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, true);
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_check = op->cb_v_break;
89	vnode->status = *status;
90
91	t = status->mtime_client;
92	inode_set_ctime_to_ts(inode, t);
93	inode_set_mtime_to_ts(inode, t);
94	inode_set_atime_to_ts(inode, t);
95	inode->i_flags |= S_NOATIME;
96	inode->i_uid = make_kuid(&init_user_ns, status->owner);
97	inode->i_gid = make_kgid(&init_user_ns, status->group);
98	set_nlink(&vnode->netfs.inode, status->nlink);
99
100	switch (status->type) {
101	case AFS_FTYPE_FILE:
102		inode->i_mode	= S_IFREG | (status->mode & S_IALLUGO);
103		inode->i_op	= &afs_file_inode_operations;
104		inode->i_fop	= &afs_file_operations;
105		inode->i_mapping->a_ops	= &afs_file_aops;
106		mapping_set_large_folios(inode->i_mapping);
107		break;
108	case AFS_FTYPE_DIR:
109		inode->i_mode	= S_IFDIR |  (status->mode & S_IALLUGO);
110		inode->i_op	= &afs_dir_inode_operations;
111		inode->i_fop	= &afs_dir_file_operations;
112		inode->i_mapping->a_ops	= &afs_dir_aops;
113		mapping_set_large_folios(inode->i_mapping);
114		break;
115	case AFS_FTYPE_SYMLINK:
116		/* Symlinks with a mode of 0644 are actually mountpoints. */
117		if ((status->mode & 0777) == 0644) {
118			inode->i_flags |= S_AUTOMOUNT;
119
120			set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
121
122			inode->i_mode	= S_IFDIR | 0555;
123			inode->i_op	= &afs_mntpt_inode_operations;
124			inode->i_fop	= &afs_mntpt_file_operations;
125			inode->i_mapping->a_ops	= &afs_symlink_aops;
126		} else {
127			inode->i_mode	= S_IFLNK | status->mode;
128			inode->i_op	= &afs_symlink_inode_operations;
129			inode->i_mapping->a_ops	= &afs_symlink_aops;
130		}
131		inode_nohighmem(inode);
132		break;
133	default:
134		dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL);
135		write_sequnlock(&vnode->cb_lock);
136		return afs_protocol_error(NULL, afs_eproto_file_type);
137	}
138
139	afs_set_i_size(vnode, status->size);
140	afs_set_netfs_context(vnode);
141
142	vnode->invalid_before	= status->data_version;
143	inode_set_iversion_raw(&vnode->netfs.inode, status->data_version);
144
145	if (!vp->scb.have_cb) {
146		/* it's a symlink we just created (the fileserver
147		 * didn't give us a callback) */
148		atomic64_set(&vnode->cb_expires_at, AFS_NO_CB_PROMISE);
149	} else {
150		vnode->cb_server = op->server;
151		atomic64_set(&vnode->cb_expires_at, vp->scb.callback.expires_at);
152	}
153
154	write_sequnlock(&vnode->cb_lock);
155	return 0;
156}
157
158/*
159 * Update the core inode struct from a returned status record.
160 */
161static void afs_apply_status(struct afs_operation *op,
162			     struct afs_vnode_param *vp)
163{
164	struct afs_file_status *status = &vp->scb.status;
165	struct afs_vnode *vnode = vp->vnode;
166	struct inode *inode = &vnode->netfs.inode;
167	struct timespec64 t;
168	umode_t mode;
169	bool unexpected_jump = false;
170	bool data_changed = false;
171	bool change_size = vp->set_size;
172
173	_enter("{%llx:%llu.%u} %s",
174	       vp->fid.vid, vp->fid.vnode, vp->fid.unique,
175	       op->type ? op->type->name : "???");
176
177	BUG_ON(test_bit(AFS_VNODE_UNSET, &vnode->flags));
178
179	if (status->type != vnode->status.type) {
180		pr_warn("Vnode %llx:%llx:%x changed type %u to %u\n",
181			vnode->fid.vid,
182			vnode->fid.vnode,
183			vnode->fid.unique,
184			status->type, vnode->status.type);
185		afs_protocol_error(NULL, afs_eproto_bad_status);
186		return;
187	}
188
189	if (status->nlink != vnode->status.nlink)
190		set_nlink(inode, status->nlink);
191
192	if (status->owner != vnode->status.owner)
193		inode->i_uid = make_kuid(&init_user_ns, status->owner);
194
195	if (status->group != vnode->status.group)
196		inode->i_gid = make_kgid(&init_user_ns, status->group);
197
198	if (status->mode != vnode->status.mode) {
199		mode = inode->i_mode;
200		mode &= ~S_IALLUGO;
201		mode |= status->mode & S_IALLUGO;
202		WRITE_ONCE(inode->i_mode, mode);
203	}
204
205	t = status->mtime_client;
206	inode_set_mtime_to_ts(inode, t);
207	if (vp->update_ctime)
208		inode_set_ctime_to_ts(inode, op->ctime);
209
210	if (vnode->status.data_version != status->data_version)
211		data_changed = true;
212
213	vnode->status = *status;
214
215	if (vp->dv_before + vp->dv_delta != status->data_version) {
216		if (vnode->cb_ro_snapshot == atomic_read(&vnode->volume->cb_ro_snapshot) &&
217		    atomic64_read(&vnode->cb_expires_at) != AFS_NO_CB_PROMISE)
218			pr_warn("kAFS: vnode modified {%llx:%llu} %llx->%llx %s (op=%x)\n",
219				vnode->fid.vid, vnode->fid.vnode,
220				(unsigned long long)vp->dv_before + vp->dv_delta,
221				(unsigned long long)status->data_version,
222				op->type ? op->type->name : "???",
223				op->debug_id);
224
225		vnode->invalid_before = status->data_version;
226		if (vnode->status.type == AFS_FTYPE_DIR) {
227			if (test_and_clear_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
228				afs_stat_v(vnode, n_inval);
229		} else {
230			set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
231		}
232		change_size = true;
233		data_changed = true;
234		unexpected_jump = true;
235	} else if (vnode->status.type == AFS_FTYPE_DIR) {
236		/* Expected directory change is handled elsewhere so
237		 * that we can locally edit the directory and save on a
238		 * download.
239		 */
240		if (test_bit(AFS_VNODE_DIR_VALID, &vnode->flags))
241			data_changed = false;
242		change_size = true;
243	}
244
245	if (data_changed) {
246		inode_set_iversion_raw(inode, status->data_version);
247
248		/* Only update the size if the data version jumped.  If the
249		 * file is being modified locally, then we might have our own
250		 * idea of what the size should be that's not the same as
251		 * what's on the server.
252		 */
253		vnode->netfs.remote_i_size = status->size;
254		if (change_size || status->size > i_size_read(inode)) {
255			afs_set_i_size(vnode, status->size);
256			if (unexpected_jump)
257				vnode->netfs.zero_point = status->size;
258			inode_set_ctime_to_ts(inode, t);
259			inode_set_atime_to_ts(inode, t);
260		}
261	}
262}
263
264/*
265 * Apply a callback to a vnode.
266 */
267static void afs_apply_callback(struct afs_operation *op,
268			       struct afs_vnode_param *vp)
269{
270	struct afs_callback *cb = &vp->scb.callback;
271	struct afs_vnode *vnode = vp->vnode;
272
273	if (!afs_cb_is_broken(vp->cb_break_before, vnode)) {
274		if (op->volume->type == AFSVL_RWVOL)
275			vnode->cb_server = op->server;
276		atomic64_set(&vnode->cb_expires_at, cb->expires_at);
277	}
278}
279
280/*
281 * Apply the received status and callback to an inode all in the same critical
282 * section to avoid races with afs_validate().
283 */
284void afs_vnode_commit_status(struct afs_operation *op, struct afs_vnode_param *vp)
285{
286	struct afs_vnode *vnode = vp->vnode;
287
288	_enter("");
289
290	write_seqlock(&vnode->cb_lock);
291
292	if (vp->scb.have_error) {
293		/* A YFS server will return this from RemoveFile2 and AFS and
294		 * YFS will return this from InlineBulkStatus.
295		 */
296		if (vp->scb.status.abort_code == VNOVNODE) {
297			set_bit(AFS_VNODE_DELETED, &vnode->flags);
298			clear_nlink(&vnode->netfs.inode);
299			__afs_break_callback(vnode, afs_cb_break_for_deleted);
300			op->flags &= ~AFS_OPERATION_DIR_CONFLICT;
301		}
302	} else if (vp->scb.have_status) {
303		if (vp->speculative &&
304		    (test_bit(AFS_VNODE_MODIFYING, &vnode->flags) ||
305		     vp->dv_before != vnode->status.data_version))
306			/* Ignore the result of a speculative bulk status fetch
307			 * if it splits around a modification op, thereby
308			 * appearing to regress the data version.
309			 */
310			goto out;
311		afs_apply_status(op, vp);
312		if (vp->scb.have_cb)
313			afs_apply_callback(op, vp);
314	} else if (vp->op_unlinked && !(op->flags & AFS_OPERATION_DIR_CONFLICT)) {
315		drop_nlink(&vnode->netfs.inode);
316		if (vnode->netfs.inode.i_nlink == 0) {
317			set_bit(AFS_VNODE_DELETED, &vnode->flags);
318			__afs_break_callback(vnode, afs_cb_break_for_deleted);
319		}
320	}
321
322out:
323	write_sequnlock(&vnode->cb_lock);
324
325	if (vp->scb.have_status)
326		afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
327}
328
329static void afs_fetch_status_success(struct afs_operation *op)
330{
331	struct afs_vnode_param *vp = &op->file[op->fetch_status.which];
332	struct afs_vnode *vnode = vp->vnode;
333	int ret;
334
335	if (vnode->netfs.inode.i_state & I_NEW) {
336		ret = afs_inode_init_from_status(op, vp, vnode);
337		afs_op_set_error(op, ret);
338		if (ret == 0)
339			afs_cache_permit(vnode, op->key, vp->cb_break_before, &vp->scb);
340	} else {
341		afs_vnode_commit_status(op, vp);
342	}
343}
344
345const struct afs_operation_ops afs_fetch_status_operation = {
346	.issue_afs_rpc	= afs_fs_fetch_status,
347	.issue_yfs_rpc	= yfs_fs_fetch_status,
348	.success	= afs_fetch_status_success,
349	.aborted	= afs_check_for_remote_deletion,
350};
351
352/*
353 * Fetch file status from the volume.
354 */
355int afs_fetch_status(struct afs_vnode *vnode, struct key *key, bool is_new,
356		     afs_access_t *_caller_access)
357{
358	struct afs_operation *op;
359
360	_enter("%s,{%llx:%llu.%u,S=%lx}",
361	       vnode->volume->name,
362	       vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique,
363	       vnode->flags);
364
365	op = afs_alloc_operation(key, vnode->volume);
366	if (IS_ERR(op))
367		return PTR_ERR(op);
368
369	afs_op_set_vnode(op, 0, vnode);
370
371	op->nr_files	= 1;
372	op->ops		= &afs_fetch_status_operation;
373	afs_begin_vnode_operation(op);
374	afs_wait_for_operation(op);
375
376	if (_caller_access)
377		*_caller_access = op->file[0].scb.status.caller_access;
378	return afs_put_operation(op);
379}
380
381/*
382 * ilookup() comparator
383 */
384int afs_ilookup5_test_by_fid(struct inode *inode, void *opaque)
385{
386	struct afs_vnode *vnode = AFS_FS_I(inode);
387	struct afs_fid *fid = opaque;
388
389	return (fid->vnode == vnode->fid.vnode &&
390		fid->vnode_hi == vnode->fid.vnode_hi &&
391		fid->unique == vnode->fid.unique);
392}
393
394/*
395 * iget5() comparator
396 */
397static int afs_iget5_test(struct inode *inode, void *opaque)
398{
399	struct afs_vnode_param *vp = opaque;
400	//struct afs_vnode *vnode = AFS_FS_I(inode);
401
402	return afs_ilookup5_test_by_fid(inode, &vp->fid);
403}
404
405/*
406 * iget5() inode initialiser
407 */
408static int afs_iget5_set(struct inode *inode, void *opaque)
409{
410	struct afs_vnode_param *vp = opaque;
411	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
412	struct afs_vnode *vnode = AFS_FS_I(inode);
413
414	vnode->volume		= as->volume;
415	vnode->fid		= vp->fid;
416
417	/* YFS supports 96-bit vnode IDs, but Linux only supports
418	 * 64-bit inode numbers.
419	 */
420	inode->i_ino		= vnode->fid.vnode;
421	inode->i_generation	= vnode->fid.unique;
422	return 0;
423}
424
425/*
426 * Get a cache cookie for an inode.
427 */
428static void afs_get_inode_cache(struct afs_vnode *vnode)
429{
430#ifdef CONFIG_AFS_FSCACHE
431	struct {
432		__be32 vnode_id;
433		__be32 unique;
434		__be32 vnode_id_ext[2];	/* Allow for a 96-bit key */
435	} __packed key;
436	struct afs_vnode_cache_aux aux;
437
438	if (vnode->status.type != AFS_FTYPE_FILE) {
439		vnode->netfs.cache = NULL;
440		return;
441	}
442
443	key.vnode_id		= htonl(vnode->fid.vnode);
444	key.unique		= htonl(vnode->fid.unique);
445	key.vnode_id_ext[0]	= htonl(vnode->fid.vnode >> 32);
446	key.vnode_id_ext[1]	= htonl(vnode->fid.vnode_hi);
447	afs_set_cache_aux(vnode, &aux);
448
449	afs_vnode_set_cache(vnode,
450			    fscache_acquire_cookie(
451				    vnode->volume->cache,
452				    vnode->status.type == AFS_FTYPE_FILE ?
453				    0 : FSCACHE_ADV_SINGLE_CHUNK,
454				    &key, sizeof(key),
455				    &aux, sizeof(aux),
456				    i_size_read(&vnode->netfs.inode)));
457#endif
458}
459
460/*
461 * inode retrieval
462 */
463struct inode *afs_iget(struct afs_operation *op, struct afs_vnode_param *vp)
464{
465	struct afs_vnode_param *dvp = &op->file[0];
466	struct super_block *sb = dvp->vnode->netfs.inode.i_sb;
467	struct afs_vnode *vnode;
468	struct inode *inode;
469	int ret;
470
471	_enter(",{%llx:%llu.%u},,", vp->fid.vid, vp->fid.vnode, vp->fid.unique);
472
473	inode = iget5_locked(sb, vp->fid.vnode, afs_iget5_test, afs_iget5_set, vp);
474	if (!inode) {
475		_leave(" = -ENOMEM");
476		return ERR_PTR(-ENOMEM);
477	}
478
479	vnode = AFS_FS_I(inode);
480
481	_debug("GOT INODE %p { vl=%llx vn=%llx, u=%x }",
482	       inode, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique);
483
484	/* deal with an existing inode */
485	if (!(inode->i_state & I_NEW)) {
486		_leave(" = %p", inode);
487		return inode;
488	}
489
490	ret = afs_inode_init_from_status(op, vp, vnode);
491	if (ret < 0)
492		goto bad_inode;
493
494	afs_get_inode_cache(vnode);
495
496	/* success */
497	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
498	unlock_new_inode(inode);
499	_leave(" = %p", inode);
500	return inode;
501
502	/* failure */
503bad_inode:
504	iget_failed(inode);
505	_leave(" = %d [bad]", ret);
506	return ERR_PTR(ret);
507}
508
509static int afs_iget5_set_root(struct inode *inode, void *opaque)
510{
511	struct afs_super_info *as = AFS_FS_S(inode->i_sb);
512	struct afs_vnode *vnode = AFS_FS_I(inode);
513
514	vnode->volume		= as->volume;
515	vnode->fid.vid		= as->volume->vid,
516	vnode->fid.vnode	= 1;
517	vnode->fid.unique	= 1;
518	inode->i_ino		= 1;
519	inode->i_generation	= 1;
520	return 0;
521}
522
523/*
524 * Set up the root inode for a volume.  This is always vnode 1, unique 1 within
525 * the volume.
526 */
527struct inode *afs_root_iget(struct super_block *sb, struct key *key)
528{
529	struct afs_super_info *as = AFS_FS_S(sb);
530	struct afs_operation *op;
531	struct afs_vnode *vnode;
532	struct inode *inode;
533	int ret;
534
535	_enter(",{%llx},,", as->volume->vid);
536
537	inode = iget5_locked(sb, 1, NULL, afs_iget5_set_root, NULL);
538	if (!inode) {
539		_leave(" = -ENOMEM");
540		return ERR_PTR(-ENOMEM);
541	}
542
543	_debug("GOT ROOT INODE %p { vl=%llx }", inode, as->volume->vid);
544
545	BUG_ON(!(inode->i_state & I_NEW));
546
547	vnode = AFS_FS_I(inode);
548	vnode->cb_v_check = atomic_read(&as->volume->cb_v_break),
549	afs_set_netfs_context(vnode);
550
551	op = afs_alloc_operation(key, as->volume);
552	if (IS_ERR(op)) {
553		ret = PTR_ERR(op);
554		goto error;
555	}
556
557	afs_op_set_vnode(op, 0, vnode);
558
559	op->nr_files	= 1;
560	op->ops		= &afs_fetch_status_operation;
561	ret = afs_do_sync_operation(op);
562	if (ret < 0)
563		goto error;
564
565	afs_get_inode_cache(vnode);
566
567	clear_bit(AFS_VNODE_UNSET, &vnode->flags);
568	unlock_new_inode(inode);
569	_leave(" = %p", inode);
570	return inode;
571
572error:
573	iget_failed(inode);
574	_leave(" = %d [bad]", ret);
575	return ERR_PTR(ret);
576}
577
578/*
579 * read the attributes of an inode
580 */
581int afs_getattr(struct mnt_idmap *idmap, const struct path *path,
582		struct kstat *stat, u32 request_mask, unsigned int query_flags)
583{
584	struct inode *inode = d_inode(path->dentry);
585	struct afs_vnode *vnode = AFS_FS_I(inode);
586	struct key *key;
587	int ret, seq;
588
589	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
590
591	if (vnode->volume &&
592	    !(query_flags & AT_STATX_DONT_SYNC) &&
593	    atomic64_read(&vnode->cb_expires_at) == AFS_NO_CB_PROMISE) {
594		key = afs_request_key(vnode->volume->cell);
595		if (IS_ERR(key))
596			return PTR_ERR(key);
597		ret = afs_validate(vnode, key);
598		key_put(key);
599		if (ret < 0)
600			return ret;
601	}
602
603	do {
604		seq = read_seqbegin(&vnode->cb_lock);
605		generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
606		if (test_bit(AFS_VNODE_SILLY_DELETED, &vnode->flags) &&
607		    stat->nlink > 0)
608			stat->nlink -= 1;
609
610		/* Lie about the size of directories.  We maintain a locally
611		 * edited copy and may make different allocation decisions on
612		 * it, but we need to give userspace the server's size.
613		 */
614		if (S_ISDIR(inode->i_mode))
615			stat->size = vnode->netfs.remote_i_size;
616	} while (read_seqretry(&vnode->cb_lock, seq));
617
618	return 0;
619}
620
621/*
622 * discard an AFS inode
623 */
624int afs_drop_inode(struct inode *inode)
625{
626	_enter("");
627
628	if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
629		return generic_delete_inode(inode);
630	else
631		return generic_drop_inode(inode);
632}
633
634/*
635 * clear an AFS inode
636 */
637void afs_evict_inode(struct inode *inode)
638{
639	struct afs_vnode_cache_aux aux;
640	struct afs_vnode *vnode = AFS_FS_I(inode);
641
642	_enter("{%llx:%llu.%d}",
643	       vnode->fid.vid,
644	       vnode->fid.vnode,
645	       vnode->fid.unique);
646
647	_debug("CLEAR INODE %p", inode);
648
649	ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
650
651	truncate_inode_pages_final(&inode->i_data);
652
653	afs_set_cache_aux(vnode, &aux);
654	netfs_clear_inode_writeback(inode, &aux);
655	clear_inode(inode);
656
657	while (!list_empty(&vnode->wb_keys)) {
658		struct afs_wb_key *wbk = list_entry(vnode->wb_keys.next,
659						    struct afs_wb_key, vnode_link);
660		list_del(&wbk->vnode_link);
661		afs_put_wb_key(wbk);
662	}
663
664	fscache_relinquish_cookie(afs_vnode_cache(vnode),
665				  test_bit(AFS_VNODE_DELETED, &vnode->flags));
666
667	afs_prune_wb_keys(vnode);
668	afs_put_permits(rcu_access_pointer(vnode->permit_cache));
669	key_put(vnode->silly_key);
670	vnode->silly_key = NULL;
671	key_put(vnode->lock_key);
672	vnode->lock_key = NULL;
673	_leave("");
674}
675
676static void afs_setattr_success(struct afs_operation *op)
677{
678	struct afs_vnode_param *vp = &op->file[0];
679	struct inode *inode = &vp->vnode->netfs.inode;
680	loff_t old_i_size = i_size_read(inode);
681
682	op->setattr.old_i_size = old_i_size;
683	afs_vnode_commit_status(op, vp);
684	/* inode->i_size has now been changed. */
685
686	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
687		loff_t size = op->setattr.attr->ia_size;
688		if (size > old_i_size)
689			pagecache_isize_extended(inode, old_i_size, size);
690	}
691}
692
693static void afs_setattr_edit_file(struct afs_operation *op)
694{
695	struct afs_vnode_param *vp = &op->file[0];
696	struct afs_vnode *vnode = vp->vnode;
697
698	if (op->setattr.attr->ia_valid & ATTR_SIZE) {
699		loff_t size = op->setattr.attr->ia_size;
700		loff_t i_size = op->setattr.old_i_size;
701
702		if (size != i_size) {
703			truncate_setsize(&vnode->netfs.inode, size);
704			netfs_resize_file(&vnode->netfs, size, true);
705			fscache_resize_cookie(afs_vnode_cache(vnode), size);
706		}
707	}
708}
709
710static const struct afs_operation_ops afs_setattr_operation = {
711	.issue_afs_rpc	= afs_fs_setattr,
712	.issue_yfs_rpc	= yfs_fs_setattr,
713	.success	= afs_setattr_success,
714	.edit_dir	= afs_setattr_edit_file,
715};
716
717/*
718 * set the attributes of an inode
719 */
720int afs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
721		struct iattr *attr)
722{
723	const unsigned int supported =
724		ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
725		ATTR_MTIME | ATTR_MTIME_SET | ATTR_TIMES_SET | ATTR_TOUCH;
726	struct afs_operation *op;
727	struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
728	struct inode *inode = &vnode->netfs.inode;
729	loff_t i_size;
730	int ret;
731
732	_enter("{%llx:%llu},{n=%pd},%x",
733	       vnode->fid.vid, vnode->fid.vnode, dentry,
734	       attr->ia_valid);
735
736	if (!(attr->ia_valid & supported)) {
737		_leave(" = 0 [unsupported]");
738		return 0;
739	}
740
741	i_size = i_size_read(inode);
742	if (attr->ia_valid & ATTR_SIZE) {
743		if (!S_ISREG(inode->i_mode))
744			return -EISDIR;
745
746		ret = inode_newsize_ok(inode, attr->ia_size);
747		if (ret)
748			return ret;
749
750		if (attr->ia_size == i_size)
751			attr->ia_valid &= ~ATTR_SIZE;
752	}
753
754	fscache_use_cookie(afs_vnode_cache(vnode), true);
755
756	/* Prevent any new writebacks from starting whilst we do this. */
757	down_write(&vnode->validate_lock);
758
759	if ((attr->ia_valid & ATTR_SIZE) && S_ISREG(inode->i_mode)) {
760		loff_t size = attr->ia_size;
761
762		/* Wait for any outstanding writes to the server to complete */
763		loff_t from = min(size, i_size);
764		loff_t to = max(size, i_size);
765		ret = filemap_fdatawait_range(inode->i_mapping, from, to);
766		if (ret < 0)
767			goto out_unlock;
768
769		/* Don't talk to the server if we're just shortening in-memory
770		 * writes that haven't gone to the server yet.
771		 */
772		if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) &&
773		    attr->ia_size < i_size &&
774		    attr->ia_size > vnode->netfs.remote_i_size) {
775			truncate_setsize(inode, attr->ia_size);
776			netfs_resize_file(&vnode->netfs, size, false);
777			fscache_resize_cookie(afs_vnode_cache(vnode),
778					      attr->ia_size);
779			ret = 0;
780			goto out_unlock;
781		}
782	}
783
784	op = afs_alloc_operation(((attr->ia_valid & ATTR_FILE) ?
785				  afs_file_key(attr->ia_file) : NULL),
786				 vnode->volume);
787	if (IS_ERR(op)) {
788		ret = PTR_ERR(op);
789		goto out_unlock;
790	}
791
792	afs_op_set_vnode(op, 0, vnode);
793	op->setattr.attr = attr;
794
795	if (attr->ia_valid & ATTR_SIZE) {
796		op->file[0].dv_delta = 1;
797		op->file[0].set_size = true;
798	}
799	op->ctime = attr->ia_ctime;
800	op->file[0].update_ctime = 1;
801	op->file[0].modification = true;
802
803	op->ops = &afs_setattr_operation;
804	ret = afs_do_sync_operation(op);
805
806out_unlock:
807	up_write(&vnode->validate_lock);
808	fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
809	_leave(" = %d", ret);
810	return ret;
811}
812