summaryrefslogtreecommitdiff
path: root/fs/smb/server/vfs_cache.c
blob: 2d0138e72d7834176224ce3c8925b27d0965bdf2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
 * Copyright (C) 2019 Samsung Electronics Co., Ltd.
 */

#include <linux/fs.h>
#include <linux/filelock.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

#include "glob.h"
#include "vfs_cache.h"
#include "oplock.h"
#include "vfs.h"
#include "connection.h"
#include "mgmt/tree_connect.h"
#include "mgmt/user_session.h"
#include "smb_common.h"

#define S_DEL_PENDING			1
#define S_DEL_ON_CLS			2
#define S_DEL_ON_CLS_STREAM		8

static unsigned int inode_hash_mask __read_mostly;
static unsigned int inode_hash_shift __read_mostly;
static struct hlist_head *inode_hashtable __read_mostly;
static DEFINE_RWLOCK(inode_hash_lock);

static struct ksmbd_file_table global_ft;
static atomic_long_t fd_limit;
static struct kmem_cache *filp_cache;

void ksmbd_set_fd_limit(unsigned long limit)
{
	limit = min(limit, get_max_files());
	atomic_long_set(&fd_limit, limit);
}

static bool fd_limit_depleted(void)
{
	long v = atomic_long_dec_return(&fd_limit);

	if (v >= 0)
		return false;
	atomic_long_inc(&fd_limit);
	return true;
}

static void fd_limit_close(void)
{
	atomic_long_inc(&fd_limit);
}

/*
 * INODE hash
 */

static unsigned long inode_hash(struct super_block *sb, unsigned long hashval)
{
	unsigned long tmp;

	tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
		L1_CACHE_BYTES;
	tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> inode_hash_shift);
	return tmp & inode_hash_mask;
}

static struct ksmbd_inode *__ksmbd_inode_lookup(struct inode *inode)
{
	struct hlist_head *head = inode_hashtable +
		inode_hash(inode->i_sb, inode->i_ino);
	struct ksmbd_inode *ci = NULL, *ret_ci = NULL;

	hlist_for_each_entry(ci, head, m_hash) {
		if (ci->m_inode == inode) {
			if (atomic_inc_not_zero(&ci->m_count))
				ret_ci = ci;
			break;
		}
	}
	return ret_ci;
}

static struct ksmbd_inode *ksmbd_inode_lookup(struct ksmbd_file *fp)
{
	return __ksmbd_inode_lookup(file_inode(fp->filp));
}

static struct ksmbd_inode *ksmbd_inode_lookup_by_vfsinode(struct inode *inode)
{
	struct ksmbd_inode *ci;

	read_lock(&inode_hash_lock);
	ci = __ksmbd_inode_lookup(inode);
	read_unlock(&inode_hash_lock);
	return ci;
}

int ksmbd_query_inode_status(struct inode *inode)
{
	struct ksmbd_inode *ci;
	int ret = KSMBD_INODE_STATUS_UNKNOWN;

	read_lock(&inode_hash_lock);
	ci = __ksmbd_inode_lookup(inode);
	if (ci) {
		ret = KSMBD_INODE_STATUS_OK;
		if (ci->m_flags & S_DEL_PENDING)
			ret = KSMBD_INODE_STATUS_PENDING_DELETE;
		atomic_dec(&ci->m_count);
	}
	read_unlock(&inode_hash_lock);
	return ret;
}

bool ksmbd_inode_pending_delete(struct ksmbd_file *fp)
{
	return (fp->f_ci->m_flags & S_DEL_PENDING);
}

void ksmbd_set_inode_pending_delete(struct ksmbd_file *fp)
{
	fp->f_ci->m_flags |= S_DEL_PENDING;
}

void ksmbd_clear_inode_pending_delete(struct ksmbd_file *fp)
{
	fp->f_ci->m_flags &= ~S_DEL_PENDING;
}

void ksmbd_fd_set_delete_on_close(struct ksmbd_file *fp,
				  int file_info)
{
	if (ksmbd_stream_fd(fp)) {
		fp->f_ci->m_flags |= S_DEL_ON_CLS_STREAM;
		return;
	}

	fp->f_ci->m_flags |= S_DEL_ON_CLS;
}

static void ksmbd_inode_hash(struct ksmbd_inode *ci)
{
	struct hlist_head *b = inode_hashtable +
		inode_hash(ci->m_inode->i_sb, ci->m_inode->i_ino);

	hlist_add_head(&ci->m_hash, b);
}

static void ksmbd_inode_unhash(struct ksmbd_inode *ci)
{
	write_lock(&inode_hash_lock);
	hlist_del_init(&ci->m_hash);
	write_unlock(&inode_hash_lock);
}

static int ksmbd_inode_init(struct ksmbd_inode *ci, struct ksmbd_file *fp)
{
	ci->m_inode = file_inode(fp->filp);
	atomic_set(&ci->m_count, 1);
	atomic_set(&ci->op_count, 0);
	atomic_set(&ci->sop_count, 0);
	ci->m_flags = 0;
	ci->m_fattr = 0;
	INIT_LIST_HEAD(&ci->m_fp_list);
	INIT_LIST_HEAD(&ci->m_op_list);
	rwlock_init(&ci->m_lock);
	return 0;
}

static struct ksmbd_inode *ksmbd_inode_get(struct ksmbd_file *fp)
{
	struct ksmbd_inode *ci, *tmpci;
	int rc;

	read_lock(&inode_hash_lock);
	ci = ksmbd_inode_lookup(fp);
	read_unlock(&inode_hash_lock);
	if (ci)
		return ci;

	ci = kmalloc(sizeof(struct ksmbd_inode), GFP_KERNEL);
	if (!ci)
		return NULL;

	rc = ksmbd_inode_init(ci, fp);
	if (rc) {
		pr_err("inode initialized failed\n");
		kfree(ci);
		return NULL;
	}

	write_lock(&inode_hash_lock);
	tmpci = ksmbd_inode_lookup(fp);
	if (!tmpci) {
		ksmbd_inode_hash(ci);
	} else {
		kfree(ci);
		ci = tmpci;
	}
	write_unlock(&inode_hash_lock);
	return ci;
}

static void ksmbd_inode_free(struct ksmbd_inode *ci)
{
	ksmbd_inode_unhash(ci);
	kfree(ci);
}

static void ksmbd_inode_put(struct ksmbd_inode *ci)
{
	if (atomic_dec_and_test(&ci->m_count))
		ksmbd_inode_free(ci);
}

int __init ksmbd_inode_hash_init(void)
{
	unsigned int loop;
	unsigned long numentries = 16384;
	unsigned long bucketsize = sizeof(struct hlist_head);
	unsigned long size;

	inode_hash_shift = ilog2(numentries);
	inode_hash_mask = (1 << inode_hash_shift) - 1;

	size = bucketsize << inode_hash_shift;

	/* init master fp hash table */
	inode_hashtable = vmalloc(size);
	if (!inode_hashtable)
		return -ENOMEM;

	for (loop = 0; loop < (1U << inode_hash_shift); loop++)
		INIT_HLIST_HEAD(&inode_hashtable[loop]);
	return 0;
}

void ksmbd_release_inode_hash(void)
{
	vfree(inode_hashtable);
}

static void __ksmbd_inode_close(struct ksmbd_file *fp)
{
	struct ksmbd_inode *ci = fp->f_ci;
	int err;
	struct file *filp;

	filp = fp->filp;
	if (ksmbd_stream_fd(fp) && (ci->m_flags & S_DEL_ON_CLS_STREAM)) {
		ci->m_flags &= ~S_DEL_ON_CLS_STREAM;
		err = ksmbd_vfs_remove_xattr(file_mnt_idmap(filp),
					     filp->f_path.dentry,
					     fp->stream.name);
		if (err)
			pr_err("remove xattr failed : %s\n",
			       fp->stream.name);
	}

	if (atomic_dec_and_test(&ci->m_count)) {
		write_lock(&ci->m_lock);
		if (ci->m_flags & (S_DEL_ON_CLS | S_DEL_PENDING)) {
			ci->m_flags &= ~(S_DEL_ON_CLS | S_DEL_PENDING);
			write_unlock(&ci->m_lock);
			ksmbd_vfs_unlink(filp);
			write_lock(&ci->m_lock);
		}
		write_unlock(&ci->m_lock);

		ksmbd_inode_free(ci);
	}
}

static void __ksmbd_remove_durable_fd(struct ksmbd_file *fp)
{
	if (!has_file_id(fp->persistent_id))
		return;

	write_lock(&global_ft.lock);
	idr_remove(global_ft.idr, fp->persistent_id);
	write_unlock(&global_ft.lock);
}

static void __ksmbd_remove_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp)
{
	if (!has_file_id(fp->volatile_id))
		return;

	write_lock(&fp->f_ci->m_lock);
	list_del_init(&fp->node);
	write_unlock(&fp->f_ci->m_lock);

	write_lock(&ft->lock);
	idr_remove(ft->idr, fp->volatile_id);
	write_unlock(&ft->lock);
}

static void __ksmbd_close_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp)
{
	struct file *filp;
	struct ksmbd_lock *smb_lock, *tmp_lock;

	fd_limit_close();
	__ksmbd_remove_durable_fd(fp);
	__ksmbd_remove_fd(ft, fp);

	close_id_del_oplock(fp);
	filp = fp->filp;

	__ksmbd_inode_close(fp);
	if (!IS_ERR_OR_NULL(filp))
		fput(filp);

	/* because the reference count of fp is 0, it is guaranteed that
	 * there are not accesses to fp->lock_list.
	 */
	list_for_each_entry_safe(smb_lock, tmp_lock, &fp->lock_list, flist) {
		spin_lock(&fp->conn->llist_lock);
		list_del(&smb_lock->clist);
		spin_unlock(&fp->conn->llist_lock);

		list_del(&smb_lock->flist);
		locks_free_lock(smb_lock->fl);
		kfree(smb_lock);
	}

	if (ksmbd_stream_fd(fp))
		kfree(fp->stream.name);
	kmem_cache_free(filp_cache, fp);
}

static struct ksmbd_file *ksmbd_fp_get(struct ksmbd_file *fp)
{
	if (!atomic_inc_not_zero(&fp->refcount))
		return NULL;
	return fp;
}

static struct ksmbd_file *__ksmbd_lookup_fd(struct ksmbd_file_table *ft,
					    u64 id)
{
	struct ksmbd_file *fp;

	if (!has_file_id(id))
		return NULL;

	read_lock(&ft->lock);
	fp = idr_find(ft->idr, id);
	if (fp)
		fp = ksmbd_fp_get(fp);
	read_unlock(&ft->lock);
	return fp;
}

static void __put_fd_final(struct ksmbd_work *work, struct ksmbd_file *fp)
{
	__ksmbd_close_fd(&work->sess->file_table, fp);
	atomic_dec(&work->conn->stats.open_files_count);
}

static void set_close_state_blocked_works(struct ksmbd_file *fp)
{
	struct ksmbd_work *cancel_work;

	spin_lock(&fp->f_lock);
	list_for_each_entry(cancel_work, &fp->blocked_works,
				 fp_entry) {
		cancel_work->state = KSMBD_WORK_CLOSED;
		cancel_work->cancel_fn(cancel_work->cancel_argv);
	}
	spin_unlock(&fp->f_lock);
}

int ksmbd_close_fd(struct ksmbd_work *work, u64 id)
{
	struct ksmbd_file	*fp;
	struct ksmbd_file_table	*ft;

	if (!has_file_id(id))
		return 0;

	ft = &work->sess->file_table;
	read_lock(&ft->lock);
	fp = idr_find(ft->idr, id);
	if (fp) {
		set_close_state_blocked_works(fp);

		if (!atomic_dec_and_test(&fp->refcount))
			fp = NULL;
	}
	read_unlock(&ft->lock);

	if (!fp)
		return -EINVAL;

	__put_fd_final(work, fp);
	return 0;
}

void ksmbd_fd_put(struct ksmbd_work *work, struct ksmbd_file *fp)
{
	if (!fp)
		return;

	if (!atomic_dec_and_test(&fp->refcount))
		return;
	__put_fd_final(work, fp);
}

static bool __sanity_check(struct ksmbd_tree_connect *tcon, struct ksmbd_file *fp)
{
	if (!fp)
		return false;
	if (fp->tcon != tcon)
		return false;
	return true;
}

struct ksmbd_file *ksmbd_lookup_foreign_fd(struct ksmbd_work *work, u64 id)
{
	return __ksmbd_lookup_fd(&work->sess->file_table, id);
}

struct ksmbd_file *ksmbd_lookup_fd_fast(struct ksmbd_work *work, u64 id)
{
	struct ksmbd_file *fp = __ksmbd_lookup_fd(&work->sess->file_table, id);

	if (__sanity_check(work->tcon, fp))
		return fp;

	ksmbd_fd_put(work, fp);
	return NULL;
}

struct ksmbd_file *ksmbd_lookup_fd_slow(struct ksmbd_work *work, u64 id,
					u64 pid)
{
	struct ksmbd_file *fp;

	if (!has_file_id(id)) {
		id = work->compound_fid;
		pid = work->compound_pfid;
	}

	fp = __ksmbd_lookup_fd(&work->sess->file_table, id);
	if (!__sanity_check(work->tcon, fp)) {
		ksmbd_fd_put(work, fp);
		return NULL;
	}
	if (fp->persistent_id != pid) {
		ksmbd_fd_put(work, fp);
		return NULL;
	}
	return fp;
}

struct ksmbd_file *ksmbd_lookup_durable_fd(unsigned long long id)
{
	return __ksmbd_lookup_fd(&global_ft, id);
}

struct ksmbd_file *ksmbd_lookup_fd_cguid(char *cguid)
{
	struct ksmbd_file	*fp = NULL;
	unsigned int		id;

	read_lock(&global_ft.lock);
	idr_for_each_entry(global_ft.idr, fp, id) {
		if (!memcmp(fp->create_guid,
			    cguid,
			    SMB2_CREATE_GUID_SIZE)) {
			fp = ksmbd_fp_get(fp);
			break;
		}
	}
	read_unlock(&global_ft.lock);

	return fp;
}

struct ksmbd_file *ksmbd_lookup_fd_inode(struct inode *inode)
{
	struct ksmbd_file	*lfp;
	struct ksmbd_inode	*ci;

	ci = ksmbd_inode_lookup_by_vfsinode(inode);
	if (!ci)
		return NULL;

	read_lock(&ci->m_lock);
	list_for_each_entry(lfp, &ci->m_fp_list, node) {
		if (inode == file_inode(lfp->filp)) {
			atomic_dec(&ci->m_count);
			lfp = ksmbd_fp_get(lfp);
			read_unlock(&ci->m_lock);
			return lfp;
		}
	}
	atomic_dec(&ci->m_count);
	read_unlock(&ci->m_lock);
	return NULL;
}

#define OPEN_ID_TYPE_VOLATILE_ID	(0)
#define OPEN_ID_TYPE_PERSISTENT_ID	(1)

static void __open_id_set(struct ksmbd_file *fp, u64 id, int type)
{
	if (type == OPEN_ID_TYPE_VOLATILE_ID)
		fp->volatile_id = id;
	if (type == OPEN_ID_TYPE_PERSISTENT_ID)
		fp->persistent_id = id;
}

static int __open_id(struct ksmbd_file_table *ft, struct ksmbd_file *fp,
		     int type)
{
	u64			id = 0;
	int			ret;

	if (type == OPEN_ID_TYPE_VOLATILE_ID && fd_limit_depleted()) {
		__open_id_set(fp, KSMBD_NO_FID, type);
		return -EMFILE;
	}

	idr_preload(GFP_KERNEL);
	write_lock(&ft->lock);
	ret = idr_alloc_cyclic(ft->idr, fp, 0, INT_MAX - 1, GFP_NOWAIT);
	if (ret >= 0) {
		id = ret;
		ret = 0;
	} else {
		id = KSMBD_NO_FID;
		fd_limit_close();
	}

	__open_id_set(fp, id, type);
	write_unlock(&ft->lock);
	idr_preload_end();
	return ret;
}

unsigned int ksmbd_open_durable_fd(struct ksmbd_file *fp)
{
	__open_id(&global_ft, fp, OPEN_ID_TYPE_PERSISTENT_ID);
	return fp->persistent_id;
}

struct ksmbd_file *ksmbd_open_fd(struct ksmbd_work *work, struct file *filp)
{
	struct ksmbd_file *fp;
	int ret;

	fp = kmem_cache_zalloc(filp_cache, GFP_KERNEL);
	if (!fp) {
		pr_err("Failed to allocate memory\n");
		return ERR_PTR(-ENOMEM);
	}

	INIT_LIST_HEAD(&fp->blocked_works);
	INIT_LIST_HEAD(&fp->node);
	INIT_LIST_HEAD(&fp->lock_list);
	spin_lock_init(&fp->f_lock);
	atomic_set(&fp->refcount, 1);

	fp->filp		= filp;
	fp->conn		= work->conn;
	fp->tcon		= work->tcon;
	fp->volatile_id		= KSMBD_NO_FID;
	fp->persistent_id	= KSMBD_NO_FID;
	fp->f_ci		= ksmbd_inode_get(fp);

	if (!fp->f_ci) {
		ret = -ENOMEM;
		goto err_out;
	}

	ret = __open_id(&work->sess->file_table, fp, OPEN_ID_TYPE_VOLATILE_ID);
	if (ret) {
		ksmbd_inode_put(fp->f_ci);
		goto err_out;
	}

	atomic_inc(&work->conn->stats.open_files_count);
	return fp;

err_out:
	kmem_cache_free(filp_cache, fp);
	return ERR_PTR(ret);
}

static int
__close_file_table_ids(struct ksmbd_file_table *ft,
		       struct ksmbd_tree_connect *tcon,
		       bool (*skip)(struct ksmbd_tree_connect *tcon,
				    struct ksmbd_file *fp))
{
	unsigned int			id;
	struct ksmbd_file		*fp;
	int				num = 0;

	idr_for_each_entry(ft->idr, fp, id) {
		if (skip(tcon, fp))
			continue;

		set_close_state_blocked_works(fp);

		if (!atomic_dec_and_test(&fp->refcount))
			continue;
		__ksmbd_close_fd(ft, fp);
		num++;
	}
	return num;
}

static bool tree_conn_fd_check(struct ksmbd_tree_connect *tcon,
			       struct ksmbd_file *fp)
{
	return fp->tcon != tcon;
}

static bool session_fd_check(struct ksmbd_tree_connect *tcon,
			     struct ksmbd_file *fp)
{
	return false;
}

void ksmbd_close_tree_conn_fds(struct ksmbd_work *work)
{
	int num = __close_file_table_ids(&work->sess->file_table,
					 work->tcon,
					 tree_conn_fd_check);

	atomic_sub(num, &work->conn->stats.open_files_count);
}

void ksmbd_close_session_fds(struct ksmbd_work *work)
{
	int num = __close_file_table_ids(&work->sess->file_table,
					 work->tcon,
					 session_fd_check);

	atomic_sub(num, &work->conn->stats.open_files_count);
}

int ksmbd_init_global_file_table(void)
{
	return ksmbd_init_file_table(&global_ft);
}

void ksmbd_free_global_file_table(void)
{
	struct ksmbd_file	*fp = NULL;
	unsigned int		id;

	idr_for_each_entry(global_ft.idr, fp, id) {
		__ksmbd_remove_durable_fd(fp);
		kmem_cache_free(filp_cache, fp);
	}

	ksmbd_destroy_file_table(&global_ft);
}

int ksmbd_init_file_table(struct ksmbd_file_table *ft)
{
	ft->idr = kzalloc(sizeof(struct idr), GFP_KERNEL);
	if (!ft->idr)
		return -ENOMEM;

	idr_init(ft->idr);
	rwlock_init(&ft->lock);
	return 0;
}

void ksmbd_destroy_file_table(struct ksmbd_file_table *ft)
{
	if (!ft->idr)
		return;

	__close_file_table_ids(ft, NULL, session_fd_check);
	idr_destroy(ft->idr);
	kfree(ft->idr);
	ft->idr = NULL;
}

int ksmbd_init_file_cache(void)
{
	filp_cache = kmem_cache_create("ksmbd_file_cache",
				       sizeof(struct ksmbd_file), 0,
				       SLAB_HWCACHE_ALIGN, NULL);
	if (!filp_cache)
		goto out;

	return 0;

out:
	pr_err("failed to allocate file cache\n");
	return -ENOMEM;
}

void ksmbd_exit_file_cache(void)
{
	kmem_cache_destroy(filp_cache);
}