loff_t old_i_size = i_size_read(inode);
834
835	op->setattr.old_i_size = old_i_size;
836	afs_vnode_commit_status(op, vp);
837	/* inode->i_size has now been changed. */
838
839	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
840		loff_t size = op->setattr.attr->ia_size;
841		if (size > old_i_size)
842			pagecache_isize_extended(inode, old_i_size, size);
843	}
844}
845
846static void afs_setattr_edit_file(struct afs_operation *op)
847{
848	struct afs_vnode_param *vp = &op->file[0];
849	struct inode *inode = &vp->vnode->netfs.inode;
850
851	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
852		loff_t size = op->setattr.attr->ia_size;
853		loff_t i_size = op->setattr.old_i_size;
854
855		if (size < i_size)
856			truncate_pagecache(inode, size);
857		if (size != i_size)
858			fscache_resize_cookie(afs_vnode_cache(vp->vnode),
859					      vp->scb.status.size);
860	}
861}
862
863static const struct afs_operation_ops afs_setattr_operation = {
864	.issue_afs_rpc	= afs_fs_setattr,
865	.issue_yfs_rpc	= yfs_fs_setattr,
866	.success	= afs_setattr_success,
867	.edit_dir	= afs_setattr_edit_file,
868};
869
870/*
871 * set the attributes of an inode
872 */
873int afs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
874		struct iattr *attr)
875{
876	const unsigned int supported =
877		ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
878		ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET | ATTR_TOUCH;
879	struct afs_operation *op;
880	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
881	struct inode *inode = &vnode->netfs.inode;
882	loff_t i_size;
883	int ret;
884
885	_enter("{%llx:%llu},{n=%pd},%x",
886	       vnode->fid.vid, vnode->fid.vnode, dentry,
887	       attr->ia_valid);
888
889	if (!(attr->ia_valid & supported)) {
890		_leave(" = 0 [unsupported]");
891		return 0;
892	}
893
894	i_size = i_size_read(inode);
895	if (attr->ia_valid & ATTR_SIZE) {
896		if (!S_ISREG(inode->i_mode))
897			return -EISDIR;
898
899		ret = inode_newsize_ok(inode, attr->ia_size);
900		if (ret)
901			return ret;
902
903		if (attr->ia_size == i_size)
904			attr->ia_valid &= ~ATTR_SIZE;
905	}
906
907	fscache_use_cookie(afs_vnode_cache(vnode), true);
908
909	/* Prevent any new writebacks from starting whilst we do this. */
910	down_write(&vnode->validate_lock);
911
912	if ((attr->ia_valid & ATTR_SIZE) && S_ISREG(inode->i_mode)) {
913		loff_t size = attr->ia_size;
914
915		/* Wait for any outstanding writes to the server to complete */
916		loff_t from = min(size, i_size);
917		loff_t to = max(size, i_size);
918		ret = filemap_fdatawait_range(inode->i_mapping, from, to);
919		if (ret < 0)
920			goto out_unlock;
921
922		/* Don't talk to the server if we're just shortening in-memory
923		 * writes that haven't gone to the server yet.
924		 */
925		if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
926		    attr->ia_size < i_size &&
927		    attr->ia_size > vnode->status.size) {
928			truncate_pagecache(inode, attr->ia_size);
 
929			fscache_resize_cookie(afs_vnode_cache(vnode),
930					      attr->ia_size);
931			i_size_write(inode, attr->ia_size);
932			ret = 0;
933			goto out_unlock;
934		}
935	}
936
937	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
938				  afs_file_key(attr->ia_file) : NULL),
939				 vnode->volume);
940	if (IS_ERR(op)) {
941		ret = PTR_ERR(op);
942		goto out_unlock;
943	}
944
945	afs_op_set_vnode(op, 0, vnode);
946	op->setattr.attr = attr;
947
948	if (attr->ia_valid & ATTR_SIZE) {
949		op->file[0].dv_delta = 1;
950		op->file[0].set_size = true;
951	}
952	op->ctime = attr->ia_ctime;
953	op->file[0].update_ctime = 1;
954	op->file[0].modification = true;
955
956	op->ops = &afs_setattr_operation;
957	ret = afs_do_sync_operation(op);
958
959out_unlock:
960	up_write(&vnode->validate_lock);
961	fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
962	_leave(" = %d", ret);
963	return ret;
964}